Memory loss and memory reorganization patterns in temporal lobe epilepsy patients undergoing anterior temporal lobe resection, as demonstrated by pre-versus post-operative functional MRI.

PubMed

Limotai, Chusak; McLachlan, Richard S; Hayman-Abello, Susan; Hayman-Abello, Brent; Brown, Suzan; Bihari, Frank; Mirsattari, Seyed M

2018-06-19

This study was aimed to longitudinally assess memory function and whole-brain memory circuit reorganization in patients with temporal lobe epilepsy (TLE) by comparing activation potentials before versus after anterior temporal lobe (ATL) resection. Nineteen patients with medically-intractable TLE (10 left TLE, 9 right TLE) and 15 healthy controls were enrolled. Group analyses were conducted pre- and post-ATL of a novelty complex scene-encoding paradigm comparing areas of blood oxygen-level-dependent (BOLD) signal activations on functional magnetic resonance imaging (fMRI). None of the pre-operative patient characteristics we studied predicted the extent of pre- to post-operative memory loss. On fMRI, extra-temporal activations were detected pre-operatively in both LTLE and RTLE, particularly in the frontal lobe. Greater activations also were noted in the contralateral hippocampus and parahippocampus in both groups. Performing within-subject comparisons, post-op relative to pre-op, pronounced ipsilateral activations were identified in the left parahippocampal gyrus in LTLE, versus the right middle temporal gyrus in RTLE patients. Memory function was impaired pre-operatively but declined after ATL resection in both RTLE and LTLE patients. Post-operative fMRI results indicate possible functional adaptations to ATL loss, primarily occurring within the left parahippocampal gyrus versus right middle temporal gyrus in LTLE versus RTLE patients, respectively. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

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

Microsurgical techniques in temporal lobe epilepsy.

PubMed

Alonso Vanegas, Mario A; Lew, Sean M; Morino, Michiharu; Sarmento, Stenio A

2017-04-01

Temporal lobe resection is the most prevalent epilepsy surgery procedure. However, there is no consensus on the best surgical approach to treat temporal lobe epilepsy. Complication rates are low and efficacy is very high regarding seizures after such procedures. However, there is still ample controversy regarding the best surgical approach to warrant maximum seizure control with minimal functional deficits. We describe the most frequently used microsurgical techniques for removal of both the lateral and mesial temporal lobe structures in the treatment of medically intractable temporal lobe epilepsy (TLE) due to mesial temporal sclerosis (corticoamygdalohippocampectomy and selective amygdalohippocampectomy). The choice of surgical technique appears to remain a surgeon's preference for the near future. Meticulous surgical technique and thorough three-dimensional microsurgical knowledge are essentials for obtaining the best results. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

What role does the anterior temporal lobe play in sentence-level processing? Neural correlates of syntactic processing in semantic PPA

PubMed Central

Wilson, Stephen M.; DeMarco, Andrew T.; Henry, Maya L.; Gesierich, Benno; Babiak, Miranda; Mandelli, Maria Luisa; Miller, Bruce L.; Gorno-Tempini, Maria Luisa

2014-01-01

Neuroimaging and neuropsychological studies have implicated the anterior temporal lobe (ATL) in sentence-level processing, with syntactic structure-building and/or combinatorial semantic processing suggested as possible roles. A potential challenge to the view that the ATL is involved in syntactic aspects of sentence processing comes from the clinical syndrome of semantic variant primary progressive aphasia (semantic PPA, also known as semantic dementia). In semantic PPA, bilateral neurodegeneration of the anterior temporal lobes is associated with profound lexical semantic deficits, yet syntax is strikingly spared. The goal of this study was to investigate the neural correlates of syntactic processing in semantic PPA, in order to determine which regions normally involved in syntactic processing are damaged in semantic PPA, and whether spared syntactic processing depends on preserved functionality of intact regions, preserved functionality of atrophic regions, or compensatory functional reorganization. We scanned 20 individuals with semantic PPA and 24 age-matched controls using structural and functional MRI. Participants performed a sentence comprehension task that emphasized syntactic processing and minimized lexical semantic demands. We found that in controls, left inferior frontal and left posterior temporal regions were modulated by syntactic processing, while anterior temporal regions were not significantly modulated. In the semantic PPA group, atrophy was most severe in the anterior temporal lobes, but extended to the posterior temporal regions involved in syntactic processing. Functional activity for syntactic processing was broadly similar in patients and controls; in particular, whole-brain analyses revealed no significant differences between patients and controls in the regions modulated by syntactic processing. The atrophic left anterior temporal lobe did show abnormal functionality in semantic PPA patients, however this took the unexpected form of a failure to deactivate. Taken together, our findings indicate that spared syntactic processing in semantic PPA depends on preserved functionality of structurally intact left frontal regions and moderately atrophic left posterior temporal regions, but no functional reorganization was apparent as a consequence of anterior temporal atrophy and dysfunction. These results suggest that the role of the anterior temporal lobe in sentence processing is less likely to relate to syntactic structure-building, and more likely to relate to higher level processes such as combinatorial semantic processing. PMID:24345172

Memory Functions following Surgery for Temporal Lobe Epilepsy in Children

ERIC Educational Resources Information Center

Jambaque, Isabelle; Dellatolas, Georges; Fohlen, Martine; Bulteau, Christine; Watier, Laurence; Dorfmuller, Georg; Chiron, Catherine; Delalande, Olivier

2007-01-01

Surgical treatment appears to improve the cognitive prognosis in children undergoing surgery for temporal lobe epilepsy (TLE). The beneficial effects of surgery on memory functions, particularly on material-specific memory, are more difficult to assess because of potentially interacting factors such as age range, intellectual level,…

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…

Relationship of Temporal Lobe Volumes to Neuropsychological Test Performance in Healthy Children

PubMed Central

Wells, Carolyn T.; Matson, Melissa A.; Kates, Wendy R.; Hay, Trisha; Horska, Alena

2008-01-01

Ecological validity of neuropsychological assessment includes the ability of tests to predict real-world functioning and/or covary with brain structures. Studies have examined the relationship between adaptive skills and test performance, with less focus on the association between regional brain volumes and neurobehavioral function in healthy children. The present study examined the relationship between temporal lobe gray matter volumes and performance on two neuropsychological tests hypothesized to measure temporal lobe functioning (Visual Perception-VP; Peabody Picture Vocabulary Test, Third Edition-PPVT-III) in 48 healthy children ages 5-18 years. After controlling for age and gender, left and right temporal and left occipital volumes were significant predictors of VP. Left and right frontal and temporal volumes were significant predictors of PPVT-III. Temporal volume emerged as the strongest lobar correlate with both tests. These results provide convergent and discriminant validity supporting VP as a measure of the “what” system; but suggest the PPVT-III as a complex measure of receptive vocabulary, potentially involving executive function demands. PMID:18513844

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.

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.

The neurobiology of cognitive disorders in temporal lobe epilepsy

PubMed Central

Bell, Brian; Lin, Jack J.; Seidenberg, Michael; Hermann, Bruce

2013-01-01

Cognitive impairment and especially memory disruption is a major complicating feature of the epilepsies. In this review we begin with a focus on the problem of memory impairment in temporal lobe epilepsy. We start with a brief overview of the early development of knowledge regarding the anatomic substrates of memory disorder in temporal lobe epilepsy, followed by discussion of the refinement of that knowledge over time as informed by the outcomes of epilepsy surgery (anterior temporal lobectomy) and the clinical efforts to predict those patients at greatest risk of adverse cognitive outcomes following epilepsy surgery. These efforts also yielded new theoretical insights regarding the function of the human hippocampus and a few examples of these insights are touched on briefly. Finally, the vastly changing view of temporal lobe epilepsy is examined including findings demonstrating that anatomic abnormalities extend far outside the temporal lobe, cognitive impairments extend beyond memory function, with linkage of these distributed cognitive and anatomic abnormalities pointing to a new understanding of the anatomic architecture of cognitive impairment in epilepsy. Challenges remain in understanding the origin of these cognitive and anatomic abnormalities, their progression over time, and most importantly, how to intervene to protect cognitive and brain health in epilepsy. PMID:21304484

Brain regions underlying word finding difficulties in temporal lobe epilepsy.

PubMed

Trebuchon-Da Fonseca, Agnes; Guedj, Eric; Alario, F-Xavier; Laguitton, Virginie; Mundler, Olivier; Chauvel, Patrick; Liegeois-Chauvel, Catherine

2009-10-01

Word finding difficulties are often reported by epileptic patients with seizures originating from the language dominant cerebral hemisphere, for example, in temporal lobe epilepsy. Evidence regarding the brain regions underlying this deficit comes from studies of peri-operative electro-cortical stimulation, as well as post-surgical performance. This evidence has highlighted a role for the anterior part of the dominant temporal lobe in oral word production. These conclusions contrast with findings from activation studies involving healthy speakers or acute ischaemic stroke patients, where the region most directly related to word retrieval appears to be the posterior part of the left temporal lobe. To clarify the neural basis of word retrieval in temporal lobe epilepsy, we tested forty-three drug-resistant temporal lobe epilepsy patients (28 left, 15 right). Comprehensive neuropsychological and language assessments were performed. Single spoken word production was elicited with picture or definition stimuli. Detailed analysis allowed the distinction of impaired word retrieval from other possible causes of naming failure. Finally, the neural substrate of the deficit was assessed by correlating word retrieval performance and resting-state brain metabolism in 18 fluoro-2-deoxy-d-glucose-Positron Emission Tomography. Naming difficulties often resulted from genuine word retrieval failures (anomic states), both in picture and in definition tasks. Left temporal lobe epilepsy patients showed considerably worse performance than right temporal lobe epilepsy patients. Performance was poorer in the definition than in the picture task. Across patients and the left temporal lobe epilepsy subgroup, frequency of anomic state was negatively correlated with resting-state brain metabolism in left posterior and basal temporal regions (Brodmann's area 20-37-39). These results show the involvement of posterior temporal regions, within a larger antero-posterior-basal temporal network, in the specific process of word retrieval in temporal lobe epilepsy. A tentative explanation for these findings is that epilepsy induces functional deafferentation between anterior temporal structures devoted to semantic processing and neocortical posterior temporal structures devoted to lexical processing.

Semantic memory is impaired in patients with unilateral anterior temporal lobe resection for temporal lobe epilepsy.

PubMed

Lambon Ralph, Matthew A; Ehsan, Sheeba; Baker, Gus A; Rogers, Timothy T

2012-01-01

Contemporary clinical and basic neuroscience studies have increasingly implicated the anterior temporal lobe regions, bilaterally, in the formation of coherent concepts. Mounting convergent evidence for the importance of the anterior temporal lobe in semantic memory is found in patients with bilateral anterior temporal lobe damage (e.g. semantic dementia), functional neuroimaging and repetitive transcranial magnetic stimulation studies. If this proposal is correct, then one might expect patients with anterior temporal lobe resection for long-standing temporal lobe epilepsy to be semantically impaired. Such patients, however, do not present clinically with striking comprehension deficits but with amnesia and variable anomia, leading some to conclude that semantic memory is intact in resection for temporal lobe epilepsy and thus casting doubt over the conclusions drawn from semantic dementia and linked basic neuroscience studies. Whilst there is a considerable neuropsychological literature on temporal lobe epilepsy, few studies have probed semantic memory directly, with mixed results, and none have undertaken the same type of systematic investigation of semantic processing that has been conducted with other patient groups. In this study, therefore, we investigated the semantic performance of 20 patients with resection for chronic temporal lobe epilepsy with a full battery of semantic assessments, including more sensitive measures of semantic processing. The results provide a bridge between the current clinical observations about resection for temporal lobe epilepsy and the expectations from semantic dementia and other neuroscience findings. Specifically, we found that on simple semantic tasks, the patients' accuracy fell in the normal range, with the exception that some patients with left resection for temporal lobe epilepsy had measurable anomia. Once the semantic assessments were made more challenging, by probing specific-level concepts, lower frequency/more abstract items or measuring reaction times on semantic tasks versus those on difficulty-matched non-semantic assessments, evidence of a semantic impairment was found in all individuals. We conclude by describing a unified, computationally inspired framework for capturing the variable degrees of semantic impairment found across different patient groups (semantic dementia, temporal lobe epilepsy, glioma and stroke) as well as semantic processing in neurologically intact participants.

Semantic memory is impaired in patients with unilateral anterior temporal lobe resection for temporal lobe epilepsy

PubMed Central

Ehsan, Sheeba; Baker, Gus A.; Rogers, Timothy T.

2012-01-01

Contemporary clinical and basic neuroscience studies have increasingly implicated the anterior temporal lobe regions, bilaterally, in the formation of coherent concepts. Mounting convergent evidence for the importance of the anterior temporal lobe in semantic memory is found in patients with bilateral anterior temporal lobe damage (e.g. semantic dementia), functional neuroimaging and repetitive transcranial magnetic stimulation studies. If this proposal is correct, then one might expect patients with anterior temporal lobe resection for long-standing temporal lobe epilepsy to be semantically impaired. Such patients, however, do not present clinically with striking comprehension deficits but with amnesia and variable anomia, leading some to conclude that semantic memory is intact in resection for temporal lobe epilepsy and thus casting doubt over the conclusions drawn from semantic dementia and linked basic neuroscience studies. Whilst there is a considerable neuropsychological literature on temporal lobe epilepsy, few studies have probed semantic memory directly, with mixed results, and none have undertaken the same type of systematic investigation of semantic processing that has been conducted with other patient groups. In this study, therefore, we investigated the semantic performance of 20 patients with resection for chronic temporal lobe epilepsy with a full battery of semantic assessments, including more sensitive measures of semantic processing. The results provide a bridge between the current clinical observations about resection for temporal lobe epilepsy and the expectations from semantic dementia and other neuroscience findings. Specifically, we found that on simple semantic tasks, the patients’ accuracy fell in the normal range, with the exception that some patients with left resection for temporal lobe epilepsy had measurable anomia. Once the semantic assessments were made more challenging, by probing specific-level concepts, lower frequency/more abstract items or measuring reaction times on semantic tasks versus those on difficulty-matched non-semantic assessments, evidence of a semantic impairment was found in all individuals. We conclude by describing a unified, computationally inspired framework for capturing the variable degrees of semantic impairment found across different patient groups (semantic dementia, temporal lobe epilepsy, glioma and stroke) as well as semantic processing in neurologically intact participants. PMID:22287382

Dichotic Listening and School Performance in Dyslexia

ERIC Educational Resources Information Center

Helland, Turid; Asbjornsen, Arve E.; Hushovd, Aud Ellen; Hugdahl, Kenneth

2008-01-01

This study focused on the relationship between school performance and performance on a dichotic listening (DL) task in dyslexic children. Dyslexia is associated with impaired phonological processing, related to functions in the left temporal lobe. DL is a frequently used task to assess functions of the left temporal lobe. Due to the predominance…

Medial Temporal Lobe Activity during Source Retrieval Reflects Information Type, Not Memory Strength

ERIC Educational Resources Information Center

Diana, Rachel A.; Yonelinas, Andrew P.; Ranganath, Charan

2010-01-01

The medial temporal lobes (MTLs) are critical for episodic memory but the functions of MTL subregions are controversial. According to memory strength theory, MTL subregions collectively support declarative memory in a graded manner. In contrast, other theories assert that MTL subregions support functionally distinct processes. For instance, one…

Hippocampal Atrophy Is Associated with Altered Hippocampus-Posterior Cingulate Cortex Connectivity in Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis.

