Determinants of brain metabolism changes in mesial temporal lobe epilepsy.

PubMed

Chassoux, Francine; Artiges, Eric; Semah, Franck; Desarnaud, Serge; Laurent, Agathe; Landre, Elisabeth; Gervais, Philippe; Devaux, Bertrand; Helal, Ourkia Badia

2016-06-01

To determine the main factors influencing metabolic changes in mesial temporal lobe epilepsy (MTLE) due to hippocampal sclerosis (HS). We prospectively studied 114 patients with MTLE (62 female; 60 left HS; 15- to 56-year-olds) with (18) F-fluorodeoxyglucose-positron emission tomography and correlated the results with the side of HS, structural atrophy, electroclinical features, gender, age at onset, epilepsy duration, and seizure frequency. Imaging processing was performed using statistical parametric mapping. Ipsilateral hypometabolism involved temporal (mesial structures, pole, and lateral cortex) and extratemporal areas including the insula, frontal lobe, perisylvian regions, and thalamus, more extensively in right HS (RHS). A relative increase of metabolism (hypermetabolism) was found in the nonepileptic temporal lobe and in posterior areas bilaterally. Voxel-based morphometry detected unilateral hippocampus atrophy and gray matter concentration decrease in both frontal lobes, more extensively in left HS (LHS). Regardless of the structural alterations, the topography of hypometabolism correlated strongly with the extent of epileptic networks (mesial, anterior-mesiolateral, widespread mesiolateral, and bitemporal according to the ictal spread), which were larger in RHS. Notably, widespread perisylvian and bitemporal hypometabolism was found only in RHS. Mirror hypermetabolism was grossly proportional to the hypometabolic areas, coinciding partly with the default mode network. Gender-related effect was significant mainly in the contralateral frontal lobe, in which metabolism was higher in female patients. Epilepsy duration correlated with the contralateral temporal metabolism, positively in LHS and negatively in RHS. Opposite results were found with age at onset. High seizure frequency correlated negatively with the contralateral metabolism in LHS. Epileptic networks, as assessed by electroclinical correlations, appear to be the main determinant of hypometabolism in MTLE. Compensatory mechanisms reflected by a relative hypermetabolism in the nonepileptic temporal lobe and in extratemporal areas seem more efficient in LHS and in female patients, whereas long duration, late onset of epilepsy, and high seizure frequency may reduce these adaptive changes. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Thalamotemporal alteration and postoperative seizures in temporal lobe epilepsy

PubMed Central

Richardson, Mark P.; Schoene‐Bake, Jan‐Christoph; O'Muircheartaigh, Jonathan; Elkommos, Samia; Kreilkamp, Barbara; Goh, Yee Yen; Marson, Anthony G.; Elger, Christian; Weber, Bernd

2015-01-01

Objective There are competing explanations for persistent postoperative seizures after temporal lobe surgery. One is that 1 or more particular subtypes of mesial temporal lobe epilepsy (mTLE) exist that are particularly resistant to surgery. We sought to identify a common brain structural and connectivity alteration in patients with persistent postoperative seizures using preoperative quantitative magnetic resonance imaging and diffusion tensor imaging (DTI). Methods We performed a series of studies in 87 patients with mTLE (47 subsequently rendered seizure free, 40 who continued to experience postoperative seizures) and 80 healthy controls. We investigated the relationship between imaging variables and postoperative seizure outcome. All patients had unilateral temporal lobe seizure onset, had ipsilateral hippocampal sclerosis as the only brain lesion, and underwent amygdalohippocampectomy. Results Quantitative imaging factors found not to be significantly associated with persistent seizures were volumes of ipsilateral and contralateral mesial temporal lobe structures, generalized brain atrophy, and extent of resection. There were nonsignificant trends for larger amygdala and entorhinal resections to be associated with improved outcome. However, patients with persistent seizures had significant atrophy of bilateral dorsomedial and pulvinar thalamic regions, and significant alterations of DTI‐derived thalamotemporal probabilistic paths bilaterally relative to those patients rendered seizure free and controls, even when corrected for extent of mesial temporal lobe resection. Interpretation Patients with bihemispheric alterations of thalamotemporal structural networks may represent a subtype of mTLE that is resistant to temporal lobe surgery. Increasingly sensitive multimodal imaging techniques should endeavor to transform these group‐based findings to individualize prediction of patient outcomes. Ann Neurol 2015;77:760–774 PMID:25627477

Intense and recurrent déjà vu experiences related to amantadine and phenylpropanolamine in a healthy male.

PubMed

Taiminen, T; Jääskeläinen, S K

2001-09-01

We report a case of a 39-year-old caucasian healthy male physician who developed intense and recurrent déjà vu experiences within 24h of initiating concomitant amantadine-phenylpropanolamine treatment against influenza. Déjà vu experiences terminated on discontinuation of medication. Findings in temporal epilepsy suggest that mesial temporal structures, including hippocampus, are related to paramnesic symptoms. On the other hand, previous case reports have confirmed that both amantadine and phenylpropanolamine alone, and particularly in combination, can induce psychotic symptoms due to their dopaminergic activity. The authors suggest that déjà vu experiences may be provoked by increased dopamine activity in mesial temporal structures of the brain. Copyright 2001 Harcourt Publishers Ltd.

Lateralising value of experiential hallucinations in temporal lobe epilepsy.

PubMed

Heydrich, Lukas; Marillier, Guillaume; Evans, Nathan; Blanke, Olaf; Seeck, Margitta

2015-11-01

Ever since John Hughlings Jackson first described the so-called 'dreamy state' during temporal lobe epilepsy, that is, the sense of an abnormal familiarity (déjà vu) or vivid memory-like hallucinations from the past (experiential hallucinations), these phenomena have been studied and repeatedly linked to mesial temporal lobe structures. However, little is known about the lateralising value of either déjà vu or experiential hallucinations. We analysed a sample of 28 patients with intractable focal epilepsy suffering from either déjà vu or experiential hallucinations. All the patients underwent thorough presurgical examination, including MRI, positron emission tomography, single-photon emission CT, EEG and neuropsychological examination. While déjà vu was due to right or left mesial temporal lobe epilepsy, experiential hallucinations were strongly lateralised to the left mesial temporal lobe. Moreover, there was a significant effect for interictal language deficits being more frequent in patients suffering from experiential hallucinations. These results suggest a lateralising value for experiential hallucinations to the left temporal lobe. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Thalamotemporal impairment in temporal lobe epilepsy: a combined MRI analysis of structure, integrity, and connectivity.

PubMed

Keller, Simon S; O'Muircheartaigh, Jonathan; Traynor, Catherine; Towgood, Karren; Barker, Gareth J; Richardson, Mark P

2014-02-01

Thalamic abnormality in temporal lobe epilepsy (TLE) is well known from imaging studies, but evidence is lacking regarding connectivity profiles of the thalamus and their involvement in the disease process. We used a novel multisequence magnetic resonance imaging (MRI) protocol to elucidate the relationship between mesial temporal and thalamic pathology in TLE. For 23 patients with TLE and 23 healthy controls, we performed T1 -weighted (for analysis of tissue structure), diffusion tensor imaging (tissue connectivity), and T1 and T2 relaxation (tissue integrity) MRI across the whole brain. We used connectivity-based segmentation to determine connectivity patterns of thalamus to ipsilateral cortical regions (occipital, parietal, prefrontal, postcentral, precentral, and temporal). We subsequently determined volumes, mean tractography streamlines, and mean T1 and T2 relaxometry values for each thalamic segment preferentially connecting to a given cortical region, and of the hippocampus and entorhinal cortex. As expected, patients had significant volume reduction and increased T2 relaxation time in ipsilateral hippocampus and entorhinal cortex. There was bilateral volume loss, mean streamline reduction, and T2 increase of the thalamic segment preferentially connected to temporal lobe, corresponding to anterior, dorsomedial, and pulvinar thalamic regions, with no evidence of significant change in any other thalamic segments. Left and right thalamotemporal segment volume and T2 were significantly correlated with volume and T2 of ipsilateral (epileptogenic), but not contralateral (nonepileptogenic), mesial temporal structures. These convergent and robust data indicate that thalamic abnormality in TLE is restricted to the area of the thalamus that is preferentially connected to the epileptogenic temporal lobe. The degree of thalamic pathology is related to the extent of mesial temporal lobe damage in TLE. © 2014 The Authors. Epilepsia published by Wiley Periodicals, Inc. on behalf of International League Against Epilepsy.

Laser interstitial thermal therapy for medically intractable mesial temporal lobe epilepsy.

PubMed

Kang, Joon Y; Wu, Chengyuan; Tracy, Joseph; Lorenzo, Matthew; Evans, James; Nei, Maromi; Skidmore, Christopher; Mintzer, Scott; Sharan, Ashwini D; Sperling, Michael R

2016-02-01

To describe mesial temporal lobe ablated volumes, verbal memory, and surgical outcomes in patients with medically intractable mesial temporal lobe epilepsy (mTLE) treated with magnetic resonance imaging (MRI)-guided stereotactic laser interstitial thermal therapy (LiTT). We prospectively tracked seizure outcome in 20 patients at Thomas Jefferson University Hospital with drug-resistant mTLE who underwent MRI-guided LiTT from December 2011 to December 2014. Surgical outcome was assessed at 6 months, 1 year, 2 years, and at the most recent visit. Volume-based analysis of ablated mesial temporal structures was conducted in 17 patients with mesial temporal sclerosis (MTS) and results were compared between the seizure-free and not seizure-free groups. Following LiTT, proportions of patients who were free of seizures impairing consciousness (including those with auras only) are as follows: 8 of 15 patients (53%, 95% confidence interval [CI] 30.1-75.2%) after 6 months, 4 of 11 patients (36.4%, 95% CI 14.9-64.8%) after 1 year, 3 of 5 patients (60%, 95% CI 22.9-88.4%) at 2-year follow-up. Median follow-up was 13.4 months after LiTT (range 1.3 months to 3.2 years). Seizure outcome after LiTT suggests an all or none response. Four patients had anterior temporal lobectomy (ATL) after LiTT; three are seizure-free. There were no differences in total ablated volume of the amygdalohippocampus complex or individual volumes of hippocampus, amygdala, entorhinal cortex, parahippocampal gyrus, and fusiform gyrus between seizure-free and non-seizure-free patients. Contextual verbal memory performance was preserved after LiTT, although decline in noncontextual memory task scores were noted. We conclude that MRI-guided stereotactic LiTT is a safe alternative to ATL in patients with medically intractable mTLE. Individualized assessment is warranted to determine whether the reduced odds of seizure freedom are worth the reduction in risk, discomfort, and recovery time. Larger prospective studies are needed to confirm our preliminary findings, and to define optimal ablation volume and ideal structures for ablation. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

A voxel-based asymmetry study of the relationship between hemispheric asymmetry and language dominance in Wada tested patients.

PubMed

Keller, Simon S; Roberts, Neil; Baker, Gus; Sluming, Vanessa; Cezayirli, Enis; Mayes, Andrew; Eldridge, Paul; Marson, Anthony G; Wieshmann, Udo C

2018-03-23

Determining the anatomical basis of hemispheric language dominance (HLD) remains an important scientific endeavor. The Wada test remains the gold standard test for HLD and provides a unique opportunity to determine the relationship between HLD and hemispheric structural asymmetries on MRI. In this study, we applied a whole-brain voxel-based asymmetry (VBA) approach to determine the relationship between interhemispheric structural asymmetries and HLD in a large consecutive sample of Wada tested patients. Of 135 patients, 114 (84.4%) had left HLD, 10 (7.4%) right HLD, and 11 (8.2%) bilateral language representation. Fifty-four controls were also studied. Right-handed controls and right-handed patients with left HLD had comparable structural brain asymmetries in cortical, subcortical, and cerebellar regions that have previously been documented in healthy people. However, these patients and controls differed in structural asymmetry of the mesial temporal lobe and a circumscribed region in the superior temporal gyrus, suggesting that only asymmetries of these regions were due to brain alterations caused by epilepsy. Additional comparisons between patients with left and right HLD, matched for type and location of epilepsy, revealed that structural asymmetries of insula, pars triangularis, inferior temporal gyrus, orbitofrontal cortex, ventral temporo-occipital cortex, mesial somatosensory cortex, and mesial cerebellum were significantly associated with the side of HLD. Patients with right HLD and bilateral language representation were significantly less right-handed. These results suggest that structural asymmetries of an insular-fronto-temporal network may be related to HLD. © 2018 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Astrocyte uncoupling as a cause of human temporal lobe epilepsy

PubMed Central

Bedner, Peter; Dupper, Alexander; Hüttmann, Kerstin; Müller, Julia; Herde, Michel K.; Dublin, Pavel; Deshpande, Tushar; Schramm, Johannes; Häussler, Ute; Haas, Carola A.; Henneberger, Christian; Theis, Martin

2015-01-01

Glial cells are now recognized as active communication partners in the central nervous system, and this new perspective has rekindled the question of their role in pathology. In the present study we analysed functional properties of astrocytes in hippocampal specimens from patients with mesial temporal lobe epilepsy without (n = 44) and with sclerosis (n = 75) combining patch clamp recording, K+ concentration analysis, electroencephalography/video-monitoring, and fate mapping analysis. We found that the hippocampus of patients with mesial temporal lobe epilepsy with sclerosis is completely devoid of bona fide astrocytes and gap junction coupling, whereas coupled astrocytes were abundantly present in non-sclerotic specimens. To decide whether these glial changes represent cause or effect of mesial temporal lobe epilepsy with sclerosis, we developed a mouse model that reproduced key features of human mesial temporal lobe epilepsy with sclerosis. In this model, uncoupling impaired K+ buffering and temporally preceded apoptotic neuronal death and the generation of spontaneous seizures. Uncoupling was induced through intraperitoneal injection of lipopolysaccharide, prevented in Toll-like receptor4 knockout mice and reproduced in situ through acute cytokine or lipopolysaccharide incubation. Fate mapping confirmed that in the course of mesial temporal lobe epilepsy with sclerosis, astrocytes acquire an atypical functional phenotype and lose coupling. These data suggest that astrocyte dysfunction might be a prime cause of mesial temporal lobe epilepsy with sclerosis and identify novel targets for anti-epileptogenic therapeutic intervention. PMID:25765328

Persistent Interictal Musical Hallucination in a Patient With Mesial Temporal Sclerosis-Related Epilepsy: First Case Report and Etiopathological Hypothesis.

PubMed

Borelli, Paolo; Vedovello, Marcella; Braga, Massimiliano; Pederzoli, Massimo; Beretta, Sandro

2016-12-01

Musical hallucination is a disorder of complex sound processing of instrumental music, songs, choirs, chants, etc. The underlying pathologies include moderate to severe acquired hearing loss (the auditory equivalent of Charles Bonnet syndrome), psychiatric illnesses (depression, schizophrenia), drug intoxication (benzodiazepines, salicylate, pentoxifylline, propranolol), traumatic lesions along the acoustic pathways, and epilepsy. The hallucinations are most likely to begin late in life; 70% of patients are women. Musical hallucination has no known specific therapy. Treating the underlying cause is the most effective approach; neuroleptic and antidepressant medications have only rarely succeeded.Musical hallucination in epilepsy typically presents as simple partial seizures originating in the lateral temporal cortex. To our knowledge, no formal report of musical hallucination in the interictal state has been published before. In contrast, other interictal psychotic features are a relatively common complication, especially in patients with long-standing drug-resistant epilepsy.We describe a 62-year-old woman with a long history of mesial temporal lobe epilepsy whose musical hallucination was solely interictal. We speculate on the possible link between temporal epilepsy and her hallucination. We hypothesize that, as a result of her epileptic activity-induced damage, an imbalance developed between the excitatory and inhibitory projections connecting the mesial temporal cortex to the other auditory structures. These structures may have generated hyperactivity in the lateral temporal cortex through a "release" mechanism that eventually resulted in musical hallucination.

Mesial Temporal Sclerosis: Accuracy of NeuroQuant versus Neuroradiologist.

PubMed

Azab, M; Carone, M; Ying, S H; Yousem, D M

2015-08-01

We sought to compare the accuracy of a volumetric fully automated computer assessment of hippocampal volume asymmetry versus neuroradiologists' interpretations of the temporal lobes for mesial temporal sclerosis. Detecting mesial temporal sclerosis (MTS) is important for the evaluation of patients with temporal lobe epilepsy as it often guides surgical intervention. One feature of MTS is hippocampal volume loss. Electronic medical record and researcher reports of scans of patients with proved mesial temporal sclerosis were compared with volumetric assessment with an FDA-approved software package, NeuroQuant, for detection of mesial temporal sclerosis in 63 patients. The degree of volumetric asymmetry was analyzed to determine the neuroradiologists' threshold for detecting right-left asymmetry in temporal lobe volumes. Thirty-six patients had left-lateralized MTS, 25 had right-lateralized MTS, and 2 had bilateral MTS. The estimated accuracy of the neuroradiologist was 72.6% with a κ statistic of 0.512 (95% CI, 0.315-0.710) [moderate agreement, P < 3 × 10(-6)]), whereas the estimated accuracy of NeuroQuant was 79.4% with a κ statistic of 0.588 (95% CI, 0.388-0.787) [moderate agreement, P < 2 × 10(-6)]). This discrepancy in accuracy was not statistically significant. When at least a 5%-10% volume discrepancy between temporal lobes was present, the neuroradiologists detected it 75%-80% of the time. As a stand-alone fully automated software program that can process temporal lobe volume in 5-10 minutes, NeuroQuant compares favorably with trained neuroradiologists in predicting the side of mesial temporal sclerosis. Neuroradiologists can often detect even small temporal lobe volumetric changes visually. © 2015 by American Journal of Neuroradiology.

The localizing value of ictal EEG in focal epilepsy.

PubMed

Foldvary, N; Klem, G; Hammel, J; Bingaman, W; Najm, I; Lüders, H

2001-12-11

To investigate the lateralization and localization of ictal EEG in focal epilepsy. A total of 486 ictal EEG of 72 patients with focal epilepsy arising from the mesial temporal, neocortical temporal, mesial frontal, dorsolateral frontal, parietal, and occipital regions were analyzed. Surface ictal EEG was adequately localized in 72% of cases, more often in temporal than extratemporal epilepsy. Localized ictal onsets were seen in 57% of seizures and were most common in mesial temporal lobe epilepsy (MTLE), lateral frontal lobe epilepsy (LFLE), and parietal lobe epilepsy, whereas lateralized onsets predominated in neocortical temporal lobe epilepsy and generalized onsets in mesial frontal lobe epilepsy (MFLE) and occipital lobe epilepsy. Approximately two-thirds of seizures were localized, 22% generalized, 4% lateralized, and 6% mislocalized/lateralized. False localization/lateralization occurred in 28% of occipital and 16% of parietal seizures. Rhythmic temporal theta at ictal onset was seen exclusively in temporal lobe seizures, whereas localized repetitive epileptiform activity was highly predictive of LFLE. Seizures arising from the lateral convexity and mesial regions were differentiated by a high incidence of repetitive epileptiform activity at ictal onset in the former and rhythmic theta activity in the latter. With the exception of mesial frontal lobe epilepsy, ictal recordings are very useful in the localization/lateralization of focal seizures. Some patterns are highly accurate in localizing the epileptogenic lobe. One limitation of ictal EEG is the potential for false localization/lateralization in occipital and parietal lobe epilepsies.

Perirhinal cortex and temporal lobe epilepsy

PubMed Central

Biagini, Giuseppe; D'Antuono, Margherita; Benini, Ruba; de Guzman, Philip; Longo, Daniela; Avoli, Massimo

2013-01-01

The perirhinal cortex—which is interconnected with several limbic structures and is intimately involved in learning and memory—plays major roles in pathological processes such as the kindling phenomenon of epileptogenesis and the spread of limbic seizures. Both features may be relevant to the pathophysiology of mesial temporal lobe epilepsy that represents the most refractory adult form of epilepsy with up to 30% of patients not achieving adequate seizure control. Compared to other limbic structures such as the hippocampus or the entorhinal cortex, the perirhinal area remains understudied and, in particular, detailed information on its dysfunctional characteristics remains scarce; this lack of information may be due to the fact that the perirhinal cortex is not grossly damaged in mesial temporal lobe epilepsy and in models mimicking this epileptic disorder. However, we have recently identified in pilocarpine-treated epileptic rats the presence of selective losses of interneuron subtypes along with increased synaptic excitability. In this review we: (i) highlight the fundamental electrophysiological properties of perirhinal cortex neurons; (ii) briefly stress the mechanisms underlying epileptiform synchronization in perirhinal cortex networks following epileptogenic pharmacological manipulations; and (iii) focus on the changes in neuronal excitability and cytoarchitecture of the perirhinal cortex occurring in the pilocarpine model of mesial temporal lobe epilepsy. Overall, these data indicate that perirhinal cortex networks are hyperexcitable in an animal model of temporal lobe epilepsy, and that this condition is associated with a selective cellular damage that is characterized by an age-dependent sensitivity of interneurons to precipitating injuries, such as status epilepticus. PMID:24009554

Astrocyte uncoupling as a cause of human temporal lobe epilepsy.

PubMed

Bedner, Peter; Dupper, Alexander; Hüttmann, Kerstin; Müller, Julia; Herde, Michel K; Dublin, Pavel; Deshpande, Tushar; Schramm, Johannes; Häussler, Ute; Haas, Carola A; Henneberger, Christian; Theis, Martin; Steinhäuser, Christian

2015-05-01

Glial cells are now recognized as active communication partners in the central nervous system, and this new perspective has rekindled the question of their role in pathology. In the present study we analysed functional properties of astrocytes in hippocampal specimens from patients with mesial temporal lobe epilepsy without (n = 44) and with sclerosis (n = 75) combining patch clamp recording, K(+) concentration analysis, electroencephalography/video-monitoring, and fate mapping analysis. We found that the hippocampus of patients with mesial temporal lobe epilepsy with sclerosis is completely devoid of bona fide astrocytes and gap junction coupling, whereas coupled astrocytes were abundantly present in non-sclerotic specimens. To decide whether these glial changes represent cause or effect of mesial temporal lobe epilepsy with sclerosis, we developed a mouse model that reproduced key features of human mesial temporal lobe epilepsy with sclerosis. In this model, uncoupling impaired K(+) buffering and temporally preceded apoptotic neuronal death and the generation of spontaneous seizures. Uncoupling was induced through intraperitoneal injection of lipopolysaccharide, prevented in Toll-like receptor4 knockout mice and reproduced in situ through acute cytokine or lipopolysaccharide incubation. Fate mapping confirmed that in the course of mesial temporal lobe epilepsy with sclerosis, astrocytes acquire an atypical functional phenotype and lose coupling. These data suggest that astrocyte dysfunction might be a prime cause of mesial temporal lobe epilepsy with sclerosis and identify novel targets for anti-epileptogenic therapeutic intervention. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Temporal lobe volume predicts Wada memory test performance in patients with mesial temporal sclerosis.

PubMed

Ding, Kan; Gong, Yunhua; Modur, Pradeep N; Diaz-Arrastia, Ramon; Agostini, Mark; Gupta, Puneet; McColl, Roderick; Hays, Ryan; Van Ness, Paul

2016-02-01

The Wada test is widely used in the presurgical evaluation of potential temporal lobectomy patients to predict postoperative memory function. Expected asymmetry (EA), defined as Wada memory lateralized to the nonsurgical hemisphere, or a higher score after injection of the surgical hemisphere would be considered favorable in terms of postoperative memory outcome. However, in some cases, nonlateralized memory (NM) results, with no appreciable asymmetry, may occur because of impaired scores after both injections, often leading to denial of surgery. The reason for such nonlateralized Wada memory in patients with intractable temporal lobe epilepsy (TLE) remains unclear. Given that quantitative morphometric magnetic resonance imaging studies in TLE patients have shown bilateral regional atrophy in temporal and extratemporal structures, we hypothesized that the volume loss in contralateral temporal structures could contribute to nonlateralized Wada memory performance. To investigate this, we examined the relationship between the volume changes of temporal structures and Wada memory scores in patients with intractable TLE with mesial temporal sclerosis (MTS) using an age- and gender-matched control group. Memory was considered nonlateralized if the absolute difference in the total correct recall scores between ipsilateral and contralateral injections was <11%. Among 21 patients, Wada memory was lateralized in 15 and nonlateralized in 6 patients, with all the nonlateralized scores being observed in left TLE. The recall scores after ipsilateral injection were significantly lower in patients with an NM profile than an EA profile (23 ± 14% vs. 59 ± 18% correct recall, p ≤ 0.001). However, the recall scores after contralateral injection were low but similar between the two groups (25 ± 17% vs. 25 ± 15% correct recall, p=0.97). Compared to controls, all the patients showed greater volume loss in the temporal regions. However, patients with a NM profile showed significantly more volume loss than those with a lateralized memory profile in both contralateral and ipsilateral temporal regions (p<0.05). Left hemispheric Wada memory performance correlated positively with the size of the left mesial and neocortical temporal structures (r=0.49-0.63, p=0.005-0.04). Our study suggests that volume loss in the nonsurgical temporal structures is associated with nonlateralized Wada memory results in patients with intractable TLE. Copyright © 2015 Elsevier B.V. All rights reserved.

The predictive value of FDG-PET with 3D-SSP for surgical outcomes in patients with temporal lobe epilepsy.

PubMed

Higo, Takuma; Sugano, Hidenori; Nakajima, Madoka; Karagiozov, Kostadin; Iimura, Yasushi; Suzuki, Masaru; Sato, Kiyoshi; Arai, Hajime

2016-10-01

We retrospectively evaluated the diagnostic value of (18)F-2-fluorodeoxy-d-glucose positron emission tomography (FDG-PET) with statistical analysis for the foci detection and predictive utility for postsurgical seizure outcome of patients with mesial temporal lobe epilepsy (mTLE). We evaluated 40 patients who were diagnosed mTLE and underwent selective amygdalohippocampectomy (SAH) or anterior temporal lobectomy (ATL) in our institute. Preoperative interictal FDG-PET with statistical analysis using three-dimensional stereotactic surface projection (3D-SSP) was detected with several clinical data including seizure semiology, MRI, scalp electroencephalography, surgical procedure with SAH or ATL and postsurgical outcome. The region of interest (ROI) was defined on 'Hippocampus & Amygdala', 'Parahippocampal gyrus & Uncus', 'T1 & T2', and 'T3 & Fusiform gyrus'. We obtained the ratio of hypometabolism difference (RHD) by 3D-SSP, and evaluated the relation among hypometabolic extent, surgical outcome and surgical procedure. The RHD in each ROIs ipsilateral to operative side was significantly higher than that of contralateral side in good outcome group. Hypometabolism of 'Hippocampus & Amygdala' was most reliable prognostic factor. Patients of discordant with presurgical examinations hardly showed obvious lateralized hypometabolism. Nevertheless, when they have significantly high RHD in mesial temporal lobe, good surgical outcome was expected. There was not significant difference of RHD distribution between SAH and ATL in good outcome group. Significant hypometabolism in mesial temporal lobe on FDG-PET with 3D-SSP is useful to predict good surgical outcome for patients with mTLE, particularly in discordant patients with hypometabolism in mesial temporal structure. However, FDG-PET is not indicative of surgical procedure. Copyright © 2016 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Methods for implantation of micro-wire bundles and optimization of single/multiunit recordings from human mesial temporal lobe

PubMed Central

Misra, A; Burke, JF; Ramayya, A; Jacobs, J; Sperling, MR; Moxon, KA; Kahana, MJ; Evans, JJ; Sharan, AD

2014-01-01

Objective The authors report methods developed for the implantation of micro-wire bundles into mesial temporal lobe structures and subsequent single neuron recording in epileptic patients undergoing in-patient diagnostic monitoring. This is done with the intention of lowering the perceived barriers to routine single neuron recording from deep brain structures in the clinical setting. Approach Over a 15 month period, 11 patients were implanted with platinum micro-wire bundles into mesial temporal structures. Protocols were developed for A) monitoring electrode integrity through impedance testing, B) ensuring continuous 24-7 recording, C) localizing micro-wire position and “splay” pattern and D) monitoring grounding and referencing to maintain the quality of recordings. Main Result Five common modes of failure were identified: 1) broken micro-wires from acute tensile force, 2) broken micro-wires from cyclic fatigue at stress points, 3) poor in-vivo micro-electrode separation, 4) motion artifact and 5) deteriorating ground connection and subsequent drop in common mode noise rejection. Single neurons have been observed up to 14 days post implantation and on 40% of micro-wires. Significance Long-term success requires detailed review of each implant by both the clinical and research teams to identify failure modes, and appropriate refinement of techniques while moving forward. This approach leads to reliable unit recordings without prolonging operative times, which will help increase the availability and clinical viability of human single neuron data. PMID:24608589

Familial mesial temporal lobe epilepsy: a benign epilepsy syndrome showing complex inheritance.

PubMed

Crompton, Douglas E; Scheffer, Ingrid E; Taylor, Isabella; Cook, Mark J; McKelvie, Penelope A; Vears, Danya F; Lawrence, Kate M; McMahon, Jacinta M; Grinton, Bronwyn E; McIntosh, Anne M; Berkovic, Samuel F

2010-11-01

Temporal lobe epilepsy is the commonest partial epilepsy of adulthood. Although generally perceived as an acquired disorder, several forms of familial temporal lobe epilepsy, with mesial or lateral seizure semiology, have been described. Descriptions of familial mesial temporal lobe epilepsy have varied widely from a benign epilepsy syndrome with prominent déjà vu and without antecedent febrile seizures or magnetic resonance imaging abnormalities, to heterogeneous, but generally more refractory epilepsies, often with a history of febrile seizures and with frequent hippocampal atrophy and high T₂ signal on magnetic resonance imaging. Compelling evidence of a genetic aetiology (rather than chance aggregation) in familial mesial temporal lobe epilepsy has come from twin studies. Dominant inheritance has been reported in two large families, though the usual mode of inheritance is not known. Here, we describe clinical and neurophysiological features of 20 new mesial temporal lobe epilepsy families including 51 affected individuals. The epilepsies in these families were generally benign, and febrile seizure history was infrequent (9.8%). No evidence of hippocampal sclerosis or dysplasia was present on brain imaging. A single individual underwent anterior temporal lobectomy, with subsequent seizure freedom and histopathological evidence of hippocampal sclerosis was not found. Inheritance patterns in probands' relatives were analysed in these families, together with 19 other temporal lobe epilepsy families previously reported by us. Observed frequencies of epilepsies in relatives were lower than predicted by dominant Mendelian models, while only a minority (8/39) of families could be compatible with recessive inheritance. These findings strongly suggest that complex inheritance, similar to that widely accepted in the idiopathic generalized epilepsies, is the usual mode of inheritance in familial mesial temporal lobe epilepsy. This disorder, which appears to be relatively common, and not typically associated with hippocampal sclerosis, is an appropriate target for contemporary approaches to complex disorders such as genome-wide association studies for common genetic variants or deep sequencing for rare variants.

Laser ablation for mesial temporal lobe epilepsy: Surgical and cognitive outcomes with and without mesial temporal sclerosis.

PubMed

Donos, Cristian; Breier, Joshua; Friedman, Elliott; Rollo, Patrick; Johnson, Jessica; Moss, Lauren; Thompson, Stephen; Thomas, Melissa; Hope, Omotola; Slater, Jeremy; Tandon, Nitin

2018-06-12

Laser interstitial thermal therapy (LITT) is a minimally invasive surgical technique for focal epilepsy. A major appeal of LITT is that it may result in fewer cognitive deficits, especially when targeting dominant hemisphere mesial temporal lobe (MTL) epilepsy. To evaluate this, as well as to determine seizure outcomes following LITT, we evaluated the relationships between ablation volumes and surgical or cognitive outcomes in 43 consecutive patients undergoing LITT for MTL epilepsy. All patients underwent unilateral LITT targeting mesial temporal structures. FreeSurfer software was used to derive cortical and subcortical segmentation of the brain (especially subregions of the MTL) using preoperative magnetic resonance imaging (MRI). Ablation volumes were outlined using a postablation T1-contrasted MRI. The percentages of the amygdala, hippocampus, and entorhinal cortex ablated were quantified objectively. The volumetric measures were regressed against changes in neuropsychological performance before and after surgery, RESULTS: A median of 73.7% of amygdala, 70.9% of hippocampus, and 28.3% of entorhinal cortex was ablated. Engel class I surgical outcome was obtained in 79.5% and 67.4% of the 43 patients at 6 and 20.3 months of follow-up, respectively. No significant differences in surgical outcomes were found across patient subgroups (hemispheric dominance, hippocampal sclerosis, or need for intracranial evaluation). Furthermore, no significant differences in volumes ablated were found between patients with Engel class IA vs Engel class II-IV outcomes. In patients undergoing LITT in the dominant hemisphere, a decline in verbal and narrative memory, but not in naming function was noted. Seizure-free outcomes following LITT may be comparable in carefully selected patients with and without MTS, and these outcomes are comparable with outcomes following microsurgical resection. Failures may result from non-mesial components of the epileptogenic network that are not affected by LITT. Cognitive declines following MTL-LITT are modest, and principally affect memory processes. Wiley Periodicals, Inc. © 2018 International League Against Epilepsy.

Network Analysis of Foramen Ovale Electrode Recordings in Drug-resistant Temporal Lobe Epilepsy Patients

PubMed Central

Sanz-García, Ancor; Vega-Zelaya, Lorena; Pastor, Jesús; Torres, Cristina V.; Sola, Rafael G.; Ortega, Guillermo J.

2016-01-01

Approximately 30% of epilepsy patients are refractory to antiepileptic drugs. In these cases, surgery is the only alternative to eliminate/control seizures. However, a significant minority of patients continues to exhibit post-operative seizures, even in those cases in which the suspected source of seizures has been correctly localized and resected. The protocol presented here combines a clinical procedure routinely employed during the pre-operative evaluation of temporal lobe epilepsy (TLE) patients with a novel technique for network analysis. The method allows for the evaluation of the temporal evolution of mesial network parameters. The bilateral insertion of foramen ovale electrodes (FOE) into the ambient cistern simultaneously records electrocortical activity at several mesial areas in the temporal lobe. Furthermore, network methodology applied to the recorded time series tracks the temporal evolution of the mesial networks both interictally and during the seizures. In this way, the presented protocol offers a unique way to visualize and quantify measures that considers the relationships between several mesial areas instead of a single area. PMID:28060326

Outcome of intracranial electroencephalography monitoring and surgery in magnetic resonance imaging-negative temporal lobe epilepsy.

PubMed

Lee, Ricky W; Hoogs, Marietta M; Burkholder, David B; Trenerry, Max R; Drazkowski, Joseph F; Shih, Jerry J; Doll, Karey E; Tatum, William O; Cascino, Gregory D; Marsh, W Richard; Wirrell, Elaine C; Worrell, Gregory A; So, Elson L

2014-07-01

We evaluated the outcomes of intracranial electroencephalography (iEEG) recording and subsequent resective surgery in patients with magnetic resonance imaging (MRI)-negative temporal lobe epilepsy (TLE). Thirty-two patients were identified from the Mayo Clinic Epilepsy Surgery Database (Arizona, Florida, and Minnesota). Eight (25.0%) had chronic iEEG monitoring that recorded neocortical temporal seizure onsets; 12 (37.5%) had mesial temporal seizure onsets; 5 (15.6%) had independent neocortical and mesial temporal seizure onsets; and 7 (21.9%) had simultaneous neocortical and mesial seizure onsets. Neocortical temporal lobe seizure semiology was the only factor significantly associated with neocortical temporal seizure onsets on iEEG. Only 33.3% of patients who underwent lateral temporal neocorticectomy had an Engel class 1 outcome, whereas 76.5% of patients with iEEG-guided anterior temporal lobectomy that included the amygdala and the hippocampus had an Engel class 1 outcome. Limitations in cohort size precluded statistical analysis of neuropsychological test data. Copyright © 2014 Elsevier B.V. All rights reserved.

Memory for Faces Dissociates from Memory for Location Following Anterior Temporal Lobectomy

ERIC Educational Resources Information Center

Chiaravalloti, Nancy D.; Glosser, Guila

2004-01-01

It has been suggested that the right and left mesial temporal lobes are specialized for processing different types of information for long-term memory (LTM). Although findings have been consistent in regard to the dominant role of the left mesial temporal lobe (MTL) in verbal memory, the role of the right MTL in non-verbal memory remains…

Time reversibility of intracranial human EEG recordings in mesial temporal lobe epilepsy

NASA Astrophysics Data System (ADS)

van der Heyden, M. J.; Diks, C.; Pijn, J. P. M.; Velis, D. N.

1996-02-01

Intracranial electroencephalograms from patients suffering from mesial temporal lobe epilepsy were tested for time reversibility. If the recorded time series is irreversible, the input of the recording system cannot be a realisation of a linear Gaussian random process. We confirmed experimentally that the measurement equipment did not introduce irreversibility in the recorded output when the input was a realisation of a linear Gaussian random process. In general, the non-seizure recordings are reversible, whereas the seizure recordings are irreversible. These results suggest that time reversibility is a useful property for the characterisation of human intracranial EEG recordings in mesial temporal lobe epilepsy.

Age at onset in patients with medically refractory temporal lobe epilepsy and mesial temporal sclerosis: impact on clinical manifestations and postsurgical outcome.

PubMed

Asadi-Pooya, Ali A; Sperling, Michael R

2015-08-01

To evaluate the demographic and clinical manifestations and postsurgical outcome of childhood-onset mesial temporal sclerosis and temporal lobe epilepsy (MTS-TLE) and establishing the potential differences as compared to the patients with adult-onset MTS-TLE. In this retrospective study all patients with a clinical diagnosis of medically refractory TLE due to mesial temporal sclerosis, who underwent epilepsy surgery at Jefferson comprehensive epilepsy center, were recruited. Patients were prospectively registered in a database from 1986 through 2014. Postsurgical outcome was classified into two groups; seizure-free or relapsed. Clinical manifestations and outcome were compared between patients with childhood-onset MTS-TLE (i.e., age at onset of the first afebrile habitual seizure below 10 years) and those with adult-onset MTS-TLE (i.e., age at onset of the first afebrile habitual seizure 20 years or above). One hundred and twelve patients had childhood-onset MTS-TLE and 76 had adult-onset MTS-TLE. Demographic, clinical, EEG and MRI characteristics of these two groups were similar. Postoperative outcome was not statistically different between these two groups of patients (P=0.9). Temporal lobe epilepsy due to mesial temporal sclerosis is a common cause of epilepsy that can start from early childhood to late adulthood. The etiology of MTS-TLE may be different in various age groups, but it seems that when mesial temporal sclerosis is the pathological substrate of TLE, clinical manifestations and response to surgical treatment of patients are very similar in patients with childhood-onset MTS-TLE compared to those with adult-onset disease. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Improved Cerebral Function in Mesial Temporal Lobe Epilepsy after Subtemporal Amygdalohippocampectomy

ERIC Educational Resources Information Center

Takaya, Shigetoshi; Mikuni, Nobuhiro; Mitsueda, Takahiro; Satow, Takeshi; Taki, Junya; Kinoshita, Masako; Miyamoto, Susumu; Hashimoto, Nobuo; Ikeda, Akio; Fukuyama, Hidenao

2009-01-01

The functional changes that occur throughout the human brain after the selective removal of an epileptogenic lesion remain unclear. Subtemporal selective amygdalohippocampectomy (SAH) has been advocated as a minimally invasive surgical procedure for patients with medically intractable mesial temporal lobe epilepsy (MTLE). We evaluated the effects…

Hippocampography Guides Consistent Mesial Resections in Neocortical Temporal Lobe Epilepsy

PubMed Central

Kilbride, Ronan; Simon, Mirela; Eskandar, Emad

2016-01-01

Background. The optimal surgery in lesional neocortical temporal lobe epilepsy is unknown. Hippocampal electrocorticography maximizes seizure freedom by identifying normal-appearing epileptogenic tissue for resection and minimizes neuropsychological deficit by limiting resection to demonstrably epileptogenic tissue. We examined whether standardized hippocampal electrocorticography (hippocampography) guides resection for more consistent hippocampectomy than unguided resection in conventional electrocorticography focused on the lesion. Methods. Retrospective chart reviews any kind of electrocorticography (including hippocampography) as part of combined lesionectomy, anterolateral temporal lobectomy, and hippocampectomy over 8 years . Patients were divided into mesial (i.e., hippocampography) and lateral electrocorticography groups. Primary outcome was deviation from mean hippocampectomy length. Results. Of 26 patients, fourteen underwent hippocampography-guided mesial temporal resection. Hippocampography was associated with 2.6 times more consistent resection. The range of hippocampal resection was 0.7 cm in the mesial group and 1.8 cm in the lateral group (p = 0.01). 86% of mesial group versus 42% of lateral group patients achieved seizure freedom (p = 0.02). Conclusions. By rationally tailoring excision to demonstrably epileptogenic tissue, hippocampography significantly reduces resection variability for more consistent hippocampectomy than unguided resection in conventional electrocorticography. More consistent hippocampal resection may avoid overresection, which poses greater neuropsychological risk, and underresection, which jeopardizes postoperative seizure freedom. PMID:27703809

Fluoxetine Restores Spatial Learning but Not Accelerated Forgetting in Mesial Temporal Lobe Epilepsy

ERIC Educational Resources Information Center

Barkas, Lisa; Redhead, Edward; Taylor, Matthew; Shtaya, Anan; Hamilton, Derek A.; Gray, William P.

2012-01-01

Learning and memory dysfunction is the most common neuropsychological effect of mesial temporal lobe epilepsy, and because the underlying neurobiology is poorly understood, there are no pharmacological strategies to help restore memory function in these patients. We have demonstrated impairments in the acquisition of an allocentric spatial task,…

When two are better than one: Bilateral mesial temporal lobe contributions associated with better vocabulary skills in children and adolescents.

PubMed

Bartha-Doering, Lisa; Novak, Astrid; Kollndorfer, Kathrin; Kasprian, Gregor; Schuler, Anna-Lisa; Berl, Madison M; Fischmeister, Florian Ph S; Gaillard, William D; Alexopoulos, Johanna; Prayer, Daniela; Seidl, Rainer

2018-06-15

This study considered the involvement of the mesial temporal lobe (MTL) in language and verbal memory functions in healthy children and adolescents. We investigated 30 healthy, right-handed children and adolescents, aged 7-16, with a fMRI language paradigm and a comprehensive cognitive test battery. We found significant MTL activations during language fMRI in all participants; 63% of them had left lateralized MTL activations, 20% exhibited right MTL lateralization, and 17% showed bilateral MTL involvement during the fMRI language paradigm. Group analyses demonstrated a strong negative correlation between the lateralization of MTL activations and language functions. Specifically, children with less lateralized MTL activation showed significantly better vocabulary skills. These findings suggest that the mesial temporal lobes of both hemispheres play an important role in language functioning, even in right-handers. Our results furthermore show that bilateral mesial temporal lobe involvement is advantageous for vocabulary skills in healthy, right-handed children and adolescents. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Right mesial temporal lobe epilepsy impairs empathy-related brain responses to dynamic fearful faces.

PubMed

Toller, Gianina; Adhimoolam, Babu; Grunwald, Thomas; Huppertz, Hans-Jürgen; Kurthen, Martin; Rankin, Katherine P; Jokeit, Hennric

2015-03-01

Unilateral mesial temporal lobe epilepsy (MTLE) has been associated with reduced amygdala responsiveness to fearful faces. However, the effect of unilateral MTLE on empathy-related brain responses in extra-amygdalar regions has not been investigated. Using functional magnetic resonance imaging, we measured empathy-related brain responses to dynamic fearful faces in 34 patients with unilateral MTLE (18 right sided), in an epilepsy (extra-MTLE; n = 16) and in a healthy control group (n = 30). The primary finding was that right MTLE (RMTLE) was associated with decreased activity predominantly in the right amygdala and also in bilateral periaqueductal gray (PAG) but normal activity in the right anterior insula. The results of the extra-MTLE group demonstrate that these reduced amygdala and PAG responses go beyond the attenuation caused by antiepileptic and antidepressant medication. These findings clearly indicate that RMTLE affects the function of mesial temporal and midbrain structures that mediate basic interoceptive input necessary for the emotional awareness of empathic experiences of fear. Together with the decreased empathic concern found in the RMTLE group, this study provides neurobehavioral evidence that patients with RMTLE are at increased risk for reduced empathy towards others' internal states and sheds new light on the nature of social-cognitive impairments frequently accompanying MTLE.

Temporal resolution in individuals with neurological disorders

PubMed Central

Rabelo, Camila Maia; Weihing, Jeffrey A; Schochat, Eliane

2015-01-01

OBJECTIVE: Temporal processing refers to the ability of the central auditory nervous system to encode and detect subtle changes in acoustic signals. This study aims to investigate the temporal resolution ability of individuals with mesial temporal sclerosis and to determine the sensitivity and specificity of the gaps-in-noise test in identifying this type of lesion. METHOD: This prospective study investigated differences in temporal resolution between 30 individuals with normal hearing and without neurological lesions (G1) and 16 individuals with both normal hearing and mesial temporal sclerosis (G2). Test performances were compared, and the sensitivity and specificity were calculated. RESULTS: There was no difference in gap detection thresholds between the two groups, although G1 revealed better average thresholds than G2 did. The sensitivity and specificity of the gaps-in-noise test for neurological lesions were 68% and 98%, respectively. CONCLUSIONS: Temporal resolution ability is compromised in individuals with neurological lesions caused by mesial temporal sclerosis. The gaps-in-noise test was shown to be a sensitive and specific measure of central auditory dysfunction in these patients. PMID:26375561

Lateral Transorbital Endoscopic Access to the Hippocampus, Amygdala, and Entorhinal Cortex: Initial Clinical Experience.

PubMed

Chen, H Isaac; Bohman, Leif-Erik; Emery, Lyndsey; Martinez-Lage, Maria; Richardson, Andrew G; Davis, Kathryn A; Pollard, John R; Litt, Brian; Gausas, Roberta E; Lucas, Timothy H

2015-01-01

Transorbital approaches traditionally have focused on skull base and cavernous sinus lesions medial to the globe. Lateral orbital approaches to the temporal lobe have not been widely explored despite several theoretical advantages compared to open craniotomy. Recently, we demonstrated the feasibility of the lateral transorbital technique in cadaveric specimens with endoscopic visualization. We describe our initial clinical experience with the endoscope-assisted lateral transorbital approach to lesions in the temporal lobe. Two patients with mesial temporal lobe pathology presenting with seizures underwent surgery. The use of a transpalpebral or Stallard-Wright eyebrow incision enabled access to the intraorbital compartment, and a lateral orbital wall 'keyhole' opening permitted visualization of the anterior temporal pole. This approach afforded adequate access to the surgical target and surrounding structures and was well tolerated by the patients. To the best of our knowledge, this report constitutes the first case series describing the endoscope-assisted lateral transorbital approach to the temporal lobe. We discuss the limits of exposure, the nuances of opening and closing, and comparisons to open craniotomy. Further prospective investigation of this approach is warranted for comparison to traditional approaches to the mesial temporal lobe. © 2015 S. Karger AG, Basel.

Widespread changes in network activity allow non-invasive detection of mesial temporal lobe seizures

PubMed Central

Zepeda, Rodrigo; Cole, Andrew J.; Cash, Sydney S.

2016-01-01

Abstract Decades of experience with intracranial recordings in patients with epilepsy have demonstrated that seizures can occur in deep cortical regions such as the mesial temporal lobes without showing any obvious signs of seizure activity on scalp electroencephalogram. Predicated on the idea that these seizures are purely focal, currently, the only way to detect these ‘scalp-negative seizures’ is with intracranial recordings. However, intracranial recordings are only rarely performed in patients with epilepsy, and are almost never performed outside of the context of epilepsy. As such, little is known about scalp-negative seizures and their role in the natural history of epilepsy, their effect on cognitive function, and their association with other neurological diseases. Here, we developed a novel approach to non-invasively identify scalp-negative seizures arising from the mesial temporal lobe based on scalp electroencephalogram network connectivity measures. We identified 25 scalp-negative mesial temporal lobe seizures in 10 patients and obtained control records from an additional 13 patients, all of whom underwent recordings with foramen ovale electrodes and scalp electroencephalogram. Scalp data from these records were used to train a scalp-negative seizure detector, which consisted of a pair of logistic regression classifiers that used scalp electroencephalogram coherence properties as input features. On cross-validation performance, this detector correctly identified scalp-negative seizures in 40% of patients, and correctly identified the side of seizure onset for each seizure detected. In comparison, routine clinical interpretation of these scalp electroencephalograms failed to identify any of the scalp-negative seizures. Among the patients in whom the detector raised seizure alarms, 80% had scalp-negative mesial temporal lobe seizures. The detector had a false alarm rate of only 0.31 per day and a positive predictive value of 75%. Of the 13 control patients, false seizure alarms were raised in only one patient. The fact that our detector specifically recognizes focal mesial temporal lobe seizures based on scalp electroencephalogram coherence features, lends weight to the hypothesis that even focal seizures are a network phenomenon that involve widespread neural connectivity. Our scalp-negative seizure detector has clear clinical utility in patients with temporal lobe epilepsy, and its potential easily translates to other neurological disorders, such as Alzheimer’s disease, in which occult mesial temporal lobe seizures are suspected to play a significant role. Importantly, our work establishes a novel approach of using computational approaches to non-invasively detect deep seizure activity, without the need for invasive intracranial recordings. PMID:27474219

EEG-fMRI evaluation of patients with mesial temporal lobe sclerosis.

PubMed

Avesani, Mirko; Giacopuzzi, Silvia; Bongiovanni, Luigi Giuseppe; Borelli, Paolo; Cerini, Roberto; Pozzi Mucelli, Roberto; Fiaschi, Antonio

2014-02-01

This preliminary study sought more information on blood oxygen level dependent (BOLD) activation, especially contralateral temporal/extratemporal spread, during continuous EEG-fMRI recordings in four patients with mesial temporal sclerosis (MTS). In two patients, EEG showed unilateral focal activity during the EEG-fMRI session concordant with the interictal focus previously identified with standard and video-poly EEG. In the other two patients EEG demonstrated a contralateral diffusion of the irritative focus. In the third patient (with the most drug-resistant form and also extratemporal clinical signs), there was an extratemporal diffusion over frontal regions, ipsilateral to the irritative focus. fMRI analysis confirmed a single activation in the mesial temporal region in two patients whose EEG showed unilateral focal activity, while it demonstrated a bilateral activation in the mesial temporal regions in the other two patients. In the third patient, fMRI demonstrated an activation in the supplementary motxor area. This study confirms the most significant activation with a high firing rate of the irritative focus, but also suggests the importance of using new techniques (such as EEG-fMRI to examine cerebral blood flow) to identify the controlateral limbic activation, and any other extratemporal activations, possible causes of drug resistance in MTS that may require a more precise pre-surgical evaluation with invasive techniques.

EEG-fMRI Evaluation of Patients with Mesial Temporal Lobe Sclerosis

PubMed Central

Avesani, Mirko; Giacopuzzi, Silvia; Bongiovanni, Luigi Giuseppe; Borelli, Paolo; Cerini, Roberto; Pozzi Mucelli, Roberto; Fiaschi, Antonio

2014-01-01

Summary This preliminary study sought more information on blood oxygen level dependent (BOLD) activation, especially contralateral temporal/extratemporal spread, during continuous EEG-fMRI recordings in four patients with mesial temporal sclerosis (MTS). In two patients, EEG showed unilateral focal activity during the EEG-fMRI session concordant with the interictal focus previously identified with standard and video-poly EEG. In the other two patients EEG demonstrated a contralateral diffusion of the irritative focus. In the third patient (with the most drug-resistant form and also extratemporal clinical signs), there was an extratemporal diffusion over frontal regions, ipsilateral to the irritative focus. fMRI analysis confirmed a single activation in the mesial temporal region in two patients whose EEG showed unilateral focal activity, while it demonstrated a bilateral activation in the mesial temporal regions in the other two patients. In the third patient, fMRI demonstrated an activation in the supplementary motxor area. This study confirms the most significant activation with a high firing rate of the irritative focus, but also suggests the importance of using new techniques (such as EEG-fMRI to examine cerebral blood flow) to identify the controlateral limbic activation, and any other extratemporal activations, possible causes of drug resistance in MTS that may require a more precise pre-surgical evaluation with invasive techniques. PMID:24571833

Predictive value of hippocampal MR imaging-based high-dimensional mapping in mesial temporal epilepsy: preliminary findings.

PubMed

Hogan, R E; Wang, L; Bertrand, M E; Willmore, L J; Bucholz, R D; Nassif, A S; Csernansky, J G

2006-01-01

We objectively assessed surface structural changes of the hippocampus in mesial temporal sclerosis (MTS) and assessed the ability of large-deformation high-dimensional mapping (HDM-LD) to demonstrate hippocampal surface symmetry and predict group classification of MTS in right and left MTS groups compared with control subjects. Using eigenvector field analysis of HDM-LD segmentations of the hippocampus, we compared the symmetry of changes in the right and left MTS groups with a group of 15 matched controls. To assess the ability of HDM-LD to predict group classification, eigenvectors were selected by a logistic regression procedure when comparing the MTS group with control subjects. Multivariate analysis of variance on the coefficients from the first 9 eigenvectors accounted for 75% of the total variance between groups. The first 3 eigenvectors showed the largest differences between the control group and each of the MTS groups, but with eigenvector 2 showing the greatest difference in the MTS groups. Reconstruction of the hippocampal deformation vector fields due solely to eigenvector 2 shows symmetrical patterns in the right and left MTS groups. A "leave-one-out" (jackknife) procedure correctly predicted group classification in 14 of 15 (93.3%) left MTS subjects and all 15 right MTS subjects. Analysis of principal dimensions of hippocampal shape change suggests that MTS, after accounting for normal right-left asymmetries, affects the right and left hippocampal surface structure very symmetrically. Preliminary analysis using HDM-LD shows it can predict group classification of MTS and control hippocampi in this well-defined population of patients with MTS and mesial temporal lobe epilepsy (MTLE).

Stereotactic Laser Ablation for Medically Intractable Epilepsy: The Next Generation of Minimally Invasive Epilepsy Surgery

PubMed Central

LaRiviere, Michael J.; Gross, Robert E.

2016-01-01

Epilepsy is a common, disabling illness that is refractory to medical treatment in approximately one-third of patients, particularly among those with mesial temporal lobe epilepsy. While standard open mesial temporal resection is effective, achieving seizure freedom in most patients, efforts to develop safer, minimally invasive techniques have been underway for over half a century. Stereotactic ablative techniques, in particular, radiofrequency (RF) ablation, were first developed in the 1960s, with refinements in the 1990s with the advent of modern computed tomography and magnetic resonance-based imaging. In the past 5 years, the most recent techniques have used MRI-guided laser interstitial thermotherapy (LITT), the development of which began in the 1980s, saw refinements in MRI thermal imaging through the 1990s, and was initially used primarily for the treatment of intracranial and extracranial tumors. The present review describes the original stereotactic ablation trials, followed by modern imaging-guided RF ablation series for mesial temporal lobe epilepsy. The developments of LITT and MRI thermometry are then discussed. Finally, the two currently available MRI-guided LITT systems are reviewed for their role in the treatment of mesial temporal lobe and other medically refractory epilepsies. PMID:27995127

Neuropsychological outcomes after Gamma Knife radiosurgery for mesial temporal lobe epilepsy: a prospective multicenter study.

PubMed

Quigg, Mark; Broshek, Donna K; Barbaro, Nicholas M; Ward, Mariann M; Laxer, Kenneth D; Yan, Guofen; Lamborn, Kathleen

2011-05-01

To assess outcomes of language, verbal memory, cognitive efficiency and mental flexibility, mood, and quality of life (QOL) in a prospective, multicenter pilot study of Gamma Knife radiosurgery (RS) for mesial temporal lobe epilepsy (MTLE). RS, randomized to 20 Gy or 24 Gy comprising 5.5-7.5 ml at the 50% isodose volume, was performed on mesial temporal structures of patients with unilateral MTLE. Neuropsychological evaluations were performed at preoperative baseline, and mean change scores were described at 12 and 24 months postoperatively. QOL data were also available at 36 months. Thirty patients were treated and 26 were available for the final 24-month neuropsychological evaluation. Language (Boston Naming Test), verbal memory (California Verbal Learning Test and Logical Memory subtest of the Wechsler Memory Scale-Revised), cognitive efficiency and mental flexibility (Trail Making Test), and mood (Beck Depression Inventory) did not differ from baseline. QOL scores improved at 24 and 36 months, with those patients attaining seizure remission by month 24s accounting for the majority of the improvement. The serial changes in cognitive outcomes, mood, and QOL are unremarkable following RS for MTLE. RS may provide an alternative to open surgery, especially in those patients at risk of cognitive impairment or who desire a noninvasive alternative to open surgery. Wiley Periodicals, Inc. © 2011 International League Against Epilepsy.

Temporal lobe epilepsy: analysis of patients with dual pathology.

PubMed

Salanova, V; Markand, O; Worth, R

2004-02-01

To determine the frequency and types of dual pathology in patients with temporal lobe epilepsy (TLE) and to analyze the clinical manifestations and surgical outcome. A total of 240 patients with TLE underwent temporal resections following a comprehensive pre-surgical evaluation. Thirty-seven (15.4%) of these had hippocampal sclerosis (HS) or temporal lobe gliosis in association with another lesion (dual pathology). Eighteen of 37 patients with dual pathology had heterotopia of the temporal lobe, nine had cortical dysplasia, four had cavernous angiomas or arteriovenous malformations, one had a dysembryoplastic neuroepithelial tumor, one had a contusion and four patients had cerebral infarctions in childhood. 68.5% had abnormal head magnetic resonance imagings, 91.3% had abnormal positron emission tomography scans, and 96% had abnormal ictal SPECT. The intracarotid amobarbital procedure (IAP) showed impaired memory of the epileptogenic side in 72% of the patients. Twenty patients had left and 17 had right-sided en bloc temporal resections, including the lesion and mesial temporal structures. Twenty-six (70.2%) became seizure-free, eight (21.6%) had rare seizures, two (5.4%) had worthwhile seizure reduction and one (2.7%) had no improvement (range of follow-up 1-16 years, mean = 7.4 years). 15.4% had dual pathology. The dual pathology was almost exclusively seen in patients whose lesions were congenital, or occurred early in life, suggesting that the hippocampus is more vulnerable and more readily develops HS in early childhood. Resections, including the lateral and mesial temporal structures led to a favorable outcome with no mortality and little morbidity.

[Two cases of mesial temporal lobe epilepsy associated with old intracerebral hemorrhage in the lateral temporal lobe without "dual pathology"].

PubMed

Morioka, T; Nishio, S; Hisada, K; Muraishi, M; Ishibashi, H; Mamiya, K; Ohfu, M; Fukui, M

1998-05-01

Two cases of intractable temporal lobe epilepsy associated with old intracerebral hemorrhage in the lateral temporal lobe were reported. Although preoperative magnetic resonance imaging (MRI) failed to reveal hippocampal atrophy with T2 hyperintensity, electrocorticographic (ECoG) recording with chronic invasive subdural electrodes indicated the mesial temporal lobe to be an ictal onset zone. After anterior temporal lobectomy involving the lesion and hippocampectomy, the patients became seizure-free. Hippocampal sclerosis, namely "dual pathology", was not noted on histological examination. Careful ECoG recording with chronic subdural electrodes is mandatory even when the preoperative MRI does not demonstrate the radiological hippocampal sclerosis.

Differential gene expression in dentate granule cells in mesial temporal lobe epilepsy with and without hippocampal sclerosis.

PubMed

Griffin, Nicole G; Wang, Yu; Hulette, Christine M; Halvorsen, Matt; Cronin, Kenneth D; Walley, Nicole M; Haglund, Michael M; Radtke, Rodney A; Skene, J H Pate; Sinha, Saurabh R; Heinzen, Erin L

2016-03-01

Hippocampal sclerosis is the most common neuropathologic finding in cases of medically intractable mesial temporal lobe epilepsy. In this study, we analyzed the gene expression profiles of dentate granule cells of patients with mesial temporal lobe epilepsy with and without hippocampal sclerosis to show that next-generation sequencing methods can produce interpretable genomic data from RNA collected from small homogenous cell populations, and to shed light on the transcriptional changes associated with hippocampal sclerosis. RNA was extracted, and complementary DNA (cDNA) was prepared and amplified from dentate granule cells that had been harvested by laser capture microdissection from surgically resected hippocampi from patients with mesial temporal lobe epilepsy with and without hippocampal sclerosis. Sequencing libraries were sequenced, and the resulting sequencing reads were aligned to the reference genome. Differential expression analysis was used to ascertain expression differences between patients with and without hippocampal sclerosis. Greater than 90% of the RNA-Seq reads aligned to the reference. There was high concordance between transcriptional profiles obtained for duplicate samples. Principal component analysis revealed that the presence or absence of hippocampal sclerosis was the main determinant of the variance within the data. Among the genes up-regulated in the hippocampal sclerosis samples, there was significant enrichment for genes involved in oxidative phosphorylation. By analyzing the gene expression profiles of dentate granule cells from surgically resected hippocampal specimens from patients with mesial temporal lobe epilepsy with and without hippocampal sclerosis, we have demonstrated the utility of next-generation sequencing methods for producing biologically relevant results from small populations of homogeneous cells, and have provided insight on the transcriptional changes associated with this pathology. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Widespread changes in network activity allow non-invasive detection of mesial temporal lobe seizures.

PubMed

Lam, Alice D; Zepeda, Rodrigo; Cole, Andrew J; Cash, Sydney S

2016-10-01

Decades of experience with intracranial recordings in patients with epilepsy have demonstrated that seizures can occur in deep cortical regions such as the mesial temporal lobes without showing any obvious signs of seizure activity on scalp electroencephalogram. Predicated on the idea that these seizures are purely focal, currently, the only way to detect these 'scalp-negative seizures' is with intracranial recordings. However, intracranial recordings are only rarely performed in patients with epilepsy, and are almost never performed outside of the context of epilepsy. As such, little is known about scalp-negative seizures and their role in the natural history of epilepsy, their effect on cognitive function, and their association with other neurological diseases. Here, we developed a novel approach to non-invasively identify scalp-negative seizures arising from the mesial temporal lobe based on scalp electroencephalogram network connectivity measures. We identified 25 scalp-negative mesial temporal lobe seizures in 10 patients and obtained control records from an additional 13 patients, all of whom underwent recordings with foramen ovale electrodes and scalp electroencephalogram. Scalp data from these records were used to train a scalp-negative seizure detector, which consisted of a pair of logistic regression classifiers that used scalp electroencephalogram coherence properties as input features. On cross-validation performance, this detector correctly identified scalp-negative seizures in 40% of patients, and correctly identified the side of seizure onset for each seizure detected. In comparison, routine clinical interpretation of these scalp electroencephalograms failed to identify any of the scalp-negative seizures. Among the patients in whom the detector raised seizure alarms, 80% had scalp-negative mesial temporal lobe seizures. The detector had a false alarm rate of only 0.31 per day and a positive predictive value of 75%. Of the 13 control patients, false seizure alarms were raised in only one patient. The fact that our detector specifically recognizes focal mesial temporal lobe seizures based on scalp electroencephalogram coherence features, lends weight to the hypothesis that even focal seizures are a network phenomenon that involve widespread neural connectivity. Our scalp-negative seizure detector has clear clinical utility in patients with temporal lobe epilepsy, and its potential easily translates to other neurological disorders, such as Alzheimer's disease, in which occult mesial temporal lobe seizures are suspected to play a significant role. Importantly, our work establishes a novel approach of using computational approaches to non-invasively detect deep seizure activity, without the need for invasive intracranial recordings. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Application of T2 relaxometry in lateralization and localization of mesial temporal lobe epilepsy and corresponding comparison with MR volumetry.

PubMed

Chen, Hui; Yu, Guilian; Wang, Jiangtao; Li, Feng; Li, Guangming

2016-09-01

Magnetic resonance (MR) volumetry is insensitive to subtle mesial temporal sclerosis (MTS), while T2 relaxometry is potential useful in detecting MTS, especially MTS in early course. To explore and compare the feasibility of T2 relaxometry and MR volumetry in evaluation of mesial temporal lobe epilepsy (MTLE) and lateralization of the epileptogenic zone, so as to optimize and enhance lesion depiction. For the 17 unilateral MTLE patients and 14 normal participants, the hippocampus and amygdala were contoured on axial T2-weighted (T2W) images and then co-registered onto T2 relaxation maps. Abnormal is defined as an elevated asymmetric ratio of larger than 2 SD. Visual and quantitative volumetric assessment were combined as outcomes of MR volumetry to distinguish MR-positive and MR-negative lesions. Operative and pathological findings were used as gold standard. T2 values of lesions were significantly elevated. In lateralizing the epileptogenic zones, T2 relaxometry yielded an overall accuracy of 94.1% (sensitivity 92.6%, specificity 100%), and MR volumetry yielded an overall accuracy of 82.4% (sensitivity 88.9%, specificity 57.1%), meaning a better performance of T2 relaxometry (P < 0.001, by chi-square test). For pathologically sclerotic structures, most (25/27) were recognized by T2 relaxometry, while 24 of 27 sclerotic structures were detected via MR volumetry. MR volumetry wrongly discerned three normal regions as MTS, while one MR-negative sclerotic hippocampus was detected by T2 relaxometry. T2 relaxometry is feasible in non-invasive lateralization of epileptogenic zone, and more advantaged than MR volumetry in detecting MR-negative lesions, facilitating prompt diagnosis and longitudinal disease monitoring. © The Foundation Acta Radiologica 2015.

Visual Memory in Post-Anterior Right Temporal Lobectomy Patients and Adult Normative Data for the Brown Location Test (BLT)

PubMed Central

Brown, Franklin C.; Tuttle, Erin; Westerveld, Michael; Ferraro, F. Richard; Chmielowiec, Teresa; Vandemore, Michelle; Gibson-Beverly, Gina; Bemus, Lisa; Roth, Robert M.; Blumenfeld, Hal; Spencer, Dennis D.; Spencer, Susan S

2010-01-01

Several large and meta-analytic studies have failed to support a consistent relationship between visual or “nonverbal” memory deficits and right mesial temporal lobe changes. However, the Brown Location Test (BLT) is a recently developed dot location learning and memory test that uses a nonsymmetrical array and provides control over many of the confounding variables (e.g., verbal influence and drawing requirements) inherent in other measures of visual memory. In the present investigation, we evaluated the clinical utility of the BLT in patients who had undergone left or right anterior mesial temporal lobectomies. We also provide adult normative data of 298 healthy adults in order to provide standardized scores. Results revealed significantly worse performance on the BLT in the right as compared to left lobectomy group and the healthy adult normative sample. The present findings support a role for the right anterior-mesial temporal lobe in dot location learning and memory. PMID:20056493

Microencephaloceles: another dual pathology of intractable temporal lobe epilepsy in childhood.

PubMed

Aquilina, Kristian; Clarke, Dave F; Wheless, James W; Boop, Frederick A

2010-04-01

Temporal lobe encephaloceles can be associated with temporal lobe epilepsy. The authors report on the case of an adolescent with multiple microencephaloceles, in the anterolateral middle fossa floor, identified at surgery (temporal lobectomy) for intractable partial-onset seizures of temporal origin. Magnetic resonance imaging revealed only hippocampal atrophy. Subdural electrodes demonstrated ictal activity arising primarily from the anterior and lateral temporal lobe, close to the microencephaloceles, spreading to the anterior and posterior mesial structures. Pathological examination revealed diffuse temporal gliosis involving the hippocampus, together with microdysgenesis of the amygdala. The literature on epilepsy secondary to encephaloceles is reviewed and the contribution of the microencephaloceles to the seizure disorder in this patient is discussed.

Sensitivity and specificity of auditory steady‐state response testing

PubMed Central

Rabelo, Camila Maia; Schochat, Eliane

2011-01-01

INTRODUCTION: The ASSR test is an electrophysiological test that evaluates, among other aspects, neural synchrony, based on the frequency or amplitude modulation of tones. OBJECTIVE: The aim of this study was to determine the sensitivity and specificity of auditory steady‐state response testing in detecting lesions and dysfunctions of the central auditory nervous system. METHODS: Seventy volunteers were divided into three groups: those with normal hearing; those with mesial temporal sclerosis; and those with central auditory processing disorder. All subjects underwent auditory steady‐state response testing of both ears at 500 Hz and 2000 Hz (frequency modulation, 46 Hz). The difference between auditory steady‐state response‐estimated thresholds and behavioral thresholds (audiometric evaluation) was calculated. RESULTS: Estimated thresholds were significantly higher in the mesial temporal sclerosis group than in the normal and central auditory processing disorder groups. In addition, the difference between auditory steady‐state response‐estimated and behavioral thresholds was greatest in the mesial temporal sclerosis group when compared to the normal group than in the central auditory processing disorder group compared to the normal group. DISCUSSION: Research focusing on central auditory nervous system (CANS) lesions has shown that individuals with CANS lesions present a greater difference between ASSR‐estimated thresholds and actual behavioral thresholds; ASSR‐estimated thresholds being significantly worse than behavioral thresholds in subjects with CANS insults. This is most likely because the disorder prevents the transmission of the sound stimulus from being in phase with the received stimulus, resulting in asynchronous transmitter release. Another possible cause of the greater difference between the ASSR‐estimated thresholds and the behavioral thresholds is impaired temporal resolution. CONCLUSIONS: The overall sensitivity of auditory steady‐state response testing was lower than its overall specificity. Although the overall specificity was high, it was lower in the central auditory processing disorder group than in the mesial temporal sclerosis group. Overall sensitivity was also lower in the central auditory processing disorder group than in the mesial temporal sclerosis group. PMID:21437442

Neuropsychological results after gamma knife radiosurgery for mesial temporal lobe epilepsy.

PubMed

Vojtěch, Zdeněk; Krámská, Lenka; Malíková, Hana; Stará, Michaela; Liščák, Roman

2015-01-01

The aim of this study is to summarize our experience with neuropsychological changes after radiosurgical treatment for mesial temporal lobe epilepsy and subsequent surgery due to insufficient seizure control. Between November 1995 and May 1999, 14 patients underwent radiosurgical entorhinoamygdalohippocampectomy with a marginal dose of 18, 20 or 25 Gy to the 50% isodose. 9 of these patients subsequently underwent surgery. We compared Memory Quotients and Intelligence Quotients before and after the interventions. We found a slight, but nonsignificant decline in intelligence and memory quotients one year after GKRS. Two years after radiosurgery there were no significant changes in any of the quotients. After surgery, we found significant increase in Global and Visual MQ, (p<0.05). There were no statistically significant changes in verbal memory and intelligence performance after surgery. Epilepsy surgery after unsuccessful radiosurgery could lead to improvements in cognitive functions in patients with mesial temporal lobe epilepsy.

Dream recall frequency and content in patients with temporal lobe epilepsy.

PubMed

Bentes, Carla; Costa, João; Peralta, Rita; Pires, Joana; Sousa, Paula; Paiva, Teresa

2011-11-01

To evaluate morning dream recall frequency and content in patients with temporal lobe epilepsy (TLE). Fifty-two patients with pharmacoresistant TLE submitted to a written dream diary during five consecutive days and continuous video-electroencephalographic (video-EEG) monitoring. A matched control group of 41 healthy subjects completed the same diary at home. The number of recalled dreams (including long dreams) and nonrecalled dream mentation were collected, and the Dream Recall Rate (DRR) was calculated. Hall and Van de Castle dream content analysis was performed. Greater than 70% of patients with TLE (37 of 52) recall their dreams, but DRR rate in these patients is lower than in controls (p ≤ 0.001). Dream recall does not appear to be influenced by the presence of neuropsychological deficits nor seizure frequency. In dreams descriptions, TLE patients (vs. controls) have a higher percentage of familiarity in settings and fewer dreams with at least one success. Onirical activity of patients with TLE is different from that of healthy subjects. Our results support the role of mesial and neocortical temporal structures in dream experience. The selective activation of dysfunctional mesial structures may be responsible for some of the observed variability. However, dream content changes can also mirror social and psychological comorbidities of patients with epilepsy. Wiley Periodicals, Inc. © 2011 International League Against Epilepsy.

Distinctive Structural and Effective Connectivity Changes of Semantic Cognition Network across Left and Right Mesial Temporal Lobe Epilepsy Patients.

PubMed

Fan, Xiaotong; Yan, Hao; Shan, Yi; Shang, Kun; Wang, Xiaocui; Wang, Peipei; Shan, Yongzhi; Lu, Jie; Zhao, Guoguang

2016-01-01

Occurrence of language impairment in mesial temporal lobe epilepsy (mTLE) patients is common and left mTLE patients always exhibit a primary problem with access to names. To explore different neuropsychological profiles between left and right mTLE patients, the study investigated both structural and effective functional connectivity changes within the semantic cognition network between these two groups and those from normal controls. We found that gray matter atrophy of left mTLE patients was more severe than that of right mTLE patients in the whole brain and especially within the semantic cognition network in their contralateral hemisphere. It suggested that seizure attacks were rather targeted than random for patients with hippocampal sclerosis (HS) in the dominant hemisphere. Functional connectivity analysis during resting state fMRI revealed that subregions of the anterior temporal lobe (ATL) in the left HS patients were no longer effectively connected. Further, we found that, unlike in right HS patients, increased causal linking between ipsilateral regions in the left HS epilepsy patients cannot make up for their decreased contralateral interaction. It suggested that weakened contralateral connection and disrupted effective interaction between subregions of the unitary, transmodal hub of the ATL may be the primary cause of anomia in the left HS patients.

Distinctive Structural and Effective Connectivity Changes of Semantic Cognition Network across Left and Right Mesial Temporal Lobe Epilepsy Patients

PubMed Central

Fan, Xiaotong; Shang, Kun; Wang, Xiaocui; Wang, Peipei; Shan, Yongzhi; Lu, Jie

2016-01-01

Occurrence of language impairment in mesial temporal lobe epilepsy (mTLE) patients is common and left mTLE patients always exhibit a primary problem with access to names. To explore different neuropsychological profiles between left and right mTLE patients, the study investigated both structural and effective functional connectivity changes within the semantic cognition network between these two groups and those from normal controls. We found that gray matter atrophy of left mTLE patients was more severe than that of right mTLE patients in the whole brain and especially within the semantic cognition network in their contralateral hemisphere. It suggested that seizure attacks were rather targeted than random for patients with hippocampal sclerosis (HS) in the dominant hemisphere. Functional connectivity analysis during resting state fMRI revealed that subregions of the anterior temporal lobe (ATL) in the left HS patients were no longer effectively connected. Further, we found that, unlike in right HS patients, increased causal linking between ipsilateral regions in the left HS epilepsy patients cannot make up for their decreased contralateral interaction. It suggested that weakened contralateral connection and disrupted effective interaction between subregions of the unitary, transmodal hub of the ATL may be the primary cause of anomia in the left HS patients. PMID:28018680

Surgical outcome in patients with epilepsy and dual pathology.

PubMed

Li, L M; Cendes, F; Andermann, F; Watson, C; Fish, D R; Cook, M J; Dubeau, F; Duncan, J S; Shorvon, S D; Berkovic, S F; Free, S; Olivier, A; Harkness, W; Arnold, D L

1999-05-01

High-resolution MRI can detect dual pathology (an extrahippocampal lesion plus hippocampal atrophy) in about 5-20% of patients with refractory partial epilepsy referred for surgical evaluation. We report the results of 41 surgical interventions in 38 adults (mean age 31 years, range 14-63 years) with dual pathology. Three patients had two operations. The mean postoperative follow-up was 37 months (range 12-180 months). The extrahippocampal lesions were cortical dysgenesis in 15, tumour in 10, contusion/infarct in eight and vascular malformation in five patients. The surgical approach aimed to remove what was considered to be the most epileptogenic lesion, and the 41 operations were classified into lesionectomy (removal of an extrahippocampal lesion); mesial temporal resection (removal of an atrophic hippocampus); and lesionectomy plus mesial temporal resection (removal of both the lesion and the atrophic hippocampus). Lesionectomy plus mesial temporal resection resulted in complete freedom from seizures in 11/15 (73%) patients, while only 2/10 (20%) patients who had mesial temporal resection alone and 2/16 (12.5%) who had a lesionectomy alone were seizure-free (P < 0.001). When classes I and II were considered together results improved to 86, 30 and 31%, respectively. Our findings indicate that in patients with dual pathology removal of both the lesion and the atrophic hippocampus is the best surgical approach and should be considered whenever possible.

Charles Bonnet syndrome in hemianopia, following antero-mesial temporal lobectomy for drug-resistant epilepsy.

PubMed

Contardi, Sara; Rubboli, Guido; Giulioni, Marco; Michelucci, Roberto; Pizza, Fabio; Gardella, Elena; Pinardi, Federica; Bartolomei, Ilaria; Tassinari, Carlo Alberto

2007-09-01

Charles Bonnet syndrome (CBS) is a disorder characterized by the occurrence of complex visual hallucinations in patients with acquired impairment of vision and without psychiatric disorders. In spite of the high incidence of visual field defects following antero-mesial temporal lobectomy for refractory temporal lobe epilepsy, reports of CBS in patients who underwent this surgical procedure are surprisingly rare. We describe a patient operated on for drug-resistant epilepsy. As a result of left antero-mesial temporal resection, she presented right homonymous hemianopia. A few days after surgery, she started complaining of visual hallucinations, such as static or moving "Lilliputian" human figures, or countryside scenes, restricted to the hemianopic field. The patient was fully aware of their fictitious nature. These disturbances disappeared progressively over a few weeks. The incidence of CBS associated with visual field defects following epilepsy surgery might be underestimated. Patients with post-surgical CBS should be reassured that it is not an epileptic phenomenon, and that it has a benign, self-limiting, course which does not usually require treatment.

Benign mesial temporal lobe epilepsy: A clinical cohort and literature review.

PubMed

AlQassmi, Amal; Burneo, Jorge G; McLachlan, Richard S; Mirsattari, Seyed M

2016-12-01

We present a single-center retrospective study of benign mesial temporal lobe epilepsy (bMTLE) between 1995 and 2014. Hospital records and clinic charts were reviewed. The clinical, Eelectroencephalographic (EEG), imaging features, and response to treatment with antiepileptic drugs (AEDs) were documented. Patients were included in this study if they were seizure-free for a minimum of 24months with or without an AED. Twenty-seven patients were identified. There were 19 (70%) females, mean age at first seizure was 32.2 (range: 15-80years). In all patients, seizures were mild, and seizure freedom was readily achieved with the initiation of AED therapy. Sixteen patients (59%) had mesial temporal sclerosis (MTS). In three patients, we attempted to discontinue AED therapy after a prolonged period of remission (5-8years), but all had seizure recurrence within 2 to 4weeks. Not all temporal lobe epilepsy is refractory to medication, despite the presence of MTS. Until clinical trials indicate otherwise, surgery is not indicated but life-long medical treatment is advocated. Copyright © 2016 Elsevier Inc. All rights reserved.

Gender differences in post-temporal lobectomy verbal memory and relationships between MRI hippocampal volumes and preoperative verbal memory.

PubMed

Trenerry, M R; Jack, C R; Cascino, G D; Sharbrough, F W; Ivnik, R J

1995-01-01

Thirty-three men and 42 women who underwent left, and 26 men and 24 women who underwent right temporal lobectomy (TL) were studied retrospectively to determine if there were sex differences in (1) verbal memory outcome, and (2) relationships between verbal memory and magnetic resonance imaging (MRI) hippocampal volumes. All patients were left hemisphere language dominant. The surgical specimen and MRI were consistent only with mesial temporal sclerosis (MTS). Verbal memory was evaluated by Logical Memory percent retention (LMPER) from the Wechsler Memory Scale-Revised (WMS-R). Women experienced a significant improvement while men experienced a significant decline in postoperative LMPER. The difference between right and left hippocampal volumes predicted verbal memory outcome in both men and women. Preoperative LMPER was positively correlated with both the left and right hippocampal volumes in left TL women only. No verbal memory sex differences or correlations between LMPER and MRI data were found in the right TL group. The data support the presence of human neurocognitive sexual dimorphism. Verbal memory abilities supported by the hippocampus are less lateralized in women with left temporal lobe epilepsy and mesial temporal sclerosis. Women appear to have greater verbal memory plasticity following early left mesial temporal lobe insult.

Brain-responsive neurostimulation in patients with medically intractable mesial temporal lobe epilepsy.

PubMed

Geller, Eric B; Skarpaas, Tara L; Gross, Robert E; Goodman, Robert R; Barkley, Gregory L; Bazil, Carl W; Berg, Michael J; Bergey, Gregory K; Cash, Sydney S; Cole, Andrew J; Duckrow, Robert B; Edwards, Jonathan C; Eisenschenk, Stephan; Fessler, James; Fountain, Nathan B; Goldman, Alicia M; Gwinn, Ryder P; Heck, Christianne; Herekar, Aamar; Hirsch, Lawrence J; Jobst, Barbara C; King-Stephens, David; Labar, Douglas R; Leiphart, James W; Marsh, W Richard; Meador, Kimford J; Mizrahi, Eli M; Murro, Anthony M; Nair, Dileep R; Noe, Katherine H; Park, Yong D; Rutecki, Paul A; Salanova, Vicenta; Sheth, Raj D; Shields, Donald C; Skidmore, Christopher; Smith, Michael C; Spencer, David C; Srinivasan, Shraddha; Tatum, William; Van Ness, Paul C; Vossler, David G; Wharen, Robert E; Worrell, Gregory A; Yoshor, Daniel; Zimmerman, Richard S; Cicora, Kathy; Sun, Felice T; Morrell, Martha J

2017-06-01

Evaluate the seizure-reduction response and safety of mesial temporal lobe (MTL) brain-responsive stimulation in adults with medically intractable partial-onset seizures of mesial temporal lobe origin. Subjects with mesial temporal lobe epilepsy (MTLE) were identified from prospective clinical trials of a brain-responsive neurostimulator (RNS System, NeuroPace). The seizure reduction over years 2-6 postimplantation was calculated by assessing the seizure frequency compared to a preimplantation baseline. Safety was assessed based on reported adverse events. There were 111 subjects with MTLE; 72% of subjects had bilateral MTL onsets and 28% had unilateral onsets. Subjects had one to four leads placed; only two leads could be connected to the device. Seventy-six subjects had depth leads only, 29 had both depth and strip leads, and 6 had only strip leads. The mean follow-up was 6.1 ± (standard deviation) 2.2 years. The median percent seizure reduction was 70% (last observation carried forward). Twenty-nine percent of subjects experienced at least one seizure-free period of 6 months or longer, and 15% experienced at least one seizure-free period of 1 year or longer. There was no difference in seizure reduction in subjects with and without mesial temporal sclerosis (MTS), bilateral MTL onsets, prior resection, prior intracranial monitoring, and prior vagus nerve stimulation. In addition, seizure reduction was not dependent on the location of depth leads relative to the hippocampus. The most frequent serious device-related adverse event was soft tissue implant-site infection (overall rate, including events categorized as device-related, uncertain, or not device-related: 0.03 per implant year, which is not greater than with other neurostimulation devices). Brain-responsive stimulation represents a safe and effective treatment option for patients with medically intractable epilepsy, including patients with unilateral or bilateral MTLE who are not candidates for temporal lobectomy or who have failed a prior MTL resection. © 2017 The Authors. Epilepsia published by Wiley Periodicals, Inc. on behalf of International League Against Epilepsy.

Network reconfiguration and working memory impairment in mesial temporal lobe epilepsy.

PubMed

Campo, Pablo; Garrido, Marta I; Moran, Rosalyn J; García-Morales, Irene; Poch, Claudia; Toledano, Rafael; Gil-Nagel, Antonio; Dolan, Raymond J; Friston, Karl J

2013-05-15

Mesial temporal lobe epilepsy (mTLE) is the most prevalent form of focal epilepsy, and hippocampal sclerosis (HS) is considered the most frequent associated pathological finding. Recent connectivity studies have shown that abnormalities, either structural or functional, are not confined to the affected hippocampus, but can be found in other connected structures within the same hemisphere, or even in the contralesional hemisphere. Despite the role of hippocampus in memory functions, most of these studies have explored network properties at resting state, and in some cases compared connectivity values with neuropsychological memory scores. Here, we measured magnetoencephalographic responses during verbal working memory (WM) encoding in left mTLE patients and controls, and compared their effective connectivity within a frontotemporal network using dynamic causal modelling. Bayesian model comparison indicated that the best model included bilateral, forward and backward connections, linking inferior temporal cortex (ITC), inferior frontal cortex (IFC), and the medial temporal lobe (MTL). Test for differences in effective connectivity revealed that patients exhibited decreased ipsilesional MTL-ITC backward connectivity, and increased bidirectional IFC-MTL connectivity in the contralesional hemisphere. Critically, a negative correlation was observed between these changes in patients, with decreases in ipsilesional coupling among temporal sources associated with increases contralesional frontotemporal interactions. Furthermore, contralesional frontotemporal interactions were inversely related to task performance and level of education. The results demonstrate that unilateral sclerosis induced local and remote changes in the dynamic organization of a distributed network supporting verbal WM. Crucially, pre-(peri) morbid factors (educational level) were reflected in both cognitive performance and (putative) compensatory changes in physiological coupling. Copyright © 2013 Elsevier Inc. All rights reserved.

Declarative long-term memory and the mesial temporal lobe: Insights from a 5-year postsurgery follow-up study on refractory temporal lobe epilepsy.

PubMed

Salvato, Gerardo; Scarpa, Pina; Francione, Stefano; Mai, Roberto; Tassi, Laura; Scarano, Elisa; Lo Russo, Giorgio; Bottini, Gabriella

2016-11-01

It is largely recognized that the mesial temporal lobe and its substructure support declarative long-term memory (LTM). So far, different theories have been suggested, and the organization of declarative verbal LTM in the brain is still a matter of debate. In the current study, we retrospectively selected 151 right-handed patients with temporal lobe epilepsy with and without hippocampal sclerosis, with a homogeneous (seizure-free) clinical outcome. We analyzed verbal memory performance within a normalized scores context, by means of prose recall and word paired-associate learning tasks. Patients were tested at presurgical baseline, 6months, 2 and 5years after anteromesial temporal lobe surgery, using parallel versions of the neuropsychological tests. Our main finding revealed a key involvement of the left temporal lobe and, in particular, of the left hippocampus in prose recall rather than word paired-associate task. We also confirmed that shorter duration of epilepsy, younger age, and withdrawal of antiepileptic drugs would predict a better memory outcome. When individual memory performance was taken into account, data showed that females affected by left temporal lobe epilepsy for longer duration were more at risk of presenting a clinically pathologic LTM at 5years after surgery. Taken together, these findings shed new light on verbal declarative memory in the mesial temporal lobe and on the behavioral signature of the functional reorganization after the surgical treatment of temporal lobe epilepsy. Copyright © 2016 Elsevier Inc. All rights reserved.

Real-Time Magnetic Resonance-Guided Stereotactic Laser Amygdalohippocampotomy for Mesial Temporal Lobe Epilepsy

PubMed Central

Willie, Jon T.; Laxpati, Nealen G.; Drane, Daniel L.; Gowda, Ashok; Appin, Christina; Hao, Chunhai; Brat, Daniel J.; Helmers, Sandra L.; Saindane, Amit; Nour, Sherif G.; Gross, Robert E.

2014-01-01

Background Open surgery effectively treats mesial temporal lobe epilepsy (MTLE), but carries risks of neurocognitive deficits, which may be reduced with minimally invasive alternatives. Objective To describe technical and clinical outcomes of stereotactic laser amygdalohippocampotomy (SLAH) with real-time magnetic resonance thermal imaging (MRTI) guidance. Methods Under general anesthesia and utilizing standard stereotactic methods, 13 adult patients with intractable MTLE (with and without mesial temporal sclerosis, MTS) prospectively underwent insertion of a saline-cooled fiber-optic laser applicator into amygdalohippocampal structures from an occipital trajectory. Computer-controlled laser ablation was performed during continuous MRTI followed by confirmatory contrast-enhanced anatomic imaging and volumetric reconstruction. Clinical outcomes were determined from seizure diaries. Results A mean 60% volume of the amygdalohippocampal complex was ablated in 13 patients (9 with MTS) undergoing 15 procedures. Median hospitalization was one day. With follow-up ranging from 5-26 (median 14) months, 77% (10/13) of patients achieved meaningful seizure reduction, of which 54% (7/13) were free of disabling seizures. Of patients with preoperative MTS, 67% (6/9) achieved seizure freedom. All recurrences were observed by<6 months. Variances in ablation volume and length did not account for individual clinical outcomes. Whereas no complications of laser therapy itself were observed, one significant complication, a visual field defect, resulted from deviated insertion of a stereotactic aligning rod, which was corrected prior to ablation. Conclusion Real-time MR-guided SLAH is a technically novel, safe, and effective alternative to open surgery. Further evaluation with larger cohorts over time is warranted. PMID:24618797

Earlier tachycardia onset in right than left mesial temporal lobe seizures.

PubMed

Kato, Kazuhiro; Jin, Kazutaka; Itabashi, Hisashi; Iwasaki, Masaki; Kakisaka, Yosuke; Aoki, Masashi; Nakasato, Nobukazu

2014-10-07

To clarify whether the presence and timing of peri-ictal heart rate (HR) change is a seizure lateralizing sign in patients with mesial temporal lobe epilepsy (mTLE). Long-term video EEGs were retrospectively reviewed in 21 patients, 7 men and 14 women aged 13 to 67 years, diagnosed as mTLE with MRI lesions in the mesial temporal structures (hippocampal sclerosis in 20 cases, amygdala hypertrophy in 1 case). Seventy-seven partial seizures without secondary generalization were extracted. Peri-ictal HR change was compared between 29 right seizures (9 patients) and 48 left seizures (12 patients). HR abruptly increased in all 29 right seizures and 42 of 48 left seizures. Onset time of HR increase in relation to ictal EEG onset was significantly earlier in right seizures than in left seizures (mean ± SD, -11.5 ± 14.8 vs 9.2 ± 21.7 seconds; p < 0.0001). Time of maximum HR was also significantly earlier in right seizures than in left seizures (36.0 ± 18.1 vs 58.0 ± 28.7 seconds; p < 0.0001). Maximum HR changes from baseline showed no significant difference between right and left seizures (47.5 ± 19.1 vs 40.8 ± 20.0/min). Significantly earlier tachycardia in right than left mTLE seizures supports previous hypotheses that the right cerebral hemisphere is dominant in the sympathetic network. No HR change, or delayed tachycardia possibly due to seizure propagation to the right hemisphere, may be a useful lateralizing sign of left mTLE seizures. © 2014 American Academy of Neurology.

H.M. never again! An analysis of H.M.'s epilepsy and treatment.

PubMed

Mauguière, F; Corkin, S

2015-03-01

On August 25, 1953, the patient H.M., aged 27, underwent a bilateral surgical destruction of the inner aspect of his temporal lobes performed by William Beecher Scoville with the aim to control H.M.'s drug refractory epileptic seizures and alleviate their impact on his quality of life. Postoperatively, H.M. presented for 55 years a "striking and totally unexpected grave loss of recent memories". This paper reports what we know about H.M.'s epilepsy before and after surgery and puts forward arguments supporting the syndromic classification of his epilepsy. We attempted to elucidate what could have been the rationale, in 1953, of Scoville's decision to carry out a bilateral ablation of H.M.'s medial temporal lobe structures, and we examined whether there was any convincing argument published before 1953 suggesting that bilateral hippocampal ablation could result in a permanent and severe amnesia. Our a posteriori analysis of H.M.'s medical history suggested that he was most probably suffering from idiopathic generalized epilepsy with absences and generalized convulsive seizures worsened by high dosage phenytoin treatment, or less probably from cryptogenic frontal lobe epilepsy. Importantly, he did not have temporal lobe epilepsy. Scoville based his proposal of bilateral mesial temporal lobe ablation on his experience as a psychosurgeon and on the assumption that the threshold of generalized epileptic activity could be lowered by some kind of hippocampal dysfunction potentially epileptic in nature. Given the scanty information on the link between amnesia and medial temporal lobe lesions that was available in humans in 1953, one can understand why Scoville was so surprised by the "striking and totally unexpected" memory loss he observed in H.M. after the bilateral ablation of his mesial temporal lobe structures. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Neuroimaging evaluation in refractory epilepsy

PubMed Central

Granados, Ana M; Orejuela, Juan F

2015-01-01

Purpose To describe the application of neuroimaging analysis, compared to neuropsychological tests and video-electroencephalogram, for the evaluation of refractory epilepsy in a reference centre in Cali, Colombia. Methods Between March 2013 and November 2014, 29 patients, 19 men and 10 women, aged 9–65 years and with refractory epilepsy, were assessed by structural and functional magnetic resonance imaging while performing tasks related to language, verbal and non-verbal memory. Also, volumetric evaluation was performed. A 1.5 Tesla magnetic resonance imaging scanner was used in all cases. Results Neuroimaging evaluation identified 13 patients with mesial temporal sclerosis. The remaining patients were classified as: 10 patients with neoplastic masses, two patients with cortical atrophy, two patients with scarring lesions and two patients with non-structural aetiology. Among patients with mesial temporal sclerosis, comparison between techniques for lateralising the epileptogenic foci was made; the κ index between functional magnetic resonance imaging and hippocampi volumetry was κ = 1.00, agreement between neuroimaging and video-electroencephalogram was good (κ = 0.78) and comparison with a neuropsychological test was mild (κ = 0.24). Conclusions Neuroimaging studies allow the assessment of functional and structural damage related to epileptogenic lesions and foci, and are helpful to select surgical treatment, conduct intraoperative neuronavigation techniques, predict surgical deficits and evaluate patient recovery. PMID:26427897

The patient had a normal magnetic resonance imaging and temporal lobe epilepsy secondary to a porencephalic cyst but showed structural lesions (hippocampal sclerosis)☆

PubMed Central

Matsubara, Teppei; Ayuzawa, Satoshi; Aoki, Tsukasa; Fujiomto, Ayataka; Osuka, Satoru; Matsumura, Akira

2013-01-01

Patients with a porencephalic cyst frequently develop intractable temporal lobe epilepsy (TLE). We report a surgically-treated male patient with intractable mesial TLE (mTLE) secondary to a porencephalic cyst. Although magnetic resonance imaging showed no hippocampal abnormalities, long-term video-electrocorticography revealed seizure onset discharges in the hippocampus. Temporal lobectomy brought an end to the patient's seizures. Hippocampal sclerosis was histopathologically confirmed (dual pathology). Careful evaluation of hippocampal epileptogenicity is required, and temporal lobectomy, which is less invasive than hemispherectomy, can be a treatment of choice for patients with mTLE secondary to a porencephalic cyst. PMID:25667851

When should temporal-lobe epilepsy be treated surgically?

PubMed

Spencer, Susan S

2002-10-01

Our current knowledge of mesial-temporal-lobe epilepsy (MTLE) is extensive, yet still insufficient to draw final conclusions on the optimal approach to its therapy. MTLE has been well characterised and can usually be identified with noninvasive studies including scalp electroencephalography (EEG) and video monitoring with ictal recording, magnetic resonance imaging, single-photon-emission computed tomography, positron emission tomography, neuropsychological assessment, and historical and clinical data. Sometimes, invasive EEG is needed to confirm mesial-temporal-lobe seizure onset, which, combined with the underlying pathological abnormality (the substrate) of mesial temporal sclerosis (hippocampal neuronal loss and gliosis), defines MTLE. This disorder is the most common refractory partial epilepsy, and also the one most often treated surgically, because medical treatment fails in 75% of cases, and surgical treatment succeeds in a similar percentage. Despite the recent publication of the first randomised trial of surgical treatment for MTLE, questions remain about the neurological consequences of both medical and surgical treatment, the ultimate gains in quality of life parameters, and the precise predictors of success. Long-term follow-up and analyses of multiple factors in large groups of contemporary patient populations will be necessary to fully answer the question, "is temporal lobe epilepsy a surgical disease?" Right now it should be considered one in most cases.

Neocortical Temporal Lobe Epilepsy

PubMed Central

Bercovici, Eduard; Kumar, Balagobal Santosh; Mirsattari, Seyed M.