PubMed

Shih, Y C; Tseng, C E; Lin, F-H; Liou, H H; Tseng, W Y I

2017-03-01

Unilateral mesial temporal lobe epilepsy and hippocampal sclerosis have structural and functional abnormalities in the mesial temporal regions. To gain insight into the pathophysiology of the epileptic network in mesial temporal lobe epilepsy with hippocampal sclerosis, we aimed to clarify the relationships between hippocampal atrophy and the altered connection between the hippocampus and the posterior cingulate cortex in patients with mesial temporal lobe epilepsy with hippocampal sclerosis. Fifteen patients with left mesial temporal lobe epilepsy with hippocampal sclerosis and 15 healthy controls were included in the study. Multicontrast MR imaging, including high-resolution T1WI, diffusion spectrum imaging, and resting-state fMRI, was performed to measure the hippocampal volume, structural connectivity of the inferior cingulum bundle, and intrinsic functional connectivity between the hippocampus and the posterior cingulate cortex, respectively. Compared with controls, patients had decreased left hippocampal volume (volume ratio of the hippocampus and controls, 0.366% ± 0.029%; patients, 0.277% ± 0.063%, corrected P = .002), structural connectivity of the bilateral inferior cingulum bundle (generalized fractional anisotropy, left: controls, 0.234 ± 0.020; patients, 0.193 ± 0.022, corrected P = .0001, right: controls, 0.226 ± 0.022; patients, 0.208 ± 0.017, corrected P = .047), and intrinsic functional connectivity between the left hippocampus and the left posterior cingulate cortex (averaged z-value: controls, 0.314 ± 0.152; patients, 0.166 ± 0.062). The left hippocampal volume correlated with structural connectivity positively (standardized β = 0.864, P = .001), but it had little correlation with intrinsic functional connectivity (standardized β = -0.329, P = .113). On the contralesional side, the hippocampal volume did not show any significant correlation with structural connectivity or intrinsic functional connectivity ( F 2,12 = 0.284, P = .757, R 2 = 0.045). In left mesial temporal lobe epilepsy with hippocampal sclerosis, the left inferior cingulum bundle undergoes degeneration in tandem with the left hippocampal volume, whereas intrinsic functional connectivity seems to react by compensating the loss of connectivity. Such insight might be helpful in understanding the development of the epileptic network in left mesial temporal lobe epilepsy with hippocampal sclerosis. © 2017 by American Journal of Neuroradiology.

Medial temporal lobe atrophy relates more strongly to sleep-wake rhythm fragmentation than to age or any other known risk.

PubMed

Van Someren, Eus J W; Oosterman, J M; Van Harten, B; Vogels, R L; Gouw, A A; Weinstein, H C; Poggesi, A; Scheltens, Ph; Scherder, E J A

2018-06-01

Atrophy of the medial temporal lobe of the brain is key to memory function and memory complaints in old age. While age and some morbidities are major risk factors for medial temporal lobe atrophy, individual differences remain, and mechanisms are insufficiently known. The largest combined neuroimaging and whole genome study to date indicates that medial temporal lobe volume is most associated with common polymorphisms in the GRIN2B gene that encodes for the 2B subunit (NR2B) of the NMDA receptor. Because sleep disruption induces a selective loss of NR2B from hippocampal synaptic membranes in rodents, and because of several other reports on medial temporal lobe sensitivity to sleep disruption, we hypothesized a contribution of the typical age-related increase in sleep-wake rhythm fragmentation to medial temporal lobe atrophy. Magnetic resonance imaging and actigraphy in 138 aged individuals showed that individual differences in sleep-wake rhythm fragmentation accounted for more (19%) of the variance in medial temporal lobe atrophy than age did (15%), or any of a list of health and brain structural indicators. The findings suggest a role of sleep-wake rhythm fragmentation in age-related medial temporal lobe atrophy, that might in part be prevented or reversible. Copyright © 2018. Published by Elsevier Inc.

Consciousness and epilepsy: why are complex-partial seizures complex?

PubMed Central

Englot, Dario J.; Blumenfeld, Hal

2010-01-01

Why do complex-partial seizures in temporal lobe epilepsy (TLE) cause a loss of consciousness? Abnormal function of the medial temporal lobe is expected to cause memory loss, but it is unclear why profoundly impaired consciousness is so common in temporal lobe seizures. Recent exciting advances in behavioral, electrophysiological, and neuroimaging techniques spanning both human patients and animal models may allow new insights into this old question. While behavioral automatisms are often associated with diminished consciousness during temporal lobe seizures, impaired consciousness without ictal motor activity has also been described. Some have argued that electrographic lateralization of seizure activity to the left temporal lobe is most likely to cause impaired consciousness, but the evidence remains equivocal. Other data correlates ictal consciousness in TLE with bilateral temporal lobe involvement of seizure spiking. Nevertheless, it remains unclear why bilateral temporal seizures should impair responsiveness. Recent evidence has shown that impaired consciousness during temporal lobe seizures is correlated with large-amplitude slow EEG activity and neuroimaging signal decreases in the frontal and parietal association cortices. This abnormal decreased function in the neocortex contrasts with fast polyspike activity and elevated cerebral blood flow in limbic and other subcortical structures ictally. Our laboratory has thus proposed the “network inhibition hypothesis,” in which seizure activity propagates to subcortical regions necessary for cortical activation, allowing the cortex to descend into an inhibited state of unconsciousness during complex-partial temporal lobe seizures. Supporting this hypothesis, recent rat studies during partial limbic seizures have shown that behavioral arrest is associated with frontal cortical slow waves, decreased neuronal firing, and hypometabolism. Animal studies further demonstrate that cortical deactivation and behavioral changes depend on seizure spread to subcortical structures including the lateral septum. Understanding the contributions of network inhibition to impaired consciousness in TLE is an important goal, as recurrent limbic seizures often result in cortical dysfunction during and between epileptic events that adversely affects patients’ quality of life. PMID:19818900

Cognitive Function Before and After Intensity-Modulated Radiation Therapy in Patients With Nasopharyngeal Carcinoma: A Prospective Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsiao, Kuan-Yin; Department of Medical Imaging and Radiological Science, I-Shou University, Kaohsiung, Taiwan; Yeh, Shyh-An, E-mail: yehsa@hotmail.co

Purpose: To evaluate the effects of radiation therapy (RT) on neurocognitive function in patients with nasopharyngeal carcinoma (NPC). Methods and Materials: Thirty patients with NPC treated with intensity-modulated RT were included. Dose-volume histograms of the temporal lobes were obtained in every patient. Neurocognitive tests were administered individually to each patient 1 day before initiation of RT and at least 12 months after completion of RT. Cognitive functioning status was evaluated as change in scores over time. Results: Among the total of 30 patients, 23 patients (76.7%) had significantly lower post-RT cognitive functioning scores compared with their pre-RT scores (p =more » 0.033). The cognitive functioning scores had significantly declined in the domains of short-term memory, language abilities, and list-generating fluency (p = 0.020, 0.023, and 0.001, respectively). Compared with patients with a mean dose to the temporal lobes of 36 Gy or less, patients with a mean dose of greater than 36 Gy had a significantly greater reduction in cognitive functioning scores (p = 0.017). Patients in whom V60 of the temporal lobes (i.e., the percentage of the temporal lobe volume that had received >60 Gy) was greater than 10% also had a greater reduction in cognitive functioning scores than those in whom V60 was 10% or less (p = 0.039). Conclusions: The results of our study indicated that RT could have deleterious effects on cognitive function in patients with NPC. Efforts should be made to reduce the radiation dose and irradiated volume of temporal lobes without compromising the coverage of target volume.« less

Abnormal activation of the occipital lobes during emotion picture processing in major depressive disorder patients

PubMed Central

Li, Jianying; Xu, Cheng; Cao, Xiaohua; Gao, Qiang; Wang, Yan; Wang, Yanfang; Peng, Juyi; Zhang, Kerang

2013-01-01

A large number of studies have demonstrated that depression patients have cognitive dysfunction. With recently developed brain functional imaging, studies have focused on changes in brain function to investigate cognitive changes. However, there is still controversy regarding abnormalities in brain functions or correlation between cognitive impairment and brain function changes. Thus, it is important to design an emotion-related task for research into brain function changes. We selected positive, neutral, and negative pictures from the International Affective Picture System. Patients with major depressive disorder were asked to judge emotion pictures. In addition, functional MRI was performed to synchronously record behavior data and imaging data. Results showed that the total correct rate for recognizing pictures was lower in patients compared with normal controls. Moreover, the consistency for recognizing pictures for depressed patients was worse than normal controls, and they frequently recognized positive pictures as negative pictures. The consistency for recognizing pictures was negatively correlated with the Hamilton Depression Rating Scale. Functional MRI suggested that the activation of some areas in the frontal lobe, temporal lobe, parietal lobe, limbic lobe, and cerebellum was enhanced, but that the activation of some areas in the frontal lobe, parietal lobe and occipital lobe was weakened while the patients were watching positive and neutral pictures compared with normal controls. The activation of some areas in the frontal lobe, temporal lobe, parietal lobe, and limbic lobe was enhanced, but the activation of some areas in the occipital lobe were weakened while the patients were watching the negative pictures compared with normal controls. These findings indicate that patients with major depressive disorder have negative cognitive disorder and extensive brain dysfunction. Thus, reduced activation of the occipital lobe may be an initiating factor for cognitive disorder in depressed patients. PMID:25206466

Cerebellar Directed Optogenetic Intervention Inhibits Spontaneous Hippocampal Seizures in a Mouse Model of Temporal Lobe Epilepsy1 2

PubMed Central

Szabo, Gergely G.; Armstrong, Caren; Oijala, Mikko; Soltesz, Ivan

2014-01-01

Abstract Cover Figure Krook-Magnuson et al. report a bidirectional functional connectivity between the hippocampus and the cerebellum in a mouse model of temporal lobe epilepsy, and demonstrate that cerebellar directed on-demand optogenetic intervention can stop seizures recorded from the hippocampus. Temporal lobe epilepsy is often medically refractory and new targets for intervention are needed. We used a mouse model of temporal lobe epilepsy, on-line seizure detection, and responsive optogenetic intervention to investigate the potential for cerebellar control of spontaneous temporal lobe seizures. Cerebellar targeted intervention inhibited spontaneous temporal lobe seizures during the chronic phase of the disorder. We further report that the direction of modulation as well as the location of intervention within the cerebellum can affect the outcome of intervention. Specifically, on-demand optogenetic excitation or inhibition of parvalbumin-expressing neurons, including Purkinje cells, in the lateral or midline cerebellum results in a decrease in seizure duration. In contrast, a consistent reduction in spontaneous seizure frequency occurs uniquely with on-demand optogenetic excitation of the midline cerebellum, and was not seen with intervention directly targeting the hippocampal formation. These findings demonstrate that the cerebellum is a powerful modulator of temporal lobe epilepsy, and that intervention targeting the cerebellum as a potential therapy for epilepsy should be revisited. PMID:25599088

Mapping a lateralization gradient within the ventral stream for auditory speech perception.

PubMed

Specht, Karsten

2013-01-01

Recent models on speech perception propose a dual-stream processing network, with a dorsal stream, extending from the posterior temporal lobe of the left hemisphere through inferior parietal areas into the left inferior frontal gyrus, and a ventral stream that is assumed to originate in the primary auditory cortex in the upper posterior part of the temporal lobe and to extend toward the anterior part of the temporal lobe, where it may connect to the ventral part of the inferior frontal gyrus. This article describes and reviews the results from a series of complementary functional magnetic resonance imaging studies that aimed to trace the hierarchical processing network for speech comprehension within the left and right hemisphere with a particular focus on the temporal lobe and the ventral stream. As hypothesized, the results demonstrate a bilateral involvement of the temporal lobes in the processing of speech signals. However, an increasing leftward asymmetry was detected from auditory-phonetic to lexico-semantic processing and along the posterior-anterior axis, thus forming a "lateralization" gradient. This increasing leftward lateralization was particularly evident for the left superior temporal sulcus and more anterior parts of the temporal lobe.

Mapping a lateralization gradient within the ventral stream for auditory speech perception

PubMed Central

Specht, Karsten

2013-01-01

Recent models on speech perception propose a dual-stream processing network, with a dorsal stream, extending from the posterior temporal lobe of the left hemisphere through inferior parietal areas into the left inferior frontal gyrus, and a ventral stream that is assumed to originate in the primary auditory cortex in the upper posterior part of the temporal lobe and to extend toward the anterior part of the temporal lobe, where it may connect to the ventral part of the inferior frontal gyrus. This article describes and reviews the results from a series of complementary functional magnetic resonance imaging studies that aimed to trace the hierarchical processing network for speech comprehension within the left and right hemisphere with a particular focus on the temporal lobe and the ventral stream. As hypothesized, the results demonstrate a bilateral involvement of the temporal lobes in the processing of speech signals. However, an increasing leftward asymmetry was detected from auditory–phonetic to lexico-semantic processing and along the posterior–anterior axis, thus forming a “lateralization” gradient. This increasing leftward lateralization was particularly evident for the left superior temporal sulcus and more anterior parts of the temporal lobe. PMID:24106470

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.

Different forms of effective connectivity in primate frontotemporal pathways.

PubMed

Petkov, Christopher I; Kikuchi, Yukiko; Milne, Alice E; Mishkin, Mortimer; Rauschecker, Josef P; Logothetis, Nikos K

2015-01-23

It is generally held that non-primary sensory regions of the brain have a strong impact on frontal cortex. However, the effective connectivity of pathways to frontal cortex is poorly understood. Here we microstimulate sites in the superior temporal and ventral frontal cortex of monkeys and use functional magnetic resonance imaging to evaluate the functional activity resulting from the stimulation of interconnected regions. Surprisingly, we find that, although certain earlier stages of auditory cortical processing can strongly activate frontal cortex, downstream auditory regions, such as voice-sensitive cortex, appear to functionally engage primarily an ipsilateral temporal lobe network. Stimulating other sites within this activated temporal lobe network shows strong activation of frontal cortex. The results indicate that the relative stage of sensory processing does not predict the level of functional access to the frontal lobes. Rather, certain brain regions engage local networks, only parts of which have a strong functional impact on frontal cortex.

Different forms of effective connectivity in primate frontotemporal pathways

PubMed Central

Petkov, Christopher I.; Kikuchi, Yukiko; Milne, Alice E.; Mishkin, Mortimer; Rauschecker, Josef P.; Logothetis, Nikos K.

2015-01-01

It is generally held that non-primary sensory regions of the brain have a strong impact on frontal cortex. However, the effective connectivity of pathways to frontal cortex is poorly understood. Here we microstimulate sites in the superior temporal and ventral frontal cortex of monkeys and use functional magnetic resonance imaging to evaluate the functional activity resulting from the stimulation of interconnected regions. Surprisingly, we find that, although certain earlier stages of auditory cortical processing can strongly activate frontal cortex, downstream auditory regions, such as voice-sensitive cortex, appear to functionally engage primarily an ipsilateral temporal lobe network. Stimulating other sites within this activated temporal lobe network shows strong activation of frontal cortex. The results indicate that the relative stage of sensory processing does not predict the level of functional access to the frontal lobes. Rather, certain brain regions engage local networks, only parts of which have a strong functional impact on frontal cortex. PMID:25613079

Temporal lobe stimulation reveals anatomic distinction between auditory naming processes.

PubMed

Hamberger, M J; Seidel, W T; Goodman, R R; Perrine, K; McKhann, G M

2003-05-13

Language errors induced by cortical stimulation can provide insight into function(s) supported by the area stimulated. The authors observed that some stimulation-induced errors during auditory description naming were characterized by tip-of-the-tongue responses or paraphasic errors, suggesting expressive difficulty, whereas others were qualitatively different, suggesting receptive difficulty. They hypothesized that these two response types reflected disruption at different stages of auditory verbal processing and that these "subprocesses" might be supported by anatomically distinct cortical areas. To explore the topographic distribution of error types in auditory verbal processing. Twenty-one patients requiring left temporal lobe surgery underwent preresection language mapping using direct cortical stimulation. Auditory naming was tested at temporal sites extending from 1 cm from the anterior tip to the parietal operculum. Errors were dichotomized as either "expressive" or "receptive." The topographic distribution of error types was explored. Sites associated with the two error types were topographically distinct from one another. Most receptive sites were located in the middle portion of the superior temporal gyrus (STG), whereas most expressive sites fell outside this region, scattered along lateral temporal and temporoparietal cortex. Results raise clinical questions regarding the inclusion of the STG in temporal lobe epilepsy surgery and suggest that more detailed cortical mapping might enable better prediction of postoperative language decline. From a theoretical perspective, results carry implications regarding the understanding of structure-function relations underlying temporal lobe mediation of auditory language processing.

Diffusion tensor imaging of normal-appearing white matter in mild cognitive impairment and early Alzheimer disease: preliminary evidence of axonal degeneration in the temporal lobe.

PubMed

Huang, J; Friedland, R P; Auchus, A P

2007-01-01

Diffusion tensor imaging (DTI) is a sensitive technique for studying cerebral white matter. We used DTI to characterize microstructural white matter changes and their associations with cognitive dysfunction in Alzheimer disease (AD) and mild cognitive impairment (MCI). We studied elderly subjects with mild AD (n = 6), MCI (n = 11), or normal cognition (n = 8). A standardized clinical and neuropsychological evaluation was conducted on each subject. DTI images were acquired, and fractional anisotropy (FA), axial diffusivity (DA), and radial diffusivity (DR) of normal-appearing white matter (NAWM) in frontal, temporal, parietal, and occipital lobes were determined. These diffusion measurements were compared across the 3 groups, and significant differences were further examined for correlations with tests of cognitive function. Compared with normal controls, AD subjects demonstrated decreased FA and increased DR in the temporal, parietal, and frontal NAWM and decreased DA in temporal NAWM. MCI subjects also showed decreased FA and decreased DA in temporal NAWM, with decreased FA and increased DR in parietal NAWM. Diffusion measurements showed no differences in occipital NAWM. Across all subjects, temporal lobe FA and DR correlated with episodic memory, frontal FA and DR correlated with executive function, and parietal DR significantly correlated with visuospatial ability. We found evidence for functionally relevant microstructural changes in the NAWM of patients with AD and MCI. These changes were present in brain regions serving higher cortical functions, but not in regions serving primary functions, and are consistent with a hypothesized loss of axonal processes in the temporal lobe.

Memory network plasticity after temporal lobe resection: a longitudinal functional imaging study

PubMed Central

Sidhu, Meneka K.; Stretton, Jason; Winston, Gavin P.; McEvoy, Andrew W.; Symms, Mark; Thompson, Pamela J.; Koepp, Matthias J.

2016-01-01

Abstract Anterior temporal lobe resection can control seizures in up to 80% of patients with temporal lobe epilepsy. Memory decrements are the main neurocognitive complication. Preoperative functional reorganization has been described in memory networks, but less is known of postoperative reorganization. We investigated reorganization of memory-encoding networks preoperatively and 3 and 12 months after surgery. We studied 36 patients with unilateral medial temporal lobe epilepsy (19 right) before and 3 and 12 months after anterior temporal lobe resection. Fifteen healthy control subjects were studied at three equivalent time points. All subjects had neuropsychological testing at each of the three time points. A functional magnetic resonance imaging memory-encoding paradigm of words and faces was performed with subsequent out-of-scanner recognition assessments. Changes in activations across the time points in each patient group were compared to changes in the control group in a single flexible factorial analysis. Postoperative change in memory across the time points was correlated with postoperative activations to investigate the efficiency of reorganized networks. Left temporal lobe epilepsy patients showed increased right anterior hippocampal and frontal activation at both 3 and 12 months after surgery relative to preoperatively, for word and face encoding, with a concomitant reduction in left frontal activation 12 months postoperatively. Right anterior hippocampal activation 12 months postoperatively correlated significantly with improved verbal learning in patients with left temporal lobe epilepsy from preoperatively to 12 months postoperatively. Preoperatively, there was significant left posterior hippocampal activation that was sustained 3 months postoperatively at word encoding, and increased at face encoding. For both word and face encoding this was significantly reduced from 3 to 12 months postoperatively. Patients with right temporal lobe epilepsy showed increased left anterior hippocampal activation on word encoding from 3 to 12 months postoperatively compared to preoperatively. On face encoding, left anterior hippocampal activations were present preoperatively and 12 months postoperatively. Left anterior hippocampal and orbitofrontal cortex activations correlated with improvements in both design and verbal learning 12 months postoperatively. On face encoding, there were significantly increased left posterior hippocampal activations that reduced significantly from 3 to 12 months postoperatively. Postoperative changes occur in the memory-encoding network in both left and right temporal lobe epilepsy patients across both verbal and visual domains. Three months after surgery, compensatory posterior hippocampal reorganization that occurs is transient and inefficient. Engagement of the contralateral hippocampus 12 months after surgery represented efficient reorganization in both patient groups, suggesting that the contralateral hippocampus contributes to memory outcome 12 months after surgery. PMID:26754787

What Is an Arteriovenous Malformation (AVM)?

MedlinePlus

... sensory information, such as interpretation of pain and temperature, light touch, vibration and more. The temporal lobe functions to process things related to hearing, memory, learning and receptive speech. The occipital lobe functions to ...

Study on memories of temporal lobes and the principles of lateralization using near infrared spectroscopy

NASA Astrophysics Data System (ADS)

Kamakura, Katsutoshi

2007-01-01

In this study we measured the variation of brain blood quantity (Oxy-Hb, Deoxy-Hb and Total-Hb) in the temporal lobes using near infrared spectroscopy (NIRS) when the tasks of the memories were presented to the subjects. The memories are classified into the short-term memory (STM) and the long-term memory (LTM) including the episodic and semantic memories. The subjects joined in this study are 11 persons who are university students including graduate students. We used the language task of letter-number sequencing, also reverse sequencing to measure STM and the task of the episodic memory to measure LTM. As a result of analysis, concerning the episodic memory, the variation of Oxy-Hb in the left temporal lobe was larger than that of Oxy-Hb in the right temporal lobe. The result might suggest that the episodic memory has a relationship with cerebral dominance concerning language area in the left temporal lobe. It seems that the episodic memory meditated with the function of language used in this study is much stored in the left temporal lobe than in the right temporal lobe. This result coincides with the principles of lateralization. The variation of Oxy-Hb in the language task of letter-number sequencing was smaller than that of Oxy-Hb in the language task of the episodic memory.

Temporal lobe anatomy: eight imaging signs to facilitate interpretation of MRI.

PubMed

Lehman, Vance T; Black, David F; Bernstein, Matt A; Welker, Kirk M

2016-05-01

The temporal lobe is anatomically and functionally complex. However, relatively few radiologic signs are described to facilitate recognition of temporal lobe sulci and gyri in clinical practice. We devised and tested 8 radiologic signs of temporal lobe anatomy. Images from volumetric magnetization-prepared rapid gradient-echo imaging were analyzed of 100 temporal lobes from 26 female and 24 male patients. Patient age ranged from 1 to 79 years (mean 19 years; standard deviation 16 years). Standardized axial, coronal, and sagittal planes were evaluated and cross-referenced. Eight signs to delineate the superior temporal gyrus, Heschl gyrus (HG), parahippocampal gyrus, rhinal sulcus, collateral sulcus proper, or the occipitotemporal sulcus, or a combination, were evaluated in the sagittal or axial plane. Two neuroradiologists independently evaluated each sign; the sign was considered present only with positive reader agreement. All 8 signs were present in most patients. The most frequent signs were the posterior insular corner to identify HG in the axial plane (100 %), pointed STG to identify STG in the axial plane (98 %), and parahippocampal Y to identify the posterior parahippocampal gyrus in the sagittal plane (98 %). The frequencies were similar between the right and left cerebral hemispheres. Temporal lobe gyri and sulci can be reliably identified in multiple planes using anatomic signs.

Anatomy of the Temporal Lobe

PubMed Central

Kiernan, J. A.

2012-01-01

Only primates have temporal lobes, which are largest in man, accommodating 17% of the cerebral cortex and including areas with auditory, olfactory, vestibular, visual and linguistic functions. The hippocampal formation, on the medial side of the lobe, includes the parahippocampal gyrus, subiculum, hippocampus, dentate gyrus, and associated white matter, notably the fimbria, whose fibres continue into the fornix. The hippocampus is an inrolled gyrus that bulges into the temporal horn of the lateral ventricle. Association fibres connect all parts of the cerebral cortex with the parahippocampal gyrus and subiculum, which in turn project to the dentate gyrus. The largest efferent projection of the subiculum and hippocampus is through the fornix to the hypothalamus. The choroid fissure, alongside the fimbria, separates the temporal lobe from the optic tract, hypothalamus and midbrain. The amygdala comprises several nuclei on the medial aspect of the temporal lobe, mostly anterior the hippocampus and indenting the tip of the temporal horn. The amygdala receives input from the olfactory bulb and from association cortex for other modalities of sensation. Its major projections are to the septal area and prefrontal cortex, mediating emotional responses to sensory stimuli. The temporal lobe contains much subcortical white matter, with such named bundles as the anterior commissure, arcuate fasciculus, inferior longitudinal fasciculus and uncinate fasciculus, and Meyer's loop of the geniculocalcarine tract. This article also reviews arterial supply, venous drainage, and anatomical relations of the temporal lobe to adjacent intracranial and tympanic structures. PMID:22934160

Functional correlates of musical and visual ability in frontotemporal dementia.

PubMed

Miller, B L; Boone, K; Cummings, J L; Read, S L; Mishkin, F

2000-05-01

The emergence of new skills in the setting of dementia suggests that loss of function in one brain area can release new functions elsewhere. To characterise 12 patients with frontotemporal dementia (FTD) who acquired, or sustained, new musical or visual abilities despite progression of their dementia. Twelve patients with FTD who acquired or maintained musical or artistic ability were compared with 46 patients with FTD in whom new or sustained ability was absent. The group with musical or visual ability performed better on visual, but worse on verbal tasks than did the other patients with FTD. Nine had asymmetrical left anterior dysfunction. Nine showed the temporal lobe variant of FTD. Loss of function in the left anterior temporal lobe may lead to facilitation of artistic or musical skills. Patients with the left-sided temporal lobe variant of FTD offer an unexpected window into the neurological mediation of visual and musical talents.

Structure and Function of the Superior Temporal Plane in Adult Males with Cleft Lip and Palate: Pathologic Enlargement with No Relationship to Childhood Hearing Deficits

ERIC Educational Resources Information Center

Shriver, A. S.; Canady, J.; Richman, L.; Andreasen, N. C.; Nopoulos, P.

2006-01-01

Background: In a previous study from our lab, adult males with non-syndromic cleft lip and/or palate (NSCLP) were shown to have significantly lower temporal lobe gray matter volume than matched controls. The current study was designed to begin a regional analysis of specific subregions of the temporal lobe. The superior temporal plane (STP) is a…

Long-term subdural strip electrocorticographic monitoring of ictal déjà vu.

PubMed

Weinand, M E; Hermann, B; Wyler, A R; Carter, L P; Oommen, K J; Labiner, D; Ahern, G; Herring, A

1994-01-01

We report a series of 8 patients with ictal déjà vu. Subdural strip electrocorticographic (ECoG) monitoring localized the ictal epileptogenic focus as follows: right (n = 6) and left (n = 2) mesiotemporal lobe. In all 8 patients, the left hemisphere was dominant for language function based on intracarotid amytal testing. In 6 right-handed patients, ictal déjà vu was associated with a right temporal lobe focus. However, in the 2 left-handed patients, the ictal focus was left temporal lobe. Although ictal déjà vu localizes the epileptic focus to temporal lobe, this experimental phenomenon appears to lateralize to the hemisphere nondominant for handedness.