2012-01-01

Complex partial seizures (CPSs) can present with various semiologies, while mesial temporal lobe epilepsy (mTLE) is a well-recognized cause of CPS, neocortical temporal lobe epilepsy (nTLE) albeit being less common is increasingly recognized as separate disease entity. Differentiating the two remains a challenge for epileptologists as many symptoms overlap due to reciprocal connections between the neocortical and the mesial temporal regions. Various studies have attempted to correctly localize the seizure focus in nTLE as patients with this disorder may benefit from surgery. While earlier work predicted poor outcomes in this population, recent work challenges those ideas yielding good outcomes in part due to better localization using improved anatomical and functional techniques. This paper provides a comprehensive review of the diagnostic workup, particularly the application of recent advances in electroencephalography and functional brain imaging, in neocortical temporal lobe epilepsy. PMID:22953057

Multimodal effective connectivity analysis reveals seizure focus and propagation in musicogenic epilepsy.

PubMed

Klamer, Silke; Rona, Sabine; Elshahabi, Adham; Lerche, Holger; Braun, Christoph; Honegger, Jürgen; Erb, Michael; Focke, Niels K

2015-06-01

Dynamic causal modeling (DCM) is a method to non-invasively assess effective connectivity between brain regions. 'Musicogenic epilepsy' is a rare reflex epilepsy syndrome in which seizures can be elicited by musical stimuli and thus represents a unique possibility to investigate complex human brain networks and test connectivity analysis tools. We investigated effective connectivity in a case of musicogenic epilepsy using DCM for fMRI, high-density (hd-) EEG and MEG and validated results with intracranial EEG recordings. A patient with musicogenic seizures was examined using hd-EEG/fMRI and simultaneous '256-channel hd-EEG'/'whole head MEG' to characterize the epileptogenic focus and propagation effects using source analysis techniques and DCM. Results were validated with invasive EEG recordings. We recorded one seizure with hd-EEG/fMRI and four auras with hd-EEG/MEG. During the seizures, increases of activity could be observed in the right mesial temporal region as well as bilateral mesial frontal regions. Effective connectivity analysis of fMRI and hd-EEG/MEG indicated that right mesial temporal neuronal activity drives changes in the frontal areas consistently in all three modalities, which was confirmed by the results of invasive EEG recordings. Seizures thus seem to originate in the right mesial temporal lobe and propagate to mesial frontal regions. Using DCM for fMRI, hd-EEG and MEG we were able to correctly localize focus and propagation of epileptic activity and thereby characterize the underlying epileptic network in a patient with musicogenic epilepsy. The concordance between all three functional modalities validated by invasive monitoring is noteworthy, both for epileptic activity spread as well as for effective connectivity analysis in general. Copyright © 2015 Elsevier Inc. All rights reserved.

Altered spontaneous brain activity in MRI-negative refractory temporal lobe epilepsy patients with major depressive disorder: A resting-state fMRI study.

PubMed

Zhu, Xi; He, Zhongqiong; Luo, Cheng; Qiu, Xiangmiao; He, Shixu; Peng, Anjiao; Zhang, Lin; Chen, Lei

2018-03-15

To investigate alterations in spontaneous brain activity in MRI-negative refractory temporal lobe epilepsy patients with major depressive disorder using resting-state functional magnetic resonance imaging (RS-fMRI). Eighteen MRI-negative refractory temporal lobe epilepsy patients with major depressive disorder (PDD), 17 MRI-negative refractory temporal lobe epilepsy patients without major depressive disorder (nPDD), and 21 matched healthy controls (HC) were recruited from West China Hospital of SiChuan University from April 2016 to June 2017. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) and 17-item Hamilton Depression Rating Scale were employed to confirm the diagnosis of major depressive disorder and assess the severity of depression. All participants underwent RS-fMRI scans using a 3.0T MRI system. MRI data were compared and analyzed using the amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) to measure spontaneous brain activity. These two methods were both used to evaluate spontaneous cerebral activity. The PDD group showed significantly altered spontaneous brain activity in the bilateral mesial prefrontal cortex, precuneus, angular gyrus, right parahippocampal gyrus, and right temporal pole. Meanwhile, compared with HC, the nPDD group demonstrated altered spontaneous brain activity in the temporal neocortex but no changes in mesial temporal structures. The PDD group showed regional brain activity alterations in the prefrontal-limbic system and dysfunction of the default mode network. The underlying pathophysiology of PDD may be provided for further studies. Copyright © 2018 Elsevier B.V. All rights reserved.

Neuropsychological functioning and brain energetics of drug resistant mesial temporal lobe epilepsy patients.

PubMed

Osório, Camila Moreira; Latini, Alexandra; Leal, Rodrigo Bainy; de Oliveira Thais, Maria Emília Rodrigues; Vascouto, Helena Dresch; Remor, Aline Pertile; Lopes, Mark William; Linhares, Marcelo Neves; Ben, Juliana; de Paula Martins, Roberta; Prediger, Rui Daniel; Hoeller, Alexandre Ademar; Markowitsch, Hans Joachim; Wolf, Peter; Lin, Kátia; Walz, Roger

2017-12-01

Interictal hypometabolism is commonly measured by 18-fluoro-deoxyglucose Positron Emission Tomography (FDG-PET) in the temporal lobe of patients with mesial temporal lobe epilepsy (MTLE-HS). Left temporal lobe interictal FDG-PET hypometabolism has been associated with verbal memory impairment, while right temporal lobe FDG-PET hypometabolism is associated with nonverbal memory impairment. The biochemical mechanisms involved in these findings remain unknown. In comparison to healthy controls (n=21), surgically treated patients with MTLE-HS (n=32, left side=17) had significant lower scores in the Rey Auditory Verbal Learning Test (RAVLT retention and delayed), Logical Memory II (LMII), Boston Naming test (BNT), Letter Fluency and Category Fluency. We investigated whether enzymatic activities of the mitochondrial enzymes Complex I (C I), Complex II (C II), Complex IV (C IV) and Succinate Dehydrogenase (SDH) from the resected samples of the middle temporal neocortex (mTCx), amygdala (AMY) and hippocampus (HIP) were associated with performance in the RAVLT, LMII, BNT and fluency tests of our patients. After controlling for the side of hippocampus sclerosis, years of education, disease duration, antiepileptic treatment and seizure outcome after surgery, no independent associations were observed between the cognitive test scores and the analyzed mitochondrial enzymatic activities (p>0.37). Results indicate that memory and language impairment observed in MTLE-HS patients are not strongly associated with the levels of mitochondrial CI, CII, SDH and C IV enzymatic activities in the temporal lobe structures ipsilateral to the HS lesion. Copyright © 2017 Elsevier B.V. All rights reserved.

Continuous high-frequency activity in mesial temporal lobe structures

PubMed Central

Mari, Francesco; Zelmann, Rina; Andrade-Valenca, Luciana; Dubeau, Francois; Gotman, Jean

2013-01-01

Summary Purpose Many recent studies have reported the importance of high-frequency oscillations (HFOs) in the intracerebral electroencephalography (EEG) of patients with epilepsy. These HFOs have been defined as events that stand out from the background. We have noticed that this background often consists itself of high-frequency rhythmic activity. The purpose of this study is to perform a first evaluation of the characteristics of high-frequency continuous or semicontinuous background activity. Methods Because the continuous high-frequency pattern was noted mainly in mesial temporal structures, we reviewed the EEG studies from these structures in 24 unselected patients with electrodes implanted in these regions. Sections of background away from interictal spikes were marked visually during periods of slow-wave sleep and wakefulness. They were then high-passed filtered at 80 Hz and categorized as having high-frequency rhythmic activity in one of three patterns: continuous/semicontinuous, irregular, sporadic. Wavelet entropy, which measures the degree of rhythmicity of a signal, was calculated for the marked background sections. Key Findings Ninety-six bipolar channels were analyzed. The continuous/semicontinuous pattern was found frequently (29/96 channels during wake and 34/96 during sleep). The different patterns were consistent between sleep and wakefulness. The continuous/semicontinuous pattern was found significantly more often in the hippocampus than in the parahippocampal gyrus and was rarely found in the amygdala. The types of pattern were not influenced by whether a channel was within the seizure-onset zone, or whether it was a lesional channel. The continuous/semicontinuous pattern was associated with a higher frequency of spikes and with high rates of ripples and fast ripples. Significance It appears that high-frequency activity (above 80 Hz) does not appear only in the form of brief paroxysmal events but also in the form of continuous rhythmic activity or very long bursts. In this study limited to mesial temporal structures, we found a clear anatomic preference for the hippocampus. Although associated with spikes and with distinct HFOs, this pattern was not clearly associated with the seizure-onset zone. Future studies will need to evaluate systematically the presence of this pattern, as it may have a pathophysiologic significance and it will also have an important influence on the very definition of HFOs. PMID:22416973

Sex, Age, and Cognitive Correlates of Asymmetries in Thickness of the Cortical Mantle Across the Life Span

PubMed Central

Plessen, Kerstin J.; Hugdahl, Kenneth; Bansal, Ravi; Hao, Xuejun

2014-01-01

We assessed the correlations of age, sex, and cognitive performance with measures of asymmetry in cortical thickness on high-resolution MRIs in 215 healthy human children and adults, 7–59 years of age. A left > right asymmetry in thickness of the cortical mantle was present throughout the entire lateral, dorsal, and mesial surfaces of the frontal lobe, extending into primary sensory, superior parietal, and anterior superior temporal cortices. A right > left asymmetry was present in the lateral, mesial, and dorsal surfaces of the posterior temporal, parietal, and occipital cortices, as well as in the entire inferior surface of the brain. An exaggerated left > right asymmetry was detected in females in anterior brain regions, and an exaggerated right > left asymmetry was detected in males in the orbitofrontal, inferior parietal, and inferior occipital cortices. Weaker moderating effects of sex were scattered along the mesial surface of the brain. Age significantly moderated asymmetry measures in the inferior sensorimotor, inferior parietal, posterior temporal, and inferior occipital cortices. The age × asymmetry interaction derived from a steeper decline in cortical thickness with age in the right hemisphere than in the left on the lateral surface, whereas it derived from a steeper decline with age in the left hemisphere than in the right on the mesial surface. Finally, measures of performance on working memory and vocabulary tasks improved with increasing magnitudes of normal asymmetries in regions thought to support these cognitive capacities. PMID:24790200

Sex, age, and cognitive correlates of asymmetries in thickness of the cortical mantle across the life span.

PubMed

Plessen, Kerstin J; Hugdahl, Kenneth; Bansal, Ravi; Hao, Xuejun; Peterson, Bradley S

2014-04-30

We assessed the correlations of age, sex, and cognitive performance with measures of asymmetry in cortical thickness on high-resolution MRIs in 215 healthy human children and adults, 7-59 years of age. A left > right asymmetry in thickness of the cortical mantle was present throughout the entire lateral, dorsal, and mesial surfaces of the frontal lobe, extending into primary sensory, superior parietal, and anterior superior temporal cortices. A right > left asymmetry was present in the lateral, mesial, and dorsal surfaces of the posterior temporal, parietal, and occipital cortices, as well as in the entire inferior surface of the brain. An exaggerated left > right asymmetry was detected in females in anterior brain regions, and an exaggerated right > left asymmetry was detected in males in the orbitofrontal, inferior parietal, and inferior occipital cortices. Weaker moderating effects of sex were scattered along the mesial surface of the brain. Age significantly moderated asymmetry measures in the inferior sensorimotor, inferior parietal, posterior temporal, and inferior occipital cortices. The age × asymmetry interaction derived from a steeper decline in cortical thickness with age in the right hemisphere than in the left on the lateral surface, whereas it derived from a steeper decline with age in the left hemisphere than in the right on the mesial surface. Finally, measures of performance on working memory and vocabulary tasks improved with increasing magnitudes of normal asymmetries in regions thought to support these cognitive capacities.

Interictal 18FDG PET findings in temporal lobe epilepsy with déjà vu.

PubMed

Adachi, N; Koutroumanidis, M; Elwes, R D; Polkey, C E; Binnie, C D; Reynolds, E H; Barrington, S F; Maisey, M N; Panayiotopoulos, C P

1999-01-01

The authors studied the functional anatomy of the déjà vu (DV) experience in nonlesional temporal lobe epilepsy (TLE), using interictal fluorine-18 fluorodeoxyglucose PET in 14 patients with and 17 patients without DV. Several clinical conditions, such as age at PET study, side of ictal onset zone, and dominance for language, were no different between the two groups. The patients with DV showed significant relative reductions in glucose metabolism in the mesial temporal structures and the parietal cortex. The findings demonstrate that ictal DV is of no lateralizing value. They further suggest that temporal lobe dysfunction is necessary but not sufficient for the generation of DV. Extensive association cortical areas may be involved as part of the network that integrates this distinct experience.

Decrease of NAA with aging outside the seizure focus in mesial temporal lobe epilepsy--a proton-MRS study at 3 Tesla.

PubMed

Riederer, Franz; Bittsanský, Michal; Lehner-Baumgartner, Eva; Baumgartner, Christoph; Mlynárik, Vladimír; Gruber, Stephan; Moser, Ewald; Kaya, Marihan; Serles, Wolfgang

2007-11-07

There is evidence that chronic pharmacoresistant temporal lobe epilepsy (TLE) is a progressive disorder accompanied by mental deterioration. We investigated effects of aging on cerebral N-acetyl-aspartate (NAA) concentrations in the temporal lobe of 12 patients with pharmacoresistant mesial TLE (mTLE) and 22 healthy controls by means of proton-magnetic resonance spectroscopy ((1)H-MRS) at 3 T. Furthermore, we calculated correlations between NAA concentrations and measures of verbal and figural memory in patients. In mTLE patients but not in healthy controls the concentration of NAA in the lateral temporal lobe was negatively correlated with age. In patients with mTLE NAA in left lateral temporal voxels correlated with verbal memory. NAA in medial temporal voxels did not correlate with age or neuropsychological measures. Significant decrease of NAA with age in the lateral temporal lobe of patients with mTLE provides evidence for progressive neuronal dysfunction with aging. NAA is a marker of neuronal integrity since it correlates with verbal memory.

Outcome after temporal lobectomy in patients with medically-refractory mesial temporal epilepsy in Iran.

PubMed

Asadi-Pooya, Ali A; Rakei, Seyed M; Kamgarpour, Ahmad; Taghipour, Mousa; Ashjazadeh, Nahid; Razmkon, Ali; Zare, Zahra; Bagheri, Mohammad H

2017-06-01

Epilepsy surgery has been proved to be feasible and cost-effective in developing countries. In the current paper, we discussed the outcome of patients with mesial temporal lobe epilepsy (MTLE) and medically-refractory seizures who had surgery at our center in Shiraz, Iran. Patients aged 18 years and older with refractory MTLE and mesial temporal sclerosis operated at Namazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran from May 2009 through December 2011 were enrolled. Presurgical evaluation included clinical history, neurological examination, 2-hour video-EEG recording, and 1.5-T MRI. All patients were submitted to standard temporal lobectomy at the side determined by MRI and video-EEG. Twenty-two patients (12 women and 10 men) underwent surgery between May 2009 and December 2011. All patients were followed postoperatively for at least 12 months (mean=24.8±7.7 months; minimum=12 months; maximum=36 months). At the last follow-up visit, 18 patients (81.8%) had a good outcome (15 patients [68.2%] had Engel class 1 and three others had Engel class 2). The total cost of presurgical evaluation and epilepsy surgery at our center was less than $500. Resources are limited for the vast majority of medically-refractory patients with epilepsy who live in the developing countries. However, it is feasible to select good surgical candidates for anterior temporal lobectomy relying on the clinical history and examination, MRI and interictal EEG. Broader application of epilepsy surgery should be encouraged in countries with limited financial resources.

Decision making under ambiguity and under risk in mesial temporal lobe epilepsy.

PubMed

Delazer, Margarete; Zamarian, Laura; Bonatti, Elisabeth; Kuchukhidze, Giorgi; Koppelstätter, Florian; Bodner, Thomas; Benke, Thomas; Trinka, Eugen

2010-01-01

Decision making is essential in everyday life. Though the importance of the mesial temporal lobe in emotional processing and feedback learning is generally recognized, decision making in mesial temporal lobe epilepsy (mTLE) is almost unexplored so far. Twenty-eight consecutive epilepsy patients with drug resistant mTLE and fifty healthy controls performed decision tasks under initial ambiguity (participants have to learn by feedback to make advantageous decisions) and under risk (advantageous choices may be made by estimating risks and by rational strategies). A subgroup analysis compared the performance of patients affected by MRI-verified abnormalities of the hippocampus or amygdala. The effect of lesion side was also assessed. In decision under ambiguity, mTLE patients showed marked deficits and did not improve over the task. Patients with hippocampus abnormality and patients with amygdala abnormality showed comparable deficits. No difference was found between right and left TLE groups. In decision under risk, mTLE patients performed at the same level as controls. Results suggest that mTLE patients have difficulties in learning from feedback and in making decisions in uncertain, ambiguous situations. By contrast, they are able to make advantageous decisions when full information is given and risks, possible gains and losses are exactly defined.

Safety of Laser Interstitial Thermal Therapy in Patients With Pacemakers.

PubMed

Grewal, Sanjeet S; Gorny, Krzysztof R; Favazza, Christopher P; Watson, Robert E; Kaufmann, Timothy J; Van Gompel, Jamie J

2018-02-10

Laser interstitial thermal therapy (LiTT) has increasingly been used as a treatment option for medically refractory epilepsy, tumors, and radiation necrosis. The use of LiTT requires intraoperative magnetic resonance (MR) thermography. This can become an issue in patients with other implanted therapeutic devices such as pacemakers and vagal nerve stimulators due to concerns regarding increases in the specific absorption rate (SAR). This is a technical case report demonstrating a successfully and safely performed LiTT in a 1.5-T magnetic resonance imaging (MRI) in a patient with a pacemaker for mesial temporal sclerosis. An 83-yr-old gentleman who had an implanted cardiac pacemaker presented with medically intractable epilepsy and was confirmed to have mesial temporal sclerosis on imaging. Video electroencephalography demonstrated concordant ipsilateral seizures and semiology. He underwent LiTT for ablation of the mesial temporal lobe. This was performed with the below described protocol with a cardiology nurse monitoring the patient's cardiac condition and a physicist monitoring SAR, and MR imaging quality without any adverse events. This study reports on a protocol of cardiac and MR SAR to safely perform MR-guided LiTT in the setting of traditional pacemakers in patients who are not pacemaker dependent. Copyright © 2018 by the Congress of Neurological Surgeons

Familial mesial temporal lobe epilepsy maps to chromosome 4q13.2-q21.3.

PubMed

Hedera, P; Blair, M A; Andermann, E; Andermann, F; D'Agostino, D; Taylor, K A; Chahine, L; Pandolfo, M; Bradford, Y; Haines, J L; Abou-Khalil, B

2007-06-12

To report results of linkage analysis in a large family with autosomal dominant (AD) familial mesial temporal lobe epilepsy (FMTLE). Although FMTLE is a heterogeneous syndrome, one important subgroup is characterized by a relatively benign course, absence of antecedent febrile seizures, and absence of hippocampal sclerosis. These patients have predominantly simple partial seizures (SPS) and infrequent complex partial seizures (CPS), and intense and frequent déjà vu phenomenon may be the only manifestation of this epilepsy syndrome. No linkage has been described in this form of FMTLE. We identified a four-generation kindred with several affected members meeting criteria for FMTLE and enrolled 21 individuals who gave informed consent. Every individual was personally interviewed and examined; EEG and MRI studies were performed on three affected subjects. DNA was extracted from every enrolled individual. We performed a genome-wide search using an 8 cM panel and fine mapping was performed in the regions with a multipoint lod score >1. We sequenced the highest priority candidate genes. Inheritance was consistent with AD mode with reduced penetrance. Eleven individuals were classified as affected with FMTLE and we also identified two living asymptomatic individuals who had affected offspring. Seizure semiologies included predominantly SPS with déjà vu feeling, infrequent CPS, and rare secondarily generalized tonic-clonic seizures. No structural abnormalities, including hippocampal sclerosis, were detected on MRI performed on three individuals. Genetic analysis detected a group of markers with lod score >3 on chromosome 4q13.2-q21.3 spanning a 7 cM region. No ion channel genes are predicted to be localized within this locus. We sequenced all coding exons of sodium bicarbonate cotransporter (SLC4A) gene, which plays an important role in tissue excitability, and cyclin I (CCNI), because of its role in the cell migration and possibility of subtle cortical abnormalities. No disease-causing mutations were identified in these genes. We report identification of a genetic locus for familial mesial temporal lobe epilepsy. The identification of a disease-causing gene will contribute to our understanding of the pathogenesis of temporal lobe epilepsies.

A Prediction Algorithm for Drug Response in Patients with Mesial Temporal Lobe Epilepsy Based on Clinical and Genetic Information

PubMed Central

Carvalho, Benilton S.; Bilevicius, Elizabeth; Alvim, Marina K. M.; Lopes-Cendes, Iscia

2017-01-01

Mesial temporal lobe epilepsy is the most common form of adult epilepsy in surgical series. Currently, the only characteristic used to predict poor response to clinical treatment in this syndrome is the presence of hippocampal sclerosis. Single nucleotide polymorphisms (SNPs) located in genes encoding drug transporter and metabolism proteins could influence response to therapy. Therefore, we aimed to evaluate whether combining information from clinical variables as well as SNPs in candidate genes could improve the accuracy of predicting response to drug therapy in patients with mesial temporal lobe epilepsy. For this, we divided 237 patients into two groups: 75 responsive and 162 refractory to antiepileptic drug therapy. We genotyped 119 SNPs in ABCB1, ABCC2, CYP1A1, CYP1A2, CYP1B1, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4, and CYP3A5 genes. We used 98 additional SNPs to evaluate population stratification. We assessed a first scenario using only clinical variables and a second one including SNP information. The random forests algorithm combined with leave-one-out cross-validation was used to identify the best predictive model in each scenario and compared their accuracies using the area under the curve statistic. Additionally, we built a variable importance plot to present the set of most relevant predictors on the best model. The selected best model included the presence of hippocampal sclerosis and 56 SNPs. Furthermore, including SNPs in the model improved accuracy from 0.4568 to 0.8177. Our findings suggest that adding genetic information provided by SNPs, located on drug transport and metabolism genes, can improve the accuracy for predicting which patients with mesial temporal lobe epilepsy are likely to be refractory to drug treatment, making it possible to identify patients who may benefit from epilepsy surgery sooner. PMID:28052106

Differentiability of simulated MEG hippocampal, medial temporal and neocortical temporal epileptic spike activity.

PubMed

Stephen, Julia M; Ranken, Doug M; Aine, Cheryl J; Weisend, Michael P; Shih, Jerry J

2005-12-01

Previous studies have shown that magnetoencephalography (MEG) can measure hippocampal activity, despite the cylindrical shape and deep location in the brain. The current study extended this work by examining the ability to differentiate the hippocampal subfields, parahippocampal cortex, and neocortical temporal sources using simulated interictal epileptic activity. A model of the hippocampus was generated on the MRIs of five subjects. CA1, CA3, and dentate gyrus of the hippocampus were activated as well as entorhinal cortex, presubiculum, and neocortical temporal cortex. In addition, pairs of sources were activated sequentially to emulate various hypotheses of mesial temporal lobe seizure generation. The simulated MEG activity was added to real background brain activity from the five subjects and modeled using a multidipole spatiotemporal modeling technique. The waveforms and source locations/orientations for hippocampal and parahippocampal sources were differentiable from neocortical temporal sources. In addition, hippocampal and parahippocampal sources were differentiated to varying degrees depending on source. The sequential activation of hippocampal and parahippocampal sources was adequately modeled by a single source; however, these sources were not resolvable when they overlapped in time. These results suggest that MEG has the sensitivity to distinguish parahippocampal and hippocampal spike generators in mesial temporal lobe epilepsy.

Visuoperceptive region atrophy independent of cognitive status in patients with Parkinson's disease with hallucinations.

PubMed

Goldman, Jennifer G; Stebbins, Glenn T; Dinh, Vy; Bernard, Bryan; Merkitch, Doug; deToledo-Morrell, Leyla; Goetz, Christopher G

2014-03-01

Visual hallucinations are frequent, disabling complications of advanced Parkinson's disease, but their neuroanatomical basis is incompletely understood. Previous structural brain magnetic resonance imaging studies suggest volume loss in the mesial temporal lobe and limbic regions in subjects with Parkinson's disease with visual hallucinations, relative to those without visual hallucinations. However, these studies have not always controlled for the presence of cognitive impairment or dementia, which are common co-morbidities of hallucinations in Parkinson's disease and whose neuroanatomical substrates may involve mesial temporal lobe and limbic regions. Therefore, we used structural magnetic resonance imaging to examine grey matter atrophy patterns associated with visual hallucinations, comparing Parkinson's disease hallucinators to Parkinson's disease non-hallucinators of comparable cognitive function. We studied 50 subjects with Parkinson's disease: 25 classified as current and chronic visual hallucinators and 25 as non-hallucinators, who were matched for cognitive status (demented or non-demented) and age (± 3 years). Subjects underwent (i) clinical evaluations; and (ii) brain MRI scans analysed using whole-brain voxel-based morphometry techniques. Clinically, the Parkinson's disease hallucinators did not differ in their cognitive classification or performance in any of the five assessed cognitive domains, compared with the non-hallucinators. The Parkinson's disease groups also did not differ significantly in age, motor severity, medication use or duration of disease. On imaging analyses, the hallucinators, all of whom experienced visual hallucinations, exhibited grey matter atrophy with significant voxel-wise differences in the cuneus, lingual and fusiform gyri, middle occipital lobe, inferior parietal lobule, and also cingulate, paracentral, and precentral gyri, compared with the non-hallucinators. Grey matter atrophy in the hallucinators occurred predominantly in brain regions responsible for processing visuoperceptual information including the ventral 'what' and dorsal 'where' pathways, which are important in object and facial recognition and identification of spatial locations of objects, respectively. Furthermore, the structural brain changes seen on magnetic resonance imaging occurred independently of cognitive function and age. Our findings suggest that when hallucinators and non-hallucinators are similar in their cognitive performance, the neural networks involving visuoperceptual pathways, rather than the mesial temporal lobe regions, distinctively contribute to the pathophysiology of visual hallucinations and may explain their predominantly visual nature in Parkinson's disease. Identification of distinct structural MRI differences associated with hallucinations in Parkinson's disease may permit earlier detection of at-risk patients and ultimately, development of therapies specifically targeting hallucinations and visuoperceptive functions.

Visuoperceptive region atrophy independent of cognitive status in patients with Parkinson’s disease with hallucinations

PubMed Central

Stebbins, Glenn T.; Dinh, Vy; Bernard, Bryan; Merkitch, Doug; deToledo-Morrell, Leyla; Goetz, Christopher G.

2014-01-01

Visual hallucinations are frequent, disabling complications of advanced Parkinson’s disease, but their neuroanatomical basis is incompletely understood. Previous structural brain magnetic resonance imaging studies suggest volume loss in the mesial temporal lobe and limbic regions in subjects with Parkinson’s disease with visual hallucinations, relative to those without visual hallucinations. However, these studies have not always controlled for the presence of cognitive impairment or dementia, which are common co-morbidities of hallucinations in Parkinson’s disease and whose neuroanatomical substrates may involve mesial temporal lobe and limbic regions. Therefore, we used structural magnetic resonance imaging to examine grey matter atrophy patterns associated with visual hallucinations, comparing Parkinson’s disease hallucinators to Parkinson’s disease non-hallucinators of comparable cognitive function. We studied 50 subjects with Parkinson’s disease: 25 classified as current and chronic visual hallucinators and 25 as non-hallucinators, who were matched for cognitive status (demented or non-demented) and age (±3 years). Subjects underwent (i) clinical evaluations; and (ii) brain MRI scans analysed using whole-brain voxel-based morphometry techniques. Clinically, the Parkinson’s disease hallucinators did not differ in their cognitive classification or performance in any of the five assessed cognitive domains, compared with the non-hallucinators. The Parkinson’s disease groups also did not differ significantly in age, motor severity, medication use or duration of disease. On imaging analyses, the hallucinators, all of whom experienced visual hallucinations, exhibited grey matter atrophy with significant voxel-wise differences in the cuneus, lingual and fusiform gyri, middle occipital lobe, inferior parietal lobule, and also cingulate, paracentral, and precentral gyri, compared with the non-hallucinators. Grey matter atrophy in the hallucinators occurred predominantly in brain regions responsible for processing visuoperceptual information including the ventral ‘what’ and dorsal ‘where’ pathways, which are important in object and facial recognition and identification of spatial locations of objects, respectively. Furthermore, the structural brain changes seen on magnetic resonance imaging occurred independently of cognitive function and age. Our findings suggest that when hallucinators and non-hallucinators are similar in their cognitive performance, the neural networks involving visuoperceptual pathways, rather than the mesial temporal lobe regions, distinctively contribute to the pathophysiology of visual hallucinations and may explain their predominantly visual nature in Parkinson’s disease. Identification of distinct structural MRI differences associated with hallucinations in Parkinson’s disease may permit earlier detection of at-risk patients and ultimately, development of therapies specifically targeting hallucinations and visuoperceptive functions. PMID:24480486

[Dual pathology].

PubMed

Rougier, A

2008-05-01

Dual pathology is defined as the association of two potentially epileptogenic lesions, hippocampal (sclerosis, neuronal loss) and extrahippocampal (temporal or extratemporal). Epileptic activity may be generated by either lesion and the relative importance of every lesion's epileptogenicity conditions the surgical strategy adopted. Most frequently associated with hippocampal sclerosis are cortical dysplasias. The common physiopathology of the two lesions is not clearly established. Extrahippocampal lesions may be undetectable on MRI (microdysgenesis, for example) and ictal discharge patterns may vary among dual pathology patients. The surgical strategy depends on the location of the extrahippocampal lesion and its relative role in seizure generation; however, reported surgical results suggest that simultaneous resection of mesial temporal structures along with the extrahippocampal lesion should be performed.

Spatial memory for asymmetrical dot locations predicts lateralization among patients with presurgical mesial temporal lobe epilepsy.

PubMed

Brown, Franklin C; Hirsch, Lawrence J; Spencer, Dennis D

2015-11-01

This study examined the ability of an asymmetrical dot location memory test (Brown Location Test, BLT) and two verbal memory tests (Verbal Selective Reminding Test (VSRT) and California Verbal Learning Test, Second Edition (CVLT-II)) to correctly lateralize left (LTLE) or right (RTLE) mesial temporal lobe epilepsy that was confirmed with video-EEG. Subjects consisted of 16 patients with medically refractory RTLE and 13 patients with medically refractory LTLE who were left hemisphere language dominant. Positive predictive values for lateralizing TLE correctly were 87.5% for the BLT, 72.7% for the VSRT, and 80% for the CVLT-II. Binary logistic regression indicated that the BLT alone correctly classified 76.9% of patients with left temporal lobe epilepsy and 87.5% of patients with right temporal lobe epilepsy. Inclusion of the verbal memory tests improved this to 92.3% of patients with left temporal lobe epilepsy and 100% correct classification of patients with right temporal lobe epilepsy. Though of a limited sample size, this study suggests that the BLT alone provides strong laterality information which improves with the addition of verbal memory tests. Copyright © 2015 Elsevier Inc. All rights reserved.

Temporal Lobe Anatomy and Psychiatric Symptoms in Velocardiofacial Syndrome (22Q11.2 Deletion Syndrome)

ERIC Educational Resources Information Center

Kates, Wendy R.; Miller, Adam M.; Abdulsabur, Nuria; Antshel, Kevin M.; Conchelos, Jena; Fremont, Wanda; Roizen, Nancy

2006-01-01

Objective: To investigate the association between mesial temporal lobe morphology, ratios of prefrontal cortex to amygdala and hippocampus volumes, and psychiatric symptomatology in children and adolescents with velocardiofacial syndrome (VCFS). Method: Scores on behavioral rating scales and volumetric measures of the amygdala, hippocampus, and…

Morphometric MRI features are associated with surgical outcome in mesial temporal lobe epilepsy with hippocampal sclerosis.

PubMed

Garcia, Maria Teresa Fernandes Castilho; Gaça, Larissa Botelho; Sandim, Gabriel Barbosa; Assunção Leme, Idaiane Batista; Carrete, Henrique; Centeno, Ricardo Silva; Sato, João Ricardo; Yacubian, Elza Márcia Targas

2017-05-01

Corticoamygdalohippocampectomy (CAH) improves seizure control, quality of life, and decreases mortality for refractory mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). One-third of patients continue having seizures, and it is pivotal to determine structural abnormalities that might influence the postoperative outcome. Studies indicate that nonhippocampal regions may play a role in the epileptogenic network in MTLE-HS and could generate seizures postoperatively. The aim of this study is to analyze areas of atrophy, not always detected on routine MRI, comparing patients who became seizure free (SF) with those non seizure free (NSF) after CAH, in an attempt to establish possible predictors of surgical outcome. 105 patients with refractory MTLE-HS submitted to CAH (59 left MTLE; 46 males) and 47 controls were enrolled. FreeSurfer was performed for cortical thickness and volume estimation comparing patients to controls and SF versus NSF patients. The final sample after post processing procedures resulted in 99 patients. Cortical thickness analyses showed reductions in left insula in NSF patients compared to those SF. Significant volume reductions in SF patients were present in bilateral thalami, hippocampi and pars opercularis, left parahippocampal gyrus and right temporal pole. In NSF patients reductions were present bilaterally in thalami, hippocampi, entorhinal cortices, superior frontal and supramarginal gyri; on the left: superior and middle temporal gyri, temporal pole, parahippocampal gyrus, pars opercularis and middle frontal gyrus; and on the right: precentral, superior, middle and inferior temporal gyri. Comparison between SF and NSF patients showed ipsilateral gray matter reductions in the right entorhinal cortex (p=0.003) and contralateral parahippocampal gyrus (p=0.05) in right MTLE-HS. Patients NSF had a longer duration of epilepsy than those SF (p=0.028). NSF patients exhibited more extensive areas of atrophy than SF ones. As entorhinal cortex and parahippocampal gyrus are reduced in NSF patients compared to those SF these structures might be implicated in the network responsible for the maintenance of postoperative seizures. Duration of epilepsy is a predictor of seizure outcome. Copyright © 2017 Elsevier B.V. All rights reserved.

Mesial temporal lobe epilepsy diminishes functional connectivity during emotion perception.

PubMed

Steiger, Bettina K; Muller, Angela M; Spirig, Esther; Toller, Gianina; Jokeit, Hennric

2017-08-01

Unilateral mesial temporal lobe epilepsy (MTLE) has been associated with impaired recognition of emotional facial expressions. Correspondingly, imaging studies showed decreased activity of the amygdala and cortical face processing regions in response to emotional faces. However, functional connectivity among regions involved in emotion perception has not been studied so far. To address this, we examined intrinsic functional connectivity (FC) modulated by the perception of dynamic fearful faces among the amygdala and limbic, frontal, temporal and brainstem regions. Regions of interest were identified in an activation analysis by presenting a block-design with dynamic fearful faces and dynamic landscapes to 15 healthy individuals. This led to 10 predominately right-hemispheric regions. Functional connectivity between these regions during the perception of fearful faces was examined in drug-refractory patients with left- (n=16) or right-sided (n=17) MTLE, epilepsy patients with extratemporal seizure onset (n=15) and a second group of 15 healthy controls. Healthy controls showed a widespread functional network modulated by the perception of fearful faces that encompassed bilateral amygdalae, limbic, cortical, subcortical and brainstem regions. In patients with left MTLE, a downsized network of frontal and temporal regions centered on the right amygdala was present. Patients with right MTLE showed almost no significant functional connectivity. A maintained network in the epilepsy control group indicates that findings in mesial temporal lobe epilepsy could not be explained by clinical factors such as seizures and antiepileptic medication. Functional networks underlying facial emotion perception are considerably changed in left and right MTLE. Alterations are present for both hemispheres in either MTLE group, but are more pronounced in right MTLE. Disruption of the functional network architecture possibly contributes to deficits in facial emotion recognition frequently reported in MTLE. Copyright © 2017 Elsevier B.V. All rights reserved.

The role of histopathologic subtype in the setting of hippocampal sclerosis-associated mesial temporal lobe epilepsy.

PubMed

Gales, Jordan M; Jehi, Lara; Nowacki, Amy; Prayson, Richard A

2017-05-01

Hippocampal sclerosis (HS) and focal cortical dysplasia (FCD) are among the most common neuropathological findings in those undergoing surgery for refractory mesial temporal lobe epilepsy. Existing data regarding differences among the most recent International League Against Epilepsy (ILAE) HS subtypes remain limited. This study sought to characterize the roles of HS subtype and coexistent FCD. Epilepsy surgery pathologic specimens in 307 cases of temporal lobe epilepsy with HS were reviewed (mean age±SD, 37±15years; 56% women). HS and coexistent FCD were classified according to ILAE guidelines. Medical records were reviewed for data on seizure recurrence and seizure burden (clinical follow-up mean duration ± SD, 5±4years). Cases of typical HS (ILAE type I) predominated (ILAE type Ia: 41%, Ib: 47%, II: 11%, and III: 0.7%]. The HS subtypes shared similar demographic and etiologic characteristics, as well as associated pathology and postoperative seizure outcomes. Individuals with type Ib HS were more likely to remain seizure free at long-term follow-up when compared with other subtypes, and they had a later age of seizure onset. Two hundred forty-three cases (79%) demonstrated FCD within the adjacent temporal lobe. Its presence was associated with a significantly decreased risk of seizure recurrence (P=.02). When present, FCD was predominantly type I (98%). HS subtype does not appear to affect epilepsy surgery outcomes despite some clinical differences between the subgroups. FCD is often observed in association with HS in mesial temporal lobe epilepsy; the finding of FCD was associated with better postoperative outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

The Characteristics and Long-Term Course of Epilepsy in Lipoid Proteinosis: A Spectrum From Mild to Severe Seizures in Relation to ECM1 Mutations.

PubMed

Oguz Akarsu, Emel; Dinçsoy Bir, Firdevs; Baykal, Can; Taşdemir, Volkan; Kara, Bülent; Bebek, Nerses; Gürses, Candan; Uyguner, Oya; Baykan, Betül

2018-05-01

Lipoid proteinosis (LP) is a rare autosomal recessive disease characterized by deposition of hyaline material in skin and mucosae. Epilepsy, as an extracutaneous manifestation associated with typical mesial temporal calcifications, has already been identified, but its characteristics and long-term prognosis have not been thoroughly investigated. We included 7 consecutive patients with LP with typical intracranial calcifications out of 16 patients with ECM1 mutations and investigated the semiologic features, ictal and interictal EEG findings, and long-term prognosis of epilepsy in this genodermatosis. Four of them had seizures (57.1%), and focal seizures with motionless staring were the most common seizure phenotype, originating from bilateral mesial temporal areas, but interictal spikes were scant. Auras were observed in three patients, mostly as epigastric sensation and déjà vu, which indicated mesial temporal lobe origin. Three patients with homozygous mutations in sixth and seventh exons of the ECM1 gene had a drug-resistant course at the end of long-term follow-up. Molecular genetic testing showed a rare compound heterozygous mutation in one patient, which was also associated with seizures but without drug-resistance. Our findings indicated a spectrum for epilepsy with a desperate drug-resistant course for decades in most patients with LP, which is still an underrecognized disease by neurologists.

Impaired facial emotion recognition in patients with mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS): Side and age at onset matters.

PubMed

Hlobil, Ulf; Rathore, Chaturbhuj; Alexander, Aley; Sarma, Sankara; Radhakrishnan, Kurupath

2008-08-01

To define the determinants of impaired facial emotion recognition (FER) in patients with mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS), we examined 76 patients with unilateral MTLE-HS, 36 prior to antero-mesial temporal lobectomy (AMTL) and 40 after AMTL, and 28 healthy control subjects with a FER test consisting of 60 items (20 each for anger, fear, and happiness). Mean percentages of the accurate responses were calculated for different subgroups: right vs. left MTLE-HS, early (age at onset <6 years) vs. late-onset, and before vs. after AMTL. After controlling for years of education, duration of epilepsy and number of antiepileptic drugs (AEDs) taken, on multivariate analysis, fear recognition was profoundly impaired in early-onset right MTLE-HS patients compared to other MTLE patients and control subjects. Happiness recognition was significantly better in post-AMTL MTLE-HS patients compared to pre-AMTL patients while anger and fear recognition did not differ. We conclude that patients with right MTLE-HS with age at seizure onset <6 years are maximally predisposed to impaired fear recognition. In them, right AMTL does not further worsen FER abilities. Longitudinal studies comparing FER in the same patients before and after AMTL will be required to refine and confirm our cross-sectional observations.

Reduced size of the amygdala in individuals with 47,XXY and 47,XXX karyotypes.

PubMed

Patwardhan, Anil J; Brown, Wendy E; Bender, Bruce G; Linden, Mary G; Eliez, Stephan; Reiss, Allan L

2002-01-08

The excess of 47,XXX and 47,XXY karyotypes found in cytogenetic screening studies of individuals with schizophrenia has given support for an increased risk of psychiatric illness among men and women with sex chromosomal aneuploidy (SCA). Mesial temporal lobe structures, including the amygdala and hippocampus, are thought to be associated with abnormalities of mood and behavior in humans and in the neurobiology of schizophrenia. This study focuses on variations in volumes of mesial temporal lobe structures in men and women with SCA. Utilizing an unselected birth cohort of subjects with SCA and high-resolution magnetic resonance imaging (MRI), we investigated the neuroanatomical consequences of a supernumerary X chromosome on the morphology of the amygdala and hippocampus. Regional and total brain volumes were measured in 10 subjects with 47,XXY, 10 subjects with 47,XXX, and 20 euploid controls. Amygdala volumes were significantly reduced in men with 47,XXY, compared to control men, while the decrease in women with 47,XXX was not as pronounced. Hippocampus volumes were preserved in both groups, compared to same-gender controls. Longitudinal studies of SCA individuals have shown an increased incidence of mild psychopathology and behavioral dysfunction in men with 47,XXY and more overt psychiatric illness in women with 47,XXX, compared to control populations. The alteration in amygdala volumes in individuals with a supernumerary X chromosome may provide a neuroanatomic basis for these findings. Copyright 2001 Wiley-Liss, Inc.

Effect of Temporal Neocortical Pathology on Seizure Freeness in Adult Patients with Temporal Lobe Epilepsy.

PubMed

Kemerdere, Rahsan; Ahmedov, Merdin Lyutviev; Alizada, Orkhan; Yeni, Seher Naz; Oz, Buge; Tanriverdi, Taner

2018-05-23

Temporal lobe epilepsy (TLE) is the most common form of focal epilepsy. Focal cortical dysplasia is the most common dual pathology found in association with the hippocampal sclerosis. In this study, the effect of dual pathology on freedom from seizure was sought in patients with TLE. This study performed a retrospective analysis of patients with TLE who underwent surgery between 2010 and 2017. Histopathologic analysis was performed on patients with and without dual pathology in the temporal neocortex. Seizure outcomes were compared. A total of 54 patients with TLE were included. The rate of overall favorable seizure outcome was found to be 96.3%. In 53.7%, dual pathology was present in the temporal cortices in addition to the hippocampal sclerosis. Patients without dual pathology showed significantly greater freedom from seizure (P = 0.02). Patients without dual pathology had a significantly higher seizure-free rate after anterior temporal resection than patients with dual pathology. Resection of the temporal cortex in addition to mesial temporal structures seems to be reasonable for better seizure outcome. Copyright © 2018 Elsevier Inc. All rights reserved.

Unique and shared validity of the "Wechsler logical memory test", the "California verbal learning test", and the "verbal learning and memory test" in patients with epilepsy.

PubMed

Helmstaedter, Christoph; Wietzke, Jennifer; Lutz, Martin T

2009-12-01

This study was set-up to evaluate the construct validity of three verbal memory tests in epilepsy patients. Sixty-one consecutively evaluated patients with temporal lobe epilepsy (TLE) or extra-temporal epilepsy (E-TLE) underwent testing with the verbal learning and memory test (VLMT, the German equivalent of the Rey auditory verbal learning test, RAVLT); the California verbal learning test (CVLT); the logical memory and digit span subtests of the Wechsler memory scale, revised (WMS-R); and testing of intelligence, attention, speech and executive functions. Factor analysis of the memory tests resulted in test-specific rather than test over-spanning factors. Parameters of the CVLT and WMS-R, and to a much lesser degree of the VLMT, were highly correlated with attention, language function and vocabulary. Delayed recall measures of logical memory and the VLMT differentiated TLE from E-TLE. Learning and memory scores off all three tests differentiated mesial temporal sclerosis from other pathologies. A lateralization of the epilepsy was possible only for a subsample of 15 patients with mesial TLE. Although the three tests provide overlapping indicators for a temporal lobe epilepsy or a mesial pathology, they can hardly be taken in exchange. The tests have different demands on semantic processing and memory organization, and they appear differentially sensitive to performance in non-memory domains. The tests capability to lateralize appears to be poor. The findings encourage the further discussion of the dependency of memory outcomes on test selection.

Atypical febrile seizures, mesial temporal lobe epilepsy, and dual pathology.

PubMed

Sanon, Nathalie T; Desgent, Sébastien; Carmant, Lionel

2012-01-01

Febrile seizures occurring in the neonatal period, especially when prolonged, are thought to be involved in the later development of mesial temporal lobe epilepsy (mTLE) in children. The presence of an often undetected, underlying cortical malformation has also been reported to be implicated in the epileptogenesis process following febrile seizures. This paper highlights some of the various animal models of febrile seizures and of cortical malformation and portrays a two-hit model that efficiently mimics these two insults and leads to spontaneous recurrent seizures in adult rats. Potential mechanisms are further proposed to explain how these two insults may each, or together, contribute to network hyperexcitability and epileptogenesis. Finally the clinical relevance of the two-hit model is briefly discussed in light of a therapeutic and preventive approach to mTLE.

Mood state and cerebral metabolism in persons with age-associated memory impairment.

PubMed

Cherrier, M M; Small, G W; Komo, S; La Rue, A

1997-12-30

People undergoing medical procedures sometimes experience feelings that may influence the results. In this study, we explore the relationship between changes in mood state self-ratings and cerebral glucose metabolism during positron emission tomography (PET) in persons with age-associated memory impairment (mean age 59.4 +/- 9.8 years). Brain regions of interest involved in both mood and memory were examined. Mood ratings of increased boredom correlated significantly with mesial temporal and parietal asymmetry and decreased parietal metabolism. Mood ratings of increased fatigue correlated with basal ganglia asymmetry and the right basal ganglia and left mesial temporal metabolism. These findings suggest that subjective mood state changes during PET may influence metabolism in brain regions implicated in emotion and memory function in people with age-related memory complaints.

Navigation-assisted trans-inferotemporal cortex selective amygdalohippocampectomy for mesial temporal lobe epilepsy; preserving the temporal stem.

PubMed

Kishima, Haruhiko; Kato, Amami; Oshino, Satoru; Tani, Naoki; Maruo, Tomoyuki; Khoo, Hui Ming; Yanagisawa, Takufumi; Edakawa, Kotaro; Kobayashi, Maki; Tanaka, Masataka; Hosomi, Koichi; Hirata, Masayuki; Yoshimine, Toshiki

2017-03-01

Selective amygdalohippocampectomy (SAH) can be used to obtain satisfactory seizure control in patients with mesial temporal lobe epilepsy (MTLE). Several SAH procedures have been reported to achieve satisfactory outcomes for seizure control, but none yield fully satisfactory outcomes for memory function. We hypothesized that preserving the temporal stem might play an important role. To preserve the temporal stem, we developed a minimally invasive surgical procedure, 'neuronavigation-assisted trans-inferotemporal cortex SAH' (TITC-SAH). TITC-SAH was performed in 23 patients with MTLE (MTLE on the language-non-dominant hemisphere, n = 11). The inferior horn of the lateral ventricle was approached via the inferior or middle temporal gyrus along the inferior temporal sulcus under neuronavigation guidance. The hippocampus was dissected in a subpial manner and resected en bloc together with the parahippocampal gyrus. Seizure control at one year and memory function at 6 months postoperatively were evaluated. One year after TITC-SAH, 20 of the 23 patients were seizure-free (ILAE class 1), 2 were class 2, and 1 was class 3. Verbal memory improved significantly in 13 patients with a diagnosis of hippocampal sclerosis, for whom WMS-R scores were available both pre- and post-operatively. Improvements were seen regardless of whether the SAH was on the language-dominant or non-dominant hemisphere. No major complication was observed. Navigation-assisted TITC-SAH performed for MTLE offers a simple, minimally invasive procedure that appears to yield excellent outcomes in terms of seizure control and preservation of memory function, because this procedure does not damage the temporal stem. TITC-SAH should be one of the feasible surgical procedures for MTLE. SAH: Amygdalohippocampectomy; MTLE: Mesial temporal lobe epilepsy (MTLE); TITC-SAH: Ttrans-inferotemporal cortex SAH; ILAE: International League Against Epilepsy (ILAE); MRI: Magnetic resonance imaging; EEG: Electroencephalography (EEG); FDG-PET: 8 F-fluorodeoxyglucose (FDG)-positron emission tomography; ECoG: Electrocorticography; MEG: Magnetoencephalography; IMZ-SPECT: N-isopropyl-p( 123 I)-iodoamphetamine single photon emission computed tomography; WMS-R: Wechsler Memory Scale-Revised.

Characterization of neurons in the cortical white matter in human temporal lobe epilepsy.

PubMed

Richter, Zsófia; Janszky, József; Sétáló, György; Horváth, Réka; Horváth, Zsolt; Dóczi, Tamás; Seress, László; Ábrahám, Hajnalka

2016-10-01

The aim of the present work was to characterize neurons in the archi- and neocortical white matter, and to investigate their distribution in mesial temporal sclerosis. Immunohistochemistry and quantification of neurons were performed on surgically resected tissue sections of patients with therapy-resistant temporal lobe epilepsy. Temporal lobe tissues of patients with tumor but without epilepsy and that from autopsy were used as controls. Neurons were identified with immunohistochemistry using antibodies against NeuN, calcium-binding proteins, transcription factor Tbr1 and neurofilaments. We found significantly higher density of neurons in the archi- and neocortical white matter of patients with temporal lobe epilepsy than in that of controls. Based on their morphology and neurochemical content, both excitatory and inhibitory cells were present among these neurons. A subset of neurons in the white matter was Tbr-1-immunoreactive and these neurons coexpressed NeuN and neurofilament marker SMI311R. No colocalization of Tbr1 was observed with the inhibitory neuronal markers, calcium-binding proteins. We suggest that a large population of white matter neurons comprises remnants of the subplate. Furthermore, we propose that a subset of white matter neurons was arrested during migration, highlighting the role of cortical maldevelopment in epilepsy associated with mesial temporal sclerosis. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

The Role of Brain Inflammation in Epileptogenesis in TSC

DTIC Science & Technology

2013-07-01

and adaptive immunity during epileptogenesis and spontaneous seizures: evidence from experimental models and human temporal lobe epilepsy . Neurobiol...tissue obtained from epilepsy patients, such as with mesial temporal sclerosis. Different types of inflammatory mediators and pathways have been...13. SUPPLEMENTARY NOTES 14. ABSTRACT Epilepsy is a common, disabling problem in patients with tuberous sclerosis complex (TSC) and

Atypical Febrile Seizures, Mesial Temporal Lobe Epilepsy, and Dual Pathology

PubMed Central

Sanon, Nathalie T.; Desgent, Sébastien; Carmant, Lionel

2012-01-01

Febrile seizures occurring in the neonatal period, especially when prolonged, are thought to be involved in the later development of mesial temporal lobe epilepsy (mTLE) in children. The presence of an often undetected, underlying cortical malformation has also been reported to be implicated in the epileptogenesis process following febrile seizures. This paper highlights some of the various animal models of febrile seizures and of cortical malformation and portrays a two-hit model that efficiently mimics these two insults and leads to spontaneous recurrent seizures in adult rats. Potential mechanisms are further proposed to explain how these two insults may each, or together, contribute to network hyperexcitability and epileptogenesis. Finally the clinical relevance of the two-hit model is briefly discussed in light of a therapeutic and preventive approach to mTLE. PMID:22957226

Imaging structural and functional brain networks in temporal lobe epilepsy.

PubMed

Bernhardt, Boris C; Hong, Seokjun; Bernasconi, Andrea; Bernasconi, Neda

2013-10-01

Early imaging studies in temporal lobe epilepsy (TLE) focused on the search for mesial temporal sclerosis, as its surgical removal results in clinically meaningful improvement in about 70% of patients. Nevertheless, a considerable subgroup of patients continues to suffer from post-operative seizures. Although the reasons for surgical failure are not fully understood, electrophysiological and imaging data suggest that anomalies extending beyond the temporal lobe may have negative impact on outcome. This hypothesis has revived the concept of human epilepsy as a disorder of distributed brain networks. Recent methodological advances in non-invasive neuroimaging have led to quantify structural and functional networks in vivo. While structural networks can be inferred from diffusion MRI tractography and inter-regional covariance patterns of structural measures such as cortical thickness, functional connectivity is generally computed based on statistical dependencies of neurophysiological time-series, measured through functional MRI or electroencephalographic techniques. This review considers the application of advanced analytical methods in structural and functional connectivity analyses in TLE. We will specifically highlight findings from graph-theoretical analysis that allow assessing the topological organization of brain networks. These studies have provided compelling evidence that TLE is a system disorder with profound alterations in local and distributed networks. In addition, there is emerging evidence for the utility of network properties as clinical diagnostic markers. Nowadays, a network perspective is considered to be essential to the understanding of the development, progression, and management of epilepsy.

Electroencephalography in Mesial Temporal Lobe Epilepsy: A Review

PubMed Central

Javidan, Manouchehr

2012-01-01

Electroencephalography (EEG) has an important role in the diagnosis and classification of epilepsy. It can provide information for predicting the response to antiseizure drugs and to identify the surgically remediable epilepsies. In temporal lobe epilepsy (TLE) seizures could originate in the medial or lateral neocortical temporal region, and many of these patients are refractory to medical treatment. However, majority of patients have had excellent results after surgery and this often relies on the EEG and magnetic resonance imaging (MRI) data in presurgical evaluation. If the scalp EEG data is insufficient or discordant, invasive EEG recording with placement of intracranial electrodes could identify the seizure focus prior to surgery. This paper highlights the general information regarding the use of EEG in epilepsy, EEG patterns resembling epileptiform discharges, and the interictal, ictal and postictal findings in mesial temporal lobe epilepsy using scalp and intracranial recordings prior to surgery. The utility of the automated seizure detection and computerized mathematical models for increasing yield of non-invasive localization is discussed. This paper also describes the sensitivity, specificity, and predictive value of EEG for seizure recurrence after withdrawal of medications following seizure freedom with medical and surgical therapy. PMID:22957235

Exome sequencing identifies SUCO mutations in mesial temporal lobe epilepsy.

PubMed

Sha, Zhiqiang; Sha, Longze; Li, Wenting; Dou, Wanchen; Shen, Yan; Wu, Liwen; Xu, Qi

2015-03-30

Mesial temporal lobe epilepsy (mTLE) is the main type and most common medically intractable form of epilepsy. Severity of disease-based stratified samples may help identify new disease-associated mutant genes. We analyzed mRNA expression profiles from patient hippocampal tissue. Three of the seven patients had severe mTLE with generalized-onset convulsions and consciousness loss that occurred over many years. We found that compared with other groups, patients with severe mTLE were classified into a distinct group. Whole-exome sequencing and Sanger sequencing validation in all seven patients identified three novel SUN domain-containing ossification factor (SUCO) mutations in severely affected patients. Furthermore, SUCO knock down significantly reduced dendritic length in vitro. Our results indicate that mTLE defects may affect neuronal development, and suggest that neurons have abnormal development due to lack of SUCO, which may be a generalized-onset epilepsy-related gene. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Familial mesial temporal lobe epilepsy (FMTLE) : a clinical and genetic study of 15 Italian families.

PubMed

Striano, Pasquale; Gambardella, Antonio; Coppola, Antonietta; Di Bonaventura, Carlo; Bovo, Giorgia; Diani, Erica; Boaretto, Francesca; Egeo, Gabriella; Ciampa, Clotilde; Labate, Angelo; Testoni, Stefania; Passarelli, Daniela; Manna, Ida; Sferro, Caterina; Aguglia, Umberto; Caranci, Ferdinando; Giallonardo, Anna Teresa; Striano, Salvatore; Nobile, Carlo; Michelucci, Roberto

2008-01-01

Familial mesial temporal lobe epilepsy (FMTLE) is characterized by prominent psychic and autonomic seizures, often without hippocampal sclerosis (HS) or a previous history of febrile seizures (FS), and good prognosis. The genetics of this condition is largely unknown.We present the electroclinical and genetic findings of 15 MTLE Italian families. FMTLE was defined when two or more first-degree relatives had epilepsy suggesting a mesial temporal lobe origin. The occurrence of seizures with auditory auras was considered an exclusion criterion. Patients underwent video-EEG recordings, 1.5-Tesla MRI particularly focused on hippocampal analysis, and neuropsychological evaluation. Genetic study included genotyping and linkage analysis of candidate loci at 4q, 18q, 1q, and 12q as well as screening for LGI1/Epitempin mutations. Most of the families showed an autosomal dominant inheritance pattern with incomplete penetrance. Fifty-four (32 F) affected individuals were investigated. Twenty-one (38.8 %) individuals experienced early FS. Forty-eight individuals fulfilled the criteria for MTLE. Epigastric/visceral sensation (72.9 %) was the most common type of aura, followed by psychic symptoms (35.4 %), and déjà vu (31.2 %). HS occurred in 13.8% of individuals, three of whom belonged to the same family. Prognosis of epilepsy was generally good. Genetic study failed to show LGI1/Epitempin mutations or significative linkage to the investigated loci. FMTLE may be a more common than expected condition, clinically and genetically heterogeneous. Some of the reported families, grouped on the basis of a specific aura, may represent an interesting subgroup on whom to focus future linkage studies.

New onset obsessive-compulsive symptoms in children and adolescents with severe traumatic brain injury.

PubMed

Grados, Marco A; Vasa, Roma A; Riddle, Mark A; Slomine, Beth S; Salorio, Cynthia; Christensen, James; Gerring, Joan

2008-01-01

Traumatic brain injury (TBI) constitutes a major source of psychiatric morbidity and disability. This study examines new onset of obsessions and compulsions (OCS) within 1 year of severe pediatric TBI. Eighty children and adolescents ages 6-18 years with severe TBI were interviewed by a child psychiatrist using the Diagnostic Interview for Children and Adolescents-Revised to diagnose OCS and comorbidities. A brain magnetic resonance imaging used a 1.5 T scanner 3 months after injury with a T1-weighted spoiled gradient-recalled-echo sequence to provide high spatial resolution and T1- and T2(*)-contrast sensitivity. Race, sex, socioeconomic status, psychosocial adversity, and injury severity were used to predict new onset OCS. Psychiatric comorbidities and brain lesion volumes in orbitofrontal, mesial prefrontal, temporal lobe, basal ganglia, and thalamus were examined in relation to new onset OCS. Twenty-one children (21/72, 29.2%) had OCS after TBI. Most common were worries about disease, cleanliness, and inappropriate actions as well as excessive cleaning, doing things a certain way and ordering. Anxiety disorders, mania, dysthymia, depressive symptoms, and posttraumatic stress disorder were significantly associated with new onset OCS. Injury severity was not associated with new onset OCS. Greater psychosocial adversity (P=0.009), and being female (P=0.005) were associated with OCS while mesial prefrontal and temporal lobe lesions were associated with new onset obsessions (P<0.05). OCS are common after severe pediatric TBI and are associated with greater comorbidities. New onset obsessions are associated with female sex, psychosocial adversity, and mesial prefrontal and temporal lesions. Published 2007 Wiley-Liss, Inc.

The influence of seizure frequency on anterograde and remote memory in mesial temporal lobe epilepsy.

PubMed

Voltzenlogel, Virginie; Vignal, Jean-Pierre; Hirsch, Edouard; Manning, Liliann

2014-10-01

Seizure frequency, although considered as an important factor in memory impairment in mesial temporal epilepsy (mTLE), is mostly confounded with other clinical variables, making it unclear to what extent recurrent seizures actually interfere with memory. The present study focuses on the influence of seizure frequency, studied as a main variable, on anterograde and remote memory. Seventy-one patients with unilateral mTLE were divided into two subgroups, as a function of their seizure frequency (monthly versus weekly seizures). Other seizure-related variables were controlled, namely, lateralisation and type of lesion, age at onset, years of ongoing seizures, etiologic factors, and number of AED. A comprehensive neuropsychological examination, including anterograde memory (verbal and non verbal recognition memory and free recall) tasks together with a large range of tests exploring different domains of remote memory, was carried out. Despite similar results on IQ, executive functions and attention, the low seizure-frequency group performed significantly better than the high seizure-frequency group on anterograde memory tests. Loss of autobiographical episodes and public-events memory, concomitant with spared personal semantic knowledge, was observed in both patient groups compared with healthy subjects. A worsening effect of high seizure frequency was recorded for autobiographical incidents and news-events memory, but unexpectedly, not for memory for famous people. The study of seizure frequency as the main variable leads us to suggest that high seizure frequency, itself, potentiates the effects of mesial temporal lobe damage on episodic memory deficits. Copyright © 2014 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

[A surgical case of mesial temporal lobe epilepsy associated with hippocampal sclerosis and traumatic neocortical lesion].

PubMed

Kitazawa, Yu; Jin, Kazutaka; Iwasaki, Masaki; Suzuki, Hiroyoshi; Tanaka, Fumiaki; Nakasato, Nobukazu

2017-11-25

A 26-year-old right-handed woman, with a history of left temporal lobe contusion caused by a fall at the age of 9 months, started to have complex partial seizures with oral automatism at the age of 7 years. The seizures occurred once or twice a month despite combination therapy with several antiepileptic agents. Her history and imaging studies suggested the diagnosis of epilepsy arising from traumatic neocortical temporal lesion. Comprehensive assessment including long-term video EEG monitoring, MRI, FDG-PET, MEG, and neuropsychological evaluation was performed at the age of 26 years. The diagnosis was left mesial temporal lobe epilepsy associated with hippocampal atrophy and traumatic temporal cortical lesion. The patient was readmitted for surgical treatment at the age of 27 years. Intracranial EEG monitoring showed that ictal discharges started in the left hippocampus and spread to the traumatic lesion in the left posterior superior temporal gyrus 10 seconds after the onset. This case could not be classified as dual pathology exactly, because the traumatic left temporal cortical lesion did not show independent epileptogenicity. However, the traumatic lesion was highly likely to be the source of the epileptogenicity, and she had right hemispheric dominance for language and functional deterioration in the whole temporal cortex. Therefore, left amygdalo-hippocampectomy and left temporal lobectomy including the traumatic lesion were performed according to the diagnosis of dual pathology. Subsequently, she remained seizure-free for 3 years. Comprehensive assessment of seizure semiology, neurophysiology, neuroradiology, and neuropsychology is important to determine the optimum therapeutic strategies for drug-resistant epilepsy.

Hippocampal activations in mesial temporal lobe epilepsy due to hippocampal sclerosis- an observational study on intramural encoding-delayed recall paradigms using task-based memory fMRI.

PubMed

Rajesh, P G; Thomas, Bejoy; Pammi, V S Chandrasekhar; Kesavadas, C; Alexander, Aley; Radhakrishnan, Ashalatha; Thomas, S V; Menon, R N

2018-05-26

To validate concurrent utility of within-scanner encoding and delayed recognition-memory paradigms to ascertain hippocampal activations during task-based memory fMRI. Memory paradigms were designed for faces, word-pairs and abstract designs. A deep-encoding task was designed comprising of a total of 9 cycles run within a 1.5T MRI scanner. A recall session was performed after 1 h within the scanner using an event-related design. Group analysis was done with 'correct-incorrect' responses applied as parametric modulators in Statistical Parametric Mapping version 8 using boot-strap method to enable estimation of laterality indices (LI) using custom anatomical masks involving the medio-basal temporal structures. Twenty seven subjects with drug-resistant mesial temporal lobe epilepsy due to hippocampal sclerosis (MTLE-HS) [17 patients of left-MTLE and 10 patients of right-MTLE] and 21 right handed age-matched healthy controls (HC) were recruited. For the encoding paradigm blood oxygen level dependent (BOLD) responses in HC demonstrated right laterality for faces, left laterality for word pairs, and bilaterality for design encoding over the regions of interest. Both right and left MTLE-HS groups revealed left lateralisation for word-pair encoding, bilateral activation for face encoding, with design encoding in right MTLE-HS demonstrating a left shift. As opposed to lateralization shown in controls, group analysis of cued-recall BOLD signals acquired within scanner in left MTLE-HS demonstrated right lateralization for word-pairs with bilaterality for faces and designs. The right MTLE-HS group demonstrated bilateral activations for faces, word-pairs and designs. Recall-based fMRI paradigms indicate hippocampal plasticity in MTLE-HS, maximal for word-pair associate recall tasks. Copyright © 2018 Elsevier B.V. All rights reserved.

Automated volumetry of hippocampus is useful to confirm unilateral mesial temporal sclerosis in patients with radiologically positive findings.

PubMed

Silva, Guilherme; Martins, Cristina; Moreira da Silva, Nádia; Vieira, Duarte; Costa, Dias; Rego, Ricardo; Fonseca, José; Silva Cunha, João Paulo

2017-08-01

Background and purpose We evaluated two methods to identify mesial temporal sclerosis (MTS): visual inspection by experienced epilepsy neuroradiologists based on structural magnetic resonance imaging sequences and automated hippocampal volumetry provided by a processing pipeline based on the FMRIB Software Library. Methods This retrospective study included patients from the epilepsy monitoring unit database of our institution. All patients underwent brain magnetic resonance imaging in 1.5T and 3T scanners with protocols that included thin coronal T2, T1 and fluid-attenuated inversion recovery and isometric T1 acquisitions. Two neuroradiologists with experience in epilepsy and blinded to clinical data evaluated magnetic resonance images for the diagnosis of MTS. The diagnosis of MTS based on an automated method included the calculation of a volumetric asymmetry index between the two hippocampi of each patient and a threshold value to define the presence of MTS obtained through statistical tests (receiver operating characteristics curve). Hippocampi were segmented for volumetric quantification using the FIRST tool and fslstats from the FMRIB Software Library. Results The final cohort included 19 patients with unilateral MTS (14 left side): 14 women and a mean age of 43.4 ± 10.4 years. Neuroradiologists had a sensitivity of 100% and specificity of 73.3% to detect MTS (gold standard, k = 0.755). Automated hippocampal volumetry had a sensitivity of 84.2% and specificity of 86.7% (k = 0.704). Combined, these methods had a sensitivity of 84.2% and a specificity of 100% (k = 0.825). Conclusions Automated volumetry of the hippocampus could play an important role in temporal lobe epilepsy evaluation, namely on confirmation of unilateral MTS diagnosis in patients with radiological suggestive findings.

Localized shape abnormalities in the thalamus and pallidum are associated with secondarily generalized seizures in mesial temporal lobe epilepsy.

PubMed

Yang, Linglin; Li, Hong; Zhu, Lujia; Yu, Xinfeng; Jin, Bo; Chen, Cong; Wang, Shan; Ding, Meiping; Zhang, Minming; Chen, Zhong; Wang, Shuang

2017-05-01

Mesial temporal lobe epilepsy (mTLE) is a common type of drug-resistant epilepsy and secondarily generalized tonic-clonic seizures (sGTCS) have devastating consequences for patients' safety and quality of life. To probe the mechanism underlying the genesis of sGTCS, we investigated the structural differences between patients with and without sGTCS in a cohort of mTLE with radiologically defined unilateral hippocampal sclerosis. We performed voxel-based morphometric analysis of cortex and vertex-wise shape analysis of subcortical structures (the basal ganglia and thalamus) on MRI of 39 patients (21 with and 18 without sGTCS). Comparisons were initially made between sGTCS and non-sGTCS groups, and subsequently made between uncontrolled-sGTCS and controlled-sGTCS subgroups. Regional atrophy of the ipsilateral ventral pallidum (cluster size=450 voxels, corrected p=0.047, Max voxel coordinate=107, 120, 65), medial thalamus (cluster size=1128 voxels, corrected p=0.049, Max voxel coordinate=107, 93, 67), middle frontal gyrus (cluster size=60 voxels, corrected p<0.05, Max voxel coordinate=-30, 49.5, 6), and contralateral posterior cingulate cortex (cluster size=130 voxels, corrected p<0.05, Max voxel coordinate=16.5, -57, 27) was found in the sGTCS group relative to the non-sGTCS group. Furthermore, the uncontrolled-sGTCS subgroup showed more pronounced atrophy of the ipsilateral medial thalamus (cluster size=1240 voxels, corrected p=0.014, Max voxel coordinate=107, 93, 67) than the controlled-sGTCS subgroup. These findings indicate a central role of thalamus and pallidum in the pathophysiology of sGTCS in mTLE. Copyright © 2017 Elsevier Inc. All rights reserved.

Hippocampal atrophy on MRI is predictive of histopathological patterns and surgical prognosis in mesial temporal lobe epilepsy with hippocampal sclerosis.

PubMed

Jardim, Anaclara Prada; Corso, Jeana Torres; Garcia, Maria Teresa Fernandes Castilho; Gaça, Larissa Botelho; Comper, Sandra Mara; Lancellotti, Carmen Lúcia Penteado; Centeno, Ricardo Silva; Carrete, Henrique; Cavalheiro, Esper Abrão; Scorza, Carla Alessandra; Yacubian, Elza Márcia Targas

2016-12-01

To correlate hippocampal volumes obtained from brain structural imaging with histopathological patterns of hippocampal sclerosis (HS), in order to predict surgical outcome. Patients with mesial temporal lobe epilepsy (MTLE) with HS were selected. Clinical data were assessed pre-operatively and surgical outcome in the first year post surgery. One block of mid hippocampal body was selected for HS classification according to ILAE criteria. NeuN-immunoreactive cell bodies were counted within hippocampal subfields, in four randomly visual fields, and cell densities were transformed into z-score values. FreeSurfer processing of 1.5T brain structural images was used for subcortical and cortical volumetric estimation of the ipsilateral hippocampus. Univariate analysis of variance and Pearson's correlation test were applied for statistical analyses. Sixty-two cases (31 female, 32 right HS) were included. ILAE type 1 HS was identified in 48 patients, type 2 in eight, type 3 in two, and four had no-HS. Better results regarding seizure control, i.e. ILAE 1, were achieved by patients with type 1 HS (58.3%). Patients with types 1 and 2 had smaller hippocampal volumes compared to those with no-HS (p<0.001 and p=0.004, respectively). Positive correlation was encountered between hippocampal volumes and CA1, CA3, CA4, and total estimated neuronal densities. CA2 was the only sector which did not correlate its neuronal density with hippocampal volume (p=0.390). This is the first study correlating hippocampal volume on MRI submitted to FreeSurfer processing with ILAE patterns of HS and neuronal loss within each hippocampal subfield, a fundamental finding to anticipate surgical prognosis for patients with drug-resistant MTLE and HS. Copyright © 2016 Elsevier B.V. All rights reserved.

Imaging structural and functional brain networks in temporal lobe epilepsy

PubMed Central

Bernhardt, Boris C.; Hong, SeokJun; Bernasconi, Andrea; Bernasconi, Neda

2013-01-01

Early imaging studies in temporal lobe epilepsy (TLE) focused on the search for mesial temporal sclerosis, as its surgical removal results in clinically meaningful improvement in about 70% of patients. Nevertheless, a considerable subgroup of patients continues to suffer from post-operative seizures. Although the reasons for surgical failure are not fully understood, electrophysiological and imaging data suggest that anomalies extending beyond the temporal lobe may have negative impact on outcome. This hypothesis has revived the concept of human epilepsy as a disorder of distributed brain networks. Recent methodological advances in non-invasive neuroimaging have led to quantify structural and functional networks in vivo. While structural networks can be inferred from diffusion MRI tractography and inter-regional covariance patterns of structural measures such as cortical thickness, functional connectivity is generally computed based on statistical dependencies of neurophysiological time-series, measured through functional MRI or electroencephalographic techniques. This review considers the application of advanced analytical methods in structural and functional connectivity analyses in TLE. We will specifically highlight findings from graph-theoretical analysis that allow assessing the topological organization of brain networks. These studies have provided compelling evidence that TLE is a system disorder with profound alterations in local and distributed networks. In addition, there is emerging evidence for the utility of network properties as clinical diagnostic markers. Nowadays, a network perspective is considered to be essential to the understanding of the development, progression, and management of epilepsy. PMID:24098281

Surgical treatment for medically refractory focal epilepsy in a patient with fragile X syndrome.

PubMed

Kenmuir, Cynthia; Richardson, Mark; Ghearing, Gena

2015-10-01

Medication resistant temporal lobe epilepsy occurs in a small population of patients with fragile X syndrome. We present the case of a 24-year-old man with medically refractory temporal lobe epilepsy and fragile X syndrome who underwent left anterior temporal lobectomy resulting in cessation of seizures. Our patient was diagnosed with fragile X syndrome with a fully mutated, fully methylated FMR1 gene resulting in 572 CGG repeats. He developed seizures initially controlled with Depakote monotherapy, but progressed to become medically refractive to combination treatment with Depakote, lamotrigine and zonisamide. Prolonged video EEG monitoring revealed interictal left temporal sharp waves and slowing as well as subclinical and clinical seizures, each with left temporal onset. 3T MRI was consistent with left mesial temporal sclerosis. After discussing the case in our multidisciplinary surgical epilepsy conference, he was referred for presurgical evaluation including neuropsychological testing and Wada testing. He underwent an asleep left anterior temporal lobectomy, sparing the superior temporal gyrus. Pathology showed neuronal loss and gliosis in the hippocampus and amygdala. Twelve months after surgery, the patient has not experienced a seizure. He is described by his parents as less perseverative and less restless. We have presented the case of a 24 year-old-man with fragile X syndrome who underwent successful left anterior temporal lobectomy for the treatment of medically refractory epilepsy who is now seizure free without further functional impairment. This case report demonstrates the feasibility of surgical treatment for a patient with comorbid fragile X syndrome and mesial temporal sclerosis. Copyright © 2015 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

The Role of Brain Inflammation in Epileptogenesis in TSC

DTIC Science & Technology

2014-07-01

human temporal lobe epilepsy . Neurobiol Dis 2008;29:142-160. 5. Ravizza T, Noe F, Zardoni D, Vaghi V, Sifringer M, Vezzani A. Interleukin...of epilepsy , as well as in human tissue obtained from epilepsy patients, such as with mesial temporal sclerosis. Different types of inflammatory...14. ABSTRACT Epilepsy is a common, disabling problem in patients with tuberous sclerosis complex (TSC) and is usually intractable to available

Magnetic resonance imaging abnormalities in familial temporal lobe epilepsy with auditory auras.

PubMed

Kobayashi, Eliane; Santos, Neide F; Torres, Fabio R; Secolin, Rodrigo; Sardinha, Luiz A C; Lopez-Cendes, Iscia; Cendes, Fernando

2003-11-01

Two forms of familial temporal lobe epilepsy (FTLE) have been described: mesial FTLE and FTLE with auditory auras. The gene responsible for mesial FTLE has not been mapped yet, whereas mutations in the LGI1 (leucine-rich, glioma-inactivated 1) gene, localized on chromosome 10q, have been found in FTLE with auditory auras. To describe magnetic resonance imaging (MRI) findings in patients with FTLE with auditory auras. We performed detailed clinical and molecular studies as well as MRI evaluation (including volumetry) in all available individuals from one family, segregating FTLE from auditory auras. We evaluated 18 of 23 possibly affected individuals, and 13 patients reported auditory auras. In one patient, auditory auras were associated with déjà vu; in one patient, with ictal aphasia; and in 2 patients, with visual misperception. Most patients were not taking medication at the time, although all of them reported sporadic auras. Two-point lod scores were positive for 7 genotyped markers on chromosome 10q, and a Zmax of 6.35 was achieved with marker D10S185 at a recombination fraction of 0.0. Nucleotide sequence analysis of the LGI1 gene showed a point mutation, VIIIS7(-2)A-G, in all affected individuals. Magnetic resonance imaging was performed in 22 individuals (7 asymptomatic, 4 of them carriers of the affected haplotype on chromosome 10q and the VIIIS7[-2]A-G mutation). Lateral temporal lobe malformations were identified by visual analysis in 10 individuals, 2 of them with global enlargement demonstrated by volumetry. Mildly reduced hippocampi were observed in 4 individuals. In this family with FTLE with auditory auras, we found developmental abnormalities in the lateral cortex of the temporal lobes in 53% of the affected individuals. In contrast with mesial FTLE, none of the affected individuals had MRI evidence of hippocampal sclerosis.

Using Correlative Properties of Neighboring Pixels to Enhance Contrast-to-Noise Ratio of Abnormal Hippocampus in Patients With Intractable Epilepsy and Mesial Temporal Sclerosis.

PubMed

Parsons, Matthew S; Sharma, Aseem; Hildebolt, Charles

2018-06-12

To test whether an image-processing algorithm can aid in visualization of mesial temporal sclerosis on magnetic resonance imaging by selectively increasing contrast-to-noise ratio (CNR) between abnormal hippocampus and normal brain. In this Institutional Review Board-approved and Health Insurance Portability and Accountability Act-compliant study, baseline coronal fluid-attenuated inversion recovery images of 18 adults (10 females, eight males; mean age 41.2 years) with proven mesial temporal sclerosis were processed using a custom algorithm to produce corresponding enhanced images. Average (Hmean) and maximum (Hmax) CNR for abnormal hippocampus were calculated relative to normal ipsilateral white matter. CNR values for normal gray matter (GM) were similarly calculated using ipsilateral cingulate gyrus as the internal control. To evaluate effect of image processing on visual conspicuity of hippocampal signal alteration, a neuroradiologist masked to the side of hippocampal abnormality rated signal intensity (SI) of hippocampi on baseline and enhanced images using a five-point scale (definitely abnormal to definitely normal). Differences in Hmean, Hmax, GM, and SI ratings for abnormal hippocampi on baseline and enhanced images were assessed for statistical significance. Both Hmean and Hmax were significantly higher in enhanced images as compared to baseline images (p < 0.0001 for both). There was no significant difference in the GM between baseline and enhanced images (p = 0.9375). SI ratings showed a more confident identification of abnormality on enhanced images (p = 0.0001). Image-processing resulted in increased CNR of abnormal hippocampus without affecting the CNR of normal gray matter. This selective increase in conspicuity of abnormal hippocampus was associated with more confident identification of hippocampal signal alteration. Copyright © 2018 Academic Radiology. Published by Elsevier Inc. All rights reserved.

Long-Term Seizure, Quality of Life, Depression, and Verbal Memory Outcomes in a Controlled Mesial Temporal Lobe Epilepsy Surgical Series Using Portuguese-Validated Instruments.

PubMed

Dias, Luis Augusto; Angelis, Geisa de; Teixeira, Wagner Afonso; Casulari, Luiz Augusto

2017-08-01

We aimed to evaluate long-term surgical outcomes in patients treated for mesial temporal lobe epilepsy compared with a similar group of patients who underwent a preoperative evaluation. Patient interviews were conducted by an independent neuropsychologist and included a sociodemographic questionnaire and validated versions of the Beck Depression Inventory-II, Adverse Events Profile, Quality of Life in Epilepsy-31, and Rey Auditory Verbal Learning Test. Seventy-one patients who underwent surgery and 20 who underwent mesial temporal lobe epilepsy preoperative evaluations were interviewed. After an 81-month mean postoperative follow-up, 44% of the surgical patients achieved complete seizure relief according to the Engel classification and 68% according to the International League Against Epilepsy classification. The surgical group had a significantly lower prevalence of depression (P = 0.002) and drug-related adverse effects (P = 0.002). Improvement on unemployment (P = 0.02) was achieved but not on driving or education. Delayed verbal memory recall was impaired in 76% of the surgical and 65% of the control cases (P = 0.32). Regarding the Quality of Life in Epilepsy-31, the operated patients scored higher in their total score (mean, 75.44 vs. mean, 60.08; P < 0.001) and in all but the cognitive functioning domain irrespective of the follow-up length. Seizure control, Beck Depression Score, and Adverse Events Profile severity explained 73% of the variance in the surgical group quality of life. Our study found that, although surgical treatment was effective, its impact on social indicators was modest. Moreover, the self-reported quality of life relied not only on seizure control but also on depressive symptoms and antiepileptic drug burden. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Postictal psychosis and its electrophysiological correlates in invasive EEG: a case report study and literature review.

PubMed

Kuba, Robert; Brázdil, Milan; Rektor, Ivan

2012-04-01

We identified two patients with medically refractory temporal lobe epilepsy, from whom intracranial EEG recordings were obtained at the time of postictal psychosis. Both patients had mesial temporal epilepsy associated with hippocampal sclerosis. In both patients, the postictal psychosis was associated with a continual "epileptiform" EEG pattern that differed from their interictal and ictal EEG findings (rhythmical slow wave and "abortive" spike-slow wave complex activity in the right hippocampus and lateral temporal cortex in case 1 and a periodic pattern of triphasic waves in the contacts recording activity from the left anterior cingulate gyrus). Some cases of postictal psychosis might be caused by the transient impairment of several limbic system structures due to the "continual epileptiform discharge" in some brain regions. Case 2 is the first report of a patient with TLE in whom psychotic symptoms were associated with the epileptiform impairment of the anterior cingulate gyrus. Copyright © 2012 Elsevier Inc. All rights reserved.

Episodic and semantic memory in children with mesial temporal sclerosis.

PubMed

Rzezak, Patricia; Guimarães, Catarina; Fuentes, Daniel; Guerreiro, Marilisa M; Valente, Kette Dualibi Ramos

2011-07-01

The aim of this study was to analyze semantic and episodic memory deficits in children with mesial temporal sclerosis (MTS) and their correlation with clinical epilepsy variables. For this purpose, 19 consecutive children and adolescents with MTS (8 to 16 years old) were evaluated and their performance on five episodic memory tests (short- and long-term memory and learning) and four semantic memory tests was compared with that of 28 healthy volunteers. Patients performed worse on tests of immediate and delayed verbal episodic memory, visual episodic memory, verbal and visual learning, mental scanning for semantic clues, object naming, word definition, and repetition of sentences. Clinical variables such as early age at seizure onset, severity of epilepsy, and polytherapy impaired distinct types of memory. These data confirm that children with MTS have episodic memory deficits and add new information on semantic memory. The data also demonstrate that clinical variables contribute differently to episodic and semantic memory performance. Copyright © 2011 Elsevier Inc. All rights reserved.

Neuronal and glial metabolite content of the epileptogenic human hippocampus.

PubMed

Petroff, Ognen A C; Errante, Laura D; Rothman, Douglas L; Kim, Jung H; Spencer, Dennis D

2002-11-01

Mesial temporal lobe epilepsy is characterized by hippocampal atrophy, hypometabolism, and decreased N-acetylaspartate, often attributed to neuron loss and gliosis. Twenty hippocampal specimens were obtained during temporal lobectomy and frozen quickly. Perchloric acid extracts of the small metabolites were analyzed by proton magnetic resonance spectroscopy. There were no significant associations between hippocampal neuron loss and the cellular content of N-acetylaspartate, glutamate, GABA, glutamine, or aspartate. The mean metabolite content of hippocampi with less than 30% of neurons remaining was the same as those with greater than 65% of neurons surviving. Mean N-acetylaspartate levels were below those reported by in vivo studies of control subjects. The highest and the lowest glutamate concentrations were seen in specimens with the worst neuron loss. A highly significant association between hippocampal N-acetylaspartate and glutamate content was seen with weak associations between N-acetylaspartate and aspartate and glutamate and aspartate. The hippocampal content of N-acetylaspartate, glutamate, GABA, glutamine, and aspartate is altered minimally by severe neuron loss in mesial temporal lobe epilepsy. The epileptic human hippocampus has increased intracellular glutamate content that may contribute to the epileptogenic nature of hippocampal sclerosis.

A case of successful treatment with donepezil of olfactory hallucination in parkinson disease.

PubMed

Osada, Osamu; Iwasaki, Akira

2017-01-31

We report a 74-year-old female patient with Parkinson disease (PD). Around 2010, she developed depression and bradykinesia and was diagnosed as PD. In July 2014, she came to our hospital, of which she lived in the neighborhood. In the last part of December 2014, she felt uneasy about her fecal smell and saw a psychiatrist in the first part of January 2015. Quetiapine (25 mg/day) was added. In the last part of January, she complained of fecal smell everywhere and could not take a meal. No-one else could detect the smell. A diagnosis of olfactory hallucination was made. The next day after increasing to 75mg/day, however, she was admitted to our hospital because of refusing to take medicine. After introducing donepezil, olfactory hallucination subsided and her appetite was improved. Brain MRI showed atrophy of the bilateral temporal lobes and N-isopropyl-p-(iodine-123)-iodoamphetamine single photon emission computed tomography ( 123 I-IMP-SPECT) revealed hypoperfusion in the bilateral mesial temporal lobes. We suppose that cholinergic denervation in the mesial temporal lobes is an important determinant of her olfactory hallucination.

One declarative memory system or two? The relationship between episodic and semantic memory in children with temporal lobe epilepsy.

PubMed

Smith, Mary Lou; Lah, Suncica

2011-09-01

This study explored verbal semantic and episodic memory in children with unilateral temporal lobe epilepsy to determine whether they had impairments in both or only 1 aspect of memory, and to examine relations between performance in the 2 domains. Sixty-six children and adolescents (37 with seizures of left temporal lobe onset, 29 with right-sided onset) were given 4 tasks assessing different aspects of semantic memory (picture naming, fluency, knowledge of facts, knowledge of word meanings) and 2 episodic memory tasks (story recall, word list recall). High rates of impairments were observed across tasks, and no differences were found related to the laterality of the seizures. Individual patient analyses showed that there was a double dissociation between the 2 aspects of memory in that some children were impaired on episodic but not semantic memory, whereas others showed intact episodic but impaired semantic memory. This double dissociation suggests that these 2 memory systems may develop independently in the context of temporal lobe pathology, perhaps related to differential effects of dysfunction in the lateral and mesial temporal lobe structures. PsycINFO Database Record (c) 2011 APA, all rights reserved.

Neuropsychological deficits in temporal lobe epilepsy: A comprehensive review

PubMed Central

Zhao, Fengqing; Kang, Hai; You, LIbo; Rastogi, Priyanka; Venkatesh, D.; Chandra, Mina

2014-01-01

Temporal lobe epilepsy (TLE) is the most prevalent form of complex partial seizures with temporal lobe origin of electrical abnormality. Studies have shown that recurrent seizures affect all aspects of cognitive functioning, including memory, language, praxis, executive functions, and social judgment, among several others. In this article, we will review these cognitive impairments along with their neuropathological correlates in a comprehensive manner. We will see that neuropsychological deficits are prevalent in TLE. Much of the effort has been laid on memory due to the notion that temporal lobe brain structures involved in TLE play a central role in consolidating information into memory. It seems that damage to the mesial structure of the temporal lobe, particularly the amygdale and hippocampus, has the main role in these memory difficulties and the neurobiological plausibility of the role of the temporal lobe in different aspects of memory. Here, we will cover the sub-domains of working memory and episodic memory deficits. This is we will further proceed to evaluate the evidences of executive function deficits in TLE and will see that set-shifting among other EFs is specifically affected in TLE as is social cognition. Finally, critical components of language related deficits are also found in the form of word-finding difficulties. To conclude, TLE affects several of cognitive function domains, but the etiopathogenesis of all these dysfunctions remain elusive. Further well-designed studies are needed for a better understanding of these disorders. PMID:25506156

Temporal lobe epilepsy surgery in children versus adults: from etiologies to outcomes

PubMed Central

Lee, Yun-Jin

2013-01-01

Temporal lobe epilepsy (TLE) is the most common type of medically intractable epilepsy in adults and children, and mesial temporal sclerosis is the most common underlying cause of TLE. Unlike in the case of adults, TLE in infants and young children often has etiologies other than mesial temporal sclerosis, such as tumors, cortical dysplasia, trauma, and vascular malformations. Differences in seizure semiology have also been reported. Motor manifestations are prominent in infants and young children, but they become less obvious with increasing age. Further, automatisms tend to become increasingly complex with age. However, in childhood and especially in adolescence, the clinical manifestations are similar to those of the adult population. Selective amygdalohippocampectomy can lead to excellent postoperative seizure outcome in adults, but favorable results have been seen in children as well. Anterior temporal lobectomy may prove to be a more successful surgery than amygdalohippocampectomy in children with intractable TLE. The presence of a focal brain lesion on magnetic resonance imaging is one of the most reliable independent predictors of a good postoperative seizure outcome. Seizure-free status is the most important predictor of improved psychosocial outcome with advanced quality of life and a lower proportion of disability among adults and children. Since the brain is more plastic during infancy and early childhood, recovery is promoted. In contrast, long epilepsy duration is an important risk factor for surgically refractory seizures. Therefore, patients with medically intractable TLE should undergo surgery as early as possible. PMID:23908666

Brain anomalies in children exposed prenatally to a common organophosphate pesticide

PubMed Central

Rauh, Virginia A.; Perera, Frederica P.; Horton, Megan K.; Whyatt, Robin M.; Bansal, Ravi; Hao, Xuejun; Liu, Jun; Barr, Dana Boyd; Slotkin, Theodore A.; Peterson, Bradley S.

2012-01-01

Prenatal exposure to chlorpyrifos (CPF), an organophosphate insecticide, is associated with neurobehavioral deficits in humans and animal models. We investigated associations between CPF exposure and brain morphology using magnetic resonance imaging in 40 children, 5.9–11.2 y, selected from a nonclinical, representative community-based cohort. Twenty high-exposure children (upper tertile of CPF concentrations in umbilical cord blood) were compared with 20 low-exposure children on cortical surface features; all participants had minimal prenatal exposure to environmental tobacco smoke and polycyclic aromatic hydrocarbons. High CPF exposure was associated with enlargement of superior temporal, posterior middle temporal, and inferior postcentral gyri bilaterally, and enlarged superior frontal gyrus, gyrus rectus, cuneus, and precuneus along the mesial wall of the right hemisphere. Group differences were derived from exposure effects on underlying white matter. A significant exposure × IQ interaction was derived from CPF disruption of normal IQ associations with surface measures in low-exposure children. In preliminary analyses, high-exposure children did not show expected sex differences in the right inferior parietal lobule and superior marginal gyrus, and displayed reversal of sex differences in the right mesial superior frontal gyrus, consistent with disruption by CPF of normal behavioral sexual dimorphisms reported in animal models. High-exposure children also showed frontal and parietal cortical thinning, and an inverse dose–response relationship between CPF and cortical thickness. This study reports significant associations of prenatal exposure to a widely used environmental neurotoxicant, at standard use levels, with structural changes in the developing human brain. PMID:22547821

Temporal lobe epilepsy: when are invasive recordings needed?

PubMed

Diehl, B; Lüders, H O

2000-01-01

Temporal lobe epilepsy (TLE) is the most common type of medically intractable partial epilepsy amenable to surgery. In the majority of cases, the underlying pathology in temporal lobe epilepsy is mesial temporal sclerosis (MTS). Whereas historically invasive recordings were required for most epilepsy surgeries, indications have dramatically changed since the introduction of high-resolution MRI, which uncovers structural lesions in a high percentage of cases. No invasive recordings are required to perform a temporal lobectomy in patients with intractable epilepsy who have structural imaging suggesting unilateral MTS and concordant interictal and ictal surface EEG recordings, functional imaging, and clinical findings. Invasive testing is needed if there is evidence of bitemporal MTS on structural imaging and/or electrophysiologically, and additional information from functional imaging, neuropsychology, and the intracarotid amobarbital (Wada) test also does not help to lateralize the epileptogenic zone. Depth electrodes can be particularly helpful in this setting. However, no surgery is indicated, even without invasive recordings, if bitemporal-independent seizures are recorded by surface EEG and all additional testing is inconclusive. Other etiologies of TLE such as a tumor, vascular malformation, encephalomalacia, or congenital developmental abnormality account for about 30% of all patients who undergo epilepsy surgery. Epilepsy surgery is indicated after limited electrophysiologic investigations if neuroimaging and electrophysiology converge. However, approaches for resection in lesional temporal lobe epilepsy vary among centers. Completeness of resection is crucial and invasive recordings may be needed to guide the resection by mapping eloquent cortex and/or to determine the extent of the non-MRI-visible epileptogenic area. Specific approaches for the different pathologies are discussed because there is evidence that the relationship between the lesions visible on MRI and the epileptogenic zone varies among lesions of different pathologies, and therefore variable surgical strategies must be applied.

Memory assessment in patients with temporal lobe epilepsy to predict memory impairment after surgery: A systematic review.

PubMed

Parra-Díaz, P; García-Casares, N

2017-04-19

Given that surgical treatment of refractory mesial temporal lobe epilepsy may cause memory impairment, determining which patients are eligible for surgery is essential. However, there is little agreement on which presurgical memory assessment methods are best able to predict memory outcome after surgery and identify those patients with a greater risk of surgery-induced memory decline. We conducted a systematic literature review to determine which presurgical memory assessment methods best predict memory outcome. The literature search of PubMed gathered articles published between January 2005 and December 2015 addressing pre- and postsurgical memory assessment in mesial temporal lobe epilepsy patients by means of neuropsychological testing, functional MRI, and other neuroimaging techniques. We obtained 178 articles, 31 of which were included in our review. Most of the studies used neuropsychological tests and fMRI; these methods are considered to have the greatest predictive ability for memory impairment. Other less frequently used techniques included the Wada test and FDG-PET. Current evidence supports performing a presurgical assessment of memory function using both neuropsychological tests and functional MRI to predict memory outcome after surgery. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Adeno-Associated Viral Vector-Induced Overexpression of Neuropeptide Y Y2 Receptors in the Hippocampus Suppresses Seizures

ERIC Educational Resources Information Center

Woldbye, David P. D.; Angehagen, Mikael; Gotzsche, Casper R.; Elbrond-Bek, Heidi; Sorensen, Andreas T.; Christiansen, Soren H.; Olesen, Mikkel V.; Nikitidou, Litsa; Hansen, Thomas v. O.; Kanter-Schlifke, Irene; Kokaia, Merab

2010-01-01

Gene therapy using recombinant adeno-associated viral vectors overexpressing neuropeptide Y in the hippocampus exerts seizure-suppressant effects in rodent epilepsy models and is currently considered for clinical application in patients with intractable mesial temporal lobe epilepsy. Seizure suppression by neuropeptide Y in the hippocampus is…

Pharmacological modulation in mesial temporal lobe epilepsy: Current status and future perspectives.

PubMed

Gambardella, Antonio; Labate, Angelo; Cifelli, Pierangelo; Ruffolo, Gabriele; Mumoli, Laura; Aronica, Eleonora; Palma, Eleonora

2016-11-01

Mesial temporal lobe epilepsy (MTLE) is frequently associated with hippocampal sclerosis (Hs), possibly caused by a primary brain injury that occurs a long time before the appearance of neurological symptoms. MTLE-Hs is, however, a heterogeneous condition that evolves with time, involving both environmental and genetic components. Recent experimental studies emphasize that drugs or drug combinations that target modulation and circuitry reorganization of the epileptogenic networks favorably modify the complex molecular and cellular alterations underlying MTLE. In particular, the link between neuroinflammation, GABA A R and epilepsy has been extensively studied mainly because of the relevant therapeutic implications that the pharmacological modulation of these phenomena would have in the clinical practice. In this review, we briefly summarize the studies that could pave the road to develop new disease-modifying therapeutic strategies for pharmacoresistant MTLE patients. Both clinical observations in human MTLE and experimental findings will be discussed, highlighting the potential modulatory crosstalk between the deregulation of the inhibitory (GABAergic) transmission and the sustained activation of the innate immune response. Copyright © 2016 Elsevier Ltd. All rights reserved.

Etomidate accurately localizes the epileptic area in patients with temporal lobe epilepsy.

PubMed

Pastor, Jesús; Wix, Rybel; Meilán, María Luisa; Martínez-Chacón, José Luís; de Dios, Eva; Domínguez-Gadea, Luis; Herrera-Peco, Iván; Sola, Rafael G

2010-04-01

A variety of drugs have been used to activate and identify the epileptogenic area in patients during presurgical evaluation. We have evaluated the safety and usefulness of etomidate in identifying the epileptic zone by measuring bioelectrical brain activity and cerebral blood flow (CBF). We studied 13 men and 9 women under presurgical evaluation for temporal lobe epilepsy. We applied etomidate (0.1 mg/kg) while patients were monitored by video-electroencephalography (VEEG) with foramen ovale electrodes. In a subset of 15 patients, we also measured CBF with single photon emission computed tomography (SPECT). (1) Etomidate induced seizures in 2 of 22 patients. (2) The main side-effects observed were myoclonus (14 of 20) and moderate pain (3 of 20). (3) No changes in capillary oxygen saturation, respiration, or heart rate were observed. (4) Irritative activity specifically increased in the temporal mesial and lateral areas. No spikes were observed in other areas, aside from those observed under baseline conditions. (5) Irritative activity induced by etomidate correctly lateralized the ictal onset zone in 19 of 20 patients. In addition, the two etomidate-induced seizures appeared in the same regions as spontaneous ones. (6) The kinetics of pharmacologically induced activity was higher in the region of the ictal-onset zone. (7) Etomidate increased the CBF in the basal ganglia and especially in the posterior hippocampus of the temporal mesial region contralateral to the ictal-onset zone. Etomidate activation is a safe, specific, and quick test that can be used to identify the epileptic region in patients evaluated as candidates for temporal lobe epilepsy surgery.