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.

Singing can improve speech function in aphasics associated with intact right basal ganglia and preserve right temporal glucose metabolism: Implications for singing therapy indication.

PubMed

Akanuma, Kyoko; Meguro, Kenichi; Satoh, Masayuki; Tashiro, Manabu; Itoh, Masatoshi

2016-01-01

Clinically, we know that some aphasic patients can sing well despite their speech disturbances. Herein, we report 10 patients with non-fluent aphasia, of which half of the patients improved their speech function after singing training. We studied ten patients with non-fluent aphasia complaining of difficulty finding words. All had lesions in the left basal ganglia or temporal lobe. They selected the melodies they knew well, but which they could not sing. We made a new lyric with a familiar melody using words they could not name. The singing training using these new lyrics was performed for 30 minutes once a week for 10 weeks. Before and after the training, their speech functions were assessed by language tests. At baseline, 6 of them received positron emission tomography to evaluate glucose metabolism. Five patients exhibited improvements after intervention; all but one exhibited intact right basal ganglia and left temporal lobes, but all exhibited left basal ganglia lesions. Among them, three subjects exhibited preserved glucose metabolism in the right temporal lobe. We considered that patients who exhibit intact right basal ganglia and left temporal lobes, together with preserved right hemispheric glucose metabolism, might be an indication of the effectiveness of singing therapy.

Medial Temporal Lobe Memory in Childhood: Developmental Transitions

ERIC Educational Resources Information Center

Townsend, Elise L.; Richmond, Jenny L.; Vogel-Farley, Vanessa K.; Thomas, Kathleen

2010-01-01

The medial temporal lobes (MTL) support declarative memory and mature structurally and functionally during the postnatal years in humans. Although recent work has addressed the development of declarative memory in early childhood, less is known about continued development beyond this period of time. The purpose of this investigation was to explore…

Local Brain Activity Differences Between Herpes Zoster and Postherpetic Neuralgia Patients: A Resting-State Functional MRI Study.

PubMed

Cao, Song; Li, Ying; Deng, Wenwen; Qin, Bangyong; Zhang, Yi; Xie, Peng; Yuan, Jie; Yu, Buwei; Yu, Tian

2017-07-01

Herpes zoster (HZ) can develop into postherpetic neuralgia (PHN), both of which are painful diseases. PHN patients suffer chronic pain and emotional disorders. Previous studies showed that the PHN brain displayed abnormal activity and structural change, but the difference in brain activity between HZ and PHN is still not known. To identify regional brain activity changes in HZ and PHN brains with resting-state functional magnetic resonance imaging (rs-fMRI) technique, and to observe the differences between HZ and PHN patients. Observational study. University hospital. Regional homogeneity (ReHo) and fractional aptitude of low-frequency fluctuation (fALFF) methods were employed to analysis resting-state brain activity. Seventy-three age and gender matched patients (50 HZ, 23 PHN) and 55 healthy controls were enrolled. ReHo and fALFF changes were analyzed to detect the functional abnormality in HZ and PHN brains. Compared with healthy controls, HZ and PHN patients exhibited abnormal ReHo and fALFF values in classic pain-related brain regions (such as the frontal lobe, thalamus, insular, and cerebellum) as well as the brainstem, limbic lobe, and temporal lobe. When HZ developed to PHN, the activity in the vast area of the cerebellum significantly increased while that of some regions in the occipital lobe, temporal lobe, parietal lobe, and limbic lobe showed an apparent decrease. (a) Relatively short pain duration (mean 12.2 months) and small sample size (n = 23) for PHN group. (b) Comparisons at different time points (with paired t-tests) for each patient may minimize individual differences. HZ and PHN induced local brain activity changed in the pain matrix, brainstem, and limbic system. HZ chronification induced functional change in the cerebellum, occipital lobe, temporal lobe, parietal lobe, and limbic lobe. These brain activity changes may be correlated with HZ-PHN transition. Herpes zoster, postherpetic neuralgia, resting-state fMRI (rs-fMRI), regional homogeneity (ReHo), fractional aptitude of low-frequency fluctuation (fALFF).

Neocortical temporal FDG-PET hypometabolism correlates with temporal lobe atrophy in hippocampal sclerosis associated with microscopic cortical dysplasia.

PubMed

Diehl, Beate; LaPresto, Eric; Najm, Imad; Raja, Shanker; Rona, Sabine; Babb, Thomas; Ying, Zhong; Bingaman, William; Lüders, Hans O; Ruggieri, Paul

2003-04-01

Medically intractable temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS), with or without cortical dysplasia (CD), is associated with atrophy of the hippocampal formation and regional fluorodeoxyglucose positron-emission tomography (FDG-PET) hypometabolism. The relation between areas of functional and structural abnormalities is not well understood. We investigate the relation between FDG-PET metabolism and temporal lobe (TL) and hippocampal atrophy in patients with histologically proven isolated HS and HS associated with CD. Twenty-three patients underwent en bloc resection of the mesial and anterolateral neocortical structures. Ten patients were diagnosed with isolated HS; 13 patients had associated microscopic CD. Temporal lobe volumes (TLVs) and hippocampal volumes were measured. Magnetic resonance imaging (MRI) and PET were co-registered, and regions of interest (ROIs) determined as gray matter of the mesial, lateral, and anterior temporal lobe. All patients (HS with or without CD) had significant ipsilateral PET hypometabolism in all three regions studied (p < 0.0001). In patients with isolated HS, the most prominent hypometabolism was in the anterior and mesial temporal lobe, whereas in dual pathology, it was in the lateral temporal lobe. TLVs and hippocampal volumes were significantly smaller on the epileptogenic side (p < 0.05). The PET asymmetries ipsilateral/contralateral to the epileptogenic zone and TLV asymmetries correlated significantly for the anterior and lateral temporal lobes (p < 0.05) in the HS+CD group, but not in the isolated HS group. Mesial temporal hypometabolism was not significantly different between the two groups. Temporal neocortical microscopic CD with concurrent HS is associated with more prominent lateral temporal metabolic dysfunction compared with isolated HS in TL atrophy. Further studies are needed to confirm these findings and correlate the PET hypometabolic patterns with outcome data in patients operated on for HS with or without CD.

The function of the left anterior temporal pole: evidence from acute stroke and infarct volume

PubMed Central

Tsapkini, Kyrana; Frangakis, Constantine E.

2011-01-01

The role of the anterior temporal lobes in cognition and language has been much debated in the literature over the last few years. Most prevailing theories argue for an important role of the anterior temporal lobe as a semantic hub or a place for the representation of unique entities such as proper names of peoples and places. Lately, a few studies have investigated the role of the most anterior part of the left anterior temporal lobe, the left temporal pole in particular, and argued that the left anterior temporal pole is the area responsible for mapping meaning on to sound through evidence from tasks such as object naming. However, another recent study indicates that bilateral anterior temporal damage is required to cause a clinically significant semantic impairment. In the present study, we tested these hypotheses by evaluating patients with acute stroke before reorganization of structure–function relationships. We compared a group of 20 patients with acute stroke with anterior temporal pole damage to a group of 28 without anterior temporal pole damage matched for infarct volume. We calculated the average percent error in auditory comprehension and naming tasks as a function of infarct volume using a non-parametric regression method. We found that infarct volume was the only predictive variable in the production of semantic errors in both auditory comprehension and object naming tasks. This finding favours the hypothesis that left unilateral anterior temporal pole lesions, even acutely, are unlikely to cause significant deficits in mapping meaning to sound by themselves, although they contribute to networks underlying both naming and comprehension of objects. Therefore, the anterior temporal lobe may be a semantic hub for object meaning, but its role must be represented bilaterally and perhaps redundantly. PMID:21685458

The effect of lifelong bilingualism on regional grey and white matter volume.

PubMed

Olsen, Rosanna K; Pangelinan, Melissa M; Bogulski, Cari; Chakravarty, M Mallar; Luk, Gigi; Grady, Cheryl L; Bialystok, Ellen

2015-07-01

Lifelong bilingualism is associated with the delayed diagnosis of dementia, suggesting bilingual experience is relevant to brain health in aging. While the effects of bilingualism on cognitive functions across the lifespan are well documented, less is known about the neural substrates underlying differential behaviour. It is clear that bilingualism affects brain regions that mediate language abilities and that these regions are at least partially overlapping with those that exhibit age-related decline. Moreover, the behavioural advantages observed in bilingualism are generally found in executive function performance, suggesting that the frontal lobes may also be sensitive to bilingualism, which exhibit volume reductions with age. The current study investigated structural differences in the brain of lifelong bilingual older adults (n=14, mean age=70.4) compared with older monolinguals (n=14, mean age=70.6). We employed two analytic approaches: 1) we examined global differences in grey and white matter volumes; and, 2) we examined local differences in volume and cortical thickness of specific regions of interest previously implicated in bilingual/monolingual comparisons (temporal pole) or in aging (entorhinal cortex and hippocampus). We expected bilinguals would exhibit greater volume of the frontal lobe and temporal lobe (grey and white matter), given the importance of these regions in executive and language functions, respectively. We further hypothesized that regions in the medial temporal lobe, which demonstrate early changes in aging and exhibit neural pathology in dementia, would be more preserved in the bilingual group. As predicted, bilinguals exhibit greater frontal lobe white matter compared with monolinguals. Moreover, increasing age was related to decreasing temporal pole cortical thickness in the monolingual group, but no such relationship was observed for bilinguals. Finally, Stroop task performance was positively correlated with frontal lobe white matter, emphasizing the importance of preserved white matter in maintaining executive function in aging. These results underscore previous findings implicating an association between bilingualism and preserved frontal and temporal lobe function in aging. This article is part of a Special Issue entitled SI: Memory Å. Copyright © 2015 Elsevier B.V. All rights reserved.

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

Temporal lobe interictal epileptic discharges affect cerebral activity in “default mode” brain regions

PubMed Central

Laufs, Helmut; Hamandi, Khalid; Salek-Haddadi, Afraim; Kleinschmidt, Andreas K; Duncan, John S; Lemieux, Louis

2007-01-01

A cerebral network comprising precuneus, medial frontal, and temporoparietal cortices is less active both during goal-directed behavior and states of reduced consciousness than during conscious rest. We tested the hypothesis that the interictal epileptic discharges affect activity in these brain regions in patients with temporal lobe epilepsy who have complex partial seizures. At the group level, using electroencephalography-correlated functional magnetic resonance imaging in 19 consecutive patients with focal epilepsy, we found common decreases of resting state activity in 9 patients with temporal lobe epilepsy (TLE) but not in 10 patients with extra-TLE. We infer that the functional consequences of TLE interictal epileptic discharges are different from those in extra-TLE and affect ongoing brain function. Activity increases were detected in the ipsilateral hippocampus in patients with TLE, and in subthalamic, bilateral superior temporal and medial frontal brain regions in patients with extra-TLE, possibly indicating effects of different interictal epileptic discharge propagation. PMID:17133385

Differential DNA methylation profiles of coding and non-coding genes define hippocampal sclerosis in human temporal lobe epilepsy

PubMed Central

Miller-Delaney, Suzanne F.C.; Bryan, Kenneth; Das, Sudipto; McKiernan, Ross C.; Bray, Isabella M.; Reynolds, James P.; Gwinn, Ryder; Stallings, Raymond L.

2015-01-01

Temporal lobe epilepsy is associated with large-scale, wide-ranging changes in gene expression in the hippocampus. Epigenetic changes to DNA are attractive mechanisms to explain the sustained hyperexcitability of chronic epilepsy. Here, through methylation analysis of all annotated C-phosphate-G islands and promoter regions in the human genome, we report a pilot study of the methylation profiles of temporal lobe epilepsy with or without hippocampal sclerosis. Furthermore, by comparative analysis of expression and promoter methylation, we identify methylation sensitive non-coding RNA in human temporal lobe epilepsy. A total of 146 protein-coding genes exhibited altered DNA methylation in temporal lobe epilepsy hippocampus (n = 9) when compared to control (n = 5), with 81.5% of the promoters of these genes displaying hypermethylation. Unique methylation profiles were evident in temporal lobe epilepsy with or without hippocampal sclerosis, in addition to a common methylation profile regardless of pathology grade. Gene ontology terms associated with development, neuron remodelling and neuron maturation were over-represented in the methylation profile of Watson Grade 1 samples (mild hippocampal sclerosis). In addition to genes associated with neuronal, neurotransmitter/synaptic transmission and cell death functions, differential hypermethylation of genes associated with transcriptional regulation was evident in temporal lobe epilepsy, but overall few genes previously associated with epilepsy were among the differentially methylated. Finally, a panel of 13, methylation-sensitive microRNA were identified in temporal lobe epilepsy including MIR27A, miR-193a-5p (MIR193A) and miR-876-3p (MIR876), and the differential methylation of long non-coding RNA documented for the first time. The present study therefore reports select, genome-wide DNA methylation changes in human temporal lobe epilepsy that may contribute to the molecular architecture of the epileptic brain. PMID:25552301

Dissociable Contributions within the Medial Temporal Lobe to Encoding of Object-Location Associations

ERIC Educational Resources Information Center

Sommer, Tobias; Rose, Michael; Glascher, Jan; Wolbers, Thomas; Buchel, Christian

2005-01-01

The crucial role of the medial temporal lobe (MTL) in episodic memory is well established. Although there is little doubt that its anatomical subregions--the hippocampus, peri-, entorhinal and parahippocampal cortex (PHC)--contribute differentially to mnemonic processes, their specific functions in episodic memory are under debate. Data from…

Adaptation to Cognitive Context and Item Information in the Medial Temporal Lobes

ERIC Educational Resources Information Center

Diana, Rachel A.; Yonelinas, Andrew P.; Ranganath, Charan

2012-01-01

The medial temporal lobes (MTL) play an essential role in episodic memory, and accumulating evidence indicates that two MTL subregions--the perirhinal (PRc) and parahippocampal (PHc) cortices--might have different functions. According to the binding of item and context theory ( [16] and [21]), PRc is involved in processing item information, the…

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,…

Working Memory, Long-Term Memory, and Medial Temporal Lobe Function

ERIC Educational Resources Information Center

Jeneson, Annette; Squire, Larry R.

2012-01-01

Early studies of memory-impaired patients with medial temporal lobe (MTL) damage led to the view that the hippocampus and related MTL structures are involved in the formation of long-term memory and that immediate memory and working memory are independent of these structures. This traditional idea has recently been revisited. Impaired performance…

Anterior Medial Temporal Lobe Activation during Encoding of Words: FMRI Methods to Optimize Sensitivity

ERIC Educational Resources Information Center

Parsons, Michael W.; Haut, Marc W.; Lemieux, Susan K.; Moran, Maria T.; Leach, Sharon G.

2006-01-01

The existence of a rostrocaudal gradient of medial temporal lobe (MTL) activation during memory encoding has historically received support from positron emission tomography studies, but less so from functional MRI (FMRI) studies. More recently, FMRI studies have demonstrated that characteristics of the stimuli can affect the location of activation…

Temporal Lobe Epilepsy in Children

PubMed Central

Nickels, Katherine C.; Wong-Kisiel, Lily C.; Moseley, Brian D.; Wirrell, Elaine C.

2012-01-01

The temporal lobe is a common focus for epilepsy. Temporal lobe epilepsy in infants and children differs from the relatively homogeneous syndrome seen in adults in several important clinical and pathological ways. Seizure semiology varies by age, and the ictal EEG pattern may be less clear cut than what is seen in adults. Additionally, the occurrence of intractable seizures in the developing brain may impact neurocognitive function remote from the temporal area. While many children will respond favorably to medical therapy, those with focal imaging abnormalities including cortical dysplasia, hippocampal sclerosis, or low-grade tumors are likely to be intractable. Expedient workup and surgical intervention in these medically intractable cases are needed to maximize long-term developmental outcome. PMID:22957247

Wisconsin Card Sorting Test performance and impulsivity in patients with temporal lobe epilepsy: suicidal risk and suicide attempts.

PubMed

Garcia Espinosa, Arlety; Andrade Machado, René; Borges González, Susana; García González, María Eugenia; Pérez Montoto, Ariadna; Toledo Sotomayor, Guillermo

2010-01-01

The goal of the study described here was to determine if executive dysfunction and impulsivity are related to risk for suicide and suicide attempts in patients with temporal lobe epilepsy. Forty-two patients with temporal lobe epilepsy were recruited. A detailed medical history, neurological examination, serial EEGs, Mini-International Neuropsychiatric Interview, executive function, and MRI were assessed. Multiple regression analysis was carried out to examine predictive associations between clinical variables and Wisconsin Card Sorting Test measures. Patients' scores on the Risk for Suicide Scale (n=24) were greater than 7, which means they had the highest relative risk for suicide attempts. Family history of psychiatric disease, current major depressive episode, left temporal lobe epilepsy, and perseverative responses and total errors on the Wisconsin Card Sorting Test increased by 6.3 and 7.5 suicide risk and suicide attempts, respectively. Executive dysfunction (specifically perseverative responses and more total errors) contributed greatly to suicide risk. Executive performance has a major impact on suicide risk and suicide attempts in patients with temporal lobe epilepsy. 2009 Elsevier Inc. All rights reserved.

Linking DMN connectivity to episodic memory capacity: What can we learn from patients with medial temporal lobe damage?

PubMed Central

McCormick, Cornelia; Protzner, Andrea B.; Barnett, Alexander J.; Cohn, Melanie; Valiante, Taufik A.; McAndrews, Mary Pat

2014-01-01

Computational models predict that focal damage to the Default Mode Network (DMN) causes widespread decreases and increases of functional DMN connectivity. How such alterations impact functioning in a specific cognitive domain such as episodic memory remains relatively unexplored. Here, we show in patients with unilateral medial temporal lobe epilepsy (mTLE) that focal structural damage leads indeed to specific patterns of DMN functional connectivity alterations, specifically decreased connectivity between both medial temporal lobes (MTLs) and the posterior part of the DMN and increased intrahemispheric anterior–posterior connectivity. Importantly, these patterns were associated with better and worse episodic memory capacity, respectively. These distinct patterns, shown here for the first time, suggest that a close dialogue between both MTLs and the posterior components of the DMN is required to fully express the extensive repertoire of episodic memory abilities. PMID:25068108

Acute marijuana effects on rCBF and cognition: a PET study.

PubMed

O'Leary, D S; Block, R I; Flaum, M; Schultz, S K; Boles Ponto, L L; Watkins, G L; Hurtig, R R; Andreasen, N C; Hichwa, R D

2000-11-27

The effects of smoking marijuana on cognition and brain function were assessed with PET using H2(15)O. Regional cerebral blood flow (rCBF) was measured in five recreational users before and after smoking a marijuana cigarette, as they repeatedly performed an auditory attention task. Blood flow increased following smoking in a number of paralimbic brain regions (e.g. orbital frontal lobes, insula, temporal poles) and in anterior cingulate and cerebellum. Large reductions in rCBF were observed in temporal lobe regions that are sensitive to auditory attention effects. Brain regions showing increased rCBF may mediate the intoxicating and mood-related effects of smoking marijuana, whereas reduction of task-related rCBF in temporal lobe cortices may account for the impaired cognitive functions associated with acute intoxication.

[Clinical characteristics of epileptic seizures in insular gliomas].

PubMed

Buklina, S B; Bykanov, A E; Pitskhelauri, D I

To study the characteristics of epileptic seizures in insular gliomas. Forty-five patients with insular gliomas were examined. The spread of a tumor was established by MRI results and intraoperational findings. A tumor within the insular only was found in 9 out of 45 patients (7 left-sided and 2 right-sided). In 36 patients, a tumor slightly spread into temporal lobe pole and medial-basal regions of the frontal lobe (27 left-sided and 18 right-sided). The control group consisted of 50 patients with tumors of temporal and frontal lobes. Paroxysmal symptoms were similar in patients with tumors of the insular and patients with tumors of temporal lobes. Seizures in patients with frontal lobe tumors differed significantly from insular and temporal tumors, with the exception of a tumor localized in the opercula area. The following quantitative differences were identified: different forms of unconsciousness were significantly less frequent in symptomatic epilepsy in patients with insular tumor than in epilepsy caused by temporal lobe tumors (36% of patients vs 84% in temporal tumors (p<0.0001)). In patients with insular tumors, olfactory and taste hallucinations occur more often compared to temporal lobe tumors (51% vs 16% (p<0.003). The frequency of paroxysmal seizures of fear and anxiety in patients with those tumors was similar (20% with insular tumors and 14 with temporal tumors). An autonomic component of episeizures did not differ between tumors of both localizations. Olfactory and taste hallucinations were qualitatively similar in insular and temporal lobe tumors: smell and taste were unpleasant or associated with a danger: smell of burning, gas, something spoiled, sour, tart chemistry, taste of somethong metallic, chemical, sour. No pleasant smell or taste were reported. Epileptic seizures in insular tumors had similarities and certain differences compared with temporal seizures that well reflect function of the insula and its links, in the first turn, with limbic system structures.

Neuropsychological outcome after traumatic temporal lobe damage.

PubMed

Formisano, R; Schmidhuber-Eiler, B; Saltuari, L; Cigany, E; Birbamer, G; Gerstenbrand, F

1991-01-01

The most frequent sequelae after severe brain injury include changes in personality traits, disturbances of emotional behaviour and impairment of cognitive functions. In particular, emotional changes and/or verbal and non verbal dysfunctions were found in patients with bilateral or unilateral temporal lobe lesions. The aim of our study is to correlate the localization of the brain damage after severe brain injury, in particular of the temporal lobe, with the cognitive impairment and the emotional and behavioural changes resulting from these lesions. The patients with right temporal lobe lesions showed significantly better scores in verbal intelligence and verbal memory in comparison with patients with left temporal lobe lesions and those with other focal brain lesions or diffuse brain damage. In contradistinction, study of the personality and the emotional changes (MMPI and FAF) failed to demonstrate pathological scores in the 3 groups with different CT lesions, without any significant difference being found between the groups with temporal lesions and those with other focal brain lesions or diffuse brain damage. The severity of the brain injury and the prolongation of the disturbance of consciousness could, in our patients, account for prevalence of congnitive impairment on personality and emotional changes.

Calibrated fMRI in the Medial Temporal Lobe During a Memory Encoding Task

PubMed Central

Restom, Khaled; Perthen, Joanna E.; Liu, Thomas T.

2008-01-01

Prior measures of the blood oxygenation level dependent (BOLD) and cerebral blood flow (CBF) responses to a memory encoding task within the medial temporal lobe have suggested that the coupling between functional changes in CBF and changes in the cerebral metabolic rate of oxgyen (CMRO2) may be tighter in the medial temporal lobe as compared to the primary sensory areas. In this study, we used a calibrated functional magnetic resonance imaging (fMRI) approach to directly estimate memory-encoding-related changes in CMRO2 and to assess the coupling between CBF and CMRO2 in the medial temporal lobe. The CBF-CMRO2 coupling ratio was estimated using a linear fit to the flow and metabolism changes observed across subjects. In addition, we examined the effect of region-of-interest (ROI) selection on the estimates. In response to the memory encoding task, CMRO2 increased by 23.1% ± 8.8 to 25.3% ± 5.7 (depending upon ROI), with an estimated CBF-CMRO2 coupling ratio of 1.66 ± 0.07 to 1.75± 0.16. There was not a significant effect of ROI selection on either the CMRO2 or coupling ratio estimates. The observed coupling ratios were significantly lower than the values (2 to 4.5) that have been reported in previous calibrated fMRI studies of the visual and motor cortices. In addition, the estimated coupling ratio was found to be less sensitive to the calibration procedure for functional responses in the medial temporal lobe as compared to the primary sensory areas. PMID:18329291

Extent of resection in temporal lobectomy for epilepsy. II. Memory changes and neurologic complications.

PubMed

Katz, A; Awad, I A; Kong, A K; Chelune, G J; Naugle, R I; Wyllie, E; Beauchamp, G; Lüders, H

1989-01-01

We present correlations of extent of temporal lobectomy for intractable epilepsy with postoperative memory changes (20 cases) and abnormalities of visual field and neurologic examination (45 cases). Postoperative magnetic resonance imaging (MRI) in the coronal plane was used to quantify anteroposterior extent of resection of various quadrants of the temporal lobe, using a 20-compartment model of that structure. The Wechsler Memory Scale-Revised (WMS-R) was administered preoperatively and postoperatively. Postoperative decrease in percentage of retention of verbal material correlated with extent of medial resection of left temporal lobe, whereas decrease in percentage of retention of visual material correlated with extent of medial resection of right temporal lobe. These correlations approached but did not reach statistical significance. Extent of resection correlated significantly with the presence of visual field defect on perimetry testing but not with severity, denseness, or congruity of the defect. There was no correlation between postoperative dysphasia and extent of resection in any quadrant. Assessment of extent of resection after temporal lobectomy allows a rational interpretation of postoperative neurologic deficits in light of functional anatomy of the temporal lobe.

The functional neuroanatomy of language

NASA Astrophysics Data System (ADS)

Hickok, Gregory

2009-09-01

There has been substantial progress over the last several years in understanding aspects of the functional neuroanatomy of language. Some of these advances are summarized in this review. It will be argued that recognizing speech sounds is carried out in the superior temporal lobe bilaterally, that the superior temporal sulcus bilaterally is involved in phonological-level aspects of this process, that the frontal/motor system is not central to speech recognition although it may modulate auditory perception of speech, that conceptual access mechanisms are likely located in the lateral posterior temporal lobe (middle and inferior temporal gyri), that speech production involves sensory-related systems in the posterior superior temporal lobe in the left hemisphere, that the interface between perceptual and motor systems is supported by a sensory-motor circuit for vocal tract actions (not dedicated to speech) that is very similar to sensory-motor circuits found in primate parietal lobe, and that verbal short-term memory can be understood as an emergent property of this sensory-motor circuit. These observations are considered within the context of a dual stream model of speech processing in which one pathway supports speech comprehension and the other supports sensory-motor integration. Additional topics of discussion include the functional organization of the planum temporale for spatial hearing and speech-related sensory-motor processes, the anatomical and functional basis of a form of acquired language disorder, conduction aphasia, the neural basis of vocabulary development, and sentence-level/grammatical processing.

Thalamic functional connectivity predicts seizure laterality in individual TLE patients: application of a biomarker development strategy.

PubMed

Barron, Daniel S; Fox, Peter T; Pardoe, Heath; Lancaster, Jack; Price, Larry R; Blackmon, Karen; Berry, Kristen; Cavazos, Jose E; Kuzniecky, Ruben; Devinsky, Orrin; Thesen, Thomas

2015-01-01

Noninvasive markers of brain function could yield biomarkers in many neurological disorders. Disease models constrained by coordinate-based meta-analysis are likely to increase this yield. Here, we evaluate a thalamic model of temporal lobe epilepsy that we proposed in a coordinate-based meta-analysis and extended in a diffusion tractography study of an independent patient population. Specifically, we evaluated whether thalamic functional connectivity (resting-state fMRI-BOLD) with temporal lobe areas can predict seizure onset laterality, as established with intracranial EEG. Twenty-four lesional and non-lesional temporal lobe epilepsy patients were studied. No significant differences in functional connection strength in patient and control groups were observed with Mann-Whitney Tests (corrected for multiple comparisons). Notwithstanding the lack of group differences, individual patient difference scores (from control mean connection strength) successfully predicted seizure onset zone as shown in ROC curves: discriminant analysis (two-dimensional) predicted seizure onset zone with 85% sensitivity and 91% specificity; logistic regression (four-dimensional) achieved 86% sensitivity and 100% specificity. The strongest markers in both analyses were left thalamo-hippocampal and right thalamo-entorhinal cortex functional connection strength. Thus, this study shows that thalamic functional connections are sensitive and specific markers of seizure onset laterality in individual temporal lobe epilepsy patients. This study also advances an overall strategy for the programmatic development of neuroimaging biomarkers in clinical and genetic populations: a disease model informed by coordinate-based meta-analysis was used to anatomically constrain individual patient analyses.

Noun-Verb Ambiguity in Chronic Undifferentiated Schizophrenia

ERIC Educational Resources Information Center

Goldfarb, Robert; Bekker, Natalie

2009-01-01

This study investigated noun-verb retrieval patterns of 30 adults with chronic undifferentiated schizophrenia and 67 typical adults, to determine if schizophrenia affected nouns (associated with temporal lobe function) differently from verbs (associated with frontal lobe function). Stimuli were homophonic homographic homonyms, balanced according…

Experimentally induced thyrotoxicosis leads to increased connectivity in temporal lobe structures: a resting state fMRI study.