Neuropsychologist's (re-)view: Resective versus ablative amygdalohippocampectomies.

PubMed

Witt, Juri-Alexander; Hoppe, Christian; Helmstaedter, Christoph

2018-05-01

Pharmacoresistant mesial temporal lobe epilepsy (mTLE) represents the major indication for epilepsy surgery. Since epilepsy surgery is an elective treatment option, preserving cognition is a high priority. Given the essential role of temporomesial structures in declarative long-term memory formation, surgical treatment for mTLE is primarily associated with a risk of material-specific memory decline, but other cognitive domains may be affected as well. The major determinants for the neuropsychological outcome are the functional integrity of surgically affected tissues, the functional reserve capacities of the remnant brain, the postoperative seizure outcome, as well as the quantitative and qualitative changes of antiepileptic drugs. Anterior temporal lobectomy has long been the standard procedure for treating mTLE. However, if an exclusive mesial pathology is present, then functional non-pathological tissues of the temporal pole and neocortex are sacrificed. As a result, more selective or tailored surgical approaches have been developed which strive towards minimizing iatrogenic effects. However, whether or not these approaches are equipotential with regard to seizure control is still a matter of debate. The quality of the presurgical diagnostics could also be decisive. Selective surgery should indeed be selective in terms of preventing evitable collateral cortical damage along the approach. Invasivity and risks of collateral damage associated with "open" selective resective surgery are further minimized by stereotactic ablative surgery via thermocoagulation, or eventually even eliminated by gamma knife surgery. From a neuropsychological point of view, this development is consequent and desirable, but no clear scientific evidence of a superior cognitive outcome after radiosurgery or thermocoagulation currently exists. The studies that are available contain significant methodological limitations. Thus, randomized head-to-head cognitive outcome studies of competing selective procedures are needed, which should meet the minimum requirements for study design and neuropsychological evaluations. Finally, none of the surgical treatment variants can systematically prevent memory decline when the hippocampus is targeted. Copyright © 2017 Elsevier B.V. All rights reserved.

Large-scale brain networks are distinctly affected in right and left mesial temporal lobe epilepsy.

PubMed

de Campos, Brunno Machado; Coan, Ana Carolina; Lin Yasuda, Clarissa; Casseb, Raphael Fernandes; Cendes, Fernando

2016-09-01

Mesial temporal lobe epilepsy (MTLE) with hippocampus sclerosis (HS) is associated with functional and structural alterations extending beyond the temporal regions and abnormal pattern of brain resting state networks (RSNs) connectivity. We hypothesized that the interaction of large-scale RSNs is differently affected in patients with right- and left-MTLE with HS compared to controls. We aimed to determine and characterize these alterations through the analysis of 12 RSNs, functionally parceled in 70 regions of interest (ROIs), from resting-state functional-MRIs of 99 subjects (52 controls, 26 right- and 21 left-MTLE patients with HS). Image preprocessing and statistical analysis were performed using UF(2) C-toolbox, which provided ROI-wise results for intranetwork and internetwork connectivity. Intranetwork abnormalities were observed in the dorsal default mode network (DMN) in both groups of patients and in the posterior salience network in right-MTLE. Both groups showed abnormal correlation between the dorsal-DMN and the posterior salience, as well as between the dorsal-DMN and the executive-control network. Patients with left-MTLE also showed reduced correlation between the dorsal-DMN and visuospatial network and increased correlation between bilateral thalamus and the posterior salience network. The ipsilateral hippocampus stood out as a central area of abnormalities. Alterations on left-MTLE expressed a low cluster coefficient, whereas the altered connections on right-MTLE showed low cluster coefficient in the DMN but high in the posterior salience regions. Both right- and left-MTLE patients with HS have widespread abnormal interactions of large-scale brain networks; however, all parameters evaluated indicate that left-MTLE has a more intricate bihemispheric dysfunction compared to right-MTLE. Hum Brain Mapp 37:3137-3152, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Lesional mesial temporal lobe epilepsy and limited resections: prognostic factors and outcome

PubMed Central

Clusmann, H; Kral, T; Fackeldey, E; Blumcke, I; Helmstaedter, C; von Oertzen, J; Urbach, H; Schramm, J

2004-01-01

Objectives: To evaluate the influence of clinical, investigational, surgical, and histopathological factors on postoperative seizure relief in patients with mesial temporal lobe epilepsy (MTLE) due to lesions other than ammonshornsclerosis (AHS). Methods: Of 738 patients operated for TLE, 78 patients underwent limited resections for lesional MTLE (1990–2000). Seventy four patients with a follow up of more than one year were included. The preoperative clinical, neuropsychological, electroencephalogram, and neuroimaging characteristics were prospectively collected in a database. The histopathological material was re-examined. Results: The mean follow up was 49 months. Fifty eight patients were classified as seizure free (78.4% Class I), and six as almost seizure free (8.1% Class II), grouped together as satisfactory seizure control (64 patients, 86.5%). Five patients (6.8%) were categorised in Classes III and IV, respectively. These were grouped as unsatisfactory seizure control (10 patients, 13.5%). Surgical procedures were: 32 amygdalohippocampectomies (AH), 17 partial anterior AH, 15 AH plus polar resection, seven AH plus basal resection, and three AH plus extended temporal lesionectomy. There was no mortality and 2.7% mild permanent morbidity. Seizure relief did neither differ significantly with these approaches, nor with different classes of pathological findings (43 developmental tumours, 12 glial tumours, 10 dysplasias, and nine others). Even operation of dysplasias resulted in 80% satisfactory seizure control. Seizure onset during childhood proved to be a negative predictor for seizure relief (p = 0.020). MRI revealed 73 suspected lesions (98.6%), one dysembryoplastic neuroepithelial tumour was missed, in four cases no structural abnormalities could be confirmed with histopathological exam. Additionally, multifactorial regression revealed the factors "seizure onset after 10 years of age", "presence of complex partial seizures", "absence of a neurological deficit", and a "correlating neuropsychological deficit" as predictive for satisfactory seizure control. Conclusions: "Preoperative tailoring" resulting in limit resections has proven to be safe and to provide a very good chance for satisfactory seizure relief in patients with lesional MTLE. PMID:15489392

Laser ablation therapy: An alternative treatment for medically resistant mesial temporal lobe epilepsy after age 50.

PubMed

Waseem, Hena; Osborn, Katie E; Schoenberg, Mike R; Kelley, Valerie; Bozorg, Ali; Cabello, Daniel; Benbadis, Selim R; Vale, Fernando L

2015-10-01

Selective anterior mesial temporal lobe (AMTL) resection is considered a safe and effective treatment for medically refractory mesial temporal lobe epilepsy (MTLE). However, as with any open surgical procedure, older patients (aged 50+) face greater risks. Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has shown recent potential as an alternative treatment for MTLE. As a less invasive procedure, MRgLITT could be particularly beneficial to older patients. To our knowledge, no study has evaluated the safety and efficacy of MRgLITT in this population. Seven consecutive patients (aged 50+) undergoing MRgLITT for MTLE were followed prospectively to assess surgical time, complications, postoperative pain control, length of stay (LOS), operating room (OR) charges, total hospitalization charges, and seizure outcome. Five of these patients were assessed at the 1-year follow-up for seizure outcome. These data were compared with data taken from 7 consecutive patients (aged 50+) undergoing AMTL resection. Both groups were of comparable age (mean: 60.7 (MRgLITT) vs. 53 (AMTL)). One AMTL resection patient had a complication of aseptic meningitis. One MRgLITT patient experienced an early postoperative seizure, and two MRgLITT patients had a partial visual field deficit. Seizure-freedom rates were comparable (80% (MRgLITT) and 100% (AMTL) (p>0.05)) beyond 1year postsurgery (mean follow-up: 1.0years (MRgLITT) vs. 1.8years (AMTL)). Mean LOS was shorter in the MRgLITT group (1.3days vs. 2.6days (p<0.05)). Neuropsychological outcomes were comparable. Short-term follow-up suggests that MRgLITT is safe and provides outcomes comparable to AMTL resection in this population. It also decreases pain medication requirement and reduces LOS. Further studies are necessary to assess the long-term efficacy of the procedure. Copyright © 2015 Elsevier Inc. All rights reserved.

Volumetric Trends Associated with MR-guided Stereotactic Laser Amygdalohippocampectomy in Mesial Temporal Lobe Epilepsy

PubMed Central

Patel, Nitesh V; Sundararajan, Sri; Keller, Irwin; Danish, Shabbar

2018-01-01

Objective: Magnetic resonance (MR)-guided stereotactic laser amygdalohippocampectomy is a minimally invasive procedure for the treatment of refractory epilepsy in patients with mesial temporal sclerosis. Limited data exist on post-ablation volumetric trends associated with the procedure. Methods: 10 patients with mesial temporal sclerosis underwent MR-guided stereotactic laser amygdalohippocampectomy. Three independent raters computed ablation volumes at the following time points: pre-ablation (PreA), immediate post-ablation (IPA), 24 hours post-ablation (24PA), first follow-up post-ablation (FPA), and greater than three months follow-up post-ablation (>3MPA), using OsiriX DICOM Viewer (Pixmeo, Bernex, Switzerland). Statistical trends in post-ablation volumes were determined for the time points. Results: MR-guided stereotactic laser amygdalohippocampectomy produces a rapid rise and distinct peak in post-ablation volume immediately following the procedure. IPA volumes are significantly higher than all other time points. Comparing individual time points within each raters dataset (intra-rater), a significant difference was seen between the IPA time point and all others. There was no statistical difference between the 24PA, FPA, and >3MPA time points. A correlation analysis demonstrated the strongest correlations at the 24PA (r=0.97), FPA (r=0.95), and 3MPA time points (r=0.99), with a weaker correlation at IPA (r=0.92). Conclusion: MR-guided stereotactic laser amygdalohippocampectomy produces a maximal increase in post-ablation volume immediately following the procedure, which decreases and stabilizes at 24 hours post-procedure and beyond three months follow-up. Based on the correlation analysis, the lower inter-rater reliability at the IPA time point suggests it may be less accurate to assess volume at this time point. We recommend post-ablation volume assessments be made at least 24 hours post-selective ablation of the amygdalohippocampal complex (SLAH).

Nonlinear correlations impair quantification of episodic memory by mesial temporal BOLD activity.

PubMed

Klamer, Silke; Zeltner, Lena; Erb, Michael; Klose, Uwe; Wagner, Kathrin; Frings, Lars; Groen, Georg; Veil, Cornelia; Rona, Sabine; Lerche, Holger; Milian, Monika

2013-07-01

Episodic memory processes can be investigated using different functional MRI (fMRI) paradigms. The purpose of the present study was to examine correlations between neuropsychological memory test scores and BOLD signal changes during fMRI scanning using three different memory tasks. Twenty-eight right-handed healthy subjects underwent three paradigms, (a) a word pair, (b) a space-labyrinth, and (c) a face-name association paradigm. These paradigms were compared for their value in memory quantification and lateralization by calculating correlations between the BOLD signals in the mesial temporal lobe and behavioral data derived from a neuropsychological test battery. As expected, group analysis showed left-sided activation for the verbal, a tendency to right-sided activation for the spatial, and bilateral activation for the face-name paradigm. No linear correlations were observed between neuropsychological data and activation in the temporo-mesial region. However, we found significant u-shaped correlations between behavioral memory performance and activation in both the verbal and the face-name paradigms, that is, BOLD signal changes were greater not only among participants who performed best on the neuropsychological tests, but also among the poorest performers. The figural learning task did not correlate with the activations in the space-labyrinth paradigm at all. We interpreted the u-shaped correlations to be due to compensatory hippocampal activations associated with low performance when people try unsuccessfully to remember presented items. Because activation levels did not linearly increase with memory performance, the latter cannot be quantified by fMRI alone, but only be used in conjunction with neuropsychological testing. PsycINFO Database Record (c) 2013 APA, all rights reserved.

EPILEPSY SURGERY IN DRUG RESISTANT TEMPORAL LOBE EPILEPSY ASSOCIATED WITH NEURONAL ANTIBODIES

PubMed Central

Carreño, Mar; Bien, Christian; Asadi-Pooya, Ali A.; Sperling, Michael; Marusic, Petr.; Elisak, Martin; Pimentel, Jose; Wehner, Tim; Mohanraj, Rajiv; Uranga, Juan; Gómez-Ibáñez, Asier; Villanueva, Vicente; Gil, Francisco; Donaire, Antonio; Bargalló, Nuria; Rumià, Jordi; Roldán, Pedro; Setoain, Xavier; Pintor, Luis; Boget, Teresa; Bailles, Eva; Falip, Mercè; Aparicio, Javier; Dalmau, Josep; Graus, Francesc

2017-01-01

We assessed the outcome of patients with drug resistant epilepsy and neuronal antibodies who underwent epilepsy surgery. Retrospective study, information collected with a questionnaire sent to epilepsy surgery centers. Thirteen patients identified, with antibodies to GAD (8), Ma2 (2), Hu (1), LGI1 (1) or CASPR2 (1). Mean age at seizure onset: 23 years. Five patients had an encephalitic phase. Three had testicular tumors and five had autoimmune diseases. All had drug resistant temporal lobe epilepsy (median: 20 seizures/month). MRI showed unilateral temporal lobe abnormalities (mainly hippocampal sclerosis) in 9 patients, bilateral abnormalities in 3, and was normal in 1. Surgical procedures included anteromesial temporal lobectomy (10 patients), selective amygdalohippocampectomy (1), temporal pole resection (1) and radiofrequency ablation of mesial structures (1). Perivascular lymphocytic infiltrates were seen in 7/12 patients. One year outcome available in all patients, at 3 years in 9. At last visit 5/13 patients (38.5%) (with Ma2, Hu, LGI1, and 2 GAD antibodies) were in Engel`s classes I or II. Epilepsy surgery may be an option for patients with drug resistant seizures associated with neuronal antibodies. Outcome seems to be worse than that expected in other etiologies, even in the presence of unilateral HS. Intracranial EEG may be required in some patients. PMID:28043058

The neuropsychology of the Klüver-Bucy syndrome in children.

PubMed

Lippe, S; Gonin-Flambois, C; Jambaqué, I

2013-01-01

The Klüver-Bucy syndrome (KBS) is characterized by a number of peculiar behavioral symptoms. The syndrome was first observed in 1939 by Heinrich Klüver and Paul Bucy in the rhesus monkey following removal of the greater portion of the monkey's temporal lobes and rhinencephalon. The animal showed (a) visual agnosia (inability to recognize objects without general loss of visual discrimination), (b) excessive oral tendency (oral exploration of objects), (c) hypermetamorphosis (excessive visual attentiveness), (d) placidity with loss of normal fear and anger responses, (e) altered sexual behavior manifesting mainly as marked and indiscriminate hypersexuality, and (f) changes in eating behavior. In humans, KBS can be complete or incomplete. It occurs as a consequence of neurological disorders that essentially cause destruction or dysfunction of bilateral mesial temporal lobe structures (i.e., Pick disease, Alzheimer disease, cerebral trauma, cerebrovascular accidents, temporal lobe epilepsy, herpetic encephalopathy, heat stroke). As for epilepsy, complete and incomplete KBS are well documented in temporal lobe epilepsy, temporal lobectomy, and partial status epilepticus. KBS can occur at any age. Children seem to show similar symptoms to adults, although some differences in the manifestations of symptoms may be related to the fact that children have not yet learned certain behaviors. Copyright © 2013 Elsevier B.V. All rights reserved.

Epilepsy diagnostic and treatment needs identified with a collaborative database involving tertiary centers in France.

PubMed

Chipaux, Mathilde; Szurhaj, William; Vercueil, Laurent; Milh, Mathieu; Villeneuve, Nathalie; Cances, Claude; Auvin, Stéphane; Chassagnon, Serge; Napuri, Sylvia; Allaire, Catherine; Derambure, Philippe; Marchal, Cécile; Caubel, Isabelle; Ricard-Mousnier, Brigitte; N'Guyen The Tich, Sylvie; Pinard, Jean-Marc; Bahi-Buisson, Nadia; de Baracé, Claire; Kahane, Philippe; Gautier, Agnès; Hamelin, Sophie; Coste-Zeitoun, Delphine; Rosenberg, Sarah-Dominique; Clerson, Pierre; Nabbout, Rima; Kuchenbuch, Mathieu; Picot, Marie-Christine; Kaminska, Anna

2016-05-01

To obtain perspective on epilepsy in patients referred to tertiary centers in France, and describe etiology, epilepsy syndromes, and identify factors of drug resistance and comorbidities. We performed a cross-sectional analysis of the characteristics of 5,794 pediatric and adult patients with epilepsy included in a collaborative database in France between 2007 and 2013. Comparisons between groups used Student's t-test or Fisher's exact test for binary or categorical variables. Factors associated with drug resistance and intellectual disability were evaluated in multi-adjusted logistic regression models. Mean age at inclusion was 17.9 years; children accounted for 67%. Epilepsy was unclassified in 20% of patients, and etiology was unknown in 65%, including those with idiopathic epilepsies. Etiologies differed significantly in adult- when compared to pediatric-onset epilepsy; however, among focal structural epilepsies, mesial temporal lobe epilepsy with hippocampal sclerosis began as often in the pediatric as in adult age range. Drug resistance concerned 53% of 4,210 patients evaluable for seizure control and was highest in progressive myoclonic epilepsy (89%), metabolic diseases (84%), focal cortical dysplasia (70%), other cortical malformations (69%), and mesial temporal lobe epilepsy with hippocampal sclerosis (67%). Fifty-nine percent of patients with focal structural epilepsy and 69% with epileptic encephalopathies were drug resistant; however, 40-50% of patients with West syndrome and epileptic encephalopathy with continuous spike-and-waves during sleep were seizure-free. Ages at onset in infancy and in young adults shared the highest risk of drug resistance. Epilepsy onset in infancy comprised the highest risk of intellectual disability, whereas specific cognitive impairment affected 36% of children with idiopathic focal epilepsy. Our study provides a snapshot on epilepsy in patients referred to tertiary centers and discloses needs for diagnosis and treatment. Large databases help identify patients with rare conditions that could benefit from specific prospective studies. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Neuropsychological functioning in children with temporal lobe epilepsy and hippocampal atrophy without mesial temporal sclerosis: a distinct clinical entity?

PubMed

Schmidt, Charlotte S M; Lassonde, Maryse; Gagnon, Louise; Sauerwein, Catherine H; Carmant, Lionel; Major, Philippe; Paquette, Natacha; Lepore, Franco; Gallagher, Anne

2015-03-01

Unilateral hippocampal atrophy (HA) is considered as a precursor of mesial temporal sclerosis (MTS) in some patients with temporal lobe epilepsy. However, in other cases, it has been suggested that HA without MTS may constitute a distinct epileptic entity. Hippocampal atrophy without MTS was defined as HA without T2-weighted hyperintensity, loss of internal architecture, or associated lesion seen on the MRI data. To date, no study has focused on the cognitive pattern of children with epilepsy with HA without MTS. The objectives of the present study were to characterize the cognitive profile of these children and to investigate the presence (or the absence) of material-specific memory deficits in these young patients, as found in patients with MTS. Toward this end, 16 young patients with epilepsy with either left or right HA without MTS completed a set of neuropsychological tests, assessing overall intelligence, verbal memory and nonverbal memory, and some aspects of attention and executive functions. Results showed normal intellectual functioning without specific memory deficits in these patients. Furthermore, comparison between patients with left HA and patients with right HA failed to reveal a material-specific lateralized memory pattern. Instead, attention and executive functions were found to be impaired in most patients. These results suggest that HA may constitute a distinct epileptic entity, and this information may help health-care providers initiate appropriate and timely interventions. Copyright © 2014 Elsevier Inc. All rights reserved.

Widespread extrahippocampal NAA/(Cr+Cho) abnormalities in TLE with and without mesial temporal sclerosis.

PubMed

Mueller, Susanne G; Ebel, Andreas; Barakos, Jerome; Scanlon, Cathy; Cheong, Ian; Finlay, Daniel; Garcia, Paul; Weiner, Michael W; Laxer, Kenneth D

2011-04-01

MR spectroscopy has demonstrated extrahippocampal NAA/(Cr+Cho) reductions in medial temporal lobe epilepsy with (TLE-MTS) and without (TLE-no) mesial temporal sclerosis. Because of the limited brain coverage of those previous studies, it was, however, not possible to assess differences in the distribution and extent of these abnormalities between TLE-MTS and TLE-no. This study used a 3D whole brain echoplanar spectroscopic imaging (EPSI) sequence to address the following questions: (1) Do TLE-MTS and TLE-no differ regarding severity and distribution of extrahippocampal NAA/(Cr+Cho) reductions? (2) Do extrahippocampal NAA/(Cr+Cho) reductions provide additional information for focus lateralization? Forty-three subjects (12 TLE-MTS, 13 TLE-no, 18 controls) were studied with 3D EPSI. Statistical parametric mapping (SPM2) was used to identify regions of significantly decreased NAA/(Cr+Cho) in TLE groups and in individual patients. TLE-MTS and TLE-no had widespread extrahippocampal NAA/(Cr+Cho) reductions. NAA/(Cr+Cho) reductions had a bilateral fronto-temporal distribution in TLE-MTS and a more diffuse, less well defined distribution in TLE-no. Extrahippocampal NAA/(Cr+Cho) decreases in the single subject analysis showed a large inter-individual variability and did not provide additional focus lateralizing information. Extrahippocampal NAA/(Cr+Cho) reductions in TLE-MTS and TLE-no are neither focal nor homogeneous. This reduces their value for focus lateralization and suggests a heterogeneous etiology of extrahippocampal spectroscopic metabolic abnormalities in TLE.

Spike voltage topography in temporal lobe epilepsy.

PubMed

Asadi-Pooya, Ali A; Asadollahi, Marjan; Shimamoto, Shoichi; Lorenzo, Matthew; Sperling, Michael R

2016-07-15

We investigated the voltage topography of interictal spikes in patients with temporal lobe epilepsy (TLE) to see whether topography was related to etiology for TLE. Adults with TLE, who had epilepsy surgery for drug-resistant seizures from 2011 until 2014 at Jefferson Comprehensive Epilepsy Center were selected. Two groups of patients were studied: patients with mesial temporal sclerosis (MTS) on MRI and those with other MRI findings. The voltage topography maps of the interictal spikes at the peak were created using BESA software. We classified the interictal spikes as polar, basal, lateral, or others. Thirty-four patients were studied, from which the characteristics of 340 spikes were investigated. The most common type of spike orientation was others (186 spikes; 54.7%), followed by lateral (146; 42.9%), polar (5; 1.5%), and basal (3; 0.9%). Characteristics of the voltage topography maps of the spikes between the two groups of patients were somewhat different. Five spikes in patients with MTS had polar orientation, but none of the spikes in patients with other MRI findings had polar orientation (odds ratio=6.98, 95% confidence interval=0.38 to 127.38; p=0.07). Scalp topographic mapping of interictal spikes has the potential to offer different information than visual inspection alone. The present results do not allow an immediate clinical application of our findings; however, detecting a polar spike in a patient with TLE may increase the possibility of mesial temporal sclerosis as the underlying etiology. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of four instruments on coronal pre-enlargement by using cone beam computed tomography.

PubMed

Sanfelice, Cintia Mussoline; da Costa, Fernanda Botega; Reis Só, Marcus Vinícius; Vier-Pelisser, Fabiana; Souza Bier, Carlos Alexandre; Grecca, Fabiana Soares

2010-05-01

This ex vivo study used cone beam computed tomography to evaluate the amount of dentin removal from the distal wall of the mesial canal of human mandibular first molars caused by 4 instruments used to flare the cervical third. Thirty-two mesial roots were divided into 4 groups prepared by using ProTaper, K3, Gates-Glidden, or LA Axxess. The dentin thickness of the distal cervical wall of mesial canals was measured before and after the preparation by using computed tomography and Adobe Photoshop software. There was no statistically significant difference between the study groups (P > 05). All the instruments used for cervical preparation seemed to be safe and did not damage the dentin structure of the distal wall of mesial root canals of mandibular molars. Copyright (c) 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Neural correlates of mirth and laughter: a direct electrical cortical stimulation study.

PubMed

Yamao, Yukihiro; Matsumoto, Riki; Kunieda, Takeharu; Shibata, Sumiya; Shimotake, Akihiro; Kikuchi, Takayuki; Satow, Takeshi; Mikuni, Nobuhiro; Fukuyama, Hidenao; Ikeda, Akio; Miyamoto, Susumu

2015-05-01

Laughter consists of both motor and emotional aspects. The emotional component, known as mirth, is usually associated with the motor component, namely, bilateral facial movements. Previous electrical cortical stimulation (ES) studies revealed that mirth was associated with the basal temporal cortex, inferior frontal cortex, and medial frontal cortex. Functional neuroimaging implicated a role for the left inferior frontal and bilateral temporal cortices in humor processing. However, the neural origins and pathways linking mirth with facial movements are still unclear. We hereby report two cases with temporal lobe epilepsy undergoing subdural electrode implantation in whom ES of the left basal temporal cortex elicited both mirth and laughter-related facial muscle movements. In one case with normal hippocampus, high-frequency ES consistently caused contralateral facial movement, followed by bilateral facial movements with mirth. In contrast, in another case with hippocampal sclerosis (HS), ES elicited only mirth at low intensity and short duration, and eventually laughter at higher intensity and longer duration. In both cases, the basal temporal language area (BTLA) was located within or adjacent to the cortex where ES produced mirth. In conclusion, the present direct ES study demonstrated that 1) mirth had a close relationship with language function, 2) intact mesial temporal structures were actively engaged in the beginning of facial movements associated with mirth, and 3) these emotion-related facial movements had contralateral dominance. Copyright © 2014 Elsevier Ltd. All rights reserved.

Modifications of EEG power spectra in mesial temporal lobe during n-back tasks of increasing difficulty. A sLORETA study.

PubMed

Imperatori, Claudio; Farina, Benedetto; Brunetti, Riccardo; Gnoni, Valentina; Testani, Elisa; Quintiliani, Maria I; Del Gatto, Claudia; Indraccolo, Allegra; Contardi, Anna; Speranza, Anna M; Della Marca, Giacomo

2013-01-01

The n-back task is widely used to investigate the neural basis of Working Memory (WM) processes. The principal aim of this study was to explore and compare the EEG power spectra during two n-back tests with different levels of difficulty (1-back vs. 3-back). Fourteen healthy subjects were enrolled (seven men and seven women, mean age 31.21 ± 7.05 years, range: 23-48). EEG was recorded while performing the N-back test, by means of 19 surface electrodes referred to joint mastoids. EEG analysis were conducted by means of the standardized Low Resolution brain Electric Tomography (sLORETA) software. The statistical comparison between EEG power spectra in the two conditions was performed using paired t-statistics on the coherence values after Fisher's z transformation available in the LORETA program package. The frequency bands considered were: delta (0.5-4 Hz); theta (4.5-7.5 Hz); alpha (8-12.5 Hz); beta (13-30 Hz); gamma (30.5-100 Hz). Significant changes occurred in the delta band: in the 3-back condition an increased delta power was localized in a brain region corresponding to the Brodmann Area (BA) 28 in the left posterior entorhinal cortex (T = 3.112; p < 0.05) and in the BA 35 in the left perirhinal cortex in the parahippocampal gyrus (T = 2.876; p < 0.05). No significant differences were observed in the right hemisphere and in the alpha, theta, beta, and gamma frequency bands. Our results indicate that the most prominent modification induced by the increased complexity of the task occur in the mesial left temporal lobe structures.

Volumetric magnetic resonance imaging evidence of bilateral hippocampal atrophy in mesial temporal lobe epilepsy.

PubMed

Quigg, M; Bertram, E H; Jackson, T; Laws, E

1997-05-01

We measured absolute volumes and volume differences of hippocampi in patients with mesial temporal lobe epilepsy (MTLE) using volumetric magnetic resonance imaging (MRI) to determine the extent of bilateral atrophy in MTLE and to relate hippocampal volumes (HV) to outcome of temporal lobectomy. HV and hippocampal differences (HD) were measured in 40 patients with MTLE determined by pathology of hippocampal sclerosis (HS) and compared with those of age-matched controls. Results were matched with surgical outcome. Hippocampi contralateral to lobectomy (right hippocampi 2.96 +/- 0.49 cm3, left 3.14 +/- 0.51 cm3) were significantly smaller than those of controls (right hippocampi 3.73 +/- 0.52 cm3, left 3.60 +/- 0.51 cm3) but were significantly larger than hippocampi ipsilateral to lobectomy (right hippocampi 2.63 +/- 0.61 cm3, 2.18 cm3) as compared across groups by analysis of variance (ANOVA: F = 27.2, p < 0.0001). The smaller hippocampus was ipsilateral to lobectomy in 39 of 40 cases. Seven of 40 MTLE patients (18%) had bilateral atrophy, defined by volumes of each hippocampi 2 SD lower than control means. Surgical outcome was independent of hippocampal asymmetry and bilateral atrophy measured by chi-square and Fisher's exact tests. We determined that most patients with MTLE have some degree of bilateral, asymmetric hippocampal pathology. However, asymmetry and bilateral atrophy have no clear relation to surgical outcome.

Historical Risk Factors Associated with Seizure Outcome After Surgery for Drug-Resistant Mesial Temporal Lobe Epilepsy.

PubMed

Asadi-Pooya, Ali A; Nei, Maromi; Sharan, Ashwini; Sperling, Michael R

2016-05-01

To investigate the possible influence of risk factors on seizure outcome after surgery for drug-resistant temporal lobe epilepsy (TLE) and mesial temporal sclerosis (MTS). This retrospective study recruited patients with drug-resistant MTS-TLE who underwent epilepsy surgery at Jefferson Comprehensive Epilepsy Center and were followed for a minimum of 1 year. Patients had been prospectively registered in a database from 1986 through 2014. After surgery outcome was classified into 2 groups: seizure-free or relapsed. The possible risk factors influencing long-term outcome after surgery were investigated. A total of 275 patients with MTS-TLE were studied. Two thirds of the patients had Engel's class 1 outcome and 48.4% of the patients had sustained seizure freedom, with no seizures since surgery. Patients with a history of tonic-clonic seizures in the year preceding surgery were more likely to experience seizure recurrence (odds ratio, 2.4; 95% confidence interval 1.19-4.80; P = 0.01). Gender, race, family history of epilepsy, history of febrile seizure, history of status epilepticus, duration of disease before surgery, intelligence quotient, and seizure frequency were not predictors of outcome. Many patients with drug-resistant MTS-TLE respond favorably to surgery. It is critical to distinguish among different types and etiologies of TLE when predicting outcome after surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

Selective amygdalohippocampectomy versus standard temporal lobectomy in patients with mesiotemporal lobe epilepsy and unilateral hippocampal sclerosis: post-operative facial emotion recognition abilities.

PubMed

Wendling, Anne-Sophie; Steinhoff, Bernhard J; Bodin, Frédéric; Staack, Anke M; Zentner, Josef; Scholly, Julia; Valenti, Maria-Paula; Schulze-Bonhage, Andreas; Hirsch, Edouard

2015-03-01

Surgical treatment of mesial temporal lobe epilepsy (mTLE) patients involves the removal either of the left or the right hippocampus. Since the mesial temporal lobe is responsible for emotion recognition abilities, we aimed to assess facial emotion recognition (FER) in two homogeneous patient cohorts that differed only in the administered surgery design since anterior temporal lobectomy (ATL) or selective amygdalohippocampectomy (SAH) were performed independently of the underlying electroclinical conditions. The patient selection for the two respective surgical procedures was carried out retrospectively between 2000 and 2009 by two independent epilepsy centres, the Kork Epilepsy Centre, Germany and the University Hospital of Strasbourg, France. All included patients had presented with unilateral hippocampus sclerosis (HS) without associated dysplasia or white matter blurring and had become seizure-free postoperatively. Psychometric evaluation was carried out with the Ekman 60 Faces Test and screened for depression and psychosomatic symptoms with the SCL-90 R and the BDI. Thirty healthy volunteers participated as control subjects. Sixty patients were included, 27 had undergone SAH and 33 ATL. Patients and controls obtained comparable scores in FER for surprise, happiness, anger and sadness. Concerning fear and disgust the patient group scored significantly worse. Left-sided operations led to the the most pronounced impairment. The ATL group scored significantly worse for recognition of fear compared with SAH patients. Inversely, after SAH scores for disgust were significantly lower than after ATL, independently of the side of resection. Unilateral temporal damage impairs FER. Different neurosurgical procedures may affect FER differently. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of EEG Biofeedback on Cognitive Flexibility in Children with Attention Deficit Hyperactivity Disorder With and Without Epilepsy.

PubMed

Bakhtadze, Sophia; Beridze, Maia; Geladze, Nana; Khachapuridze, Nana; Bornstein, Natan

2016-03-01

Attention deficit hyperactivity disorder (ADHD) is one of the most common developmental disorders in school-aged children. Symptoms consistent with ADHD have been observed in 8-77 % of children with epilepsy. Researchers have been motivated to search for alternative forms of treatment because 30 % of patients with ADHD cannot be treated by psychostimulants. Several studies support the use of a multimodal treatment approach that includes neurofeedback (NF) for the long-term management of ADHD. These studies have shown that NF provides a sustained effect, even without concurrent treatment with stimulants. We aimed to assess cognitive flexibility in ADHD children with and without temporal lobe epilepsy (TLE), and to evaluate the effects of NF on cognitive flexibility in these groups of children. We prospectively evaluated 69 patients with ADHD aged 9-12 years. The control group was 26 ADHD children without TLE who received no treatment. The first experimental group comprised 18 children with ADHD. The second experimental group comprised 25 age-matched ADHD children with TLE. This group was further divided in two subgroups. One subgroup comprised those with mesial temporal lobe epilepsy (16 patients, 9 with hippocampal sclerosis and 7 with hippocampal atrophy), and the other with lateral temporal lobe epilepsy (9 patients, 5 with temporal lobe dysplasia, 3 with temporal lobe cysts, and 1 with a temporal lobe cavernoma). We treated their ADHD by conducting 30 sessions of EEG NF. Reaction time and error rates on the Trail Making Test Part B were compared before and after treatment, and significant differences were found for all groups of patients except those who had mesial temporal lobe epilepsy with hippocampal atrophy. Our results demonstrate that in most cases, NF can be considered an alternative treatment option for ADHD children even if they have TLE. Additional studies are needed to confirm our results.

Sleep affects cortical source modularity in temporal lobe epilepsy: A high-density EEG study.

PubMed

Del Felice, Alessandra; Storti, Silvia Francesca; Manganotti, Paolo

2015-09-01

Interictal epileptiform discharges (IEDs) constitute a perturbation of ongoing cerebral rhythms, usually more frequent during sleep. The aim of the study was to determine whether sleep influences the spread of IEDs over the scalp and whether their distribution depends on vigilance-related modifications in cortical interactions. Wake and sleep 256-channel electroencephalography (EEG) data were recorded in 12 subjects with right temporal lobe epilepsy (TLE) differentiated by whether they had mesial or neocortical TLE. Spikes were selected during wake and sleep. The averaged waking signal was subtracted from the sleep signal and projected on a bidimensional scalp map; sleep and wake spike distributions were compared by using a t-test. The superimposed signal of sleep and wake traces was obtained; the rising phase of the spike, the peak, and the deflections following the spike were identified, and their cortical generator was calculated using low-resolution brain electromagnetic tomography (LORETA) for each group. A mean of 21 IEDs in wake and 39 in sleep per subject were selected. As compared to wake, a larger IED scalp projection was detected during sleep in both mesial and neocortical TLE (p<0.05). A series of EEG deflections followed the spike, the cortical sources of which displayed alternating activations of different cortical areas in wake, substituted by isolated, stationary activations in sleep in mesial TLE and a silencing in neocortical TLE. During sleep, the IED scalp region increases, while cortical interaction decreases. The interaction of cortical modules in sleep and wake in TLE may influence the appearance of IEDs on scalp EEG; in addition, IEDs could be proxies for cerebral oscillation perturbation. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Termination Patterns of Complex Partial Seizures: An Intracranial EEG Study

PubMed Central

Afra, Pegah; Jouny, Christopher C.; Bergey, Gregory K.

2015-01-01

Purpose While seizure onset patterns have been the subject of many reports, there have been few studies of seizure termination. In this study we report the incidence of synchronous and asynchronous termination patterns of partial seizures recorded with intracranial arrays. Methods Data were collected from patients with intractable complex partial seizures undergoing presurgical evaluations with intracranial electrodes. Patients with seizures originating from mesial temporal and neocortical regions were grouped into three groups based on patterns of seizure termination: synchronous only (So), asynchronous only (Ao), or mixed (S/A, with both synchronous and asynchronous termination patterns). Results 88% of the patients in the MT group had seizures with a synchronous pattern of termination exclusively (38%) or mixed (50%). 82% of the NC group had seizures with synchronous pattern of termination exclusively (52%) or mixed (30%). In the NC group, there was a significant difference of the range of seizure durations between So and Ao groups, with Ao exhibiting higher variability. Seizures with synchronous termination had low variability in both groups. Conclusions Synchronous seizure termination is a common pattern for complex partial seizures of both mesial temporal or neocortical onset. This may reflect stereotyped network behavior or dynamics at the seizure focus. PMID:26552555

Atypical handedness in mesial temporal lobe epilepsy.

PubMed

Doležalová, Irena; Schachter, Steven; Chrastina, Jan; Hemza, Jan; Hermanová, Markéta; Rektor, Ivan; Pažourková, Marta; Brázdil, Milan

2017-07-01

The main aim of our study was to investigate the handedness of patients with mesial temporal lobe epilepsy (MTLE). We also sought to identify clinical variables that correlated with left-handedness in this population. Handedness (laterality quotient) was assessed in 73 consecutive patients with MTLE associated with unilateral hippocampal sclerosis (HS) using the Edinburgh Handedness Inventory. Associations between right- and left-handedness and clinical variables were investigated. We found that 54 (74.0%) patients were right-handed, and 19 (26%) patients were left-handed. There were 15 (36.6%) left-handed patients with left-sided seizure onset compared to 4 (12.5%) left-handed patients with right-sided seizure onset (p=0.030). Among patients with left-sided MTLE, age at epilepsy onset was significantly correlated with handedness (8years of age [median; min-max 0.5-17] in left-handers versus 15years of age [median; min-max 3-30] in right-handers (p<0.001). Left-sided MTLE is associated with atypical handedness, especially when seizure onset occurs during an active period of brain development, suggesting a bi-hemispheric neuroplastic process for establishing motor dominance in patients with early-onset left-sided MTLE. Copyright © 2017 Elsevier Inc. All rights reserved.

Neurosyphilis: mighty imitator forays with benign presentation and unique neuroimaging findings.

PubMed

Tiwana, Harmanpreet; Ahmed, Aiesha

2018-04-30

Background: Common causes of temporal lobe hyper intensities are central nervous system infections like herpes simplex encephalitis, Lyme disease, limbic encephalitis and vascular pathology like Cerebral Autosomal Dominant Arteriopathy with Subcortical infarcts and Leukoencephalopathy. Methods: Personal assessment, laboratory data analysis and neuroimaging for the patient who was admitted to a central Pennsylvania tertiary care referral centre were conducted. Results: A 52-year-old male presented with a 1-year history of diffuse dysesthesia in upper and lower extremities with associated intermittent headaches and neck stiffness. Evaluation with lumbar puncture revealed increased nucleated cells (50ul) with lymphocytic predominance (96%) and an elevated protein level of 109mg/dl. Magnetic resonance imaging (MRI) of the brain showed T2/FLAIR hyper intensity in bilateral subcortical temporal white matter, left-greater-than-right and associated volume loss in cerebral parenchyma. Additional abnormal work up included reactive serum reactive plasma regain and Treponema pallidum antibody particle agglutination. Diagnosis of neurosyphilis was made and the patient was treated with intramuscular (IM) penicillin for 3 weeks. At the time of discharge, his headache and neck stiffness resolved and dysesthesias were decreased in intensity. Conclusions: The diagnosis of neurosyphilis is intricate, and no reference standard exists. Neuroimaging findings of neurosyphilis commonly are cerebral infarctions, leptomeningeal enhancement or non-specific white matter lesions. Less common features on fluid-attenuated inversion recovery (FLAIR) sequences are cortical atrophy and mesial temporal parenchymal signal changes. It is prudent to keep neurosyphilis in differential of mesial temporal lobe white matter changes, as early diagnosis and treatment results in better prognosis.

Long-term outcome of surgical disconnection of the epileptic zone as an alternative to resection for nonlesional mesial temporal epilepsy.

PubMed

Massager, Nicolas; Tugendhaft, Patrick; Depondt, Chantal; Coppens, Thomas; Drogba, Landry; Benmebarek, Nadir; De Witte, Olivier; Van Bogaert, Patrick; Legros, Benjamin

2013-12-01

Pharmacoresistant epilepsy can be treated by either resection of the epileptic focus or functional isolation of the epileptic focus through complete disconnection of the pathways of propagation of the epileptic activity. To evaluate long-term seizure outcome and complications of temporal lobe disconnection (TLD) without resection for mesial temporal lobe epilepsy (MTLE). Data of 45 patients operated on for intractable MTLE using a functional disconnection procedure have been studied. Indication of TLD surgery was retained after a standard preoperative evaluation of refractory epilepsy and using the same criteria as for standard temporal resection. Mean follow-up duration was 3.7 years. At the last follow-up, 30 patients (67%) were completely seizure-free (Engel-Ia/International League Against Epilepsy class 1) and 39 patients (87%) remained significantly improved (Engel-I or -II) by surgery. Actuarial outcome displays a 77.7% probability of being seizure-free and an 85.4% probability of being significantly improved at 5 years. No patient died after surgery and no subdural haematoma or hygroma occurred. Permanent morbidity included hemiparesis, hemianopia and oculomotor paresis found in three, five and one patient, respectively, after TLD. TLD is acceptable alternative surgical technique for patients with intractable MTLE. The results of TLD are in the range of morbidity and long-term seizure outcome rates after standard surgical resection. We observed a slightly higher rate of complications after TLD in comparison with usual rates of morbidity of resection procedures. TLD may be used as an alternative to resection and could reduce operating time and the risks of subdural collections.

Pre- and post-operative Wisconsin card sorting test performance in patients with temporal lobe epilepsy due to hippocampal sclerosis

PubMed Central

Tisser, Luciana; Palmini, Andre; Paglioli, Eliseu; Portuguez, Mirna; Azambuja, Ney; da Costa, Jaderson Costa; Paglioli, Eduardo; Torres, Carolina; Martinez, Jose Victor

2007-01-01

Patients with temporal lobe epilepsy due to hippocampal sclerosis (TLE/HS) have a distinct neuropsychological profile, but there is still debate on whether executive dysfunction is part of this profile and also whether temporal lobe surgery can modify this dysfunction. Objective To study the presence and reversibility of executive dysfunction in patients with unilateral TLE/HS. Methods Twenty-five patients with refractory seizures due to TLE/HS underwent presurgical evaluation which included the application of the Wiconsin Card Sorting Test (WCST). Nineteen were re-evaluated in follow up, at least 6 months after selective amygdalo-hippocampectomy (SAH). Twenty-two control subjects matched for age and education also performed the WCST. Results Sixteen of the 25 patients (64%) completed fewer than four categories in the WCST whereas only 4 of the 22 controls (18%) did not complete at least four categories (p<0.005). In addition, the performance of the patients involved significantly more perseverative responses and errors compared to controls. The patient group demonstrated significant post-operative improvement in many measures of the WCST following SAH. Conclusions These findings support the presence of executive dysfunction in patients with TLE/HS and suggest that such dysfunction can be partially reversed by selective resection of epileptogenic mesial temporal structures. PMID:29213385

Functional network alterations and their structural substrate in drug-resistant epilepsy

PubMed Central

Caciagli, Lorenzo; Bernhardt, Boris C.; Hong, Seok-Jun; Bernasconi, Andrea; Bernasconi, Neda

2014-01-01

The advent of MRI has revolutionized the evaluation and management of drug-resistant epilepsy by allowing the detection of the lesion associated with the region that gives rise to seizures. Recent evidence indicates marked chronic alterations in the functional organization of lesional tissue and large-scale cortico-subcortical networks. In this review, we focus on recent methodological developments in functional MRI (fMRI) analysis techniques and their application to the two most common drug-resistant focal epilepsies, i.e., temporal lobe epilepsy related to mesial temporal sclerosis and extra-temporal lobe epilepsy related to focal cortical dysplasia. We put particular emphasis on methodological developments in the analysis of task-free or “resting-state” fMRI to probe the integrity of intrinsic networks on a regional, inter-regional, and connectome-wide level. In temporal lobe epilepsy, these techniques have revealed disrupted connectivity of the ipsilateral mesiotemporal lobe, together with contralateral compensatory reorganization and striking reconfigurations of large-scale networks. In cortical dysplasia, initial observations indicate functional alterations in lesional, peri-lesional, and remote neocortical regions. While future research is needed to critically evaluate the reliability, sensitivity, and specificity, fMRI mapping promises to lend distinct biomarkers for diagnosis, presurgical planning, and outcome prediction. PMID:25565942

Non ictal onset zone: A window to ictal dynamics.

PubMed

Afra, Pegah; Hanrahan, Sara J; Kellis, Spencer Sterling; House, Paul

2017-01-01

The focal and network concepts of epilepsy present different aspects of electroclinical phenomenon of seizures. Here, we present a 23-year-old man undergoing surgical evaluation with left fronto-temporal electrocorticography (ECoG) and microelectrode-array (MEA) in the middle temporal gyrus (MTG). We compare action-potential (AP) and local field potentials (LFP) recorded from MEA with ECoG. Seizure onset in the mesial-temporal lobe was characterized by changes in the pattern of AP-firing without clear changes in LFP or ECoG in MTG. This suggests simultaneous analysis of neuronal activity in differing spatial scales and frequency ranges provide complementary insights into how focal and network neurophysiological activity contribute to ictal activity.

Epilepsy surgery in drug resistant temporal lobe epilepsy associated with neuronal antibodies.

PubMed

Carreño, Mar; Bien, Christian G; Asadi-Pooya, Ali A; Sperling, Michael; Marusic, Petr; Elisak, Martin; Pimentel, Jose; Wehner, Tim; Mohanraj, Rajiv; Uranga, Juan; Gómez-Ibáñez, Asier; Villanueva, Vicente; Gil, Francisco; Donaire, Antonio; Bargalló, Nuria; Rumià, Jordi; Roldán, Pedro; Setoain, Xavier; Pintor, Luis; Boget, Teresa; Bailles, Eva; Falip, Mercè; Aparicio, Javier; Dalmau, Josep; Graus, Francesc

2017-01-01

We assessed the outcome of patients with drug resistant epilepsy and neuronal antibodies who underwent epilepsy surgery. Retrospective study, information collected with a questionnaire sent to epilepsy surgery centers. Thirteen patients identified, with antibodies to GAD (8), Ma2 (2), Hu (1), LGI1 (1) or CASPR2 (1). Mean age at seizure onset: 23 years. Five patients had an encephalitic phase. Three had testicular tumors and five had autoimmune diseases. All had drug resistant temporal lobe epilepsy (median: 20 seizures/month). MRI showed unilateral temporal lobe abnormalities (mainly hippocampal sclerosis) in 9 patients, bilateral abnormalities in 3, and was normal in 1. Surgical procedures included anteromesial temporal lobectomy (10 patients), selective amygdalohippocampectomy (1), temporal pole resection (1) and radiofrequency ablation of mesial structures (1). Perivascular lymphocytic infiltrates were seen in 7/12 patients. One year outcome available in all patients, at 3 years in 9. At last visit 5/13 patients (38.5%) (with Ma2, Hu, LGI1, and 2 GAD antibodies) were in Engel's classes I or II. Epilepsy surgery may be an option for patients with drug resistant seizures associated with neuronal antibodies. Outcome seems to be worse than that expected in other etiologies, even in the presence of unilateral HS. Intracranial EEG may be required in some patients. Copyright © 2016 Elsevier B.V. All rights reserved.

[Clinical and pathological definition of temporal medium epilepsy subtypes with hypocampic sclerosis].

PubMed

Olivares-Granados, Gonzalo; Ríos-Pelegrina, Rosa María; Ruiz-Giménez, Jesús; Galdón-Castillo, Alberto; Escobar-Delgado, Teresa; García Del Moral, Raimundo

Mesial temporal lobe epilepsy with hippocampal sclerosis is the most common cause of refractory epilepsy, and the most common indication for surgery. Although effective, surgery fails in up to 40% of patients. The objective of our study was to establish a correlation between the different histological subtypes of mesial temporal lobe epilepsy with hippocampal sclerosis and the prognosis, seizures control, side effects and anticonvulsivant drug withdrawal in patients with refractory epilepsy. Clinical histories and anatomopathological specimens of 228 patients with temporal epilepsy surgically obtained at our hospital between 1993 and 2014 were retrospectively analysed. All patients underwent a standard preoperative evaluation and anterior temporal resection (modified from Spencer). The anatomopathological study included the standard hematoxylin-eosin and immunohistochemical protocol, with special interest in the assessment of neuronal loss with NeuN. Seizure control was assessed according to the scale of results of the ILAE and Engel. The mean follow-up was 8.6 years (2-19). At 10 years after the intervention, 67.9% of patients were seizure-free (ILAE 1) and as many as 77.5% of the patients were seizure-free (Engel 1) at the end of the follow-up. The probability of not having a seizure (ILAE 1) after surgery at 2 (p=.042), 5 (p=.001) and 7 years (p=.22) was higher in classic and severe forms compared to isolated sclerosis CA1 and CA4 forms. Higher neuronal loss measured with the NeuN immunostain in CA1 was associated with better outcome in seizure management (multivariate analysis, p=.08). The presence of a personal history of epilepsy was associated with greater neuronal loss in CA1 (p=.028) and CA3 (p=.034), and the presence of psychic auras was related with greater neuronal loss in CA3 (p=.025). In our case, the probability of medication withdrawal was related to the presence of personal history (p=.003) and, inversely, to neuronal loss in CA1 (p=.036) and CA3 (p=.038). The greatest impairment of verbal memory occurred in those patients with a lower neuronal loss in CA1 (p=.023), CA2 (p=.049) and CA3 (p=.035). The results indicate that the classical and severe subtypes have a better prognosis in the control of seizures against the atypical forms, validating the clinical and prognostic utility of the classification of histological subtypes of hippocampal sclerosis from the ILAE. The value of the immunohistochemistry in the mesial temporal lobe epilepsy with hippocampal sclerosis has been demonstrated as a key element to determine the neuropsychological prognosis and seizure management of the patients after surgery. Copyright © 2017 Sociedad Española de Neurocirugía. Publicado por Elsevier España, S.L.U. All rights reserved.

Decline in word-finding: The objective cognitive finding most relevant to patients after mesial temporal lobe epilepsy surgery.

PubMed

Pauli, Carla; de Oliveira Thais, Maria Emilia Rodrigues; Guarnieri, Ricardo; Schwarzbold, Marcelo Liborio; Diaz, Alexandre Paim; Ben, Juliana; Linhares, Marcelo Neves; Markowitsch, Hans Joachim; Wolf, Peter; Wiebe, Samuel; Lin, Katia; Walz, Roger

2017-10-01

The purpose of this study was to investigate the following: i) the objective impairment in neuropsychological tests that were associated with the subjective perception of cognitive function decline in Brazilian patients who underwent mesial temporal lobe epilepsy (MTLE) surgery and ii) the predictive variables for those impaired objective neuropsychological tests. Forty-eight adults with MTLE (27 right HS and 23 male) were divided according to their perception of changes (Decline or No-decline) of cognitive function domain of the QOLIE-31 questionnaire applied before and 1year after the ATL. The mean (SD) of changes in the raw score difference of the neuropsychological tests before and after the ATL was compared between Decline and No-decline groups. Receiver Operating Characteristic curves, sensitivity, specificity, and predictive values were used to assess the optimum cutoff points of neuropsychological test score changes to predict patient-reported subjective cognitive decline. Six (12.5%) patients reported a perception of cognitive function decline after ATL. Among the 25 cognitive tests analyzed, only changes in the Boston Naming Test (BNT) were associated with subjective cognitive decline reported by patients. A reduction of ≥8 points in the raw score of BNT after surgery had 91% of sensitivity and 45% specificity for predicting subjective perception of cognitive function decline by the patient. Left side surgery and age older than 40years were more associated with an important BNT reduction with overall accuracy of 91.7%, 95% predictive ability for no impairment, and 75% for impairment of cognitive function. Impairment in word-finding seems to be the objective cognitive finding most relevant to Brazilian patients after mesial temporal lobe epilepsy surgery. Similar to American patients, the side of surgery and age are good predictors for no decline in the BNT, but shows a lower accuracy to predict its decline. If replicated in other populations, the results may have wider implications for the surgical management of patients with drug-resistant MTLE. Copyright © 2017 Elsevier Inc. All rights reserved.

Limbic encephalitis associated with anti-voltage-gated potassium channel complex antibodies as a cause of adult-onset mesial temporal lobe epilepsy.

PubMed

Toyota, Tomoko; Akamatsu, Naoki; Tsuji, Sadatoshi; Nishizawa, Shigeru

2014-06-01

Recently, some reports have indicated that limbic encephalitis associated with anti-voltage-gated potassium channel complex antibodies (VGKC-Ab) is a cause of adult-onset mesial temporal lobe epilepsy (MTLE). We report a 53-year-old woman who had her first epileptic seizure at the age of 50 years old. Examination by 3-Tesla brain MRI revealed left hippocampal high signal intensity and swelling on fluid-attenuated inversion recovery (FLAIR) and T2-weighted imaging at 2 months after her first seizure. The patient received intravenous methylprednisolone and carbamazepine 300 mg/day. One month later, MRI revealed improvement of her left hippocampal abnormalities. Thereafter, she had no seizures, however, three years after her first seizure, EEG revealed a seizure pattern in the left temporal region. Brain MRI revealed left hippocampal high signal intensity and brain fluorodeoxyglucose positron emission tomography revealed hypermetabolism. Her serum VGKC-Ab levels were 118 pM(normal < 100 pM). Intravenous methylprednisolone therapy was reinitiated. Two months later, her hippocampal abnormalities had improved and 3 months later her VGKC-Ab levels decreased to 4.4 pM. Remission of the epileptic seizures was also observed. This MTLE in the middle age was considered as limbic encephalitis associated with anti- VGKC-Ab. In cases of unexplained adult-onset MTLE, limbic encephalitis associated with anti-VGKC-Ab, which responds well to immunotherapy, should be considered in the differential diagnosis.

Cavernomas de la región temporal mesial: Anatomía microquirúrgica y abordajes

PubMed Central

Campero, Alvaro

2015-01-01

Objetivo: Describir la anatomía microquirúrgica y los abordajes a la región temporal mesial (RTM), en relación a cavernomas de dicho sector. Materiales y Método: Cinco cabezas de cadáveres adultos, fijadas en formol e inyectadas con silicona coloreada, fueron estudiadas. Además, desde enero de 2007 a junio de 2014, 7 pacientes con cavernomas localizados en la RTM fueron operados por el autor. Resultados: Anatomia: La RTM fue dividida en 3 sectores: Anterior, medio y posterior. Pacientes: 7 enfermos con cavernomas de la RTM fueron operados por el autor. De acuerdo a la ubicacion en la RTM, 4 cavernomas se ubicaron en el sector anterior, 2 cavernomas se localizaron en el sector medio y 1 cavernoma se ubico en el sector posterior. Para el sector anterior de la RTM se utilizo un abordaje transsilviano-transinsular; para el sector medio de la RTM se utilizo un abordaje transtemporal (lobectomia temporal anterior); y para el sector posterior de la RTM se utilizo un abordaje supracerebeloso-transtentorial. Conclusión: Dividir la RTM en 3 sectores nos permite adecuar el abordaje en función a la localización de la lesión. Así, el sector anterior es bien abordable a través de la fisura silviana; el sector medio a través de una vía transtemporal; y el sector posterior por un abordaje supracerebeloso. PMID:26600986

Pathophysiogenesis of Mesial Temporal Lobe Epilepsy: Is Prevention of Damage Antiepileptogenic?

PubMed Central

Curia, G.; Lucchi, C.; Vinet, J.; Gualtieri, F.; Marinelli, C.; Torsello, A.; Costantino, L.; Biagini*,, G.

2014-01-01

Temporal lobe epilepsy (TLE) is frequently associated with hippocampal sclerosis, possibly caused by a primary brain injury that occurred a long time before the appearance of neurological symptoms. This type of epilepsy is characterized by refractoriness to drug treatment, so to require surgical resection of mesial temporal regions involved in seizure onset. Even this last therapeutic approach may fail in giving relief to patients. Although prevention of hippocampal damage and epileptogenesis after a primary event could be a key innovative approach to TLE, the lack of clear data on the pathophysiological mechanisms leading to TLE does not allow any rational therapy. Here we address the current knowledge on mechanisms supposed to be involved in epileptogenesis, as well as on the possible innovative treatments that may lead to a preventive approach. Besides loss of principal neurons and of specific interneurons, network rearrangement caused by axonal sprouting and neurogenesis are well known phenomena that are integrated by changes in receptor and channel functioning and modifications in other cellular components. In particular, a growing body of evidence from the study of animal models suggests that disruption of vascular and astrocytic components of the blood-brain barrier takes place in injured brain regions such as the hippocampus and piriform cortex. These events may be counteracted by drugs able to prevent damage to the vascular component, as in the case of the growth hormone secretagogue ghrelin and its analogues. A thoroughly investigation on these new pharmacological tools may lead to design effective preventive therapies. PMID:24251566

Comparison of mandibular first molar mesial root canal morphology using micro-computed tomography and clearing technique.

PubMed

Kim, Yeun; Perinpanayagam, Hiran; Lee, Jong-Ki; Yoo, Yeon-Jee; Oh, Soram; Gu, Yu; Lee, Seung-Pyo; Chang, Seok Woo; Lee, Woocheol; Baek, Seung-Ho; Zhu, Qiang; Kum, Kee-Yeon

2015-08-01

Micro-computed tomography (MCT) with alternative image reformatting techniques shows complex and detailed root canal anatomy. This study compared two-dimensional (2D) and 3D MCT image reformatting with standard tooth clearing for studying mandibular first molar mesial root canal morphology. Extracted human mandibular first molar mesial roots (n=31) were scanned by MCT (Skyscan 1172). 2D thin-slab minimum intensity projection (TS-MinIP) and 3D volume rendered images were constructed. The same teeth were then processed by clearing and staining. For each root, images obtained from clearing, 2D, 3D and combined 2D and 3D techniques were examined independently by four endodontists and categorized according to Vertucci's classification. Fine anatomical structures such as accessory canals, intercanal communications and loops were also identified. Agreement among the four techniques for Vertucci's classification was 45.2% (14/31). The most frequent were Vertucci's type IV and then type II, although many had complex configurations that were non-classifiable. Generally, complex canal systems were more clearly visible in MCT images than with standard clearing and staining. Fine anatomical structures such as intercanal communications, accessory canals and loops were mostly detected with a combination of 2D TS-MinIP and 3D volume-rendering MCT images. Canal configurations and fine anatomic structures were more clearly observed in the combined 2D and 3D MCT images than the clearing technique. The frequency of non-classifiable configurations demonstrated the complexity of mandibular first molar mesial root canal anatomy.

Interictal spike detection comparing subdural and depth electrodes during electrocorticography.

PubMed

Privitera, M D; Quinlan, J G; Yeh, H S

1990-11-01

We compared the ability of subdural and depth electrodes to detect and localize interictal epileptiform discharges (IEDs) in the temporal lobe. Sixteen patients had simultaneous intraoperative recordings with depth and subdural electrodes while undergoing anterior temporal lobe resections under local anesthesia for medically intractable seizures. IEDs that were focal (detected at just 1 or 2 electrode contacts) typically registered at the nearest contact, regardless of type. IEDs that were regional (engaging more than 2 electrode contacts) typically appeared simultaneously at both electrode types. Neither method was better able to indicate whether an IED was mesial or lateral, posterior or anterior. Subdural and depth electrodes seem to provide complementary information on the location of IEDs within the temporal lobe.

Recording temporal lobe epileptic activity with MEG in a light-weight magnetic shield.

PubMed

Carrette, Evelien; Op de Beeck, Marc; Bourguignon, Mathieu; Boon, Paul; Vonck, Kristl; Legros, Benjamin; Goldman, Serge; Van Bogaert, Patrick; De Tiège, Xavier

2011-06-01

To assess the interictal epileptic discharges (IEDs) detection rate of magnetoencephalography (MEG) recordings performed in a new light-weight magnetic shielding (LMSR) concept in a large group of consecutive patients with presumed mesiotemporal lobe epilepsy (MTLE). Thirty-eight patients (23 women; age range: 6-63 years) with presumed MTLE were prospectively studied. MEG investigations were performed with the 306-channel Elekta Neuromag® MEG-system installed in a normal hospital environment into a LMSR (MaxShield, Elekta Oy). Equivalent current dipoles (ECD, g/% > 80%) corresponding to epileptic events were fitted to each patient's spherical head model at IEDs onset and peak and then superimposed on the patient's co-registered MRI. IEDs were observed in 26 out of 38 patients (68.4%). Temporal ECDs were mesial in 14 patients, anterior in 23 patients and posterior in 8 patients. Interestingly, in 6 patients, ECDs fitted at spike-onset were localized in the hippocampus while at the peak of the spike, they had an anterior temporal location. MEG using LMSR provides adequate signal to noise ratio (SNR) to allow reliable detection and localization of single epileptic abnormalities on continuous MEG data in 68% of patients with presumed MTLE. Moreover, mesial temporal epileptic sources were detected in 54% of patients with abnormal MEG. The SNR of MEG data acquired using the LMSR is therefore suitable for the non-invasive localization of epileptic foci in patients with MTLE. The use of LMSR, which are cheaper and smaller than conventional MSR, should facilitate the development of MEG in clinical environments. Copyright © 2011 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Multimodal data and machine learning for surgery outcome prediction in complicated cases of mesial temporal lobe epilepsy.

PubMed

Memarian, Negar; Kim, Sally; Dewar, Sandra; Engel, Jerome; Staba, Richard J

2015-09-01

This study sought to predict postsurgical seizure freedom from pre-operative diagnostic test results and clinical information using a rapid automated approach, based on supervised learning methods in patients with drug-resistant focal seizures suspected to begin in temporal lobe. We applied machine learning, specifically a combination of mutual information-based feature selection and supervised learning classifiers on multimodal data, to predict surgery outcome retrospectively in 20 presurgical patients (13 female; mean age±SD, in years 33±9.7 for females, and 35.3±9.4 for males) who were diagnosed with mesial temporal lobe epilepsy (MTLE) and subsequently underwent standard anteromesial temporal lobectomy. The main advantage of the present work over previous studies is the inclusion of the extent of ipsilateral neocortical gray matter atrophy and spatiotemporal properties of depth electrode-recorded seizures as training features for individual patient surgery planning. A maximum relevance minimum redundancy (mRMR) feature selector identified the following features as the most informative predictors of postsurgical seizure freedom in this study's sample of patients: family history of epilepsy, ictal EEG onset pattern (positive correlation with seizure freedom), MRI-based gray matter thickness reduction in the hemisphere ipsilateral to seizure onset, proportion of seizures that first appeared in ipsilateral amygdala to total seizures, age, epilepsy duration, delay in the spread of ipsilateral ictal discharges from site of onset, gender, and number of electrode contacts at seizure onset (negative correlation with seizure freedom). Using these features in combination with a least square support vector machine (LS-SVM) classifier compared to other commonly used classifiers resulted in very high surgical outcome prediction accuracy (95%). Supervised machine learning using multimodal compared to unimodal data accurately predicted postsurgical outcome in patients with atypical MTLE. Published by Elsevier Ltd.

Second operation after the failure of previous resection for epilepsy.

PubMed

Awad, I A; Nayel, M H; Lüders, H

1991-04-01

We present our surgical experience with second operations in 15 patients with recurrent intractable partial seizures after resection for epilepsy. The interval from the first operation until the first recurrence of seizures ranged from 1 day to 7 months (mean, 62 days). The interval between the first and second operations ranged from 3 months to 12 years (mean, 38 months). Detailed video-electroencephalographic interictal and ictal recording was performed in all patients (invasive electrodes were used in 11 patients). Ictal onset was shown to be remote from the zone of previous resection in 3 of 15 cases (all 3 extratemporal and in the ipsilateral hemisphere). Recurrent seizures arose from the area of previous extratemporal resection in 2 of 15 patients, and from the area of previous temporal resection in 10 of 15 patients. Both cases of extratemporal recurrences and 3 of the 10 cases of temporal lobe recurrences in the area of previous resection were associated with residual unresected structural lesion. Of the 10 patients with local temporal recurrence, 6 had proven epileptogenicity in the residual mesial structures, and 4 had residual epileptogenicity in the unresected lateral temporal lobe. The patients have been monitored for 8 to 82 months (mean, 18 months) after the second operation: 7 patients (47%) have remained seizure-free and another 5 (33%) have achieved a reduction in seizure frequency of more than 90%. There was no mortality or significant morbidity in this series. We conclude that the extent and distribution of residual epileptogenicity after failed epilepsy surgery are highly variable.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrophysiological resting-state biomarker for diagnosing mesial temporal lobe epilepsy with hippocampal sclerosis.

PubMed

Jin, Seung-Hyun; Chung, Chun Kee

2017-01-01

The main aim of the present study was to evaluate whether resting-state functional connectivity of magnetoencephalography (MEG) signals can differentiate patients with mesial temporal lobe epilepsy (MTLE) from healthy controls (HC) and can differentiate between right and left MTLE as a diagnostic biomarker. To this end, a support vector machine (SVM) method among various machine learning algorithms was employed. We compared resting-state functional networks between 46 MTLE (right MTLE=23; left MTLE=23) patients with histologically proven HS who were free of seizure after surgery, and 46 HC. The optimal SVM group classifier distinguished MTLE patients with a mean accuracy of 95.1% (sensitivity=95.8%; specificity=94.3%). Increased connectivity including the right posterior cingulate gyrus and decreased connectivity including at least one sensory-related resting-state network were key features reflecting the differences between MTLE patients and HC. The optimal SVM model distinguished between right and left MTLE patients with a mean accuracy of 76.2% (sensitivity=76.0%; specificity=76.5%). We showed the potential of electrophysiological resting-state functional connectivity, which reflects brain network reorganization in MTLE patients, as a possible diagnostic biomarker to differentiate MTLE patients from HC and differentiate between right and left MTLE patients. Copyright © 2016 Elsevier B.V. All rights reserved.

[18F]-Fluoro-Deoxy-Glucose Positron Emission Tomography Scan Should Be Obtained Early in Cases of Autoimmune Encephalitis

PubMed Central

Sarwal, A.; Hantus, S.

2016-01-01

Introduction. Autoimmune encephalitis (AE) is a clinically challenging diagnosis with nonspecific neurological symptoms. Prompt diagnosis is important and often relies on neuroimaging. We present a case series of AE highlighting the importance of an early [18F]-fluoro-deoxy-glucose positron emission tomography (FDG-PET) scan. Methods. Retrospective review of seven consecutive cases of autoimmune encephalitis. Results. All patients had both magnetic resonance imaging (MRI) and FDG-PET scans. Initial clinical presentations included altered mental status and/or new onset seizures. Six cases had serum voltage-gated potassium channel (VGKC) antibody and one had serum N-methyl-D-aspartate (NMDA) antibody. MRI of brain showed mesial temporal lobe hyperintensity in five cases of VGKC. The other two patients with VGKC or NMDA AE had restiform body hyperintensity on MRI brain or a normal MRI, respectively. Mesial temporal lobe hypermetabolism was noted in three cases on FDG-PET, despite initial unremarkable MRI. Malignancy workup was negative in all patients. Conclusion. A high index of suspicion for AE should be maintained in patients presenting with cognitive symptoms, seizures, and limbic changes on neuroimaging. In cases with normal initial brain MRI, FDG-PET can be positive. Additionally, extralimbic hyperintensity on MRI may also be observed. PMID:27559482

Termination patterns of complex partial seizures: An intracranial EEG study.

PubMed

Afra, Pegah; Jouny, Christopher C; Bergey, Gregory K

2015-11-01

While seizure onset patterns have been the subject of many reports, there have been few studies of seizure termination. In this study we report the incidence of synchronous and asynchronous termination patterns of partial seizures recorded with intracranial arrays. Data were collected from patients with intractable complex partial seizures undergoing presurgical evaluations with intracranial electrodes. Patients with seizures originating from mesial temporal and neocortical regions were grouped into three groups based on patterns of seizure termination: synchronous only (So), asynchronous only (Ao), or mixed (S/A, with both synchronous and asynchronous termination patterns). 88% of the patients in the MT group had seizures with a synchronous pattern of termination exclusively (38%) or mixed (50%). 82% of the NC group had seizures with synchronous pattern of termination exclusively (52%) or mixed (30%). In the NC group, there was a significant difference of the range of seizure durations between So and Ao groups, with Ao exhibiting higher variability. Seizures with synchronous termination had low variability in both groups. Synchronous seizure termination is a common pattern for complex partials seizures of both mesial temporal or neocortical onset. This may reflect stereotyped network behavior or dynamics at the seizure focus. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Collateral brain damage, a potential source of cognitive impairment after selective surgery for control of mesial temporal lobe epilepsy.

PubMed

Helmstaedter, C; Van Roost, D; Clusmann, H; Urbach, H; Elger, C E; Schramm, J

2004-02-01

Highly selective epilepsy surgery in temporal lobe epilepsy is intended to achieve seizure freedom at a lower cognitive risk than standard en bloc resections, but bears the risk of collateral cortical damage resulting from the surgical approach. To investigate cortical damage associated with selective amygdalo-hippocampectomy (SAH). 34 epileptic patients were evaluated. They were randomly assigned to SAH using either a sylvian (9 left/10 right) or a transcortical surgical approach (5 left/10 right). Postoperative MRI signal intensity changes adjacent to the approach were correlated with performance changes in serial word and design list learning. Losses in verbal learning and recognition memory were positively related to signal intensity changes, independent of the side of the resection, the surgical approach, or the extent of the mesial resection. Losses in consolidation/retrieval (memory) were greater after left sided surgery. Losses in design learning were related to right sided surgery and signal intensity changes. Seizure outcome (85% seizure-free) did not differ depending on the side or type of surgery. Collateral damage to cortical tissues adjacent to the surgical approach contributes to postoperative verbal and figural memory outcome after SAH. Controlling for collateral damage may clarify the controversial memory outcomes after SAH reported by different surgical centres.

A Stereological Study of Synapse Number in the Epileptic Human Hippocampus

PubMed Central

Alonso-Nanclares, Lidia; Kastanauskaite, Asta; Rodriguez, Jose-Rodrigo; Gonzalez-Soriano, Juncal; DeFelipe, Javier

2011-01-01

Hippocampal sclerosis is the most frequent pathology encountered in resected mesial temporal structures from patients with intractable temporal lobe epilepsy (TLE). Here, we have used stereological methods to compare the overall density of synapses and neurons between non-sclerotic and sclerotic hippocampal tissue obtained by surgical resection from patients with TLE. Specifically, we examined the possible changes in the subiculum and CA1, regions that seem to be critical for the development and/or maintenance of seizures in these patients. We found a remarkable decrease in synaptic and neuronal density in the sclerotic CA1, and while the subiculum from the sclerotic hippocampus did not display changes in synaptic density, the neuronal density was higher. Since the subiculum from the sclerotic hippocampus displays a significant increase in neuronal density, as well as a various other neurochemical changes, we propose that the apparently normal subiculum from the sclerotic hippocampus suffers profound alterations in neuronal circuits at both the molecular and synaptic level that are likely to be critical for the development or maintenance of seizure activity. PMID:21390290

Negative BOLD in default-mode structures measured with EEG-MREG is larger in temporal than extra-temporal epileptic spikes

PubMed Central

Jacobs, Julia; Menzel, Antonia; Ramantani, Georgia; Körbl, Katharina; Assländer, Jakob; Schulze-Bonhage, Andreas; Hennig, Jürgen; LeVan, Pierre

2014-01-01

Introduction: EEG-fMRI detects BOLD changes associated with epileptic interictal discharges (IED) and can identify epileptogenic networks in epilepsy patients. Besides positive BOLD changes, negative BOLD changes have sometimes been observed in the default-mode network, particularly using group analysis. A new fast fMRI sequence called MREG (Magnetic Resonance Encephalography) shows increased sensitivity to detect IED-related BOLD changes compared to the conventional EPI sequence, including frequent occurrence of negative BOLD responses in the DMN. The present study quantifies the concordance between the DMN and negative BOLD related to IEDs of temporal and extra-temporal origin. Methods: Focal epilepsy patients underwent simultaneous EEG-MREG. Areas of overlap were calculated between DMN regions, defined as precuneus, posterior cingulate, bilateral inferior parietal and mesial prefrontal cortices according to a standardized atlas, and significant negative BOLD changes revealed by an event-related analysis based on the timings of IED seen on EEG. Correlation between IED number/lobe of origin and the overlap were calculated. Results: 15 patients were analyzed, some showing IED over more than one location resulting in 30 different IED types. The average overlap between negative BOLD and DMN was significantly larger in temporal (23.7 ± 19.6 cm3) than extra-temporal IEDs (7.4 ± 5.1 cm3, p = 0.008). There was no significant correlation between the number of IEDs and the overlap between DMN structures and negative BOLD areas. Discussion: MREG results in an increased sensitivity to detect negative BOLD responses related to focal IED in single patients, with responses often occurring in DMN regions. In patients with high overlap with the DMN, this suggests that epileptic IEDs may be associated with a brief decrease in attention and cognitive ability. Interestingly this observation was not dependent on the frequency of IED but more common in IED of temporal origin. PMID:25477775

The overall pathological status of the left hippocampus determines preoperative verbal memory performance in left mesial temporal lobe epilepsy.

PubMed

Witt, Juri-Alexander; Coras, Roland; Schramm, Johannes; Becker, Albert J; Elger, Christian E; Blümcke, Ingmar; Helmstaedter, Christoph

2014-04-01

Studies on hippocampal cell loss in epilepsy have produced diverging evidence as to which subfields are specifically related to memory. This may be due to rather small and often heterogeneous samples, or to different memory measures. Therefore, the current study examined hippocampal cell densities and memory in a large sample of patients with solely mesial temporal lobe epilepsy (mTLE), employing measures with proven sensitivity to mesiotemporal pathology. In 104 patients who had undergone epilepsy surgery for mTLE, we evaluated the role of segmental hippocampal cell loss and its underlying factor structure with regard to presurgical verbal and figural memory while controlling for side-of-surgery and hemispheric dominance. First of all, patients showed material-specific memory impairment concordant with the lateralization of epilepsy. Factor analysis of segmental cell loss revealed a single factor reflecting the overall integrity of the hippocampus. The overall pathological status of the left hippocampus correlated with verbal memory parameters (r = 0.33-0.34, P < 0.05), especially when controlling for atypical hemispheric dominance (r = 0.50-0.57, P < 0.01), and explained up to 33% of the observed variance. Further analyses revealed no superior role of a single subfield or cell loss pattern for memory performance. No systematic relations between neuronal cell densities of the right hippocampus and memory function were found, nor did left or right hippocampal pathology explain figural memory parameters. The results suggest that the overall pathological status of the left hippocampus - rather than a specific subfield pathology - is predictive for verbal memory in mTLE. The finding that figural memory parameters, although sensitive to right mTLE, were not related to neuronal cell densities of the right hippocampus, puts the left/right hippocampus verbal/nonverbal memory dichotomy into perspective. Copyright © 2013 Wiley Periodicals, Inc.

Absence of simple partial seizure in temporal lobe epilepsy: its diagnostic and prognostic significance.

PubMed

Inoue, Y; Mihara, T; Matsuda, K; Tottori, T; Otsubo, T; Yagi, K

2000-02-01

The diagnostic and prognostic significance of the absence of simple partial seizures (SPS) immediately preceding complex partial seizures (CPS) was examined in patients with temporal lobe epilepsy. The status of self-reported SPS in 193 patients with temporal lobe epilepsy who had surgical therapy more than 2 years ago was reviewed. Before surgery, 37 patients never experienced SPS before CPS (Group A), 156 patients either always or occasionally had SPS before CPS (Group B). The frequency of mesial temporal sclerosis (MTS) was lower and the age at onset of epilepsy was higher in Group A. The seizure focus was in the language-dominant temporal lobe in 73% of the cases in Group A, compared with 40% in Group B. The surgical outcome did not differ between the two groups. The findings suggest that temporal lobe seizures without preceding SPS tend to originate in the language-dominant temporal lobe that contains a pathologic etiology other than MTS, especially in the lateral temporal lobe. The surgical outcome in patients without SPS is similar to that in patients with SPS.

Lateralization of temporal lobe epilepsy by multimodal multinomial hippocampal response-driven models.

PubMed

Nazem-Zadeh, Mohammad-Reza; Elisevich, Kost V; Schwalb, Jason M; Bagher-Ebadian, Hassan; Mahmoudi, Fariborz; Soltanian-Zadeh, Hamid

2014-12-15

Multiple modalities are used in determining laterality in mesial temporal lobe epilepsy (mTLE). It is unclear how much different imaging modalities should be weighted in decision-making. The purpose of this study is to develop response-driven multimodal multinomial models for lateralization of epileptogenicity in mTLE patients based upon imaging features in order to maximize the accuracy of noninvasive studies. The volumes, means and standard deviations of FLAIR intensity and means of normalized ictal-interictal SPECT intensity of the left and right hippocampi were extracted from preoperative images of a retrospective cohort of 45 mTLE patients with Engel class I surgical outcomes, as well as images of a cohort of 20 control, nonepileptic subjects. Using multinomial logistic function regression, the parameters of various univariate and multivariate models were estimated. Based on the Bayesian model averaging (BMA) theorem, response models were developed as compositions of independent univariate models. A BMA model composed of posterior probabilities of univariate response models of hippocampal volumes, means and standard deviations of FLAIR intensity, and means of SPECT intensity with the estimated weighting coefficients of 0.28, 0.32, 0.09, and 0.31, respectively, as well as a multivariate response model incorporating all mentioned attributes, demonstrated complete reliability by achieving a probability of detection of one with no false alarms to establish proper laterality in all mTLE patients. The proposed multinomial multivariate response-driven model provides a reliable lateralization of mesial temporal epileptogenicity including those patients who require phase II assessment. Copyright © 2014 Elsevier B.V. All rights reserved.

Stereotactic radiosurgery for the treatment of mesial temporal lobe epilepsy.

PubMed

Feng, E-S; Sui, C-B; Wang, T-X; Sun, G-L

2016-12-01

Stereotactic radiosurgery (RS) is a potential option for some patients with temporal lobe epilepsy (TLE). The aim of this meta-analysis was to determine the pooled seizure-free rate and the time interval to seizure cessation in patients with lesions in the mesial temporal lobe, and who were eligible for either stereotactic or gamma knife RS. We searched the Medline, Cochrane, EMBASE, and Google Scholar databases using combinations of the following terms: RS, stereotactic radiosurgery, gamma knife, and TLE. We screened 103 articles and selected 13 for inclusion in the meta-analysis. Significant study heterogeneity was detected; however, the included studies displayed an acceptable level of quality. We show that approximately half of the patients were seizure free over a follow-up period that ranged from 6 months to 9 years [pooled estimate: 50.9% (95% confidence interval: 0.381-0.636)], with an average of 14 months to seizure cessation [pooled estimate: 14.08 months (95% confidence interval: 11.95-12.22 months)]. Nine of 13 included studies reported data for adverse events (AEs), which included visual field deficits and headache (the two most common AEs), verbal memory impairment, psychosis, psychogenic non-epileptic seizures, and dysphasia. Patients in the individual studies experienced AEs at rates that ranged from 8%, for non-epileptic seizures, to 85%, for headache. Our findings indicate that RS may have similar or slightly less efficacy in some patients compared with invasive surgery. Randomized controlled trials of both treatment regimens should be undertaken to generate an evidence base for patient decision-making. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Imaging of odor perception delineates functional disintegration of the limbic circuits in mesial temporal lobe epilepsy.

PubMed

Ciumas, Carolina; Lindström, Per; Aoun, Bernard; Savic, Ivanka

2008-01-15

Metabolic and neuro-receptor abnormalities within the extrafocal limbic circuits are established in mesial temporal lobe epilepsy (MTLE). However, very little is known about how these circuits process external stimuli. We tested whether odor activation can help delineate limbic functional disintegration in MTLE, and measured cerebral blood flow with PET during birhinal smelling of familiar and unfamiliar odors, using smelling of odorless air as the baseline condition. Patients with MTLE (13 left-sided, 10 right-sided) and 21 controls were investigated. In addition to odor activation, the analysis included functional connectivity, using right and left piriform cortex as seed regions. Healthy controls activated the amygdala, piriform, anterior insular, and cingulate cortices on both sides. Smelling of familiar odors engaged, in addition, the right parahippocampus, and the left Brodmann Area (BA) 44, 45, 47. Patients failed to activate the amygdala, piriform and the anterior insular cortex in the epileptogenic hemisphere. Furthermore, those with left MTLE did not activate the left BA 44, 45 and 47 with familiar odors, which they perceived as less familiar than controls. Congruent with the activation data each seed region was in patients functionally disconnected with the contralateral amygdala+piriform+insular cortex. The functional disintegration in patients exceeded the reduced activation, and included the contralateral temporal neocortex, and in subjects with right MTLE also the right orbitofrontal cortex. Imaging of odor perception may be used to delineate functional disintegration of the limbic networks in MTLE. It shows an altered response in several regions, which may underlie some interictal behavioral problems associated with this condition.

‘Forced normalisation’ in the neurosurgical era

PubMed Central

Shahani, Lokesh

2012-01-01

The correlation between epilepsy and behavioural disorders is well known. Forced normalisation is a phenomenon where there is worsening of the patient's behavioural disorder when a better seizure control has been obtained. A complication of anti-epileptic treatment worsening the behavioural disorder is sometimes the proposed mechanism. The author presents the report of a young man with temporal lobe epilepsy and poor seizure control in the past 12 years. The patient had comorbid impulse control disorder previously well controlled with medications. MRI demonstrated left mesial temporal sclerosis and intracranial EEG recording located seizure foci in the left medial temporal lobe. The patient underwent left temporal lobectomy for seizure control with partial success. However, after operation, the patient's impulse control disorder worsened and he was involved in physical altercations leading to incarceration. This illustrates a case where partial seizure control was obtained with a surgical procedure, but resulted in worsening of the patient's behavioural disorder. PMID:22684833

Temporal lobe epilepsy: origin and significance of simple and complex auras.

PubMed Central

Taylor, D C; Lochery, M

1987-01-01

The aura experience of 88 patients with temporal lobe epilepsy was recorded, classified and analysed. Despite the great richness of the 215 experiences described, correlations with left or right brain, nature of lesion, age of onset, etc. were only apparent when a classification into three aura groups was used. "Simple primitive" auras as sole auras were more likely with early onset epilepsy, in lower IQ patients, in males, from the right temporal lobe, and with mesial temporal sclerosis. Exclusively "intellectual" auras were confined to a group of high IQ males. The number of aura experiences described per person correlated with Verbal IQ for males but not females, but also varied with side, sex, and nature of lesion. The results are discussed in terms of the necessary conditions for aura and their relevance and in relationship to the results of brain stimulation studies by Penfield and others. PMID:3612148

Global Interactions Analysis of Epileptic ECoG Data

NASA Astrophysics Data System (ADS)

Ortega, Guillermo J.; Sola, Rafael G.; Pastor, Jesús

2007-05-01

Localization of the epileptogenic zone is an important issue in epileptology, even though there is not a unique definition of the epileptic focus. The objective of the present study is to test ultrametric analysis to uncover cortical interactions in human epileptic data. Correlation analysis has been carried out over intraoperative Electro-Corticography (ECoG) data in 2 patients suffering from temporal lobe epilepsy (TLE). Recordings were obtained using a grid of 20 electrodes (5×4) covering the lateral temporal lobe and a strip of either 4 or 8 electrodes at the mesial temporal lobe. Ultrametric analysis was performed in the averaged final correlation matrices. By using the matrix of linear correlation coefficients and the appropriate metric distance between pairs of electrodes time series, we were able to construct Minimum Spanning Trees (MST). The topological connectivity displayed by these trees gives useful and valuable information regarding physiological and pathological information in the temporal lobe of epileptic patients.

Atypical language organization in temporal lobe epilepsy revealed by a passive semantic paradigm

PubMed Central

2014-01-01

Background Mesial temporal lobe epilepsy (MTLE) is the most common type of focal epilepsy in adults and can be successfully cured by surgery. One of the main complications of this surgery however is a decline in language abilities. The magnitude of this decline is related to the degree of language lateralization to the left hemisphere. Most fMRI paradigms used to determine language dominance in epileptic populations have used active language tasks. Sometimes, these paradigms are too complex and may result in patient underperformance. Only a few studies have used purely passive tasks, such as listening to standard speech. Methods In the present study we characterized language lateralization in patients with MTLE using a rapid and passive semantic language task. We used functional magnetic resonance imaging (fMRI) to study 23 patients [12 with Left (LMTLE), 11 with Right mesial temporal lobe epilepsy (RMTLE)] and 19 healthy right-handed controls using a 6 minute long semantic task in which subjects passively listened to groups of sentences (SEN) and pseudo sentences (PSEN). A lateralization index (LI) was computed using a priori regions of interest of the temporal lobe. Results The LI for the significant contrasts produced activations for all participants in both temporal lobes. 81.8% of RMTLE patients and 79% of healthy individuals had a bilateral language representation for this particular task. However, 50% of LMTLE patients presented an atypical right hemispheric dominance in the LI. More importantly, the degree of right lateralization in LMTLE patients was correlated with the age of epilepsy onset. Conclusions The simple, rapid, non-collaboration dependent, passive task described in this study, produces a robust activation in the temporal lobe in both patients and controls and is capable of illustrating a pattern of atypical language organization for LMTLE patients. Furthermore, we observed that the atypical right-lateralization patterns in LMTLE patients was associated to earlier age at epilepsy onset. These results are in line with the idea that early onset of epileptic activity is associated to larger neuroplastic changes. PMID:24885511

Silent hippocampal seizures and spikes identified by foramen ovale electrodes in Alzheimer's disease.

PubMed

Lam, Alice D; Deck, Gina; Goldman, Alica; Eskandar, Emad N; Noebels, Jeffrey; Cole, Andrew J

2017-06-01

We directly assessed mesial temporal activity using intracranial foramen ovale electrodes in two patients with Alzheimer's disease (AD) without a history or EEG evidence of seizures. We detected clinically silent hippocampal seizures and epileptiform spikes during sleep, a period when these abnormalities were most likely to interfere with memory consolidation. The findings in these index cases support a model in which early development of occult hippocampal hyperexcitability may contribute to the pathogenesis of AD.

Importance of third mesial canals in mandibular molars: report of 2 cases.

PubMed

Yesilsoy, Cemil; Porras, Omar; Gordon, Wanda

2009-07-01

Most mandibular first molars have 2 mesial canals. Two cases of failed endodontically treated first mandibular molars are presented with 2 obturated mesial canals. The cases were retreated with a third mesial canal identified, and instrumented and obturated with resolution of the patients' signs and symptoms. These cases show that consideration must be made to recognize the possibility of a third mesial canal and perform complete treatment to minimize the possibility of failure.

Perspectives on treatment options for mesial temporal lobe epilepsy with hippocampal sclerosis.

PubMed

Palleria, Caterina; Coppola, Antonietta; Citraro, Rita; Del Gaudio, Luigi; Striano, Salvatore; De Sarro, Giovambattista; Russo, Emilio

2015-01-01

Mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS) is a syndrome that is often refractory to drug treatment. The effects on specific syndromes are not currently available from the pre-marketing clinical development of new AEDs; this does not allow the prediction of whether new drugs will be more effective in the treatment of some patients. We have reviewed all the existing literature relevant to the understanding of a potential effectiveness in MTLE-HS patients for the latest AEDs, namely brivaracetam, eslicarbazepine, lacosamide, perampanel and retigabine also including the most relevant clinical data and a brief description of their pharmacological profile. Records were identified using predefined search criteria using electronic databases (e.g., PubMed, Cochrane Library Database of Systematic Reviews). Primary peer-reviewed articles published up to the 15 June 2015 were included. All the drugs considered have the potential to be effective in the treatment of MTLE-HS; in fact, they possess proven efficacy in animal models; currently considered valuable tools for predicting drug efficacy in TLE. Furthermore, for some of these (e.g., lacosamide and eslicarbazepine) data are already available from post-marketing studies while brivaracetam acting on SV2A like levetiracetam might have the same potential effectiveness with the possibility to be more efficacious considering its ability to inhibit voltage gated sodium channels; finally, perampanel and retigabine are very effective drugs in animal models of TLE.

Pure topographical disorientation in a patient with right occipito-temporal lesion.

PubMed

Caglio, Marcella; Castelli, Lorys; Cerrato, Paolo; Latini-Corazzini, Luca

2011-01-01

We describe a patient who presented with a pure topographical disorientation after a stroke involving the right mesial occipito-temporal cortex. He could not point to external unseen landmarks or draw a map of his city, while he could recognize landmarks, and judge the distance, and describe the route between pairs of landmarks of the same city. He underwent standardized cognitive tests, and 6 tasks were used to assess a topographical orientation route-survey. This study provides evidence that topographical disorientation can be subdivided into very specific components. The results suggest that one of these components might refer to the processing of an allocentric map separable from the representation of route knowledge.

Amygdala Volumetry in Patients with Temporal Lobe Epilepsy and Normal Magnetic Resonance Imaging

PubMed Central

Singh, Paramdeep; Kaur, Rupinderjeet; Saggar, Kavita; Singh, Gagandeep; Aggarwal, Simmi

2016-01-01

Summary Background It has been suggested that the pathophysiology of temporal lobe epilepsy may relate to abnormalities in various brain structures, including the amygdala. Patients with mesial temporal lobe epilepsy (MTLE) without MRI abnormalities (MTLE-NMRI) represent a challenge for diagnosis of the underlying abnormality and for presurgical evaluation. To date, however, only few studies have used quantitative structural Magnetic Resonance Imaging-based techniques to examine amygdalar pathology in these patients. Material/Methods Based on clinical examination, 24-hour video EEG recordings and MRI findings, 50 patients with EEG lateralized TLE and normal structural Magnetic Resonance Imaging results were included in this study. Volumetric magnetic resonance imaging (MRI) studies of the amygdalas and hippocampi were conducted in 50 non-epileptic controls (age 7–79 years) and 50 patients with MTLE with normal MRI on a 1.5-Tesla scanner. Visual assessment and amygdalar volumetry were performed on oblique coronal T2W and T1W MP-RAGE images respectively. The T2 relaxation times were measured using the 16-echo Carr-Purcell-Meiboom-Gill sequence (TE, 22–352). Volumetric data were normalized for variation in head size between individuals. Results were assessed by SSPS statistic program. Results Individual manual volumetric analysis confirmed statistically significant amygdala enlargement (AE) in eight (16%) patients. Overall, among all patients with AE and a defined epileptic focus, 7 had predominant increased volume ipsilateral to the epileptic focus. The T2 relaxometry demonstrated no hyperintense signal of the amygdala in any patient with significant AE. Conclusions This paper presented AE in a few patients with TLE and normal MRI. These findings support the hypothesis that there might be a subgroup of patients with MTLE-NMRI in which the enlarged amygdala could be related to the epileptogenic process. PMID:27231493

Route Learning Impairment in Temporal Lobe Epilepsy

PubMed Central

Bell, Brian D.

2012-01-01

Memory impairment on neuropsychological tests is relatively common in temporal lobe epilepsy (TLE) patients. But memory rarely has been evaluated in more naturalistic settings. This study assessed TLE (n = 19) and control (n = 32) groups on a real-world route learning (RL) test. Compared to the controls, the TLE group committed significantly more total errors across the three RL test trials. RL errors correlated significantly with standardized auditory and visual memory and visual-perceptual test scores in the TLE group. In the TLE subset for whom hippocampal data were available (n = 14), RL errors also correlated significantly with left hippocampal volume. This is one of the first studies to demonstrate real-world memory impairment in TLE patients and its association with both mesial temporal lobe integrity and standardized memory test performance. The results support the ecological validity of clinical neuropsychological assessment. PMID:23041173

Neuroimaging of epilepsy

PubMed Central

Cendes, Fernando; Theodore, William H.; Brinkmann, Benjamin H.; Sulc, Vlastimil; Cascino, Gregory D.

2017-01-01

Imaging is pivotal in the evaluation and management of patients with seizure disorders. Elegant structural neuroimaging with magnetic resonance imaging (MRI) may assist in determining the etiology of focal epilepsy and demonstrating the anatomical changes associated with seizure activity. The high diagnostic yield of MRI to identify the common pathological findings in individuals with focal seizures including mesial temporal sclerosis, vascular anomalies, low-grade glial neoplasms and malformations of cortical development has been demonstrated. Positron emission tomography (PET) is the most commonly performed interictal functional neuroimaging technique that may reveal a focal hypometabolic region concordant with seizure onset. Single photon emission computed tomography (SPECT) studies may assist performance of ictal neuroimaging in patients with pharmacoresistant focal epilepsy being considered for neurosurgical treatment. This chapter highlights neuroimaging developments and innovations, and provides a comprehensive overview of the imaging strategies used to improve the care and management of people with epilepsy. PMID:27430454

Levetiracetam reduces abnormal network activations in temporal lobe epilepsy.

PubMed

Wandschneider, Britta; Stretton, Jason; Sidhu, Meneka; Centeno, Maria; Kozák, Lajos R; Symms, Mark; Thompson, Pamela J; Duncan, John S; Koepp, Matthias J

2014-10-21

We used functional MRI (fMRI) and a left-lateralizing verbal and a right-lateralizing visual-spatial working memory (WM) paradigm to investigate the effects of levetiracetam (LEV) on cognitive network activations in patients with drug-resistant temporal lobe epilepsy (TLE). In a retrospective study, we compared task-related fMRI activations and deactivations in 53 patients with left and 54 patients with right TLE treated with (59) or without (48) LEV. In patients on LEV, activation patterns were correlated with the daily LEV dose. We isolated task- and syndrome-specific effects. Patients on LEV showed normalization of functional network deactivations in the right temporal lobe in right TLE during the right-lateralizing visual-spatial task and in the left temporal lobe in left TLE during the verbal task. In a post hoc analysis, a significant dose-dependent effect was demonstrated in right TLE during the visual-spatial WM task: the lower the LEV dose, the greater the abnormal right hippocampal activation. At a less stringent threshold (p < 0.05, uncorrected for multiple comparisons), a similar dose effect was observed in left TLE during the verbal task: both hippocampi were more abnormally activated in patients with lower doses, but more prominently on the left. Our findings suggest that LEV is associated with restoration of normal activation patterns. Longitudinal studies are necessary to establish whether the neural patterns translate to drug response. This study provides Class III evidence that in patients with drug-resistant TLE, levetiracetam has a dose-dependent facilitation of deactivation of mesial temporal structures. © 2014 American Academy of Neurology.

Deviations of Mesial Root Canals of Mandibular First Molar Teeth at the Apical Third: A Micro-computed Tomographic Study.