PubMed

Göttlich, Martin; Heldmann, Marcus; Göbel, Anna; Dirk, Anna-Luise; Brabant, Georg; Münte, Thomas F

2015-06-01

Adult onset hyperthyroidism may impact on different cognitive domains, including attention and concentration, memory, perceptual function, language and executive function. Previous PET studies implicated changed functionality of limbic regions, the temporal and frontal lobes in hyperthyroidism, whereas it is unknown whether cognitive effects of hyperthyroidism may be due to changed brain connectivity. This study aimed to investigate the effect of experimentally induced short-term hyperthyroidism thyrotoxicosis on resting-state functional connectivity using functional magnetic resonance imaging. Twenty-nine healthy male right-handed subjects were examined twice, once prior and once after 8 weeks of oral administration of 250 μg levothyroxine per day. Resting-state fMRI was subjected to graph-theory based analysis methods to investigate whole-brain intrinsic functional connectivity. Despite a lack of subjective changes noticed by the subjects significant thyrotoxicosis was confirmed in all subjects. This induced a significant increase in resting-state functional connectivity specifically in the rostral temporal lobes (0.05 FDR corrected at the cluster level), which is caused by an increased connectivity to the cognitive control network. The increased connectivity between temporal poles and the cognitive control network shown here under experimental conditions supports an important function of thyroid hormones in the regulation of paralimbic structures. Copyright © 2015 Elsevier Ltd. All rights reserved.

A functional magnetic resonance imaging study mapping the episodic memory encoding network in temporal lobe epilepsy

PubMed Central

Sidhu, Meneka K.; Stretton, Jason; Winston, Gavin P.; Bonelli, Silvia; Centeno, Maria; Vollmar, Christian; Symms, Mark; Thompson, Pamela J.; Koepp, Matthias J.

2013-01-01

Functional magnetic resonance imaging has demonstrated reorganization of memory encoding networks within the temporal lobe in temporal lobe epilepsy, but little is known of the extra-temporal networks in these patients. We investigated the temporal and extra-temporal reorganization of memory encoding networks in refractory temporal lobe epilepsy and the neural correlates of successful subsequent memory formation. We studied 44 patients with unilateral temporal lobe epilepsy and hippocampal sclerosis (24 left) and 26 healthy control subjects. All participants performed a functional magnetic resonance imaging memory encoding paradigm of faces and words with subsequent out-of-scanner recognition assessments. A blocked analysis was used to investigate activations during encoding and neural correlates of subsequent memory were investigated using an event-related analysis. Event-related activations were then correlated with out-of-scanner verbal and visual memory scores. During word encoding, control subjects activated the left prefrontal cortex and left hippocampus whereas patients with left hippocampal sclerosis showed significant additional right temporal and extra-temporal activations. Control subjects displayed subsequent verbal memory effects within left parahippocampal gyrus, left orbitofrontal cortex and fusiform gyrus whereas patients with left hippocampal sclerosis activated only right posterior hippocampus, parahippocampus and fusiform gyrus. Correlational analysis showed that patients with left hippocampal sclerosis with better verbal memory additionally activated left orbitofrontal cortex, anterior cingulate cortex and left posterior hippocampus. During face encoding, control subjects showed right lateralized prefrontal cortex and bilateral hippocampal activations. Patients with right hippocampal sclerosis showed increased temporal activations within the superior temporal gyri bilaterally and no increased extra-temporal areas of activation compared with control subjects. Control subjects showed subsequent visual memory effects within right amygdala, hippocampus, fusiform gyrus and orbitofrontal cortex. Patients with right hippocampal sclerosis showed subsequent visual memory effects within right posterior hippocampus, parahippocampal and fusiform gyri, and predominantly left hemisphere extra-temporal activations within the insula and orbitofrontal cortex. Correlational analysis showed that patients with right hippocampal sclerosis with better visual memory activated the amygdala bilaterally, right anterior parahippocampal gyrus and left insula. Right sided extra-temporal areas of reorganization observed in patients with left hippocampal sclerosis during word encoding and bilateral lateral temporal reorganization in patients with right hippocampal sclerosis during face encoding were not associated with subsequent memory formation. Reorganization within the medial temporal lobe, however, is an efficient process. The orbitofrontal cortex is critical to subsequent memory formation in control subjects and patients. Activations within anterior cingulum and insula correlated with better verbal and visual subsequent memory in patients with left and right hippocampal sclerosis, respectively, representing effective extra-temporal recruitment. PMID:23674488

Hippocampal and Parahippocampal Volumes in Schizophrenia: A Structural MRI Study

PubMed Central

Sim, Kang; DeWitt, Iain; Ditman, Tali; Zalesak, Martin; Greenhouse, Ian; Goff, Donald; Weiss, Anthony P; Heckers, Stephan

2006-01-01

Smaller medial temporal lobe volume is a frequent finding in studies of patients with schizophrenia, but the relative contributions of the hippocampus and three surrounding cortical regions (entorhinal cortex, perirhinal cortex, and parahippocampal cortex) are poorly understood. We tested the hypothesis that the volumes of medial temporal lobe regions are selectively changed in schizophrenia. We studied 19 male patients with schizophrenia and 19 age-matched male control subjects. Hippocampal and cortical volumes were estimated using a three-dimensional morphometric protocol for the analysis of high-resolution structural magnetic resonance images, and repeated measures ANOVA was used to test for region-specific differences. Patients had smaller overall medial temporal lobe volumes compared to controls. The volume difference was not specific for either region or hemisphere. The finding of smaller medial temporal lobe volumes in the absence of regional specificity has important implications for studying the functional role of the hippocampus and surrounding cortical regions in schizophrenia. PMID:16319377

Selective Familiarity Deficits after Left Anterior Temporal-Lobe Removal with Hippocampal Sparing Are Material Specific

ERIC Educational Resources Information Center

Martin, Chris B.; Bowles, Ben; Mirsattari, Seyed M.; Kohler, Stefan

2011-01-01

Research has firmly established a link between recognition memory and the functional integrity of the medial temporal lobes (MTL). Dual-process models of MTL organization maintain that there is a division of labour within the MTL, with the hippocampus (HC) supporting recollective processes and perirhinal cortex (PRc) supporting familiarity…

Mapping Anterior Temporal Lobe Language Areas with FMRI: A Multi-Center Normative Study

PubMed Central

Binder, Jeffrey R.; Gross, William L.; Allendorfer, Jane B.; Bonilha, Leonardo; Chapin, Jessica; Edwards, Jonathan C.; Grabowski, Thomas J.; Langfitt, John T.; Loring, David W.; Lowe, Mark J.; Koenig, Katherine; Morgan, Paul S.; Ojemann, Jeffrey G.; Rorden, Christopher; Szaflarski, Jerzy P.; Tivarus, Madalina E.; Weaver, Kurt E.

2010-01-01

Removal of the anterior temporal lobe (ATL) is an effective surgical treatment for intractable temporal lobe epilepsy but carries a risk of language and verbal memory deficits. Preoperative localization of functional zones in the ATL might help reduce these risks, yet fMRI protocols in current widespread use produce very little activation in this region. Based on recent evidence suggesting a role for the ATL in semantic integration, we designed an fMRI protocol comparing comprehension of brief narratives (Story task) with a semantically shallow control task involving serial arithmetic (Math task). The Story > Math contrast elicited strong activation throughout the ATL, lateral temporal lobe, and medial temporal lobe bilaterally in an initial cohort of 18 healthy participants. The task protocol was then implemented at 6 other imaging centers using identical methods. Data from a second cohort of participants scanned at these centers closely replicated the results from the initial cohort. The Story-Math protocol provides a reliable method for activation of surgical regions of interest in the ATL. The bilateral activation supports previous claims that conceptual processing involves both temporal lobes. Used in combination with language lateralization measures, reliable ATL activation maps may be useful for predicting cognitive outcome in ATL surgery, though the validity of this approach needs to be established in a prospective surgical series. PMID:20884358

Temporal order processing of syllables in the left parietal lobe.

PubMed

Moser, Dana; Baker, Julie M; Sanchez, Carmen E; Rorden, Chris; Fridriksson, Julius

2009-10-07

Speech processing requires the temporal parsing of syllable order. Individuals suffering from posterior left hemisphere brain injury often exhibit temporal processing deficits as well as language deficits. Although the right posterior inferior parietal lobe has been implicated in temporal order judgments (TOJs) of visual information, there is limited evidence to support the role of the left inferior parietal lobe (IPL) in processing syllable order. The purpose of this study was to examine whether the left inferior parietal lobe is recruited during temporal order judgments of speech stimuli. Functional magnetic resonance imaging data were collected on 14 normal participants while they completed the following forced-choice tasks: (1) syllable order of multisyllabic pseudowords, (2) syllable identification of single syllables, and (3) gender identification of both multisyllabic and monosyllabic speech stimuli. Results revealed increased neural recruitment in the left inferior parietal lobe when participants made judgments about syllable order compared with both syllable identification and gender identification. These findings suggest that the left inferior parietal lobe plays an important role in processing syllable order and support the hypothesized role of this region as an interface between auditory speech and the articulatory code. Furthermore, a breakdown in this interface may explain some components of the speech deficits observed after posterior damage to the left hemisphere.

Temporal Order Processing of Syllables in the Left Parietal Lobe

PubMed Central

Baker, Julie M.; Sanchez, Carmen E.; Rorden, Chris; Fridriksson, Julius

2009-01-01

Speech processing requires the temporal parsing of syllable order. Individuals suffering from posterior left hemisphere brain injury often exhibit temporal processing deficits as well as language deficits. Although the right posterior inferior parietal lobe has been implicated in temporal order judgments (TOJs) of visual information, there is limited evidence to support the role of the left inferior parietal lobe (IPL) in processing syllable order. The purpose of this study was to examine whether the left inferior parietal lobe is recruited during temporal order judgments of speech stimuli. Functional magnetic resonance imaging data were collected on 14 normal participants while they completed the following forced-choice tasks: (1) syllable order of multisyllabic pseudowords, (2) syllable identification of single syllables, and (3) gender identification of both multisyllabic and monosyllabic speech stimuli. Results revealed increased neural recruitment in the left inferior parietal lobe when participants made judgments about syllable order compared with both syllable identification and gender identification. These findings suggest that the left inferior parietal lobe plays an important role in processing syllable order and support the hypothesized role of this region as an interface between auditory speech and the articulatory code. Furthermore, a breakdown in this interface may explain some components of the speech deficits observed after posterior damage to the left hemisphere. PMID:19812331

Disrupted dynamic network reconfiguration of the language system in temporal lobe epilepsy.

PubMed

He, Xiaosong; Bassett, Danielle S; Chaitanya, Ganne; Sperling, Michael R; Kozlowski, Lauren; Tracy, Joseph I

2018-05-01

Temporal lobe epilepsy tends to reshape the language system causing maladaptive reorganization that can be characterized by task-based functional MRI, and eventually can contribute to surgical decision making processes. However, the dynamic interacting nature of the brain as a complex system is often neglected, with many studies treating the language system as a static monolithic structure. Here, we demonstrate that as a specialized and integrated system, the language network is inherently dynamic, characterized by rich patterns of regional interactions, whose transient dynamics are disrupted in patients with temporal lobe epilepsy. Specifically, we applied tools from dynamic network neuroscience to functional MRI data collected from 50 temporal lobe epilepsy patients and 30 matched healthy controls during performance of a verbal fluency task, as well as during rest. By assigning 16 language-related regions into four subsystems (i.e. bilateral frontal and temporal), we observed regional specialization in both the probability of transient interactions and the frequency of such changes, in both healthy controls and patients during task performance but not rest. Furthermore, we found that both left and right temporal lobe epilepsy patients displayed reduced interactions within the left frontal 'core' subsystem compared to the healthy controls, while left temporal lobe epilepsy patients were unique in showing enhanced interactions between the left frontal 'core' and the right temporal subsystems. Also, both patient groups displayed reduced flexibility in the transient interactions of the left temporal and right frontal subsystems, which formed the 'periphery' of the language network. Importantly, such group differences were again evident only during task condition. Lastly, through random forest regression, we showed that dynamic reconfiguration of the language system tracks individual differences in verbal fluency with superior prediction accuracy compared to traditional activation-based static measures. Our results suggest dynamic network measures may be an effective biomarker for detecting the language dysfunction associated with neurological diseases such as temporal lobe epilepsy, specifying both the type of neuronal communications that are missing in these patients and those that are potentially added but maladaptive. Further advancements along these lines, transforming how we characterize and map language networks in the brain, have a high probability of altering clinical decision making in neurosurgical centres.10.1093/brain/awy042_video1awy042media15754656112001.

Accelerated long-term forgetting in temporal lobe epilepsy: evidence of improvement after left temporal pole lobectomy.

PubMed

Gallassi, Roberto; Sambati, Luisa; Poda, Roberto; Stanzani Maserati, Michelangelo; Oppi, Federico; Giulioni, Marco; Tinuper, Paolo

2011-12-01

Accelerated long term forgetting (ALF) is a characteristic cognitive aspect in patients affected by temporal lobe epilepsy that is probably due to an impairment of memory consolidation and retrieval caused by epileptic activity in hippocampal and parahippocampal regions. We describe a case of a patient with TLE who showed improvement in ALF and in remote memory impairment after an anterior left temporal pole lobectomy including the uncus and amygdala. Our findings confirm that impairment of hippocampal functioning leads to pathological ALF, whereas restoration of hippocampal functioning brings ALF to a level comparable to that of controls. Copyright © 2011 Elsevier Inc. All rights reserved.

Low-resolution electromagnetic tomography (LORETA) in children with cochlear implants: a preliminary report.

PubMed

Henkin, Yael; Kishon-Rabin, Liat; Tatin-Schneider, Simona; Urbach, Doron; Hildesheimer, Minka; Kileny, Paul R

2004-12-01

The current preliminary report describes the utilization of low-resolution electromagnetic tomography (LORETA) in a small group of highly performing children using the Nucleus 22 cochlear implant (CI) and in normal-hearing (NH) adults. LORETA current density estimations were performed on an averaged target P3 component that was elicited by non-speech and speech oddball discrimination tasks. The results indicated that, when stimulated with tones, patients with right implants and NH adults (regardless of stimulated ear) showed enhanced activation in the right temporal lobe, whereas patients with left implants showed enhanced activation in the left temporal lobe. When stimulated with speech, patients with right implants showed bilateral activation of the temporal and frontal lobes, whereas patients with left implants showed only left temporal lobe activation. NH adults (regardless of stimulated ear) showed enhanced bilateral activation of the temporal and parietal lobes. The differences in activation patterns between patients with CI and NH subjects may be attributed to the long-term exposure to degraded input conditions which may have resulted in reorganization in terms of functional specialization. The difference between patients with right versus left implants, however, is intriguing and requires further investigation.