PubMed

Keles, Ali; Keskin, Cangül

2018-06-01

The present study aimed to quantitatively analyze apical foramen deviations of mesial root canals of mandibular first molar teeth by means of micro-computed tomographic (micro-CT) imaging. Micro-CT images of the mesial roots of 109 mandibular first molar teeth with independent mesiobuccal (MB) and mesiolingual (ML) root canals were analyzed. The deviations of the apical foramina of the MB, ML, and middle mesial root canals from the anatomic apex were measured. The vertical distance between the apical foramina of each mesial root canal in relation to each other was also calculated. The distances from the apical foramina of the MB, ML, and middle mesial root canals to the anatomic apex of the mesial root were up to 2.51 mm, 3.21 mm, and 5.67 mm, respectively. There was no significant difference between the deviations of MB and ML root canals from each other (P > .05). The middle mesial root canal showed the greatest deviation compared with the MB and ML canals (P < .05). The apical foramina of mesial root canals of mandibular first molar teeth showed greater variations from each other and anatomic apices than previously reported. Clinically, the use of electronic apex locators for the detection of minor apical foramen of each mesial root canal is of the utmost important. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Clinical characteristics, surgical and neuropsychological outcomes in drug resistant tumoral temporal lobe epilepsy.

PubMed

Ravat, Sangeeta; Iyer, Vivek; Muzumdar, Dattatraya; Shah, Urvashi; Pradhan, Pranjali; Jain, Neeraj; Godge, Yogesh

2016-12-01

Glioneuronal tumors are found in nearly one third patients who undergo surgery for pharmacoresistant epilepsy with temporal lobe being the most common location. Few studies, however have concentrated on the neurological and neuropsychological outcomes after surgery, hitherto none from India. We studied 34 patients with temporal lobe tumors and drug resistant epilepsy. These patients underwent anterior temporal lobectomy or lesionectomy based on the involvement of the hippocampus and mesial temporal structures. The clinical history, EEG, neuropsychology profile and MRI were compared. Seizure outcome was categorized using Engel's classification. At a mean follow up of 62 months, 85.29% of the patients were seizure free (Engel's Class I). All 8 patients with intraoperative electrocorticography (ECoG) guided resection were seizure free. Presence of a residual lesion was significantly associated with persistence of seizures post surgery (p = 0.002). Group analysis revealed no significant shifts in IQ and memory scores postoperatively. There was a significant improvement in the quality of life scores (total and across all subdomains) in all patients (p < 0.001). Postoperative EEG abnormalities predicted unfavorable ​seizure outcome. Surgery for temporal lobe tumors and refractory epilepsy offers complete seizure freedom in majority. Complete surgical excision of the epileptogenic zone is of paramount importance in achieving seizure freedom. Intraoperative electrocorticography (EcoG) is a useful adjunct to ensure complete removal of epileptogenic zone, thus achieving optimal seizure freedom. There is a significant improvement in the quality of life scores (p < 0.001) with no negative impact of surgery on memory and intelligence. Even the patients who are not seizure free can achieve worthwhile improvement post surgery. Copyright © 2015 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

Minimally invasive surgical approaches for temporal lobe epilepsy

PubMed Central

Chang, Edward F.; Englot, Dario J.; Vadera, Sumeet

2016-01-01

Surgery can be a highly effective treatment for medically refractory temporal lobe epilepsy (TLE). The emergence of minimally invasive resective and nonresective treatment options has led to interest in epilepsy surgery among patients and providers. Nevertheless, not all procedures are appropriate for all patients, and it is critical to consider seizure outcomes with each of these approaches, as seizure freedom is the greatest predictor of patient quality of life. Standard anterior temporal lobectomy (ATL) remains the gold standard in the treatment of TLE, with seizure freedom resulting in 60–80% of patients. It is currently the only resective epilepsy surgery supported by randomized controlled trials and offers the best protection against lateral temporal seizure onset. Selective amygdalohippocampectomy techniques preserve the lateral cortex and temporal stem to varying degrees and can result in favorable rates of seizure freedom but the risk of recurrent seizures appears slightly greater than with ATL, and it is not clear whether neuropsychological outcomes are improved with selective approaches. Stereotactic radiosurgery presents an opportunity to avoid surgery altogether, with seizure outcomes now under investigation. Stereotactic laser thermo-ablation allows destruction of the mesial temporal structures with low complication rates and minimal recovery time, and outcomes are also under study. Finally, while neuromodulatory devices such as responsive neurostimulation, vagus nerve stimulation, and deep brain stimulation have a role in the treatment of certain patients, these remain palliative procedures for those who are not candidates for resection or ablation, as complete seizure freedom rates are low. Further development and investigation of both established and novel strategies for the surgical treatment of TLE will be critical moving forward, given the significant burden of this disease. PMID:26017774

Clinico-pathological factors influencing surgical outcome in drug resistant epilepsy secondary to mesial temporal sclerosis.

PubMed

Savitr Sastri, B V; Arivazhagan, A; Sinha, Sanjib; Mahadevan, Anita; Bharath, R D; Saini, J; Jamuna, R; Kumar, J Keshav; Rao, S L; Chandramouli, B A; Shankar, S K; Satishchandra, P

2014-05-15

Mesial temporal sclerosis (MTS) is the most common cause of drug resistant epilepsy amenable for surgical treatment and seizure control. This study analyzed the outcome of patients with MTS following anterior temporal lobectomy and amygdalohippocampectomy (ATL-AH) over 10 years and correlated the electrophysiological and radiological factors with the post operative seizure outcome. Eighty seven patients were included in the study. Sixty seven (77.2%) patients had an Engel Class 1 outcome, 9 (11.4%) had Class 2 outcome. Engel's class 1 outcome was achieved in 89.9% at 1 year, while it reduced slightly to 81.9% at 2 years and 76.2% at 5 year follow up. Seventy seven (88.5%) patients had evidence of hippocampal sclerosis on histopathology. Dual pathology was observed in 19 of 77 specimens with hippocampal sclerosis, but did not influence the outcome. Factors associated with an unfavorable outcome included male gender (p=0.04), and a higher frequency of pre-operative seizures (p=0.005), whereas the presence of febrile seizures (p=0.048) and loss of hippocampal neurons in CA4 region on histopathology (p=0.040) were associated with favorable outcome. The effect of CA4 loss on outcome is probably influenced by neuronal loss in other subfields as well since isolated CA4 loss was rare. Abnormal post operative EEG at the end of 1 week was found to be a significant factor predicting unfavorable outcome (p=0.005). On multivariate analysis, the pre-operative seizure frequency was the only significant factor affecting outcome. The present study observed excellent seizure free outcome in a carefully selected cohort of patients with MTS with refractory epilepsy. The presence of dual pathology did not influence the outcome. Copyright © 2014 Elsevier B.V. All rights reserved.

Gender differences in prevalence of psychiatric disorders, levels of alexithymia, and coping strategies in patients with refractory mesial temporal epilepsy and comorbid psychogenic nonepileptic seizures.

PubMed

de Barros, Amanda Cristian Serafim; Furlan, Ana Eliza Romano; Marques, Lucia Helena Neves; de Araújo Filho, Gerardo Maria

2018-05-01

The objective of this study was to investigate the psychological aspects and psychiatric disorders (PDs) in patients dually diagnosed with refractory temporal lobe epilepsy and mesial temporal sclerosis (TLE-MTS) with psychogenic nonepileptic seizures (PNES) treated in a tertiary center in order to find any gender differences in psychiatric, clinical, and sociodemographic characteristics. Psychiatric assessment was performed through the Diagnostic and Statistical Manual for Psychiatric Disorders - 5th edition (DSM-5). The Brazilian versions of the Medical Outcomes Study 36 (SF-36), Toronto Alexithymia Scale (TAS-20), Hamilton Depression Scale (HAM-D), Hamilton Anxiety Scale (HAM-A), and Ways of Coping Checklist (WCC) were applied. Of the 47 patients enrolled (25 females; 53.2%), females were significantly more likely to have a history of previous psychiatric treatment (P=0.02), family history of epilepsy (P=0.01), and family history of PD (P=0.03). They also presented earlier onset of PNES (P=0.01) and higher PNES duration (P=0.02) compared with males. Major depressive disorder (MDD) was the most frequent PD (24; 51.0%). Females presented more psychiatric diagnoses (P<0.001), more diagnoses of MDD (P<0.001), and posttraumatic stress disorder (PTSD) (P<0.001). Several differences regarding quality of life, levels of alexithymia, anxiety/depressive symptoms, and coping strategies were observed between groups. There are significant gender differences in psychiatric, clinical, and sociodemographic aspects in a group of patients with TLE-MTS and PNES, as well as in quality of life, levels of alexithymia, anxiety/depressive symptoms, and coping strategies. These gender differences suggest that specific approaches might be adopted depending on the patient's gender and, consequently, their distinct psychological/psychiatric profile. Copyright © 2018 Elsevier Inc. All rights reserved.

Predictive factors of long-term outcomes of surgery for mesial temporal lobe epilepsy associated with hippocampal sclerosis.

PubMed

Mathon, Bertrand; Bielle, Franck; Samson, Séverine; Plaisant, Odile; Dupont, Sophie; Bertrand, Anne; Miles, Richard; Nguyen-Michel, Vi-Huong; Lambrecq, Virginie; Calderon-Garcidueñas, Ana Laura; Duyckaerts, Charles; Carpentier, Alexandre; Baulac, Michel; Cornu, Philippe; Adam, Claude; Clemenceau, Stéphane; Navarro, Vincent

2017-08-01

The reasons for failure of surgical treatment for mesial temporal lobe epilepsy (MTLE) associated with hippocampal sclerosis (HS) remain unclear. This retrospective study analyzed seizure, cognitive, and psychiatric outcomes, searching for factors associated with seizure relapse or cognitive and psychiatric deterioration after MTLE-HS surgery. Seizure, cognitive, and psychiatric outcomes were reviewed after 389 surgeries performed between 1990 and 2015 on patients aged 15-67 years at a tertiary center. Three surgical approaches were used: anterior temporal lobectomy (ATL; n = 209), transcortical selective amygdalohippocampectomy (SAH; n = 144), and transsylvian SAH (n = 36). With an average follow-up of 8.7 years (range = 1.0-25.2), seizure outcome was classified as Engel I in 83.7% and Engel Ia in 57.1% of patients. The histological classification of HS was type 1 for 75.3% of patients, type 2 for 18.7%, and type 3 for 1.2%. Two factors were significantly associated with seizure recurrence: past history of status epilepticus and preoperative intracranial electroencephalographic recording. In contrast, neither HS type, the presence of a dual pathology, nor surgical approach was associated with seizure outcome. Risk of cognitive impairment was 3.12 (95% confidence interval = 1.27-7.70), greater in patients after ATL than in patients after transcortical SAH. A presurgical psychiatric history and postoperative cognitive impairment were associated with poor psychiatric outcome. The SAH and ATL approaches have similar beneficial effects on seizure control, whereas transcortical SAH tends to minimize cognitive deterioration after surgery. Variation in postsurgical outcome with the class of HS should be investigated further. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

Memory for fearful faces across development: specialization of amygdala nuclei and medial temporal lobe structures.

PubMed

Pinabiaux, Charlotte; Hertz-Pannier, Lucie; Chiron, Catherine; Rodrigo, Sébastian; Jambaqué, Isabelle; Noulhiane, Marion

2013-01-01

Enhanced memory for emotional faces is a significant component of adaptive social interactions, but little is known on its neural developmental correlates. We explored the role of amygdaloid complex (AC) and medial temporal lobe (MTL) in emotional memory recognition across development, by comparing fMRI activations of successful memory encoding of fearful and neutral faces in children (n = 12; 8-12 years) and adolescents (n = 12; 13-17 years). Memory for fearful faces was enhanced compared with neutral ones in adolescents, as opposed to children. In adolescents, activations associated with successful encoding of fearful faces were centered on baso-lateral AC nuclei, hippocampus, enthorhinal and parahippocampal cortices. In children, successful encoding of fearful faces relied on activations of centro-mesial AC nuclei, which was not accompanied by functional activation of MTL memory structures. Successful encoding of neutral faces depended on activations in anterior MTL region (hippocampal head and body) in adolescents, but more posterior ones (hippocampal tail and parahippocampal cortex) in children. In conclusion, two distinct functional specializations emerge from childhood to adolescence and result in the enhancement of memory for these particular stimuli: the specialization of baso-lateral AC nuclei, which is associated with the expertise in processing emotional facial expression, and which is intimately related to the specialization of MTL memory network. How the interplay between specialization of AC nuclei and of MTL memory structures is fundamental for the edification of social interactions remains to be elucidated.

Memory for fearful faces across development: specialization of amygdala nuclei and medial temporal lobe structures

PubMed Central

Pinabiaux, Charlotte; Hertz-Pannier, Lucie; Chiron, Catherine; Rodrigo, Sébastian; Jambaqué, Isabelle; Noulhiane, Marion

2013-01-01

Enhanced memory for emotional faces is a significant component of adaptive social interactions, but little is known on its neural developmental correlates. We explored the role of amygdaloid complex (AC) and medial temporal lobe (MTL) in emotional memory recognition across development, by comparing fMRI activations of successful memory encoding of fearful and neutral faces in children (n = 12; 8–12 years) and adolescents (n = 12; 13–17 years). Memory for fearful faces was enhanced compared with neutral ones in adolescents, as opposed to children. In adolescents, activations associated with successful encoding of fearful faces were centered on baso-lateral AC nuclei, hippocampus, enthorhinal and parahippocampal cortices. In children, successful encoding of fearful faces relied on activations of centro-mesial AC nuclei, which was not accompanied by functional activation of MTL memory structures. Successful encoding of neutral faces depended on activations in anterior MTL region (hippocampal head and body) in adolescents, but more posterior ones (hippocampal tail and parahippocampal cortex) in children. In conclusion, two distinct functional specializations emerge from childhood to adolescence and result in the enhancement of memory for these particular stimuli: the specialization of baso-lateral AC nuclei, which is associated with the expertise in processing emotional facial expression, and which is intimately related to the specialization of MTL memory network. How the interplay between specialization of AC nuclei and of MTL memory structures is fundamental for the edification of social interactions remains to be elucidated. PMID:24399958

Frequency and characteristics of dual pathology in patients with lesional epilepsy.

PubMed

Cendes, F; Cook, M J; Watson, C; Andermann, F; Fish, D R; Shorvon, S D; Bergin, P; Free, S; Dubeau, F; Arnold, D L

1995-11-01

We studied 167 patients who had identifiable lesions and temporal or extratemporal partial epilepsy. Pathology included neuronal migration disorders (NMDs) (48), low-grade tumors (52), vascular malformations (34), porencephalic cysts (16), and gliotic lesions as a result of cerebral insults early in life (17). MRI volumetric studies using thin (1.5- or 3-mm) coronal images were performed in all patients and in 44 age-matched normal controls. An atrophic hippocampal formation (HF), indicating dual pathology, was present in 25 patients (15%). Abnormal HF volumes were present in those with lesions involving temporal (17%) but also extratemporal (14%) areas. Age at onset and duration of epilepsy did not influence the presence of HF atrophy. However, febrile seizures in early childhood were more frequently, although not exclusively, found in patients with hippocampal atrophy. The frequency of hippocampal atrophy in our patients with low-grade tumors (2%) and vascular lesions (9%) was low. Dual pathology was far more common in patients with NMDs (25%), porencephalic cysts (31%), and reactive gliosis (23.5%). Some structural lesions, such as NMDs, are more likely to be associated with hippocampal atrophy, independent of the distance of the lesion from the HF. In other types of lesions, such as vascular malformations, dual pathology was found when the lesion was close to the HF. A common pathogenic mechanism during pre- or perinatal development may explain the occurrence of concomitant mesial temporal sclerosis and other structural lesions because of either (1) associated developmental abnormalities or (2) predisposition to prolonged febrile convulsions.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical Management and Long-Term Seizure Outcome After Surgery for Temporal Lobe Epilepsy Associated with Cerebral Cavernous Malformations.

PubMed

Yang, Peng-Fan; Pei, Jia-Sheng; Jia, Yan-Zeng; Lin, Qiao; Xiao, Hui; Zhang, Ting-Ting; Zhong, Zhong-Hui

2018-02-01

Operative strategies for cerebral cavernous malformation (CCM)-associated temporal lobe epilepsy and timing of surgical intervention continue to be debated. This study aimed to establish an algorithm to evaluate the efficacy of surgical intervention strategies, to maximize positive surgical outcomes and minimize postsurgical neurologic deficits. 47 patients having undergone operation for CCM-associated temporal lobe epilepsy were retrospectively reviewed. They had received a diagnostic series for seizure localization, including long-term video electroencephalography (vEEG), high-resolution magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET-CT). In patients with mesial temporal lobe CCMs, the involved structures (amygdala, hippocampus, or parahippocampal gyrus) were resected in addition to the lesions. Patients with neocortical epileptogenic CCM underwent extended lesionectomy guided by intraoperative electrocorticography; further performance of amygdalohippocampectomy depended on the extent of hippocampal epileptogenicity. The study cohort contained 28 patients with drug-resistant epilepsy (DRE), 12 with chronic epilepsy (CE), and 7 with sporadic seizure (SS). Normal temporal lobe metabolism was seen in 7/7 patients of the SS group. Hypometabolism was found in all patients with chronic disease except for those with posterior inferior and middle temporal gyrus cavernous malformations (CMs). Of the 31 patients with superficial neocortical CCM, 7 had normal PET without hippocampal sclerosis, 14 had ipsilateral temporal lobe hypometabolism without hippocampal sclerosis, and 10 had obvious hippocampal sclerosis and hypometabolism. Seizure freedom in DRE, CE, and SS was 82.1%, 75%, and 100%, respectively. A significant difference was found between lesion laterality and postoperative seizure control; the rate was lower in left-sided cases because of less aggressive resection. Our study demonstrates that the data from the presurgical evaluation, particularly regarding CM location, responsiveness to antiepileptic drugs, and temporal lobe metabolism, are crucial parameters for choosing surgical approaches to CCM-associated temporal lobe epilepsy. By this operative strategy, patients may receive maximized seizure control and minimized postsurgical neurologic sequelae. Copyright © 2017 Elsevier Inc. All rights reserved.

Temporal plus epilepsy: Anatomo-electroclinical subtypes

PubMed Central

Andrade-Machado, René; Benjumea-Cuartas, Vanessa

2016-01-01

Background: Mesial temporal lobe epilepsy (TLE) is a remediable epileptic syndrome. About 40% of patients continue to have seizures after standard temporal lobectomy. It has been suggested that some of these patients could actually suffer from a more complex epileptogenic network. Because a few papers have been dedicated to this topic, we decided to write an article updating this theme. Methods: We performed a literature search using the following terminology: “temporal plus epilepsy and networks,” “temporal plus epilepsy,” “orbito-temporal epilepsy,” “temporo-insular epilepsy,” “temporo-parieto-occipital (TPO) epilepsy,” “parieto-temporal epilepsy,” “intracortical evoked potential and temporal plus epilepsy,” “temporal lobe connectivity and epilepsy,” “intracortical evoked potential and epilepsy surgery,” “role of extratemporal structures in TLE,” “surgical failure after temporal lobectomy,” “Diffusion tensor imaging (DTI) and temporal epilepsy,” and “positron emission tomography (PET) in temporal plus lobe epilepsy” in the existing PubMed databases. We searched only English and Spanish literature. Only papers that fit with the above-mentioned descriptors were included as part of the evidence. Other articles were used to reference some aspects of the temporal plus epilepsy. Results: A total of 48 papers from 2334 were revised. The most frequently reported auras in these groups of patients are gustatory hallucinations, vestibular illusions, laryngeal and throat constriction, atypical distribution of somatosensory symptoms (perioral and hands, bilaterally hands paresthesias, trunk and other). The most common signs are tonic posturing, hemifacial twist, and frequent bilateral clonic movements. Interictal electroencephalographic (EEG) patterns exhibit regional and frequently bilateral spikes and/or slow waves. The first ictal electrographic change is mostly regional. It is important to note that the evidence is supported by case series or case reports. Thus, most of the data presented could represent the features on these cases and not actually the totality of the iceberg. Conclusion: Temporal plus epilepsy is a diagnosis that can be done only after the invasive recordings have been analyzed but an adequate suspicion may arise based on clinical, EEG and imaging data. PMID:27648177

Micro computed tomography evaluation of the Self-adjusting file and ProTaper Universal system on curved mandibular molars.

PubMed

Serefoglu, Burcu; Piskin, Beyser

2017-09-26

The aim of this investigation was to compare the cleaning and shaping efficiency of Self-adjusting file and Protaper, and to assess the correlation between root canal curvature and working time in mandibular molars using micro-computed tomography. Twenty extracted mandibular molars instrumented with Protaper and Self-adjusting file and the total working time was measured in mesial canals. The changes in canal volume, surface area and structure model index, transportation, uninstrumented area and the correlation between working-time and the curvature were analyzed. Although no statistically significant difference was observed between two systems in distal canals (p>0.05), a significantly higher amount of removed dentin volume and lower uninstrumented area were provided by Protaper in mesial canals (p<0.0001). A correlation between working-time and the canal-curvature was also observed in mesial canals for both groups (SAFr 2 =0.792, p<0.0004, PTUr 2 =0.9098, p<0.0001).

Temporal Lobe Epilepsy Semiology

PubMed Central

Blair, Robert D. G.

2012-01-01

Epilepsy represents a multifaceted group of disorders divided into two broad categories, partial and generalized, based on the seizure onset zone. The identification of the neuroanatomic site of seizure onset depends on delineation of seizure semiology by a careful history together with video-EEG, and a variety of neuroimaging technologies such as MRI, fMRI, FDG-PET, MEG, or invasive intracranial EEG recording. Temporal lobe epilepsy (TLE) is the commonest form of focal epilepsy and represents almost 2/3 of cases of intractable epilepsy managed surgically. A history of febrile seizures (especially complex febrile seizures) is common in TLE and is frequently associated with mesial temporal sclerosis (the commonest form of TLE). Seizure auras occur in many TLE patients and often exhibit features that are relatively specific for TLE but few are of lateralizing value. Automatisms, however, often have lateralizing significance. Careful study of seizure semiology remains invaluable in addressing the search for the seizure onset zone. PMID:22957241

Glutamate metabolism in temporal lobe epilepsy as revealed by dynamic proton MRS following the infusion of [U13-C] glucose.

PubMed

Bartnik-Olson, Brenda L; Ding, Daniel; Howe, John; Shah, Amul; Losey, Travis

2017-10-01

Focal metabolic dysfunction commonly observed in temporal lobe epilepsy (TLE), and is associated with the development of medical intractability and neurocognitive deficits. It has not been established if this dysfunction is due to cell loss or biochemical dysfunction in metabolic pathways. To explore this question, dynamic 1 H MRS following an infusion of [U 13 - C] glucose was performed to measure glutamate (Glu) metabolism. Subjects (n=6) showed reduced Glu levels (p<0.01) in the ipsilateral mesial temporal lobe (MTL) compared with controls (n=4). However, the rate of 13 C incorporation into Glu did not differ between those with epilepsy and controls (p=0.77). This suggests that reduced Glu concentrations in the region of the seizure focus are not due to disruptions in metabolic pathways, but may instead be due to neuronal loss or simplification. Copyright © 2017 Elsevier B.V. All rights reserved.

Randomized clinical trial comparing control of maxillary anchorage with 2 retraction techniques.

PubMed

Xu, Tian-Min; Zhang, Xiaoyun; Oh, Hee Soo; Boyd, Robert L; Korn, Edward L; Baumrind, Sheldon

2010-11-01

The objective of this pilot randomized clinical trial was to investigate the relative effectiveness of anchorage conservation of en-masse and 2-step retraction techniques during maximum anchorage treatment in patients with Angle Class I and Class II malocclusions. Sixty-four growing subjects (25 boys, 39 girls; 10.2-15.9 years old) who required maximum anchorage were randomized to 2 treatment techniques: en-masse retraction (n = 32) and 2-step retraction (n = 32); the groups were stratified by sex and starting age. Each patient was treated by a full-time clinic instructor experienced in the use of both retraction techniques at the orthodontic clinic of Peking University School of Stomatology in China. All patients used headgear, and most had transpalatal appliances. Lateral cephalograms taken before treatment and at the end of treatment were used to evaluate treatment-associated changes. Differences in maxillary molar mesial displacement and maxillary incisor retraction were measured with the before and after treatment tracings superimposed on the anatomic best fit of the palatal structures. Differences in mesial displacement of the maxillary first molar were compared between the 2 treatment techniques, between sexes, and between different starting-age groups. Average mesial displacement of the maxillary first molar was slightly less in the en-masse group than in the 2-step group (mean, -0.36 mm; 95% CI, -1.42 to 0.71 mm). The average mesial displacement of the maxillary first molar for both treatment groups pooled (n = 63, because 1 patient was lost to follow-up) was 4.3 ± 2.1 mm (mean ± standard deviation). Boys had significantly more mesial displacement than girls (mean difference, 1.3 mm; P <0.03). Younger adolescents had significantly more mesial displacement than older adolescents (mean difference, 1.3 mm; P <0.02). Average mesial displacement of the maxillary first molar with 2-step retraction was slightly greater than that for en-masse retraction, but the difference did not reach statistical significance. This finding appears to contradict the belief of many clinicians that 2-step canine retraction is more effective than en-masse retraction in preventing clinically meaningful anchorage loss. Copyright © 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Effects of dual pathology on cognitive outcome following left anterior temporal lobectomy for treatment of epilepsy.

PubMed

Prayson, B E; Prayson, R A; Kubu, C S; Bingaman, W; Najm, I M; Busch, R M

2013-09-01

The objective of this retrospective study was to determine if dual pathology [DUAL - focal cortical dysplasia (FCD) and mesial temporal sclerosis (MTS)] in patients with left temporal lobe epilepsy is associated with greater risk for cognitive decline following temporal lobectomy than single pathology (MTS only). Sixty-three adults (Mage=36.5years, female: 52.4%) who underwent left anterior temporal lobectomy for treatment of epilepsy (MTS=28; DUAL=35) completed preoperative and postoperative neuropsychological evaluations. The base rate of dual pathology was 55.5%. Repeated measures ANOVAs yielded significant 2-way interactions (group×time) on most measures of language and memory with generally moderate effect sizes. Specifically, patients with MTS only demonstrated postoperative declines, while those with dual pathology remained unchanged or improved. Results suggest that dual pathology may be associated with better cognitive outcome following epilepsy surgery than MTS alone, possibly reflecting limited functionality of the resected tissue or intrahemispheric reorganization of function in the context of a developmental lesion. Copyright © 2013 Elsevier Inc. All rights reserved.

Childhood temporal lobe epilepsy: correlation between electroencephalography and magnetic resonance spectroscopy: a case-control study.

PubMed

Azab, Seham Fa; Sherief, Laila M; Saleh, Safaa H; Elshafeiy, Mona M; Siam, Ahmed G; Elsaeed, Wafaa F; Arafa, Mohamed A; Bendary, Eman A; Sherbiny, Hanan S; Elbehedy, Rabab M; Aziz, Khalid A

2015-04-18

The diagnosis of epilepsy should be made as early as possible to give a child the best chance for treatment success and also to decrease complications such as learning difficulties and social and behavioral problems. In this study, we aimed to assess the ability of magnetic resonance spectroscopy (MRS) in detecting the lateralization side in patients with Temporal lobe epilepsy (TLE) in correlation with EEG and MRI findings. This was a case-control study including 40 patients diagnosed (clinically and by EEG) as having temporal lobe epilepsy aged 8 to 14 years (mean, 10.4 years) and 20 healthy children with comparable age and gender as the control group. All patients were subjected to clinical examination, interictal electroencephalography and magnetic resonance imaging (MRI). Proton magnetic resonance spectroscopic examination (MRS) was performed to the patients and the controls. According to the findings of electroencephalography, our patients were classified to three groups: Group 1 included 20 patients with unitemporal (lateralized) epileptic focus, group 2 included 12 patients with bitemporal (non-lateralized) epileptic focus and group 3 included 8 patients with normal electroencephalography. Magnetic resonance spectroscopy could lateralize the epileptic focus in 19 patients in group 1, nine patients in group2 and five patients in group 3 with overall lateralization of (82.5%), while electroencephalography was able to lateralize the focus in (50%) of patients and magnetic resonance imaging detected lateralization of mesial temporal sclerosis in (57.5%) of patients. Magnetic resonance spectroscopy is a promising tool in evaluating patients with epilepsy and offers increased sensitivity to detect temporal pathology that is not obvious on structural MRI imaging.

Functional substrate for memory function differences between patients with left and right mesial temporal lobe epilepsy associated with hippocampal sclerosis.

PubMed

Jin, Seung-Hyun; Chung, Chun Kee

2015-10-01

Little is known about the functional substrate for memory function differences in patients with left or right mesial temporal lobe epilepsy (mTLE) associated with hippocampal sclerosis (HS) from an electrophysiological perspective. To characterize these differences, we hypothesized that hippocampal theta connectivity in the resting-state might be different between patients with left and right mTLE with HS and be correlated with memory performance. Resting-state hippocampal theta connectivity, identified via whole-brain magnetoencephalography, was evaluated. Connectivity and memory function in 41 patients with mTLE with HS (left mTLE=22; right mTLE=19) were compared with those in 46 age-matched healthy controls and 28 patients with focal cortical dysplasia (FCD) but without HS. Connectivity between the right hippocampus and the left middle frontal gyrus was significantly stronger in patients with right mTLE than in patients with left mTLE. Moreover, this connectivity was positively correlated with delayed verbal recall and recognition scores in patients with mTLE. Patients with left mTLE had greater delayed recall impairment than patients with right mTLE and FCD. Similarly, delayed recognition performance was worse in patients with left mTLE than in patients with right mTLE and FCD. No significant differences in memory function between patients with right mTLE and FCD were detected. Patients with right mTLE showed significantly stronger hippocampal theta connectivity between the right hippocampus and left middle frontal gyrus than patients with FCD and left mTLE. Our results suggest that right hippocampal-left middle frontal theta connectivity could be a functional substrate that can account for differences in memory function between patients with left and right mTLE. This functional substrate might be related to different compensatory mechanisms against the structural hippocampal lesions in left and right mTLE groups. Given the positive correlation between connectivity and delayed verbal memory function, hemispheric-specific hippocampal-frontal theta connectivity assessment could be useful as an electrophysiological indicator of delayed verbal memory function in patients with mTLE with HS. Copyright © 2015 Elsevier Inc. All rights reserved.

Magnetic resonance imaging of the brain in epileptic adult patients: experience in Ramathibodi Hospital.

PubMed

Solosrungruang, Anusorn; Laothamatas, Jiraporn; Chinwarun, Yotin

2007-04-01

The purpose of the present study was to classify the imaging structural abnormalities of epileptic adult patients referred for magnetic resonance imaging (MR imaging) of the brain at Ramathibodi Hospital and to correlate with the clinical data and EEG. MR imaging of 91 adult epileptic patients (age ranging from 15-85 years old with an average of 36.90 years old) were retrospectively reviewed and classified into eight groups according to etiologies. Then clinical data and EEG correlations were analyzed using the Kappa analysis. All of the MR imaging of the brain were performed at Ramathibodi Hospital from January 2001 to December 2002. Secondary generalized tonic clonic seizure was the most common clinical presenting seizure type. Extra temporal lobe epilepsy was the most common clinical diagnosis. Of the thirty-three patients who underwent EEG before performing MR imaging, 17 had normal EEG From MR imaging, temporal lobe lesion was the main affected location and mesial temporal sclerosis (MTS) was the most common cause of the epilepsy in patients. For age group classification, young adult (15-34 years old) and adult (35-64 years old) age groups, MTS was the most common etiology of epilepsy with cortical dysplasia being the second most common cause for the first group and vascular disease for the latter group. For the older age group (> 64 years old), vascular disease and idiopathic cause were equally common etiologies. MRI, EEG findings, and clinical data were all concordant with statistical significance. MRI is the non-invasive modality of choice for evaluation of the epileptic patients. The result is concordant with the clinical and EEG findings. It can detect and localize the structural abnormality accurately and is useful in the treatment planning.

Brain network dynamics characterization in epileptic seizures. Joint directed graph and pairwise synchronization measures

NASA Astrophysics Data System (ADS)

Rodrigues, A. C.; Machado, B. S.; Florence, G.; Hamad, A. P.; Sakamoto, A. C.; Fujita, A.; Baccalá, L. A.; Amaro, E.; Sameshima, K.

2014-12-01

Here we propose and evaluate a new approach to analyse multichannel mesial temporal lobe epilepsy EEG data from eight patients through complex network and synchronization theories. The method employs a Granger causality test to infer the directed connectivity graphs and a wavelet transform based phase synchronization measure whose characteristics allow studying dynamical transitions during epileptic seizures. We present a new combined graph measure that quantifies the level of network hub formation, called network hub out-degree, which closely reflects the level of synchronization observed during the ictus.

Diminution of context association memory structure in subjects with subjective cognitive decline.

PubMed

Fan, Ling-Yun; Lai, Ya-Mei; Chen, Ta-Fu; Hsu, Yung-Chin; Chen, Pin-Yu; Huang, Kuo-Zhou; Cheng, Ting-Wen; Tseng, Wen-Yi Isaac; Hua, Mau-Sun; Chen, Ya-Fang; Chiu, Ming-Jang

2018-06-01

Alzheimer's disease (AD) progresses insidiously from the preclinical stage to dementia. While people with subjective cognitive decline (SCD) have normal cognitive performance, some may be in the preclinical stage of AD. Neurofibrillary tangles appear first in the transentorhinal cortex, followed by the entorhinal cortex in the clinically silent stage of AD. We expected the earliest changes in subjects with SCD to occur in medial temporal subfields other than the hippocampal proper. These selective structural changes would affect specific memory subcomponents. We used the Family Picture subtest of the Wechsler Memory Scale-III, which was modified to separately compute character, activity, and location subscores for episodic memory subcomponents. We recruited 43 subjects with SCD, 44 subjects with amnesic mild cognitive impairment, and 34 normal controls. MRI was used to assess cortical thickness, subcortical gray matter volume, and fractional anisotropy. The results demonstrated that SCD subjects showed significant cortical atrophy in their bilateral parahippocampus and perirhinal and the left entorhinal cortices but not in their hippocampal regions. SCD subjects also exhibited significantly decreased mean fractional anisotropy in their bilateral uncinate fasciculi. The diminution of cortical thickness over the mesial temporal subfields corresponded to brain areas with early tangle deposition, and early degradation of the uncinate fasciculus was in accordance with the retrogenesis hypothesis. The parahippocampus and perirhinal cortex contribute mainly to context association memory while the entorhinal cortex, along with the uncinate fasciculus, contributes to content-related contextual memory. We proposed that context association and related memory structures are vulnerable in the SCD stage. © 2018 Wiley Periodicals, Inc.

Mesial frontal lobe epilepsy.

PubMed

Unnwongse, Kanjana; Wehner, Tim; Foldvary-Schaefer, Nancy

2012-10-01

Mesial frontal lobe epilepsies can be divided into epilepsies arising from the anterior cingulate gyrus and those of the supplementary sensorimotor area. They provide diagnostic challenges because they often lack lateralizing or localizing features on clinical semiology and interictal and ictal scalp electroencephalographic (EEG) recordings. A number of unique semiologic features have been described over the last decade in patients with mesial frontal lobe epilepsy (FLE). There are few reports of applying advanced neurophysiologic techniques such as electrical source imaging, magnetoencephalography, EEG/functional magnetic resonance imaging, or analysis of high-frequency oscillations in patients with mesial FLE. Despite these diagnostic challenges, it seems that patients with mesial FLE benefit from epilepsy surgery to the same extent or even better than patients with FLE do, as a whole.

Mandibular first and second molars with three mesial canals: a case series

PubMed Central

Aminsobhani, Mohsen; Bolhari, Behnam; Shokouhinejad, Noushin; Ghorbanzadeh, Abdollah; Ghabraei, Sholeh; Rahmani, Mohamad Bagher

2010-01-01

Adequate cleaning, shaping and filling of the root canal system are mandatory for successful root canal treatment. Thorough knowledge of root canal morphology and unusual anatomy of the tooth is critical for the practitioner. The occurrence and location of the third mesial canal (Middle Mesial Canal) in mandibular first and second molars in relation to other two mesial canals that were treated in private practice were studied. In 27 clinical cases, the presence of a middle mesial canal was demonstrated. The third canal was located in the middle of the distance between the mesiobuccal and mesiolingual canals. This canal configuration was found in six second lower molars and twenty one first molars. Middle mesial canal in all of our cases joined to mesiobuccal or mesiolingual canals. None of the teeth consisted of three independent canals with three apical foramina. In conclusion, every attempt should be made to find and treat all root canals of a tooth. PMID:24778681

DEPDC5 mutations are not a frequent cause of familial temporal lobe epilepsy.

PubMed

Striano, Pasquale; Serioli, Elena; Santulli, Lia; Manna, Ida; Labate, Angelo; Dazzo, Emanuela; Pasini, Elena; Gambardella, Antonio; Michelucci, Roberto; Striano, Salvatore; Nobile, Carlo

2015-10-01

Mutations in the DEPDC5 (DEP domain-containing protein 5) gene are a major cause of familial focal epilepsy with variable foci (FFEVF) and are predicted to account for 12-37% of families with inherited focal epilepsies. To assess the clinical impact of DEPDC5 mutations in familial temporal lobe epilepsy, we screened a collection of Italian families with either autosomal dominant lateral temporal epilepsy (ADLTE) or familial mesial temporal lobe epilepsy (FMTLE). The probands of 28 families classified as ADLTE and 17 families as FMTLE were screened for DEPDC5 mutations by whole exome or targeted massive parallel sequencing. Putative mutations were validated by Sanger sequencing. We identified a DEPDC5 nonsense mutation (c.918C>G; p.Tyr306*) in a family with two affected members, clinically classified as FMTLE. The proband had temporal lobe seizures with prominent psychic symptoms (déjà vu, derealization, and forced thoughts); her mother had temporal lobe seizures, mainly featuring visceral epigastric auras and anxiety. In total, we found a single DEPDC5 mutation in one of (2.2%) 45 families with genetic temporal lobe epilepsy, a proportion much lower than that reported in other inherited focal epilepsies. © 2015 The Authors. Epilepsia published by Wiley Periodicals Inc. on behalf of International League Against Epilepsy.

Familial temporal lobe epilepsy due to focal cortical dysplasia type IIIa.

PubMed

Fabera, Petr; Krijtova, Hana; Tomasek, Martin; Krysl, David; Zamecnik, Josef; Mohapl, Milan; Jiruska, Premysl; Marusic, Petr

2015-09-01

Focal cortical dysplasia (FCD) represents a common cause of refractory epilepsy. It is considered a sporadic disorder, but its occasional familial occurrence suggests the involvement of genetic mechanisms. Siblings with intractable epilepsy were referred for epilepsy surgery evaluation. Both patients were examined using video-EEG monitoring, MRI examination and PET imaging. They underwent left anteromedial temporal lobe resection. Electroclinical features pointed to left temporal lobe epilepsy and MRI examination revealed typical signs of left-sided hippocampal sclerosis and increased white matter signal intensity in the left temporal pole. PET examination confirmed interictal hypometabolism in the left temporal lobe. Histopathological examination of resected tissue demonstrated the presence FCD type IIIa, i.e. hippocampal sclerosis and focal cortical dysplasia in the left temporal pole. We present a unique case of refractory mesial temporal lobe epilepsy in siblings, characterized by an identical clinical profile and histopathology of FCD type IIIa, who were successfully treated by epilepsy surgery. The presence of such a high concordance between the clinical and morphological data, together with the occurrence of epilepsy and febrile seizures in three generations of the family pedigree points towards a possible genetic nature of the observed FCD type IIIa. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Early tissue damage and microstructural reorganization predict disease severity in experimental epilepsy

PubMed Central

Janz, Philipp; Schwaderlapp, Niels; Heining, Katharina; Häussler, Ute; Korvink, Jan G; von Elverfeldt, Dominik; Hennig, Jürgen; Egert, Ulrich

2017-01-01

Mesial temporal lobe epilepsy (mTLE) is the most common focal epilepsy in adults and is often refractory to medication. So far, resection of the epileptogenic focus represents the only curative therapy. It is unknown whether pathological processes preceding epilepsy onset are indicators of later disease severity. Using longitudinal multi-modal MRI, we monitored hippocampal injury and tissue reorganization during epileptogenesis in a mouse mTLE model. The prognostic value of MRI biomarkers was assessed by retrospective correlations with pathological hallmarks Here, we show for the first time that the extent of early hippocampal neurodegeneration and progressive microstructural changes in the dentate gyrus translate to the severity of hippocampal sclerosis and seizure burden in chronic epilepsy. Moreover, we demonstrate that structural MRI biomarkers reflect the extent of sclerosis in human hippocampi. Our findings may allow an early prognosis of disease severity in mTLE before its first clinical manifestations, thus expanding the therapeutic window. DOI: http://dx.doi.org/10.7554/eLife.25742.001 PMID:28746029

Middle mesial canal of the permanent mandibular first molars: an anatomical challenge directly related to the outcome of endodontic treatment.

PubMed

Perlea, Paula; Nistor, Cristina Coralia; Imre, Marina; Gheorghiu, Irina Maria; Iliescu, Alexandru Andrei

2017-01-01

To effectively clean and shape the mandibular permanent first molars it is mandatory to understand in detail their complex internal anatomy. The middle mesial canal is an additional canal located between the usual mesiobuccal and mesiolingual canals in the mesial root of mandibular first molars. The incidence of the middle mesial canal, its relationship with main canals of the mesial root and the possibility for it to be negotiated is an important practical issue in endodontics. To identify the presence of this canal is mandatory. Accordingly, a modified endodontic access, the use of the operating microscope and periapical radiographs in two different horizontal projections are indicated to enhance the long-term favorable outcome of the endodontic treatment.

Quantification of mu and non-mu opiate receptors in temporal lobe epilepsy using positron emission tomography.

PubMed

Mayberg, H S; Sadzot, B; Meltzer, C C; Fisher, R S; Lesser, R P; Dannals, R F; Lever, J R; Wilson, A A; Ravert, H T; Wagner, H N

1991-07-01

Alterations in a variety of neurotransmitter systems have been identified in experimental models of epilepsy and in brain tissue from patients with intractable temporal lobe seizures. The availability of new high-affinity radioligands permits the study of some neuroreceptors in vivo with positron emission tomography (PET). We previously characterized the in vivo binding of 11C-carfentanil, a potent and selective mu opiate receptor agonist, and described increases in 11C-carfentanil binding in the temporal neocortex of patients with unilateral temporal lobe epilepsy. These studies have been extended to 11C-diprenorphine, which labels mu, kappa, and delta opiate receptor subtypes. Paired measurements of opiate receptor binding were performed with PET using 11C-carfentanil and 11C-diprenorphine in patients with unilateral temporal lobe seizures. Carfentanil binding, reflecting changes in mu opiate receptors, was increased in the temporal neocortex and decreased in the amygdala on the side of the epileptic focus. Diprenorphine binding, reflecting mu as well as non-mu opiate subtypes, was not significantly different among regions in the focus and nonfocus temporal lobes. Regional glucose metabolism, measured using 18F-2-fluoro-2-deoxyglucose, was decreased in the mesial and lateral aspects of the temporal lobe ipsilateral to the epileptogenic focus. The variation in pattern of carfentanil and diprenorphine binding supports a differential regulation of opiate subtypes in unilateral temporal lobe epilepsy.

Mesial temporal lobe epilepsy lateralization using SPHARM-based features of hippocampus and SVM

NASA Astrophysics Data System (ADS)

Esmaeilzadeh, Mohammad; Soltanian-Zadeh, Hamid; Jafari-Khouzani, Kourosh

2012-02-01

This paper improves the Lateralization (identification of the epileptogenic hippocampus) accuracy in Mesial Temporal Lobe Epilepsy (mTLE). In patients with this kind of epilepsy, usually one of the brain's hippocampi is the focus of the epileptic seizures, and resection of the seizure focus is the ultimate treatment to control or reduce the seizures. Moreover, the epileptogenic hippocampus is prone to shrinkage and deformation; therefore, shape analysis of the hippocampus is advantageous in the preoperative assessment for the Lateralization. The method utilized for shape analysis is the Spherical Harmonics (SPHARM). In this method, the shape of interest is decomposed using a set of bases functions and the obtained coefficients of expansion are the features describing the shape. To perform shape comparison and analysis, some pre- and post-processing steps such as "alignment of different subjects' hippocampi" and the "reduction of feature-space dimension" are required. To this end, first order ellipsoid is used for alignment. For dimension reduction, we propose to keep only the SPHARM coefficients with maximum conformity to the hippocampus shape. Then, using these coefficients of normal and epileptic subjects along with 3D invariants, specific lateralization indices are proposed. Consequently, the 1536 SPHARM coefficients of each subject are summarized into 3 indices, where for each index the negative (positive) value shows that the left (right) hippocampus is deformed (diseased). Employing these indices, the best achieved lateralization accuracy for clustering and classification algorithms are 85% and 92%, respectively. This is a significant improvement compared to the conventional volumetric method.

Default mode network connectivity indicates episodic memory capacity in mesial temporal lobe epilepsy.

PubMed

McCormick, Cornelia; Quraan, Maher; Cohn, Melanie; Valiante, Taufik A; McAndrews, Mary Pat

2013-05-01

The clinical relevance of resting state functional connectivity in neurologic disorders, including mesial temporal lobe epilepsy (mTLE), remains unclear. This study investigated how connectivity in the default mode network changes with unilateral damage to one of its nodes, the hippocampus (HC), and how such connectivity can be exploited clinically to characterize memory deficits and indicate postsurgical memory change. Functional magnetic resonance imaging (fMRI) resting state scans and neuropsychological memory assessments (Warrington Recognition Tests for Words and Faces) were performed on 19 healthy controls, 20 patients with right mTLE, and 18 patients with left mTLE. In addition, postsurgical fMRI resting state and memory change (postsurgical memory performance-presurgical memory performance) data were available for half of these patients. Patients with mTLE showed reduced connectivity from the posterior cingulate cortex (PCC) to the epileptogenic HC and increased PCC connectivity to the contralateral HC. Stronger PCC connectivity to the epileptogenic HC was associated with better presurgical memory and with greater postsurgical memory decline. Stronger PCC connectivity to the contralateral HC was associated with less postsurgical memory decline. Following surgery, PCC connectivity to the remaining HC increased from presurgical values and showed enhanced correlation with postsurgical memory function. It is notable that this index was superior to others (hippocampal volume, preoperative memory scores) in explaining variance in memory change following surgery. Our results demonstrate the striking clinical significance of the brain's intrinsic connectivity in evaluating cognitive capacity and indicating the potential of postsurgical cognitive morbidity in patients with mTLE. Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.

Age-Dependent Mesial Temporal Lobe Lateralization in Language FMRI

PubMed Central

Sepeta, Leigh N.; Berl, Madison M.; Wilke, Marko; You, Xiaozhen; Mehta, Meera; Xu, Benjamin; Inati, Sara; Dustin, Irene; Khan, Omar; Austermuehle, Alison; Theodore, William H.; Gaillard, William D.

2015-01-01

Objective FMRI activation of the mesial temporal lobe (MTL) may be important for epilepsy surgical planning. We examined MTL activation and lateralization during language fMRI in children and adults with focal epilepsy. Methods 142 controls and patients with left hemisphere focal epilepsy (Pediatric: epilepsy, n = 17, mean age = 9.9 ± 2.0; controls, n = 48; mean age = 9.1 ± 2.6; Adult: epilepsy, n = 20, mean age = 26.7 ± 5.8; controls, n = 57, mean age = 26.2 ± 7.5) underwent 3T fMRI using a language task (auditory description decision task). Image processing and analyses were conducted in SPM8; ROIs included MTL, Broca’s area, and Wernicke’s area. We assessed group and individual MTL activation, and examined degree of lateralization. Results Patients and controls (pediatric and adult) demonstrated group and individual MTL activation during language fMRI. MTL activation was left lateralized for adults but less so in children (p’s < 0.005). Patients did not differ from controls in either age group. Stronger left-lateralized MTL activation was related to older age (p = 0.02). Language lateralization (Broca’s and Wernicke’s) predicted 19% of the variance in MTL lateralization for adults (p = 0.001), but not children. Significance Language fMRI may be used to elicit group and individual MTL activation. The developmental difference in MTL lateralization and its association with language lateralization suggests a developmental shift in lateralization of MTL function, with increased left lateralization across the age span. This shift may help explain why children have better memory outcomes following resection compared to adults. PMID:26696589

Altered self-identity and autobiographical memory in epilepsy.

PubMed

Allebone, James; Rayner, Genevieve; Siveges, Benjamin; Wilson, Sarah J

2015-12-01

Research suggests that individuals with chronic epilepsy display differences in their self-identity. The mechanisms by which self-identity is altered, however, are not well understood. Neural networks supporting autobiographical memory retrieval in the mesial temporal (MT) lobe are thought to be fundamental to self-identity processes. Thus, we examined differences in self-identity and autobiographical memory in patients with either MT or non-mesial temporal (NMT) foci with early or late age of habitual seizure onset. Participants included 102 adults: 51 healthy individuals and 51 patients with drug-resistant focal seizures (19 MT, 32 NMT). We used the Ego Identity Process Questionnaire to profile the identity development of participants, and examined how this related to memory function assessed using the Autobiographical Memory Test. Patients and controls had strikingly different self-identity profiles, with early onset MT patients showing the least identity development compared to controls and other patient groups. In contrast, late-onset NMT patients showed the highest level of identity development of the patient groups and closely resembled healthy controls (p < 0.05 for all comparisons). For all MT patients, poor autobiographical memory retrieval was correlated with altered self-identity (p < 0.001). No associations between autobiographical memory and self-identity were evident in the NMT group. Self-identity in epilepsy may be modulated by the extent to which seizure foci impinge on the autobiographical memory network and the timing of seizure onset. Early disruption to MT regions of the autobiographical memory network may constitute a neurocognitive mechanism by which self-identity is altered in chronic focal epilepsy. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

Network specific change in white matter integrity in mesial temporal lobe epilepsy.

PubMed

Imamura, Hisaji; Matsumoto, Riki; Takaya, Shigetoshi; Nakagawa, Tomokazu; Shimotake, Akihiro; Kikuchi, Takayuki; Sawamoto, Nobukatsu; Kunieda, Takeharu; Mikuni, Nobuhiro; Miyamoto, Susumu; Fukuyama, Hidenao; Takahashi, Ryosuke; Ikeda, Akio

2016-02-01

To identify the specific change of white matter integrity that occurs in the brain network related to epileptic activity in patients with mesial temporal lobe epilepsy (MTLE). We recruited 18 patients with MTLE and 18 healthy subjects. In MTLE patients, the remote functional-deficit zone was delineated using fluorodeoxyglucose positron emission tomography as an extratemporal region showing glucose hypometabolism. Using diffusion magnetic resonance imaging tractography, we defined a seizure propagation tract (PT) as a white matter pathway that connects the focus with a remote functional deficit zone. We also used the corticospinal tract (CST) and inferior longitudinal fasciculus (ILF) as control tracts in the hemisphere ipsilateral to the focus. Fractional anisotropy (FA), mean diffusivity (MD), and volume of the tracts were compared among PT, CST, and ILF. Tractographic analysis identified the uncinate fasciculus, arcuate fasciculus, and fornix as PTs. A decrease in FA was found in MTLE patients compared with healthy subjects in all tracts, but PTs showed a more significant decrease in FA than did the two control tracts. Although the change in MD was also found in MTLE patients compared with healthy controls, a tract-specific change was not observed. Although white-matter damage was observed in all candidate tracts examined, the integrity of white matter was most significantly decreased in PTs in MTLE. The change in white matter integrity occurs specifically in the pathways that connect the focus and remote functional deficit zones in patients with MTLE, i.e., the pathways that are assume to be associated with seizure propagation. Copyright © 2015 Elsevier B.V. All rights reserved.

Contralateral interictal and ictal EEG epileptiform activity accentuate memory impairment in unilateral mesial temporal sclerosis patients.

PubMed

Pinto, Lecio F; Adda, Carla C; Silva, Liliane C A; Banaskiwitz, Natalie H C; Passarelli, Valmir; Jorge, Carmen L; Valerio, Rosa M; Castro, Luiz H

2017-03-01

Memory impairment is a recognized complication of mesial temporal sclerosis (MTS). Epileptiform activity may negatively impact on cognition. We evaluated the impact of contralateral EEG involvement on memory in unilateral MTS (uMTS) patients. Retrospective review of 121 right-handed uMTS patients (69 left) evaluated with prolonged video-EEG and verbal and nonverbal memory tests (Rey Auditory Verbal Learning Test and Rey-Osterrieth Complex figure), with additional very delayed trials. Patients were classified according to ictal/interictal EEG findings and MTS side as left or right concordant or discordant. Thirty-nine normal individuals who underwent the same neuropsychological battery served as controls. Demographic, disease, and treatment features did not differ among groups. On the 7-day verbal memory free recall, left discordant performed significantly worse than controls and right concordant, recognized fewer words, and had more recognition errors than all other groups, including left concordant. For nonverbal memory, right discordant performed significantly worse than controls on delayed recall, and attained lower scores than other groups on immediate and 7-day recall, but this difference did not reach statistical significance. Left discordant had higher scores of memory complaints than controls and disclosed a trend toward accentuated memory impairment compared with the other groups over time. Our results suggest that contralateral electrographic involvement in uMTS was associated with more pronounced memory impairment for verbal material in left discordant patients, and to a lesser extent, for nonverbal material in right discordant patients. Left discordant group also had increased memory complaints. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

HMGB1-TLR4 Axis Plays a Regulatory Role in the Pathogenesis of Mesial Temporal Lobe Epilepsy in Immature Rat Model and Children via the p38MAPK Signaling Pathway.

PubMed

Yang, Weihong; Li, Jing; Shang, Yun; Zhao, Li; Wang, Mingying; Shi, Jipeng; Li, Shujun

2017-04-01

The HMGB1-TLR4 axis is activated in adult mouse models of acute and chronic seizure. Nevertheless, whether HMGB1 was involved in the pathogenesis of mesial temporal lobe epilepsy (MTLE) remains unknown. In this study, we first measured the dynamic expression patterns of HMGB1 and TLR4 in the hippocampi of a rat model and in children with MTLE, as well as the levels of TNF-α and IL-1β. In addition, HMGB1 was added to mimic the process of inflammatory response in neurons. Neuronal somatic size and dendritic length were measured by immunohistochemistry and digital imaging. The results showed that the expression of HMGB1 and TLR4 as well as the levels of TNF-α and IL-1β were higher in the three stages of MTLE development in the rat model and in the children with MTLE. HMGB1 increased the levels of TNF-α and IL-1β, upregulated the protein level of p-p38MAPK and promoted the growth of cell somatic size and dendritic length in neurons. Pre-treatment with p38MAPK inhibitor SB203580 decreased the levels of TNF-α and IL-1β, while downregulation of TLR4 significantly reduced HMGB1-induced p38MAPK signaling pathway activation. These data demonstrated that the HMGB1-TLR4 axis may play an important role in the pathogenesis of MTLE via the p38MAPK signaling pathway.

Microneurosurgical management of temporal lobe epilepsy by amygdalohippocampectomy (AH) plus standard anterior temporal lobectomy (ATL): a report of our initial five cases in Bangladesh

PubMed Central

Chowdhury, F H; Haque, M R; Islam, M S; Sarker, MH; Kawsar, KA; Sarker, AC

2010-01-01

Patient presenting as a case of Temporal Lobe Epilepsy (TLE) are usually resistant to antiepileptic drugs and surgery is the treatment of choice. This type of epilepsy may be due to Mesial Temporal Sclerosis (MTS), tumors [i.e. low grade glioma, Arterio-Venous Malformation (AVM) etc], trauma, infection (Tuberculosis) etc. Here we report five cases of surgically treated TLE that were due to a MTS, MTS with arachnoid cyst, low grade ganglioglioma, high grade ganglioglioma and a tuberculoma in the department of neurosurgery, Dhaka Medical College Hospital and Islami Bank Central Hospital, Dhaka, Bangladesh from August 2009 to February 2010. In all cases the only presenting symptoms was complex partial seizures (psychomotor epilepsy) for which all underwent scalp EEG (Electro Encephalogram) and MRI (Magnetic Resonance Imaging) of Brain. All patients were managed by amygdalohippocampectomy plus standard anterior lobectomy. One patient with high grade ganglioglioma recurred within two months of operation and expired within five months. The rest of the cases are seizure and disease free till the last follow up. PMID:22028754

Neuronal autoantibodies in mesial temporal lobe epilepsy with hippocampal sclerosis.

PubMed

Vanli-Yavuz, Ebru Nur; Erdag, Ece; Tuzun, Erdem; Ekizoglu, Esme; Baysal-Kirac, Leyla; Ulusoy, Canan; Peach, Sian; Gundogdu, Gokcen; Sencer, Serra; Sencer, Altay; Kucukali, Cem Ismail; Bebek, Nerses; Gurses, Candan; Gokyigit, Aysen; Baykan, Betul

2016-07-01

Our aim was to investigate the prevalence of neuronal autoantibodies (NAbs) in a large consecutive series with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) and to elucidate the clinical and laboratory clues for detection of NAbs in this prototype of frequent, drug-resistant epilepsy syndrome. Consecutive patients diagnosed with MTLE fulfilling the MRI criteria for HS were enrolled. The sera of patients and various control groups (80 subjects) were tested for eight NAbs after ethical approval and signed consents. Brain tissues obtained from surgical specimens were also investigated by immunohistochemical analysis for the presence of inflammatory infiltrates. The features of seropositive versus seronegative groups were compared and binary logistic regression analysis was performed to explore the differentiating variables. We found antibodies against antigens, contactin-associated protein-like 2 in 11 patients, uncharacterised voltage-gated potassium channel (VGKC)-complex antigens in four patients, glycine receptor (GLY-R) in 5 patients, N-methyl-d-aspartate receptor in 4 patients and γ-aminobutyric acid receptor A in 1 patient of 111 patients with MTLE-HS and none of the control subjects. The history of status epilepticus, diagnosis of psychosis and positron emission tomography or single-photon emission CT findings in temporal plus extratemporal regions were found significantly more frequently in the seropositive group. Binary logistic regression analysis disclosed that status epilepticus, psychosis and cognitive dysfunction were statistically significant variables to differentiate between the VGKC-complex subgroup versus seronegative group. This first systematic screening study of various NAbs showed 22.5% seropositivity belonging mostly to VGKC-complex antibodies in a large consecutive series of patients with MTLE-HS. Our results indicated a VGKC-complex autoimmunity-related subgroup in the syndrome of MTLE-HS. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Clinical and electrophysiological findings in mesial temporal lobe epilepsy with hippocampal sclerosis, based on the recent histopathological classifications.

PubMed

Tezer, F Irsel; Xasiyev, Farid; Soylemezoglu, Figen; Bilginer, Burcak; Oguz, Kader Karli; Saygi, Serap

2016-11-01

Hippocampal sclerosis (HS) is a common pathology in MTLE, patients may show different surgical outcomes and clinical features. The 2013 ILAE classification subdivides HS into 3 types (HS type 1: severe neuronal loss and gliosis predominantly in CA1 and CA4 regions; - HS type 2: CA1 predominant; HS type 3: CA4 predominant) and includes "gliosis only, as no-HS". The association of clinical and electrophysiological findings with different HS types has not been reported previously in detail. 48 patients who had undergone temporal lobectomy with amygdalohippocampectomy due to mesial TLE-HS between February 2014 and February 2016 were included. The patients were divided into five groups: patients with HS ILAE type 1, HS ILAE type 2, HS ILAE type 3, FCD type IIIa, or gliosis/no HS. The correlation between HS ILAE types and clinical/EEG findings in patients with MTLE due to HS was investigated. Of the 48 patients 30 were male. In 23 patients, the resection was on the left side (48%). Three patients had only gliosis, 25 patients had HS ILAE type 1, 7 had HS ILAE type 2, and 4 had HS ILAE type 3. Nine of the 48 patients had cortical lamination abnormalities in the temporal lobe associated with HS (FCD type IIIa). All patients were seizure free for early follow up. There was no association between type of HS in terms of duration of epilepsy, onset age of epilepsy, lateralized or localized semiological findings, or interictal/ictal EEG findings. Family history of epilepsy or SGTCSs were statistically more frequent in patients with types 2 and 3 HS and status epilepticus was more frequent in patients with HS-FCD type IIIa. The patients with HS types 2 and 3 have more frequent SGTCS or status epilepticus as well as increased family history of epilepsy. These findings can be helpful in understanding the epileptogenicity-prognoses of HS. Copyright © 2016 Elsevier B.V. All rights reserved.

Parahippocampectomy as a New Surgical Approach to Mesial Temporal Lobe Epilepsy Caused By Hippocampal Sclerosis: A Pilot Randomized Comparative Clinical Trial.

PubMed

Alonso-Vanegas, Mario Arturo; Freire Carlier, Iván D; San-Juan, Daniel; Martínez, Alma Rosa; Trenado, Carlos

2018-02-01

The parahippocampal gyrus plays an important role in the epileptogenic pathways of mesial temporal lobe epilepsy caused by hippocampal sclerosis (mTLE-HS); its resection could prevent epileptic seizures with fewer complications. This study evaluates the initial efficacy and safety of anterior temporal lobectomy (ATL), selective amygdalohipppocampectomy (SAH), and parahippocampectomy (PHC) surgical approaches in mTLE-HS. A randomized comparative pilot clinical trial (2008-2011) was performed that included patients with mTLE-HS who underwent ATL, trans-T3 SAH, and trans-T3 PHC. Their sociodemographic characteristics, visual field profiles, verbal and visual memory profiles, and Engel scale outcome at baseline and at 1 and 5 years are described, using descriptive statistics along with parametric and nonparametric tests. Forty-three patients with a mean age of 35.2 years (18-56 years), 65% female, were analyzed: 14 underwent PHC, 14 ATL, and 15 SAH. The following percentages refer to those patients who were seizure free (Engel class IA) at 1-year and 5-year follow-up, respectively: 42.9% PHC, 71.4% ATL, and 60% SAH (P = 0.304); 28.6% PHC, 50% ATL, and 53.3% SAH (P = 0.353). Postoperative visual field deficits were 0% PHC, 85.7% ATL, and 46.7% SAH (P = 0.001). Verbal and/or visual memory worsening were present in 21.3% PHC, 42.8% ATL, and 33.4% SAH (P = 0.488) and preoperative and postoperative visual memory scores were significantly different in the SAH group only (P = 0.046). PHC, ALT, and SAH show a preliminary similar efficacy in short-term seizure-free rates in patients with mTLE-HS. However, PHC efficacy in the long-term decreases compared with the other surgical techniques. PHC does not produce postoperative visual field deficits. Copyright © 2017 Elsevier Inc. All rights reserved.

[Epilepsy in the temporal lobe: déjà vu in Primary Care].

PubMed

Miguéns Blanco, I; Rodríguez Acevedo, B

2013-10-01

Epilepsy is a common disease in the general population. 10% of the population will present a seizure throughout his life, although only 1% will have an epileptic condition. We can divide the generalized epilepsy and focal. Es in the latter that more diagnostic and management difficulties may arise in clinical practice, for its wide variety of symptoms and their identification difficult. These symptoms may be referred to differently by each patient, often dismissively. In focal epilepsy, the most prevalent epilepsy that originates in the temporal lobe. The identification and study of this pathology is very important because the patient may have episodes of disconnecting means and in one third of cases secondarily generalized crises. Although most patients the culprit lesion is mesial temporal sclerosis, one must rule out other causes such as tumors or infections. Copyright © 2012 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

Absence of gender effect on amygdala volume in temporal lobe epilepsy.

PubMed

Silva, Ivaldo; Lin, Katia; Jackowski, Andrea P; Centeno, Ricardo da Silva; Pinto, Magali L; Carrete, Henrique; Yacubian, Elza M; Amado, Débora

2010-11-01

Sexual dimorphism has already been described in temporal lobe epilepsy with mesial temporal sclerosis (TLE-MTS). This study evaluated the effect of gender on amygdala volume in patients with TLE-MTS. One hundred twenty-four patients with refractory unilateral or bilateral TLE-MTS who were being considered for epilepsy surgery underwent a comprehensive presurgical evaluation and MRI. Amygdalas of 67 women (27 with right; 32 with left, and 8 with bilateral TLE) and 57 men (22 with right, 30 with left, and 5 with bilateral TLE) were manually segmented. Significant ipsilateral amygdala volume reduction was observed for patients with right and left TLE. No gender effect on amygdala volume was observed. Contralateral amygdalar asymmetry was observed for patients with right and left TLE. Although no gender effect was observed on amygdala volume, ipsilateral amygdala volume reductions in patients with TLE might be related to differential rates of cerebral maturation between hemispheres. Copyright © 2010 Elsevier Inc. All rights reserved.

A mandibular third molar with three mesial roots: a case report.

PubMed

Plotino, Gianluca

2008-02-01

Although its most common configuration is 2 roots and 3 root canals, mandibular molars might have many different combinations. A case of unusual root canal morphology is presented to demonstrate anatomic variations in mandibular molars. Endodontic therapy was performed in a mandibular third molar with 3 separate mesial roots. The appearance of the pulp chamber floor revealed 4 separate canal orifices. Radiographically the 4 root canals ended in their own distinct foramen. Many reports deal with 3 orifices or 3 independent canals in the mesial root, but none described 3 mesial canals in 3 separate mesial roots, indicating a rare anatomic configuration. This report points out the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise might have ended in failure.

Frontal lobe epilepsy.

PubMed

Kellinghaus, Christoph; Lüders, Hans O

2004-12-01

Frontal lobe epilepsy accounts for only 10-20% of the patients in surgical series, but the incidence in non-surgical patient cohorts seems to be much higher. The typical clinical presentation of the seizures includes contralateral clonic movements, uni- or bilateral tonic motor activity as well as complex automatism. The yield of surface EEG may be limited due to the difficulty in detection of mesial or basal foci, and the patient may be misdiagnosed as having non-epileptic events. In addition, in patients with mesial frontal foci the epileptiform discharges may be mislateralized ("paradoxical lateralization"). Therefore, epilepsy surgery has been commonly considered as less promising in patients with frontal lobe epilepsy. However, the advent of sophisticated neuroimaging techniques, particularly MRI with epilepsy-specific sequences, has made it possible to delineate the epileptogenic lesion and detect a specific etiology, in an increasing number of patients. Thus, the success rate of epilepsy surgery in frontal lobe epilepsy is currently comparable to temporal lobe epilepsy, if the candidates are carefully selected. Patients with frontal lobe epilepsy who do not respond to anticonvulsive medication, and who are not eligible for epilepsy surgery may benefit from alternative approaches such as electrical brain stimulation.

Network-Level Analysis of Cortical Thickness of the Epileptic Brain

PubMed Central

Raj, A; Mueller, S.G; Young, K; Laxer, K.D.; Weiner, M

2010-01-01

Temporal lobe epilepsy (TLE) characterized by an epileptogenic focus in the medial temporal lobe is the most common form of focal epilepsy. However, the seizures are not confined to the temporal lobe but can spread to other, anatomically connected brain regions where they can cause similar structural abnormalities as observed in the focus. The aim of this study was to derive whole brain networks from volumetric data and obtain network-centric measures which can capture cortical thinning characteristic for TLE and can be used for classifying a given MRI into TLE or normal, and to obtain additional summary statistics which relate to the extent and spread of the disease. T1 weighted whole brain images were acquired on a 4T magnet in 13 patients with TLE with mesial temporal lobe sclerosis (TLE-MTS), 14 patients with TLE with normal MRI (TLE-no) and 30 controls. Mean cortical thickness and curvature measurements were obtained using the Freesurfer software. These values were used to derive a graph, or network, for each subject. The nodes of the graph are brain regions, and edges represent disease progression paths. We show how to obtain summary statistics like mean, median and variance defined for these networks and to perform exploratory analyses like correlation and classification. Our results indicate that the proposed network approach can improve accuracy of classifying subjects into 2 groups (control and TLE), from 78% for non-network classifiers to 93% using the proposed approach. We also obtain network “peakiness” values using statistical measures like entropy and complexity - this appears to be a good characterizer of the disease, and may have utility in surgical planning. PMID:20553893

Imaging of patients with hippocampal sclerosis at 7 Tesla: initial results.

PubMed

Breyer, Tobias; Wanke, Isabel; Maderwald, Stefan; Woermann, Friedrich G; Kraff, Oliver; Theysohn, Jens M; Ebner, Alois; Forsting, Michael; Ladd, Mark E; Schlamann, Marc

2010-04-01

Focal epilepsies potentially can be cured by neurosurgery; other treatment options usually remain symptomatic. High-resolution magnetic resonance (MR) imaging is the central imaging strategy in the evaluation of focal epilepsy. The most common substrate of temporal epilepsies is hippocampal sclerosis (HS), which cannot always be sufficiently characterized with current MR field strengths. Therefore, the purpose of our study was to demonstrate the feasibility of high-resolution MR imaging at 7 Tesla in patients with focal epilepsy resulting from a HS and to improve image resolution at 7 Tesla in patients with HS. Six patients with known HS were investigated with T1-, T2-, T2(*)-, and fluid-attenuated inversion recovery-weighted sequences at 7 Tesla with an eight-channel transmit-receive head coil. Total imaging time did not exceed 90 minutes per patient. High-resolution imaging at 7 Tesla is feasible and reveals high resolution of intrahippocampal structures in vivo. HS was confirmed in all patients. The maximum non-interpolated in-plane resolution reached 0.2 x 0.2 mm(2) in T2(*)-weighted images. The increased susceptibility effects at 7 Tesla revealed identification of intrahippocampal structures in more detail than at 1.5 Tesla, but otherwise led to stronger artifacts. Imaging revealed regional differences in hippocampal atrophy between patients. The scan volume was limited because of specific absorption rate restrictions, scanning time was reasonable. High-resolution imaging at 7 Tesla is promising in presurgical epilepsy imaging. "New" contrasts may further improve detection of even very small intrahippocampal structural changes. Therefore, further investigations will be necessary to demonstrate the potential benefit for presurgical selection of patients with various lesion patterns in mesial temporal epilepsies resulting from a unilateral HS. Copyright 2010 AUR. Published by Elsevier Inc. All rights reserved.

Visceral fat is associated with brain structure independent of human immunodeficiency virus infection status.

PubMed

Lake, Jordan E; Popov, Mikhail; Post, Wendy S; Palella, Frank J; Sacktor, Ned; Miller, Eric N; Brown, Todd T; Becker, James T

2017-06-01

The combined effects of human immunodeficiency virus (HIV), obesity, and elevated visceral adipose tissue (VAT) on brain structure are unknown. In a cross-sectional analysis of Multicenter AIDS Cohort Study (MACS) participants, we determined associations between HIV serostatus, adiposity, and brain structure. Men (133 HIV+, 84 HIV-) in the MACS Cardiovascular 2 and magnetic resonance imaging (MRI) sub-studies with CT-quantified VAT and whole brain MRI measured within 1 year were assessed. Voxel-based morphometry analyzed brain volumes. Men were stratified by elevated (eVAT, ≥100cm 2 ) or "normal" (nVAT, <100cm 2 ) VAT. Forward stepwise modeling determined associations between clinical and demographic variables and regional brain volumes. eVAT was present in 67% of men. Groups were similar in age and education, but eVAT men were more likely to be HIV+ and have hypertension, diabetes mellitus, body mass index >25 kg/m 2 , smaller gray and white matter volumes, and larger cerebrospinal fluid volume than nVAT men. In multivariate analysis, hypertension, higher adiponectin, higher interleukin-6, age, diabetes mellitus, higher body mass index, and eVAT were associated with brain atrophy (p < 0.05, ordered by increasing strength of association), but HIV serostatus and related factors were generally not. No interactions were observed. Greater VAT was associated with smaller bilateral posterior hippocampus and left mesial temporal lobe and temporal stem white matter volume. Traditional risk factors are more strongly associated with brain atrophy than HIV serostatus, with VAT having the strongest association. However, HIV+ MACS men had disproportionately greater VAT, suggesting the risk for central nervous system effects may be amplified in this population.

A micro-computed tomographic study of band-shaped root canal isthmuses, having their floor in the apical third of mesial roots of mandibular first molars.

PubMed

Keleş, A; Keskin, C

2018-02-01

To conduct a quantitative and qualitative analysis of the band-shaped isthmus area, the floor of which was in the apical third in the mesial roots of mandibular first molars using micro-computed tomography (micro-CT). Micro-CT images of 269 mesial roots of mandibular first molars were evaluated, and 40 specimens with a band-shaped isthmus, with a floor in the apical third, were selected. The major diameter, minor diameter, roundness, area and perimeter values for the most coronal and apical slices where the isthmus was visible were measured. The distances between these slices were measured as the isthmus length, and the total volume, structure model index and surface area of the isthmus were measured. The distances between the isthmus floor and two apical foramina and the number of root canal orifices were calculated. The dimensions of the isthmus roof and the floor were compared, and the data were analysed using descriptive statistics and Student's t-tests with a significance threshold set at 5%. A total of 15% of the specimens had band-shaped isthmuses with a floor in the apical third. The isthmus roof exhibited significantly greater major and minor diameter values compared to the isthmus floor (P < 0.05). No significant difference was detected between the isthmus roof and the floor with regard to roundness (P > 0.05). Three- and two-dimensional analyses of the mesial roots of mandibular molars revealed that band-shaped isthmuses had complex shapes. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Anatomical analysis of the resected roots of mandibular first molars after failed non-surgical retreatment

PubMed Central

2018-01-01

Objectives Understanding the reason for an unsuccessful non-surgical endodontic treatment outcome, as well as the complex anatomy of the root canal system, is very important. This study examined the cross-sectional root canal structure of mandibular first molars confirmed to have failed non-surgical root canal treatment using digital images obtained during intentional replantation surgery, as well as the causative factors of the failed conventional endodontic treatments. Materials and Methods This study evaluated 115 mandibular first molars. Digital photographic images of the resected surface were taken at the apical 3 mm level and examined. The discolored dentin area around the root canal was investigated by measuring the total surface area, the treated areas as determined by the endodontic filling material, and the discolored dentin area. Results Forty 2-rooted teeth showed discolored root dentin in both the mesial and distal roots. Compared to the original filled area, significant expansion of root dentin discoloration was observed. Moreover, the mesial roots were significantly more discolored than the distal roots. Of the 115 molars, 92 had 2 roots. Among the mesial roots of the 2-rooted teeth, 95.7% of the roots had 2 canals and 79.4% had partial/complete isthmuses and/or accessory canals. Conclusions Dentin discoloration that was not visible on periapical radiographs and cone-beam computed tomography was frequently found in mandibular first molars that failed endodontic treatment. The complex anatomy of the mesial roots of the mandibular first molars is another reason for the failure of conventional endodontic treatment. PMID:29765897

Mirrored and rotated stimuli are not the same: A neuropsychological and lesion mapping study.

PubMed

Martinaud, Olivier; Mirlink, Nicolas; Bioux, Sandrine; Bliaux, Evangéline; Champmartin, Cécile; Pouliquen, Dorothée; Cruypeninck, Yohann; Hannequin, Didier; Gérardin, Emmanuel

2016-05-01

Agnosia for mirrored stimuli is a rare clinical deficit. Only eight patients have been reported in the literature so far and little is known about the neural substrates of this agnosia. Using a previously developed experimental test designed to assess this agnosia, namely the Mirror and Orientation Agnosia Test (MOAT), as well as voxel-lesion symptom mapping (VLSM), we tested the hypothesis that focal brain-injured patients with right parietal damage would be impaired in the discrimination between the canonical view of a visual object and its mirrored and rotated images. Thirty-four consecutively recruited patients with a stroke involving the right or left parietal lobe have been included: twenty patients (59%) had a deficit on at least one of the six conditions of the MOAT, fourteen patients (41%) had a deficit on the mirror condition, twelve patients (35%) had a deficit on at least one the four rotated conditions and one had a truly selective agnosia for mirrored stimuli. A lesion analysis showed that discrimination of mirrored stimuli was correlated to the mesial part of the posterior superior temporal gyrus and the lateral part of the inferior parietal lobule, while discrimination of rotated stimuli was correlated to the lateral part of the posterior superior temporal gyrus and the mesial part of the inferior parietal lobule, with only a small overlap between the two. These data suggest that the right visual 'dorsal' pathway is essential for accurate perception of mirrored and rotated stimuli, with a selective cognitive process and anatomical network underlying our ability to discriminate between mirrored images, different from the process of discriminating between rotated images. Copyright © 2016 Elsevier Ltd. All rights reserved.

Immunogenetic predisposing factors for mesial temporal lobe epilepsy with hippocampal sclerosis.

PubMed

Leal, Bárbara; Chaves, João; Carvalho, Cláudia; Bettencourt, Andreia; Brito, Cláudia; Boleixa, Daniela; Freitas, Joel; Brás, Sandra; Lopes, João; Ramalheira, João; Costa, Paulo P; da Silva, Berta Martins; da Silva, António Martins

2018-04-01

Neuroinflammation appears as an important epileptogenic mechanism. Experimental and clinical studies have demonstrated an upregulation of pro-inflammatory cytokines such as IL-1β and TNF-α, in mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). Expression of these cytokines can be modulated by polymorphisms such as rs16944 and rs1800629, respectively, both of which have been associated with febrile seizures (FS) and MTLE-HS development. The human leukocyte antigen (HLA) system has also been implicated in diverse epileptic entities, suggesting a variable role of this system in epilepsy. Our aim was to analyse the association between immunogenetic factors and MTLE-HS development. For that rs16944 (-511 T>C, IL-1β), rs1800629 (-308 G>A, TNF-α) polymorphisms and HLA-DRB1 locus were genotyped in a Portuguese Population. We studied 196 MTLE-HS patients (108 females, 88 males, 44.7 ± 12.0 years, age of onset = 13.6 ± 10.3 years, 104 with FS antecedents) and 282 healthy controls in a case-control study. The frequency of rs16944 TT genotype was higher in MTLE-HS patients compared to controls (14.9% in MTLE-HS vs. 7.7% in controls, p = 0.021, OR [95% CI] = 2.20 [1.13-4.30]). This association was independent of FS antecedents. No association was observed between rs1800629 genotypes or HLA-DRB1 alleles and MTLE-HS susceptibility. Also, no correlation was observed between the studied polymorphisms and disease age of onset. The rs16944 TT genotype is associated with MTLE-HS development what may be explained by the higher IL-1β levels produced by this genotype. High IL-1β levels may have neurotoxic effects or imbalance neurotransmission leading to seizures.

Multivariate pattern analysis reveals anatomical connectivity differences between the left and right mesial temporal lobe epilepsy.

PubMed

Fang, Peng; An, Jie; Zeng, Ling-Li; Shen, Hui; Chen, Fanglin; Wang, Wensheng; Qiu, Shijun; Hu, Dewen

2015-01-01

Previous studies have demonstrated differences of clinical signs and functional brain network organizations between the left and right mesial temporal lobe epilepsy (mTLE), but the anatomical connectivity differences underlying functional variance between the left and right mTLE remain uncharacterized. We examined 43 (22 left, 21 right) mTLE patients with hippocampal sclerosis and 39 healthy controls using diffusion tensor imaging. After the whole-brain anatomical networks were constructed for each subject, multivariate pattern analysis was applied to classify the left mTLE from the right mTLE and extract the anatomical connectivity differences between the left and right mTLE patients. The classification results reveal 93.0% accuracy for the left mTLE versus the right mTLE, 93.4% accuracy for the left mTLE versus controls and 90.0% accuracy for the right mTLE versus controls. Compared with the right mTLE, the left mTLE exhibited a different connectivity pattern in the cortical-limbic network and cerebellum. The majority of the most discriminating anatomical connections were located within or across the cortical-limbic network and cerebellum, thereby indicating that these disease-related anatomical network alterations may give rise to a portion of the complex of emotional and memory deficit between the left and right mTLE. Moreover, the orbitofrontal gyrus, cingulate cortex, hippocampus and parahippocampal gyrus, which exhibit high discriminative power in classification, may play critical roles in the pathophysiology of mTLE. The current study demonstrated that anatomical connectivity differences between the left mTLE and the right mTLE may have the potential to serve as a neuroimaging biomarker to guide personalized diagnosis of the left and right mTLE.

Memory impairment is not necessarily related to seizure frequency in mesial temporal lobe epilepsy with hippocampal sclerosis.

PubMed

Pacagnella, Denise; Lopes, Tatila M; Morita, Marcia E; Yasuda, Clarissa L; Cappabianco, Fabio A M; Bergo, Felipe; Balthazar, Marcio L F; Coan, Ana C; Cendes, Fernando

2014-08-01

To investigate the effect of seizure frequency on memory, we performed a cross sectional study comparing mesial temporal lobe epilepsy (MTLE) patients with frequent and infrequent seizures. We performed magnetic resonance imaging (MRI) hippocampal volume (HV) measurements and neuropsychological assessment in 22 patients with frequent seizures (at least one dyscognitive seizure [DS] per month) that were refractory to antiepileptic drugs and 20 patients with infrequent seizures (three or less DS per year and no event evolving to a bilateral convulsive seizure), all with MRI signs of hippocampal sclerosis (HS) on visual analysis. We also included 29 controls for comparison of volumetric data. There was no difference in memory performance between patients with frequent seizures and infrequent seizures. We observed a significant bilateral reduction of HV in patients with MTLE when compared to controls (p < 0.001). The degree of hippocampal atrophy (HA) between patients with frequent and infrequent seizures was not different. There was a negative correlation between seizure frequency and HV, with r = -0.3 for the HV ipsilateral to the HS and r = -0.55 for the contralateral side, thus, explaining only 9% and 30% of the HV loss. There was a positive correlation between age of onset and degree of HA (r = 0.37). Our data suggest that seizure frequency does not explain most of the HV loss or memory impairment in MTLE. Memory impairment appears to be more influenced by hippocampal damage than by seizure frequency. Further studies are necessary to identify the factors that influence memory decline in patients with MTLE. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

Familial mesial temporal lobe epilepsy and the borderland of déjà vu.

PubMed

Perucca, Piero; Crompton, Douglas E; Bellows, Susannah T; McIntosh, Anne M; Kalincik, Tomas; Newton, Mark R; Vajda, Frank J E; Scheffer, Ingrid E; Kwan, Patrick; O'Brien, Terence J; Tan, K Meng; Berkovic, Samuel F

2017-08-01

The cause of mesial temporal lobe epilepsy (MTLE) is often unknown. We ascertained to what extent newly diagnosed nonlesional MTLE actually represents familial MTLE (FMTLE). We identified all consecutive patients presenting to the Austin Health First Seizure Clinic with MTLE and normal magnetic resonance imaging (MRI) or MRI evidence of hippocampal sclerosis over a 10-year period. Patients' first-degree relatives and pairwise age- and sex-matched controls underwent a comprehensive epilepsy interview. Each interview transcript was reviewed independently by 2 epileptologists, blinded to relative or control status. Reviewers classified each subject as follows: epilepsy, specifying if MTLE; manifestations suspicious for epilepsy; or unaffected. Physiological déjà vu was noted. Forty-four patients were included. At the Clinic, MTLE had been recognized to be familial in 2 patients only. Among 242 subjects interviewed, MTLE was diagnosed in 9 of 121 relatives versus 0 of 121 controls (p = 0.008). All affected relatives had seizures with intense déjà vu and accompanying features; 6 relatives had not been previously diagnosed. Déjà vu experiences that were suspicious, but not diagnostic, of MTLE occurred in 6 additional relatives versus none of the controls (p = 0.04). Physiological déjà vu was common, and did not differ significantly between relatives and controls. After completing the relatives' interviews, FMTLE was diagnosed in 8 of 44 patients (18.2%). FMTLE accounts for almost one-fifth of newly diagnosed nonlesional MTLE, and it is largely unrecognized without direct questioning of relatives. Relatives of patients with MTLE may experience déjà vu phenomena that clinically lie in the "borderland" between epileptic seizures and physiological déjà vu. Ann Neurol 2017;82:166-176. © 2017 American Neurological Association.

Enhanced sequential reaction time task performance in a rat model of mesial temporal lobe epilepsy with classic hippocampal sclerosis.

PubMed

Will, Johanna L; Eckart, Moritz T; Rosenow, Felix; Bauer, Sebastian; Oertel, Wolfgang H; Schwarting, Rainer K W; Norwood, Braxton A

2013-06-15

The human serial reaction time task (SRTT) has widely been used to study the neural basis of implicit learning. It is well documented, in both human and animal studies, that striatal dopaminergic processes play a major role in this task. However, findings on the role of the hippocampus - which is mainly associated with declarative memory - in implicit learning and performance are less univocal. We used a SRTT to evaluate implicit learning and performance in rats with perforant pathway stimulation-induced hippocampal neuron loss; a clinically-relevant animal model of mesial temporal lobe epilepsy (MTLS-HS). As has been previously reported for the Sprague-Dawley strain, 8h of continuous stimulation in male Wistar rats reliably induced widespread neuron loss in areas CA3 and CA1 with a characteristic sparing of CA2 and the granule cells. Histological analysis revealed that hippocampal volume was reduced by an average of 44%. Despite this severe hippocampal injury, rats showed superior performance in our instrumental SRTT, namely shorter reaction times, and without a loss in accuracy, especially during the second half of our 16-days testing period. These results demonstrate that a hippocampal lesion can improve performance in a rat SRTT, which is probably due to enhanced instrumental performance. In line with our previous findings based on ibotenic-acid induced hippocampal lesion, these data support the hypothesis that loss or impairment of hippocampal function can enhance specific task performance, especially when it is dependent on procedural (striatum-dependent) mechanisms with minimal spatial requirements. As the animal model used here exhibits the defining characteristics of MTLE-HS, these findings may have implications for the study and management of patients with MTLE. Copyright © 2013 Elsevier B.V. All rights reserved.

Hyperventilation induces sympathetic overactivation in mesial temporal epilepsy.

PubMed

Assenza, Giovanni; Mecarelli, Oriano; Tombini, Mario; Pulitano, Patrizia; Pellegrino, Giovanni; Benvenga, Antonella; Assenza, Federica; Campana, Chiara; Di Pino, Giovanni; Di Lazzaro, Vincenzo

2015-02-01

Hyperventilation (HV) during electroencephalography (EEG) is a standard clinical procedure to trigger seizures in patients affected by mesial temporal lobe epilepsy (MTLE). Despite the pathophysiology of this susceptibility to HV is not definitively understood, it may be hypothesized to be related to ictal and interictal sympathetic nervous system abnormalities, the presence of which is well known in MTLE patients. In order to test this hypothesis we investigated the HV effect on heart rate variability (HRV) in a group of MTLE patients, compared to a matched group of healthy controls. Forty patients affected by MTLE and 40 age- and sex-matched controls were enrolled in the study. In those subjects, a standard electroencephalographic recording has been acquired and the high and the low frequency components (HF, LF) of heart rate variability (HRV) and their ratio (LF/HF) have been analyzed at rest and during the HV. Indeed, LF/HF is a reliable index of sympathetic tone modulation. HRV did not differ between MTLE and healthy subjects at rest, whereas HV induced a significant LF/HF increase only in MTLE. Within the MTLE group, males showed higher LF/HF increase during HV respect to females, while no differences related to the side of the epileptic focus were found. MTLE patients showed an increased sympathetic response to HV compared to healthy subjects. HRV analysis points towards an autonomic overactivation as a pathophysiological pathway subtending seizure triggered by hyperventilation in MTLE. Autonomic susceptibility in MTLE may help to explain the increased prevalence of arrhythmic events in these patients, potentially predisposing to Sudden Unexpected Death in Epilepsy (SUDEP). Copyright © 2014 Elsevier B.V. All rights reserved.

The Viral Hypothesis of Mesial Temporal Lobe Epilepsy - Is Human Herpes Virus-6 the Missing Link? A systematic review and meta-analysis.

PubMed

Wipfler, P; Dunn, N; Beiki, O; Trinka, E; Fogdell-Hahn, A

2018-01-01

Mesial temporal lobe epilepsy (MTLE) is a common epileptic disorder. Although likely multifactorial, the mechanisms underlying the etiology and pathogenesis of the disease remains unknown in majority of patients. Viruses, particularly Human Herpes Virus 6A and B (HHV-6), two neurotropic herpes viruses, have been implicated in MTLE due to their ubiquitous nature and ability to establish lifelong latency with risk of reactivation. However, the results of studies investigating this relationship are conflicting. This systematic review and meta-analysis was conducted to determine the relationship between HHV-6 DNA (not specifying if A or B) in brain tissue and MTLE based on the current evidence. Two independent assessors carried out a comprehensive electronic search to identify all relevant studies. Both fixed- and random-effects models were used to determine the overall odds ratio. A total of 10 studies met the inclusion criteria for the systematic review and eight for the meta-analysis. In 19.6% of all MTLE patients HHV-6 DNA was detected in brain tissue compared to 10.3% of all controls (p >0.05). The pooled odds ratio of HHV-6 positive cases in MTLE patients was 2.016 [95%-CI: 1.16-3.50] in the fixed effect model. The results of this meta-analysis indicate an association between HHV-6 DNA and MTLE surgically resected tissue samples, unspecified if A or B or both. However, the casual relationship and possible pathological role of HHV-6 in MTLE are yet to be elucidated. This study's results provide a basis for future studies continuing the investigation into pathological implications of HHV-6. Copyright © 2017 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

MRI-negative PET-positive temporal lobe epilepsy: a distinct surgically remediable syndrome.

PubMed

Carne, R P; O'Brien, T J; Kilpatrick, C J; MacGregor, L R; Hicks, R J; Murphy, M A; Bowden, S C; Kaye, A H; Cook, M J

2004-10-01

Most patients with non-lesional temporal lobe epilepsy (NLTLE) will have the findings of hippocampal sclerosis (HS) on a high resolution MRI. However, a significant minority of patients with NLTLE and electroclinically well-lateralized temporal lobe seizures have no evidence of HS on MRI. Many of these patients have concordant hypometabolism on fluorodeoxyglucose-PET ([18F]FDG-PET). The pathophysiological basis of this latter group remains uncertain. We aimed to determine whether NLTLE without HS on MRI represents a variant of or a different clinicopathological syndrome from that of NLTLE with HS on MRI. The clinical, EEG, [18F]FDG-PET, histopathological and surgical outcomes of 30 consecutive NLTLE patients with well-lateralized EEG but without HS on MRI (HS-ve TLE) were compared with 30 consecutive age- and sex-matched NLTLE patients with well-lateralized EEG with HS on MRI (HS+ve TLE). Both the HS+ve TLE group and the HS-ve TLE patients had a high degree of [18F]FDG-PET concordant lateralization (26 out of 30 HS-ve TLE versus 27 out of 27 HS+ve TLE). HS-ve TLE patients had more widespread hypometabolism on [18F]FDG-PET by blinded visual analysis [odds ratio (OR = + infinity (2.51, -), P = 0.001]. The HS-ve TLE group less frequently had a history of febrile convulsions [OR = 0.077 (0.002-0.512), P = 0.002], more commonly had a delta rhythm at ictal onset [OR = 3.67 (0.97-20.47), P = 0.057], and less frequently had histopathological evidence of HS [OR = 0 (0-0.85), P = 0.031]. There was no significant difference in surgical outcome despite half of those without HS having a hippocampal-sparing procedure. Based on the findings outlined, HS-ve PET-positive TLE may be a surgically remediable syndrome distinct from HS+ve TLE, with a pathophysiological basis that primarily involves lateral temporal neocortical rather than mesial temporal structures.

Esthetic perception of maxillary lateral incisor agenesis treatment by canine mesialization.

PubMed

Mota, Antonino; Pinho, Teresa

2016-03-01

The objective of this study was to evaluate perception of the smile in maxillary lateral incisor agenesis (MLIA) cases treated by mesialization of a canine. Nine images were digitally modified from the same frontal intraoral photograph to simulate various treatment options for space closure in MLIA. A questionnaire was submitted to laypersons (303), general dentists (215), prosthodontists (55) and orthodontists (81). Statistical tests with a significance level of P<0.05 were used. The views of MLIA treatment judged to be most attractive showed unilateral dental and gingival reshaping. All study groups considered the simple dental reshaping of the mesial edge of the canine to be attractive. In the analysis of the images grouped together for both unilateral and bilateral MLIA, the view showing dental and gingival reshaping was considered the most attractive whereas unmodified mesialization was considered the least attractive. Regarding the space closure treatments, although all groups regarded simple dental reshaping of the canine to be attractive, the dental professionals considered gingival and crown reshaping to be more esthetic. In contrast, laypersons were not significantly responsive to this dental and gingival modification as compared to only slight reshaping of the mesial edge of the cusp of the mesialized canine in MLIA. Copyright © 2015 CEO. Published by Elsevier Masson SAS. All rights reserved.

Abnormalities in cortical gray matter density in borderline personality disorder

PubMed Central

Rossi, Roberta; Lanfredi, Mariangela; Pievani, Michela; Boccardi, Marina; Rasser, Paul E; Thompson, Paul M; Cavedo, Enrica; Cotelli, Maria; Rosini, Sandra; Beneduce, Rossella; Bignotti, Stefano; Magni, Laura R; Rillosi, Luciana; Magnaldi, Silvia; Cobelli, Milena; Rossi, Giuseppe; Frisoni, Giovanni B

2015-01-01

Background Borderline personality disorder (BPD) is a chronic condition with a strong impact on patients‘ affective,cognitive and social functioning. Neuroimaging techniques offer invaluable tools to understand the biological substrate of the disease. We aimed to investigate gray matter alterations over the whole cortex in a group of Borderline Personality Disorder (BPD) patients compared to healthy controls (HC). Methods Magnetic resonance-based cortical pattern matching was used to assess cortical gray matter density (GMD) in 26 BPD patients and in their age- and sex-matched HC (age: 38±11; females: 16, 61%). Results BPD patients showed widespread lower cortical GMD compared to HC (4% difference) with peaks of lower density located in the dorsal frontal cortex, in the orbitofrontal cortex, the anterior and posterior cingulate, the right parietal lobe, the temporal lobe (medial temporal cortex and fusiform gyrus) and in the visual cortex (p<0.005). Our BPD subjects displayed a symmetric distribution of anomalies in the dorsal aspect of the cortical mantle, but a wider involvement of the left hemisphere in the mesial aspect in terms of lower density. A few restricted regions of higher density were detected in the right hemisphere. All regions remained significant after correction for multiple comparisons via permutation testing. Conclusions BPD patients feature specific morphology of the cerebral structures involved in cognitive and emotional processing and social cognition/mentalization, consistent with clinical and functional data. PMID:25561291

Specific imbalance of excitatory/inhibitory signaling establishes seizure onset pattern in temporal lobe epilepsy

PubMed Central

de Curtis, Marco; Gnatkovsky, Vadym; Gotman, Jean; Köhling, Rüdiger; Lévesque, Maxime; Manseau, Frédéric; Shiri, Zahra; Williams, Sylvain

2016-01-01

Low-voltage fast (LVF) and hypersynchronous (HYP) patterns are the seizure-onset patterns most frequently observed in intracranial EEG recordings from mesial temporal lobe epilepsy (MTLE) patients. Both patterns also occur in models of MTLE in vivo and in vitro, and these studies have highlighted the predominant involvement of distinct neuronal network/neurotransmitter receptor signaling in each of them. First, LVF-onset seizures in epileptic rodents can originate from several limbic structures, frequently spread, and are associated with high-frequency oscillations in the ripple band (80–200 Hz), whereas HYP onset seizures initiate in the hippocampus and tend to remain focal with predominant fast ripples (250–500 Hz). Second, in vitro intracellular recordings from principal cells in limbic areas indicate that pharmacologically induced seizure-like discharges with LVF onset are initiated by a synchronous inhibitory event or by a hyperpolarizing inhibitory postsynaptic potential barrage; in contrast, HYP onset is associated with a progressive impairment of inhibition and concomitant unrestrained enhancement of excitation. Finally, in vitro optogenetic experiments show that, under comparable experimental conditions (i.e., 4-aminopyridine application), the initiation of LVF- or HYP-onset seizures depends on the preponderant involvement of interneuronal or principal cell networks, respectively. Overall, these data may provide insight to delineate better therapeutic targets in the treatment of patients presenting with MTLE and, perhaps, with other epileptic disorders as well. PMID:27075542

Hush sign: a new clinical sign in temporal lobe epilepsy.