[Study of the relationship between the acupoints of Zhongzhu (TE 3), Yanglingquan (GB 34) and their corresponding cortical areas with the functional MRI].

PubMed

Tian, Li-Fang; Zhou, Cheng; Chen, Min; Zou, Ming-Zhu; Yang, Zheng-Han

2009-07-01

Using the functional magnetic resonance imaging (fMRI) to observe the distributed characteristic of excited cerebral cortical areas that induced by acupuncture-stimulating the Zhongzhu (TE 3) of the meridian of Hand-Shaoyang and Yanglingquan (GB 34) of the meridian of Foot-Shaoyang, and investigate the central neural mechanism on the effect of meridians and acupoints. Forty-two right handed healthy volunteers were randomly divided into Zhongzhu (TE 3) group and Yanglingquan (GB 34) group. The functional cortical changes during acupuncture-stimulating the Zhongzhu (TE 3) and Yanglingquan (GB 34) were successively scanned with fMRI, and the effected areas were determined through analysing the obtained data with SPM2 software. The main excited areas were bilateral frontal lobes, temporal lobes, cerebellum and occipital lobes successively in Zhongzhu (TE 3) group, and bilateral occipital lobes, cerebellum, frontal lobes and temporal lobes in Yanglingquan (GB 34) group in contrast. Acupuncture-stimulating both Zhongzhu (TE 3) and Yanglingquan (GB 34) can excite bilateral acoustic, visual and somatomotor cortices, which might be the central neural basis for clinical treatment on related diseases.

The Impact of Sex and Language Dominance on Material-Specific Memory Before and After Left Temporal Lobe Surgery

ERIC Educational Resources Information Center

Helmstaedter, C.; Brosch, T.; Kurthen, M.; Elger, C. E.

2004-01-01

Recent findings raised evidence that in early-onset left temporal lobe epilepsy, women show greater functional plasticity for verbal memory than men. In particular, women with lesion- or epilepsy-driven atypical language dominance show an advantage over men. The question asked in this study was whether there is evidence of sex- and language…

Frontal and temporal lobe involvement on verbal fluency measures in amyotrophic lateral sclerosis.

PubMed

Lepow, Lauren; Van Sweringen, James; Strutt, Adriana M; Jawaid, Ali; MacAdam, Claire; Harati, Yadollah; Schulz, Paul E; York, Michele K

2010-11-01

Amyotrophic lateral sclerosis (ALS) has been associated with changes in frontal and temporal lobe-mediated cognitive and behavioral functions. Verbal fluency, a sensitive measure to these changes, was utilized to investigate phonemic and semantic abilities in 49 ALS patients and 25 healthy controls (HCs). A subset of the ALS patients was classified as ALS-intact, ALS with mild cognitive impairments (ALS-mild), and ALS with fronto-temporal dementia (ALS-FTD) based on a comprehensive neuropsychological evaluation. Clustering and switching, the underlying component processes of verbal fluency, were analyzed using Troyer's (Troyer, Moscovitch, & Winocur, 1997) and Abwender's (Abwender, Swan, Bowerman, & Connolly, 2001) scoring systems. ALS patients exhibited decreased fluency versus HCs. For phonemic fluency, the intact ALS sample generated fewer clusters and more switches than the ALS-mild and ALS-FTD patients using both scoring systems. This suggests temporal involvement in ALS patients, with increasing frontal lobe involvement in patients with greater cognitive dysfunction. For semantic fluency, similar results were obtained with a greater emphasis on declines in clustering or increased temporal lobe dysfunction. These results suggest that verbal fluency measures identify frontal and temporal lobe involvement in the cognitive decline associated with ALS, particularly when the component processes are evaluated. The clinical utility of these scoring systems with ALS patients is also discussed.

Decreased functional connectivity and structural deficit in alertness network with right-sided temporal lobe epilepsy.

PubMed

Gao, Yujun; Zheng, Jinou; Li, Yaping; Guo, Danni; Wang, Mingli; Cui, Xiangxiang; Ye, Wei

2018-04-01

Patients with temporal lobe epilepsy (TLE) often suffer from alertness alterations. However, specific regions connected with alertness remain controversial, and whether these regions have structural impairment is also elusive. This study aimed to investigate the characteristics and neural mechanisms underlying the functions and structures of alertness network in patients with right-sided temporal lobe epilepsy (rTLE) by performing the attentional network test (ANT), resting-state functional magnetic resonance imaging (R-SfMRI), and diffusion tensor imaging (DTI).A total of 47 patients with rTLE and 34 healthy controls underwent ANT, R-SfMRI, and DTI scan. The seed-based functional connectivity (FC) method and deterministic tractography were used to analyze the data.Patients with rTLE had longer reaction times in the no-cue and double-cue conditions. However, no differences were noted in the alertness effect between the 2 groups. The patient group had lower FC compared with the control group in the right inferior parietal lobe (IPL), amygdala, and insula. Structural deficits were found in the right parahippocampal gyrus, superior temporal pole, insula, and amygdala in the patient group compared with the control group. Also significantly negative correlations were observed between abnormal fractional anisotropy (between the right insula and the superior temporal pole) and illness duration in the patients with rTLE.The findings of this study suggested abnormal intrinsic and phasic alertness, decreased FC, and structural deficits within the alerting network in the rTLE. This study provided new insights into the mechanisms of alertness alterations in rTLE.

The Semantic Network at Work and Rest: Differential Connectivity of Anterior Temporal Lobe Subregions.

PubMed

Jackson, Rebecca L; Hoffman, Paul; Pobric, Gorana; Lambon Ralph, Matthew A

2016-02-03

The anterior temporal lobe (ATL) makes a critical contribution to semantic cognition. However, the functional connectivity of the ATL and the functional network underlying semantic cognition has not been elucidated. In addition, subregions of the ATL have distinct functional properties and thus the potential differential connectivity between these subregions requires investigation. We explored these aims using both resting-state and active semantic task data in humans in combination with a dual-echo gradient echo planar imaging (EPI) paradigm designed to ensure signal throughout the ATL. In the resting-state analysis, the ventral ATL (vATL) and anterior middle temporal gyrus (MTG) were shown to connect to areas responsible for multimodal semantic cognition, including bilateral ATL, inferior frontal gyrus, medial prefrontal cortex, angular gyrus, posterior MTG, and medial temporal lobes. In contrast, the anterior superior temporal gyrus (STG)/superior temporal sulcus was connected to a distinct set of auditory and language-related areas, including bilateral STG, precentral and postcentral gyri, supplementary motor area, supramarginal gyrus, posterior temporal cortex, and inferior and middle frontal gyri. Complementary analyses of functional connectivity during an active semantic task were performed using a psychophysiological interaction (PPI) analysis. The PPI analysis highlighted the same semantic regions suggesting a core semantic network active during rest and task states. This supports the necessity for semantic cognition in internal processes occurring during rest. The PPI analysis showed additional connectivity of the vATL to regions of occipital and frontal cortex. These areas strongly overlap with regions found to be sensitive to executively demanding, controlled semantic processing. Previous studies have shown that semantic cognition depends on subregions of the anterior temporal lobe (ATL). However, the network of regions functionally connected to these subregions has not been demarcated. Here, we show that these ventrolateral anterior temporal subregions form part of a network responsible for semantic processing during both rest and an explicit semantic task. This demonstrates the existence of a core functional network responsible for multimodal semantic cognition regardless of state. Distinct connectivity is identified in the superior ATL, which is connected to auditory and language areas. Understanding the functional connectivity of semantic cognition allows greater understanding of how this complex process may be performed and the role of distinct subregions of the anterior temporal cortex. Copyright © 2016 Jackson et al.

The Semantic Network at Work and Rest: Differential Connectivity of Anterior Temporal Lobe Subregions

PubMed Central

Jackson, Rebecca L.; Hoffman, Paul; Pobric, Gorana

2016-01-01

The anterior temporal lobe (ATL) makes a critical contribution to semantic cognition. However, the functional connectivity of the ATL and the functional network underlying semantic cognition has not been elucidated. In addition, subregions of the ATL have distinct functional properties and thus the potential differential connectivity between these subregions requires investigation. We explored these aims using both resting-state and active semantic task data in humans in combination with a dual-echo gradient echo planar imaging (EPI) paradigm designed to ensure signal throughout the ATL. In the resting-state analysis, the ventral ATL (vATL) and anterior middle temporal gyrus (MTG) were shown to connect to areas responsible for multimodal semantic cognition, including bilateral ATL, inferior frontal gyrus, medial prefrontal cortex, angular gyrus, posterior MTG, and medial temporal lobes. In contrast, the anterior superior temporal gyrus (STG)/superior temporal sulcus was connected to a distinct set of auditory and language-related areas, including bilateral STG, precentral and postcentral gyri, supplementary motor area, supramarginal gyrus, posterior temporal cortex, and inferior and middle frontal gyri. Complementary analyses of functional connectivity during an active semantic task were performed using a psychophysiological interaction (PPI) analysis. The PPI analysis highlighted the same semantic regions suggesting a core semantic network active during rest and task states. This supports the necessity for semantic cognition in internal processes occurring during rest. The PPI analysis showed additional connectivity of the vATL to regions of occipital and frontal cortex. These areas strongly overlap with regions found to be sensitive to executively demanding, controlled semantic processing. SIGNIFICANCE STATEMENT Previous studies have shown that semantic cognition depends on subregions of the anterior temporal lobe (ATL). However, the network of regions functionally connected to these subregions has not been demarcated. Here, we show that these ventrolateral anterior temporal subregions form part of a network responsible for semantic processing during both rest and an explicit semantic task. This demonstrates the existence of a core functional network responsible for multimodal semantic cognition regardless of state. Distinct connectivity is identified in the superior ATL, which is connected to auditory and language areas. Understanding the functional connectivity of semantic cognition allows greater understanding of how this complex process may be performed and the role of distinct subregions of the anterior temporal cortex. PMID:26843633

Increased Expression of Brain-Derived Neurotrophic Factor Transcripts I and VI, cAMP Response Element Binding, and Glucocorticoid Receptor in the Cortex of Patients with Temporal Lobe Epilepsy.

PubMed

Martínez-Levy, G A; Rocha, L; Rodríguez-Pineda, F; Alonso-Vanegas, M A; Nani, A; Buentello-García, R M; Briones-Velasco, M; San-Juan, D; Cienfuegos, J; Cruz-Fuentes, C S

2018-05-01

A body of evidence supports a relevant role of brain-derived neurotrophic factor (BDNF) in temporal lobe epilepsy (TLE). Magnetic resonance data reveal that the cerebral atrophy extends to regions that are functionally and anatomically connected with the hippocampus, especially the temporal cortex. We previously reported an increased expression of BDNF messenger for the exon VI in the hippocampus of temporal lobe epilepsy patients compared to an autopsy control group. Altered levels of this particular transcript were also associated with pre-surgical use of certain psychotropic. We extended here our analysis of transcripts I, II, IV, and VI to the temporal cortex since this cerebral region holds intrinsic communication with the hippocampus and is structurally affected in patients with TLE. We also assayed the cyclic adenosine monophosphate response element-binding (CREB) and glucocorticoid receptor (GR) genes as there is experimental evidence of changes in their expression associated with BDNF and epilepsy. TLE and pre-surgical pharmacological treatment were considered as the primary clinical independent variables. Transcripts BDNF I and BDNF VI increased in the temporal cortex of patients with pharmacoresistant TLE. The expression of CREB and GR expression follow the same direction. Pre-surgical use of selective serotonin reuptake inhibitors, carbamazepine (CBZ) and valproate (VPA), was associated with the differential expression of specific BDNF transcripts and CREB and GR genes. These changes could have functional implication in the plasticity mechanisms related to temporal lobe epilepsy.

Interictal epileptic discharge correlates with global and frontal cognitive dysfunction in temporal lobe epilepsy.

PubMed

Dinkelacker, Vera; Xin, Xu; Baulac, Michel; Samson, Séverine; Dupont, Sophie

2016-09-01

Temporal lobe epilepsy (TLE) with hippocampal sclerosis has widespread effects on structural and functional connectivity and often entails cognitive dysfunction. EEG is mandatory to disentangle interactions in epileptic and physiological networks which underlie these cognitive comorbidities. Here, we examined how interictal epileptic discharges (IEDs) affect cognitive performance. Thirty-four patients (right TLE=17, left TLE=17) were examined with 24-hour video-EEG and a battery of neuropsychological tests to measure intelligence quotient and separate frontal and temporal lobe functions. Hippocampal segmentation of high-resolution T1-weighted imaging was performed with FreeSurfer. Partial correlations were used to compare the number and distribution of clinical interictal spikes and sharp waves with data from imagery and psychological tests. The number of IEDs was negatively correlated with executive functions, including verbal fluency and intelligence quotient (IQ). Interictal epileptic discharge affected cognitive function in patients with left and right TLE differentially, with verbal fluency strongly related to temporofrontal spiking. In contrast, IEDs had no clear effects on memory functions after corrections with partial correlations for age, age at disease onset, disease duration, and hippocampal volume. In patients with TLE of long duration, IED occurrence was strongly related to cognitive deficits, most pronounced for frontal lobe function. These data suggest that IEDs reflect dysfunctional brain circuitry and may serve as an independent biomarker for cognitive comorbidity. Copyright © 2016. Published by Elsevier Inc.

The relationship between neuropsychological tests of visuospatial function and lobar cortical thickness.

PubMed

Zink, Davor N; Miller, Justin B; Caldwell, Jessica Z K; Bird, Christopher; Banks, Sarah J

2018-06-01

Tests of visuospatial function are often administered in comprehensive neuropsychological evaluations. These tests are generally considered assays of parietal lobe function; however, the neural correlates of these tests, using modern imaging techniques, are not well understood. In the current study we investigated the relationship between three commonly used tests of visuospatial function and lobar cortical thickness in each hemisphere. Data from 374 patients who underwent a neuropsychological evaluation and MRI scans in an outpatient dementia clinic were included in the analysis. We examined the relationships between cortical thickness, as assessed with Freesurfer, and performance on three tests: Judgment of Line Orientation (JoLO), Block Design (BD) from the Fourth edition of the Wechsler Adult Intelligence Scale, and Brief Visuospatial Memory Test-Revised Copy Trial (BVMT-R-C) in patients who showed overall average performance on these tasks. Using a series of multiple regression models, we assessed which lobe's overall cortical thickness best predicted test performance. Among the individual lobes, JoLO performance was best predicted by cortical thickness in the right temporal lobe. BD performance was best predicted by cortical thickness in the right parietal lobe, and BVMT-R-C performance was best predicted by cortical thickness in the left parietal lobe. Performance on constructional tests of visuospatial function appears to correspond best with underlying cortical thickness of the parietal lobes, while performance on visuospatial judgment tests appears to correspond best to temporal lobe thickness. Future research using voxel-wise and connectivity techniques and including more diverse samples will help further understanding of the regions and networks involved in visuospatial tests.