PubMed

Kutlu, Gulnihal; Bilir, Erhan; Erdem, Atilla; Gomceli, Yasemin B; Kurt, G Semiha; Serdaroglu, Ayse

2005-05-01

Neurologists have been analyzing the clinical behaviors that occur during seizures for many years. Several ictal behaviors have been defined in temporal lobe epilepsy (TLE). Ictal behaviors are especially important in the evaluation of epilepsy surgery candidates. We propose a new lateralizing sign in TLE originating from the nondominant hemisphere-the "hush" sign. Our patients were 30- and 21-year old women (Cases 1 and 2, respectively). Their epileptogenic foci were localized to the right mesial temporal region after noninvasive presurgical investigations. Case 1 had no cranial MRI abnormality, whereas cranial MRI revealed right hippocampal atrophy in Case 2. These women repeatedly moved their right index fingers to their mouth while puckering their lips during complex partial seizures. We have named this ictal behavior the "hush" sign. Anterior temporal lobectomy with amygdalohippocampectomy was performed in both patients, and pathological examinations revealed hippocampal sclerosis. The "hush" sign no longer occurred after seizures were controlled. They were seizure free as of 30 and 31 months of follow-up, respectively. We believe that the "hush" sign may be supportive of a diagnosis of TLE originating from the nondominant hemisphere. This sign may occur as a result of ictal activation of a specific brain region in this hemisphere.

Limbic encephalitis associated with systemic lupus erythematosus.

PubMed

Kano, O; Arasaki, K; Ikeda, K; Aoyagi, J; Shiraishi, H; Motomura, M; Iwasaki, Y

2009-12-01

A 34-year-old woman with systemic lupus erythematosus (SLE) presented with general fatigue, seizures and memory loss. Magnetic resonance imaging of the brain showed a high signal area in the mesial temporal lobe bilaterally. Computed tomography scan of the chest and abdomen and ultrasound of pelvis detected no malignancy and tumour marker, antibodies to antineuronal antibodies (anti-Hu, anti-Ta and anti-Ma) and antibodies to voltage-gated potassium channels were all negative. The present case is limbic encephalitis (LE) associated with SLE and the pathogenesis may include autoimmunity shared. Our experience indicates that the immunologic spectrum of LE will expand to include additional immune mechanisms.

Ligands for Ionotropic Glutamate Receptors

PubMed Central

Swanson, Geoffrey T.; Sakai, Ryuichi

2010-01-01

Marine-derived small molecules and peptides have played a central role in elaborating pharmacological specificities and neuronal functions of mammalian ionotropic glutamate receptors (iGluRs), the primary mediators of excitatory synaptic transmission in the central nervous system (CNS). As well, the pathological sequelae elicited by one class of compounds (the kainoids) constitute a widely-used animal model for human mesial temporal lobe epilepsy (mTLE). New and existing molecules could prove useful as lead compounds for the development of therapeutics for neuropathologies that have aberrant glutamatergic signaling as a central component. In this chapter we discuss natural source origins and pharmacological activities of those marine compounds that target ionotropic glutamate receptors. PMID:19184587

The paramedian supracerebellar infratentorial approach.

PubMed

La Pira, Biagia; Sorenson, Thomas; Quillis-Quesada, Vicent; Lanzino, Giuseppe

2017-08-01

Lesions of the superior cerebellar surface, pineal region, lateral and dorsal midbrain and mesial temporal lobe are challenging to treat and often require neurosurgical intervention. The paramedian variation of the supracerebellar infratentorial approach utilizes the downward slope of the cerebellum to facilitate exposure and the lower density of cerebellar bridging veins away from the midline decreases the need to sacrifice larger venous channels. We also discuss our experiences with the approach, and some of the drawbacks and nuances that we have encountered as it has evolved over the years. This approach is versatile and effective and the authors' surgical approach of choice for resecting these challenging lesions.

Ligands for Ionotropic Glutamate Receptors

NASA Astrophysics Data System (ADS)

Swanson, Geoffrey T.; Sakai, Ryuichi

Marine-derived small molecules and peptides have played a central role in elaborating pharmacological specificities and neuronal functions of mammalian ionotropic glutamate receptors (iGluRs), the primary mediators of excitatory syn-aptic transmission in the central nervous system (CNS). As well, the pathological sequelae elicited by one class of compounds (the kainoids) constitute a widely-used animal model for human mesial temporal lobe epilepsy (mTLE). New and existing molecules could prove useful as lead compounds for the development of therapeutics for neuropathologies that have aberrant glutamatergic signaling as a central component. In this chapter we discuss natural source origins and pharmacological activities of those marine compounds that target ionotropic glutamate receptors.

Peri-ictal water drinking and other ictal vegetative symptoms: Localizing and lateralizing the epileptogenic zone in temporal lobe epilepsy? Two case reports and review of the literature.

PubMed

Errguig, L; Lahjouji, F; Belaidi, H; Jiddane, M; Elkhamlichi, A; Dakka, T; Ouazzani, R

2013-11-01

Peri-ictal behavior disorders can be helpful in localizing and lateralizing seizure onset in partial epilepsies, especially those originating in the temporal lobe. In this paper, we present the case of two right-handed women aged 36 and 42 years who presented with partial seizures of mesial temporal type. Both of the patients had drug resistant epilepsy and undergone presurgical evaluation tests including brain magnetic resonance imaging, video-EEG monitoring and neuropsychological testing. The two patients had hippocampal sclerosis in the right temporal lobe and exhibited PIWD behavior concomitant with right temporal lobe discharges documented during video-EEG recordings. Anterior temporal lobectomy was performed in one case with an excellent outcome after surgery. The patient was free of seizures at 3 years follow-up. We reviewed other publications of peri-ictal autonomic symptoms considered to have a lateralizing significance, such as peri-ictal vomiting, urinary urge, ictal pilo-erection. Clinicians should search for these symptoms, even if not spontaneously reported by the patient, because they are often under-estimated, both by the patients themselves and by physicians. Additionally, patients with lateralizing auras during seizures have a significantly better outcome after epilepsy surgery than those without lateralizing features. Copyright © 2013. Published by Elsevier Masson SAS.

Intracranial evaluation and laser ablation for epilepsy with periventricular nodular heterotopia.

PubMed

Thompson, Stephen A; Kalamangalam, Giridhar P; Tandon, Nitin

2016-10-01

Surgical treatment of focal epilepsy in the presence of periventricular nodular heterotopia (PVNH) poses a challenge, as the relative roles of the nodular tissue and the overlying cortex in the generation of seizures can be complex and variable. Here, we review the literature on chronic invasive EEG recordings in humans with this substrate and present two illustrative cases from our practice. We found that while inter-ictal spiking from nodules is common, clinical seizures rarely arise solely from nodular tissue. More typically, ictal onset is simultaneous with overlying neocortex or mesial temporal structures. Surgical outcome is more favorable in cases with unilateral (as opposed to bilateral) PVNH, and when a substantial or complete ablation of PVNH is performed. In rare cases, nodular ablation alone may be sufficient, as may be completed by MRI-guided laser interstitial thermal therapy. The mechanism(s) by which PNVH interacts with overlying cortex are not fully understood, but we suggest that PVNH either orchestrates or amplifies local network epileptogenicity. At present, invasive recordings with penetrating depth electrodes are required prior to surgical therapy, as illustrated in our cases. Published by Elsevier Ltd.

Identification of common variants associated with human hippocampal and intracranial volumes.

PubMed

Stein, Jason L; Medland, Sarah E; Vasquez, Alejandro Arias; Hibar, Derrek P; Senstad, Rudy E; Winkler, Anderson M; Toro, Roberto; Appel, Katja; Bartecek, Richard; Bergmann, Ørjan; Bernard, Manon; Brown, Andrew A; Cannon, Dara M; Chakravarty, M Mallar; Christoforou, Andrea; Domin, Martin; Grimm, Oliver; Hollinshead, Marisa; Holmes, Avram J; Homuth, Georg; Hottenga, Jouke-Jan; Langan, Camilla; Lopez, Lorna M; Hansell, Narelle K; Hwang, Kristy S; Kim, Sungeun; Laje, Gonzalo; Lee, Phil H; Liu, Xinmin; Loth, Eva; Lourdusamy, Anbarasu; Mattingsdal, Morten; Mohnke, Sebastian; Maniega, Susana Muñoz; Nho, Kwangsik; Nugent, Allison C; O'Brien, Carol; Papmeyer, Martina; Pütz, Benno; Ramasamy, Adaikalavan; Rasmussen, Jerod; Rijpkema, Mark; Risacher, Shannon L; Roddey, J Cooper; Rose, Emma J; Ryten, Mina; Shen, Li; Sprooten, Emma; Strengman, Eric; Teumer, Alexander; Trabzuni, Daniah; Turner, Jessica; van Eijk, Kristel; van Erp, Theo G M; van Tol, Marie-Jose; Wittfeld, Katharina; Wolf, Christiane; Woudstra, Saskia; Aleman, Andre; Alhusaini, Saud; Almasy, Laura; Binder, Elisabeth B; Brohawn, David G; Cantor, Rita M; Carless, Melanie A; Corvin, Aiden; Czisch, Michael; Curran, Joanne E; Davies, Gail; de Almeida, Marcio A A; Delanty, Norman; Depondt, Chantal; Duggirala, Ravi; Dyer, Thomas D; Erk, Susanne; Fagerness, Jesen; Fox, Peter T; Freimer, Nelson B; Gill, Michael; Göring, Harald H H; Hagler, Donald J; Hoehn, David; Holsboer, Florian; Hoogman, Martine; Hosten, Norbert; Jahanshad, Neda; Johnson, Matthew P; Kasperaviciute, Dalia; Kent, Jack W; Kochunov, Peter; Lancaster, Jack L; Lawrie, Stephen M; Liewald, David C; Mandl, René; Matarin, Mar; Mattheisen, Manuel; Meisenzahl, Eva; Melle, Ingrid; Moses, Eric K; Mühleisen, Thomas W; Nauck, Matthias; Nöthen, Markus M; Olvera, Rene L; Pandolfo, Massimo; Pike, G Bruce; Puls, Ralf; Reinvang, Ivar; Rentería, Miguel E; Rietschel, Marcella; Roffman, Joshua L; Royle, Natalie A; Rujescu, Dan; Savitz, Jonathan; Schnack, Hugo G; Schnell, Knut; Seiferth, Nina; Smith, Colin; Steen, Vidar M; Valdés Hernández, Maria C; Van den Heuvel, Martijn; van der Wee, Nic J; Van Haren, Neeltje E M; Veltman, Joris A; Völzke, Henry; Walker, Robert; Westlye, Lars T; Whelan, Christopher D; Agartz, Ingrid; Boomsma, Dorret I; Cavalleri, Gianpiero L; Dale, Anders M; Djurovic, Srdjan; Drevets, Wayne C; Hagoort, Peter; Hall, Jeremy; Heinz, Andreas; Jack, Clifford R; Foroud, Tatiana M; Le Hellard, Stephanie; Macciardi, Fabio; Montgomery, Grant W; Poline, Jean Baptiste; Porteous, David J; Sisodiya, Sanjay M; Starr, John M; Sussmann, Jessika; Toga, Arthur W; Veltman, Dick J; Walter, Henrik; Weiner, Michael W; Bis, Joshua C; Ikram, M Arfan; Smith, Albert V; Gudnason, Vilmundur; Tzourio, Christophe; Vernooij, Meike W; Launer, Lenore J; DeCarli, Charles; Seshadri, Sudha; Andreassen, Ole A; Apostolova, Liana G; Bastin, Mark E; Blangero, John; Brunner, Han G; Buckner, Randy L; Cichon, Sven; Coppola, Giovanni; de Zubicaray, Greig I; Deary, Ian J; Donohoe, Gary; de Geus, Eco J C; Espeseth, Thomas; Fernández, Guillén; Glahn, David C; Grabe, Hans J; Hardy, John; Hulshoff Pol, Hilleke E; Jenkinson, Mark; Kahn, René S; McDonald, Colm; McIntosh, Andrew M; McMahon, Francis J; McMahon, Katie L; Meyer-Lindenberg, Andreas; Morris, Derek W; Müller-Myhsok, Bertram; Nichols, Thomas E; Ophoff, Roel A; Paus, Tomas; Pausova, Zdenka; Penninx, Brenda W; Potkin, Steven G; Sämann, Philipp G; Saykin, Andrew J; Schumann, Gunter; Smoller, Jordan W; Wardlaw, Joanna M; Weale, Michael E; Martin, Nicholas G; Franke, Barbara; Wright, Margaret J; Thompson, Paul M

2012-04-15

Identifying genetic variants influencing human brain structures may reveal new biological mechanisms underlying cognition and neuropsychiatric illness. The volume of the hippocampus is a biomarker of incipient Alzheimer's disease and is reduced in schizophrenia, major depression and mesial temporal lobe epilepsy. Whereas many brain imaging phenotypes are highly heritable, identifying and replicating genetic influences has been difficult, as small effects and the high costs of magnetic resonance imaging (MRI) have led to underpowered studies. Here we report genome-wide association meta-analyses and replication for mean bilateral hippocampal, total brain and intracranial volumes from a large multinational consortium. The intergenic variant rs7294919 was associated with hippocampal volume (12q24.22; N = 21,151; P = 6.70 × 10(-16)) and the expression levels of the positional candidate gene TESC in brain tissue. Additionally, rs10784502, located within HMGA2, was associated with intracranial volume (12q14.3; N = 15,782; P = 1.12 × 10(-12)). We also identified a suggestive association with total brain volume at rs10494373 within DDR2 (1q23.3; N = 6,500; P = 5.81 × 10(-7)).

Subcortical aphasia: a longitudinal PET study.

PubMed

de Boissezon, Xavier; Démonet, Jean-François; Puel, Michèle; Marie, Nathalie; Raboyeau, Gaëlle; Albucher, Jean-François; Chollet, François; Cardebat, Dominique

2005-07-01

Very few neuroimaging studies have focused on follow-up of subcortical aphasia. Here, overt language production tasks were used to correlate regional cerebral blood flow (rCBF) changes and language performance in patients with vascular subcortical lesions. Seven aphasic patients were scanned twice with positron emission tomography (PET) at 1-year interval during a word-generation task. Using SPM2, Language-Rest contrast at PET1 was correlated to language performance and to time-lag from stroke. The same contrast was performed at PET2 and session effect (PET2-PET1) was correlated with performance improvement. At PET1, correlation between rCBF and delay from stroke involved mainly ventral regions of the left temporal cortex and mesial frontal cortex. Correlations between rCBF and performance showed predominantly left dorsal regions in the frontal, temporal, and parietal lobes, but also the left ventral temporal cortex. One year apart, language performance improved and rCBF increased in perisylvian regions bilaterally. Best performers at PET2 showed an increase of activity in left ventral temporal cortex as well as in right middle temporal gyrus. On follow-up, expected language improvement and increase of activation in the classical language areas and their counterparts were observed. Moreover, all correlational analyses both at PET1 and on follow-up implicated the anterior part of the left inferior temporal gyrus, suggesting a disconnection between the superior and inferior parts of the left temporal cortex and a specific role for this region in lexical semantic processing.

Role of ictal baseline shifts and ictal high-frequency oscillations in stereo-electroencephalography analysis of mesial temporal lobe seizures.

PubMed

Wu, Shasha; Kunhi Veedu, Hari Prasad; Lhatoo, Samden D; Koubeissi, Mohamad Z; Miller, Jonathan P; Lüders, Hans O

2014-05-01

To assess the role of ictal baseline shifts (IBS) and ictal high-frequency oscillations (iHFOs) in intracranial electroencephalography (EEG) presurgical evaluation by analysis of the spatial and temporal relationship of IBS, iHFOs with ictal conventional stereo-electroencephalography (icEEG) in mesial temporal lobe seizures (MTLS). We studied 15 adult patients with medically refractory MTLS who underwent monitoring with depth electrodes. Seventy-five ictal EEG recordings at 1,000 Hz sampling rate were studied. Visual comparison of icEEG, IBS, and iHFOs were performed using Nihon-Kohden Neurofax systems (acquisition range 0.016-300 Hz). Each recorded ictal EEG was analyzed with settings appropriate for displaying icEEG, IBS, and iHFOs. IBS and iHFOs were observed in all patients and in 91% and 81% of intracranial seizures, respectively. IBS occurred before (22%), at (57%), or after (21%) icEEG onset. In contrast, iHFOs occurred at (30%) or after (70%) icEEG onset. The onset of iHFOs was 11.5 s later than IBS onset (p < 0.0001). All of the earliest onset of IBS and 70% of the onset of iHFOs overlapped with the ictal onset zone (IOZ). Compared with iHFOs, interictal HFOs (itHFOs) were less correlated with IOZ. In contrast to icEEG, IBS and iHFOs had smaller spatial distributions in 70% and 100% of the seizures, respectively. An IBS dipole was observed in 66% of the seizures. Eighty-seven percent of the dipoles had a negative pole at the anterior/medial part of amygdala/hippocampus complex (A-H complex) and a positive pole at the posterior/lateral part of the A-H complex. The results suggest that evaluation of IBS and iHFOs, in addition to routine icEEG, helps in more accurately defining the IOZ. This study also shows that the onset and the spatial distribution of icEEG, IBS, and iHFOs do not overlap, suggesting that they reflect different cellular or network dynamics. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

[A mandibular second molar with three mesial roots: report of one case].

PubMed

Zhang, Ping

2010-02-01

A case of unusual root canal morphology was presented to demonstrate anatomic variations in mandibular second molars. This case report presented the endodontic therapy of a mandibular second molar with three canals in the mesial root. A mesial middle canal was found between the mesiobuccal and mesiolingual canals. This report indicated the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise to fail.

Correlation of root dentin thickness and length of roots in mesial roots of mandibular molars.

PubMed

Dwivedi, Shweta; Dwivedi, Chandra Dhar; Mittal, Neelam

2014-09-01

The purpose of this study was to analyze the relation of tooth length and distal wall thickness of mesial roots in mandibular molars at different locations (ie, 2 mm below the furcation and at the junction between the middle and apical third). Forty-five mandibular first molars were taken, and the length of each tooth was measured. Then, specimens were divided into three groups according to their length: group I-long (24.2 mm ± 1.8), group II-medium (21 mm ± 1.5) and group III-short (16.8 mm ± 1.8). mesial root of each marked at two levels - at 2 mm below the furcation as well as at junction of apical and middle third of roots. The minimum thickness of the distal root dentine associated with the buccal and lingual canals of the mesial roots was measured, The distance between the buccal and lingual canals and the depth of concavity in the distal surface of the mesial roots were also measured. Statistical analysis was performed by using analysis of variance and the Student-Newman-Keuls test. The minimum thickness of the distal wall of the mesiobuccal canal was significantly different (P < .001) between groups 1 (long) and 3 (short). Distal wall thickness of the mesiobuccal root and distal concavity of the mesial root of mandibular first molars were found to be thinner in longer teeth compared with shorter teeth. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Mesial temporal lobe morphology in intractable pediatric epilepsy: so-called hippocampal malrotation, associated findings, and relevance to presurgical assessment.

PubMed

Leach, James L; Awwad, Reem; Greiner, Hansel M; Vannest, Jennifer J; Miles, Lili; Mangano, Francesco T

2016-06-01

OBJECTIVE Diagnostic criteria for hippocampal malrotation (HIMAL) on brain MRI typically include a rounded hippocampus, vertical collateral sulcus, and architectural blurring. Relationship to epileptogenesis remains speculative, and usefulness for surgical guidance is unknown. The study was performed to determine the prevalence of hippocampal rotational anomalies in a cohort of pediatric patients with intractable epilepsy undergoing evaluation for surgery and to determine the significance of this finding in the context of surgical planning. METHODS Forty-eight surgically treated children with intractable epilepsy were compared with matched healthy subjects; reviewers were blinded to surgical side. Each temporal lobe was evaluated for rounded hippocampus, blurring, vertical collateral sulcus, wide choroidal fissure, enlarged temporal horn, low fornix, hippocampal signal, and findings of hippocampal sclerosis. A mesial temporal lobe (MTL) score was calculated by summing the number of features, and the collateral sulcus angle (CSA) was measured in each temporal lobe. Surgical side, pathological diagnosis, and imaging findings elsewhere in the brain were tabulated. Presence of HIMAL, associated imaging features, and MTL score were compared between sides, between epilepsy and control groups, in relationship to side of surgery, and in relationship to postoperative outcome. RESULTS Only 3 epilepsy patients (6.2%) and no controls exhibited all 3 features of HIMAL (p = 0.12). Eight of 48 (16.7%) epilepsy versus 2 of 48 (4.6%) control subjects had both a rounded hippocampus and vertical collateral sulcus (suggesting HIMAL) (p = 0.045). In control and epilepsy subjects, most findings were more prevalent on the left, and the left CSA was more vertical (p < 0.0001). Epilepsy subjects had higher MTL scores (z = -2.95, p = 0.002) and more acute CSAs (p = 0.04) than controls. Only lateralizing raw MTL score had a significant association with surgical side (p = 0.03, OR 7.33); however, this was not significant when hippocampal sclerosis cases were excluded. HIMAL findings were more prevalent and MTL scores were higher in patients with resections involving the temporal lobes. On group analysis, HIMAL findings did not predict eventual surgical side and did not predict outcome, although the numbers are small. In 4 patients the abnormally rotated hippocampus was resected and showed hippocampal sclerosis and/or dysplastic changes on histopathology. All of these patients had a good outcome after surgery. CONCLUSIONS While increased in prevalence in children with intractable epilepsy, imaging findings of HIMAL did not have preoperative lateralizing utility in this group. Findings of HIMAL (including round hippocampus, architectural blurring, and vertical collateral sulcus) did not predict outcome after surgery, although the small number of patients with these findings limits evaluation. In the small number of patients in which the malrotated hippocampus was removed, outcome was good. Further research is needed to continue to define this association in children with intractable epilepsy, focusing on a temporal lobe cohort.

Comparative analysis of different joining techniques to improve the passive fit of cobalt-chromium superstructures.

PubMed

Barbi, Francisco C L; Camarini, Edevaldo T; Silva, Rafael S; Endo, Eliana H; Pereira, Jefferson R

2012-12-01

The influence of different joining techniques on passive fit at the interface structure/abutment of cobalt-chromium (Co-Cr) superstructures has not yet been clearly established. The purpose of this study was to compare 3 different techniques of joining Co-Cr superstructures by measuring the resulting marginal misfit in a simulated prosthetic assembly. A specially designed metal model was used for casting, sectioning, joining, and measuring marginal misfit. Forty-five cast bar-type superstructures were fabricated in a Co-Cr alloy and randomly assigned by drawing lots to 3 groups (n=15) according to the joining method used: conventional gas-torch brazing (G-TB), laser welding (LW), and tungsten inert gas welding (TIG). Joined specimens were assembled onto abutment analogs in the metal model with the 1-screw method. The resulting marginal misfit was measured with scanning electron microscopy (SEM) at 3 different points: distal (D), central (C), and mesial (M) along the buccal aspect of both abutments: A (tightened) and B (without screw). The Levene test was used to evaluate variance homogeneity and then the Welsch ANOVA for heteroscedastic data (α=.05). Significant differences were found on abutment A between groups G-TB and LW (P=.013) measured mesially and between groups G-TB and TIG (P=.037) measured centrally. On abutment B, significant differences were found between groups G-TB and LW (P<.001) and groups LW and TIG (P<.001) measured mesially; groups G-TB and TIG (P=.007) measured distally; and groups G-TB and TIG (P=.001) and LW and TIG (P=.007) measured centrally. The method used for joining Co-Cr prosthetic structures had an influence on the level of resulting passive fit. Structures joined by the tungsten inert gas method produced better mean results than did the brazing or laser method. Copyright © 2012 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Cognitive consequences of coexisting temporal lobe developmental malformations and hippocampal sclerosis.

PubMed

Martin, R; Dowler, R; Gilliam, F; Faught, E; Morawetz, R; Kuzniecky, R

1999-09-11

To characterize patterns of cognitive functioning in a well-defined group of patients with MRI-identified coexisting left temporal lobe developmental malformations (TLDM) and mesial temporal sclerosis (MTS), and to examine neuropsychological outcome in this dual-pathology group following epilepsy surgery. Cognitive functioning in patients with left TLDM and MTS (n = 15) was compared with patients with isolated left MTS (n = 40). TLDM and MTS were identified by high-quality MRI protocol. Patients were administered a battery of neuropsychology tests as part of their presurgical workup for possible epilepsy surgery. Unilateral temporal lobe resection was performed on 10 of the dual-pathology patients and 34 of the isolated MTS patients. Postoperative cognitive performance was also assessed. Both groups displayed impairments in verbal and visual memory, language, and academic achievement. Performance on measures of psychometric intelligence, executive function, and attention were not impaired and were similar between groups. Presence of dual pathology was associated with a significantly less efficient verbal encoding strategy on the word list learning task. Postoperatively, declines were noted for both groups across tasks of verbal memory and language. Groups were not different significantly in terms of neuropsychological outcome after surgery. Patients with coexisting TLDM and MTS have impaired cognitive functioning similar to MTS patients-in particular, with regard to episodic memory and language deficits. Temporal lobe resection produces similar cognitive changes in both groups.

Temporal lobe developmental malformations and epilepsy: dual pathology and bilateral hippocampal abnormalities.

PubMed

Ho, S S; Kuzniecky, R I; Gilliam, F; Faught, E; Morawetz, R

1998-03-01

Temporal lobe developmental malformations (TLDM) with focal cortical dysplasia and balloon cells may coexist with mesial temporal sclerosis. The true incidence of this dual pathology is unknown. Our aim was to assess the frequency of amygdala (AM)-hippocampal abnormality in a homogeneous population with this specific developmental malformation. MRI-based volumetry of the AM and hippocampal formation (HF) in 30 patients with unilateral TLDM and intractable partial epilepsy was performed. A volume normalization process defined a normal range of HF and AM volumes in control subjects, and enabled the detection of bilateral volume loss. Normalized volumes detected HF atrophy in 26 patients (nine unilateral and 17 bilateral) and AM atrophy in 18 patients (three unilateral and 15 bilateral). Visual analysis detected unilateral HF abnormality in 21 patients and bilateral abnormality in two. When compared with a group of patients with temporal lobe epilepsy and pure hippocampal sclerosis (N = 92), where volumetry revealed bilateral HF atrophy in 18%, a significant difference in the frequency of bilateral HF atrophy was found (p < 0.0001). Dual pathology is frequent in patients with TLDM (87%), and the AM-HF abnormality is often bilateral (57%). Our data suggest that more widespread and potentially epileptogenic lesions coexist with visibly detectable unilateral TLDM. This has implications for the selection of patients for temporal lobe surgery and may influence surgical strategies.

Epilepsy surgery in a liver-transplanted girl with temporal lobe epilepsy and hippocampal sclerosis following PRES with status epilepticus.

PubMed

Dilena, Robertino; Nebbia, Gabriella; Fiorica, Lorenzo; Farallo, Marcello; Degrassi, Irene; Gozzo, Francesca; Pelliccia, Veronica; Barbieri, Sergio; Cossu, Massimo; Tassi, Laura

2016-07-01

Posterior reversible encephalopathy syndrome (PRES) with status epilepticus may occur after liver transplant. This may rarely lead to refractory epilepsy and hippocampal sclerosis (HS). We report the first case of epilepsy surgery in a liver-transplanted patient with refractory temporal lobe epilepsy. A 3-year-old girl underwent liver transplant for congenital biliary atresia. Four days after transplant she manifested PRES with status epilepticus, but she recovered within a couple of weeks. At the age of 5 years she started presenting complex partial seizures, that became refractory to antiepileptic drugs (AED), worsening psychosocial performances. The pre-surgical work-up identified a left HS and temporal pole alterations. A left antero-mesial temporal lobectomy was performed, leading to epilepsy remission and allowing AED withdrawal. Drug-resistant temporal lobe epilepsy and HS may occur as sequelae of PRES with status epilepticus related to liver transplant and cyclosporine use. In this setting early epilepsy surgery may reduce the time of chronic exposure to AED and severe illness due to repeated seizures. This option might have additional advantages in the subgroup of epileptic patients with liver transplant, preserving the liver from the potential damage due to multiple AED trials and their interaction with commonly used immunosuppressant drugs. Copyright © 2016 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

Outcome of temporal lobe epilepsy surgery predicted by statistical parametric PET imaging.

PubMed

Wong, C Y; Geller, E B; Chen, E Q; MacIntyre, W J; Morris, H H; Raja, S; Saha, G B; Lüders, H O; Cook, S A; Go, R T

1996-07-01

PET is useful in the presurgical evaluation of temporal lobe epilepsy. The purpose of this retrospective study is to assess the clinical use of statistical parametric imaging in predicting surgical outcome. Interictal 18FDG-PET scans in 17 patients with surgically-treated temporal lobe epilepsy (Group A-13 seizure-free, group B = 4 not seizure-free at 6 mo) were transformed into statistical parametric imaging, with each pixel representing a z-score value by using the mean and s.d. of count distribution in each individual patient, for both visual and quantitative analysis. Mean z-scores were significantly more negative in anterolateral (AL) and mesial (M) regions on the operated side than the nonoperated side in group A (AL: p < 0.00005, M: p = 0.0097), but not in group B (AL: p = 0.46, M: p = 0.08). Statistical parametric imaging correctly lateralized 16 out of 17 patients. Only the AL region, however, was significant in predicting surgical outcome (F = 29.03, p < 0.00005). Using a cut-off z-score value of -1.5, statistical parametric imaging correctly classified 92% of temporal lobes from group A and 88% of those from Group B. The preliminary results indicate that statistical parametric imaging provides both clinically useful information for lateralization in temporal lobe epilepsy and a reliable predictive indicator of clinical outcome following surgical treatment.

Magnetoencephalography with temporal spread imaging to visualize propagation of epileptic activity.

PubMed

Shibata, Sumiya; Matsuhashi, Masao; Kunieda, Takeharu; Yamao, Yukihiro; Inano, Rika; Kikuchi, Takayuki; Imamura, Hisaji; Takaya, Shigetoshi; Matsumoto, Riki; Ikeda, Akio; Takahashi, Ryosuke; Mima, Tatsuya; Fukuyama, Hidenao; Mikuni, Nobuhiro; Miyamoto, Susumu

2017-05-01

We describe temporal spread imaging (TSI) that can identify the spatiotemporal pattern of epileptic activity using Magnetoencephalography (MEG). A three-dimensional grid of voxels covering the brain is created. The array-gain minimum-variance spatial filter is applied to an interictal spike to estimate the magnitude of the source and the time (Ta) when the magnitude exceeds a predefined threshold at each voxel. This calculation is performed through all spikes. Each voxel has the mean Ta () and spike number (N sp ), which is the number of spikes whose source exceeds the threshold. Then, a random resampling method is used to determine the cutoff value of N sp for the statistically reproducible pattern of the activity. Finally, all the voxels where the source exceeds the threshold reproducibly shown on the MRI with a color scale representing . Four patients with intractable mesial temporal lobe epilepsy (MTLE) were analyzed. In three patients, the common pattern of the overlap between the propagation and the hypometabolism shown by fluorodeoxyglucose-positron emission tomography (FDG-PET) was identified. TSI can visualize statistically reproducible patterns of the temporal and spatial spread of epileptic activity. TSI can assess the statistical significance of the spatiotemporal pattern based on its reproducibility. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Subliminal convergence of Kanji and Kana words: further evidence for functional parcellation of the posterior temporal cortex in visual word perception.

PubMed

Nakamura, Kimihiro; Dehaene, Stanislas; Jobert, Antoinette; Le Bihan, Denis; Kouider, Sid

2005-06-01

Recent evidence has suggested that the human occipitotemporal region comprises several subregions, each sensitive to a distinct processing level of visual words. To further explore the functional architecture of visual word recognition, we employed a subliminal priming method with functional magnetic resonance imaging (fMRI) during semantic judgments of words presented in two different Japanese scripts, Kanji and Kana. Each target word was preceded by a subliminal presentation of either the same or a different word, and in the same or a different script. Behaviorally, word repetition produced significant priming regardless of whether the words were presented in the same or different script. At the neural level, this cross-script priming was associated with repetition suppression in the left inferior temporal cortex anterior and dorsal to the visual word form area hypothesized for alphabetical writing systems, suggesting that cross-script convergence occurred at a semantic level. fMRI also evidenced a shared visual occipito-temporal activation for words in the two scripts, with slightly more mesial and right-predominant activation for Kanji and with greater occipital activation for Kana. These results thus allow us to separate script-specific and script-independent regions in the posterior temporal lobe, while demonstrating that both can be activated subliminally.

Cortical stimulation study of the role of rhinal cortex in déjà vu and reminiscence of memories.

PubMed

Bartolomei, F; Barbeau, E; Gavaret, M; Guye, M; McGonigal, A; Régis, J; Chauvel, P

2004-09-14

To study the role of perirhinal (PC) and entorhinal cortices (EC) in dreamy state symptoms (déjà vu and reminiscence of scenes). These phenomena have been attributed to functional alteration of memory networks supported by the medial temporal lobes, principally involving the amygdala and hippocampus. The role of sub-hippocampal structures (EC and PC) in inducing these phenomena has not previously been addressed. The authors studied the symptoms evoked by direct electrical stimulations of PC and EC in comparison with those obtained after stimulation of the amygdala and hippocampus. Stimulations were performed in a group of 24 patients with epilepsy, during stereoelectroencephalographic (SEEG) recordings in the setting of presurgical evaluation. All patients had electrodes that sampled the rhinal cortices, amygdala, and hippocampus. A total of 280 stimulations were analyzed. Entorhinal and perirhinal stimulations induced classic mesial temporal lobe responses (emotional, dysautonomic) but also more specific responses, particularly the déjà vu phenomenon and reminiscence of scenes. Such déjà vu or déjà vécu type responses were produced proportionately more often by stimulation of the EC than by stimulation of the amygdala and hippocampus. In particular, déjà vu was associated with stimulation of the EC and reminiscence of memories with PC stimulation. This study strongly suggests that experiential symptoms are largely dependent upon functional modification of the physiology of the rhinal cortices.

External root resorption of the second molar associated with mesially and horizontally impacted mandibular third molar: evidence from cone beam computed tomography.

PubMed

Wang, Dongmiao; He, Xiaotong; Wang, Yanling; Li, Zhongwu; Zhu, Yumin; Sun, Chao; Ye, Jinhai; Jiang, Hongbing; Cheng, Jie

2017-05-01

The aim of the present study was to assess the incidence and risk factors of ERR in second molars with mesially and horizontally impacted mandibular third molars using cone beam computed tomography (CBCT) images from patients in a Chinese tertiary referral hospital. A total number of 216 patients with 362 mesially and horizontally impacted mandibular third molars who were treated at our institution from 2014 to 2015 was retrospectively included. The ERR in second molars was identified on CBCT multiplanar images. The associations between incidence of ERR and multiple clinical parameters were statistically analyzed by Chi-square test. Moreover, the risk factors for ERR in second molars were further assessed by multivariate regression analysis. The overall incidence of ERR in second molars was 20.17 % (73/362) as detected on CBCT images. The presence of ERR significantly associated with patients age and impaction depth of mandibular third molars. However, no significant relationship was found between ERR severity and impaction depth or ERR location. Multivariate regression analyses further revealed age over 35 years and impaction depth as important risk factors affecting the ERR incidence caused by mesial and horizontal impaction of mandibular third molar. ERR in second molar resulted from mesially and horizontally impacted mandibular third molar is not very rare and can be reliably identified via CBCT scan. Given the possibility of ERR associated with third molar impaction, the prophylactic removal of these impacted teeth could be considered especially for those patients with over 35 years and mesially and horizontally impacted teeth.

Current dipole orientation and distribution of epileptiform activity correlates with cortical thinning in left mesiotemporal epilepsy

PubMed Central

Reinsberger, Claus; Tanaka, Naoaki; Cole, Andrew J.; Woo Lee, Jong; Dworetzky, Barbara A.; Bromfield, Edward B.; Hamiwka, Lorie; Bourgeois, Blaise F.; Golby, Alexandra J.; Madsen, Joseph R.; Stufflebeam, Steven M.

2011-01-01

To evaluate cortical architecture in mesial temporal lobe epilepsy (MTLE) with respect to electrophysiology, we analyze both magnetic resonance imaging (MRI) and magnetoencephalography (MEG) in 19 patients with left MTLE. We divide the patients into two groups: 9 patients (Group A) had vertically oriented antero-medial equivalent current dipoles (ECDs). 10 patients (Group B) had ECDs that were diversely oriented and widely distributed. Group analysis of MRI data showed widespread cortical thinning in Group B compared with Group A, in the left hemisphere involving the cingulate, supramarginal, occipito-temporal and parahippocampal gyri, precuneus and parietal lobule, and in the right hemisphere involving the fronto-medial, -central and -basal gyri and the precuneus. These results suggest that regardless of the presence of hippocampal sclerosis, in a subgroup of patients with MTLE a large cortical network is affected. This finding may, in part, explain the unfavorable outcome in some MTLE patients after epilepsy surgery. PMID:20472073

Three-Dimensional Anatomy of the White Matter Fibers of the Temporal Lobe: Surgical Implications.

PubMed

Pescatori, Lorenzo; Tropeano, Maria Pia; Manfreda, Andrea; Delfini, Roberto; Santoro, Antonio

2017-04-01

The aim of this work is to describe in detail the complex 3-dimensional organization of the white matter of the temporal lobe and discuss the surgical implications of the approaches to lesions located into the mesial temporal region and within the temporal horn and the atrium of the lateral ventricles. Sixteen human cerebral hemispheres fixed in a 10% formalin solution for at least 40 days were studied. After removal of the arachnoid membrane, the hemispheres were frozen at -15°C for at least 14 days, and the Klingler technique, which consists of the microscopic dissection and progressive identification of white matter fibers, was performed. The dissection allowed us to appreciate the topographical organization of the white matter of the temporal lobe identifying the most important association, projection, and commissural fasciculi. The dissection from the lateral side allowed the progressive visualization of the superior longitudinal fasciculus and its components, the extreme and external capsule, the uncinate fasciculus, the inferior fronto-occipital fasciculus, the anterior commissure, the internal capsule, and the optic radiations. The dissection was completed from the inferior and medial side for identification of the cingulum and the fornix. The complex 3-dimensional organization of the white matter substance of the temporal lobe is characterized by 2 main systems of boundaries: the sagittal stratum and the temporal stem. Their knowledge is essential for the appropriate treatment of pathologies localized in this region as demonstrated by the 2 clinical cases presented in this work. Copyright © 2017 Elsevier Inc. All rights reserved.

A finite element analysis of the optimal bending angles in a running loop for mesial translation of a mandibular molar using indirect skeletal anchorage.

PubMed

Kim, M-J; Park, J H; Kojima, Y; Tai, K; Chae, J-M

2018-02-01

To estimate the optimal bending angles in the running loop for mesial translation of a mandibular second molar using indirect skeletal anchorage and to clarify the mechanics of tipping and rotating the molar. A three-dimensional finite element model was developed for predicting tooth movement, and a mechanical model based on the beam theory was constructed for clarifying the force systems. When using a running loop without bends, the molar tipped mesially 14.4° and lingually 0.6°, rotated counterclockwise 4.1°, and the incisors retracted 0.02 mm and intruded 0.05 mm. These angles were about the same as those estimated by the beam theory. When the amount of tip back and toe-in angles was 11.0°, mesial translation of the molar was achieved, and incisors retracted 0.10 mm and intruded 0.30 mm. Mesial translation of a mandibular second molar without any significant movement of anterior teeth was achieved during protraction by controlling the tip back and toe-in angles and enhancing anterior anchorage with the combined use of a running loop and indirect skeletal anchorage. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effect of Alzheimer disease risk on brain function during self-appraisal in healthy middle-aged adults.

PubMed

Johnson, Sterling C; Ries, Michele L; Hess, Timothy M; Carlsson, Cynthia M; Gleason, Carey E; Alexander, Andrew L; Rowley, Howard A; Asthana, Sanjay; Sager, Mark A

2007-10-01

Asymptomatic middle-aged adult children of patients with Alzheimer disease (AD) recently were found to exhibit functional magnetic resonance imaging (fMRI) deficits in the mesial temporal lobe during an encoding task. Whether this effect will be observed on other fMRI tasks is yet unknown. This study examines the neural substrates of self-appraisal (SA) in persons at risk for AD. Accurate appraisal of deficits is a problem for many patients with AD, and prior fMRI studies of healthy young adults indicate that brain areas vulnerable to AD such as the anterior mesial temporal lobe and posterior cingulate are involved during SA tasks. To determine whether parental family history of AD (hereafter referred to as FH) or presence of the epsilon4 allele of the apolipoprotein E gene (APOE4) exerts independent effects on brain function during SA. Cross-sectional factorial design in which APOE4 status (present vs absent) was one factor and FH was the other. All participants received cognitive testing, genotyping, and an fMRI task that required subjective SA decisions regarding trait adjective words in comparison with semantic decisions about the same words. An academic medical center with a research-dedicated 3.0-T MR imaging facility. Cognitively normal middle-aged adults (n = 110), 51 with an FH and 59 without an FH. Blood oxygen-dependent contrast measured using T2*-weighted echo-planar imaging. Parental family history of AD and APOE4 status interacted in the posterior cingulate and left superior and medial frontal regions. There were main effects of FH (FH negative > FH positive) in the left hippocampus and ventral posterior cingulate. There were no main effects of APOE genotype. Our results suggest that FH may affect brain function during subjective SA in regions commonly affected by AD. Although the participants in this study were asymptomatic and middle-aged, the findings suggest that there may be subtle alterations in brain function attributable to AD risk factors.

Data mining neocortical high-frequency oscillations in epilepsy and controls

PubMed Central

Stead, Matt; Krieger, Abba; Stacey, William; Maus, Douglas; Marsh, Eric; Viventi, Jonathan; Lee, Kendall H.; Marsh, Richard; Litt, Brian; Worrell, Gregory A.

2011-01-01

Transient high-frequency (100–500 Hz) oscillations of the local field potential have been studied extensively in human mesial temporal lobe. Previous studies report that both ripple (100–250 Hz) and fast ripple (250–500 Hz) oscillations are increased in the seizure-onset zone of patients with mesial temporal lobe epilepsy. Comparatively little is known, however, about their spatial distribution with respect to seizure-onset zone in neocortical epilepsy, or their prevalence in normal brain. We present a quantitative analysis of high-frequency oscillations and their rates of occurrence in a group of nine patients with neocortical epilepsy and two control patients with no history of seizures. Oscillations were automatically detected and classified using an unsupervised approach in a data set of unprecedented volume in epilepsy research, over 12 terabytes of continuous long-term micro- and macro-electrode intracranial recordings, without human preprocessing, enabling selection-bias-free estimates of oscillation rates. There are three main results: (i) a cluster of ripple frequency oscillations with median spectral centroid = 137 Hz is increased in the seizure-onset zone more frequently than a cluster of fast ripple frequency oscillations (median spectral centroid = 305 Hz); (ii) we found no difference in the rates of high frequency oscillations in control neocortex and the non-seizure-onset zone neocortex of patients with epilepsy, despite the possibility of different underlying mechanisms of generation; and (iii) while previous studies have demonstrated that oscillations recorded by parenchyma-penetrating micro-electrodes have higher peak 100–500 Hz frequencies than penetrating macro-electrodes, this was not found for the epipial electrodes used here to record from the neocortical surface. We conclude that the relative rate of ripple frequency oscillations is a potential biomarker for epileptic neocortex, but that larger prospective studies correlating high-frequency oscillations rates with seizure-onset zone, resected tissue and surgical outcome are required to determine the true predictive value. PMID:21903727

Data mining neocortical high-frequency oscillations in epilepsy and controls.

PubMed

Blanco, Justin A; Stead, Matt; Krieger, Abba; Stacey, William; Maus, Douglas; Marsh, Eric; Viventi, Jonathan; Lee, Kendall H; Marsh, Richard; Litt, Brian; Worrell, Gregory A

2011-10-01

Transient high-frequency (100-500 Hz) oscillations of the local field potential have been studied extensively in human mesial temporal lobe. Previous studies report that both ripple (100-250 Hz) and fast ripple (250-500 Hz) oscillations are increased in the seizure-onset zone of patients with mesial temporal lobe epilepsy. Comparatively little is known, however, about their spatial distribution with respect to seizure-onset zone in neocortical epilepsy, or their prevalence in normal brain. We present a quantitative analysis of high-frequency oscillations and their rates of occurrence in a group of nine patients with neocortical epilepsy and two control patients with no history of seizures. Oscillations were automatically detected and classified using an unsupervised approach in a data set of unprecedented volume in epilepsy research, over 12 terabytes of continuous long-term micro- and macro-electrode intracranial recordings, without human preprocessing, enabling selection-bias-free estimates of oscillation rates. There are three main results: (i) a cluster of ripple frequency oscillations with median spectral centroid = 137 Hz is increased in the seizure-onset zone more frequently than a cluster of fast ripple frequency oscillations (median spectral centroid = 305 Hz); (ii) we found no difference in the rates of high frequency oscillations in control neocortex and the non-seizure-onset zone neocortex of patients with epilepsy, despite the possibility of different underlying mechanisms of generation; and (iii) while previous studies have demonstrated that oscillations recorded by parenchyma-penetrating micro-electrodes have higher peak 100-500 Hz frequencies than penetrating macro-electrodes, this was not found for the epipial electrodes used here to record from the neocortical surface. We conclude that the relative rate of ripple frequency oscillations is a potential biomarker for epileptic neocortex, but that larger prospective studies correlating high-frequency oscillations rates with seizure-onset zone, resected tissue and surgical outcome are required to determine the true predictive value.

Aberrant expression of miR-218 and miR-204 in human mesial temporal lobe epilepsy and hippocampal sclerosis-convergence on axonal guidance.

PubMed

Kaalund, Sanne S; Venø, Morten T; Bak, Mads; Møller, Rikke S; Laursen, Henning; Madsen, Flemming; Broholm, Helle; Quistorff, Bjørn; Uldall, Peter; Tommerup, Niels; Kauppinen, Sakari; Sabers, Anne; Fluiter, Kees; Møller, Lisbeth B; Nossent, Anne Y; Silahtaroglu, Asli; Kjems, Jørgen; Aronica, Eleonora; Tümer, Zeynep

2014-12-01

Mesial temporal lobe epilepsy (MTLE) is one of the most common types of the intractable epilepsies and is most often associated with hippocampal sclerosis (HS), which is characterized by pronounced loss of hippocampal pyramidal neurons. microRNAs (miRNAs) have been shown to be dysregulated in epilepsy and neurodegenerative diseases, and we hypothesized that miRNAs could be involved in the pathogenesis of MTLE and HS. miRNA expression was quantified in hippocampal specimens from human patients using miRNA microarray and quantitative real-time polymerase chain reaction RT-PCR, and by RNA-seq on fetal brain specimens from domestic pigs. In situ hybridization was used to show the spatial distribution of miRNAs in the human hippocampus. The potential effect of miRNAs on targets genes was investigated using the dual luciferase reporter gene assay. miRNA expression profiling showed that 25 miRNAs were up-regulated and 5 were down-regulated in hippocampus biopsies of MTLE/HS patients compared to controls. We showed that miR-204 and miR-218 were significantly down-regulated in MTLE and HS, and both were expressed in neurons in all subfields of normal hippocampus. Moreover, miR-204 and miR-218 showed strong changes in expression during fetal development of the hippocampus in pigs, and we identified four target genes, involved in axonal guidance and synaptic plasticity, ROBO1, GRM1, SLC1A2, and GNAI2, as bona fide targets of miR-218. GRM1 was also shown to be a direct target of miR-204. miR-204 and miR-218 are developmentally regulated in the hippocampus and may contribute to the molecular mechanisms underlying the pathogenesis of MTLE and HS. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

MicroRNA and mesial temporal lobe epilepsy with hippocampal sclerosis: Whole miRNome profiling of human hippocampus.

PubMed

Bencurova, Petra; Baloun, Jiri; Musilova, Katerina; Radova, Lenka; Tichy, Boris; Pail, Martin; Zeman, Martin; Brichtova, Eva; Hermanova, Marketa; Pospisilova, Sarka; Mraz, Marek; Brazdil, Milan

2017-10-01

Mesial temporal lobe epilepsy (mTLE) is a severe neurological disorder characterized by recurrent seizures. mTLE is frequently accompanied by neurodegeneration in the hippocampus resulting in hippocampal sclerosis (HS), the most common morphological correlate of drug resistance in mTLE patients. Incomplete knowledge of pathological changes in mTLE+HS complicates its therapy. The pathological mechanism underlying mTLE+HS may involve abnormal gene expression regulation, including posttranscriptional networks involving microRNAs (miRNAs). miRNA expression deregulation has been reported in various disorders, including epilepsy. However, the miRNA profile of mTLE+HS is not completely known and needs to be addressed. Here, we have focused on hippocampal miRNA profiling in 33 mTLE+HS patients and nine postmortem controls to reveal abnormally expressed miRNAs. In this study, we significantly reduced technology-related bias (the most common source of false positivity in miRNA profiling data) by combining two different miRNA profiling methods, namely next generation sequencing and miRNA-specific quantitative real-time polymerase chain reaction. These methods combined have identified and validated 20 miRNAs with altered expression in the human epileptic hippocampus; 19 miRNAs were up-regulated and one down-regulated in mTLE+HS patients. Nine of these miRNAs have not been previously associated with epilepsy, and 19 aberrantly expressed miRNAs potentially regulate the targets and pathways linked with epilepsy (such as potassium channels, γ-aminobutyric acid, neurotrophin signaling, and axon guidance). This study extends current knowledge of miRNA-mediated gene expression regulation in mTLE+HS by identifying miRNAs with altered expression in mTLE+HS, including nine novel abnormally expressed miRNAs and their putative targets. These observations further encourage the potential of microRNA-based biomarkers or therapies. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

Features of amygdala in patients with mesial temporal lobe epilepsy and hippocampal sclerosis: An MRI volumetric and histopathological study.

PubMed

Nakayama, Yoko; Masuda, Hiroshi; Shirozu, Hiroshi; Ito, Yosuke; Higashijima, Takefumi; Kitaura, Hiroki; Fujii, Yukihiko; Kakita, Akiyoshi; Fukuda, Masafumi

2017-09-01

It is well-known that there is a correlation between the neuropathological grade of hippocampal sclerosis (HS) and neuroradiological atrophy of the hippocampus in mesial temporal lobe epilepsy (mTLE) patients. However, there is no strict definition or criterion regarding neuron loss and atrophy of the amygdala neighboring the hippocampus. We examined the relationship between HS and neuronal loss in the amygdala. Nineteen mTLE patients with neuropathological proof of HS were assigned to Group A, while seven mTLE patients without HS were assigned to Group B. We used FreeSurfer software to measure amygdala volume automatically based on pre-operation magnetic resonance images. Neurons observed using Klüver-Barrera (KB) staining in resected amygdala tissue were counted. and the extent of immunostaining with stress marker antibodies was semiquantitatively evaluated. There was no significant difference in amygdala volume between the two groups (Group A: 1.41±0.24; Group B: 1.41±0.29cm 3 ; p=0.98), nor in the neuron cellularity of resected amygdala specimens (Group A: 3.98±0.97; Group B: 3.67±0.67 10× -4 number of neurons/μm 2 ; p=0.40). However, the HSP70 level, representing acute stress against epilepsy, in Group A patients was significantly larger than that in Group B. There was no significant difference in the level of Bcl-2, which is known as a protein that inhibits cell death, between the two groups. Neuronal loss and volume loss in the amygdala may not necessarily follow hippocampal sclerosis. From the analysis of stress proteins, epileptic attacks are as likely to damage the amygdala as the hippocampus but do not lead to neuronal death in the amygdala. Copyright © 2017 Elsevier B.V. All rights reserved.

Impact of hippocampal subfield histopathology in episodic memory impairment in mesial temporal lobe epilepsy and hippocampal sclerosis.

PubMed

Comper, Sandra Mara; Jardim, Anaclara Prada; Corso, Jeana Torres; Gaça, Larissa Botelho; Noffs, Maria Helena Silva; Lancellotti, Carmen Lúcia Penteado; Cavalheiro, Esper Abrão; Centeno, Ricardo Silva; Yacubian, Elza Márcia Targas

2017-10-01

The objective of the study was to analyze preoperative visual and verbal episodic memories in a homogeneous series of patients with mesial temporal lobe epilepsy (MTLE) and unilateral hippocampal sclerosis (HS) submitted to corticoamygdalohippocampectomy and its association with neuronal cell density of each hippocampal subfield. The hippocampi of 72 right-handed patients were collected and prepared for histopathological examination. Hippocampal sclerosis patterns were determined, and neuronal cell density was calculated. Preoperatively, two verbal and two visual memory tests (immediate and delayed recalls) were applied, and patients were divided into two groups, left and right MTLE (36/36). There were no statistical differences between groups regarding demographic and clinical data. Cornu Ammonis 4 (CA4) neuronal density was significantly lower in the right hippocampus compared with the left (p=0.048). The groups with HS presented different memory performance - the right HS were worse in visual memory test [Complex Rey Figure, immediate (p=0.001) and delayed (p=0.009)], but better in one verbal task [RAVLT delayed (p=0.005)]. Multiple regression analysis suggested that the verbal memory performance of the group with left HS was explained by CA1 neuronal density since both tasks were significantly influenced by CA1 [Logical Memory immediate recall (p=0.050) and Logical Memory and RAVLT delayed recalls (p=0.004 and p=0.001, respectively)]. For patients with right HS, both CA1 subfield integrity (p=0.006) and epilepsy duration (p=0.012) explained Complex Rey Figure immediate recall performance. Ultimately, epilepsy duration also explained the performance in the Complex Rey Figure delayed recall (p<0.001). Cornu Ammonis 1 (CA1) hippocampal subfield was related to immediate and delayed recalls of verbal memory tests in left HS, while CA1 and epilepsy duration were associated with visual memory performance in patients with right HS. Copyright © 2017 Elsevier Inc. All rights reserved.

Ripples on spikes show increased phase-amplitude coupling in mesial temporal lobe epilepsy seizure onset zones

PubMed Central

Weiss, Shennan A; Orosz, Iren; Salamon, Noriko; Moy, Stephanie; Wei, Linqing; Van ’t Klooster, Maryse A; Knight, Robert T; Harper, Ronald M; Bragin, Anatol; Fried, Itzhak; Engel, Jerome; Staba, Richard J

2016-01-01

Objective Ripples (80–150 Hz) recorded from clinical macroelectrodes have been shown to be an accurate biomarker of epileptogenic brain tissue. We investigated coupling between epileptiform spike phase and ripple amplitude to better understand the mechanisms that generate this type of pathological ripple (pRipple) event. Methods We quantified phase amplitude coupling (PAC) between epileptiform EEG spike phase and ripple amplitude recorded from intracranial depth macroelectrodes during episodes of sleep in 12 patients with mesial temporal lobe epilepsy. PAC was determined by 1) a phasor transform that corresponds to the strength and rate of ripples coupled with spikes, and a 2) ripple-triggered average to measure the strength, morphology, and spectral frequency of the modulating and modulated signals. Coupling strength was evaluated in relation to recording sites within and outside the seizure onset zone (SOZ). Results Both the phasor transform and ripple-triggered averaging methods showed ripple amplitude was often robustly coupled with epileptiform EEG spike phase. Coupling was more regularly found inside than outside the SOZ, and coupling strength correlated with the likelihood a macroelectrode’s location was within the SOZ (p<0.01). The ratio of the rate of ripples coupled with EEG spikes inside the SOZ to rates of coupled ripples in non-SOZ was greater than the ratio of rates of ripples on spikes detected irrespective of coupling (p<0.05). Coupling strength correlated with an increase in mean normalized ripple amplitude (p<0.01), and a decrease in mean ripple spectral frequency (p<0.05). Significance Generation of low-frequency (80–150 Hz) pRipples in the SOZ involves coupling between epileptiform spike phase and ripple amplitude. The changes in excitability reflected as epileptiform spikes may also cause clusters of pathologically interconnected bursting neurons to grow and synchronize into aberrantly large neuronal assemblies. PMID:27723936

Frequent Seizures Are Associated with a Network of Gray Matter Atrophy in Temporal Lobe Epilepsy with or without Hippocampal Sclerosis

PubMed Central

Coan, Ana C.; Campos, Brunno M.; Yasuda, Clarissa L.; Kubota, Bruno Y.; Bergo, Felipe PG.; Guerreiro, Carlos AM.; Cendes, Fernando

2014-01-01

Objective Patients with temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS) have diffuse subtle gray matter (GM) atrophy detectable by MRI quantification analyses. However, it is not clear whether the etiology and seizure frequency are associated with this atrophy. We aimed to evaluate the occurrence of GM atrophy and the influence of seizure frequency in patients with TLE and either normal MRI (TLE-NL) or MRI signs of HS (TLE-HS). Methods We evaluated a group of 172 consecutive patients with unilateral TLE-HS or TLE-NL as defined by hippocampal volumetry and signal quantification (122 TLE-HS and 50 TLE-NL) plus a group of 82 healthy individuals. Voxel-based morphometry was performed with VBM8/SPM8 in 3T MRIs. Patients with up to three complex partial seizures and no generalized tonic-clonic seizures in the previous year were considered to have infrequent seizures. Those who did not fulfill these criteria were considered to have frequent seizures. Results Patients with TLE-HS had more pronounced GM atrophy, including the ipsilateral mesial temporal structures, temporal lobe, bilateral thalami and pre/post-central gyri. Patients with TLE-NL had more subtle GM atrophy, including the ipsilateral orbitofrontal cortex, bilateral thalami and pre/post-central gyri. Both TLE-HS and TLE-NL showed increased GM volume in the contralateral pons. TLE-HS patients with frequent seizures had more pronounced GM atrophy in extra-temporal regions than TLE-HS with infrequent seizures. Patients with TLE-NL and infrequent seizures had no detectable GM atrophy. In both TLE-HS and TLE-NL, the duration of epilepsy correlated with GM atrophy in extra-hippocampal regions. Conclusion Although a diffuse network GM atrophy occurs in both TLE-HS and TLE-NL, this is strikingly more evident in TLE-HS and in patients with frequent seizures. These findings suggest that neocortical atrophy in TLE is related to the ongoing seizures and epilepsy duration, while thalamic atrophy is more probably related to the original epileptogenic process. PMID:24475055

Lateralization of Temporal Lobe Epilepsy using a Novel Uncertainty Analysis of MR Diffusion in Hippocampus, Cingulum, and Fornix, and Hippocampal Volume and FLAIR Intensity

PubMed Central

Nazem-Zadeh, Mohammad-Reza; Schwalb, Jason M.; Elisevich, Kost V.; Bagher-Ebadian, Hassan; Hamidian, Hajar; Akhondi-Asl, Ali-Reza; Jafari-Khouzani, Kourosh; Soltanian-Zadeh, Hamid

2014-01-01

Purpose To analyze the utility of a quantitative uncertainty analysis approach for evaluation and comparison of various MRI findings for lateralization of epileptogenicity in mesial temporal lobe epilepsy (mTLE), including novel diffusion-based analyses. Methods We estimated the hemispheric variation uncertainty (HVU) of hippocampal T1 volumetry and FLAIR (Fluid Attenuated Inversion Recovery) intensity. Using diffusion tensor images of 23 nonepileptic subjects, we estimated the HVU levels of mean diffusivity (MD) in the hippocampus, and fractional anisotropy (FA) in the posteroinferior cingulum and crus of fornix. Imaging from a retrospective cohort of 20 TLE patients who had undergone surgical resection with Engel class I outcomes was analyzed to determine whether asymmetry of preoperative volumetrics, FLAIR intensities, and MD values in hippocampi, as well as FA values in posteroinferior cingula and fornix crura correctly predicted laterality of seizure onset. Ten of the cohort had pathologically proven mesial temporal sclerosis (MTS). Seven of these patients had undergone extra-operative electrocorticography (ECoG) for lateralization or to rule out extra-temporal foci. Results HVU was estimated to be 3.1 × 10−5 for hippocampal MD, 0.027 for FA in posteroinferior cingulum, 0.018 for FA in crus of fornix, 0.069 for hippocampal normalized volume, and 0.099 for hippocampal normalized FLAIR intensity. Using HVU analysis, a higher hippocampal MD value, lower FA within the posteroinferior cingulum and crus of fornix, shrinkage in hippocampal volume, and higher hippocampal FLAIR intensity were observed beyond uncertainty on the side ipsilateral to seizure onset for 10, 10, 9, 9, and 10 out of 10 pathology-proven MTS patients, respectively. Considering all 20 TLE patients, these numbers were 18, 15, 14, 13, and 16, respectively. However, consolidating lateralization results of HVU analysis on these quantities by majority voting detected the epileptogenic side for 19 out of 20 cases with no wrong lateralization. Conclusion The presence of MTS in TLE patients is associated with an elevated MD value in the ipsilateral hippocampus and a reduced FA value in the posteroinferior subregion of the ipsilateral cingulum and crus of ipsilateral fornix. When considering all TLE patients, among the mentioned biomarkers the hippocampal MD had the best performance with true detection rate of 90% without any wrong lateralization. The proposed uncertainty based analyses hold promise for improving decision-making for surgical resection. PMID:24857759

Lateralization of temporal lobe epilepsy using a novel uncertainty analysis of MR diffusion in hippocampus, cingulum, and fornix, and hippocampal volume and FLAIR intensity.

PubMed

Nazem-Zadeh, Mohammad-Reza; Schwalb, Jason M; Elisevich, Kost V; Bagher-Ebadian, Hassan; Hamidian, Hajar; Akhondi-Asl, Ali-Reza; Jafari-Khouzani, Kourosh; Soltanian-Zadeh, Hamid

2014-07-15

To analyze the utility of a quantitative uncertainty analysis approach for evaluation and comparison of various MRI findings for the lateralization of epileptogenicity in mesial temporal lobe epilepsy (mTLE), including novel diffusion-based analyses. We estimated the hemispheric variation uncertainty (HVU) of hippocampal T1 volumetry and FLAIR (Fluid Attenuated Inversion Recovery) intensity. Using diffusion tensor images of 23 nonepileptic subjects, we estimated the HVU levels of mean diffusivity (MD) in the hippocampus, and fractional anisotropy (FA) in the posteroinferior cingulum and crus of fornix. Imaging from a retrospective cohort of 20 TLE patients who had undergone surgical resection with Engel class I outcomes was analyzed to determine whether asymmetry of preoperative volumetrics, FLAIR intensities, and MD values in hippocampi, as well as FA values in posteroinferior cingula and fornix crura correctly predicted laterality of seizure onset. Ten of the cohort had pathologically proven mesial temporal sclerosis (MTS). Seven of these patients had undergone extraoperative electrocorticography (ECoG) for lateralization or to rule out extra-temporal foci. HVU was estimated to be 3.1×10(-5) for hippocampal MD, 0.027 for FA in posteroinferior cingulum, 0.018 for FA in crus of fornix, 0.069 for hippocampal normalized volume, and 0.099 for hippocampal normalized FLAIR intensity. Using HVU analysis, a higher hippocampal MD value, lower FA within the posteroinferior cingulum and crus of fornix, shrinkage in hippocampal volume, and higher hippocampal FLAIR intensity were observed beyond uncertainty on the side ipsilateral to seizure onset for 10, 10, 9, 9, and 10 out of 10 pathology-proven MTS patients, respectively. Considering all 20 TLE patients, these numbers were 18, 15, 14, 13, and 16, respectively. However, consolidating the lateralization results of HVU analysis on these quantities by majority voting has detected the epileptogenic side for 19 out of 20 cases with no wrong lateralization. The presence of MTS in TLE patients is associated with an elevated MD value in the ipsilateral hippocampus and a reduced FA value in the posteroinferior subregion of the ipsilateral cingulum and crus of ipsilateral fornix. When considering all TLE patients, among the mentioned biomarkers the hippocampal MD had the best performance with true detection rate of 90% without any wrong lateralization. The proposed uncertainty based analyses hold promise for improving decision-making for surgical resection. Copyright © 2014 Elsevier B.V. All rights reserved.

Brain region and epilepsy-associated differences in inflammatory mediator levels in medically refractory mesial temporal lobe epilepsy.

PubMed

Strauss, Kenneth I; Elisevich, Kost V

2016-10-13

Epilepsy patients have distinct immune/inflammatory cell profiles and inflammatory mediator levels in the blood. Although the neural origin of inflammatory cells and mediators has been implied, few studies have measured these inflammatory components in the human brain itself. This study examines the brain levels of chemokines (8), cytokines (14), and vascular injury mediators (3) suspected of being altered in epilepsy. Soluble protein extracts of fresh frozen resected hippocampus, entorhinal cortex, and temporal cortex from 58 medically refractory mesial temporal lobe epilepsy subjects and 4 nonepileptic neurosurgical subjects were assayed for 25 inflammation-related mediators using ultrasensitive low-density arrays. Brain mediator levels were compared between regions and between epileptic and nonepileptic cases, showing a number of regional and possible epilepsy-associated differences. Eotaxin, interferon-γ, interleukin (IL)-2, IL-4, IL-12 p70, IL-17A, tumor necrosis factor-α, and intercellular adhesion molecule (ICAM)-1 levels were highest in the hippocampus, the presumptive site of epileptogenesis. Surprisingly, IL-1β and IL-1α were lowest in the hippocampus, compared to cortical regions. In the temporal cortex, IL-1β, IL-8, and MIP-1α levels were highest, compared to the entorhinal cortex and the hippocampus. The most pronounced epilepsy-associated differences were decreased levels of eotaxin, IL-1β, C-reactive protein, and vascular cell adhesion molecule (VCAM)-1 and increased IL-12 p70 levels. Caution must be used in interpreting these results, however, because nonepileptic subjects were emergent neurosurgical cases, not a control group. Correlation analyses of each mediator in each brain region yielded valuable insights into the regulation of these mediator levels in the brain. Over 70 % of the associations identified were between different mediators in a single brain region, providing support for local control of mediator levels. Correlations of different mediators in different brain regions suggested more distributed control mechanisms, particularly in the hippocampus. Interestingly, only four mediators showed robust correlations between the brain regions, yet levels in three of these were significantly different between regions, indicating both global and local controls for these mediators. Both brain region-specific and epilepsy-associated changes in inflammation-related mediators were detected. Correlations in mediator levels within and between brain regions indicated local and global regulation, respectively. The hippocampus showed the majority of interregional associations, suggesting a focus of inflammatory control between these regions.

Generalized epilepsy syndromes and callosal thickness: Differential effects between patients with juvenile myoclonic epilepsy and those with generalized tonic-clonic seizures alone.

PubMed

Anastasopoulou, Stavroula; Kurth, Florian; Luders, Eileen; Savic, Ivanka

2017-01-01

The definition of two well-studied genetic generalized epilepsy syndromes (GGE) - juvenile myoclonic epilepsy (JME) and epilepsy with generalized tonic-clonic seizures alone (GTCS) - suggests the absence of structural cerebral abnormalities. Nevertheless, there are various reports of such abnormalities (especially in JME), where effects mainly occur within thalamus and mesial prefrontal regions. This raises the question of whether JME is particularly linked to midline structure abnormalities, which may also involve the corpus callosum. We studied callosal morphology in a well-matched sample of 22 JME patients, 15 GTCS patients, and 42 controls (CTL) for all of whom we obtained T1-weighted data on a 3T MRI scanner. More specifically, we measured callosal thickness at 100 equidistant points across the callosal surface, and subsequently compared the three groups (JME, GTCS, and CTL) against each other. Significant differences between JME patients and controls were observed within the callosal genu, anterior midbody, and isthmus, with thinner regions in JME patients. There were no significant differences between GTCS patients and controls, and also not between JME patients and GTCS patients. The present outcomes point to callosal abnormalities in JME patients suggesting an impairment of interhemisperic communication between prefrontal, motor, parietal and temporal cortices. These findings further support the notion that structural aberrations are present and differentiated across GGE syndromes, with significant callosal deviations from normality in JME. Copyright © 2016 Elsevier B.V. All rights reserved.

Regional cortical thinning in subjects with violent antisocial personality disorder or schizophrenia.

PubMed

Narayan, Veena M; Narr, Katherine L; Kumari, Veena; Woods, Roger P; Thompson, Paul M; Toga, Arthur W; Sharma, Tonmoy

2007-09-01

Violent behavior is associated with antisocial personality disorder and to a lesser extent with schizophrenia. Neuroimaging studies have suggested that several biological systems are disturbed in schizophrenia, and structural changes in frontal and temporal lobe regions are reported in both antisocial personality disorder and schizophrenia. The neural substrates that underlie violent behavior specifically and their structural analogs, however, remain poorly understood. Nor is it known whether a common biological basis exists for aggressive, impulsive, and violent behavior across these clinical populations. To explore the correlates of violence with brain structure in antisocial personality disorder and schizophrenia, the authors used magnetic resonance imaging data to investigate for the first time, to the authors' knowledge, regional differences in cortical thickness in violent and nonviolent individuals with schizophrenia and/or antisocial personality disorder and in healthy comparison subjects. Subject groups included right-handed men closely matched for demographic variables (total number of subjects=56). Violence was associated with cortical thinning in the medial inferior frontal and lateral sensory motor cortex, particularly in the right hemisphere, and surrounding association areas (Brodmann's areas 10, 11, 12, and 32). Only violent subjects with antisocial personality disorder exhibited cortical thinning in inferior mesial frontal cortices. The biological underpinnings of violent behavior may therefore vary between these two violent subject groups in which the medial frontal cortex is compromised in antisocial personality disorder exclusively, but laminar abnormalities in sensorimotor cortices may relate to violent behavior in both antisocial personality disorder and schizophrenia.

Regional Cortical Thinning in Subjects With Violent Antisocial Personality Disorder or Schizophrenia

PubMed Central

Narayan, Veena M.; Narr, Katherine L.; Kumari, Veena; Woods, Roger P.; Thompson, Paul M.; Toga, Arthur W.; Sharma, Tonmoy

2011-01-01

Violent behavior is associated with antisocial personality disorder and to a lesser extent with schizophrenia. Neuroimaging studies have suggested that several biological systems are disturbed in schizophrenia, and structural changes in frontal and temporal lobe regions are reported in both antisocial personality disorder and schizophrenia. The neural substrates that underlie violent behavior specifically and their structural analogs, however, remain poorly understood. Nor is it known whether a common biological basis exists for aggressive, impulsive, and violent behavior across these clinical populations. To explore the correlates of violence with brain structure in antisocial personality disorder and schizophrenia, the authors used magnetic resonance imaging data to investigate for the first time, to the authors’ knowledge, regional differences in cortical thickness in violent and nonviolent individuals with schizophrenia and/or antisocial personality disorder and in healthy comparison subjects. Subject groups included right-handed men closely matched for demographic variables (total number of subjects=56). Violence was associated with cortical thinning in the medial inferior frontal and lateral sensory motor cortex, particularly in the right hemisphere, and surrounding association areas (Brodmann’s areas 10, 11, 12, and 32). Only violent subjects with antisocial personality disorder exhibited cortical thinning in inferior mesial frontal cortices. The biological underpinnings of violent behavior may therefore vary between these two violent subject groups in which the medial frontal cortex is compromised in antisocial personality disorder exclusively, but laminar abnormalities in sensorimotor cortices may relate to violent behavior in both antisocial personality disorder and schizophrenia. PMID:17728428

Identification of common variants associated with human hippocampal and intracranial volumes

PubMed Central

Stein, Jason L; Medland, Sarah E; Vasquez, Alejandro Arias; Hibar, Derrek P; Senstad, Rudy E; Winkler, Anderson M; Toro, Roberto; Appel, Katja; Bartecek, Richard; Bergmann, Ørjan; Bernard, Manon; Brown, Andrew A; Cannon, Dara M; Chakravarty, M Mallar; Christoforou, Andrea; Domin, Martin; Grimm, Oliver; Hollinshead, Marisa; Holmes, Avram J; Homuth, Georg; Hottenga, Jouke-Jan; Langan, Camilla; Lopez, Lorna M; Hansell, Narelle K; Hwang, Kristy S; Kim, Sungeun; Laje, Gonzalo; Lee, Phil H; Liu, Xinmin; Loth, Eva; Lourdusamy, Anbarasu; Mattingsdal, Morten; Mohnke, Sebastian; Maniega, Susana Muñoz; Nho, Kwangsik; Nugent, Allison C; O’Brien, Carol; Papmeyer, Martina; Pütz, Benno; Ramasamy, Adaikalavan; Rasmussen, Jerod; Rijpkema, Mark; Risacher, Shannon L; Roddey, J Cooper; Rose, Emma J; Ryten, Mina; Shen, Li; Sprooten, Emma; Strengman, Eric; Teumer, Alexander; Trabzuni, Daniah; Turner, Jessica; van Eijk, Kristel; van Erp, Theo G M; van Tol, Marie-Jose; Wittfeld, Katharina; Wolf, Christiane; Woudstra, Saskia; Aleman, Andre; Alhusaini, Saud; Almasy, Laura; Binder, Elisabeth B; Brohawn, David G; Cantor, Rita M; Carless, Melanie A; Corvin, Aiden; Czisch, Michael; Curran, Joanne E; Davies, Gail; de Almeida, Marcio A A; Delanty, Norman; Depondt, Chantal; Duggirala, Ravi; Dyer, Thomas D; Erk, Susanne; Fagerness, Jesen; Fox, Peter T; Freimer, Nelson B; Gill, Michael; Göring, Harald H H; Hagler, Donald J; Hoehn, David; Holsboer, Florian; Hoogman, Martine; Hosten, Norbert; Jahanshad, Neda; Johnson, Matthew P; Kasperaviciute, Dalia; Kent, Jack W; Kochunov, Peter; Lancaster, Jack L; Lawrie, Stephen M; Liewald, David C; Mandl, René; Matarin, Mar; Mattheisen, Manuel; Meisenzahl, Eva; Melle, Ingrid; Moses, Eric K; Mühleisen, Thomas W; Nauck, Matthias; Nöthen, Markus M; Olvera, Rene L; Pandolfo, Massimo; Pike, G Bruce; Puls, Ralf; Reinvang, Ivar; Rentería, Miguel E; Rietschel, Marcella; Roffman, Joshua L; Royle, Natalie A; Rujescu, Dan; Savitz, Jonathan; Schnack, Hugo G; Schnell, Knut; Seiferth, Nina; Smith, Colin; Steen, Vidar M; Valdés Hernández, Maria C; Van den Heuvel, Martijn; van der Wee, Nic J; Van Haren, Neeltje E M; Veltman, Joris A; Völzke, Henry; Walker, Robert; Westlye, Lars T; Whelan, Christopher D; Agartz, Ingrid; Boomsma, Dorret I; Cavalleri, Gianpiero L; Dale, Anders M; Djurovic, Srdjan; Drevets, Wayne C; Hagoort, Peter; Hall, Jeremy; Heinz, Andreas; Jack, Clifford R; Foroud, Tatiana M; Le Hellard, Stephanie; Macciardi, Fabio; Montgomery, Grant W; Poline, Jean Baptiste; Porteous, David J; Sisodiya, Sanjay M; Starr, John M; Sussmann, Jessika; Toga, Arthur W; Veltman, Dick J; Walter, Henrik; Weiner, Michael W; Bis, Joshua C; Ikram, M Arfan; Smith, Albert V; Gudnason, Vilmundur; Tzourio, Christophe; Vernooij, Meike W; Launer, Lenore J; DeCarli, Charles; Seshadri, Sudha; Andreassen, Ole A; Apostolova, Liana G; Bastin, Mark E; Blangero, John; Brunner, Han G; Buckner, Randy L; Cichon, Sven; Coppola, Giovanni; de Zubicaray, Greig I; Deary, Ian J; Donohoe, Gary; de Geus, Eco J C; Espeseth, Thomas; Fernández, Guillén; Glahn, David C; Grabe, Hans J; Hardy, John; Hulshoff Pol, Hilleke E; Jenkinson, Mark; Kahn, René S; McDonald, Colm; McIntosh, Andrew M; McMahon, Francis J; McMahon, Katie L; Meyer-Lindenberg, Andreas; Morris, Derek W; Müller-Myhsok, Bertram; Nichols, Thomas E; Ophoff, Roel A; Paus, Tomas; Pausova, Zdenka; Penninx, Brenda W; Potkin, Steven G; Sämann, Philipp G; Saykin, Andrew J; Schumann, Gunter; Smoller, Jordan W; Wardlaw, Joanna M; Weale, Michael E; Martin, Nicholas G; Franke, Barbara; Wright, Margaret J; Thompson, Paul M

2013-01-01

Identifying genetic variants influencing human brain structures may reveal new biological mechanisms underlying cognition and neuropsychiatric illness. The volume of the hippocampus is a biomarker of incipient Alzheimer’s disease1,2 and is reduced in schizophrenia3, major depression4 and mesial temporal lobe epilepsy5. Whereas many brain imaging phenotypes are highly heritable6,7, identifying and replicating genetic influences has been difficult, as small effects and the high costs of magnetic resonance imaging (MRI) have led to underpowered studies. Here we report genome-wide association meta-analyses and replication for mean bilateral hippocampal, total brain and intracranial volumes from a large multinational consortium. The intergenic variant rs7294919 was associated with hippocampal volume (12q24.22; N = 21,151; P = 6.70 × 10−16) and the expression levels of the positional candidate gene TESC in brain tissue. Additionally, rs10784502, located within HMGA2, was associated with intracranial volume (12q14.3; N = 15,782; P = 1.12 × 10−12). We also identified a suggestive association with total brain volume at rs10494373 within DDR2 (1q23.3; N = 6,500; P = 5.81 × 10−7). PMID:22504417

Diffusion analysis of one photosensitizer in bovine teeth using fluorescence optical imaging

NASA Astrophysics Data System (ADS)

Montanha, S.; Pratavieira, S.; Jacomassi, D. P.; Rastelli, A. N. S.; Bagnato, V. S.

2012-01-01

Some photosensitizers (PSs) used for PACT (Antimicrobial Photodynamic Therapy) show an affinity for bacterial walls and can be photo-activated to cause the desired damage. However, on dentine bacterias may be less susceptible to PACT as a result of limited penetration of the PS. The aim of this study was to evaluate the diffusion of one PS based on hematoporphyrin on dentine structures. Twelve bovine incisors were used. Class III cavities (3 x 3 x 1mm) were prepared on the mesial or distal surfaces using a diamond bur. Photogem® solution at 1 mg/mL (10 uL for each cavity) was used. The experimental Groups were divided according to thickness of dentine remaining and etched or no-etched before the PS application. The fluorescence excitation source was a VelScope® system. For image capture a scientific CCD color camera PixelFly® was coupled to VelScope. For image acquisition and processing, a computational routine was developed at Matlab®. Fick's Law was used to obtain the average diffusion coefficient of PS. Differences were found between all Groups. The longitudinal temporal diffusion was influenced by the different times, thickness and acid etching.

Magnetic resonance volumetry of the hippocampus in familial spontaneous epileptic cats.

PubMed

Mizoguchi, Shunta; Hasegawa, Daisuke; Kuwabara, Takayuki; Hamamoto, Yuji; Ogawa, Fukie; Fujiwara, Aki; Matsuki, Naoaki; Fujita, Michio

2014-12-01

A strain of familial spontaneous epileptic cats (FSECs) with typical limbic seizures was identified in 2010. The electroencephalographic features suggested that an epileptogenic zone is present in the mesial temporal structures (i.e., amygdala and/or hippocampus). In this study, visual evaluations and quantitative analyses were performed by using 3D MR hippocampal volumetry in comparing FSECs with age-matched controls. Visual hippocampal asymmetries were seen in 8 of 14 (57.1%) FSECs. The FSEC group showed a significantly higher asymmetric ratio (4.15%) than the control group (0.99%). The smaller side of hippocampal volume (HV) (0.206 cm(3)) in FSECs was significantly smaller than the mean HV in controls (0.227 cm(3)). However, the means of left and right HVs and total HVs in FSECs showed no differences because the laterality of hippocampal atrophy was different in each individual. Therefore, since FSECs represent a true model of spontaneous epilepsy, hippocampal volumetry should be evaluated in each individual as well as in human patients. The significant asymmetry of HV suggests the potential for hippocampal atrophy in FSECs. Copyright © 2014 Elsevier B.V. All rights reserved.

Endodontic management of a mandibular first molar with six root canal systems.

PubMed

Jain, Dilip; Reddy, Smitha; Venigalla, Bhuvan Shome; Kamishetty, Shekhar

2015-01-01

Internal anatomy of pulp is complex. The first mandibular molars typically have two roots, one mesial with two root canals and another distal root, which contains one or two canals. A 20-year-old female patient reported with intermittent pain and incomplete root canal treatment in left lower back region since 1-week. Refined access cavity revealed initially two canals in mesial and two canals in the distal root. With operating microscope and cone beam computerized tomography, two additional canals (L-mesio-buccal and B-mesio-lingual) were identified in mesial root. One-year follow-up showed patient was asymptomatic and complete healing of periapical radiolucency.

Olfactory identification and Stroop interference converge in schizophrenia.

PubMed Central

Purdon, S E

1998-01-01

OBJECTIVE: To test the discriminant validity of a model predicting a dissociation between measures of right and left frontal lobe function in people with schizophrenia. PARTICIPANTS: Twenty-one clinically stable outpatients with schizophrenia. INTERVENTIONS: Patients were administered the University of Pennsylvania Smell Identification Test (UPSIT), the Stroop Color-Word Test (Stroop), and the Positive and Negative Syndrome Scale (PANSS). OUTCOME MEASURES: Scores on these tests and relation among scores. RESULTS: There was a convergence of UPSII and Stroop interference scores consistent with a common cerebral basis for limitations in olfactory identification and inhibition of distraction. There was also a divergence of UPSIT and Stroop reading scores suggesting that the olfactory identification limitation is distinct from a general limitation of attention or a dysfunction of the left dorsolateral prefrontal cortex. Most notable was the 81% classification convergence between the UPSIT and Stroop incongruous colour naming scores compared with the near-random 57% classification convergence of the UPSIT and Stroop reading scores. CONCLUSIONS: These data are consistent with a right orbitofrontal dysfunction in a subgroup of patients with schizophrenia, although the involvement of mesial temporal structures in both tasks must be ruled out with further study. A multifactorial model depicting contributions from diverse cerebral structures is required to describe the pathophysiology of schizophrenia. Valid behavioural methods for classifying suspected subgroups of patients with particular cerebral dysfunction would be of value in the construction of this model. PMID:9595890

How can we explain the frontal presentation of insular lobe epilepsy? The impact of non-linear analysis of insular seizures.

PubMed

Hagiwara, Koichi; Jung, Julien; Bouet, Romain; Abdallah, Chifaou; Guénot, Marc; Garcia-Larrea, Luis; Mauguière, François; Rheims, Sylvain; Isnard, Jean

2017-05-01

For a decade it has been known that the insular lobe epilepsy can mimic frontal lobe epilepsy. We aimed to clarify the pattern of functional coupling occurring during the frontal presentation. We analyzed five insular lobe epilepsy patients. Frontal semiology was predominant for three of them, whereas insular semiology was predominant for the two others. We applied the non-linear regression analysis to stereoelectroencephalography-recorded seizures. A directed functional coupling index was calculated during clonic discharge periods that were accompanied either with frontal or insular semiology. We found significant functional coupling between the insula and mesial frontal/cingulate regions, with the former being a leader region for seizures propagation. Extra-insular regions showed significantly less or even no coupling with the mesial hemispheric regions. The three patients with frontal semiology showed strong couplings with the mesial frontal as well as cingulate regions, including the medial orbitofrontal cortex, pre-SMA/SMA, and the anterior to posterior cingulate. The two patients with the insular semiology only showed couplings between the insula and cingulate regions. The frontal semiology was expressed by strong functional couplings between the insula and mesial frontal regions. The insular origin of seizure should be considered in cryptogenic mesial frontal epilepsies. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Correlates of local cerebral blood flow (CBF) in normal pressure hydrocephalus patients before and after shunting--A retrospective analysis of [(15)O]H(2)O PET-CBF studies in 65 patients.

PubMed

Klinge, Petra M; Brooks, David J; Samii, Amir; Weckesser, Eva; van den Hoff, Jörg; Fricke, Harald; Brinker, Thomas; Knapp, Wolfram H; Berding, Georg

2008-04-01

Findings in local cerebral blood flow (rCBF) in Normal pressure hydrocephalus (NPH) have always been challenged by the variable and inconsistent relation to clinical symptoms before and after shunt treatment. [(15)O]H(2)O PET data from a consecutive cohort of 65 idiopathic NPH patients were retrospectively analyzed questioning whether the functional status before and after shunt treatment might correlate with local blood flow. Using statistical parametric mapping (SPM99, Wellcome Department of Cognitive Neurology, London), the [(15)O]H(2)O uptake was correlated with the preoperative clinical scores, graded according to a modified Stein and Langfitt score. Furthermore, differences in the uptake in the pre-and post-shunt treatment study after seven to 10 days in patients with and without clinical improvement were studied. A higher clinical score significantly correlated with a reduced tracer uptake in mesial frontal (k=1,239 voxel, Z=4.41) and anterior temporal (k=469, Z=4.07) areas. In the mesial frontal areas, tracer uptake showed significant reciprocal changes in the clinically improved vs. the unimproved patients. Matched with the existing literature, the regional blood flow alterations are suggested relevant to the NPH syndrome and to post-treatment functional changes. The present rCBF findings warrant prospective studies on the accuracy of neuroimaging studies as they may provide a more specific insight into disease mechanisms.

Influence of implant inclination associated with mandibular class I removable partial denture.

PubMed

de Freitas Santos, Ciandrus Moraes; Pellizzer, Eduardo Piza; Verri, Fellippo Ramos; de Moraes, Sandra Lúcia Dantas; Falcón-Antenucci, Rosse Mary

2011-03-01

The aim of this study was to use two-dimensional finite element method to evaluate the displacement and stress distribution transmitted by a distal extension removable partial denture (DERPD) associated with an implant placed at different inclinations (0, 5, 15, and 30 degrees) in the second molar region of the edentulous mandible ridge. Six hemimandibular models were created: model A, only with the presence of the natural tooth 33; model B, similar to model A, with the presence of a conventional DERPD replacing the missing teeth; model C, similar to the previous model, with a straight implant (0 degrees) in the distal region of the ridge, under the denture base; model D, similar to model C, with the implant angled at 5 degrees in the mesial direction; model E, similar to model C, with the implant angled at 15 degrees in the mesial direction; and model F, similar to ME, with the implant angled at 30 degrees in the mesial direction. The models were created with the use of the AutoCAD 2000 program (Autodesk, Inc, San Rafael, CA) and processed for finite element analysis by the ANSYS 8.0 program (Swanson Analysis Systems, Houston, PA). The force applied was vertical of 50 N on each cusp tip. The results showed that the introduction of the RPD overloaded the supporting structures of the RPD and that the introduction of the implant helped to relieve the stresses of the mucosa alveolar, cortical bone, and trabecular bone. The best stress distribution occurred in model D with the implant angled at 5 degrees. The use of an implant as a support decreased the displacement of alveolar mucosa for all inclinations simulated. The stress distribution transmitted by the DERPD to the supporting structures was improved by the use of straight or slightly inclined implants. According to the displacement analysis and von Mises stress, it could be expected that straight or slightly inclined implants do not represent biomechanical risks to use.

Regional structural characteristics of bovine periodontal ligament samples and their suitability for biomechanical tests.

PubMed

Bosshardt, Dieter D; Bergomi, Marzio; Vaglio, Giovanna; Wiskott, Anselm

2008-03-01

Mechanical testing of the periodontal ligament requires a practical experimental model. Bovine teeth are advantageous in terms of size and availability, but information is lacking as to the anatomy and histology of their periodontium. The aim of this study, therefore, was to characterize the anatomy and histology of the attachment apparatus in fully erupted bovine mandibular first molars. A total of 13 teeth were processed for the production of undecalcified ground sections and decalcified semi-thin sections, for NaOH maceration, and for polarized light microscopy. Histomorphometric measurements relevant to the mechanical behavior of the periodontal ligament included width, number, size and area fraction of blood vessels and fractal analysis of the two hard-soft tissue interfaces. The histological and histomorphometric analyses were performed at four different root depths and at six circumferential locations around the distal and mesial roots. The variety of techniques applied provided a comprehensive view of the tissue architecture of the bovine periodontal ligament. Marked regional variations were observed in width, surface geometry of the two bordering hard tissues (cementum and alveolar bone), structural organization of the principal periodontal ligament connective tissue fibers, size, number and numerical density of blood vessels in the periodontal ligament. No predictable pattern was observed, except for a statistically significant increase in the area fraction of blood vessels from apical to coronal. The periodontal ligament width was up to three times wider in bovine teeth than in human teeth. The fractal analyses were in agreement with the histological observations showing frequent signs of remodeling activity in the alveolar bone - a finding which may be related to the magnitude and direction of occlusal forces in ruminants. Although samples from the apical root portion are not suitable for biomechanical testing, all other levels in the buccal and lingual aspects of the mesial and distal roots may be considered. The bucco-mesial aspect of the distal root appears to be the most suitable location.

Three new species of freshwater crabs of the genus Pseudothelphusa (De Saussure, 1857) (Crustacea: Decapoda: Pseudothelphusidae) from Mexico.

PubMed

Ojeda-Escoto, Juan Carlos; Villalobos, José Luis; Álvarez, Fernando

2017-01-11

Three new species of freshwater crabs of the genus Pseudothelphusa (De Saussure, 1857) from south-central Mexico are described: Pseudothelphusa acahuizotla n. sp., P. ixtapan n. sp., and P. purhepecha n. sp. The new species are included in Pseudothelphusa due to a male gonopod with torsion and the presence of the characteristic mesial process and caudomarginal projection. Pseudothelphusa acahuizotla n. sp. is morphologically similar to P. belliana Rathbun, 1898, but can be distinguished by the relative size of the distal lobe of the caudomarginal projection and by the presence of a conical tooth on the caudal surface of the mesial process of the male gonopod. Pseudothelphusa ixtapan n. sp. is similar to P. dilatata Rathbun, 1898, and P. morelosis Pretzmann, 1968, and can be distinguished by a mesial process of the male gonopod with only one lateral tooth and an inferior margin with small teeth. Pseudothelphusa puerhepechae n. sp. exhibits a mesial process of the male gonopod with two triangular spines on its lateral margin, a character that with some variations is present in P. nayaritae Álvarez & Villalobos, 1994, P. rechingeri Pretzmann, 1965, P. lophophallus Rodríguez & Smalley, 1969, and P. parabelliana Álvarez 1989; but it can be distinguished by the separation and shape of the two spines of the mesial process and the shape of the lobes of the caudomarginal projection. With the new species described herein there are now 29 species in the genus Pseudothelphusa.

Determining Surgical Candidacy in Temporal Lobe Epilepsy

PubMed Central

Mansouri, Alireza; Fallah, Aria; Valiante, Taufik A.

2012-01-01

Temporal lobe epilepsy (TLE) is the most common form of adult epilepsy that is amenable to surgical treatment. In the carefully selected patient, excellent seizure outcome can be achieved with minimal or no side effects from surgery. This may result in improved psychosocial functioning, achieving higher education, and maintaining or gaining employment. The objective of this paper is to discuss the surgical selection process of a patient with TLE. We define what constitutes a patient that has medically refractory TLE, describe the typical history and physical examination, and distinguish between mesial TLE and neocortical TLE. We then review the role of routine (ambulatory/sleep-deprived electroencephalography (EEG), video EEG, magnetic resonance imaging (MRI), neuropsychological testing, and Wada testing) and ancillary preoperative testing (positron emission tomography, single-photon emission computed tomography (SPECT), subtraction ictal SPECT correlated to MRI (SISCOM), magnetoencephalography, magnetic resonance spectroscopy, and functional MRI) in selecting surgical candidates. We describe the surgical options for resective epilepsy surgery in TLE and its commonly associated risks while highlighting some of the controversies. Lastly, we present teaching cases to illustrate the presurgical workup of patients with medically refractory TLE. PMID:22957238

Community Structure Analysis of Transcriptional Networks Reveals Distinct Molecular Pathways for Early- and Late-Onset Temporal Lobe Epilepsy with Childhood Febrile Seizures

PubMed Central

Moreira-Filho, Carlos Alberto; Bando, Silvia Yumi; Bertonha, Fernanda Bernardi; Iamashita, Priscila; Silva, Filipi Nascimento; Costa, Luciano da Fontoura; Silva, Alexandre Valotta; Castro, Luiz Henrique Martins; Wen, Hung-Tzu

2015-01-01

Age at epilepsy onset has a broad impact on brain plasticity and epilepsy pathomechanisms. Prolonged febrile seizures in early childhood (FS) constitute an initial precipitating insult (IPI) commonly associated with mesial temporal lobe epilepsy (MTLE). FS-MTLE patients may have early disease onset, i.e. just after the IPI, in early childhood, or late-onset, ranging from mid-adolescence to early adult life. The mechanisms governing early (E) or late (L) disease onset are largely unknown. In order to unveil the molecular pathways underlying E and L subtypes of FS-MTLE we investigated global gene expression in hippocampal CA3 explants of FS-MTLE patients submitted to hippocampectomy. Gene coexpression networks (GCNs) were obtained for the E and L patient groups. A network-based approach for GCN analysis was employed allowing: i) the visualization and analysis of differentially expressed (DE) and complete (CO) - all valid GO annotated transcripts - GCNs for the E and L groups; ii) the study of interactions between all the system’s constituents based on community detection and coarse-grained community structure methods. We found that the E-DE communities with strongest connection weights harbor highly connected genes mainly related to neural excitability and febrile seizures, whereas in L-DE communities these genes are not only involved in network excitability but also playing roles in other epilepsy-related processes. Inversely, in E-CO the strongly connected communities are related to compensatory pathways (seizure inhibition, neuronal survival and responses to stress conditions) while in L-CO these communities harbor several genes related to pro-epileptic effects, seizure-related mechanisms and vulnerability to epilepsy. These results fit the concept, based on fMRI and behavioral studies, that early onset epilepsies, although impacting more severely the hippocampus, are associated to compensatory mechanisms, while in late MTLE development the brain is less able to generate adaptive mechanisms, what has implications for epilepsy management and drug discovery. PMID:26011637

Can Tooth Preparation Design Affect the Fit of CAD/CAM Restorations?

PubMed

Roperto, Renato Cassio; Oliveira, Marina Piolli; Porto, Thiago Soares; Ferreira, Lais Alaberti; Melo, Lucas Simino; Akkus, Anna

2017-03-01

The purpose of this study was to evaluate if the marginal fit of computer-aided design and computer-aided manufacturing (CAD/CAM) restorations manufactured with CAD/CAM systems can be affected by different tooth preparation designs. Twenty-six typodont (plastic) teeth were divided into two groups (n = 13) according to the occlusal curvature of the tooth preparation. These were the group 1 (control group) (flat occlusal design) and group 2 (curved occlusal design). Scanning of the preparations was performed, and crowns were milled using ceramic blocks. Blocks were cemented using epoxy glue on the pulpal floor only, and finger pressure was applied for 1 minute. On completion of the cementation step, poor fits between the restoration and abutment were measured by microphotography and the silicone replica technique using light-body silicon material on mesial, distal, buccal, and lingual surfaces. Two-way ANOVA analysis did not reveal a statistical difference between flat (83.61 ± 50.72) and curved (79.04 ± 30.97) preparation designs. Buccal, mesial, lingual, and distal sites on the curved design preparation showed less of a gap when compared with flat design. No difference was found on flat preparations among mesial, buccal, and distal sites (P < .05). The lingual aspect had no difference from the distal side but showed a statistically significant difference from mesial and buccal (P < .05). Difference in occlusal design did not significantly impact the marginal fit. Marginal fit was significantly affected by the location of the margin; lingual and distal locations exhibited greater margin gap values compared with buccal and mesial sites regardless of the preparation design.

Correlative bacteriologic and micro-computed tomographic analysis of mandibular molar mesial canals prepared by self-adjusting file, reciproc, and twisted file systems.

PubMed

Siqueira, José F; Alves, Flávio R F; Versiani, Marco A; Rôças, Isabela N; Almeida, Bernardo M; Neves, Mônica A S; Sousa-Neto, Manoel D

2013-08-01

This ex vivo study evaluated the disinfecting and shaping ability of 3 protocols used in the preparation of mesial root canals of mandibular molars by means of correlative bacteriologic and micro-computed tomographic (μμCT) analysis. The mesial canals of extracted mandibular molars were contaminated with Enterococcus faecalis for 30 days and assigned to 3 groups based on their anatomic configuration as determined by μCT analysis according to the preparation technique (Self-Adjusting File [ReDent-Nova, Ra'anana, Israel], Reciproc [VDW, Munich, Germany], and Twisted File [SybronEndo, Orange, CA]). In all groups, 2.5% NaOCl was the irrigant. Canal samples were taken before (S1) and after instrumentation (S2), and bacterial quantification was performed using culture. Next, mesial roots were subjected to additional μCT analysis in order to evaluate shaping of the canals. All instrumentation protocols promoted a highly significant intracanal bacterial reduction (P < .001). Intergroup quantitative and qualitative comparisons disclosed no significant differences between groups (P > .05). As for shaping, no statistical difference was observed between the techniques regarding the mean percentage of volume increase, the surface area increase, the unprepared surface area, and the relative unprepared surface area (P > .05). Correlative analysis showed no statistically significant relationship between bacterial reduction and the mean percentage increase of the analyzed parameters (P > .05). The 3 instrumentation systems have similar disinfecting and shaping performance in the preparation of mesial canals of mandibular molars. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

A comparison of mesial molar root canal preparations using two engine-driven instruments and the balanced-force technique.

PubMed

Imura, N; Kato, A S; Novo, N F; Hata, G; Uemura, M; Toda, T

2001-10-01

The purpose of this study was to compare the effects of two engine-driven, nickel-titanium instrument systems with hand files in the final shape of slight and moderately curved canals. A total of 72 mesial roots of extracted human mandibular molars were divided into three groups: ProFile .04 taper, Pow-R rotary systems, and Flex-R hand-filing technique. The roots were mounted and cross-sectioned at two different horizontal levels using a modified Bramante technique. Pre- and postinstrumented cross-sectional roots were imaged, recorded, and computer analyzed. Results showed that, at the middle third, in almost all groups, there was a tendency of cutting more toward the mesial side with only one exception: Pow-R cut more to the distal side (danger zone) (p < 0.02). At the apical third, Flex-R (p < 0.03) and ProFile (0.001) transported to the mesial side (danger zone) when the curvature increased. When the three techniques were compared analyzing each side and considering the two groups of curvature, at the middle third in the moderately curved-canal group, Flex-R cut statistically more than Pow-R toward the lingual side. The other comparisons showed no statistically significant difference. When the techniques were compared in relation with the degree of curvature, in the apical third, ProFile .04 cut statistically more toward the mesial side in the moderately curved canal group than in the slightly curved canal group. The other comparisons showed no statistically significant difference. Canal preparation time was shorter with hand instrumentation (p < .05) in a few instances.

Patient with oligodontia treated with a miniscrew for unilateral mesial movement of the maxillary molars and alignment of an impacted third molar.

PubMed

Maeda, Aya; Sakoguchi, Yoko; Miyawaki, Shouichi

2013-09-01

This report describes the treatment of a 20-year-old woman with a dental midline deviation and 7 congenitally missing premolars. She had retained a maxillary right deciduous canine and 4 deciduous second molars, and she had an impacted maxillary right third molar. The maxillary right deciduous second molar was extracted, and the space was nearly closed by mesial movement of the maxillary right molars using an edgewise appliance and a miniscrew for absolute anchorage. The miniscrew was removed, and the extraction space of the maxillary right deciduous canine was closed, correcting the dental midline deviation. After the mesial movement of the maxillary right molars, the impacted right third molar was aligned. To prevent root resorption, the retained left deciduous second molars were not aligned by the edgewise appliance. The occlusal contact area and the maximum occlusal force increased over the 2 years of retention. The miniscrew was useful for absolute anchorage for unilateral mesial movement of the maxillary molars and for the creation of eruption space and alignment of the impacted third molar in a patient with oligodontia. Copyright © 2013 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Position and Eruption of Permanent Maxillary Canines in Cases of Maxillary Lateral Incisor Agenesis in Mixed Dentition.

PubMed

Lamas, Cátia; Lavall, Asela; Pinho, Teresa

2018-01-01

Assess whether the permanent maxillary canine (MC) has a natural tendency to erupt mesially in children with maxillary lateral incisors agenesis (MLIA), compared to children without agenesis. This retrospective, observational, cross-sectional study consisted of children between 5 and 12 years old divided into three groups: the first group with unilateral MLIA, in which an intraindividual analysis was performed, the second group presented bilateral MLIA, and the third group with patients without agenesis. These last two groups were matched for comparison interindividual, being pared by sex and maturation of the MC. The canine position in the horizontal sector showed a clear mesial positioning of the MC on the agenesis side in individuals with unilateral MLIA (group 1) when compared with the counter lateral side; and in individuals with bilateral MLIA (Group 2) compared with control Individuals without agenesis (group 3). Even with the maintenance of this deciduous tooth in the dental arch, the MC keeps its tendency to mesial eruption. There is a greater tendency for mesial angulation of the maxillary canine in patients with MLIA, regardless of the presence or absence of deciduous lateral incisor.

Supratentorial white matter blurring associated with voltage-gated potassium channel-complex limbic encephalitis.

PubMed

Urbach, H; Rauer, S; Mader, I; Paus, S; Wagner, J; Malter, M P; Prüss, H; Lewerenz, J; Kassubek, J; Hegen, H; Auer, M; Deisenhammer, F; Ufer, F; Bien, C G; Baumgartner, A

2015-12-01

Limbic encephalitis (LE) associated with voltage-gated potassium channel-complex antibodies (VGKC-LE) is frequently non-paraneoplastic and associated with marked improvement following corticosteroid therapy. Mesial temporal lobe abnormalities are present in around 80 % of patients. If associated or preceded by faciobrachial dystonic seizures, basal ganglia signal changes may occur. In some patients, blurring of the supratentorial white matter on T2-weighted images (SWMB) may be seen. The purpose of this study was to evaluate the incidence of SWMB and whether it is specific for VGKC-LE. Two experienced neuroradiologists independently evaluated signal abnormalities on FLAIR MRI in 79 patients with LE while unaware on the antibody type. SWMB was independently assessed as present in 10 of 36 (28 %) compared to 2 (5 %) of 43 non-VGKC patients (p = 0.009). It was not related to the presence of LGI1 or CASPR2 proteins of VGKC antibodies. MRI showed increased temporomesial FLAIR signal in 22 (61 %) VGKC compared to 14 (33 %) non-VGKC patients (p = 0.013), and extratemporomesial structures were affected in one VGKC (3 %) compared to 11 (26 %) non-VGKC patients (p = 0.005). SWMB is a newly described MRI sign rather specific for VGKC-LE.

Auditory hedonic phenotypes in dementia: A behavioural and neuroanatomical analysis

PubMed Central

Fletcher, Phillip D.; Downey, Laura E.; Golden, Hannah L.; Clark, Camilla N.; Slattery, Catherine F.; Paterson, Ross W.; Schott, Jonathan M.; Rohrer, Jonathan D.; Rossor, Martin N.; Warren, Jason D.

2015-01-01

Patients with dementia may exhibit abnormally altered liking for environmental sounds and music but such altered auditory hedonic responses have not been studied systematically. Here we addressed this issue in a cohort of 73 patients representing major canonical dementia syndromes (behavioural variant frontotemporal dementia (bvFTD), semantic dementia (SD), progressive nonfluent aphasia (PNFA) amnestic Alzheimer's disease (AD)) using a semi-structured caregiver behavioural questionnaire and voxel-based morphometry (VBM) of patients' brain MR images. Behavioural responses signalling abnormal aversion to environmental sounds, aversion to music or heightened pleasure in music (‘musicophilia’) occurred in around half of the cohort but showed clear syndromic and genetic segregation, occurring in most patients with bvFTD but infrequently in PNFA and more commonly in association with MAPT than C9orf72 mutations. Aversion to sounds was the exclusive auditory phenotype in AD whereas more complex phenotypes including musicophilia were common in bvFTD and SD. Auditory hedonic alterations correlated with grey matter loss in a common, distributed, right-lateralised network including antero-mesial temporal lobe, insula, anterior cingulate and nucleus accumbens. Our findings suggest that abnormalities of auditory hedonic processing are a significant issue in common dementias. Sounds may constitute a novel probe of brain mechanisms for emotional salience coding that are targeted by neurodegenerative disease. PMID:25929717

MEG Coherence and DTI Connectivity in mTLE

PubMed Central

Nazem-Zadeh, Mohammad-Reza; Bowyer, Susan M.; Moran, John E.; Davoodi-Bojd, Esmaeil; Zillgitt, Andrew; Weiland, Barbara J.; Bagher-Ebadian, Hassan; Mahmoudi, Fariborz; Elisevich, Kost; Soltanian-Zadeh, Hamid

2017-01-01

Purpose Magnetoencephalography (MEG) is a noninvasive imaging method for localization of focal epileptiform activity in patients with epilepsy. Diffusion tensor imaging (DTI) is a noninvasive imaging method for measuring the diffusion properties of the underlying white matter tracts through which epileptiform activity is propagated. This study investigates the relationship between the cerebral functional abnormalities quantified by MEG coherence and structural abnormalities quantified by DTI in mesial temporal lobe epilepsy (mTLE). Methods Resting state MEG data was analyzed using MEG coherence source imaging (MEG-CSI) method to determine the coherence in 54 anatomical sites in 17 adult mTLE patients with surgical resection and Engel class I outcome, and 17 age- and gender- matched controls. DTI tractography identified the fiber tracts passing through these same anatomical sites of the same subjects. Then, DTI nodal degree and laterality index were calculated and compared with the corresponding MEG coherence and laterality index. Results MEG coherence laterality, after Bonferroni adjustment, showed significant differences for right versus left mTLE in insular cortex and both lateral orbitofrontal and superior temporal gyri (p<0.017). Likewise, DTI nodal degree laterality, after Bonferroni adjustment, showed significant differences for right versus left mTLE in gyrus rectus, insular cortex, precuneus and superior temporal gyrus (p<0.017). In insular cortex, MEG coherence laterality correlated with DTI nodal degree laterality (R2 = 0.46; p = 0.003) in the cases of mTLE. None of these anatomical sites showed statistically significant differences in coherence laterality between right and left sides of the controls. Coherence laterality was in agreement with the declared side of epileptogenicity in insular cortex (in 82% of patients) and both lateral orbitofrontal (88%) and superior temporal gyri (88%). Nodal degree laterality was also in agreement with the declared side of epileptogenicity in gyrus rectus (in 88% of patients), insular cortex (71%), precuneus (82%) and superior temporal gyrus (94%). Combining all significant laterality indices improved the lateralization accuracy to 94% and 100% for the coherence and nodal degree laterality indices, respectively. Conclusion The associated variations in diffusion properties of fiber tracts quantified by DTI and coherence measures quantified by MEG with respect to epileptogenicity possibly reflect the chronic microstructural cerebral changes associated with functional interictal activity. The proposed methodology for using MEG and DTI to investigate diffusion abnormalities related to focal epileptogenicity and propagation may provide a further means of noninvasive lateralization. PMID:27060092

Predictors of spontaneous transient seizure remission in patients of medically refractory epilepsy due to mesial temporal sclerosis (MTS).

PubMed

Dhiman, Vikas; Sinha, Sanjib; Arimappamagan, Arivazhagan; Mahadevan, Anita; Bharath, Rose Dawn; Saini, Jitender; Rajeswaran, Jamuna; Rao, Malla Bhaskar; Shankar, Susrala K; Satishchandra, Parathasarthy

2015-02-01

To analyze the predictors of spontaneous transient seizure remission for ≥1 year in patients with drug-resistant epilepsy (DRE) due to mesial temporal sclerosis (MTS). This analysis included 38 patients with DRE (M:F = 20:18, age: 31.7 ± 10.9 years) diagnosed with unilateral MTS (right:left = 16:22). Group I ('remission' group) comprised of patients with seizure remission (M:F = 10:8, age: 32.8 ± 12.3 years, mean seizure free period: 2.2 ± 1.1 years; median: 2.1 years). Group II ('non-remission' group) comprised of age and gender matched 20 patients (M:F = 10:10, age: 30.7 ± 9.7 years) with unilateral MTS who never had seizure remission and subsequently underwent epilepsy surgery. Groups I and II were compared to find the predictors associated with transient seizure remission. The age at onset of seizures in group I was 13.2 ± 11.8 years and in group II was 12.0 ± 7.6 years. The duration of seizure was: group I - 19.7 ± 12.5 years and group II - 19.3 ± 7.7 years. Past history of seizure remissions (p < 0.001), frequent periods of remissions (p < 0.001), first remission within a year of onset of seizures (p = 0.04) and normal EEG (p = 0.04) were the important clinical predictors associated with seizure remission in this cohort. Fifteen patients in group I (83.3%) experienced remission following either change in AED (p ≤ 0.001) or increase in AED dosages (p < 0.001). There was no difference between the two groups regarding the type of semiology (partial vs. secondarily generalized) (p = 0.50), family history of seizures (p = 1.0), side of the lesion (p = 0.34), history of febrile seizures (p = 1.0) and the number of AEDs used (p = 0.53). The present study unfolds, some of the clinically relevant predictors associated with transient seizure remission in patients with DRE and MTS. Future molecular and network studies are required to understand its mechanism. Copyright © 2014 Elsevier B.V. All rights reserved.

A functional magnetic resonance imaging investigation of theory of mind impairments in patients with temporal lobe epilepsy.

PubMed

Hennion, Sophie; Delbeuck, Xavier; Koelkebeck, Katja; Brion, Marine; Tyvaert, Louise; Plomhause, Lucie; Derambure, Philippe; Lopes, Renaud; Szurhaj, William

2016-12-01

Although patients with mesial temporal lobe epilepsy (mTLE) are known to have theory of mind (ToM) impairments, the latter's neural functional bases have yet to be explored. We used functional magnetic resonance imaging (fMRI) to gain insights into the neural dysfunction associated with ToM impairments in patients with mTLE. Twenty-five patients (12 and 13 with right and left mTLE, respectively) and 25 healthy controls performed the "animated shapes" task during fMRI. This complex ToM task requires both explicit reasoning about mental states and implicit processing of information on biological motion and action. The animated shapes evoke both ToM and non-ToM interaction perception, and the corresponding neural activation patterns were compared. Behavioral performance (i.e. categorization of the interactions) was also recorded. Relative to healthy controls, both patients with right and left mTLE were impaired in categorizing ToM interactions. The fMRI results showed that both patients with right and left mTLE had less intense neural activation (relative to controls) in regions involved in the implicit component of ToM processes (i.e. the fusiform gyrus in patients with right mTLE and the supplementary motor area in patients with left mTLE). In patients with right mTLE, we also observed more intense activation (relative to controls) in regions involved in the explicit component of ToM processes (i.e. the dorsal medial prefrontal cortex); age at onset of epilepsy also mediated activation in regions involved in the explicit component (i.e. the ventral medial prefrontal cortex and the temporoparietal junction). Patients with left mTLE displayed greater activation of the contralateral mesial regions (relative to controls); we speculate that this may correspond to the deployment of a compensatory mechanism. This study provides insights into the disturbances of the implicit/explicit ToM neural network in patients with mTLE. These impairments in the ToM neural network depend on clinical characteristics, such as the laterality (right or left mTLE) and the age at onset of epilepsy. Copyright © 2016 Elsevier Ltd. All rights reserved.

Validation of diagnostic tests for depressive disorder in drug-resistant mesial temporal lobe epilepsy.

PubMed

de Lemos Zingano, Bianca; Guarnieri, Ricardo; Diaz, Alexandre Paim; Schwarzbold, Marcelo Liborio; Bicalho, Maria Alice Horta; Claudino, Lucia Sukys; Markowitsch, Hans J; Wolf, Peter; Lin, Katia; Walz, Roger

2015-09-01

This study aimed to evaluate the diagnostic accuracy of the Hamilton Rating Scale for Depression (HRSD), the Beck Depression Inventory (BDI), the Hospital Anxiety and Depression Scale (HADS), and the Hospital Anxiety and Depression Scale-Depression subscale (HADS-D) as diagnostic tests for depressive disorder in drug-resistant mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS). One hundred three patients with drug-resistant MTLE-HS were enrolled. All patients underwent a neurological examination, interictal and ictal video-electroencephalogram (V-EEG) analyses, and magnetic resonance imaging (MRI). Psychiatric interviews were based on DSM-IV-TR criteria and ILAE Commission of Psychobiology classification as a gold standard; HRSD, BDI, HADS, and HADS-D were used as psychometric diagnostic tests, and receiver operating characteristic (ROC) curves were used to determine the optimal threshold scores. For all the scales, the areas under the curve (AUCs) were approximately 0.8, and they were able to identify depression in this sample. A threshold of ≥9 on the HRSD and a threshold of ≥8 on the HADS-D showed a sensitivity of 70% and specificity of 80%. A threshold of ≥19 on the BDI and HADS-D total showed a sensitivity of 55% and a specificity of approximately 90%. The instruments showed a negative predictive value of approximately 87% and a positive predictive value of approximately 65% for the BDI and HADS total and approximately 60% for the HRSD and HADS-D. HRSD≥9 and HADS-D≥8 had the best balance between sensitivity (approximately 70%) and specificity (approximately 80%). However, with these thresholds, these diagnostic tests do not appear useful in identifying depressive disorder in this population with epilepsy, and their specificity (approximately 80%) and PPV (approximately 55%) were lower than those of the other scales. We believe that the BDI and HADS total are valid diagnostic tests for depressive disorder in patients with MTLE-HS, as both scales showed acceptable (though not high) specificity and PPV for this type of study. Copyright © 2015 Elsevier Inc. All rights reserved.

Treatment of endo-periodontal lesion using leukocyte-platelet-rich fibrin. A case report

PubMed Central

Elgueta, Ricardo; Fuentes, Ramon

2017-01-01

Abstract Case Description: The main objective of this paper was to report the clinical effectiveness of leukocyte- platelet- rich fibrin (L-PRF) in the treatment of a combined endo-periodontal lesion of an upper first premolar. Clinical Findings: The tooth had a profound abfraction on the vestibular aspect and presented no mobility but revealed a deep pocket measuring of 11 mm on the mesial vestibular aspect and 14 mm on the mesial palatine aspect. The three dimensional image analysis showed total bone loss in the mesial aspect and an extensively bone loss of the vestibular aspect of the vestibular root. Treatment and Outcome: Endodontic treatment was performed and periodontal access surgery (surgical periodontal therapy) was done with the application of autologous L-PRF. Three month and 6 months after surgery, the cone beam computed tomography (CBCT) exams showed no bone regeneration in any aspect of the tooth. However, periodontal examination showed a significative improvement in the deepness of surcus. The mesial vestibular aspect had a deep pocket of 3 mm and 5 mm on the mesial palatine aspect showing a reduction in deepness of 8 mm and 9 mm, respectively. Clinical Relevance: The actual treatment for teeth with bad prognosis is the extraction and replacement with implants. Even though implants are capable of restore function and aesthetic, the abuse of this approach have led to the loss of teeth that could be successfully treated with a less invasive technique. The prognosis of teeth with endoperiodontal lesion is poor but could be enhanced with regenerative therapies. Until now there are no clinical trials and just four case report about the treatment of these teeth with platelet rich fibrin. PMID:29662262

Evaluation of isthmus prevalence, location, and types in mesial roots of mandibular molars in the Iranian Population

PubMed Central

Mehrvarzfar, Payman; Akhlagi, Nahid Mohammadzade; Khodaei, Fatemeh; Shojaee, Golnaz; Shirazi, Sara

2014-01-01

Background: Management of canal isthmus is considered as an important factor for successful endodontic treatment. Accordingly, this study was designed to determine the prevalence, location, and types of isthmus in mesial root canals of extracted mandibular molars in a sample of Iranian population. Materials and Methods: In this cross-sectional descriptive study, 60 extracted molars with two mesial canals were included. The samples were initially decoronated and then, roots were sectioned horizontally at 2, 4, and 6 mm levels from the apex via a low-speed handpiece with a thin metallic disk and finally prepared and stained with Indian ink. All sections were examined using a stereomicroscope at a magnification of ×30. Prevalence, location, and types of isthmus were evaluated based on the classifications by Kim and Teixeira and all data were statistically analyzed by the chi-squared test. The statistical significance level was established at 0.05. Results: Eighty-three percent of extracted mandibular molars had an isthmus at the mesial root. This prevalence increased with distance from the apex, that is, 92% at 6 mm from the apex and 70% at 2 mm from the apex. A statistically significant difference was found between the sections at 2 and 6 mm from the apex (P < 0.05), but no other significant differences between other levels (P > 0.05). Conclusion: Isthmus is very common in the mesial roots of the mandibular permanent molars in the Iranian population, with the highest prevalence in the 6 mm distance from the root apex. Therefore, detection, cleaning, and filling of these apical 6 mm isthmuses are of great benefit in modern endodontics. PMID:24932198

Development of caries in permanent first molars adjacent to primary second molars with interproximal caries: four-year prospective radiographic study.

PubMed

Vanderas, Apostole P; Kavvadia, Katerina; Papagiannoulis, Lisa

2004-01-01

This study investigated the effect of the primary second molars' distal surface caries on the incidence of the permanent first molars' mesial surface caries in 613 paired tooth surfaces of children ages 6 to 8 years at baseline examination. Proximal caries and its progression were diagnosed by bite-wing radiographs taken at a 1-year interval over a period of 4 years. The permanent first molars' mesial surfaces and primary second molars' distal surfaces were examined. Recorded were: (1) sound surfaces; (2) carious lesions on the enamel's external and internal half and on the dentin's external, middle, and internal third; (3) filled, extracted, and exfoliated teeth. The logistic model for panel data was employed to estimate the effect of proximal caries of the primary second molars' distal surfaces on the incidence of the permanent first molars' mesial surface caries. The 95% confidence interval probability was used. Sensitivity and specificity as well as the positive and negative predictive rates were computed. The results showed that the presence of proximal caries on each primary second molars' distal surfaces significantly affected the development of proximal caries on the corresponding permanent first molar's mesial surfaces. Age was estimated to exert a positive and highly significant impact, while gender had no effect. The odds ratio values ranged from 4.86 to 63.43. The values of sensitivity and specificity ranged from 45% to 97% and 80% to 89%, respectively, while the positive and negative rates ranged from 40% to 56% and 90% to 99%, respectively. Proximal caries present on the primary second molars' distal surfaces increases the risk of developing caries on the permanent first molars' mesial surfaces. This risk, however, is different among the paired surfaces studied.

Maxillary anterior en masse retraction using different antero-posterior position of mini screw: a 3D finite element study.

PubMed

Hedayati, Zohreh; Shomali, Mehrdad

2016-12-01

Nowadays, mini screws are used in orthodontic tooth movement to obtain maximum or absolute anchorage. They have gained popularity among orthodontists for en masse retraction of anterior teeth after first premolar extraction in maximum anchorage cases. The purpose of this study was to determine the type of anterior tooth movement during the time when force was applied from different mini screw placements to the anterior power arm with various heights. A finite element method was used for modeling maxillary teeth and bone structure. Brackets, wire, and hooks were also designed for modeling. Two appropriate positions for mini screw in the mesial and distal of the second premolar were designed as fixed nodes. Forces were applied from the mini screw to four different levels of anterior hook height: 0, 3, 6, and 9 mm. Initial tooth movement in eight different conditions was analyzed and calculated with ANSYS software. Rotation of anterior dentition was decreased with a longer anterior power arm and the mesial placement of the mini screw. Bodily movements occurred with the 9-mm height of the power arm in both mini screw positions. Intrusion or extrusion of the anterior teeth segment depended on the level of the mini screw and the edge of the power arm on the Z axis. According to the findings of this study, the best control in the sagittal plane during anterior en masse retraction was achieved by mesial placement of the mini screw and the 9-mm height of the anterior power arm. Where control in the vertical plane was concerned, distal placement of the mini screw with the 6-mm power arm height had minimum adverse effect on anterior dentition.

Control of excessive neural circuit excitability and prevention of epileptic seizures by endocannabinoid signaling.

PubMed

Sugaya, Yuki; Kano, Masanobu

2018-05-08

Progress in research on endocannabinoid signaling has greatly advanced our understanding of how it controls neural circuit excitability in health and disease. In general, endocannabinoid signaling at excitatory synapses suppresses seizures by inhibiting glutamate release. In contrast, endocannabinoid signaling promotes seizures by inhibiting GABA release at inhibitory synapses. The physiological distribution of endocannabinoid signaling molecules becomes disrupted with the development of epileptic focus in patients with mesial temporal lobe epilepsy and in animal models of experimentally induced epilepsy. Augmentation of endocannabinoid signaling can promote the development of epileptic focus at initial stages. However, at later stages, increased endocannabinoid signaling delays it and suppresses spontaneous seizures. Thus, the regulation of endocannabinoid signaling at specific synapses that cause hyperexcitability during particular stages of disease development may be effective for treating epilepsy and epileptogenesis.

A rare case of autoimmune limbic encephalitis: an uncharted territory!

PubMed Central

Ibrahim, Hatim; Al Jasser, Abdulelah N.; Khan, Sonia A.; Tlili, Kalthoum G.

2017-01-01

Autoimmune encephalitis is rare. Several auto- antibodies are described in autoimmune encephalitis. We describe a case of autoimmune limbic encephalitis associated with positive voltage gated potassium channel (VGKC) antibodies and positive leucine-rich glioma inactivated protein 1 antibodies (LGI1). A 33-year-old Saudi housewife, she presented with 2 months history of cognitive deterioration and recurrent left facio-brachial dystonic seizures followed by generalized tonic clonic seizures. At times the seizures are preceded by rising epigastric aura and shortness of breath. The neurological examination was normal apart from upgoing left plantar reflex. She had borderline IQ of 76 with impaired verbal fluency and impaired visual and verbal memory. Magnetic resonance imaging of the brain showed right mesial temporal non-enhancing lesion. Cerebrospinal fluid examination was positive for LGI1 and VGKC. Optimal seizure control was achieved with immunotherapy. PMID:29057855

A rare case of autoimmune limbic encephalitis: an uncharted territory!

PubMed

Ibrahim, Hatim; Al Jasser, Abdulelah N; Khan, Sonia A; Tlili, Kalthoum G

2017-10-01

Autoimmune encephalitis is rare. Several auto- antibodies are described in autoimmune encephalitis. We describe a case of autoimmune limbic encephalitis associated with positive voltage gated potassium channel (VGKC) antibodies and positive leucine-rich glioma inactivated protein 1 antibodies (LGI1). A 33-year-old Saudi housewife, she presented with 2 months history of cognitive deterioration and recurrent left facio-brachial dystonic seizures followed by generalized tonic clonic seizures. At times the seizures are preceded by rising epigastric aura and shortness of breath. The neurological examination was normal apart from upgoing left plantar reflex. She had borderline IQ of 76 with impaired verbal fluency and impaired visual and verbal memory. Magnetic resonance imaging of the brain showed right mesial temporal non-enhancing lesion. Cerebrospinal fluid examination was positive for LGI1 and VGKC. Optimal seizure control was achieved with immunotherapy.

Mandibular molar uprighting using mini-implants: different approaches for different clinical cases--two case reports.

PubMed

Derton, Nicola; Perini, Alessandro; Mutinelli, Sabrina; Gracco, Antonio

2012-01-01

To detail two different clinical protocols and case studies using mini-implant anchorage developed to respond to certain clinical conditions. Two clinical protocols are described to upright mesially tilted mandibular molars. In the first protocol, a single mini-implant is inserted distally to the molar to be uprighted, and an elastic traction chain is applied to the tooth. In the second clinical approach, two mini-implants are inserted mesially. A screw-suspended TMA sectional archwire is applied (Derton-Perini technique). Two cases, descriptive of the two different treatment protocols, are described. In the first case, the mandibular right second premolar was missing and the adjacent first molar needed to be uprighted. A single screw was inserted distally to the first molar, and an elastic chain was applied. In the second case, the mandibular left second molar was missing and the third molar needed to be uprighted. Two mini-implants were inserted mesially and a fully screw-supported sectional archwire was used to upright and bodily mesialize the third molar. Both uprighting approaches uprighted the molar axis without loss of anchorage. The two approaches to mandibular molar uprighting, developed as rational responses to different clinical cases, were both found to be effective.

Theta frequency decreases throughout the hippocampal formation in a focal epilepsy model.

PubMed

Kilias, Antje; Häussler, Ute; Heining, Katharina; Froriep, Ulrich P; Haas, Carola A; Egert, Ulrich

2018-06-01

Mesial temporal lobe epilepsy is characterized by focal, recurrent spontaneous seizures, sclerosis and granule cell dispersion (GCD) in the hippocampal formation. Changes in theta rhythm properties have been correlated with the severity of hippocampal restructuring and were suggested as a cause of memory deficits accompanying epilepsy. For severe sclerosis, it has even been questioned whether theta band oscillations persist. We asked how theta oscillations change with graded restructuring along the longitudinal hippocampal axis and whether these changes correlate with the overall severity of temporal lobe epilepsy. We recorded local field potentials in the medial entorhinal cortex and along the septo-temporal axis of the dentate gyrus at sites with different degrees of GCD in freely behaving epileptic mice. Theta frequency was decreased at all recording positions throughout the dentate gyrus and in the medial entorhinal cortex, irrespective of the extent of GCD or the rate of severe epileptic events. The frequency reduction by up to 1.7 Hz, corresponding to 1/3 octaves within the theta range, was present during rest, exploration and running. Despite the frequency reduction, theta oscillations remained coherent across the hippocampal formation and were modulated by running speed as in controls. The reduction in theta frequency thus is likely not a consequence of the local restructuring but rather a global phenomenon affecting the hippocampal formation as a whole. © 2018 Wiley Periodicals, Inc.

Incidence and localizing value of vertigo and dizziness in patients with epilepsy: Video-EEG monitoring study.

PubMed

Kim, Dong Wook; Sunwoo, Jun-Sang; Lee, Sang Kun

2016-10-01

Vertigo and dizziness are common neurological complaints that have long been associated with epilepsy. However, studies of patients with epileptic vertigo or dizziness with concurrent EEG monitoring are scarce. We performed the present study to investigate the incidence and localizing value of vertigo and dizziness in patients with epilepsy who had confirmation of EEG changes via video-EEG monitoring. Data of aura and clinical seizure episodes of 831 consecutive patients who underwent video-EEG monitoring were analyzed retrospectively. Out of 831 patients, 40 patients (4.8%) experienced vertigo or dizziness as aura (mean age, 32.8±11.8years), all of whom had partial seizures. Eight had mesial temporal, 20 had lateral temporal, four had frontal, one had parietal, and seven had occipital lobe onset seizures. An intracranial EEG with cortical stimulation study was performed in seven patients, and the area of stimulation-induced vertigo or dizziness coincided with the ictal onset area in only one patient. Our study showed that vertigo or dizziness is a common aura in patients with epilepsy, and that the temporal lobe is the most frequent ictal onset area in these patients. However, it can be suggested that the symptomatogenic area in patients with epileptic vertigo and dizziness may not coincide with the ictal onset area. Copyright © 2016 Elsevier B.V. All rights reserved.

Coprolalia as a manifestation of epileptic seizures.

PubMed

Massot-Tarrús, Andreu; Mousavi, Seyed Reza; Dove, Carin; Hayman-Abello S, Susan; Hayman-Abello, Brent; Derry, Paul A; Diosy, David C; McLachlan, Richard S; Burneo, Jorge G; Steven, David A; Mirsattari, Seyed M

2016-07-01

The aim of this study was to investigate the lateralizing and localizing value of ictal coprolalia and brain areas involved in its production. A retrospective search for patients manifesting ictal coprolalia was conducted in our EMU database. Continuous video-EEG recordings were reviewed, and EEG activity before and during coprolalia was analyzed using independent component analysis (ICA) technique and was compared to the seizures without coprolalia among the same patients. Nine patients were evaluated (five women), eight with intracranial video-EEG recordings (icVEEG). Four had frontal or temporal lesions, and five had normal MRIs. Six patients showed impairment in the language functions and five in the frontal executive tasks. Two hundred six seizures were reviewed (60.7% from icVEEG). Ictal coprolalia occurred in 46.6% of them, always associated with limbic auras or automatisms. They arose from the nondominant hemisphere in five patients, dominant hemisphere in three, and independently from the right and left hippocampus-parahippocampus in one. Electroencephalographic activity always involved orbitofrontal and/or mesial temporal regions of the nondominant hemisphere when coprolalia occurred. Independent component analysis of 31 seizures in seven patients showed a higher number of independent components in the nondominant hippocampus-parahippocampus before and during coprolalia and in the dominant lateral temporal region in those seizures without coprolalia (p=0.009). Five patients underwent surgery, and all five had an ILAE class 1 outcome. Ictal coprolalia occurs in both males and females with temporal or orbitofrontal epilepsy and has a limited lateralizing value to the nondominant hemisphere but can be triggered by seizures from either hemisphere. It involves activation of the paralimbic temporal-orbitofrontal network. Copyright © 2016 Elsevier Inc. All rights reserved.

Characterization of Early Partial Seizure Onset: Frequency, Complexity and Entropy

PubMed Central

Jouny, Christophe C.; Bergey, Gregory K.

2011-01-01

Objective A clear classification of partial seizures onset features is not yet established. Complexity and entropy have been very widely used to describe dynamical systems, but a systematic evaluation of these measures to characterize partial seizures has never been performed. Methods Eighteen different measures including power in frequency bands up to 300Hz, Gabor atom density (GAD), Higuchi fractal dimension (HFD), Lempel-Ziv complexity, Shannon entropy, sample entropy, and permutation entropy, were selected to test sensitivity to partial seizure onset. Intracranial recordings from forty-five patients with mesial temporal, neocortical temporal and neocortical extratemporal seizure foci were included (331 partial seizures). Results GAD, Lempel-Ziv complexity, HFD, high frequency activity, and sample entropy were the most reliable measures to assess early seizure onset. Conclusions Increases in complexity and occurrence of high-frequency components appear to be commonly associated with early stages of partial seizure evolution from all regions. The type of measure (frequency-based, complexity or entropy) does not predict the efficiency of the method to detect seizure onset. Significance Differences between measures such as GAD and HFD highlight the multimodal nature of partial seizure onsets. Improved methods for early seizure detection may be achieved from a better understanding of these underlying dynamics. PMID:21872526

Cognitive impairment and memory loss associated with histoplasmosis: a case study.

PubMed

Loughan, Ashlee R; Perna, Robert; Hertza, Jeremy

2014-01-01

Histoplasmosis is a rare disease caused by inhalation of the fungus Histoplasma capsulatum. It can spread via cerebral circulation to the central nervous system as a manifestation of a disseminated infection; particularly in patients with immune suppression, which can result in isolated ring-enhancing lesions and inflammation in the brain. Of the reported disseminated histoplasmosis cases (approximately 1 in 2000 per year), only 5-20% have evidence of central nervous system involvement. This paper reviews a single case study of a 57-year-old female diagnosed with disseminated CNS histoplasmosis. Patient's complaints included reduced short-term memory, word-finding problems, and difficulty organizing, making decisions, getting lost while driving, recalling names, retaining information while reading, and slowed processing speed. There was also a history of mild depression and anxiety. Direct testing revealed deficits in multiple cognitive domains including complex attention, processing speed, semantic fluency, visual scanning, motor speed, set-shifting, naming, nonverbal memory, and verbal memory. Neuropsychological deficits suggest cortical and subcortical brain dysfunction, including anterior, temporal, and mesial-temporal regions. This case illustrates the need for neuropsychologists to understand histoplasmosis, the related pathophysiology, and the neuropsychological impact; particularly with the potential for delayed progression.

Subfield-specific loss of hippocampal N-acetyl aspartate in temporal lobe epilepsy.

PubMed

Vielhaber, Stefan; Niessen, Heiko G; Debska-Vielhaber, Grazyna; Kudin, Alexei P; Wellmer, Jörg; Kaufmann, Jörn; Schönfeld, Mircea Ariel; Fendrich, Robert; Willker, Wieland; Leibfritz, Dieter; Schramm, Johannes; Elger, Christian E; Heinze, Hans-Jochen; Kunz, Wolfram S

2008-01-01

In patients with mesial temporal lobe epilepsy (MTLE) it remains an unresolved issue whether the interictal decrease in N-acetyl aspartate (NAA) detected by proton magnetic resonance spectroscopy ((1)H-MRS) reflects the epilepsy-associated loss of hippocampal pyramidal neurons or metabolic dysfunction. To address this problem, we applied high-resolution (1)H-MRS at 14.1 Tesla to measure metabolite concentrations in ex vivo tissue slices from three hippocampal subfields (CA1, CA3, dentate gyrus) as well as from the parahippocampal region of 12 patients with MTLE. In contrast to four patients with lesion-caused MTLE, we found a large variance of NAA concentrations in the individual hippocampal regions of patients with Ammon's horn sclerosis (AHS). Specifically, in subfield CA3 of AHS patients despite of a moderate preservation of neuronal cell densities the concentration of NAA was significantly lowered, while the concentrations of lactate, glucose, and succinate were elevated. We suggest that these subfield-specific alterations of metabolite concentrations in AHS are very likely caused by impairment of mitochondrial function and not related to neuronal cell loss. A subfield-specific impairment of energy metabolism is the probable cause for lowered NAA concentrations in sclerotic hippocampi of MTLE patients.

Asymmetry in mesial root number and morphology in mandibular second molars: a case report

PubMed Central

Shetty, Shashit; Shekhar, Rhitu

2014-01-01

Ambiguity in the root morphology of the mandibular second molars is quite common. The most common root canal configuration is 2 roots and 3 canals, nonetheless other possibilities may still exist. The presence of accessory roots is an interesting example of anatomic root variation. While the presence of radix entomolaris or radix paramolaris is regarded as a typical clinical finding of a three-rooted mandibular second permanent molar, the occurrence of an additional mesial root is rather uncommon and represents a possibility of deviation from the regular norms. This case report describes successful endodontic management of a three-rooted mandibular second molar presenting with an unusual accessory mesial root, which was identified with the aid of multiangled radiographs and cone-beam computed tomography imaging. This article also discusses the prevalence, etiology, morphological variations, clinical approach to diagnosis, and significance of supernumerary roots in contemporary clinical dentistry. PMID:24516829

Enamel thickness of the posterior dentition: its implications for nonextraction treatment.

PubMed

Stroud, J L; English, J; Buschang, P H

1998-04-01

This study describes mesial and distal enamel thickness of the permanent posterior mandibular dentition. The sample comprised 98 Caucasian adults (59 males, 39 females) 20 to 35 years old. Bitewing radiographs of the right permanent mandibular premolars and first and second molars were illuminated and transferred to a computer at a fixed magnification via a video camera. Enamel and dentin thicknesses were identified and digitized on the plane representing the maximum mesiodistal diameter of each tooth. The results showed that there were no significant sex differences in either mesial or distal enamel thickness. Enamel on the second molars was significantly thicker (0.3 to 0.4 mm) than enamel on the premolars. Distal enamel was significantly thicker than mesial enamel. There was approximately 10 mm of total enamel on the four teeth combined. Assuming 50% enamel reduction, the premolars and molars should provide 9.8 mm of additional space for realignment of mandibular teeth.

Endodontic management of middle mesial canal of the mandibular molar

PubMed Central

Sundaresh, K J; Srinivasan, Raghu; Mallikarjuna, Rachappa; Rajalbandi, Sandeep

2013-01-01

Thorough knowledge of root canal morphology and unusual anatomy of the tooth is critical for successful endodontic treatment. Although the most common configuration is two roots and three root canals, mandibular molars might have many different combinations. In the literature, it is less described about three mesial canals and two distal canals in mandibular second molars, indicating a rare anatomical configuration. A case of unusual root canal morphology is presented to demonstrate anatomical variations in mandibular molars. Endodontic therapy was performed in a mandibular second molar with five separate canals, three mesial and two distal. This report points out the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise might have ended in failure. In conclusion, every attempt should be made to find and treat all root canals of a tooth. PMID:23349182

[Pathological neocortical findings in patients with medication-resistant medial temporal lobe epilepsy submitted to surgery].

PubMed

Estupiñán-Díaz, B; Morales-Chacón, L M; Lorigados-Pedre, L; García-Maeso, I; Bender-del Busto, J E; Trápaga-Quincoses, O; Hidalgo-Portal, L; García-Navarro, M E; Sánchez-Coroneaux, A; Orozco-Suárez, S

The dual pathology consisting of hippocampal sclerosis plus focal cortical dysplasia (FCD) is often reported in patients with medication-resistant medial temporal lobe epilepsy (MTLE). To determine the histopathological changes that take place in the neocortex of patients with medication-resistant MTLE submitted to surgery and to evaluate the relation between the histopathological changes, pathological background and the clinical course of patients who had received surgical treatment. Tissue obtained by en bloc resection from the neocortex of 18 patients with MTLE refractory to medical treatment was processed histologically and a tailored temporal lobectomy was performed with electrocorticography. Dual pathology was diagnosed in 13 patients (72.2%). Imaging studies confirmed the existence of mesial sclerosis of the temporal in 100% of cases and there was no evidence of neocortical lesions. Histologically, 46.15% and 38.46% of the patients were diagnosed as belonging to FCD type 1a and FCD type 1b, respectively. Only one patient presented FCD type 2a. A statistically significant relation was found between the presence of dual pathology and the existence of an early precipitating injury (p = 0.04). One year after surgery, 72.7% (8/11) patients with dual pathology were classified as belonging to Engel class I. In patients with MTLE there are microscopic FCD-type alterations in the neocortex. There is an association between these alterations and the existence of an initial precipitating injury. Complete resection of the epileptogenic area, which is guaranteed by the lobectomy tailored by electrocorticography, allows patients to enjoy a favourable post-surgical progression one year after surgery.

Stability of Synchronization Clusters and Seizurability in Temporal Lobe Epilepsy

PubMed Central

Palmigiano, Agostina; Pastor, Jesús; García de Sola, Rafael; Ortega, Guillermo J.

2012-01-01

Purpose Identification of critical areas in presurgical evaluations of patients with temporal lobe epilepsy is the most important step prior to resection. According to the “epileptic focus model”, localization of seizure onset zones is the main task to be accomplished. Nevertheless, a significant minority of epileptic patients continue to experience seizures after surgery (even when the focus is correctly located), an observation that is difficult to explain under this approach. However, if attention is shifted from a specific cortical location toward the network properties themselves, then the epileptic network model does allow us to explain unsuccessful surgical outcomes. Methods The intraoperative electrocorticography records of 20 patients with temporal lobe epilepsy were analyzed in search of interictal synchronization clusters. Synchronization was analyzed, and the stability of highly synchronized areas was quantified. Surrogate data were constructed and used to statistically validate the results. Our results show the existence of highly localized and stable synchronization areas in both the lateral and the mesial areas of the temporal lobe ipsilateral to the clinical seizures. Synchronization areas seem to play a central role in the capacity of the epileptic network to generate clinical seizures. Resection of stable synchronization areas is associated with elimination of seizures; nonresection of synchronization clusters is associated with the persistence of seizures after surgery. Discussion We suggest that synchronization clusters and their stability play a central role in the epileptic network, favoring seizure onset and propagation. We further speculate that the stability distribution of these synchronization areas would differentiate normal from pathologic cases. PMID:22844524

Disrupted topological properties of brain white matter networks in left temporal lobe epilepsy: a diffusion tensor imaging study.

PubMed

Xu, Y; Qiu, S; Wang, J; Liu, Z; Zhang, R; Li, S; Cheng, L; Liu, Z; Wang, W; Huang, R

2014-10-24

Mesial temporal lobe epilepsy (mTLE) is the most common drug-refractory focal epilepsy in adults. Although previous functional and morphological studies have revealed abnormalities in the brain networks of mTLE, the topological organization of the brain white matter (WM) networks in mTLE patients is still ambiguous. In this study, we constructed brain WM networks for 14 left mTLE patients and 22 age- and gender-matched normal controls using diffusion tensor tractography and estimated the alterations of network properties in the mTLE brain networks using graph theoretical analysis. We found that networks for both the mTLE patients and the controls exhibited prominent small-world properties, suggesting a balanced topology of integration and segregation. However, the brain WM networks of mTLE patients showed a significant increased characteristic path length but significant decreased global efficiency, which indicate a disruption in the organization of the brain WM networks in mTLE patients. Moreover, we found significant between-group differences in the nodal properties in several brain regions, such as the left superior temporal gyrus, left hippocampus, the right occipital and right temporal cortices. The robustness analysis showed that the results were likely to be consistent for the networks constructed with different definitions of node and edge weight. Taken together, our findings may suggest an adverse effect of epileptic seizures on the organization of large-scale brain WM networks in mTLE patients. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Subtle pathological changes in neocortical temporal lobe epilepsy.

PubMed

Ochoa, Juan G; Hentgarden, Diana; Paulzak, Audrey; Ogden, Melissa; Pryson, Richard; Lamle, Markus; Rusyniak, Walter G

2017-06-01

This was a prospective observational study to correlate the clinical symptoms, electrophysiology, imaging, and surgical pathology of patients with temporal lobe epilepsy (TLE) without hippocampal sclerosis. We selected consecutive patients with TLE and normal MRI undergoing temporal lobe resection between April and September 2015. Clinical features, imaging, and functional data were reviewed. Intracranial monitoring and language mapping were performed when it was required according to our team recommendation. Prior to hippocampal resection, intraoperative electrocorticography was performed using depth electrodes in the amygdala and the hippocampus. The resected hippocampus was sent for pathological analysis. Five patients with diagnosis with non-lesional TLE were included. We did not find distinctive clinical features that could be a characteristic of non-lesional TLE. The mean follow-up was 13.2months (11-15months); 80% of patients achieved Engel Class I outcome. There was no distinctive electrographic findings in these patients. Histopathologic analysis was negative for mesial temporal sclerosis. A second blinded independent neuropathologist with expertise in epilepsy found ILAE type I focal cortical dysplasia in the parahippocampal gyrus in all patients. A third independent neuropathologist reported changes in layer 2 with larger pyramidal neurons in 4 cases but concluded that none of these cases met the diagnostic criteria of FCD. Subtle pathological changes could be associated with a parahippocampal epileptic zone and should be investigated in patients with MRI-negative TLE. This study also highlights the lack of interobserver reliability for the diagnosis of mild cortical dysplasia. Finally, selective amygdalo-hippocampectomy or laser ablation of the hippocampus may not control intractable epilepsy in this specific population. Copyright © 2017 Elsevier Inc. All rights reserved.

Multispectral brain morphometry in Tourette syndrome persisting into adulthood

PubMed Central

Martino, Davide; Cavanna, Andrea E.; Hutton, Chloe; Orth, Michael; Robertson, Mary M.; Critchley, Hugo D.; Frackowiak, Richard S.

2010-01-01

Tourette syndrome is a childhood-onset neuropsychiatric disorder with a high prevalence of attention deficit hyperactivity and obsessive-compulsive disorder co-morbidities. Structural changes have been found in frontal cortex and striatum in children and adolescents. A limited number of morphometric studies in Tourette syndrome persisting into adulthood suggest ongoing structural alterations affecting frontostriatal circuits. Using cortical thickness estimation and voxel-based analysis of T1- and diffusion-weighted structural magnetic resonance images, we examined 40 adults with Tourette syndrome in comparison with 40 age- and gender-matched healthy controls. Patients with Tourette syndrome showed relative grey matter volume reduction in orbitofrontal, anterior cingulate and ventrolateral prefrontal cortices bilaterally. Cortical thinning extended into the limbic mesial temporal lobe. The grey matter changes were modulated additionally by the presence of co-morbidities and symptom severity. Prefrontal cortical thickness reduction correlated negatively with tic severity, while volume increase in primary somatosensory cortex depended on the intensity of premonitory sensations. Orbitofrontal cortex volume changes were further associated with abnormal water diffusivity within grey matter. White matter analysis revealed changes in fibre coherence in patients with Tourette syndrome within anterior parts of the corpus callosum. The severity of motor tics and premonitory urges had an impact on the integrity of tracts corresponding to cortico-cortical and cortico-subcortical connections. Our results provide empirical support for a patho-aetiological model of Tourette syndrome based on developmental abnormalities, with perturbation of compensatory systems marking persistence of symptoms into adulthood. We interpret the symptom severity related grey matter volume increase in distinct functional brain areas as evidence of ongoing structural plasticity. The convergence of evidence from volume and water diffusivity imaging strengthens the validity of our findings and attests to the value of a novel multimodal combination of volume and cortical thickness estimations that provides unique and complementary information by exploiting their differential sensitivity to structural change. PMID:21071387

The effect of larger apical preparations in the danger zone of lower molars prepared using the Mtwo and Reciproc systems.

PubMed

Sant'Anna Júnior, Arnaldo; Cavenago, Bruno Cavalini; Ordinola-Zapata, Ronald; De-Deus, Gustavo; Bramante, Clovis Monteiro; Duarte, Marco Antonio Hungaro

2014-11-01

The aim of this study was to evaluate the effects of large apical preparations in the danger zones of the mesial root canals of mandibular molars instrumented with the Mtwo and Reciproc systems (VDW, Munich, Germany) until reaching apical diameters of 0.25 and 0.40 mm. Twelve mandibular molars, the mesial roots of which presented distinct foramens and similar anatomies, were selected using micro-computed tomographic scanning. Mtwo and Reciproc instruments were used to shape the mesiobuccal or mesiolingual canals. The mesial canals were scanned before and after the use of 0.25- and 0.40-mm Mtwo and Reciproc instruments. The analyzed parameters included the root canal volume and remaining dentin thickness at 5 different levels. The obtained data were subjected to paired analysis of variance and Tukey or Friedman and Dunn tests for intragroup analysis and the Mann-Whitney U test for comparison between the mesial and distal walls. There were no significant differences between the mesial and distal dentin thickness for the points analyzed with both instrumentation techniques (P > .05). The volumetric analysis revealed a significant difference (P < .05) among the initial volume and after the use of the 0.25- and 0.40-mm instruments for both systems. The use of the 0.40-mm instrument increased the root canal volume in comparison to the 0.25-mm instrument (P < .05). Both systems performed similarly for the preparation of curved root canals with separate apical foramens. The increase of the root canal preparation with the 0.40-mm instrument significantly increased the root canal volume at the apical third without significantly reducing the dentin thickness in the danger zone for both instrument systems. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Effect of Eruption Status of the Mandibular Third Molar on Distal Caries in the Adjacent Second Molar.

PubMed

Kang, Feiwu; Huang, Cheng; Sah, Manoj Kumar; Jiang, Beizhan

2016-04-01

To analyze the effect of the eruption status of the mandibular third molar (MTM) on distal caries in the mandibular second molar (MSM) by cone-beam computed tomography (CBCT). Five hundred CBCT images of MTMs from 469 patients were evaluated. Presence of distal caries in MSMs, impaction depths and angulations of MTMs, cementoenamel junction (CEJ) distances between distal MSMs and mesial MTMs, presence of pericoronitis in MTMs, and patient characteristics (age and gender) were assessed. Data were analyzed by χ(2) test, univariate and multivariate logistic regression analyses, and Spearman correlation analysis. Descriptive and bivariate statistics were computed and the P value was set at .05. The overall prevalence of distal caries in the MSM was 52.0%. According to the classification of Pell and Gregory, position A was the impaction depth at which most distal caries in MSMs were present (P = .036). For angulation of the MTM, when mesial angulations were 43° to 73°, MSMs developed more distal caries (P < .0001). For the CEJ distance between the distal MSM and the mesial MTM, when distances ranged from 6 to 15 mm, distal caries in MSMs occurred more frequently (6 to 8 mm, P < .0001; 8 to 15 mm, P = .037). Furthermore, there was a linear correlation between angulation of the MTM and the CEJ distance between the distal MSM and the mesial MTM (P < .0001). Impaction depth and angulation of the MTM are associated with distal caries in the MSM. Angulation of the MTM is more stable and reliable than the CEJ distance between the distal MSM and the mesial MTM for the estimation of risk factors related to the MTM. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

PET of serotonin 1A receptors and cerebral glucose metabolism for temporal lobectomy.

PubMed

Theodore, William H; Martinez, Ashley R; Khan, Omar I; Liew, Clarissa J; Auh, Sungyoung; Dustin, Irene M; Heiss, John; Sato, Susumu

2012-09-01

The objective of this study was to compare 5-hydroxytryptamine receptor 1A (5-HT(1A)) PET with cerebral metabolic rate of glucose (CMRglc) PET for temporal lobectomy planning. We estimated 5-HT(1A) receptor binding preoperatively with (18)F-trans-4-fluoro-N-2-[4-(2-methoxyphenyl) piperazin-1-yl]ethyl-N-(2-pyridyl) cyclohexane carboxamide ((18)F-FCWAY) PET and CMRglc measurement with (18)F-FDG in regions drawn on coregistered MRI after partial-volume correction in 41 patients who had anterior temporal lobectomy with at least a 1-y follow-up. Surgery was tailored to individual preresection evaluations and intraoperative electrocorticography. Mean regional asymmetry values and the number of regions with asymmetry exceeding 2 SDs in 16 healthy volunteers were compared between seizure-free and non-seizure-free patients. (18)F-FCWAY but not (18)F-FDG and MRI data were masked for surgical decisions and outcome assessment. Twenty-six of 41 (63%) patients seizure-free since surgery had significantly different mesial temporal asymmetries, compared with 15 non-seizure-free patients for both (18)F-FCWAY (F(1,39) = 5.87; P = 0.02) and (18)F-FDG PET (F(1,38) = 5.79; P = 0.021). The probability of being seizure-free was explained by both (18)F-FDG and (18)F-FCWAY PET, but not MRI, with a significant additional (18)F-FCWAY effect (chi(2)(2) = 9.8796; P = 0.0072) after the probability of being seizure-free was explained by (18)F-FDG. Although MRI alone was not predictive, any combination of 2 lateralizing imaging studies was highly predictive of seizure freedom. Our study provides class III evidence that both 5-HT(1A) receptor PET and CMRglc PET can contribute to temporal lobectomy planning. Additional studies should explore the potential for temporal lobectomy based on interictal electroencephalography and minimally invasive imaging studies.

Temporal lobe epilepsy and focal cortical dysplasia in children: A tip to find the abnormality.

PubMed

Bartolini, Luca; Whitehead, Matthew T; Ho, Cheng-Ying; Sepeta, Leigh N; Oluigbo, Chima O; Havens, Kathryn; Freilich, Emily R; Schreiber, John M; Gaillard, William D

2017-01-01

To demonstrate an association between magnetic resonance imaging (MRI) findings and pathologic characteristics in children who had surgery for medically refractory epilepsy due to focal cortical dysplasia (FCD). We retrospectively studied 110 children who had epilepsy surgery. Twenty-seven patients with FCD were included. Thirteen had temporal lobe epilepsy (TLE) and 14 had extra-temporal lobe epilepsy (ETLE). Three patients had associated mesial temporal sclerosis. Preoperative 3T MRIs interleaved with nine controls were blindly re-reviewed and categorized according to signal alteration. Pathologic specimens were classified according to the 2011 International League Against Epilepsy (ILAE) classification and compared to MRI studies. Rates of pathology subtypes differed between TLE and ETLE (χ 2 (3) = 8.57, p = 0.04). FCD type I was more frequent in TLE, whereas FCD type II was more frequent in ETLE. In the TLE group, nine patients had temporal tip abnormalities. They all exhibited gray-white matter blurring with decreased myelination and white matter hyperintense signal. Blurring involved the whole temporal tip, not just the area of dysplasia. These patients were less likely to demonstrate cortical thickening compared to those without temporal tip findings (χ 2 (1) = 9.55, p = 0.002). Three of them had FCD Ib, three had FCD IIa, two had FCD IIIa, and one had FCD IIb; MRI features could not entirely distinguish between FCD subtypes. TLE patients showed more pronounced findings than ETLE on MRI (χ 2 (1) = 11.95, p = 0.003, odds ratio [OR] 18.00). In all cases of FCD, isolated blurring was more likely to be associated with FCD II, whereas blurring with decreased myelination was seen with FCD I (χ 2 (6) = 13.07, p = 0.042). Our study described associations between MRI characteristics and pathology in children with FCD and offered a detailed analysis of temporal lobe tip abnormalities and FCD subtypes in children with TLE. These findings may contribute to the presurgical evaluation of patients with refractory epilepsy. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Source localization of small sharp spikes: low resolution electromagnetic tomography (LORETA) reveals two distinct cortical sources.

PubMed

Zumsteg, Dominik; Andrade, Danielle M; Wennberg, Richard A

2006-06-01

We have investigated the cortical sources and electroencephalographic (EEG) characteristics of small sharp spikes (SSS) by using statistical non-parametric mapping (SNPM) of low resolution electromagnetic tomography (LORETA). We analyzed 7 SSS patterns (501 individual SSS) in 6 patients who underwent sleep EEG studies with 29 or 23 scalp electrodes. The scalp signals were averaged time-locked to the SSS peak activity and subjected to SNPM of LORETA values. All 7 SSS patterns (mean 72 individual SSS, range 11-200) revealed a very similar and highly characteristic transhemispheric oblique scalp voltage distribution comprising a first negative field maximum over ipsilateral lateral temporal areas, followed by a second negative field maximum over the contralateral subtemporal region approximately 30 ms later. SNPM-LORETA consistently localized the first component into the ipsilateral posterior insular region, and the second component into ipsilateral posterior mesial temporo-occipital structures. SSS comprise an amalgam of two sequential, distinct cortical components, showing a very uniform and peculiar EEG pattern and cortical source solutions. As such, they must be clearly distinguished from interictal epileptiform discharges in patients with epilepsy. The awareness of these peculiar EEG characteristics may increase our ability to differentiate SSS from interictal epileptiform activity. The finding of a posterior insular source might serve as an inspiration for new physiological considerations regarding these enigmatic waveforms.

Detection of small human cerebral cortical lesions with MRI under different levels of Gaussian smoothing: applications in epilepsy

NASA Astrophysics Data System (ADS)

Cantor-Rivera, Diego; Goubran, Maged; Kraguljac, Alan; Bartha, Robert; Peters, Terry

2010-03-01

The main objective of this study was to assess the effect of smoothing filter selection in Voxel-Based Morphometry studies on structural T1-weighted magnetic resonance images. Gaussian filters of 4 mm, 8 mm or 10 mm Full Width at High Maximum are commonly used, based on the assumption that the filter size should be at least twice the voxel size to obtain robust statistical results. The hypothesis of the presented work was that the selection of the smoothing filter influenced the detectability of small lesions in the brain. Mesial Temporal Sclerosis associated to Epilepsy was used as the case to demonstrate this effect. Twenty T1-weighted MRIs from the BrainWeb database were selected. A small phantom lesion was placed in the amygdala, hippocampus, or parahippocampal gyrus of ten of the images. Subsequently the images were registered to the ICBM/MNI space. After grey matter segmentation, a T-test was carried out to compare each image containing a phantom lesion with the rest of the images in the set. For each lesion the T-test was repeated with different Gaussian filter sizes. Voxel-Based Morphometry detected some of the phantom lesions. Of the three parameters considered: location,size, and intensity; it was shown that location is the dominant factor for the detection of the lesions.

Statistical Validation of Automatic Methods for Hippocampus Segmentation in MR Images of Epileptic Patients

PubMed Central

Hosseini, Mohammad-Parsa; Nazem-Zadeh, Mohammad R.; Pompili, Dario; Soltanian-Zadeh, Hamid

2015-01-01

Hippocampus segmentation is a key step in the evaluation of mesial Temporal Lobe Epilepsy (mTLE) by MR images. Several automated segmentation methods have been introduced for medical image segmentation. Because of multiple edges, missing boundaries, and shape changing along its longitudinal axis, manual outlining still remains the benchmark for hippocampus segmentation, which however, is impractical for large datasets due to time constraints. In this study, four automatic methods, namely FreeSurfer, Hammer, Automatic Brain Structure Segmentation (ABSS), and LocalInfo segmentation, are evaluated to find the most accurate and applicable method that resembles the bench-mark of hippocampus. Results from these four methods are compared against those obtained using manual segmentation for T1-weighted images of 157 symptomatic mTLE patients. For performance evaluation of automatic segmentation, Dice coefficient, Hausdorff distance, Precision, and Root Mean Square (RMS) distance are extracted and compared. Among these four automated methods, ABSS generates the most accurate results and the reproducibility is more similar to expert manual outlining by statistical validation. By considering p-value<0.05, the results of performance measurement for ABSS reveal that, Dice is 4%, 13%, and 17% higher, Hausdorff is 23%, 87%, and 70% lower, precision is 5%, -5%, and 12% higher, and RMS is 19%, 62%, and 65% lower compared to LocalInfo, FreeSurfer, and Hammer, respectively. PMID:25571043

Selective Cognitive Dysfunction Is Related to a Specific Pattern of Cerebral Damage in Persons With Severe Traumatic Brain Injury.

PubMed

Di Paola, Margherita; Phillips, Owen; Costa, Alberto; Ciurli, Paola; Bivona, Umberto; Catani, Sheila; Formisano, Rita; Caltagirone, Carlo; Carlesimo, Giovanni Augusto

2015-01-01

Cognitive dysfunction is a common sequela of traumatic brain injury (TBI); indeed, patients show a heterogeneous pattern of cognitive deficits. This study was aimed at investigating whether patients who show selective cognitive dysfunction after TBI present a selective pattern of cerebral damage. Post-Coma Unit, IRCCS Santa Lucia Foundation, Rome, Italy. We collected data from 8 TBI patients with episodic memory disorder and without executive deficits, 7 patients with executive function impairment and preserved episodic memory capacities, and 16 healthy controls. We used 2 complementary analyses: (1) an exploratory and qualitative approach in which we investigated the distribution of lesions in the TBI groups, and (2) a hypothesis-driven and quantitative approach in which we calculated the volume of hippocampi of individuals in the TBI and control groups. Neuropsychological scores and hippocampal volumes. We found that patients with TBI and executive functions impairment presented focal lesions involving the frontal lobes, whereas patients with TBI and episodic memory disorders showed atrophic changes of the mesial temporal structure (hippocampus). The complexity of TBI is due to several heterogeneous factors. Indeed, studying patients with TBI and selective cognitive dysfunction should lead to a better understanding of correlations with specific brain impairment and damage, better follow-up of long-term outcome scenarios, and better planning of selective and focused rehabilitation programs.

In vivo microcomputed tomography evaluation of rat alveolar bone and root resorption during orthodontic tooth movement.

PubMed

Ru, Nan; Liu, Sean Shih-Yao; Zhuang, Li; Li, Song; Bai, Yuxing

2013-05-01

To observe the real-time microarchitecture changes of the alveolar bone and root resorption during orthodontic treatment. A 10 g force was delivered to move the maxillary left first molars mesially in twenty 10-week-old rats for 14 days. The first molar and adjacent alveolar bone were scanned using in vivo microcomputed tomography at the following time points: days 0, 3, 7, and 14. Microarchitecture parameters, including bone volume fraction, structure model index, trabecular thickness, trabecular number, and trabecular separation of alveolar bone, were measured on the compression and tension side. The total root volume was measured, and the resorption crater volume at each time point was calculated. Univariate repeated measures analysis of variance with Bonferroni corrections were performed to compare the differences in each parameter between time points with significance level at P < .05. From day 3 to day 7, bone volume fraction, structure model index, trabecular thickness, and trabecular separation decreased significantly on the compression side, but the same parameters increased significantly on the tension side from day 7 to day 14. Root resorption volume of the mesial root increased significantly on day 7 of orthodontic loading. Real-time root and bone resorption during orthodontic movement can be observed in 3 dimensions using in vivo micro-CT. Alveolar bone resorption and root resorption were observed mostly in the apical third on day 7 on the compression side; bone formation was observed on day 14 on the tension side during orthodontic tooth movement.

Three Dimensional Finite Element Analysis of Distal Abutment Stresses of Removable Partial Dentures with Different Retainer Designs.

PubMed

Zarrati, Simindokht; Bahrami, Mehran; Heidari, Fatemeh; Kashani, Jamal

2015-06-01

This finite element method study aimed to compare the amount of stress on an isolated mandibular second premolar in two conventional reciprocal parallel interface designs of removable partial dentures (RPDs) and the same RPD abutment tooth (not isolated). A Kennedy Class 1, modification 1 RPD framework was simulated on a 3D model of mandible with three different designs: an isolated tooth with a mesial rest, an isolated tooth with mesial and distal rests and an abutment with a mesial rest (which was not isolated); 26 N occlusal forces were exerted bilaterally on the first molar sites. Stress on the abutment teeth was analyzed using Cosmos Works 2009 Software. In all designs, the abutment tooth stress concentration was located in the buccal alveolar crest. In the first model, the von Mises stress distribution in the contact area of I-bar clasp and cervical portion of the tooth was 19 MPa and the maximum stress was 30 MPa. In the second model, the maximum von Mises stress distribution was 15 MPa in the cervical of the tooth. In the third model, the maximum von Mises stress was located in the cervical of the tooth and the distal proximal plate. We recommend using both mesial and distal rests on the distal abutment teeth of distal extension RPDs. The abutment of an extension base RPD, which is not isolated in presence of its neighboring more anterior tooth, may have a better biomechanical prognosis.

Lacosamide modulates interictal spiking and high-frequency oscillations in a model of mesial temporal lobe epilepsy

PubMed Central

Behr, Charles; Lévesque, Maxime; Ragsdale, David; Avoli, Massimo

2016-01-01

Objective Nearly one third of patients presenting with mesial temporal lobe epilepsy (MTLE), the most prevalent lesion-related epileptic disorder in adulthood, do not respond to currently available antiepileptic medications. Thus, there is a need to identify and characterize new antiepileptic drugs. In this study, we used the pilocarpine model of MTLE to establish the effects of a third generation drug, lacosamide (LCM), on seizures, interictal spikes and high-frequency oscillations (HFOs, ripples: 80–200 Hz, fast ripples: 250–500 Hz). Methods Sprague–Dawley rats (250–300 g) were injected with pilocarpine to induce a status epilepticus (SE) that was pharmacologically terminated after 1 h. Eight pilocarpine-treated rats were then injected with LCM (30 mg/kg, i.p.) 4 h after SE and daily for 14 days. Eight pilocarpine-treated rats were used as controls and treated with saline. Three days after SE, all rats were implanted with bipolar electrodes in the hippocampal CA3 region, entorhinal cortex (EC), dentate gyrus (DG) and subiculum and EEG-video monitored from day 4 to day 14 after SE. Results LCM-treated animals showed lower rates of seizures (0.21 (±0.11) seizures/day) than controls (2.6 (±0.57), p < 0.05), and a longer latent period (LCM: 11 (±1) days, controls: 6.25 (±1), p < 0.05). Rates of interictal spikes in LCM-treated rats were significantly lower than in controls in CA3 and subiculum (p < 0.05). Rates of ripples and fast ripples associated with interictal spikes in CA3 and subiculum as well as rates of fast ripples occurring outside of interictal spikes in CA3 were also significantly lower in LCM-treated animals. In controls, interictal spikes and associated HFOs correlated to seizure clustering, while this was not the case for isolated HFOs. Significance Our findings show that early treatment with LCM has powerful anti-ictogenic properties in the pilocarpine model of MTLE. These effects are accompanied by decreased rates of interictal spikes and associated HFOs. Isolated HFOs were also modulated by LCM, in a manner that appeared to be unrelated to its antiictogenic effects. These results thus suggest that distinct mechanisms may underlie interictal-associated and isolated HFOs in the pilocarpine model of MTLE. PMID:26220372

Clinical efficacy of gamma knife and surgery treatment of mesial temporal lobe epilepsy and their effects on EF-Tumt and EF-Tsmt expression.

PubMed

Wang, X-Q; Zhang, X-D; Han, Y-M; Shi, X-F; Lan, Z-B; Men, X-X; Pan, Y-W

2017-04-01

To study the clinical efficacy of gamma knife and surgery treatment of mesial temporal lobe epilepsy (MTLE) and their effects on EF-Tumt and EF-Tsmt expression. The data of 78 cases of MTLE patients treated in our hospital from April 2011 to March 2013 were retrospectively analyzed. The patients were divided into two groups according to the treatment methods: the surgery group (including 41 cases) and the gamma knife group (including 37 cases). The clinical efficacy, the occurrence and recurrence of complications were evaluated, respectively; meanwhile, the expression of the EF-Tumt protein and EF-Tsmt protein in brain tissue were analyzed. The difference between the efficacy rate of the two groups showed no statistical significance (χ2=0.960, p>0.05). The complication rate of the gamma knife group was significantly lower than that of the control group (χ2=6.430, p<0.05). The recurrence rate of the patients in the gamma knife group was significantly lower than that of the patients in the surgery group (p>0.05). Within the two groups, the positive expression granum of EF-Tsmt protein and EF-Tumt protein of the two groups after treatment were significantly lower than that before treatment (p<0.05). After treatment, the positive expression granum of EF-Tsmt protein of the patients in the gamma knife group was obviously more than that of the patients in the surgery group (p<0.05). The difference between the positive expression granum of EF-Tumt protein of the two groups showed no statistical significance (p>0.05). Before and after treatment within the group, the positive cell of EF-Tsmt protein and EF-Tumt protein of the two groups of patients after treatment were significantly lower than that before treatment (p<0.05). After treatment, the difference between the EF-Tsmt protein positive cell and the EF-Tumt protein positive cell of the two groups of patients showed no statistical significance (p>0.05). Both surgery and gamma knife could treat MTLE effectively, and the efficacy may be related to the ability to reduce the expression of EF-Tsmt protein and EF-Tumt protein in brain tissue.

Phase-amplitude coupling and epileptogenesis in an animal model of mesial temporal lobe epilepsy.

PubMed

Samiee, Soheila; Lévesque, Maxime; Avoli, Massimo; Baillet, Sylvain

2018-06-01

Polyrhythmic coupling of oscillatory components in electrophysiological signals results from the interactions between neuronal sub-populations within and between cell assemblies. Since the mechanisms underlying epileptic disorders should affect such interactions, abnormal level of cross-frequency coupling is expected to provide a signal marker of epileptogenesis. We measured phase-amplitude coupling (PAC), a form of cross-frequency coupling between neural oscillations, in a rodent model of mesial temporal lobe epilepsy. Sprague-Dawley rats (n = 4, 250-300 g) were injected with pilocarpine (380 mg/kg, i.p) to induce a status epilepticus (SE) that was stopped after 1 h with diazepam (5 mg/kg, s.c.) and ketamine (50 mg/kg, s.c.). Control animals (n = 6) did not receive any injection or treatment. Three days after SE, all animals were implanted with bipolar electrodes in the hippocampal CA3 subfield, entorhinal cortex, dentate gyrus and subiculum. Continuous video/EEG recordings were performed 24/7 at a sampling rate of 2 kHz, over 15 consecutive days. Pilocarpine-treated animals showed interictal spikes (5.25 (±2.5) per minute) and seizures (n = 32) that appeared 7 (±0.8) days after SE. We found that CA3 was the seizure onset zone in most epileptic animals, with stronger ongoing PAC coupling between seizures than in controls (Kruskal-Wallis test: chi 2 (1,36) = 46.3, Bonferroni corrected, p < 0.001). Strong PAC in CA3 occurred between the phase of slow-wave oscillations (<1 Hz) and the amplitude of faster rhythms (50-180 Hz), with the strongest bouts of high-frequency activity occurring preferentially on the ascending phase of the slow wave. We also identified that cross-frequency coupling in CA3 (rho = 0.44, p < 0.001) and subiculum (rho = 0.41, p < 0.001) was positively correlated with the daily number of seizures. Overall, our study demonstrates that cross-frequency coupling may represent a signal marker in epilepsy and suggests that this methodology could be transferred to clinical scalp MEG and EEG recordings. Copyright © 2018 Elsevier Inc. All rights reserved.

The presence of polyglucosan bodies in temporal lobe epilepsy: its role and significance.

PubMed

Abubakr, Abuhuziefa; Wambacq, Ilse; Donahue, John E; Zappulla, Rosario

2005-11-01

Mesial temporal sclerosis (MTS) is an important pathology in temporal lobe epilepsy (TLE) and often associated with good surgical outcome, however prognostic factors for surgical outcome are conflicting. The authors examine seizure outcome after surgery for TLE due to MTS, with focus on the presence of polyglucosan bodies (PGBs), and its relation to the epileptogenic process. Records of 44 consecutive patients with intractable TLE who underwent anterior temporal lobectomy (ATL) at JFK medical center between 1994-2001 were reviewed. Details of clinical, electrophysiological evaluation, and outcome were collected. All slides were reviewed for the presence of MTS. In twenty-one patients with MTS, detailed histology of surgical specimens was reviewed and relative concentration of PGBs was assessed. The postoperative follow-up duration ranges between 28-74 months. Surgical outcome was evaluated according to Engel's classification. Data of fourteen females (mean age 32.8 years) and 7 males (mean age 34.2) were analyzed. PBGs were identified in 10 patients (8 females and 2 males). All 10 patients had good surgical outcome, with 6 patients (60%) being seizure free (class 1) and 4 patients as class 2. While 11 patients (6 males and 5 females) with absent PGB, 72.8% had good surgical outcome. Of these, 7 (63.8%) had class 1, 1 patient had class 2, and 3 patients had class 3&4. Assessing several risk factors, the only significant difference between the two groups was epilepsy duration, which was significantly longer in patients with PGBs (P = 0.011). The histological presence of PGB is associated with long duration of epilepsy and could be the consequence of epilepsy. Despite prolonged duration of epilepsy, the surgical outcome in PGBs +ve is similar to PGBs -ve patients.

Verbal learning and memory outcome in selective amygdalohippocampectomy versus temporal lobe resection in patients with hippocampal sclerosis.

PubMed

Foged, Mette Thrane; Vinter, Kirsten; Stauning, Louise; Kjær, Troels W; Ozenne, Brice; Beniczky, Sándor; Paulson, Olaf B; Madsen, Flemming Find; Pinborg, Lars H

2018-02-01

With the advent of new very selective techniques like thermal laser ablation to treat drug-resistant focal epilepsy, the controversy of resection size in relation to seizure outcome versus cognitive deficits has gained new relevance. The purpose of this study was to test the influence of the selective amygdalohippocampectomy (SAH) versus nonselective temporal lobe resection (TLR) on seizure outcome and cognition in patients with mesial temporal lobe epilepsy (MTLE) and histopathological verified hippocampal sclerosis (HS). We identified 108 adults (>16years) with HS, operated between 1995 and 2009 in Denmark. Exclusion criteria are the following: Intelligence below normal range, right hemisphere dominance, other native languages than Danish, dual pathology, and missing follow-up data. Thus, 56 patients were analyzed. The patients were allocated to SAH (n=22) or TLR (n=34) based on intraoperative electrocorticography. Verbal learning and verbal memory were tested pre- and postsurgery. Seizure outcome did not differ between patients operated using the SAH versus the TLR at 1year (p=0.951) nor at 7years (p=0.177). Verbal learning was more affected in patients resected in the left hemisphere than in the right (p=0.002). In patients with left-sided TLR, a worsening in verbal memory performance was found (p=0.011). Altogether, 73% were seizure-free for 1year and 64% for 7years after surgery. In patients with drug-resistant focal MTLE, HS and no magnetic resonance imaging (MRI) signs of dual pathology, selective amygdalohippocampectomy results in sustained seizure freedom and better memory function compared with patients operated with nonselective temporal lobe resection. Copyright © 2017 Elsevier Inc. All rights reserved.

Epilepsy Surgery Series: A Study of 502 Consecutive Patients from a Developing Country

PubMed Central

Al-Otaibi, Faisal; Baz, Salah; Althubaiti, Ibrahim; Aldhalaan, Hisham; MacDonald, David; Abalkhail, Tareq; Fiol, Miguel E.; Alyamani, Suad; Chedrawi, Aziza; Leblanc, Frank; Parrent, Andrew; Maclean, Donald; Girvin, John

2014-01-01

Purpose. To review the postoperative seizure outcomes of patients that underwent surgery for epilepsy at King Faisal Specialist Hospital & Research Centre (KFSHRC). Methods. A descriptive retrospective study for 502 patients operated on for medically intractable epilepsy between 1998 and 2012. The surgical outcome was measured using the ILAE criteria. Results. The epilepsy surgery outcome for temporal lobe epilepsy surgery (ILAE classes 1, 2, and 3) at 12, 36, and 60 months is 79.6%, 74.2%, and 67%, respectively. The favorable 12- and 36-month outcomes for frontal lobe epilepsy surgery are 62% and 52%, respectively. For both parietal and occipital epilepsy lobe surgeries the 12- and 36-month outcomes are 67%. For multilobar epilepsy surgery, the 12- and 36-month outcomes are 65% and 50%, respectively. The 12- and 36-month outcomes for functional hemispherectomy epilepsy surgery are 64.2% and 63%, respectively. According to histopathology diagnosis, mesiotemporal sclerosis (MTS) and benign CNS tumors had the best favorable outcome after surgery at 1 year (77.27% and 84.3%, resp.,) and 3 years (76% and 75%, resp.,). The least favorable seizure-free outcome after 3 years occurred in cases with dual pathology (66.6%). Thirty-four epilepsy patients with normal magnetic resonance imaging (MRI) brain scans were surgically treated. The first- and third-year epilepsy surgery outcome of 17 temporal lobe surgeries were (53%) and (47%) seizure-free, respectively. The first- and third-year epilepsy surgery outcomes of 15 extratemporal epilepsy surgeries were (47%) and (33%) seizure-free. Conclusion. The best outcomes are achieved with temporal epilepsy surgery, mesial temporal sclerosis, and benign CNS tumor. The worst outcomes are from multilobar surgery, dual pathology, and normal MRI. PMID:24627805

Technetium-99m HMPAO brain SPECT in autistic children and their families.

PubMed

Degirmenci, Berna; Miral, Süha; Kaya, Gamze Capa; Iyilikçi, Leyla; Arslan, Gulhan; Baykara, Ayşen; Evren, Ismail; Durak, Hatice

2008-04-15

The purpose of the study was to investigate perfusion patterns in autistic children (AC) and their families. Ten AC (9 boys, 1 girl; mean age: 6.9+/-1.7 years) with autistic disorder defined by DSM-III-R criteria, five age-matched children (3 boys, 2 girls) as a control group, and the immediate family members of eight AC (8 mothers, 8 fathers, 7 siblings; mean ages: 39+/-4 years, 36+/-5 years and 13+/-5 years, respectively) were included in the study. Age- and sex-matched control groups for both the parents and the siblings were also included in the study. Brain perfusion images were obtained 1 h after the intravenous injection of an adjusted dose of Tc-99m HMPAO to children and the adults. Visual and semiquantitative evaluations were performed. Hypoperfusion was seen in the right posterior parietal cortex in three AC, in bilateral parietal cortex in one AC, bilateral frontal cortex in two AC, left parietal and temporal cortex in one AC, and right parietal and temporal cortex in one AC. Asymmetric perfusion was observed in the caudate nucleus in four AC. In semiquantitative analyses, statistically significant hypoperfusion was found in the right inferior and superior frontal, left superior frontal, right parietal, right mesial temporal and right caudate nucleus. In parents of AC, significant hypoperfusion was noted in the right parietal and bilateral inferior frontal cortex. In siblings of AC, perfusion in the right frontal cortex, right nucleus caudate and left parietal cortex was significantly decreased. This preliminary study suggests the existence of regional brain perfusion alterations in frontal, temporal, and parietal cortex and in caudate nucleus in AC and in their first-degree family members.

Proton MR spectroscopy in patients with acute temporal lobe seizures.

PubMed

Castillo, M; Smith, J K; Kwock, L

2001-01-01

Decreases in N-acetyl aspartate (NAA) as seen by proton MR spectroscopy are found in hippocampal sclerosis, and elevated levels of lipids/lactate have been observed after electroconvulsive therapy. Our purpose was to determine whether increased levels of lipids/lactate are found in patients with acute seizures of hippocampal origin. Seventeen patients with known temporal lobe epilepsy underwent proton MR spectroscopy of the mesial temporal lobes within 24 hours of their last seizure. Four of them were restudied when they were seizure-free. Five healthy individuals were used as control subjects. All MR spectroscopy studies were obtained using a single-voxel technique with TEs of 135 and 270. The relationship between the presence of lipids/lactate and seizures was tested using Fisher's exact test. Mean and standard deviations for NAA/creatine (Cr) were obtained in the hippocampi in patients with seizures on initial and follow-up studies and these values were compared with those in the control subjects. Seizure lateralization was obtained in 15 patients. Of the 17 seizure locations that involved hippocampi, 16 showed lipids/lactate by proton MR spectroscopy. Of the 13 hippocampi not directly affected by seizures, 10 showed no lipids/lactate and three showed lipids/lactate. The relationship between lipids/lactate and seizure location was confirmed. A comparison of NAA/Cr ratios for the involved hippocampi with those in control subjects showed significant differences on initial MR spectroscopy; however, no significant difference was found between acute and follow-up NAA/Cr ratios in hippocampi affected by seizures. Lipids/lactate were present in the hippocampi of patients with acute seizures and decreased when the patients were seizure-free. Thus, lipids/lactate may be a sensitive marker for acute temporal lobe seizures.

Why epilepsy challenges social life.

PubMed

Steiger, Bettina K; Jokeit, Hennric

2017-01-01

Social bonds are at the center of our daily living and are an essential determinant of our quality of life. In people with epilepsy, numerous factors can impede cognitive and affective functions necessary for smooth social interactions. Psychological and psychiatric complications are common in epilepsy and may hinder the processing of social information. In addition, neuropsychological deficits such as slowed processing speed, memory loss or attentional difficulties may interfere with enjoyable reciprocity of social interactions. We consider societal, psychological, and neuropsychological aspects of social life with particular emphasis on socio-cognitive functions in temporal lobe epilepsy. Deficits in emotion recognition and theory of mind, two main aspects of social cognition, are frequently observed in individuals with mesial temporal lobe epilepsy. Results from behavioural studies targeting these functions will be presented with a focus on their relevance for patients' daily life. Furthermore, we will broach the issue of pitfalls in current diagnostic tools and potential directions for future research. By giving a broad overview of individual and interpersonal determinants of social functioning in epilepsy, we hope to provide a basis for future research to establish social cognition as a key component in the comprehensive assessment and care of those with epilepsy. Copyright © 2016 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

VGKC antibodies in pediatric encephalitis presenting with status epilepticus.

PubMed

Suleiman, J; Brenner, T; Gill, D; Brilot, F; Antony, J; Vincent, A; Lang, B; Dale, R C

2011-04-05

Voltage-gated potassium channel antibodies (VGKC Ab) are associated with limbic encephalitis and neuromyotonia in adults. There have been no systematic investigations in children to date. We looked for antibodies that are associated with CNS syndromes in adults including antibodies to VGKCs, NMDARs, glutamic acid decarboxylase (GAD), and glycine receptor (GlyR) in the stored acute serum from 10 children with unexplained encephalitis presenting with encephalopathy and status epilepticus. We also looked for antibodies to leucine-rich glioma-inactivated 1 (Lgi1) and contactin-associated protein-like 2 (Caspr2), which are now known to be tightly complexed with VGKCs in vivo. Sixty-nine pediatric controls were used for comparison. An elevated VGKC Ab (>100 pM) was detected in 4/10 patients with encephalitis compared to only 1/69 controls (p < 0.001). The outcome in the 4 VGKC Ab-positive patients with encephalitis was variable including good recovery (n = 1), cognitive impairment (n = 3), temporal lobe epilepsy (n = 2), and mesial temporal sclerosis (n = 1). No other antibodies were detected, including those to Lgi1 and Caspr2. Encephalitis associated with VGKC Ab occurs in children and presents with status epilepticus and focal epilepsy. These antibodies are not directed against Lgi1 or Caspr2.

Current Surgical Options for Patients with Epilepsy.

PubMed

Rasul, Fahid T; Bal, Jarnail; Pereira, Erlick A; Tisdall, Martin; Themistocleous, Marios; Haliasos, Nikolaos

2017-01-01

Surgery for epilepsy dates back to 1886 and has undergone significant developments. Today it is considered a key treatment modality in patients who are resistant to pharmacological intervention. It improves seizure control, cognition and quality of life. New technologies, advances in surgical technique and progress in scientific research underlie the expansion of surgery in epilepsy treatment. Effectiveness of surgical treatment depends on several factors including the type of epilepsy, the underlying pathology and the localisation of the epileptogenic zone. Timely referral to an experienced epilepsy surgery centre is important to allow the greatest chance of seizure control and to minimise associated morbidity and mortality. Following referral, patients undergo thorough presurgical investigation to evaluate their suitability for surgery. The commonest form of epilepsy treated by surgery is mesial temporal lobe sclerosis and there is Class I evidence for the medium-term efficacy of temporal lobe resection from two randomised control trials. Various other forms of epilepsy are now considered for resective and neuromodulatory surgical intervention due to favourable results. In this article, the authors review the current status of surgical treatment for epilepsy including the presurgical evaluation of patients, surgical techniques and the future directions in epilepsy surgery. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Comparison of isthmus detection methods in the apical third of mesial roots of maxillary and mandibular first molars: macroscopic observation versus operating microscope.

PubMed

Kontakiotis, Evangelos G; Palamidakis, Fotios D; Farmakis, Eleftherios-Terry R; Tzanetakis, Giorgos N

2010-01-01

The aims of this study were to assess the presence and the frequency of isthmuses in the mesial roots of the maxillary and mandibular first molars (at two resection levels from the apex), and to compare the findings obtained by macroscopic observation (MO) and operating microscope (OM). Forty maxillary and 40 mandibular mesial roots were observed at 3 and 5 mm from the apex initially macroscopically and then with the use of an OM. The presence of an isthmus and the number of root canals detected were recorded. Data were analyzed statistically by Fisher's exact test for isthmus evaluation and Wilcoxon signed rank-test for number of root canals at a confidence interval of 95%. Comparison between MO and OM regarding the number of roots with isthmuses provided the following results: Mandibular group: At 3 mm level: MO 19 ?s. OM 27; at 5 mm level: MO 31 ?s. OM 32. Maxillary group: At 3 mm level: MO 9 ?s. OM 14; at 5 mm level: MO 19 ?s. OM 21. Significant differences (p<0.05) were found concerning the accuracy of the isthmus detection methods at both resection levels (3 and 5 mm) and both types of roots, as well as for the number of the canals inspected under the OM between the two resection levels of the mesial roots of the maxillary first molars. Under the tested conditions, OM increased the diagnostic accuracy of isthmus detection at both resection levels and root types.

Determination of the Optimum Torque to Tighten the Smartpegs of Magnetic Resonance Frequency Analyses Devices: An Ex Vivo Study.

PubMed

Geckili, Onur; Cilingir, Altug; Bural, Canan; Bilmenoglu, Caglar; Bilhan, Hakan

2015-12-01

The aim of this study was to find an optimal value for tightening the Smartpegs for magnetic radiofrequency analysis devices (RFAs) devices. Thirty implants were placed in 3 cow ribs. The RFA value of each implant was measured in buccal and mesial directions after tightening the Smartpegs with 1, 3, 4, 8, 9, 10, and 11 Ncm. Additionally, 4 different examiners measured the RFA after hand tightening the Smartpegs, and the results were compared. The buccal implant stability quotient (ISQ) values when the Smartpegs were tightened to 1Ncm were significantly lower than the ISQ values when the Smartpegs were tightened to 3, 4, 8, 9, 10, and 11 Ncm (P < .05). The mesial ISQ values when the Smartpegs were tightened to 1, 3, and 4 Ncm were significantly lower than the ISQ values when the Smartpegs were tightened with higher torque values (P < .05). The buccal measurements made by 1 examiner was significantly lower than 3 Ncm (P < .05), and the buccal measurements made by 1 examiner was significantly lower than 4 Ncm (P < .05). The mesial ISQ values measured by 2 examiners were significantly lower than 3 Ncm (P < .05), and the mesial ISQ values measured by the other 2 examiners were significantly lower than 8 Ncm (P < .05). The tightening of the Smartpegs should be standardized by the manufacturer to a range of 5-8 Ncm in order to gain reliable objective RFA values, instead of leaving it to subjective finger pressure.

Use of cone-beam computed tomography to evaluate root and canal morphology of mandibular first and second molars in Turkish individuals

PubMed Central

Sekerci, Ahmet E.; Dinçer, Asiye N.; Cayabatmaz, Muhammed; Zorba, Yahya O.

2013-01-01

Objective: The aim of this study was to investigate the root and canal morphology of mandibular first and second molars in a Turkish population by using cone beam computed tomography (CBCT). Study design: CBCT images of mandibular first (n = 823) and second molar (n = 925) teeth from 605 Turkish patients were analyzed. The root canal configurations were classified according to the method of Vertucci. Results: The majority of mandibular molars (95.8% of first molars, 85.4% of second molars) had two separate roots; however, three roots were identified in 2.06% of first molars and 3.45% of second molars. C-shaped canals occurred 0.85% of first molars and 4.1% of second molars. Three canals were found in 79.9% of first molars and 72.8% of second molars. Most distal roots had a simple type I configuration, whereas mesial roots had more complex canal systems, with more than one canal. The most common root morphology of first and second molars is the two rooted morphology with three canals. Both the mesial and distal roots showed wide variations in canal anatomy with type IV and type I canal configuration predominating in the mesial and distal roots, respectively. Conclusion: Vertucci type I and IV canal configurations were the most prevalent in the distal and mesial roots, respectively, of both the mandibular first and second permanent molar teeth. Key words:Cone-beam CT, Turkish, mandibular molars, root and canal morphology. PMID:23524421

Shaping ability of reciproc and TF adaptive systems in severely curved canals of rapid microCT-based prototyping molar replicas.

PubMed

Ordinola-Zapata, Ronald; Bramante, Clovis Monteiro; Duarte, Marco Antonio Húngaro; Cavenago, Bruno Cavalini; Jaramillo, David; Versiani, Marco Aurélio

2014-01-01

To evaluate the shaping ability of Reciproc and Twisted-File Adaptive systems in rapid prototyping replicas. Two mandibular molars showing S-shaped and 62-degree curvatures in the mesial root were scanned by using a microcomputed tomography (μCT) system. The data were exported in the stereolitograhic format and 20 samples of each molar were printed at 16 µm resolution. The mesial canals of 10 replicas of each specimen were prepared with each system. Transportation was measured by overlapping radiographs taken before and after preparation and resin thickness after instrumentation was measured by μCT. Both systems maintained the original shape of the apical third in both anatomies (P>0.05). Overall, considering the resin thickness in the 62-degree replicas, no statistical difference was found between the systems (P>0.05). In the S-shaped curvature replica, Reciproc significantly decreased the thickness of the resin walls in comparison with TF Adaptive. The evaluated systems were able to maintain the original shape at the apical third of severely curved mesial canals of molar replicas.

A reconstructed computerized tomographic comparison of Ni-Ti rotary GT files versus traditional instruments in canals shaped by novice operators.

PubMed

Gluskin, A H; Brown, D C; Buchanan, L S

2001-09-01

The aim of this study was to compare the effects of preparation with conventional stainless steel Flexofiles and Gates Glidden burs versus nickel-titanium GT rotary files in the shaping of mesial root canals of extracted mandibular molars. A total of 54 canals from 27 mesial roots of mandibular molar teeth were prepared using one of two methods by novice dental students. One canal in each root was prepared by a crown-down approach. utilizing stainless steel Flexofiles and Gates Glidden burs. The other canal was prepared using nickel-titanium GT rotary files in a crown-down fashion as recommended by the manufacturer. Preoperative CT scans of each root were recorded and 50 canal specimens were available for postoperative comparisons. Following canal shaping, postoperative scans were superimposed on the original images. Changes in canal area, canal transportation and thickness of remaining root structure at strategic levels of the root were analyzed. The time taken for each method was also noted. At the coronal and mid-root coronal one-third sections, the rotary GT files produced a significantly smaller postoperative canal area (P < 0.05). In the mid-root sections there was significantly less transportation of the root canal toward the furcation, and less thinning of the root structure with GT files compared to the stainless steel files (P < 0.05). Overall, there was greater conservation of structure coronally and more adequate shape in the mid-root level. The GT rotary technique was significantly faster than the stainless steel hand-held file technique (P < 0.0001). Two GT instruments fractured during the study. Under the conditions of this study, novice dental students were able to prepare curved root canals with Ni-Ti GT rotary files with less transportation and greater conservation of tooth structure, compared to canals prepared with hand instruments. The rotary technique was significantly faster.

Brain Perfusion and Diffusion Abnormalities in Children Treated for Posterior Fossa Brain Tumors.

PubMed

Li, Matthew D; Forkert, Nils D; Kundu, Palak; Ambler, Cheryl; Lober, Robert M; Burns, Terry C; Barnes, Patrick D; Gibbs, Iris C; Grant, Gerald A; Fisher, Paul G; Cheshier, Samuel H; Campen, Cynthia J; Monje, Michelle; Yeom, Kristen W

2017-06-01

To compare cerebral perfusion and diffusion in survivors of childhood posterior fossa brain tumor with neurologically normal controls and correlate differences with cognitive dysfunction. We analyzed retrospectively arterial spin-labeled cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) in 21 patients with medulloblastoma (MB), 18 patients with pilocytic astrocytoma (PA), and 64 neurologically normal children. We generated ANCOVA models to evaluate treatment effects on the cerebral cortex, thalamus, caudate, putamen, globus pallidus, hippocampus, amygdala, nucleus accumbens, and cerebral white matter at time points an average of 5.7 years after original diagnosis. A retrospective review of patient charts identified 12 patients with neurocognitive data and in whom the relationship between IQ and magnetic resonance imaging variables was assessed for each brain structure. Patients with MB (all treated with surgery, chemotherapy, and radiation) had significantly lower global CBF relative to controls (10%-23% lower, varying by anatomic region, all adjusted P?

Preoperative automated fibre quantification predicts postoperative seizure outcome in temporal lobe epilepsy.

PubMed

Keller, Simon S; Glenn, G Russell; Weber, Bernd; Kreilkamp, Barbara A K; Jensen, Jens H; Helpern, Joseph A; Wagner, Jan; Barker, Gareth J; Richardson, Mark P; Bonilha, Leonardo

2017-01-01

Approximately one in every two patients with pharmacoresistant temporal lobe epilepsy will not be rendered completely seizure-free after temporal lobe surgery. The reasons for this are unknown and are likely to be multifactorial. Quantitative volumetric magnetic resonance imaging techniques have provided limited insight into the causes of persistent postoperative seizures in patients with temporal lobe epilepsy. The relationship between postoperative outcome and preoperative pathology of white matter tracts, which constitute crucial components of epileptogenic networks, is unknown. We investigated regional tissue characteristics of preoperative temporal lobe white matter tracts known to be important in the generation and propagation of temporal lobe seizures in temporal lobe epilepsy, using diffusion tensor imaging and automated fibre quantification. We studied 43 patients with mesial temporal lobe epilepsy associated with hippocampal sclerosis and 44 healthy controls. Patients underwent preoperative imaging, amygdalohippocampectomy and postoperative assessment using the International League Against Epilepsy seizure outcome scale. From preoperative imaging, the fimbria-fornix, parahippocampal white matter bundle and uncinate fasciculus were reconstructed, and scalar diffusion metrics were calculated along the length of each tract. Altogether, 51.2% of patients were rendered completely seizure-free and 48.8% continued to experience postoperative seizure symptoms. Relative to controls, both patient groups exhibited strong and significant diffusion abnormalities along the length of the uncinate bilaterally, the ipsilateral parahippocampal white matter bundle, and the ipsilateral fimbria-fornix in regions located within the medial temporal lobe. However, only patients with persistent postoperative seizures showed evidence of significant pathology of tract sections located in the ipsilateral dorsal fornix and in the contralateral parahippocampal white matter bundle. Using receiver operating characteristic curves, diffusion characteristics of these regions could classify individual patients according to outcome with 84% sensitivity and 89% specificity. Pathological changes in the dorsal fornix were beyond the margins of resection, and contralateral parahippocampal changes may suggest a bitemporal disorder in some patients. Furthermore, diffusion characteristics of the ipsilateral uncinate could classify patients from controls with a sensitivity of 98%; importantly, by co-registering the preoperative fibre maps to postoperative surgical lacuna maps, we observed that the extent of uncinate resection was significantly greater in patients who were rendered seizure-free, suggesting that a smaller resection of the uncinate may represent insufficient disconnection of an anterior temporal epileptogenic network. These results may have the potential to be developed into imaging prognostic markers of postoperative outcome and provide new insights for why some patients with temporal lobe epilepsy continue to experience postoperative seizures. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain.

Preoperative automated fibre quantification predicts postoperative seizure outcome in temporal lobe epilepsy

PubMed Central

Keller, Simon S; Glenn, G Russell; Weber, Bernd; Kreilkamp, Barbara A K; Jensen, Jens H; Helpern, Joseph A; Wagner, Jan; Barker, Gareth J; Richardson, Mark P; Bonilha, Leonardo

2017-01-01

Abstract Approximately one in every two patients with pharmacoresistant temporal lobe epilepsy will not be rendered completely seizure-free after temporal lobe surgery. The reasons for this are unknown and are likely to be multifactorial. Quantitative volumetric magnetic resonance imaging techniques have provided limited insight into the causes of persistent postoperative seizures in patients with temporal lobe epilepsy. The relationship between postoperative outcome and preoperative pathology of white matter tracts, which constitute crucial components of epileptogenic networks, is unknown. We investigated regional tissue characteristics of preoperative temporal lobe white matter tracts known to be important in the generation and propagation of temporal lobe seizures in temporal lobe epilepsy, using diffusion tensor imaging and automated fibre quantification. We studied 43 patients with mesial temporal lobe epilepsy associated with hippocampal sclerosis and 44 healthy controls. Patients underwent preoperative imaging, amygdalohippocampectomy and postoperative assessment using the International League Against Epilepsy seizure outcome scale. From preoperative imaging, the fimbria-fornix, parahippocampal white matter bundle and uncinate fasciculus were reconstructed, and scalar diffusion metrics were calculated along the length of each tract. Altogether, 51.2% of patients were rendered completely seizure-free and 48.8% continued to experience postoperative seizure symptoms. Relative to controls, both patient groups exhibited strong and significant diffusion abnormalities along the length of the uncinate bilaterally, the ipsilateral parahippocampal white matter bundle, and the ipsilateral fimbria-fornix in regions located within the medial temporal lobe. However, only patients with persistent postoperative seizures showed evidence of significant pathology of tract sections located in the ipsilateral dorsal fornix and in the contralateral parahippocampal white matter bundle. Using receiver operating characteristic curves, diffusion characteristics of these regions could classify individual patients according to outcome with 84% sensitivity and 89% specificity. Pathological changes in the dorsal fornix were beyond the margins of resection, and contralateral parahippocampal changes may suggest a bitemporal disorder in some patients. Furthermore, diffusion characteristics of the ipsilateral uncinate could classify patients from controls with a sensitivity of 98%; importantly, by co-registering the preoperative fibre maps to postoperative surgical lacuna maps, we observed that the extent of uncinate resection was significantly greater in patients who were rendered seizure-free, suggesting that a smaller resection of the uncinate may represent insufficient disconnection of an anterior temporal epileptogenic network. These results may have the potential to be developed into imaging prognostic markers of postoperative outcome and provide new insights for why some patients with temporal lobe epilepsy continue to experience postoperative seizures. PMID:28031219

Resting-state functional connectivity predicts the strength of hemispheric lateralization for language processing in temporal lobe epilepsy and normals

PubMed Central

Doucet, Gaëlle E.; Pustina, Dorian; Skidmore, Christopher; Sharan, Ashwini; Sperling, Michael R.; Tracy, Joseph I.

2015-01-01

In temporal lobe epilepsy (TLE), determining the hemispheric specialization for language before surgery is critical to preserving a patient's cognitive abilities post-surgery. To date, the major techniques utilized are limited by the capacity of patients to efficiently realize the task. We determined whether resting-state functional connectivity (rsFC) is a reliable predictor of language hemispheric dominance in right and left TLE patients, relative to controls. We chose three subregions of the inferior frontal cortex (pars orbitalis, pars triangularis and pars opercularis) as the seed regions. All participants performed both a verb generation task and a resting-state fMRI procedure. Based on the language task, we computed a laterality index (LI) for the resulting network. This revealed that 96% of the participants were left-hemisphere dominant, although there remained a large degree of variability in the strength of left lateralization. We tested whether LI correlated with rsFC values emerging from each seed. We revealed a set of regions that was specific to each group. Unique correlations involving the epileptic mesial temporal lobe were revealed for the right and left TLE patients, but not for the controls. Importantly, for both TLE groups, the rsFC emerging from a contralateral seed was the most predictive of LI. Overall, our data depict the broad patterns of rsFC that support strong versus weak left hemisphere language laterality. This project provides the first evidence that rsFC data may potentially be used on its own to verify the strength of hemispheric dominance for language in impaired or pathologic populations. PMID:25187327

Lateralization of temporal lobe epilepsy and learning disabilities, as defined by disability-related civil rights law.

PubMed

Butterbaugh, Grant; Olejniczak, Piotr; Roques, Betsy; Costa, Richard; Rose, Marcy; Fisch, Bruce; Carey, Michael; Thomson, Jessica; Skinner, John

2004-08-01

Epilepsy research has identified higher rates of learning disorders in patients with temporal lobe epilepsy (TLE). However, most studies have not adequately assessed complex functional adult learning skills, such as reading comprehension and written language. We designed this study to evaluate our predictions that higher rates of reading comprehension, written language, and calculation disabilities would be associated with left TLE versus right TLE. Reading comprehension, written language, and calculation skills were assessed by using selected subtests from the Woodcock-Johnson Psycho-Educational Tests of Achievement-Revised in a consecutive series of 31 presurgical patients with TLE. Learning disabilities were defined by one essential criterion consistent with the Americans with Disabilities Act of 1990. Patients had left hemisphere language dominance based on Wada results, left or right TLE based on inpatient EEG monitoring, and negative magnetic resonance imaging (MRI), other than MRI correlates of mesial temporal sclerosis. Higher rates of reading comprehension, written language, and calculation disabilities were associated with left TLE, as compared with right TLE. Nearly 75% of patients with left TLE, whereas fewer than 10% of those with right TLE, had at least one learning disability. Seizure onset in the language-dominant hemisphere, as compared with the nondominant hemisphere, was associated with higher rates of specific learning disabilities and a history of poor literacy or career development or both. These results support the potential clinical benefits of using lateralization of seizure onset as a predictor of the risk of learning disabilities that, once evaluated, could be accommodated to increase the participation of patients with epilepsy in work and educational settings.

Mapping the convergent temporal epileptic network in left and right temporal lobe epilepsy.

PubMed

Fang, Peng; An, Jie; Zeng, Ling-Li; Shen, Hui; Qiu, Shijun; Hu, Dewen

2017-02-03

Left and right mesial temporal lobe epilepsy (mTLE) with hippocampal sclerosis (HS) exhibits similar functional and clinical dysfunctions, such as depressive mood and emotional dysregulation, implying that the left and right mTLE may share a common network substrate. However, the convergent anatomical network disruption between the left and right HS remains largely uncharacterized. This study aimed to investigate whether the left and right mTLE share a similar anatomical network. We examined 43 (22 left, 21 right) mTLE patients with HS and 39 healthy controls using diffusion tensor imaging. Machine learning approaches were applied to extract the abnormal anatomical connectivity patterns in both the left and right mTLE. The left and right mTLE showed that 28 discriminating connections were exactly the same when compared to the controls. The same 28 connections showed high discriminating power in comparisons of the left mTLE versus controls (91.7%) and the right mTLE versus controls (90.0%); however, these connections failed to discriminate the left from the right mTLE. These discriminating connections, which were diminished both in the left and right mTLE, were primarily located in the limbic-frontal network, partially agreeing with the limbic-frontal dysregulation model of depression. These findings suggest that left and right mTLE share a convergent circuit, which may account for the mood and emotional deficits in mTLE and may suggest the neuropathological mechanisms underlying the comorbidity of depression and mTLE. Copyright © 2016. Published by Elsevier B.V.

Predictors of meaningful improvement in quality of life after temporal lobe epilepsy surgery: A prospective study.

PubMed

Pauli, Carla; Schwarzbold, Marcelo Liborio; Diaz, Alexandre Paim; de Oliveira Thais, Maria Emilia Rodrigues; Kondageski, Charles; Linhares, Marcelo Neves; Guarnieri, Ricardo; de Lemos Zingano, Bianca; Ben, Juliana; Nunes, Jean Costa; Markowitsch, Hans Joachim; Wolf, Peter; Wiebe, Samuel; Lin, Katia; Walz, Roger

2017-05-01

To investigate prospectively the independent predictors of a minimum clinically important change (MCIC) in quality of life (QOL) after anterior temporal lobectomy (ATL) for drug-resistant mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) in Brazilian patients. Multiple binary logistic regression analysis was performed to identify the clinical, demographic, radiologic, and electrophysiologic variables independently associated with MCIC in the Quality of Life in Epilepsy-31 Inventory (QOLIE-31) overall score 1 year after ATL in 77 consecutive patients with unilateral MTLE-HS. The overall QOLIE-31 score and all its subscale scores increased significantly (p < 0.0001) 1 year after ATL. In the final logistic regression model, absence of presurgical diagnosis of depression (adjusted odds ratio [OR] 4.4, 95% confidence interval [CI] 1.1-16.1, p = 0.02) and a complete postoperative seizure control (adjusted OR 4.1, 95% CI 1.2-14.5, p = 0.03) were independently associated with improvement equal to or greater than the MCIC in QOL after ATL. The overall model accuracy for MCIC improvement in the QOL was 85.6%, with a 95.2% of sensitivity and 46.7% of specificity. These results in Brazilian patients reinforce the external validation of previous findings in Canadian patients showing that presurgical depression and complete seizure control after surgery are independent predictors for meaningful improvement in QOL after ATL, and have implications for the surgical management of MTLE patients. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

Current Topics in Epilepsy Surgery.

PubMed

Usui, Naotaka

2016-05-15

This article reviews the current topics in the field of epilepsy surgery. Each type of epilepsy is associated with a different set of questions and goals. In mesial temporal lobe epilepsy (MTLE) with hippocampal sclerosis (HS), postoperative seizure outcome is satisfactory. A recent meta-analysis revealed superior seizure outcome after anterior temporal lobectomy compared with selective amygdalohippocampectomy; in terms of cognitive outcome; however, amygdalohippocampectomy may be beneficial. In temporal lobe epilepsy with normal magnetic resonance imaging (MRI), postoperative seizure outcome is not as favorable as it is in MTLE with HS; further improvement of seizure outcome in these cases is necessary. Focal cortical dysplasia is the most common substrate in intractable neocortical epilepsy, especially in children, as well as in MRI-invisible neocortical epilepsy. Postoperative seizure-free outcome is approximately 60-70%; further diagnostic and therapeutic improvement is required. Regarding diagnostic methodology, an important topic currently under discussion is wideband electroencephalogram (EEG) analysis. Although high-frequency oscillations and ictal direct current shifts are considered important markers of epileptogenic zones, the clinical significance of these findings should be clarified further. Regarding alternatives to surgery, neuromodulation therapy can be an option for patients who are not amenable to resective surgery. In addition to vagus nerve stimulation, intracranial stimulation such as responsive neurostimulation or anterior thalamic stimulation is reported to have a modest seizure suppression effect. Postoperative management such as rehabilitation and antiepileptic drug (AED) management is important. It has been reported that postoperative rehabilitation improves postoperative employment status. Pre- and post-operative comprehensive care is mandatory for postoperative improvement of quality of life.

Factors Predisposing to Maxillary Anchorage Loss: A Retrospective Study of 1403 Cases

PubMed Central

Su, Hong; Han, Bing; Li, Sa; Na, Bin; Ma, Wen; Xu, Tian-Min

2014-01-01

Anchorage loss is very disturbing for orthodontists and patients during orthodontic treatment, which usually results in bad treatment effects. Despite the same treatment strategy, different patients show different tendencies toward anchorage loss, which influences the treatment results and should preferably be predicted before the treatment is begun. However, relatively little research has been conducted on which patients are more likely to lose anchorage. The mesial tipping of the first molar marks the onset of anchorage loss, and changes in the angulation of the first molar are closely related to anchorage loss. This cross-sectional study aimed to determine how the mesiodistal angulation of the upper first molars changes during general orthodontic treatment and to identify the individual physiologic factors leading to these changes in a large sample of 1403 patients with malocclusion. The data indicate that the upper first molars tend to be tipped mesially during orthodontic treatment, and this constitutes a type of anchorage loss that orthodontists should consider carefully. Compared to treatment-related factors, patients' physiologic characteristics have a greater influence on changes in the angulation of the upper first molars during orthodontic treatment. The more distally tipped the upper first molars are before treatment, the more they will tip mesially during treatment. Mesial tipping of the upper first molars, and therefore, anchorage loss, is more likely to occur in adolescents, males, patients with class II malocclusion and patients who have undergone maxillary premolar extraction. This finding is of clinical significance to orthodontists who wish to prevent iatrogenic anchorage loss by tipping originally distally tipped upper molars forward, and provides a new perspective on anchorage during orthodontic treatment planning. PMID:25299164

Factors predisposing to maxillary anchorage loss: a retrospective study of 1403 cases.

PubMed

Su, Hong; Han, Bing; Li, Sa; Na, Bin; Ma, Wen; Xu, Tian-Min

2014-01-01

Anchorage loss is very disturbing for orthodontists and patients during orthodontic treatment, which usually results in bad treatment effects. Despite the same treatment strategy, different patients show different tendencies toward anchorage loss, which influences the treatment results and should preferably be predicted before the treatment is begun. However, relatively little research has been conducted on which patients are more likely to lose anchorage. The mesial tipping of the first molar marks the onset of anchorage loss, and changes in the angulation of the first molar are closely related to anchorage loss. This cross-sectional study aimed to determine how the mesiodistal angulation of the upper first molars changes during general orthodontic treatment and to identify the individual physiologic factors leading to these changes in a large sample of 1403 patients with malocclusion. The data indicate that the upper first molars tend to be tipped mesially during orthodontic treatment, and this constitutes a type of anchorage loss that orthodontists should consider carefully. Compared to treatment-related factors, patients' physiologic characteristics have a greater influence on changes in the angulation of the upper first molars during orthodontic treatment. The more distally tipped the upper first molars are before treatment, the more they will tip mesially during treatment. Mesial tipping of the upper first molars, and therefore, anchorage loss, is more likely to occur in adolescents, males, patients with class II malocclusion and patients who have undergone maxillary premolar extraction. This finding is of clinical significance to orthodontists who wish to prevent iatrogenic anchorage loss by tipping originally distally tipped upper molars forward, and provides a new perspective on anchorage during orthodontic treatment planning.

Evolutionary and Biological Implications of Dental Mesial Drift in Rodents: The Case of the Ctenodactylidae (Rodentia, Mammalia)

PubMed Central

Gomes Rodrigues, Helder; Solé, Floréal; Charles, Cyril; Tafforeau, Paul; Vianey-Liaud, Monique; Viriot, Laurent

2012-01-01

Dental characters are importantly used for reconstructing the evolutionary history of mammals, because teeth represent the most abundant material available for the fossil species. However, the characteristics of dental renewal are presently poorly used, probably because dental formulae are frequently not properly established, whereas they could be of high interest for evolutionary and developmental issues. One of the oldest rodent families, the Ctenodactylidae, is intriguing in having longstanding disputed dental formulae. Here, we investigated 70 skulls among all extant ctenodactylid genera (Ctenodactylus, Felovia, Massoutiera and Pectinator) by using X-ray conventional and synchrotron microtomography in order to solve and discuss these dental issues. Our study clearly indicates that Massoutiera, Felovia and Ctenodactylus differ from Pectinator not only by a more derived dentition, but also by a more derived eruptive sequence. In addition to molars, their dentition only includes the fourth deciduous premolars, and no longer bears permanent premolars, conversely to Pectinator. Moreover, we found that these premolars are lost during adulthood, because of mesial drift of molars. Mesial drift is a striking mechanism involving migration of teeth allowed by both bone remodeling and dental resorption. This dental innovation is to date poorly known in rodents, since it is only the second report described. Interestingly, we noted that dental drift in rodents is always associated with high-crowned teeth favoring molar size enlargement. It can thus represent another adaptation to withstand high wear, inasmuch as these rodents inhabit desert environments where dust is abundant. A more accurate study of mesial drift in rodents would be very promising from evolutionary, biological and orthodontic points of view. PMID:23185576

Acid and Alkaline Phosphatase Levels in GCF during Orthodontic Tooth Movement

PubMed Central

Farahani, Mohammad; Safavi, Seyed Mohammadreza; Dianat, Omid; Khoramian Tusi, Somayeh; Younessian, Farnaz

2015-01-01

Statement of the Problem The present constituents of gingival crevicular fluid (GCF) can reflect the changes occurring in underlying tissues. Considering variety of biologic bone markers, alkaline phosphatase and acid phosphatase have been examined as bone turn over markers in orthodontic tooth movement. Purpose The current study designed in a longitudinal pattern to determine the changes of acid and alkaline phosphatase (ACP & ALP) in GCF during orthodontic tooth movement. Materials and Method An upper canines from twelve patients (mean age: 14±2 years) undergoing extraction orthodontic treatment for distal movement served as the test tooth (DC), and its contralateral (CC) and antagonist (AC) canines were used as controls. The CC was included in orthodontic appliance without orthodontic force; the AC was free from any orthodontic appliance. The GCF around the experimental teeth was harvested from mesial and distal tooth sites immediately before appliance placement (T0), and 14 (T2) and 28 days (T3) after it and ALP and ACP concentration were determined spectrophotometrically. Results ALP concentration was elevated significantly in DC and CC groups at days 14 and 28 compared with the AC. In DC group, the ALP was significantly greater in mesial sites than distal site, while no significant changes were found between both sites of CC. The peak level of ALP was observed in mesial sites of DC at T2. Regarding ACP, significant elevation of this enzyme was seen in DC group both in mesial and distal sites at T2 and T3. The peak level of this enzyme was seen at T2. Conclusion Monitoring simultaneous changes of ALP and ACP levels in GCF can reflect the tissue responses occur in periodontium during bone formation and bone resorption during orthodontic tooth movement, respectively. PMID:26535403

En-masse retraction with a preformed nickel-titanium and stainless steel archwire assembly and temporary skeletal anchorage devices without posterior bonding

PubMed Central

Jee, Jeong-Hyun; Ahn, Hyo-Won; Seo, Kyung-Won; Kook, Yoon-Ah; Chung, Kyu-Rhim; Nelson, Gerald

2014-01-01

Objective To evaluate the therapeutic effects of a preformed assembly of nickel-titanium (NiTi) and stainless steel (SS) archwires (preformed C-wire) combined with temporary skeletal anchorage devices (TSADs) as the sole source of anchorage and to compare these effects with those of a SS version of C-wire (conventional C-wire) for en-masse retraction. Methods Thirty-one adult female patients with skeletal Class I or II dentoalveolar protrusion, mild-to-moderate anterior crowding (3.0-6.0 mm), and stable Class I posterior occlusion were divided into conventional (n = 15) and preformed (n = 16) C-wire groups. All subjects underwent first premolar extractions and en-masse retraction with pre-adjusted edgewise anterior brackets, the assigned C-wire, and maxillary C-tubes or C-implants; bonded mesh-tube appliances were used in the mandibular dentition. Differences in pretreatment and post-retraction measurements of skeletal, dental, and soft-tissue cephalometric variables were statistically analyzed. Results Both groups showed full retraction of the maxillary anterior teeth by controlled tipping and space closure without altered posterior occlusion. However, the preformed C-wire group had a shorter retraction period (by 3.2 months). Furthermore, the maxillary molars in this group showed no significant mesialization, mesial tipping, or extrusion; some mesialization and mesial tipping occurred in the conventional C-wire group. Conclusions Preformed C-wires combined with maxillary TSADs enable simultaneous leveling and space closure from the beginning of the treatment without maxillary posterior bonding. This allows for faster treatment of dentoalveolar protrusion without unwanted side effects, when compared with conventional C-wire, evidencing its clinical expediency. PMID:25309863

Internal and external morphology of mandibular molars: An original micro-CT study and meta-analysis with review of implications for endodontic therapy.

PubMed

Tomaszewska, Iwona M; Skinningsrud, Bendik; Jarzębska, Anna; Pękala, Jakub R; Tarasiuk, Jacek; Iwanaga, Joe

2018-03-25

The aim of this radiological micro-CT study and meta-analysis was to determine the morphological features of the root canal anatomy of the mandibular molars. The radiological study included micro-CT scans of 108 mandibular first, 120 mandibular second, and 146 mandibular third molars. For our meta-analysis, an extensive search was conducted through PubMed, Embase, and Web of Science to identify articles eligible for inclusion. Data extracted included investigative method (cadaveric, intraoperative, or imaging), Vertucci type of canal configuration, presence/number of canals, roots, apical foramina, apical deltas, and intercanal communications. In the mesial roots of mandibular molars, the most frequent Vertucci type of canal configuration was type IV, except for the mandibular third molar where type I was most common. Type I was most common in the distal root. There were usually two canals in the mesial root and one in the distal root. Two was the most common number of roots, and a third root was most prevalent in Asia. One apical foramen was most common in the distal root and two apical foramina in the mesial root. Intercanal communications were most frequent in the mesial root. Knowledge of the complex anatomy of the mandibular molars can make root canal therapy more likely to succeed. We recommend the use of cone-beam computed tomography before and after endodontic treatment to enable the root anatomy to be accurately described and properly diagnosed, and treatment outcome to be assessed. Clin. Anat. 00:000-000, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Root Canal Morphology and Configuration of 118 Mandibular First Molars by Means of Micro-Computed Tomography: An Ex Vivo Study.

PubMed

Wolf, Thomas Gerhard; Paqué, Frank; Zeller, Maximilian; Willershausen, Brita; Briseño-Marroquín, Benjamín

2016-04-01

The aim of this study was to investigate the root canal system morphology of the mandibular first molar by means of micro-computed tomography. The root canal configuration, foramina, and accessory canals frequency of 118 mandibular first molars were investigated by means of micro-computed tomography and 3-dimensional software imaging. A 4-digit system describes the root canal configuration from the coronal to apical thirds and the main foramina number. The most frequent root canal configurations in mesial root were 2-2-2/2 (31.4%), 2-2-1/1 (15.3%), and 2-2-2/3 (11.9%); another 24 different root canal configurations were observed in this root. A 1-1-1/1 (58.5%), 1-1-1/2 (10.2%), and 16 other root canal configurations were observed in the distal root. The mesiobuccal root canal showed 1-4 foramina in 24.6%, and the mesiolingual showed 1-3 foramina in 28.0%. One connecting canal between the mesial root canals was observed in 30.5% and 2 in 3.4%. The distolingual root canal showed 1-4 foramina in 23.7%, whereas a foramen in the distobuccal root canal was rarely detected (3.4%). The mesiobuccal, mesiolingual, and distolingual root canals showed at least 1 accessory canal (14.3, 10.2, and 4.2%, respectively), but the distobuccal had none. The root canal configuration of mandibular first molars varies strongly. According to our expectations, both the mesial and distal roots showed a high number of morphologic diversifications. The root canal system of the mesial root showed more root canal configuration variations, connecting and accessory canals than the distal root. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Computed Tomographic Morphometry of the Internal Anatomy of Mandibular Second Primary Molars.

PubMed

Kurthukoti, Ameet J; Sharma, Pranjal; Swamy, Dinesh Francis; Shashidara, R; Swamy, Elaine Barretto

2015-01-01

Need for the study: The most important procedure for a successful endodontic treatment is the cleaning and shaping of the canal system. Understanding the internal anatomy of teeth provides valuable information to the clinician that would help him achieve higher clinical success during endodontic therapy. To evaluate by computed tomography-the internal anatomy of mandibular second primary molars with respect to the number of canals, cross-sectional shape of canals, cross-sectional area of canals and the root dentin thickness. A total of 31 mandibular second primary molars were subjected to computed-tomographic evaluation in the transverse plane, after mounting them in a prefabricated template. The images, thus, obtained were analyzed using De-winter Bio-wizard® software. All the samples demonstrated two canals in the mesial root, while majority of the samples (65.48%) demonstrated two canals in the distal root. The cross-sectional images of the mesial canals demonstrated a round shape, while the distal canals demonstrated an irregular shape. The root dentin thickness was highly reduced on the distal aspect of mesial and mesial aspect of distal canals. The mandibular second primary molars demonstrated wide variation and complexities in their internal anatomy. A thorough understanding of the complexity of the root canal system is essential for understanding the principles and problems of shaping and cleaning, determining the apical limits and dimensions of canal preparations, and for performing successful endodontic procedures. How to cite this article: Kurthukoti AJ, Sharma P, Swamy DF, Shashidara R, Swamy EB. Computed Tomographic Morphometry of the Internal Anatomy of Mandibular Second Primary Molars. Int J Clin Pediatr Dent 2015;8(3):202-207.

Computed Tomographic Morphometry of the Internal Anatomy of Mandibular Second Primary Molars

PubMed Central

Sharma, Pranjal; Swamy, Dinesh Francis; Shashidara, R; Swamy, Elaine Barretto

2015-01-01

ABSTRACT Need for the study: The most important procedure for a successful endodontic treatment is the cleaning and shaping of the canal system. Understanding the internal anatomy of teeth provides valuable information to the clinician that would help him achieve higher clinical success during endodontic therapy. Aims: To evaluate by computed tomography—the internal anatomy of mandibular second primary molars with respect to the number of canals, cross-sectional shape of canals, cross-sectional area of canals and the root dentin thickness. Materials and methods: A total of 31 mandibular second primary molars were subjected to computed-tomographic evaluation in the transverse plane, after mounting them in a prefabricated template. The images, thus, obtained were analyzed using De-winter Bio-wizard® software. Results: All the samples demonstrated two canals in the mesial root, while majority of the samples (65.48%) demonstrated two canals in the distal root. The cross-sectional images of the mesial canals demonstrated a round shape, while the distal canals demonstrated an irregular shape. The root dentin thickness was highly reduced on the distal aspect of mesial and mesial aspect of distal canals. Conclusion: The mandibular second primary molars demonstrated wide variation and complexities in their internal anatomy. A thorough understanding of the complexity of the root canal system is essential for understanding the principles and problems of shaping and cleaning, determining the apical limits and dimensions of canal preparations, and for performing successful endodontic procedures. How to cite this article: Kurthukoti AJ, Sharma P, Swamy DF, Shashidara R, Swamy EB. Computed Tomographic Morphometry of the Internal Anatomy of Mandibular Second Primary Molars. Int J Clin Pediatr Dent 2015;8(3):202-207. PMID:26628855

Epilepsy after cerebral infection: review of the literature and the potential for surgery.

PubMed

Ramantani, Georgia; Holthausen, Hans

2017-06-01

The risk of unprovoked seizures in population-based cohorts of cerebral infection survivors is 7-8% in developed countries, rising to considerably higher rates in resource-poor countries. The main risk factors for epilepsy after cerebral infection, besides acute seizures, are infection-associated brain lesions and status epilepticus during the acute phase. Despite the high prevalence of pharmacoresistant epilepsies after cerebral infections, especially in patients with MRI-identifiable lesions, only a small minority undergoes epilepsy surgery. However, excellent surgical candidates are particularly those with a history of meningitis or encephalitis in early childhood, hippocampal sclerosis on MRI, as well as a history, seizure semiology, and EEG-findings compatible with the diagnosis of a mesial temporal lobe epilepsy syndrome. More challenging are patients with neocortical/extratemporal lobe epilepsies post cerebral infection. Finally, patients with a severe hemispheric injury with contralateral hemiparesis are candidates for hemispherectomy/hemispherotomy. This review attempts to shed some light on this frequent cause of symptomatic focal epilepsy, with an emphasis on the chances offered by epilepsy surgery.

Isolated amygdala neurocysticercosis in a patient presenting with déjà vu and olfactory auras. Case report.

PubMed

Lee, Darrin J; Owen, Christopher M; Khanifar, Elham; Kim, Ronald C; Binder, Devin K

2009-06-01

Neurocysticercosis is the most common parasitic infection in the CNS and a leading cause of epilepsy. Since it is a circumscribed lesional cause of epilepsy, specific locations of neurocysticercal lesions may lead to specific clinical presentations. The authors describe a 17-year-old Hispanic boy who had a single enhancing bilobar mass in the right amygdala. Initially, the patient presented with secondarily generalized tonic-clonic seizures, which resolved with antiepilepsy drug therapy. On further investigation, he was found to have persistent olfactory and déjà vu auras. A right amygdalectomy without hippocampectomy was performed, and both the seizures and auras immediately resolved. Pathological analysis revealed neurocysticercosis. To the authors' knowledge, this case is the first reported instance of 2 distinct mesial temporal aura semiologies associated with localized neurocysticercosis in the amygdala and successfully treated with resection. Uniquely, the case demonstrates that both olfactory and déjà vu auras can emanate from the amygdala.

Serotonin 1A receptors, depression, and memory in temporal lobe epilepsy.

PubMed

Theodore, William H; Wiggs, Edythe A; Martinez, Ashley R; Dustin, Irene H; Khan, Omar I; Appel, Shmuel; Reeves-Tyer, Pat; Sato, Susumu

2012-01-01

Memory deficits and depression are common in patients with temporal lobe epilepsy (TLE). Previous positron emission tomography (PET) studies have shown reduced mesial temporal 5HT1A-receptor binding in these patients. We examined the relationships among verbal memory performance, depression, and 5HT1A-receptor binding measured with 18F-trans-4-fluoro-N-2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl-N-(2-pyridyl) cyclohexane carboxamide (18FCWAY) PET in a cross-sectional study. We studied 40 patients (24 male; mean age 34.5 ± 10.7 years) with TLE. Seizure diagnosis and focus localization were based on ictal video-electroencephalography (EEG) recording. Patients had neuropsychological testing with Wechsler Adult Intelligence Score III (WAIS III) and Wechsler Memory Score III (WMS III) on stable antiepileptic drug (AED) regimens at least 24 h since the last seizure. Beck Depression Inventory (BDI) scores were obtained. We performed interictal PET with 18FCWAY, a fluorinated derivative of WAY 100635, a highly specific 5HT1A ligand, and structural magnetic resonance imaging (MRI) scans to estimate partial volume and plasma free fraction corrected 18FCWAY volume of distribution (V/f1). Hippocampal V/f1 was significantly lower in area ipsilateral than contralateral to the epileptic focus (73.7 ± 27.3 vs. 95.4 ± 28.4; p < 0.001). We found a significant relation between both left hippocampal 18FCWAY V/f1 (r = 0.41; p < 0.02) and left hippocampal volume (r = 0.36; p < 0.03) and delayed auditory memory score. On multiple regression, there was a significant effect of the interaction of left hippocampal 18FCWAY V/f1 and left hippocampal volume on delayed auditory memory, but not of either alone. High collinearity was present. In an analysis of variance including the side of the seizure focus, the effect of left hippocampal 18FCWAY V/f1 but not focus laterality retained significance. Mean BDI was 8.3 ± 7.0. There was a significant inverse relation between BDI and 18FCWAY V/f1 ipsilateral to the patient's epileptic focus (r = 0.38 p < 0.02). There was no difference between patients with a right or left temporal focus. There was no relation between BDI and immediate or delayed auditory memory. Our study suggests that reduced left hippocampal 5HT1A-receptor binding may play a role in memory impairment in patients with TLE. Wiley Periodicals, Inc. © 2011 International League Against Epilepsy.

Endodontic treatment of a mandibular first molar with three mesial canals and broken instrument removal.

PubMed

Faramarzi, Farhad; Fakhri, Hamidreza; Fakri, Hamidreza; Javaheri, Homan H

2010-04-01

To succeed in any dental procedure, the clinician's awareness of the patient's dental anatomy and its variations is crucial. In endodontic therapy, obtaining full information about the root canals' variations can affect the outcome substantially. This case report presents the endodontic treatment of a mandibular first molar exhibiting three mesial root canals with 4 mm of a separated K-file in the coronal third of the mesiolingual canal on an 18-year-old female patient. This case demonstrates the importance of locating additional canals in any roots undergoing endodontic treatment and how the clinician's awareness of aberrant internal anatomy may change the treatment results.

Shaping ability of Reciproc and TF Adaptive systems in severely curved canals of rapid microCT-based prototyping molar replicas

PubMed Central

ORDINOLA-ZAPATA, Ronald; BRAMANTE, Clovis Monteiro; DUARTE, Marco Antonio Húngaro; CAVENAGO, Bruno Cavalini; JARAMILLO, David; VERSIANI, Marco Aurélio

2014-01-01

Objective: To evaluate the shaping ability of Reciproc and Twisted-File Adaptive systems in rapid prototyping replicas. Material and Methods: Two mandibular molars showing S-shaped and 62-degree curvatures in the mesial root were scanned by using a microcomputed tomography (μCT) system. The data were exported in the stereolitograhic format and 20 samples of each molar were printed at 16 µm resolution. The mesial canals of 10 replicas of each specimen were prepared with each system. Transportation was measured by overlapping radiographs taken before and after preparation and resin thickness after instrumentation was measured by μCT. Results: Both systems maintained the original shape of the apical third in both anatomies (P>0.05). Overall, considering the resin thickness in the 62-degree replicas, no statistical difference was found between the systems (P>0.05). In the S-shaped curvature replica, Reciproc significantly decreased the thickness of the resin walls in comparison with TF Adaptive. Conclusions: The evaluated systems were able to maintain the original shape at the apical third of severely curved mesial canals of molar replicas. PMID:24918662

Alkaline phosphatase activity in gingival crevicular fluid during canine retraction.

PubMed

Batra, P; Kharbanda, Op; Duggal, R; Singh, N; Parkash, H

2006-02-01

The aim of the study was to investigate alkaline phosphatase activity in the gingival crevicular fluid (GCF) during orthodontic tooth movement in humans. Postgraduate orthodontic clinic. Ten female patients requiring all first premolar extractions were selected and treated with standard edgewise mechanotherapy. Canine retraction was done using 100 g sentalloy springs. Maxillary canine on one side acted as experimental site while the contralateral canine acted as control. Gingival crevicular fluid was collected from mesial and distal of canines before initiation of canine retraction (baseline), immediately after initiation of retraction, and on 1st, 7th, 14th and 21st day and the alkaline phosphatase activity was estimated. The results show significant (p < 0.05) changes in alkaline phosphatase activity on the 7th, 14th and 21st day on both mesial and distal aspects of the compared experimental and control sides. The peak in enzyme activity occurred on the 14th day of initiation of retraction followed by a significant fall in activity especially on the mesial aspect. The study showed that alkaline phosphatase activity could be successfully estimated in the GCF using calorimetric estimation assay kits. The enzyme activity showed variation according to the amount of tooth movement.

Feasibility of Shape-Memory Ni/Ti Alloy Wire Containing Tube Elevators for Transcrestal Detaching Maxillary Sinus Mucosa: Ex Vivo Study.

PubMed

Li, Yanfeng; Wang, Fuli; Hu, Pin; Fan, Jiadong; Han, Yishi; Liu, Bin; Liu, Tao; Yang, Chunhao; Gu, Xiangmin

2016-01-01

Osteotome sinus floor elevation is a less invasive approach to augment an insufficient alveolar bone at the posterior maxilla for dental implantation. However, this approach has some limitations due to the lack of sinus lift tools available for clinical use and the small transcrestal access to the maxillary sinus floor. We recently invented shape-memory Ni/Ti alloy wire containing tube elevators for transcrestal detaching maxillary sinus mucosa, and developed goat ex vivo models for direct visualizing the effectiveness of detaching sinus mucosa in real time during transcrestal maxillary sinus floor elevation. We evaluated our invented elevators, namely elevator 012 and elevator 014, for their effectiveness for transcrestal detaching maxillary sinus mucosa using the goat ex vivo models. We measured the length of sinus mucosa detached in mesial and distal directions or buccal and palatal directions, and the space volume created by detaching maxillary sinus mucosa in mesial, distal, buccal and palatal directions using the invented elevators. Elevator 012 had a shape-memory Ni/Ti alloy wire with a diameter of 0.012 inch, while elevator 014 had its shape-memory Ni/Ti alloy wire with a diameter of 0.014 inch. Elevator 012 could detach the goat maxillary sinus mucosa in the mesial or distal direction for 12.1±4.3 mm, while in the buccal or palatal direction for 12.5±6.7 mm. The elevator 014 could detach the goat maxillary sinus mucosa for 23.0±4.9 mm in the mesial or distal direction, and for 19.0±8.1 mm in the buccal or palatal direction. An average space volume of 1.7936±0.2079 ml was created after detaching the goat maxillay sinus mucosa in both mesial/distal direction and buccal/palatal direction using elevator 012; while the average space volume created using elevator 014 was 1.8764±0.2366 ml. Both two newly invented tube elevators could effectively detach the maxillary sinus mucosa on the goat ex vivo sinus models. Moreover, elevator 014 has advantages over the elevator 012 for the capability to detach sinus mucosa. © 2016 The Author(s) Published by S. Karger AG, Basel.

Radiosurgery for epilepsy: Systematic review and International Stereotactic Radiosurgery Society (ISRS) practice guideline.

PubMed

McGonigal, Aileen; Sahgal, Arjun; De Salles, Antonio; Hayashi, Motohiro; Levivier, Marc; Ma, Lijun; Martinez, Roberto; Paddick, Ian; Ryu, Samuel; Slotman, Ben J; Régis, Jean

2017-11-01

While there are many reports of radiosurgery for treatment of drug-resistant epilepsy, a literature review is lacking. The aim of this systematic review is to summarize current literature on the use of stereotactic radiosurgery (RS) for treatment of epilepsy. Literature search was performed using various combinations of the search terms "radiosurgery", "stereotactic radiosurgery", "Gamma Knife", "epilepsy" and "seizure", from 1990 until October 2015. Level of evidence was assessed according to the PRISMA guidelines. Fifty-five articles fulfilled inclusion criteria. Level 2 evidence (prospective studies) was available for the clinical indications of mesial temporal lobe epilepsy (MTLE) and hypothalamic hamartoma (HH) treated by Gamma Knife (GK) RS. For remaining indications including corpus callosotomy as palliative treatment, epilepsy related to cavernous malformation and extra-temporal epilepsy, only Level 4 data was available (case report, prospective observational study, or retrospective case series). No Level 1 evidence was available. Based on level 2 evidence, RS is an efficacious treatment to control seizures in MTLE, possibly resulting in superior neuropsychological outcomes and quality of life metrics in selected subjects compared to microsurgery. RS has a better risk-benefit ratio for small hypothalamic hamartomas compared to surgical methods Delayed therapeutic effect resulting in ongoing seizures is associated with morbidity and mortality risk. Lack of level 1 evidence precludes the formation of guidelines at present. Copyright © 2017 Elsevier B.V. All rights reserved.

Function Lateralization via Measuring Coherence Laterality

PubMed Central

Wang, Ze; Mechanic-Hamilton, Dawn; Pluta, John; Glynn, Simon; Detre, John A.

2009-01-01

A data-driven approach for lateralization of brain function based on the spatial coherence difference of functional MRI (fMRI) data in homologous regions-of-interest (ROI) in each hemisphere is proposed. The utility of using coherence laterality (CL) to determine function laterality was assessed first by examining motor laterality using normal subjects’ data acquired both at rest and with a simple unilateral motor task and subsequently by examining mesial temporal lobe memory laterality in normal subjects and patients with temporal lobe epilepsy. The motor task was used to demonstrate that CL within motor ROI correctly lateralized functional stimulation. In patients with unilateral epilepsy studied during a scene-encoding task, CL in a hippocampus-parahippocampus-fusiform (HPF) ROI was concordant with lateralization based on task activation, and the CL index (CLI) significantly differentiated the right side group to the left side group. By contrast, normal controls showed a symmetric HPF CLI distribution. Additionally, similar memory laterality prediction results were still observed using CL in epilepsy patients with unilateral seizures after the memory encoding effect was removed from the data, suggesting the potential for lateralization of pathological brain function based on resting fMRI data. A better lateralization was further achieved via a combination of the proposed approach and the standard activation based approach, demonstrating that assessment of spatial coherence changes provides a complementary approach to quantifying task-correlated activity for lateralizing brain function. PMID:19345736

Effects of smoking marijuana on brain perfusion and cognition.

PubMed

O'Leary, Daniel S; Block, Robert I; Koeppel, Julie A; Flaum, Michael; Schultz, Susan K; Andreasen, Nancy C; Ponto, Laura Boles; Watkins, G Leonard; Hurtig, Richard R; Hichwa, Richard D

2002-06-01

The effects of smoking marijuana on regional cerebral blood flow (rCBF) and cognitive performance were assessed in 12 recreational users in a double-blinded, placebo-controlled study. PET with [(15)Oxygen]-labeled water ([(15)O]H(2)O) was used to measure rCBF before and after smoking of marijuana and placebo cigarettes, as subjects repeatedly performed an auditory attention task. Smoking marijuana resulted in intoxication, as assessed by a behavioral rating scale, but did not significantly alter mean behavioral performance on the attention task. Heart rate and blood pressure increased dramatically following smoking of marijuana but not placebo cigarettes. However, mean global CBF did not change significantly. Increased rCBF was observed in orbital and mesial frontal lobes, insula, temporal poles, anterior cingulate, as well as in the cerebellum. The increases in rCBF in anterior brain regions were predominantly in "paralimbic" regions and may be related to marijuana's mood-related effects. Reduced rCBF was observed in temporal lobe auditory regions, in visual cortex, and in brain regions that may be part of an attentional network (parietal lobe, frontal lobe and thalamus). These rCBF decreases may be the neural basis of perceptual and cognitive alterations that occur with acute marijuana intoxication. There was no significant rCBF change in the nucleus accumbens or other reward-related brain regions, nor in basal ganglia or hippocampus, which have a high density of cannabinoid receptors.

Correlation of invasive EEG and scalp EEG.

PubMed

Ramantani, Georgia; Maillard, Louis; Koessler, Laurent

2016-10-01

Ever since the implementation of invasive EEG recordings in the clinical setting, it has been perceived that a considerable proportion of epileptic discharges present at a cortical level are missed by routine scalp EEG recordings. Several in vitro, in vivo, and simulation studies have been performed in the past decades aiming to clarify the interrelations of cortical sources with their scalp and invasive EEG correlates. The amplitude ratio of cortical potentials to their scalp EEG correlates, the extent of the cortical area involved in the discharge, as well as the localization of the cortical source and its geometry have been each independently linked to the recording of the cortical discharge with scalp electrodes. The need to elucidate these interrelations has been particularly imperative in the field of epilepsy surgery with its rapidly growing EEG-based localization technologies. Simultaneous multiscale EEG recordings with scalp, subdural and/or depth electrodes, applied in presurgical epilepsy workup, offer an excellent opportunity to shed some light to this fundamental issue. Whereas past studies have considered predominantly neocortical sources in the context of temporal lobe epilepsy, current investigations have included deep sources, as in mesial temporal epilepsy, as well as extratemporal sources. Novel computational tools may serve to provide surrogates for the shortcomings of EEG recording methodology and facilitate further developments in modern electrophysiology. Copyright © 2016 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Unbiased quantitative testing of conventional orthodontic beliefs.

PubMed

Baumrind, S

1998-03-01

This study used a preexisting database to test in hypothesis from the appropriateness of some common orthodontic beliefs concerning upper first molar displacement and changes in facial morphology associated with conventional full bonded/banded treatment in growing subjects. In an initial pass, the author used data from a stratified random sample of 48 subjects drawn retrospectively from the practice of a single, experienced orthodontist. This sample consisted of 4 subgroups of 12 subjects each: Class I nonextraction, Class I extraction, Class II nonextraction, and Class II extraction. The findings indicate that, relative to the facial profile, chin point did not, on average, displace anteriorly during treatment, either overall or in any subgroup. Relative to the facial profile, Point A became significantly less prominent during treatment, both overall and in each subgroup. The best estimate of the mean displacement of the upper molar cusp relative to superimposition on Anterior Cranial Base was in the mesial direction in each of the four subgroups. In only one extraction subject out of 24 did the cusp appear to be displaced distally. Mesial molar cusp displacement was significantly greater in the Class II extraction subgroup than in the Class II nonextraction subgroup. Relative to superimposition on anatomical "best fit" of maxillary structures, the findings for molar cusp displacement were similar, but even more dramatic. Mean mesial migration was highly significant in both the Class II nonextraction and Class II extraction subgroups. In no subject in the entire sample was distal displacement noted relative to this superimposition. Mean increase in anterior Total Face Height was significantly greater in the Class II extraction subgroup than in the Class II nonextraction subgroup. (This finding was contrary to the author's original expectation.) The generalizability of the findings from the initial pass to other treated growing subjects was then assessed by retesting modified hypotheses against a second database stored sample that earlier had been drawn randomly from two other orthodontic practices. The implications of the author's study strategy to the design of future shared digital databases is discussed briefly.

Electroclinical findings of minor motor events during sleep in temporal lobe epilepsy.

PubMed

Giuliano, Loretta; Uccello, Denise; Fatuzzo, Daniela; Mainieri, Greta; Zappia, Mario; Sofia, Vito

2017-07-01

It is well known that sleep-related motor seizures can originate from the temporal lobe. However, little is known about the clinical features of minor motor manifestations during sleep in patients with temporal lobe epilepsy. The main objective of our study was to verify the existence of minor motor events during sleep in patients with mesial temporal lobe epilepsy (MTLE) and to define their clinical features and electroencephalography (EEG) correlations. We enrolled in the study patients with diagnosis of symptomatic MTLE and a group of healthy controls. All patients and controls underwent long-term video -EEG monitoring, including at least one night of nocturnal sleep. We analyzed all the movements recorded during nocturnal sleep of patients and controls and their electroencephalographic correlations. We analyzed the nocturnal sleep of 15 patients with symptomatic MTLE (8 males and 7 females; mean age ± standard deviation [SD]31.8 ± 14.9 years) and of 15 healthy controls (6 males and 9 females; mean age ± SD 32.8 ± 11.2 years). The analysis of movements during sleep revealed significant differences between groups, with the patients presenting significantly more movements in sleep than healthy controls (56.7 ± 39.2 vs. 15 ± 6.1; p < 0.001) with significant differences regarding oroalimentary automatisms, limb dystonia, straightening movements and gestural automatisms. EEG analysis showed that the proportion of movements preceded by EEG abnormalities was significantly higher in patients than in controls (57.8 ± 35.9 movements vs. 16.6 ± 13.4 movements; p < 0.001). The results of our study demonstrated the presence of minor motor events during sleep in patients with MTLE, suggesting an epileptic origin of these episodes. The study of nocturnal sleep in MTLE patients is useful in helping the clinicians in the diagnostic and therapeutic workup of these patients. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

Hair sparing does not compromise real-time magnetic resonance imaging guided stereotactic laser fiber placement for temporal lobe epilepsy.

PubMed

Singh, Shikha; Kumar, Kevin K; Rabon, Matthew J; Dolce, Dana; Halpern, Casey H

2018-06-01

Pre-operative scalp shaving is conventionally thought to simplify postoperative cranial wound care, lower the rate of wound infections, and ease optimal incision localization. Over the past few decades, some neurosurgeons have refrained from scalp shaving in order to improve patient satisfaction with brain surgery. However, this hair-sparing approach has not yet been explored in the growing field of magnetic resonance-guided laser interstitial thermal therapy (MRgLITT). This study investigated the initial impact of a no-shave technique on post-operative wound infection rate as well as on entry and target accuracy in MRgLITT for mesial temporal epilepsy. Eighteen patients selected by the Stanford Comprehensive Epilepsy Program between November 2015 and August 2017 were included in the study. All patients underwent functional selective amygdalohippocampotomies using MRgLITT entirely within a diagnostic MRI suite. No hair was removed and no additional precautions were taken for hair or scalp care. Otherwise, routine protocols for surgical preparations and wound closure were followed. The study was performed under approval from Stanford University's Internal Review Board (IRB-37830). No post-operative wound infections or erosions occurred for any patient. The mean entry point error was 2.87 ± 1.3 mm and the mean target error was 1.0 ± 0.9 mm. There have been no other complications associated with this hair-sparing approach. The study's results suggest that hair sparing in MRgLITT surgery for temporal epilepsy does not increase the risk of wound complications or compromise accuracy. This preferred cosmetic approach may thus appeal to epilepsy patients considering such interventions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Resting-state functional connectivity predicts the strength of hemispheric lateralization for language processing in temporal lobe epilepsy and normals.

PubMed

Doucet, Gaëlle E; Pustina, Dorian; Skidmore, Christopher; Sharan, Ashwini; Sperling, Michael R; Tracy, Joseph I

2015-01-01

In temporal lobe epilepsy (TLE), determining the hemispheric specialization for language before surgery is critical to preserving a patient's cognitive abilities post-surgery. To date, the major techniques utilized are limited by the capacity of patients to efficiently realize the task. We determined whether resting-state functional connectivity (rsFC) is a reliable predictor of language hemispheric dominance in right and left TLE patients, relative to controls. We chose three subregions of the inferior frontal cortex (pars orbitalis, pars triangularis, and pars opercularis) as the seed regions. All participants performed both a verb generation task and a resting-state fMRI procedure. Based on the language task, we computed a laterality index (LI) for the resulting network. This revealed that 96% of the participants were left-hemisphere dominant, although there remained a large degree of variability in the strength of left lateralization. We tested whether LI correlated with rsFC values emerging from each seed. We revealed a set of regions that was specific to each group. Unique correlations involving the epileptic mesial temporal lobe were revealed for the right and left TLE patients, but not for the controls. Importantly, for both TLE groups, the rsFC emerging from a contralateral seed was the most predictive of LI. Overall, our data depict the broad patterns of rsFC that support strong versus weak left hemisphere language laterality. This project provides the first evidence that rsFC data may potentially be used on its own to verify the strength of hemispheric dominance for language in impaired or pathologic populations. © 2014 Wiley Periodicals, Inc.

Remote infarct of the temporal lobe with coexistent hippocampal sclerosis in mesial temporal lobe epilepsy.

PubMed

Gales, Jordan M; Prayson, Richard A

2016-02-01

In patients undergoing surgery for temporal lobe epilepsy, hippocampal sclerosis remains the most commonly observed pathology. In addition to hippocampal sclerosis, 5% to 30% of these resections on magnetic resonance imaging contain a second independently epileptogenic lesion, commonly referred to as dual pathology. A second etiology of seizure activity, as seen in dual pathology, may serve as an important cause of treatment failure in striving for post-operative seizure control. Dual pathology, consisting of hippocampal sclerosis and a remote infarct of the adjacent cortex, has been rarely reported. Cases of pathologically confirmed hippocampal sclerosis diagnosed between January 2000 and December 2012 (n = 349) were reviewed, and 7 cases of coexistent infarct (2%) formed the study group. Seven individuals (mean age, 29years; range, 5-47 years) with a mean epilepsy duration of 12.5years (3.3-25 years) and a mean pre-surgery frequency of 15 seizures per week (range, 0.5-56 seizures/week) were followed up postoperatively for a mean duration of 64months (range, 3-137 months). Pathologically, the most common form of hippocampal sclerosis observed was International League against Epilepsy type Ib or severe variant (n = 4). Four of the six individuals with post-surgery follow-up were seizure free at last encounter. The reported incidence of dual pathology, including hippocampal sclerosis and remote infarct, is low (2% in the present study) but may indicate a slightly increased risk of developing hippocampal sclerosis in the setting of a remote infarct. Surgical intervention for such cases anecdotally appears effective in achieving seizure control. Copyright © 2015 Elsevier Inc. All rights reserved.

Learning of serial digits leads to frontal activation in functional MR imaging.

PubMed

Karakaş, Hakki Muammer; Karakaş, Sirel

2006-03-01

Clinical studies have shown that performance on the serial digit learning test (SDLT) is dependent upon the mesial temporal lobes, which are responsible for learning and its consolidation. However, an effective SDLT performance is also dependent upon sequencing, temporal ordering, and the utilization of mnemonic strategies. All of these processes are among the functions of the frontal lobes; in spite of this, the relationship between SDLT performance and the frontal lobes has not been demonstrated with previously used mapping techniques. The aim of this study was to investigate the areas of the brain that are activated by SDLT performance. Ten healthy, right handed volunteers (mean age, 20.1 years; SD: 3.3) who had 12 years of education were studied with a 1.0 T MR imaging scanner. BOLD (blood oxygen level dependent) contrast and a modified SDLT were used. Activated loci were automatically mapped using a proportional grid. In learning, the most consistent activation was observed in B-a-7 of the right (80%) and the left hemispheres (50%). In recall, the most consistent activation was observed in B-a-7 of the right hemisphere (60%). Activations were observed in 2.5+/-0.97 Talairach volumes in learning, whereas they encompassed 1.7+/-0.95 volumes in recall. The difference between both phases (learning and recall) regarding total activated volume was significant (p < 0.05). The prefrontal activation during SDLT performance was not related to learning or to recall, but to a function that is common to both of these cognitive processes. A candidate for this common factor may be the executive functions, which also include serial position processing and temporal ordering.

Verbal Dominant Memory Impairment and Low Risk for Post-operative Memory Worsening in Both Left and Right Temporal Lobe Epilepsy Associated with Hippocampal Sclerosis.

PubMed

Khalil, Amr Farid; Iwasaki, Masaki; Nishio, Yoshiyuki; Jin, Kazutaka; Nakasato, Nobukazu; Tominaga, Teiji

2016-11-15

Post-operative memory changes after temporal lobe surgery have been established mainly by group analysis of cognitive outcome. This study investigated individual patient-based memory outcome in surgically-treated patients with mesial temporal lobe epilepsy (TLE). This study included 84 consecutive patients with intractable TLE caused by unilateral hippocampal sclerosis (HS) who underwent epilepsy surgery (47 females, 41 left [Lt] TLE). Memory functions were evaluated with the Wechsler Memory Scale-Revised before and at 1 year after surgery. Pre-operative memory function was classified into three patterns: verbal dominant memory impairment (Verb-D), visual dominant impairment (Vis-D), and no material-specific impairment. Post-operative changes in verbal and visual memory indices were classified into meaningful improvement, worsening, or no significant changes. Pre-operative patterns and post-operative changes in verbal and visual memory function were compared between the Lt and right (Rt) TLE groups. Pre-operatively, Verb-D was the most common type of impairment in both the Lt and Rt TLE groups (65.9 and 48.8%), and verbal memory indices were lower than visual memory indices, especially in the Lt compared with Rt TLE group. Vis-D was observed only in 11.6% of Rt and 7.3% of Lt TLE patients. Post-operatively, meaningful improvement of memory indices was observed in 23.3-36.6% of the patients, and the memory improvement was equivalent between Lt and Rt TLE groups and between verbal and visual materials. In conclusion, Verb-D is most commonly observed in patients with both the Lt and Rt TLE associated with HS. Hippocampectomy can improve memory indices in such patients regardless of the side of surgery and the function impaired.

GABAA-current rundown of temporal lobe epilepsy is associated with repetitive activation of GABAA “phasic” receptors

PubMed Central

Palma, Eleonora; Roseti, Cristina; Maiolino, Francesca; Fucile, Sergio; Martinello, Katiuscia; Mazzuferi, Manuela; Aronica, Eleonora; Manfredi, Mario; Esposito, Vincenzo; Cantore, Gianpaolo; Miledi, Ricardo; Simonato, Michele; Eusebi, Fabrizio

2007-01-01

A study was made of the “rundown” of GABAA receptors, microtransplanted to Xenopus oocytes from surgically resected brain tissues of patients afflicted with drug-resistant human mesial temporal lobe epilepsy (mTLE). Cell membranes, isolated from mTLE neocortex specimens, were injected into frog oocytes that rapidly incorporated functional GABAA receptors. Upon repetitive activation with GABA (1 mM), “epileptic” GABAA receptors exhibited a GABAA-current (IGABA) rundown that was significantly enhanced by Zn2+ (≤250 μM), and practically abolished by the high-affinity GABAA receptor inverse agonist SR95531 (gabazine; 2.5–25 μM). Conversely, IGABA generated by “control” GABAA receptors microtransplanted from nonepileptic temporal lobe, lesional TLE, or authoptic disease-free tissues remained stable during repetitive stimulation, even in oocytes treated with Zn2+. We conclude that rundown of mTLE epileptic receptors depends on the presence of “phasic GABAA receptors” that have low sensitivity to antagonism by Zn2+. Additionally, we found that GABAA receptors, microtransplanted from the cerebral cortex of adult rats exhibiting recurrent seizures, caused by pilocarpine-induced status epilepticus, showed greater rundown than control tissue, an event also occurring in patch-clamped rat pyramidal neurons. Rundown of epileptic rat receptors resembled that of human mTLE receptors, being enhanced by Zn2+ (40 μM) and sensitive to the antiepileptic agent levetiracetam, the neurotrophin brain-derived neurotrophic factor, and the phosphatase blocker okadaic acid. Our findings point to the rundown of GABAA receptors as a hallmark of TLE and suggest that modulating tonic and phasic mTLE GABAA receptor activity may represent a useful therapeutic approach to the disease. PMID:18083839

Improved operative efficiency using a real-time MRI-guided stereotactic platform for laser amygdalohippocampotomy.

PubMed

Ho, Allen L; Sussman, Eric S; Pendharkar, Arjun V; Le, Scheherazade; Mantovani, Alessandra; Keebaugh, Alaine C; Drover, David R; Grant, Gerald A; Wintermark, Max; Halpern, Casey H

2018-04-01

OBJECTIVE MR-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive method for thermal destruction of benign or malignant tissue that has been used for selective amygdalohippocampal ablation for the treatment of temporal lobe epilepsy. The authors report their initial experience adopting a real-time MRI-guided stereotactic platform that allows for completion of the entire procedure in the MRI suite. METHODS Between October 2014 and May 2016, 17 patients with mesial temporal sclerosis were selected by a multidisciplinary epilepsy board to undergo a selective amygdalohippocampal ablation for temporal lobe epilepsy using MRgLITT. The first 9 patients underwent standard laser ablation in 2 phases (operating room [OR] and MRI suite), whereas the next 8 patients underwent laser ablation entirely in the MRI suite with the ClearPoint platform. A checklist specific to the real-time MRI-guided laser amydalohippocampal ablation was developed and used for each case. For both cohorts, clinical and operative information, including average case times and accuracy data, was collected and analyzed. RESULTS There was a learning curve associated with using this real-time MRI-guided system. However, operative times decreased in a linear fashion, as did total anesthesia time. In fact, the total mean patient procedure time was less in the MRI cohort (362.8 ± 86.6 minutes) than in the OR cohort (456.9 ± 80.7 minutes). The mean anesthesia time was significantly shorter in the MRI cohort (327.2 ± 79.9 minutes) than in the OR cohort (435.8 ± 78.4 minutes, p = 0.02). CONCLUSIONS The real-time MRI platform for MRgLITT can be adopted in an expedient manner. Completion of MRgLITT entirely in the MRI suite may lead to significant advantages in procedural times.

Vision after trans-sylvian or temporobasal selective amygdalohippocampectomy: a prospective randomised trial.

PubMed

Delev, Daniel; Wabbels, Bettina; Schramm, Johannes; Nelles, Michael; Elger, Christian E; von Lehe, Marec; Clusmann, Hans; Grote, Alexander

2016-09-01

Selective amygdalohippocampectomy (SAH) is an accepted surgical procedure for treatment of pharmacoresistant mesial temporal lobe epilepsy, but it may lead to postoperative visual field deficits (VFDs). Here we present a prospective randomised trial comparing the postoperative VFDs after either a trans-sylvian or temporobasal approach for SAH. Forty-eight patients were randomly assigned to trans-sylvian (n = 24) or temporobasal (n = 24) SAH. Postoperative VFD were quantitatively evaluated using automated static and kinetic perimetry. In 24 cases, diffusion tensor imaging-based deterministic fibre-tracking of the optic radiation was performed. The primary endpoint was absence of postoperative VFD. The secondary endpoint was seizure outcome and driving ability. Three patients (13 %) from the trans-sylvian group showed no VFD, compared to 11 patients (46 %) from the temporobasal group without VFD (p = 0.01, RR = 3.7; CI = 1.2-11.5). Fifteen patients from each group (63 %) became completely seizure-free (ILAE1). Among those seizure-free cases, five trans-sylvian (33 %) and ten temporobasal (66 %) patients could apply for a driving licence (NNT = 3) when VFDs were considered. Although the trans-sylvian group experienced more frequent VFDs, the mean functional visual impairment showed a tendency to be less pronounced compared with the temporobasal group. DTI-based tracking of the optic radiation revealed that a lower distance of optic radiation to the temporal base correlated with increased rate of VFD in the temporobasal group. Temporobasal SAH shows significantly fewer VFDs and equal seizure-free rate compared with the trans-sylvian SAH. However, in patients in whom the optic radiation is close to the temporal base, the trans-sylvian approach may be a preferred alternative.

CBF tomograms with (/sup 99m/Tc-HM-PAO in patients with dementia (Alzheimer type and HIV) and Parkinson's disease--initial results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Costa, D.C.; Ell, P.J.; Burns, A.

1988-12-01

We present preliminary data on the utility of functional brain imaging with (99mTc)-d,l-HM-PAO and single photon emission computed tomography (SPECT) in the study of patients with dementia of the Alzheimer type (DAT), HIV-related dementia syndrome, and the on-off syndrome of Parkinson's disease. In comparison with a group of age-matched controls, the DAT patients revealed distinctive bilateral temporal and posterior parietal deficits, which correlate with detailed psychometric evaluation. Patients with amnesia as the main symptom (group A) showed bilateral mesial temporal lobe perfusion deficits (p less than 0.02). More severely affected patients (group B) with significant apraxia, aphasia, or agnosia exhibitedmore » patterns compatible with bilateral reduced perfusion in the posterior parietal cortex, as well as reduced perfusion to both temporal lobes, different from the patients of the control group (p less than 0.05). SPECT studies of HIV patients with no evidence of intracraneal space occupying pathology showed marked perfusion deficits. Patients with Parkinson's disease and the on-off syndrome studied during an on phase (under levodopa therapy) and on another occasion after withdrawal of levodopa (off) demonstrated a significant change in the uptake of (99mTc)-d,l-HM-PAO in the caudate nucleus (lower on off) and thalamus (higher on off). These findings justify the present interest in the functional evaluation of the brain of patients with dementia. (99mTc)-d,l-HM-PAO and regional cerebral blood flow (rCBF)/SPECT appear useful and highlight individual disorders of flow in a variety of neuropsychiatric conditions.« less

Three rooted, four canalled mandibular first molar (Radix Entomolaris).

PubMed

Parolia, Abhishek; Kundabala, M; Thomas, M S; Mohan, M; Joshi, N

2009-01-01

A mandibular first molar with two distal roots is an interesting example of anatomic variation. This paper describes case reports of mandibular first molar with three roots (one mesial and two distal) and four canals (two in mesial and one in each distobuccal and distolingual root). The canals were shaped with protaper rotary files and irrigated with 5.25% sodium hyochlorite, 0.2 %w/v of chlorhexidine gluconate and normal saline as the fi nal irrigant. The canals were then obturated with gutta- percha and AH plus sealer. These case reports show an anatomic variation of internal morphology of the tooth and points out the importance of searching for additional canals.

Evaluation of the preparation of the coronal part of the mesial canals of lower molars.

PubMed

Sinan, A; Georgelin-Gurgel, M; Diemer, F

2011-03-01

Canal entrances can be flared using specific, low speed, continuously rotating Ni-Ti instruments. Two such instruments were evaluated for their capacity to flare the canal entrance while respecting the initial canal axis. Lower molars (n = 20) with two distinct mesial canals were prepared to within 2.5 mm of the pulp chamber floor using Bramante's technique. Canal entrances were flared with a QUANTEC FLARE LX or an ENDOFLARE. They both had a 0.12 taper and a #25 tip diameter. The instruments were first inserted in the canals using an axial movement and then withdrawn with a selective circumferential brushing action. Photographs taken before and after each preparation were compared. No ledging or significant modification of the working length was noted. The centre of mass was displaced on average by 0.138 mm with no brushing action and 0.274 mm with brushing action. In most cases (87.5%), the centre of mass was displaced mesially. The two instruments behaved in an identical mode, both before (p = 0.3497) and after (p = 0.9304) the brushing action. Ni-Ti flaring instruments can be used to flare the canal entrance with little displacement of the initial canal axis, even when a brushing action is used.

Cervical shaping in curved root canals: comparison of the efficiency of two endodontic instruments.

PubMed

Busquim, Sandra Soares Kühne; dos Santos, Marcelo

2002-01-01

The aim of this study was to determine the removal of dentin produced by number 25 (0.08) Flare files (Quantec Flare Series, Analytic Endodontics, Glendora, California, USA) and number 1 e 2 Gates-Glidden burs (Dentsply - Maillefer, Ballaigues, Switzerland), in the mesio-buccal and mesio-lingual root canals, respectively, of extracted human permanent inferior molars, by means of measuring the width of dentinal walls prior and after instrumentation. The obtained values were compared. Due to the multiple analyses of data, a nonparametric test was used, and the Kruskal-Wallis test was chosen. There was no significant difference between the instruments as to the removal of dentin in the 1st and 2nd millimeters. However, when comparing the performances of the instruments in the 3rd millimeter, Flare files promoted a greater removal than Gates-Glidden drills (p > 0.05). The analysis revealed no significant differences as to mesial wear, which demonstrates the similar behavior of both instruments. Gates-Glidden drills produced an expressive mesial detour in the 2nd and 3rd millimeters, which was detected trough a statistically significant difference in the wear of this region (p > 0.05). There was no statistically significant difference between mesial and lateral wear when Flare instruments were employed.

Morphological changes related to age in mesial root canals of permanent mandibular first molars.

PubMed

Gani, Omar A; Boiero, Claudio F; Correa, Carolina; Masin, Ivana; Machado, Ricardo; Silva, Emmanuel J N L; Vansan, Luiz Pascoal

2014-01-01

The aim of this study was to evaluate age-related morphological canal changes in mesial root canals of mandibular first molars of known ages. Fifty-six specimens were selected for this study and distributed into the following four age groups (n. 14): a) Group of children under 13 years, b) Group of adolescents (from 14 to 19 years), c) Group of young adults (from 20 to 39 years) and d) Group of older adults (over 40 years). The specimens were in perfect condition because after extraction they were carefully cleaned, sterilized, identified and stored in water. In order to improve the cleaning, they were placed in 1% sodium hypochlorite solution for four hours and rinsed in 10 vol. hydrogen peroxide for 8 hours. After that, a clearing technique was performed to illustrate root canal anatomy. Digitalized images of all samples were obtained by use of a stereomicroscope. Canals were noticeably simpler in older adults: they were sharply defined and narrow, sometimes too narrow. Calcification nuclei were not found and there were only a few remains of internuclear spaces. The canal system appeared cleaner, clearer and more sharply defined than in the other age groups. It may be concluded that there is a correlation between aging and morphological changes in the mesial root canals of mandibular first molars.

Etiopathogenesis of Mandibulofacial and Maxillofacial Abscesses in Mice

PubMed Central

2010-01-01

The etiologic agent of mandibulofacial and maxillofacial abscesses in mice is reportedly coagulase-positive Staphylococcus aureus. Although suggested to be through the oral cavity, the exact route of entry has not been documented. Among the clinical cases of mandibulofacial and maxillofacial abscess we report here, each case that was cultured yielded coagulase-positive S. aureus. Histologically, all of the abscesses examined were directly associated with intralesional hair shafts, both vibrissae and pelage, that were introduced into the submucosa via the maxillary or mandibular molar gingival sulci. Grossly, a variable amount of hair was imbedded in the lingual, buccal, or mesial gingival sulci of the maxillary or mandibular molars or both. Computed tomography revealed that the presence of the hair resulted in inflammation and resorption of alveolar bone. With these findings, we propose that mandibulofacial and maxillofacial abscesses are induced by the mastication and fragmentation of hair ingested during the barbering process. From the resulting foreign body periodontitis, abscess formation originates at the maxillary lingual, buccal, or mesial gingival sulci, resulting in infection of the maxillary molar tooth roots with swelling or rupture through the skin inferior to the eye, or at the mandibular lingual, buccal, and or mesial gingival sulci, resulting in infection of the mandibular molar tooth roots and osteomyelitis with drainage through the skin of the ventral mandible. PMID:20579435

Event-related brain potentials in memory: correlates of episodic, semantic and implicit memory.

PubMed

Wieser, Stephan; Wieser, Heinz Gregor

2003-06-01

To study cognitive evoked potentials, recorded from scalp EEG and foramen ovale electrodes, during activation of explicit and implicit memory. The subgroups of explicit memory, episodic and semantic memory, are looked at separately. A word-learning task was used, which has been shown to activate hippocampus in H(2)(15)O positron emission tomography studies. Subjects had to study and remember word pairs using different learning strategies: (i) associative word learning (AWL), which activates the episodic memory, (ii) deep single word encoding (DSWE), which activates the semantic memory, and (iii) shallow single word encoding (SSWE), which activates the implicit memory and serves as a baseline. The test included the 'remember/know' paradigm as a behavioural learning control. During the task condition, a 10-20 scalp EEG with additional electrodes in both temporal lobes regions was recorded from 11 healthy volunteers. In one patient with mesiotemporal lobe epilepsy, the EEG was recorded from bilateral foramen ovale electrodes directly from mesial temporal lobe structures. Event-related potentials (ERPs) were calculated off-line and visual and statistical analyses were made. Associative learning strategy produced the best memory performance and the best noetic awareness experience, whereas shallow single word encoding produced the worst performance and the smallest noetic awareness. Deep single word encoding performance was in between. ERPs differed according to the test condition, during both encoding and retrieval, from both the scalp EEG and the foramen ovale electrode recordings. Encoding showed significant differences between the shallow single word encoding (SSWE), which is mainly a function of graphical characteristics, and the other two strategies, deep single word (DSWE) and associative learning (AWL), in which there is a semantic processing of the meaning. ERPs generated by these two categories, which are both functions of explicit memory, differed as well, indicating the presence or the absence of associative binding. Retrieval showed a significant test effect between the word pairs learned by association (AWL) and the ones learned by encoding the words in isolation of each other (DSWE and SSWE). The comparison of the ERPs generated by autonoetic awareness ('remember') and noetic awareness ('know') exhibited a significant test effect as well. The results of behavioural data, in particular that of the 'remember/know' procedure, are evidence that the task paradigm was efficient in activating different kinds of memory. Associative word learning generated a high degree of autonoetic awareness, which is a result of the episodic memory, whereas both kinds of single word learning generated less. AWL, DSWE and SSWE resulted in different electrophysiological correlates, both for encoding as well as retrieval, indicating that different brain structures were activated in different temporal sequence.

Root and Canal Morphology of Mandibular Molars in a Selected Iranian Population Using Cone-Beam Computed Tomography

PubMed Central

Madani, Zahra Sadat; Mehraban, Nika; Moudi, Ehsan; Bijani, Ali

2017-01-01

Introduction: The aim of this study was to evaluate the root canal morphology of mandibular first and second molars using cone-beam computed tomography (CBCT) in northern Iranian population and also to indicate the thinnest area around root canals. Methods and Materials: We evaluated CBCT images of 154 first molars and 147 second molars. By evaluating three axial, sagittal and coronal planes of each tooth we determined the number of root canals, prevalence of C-shaped Melton types, and prevalence of Vertucci configuration and inter orifice distance. Also the minimum wall thickness of root canals was determined by measuring buccal, lingual, distal and mesial wall thicknesses of each canal in levels with 2 mm intervals from apex to orifice. Results: Amongst 154 first mandibular molars, 149 (96.7%) had two roots, 3 (1.9%) had three roots and 2 (1.2%) had C-shaped root configuration. Of 147 second mandibular molars, 120 (81.6%) had two roots, 1 (0.6%) had three roots and 26 (17.6%) had C-shaped roots. There was no significant difference in the prevalence of Vertucci’s type between two genders. The most common configuration in mesial roots of first and second molars were type IV (57%-42.9%) and type II (31.5%-28%). Mesial and distal walls had the most frequency as the thinnest wall in all levels of root canals with mostly less than 1 mm thickness. In second molars the DB-DL inter orifice distance and in first molars the MB-ML distance were the minimum. MB-D in first molars had the maximum distance while ML-DL, MB-DB and ML-D had the same and maximum distance in second molars. Conclusion: Vertucci’s type IV and type I were the most prevalent configurations in mesial and distal roots of first and second mandibular molars and the thickness of thinnest area around the canals should be considered during endodontic treatments. PMID:28512476

Enamel thickness variation of deciduous first and second upper molars in modern humans and Neanderthals.

PubMed

Fornai, Cinzia; Benazzi, Stefano; Svoboda, Jiří; Pap, Ildikó; Harvati, Katerina; Weber, Gerhard W

2014-11-01

Enamel thickness and dental tissue proportions have been recognized as effective taxonomic discriminators between Neanderthal and modern humans teeth. However, most of the research on this topic focused on permanent teeth, and little information is available for the deciduous dentition. Moreover, although worn teeth are more frequently found than unworn teeth, published data for worn teeth are scarce and methods for the assessment of their enamel thickness need to be developed. Here, we addressed this issue by studying the 2D average enamel thickness (AET) and 2D relative enamel thickness (RET) of Neanderthal and modern humans unworn to moderately worn upper first deciduous molars (dm(1)s) and upper second deciduous molars (dm(2)s). In particular, we used 3D μCT data to investigate the mesial section for dm(1)s and both mesial and buccal sections for dm(2)s. Our results confirmed previous findings of an Neanderthal derived condition of thin enamel, and thinner enamel in dm(1)s than dm(2)s in both Neanderthal and modern humans. We demonstrated that the Neanderthal 2D RET indices are significantly lower than those of modern humans at similar wear stages in both dm(1)s and dm(2)s (p < 0.05). The discriminant analysis showed that using 2D RET from dm(1) and dm(2) sections at different wear stages up to 93% of the individuals are correctly classified. Moreover, we showed that the dm(2) buccal sections, although non-conventionally used, might have an advantage on mesial sections since they distinguish as well as mesial sections but tend to be less worn. Therefore, the 2D analysis of enamel thickness is suggested as a means for taxonomic discrimination between modern humans and Neanderthal unworn to moderately worn upper deciduous molars. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Effect of the vacuum-formed retainer on preventing the proximal contact loss between implant supported crown and adjacent natural teeth].

PubMed

Zeng, B J; Guo, Y; Yu, R Y

2018-06-18

To evaluate the effect of the vacuum-formed retainer on preventing the proximal contact loss between the implant supported crown and its adjacent natural teeth. Forty-six posterior implant crowns in the mandible including 92 interproximal contacts in 46 patients (19 men, 27 women) aged from 25 to 66 years were included. The participants in experimental group (22 cases) were vacuum-formed retainers at night, while participants in control group (24 cases) only received routine examination. The two groups were not different in age, gender, the time interval of the tooth loss and tooth position at baseline. Mesial and distal proximal contact tightness was measured using the orthodontic dynamometer and metallic articulating film immediately after crown delivery, and 1-month, 3-month, 6-month, and 1-year follow-up respectively. The articulating film was inserted interdentally from the occlusal direction, and then it was slowly removed in the buccallingual direction by the dynamometer. Increasing the number of films (N) piece by piece until the frictional force (F) was great than 0, and the number of films (N) was recorded. At each follow-up, proximal contact between implant crown and its adjacent teeth was considered to be loss if the number of films (N) used at immediate crown delivery passed without frictional force (F=0). Besides, the periodontal conditions [scored according to the probing depth (PD), bleeding index (BI), mobility (M)] and complaint of food impaction were recorded. The mesial and distal proximal contact loss rates were compared between the two groups at different times. Chi-square test or Fisher's exact test was used for statistical analysis. The proximal contact loss rate on the mesial surface of the implant supported crown continuously increased over the follow-up periods. At the end of the 1-, 3-, and 6-month follow ups, 18.2%, 22.7% and 27.3% were identified for the contact loss rates on the mesial surface of the implant supported crown in the experimental group, respectively. Meanwhile in control group, the rates were 20.8%, 37.5% and 45.8%. No significant differences were observed at the end of the 1-, 3-, and 6-month follow ups(1-month: χ 2 =0.000, P=1.000; 3-month: χ 2 =1.183, P=0.277; 6-month: χ 2 =1.697, P=0.193). The proximal contact loss rate on the mesial surface in control group (62.5%) was significantly higher than that in the experimental group (31.8%, χ 2 =4.330, P=0.037) at the end of the 1-year follow-up. However, no statistical difference was found on the distal surfaces between the two groups during the whole follow-up periods. The first open contact was noted 1 month after crown insertion. By wearing vacuum-formed retainer for one year, the incidence of open contacts between the posterior implant prostheses and mesial adjacent teeth in the mandible has been reduced.

Marginal bone levels at single tooth implants with a conical fixture design. The influence of surface macro- and microstructure.

PubMed

Norton, M R

1998-04-01

The concept of a conical implant design to accommodate single tooth replacement, has previously been shown to result in excessive bone loss, around the machined titanium conical collar, usually down to the 1st thread. This unusually aggressive loss of bone was shown to occur within a short period of time, post loading, with greater than 3 mm of bone loss occurring within the 1st 6 months to 1 year. The influence of implant design, surface texture and microleakage have all been highlighted as a potential cause. A modification of the surface structure, both at the macroscopic and microscopic level, as well as an altered fixture-abutment interface design has resulted in the maintenance of marginal bone around a single tooth titanium implant with a similar conical design. The radiographic follow-up of 33 implants loaded for up to 4 years, has revealed, by comparison, a most favourable maintenance of marginal bone around the conical collar, with a mean marginal bone loss of 0.32 mm mesially and 0.34 mm distally for the whole group. The cumulative mean marginal bone loss mesially and distally is 0.42 mm and 0.40 mm from 1 to 2 years, 0.54 mm and 0.43 mm from 2 to 3 years, 0.51 mm and 0.24 mm from 3 to 4 years, and 0.62 mm and 0.60 mm for implants past their 4 year recall.

Comparative evaluation of effect of rotary and reciprocating single-file systems on pericervical dentin: A cone-beam computed tomography study.

PubMed

Zinge, Priyanka Ramdas; Patil, Jayaprakash

2017-01-01

The aim of this study is to evaluate and compare the effect of one shape, Neolix rotary single-file systems and WaveOne, Reciproc reciprocating single-file systems on pericervical dentin (PCD) using cone-beam computed tomography (CBCT). A total of 40 freshly extracted mandibular premolars were collected and divided into two groups, namely, Group A - Rotary: A 1 - Neolix and A 2 - OneShape and Group B - Reciprocating: B 1 - WaveOne and B 2 - Reciproc. Preoperative scans of each were taken followed by conventional access cavity preparation and working length determination with 10-k file. Instrumentation of the canal was done according to the respective file system, and postinstrumentation CBCT scans of teeth were obtained. 90 μm thick slices were obtained 4 mm apical and coronal to the cementoenamel junction. The PCD thickness was calculated as the shortest distance from the canal outline to the closest adjacent root surface, which was measured in four surfaces, i.e., facial, lingual, mesial, and distal for all the groups in the two obtained scans. There was no significant difference found between rotary single-file systems and reciprocating single-file systems in their effect on PCD, but in Group B 2 , there was most significant loss of tooth structure in the mesial, lingual, and distal surface ( P < 0.05). Reciproc single-file system removes more PCD as compared to other experimental groups, whereas Neolix single file system had the least effect on PCD.

Realistic simulated MRI and SPECT databases. Application to SPECT/MRI registration evaluation.

PubMed

Aubert-Broche, Berengere; Grova, Christophe; Reilhac, Anthonin; Evans, Alan C; Collins, D Louis

2006-01-01

This paper describes the construction of simulated SPECT and MRI databases that account for realistic anatomical and functional variability. The data is used as a gold-standard to evaluate four SPECT/MRI similarity-based registration methods. Simulation realism was accounted for using accurate physical models of data generation and acquisition. MRI and SPECT simulations were generated from three subjects to take into account inter-subject anatomical variability. Functional SPECT data were computed from six functional models of brain perfusion. Previous models of normal perfusion and ictal perfusion observed in Mesial Temporal Lobe Epilepsy (MTLE) were considered to generate functional variability. We studied the impact noise and intensity non-uniformity in MRI simulations and SPECT scatter correction may have on registration accuracy. We quantified the amount of registration error caused by anatomical and functional variability. Registration involving ictal data was less accurate than registration involving normal data. MR intensity nonuniformity was the main factor decreasing registration accuracy. The proposed simulated database is promising to evaluate many functional neuroimaging methods, involving MRI and SPECT data.

Severe anterograde amnesia with onset in childhood as a result of anoxic encephalopathy.

PubMed

Broman, M; Rose, A L; Hotson, G; Casey, C M

1997-03-01

Our patient (M.S.) had an abrupt onset of amnesia due to a respiratory arrest at the age of 8 years and has been followed by one of us (A.L.R.) for 19 years. A specially designed MRI study indicated that the neuroanatomical localization of his lesion is restricted to the hippocampal formation bilaterally. Comparison of M.S.'s present IQ and academic scores with earlier scores revealed that his literacy skills, certain basic language functions and vocabulary development were arrested by his memory disorder. In contrast, development of mathematical skill was less curtailed, and verbal and nonverbal logical abilities developed to adult levels. Neuropsychological examination at the age of 27 years elicited a pattern of memory deficits similar to those found in a case (H.M.) of known mesial temporal lobe damage in adulthood. The neuropsychological pattern revealed those aspects of cognitive development that do, and those that do not, require intact memory. The limitations to intellectual development imposed by severe amnesia in childhood are not pervasive, but rather, are limited to specific types of abilities.

Hippocampal volumetry: Normative data in the Indian population.

PubMed

Mohandas, Aravind Narayan; Bharath, Rose Dawn; Prathyusha, Parthipulli Vasuki; Gupta, Arun K

2014-07-01

Mesial temporal sclerosis (MTS) is the most common cause of temporal lobe epilepsy. Quantitative analysis of the hippocampus using volumetry is commonly being used in the diagnosis of MTS and is being used as a marker in prognostication of seizure control. Although normative data for hippocampal volume (HV) is available for the western population, no such data is available for the Indian population. The aim of the study was to establish normative data for HV for the Indian population, which can aid in the accurate diagnosis of MTS. Magnetic resonance imaging (MRI) scans of 200 healthy volunteers were acquired using a 3 Tesla (3T) MRI scanner. Manual segmentation and volumetry was done using Siemens Syngo software. The data was analyzed using two tailed t-test to detect associations between HV and age, gender, and education. The data so obtained was also correlated with the data available from the rest of the world. A mean HV of 2.411 cm(3) (standard deviation -0.299) was found in the study, which was significantly smaller when compared to the data from the western population. The right hippocampus was larger than the left, with a mean volume of 2.424 cm(3) and 2.398 cm(3), respectively. HV was detected to be significantly higher in males. No association was found between HV and age and education. The values obtained in this study may be adopted as a standard in the evaluation of patients with intractable epilepsy.

The Reliability of Panoramic Radiography Versus Cone Beam Computed Tomography when Evaluating the Distance to the Alveolar Nerve in the Site of Lateral Teeth.

PubMed

Česaitienė, Gabrielė; Česaitis, Kęstutis; Junevičius, Jonas; Venskutonis, Tadas

2017-07-04

BACKGROUND The aim of this study was to compare the reliability of panoramic radiography (PR) and cone beam computed tomography (CBCT) in the evaluation of the distance of the roots of lateral teeth to the inferior alveolar nerve canal (IANC). MATERIAL AND METHODS 100 PR and 100 CBCT images that met the selection criteria were selected from the database. In PR images, the distances were measured using an electronic caliper with 0.01 mm accuracy and white light x-ray film reviewer. Actual values of the measurements were calculated taking into consideration the magnification used in PR images (130%). Measurements on CBCT images were performed using i-CAT Vision software. Statistical data analysis was performed using R software and applying Welch's t-test and the Wilcoxon test. RESULTS There was no statistically significant difference in the mean distance from the root of the second premolar and the mesial and distal roots of the first molar to the IANC between PR and CBCT images. The difference in the mean distance from the mesial and distal roots of the second and the third molars to the IANC measured in PR and CBCT images was statistically significant. CONCLUSIONS PR may be uninformative or misleading when measuring the distance from the mesial and distal roots of the second and the third molars to the IANC.

The Reliability of Panoramic Radiography Versus Cone Beam Computed Tomography when Evaluating the Distance to the Alveolar Nerve in the Site of Lateral Teeth

PubMed Central

Česaitienė, Gabrielė; Česaitis, Kęstutis; Junevičius, Jonas; Venskutonis, Tadas

2017-01-01

Background The aim of this study was to compare the reliability of panoramic radiography (PR) and cone beam computed tomography (CBCT) in the evaluation of the distance of the roots of lateral teeth to the inferior alveolar nerve canal (IANC). Material/Methods 100 PR and 100 CBCT images that met the selection criteria were selected from the database. In PR images, the distances were measured using an electronic caliper with 0.01 mm accuracy and white light x-ray film reviewer. Actual values of the measurements were calculated taking into consideration the magnification used in PR images (130%). Measurements on CBCT images were performed using i-CAT Vision software. Statistical data analysis was performed using R software and applying Welch’s t-test and the Wilcoxon test. Results There was no statistically significant difference in the mean distance from the root of the second premolar and the mesial and distal roots of the first molar to the IANC between PR and CBCT images. The difference in the mean distance from the mesial and distal roots of the second and the third molars to the IANC measured in PR and CBCT images was statistically significant. Conclusions PR may be uninformative or misleading when measuring the distance from the mesial and distal roots of the second and the third molars to the IANC. PMID:28674379

Distribution of sup 3 H-proline within transseptal fibers of the rat following release of orthodontic forces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Row, K.L.; Johnson, R.B.

1990-10-01

Maxillary right first molar teeth of rats were tipped mesially with an orthodontic appliance for 2 weeks (experimental group), {sup 3}H-proline was injected, and orthodontic forces were removed 6 hr later (time 0). The contralateral molar teeth of treated (internal control group) and age- and weight-matched untreated animals (external control group) were also studied. Diastemata were created between the molar teeth by the orthodontic appliance, and transseptal fibers between first and second (P less than 0.001) and second and third molars (P less than 0.005) were significantly lengthened as compared to external and internal controls at time 0. Diastemata betweenmore » molar teeth were closed 5 days after removal of orthodontic force. Transseptal fibers adjacent to the source of the orthodontic force (mesial region) had the highest mean number of {sup 3}H-proline-labeled proteins at time 0 and at all times following removal of the force (P less than 0.001), and had the highest rate of labeled protein removal (P less than 0.001). Half-lives for removal of 3H-proline-labeled transseptal fiber proteins were significantly greater in mesial and distal regions and significantly less in middle regions of experimentals than in corresponding regions of external controls (P less than 0.001).« less

The Synergistic Effect of Leukocyte Platelet-Rich Fibrin and Micrometer/Nanometer Surface Texturing on Bone Healing around Immediately Placed Implants: An Experimental Study in Dogs

PubMed Central

Neiva, Rodrigo F.; Gil, Luiz Fernando; Tovar, Nick; Janal, Malvin N.; Marao, Heloisa Fonseca; Pinto, Nelson; Coelho, Paulo G.

2016-01-01

Aims. This study evaluated the effects of L-PRF presence and implant surface texture on bone healing around immediately placed implants. Methods. The first mandibular molars of 8 beagle dogs were bilaterally extracted, and implants (Blossom™, Intra-Lock International, Boca Raton, FL) were placed in the mesial or distal extraction sockets in an interpolated fashion per animal. Two implant surfaces were distributed per sockets: (1) dual acid-etched (DAE, micrometer scale textured) and (2) micrometer/nanometer scale textured (Ossean™ surface). L-PRF (Intraspin system, Intra-Lock International) was placed in a split-mouth design to fill the macrogap between implant and socket walls on one side of the mandible. The contralateral side received implants without L-PRF. A mixed-model ANOVA (at α = 0.05) evaluated the effect of implant surface, presence of L-PRF, and socket position (mesial or distal), individually or in combination on bone area fraction occupancy (BAFO). Results. BAFO values were significantly higher for the Ossean relative to the DAE surface on the larger mesial socket. The presence of L-PRF resulted in higher BAFO. The Ossean surface and L-PRF presence resulted in significantly higher BAFO. Conclusion. L-PRF and the micro-/nanometer scale textured surface resulted in increased bone formation around immediately placed implants. PMID:28042577

Effects of unilateral molar distalization with a modified pendulum appliance.

PubMed

Schütze, Stefan F; Gedrange, Tomas; Zellmann, Markus R; Harzer, Winfried

2007-05-01

The purpose of this study was to evaluate skeletal and dentoalveolar changes due to unilateral distalization and to determine side effects. Cephalograms and dental casts before and after distal movement of the maxillary molars with pendulum appliances in 15 consecutively treated patients (5 girls and 10 boys, 12.06 +/- 1.32 years), were included in this study. The duration of distalization was 8.46 +/- 2.23 months. Cephalometric analysis showed no remarkable growth between the 2 measurement times. The mean value for distalization of the first molars was 3.83 +/- 1.09 mm, with distal tipping of 6.45 degrees . The maxillary second molars were also moved distally 2.83 +/- 1.32 mm and tipped distally 14.7 degrees . No significant changes in the position of the third molars were measured. The mean reciprocal mesial movement of the premolars was 1.18 +/- 1.31 mm, with distal tipping of 1.94 degrees . The incisors moved 0.84 +/- 0.79 mm mesially, with mesial tipping of 0.02 degrees and extrusion of 1.21 mm. There was also a significant influence on the contralateral anchorage unit. However, unilateral distalization reduced incisor proclination and induced moderate distal movement of the contralateral anchorage unit based on rotation around a virtual axis perpendicular to the Nance button. Effective distal molar movement and less anchorage loss at the front teeth are advantages of unilateral distalization.

Effects of diabetes on tooth movement and root resorption after orthodontic force application in rats.

PubMed

Arita, K; Hotokezaka, H; Hashimoto, M; Nakano-Tajima, T; Kurohama, T; Kondo, T; Darendeliler, M A; Yoshida, N

2016-05-01

To investigate the effects of diabetes on orthodontic tooth movement and orthodontically induced root resorption in rats. Twenty-three 10-week-old male Sprague-Dawley rats divided into control (n = 7), diabetes (n = 9), and diabetes + insulin (n = 7) groups. Diabetes was induced by administering a single intraperitoneal injection of streptozotocin. Rats with a blood glucose level exceeding 250 mg/dl were assigned to the diabetes group. Insulin was administered daily to the diabetes + insulin group. A nickel-titanium closed-coil spring of 10 g was applied for 2 weeks to the maxillary left first molar in all rats to induce mesial tooth movement. Tooth movement was measured using microcomputed tomography images. To determine the quantity of root resorption, the mesial surfaces of the mesial and distal roots of the first molar were analyzed using both scanning electron microscopy and scanning laser microscopy. After 2 weeks, the amount of tooth movement in the diabetic rats was lower than that in the control rats. Root resorption was also significantly lower in the diabetic rats. These responses of the rats caused by diabetes were mostly diminished by insulin administration. Diabetes significantly reduced orthodontic tooth movement and orthodontically induced root resorption in rats. The regulation of blood glucose level through insulin administration largely reduced these abnormal responses to orthodontic force application. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Canal Transportation, Unprepared Areas, and Dentin Removal after Preparation with BT-RaCe and ProTaper Next Systems.

PubMed

Brasil, Sabrina C; Marceliano-Alves, Marília F; Marques, Márcia L; Grillo, João P; Lacerda, Mariane F L S; Alves, Flávio R F; Siqueira, José F; Provenzano, José C

2017-10-01

This study compared the shaping ability of ProTaper Next (Dentsply Sirona, Tulsa, OK) and BT-RaCe (FKG Dentaire, La Chaux-de-Fonds, Switzerland) instrument systems in the mesial canals of mandibular molars using micro-computed tomographic (micro-CT) imaging. A total of 17 type IV mesial roots of extracted first mandibular molars were scanned using micro-CT imaging before and after root canal preparation with the 2 instrument systems. Both systems were used in the same root but alternating the mesial canals from root to root. The following parameters were analyzed: root canal volume, surface area, unprepared surface areas, transportation, canal/root width ratio, and preparation time. There were no statistically significant differences between the 2 systems for all evaluated parameters (P > .05). The unprepared surface areas for the full canal length and the apical 5-mm segment were 33% and 14% for BT-RaCe and 31% and 14% for ProTaper Next, respectively. After preparation, all root canals had a diameter that was not larger than 35% of the root diameter at the coronal and middle segments. The 2 systems showed no differences in any of the evaluated shaping parameters. None of the tested systems put the roots at risk of fracture because of excessive dentin removal. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Selective deficit of spatial short-term memory: Role of storage and rehearsal mechanisms.

PubMed

Bonnì, Sonia; Perri, Roberta; Fadda, Lucia; Tomaiuolo, Francesco; Koch, Giacomo; Caltagirone, Carlo; Carlesimo, Giovanni Augusto

2014-10-01

We report the neuropsychological and MRI investigation of a patient (GP) who developed a selective impairment of spatial short-term memory (STM) following damage to the dorso-mesial areas of the right frontal lobe. We assessed in this patient spatial STM with an experimental procedure that evaluated immediate and 5-20 s delayed recall of verbal, visual and spatial stimuli. The patient scored significantly worse than normal controls on tests that required delayed recall of spatial data. This could not be ascribed to a deficit of spatial episodic long-term memory because amnesic patients performed normally on these tests. Conversely, the patient scored in the normal range on tests of immediate recall of verbal, visual and spatial data and tests of delayed recall of verbal and visual data. Comparison with a previously described patient who had a selective deficit in immediate spatial recall and an ischemic lesion that affected frontal and parietal dorso-mesial areas in the right hemisphere (Carlesimo GA, Perri R, Turriziani P, Tomaiuolo F, Caltagirone C. Remembering what but not where: independence of spatial and visual working memory in the human brain. Cortex. 2001 Sep; 37(4):519-34) suggests that the right parietal areas are involved in the short-term storage of spatial information and that the dorso-mesial regions of the right frontal underlie mechanisms for the delayed maintenance of the same data.

Where is your shoulder? Neural correlates of localizing others' body parts.

PubMed

Felician, Olivier; Anton, Jean-Luc; Nazarian, Bruno; Roth, Muriel; Roll, Jean-Pierre; Romaiguère, Patricia

2009-07-01

Neuropsychological studies, based on pointing to body parts paradigms, suggest that left posterior parietal lobe is involved in the visual processing of other persons' bodies. In addition, some patients have been found with mild deficit when dealing with abstract human representations but marked impairment with realistically represented bodies, suggesting that this processing could be modulated by the abstraction level of the body to be analyzed. These issues were examined in the present fMRI experiment, designed to evaluate the effects of visually processing human bodies of different abstraction levels on brain activity. The human specificity of the studied processes was assessed using whole-body representations of humans and of dogs, while the effects of the abstraction level of the representation were assessed using drawings, photographs, and videos. To assess the effect of species and stimulus complexity on BOLD signal, we performed a two-way ANOVA with factors species (human versus animal) and stimulus complexity (drawings, photographs and videos). When pointing to body parts irrespective of the stimulus complexity, we observed a positive effect of humans upon animals in the left angular gyrus (BA 39), as suggested by lesion studies. This effect was also present in midline cortical structures including mesial prefrontal, anterior cingulate and precuneal regions. When pointing to body parts irrespective of the species to be processed, we observed a positive effect of videos upon photographs and drawings in the right superior parietal lobule (BA 7), and bilaterally in the superior temporal sulcus, the supramarginal gyrus (BA 40) and the lateral extrastriate visual cortex (including the "extrastriate body area"). Taken together, these data suggest that, in comparison with other mammalians, the visual processing of other humans' bodies is associated with left angular gyrus activity, but also with midline structures commonly implicated in self-reference. They also suggest a role of the lateral extrastriate cortex in the processing of dynamic and biologically relevant body representations.

The use of hippocampal volumetric measurements to improve diagnostic accuracy in pediatric patients with mesial temporal sclerosis.

PubMed

Guzmán Pérez-Carrillo, Gloria J; Owen, Christopher; Schwetye, Katherine E; McFarlane, Spencer; Vellimana, Ananth K; Mar, Soe; Miller-Thomas, Michelle M; Shimony, Joshua S; Smyth, Matthew D; Benzinger, Tammie L S

2017-06-01

OBJECTIVE Many patients with medically intractable epilepsy have mesial temporal sclerosis (MTS), which significantly affects their quality of life. The surgical excision of MTS lesions can result in marked improvement or even complete resolution of the epileptic episodes. Reliable radiological diagnosis of MTS is a clinical challenge. The purpose of this study was to evaluate the utility of volumetric mapping of the hippocampi for the identification of MTS in a case-controlled series of pediatric patients who underwent resection for medically refractory epilepsy, using pathology as a gold standard. METHODS A cohort of 57 pediatric patients who underwent resection for medically intractable epilepsy between 2005 and 2015 was evaluated. On pathological investigation, this group included 24 patients with MTS and 33 patients with non-MTS findings. Retrospective quantitative volumetric measurements of the hippocampi were acquired for 37 of these 57 patients. Two neuroradiologists with more than 10 years of experience who were blinded to the patients' MTS status performed the retrospective review of MR images. To produce the volumetric data, MR scans were parcellated and segmented using the FreeSurfer software suite. Hippocampal regions of interest were compared against an age-weighted local regression curve generated with data from the pediatric normal cohort. Standard deviations and percentiles of specific subjects were calculated. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were determined for the original clinical read and the expert readers. Receiver operating characteristic curves were generated for the methods of classification to compare results from the readers with the authors' results, and an optimal threshold was determined. From that threshold the sensitivity, specificity, PPV, and NPV were calculated for the volumetric analysis. RESULTS With the use of quantitative volumetry, a sensitivity of 72%, a specificity of 95%, a PPV of 93%, an NPV of 78%, and an area under the curve of 0.84 were obtained using a percentage difference of normalized hippocampal volume. The resulting specificity (95%) and PPV (93%) are superior to the original clinical read and to Reader A and Reader B's findings (range for specificity 74%-86% and for PPV 64%-71%). The sensitivity (72%) and NPV (78%) are comparable to Reader A's findings (73% and 81%, respectively) and are better than those of the original clinical read and of Reader B (sensitivity 45% and 63% and NPV 71% and 70%, respectively). CONCLUSIONS Volumetric measurement of the hippocampi outperforms expert readers in specificity and PPV, and it demonstrates comparable to superior sensitivity and NPV. Volumetric measurements can complement anatomical imaging for the identification of MTS, much like a computer-aided detection tool would. The implementation of this approach in the daily clinical workflow could significantly improve diagnostic accuracy.

Structural brain abnormalities in the common epilepsies assessed in a worldwide ENIGMA study

PubMed Central

Altmann, Andre; Botía, Juan A; Jahanshad, Neda; Hibar, Derrek P; Absil, Julie; Alhusaini, Saud; Alvim, Marina K M; Auvinen, Pia; Bartolini, Emanuele; Bergo, Felipe P G; Bernardes, Tauana; Blackmon, Karen; Braga, Barbara; Caligiuri, Maria Eugenia; Calvo, Anna; Carr, Sarah J; Chen, Jian; Chen, Shuai; Cherubini, Andrea; David, Philippe; Domin, Martin; Foley, Sonya; França, Wendy; Haaker, Gerrit; Isaev, Dmitry; Keller, Simon S; Kotikalapudi, Raviteja; Kowalczyk, Magdalena A; Kuzniecky, Ruben; Langner, Soenke; Lenge, Matteo; Leyden, Kelly M; Liu, Min; Loi, Richard Q; Martin, Pascal; Mascalchi, Mario; Morita, Marcia E; Pariente, Jose C; Rodríguez-Cruces, Raul; Rummel, Christian; Saavalainen, Taavi; Semmelroch, Mira K; Severino, Mariasavina; Thomas, Rhys H; Tondelli, Manuela; Tortora, Domenico; Vaudano, Anna Elisabetta; Vivash, Lucy; von Podewils, Felix; Wagner, Jan; Weber, Bernd; Yao, Yi; Yasuda, Clarissa L; Zhang, Guohao; Bargalló, Nuria; Bender, Benjamin; Bernasconi, Neda; Bernasconi, Andrea; Bernhardt, Boris C; Blümcke, Ingmar; Carlson, Chad; Cavalleri, Gianpiero L; Cendes, Fernando; Concha, Luis; Delanty, Norman; Depondt, Chantal; Devinsky, Orrin; Doherty, Colin P; Focke, Niels K; Gambardella, Antonio; Guerrini, Renzo; Hamandi, Khalid; Jackson, Graeme D; Kälviäinen, Reetta; Kochunov, Peter; Kwan, Patrick; Labate, Angelo; McDonald, Carrie R; Meletti, Stefano; O'Brien, Terence J; Ourselin, Sebastien; Richardson, Mark P; Striano, Pasquale; Thesen, Thomas; Wiest, Roland; Zhang, Junsong; Vezzani, Annamaria; Ryten, Mina; Thompson, Paul M

2018-01-01

Abstract Progressive functional decline in the epilepsies is largely unexplained. We formed the ENIGMA-Epilepsy consortium to understand factors that influence brain measures in epilepsy, pooling data from 24 research centres in 14 countries across Europe, North and South America, Asia, and Australia. Structural brain measures were extracted from MRI brain scans across 2149 individuals with epilepsy, divided into four epilepsy subgroups including idiopathic generalized epilepsies (n =367), mesial temporal lobe epilepsies with hippocampal sclerosis (MTLE; left, n = 415; right, n = 339), and all other epilepsies in aggregate (n = 1026), and compared to 1727 matched healthy controls. We ranked brain structures in order of greatest differences between patients and controls, by meta-analysing effect sizes across 16 subcortical and 68 cortical brain regions. We also tested effects of duration of disease, age at onset, and age-by-diagnosis interactions on structural measures. We observed widespread patterns of altered subcortical volume and reduced cortical grey matter thickness. Compared to controls, all epilepsy groups showed lower volume in the right thalamus (Cohen’s d = −0.24 to −0.73; P < 1.49 × 10−4), and lower thickness in the precentral gyri bilaterally (d = −0.34 to −0.52; P < 4.31 × 10−6). Both MTLE subgroups showed profound volume reduction in the ipsilateral hippocampus (d = −1.73 to −1.91, P < 1.4 × 10−19), and lower thickness in extrahippocampal cortical regions, including the precentral and paracentral gyri, compared to controls (d = −0.36 to −0.52; P < 1.49 × 10−4). Thickness differences of the ipsilateral temporopolar, parahippocampal, entorhinal, and fusiform gyri, contralateral pars triangularis, and bilateral precuneus, superior frontal and caudal middle frontal gyri were observed in left, but not right, MTLE (d = −0.29 to −0.54; P < 1.49 × 10−4). Contrastingly, thickness differences of the ipsilateral pars opercularis, and contralateral transverse temporal gyrus, were observed in right, but not left, MTLE (d = −0.27 to −0.51; P < 1.49 × 10−4). Lower subcortical volume and cortical thickness associated with a longer duration of epilepsy in the all-epilepsies, all-other-epilepsies, and right MTLE groups (beta, b < −0.0018; P < 1.49 × 10−4). In the largest neuroimaging study of epilepsy to date, we provide information on the common epilepsies that could not be realistically acquired in any other way. Our study provides a robust ranking of brain measures that can be further targeted for study in genetic and neuropathological studies. This worldwide initiative identifies patterns of shared grey matter reduction across epilepsy syndromes, and distinctive abnormalities between epilepsy syndromes, which inform our understanding of epilepsy as a network disorder, and indicate that certain epilepsy syndromes involve more widespread structural compromise than previously assumed. PMID:29365066

Endodontic management of permanent mandibular molars with 6 root canals: report of 3 cases.

PubMed

Malhotra, Amit; Ahlawat, Jyoti; Bansal, Chirag; Tahiliani, Divya

2016-01-01

Aberrations in the internal dental anatomy present challenges for clinicians performing endodontic therapy. These challenges have been partly resolved in recent years by a more comprehensive knowledge of root canal anatomy as well as advancements in the endodontic armamentarium. The aim of this case series is to describe successful root canal treatment, under magnification, in 3 cases of mandibular first molars with 6 root canals. Two of these teeth had 2 roots (mesial and distal) with 3 canals in each root; the third tooth had 3 root canals located mesially and 3 present distally as well as a radix entomolaris. A distal root with 3 canals is rare; however, it is important to look for such anatomical variations to ensure successful endodontic therapy.

Four canals in the mesial root of a mandibular first molar. A case report under the operating microscope.

PubMed

Kontakiotis, Evangelos G; Tzanetakis, Giorgos N

2007-08-01

In this era of microscope-assisted endodontics, finding variations in root canal system anatomy is not uncommon. Operating microscopes combined with careful clinical examination and radiographic interpretation can aid the clinician to successfully treat cases with such internal anatomy. The understanding of this view enables the possible location of additional canals in any tooth requiring endodontic treatment. The present clinical article demonstrates a rare anatomical complexity in the mesial root of a mandibular first molar. Four independent root canal orifices were found in this root by clinical detection with the aid of a dental operating microscope. This case shows that additional canals can be located in any root undergoing endodontic treatment and clinicians should always be aware of aberrant internal anatomy.

Adaptation and micro-structure of Co-Cr alloy maxillary complete denture base plates fabricated by selective laser melting technique.

PubMed

Ye, Ye; Jiao, Ting; Zhu, Jiarui; Sun, Jian

2018-01-24

The purpose of the study was to evaluate the adaptation and micro-structure of Co-Cr alloy maxillary complete denture base plates fabricated by the selective laser melting (SLM) technique. Twenty pairs of edentulous casts were randomly and evenly divided into two groups, and manufacturing of the Co-Cr alloy maxillary complete denture base was conducted either by the SLM technique or by the conventional method. The base-cast sets were transversally sectioned into three sections at the distal canines, mesial of the first molars and the posterior palatal zone. The gap between the metal base and cast was measured in these three sections with a stereoscopic microscope, and the data were analysed using t tests. A total of five specimens of 5 mm diameter were fabricated with the Co-Cr alloy by SLM and the traditional casting technology. A scanning electron microscope (SEM) was used to evaluate the differences in microstructure between these specimens. There was no statistical difference between the three sections in all four groups (P > 0.05). At the region of the canines, the clearance value for the SLM Co-Cr alloy group was larger than that of the conventional method group (P < 0.05). At the mesial of the first molar region and the posterior palatal zone, there was no statistical difference between the gaps observed in the two groups (P > 0.05). The SLM Co-Cr alloy has a denser microstructure behaviour and less casting defect than the cast Co-Cr alloy. The SLM technique showed initial feasibility for the manufacture of dental bases of complete dentures, but large sample studies are needed to prove its reliability in clinical applications. The mechanical properties and microstructure of the denture frameworks prepared by selective laser melting indicate that these dentures are appropriate for clinical use.

Interaction of the Left Dorsolateral Prefrontal Cortex (l-DLPFC) and Right Orbitofrontal Cortex (OFC) in Hot and Cold Executive Functions: Evidence from Transcranial Direct Current Stimulation (tDCS).

PubMed

Nejati, Vahid; Salehinejad, Mohammad Ali; Nitsche, Michael A

2018-01-15

An organizing principle which has recently emerged proposes that executive functions (EF) can be divided into cognitive (cold) and affective/reward-related (hot) processes related to the dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC) respectively. A controversial question is whether cold and hot EF are functionally and structurally independent or not. This study investigated how the left DLPFC (l-DLPFC) and right OFC (r-OFC) interact in hot and cold EF using transcranial direct current stimulation (tDCS). Twenty-four healthy male subjects received anodal, cathodal and sham tDCS (20 min, 1.5 mA) over the l-DLPFC (F3) and r-OFC (Fp2) with a 72-h interval between each stimulation condition. After five minutes of stimulation, participants underwent a series of cold and hot EF tasks including the Go/No-Go and Tower of Hanoi (TOH) as measures of cold EF and the BART and temporal discounting tasks as measures of hot EF. Inhibitory control mostly benefited from anodal l-DLPFC/cathodal r-OFC tDCS. Planning and problem solving were more prominently affected by anodal l-DLPFC/cathodal r-OFC stimulation, although the reversed electrode position with the anode positioned over the r-OFC also affected some aspects of task performance. Risk-taking behavior and risky decision-making decreased under both anodal l-DLPFC/cathodal r-OFC and anodal r-OFC/cathodal l-DLPFC tDCS. Cold EF rely on DLPFC activation while hot EF rely on both, DLPFC and OFC activation. Results suggest that EF are placed on continuum with lateral and mesial prefrontal areas contributing to cold and hot aspects respectively. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Verbal memory decline from hippocampal depth electrodes in temporal lobe surgery for epilepsy.

PubMed

Ljung, Hanna; Nordlund, Arto; Strandberg, Maria; Bengzon, Johan; Källén, Kristina

2017-12-01

To explore whether patients with refractory mesial temporal lobe epilepsy risk aggravated verbal memory loss from intracranial electroencephalography (EEG) recording with longitudinal hippocampal electrodes in the language-dominant hemisphere. A long-term neuropsychological follow-up (mean 61.5 months, range 22-111 months) was performed in 40 patients after ictal registration with left hippocampal depth electrodes (study group, n = 16) or no invasive EEG, only extracranial registration (reference group, n = 24). The groups were equal with respect to education, age at seizure onset, epilepsy duration, and prevalence of pharmacoresistant temporal lobe epilepsy (TLE; 75%) versus seizure freedom (25%). Retrospective neuropsychological data from preoperative surgical workup (T1) and prospective follow-up neuropsychological data (T2) were compared. A ≥1 SD intrapatient decline was considered as clinically relevant deterioration of verbal memory. Significant decline in verbal memory was seen in 56% of the patients in the study group compared to 21% in the reference group. At T1, there were no statistical between-group differences in memory performance. At T2, between-group comparison showed significantly greater verbal memory decline for the study group (Claeson Dahl Learning and Retention Test, Verbal Learning: p = 0.05; Rey Auditory Verbal Learning Test, Total Learning: p = 0.04; Claeson Dahl Learning and Retention Test, Verbal Retention: p = 0.04). An odds ratio (OR) of 7.1 (90% confidence interval [CI] 1.3-37.7) for verbal memory decline was seen if right temporal lobe resection (R TLR) had been performed between T1 and T2. The difference between groups remained unchanged when patients who had undergone R TLR were excluded from the analysis, with a remaining aggravated significant decline in verbal memory performance for the study group compared to the reference group. Our results suggest a risk of verbal memory deterioration after the use of depth electrodes along the longitudinal axis of the hippocampus. Until this issue is further investigated, caution regarding depth electrodes in the language-dominant hemisphere hippocampus seems advisable. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

Risk to verbal memory following anterior temporal lobectomy in patients with severe left-sided hippocampal sclerosis.

PubMed

Martin, Roy C; Kretzmer, Tracy; Palmer, Cheryl; Sawrie, Stephen; Knowlton, Robert; Faught, Edward; Morawetz, Richard; Kuzniecky, Ruben

2002-12-01

Previous investigations indicate low risk for memory loss following anterior temporal lobectomy (ATL) in patients with severe hippocampal sclerosis (HS) compared with patients with mild HS. However, these conclusions have been established primarily with group-level analyses. To investigate individual base rate risk for verbal memory loss following ATL in patients who have pathologically verified mild, moderate, or severe HS. One hundred fifteen patients with unilateral temporal lobe epilepsy (68 with left-sided and 47 with right-sided epilepsy) were included. Acquisition, retrieval, and recognition components of verbal memory, as measured by the California Verbal Learning Test, were assessed before and after ATL. Postoperatively, the degree of neuronal loss and reactive gliosis of the hippocampus was assessed via a 3-tiered rating system establishing mild, moderate, and severe pathologic features. Patients with preoperative magnetic resonance imaging-based evidence of lesions outside the mesial temporal area (side of surgical resection) were excluded. Neither seizure laterality nor severity of HS was associated with preoperative verbal memory performance. Postoperatively, the left-sided ATL group demonstrated significant decline across the acquisition (P<.01), retrival (P<.001), and recognition (P<.001) verbal memory components compared with the right-sided ATL group. Patients who underwent left-sided ATL and had mild HS displayed the largest magnitude and percentage proportion of postoperative decline across all verbal memory components. However, 28 (48%) of the 58 patients who underwent left-sided ATL and who had moderate and severe HS displayed statistically reliable declines on retrieval aspects of verbal memory. Most patients undergoing right-sided ATL, regardless of the extent of hippocampal pathologic features, displayed no postoperative memory change. Substantial individual heterogeneity of memory outcome exists across groups of patients undergoing ATL, with various degrees of pathologically verified HS. Patients undergoing left-sided ATL who have mild HS seem at greatest risk for broad-spectrum verbal memory decline. However, when examining outcome on a patient-by-patient basis, many patients undergoing left-sided ATL who have moderate to severe HS were also vulnerable to verbal memory loss. This risk seems selective to a retrieval-based aspect of verbal memory.

Revascularization and Apical Plug in an Immature Molar

PubMed Central

Roghanizadeh, Leyla; Fazlyab, Mahta

2018-01-01

Managing of necrotic permanent teeth with immature apices is a treatment challenges. Treatment of such teeth includes apexification, apical plug and more recently, revascularization technique with the probable advantage of continuation of root development. In the present case report the referred patient had discomfort with a necrotic immature mandibular first molar. Periapical radiography showed a rather large apical lesion around immature roots. Revascularization protocol using calcium-enriched mixture (CEM) cement was indicated for the mesial root. However, in distal canal apical plug technique was applied. At 2-year follow-up, both procedures were successful in relieving patient’s symptoms. Dentin formation and increase in length of the mesial root was obvious. Apical plug and revascularization technique proved to be successful in management of necrotic immature teeth; moreover, revascularization carried the advantage of continuation of root development. PMID:29692851

Quantity and distribution of plaque in orthodontic patients treated with molar bands.

PubMed

Erbe, Christina; Hornikel, Sandra; Schmidtmann, Irene; Wehrbein, Heiner

2011-03-01

The placement of orthodontic bands usually increases plaque accumulation due to numerous mechanical retention sites. The purpose of this investigation was to evaluate the amount and distribution pattern of biofilm in the oral (palatal and lingual) and interproximal regions surrounding orthodontic bands. We evaluated the formation of biofilm on 32 orthodontic bands which had been placed intraorally for 6-37 months. Two parameters were measured: the percentage of surface covered by biofilm (quantity) and the biofilm distribution pattern of accumulation. We measured these two parameters in four regions of interest: the mesial and distal interproximal regions, as well as the mesial and distal regions of the oral attachment. The quantity of biofilm formation was similar in all four regions of interest, ranging from 13.3% to 16.8%. In contrast to biofilm quantity, distribution patterns differed in the four regions. In the mesial and distal interproximal regions it appeared as extensive insular areas in 87.5% and 71.9%, respectively, whereas it appeared more often supragingival and linear in nature in regions adjacent to the oral attachment, i.e. in 65.6% and 68.8%, respectively. Our results indicate that firstly, oral hygiene in the palatal and lingual regions of orthodontic bands seems as difficult as it is in the interproximal areas, thus requiring thorough hygiene in both areas. Secondly, orthodontic patients with a history of periodontal disease require special attention regarding the use of orthodontic bands.

Sinus Floor Elevation with Modified Crestal Approach and Single Loaded Short Implants: A Case Report with 4 Years of Follow-Up

PubMed Central

Perelli, Michele; Abundo, Roberto; Corrente, Giuseppe; Saccone, Carlo

2017-01-01

Tooth extraction is usually followed by bone reduction. In the maxillary posterior region, this remodelling combined with sinus pneumatisation and periodontal defects may lead to a reduced basal bone height available for implant placement. Sinus floor elevation can be performed with different surgical techniques. Crestal approach has demonstrated to be effective, less invasive, and associated with a reduced morbidity. This article reports a modified sinus floor elevation by means of rotary, noncutting instruments, addition of xenograft, and 2 short-threaded implant placements. The aim of the study was to evaluate the implant's success and intrasinus radiographical bone gain after 4 years of functional loading. The premolar implant site presented a starting basal bone height of 6 mm, while the molar site was of 2 mm. In the first surgical step, sinus floor elevation was performed mesially and the implant was inserted, and distally only sinus floor elevation was performed. After 6 months, the mesial implant was uncovered and the second implant was inserted; 4 months later, the second fixture was uncovered, and both fixtures were loaded with single provisional screw-retained crowns and later with single screw-retained porcelain fused to metal crowns. Implants integrated successfully, and crestal bone remodelling did not exceed the smooth collar. Bone gain was 3 mm for the mesial implant and more than 5 mm for the distal one. PMID:29403665

Fabrication and Evaluation of a Noncompliant Molar Distalizing Appliance: Bonded Molar Distalizer

PubMed Central

Sodagar, A.; Ahmad Akhoundi, M. S.; Rafighii, A.; Arab, S.

2011-01-01

Objective Attempts to treat class II malocclusions without extraction in non-compliant patients have led to utilization of intraoral molar distalizing appliances. The purpose of this study was to investigate dental and skeletal effects of Bonded Molar Distalizer (BMD) which is a simple molar distalizing appliance. Materials and Methods Sixteen patients (12 girls, four boys) with bilateral half-cusp class II molar relationship, erupted permanent second molars and normal or vertical growth pattern were selected for bilateral distalization of maxillary molars via BMD. The screws were activated every other day, alternately. Lateral cephalograms and study models were obtained before treatment and after 11 weeks activation of the appliance. Results Significant amounts of molar distalization, molar distal tipping and anchorage loss were observed. The mean maxillary first molar distal movement was 1.22±0.936 mm with a distal tipping of 2.97±3.74 degrees in 11 weeks. The rate of distal movement was 0.48 mm per month. Reciprocal mesial movement of the first premolars was 2.26±1.12 mm with a mesial tipping of 4.25±3.12 degrees. Maxillary incisors moved 3.55±1.46 mm and tipped 9.87±5.03 degrees mesially. Lower anterior face height (LAFH) decreased 1.28±1.36 mm. Conclusion BMD is appropriate for distalizing maxillary molars, especially in patients with critical LAFH, although significant amounts of anchorage loss occur using this appliance. PMID:22457837

Sinus Floor Elevation with Modified Crestal Approach and Single Loaded Short Implants: A Case Report with 4 Years of Follow-Up.

PubMed

Perelli, Michele; Abundo, Roberto; Corrente, Giuseppe; Saccone, Carlo; Arduino, Paolo G

2017-01-01

Tooth extraction is usually followed by bone reduction. In the maxillary posterior region, this remodelling combined with sinus pneumatisation and periodontal defects may lead to a reduced basal bone height available for implant placement. Sinus floor elevation can be performed with different surgical techniques. Crestal approach has demonstrated to be effective, less invasive, and associated with a reduced morbidity. This article reports a modified sinus floor elevation by means of rotary, noncutting instruments, addition of xenograft, and 2 short-threaded implant placements. The aim of the study was to evaluate the implant's success and intrasinus radiographical bone gain after 4 years of functional loading. The premolar implant site presented a starting basal bone height of 6 mm, while the molar site was of 2 mm. In the first surgical step, sinus floor elevation was performed mesially and the implant was inserted, and distally only sinus floor elevation was performed. After 6 months, the mesial implant was uncovered and the second implant was inserted; 4 months later, the second fixture was uncovered, and both fixtures were loaded with single provisional screw-retained crowns and later with single screw-retained porcelain fused to metal crowns. Implants integrated successfully, and crestal bone remodelling did not exceed the smooth collar. Bone gain was 3 mm for the mesial implant and more than 5 mm for the distal one.

Rationale of lymph node dissection for breast cancer--from the viewpoint of analysis of axillary lymphatic flow using activated carbon particle CH40.

PubMed

Sawai, K; Hagiwara, A; Shimotsuma, M; Sakakibara, T; Imanishi, T; Takemoto, Y; Takahashi, T

1996-03-01

In order to rationalize lymph node dissection for breast cancer, we reviewed regional lymphatic flow from the mesial and outer half of the breast using intra-tumoral injection of activated carbon particles (CH40). Seventy patients with breast cancer were included in this study. Cancers were located in the mesial half of the breast in 25 cases and in its outer half in 41 cases. Since regional lymph nodes were blackened by CH40, lymph node dissection was performed easily and small lymph nodes could be readily examined. The average number of resected nodes in each case was 29.4. When CH40 was injected into the mesial half of the breast, the rates of blackened nodes (number of macroscopically blackened lymph nodes/number of total removed lymph nodes) in the stations were 46.6% (No. 1a), 41.4% (No. 1b), 62.1% (No. 1c), 61.8% (No. 2), 69.2.% (No. 2h), and 65.6% (No. 3). When CH40 was injected into outer half of the breast, those were 62.0% (No. 1a), 64.3% (No. 1b), 68.7% (No. 1c), 75.3% (No. 2), and 67.8% (No. 2h). Regardless of tumor location, the rates of blackened nodes were high in each station. In conclusion, regardless of tumor location it is impossible to determine the level of axillary dissection for breast cancer. It should be all or nothing.

Root Canal Anatomy and Morphology of Mandibular First Molars in a Selected Iranian Population: An In Vitro Study

PubMed Central

Mohammadzadeh Akhlaghi, Nahid; Khalilak, Zohreh; Vatanpour, Mehdi; Mohammadi, Saman; Pirmoradi, Sakineh; Fazlyab, Mahta; Safavi, Kamran

2017-01-01

Introduction: The aim of this study was to evaluate root canal anatomy of mandibular first molars (MFM) in a selected Iranian Population using clearing technique. Methods and Materials: A total of 150 extracted MFMs were cleared. The root canal morphology (including the root numbers and root length) and the anatomy of the root canal system (including is the number and type of canals based on Vertucci’s classification, canal curvature according to Schneider's method and the presence of isthmus) was evaluated using the buccolingual and mesiodistal parallel x-rays and stereomicroscope. The data were analyzed using the chi-square test. Results: Two and three roots were present in 96.7% and 33% of the teeth, respectively (P=0.0001). All the teeth (100%) had two canals in the mesial root, while 61.3% of the samples had one distal root canal (P=0.006). The root canal configuration in the mesial canal included type IV (55.3%) and type II (41.3%) (P=0.0001). In doubled-canalled distal roots, 68.8% and 24.3% were type II and type IV, respectively (P=0.0001). Isthmii were observed in 44.6% of mesial and 27.3% of distal roots (P=0.0001). Conclusion: The notable prevalence of type IV configuration in both roots of mandibular first molars, presence of isthmus and root curvature, necessitates the careful negotiation and cleaning of all accessible canal spaces. PMID:28179932

Reduction of hard-tissue debris accumulation during rotary root canal instrumentation by etidronic acid in a sodium hypochlorite irrigant.

PubMed

Paqué, Frank; Rechenberg, Dan-Krister; Zehnder, Matthias

2012-05-01

Hard-tissue debris is accumulated during rotary instrumentation. This study investigated to what extent a calcium-complexing agent that has good short-term compatibility with sodium hypochlorite (NaOCl) could reduce debris accumulation when applied in an all-in-one irrigant during root canal instrumentation. Sixty extracted mandibular molars with isthmuses in the mesial root canal system were selected based on prescans using a micro-computed tomography system. Thirty teeth each were randomly assigned to be instrumented with a rotary system and irrigated with either 2.5% NaOCl or 2.5% NaOCl containing 9% (wt/vol) etidronic acid (HEBP). Using a side-vented irrigating tip, 2 mL of irrigant was applied by 1 blinded investigator to the mesial canals after each instrument. Five milliliters of irrigant was applied per canal as the final rinse. Mesial root canal systems were scanned at high resolution before and after treatment, and accumulated hard-tissue debris was calculated as vol% of the original canal anatomy. Values between groups were compared using the Student's t test (α < .05). Irrigation with 2.5% NaOCl resulted in 5.5 ± 3.6 vol% accumulated hard-tissue debris compared with 3.8 ± 1.8 vol% when HEBP was contained in the irrigant (P < .05). A hypochlorite-compatible chelator can reduce but not completely prevent hard-tissue debris accumulation during rotary root canal instrumentation. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Present and future in the use of micro-CT scanner 3D analysis for the study of dental and root canal morphology.

PubMed

Grande, Nicola M; Plotino, Gianluca; Gambarini, Gianluca; Testarelli, Luca; D'Ambrosio, Ferdinando; Pecci, Raffaella; Bedini, Rossella

2012-01-01

The goal of the present article is to illustrate and analyze the applications and the potential of microcomputed tomography (micro-CT) in the analysis of tooth anatomy and root canal morphology. The authors performed a micro-CT analysis of the following different teeth: maxillary first molars with a second canal in the mesiobuccal (MB) root, mandibular first molars with complex anatomy in the mesial root, premolars with single and double roots and with complicated apical anatomy. The hardware device used in this study was a desktop X-ray microfocus CT scanner (SkyScan 1072, SkyScan bvba, Aartselaar, Belgium). A specific software ResolveRT Amira (Visage Imaging) was used for the 3D analysis and imaging. The authors obtained three-dimensional images from 15 teeth. It was possible to precisely visualize and analyze external and internal anatomy of teeth, showing the finest details. Among the 5 upper molars analyzed, in three cases, the MB canals joined into one canal, while in the other two molars the two mesial canals were separate. Among the lower molars two of the five samples exhibited a single canal in the mesial root, which had a broad, flat appearance in a mesiodistal dimension. In the five premolar teeth, the canals were independent; however, the apical delta and ramifications of the root canals were quite complex. Micro-CT offers a simple and reproducible technique for 3D noninvasive assessment of the anatomy of root canal systems.

Comparative performance evaluation of automated segmentation methods of hippocampus from magnetic resonance images of temporal lobe epilepsy patients.

PubMed

Hosseini, Mohammad-Parsa; Nazem-Zadeh, Mohammad-Reza; Pompili, Dario; Jafari-Khouzani, Kourosh; Elisevich, Kost; Soltanian-Zadeh, Hamid

2016-01-01

Segmentation of the hippocampus from magnetic resonance (MR) images is a key task in the evaluation of mesial temporal lobe epilepsy (mTLE) patients. Several automated algorithms have been proposed although manual segmentation remains the benchmark. Choosing a reliable algorithm is problematic since structural definition pertaining to multiple edges, missing and fuzzy boundaries, and shape changes varies among mTLE subjects. Lack of statistical references and guidance for quantifying the reliability and reproducibility of automated techniques has further detracted from automated approaches. The purpose of this study was to develop a systematic and statistical approach using a large dataset for the evaluation of automated methods and establish a method that would achieve results better approximating those attained by manual tracing in the epileptogenic hippocampus. A template database of 195 (81 males, 114 females; age range 32-67 yr, mean 49.16 yr) MR images of mTLE patients was used in this study. Hippocampal segmentation was accomplished manually and by two well-known tools (FreeSurfer and hammer) and two previously published methods developed at their institution [Automatic brain structure segmentation (ABSS) and LocalInfo]. To establish which method was better performing for mTLE cases, several voxel-based, distance-based, and volume-based performance metrics were considered. Statistical validations of the results using automated techniques were compared with the results of benchmark manual segmentation. Extracted metrics were analyzed to find the method that provided a more similar result relative to the benchmark. Among the four automated methods, ABSS generated the most accurate results. For this method, the Dice coefficient was 5.13%, 14.10%, and 16.67% higher, Hausdorff was 22.65%, 86.73%, and 69.58% lower, precision was 4.94%, -4.94%, and 12.35% higher, and the root mean square (RMS) was 19.05%, 61.90%, and 65.08% lower than LocalInfo, FreeSurfer, and hammer, respectively. The Bland-Altman similarity analysis revealed a low bias for the ABSS and LocalInfo techniques compared to the others. The ABSS method for automated hippocampal segmentation outperformed other methods, best approximating what could be achieved by manual tracing. This study also shows that four categories of input data can cause automated segmentation methods to fail. They include incomplete studies, artifact, low signal-to-noise ratio, and inhomogeneity. Different scanner platforms and pulse sequences were considered as means by which to improve reliability of the automated methods. Other modifications were specially devised to enhance a particular method assessed in this study.

Comparative performance evaluation of automated segmentation methods of hippocampus from magnetic resonance images of temporal lobe epilepsy patients

PubMed Central

Hosseini, Mohammad-Parsa; Nazem-Zadeh, Mohammad-Reza; Pompili, Dario; Jafari-Khouzani, Kourosh; Elisevich, Kost; Soltanian-Zadeh, Hamid

2016-01-01

Purpose: Segmentation of the hippocampus from magnetic resonance (MR) images is a key task in the evaluation of mesial temporal lobe epilepsy (mTLE) patients. Several automated algorithms have been proposed although manual segmentation remains the benchmark. Choosing a reliable algorithm is problematic since structural definition pertaining to multiple edges, missing and fuzzy boundaries, and shape changes varies among mTLE subjects. Lack of statistical references and guidance for quantifying the reliability and reproducibility of automated techniques has further detracted from automated approaches. The purpose of this study was to develop a systematic and statistical approach using a large dataset for the evaluation of automated methods and establish a method that would achieve results better approximating those attained by manual tracing in the epileptogenic hippocampus. Methods: A template database of 195 (81 males, 114 females; age range 32–67 yr, mean 49.16 yr) MR images of mTLE patients was used in this study. Hippocampal segmentation was accomplished manually and by two well-known tools (FreeSurfer and hammer) and two previously published methods developed at their institution [Automatic brain structure segmentation (ABSS) and LocalInfo]. To establish which method was better performing for mTLE cases, several voxel-based, distance-based, and volume-based performance metrics were considered. Statistical validations of the results using automated techniques were compared with the results of benchmark manual segmentation. Extracted metrics were analyzed to find the method that provided a more similar result relative to the benchmark. Results: Among the four automated methods, ABSS generated the most accurate results. For this method, the Dice coefficient was 5.13%, 14.10%, and 16.67% higher, Hausdorff was 22.65%, 86.73%, and 69.58% lower, precision was 4.94%, −4.94%, and 12.35% higher, and the root mean square (RMS) was 19.05%, 61.90%, and 65.08% lower than LocalInfo, FreeSurfer, and hammer, respectively. The Bland–Altman similarity analysis revealed a low bias for the ABSS and LocalInfo techniques compared to the others. Conclusions: The ABSS method for automated hippocampal segmentation outperformed other methods, best approximating what could be achieved by manual tracing. This study also shows that four categories of input data can cause automated segmentation methods to fail. They include incomplete studies, artifact, low signal-to-noise ratio, and inhomogeneity. Different scanner platforms and pulse sequences were considered as means by which to improve reliability of the automated methods. Other modifications were specially devised to enhance a particular method assessed in this study. PMID:26745947

The Localizing and Lateralizing Value of Auras in Lesional Partial Epilepsy Patients

PubMed Central

Ye, Byoung Seok; Cho, Yang-Je; Jang, Sang Hyun; Lee, Moon Kyu; Lee, Byung In

2012-01-01

Purpose We investigated the localizing and lateralizing values of auras in patients with lesional partial epilepsy on an outpatient basis. Materials and Methods A total of 276 subjects were retrospectively selected for this study if they had a unilateral single lobar lesion based on magnetic resonance image (MRI) results, and their scalp electroencephalography (EEG) findings were not discordant with the MRI-defined lobar localization and lateralization. According to the lesion locations, subjects were considered as having mesial temporal (MTLE), lateral temporal (LTLE), frontal (FLE), parietal (PLE), or occipital (OLE) lobe epilepsies. Auras were classified into 13 categories. Results A hundred and seventy-six subjects (63.8%) had experienced at least one aura. FLE subjects had the fewest number of auras. Epigastric and psychic auras were frequent among MTLE subjects, while visual auras were common in those with PLE and OLE. Somatosensory auras and whole body sensations were more frequent in the subjects with PLE than those without. Autonomic auras were more common in MTLE subjects than in LTLE subjects. Dysphasic auras were more frequently found in left-sided epilepsies. Five pairs of aura categories showed concurrent tendencies, which were the epigastric and autonomic auras, autonomic and emotional auras, visual and vestibular auras, auditory and vestibular auras, and whole-body sensation and auditory auras. Autonomic and emotional auras had a concurrent tendency in left-sided epilepsies, but not in right-sided epilepsies. Conclusion Our results support the previously known localizing value of auras, and suggest that dysphasic auras and the association of emotional and autonomic auras may have a lateralizing value. PMID:22476989

Rabies Tracing of Birthdated Dentate Granule Cells in Rat Temporal Lobe Epilepsy

PubMed Central

Du, Xi; Zhang, Helen; Parent, Jack M.

2017-01-01

Objective To understand how monosynaptic inputs onto adult-born dentate granule cells (DGCs) are altered in experimental mesial temporal lobe epilepsy (mTLE) and whether their integration differs from early-born DGCs that are mature at the time of epileptogenesis. Methods A dual-virus tracing strategy combining retroviral birthdating with rabies virus-mediated putative retrograde trans-synaptic tracing was used to identify and compare presynaptic inputs onto adult- and early-born DGCs in the rat pilocarpine model of mTLE. Results Our results demonstrate that hilar ectopic DGCs preferentially synapse onto adult-born DGCs after pilocarpine-induced status epilepticus (SE) while normotopic DGCs synapse onto both adult- and early-born DGCs. We also find that parvalbumin+ and somatostatin+ interneuron inputs are greatly diminished onto early-born DGCs after SE. However, somatostatin+ interneuron inputs onto adult-born DGCs are maintained, likely due to preferential sprouting. Intriguingly, CA3 pyramidal cell backprojections that specifically target adult-born DGCs arise in the epileptic brain, while axons of interneurons and pyramidal cells in CA1 appear to sprout across the hippocampal fissure to preferentially synapse onto early-born DGCs. Interpretation These data support the presence of substantial hippocampal circuit remodeling after an epileptogenic insult that generates prominent excitatory monosynaptic inputs, both local recurrent and widespread feedback loops, involving DGCs. Both adult- and early-born DGCs are targets of new inputs from other DGCs as well as from CA3 and CA1 pyramidal cells after pilocarpine-treatment, changes that likely contribute to epileptogenesis in experimental mTLE. PMID:28470680

Longitudinal positron emission tomography imaging of glial cell activation in a mouse model of mesial temporal lobe epilepsy: Toward identification of optimal treatment windows.

PubMed

Nguyen, Duc-Loc; Wimberley, Catriona; Truillet, Charles; Jego, Benoit; Caillé, Fabien; Pottier, Géraldine; Boisgard, Raphaël; Buvat, Irène; Bouilleret, Viviane

2018-06-01

Mesiotemporal lobe epilepsy is the most common type of drug-resistant partial epilepsy, with a specific history that often begins with status epilepticus due to various neurological insults followed by a silent period. During this period, before the first seizure occurs, a specific lesion develops, described as unilateral hippocampal sclerosis (HS). It is still challenging to determine which drugs, administered at which time point, will be most effective during the formation of this epileptic process. Neuroinflammation plays an important role in pathophysiological mechanisms in epilepsy, and therefore brain inflammation biomarkers such as translocator protein 18 kDa (TSPO) can be potent epilepsy biomarkers. TSPO is associated with reactive astrocytes and microglia. A unilateral intrahippocampal kainate injection mouse model can reproduce the defining features of human temporal lobe epilepsy with unilateral HS and the pattern of chronic pharmacoresistant temporal seizures. We hypothesized that longitudinal imaging using TSPO positron emission tomography (PET) with 18 F-DPA-714 could identify optimal treatment windows in a mouse model during the formation of HS. The model was induced into the right dorsal hippocampus of male C57/Bl6 mice. Micro-PET/computed tomographic scanning was performed before model induction and along the development of the HS at 7 days, 14 days, 1 month, and 6 months. In vitro autoradiography and immunohistofluorescence were performed on additional mice at each time point. TSPO PET uptake reached peak at 7 days and mostly related to microglial activation, whereas after 14 days, reactive astrocytes were shown to be the main cells expressing TSPO, reflected by a continuing increased PET uptake. TSPO-targeted PET is a highly potent longitudinal biomarker of epilepsy and could be of interest to determine the therapeutic windows in epilepsy and to monitor response to treatment. Wiley Periodicals, Inc. © 2018 International League Against Epilepsy.

Is 'burned-out hippocampus' syndrome a distinct electro-clinical variant of MTLE-HS syndrome?

PubMed

Nair, Pradeep P; Menon, Ramshekhar N; Radhakrishnan, Ashalatha; Cherian, Ajit; Abraham, Mathew; Vilanilam, George; Kesavadas, C; Thomas, Bejoy; Alexander, Aley; Thomas, Sanjeev V

2017-04-01

To study the clinical, electrophysiological and imaging characteristics of patients with unilateral mesial temporal lobe epilepsy (MTLE) with contralateral ictal onset on scalp EEG, viz. 'burned-out hippocampus' syndrome (MTLE-BHS). MTLE-BHS was defined as TLE with unilateral hippocampal sclerosis (HS) without any dual pathology on MRI and contralateral ictal onset on scalp EEG, unlike in classical hippocampal sclerosis (HS). Consecutive "MTLE-BHS" patients evaluated at our Centre for Comprehensive Epilepsy Care from January 2005 to July 2014 were studied. Twenty-five cases of classic MTLE-HS operated during the same period were also analyzed for comparison. Seventeen patients were diagnosed to have MTLE-BHS. Mean age of seizure onset was 9.5±7.7years and the mean duration of epilepsy was18.2±7.3years. Epigastric aura was more common in MTLE-HS and fear, secondary generalized seizures and temporal polar changes on MRI were more prevalent in the MTLE-BHS subgroup. In the latter group, five (29%) exhibited seizure semiology and 2 (12%) had interictal discharges discordant to the side of MTS. Eight (47%) patients in the MTLE-BHS sub-group had normal medial temporal volume on Scheltens scale. Eight patients among MTLE-BHS underwent surgery (4 following intracranial monitoring that localized to the side of HS) with Engel class I outcome at 1year follow-up in 6 and Engel class II outcome in 2. Attenuation of ipsilateral fast ictal rhythms on scalp EEG as well as neocortical changes are likely to be deterministic factors for MTLE-BHS as opposed to the severity of hippocampal atrophy. Considering good post-operative outcomes, intracranial monitoring for surgical selection is not mandatory in MTLE-BHS despite discordant semiology and ictal onset, in the presence of inter-ictal, functional imaging and neuropsychology data concordant to the side of HS. Copyright © 2017 Elsevier Inc. All rights reserved.

Better Object Recognition and Naming Outcome With MRI-Guided Stereotactic Laser Amygdalohippocampotomy for Temporal Lobe Epilepsy

PubMed Central

Drane, Daniel L.; Loring, David W.; Voets, Natalie L.; Price, Michele; Ojemann, Jeffrey G.; Willie, Jon T.; Saindane, Amit M.; Phatak, Vaishali; Ivanisevic, Mirjana; Millis, Scott; Helmers, Sandra L.; Miller, John W.; Meador, Kimford J.; Gross, Robert E.

2015-01-01

SUMMARY OBJECTIVES Temporal lobe epilepsy (TLE) patients experience significant deficits in category-related object recognition and naming following standard surgical approaches. These deficits may result from a decoupling of core processing modules (e.g., language, visual processing, semantic memory), due to “collateral damage” to temporal regions outside the hippocampus following open surgical approaches. We predicted stereotactic laser amygdalohippocampotomy (SLAH) would minimize such deficits because it preserves white matter pathways and neocortical regions critical for these cognitive processes. METHODS Tests of naming and recognition of common nouns (Boston Naming Test) and famous persons were compared with nonparametric analyses using exact tests between a group of nineteen patients with medically-intractable mesial TLE undergoing SLAH (10 dominant, 9 nondominant), and a comparable series of TLE patients undergoing standard surgical approaches (n=39) using a prospective, non-randomized, non-blinded, parallel group design. RESULTS Performance declines were significantly greater for the dominant TLE patients undergoing open resection versus SLAH for naming famous faces and common nouns (F=24.3, p<.0001, η2=.57, & F=11.2, p<.001, η2=.39, respectively), and for the nondominant TLE patients undergoing open resection versus SLAH for recognizing famous faces (F=3.9, p<.02, η2=.19). When examined on an individual subject basis, no SLAH patients experienced any performance declines on these measures. In contrast, 32 of the 39 undergoing standard surgical approaches declined on one or more measures for both object types (p<.001, Fisher’s exact test). Twenty-one of 22 left (dominant) TLE patients declined on one or both naming tasks after open resection, while 11 of 17 right (non-dominant) TLE patients declined on face recognition. SIGNIFICANCE Preliminary results suggest 1) naming and recognition functions can be spared in TLE patients undergoing SLAH, and 2) the hippocampus does not appear to be an essential component of neural networks underlying name retrieval or recognition of common objects or famous faces. PMID:25489630

The Relative Importance of Spatial Versus Temporal Structure in the Perception of Biological Motion: An Event-Related Potential Study

ERIC Educational Resources Information Center

Hirai, Masahiro; Hiraki, Kazuo

2006-01-01

We investigated how the spatiotemporal structure of animations of biological motion (BM) affects brain activity. We measured event-related potentials (ERPs) during the perception of BM under four conditions: normal spatial and temporal structure; scrambled spatial and normal temporal structure; normal spatial and scrambled temporal structure; and…

Status epilepticus does not induce acute brain inflammatory response in the Amazon rodent Proechimys, an animal model resistant to epileptogenesis.

PubMed

Scorza, Carla A; Marques, Marcia J G; Gomes da Silva, Sérgio; Naffah-Mazzacoratti, Maria da Graça; Scorza, Fulvio A; Cavalheiro, Esper A

2018-03-06

Mesial temporal lobe epilepsy is a serious brain disorder in adults that is often preceded by an initial brain insult, such as status epilepticus (SE), that after a latent period leads to recurrent seizures. Post-SE models are widely used for studies on epileptogenic processes. Previous findings of our laboratory suggested that the Neotropical rodents Proechimys exhibit endogenous antiepileptogenic mechanisms in post-SE models. Strong body of research supports that SE triggers a rapid and dramatic upregulation of inflammatory mediators and vascular endothelial growth factor (VEGF). In this work we found that, in the epilepsy-resistant Proechimys, hippocampal and cortical levels of inflammatory cytokines (IL-1β, IL-6, IL-10, TNF-α) and VEGF remained unchanged 24h after SE, strongly contrasting to the high levels of post-SE changes observed in Wistar rats. Furthermore, substantial differences in the brain baseline levels of these proteins were encountered between animal species studied. Since inflammatory cytokines and VEGF have been recognized as major orchestrators of the epileptogenic process, our results suggest their role in the antiepileptogenic mechanisms previously described in Proechimys. Copyright © 2017 Elsevier B.V. All rights reserved.

Metabolic networks in epilepsy by MR spectroscopic imaging.

PubMed

Pan, J W; Spencer, D D; Kuzniecky, R; Duckrow, R B; Hetherington, H; Spencer, S S

2012-12-01

The concept of an epileptic network has long been suggested from both animal and human studies of epilepsy. Based on the common observation that the MR spectroscopic imaging measure of NAA/Cr is sensitive to neuronal function and injury, we use this parameter to assess for the presence of a metabolic network in mesial temporal lobe epilepsy (MTLE) patients. A multivariate factor analysis is performed with controls and MTLE patients, using NAA/Cr measures from 12 loci: the bilateral hippocampi, thalami, basal ganglia, and insula. The factor analysis determines which and to what extent these loci are metabolically covarying. We extract two independent factors that explain the data's variability in control and MTLE patients. In controls, these factors characterize a 'thalamic' and 'dominant subcortical' function. The MTLE patients also exhibit a 'thalamic' factor, in addition to a second factor involving the ipsilateral insula and bilateral basal ganglia. These data suggest that MTLE patients demonstrate a metabolic network that involves the thalami, also seen in controls. The MTLE patients also display a second set of metabolically covarying regions that may be a manifestation of the epileptic network that characterizes limbic seizure propagation. © 2012 John Wiley & Sons A/S.

Dengue encephalitis with predominant cerebellar involvement: report of eight cases with MR and CT imaging features.

PubMed

Hegde, Vinay; Aziz, Zarina; Kumar, Sharath; Bhat, Maya; Prasad, Chandrajit; Gupta, A K; Netravathi, M; Saini, Jitender

2015-03-01

CNS dengue infection is a rare condition and the pattern of brain involvement has not been well described. We report the MR imaging (MRI) features in eight cases of dengue encephalitis. We retrospectively searched cases of dengue encephalitis in which imaging was performed. Eight cases (three men, five women; age range: 8-42 years) diagnosed with dengue encephalitis were included in the study. MR studies were performed on 3-T and 1.5-T MR clinical systems. Two neuroradiologists retrospectively reviewed the MR images and analysed the type of lesions, as well as their distribution and imaging features. All eight cases exhibited MRI abnormalities and the cerebellum was involved in all cases. In addition, MRI signal changes were also noted in the brainstem, thalamus, basal ganglia, internal capsule, insula, mesial temporal lobe, and cortical and cerebral white matter. Areas of susceptibility, diffusion restriction, and patchy post-contrast enhancement were the salient imaging features in our cohort of cases. A pattern of symmetrical cerebellar involvement and presence of microbleeds/haemorrhage may serve as a useful imaging marker and may help in the diagnosis of dengue encephalitis.

Transient global amnesia after taking sibutramine: a case report.

PubMed

Fu, Pin-Kuei; Hsu, Hung-Yi; Wang, Pao-Yu

2010-03-01

Sibutramine (Meridia in the United States, Reductil in Europe) is approved for weight reduction and weight maintenance. Although amnesia and seizure is listed as a reported adverse event of sibutramine in the US product information, our literature search in the PubMed website database found no published reports of theses adverse events. We report a 39-year-old healthy woman who had an episode of sudden memory loss lasting for several hours after taking sibutramine for 4 days. Cranial computed tomography scan, magnetic resonance imaging, and magnetic resonance angiography of the head all showed normal results. Electroencephalogram showed spike and wave complexes with phase reversal in the left mesial temporal area. Transient global amnesia was suspected clinically and transient epileptic amnesia provoked by sibutramine was also proposed. Three months after this episode, the follow-up electroencephalogram was normal. This patient did not take any anticonvulsant, and there were no more episodes of memory impairment. This case serves to emphasize that sibutramine which was used for weight reduction might induce transient global amnesia or provoke transient epileptic amnesia. Physicians should be careful to monitor for this adverse effect when sibutramine is prescribed.

Morphologic study of tissue changes occurring in the apical third and periapex of rat molars after endodontic treatment performed under different occlusal conditions.

PubMed

Sato, E F; Antoniazzi, J H; Bauer, J A

1994-01-01

The purpose of the present study was to carry out a histologic study of the periapical changes of the maxillary first molar of rats submitted to endodontic treatment under different occlusal conditions. The experiment was carried out under conditions analogous to those used in clinical practice. Pulpotomy, pulpectomy and chemomechanical preparation of the mesial root canal were carried out according to previously established techniques and the mesial root canal was filled with cement and gutta-percha. A glass ionomer cement was used as restorative material under conditions of subocclusion, normal occlusion and excessive occlusal forces. No inflammatory reaction of periapical tissue was observed under the three conditions used, and active closing of the root canal was observed 15 days after the procedure, with the formation of cementum replacing the pulpar remnant.

[The role of temporal fine structure in tone recognition and music perception].

PubMed

Zhou, Q; Gu, X; Liu, B

2017-11-07

The sound signal can be decomposed into temporal envelope and temporal fine structure information. The temporal envelope information is crucial for speech perception in quiet environment, and the temporal fine structure information plays an important role in speech perception in noise, Mandarin tone recognition and music perception, especially the pitch and melody perception.

Hyaluronic Acid Improves Bone Formation in Extraction Sockets With Chronic Pathology: A Pilot Study in Dogs.

PubMed

Kim, Jung-Ju; Song, Hyun Young; Ben Amara, Heithem; Kyung-Rim, Kang; Koo, Ki-Tae

2016-07-01

Previous studies on ridge preservation focusing on fresh extraction sockets using graft materials for ridge preservation procedures have reported a delay in the tissue modeling and remodeling phases. The objective of this study is to evaluate the effect of hyaluronic acid (HA) on healing of infected sockets. Six beagle dogs were used in this study. Both mandibular third premolars were hemisected, and the distal roots were extracted. Subsequently, periodontal and endodontic lesions were induced at the remaining mesial root. After communication of the periodontal lesion, an endodontic periapical lesion was observed at 4 months, and the mesial roots of both the right and left sides were extracted. HA was applied into the socket of the test group, and no treatment was administered to the other group (control group). Three months after extraction of the mesial roots, the dogs were sacrificed, and histologic evaluations were performed. The sockets were filled by mineralized bone (47.80% ± 6.60%) and bone marrow (50.47% ± 6.38%) in the control group, whereas corresponding values were 63.29% ± 9.78% and 34.73% ± 8.97% for the test group, respectively. There was a statistically significant difference between the groups. Reversal lines and a copious lineup of osteoblasts were observed in the middle and apical parts of the sockets in the test group. An infected socket shows delayed healing of the socket wound, and HA, because of its osteoinductive, bacteriostatic, and anti-inflammatory properties, may improve bone formation and accelerate wound healing in infected sockets.

Efficacy of ultrasonic activation of NaOCl and orange oil in removing filling material from mesial canals of mandibular molars with and without isthmus

PubMed Central

Barreto, Mirela Sangoi; da Rosa, Ricardo Abreu; Santini, Manuela Favarin; Cavenago, Bruno Cavalini; Duarte, Marco Antônio Húngaro; Bier, Carlos Alexandre Souza; Só, Marcos Vinícius Reis

2016-01-01

ABSTRACT Objectives The aim of this study was to evaluate the volume of remaining filling material after passive ultrasonic irrigation (PUI) of sodium hypochlorite (NaOCl) and orange oil in mesial canals of mandibular molars, with and without isthmus. Material and Methods Thirty mesial roots of mandibular molars were divided according to the presence or absence of isthmus. Canals were prepared and filled (Micro-CT #1). Filling was removed using rotary instruments, and specimens were sub-divided into three groups according to the irrigation procedures: Conventional – conventional irrigation with NaOCl, PUI/NaOCl – PUI of NaOCl (three activations, 20 seconds each), and PUI/orange oil – PUI of orange oil (Micro-CT#2). Specimens were enlarged using the X2 and X3 ProTaper Next instruments and submitted to the same irrigation protocols (Micro-CT #3). Results No differences were found between the experimental groups in each stage of assessment (P>0.05). The volume of residual filling material was similar to those in Micro-CT #2 and Micro-CT #3, but lower than those observed in Micro-CT #1 (P<0.05). When groups were pooled according to the presence or absence of an isthmus, volume of residual filling material was higher in specimens presenting isthmus (P<0.05). Conclusions PUI of NaOCl or orange oil did not improve filling removal. Isthmus consists in an anatomical obstacle that impairs the removal of filling material. PMID:26200525

Pattern of maxillary and mandibular proximal enamel thickness at the contact area of the permanent dentition from first molar to first molar.

PubMed

Sarig, Rachel; Vardimon, Alexander D; Sussan, Celine; Benny, Lea; Sarne, Ofer; Hershkovitz, Israel; Shpack, Nir

2015-04-01

Proximal enamel thickness (PET) at the mesial and distal contact areas of the complete permanent dentition has not been previously reported. Anatomic investigation of PET is essential for interproximal reduction treatment. Our objectives were to measure the PETs of the complete maxillary and mandibular dentitions at the contact areas, to compare the PETs of adjacent teeth, and to evaluate the vertical position of each contact area. We evaluated 720 extracted teeth; of these, 109 intact teeth were selected. The mesial and distal contact areas were demarcated, and each tooth was embedded in transparent epoxy resin. Blocks were prepared so that the 2 demarcated contact areas were exposed, and 6 measurements were taken and statistically analyzed. Both jaws showed the same PET pattern characterized by 5 features: PET increased progressively from incisor (0.63 mm) to first molar (1.48 mm). Per tooth, mesial and distal PET did not differ. Total maxillary (26.86 mm) and mandibular (24.52 mm) PETs were similar. Paired PETs at the interproximal interface were similar, with the exception of the lateral incisor-canine interfaces. From incisor to first molar, the contact area becomes located farther gingivally. The existing guideline of maximal 0.5-mm interproximal reduction per 2 adjacent teeth should be kept in the anterior region and could be increased to 1 mm in the posterior region, when an equal amount is removed. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

The variable position of the inferior alveolar nerve (IAN) in the mandibular ramus: a computed tomography (CT) study.

PubMed

Yeh, Andrew Y E; Finn, Brian P; Jones, Robert H B; Goss, Alastair N

2018-06-01

This study was designed to quantify the important anatomical landmarks and the path of the inferior alveolar nerve (IAN) within the human mandibular body and ramus, in particular with reference to the bilateral sagittal split osteotomy (BSSO). Four hundred and eleven CT scans were studied, 299 of these were involved in determining the position of lingula; and 230 were involved in determining the course of IAN in the mandibular molar region, namely from the mesial of the mandibular first molar to the distal of the mandibular second molar; 118 were involved with both measurements. On average, the lingula was located 17.0 ± 2.2 mm from the external oblique ridge; 11.6 ± 2.0 mm from the internal oblique ridge; 17.2 ± 2.7 mm from the sigmoid notch; and 15.6 ± 1.9 mm from the posterior border of the mandible. The course of the IAN in the mandibular molar region was found to descend vertically from the distal of the mandibular second molar (7) to reach its lowest point between the first and second molars (6 and 7), and then ascend towards the mesial of the first molar (6). Horizontally, the IAN was found to traverse medially between the distal of the 7 and the middle of the 7, and then changes its path laterally towards the mesial of the 6. Precise knowledge of the individual's position of the IAN will help surgical planning.

Middle mesial canals in mandibular molars: incidence and related factors.

PubMed

Nosrat, Ali; Deschenes, Raney J; Tordik, Patricia A; Hicks, M Lamar; Fouad, Ashraf F

2015-01-01

Although the internal anatomy of mandibular molars has been extensively studied, information about middle mesial (MM) canals is limited. The primary aim of this retrospective study was to evaluate the incidence of MM canals in mandibular first and second molars. The secondary aim was to correlate the incidence of MM canals with variables of molar type, sex, age, ethnicity, and presence of a second distal canal. All mature permanent first and second mandibular molars treated from August 2012 to May 2014 were included in the analysis. After completion of root canal instrumentation in all main canals, the clinician inspected the isthmus area of the mesial root using the dental operating microscope. If there was a catch point in this area with a file or explorer, the operator spent more time attempting to negotiate an MM canal. Seventy-five mandibular first and second molars were treated during the specified period. Fifteen (20%) teeth had negotiable MM canals. The incidence of MM canals was 32.1% in patients ≤ 20 years old, 23.8% in patients 21-40 years old, and 3.8% in patients > 40 years. Analysis of data revealed a significant difference in the distribution of MM canals among different age groups (P < .05). The differences in the distribution of MM canals based on sex, ethnicity, molar type, and presence of a second distal canal were not significant. The incidence of negotiable MM canals overall and their frequency of identification in younger patients were higher than in previous reports. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Primary failure of eruption: further characterization of a rare eruption disorder.

PubMed

Frazier-Bowers, Sylvia A; Koehler, Karen E; Ackerman, James L; Proffit, William R

2007-05-01

Posterior open bite has several possible causes, including primary failure of eruption (PFE) that affects all teeth distal to the most mesial involved tooth, mechanical failure of eruption (MFE) (primarily ankylosis) that affects only the involved tooth or teeth, and soft-tissue interferences with eruption (other). Radiographs and other clinical records for 97 cases of failure of posterior eruption submitted for consultation were analyzed to further characterize PFE and distinguish it from MFE. Of the 97 cases, 38 were judged to be clear-cut PFE; 19 were diagnosed as MFE; 32 were classified as indeterminate failure because they were too young to be certain of the distinction between PFE and MFE; and 8 were placed in the "other" category. Two subtypes of PFE were observed. In type 1, eruption failure occurred at or near the same time for all teeth in an affected quadrant. In type 2, a gradient of the time of failure was present, so that some further development of the teeth posterior to the most mesial affected tooth was observed before eruption failure. A family history of eruption problems was noted in 10 of the 38 PFE subjects (26%), and a pedigree analysis was done for 4 families. This was consistent with autosomal dominant transmission. The distinction between PFE and MFE is clinically important because it determines whether all posterior teeth, or only individual affected teeth, will not respond to orthodontic force. Certain diagnosis often requires progress radiographs so that the pattern of eruption of teeth distal to the most mesial affected tooth can be observed.

Radicular anatomy of permanent mandibular second molars in an Iranian population: A preliminary study

PubMed Central

Akhlaghi, Nahid M.; Abbas, Fatemeh Mashadi; Mohammadi, Mostafa; Shamloo, Mohammad Reza Karami; Radmehr, Orkideh; Kaviani, Ramin; Rakhshan, Vahid

2016-01-01

Background: Root morphology is of utmost importance to endodontic sciences. Since there are a few studies on the morphology of mandibular second molars' roots, and some anatomical variables are not evaluated before, the aim of this study was to investigate thoroughly radicular anatomy of this tooth. Materials and Methods: This ex vivo study was performed on 150 intact mandibular second molars. After access cavity preparation and ensuring canal patency, Indian ink was injected into root canals from the orifices. The teeth became transparent using methyl salicylate storage. Then, they were inspected by an endodontist under a ×10 stereomicroscope regarding numerous root morphological variables. Data were analyzed using chi-square test and analysis of variance (α = 0.05). Results: About 86.7% of teeth had two roots and 13.3% were single-rooted (P = 0.0001), of which, 50% were C-shaped (6.7% of all teeth, P = 0.0001). 86.7% of mesial roots were double canalled, whereas 75.3% of distal roots were single canalled (P = 0.0001). 71.45% and 95.3% of the mesial and distal roots had one apical foramen, respectively (P = 0.0001). Apical foramens were mostly central followed by lingual in most cases. Distances between apical foramen and apical constriction ranged between 0.27 and 0.40 mm (P = 0.0545). Distances between apical foramen and root apices ranged between 0.30 and 0.47 mm (P = 0.0001). Vertucci classifications of mesial canals were Type II in 62.6% and Type IV in 37.4%. 86.2% of single-canal distal roots were Type I. 66.7% of double-canal distal roots were Type II and 33.3% were Type IV (P = 0.0001). The mean root lengths from cervical to apex of mesial, distal, and single roots were 14.02 ± 0.85 (95% confidence interval [CI] = 13.87–14.17), 13.35 ± 0.91 (95% CI = 13.19–13.50), and 14.25 ± 0.72 mm (95% CI = 13.91–14.58), respectively. The extents of canal curvatures varied between 20° and 31° buccolingually (P = 0.0000), and between 19° and 27° mesiodistally (P = 0.0000). Conclusion: There was a considerable rate of eccentric apical foramen in mandibular second molars. PMID:27605995

Temporal Structure and Complexity Affect Audio-Visual Correspondence Detection

PubMed Central

Denison, Rachel N.; Driver, Jon; Ruff, Christian C.

2013-01-01

Synchrony between events in different senses has long been considered the critical temporal cue for multisensory integration. Here, using rapid streams of auditory and visual events, we demonstrate how humans can use temporal structure (rather than mere temporal coincidence) to detect multisensory relatedness. We find psychophysically that participants can detect matching auditory and visual streams via shared temporal structure for crossmodal lags of up to 200 ms. Performance on this task reproduced features of past findings based on explicit timing judgments but did not show any special advantage for perfectly synchronous streams. Importantly, the complexity of temporal patterns influences sensitivity to correspondence. Stochastic, irregular streams – with richer temporal pattern information – led to higher audio-visual matching sensitivity than predictable, rhythmic streams. Our results reveal that temporal structure and its complexity are key determinants for human detection of audio-visual correspondence. The distinctive emphasis of our new paradigms on temporal patterning could be useful for studying special populations with suspected abnormalities in audio-visual temporal perception and multisensory integration. PMID:23346067

[Evolution of ideas and techniques, and future prospects in epilepsy surgery].

PubMed

Mathon, B; Bédos-Ulvin, L; Baulac, M; Dupont, S; Navarro, V; Carpentier, A; Cornu, P; Clemenceau, S

2015-02-01

The aim of this article was to review and evaluate the published literature related to the outcome of epilepsy surgery, while placing it in an historical perspective, and to describe the future prospects in this field. Temporal lobe surgery achieves seizure freedom in about 70% of cases. Seizure outcome is similar in the pediatric population. Extratemporal resections impart good results to 40% to 60% of patients, with a better prognosis in the case of frontal lobe surgery. Pediatric hemispherotomy leads to seizure control in about 80% of children. Radiosurgery used as a treatment for temporal mesial epilepsy has an outcome quite similar to that obtained with surgical resection, but provides a neuropsychological advantage. Radiosurgery is also effective in 60% of children treated for seizures related to hypothalamic hamartoma. Regarding palliative surgery, callosotomy and multiple subpial transections show satisfactory outcomes in over 60% of cases. Neuromodulation techniques (vagus nerve stimulation and bilateral stimulation of the anterior nucleus of the thalamus) allow a 50% reduction of seizures in half of patients. Transcranial magnetic stimulation combined with electroencephalography seems a promising technique because of its diagnostic, prognostic and therapeutic applications. Transcranial ultrasound stimulation, which can reversibly control neuronal activity, is also under consideration. Concerning neuromodulation, trigeminal nerve stimulation may become an alternative to vagus nerve stimulation; while other targets of deep brain stimulation are being evaluated. Also, the possibility of coupling SEEG seizure focus detection with concomitant laser or radiofrequency focus destruction is under development. Constant evolution of epilepsy surgery has improved patient outcomes over time. Current research and development axes suggest the continuation of this trend and a reduction of the invasiveness of surgical procedures. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Morphological features of the neonatal brain support development of subsequent cognitive, language, and motor abilities.

PubMed

Spann, Marisa N; Bansal, Ravi; Rosen, Tove S; Peterson, Bradley S

2014-09-01

Knowledge of the role of brain maturation in the development of cognitive abilities derives primarily from studies of school-age children to adults. Little is known about the morphological features of the neonatal brain that support the subsequent development of abilities in early childhood, when maturation of the brain and these abilities are the most dynamic. The goal of our study was to determine whether brain morphology during the neonatal period supports early cognitive development through 2 years of age. We correlated morphological features of the cerebral surface assessed using deformation-based measures (surface distances) of high-resolution MRI scans for 33 healthy neonates, scanned between the first to sixth week of postmenstrual life, with subsequent measures of their motor, language, and cognitive abilities at ages 6, 12, 18, and 24 months. We found that morphological features of the cerebral surface of the frontal, mesial prefrontal, temporal, and occipital regions correlated with subsequent motor scores, posterior parietal regions correlated with subsequent language scores, and temporal and occipital regions correlated with subsequent cognitive scores. Measures of the anterior and middle portions of the cingulate gyrus correlated with scores across all three domains of ability. Most of the significant findings were inverse correlations located bilaterally in the brain. The inverse correlations may suggest either that a more protracted morphological maturation or smaller local volumes of neonatal brain tissue supports better performance on measures of subsequent motor, language, and cognitive abilities throughout the first 2 years of postnatal life. The correlations of morphological measures of the cingulate with measures of performance across all domains of ability suggest that the cingulate supports a broad range of skills in infancy and early childhood, similar to its functions in older children and adults. Copyright © 2014 Wiley Periodicals, Inc.

Long-term outcome characteristics in mesial temporal lobe epilepsy with and without associated cortical dysplasia.

PubMed

Schmeiser, B; Hammen, T; Steinhoff, B J; Zentner, J; Schulze-Bonhage, A

2016-10-01

The intention of our study was to identify predictive characteristics for long-term seizure control and running down phenomenon after surgical treatment of pharmacoresistant mesiotemporal lobe epilepsy (mTLE) with and without associated cortical dysplasia. Our study comprises a consecutive series of 458 patients who underwent surgical treatment for intractable mTLE at the Epilepsy Center Freiburg. Data evaluated included semiology, duration and frequency of seizures, results of presurgical diagnostics including video-EEG monitoring, MRI, PET and SPECT as well as postoperative seizure outcome. Results were evaluated forming two groups: Group A consisted of isolated mesiotemporal lesions. Group B comprised patients with mTLE and additional focal cortical dysplasia (FCD). Statistical evaluation was based on the Kaplan Meier survival analysis, using log-rank-tests and a multivariate regression model. Postoperative running down phenomenon was defined as seizure freedom after a period of gradual reduction of postoperative seizure frequency. This was compared to patients with ongoing epilepsy. Complete seizure freedom was achieved in 65.0% of investigated patients at 1year and in 56.5% at long-term follow-up of ≥5 years after surgery. Corresponding results were 64.2% and 56.8% at 1 and ≥5 years, respectively in group A and 66.4% and 56.0%, respectively in group B. Predictive for favorable postoperative outcome in the total group were younger age at surgery, shorter duration of epilepsy, absence of secondarily generalized tonic-clonic seizures (SGTCS), presence of strictly ipsilateral temporal interictal epileptiform discharges (IEDs), complete resection of the lesion as well as absence of postoperative epileptiform activity and of early postoperative seizures. In subgroup analyses, patients of group A demonstrated longer postoperative seizure-free intervals with adolescent age at surgery, short duration of epilepsy before surgery and absence of SGTCS, whereas in patients of group B ipsilateral temporal seizure onset and strictly unilateral IEDs in EEG as well as complete resection were predictors for favorable seizure outcome. Furthermore, absence of early postoperative seizures and of spikes in EEG were predictive factors for long-term seizure-freedom in both subgroups. The running down phenomenon was found in 33 (7.2%) patients. None of the parameters evaluated demonstrated significant predictive power. Only late seizure onset and neoplastic lesions showed a trend for postoperative gradual seizure reduction in multivariate analyses. Depending on the presence or absence of focal cortical dysplasia in addition to mesiotemporal structural alterations, predictors of long-term seizure control differed regarding the relevant clinical and electrophysiological features. This is important for specific patient counseling in respective groups. Copyright © 2016 Elsevier B.V. All rights reserved.

Modeling and characterization of the CEJ for optimization of esthetic implant design.

PubMed

Gallucci, German O; Belser, Urs C; Bernard, Jean-Pierre; Magne, Pascal

2004-02-01

This study evaluated the dimensions and characteristics of the cementoenamel junction (CEJ) of maxillary anterior teeth; the natural CEJ was compared to current implant design and used for design optimization. Standardized digital images of 137 extracted human teeth (45 central incisors, 46 lateral incisors, and 46 canines) were used to measure cervical dimensions, CEJ curvature, and distance from zenith of CEJ to interdental contact on proximal views. The x- and y-coordinates of the CEJ contour were digitized before mathematic processing to allow the representation of a single average curve for buccal, palatal, mesial, and distal surfaces for each tooth type. These measurements were combined to existing data related to dentogingival and "implantomucosal" junction to extrapolate specific biologic landmarks around teeth and implants. Mean cervical dimensions, distance from zenith of CEJ to interdental contact, and CEJ curvature were compared. Cervical dimensions significantly differed, with a more symmetric cervical cross-section for central incisors, slightly more rectangular shape for lateral incisors, and distinctly rectangular shape for canines. CEJ curvature was statistically different between all tooth groups (centrals > laterals > canines); within groups, curvature value was always superior at the mesial aspect compared to distally (3.46 mm vs 3.13 mm for centrals, 2.97 mm vs 2.38 mm for laterals, and 2.55 mm vs 1.60 mm for canines). Tooth-implant biologic width discrepancies ranged from 4.10 to 5.96 mm and were different between all groups of teeth (centrals > laterals > canines); within groups, the discrepancy was always superior at the mesial aspect compared to distally. Current implant design featuring a flat, rotation-symmetric shoulder should be reconsidered in view of natural CEJ contour to improve biologic considerations and related esthetics.

Root canal preparation of mandibular molars with 3 nickel-titanium rotary instruments: a micro-computed tomographic study.

PubMed

Zhao, Dan; Shen, Ya; Peng, Bin; Haapasalo, Markus

2014-11-01

The aim of this study was to describe the canal shaping properties of ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Universal (PTU; Dentsply Tulsa Dental Specialties, Johnson City, TN), and WaveOne (Dentsply Maillefer) nickel-titanium instruments in mandibular first molars by using micro-computed tomographic (micro-CT) scanning. A total of 36 maxillary first molars with 2 separate mesial canals and 1 distal canal were selected and scanned preoperatively and postoperatively by using micro-CT scanning with a voxel size of 30 μm. Canals were prepared with PTU, PTN, and WaveOne systems under hypochlorite irrigation. The volume of the untreated canal; the volume of dentin removed after preparation; the amount of the uninstrumented area; and the transportation to the coronal, middle, and apical thirds of canals were measured. The preparation time and instrument failure were also recorded. Instrumentation of canals increased their volume and surface area. The distal canals had a significantly higher proportion of unprepared surfaces than mesial canals (P < .05). The PTN system produced less transportation than the WaveOne and PTU systems in the apical third of the mesial canals (P < .05). There was no significant difference on apical transportation in distal canals among the 3 instrument systems. Instrumentation with WaveOne was significantly faster than with the other 2 instruments (P < .05). The PTN, PTU, and WaveOne instruments shaped root canals in mandibular first molars in vitro without significant shaping errors. The curved canals prepared using PTN had less apical transportation than the canals prepared using WaveOne and PTU. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Efficacy of xylene and passive ultrasonic irrigation on remaining root filling material during retreatment of anatomically complex teeth.

PubMed

Cavenago, B C; Ordinola-Zapata, R; Duarte, M A H; del Carpio-Perochena, A E; Villas-Bôas, M H; Marciano, M A; Bramante, C M; Moraes, I G

2014-11-01

To evaluate the volume of remaining filling material in the mesial root canals of mandibular molars after root canal retreatment with different procedures performed sequentially. The mesial root canals of 12 human first mandibular molars were instrumented using the BioRace system until a size 25, .06 taper instrument. The mesial roots were filled with gutta-percha and AH-Plus using a vertical compaction technique. The specimens were scanned using microcomputed tomography with a voxel size of 16.8 μm before and after the retreatment procedures. To remove the filling material, the root canals were enlarged until the size 40, .04 taper instrument. The second step was to irrigate the root canals with xylene in the attempt to clean the root canals with paper points. In the third step, the passive ultrasonic irrigation technique (PUI) was performed using 2.5% sodium hypochlorite. The initial and residual filling material volume (mm(3) ) after each step was evaluated from the 0.5 to 6.5 mm level. The obtained data were expressed in terms of percentage of residual filling material. Statistical analysis was performed using the Friedman test (P < 0.05). All specimens had residual filling materials after all retreatment procedures. Passive ultrasonic irrigation enhanced the elimination of residual filling material in comparison with the mechanical stage at the 0.5-2.5 mm and 4.5-6.5 mm levels (P < 0.05). No significant difference was found between xylene and PUI methods. Filling materials were not completely removed by any of the retreatment procedures. The use of xylene and PUI after mechanical instrumentation enhanced removal of materials during endodontic retreatment of anatomically complex teeth. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

The effect of filler content and processing variables on dimensional accuracy of experimental composite inlay material.

PubMed

Razak, A A; Harrison, A

1997-04-01

Dimensional accuracy of a composite inlay restoration is important to ensure an accurate fit and to minimize cementation stresses. A method was developed to measure dimensional accuracy and stability of a composite inlay. A standard Class II (MOD) inlay cavity stainless steel mold was made with six circular indentations placed on the occlusal floor of the cavity and four indentations on each gingival floor to act as datum points in the measurement of linear polymerization shrinkage. The inlay restorations were prepared from an inlay-onlay composite material of different filler contents (50%, 65%, and 79% by weight). For each filler content group, three curing methods were used: light curing only, light curing and heat curing at 100 degrees C for 5 minutes, and light curing and heat curing at 100 degrees C for 5 minutes and then storage in distilled water for 7 days. The accuracy of the MOD inlays was determined by measuring the shrinkage of the restoration on the occlusal floor areas and the gingival seats. The results demonstrated an inverse linear relationship between filler content and polymerization shrinkage. There was a tendency for the light-curing and heat-curing method to show an increase in polymerization shrinkage. An expansion was recorded between the mesial and distal boxes when the specimens were soaked in water for 7 days. This study suggested that the inlay mold limits the physical shrinkage that can occur between the mesial and distal axial walls of the inlay restoration because the inlay cannot shrink to a smaller dimension than the mold. Water sorption then causes hygroscopic expansion, which enlarges the distance between the mesial and distal walls.

Immediate Single-Tooth Implant Placement in Bony Defects in the Esthetic Zone: A 1-Year Randomized Controlled Trial.

PubMed

Slagter, Kirsten W; Meijer, Henny J A; Bakker, Nicolaas A; Vissink, Arjan; Raghoebar, Gerry M

2016-06-01

This study aims to assess, with regard to marginal bone level (MBL), whether the outcome of immediate implant placement in bony defects in the esthetic zone was non-inferior to delayed implant placement after 1 year. Forty patients with a failing tooth in the esthetic zone and a labial bony defect of ≥5 mm after removal of a tooth were randomly assigned for immediate (n = 20) or delayed (n = 20) implant placement. Second-stage surgery and provisionalization occurred after 3 months of healing. Follow-up was at 1 month and 1 year after definitive crown placement. The study was powered to detect a difference in MBL of >0.9 mm. Buccal bone thickness, soft tissue peri-implant parameters, esthetic indices, and patient satisfaction were also assessed. One year after definitive crown placement, MBL loss was 0.56 ± 0.39 mm mesially and 0.74 ± 0.51 mm distally for the immediate placement group and 0.51 ± 0.43 mesially and 0.54 ± 0.45 distally mm for the delayed placement group, respectively (not significant). Regarding differences in means, non-inferiority was observed after 1 year (difference in mean for immediate versus delayed: mesially 0.04 mm [95% confidence interval (CI) = -0.22 to 0.30 mm, P = 0.40]; distally 0.21 mm [95% CI = -0.10 to 0.51 mm, P = 0.58]). No significant differences in the other outcome variables were observed. Immediate implant placement with delayed provisionalization was non-inferior to delayed implant placement with delayed provisionalization in labial bony defects of ≥5 mm regarding change in MBL. Although not powered for other outcome variables, no clinically relevant differences were observed in these variables.

Orthodontic treatment need in adolescent Kuwaitis: prevalence, severity and manpower requirements.

PubMed

Al-Azemi, Rashed; Artun, Jon

2010-01-01

Our purpose was to determine the orthodontic treatment need in adolescent Kuwaitis, adjusting for treatment experience and acquired need due to mesial migration or loss of the first molars, and to assess the orthodontic manpower requirements. A population-based sample of 753 boys and 728 girls, representing about 7% of all 13- to 14-year-old Kuwaitis, was examined in a classroom setting. Orthodontic treatment need was graded according to the Dental Health Component (DHC) and the Aesthetic Component (AC) of the Index of Orthodontic Treatment Need (IOTN). Subjects with treatment experience were scored on initial study models. The DHC and AC grades were categorized in 3 groups and aggregated to 3 IOTN groups according to the highest DHC or AC group. Group 1 was labeled as 'no need', 2 as 'moderate need', and 3 as 'definite need for orthodontic treatment'. According to the IOTN, 31.1% of the subjects demonstrated a definite need and 40.2% no need for treatment. Excluding DHC group 3 categories attributed to mesial migration and/or loss of first molars, definite need was reduced to 23.9%. Definite treatment need was more prevalent when estimated according to the DHC than according to the AC, while moderate and no need were more prevalent according to the AC (p < 0.001). No gender differences were detected (p > 0.05). About 30% of adolescent Kuwaitis have definite need for orthodontic treatment. The prevalence may be reduced towards 25%, provided loss or mesial migration of the first molars can be prevented. About 50-60 orthodontists are needed to meet the severe need in adolescent Kuwaitis. Copyright 2010 S. Karger AG, Basel.

A novel surgical approach to impacted mandibular third molars to reduce the risk of paresthesia: a case series.

PubMed

Landi, Luca; Manicone, Paolo Francesco; Piccinelli, Stefano; Raia, Alessandro; Raia, Roberto

2010-05-01

Extraction of impacted mandibular third molars (M3s) may cause temporary or permanent neurosensorial disturbances of the inferior alveolar nerve (IAN). Although the incidence of this complication is low, a great range of variability has been reported in the literature. Several methods to reduce or eliminate this complication have been proposed, such as orthodontic-assisted extraction, extraction of the second molar, or intentional odontoectomy. The purpose of this series of cases is to present a novel approach for a riskless extraction of impacted mandibular M3s in contact with the IAN. Nine consecutive patients (4 male and 5 female; mean age 24.9 years, range 18-43 years) required the extraction of 10 horizontally or mesioangular impacted mandibular M3s. In all cases the M3 was in contact with the IAN with a high risk of nerve injury. A staged approached was proposed and accepted by the patients. This approach consisted in the surgical removal of the mesial portion of the anatomic crown to create adequate space for mesial M3 migration. After the migration of the M3 had taken place, the extraction could then be accomplished in a second surgical session minimizing neurological risks. All M3s moved mesially within 6 months (mean 174.1 days, range 92-354 days) and could be successfully removed without any neurological consequences. This technique may be considered as an alternative approach to the extraction of horizontally or mesioangular impacted M3s in proximity to the IAN. Copyright 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Influence of NiTi alloy on the root canal shaping capabilities of the ProTaper Universal and ProTaper Gold rotary instrument systems.

PubMed

Duque, Jussaro Alves; Vivan, Rodrigo Ricci; Cavenago, Bruno Cavalini; Amoroso-Silva, Pablo Andrés; Bernardes, Ricardo Affonso; Vasconcelos, Bruno Carvalho de; Duarte, Marco Antonio Hungaro

2017-01-01

This study aimed to evaluate the influence of the NiTi wire in Conventional NiTi (ProTaper Universal PTU) and Controlled Memory NiTi (ProTaper Gold PTG) instrument systems on the quality of root canal preparation. Twelve mandibular molars with separate mesial canals were scanned using a high-definition microcomputed tomography system. The PTU and PTG instruments were used to shape twelve mesial canals each. The canals were scanned after preparation with F2 and F3 instruments of the PTU and PTG systems. The analyzed parameters included the remaining dentin thickness at the apical and cervical levels, root canal volume and untouched canal walls. Data was analyzed for statistical significance by the Friedman and Dunn's tests. For the comparison of data between groups, the Mann-Whitney test was used. In the pre-operative analysis, there were no statistically significant differences between the groups in terms of the area and volume of root canals (P>.05). There was also no statistically significant difference between the systems with respect to root canal volume after use of the F2 and F3 instruments. There was no statistical difference in the dentin thickness at the first apical level between, before and after instrumentation for both systems. At the 3 cervical levels, the PTG maintained centralization of the preparation on the transition between the F2 and F3 instruments, which did not occur with the PTU. Conclusion The Conventional NiTi (PTU) and Controlled Memory NiTi (PTG) instruments displayed comparable capabilities for shaping the straight mesial root canals of mandibular molars, although the PTG was better than the PTU at maintaining the centralization of the shape in the cervical portion.

In vivo efficacy of three different endodontic irrigation systems for irrigant delivery to working length of mesial canals of mandibular molars.

PubMed

Munoz, Hugo Roberto; Camacho-Cuadra, Karla

2012-04-01

Many in vitro studies have debated over the ability of different irrigant delivery and/or agitation systems to reach the apical third of curved root canals; however, little is known about irrigant penetration in vivo. Therefore, the purpose of this study was to compare the efficacy of the conventional endodontic irrigation needle, passive ultrasonic irrigation (PUI), and a negative pressure system for irrigant delivery to working length (WL) of mesial canals of mandibular molars. Thirty mesial canals of 30 vital mandibular first or second molars were randomly assigned into 3 groups (n = 10): (1) Monoject syringe with 27-gauge needle; (2) PUI with IrriSafe tip; and (3) EndoVac system. All canals were treated following the same preparation protocol to size 35/0.04 by using 5.25% NaOCl as irrigant during preparation procedure. Before obturation, canals were irrigated with 1 mL of a radiopaque solution by using the assigned irrigation system, and a digital radiograph was taken by using a parallel technique. With the aid of image editing software the distance between WL and maximum irrigant penetration was measured. Mean distances for Monoject, PUI, and EndoVac groups were 1.51 mm, 0.21 mm, and 0.42 mm, respectively. Analysis of variance test showed statistically significant differences between groups (P < .001). Tukey honestly significant difference test showed statistically significant differences between the Monoject group and the other 2 groups (P < .001) but no significant differences between PUI and EndoVac groups (P = .06). PUI and EndoVac are more effective than the conventional endodontic needle in delivering irrigant to WL of root canals. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Radiographic bone fill following debridement of a periodontal abscess. A case report.

PubMed

Khocht, A; Faldu, M G

1998-01-01

A periodontal abscess often develops in association with deepened periodontal pockets. Traditional management is by establishing drainage and prescribing antibiotics. This is usually followed by surgical pocket reduction. This case report discusses the remarkable healing of a periodontal abscess by establishing drainage alone without resorting to surgical pocket reduction. A 42-year-old white male presented with swollen gingivae associated with the mesiolingual of tooth #23. Increased probing depth and suppuration were evident. Radiographic bone loss on mesial #23 was present. A diagnosis of periodontal abscess was established. The abscess was drained through the orifice of the pocket. The patient failed to return for follow-up as instructed. A year later, the patient came back. Clinical evaluation showed healthy gingival tissues with probing depth of 3 mm on the mesiolingual of tooth #23. Radiographic evaluation showed bone fill of the osseous defect on the mesial of #23. The results of this case suggest that sufficient time should be allowed for healing prior to surgical pocket reduction.

Histological evaluation of the cleaning effectiveness of two reciprocating single-file systems in severely curved root canals: Reciproc versus WaveOne.

PubMed

Carvalho, Maira de Souza; Junior, Emílio Carlos Sponchiado; Bitencourt Garrido, Angela Delfina; Roberti Garcia, Lucas da Fonseca; Franco Marques, André Augusto

2015-01-01

The aim of this study was to evaluate the cleaning effectiveness achieved with two reciprocating single-file systems in severely curved root canals: Reciproc and WaveOne. Twenty-five mesial roots of mandibular molars were randomly separated into two groups, according to the instrumentation system used. The negative control group consisted of five specimens that were not instrumented. The mesial canals (buccal and lingual) in Reciproc Group were instrumented with file R25 and the WaveOne group with the Primary file. The samples were submitted to histological processing and analyzed under a digital microscope. The WaveOne group presented a larger amount of debris than the Reciproc Group, however, without statistically significant difference (P > 0.05). A larger amount of debris in the control group was observed, with statistically significant difference to Reciproc and WaveOne groups (P < 0.05). The two reciprocating single-file instrumentation systems presented similar effectiveness for root canal cleaning.

Cone beam computed tomography evaluation and endodontic management of permanent mandibular second molar with four roots: A rare case report and literature review

PubMed Central

Rajasekhara, Subhashini; Sharath Chandra, SM; Parthasarathy, Late Bharath

2014-01-01

The morphological variation in the number of roots and root canals, especially in multi-rooted teeth is a constant challenge for diagnosis and successful endodontic therapy. Knowledge of the most common anatomic characteristics and their possible variations is fundamental. Although, endodontic management of four-rooted mandibular first molars have been observed on a few occasions in the literature, to the best of our knowledge four-rooted mandibular second molars having two mesial and two distal roots have not been reported. This paper highlights endodontic management of mandibular second molar with four roots (two mesial and two distal) with one canal in each root and its cone beam computed tomography (CBCT) evaluation which was primarily done for post treatment assessment for diagnosing post-endodontic complications, at the same time confirmed our radiographic diagnosis of this variation. This also helped us portraying the anatomy of this rare variation. PMID:25125856

Endodontic management of mandibular third molar with three mesial roots using spiral computed tomography scan as a diagnostic aid: a case report.

PubMed

Tomar, Deepak; Dhingra, Anil; Tomer, Anil; Sharma, Shalini; Sharma, Vivek; Miglani, Anjali

2013-05-01

Aberrant root canal anatomy is diagnostically and clinically challenging for clinicians. The most common root canal configuration of human molars is 2 roots and 3 canals, but various combinations may still exist. Third molars are known to have the most unusual anatomy among human teeth. Restorative, prosthetic, and orthodontic considerations often require endodontic treatment of third molars in order for them to be retained as functional components of the dental arch. The present case report demonstrates unusual root canal morphology of the mandibular third molar. Roentgenographic examination, which included spiral CT scan, revealed 3 separate mesial roots in tooth #48 with 3 independent canals and 3 canal orifices, indicating an endodontic rarity. The present case report puts impetus on exploration of additional canals using advanced diagnostic aids, such as spiral computed tomography, which can have a huge impact on the successful outcome of endodontic therapy. Copyright © 2013 Elsevier Inc. All rights reserved.

Comparison of three-dimensional orthodontic load systems of different commercial archwires for space closure.

PubMed

Gajda, Steven; Chen, Jie

2012-03-01

To experimentally quantify the effects of the loop design on three-dimensional orthodontic load systems of two types of commercial closing loop archwires: Teardrop and Keyhole. An orthodontic force tester and custom-made dentoform were used to measure the load systems produced on two teeth during simulated space closure. The system included three force components along and three moment components about three clinically defined axes on two target teeth: the left maxillary canine and the lateral incisor. The archwires were attached to the dentoform and were activated following a standard clinical procedure. The resulting six load components produced by the two archwires were reported and compared. The results were also compared with those of the T-loop archwire published previously. The three designs deliver similar loading patterns; however, the component magnitudes are dependent on the design. All of the designs result in lingual tipping of the teeth, canine lingual-mesial displacement, canine crown-mesial-in rotation, and incisor crown-distal-in rotation.

Structural covariance mapping delineates medial and medio-lateral temporal networks in déjà vu.

PubMed

Shaw, Daniel Joel; Mareček, Radek; Brázdil, Milan

2016-12-01

Déjà vu (DV) is an eerie phenomenon experienced frequently as an aura of temporal lobe epilepsy, but also reported commonly by healthy individuals. The former pathological manifestation appears to result from aberrant neural activity among brain structures within the medial temporal lobes. Recent studies also implicate medial temporal brain structures in the non-pathological experience of DV, but as one element of a diffuse neuroanatomical correlate; it remains to be seen if neural activity among the medial temporal lobes also underlies this benign manifestation. The present study set out to investigate this. Due to its unpredictable and infrequent occurrence, however, non-pathological DV does not lend itself easily to functional neuroimaging. Instead, we draw on research showing that brain structure covaries among regions that interact frequently as nodes of functional networks. Specifically, we assessed whether grey-matter covariance among structures implicated in non-pathological DV differs according to the frequency with which the phenomenon is experienced. This revealed two diverging patterns of structural covariation: Among the first, comprised primarily of medial temporal structures and the caudate, grey-matter volume becomes more positively correlated with higher frequency of DV experience. The second pattern encompasses medial and lateral temporal structures, among which greater DV frequency is associated with more negatively correlated grey matter. Using a meta-analytic method of co-activation mapping, we demonstrate a higher probability of functional interactions among brain structures constituting the former pattern, particularly during memory-related processes. Our findings suggest that altered neural signalling within memory-related medial temporal brain structures underlies both pathological and non-pathological DV.

The Voronoi spatio-temporal data structure

NASA Astrophysics Data System (ADS)

Mioc, Darka

2002-04-01

Current GIS models cannot integrate the temporal dimension of spatial data easily. Indeed, current GISs do not support incremental (local) addition and deletion of spatial objects, and they can not support the temporal evolution of spatial data. Spatio-temporal facilities would be very useful in many GIS applications: harvesting and forest planning, cadastre, urban and regional planning, and emergency planning. The spatio-temporal model that can overcome these problems is based on a topological model---the Voronoi data structure. Voronoi diagrams are irregular tessellations of space, that adapt to spatial objects and therefore they are a synthesis of raster and vector spatial data models. The main advantage of the Voronoi data structure is its local and sequential map updates, which allows us to automatically record each event and performed map updates within the system. These map updates are executed through map construction commands that are composed of atomic actions (geometric algorithms for addition, deletion, and motion of spatial objects) on the dynamic Voronoi data structure. The formalization of map commands led to the development of a spatial language comprising a set of atomic operations or constructs on spatial primitives (points and lines), powerful enough to define the complex operations. This resulted in a new formal model for spatio-temporal change representation, where each update is uniquely characterized by the numbers of newly created and inactivated Voronoi regions. This is used for the extension of the model towards the hierarchical Voronoi data structure. In this model, spatio-temporal changes induced by map updates are preserved in a hierarchical data structure that combines events and corresponding changes in topology. This hierarchical Voronoi data structure has an implicit time ordering of events visible through changes in topology, and it is equivalent to an event structure that can support temporal data without precise temporal information. This formal model of spatio-temporal change representation is currently applied to retroactive map updates and visualization of map evolution. It offers new possibilities in the domains of temporal GIS, transaction processing, spatio-temporal queries, spatio-temporal analysis, map animation and map visualization.

Soft and Hard Tissue Changes Following Immediate Placement or Immediate Restoration of Single-Tooth Implants in the Esthetic Zone: A Systematic Review and Meta-Analysis.

PubMed

Yan, Qi; Xiao, Li-Qun; Su, Mei-Ying; Mei, Yan; Shi, Bin

This systematic review aimed to compare immediate protocols with conventional protocols of single-tooth implants in terms of changes in the surrounding hard and soft tissue in the esthetic area. Electronic and manual searches were performed in PubMed, EMBASE, Cochrane, and other data systems for research articles published between January 2001 and December 2014. Only randomized controlled trials (RCTs) reporting on hard and or soft tissue characteristics following a single-tooth implant were included. Based on the protocol used in each study, the included studies were categorized into three groups to assess the relationships between the factors and related esthetic indexes. Variables such as marginal bone level changes (mesial, distal, and mean bone level), peri-implant soft tissue changes (papilla level, midbuccal mucosa, and probing depth), and other esthetic indices were taken into consideration. The data were analyzed using RevMan version 5.3, Stata 12, and GRADEpro 3.6.1 software. A total of 13 RCTs met the inclusion criteria. Four studies examined immediate implant placement, five studies examined immediate implant restoration, and four studies examined immediate loading. Comparing the bone level changes following immediate and conventional restoration, no significant differences were found in the bone level of the mesial site (standard mean difference [SMD] = -0.04 mm; 95% confidence interval [CI]: -0.25 to 0.17 mm), the distal site (SMD = -0.15 mm; 95% CI: -0.38 to 0.09 mm), and the mean bone level changes (SMD = 0.05 mm; 95% CI: -0.18 to 0.27 mm). The difference in the marginal bone level changes between immediate and conventional loading was also not statistically significant (SMD = -0.05 mm; 95% CI: -0.15 to 0.06 mm for the mesial site and SMD = -0.02 mm; 95% CI: -0.09 to 0.05 mm for the distal site). Soft tissue changes following immediate and conventional restoration reported no significant differences in the papillae level of the mesial site (SMD = 0.18 mm; 95% CI: -0.00 to 0.37 mm), the papillae level of the distal site (SMD = -0.12 mm; 95% CI: -0.34 to 0.09 mm), and the midbuccal mucosa (SMD = -0.22 mm; 95% CI: -1.29 to 0.85 mm). Within the limitations, it can be concluded that immediately placed, restored, or loaded single-tooth implants in the esthetic zone result in similar hard and soft tissue changes compared with conventional protocols.

Continuous High Frequency Activity: A peculiar SEEG pattern related to specific brain regions

PubMed Central

Melani, Federico; Zelmann, Rina; Mari, Francesco; Gotman, Jean

2015-01-01

Objective While visually marking the high frequency oscillations in the stereo-EEG of epileptic patients, we observed a continuous/semicontinuous activity in the ripple band (80–250 Hz), which we defined continuous High Frequency Activity (HFA). We aim to analyze in all brain regions the occurrence and significance of this particular pattern. Methods Twenty patients implanted in mesial temporal and neocortical areas were studied. One minute of slow-wave sleep was reviewed. The background was classified as continuous/semicontinuous, irregular, or sporadic based on the duration of the fast oscillations. Each channel was classified as inside/outside the seizure onset zone (SOZ) or a lesion. Results The continuous/semicontinuous HFA occurred in 54 of the 790 channels analyzed, with a clearly higher prevalence in hippocampus and occipital lobe. No correlation was found with the SOZ or lesions. In the occipital lobe the continuous/semicontinuous HFA was present independently of whether eyes were open or closed. Conclusions We describe what appears to be a new physiological High Frequency Activity, independent of epileptogenicity, present almost exclusively in the hippocampus and occipital cortex but independent of the alpha rhythm. Significance The continuous HFA may be an intrinsic characteristic of specific brain regions, reflecting a particular type of physiological neuronal activity. PMID:23768436

Detection of changes of high-frequency activity by statistical time-frequency analysis in epileptic spikes

PubMed Central

Kobayashi, Katsuhiro; Jacobs, Julia; Gotman, Jean

2013-01-01

Objective A novel type of statistical time-frequency analysis was developed to elucidate changes of high-frequency EEG activity associated with epileptic spikes. Methods The method uses the Gabor Transform and detects changes of power in comparison to background activity using t-statistics that are controlled by the false discovery rate (FDR) to correct type I error of multiple testing. The analysis was applied to EEGs recorded at 2000 Hz from three patients with mesial temporal lobe epilepsy. Results Spike-related increase of high-frequency oscillations (HFOs) was clearly shown in the FDR-controlled t-spectra: it was most dramatic in spikes recorded from the hippocampus when the hippocampus was the seizure onset zone (SOZ). Depression of fast activity was observed immediately after the spikes, especially consistently in the discharges from the hippocampal SOZ. It corresponded to the slow wave part in case of spike-and-slow-wave complexes, but it was noted even in spikes without apparent slow waves. In one patient, a gradual increase of power above 200 Hz preceded spikes. Conclusions FDR-controlled t-spectra clearly detected the spike-related changes of HFOs that were unclear in standard power spectra. Significance We developed a promising tool to study the HFOs that may be closely linked to the pathophysiology of epileptogenesis. PMID:19394892