Short-Term Memory for Space and Time Flexibly Recruit Complementary Sensory-Biased Frontal Lobe Attention Networks.

PubMed

Michalka, Samantha W; Kong, Lingqiang; Rosen, Maya L; Shinn-Cunningham, Barbara G; Somers, David C

2015-08-19

The frontal lobes control wide-ranging cognitive functions; however, functional subdivisions of human frontal cortex are only coarsely mapped. Here, functional magnetic resonance imaging reveals two distinct visual-biased attention regions in lateral frontal cortex, superior precentral sulcus (sPCS) and inferior precentral sulcus (iPCS), anatomically interdigitated with two auditory-biased attention regions, transverse gyrus intersecting precentral sulcus (tgPCS) and caudal inferior frontal sulcus (cIFS). Intrinsic functional connectivity analysis demonstrates that sPCS and iPCS fall within a broad visual-attention network, while tgPCS and cIFS fall within a broad auditory-attention network. Interestingly, we observe that spatial and temporal short-term memory (STM), respectively, recruit visual and auditory attention networks in the frontal lobe, independent of sensory modality. These findings not only demonstrate that both sensory modality and information domain influence frontal lobe functional organization, they also demonstrate that spatial processing co-localizes with visual processing and that temporal processing co-localizes with auditory processing in lateral frontal cortex. Copyright © 2015 Elsevier Inc. All rights reserved.

Widespread temporo-occipital lobe dysfunction in amyotrophic lateral sclerosis

NASA Astrophysics Data System (ADS)

Loewe, Kristian; Machts, Judith; Kaufmann, Jörn; Petri, Susanne; Heinze, Hans-Jochen; Borgelt, Christian; Harris, Joseph Allen; Vielhaber, Stefan; Schoenfeld, Mircea Ariel

2017-01-01

Recent studies suggest that amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) lie on a single clinical continuum. However, previous neuroimaging studies have found only limited involvement of temporal lobe regions in ALS. To better delineate possible temporal lobe involvement in ALS, the present study aimed to examine changes in functional connectivity across the whole brain, particularly with regard to extra-motor regions, in a group of 64 non-demented ALS patients and 38 healthy controls. To assess between-group differences in connectivity, we computed edge-level statistics across subject-specific graphs derived from resting-state functional MRI data. In addition to expected ALS-related decreases in functional connectivity in motor-related areas, we observed extensive changes in connectivity across the temporo-occipital cortex. Although ALS patients with comorbid FTD were deliberately excluded from this study, the pattern of connectivity alterations closely resembles patterns of cerebral degeneration typically seen in FTD. This evidence for subclinical temporal dysfunction supports the idea of a common pathology in ALS and FTD.

Early seizures and temporal lobe trauma predict post-traumatic epilepsy: A longitudinal study.

PubMed

Tubi, Meral A; Lutkenhoff, Evan; Blanco, Manuel Buitrago; McArthur, David; Villablanca, Pablo; Ellingson, Benjamin; Diaz-Arrastia, Ramon; Van Ness, Paul; Real, Courtney; Shrestha, Vikesh; Engel, Jerome; Vespa, Paul M; Agoston, Denes; Au, Alicia; Bell, Michael J; Branch, Craig; Buitrago Blanco, Manuel; Bullock, Ross; Claassen, Jan; Clarke, Robert; Cloyd, James; Coles, Lisa; Crawford, Karen; Diaz-Arrastia, Ramon; Duncan, Dominique; Ellingson, Benjamin; Engel, Jerome; Foreman, Brandon; Galanopoulou, Aristea; Gilmore, Emily; Olli, Grohn; Harris, Neil; Hartings, Jed; Lawrence, Hirsch; Hunn, Martin; Jette, Nathalie; Johnston, Leigh; Jones, Nigel; Kanner, Andres; McArthur, David; Monti, Martin; Morokoff, Andrew; Moshe, Solomon; Mowrey, Wenzhu; Naughton, Tomas; O'Brien, Terence; O'Phelan, Kristine; Pitkanen, Asla; Raman, Rema; Robertson, Courtney; Rosenthal, Eric; Shultz, Sandy; Snutch, Terrance; Staba, Richard; Toga, Arthur; Van Horn, Jack; Vespa, Paul; Willyerd, Frederick; Zimmermann, Lara

2018-05-31

Injury severity after traumatic brain injury (TBI) is a well-established risk factor for the development of post-traumatic epilepsy (PTE). However, whether lesion location influences the susceptibility of seizures and development of PTE longitudinally has yet to be defined. We hypothesized that lesion location, specifically in the temporal lobe, would be associated with an increased incidence of both early seizures and PTE. As secondary analysis measures, we assessed the degree of brain atrophy and functional recovery, and performed a between-group analysis, comparing patients who developed PTE with those who did not develop PTE. We assessed early seizure incidence (n = 90) and longitudinal development of PTE (n = 46) in a prospective convenience sample of patients with moderate-severe TBI. Acutely, patients were monitored with prospective cEEG and a high-resolution Magnetic Resonance Imaging (MRI) scan for lesion location classification. Chronically, patients underwent a high-resolution MRI, clinical assessment, and were longitudinally monitored for development of epilepsy for a minimum of 2 years post-injury. Early seizures, occurring within the first week post-injury, occurred in 26.7% of the patients (n = 90). Within the cohort of subjects who had evidence of early seizures (n = 24), 75% had a hemorrhagic temporal lobe injury on admission. For longitudinal analyses (n = 46), 45.7% of patients developed PTE within a minimum of 2 years post-injury. Within the cohort of subjects who developed PTE (n = 21), 85.7% had a hemorrhagic temporal lobe injury on admission and 38.1% had early (convulsive or non-convulsive) seizures on cEEG monitoring during their acute ICU stay. In a between-group analysis, patients with PTE (n = 21) were more likely than patients who did not develop PTE (n = 25) to have a hemorrhagic temporal lobe injury (p < 0.001), worse functional recovery (p = 0.003), and greater temporal lobe atrophy (p = 0.029). Our results indicate that in a cohort of patients with a moderate-severe TBI, 1) lesion location specificity (e.g. the temporal lobe) is related to both a high incidence of early seizures and longitudinal development of PTE, 2) early seizures, whether convulsive or non-convulsive in nature, are associated with an increased risk for PTE development, and 3) patients who develop PTE have greater chronic temporal lobe atrophy and worse functional outcomes, compared to those who do not develop PTE, despite matched injury severity characteristics. This study provides the foundation for a future prospective study focused on elucidating the mechanisms and risk factors for epileptogenesis. Copyright © 2017. Published by Elsevier Inc.

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.

Decreased subcortical cholinergic arousal in focal seizures

PubMed Central

Motelow, Joshua E.; Li, Wei; Zhan, Qiong; Mishra, Asht M.; Sachdev, Robert N. S.; Liu, Geoffrey; Gummadavelli, Abhijeet; Zayyad, Zaina; Lee, Hyun Seung; Chu, Victoria; Andrews, John P.; Englot, Dario J.; Herman, Peter; Sanganahalli, Basavaraju G.; Hyder, Fahmeed; Blumenfeld, Hal

2015-01-01

SUMMARY Impaired consciousness in temporal lobe seizures has a major negative impact on quality of life. The prevailing view holds that this disorder impairs consciousness by seizure spread to the bilateral temporal lobes. We propose instead that seizures invade subcortical regions and depress arousal, causing impairment through decreases rather than through increases in activity. Using functional magnetic resonance imaging in a rodent model, we found increased activity in regions known to depress cortical function including lateral septum and anterior hypothalamus. Importantly, we found suppression of intralaminar thalamic and brainstem arousal systems and suppression of the cortex. At a cellular level, we found reduced firing of identified cholinergic neurons in the brainstem pedunculopontine tegmental nucleus and basal forebrain. Finally, we used enzyme-based amperometry to demonstrate reduced cholinergic neurotransmission in both cortex and thalamus. Decreased subcortical arousal is a novel mechanism for loss of consciousness in focal temporal lobe seizures. PMID:25654258

Going beyond LTM in the MTL: A Synthesis of Neuropsychological and Neuroimaging Findings on the Role of the Medial Temporal Lobe in Memory and Perception

ERIC Educational Resources Information Center

Graham, Kim S.; Barense, Morgan D.; Lee, Andy C. H.

2010-01-01

Studies in rats and non-human primates suggest that medial temporal lobe (MTL) structures play a role in perceptual processing, with the hippocampus necessary for spatial discrimination, and the perirhinal cortex for object discrimination. Until recently, there was little convergent evidence for analogous functional specialisation in humans, or…

Research on spontaneous activity in adult anisometropic amblyopia with regional homogeneity

NASA Astrophysics Data System (ADS)

Huang, Yufeng; Zhou, Yifeng

2017-06-01

Amblyopia usually occurs in early childhood and results in monocular visual impairment. The functional magnetic resonance imaging (fMRI) studies have reflected functional anomaly in amblyopia. In resting-state fMRI study, spontaneous activity changes abnormally in anisometropic amblyopia could be revealed by the regional homogeneity (ReHo). Twenty two adult anisometropic amblyopes and Twenty one normal controls participated in this fMRI study. Two sample T test was carried out to analysis ReHo within the whole brain for the inter groups. Compare with normal group, our study found that the amblyopia’s ReHo mainly increased in the left frontal lobe, while decreased in the left cerebellum, the temporal lobe (left and right), and the left parietal lobe. And the ReHo values in middle and inferior temporal lobe, the prefrontal lobe, frontal lobe (positive) and parietal lobe and medial frontal gyrus (negative) could be correlated with the acuity deficit of amblyopia. The results increased in ReHo may indicate compensatory plasticity in higher vision information process, while the decreased in ReHo may reflect decreased ability in eye movement, spatial sense and visuo-motor coordination. The correlation revealed that the vision deficit may correspond to the spontaneous in certain brain area.

Evaluation of Posterior Hippocampal Epileptogenicity During Epilepsy Surgery For Temporal Lobe Cavernoma by the Occipital Approach.

PubMed

Akiyama, Yukinori; Suzuki, Kengo; Ochi, Satoko; Miyamoto, Susumu; Mikuni, Nobuhiro

2015-11-01

Cavernomas frequently are associated with intractable epilepsy. When cavernomas located in the temporal lobe are associated with intractable epilepsy, the hippocampus also may have an epileptic focus. The objective in the present study was to clarify the importance of evaluation of the posterior hippocampal epileptogenicity during epilepsy surgery for posteromedial temporal lobe cavernoma. In this study, we describe 2 rare cases of medically intractable epilepsy in patients with posteromedial temporal lobe cavernomas who underwent surgery via the occipital approach. Using longitudinal insertion of depth electrodes into the hippocampus, we evaluated epileptogenicity in both patients from the cavernoma cavity and its surrounding hemosiderin, as well as from the posterior hippocampus near the cavernoma. We show that the transoccipital approach to the posteromedial temporal lobe is compatible with depth electrode insertion and subdural electrode placement on the temporal lobe, enabling an accurate evaluation of potential epileptogenic zones in the posterior part of the hippocampus. Both patients did not experience any seizures and had no postoperative neurologic deficits, and their cognitive functions were intact. The transoccipital approach enables the optimization of the extent of posterior hippocampectomy while avoiding unnecessary resection for seizure control. We suggest resecting the posterior part of the hippocampus in addition to the cavernoma and surrounding areas in patients with medically refractory epilepsy due to a posteromedial temporal cavernoma. Tailored systematic resection guided by intraoperative electrocorticography and electroencephalography with a depth electrode was important and necessary in the present cases. Copyright © 2015 Elsevier Inc. 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.

Fornix and medial temporal lobe lesions lead to comparable deficits in complex visual perception.

PubMed

Lech, Robert K; Koch, Benno; Schwarz, Michael; Suchan, Boris

2016-05-04

Recent research dealing with the structures of the medial temporal lobe (MTL) has shifted away from exclusively investigating memory-related processes and has repeatedly incorporated the investigation of complex visual perception. Several studies have demonstrated that higher level visual tasks can recruit structures like the hippocampus and perirhinal cortex in order to successfully perform complex visual discriminations, leading to a perceptual-mnemonic or representational view of the medial temporal lobe. The current study employed a complex visual discrimination paradigm in two patients suffering from brain lesions with differing locations and origin. Both patients, one with extensive medial temporal lobe lesions (VG) and one with a small lesion of the anterior fornix (HJK), were impaired in complex discriminations while showing otherwise mostly intact cognitive functions. The current data confirmed previous results while also extending the perceptual-mnemonic theory of the MTL to the main output structure of the hippocampus, the fornix. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Temporal Lobe and “Default” Hemodynamic Brain Modes Discriminate Between Schizophrenia and Bipolar Disorder

PubMed Central

Calhoun, Vince D.; Maciejewski, Paul K.; Pearlson, Godfrey D.; Kiehl, Kent A.

2009-01-01

Schizophrenia and bipolar disorder are currently diagnosed on the basis of psychiatric symptoms and longitudinal course. The determination of a reliable, biologically-based diagnostic indicator of these diseases (a biomarker) could provide the groundwork for developing more rigorous tools for differential diagnosis and treatment assignment. Recently, methods have been used to identify distinct sets of brain regions or “spatial modes” exhibiting temporally coherent brain activity. Using functional magnetic resonance imaging (fMRI) data and a multivariate analysis method, independent component analysis, we combined the temporal lobe and the default modes to discriminate subjects with bipolar disorder, chronic schizophrenia, and healthy controls. Temporal lobe and default mode networks were reliably identified in all participants. Classification results on an independent set of individuals revealed an average sensitivity and specificity of 90 and 95%, respectively. The use of coherent brain networks such as the temporal lobe and default mode networks may provide a more reliable measure of disease state than task-correlated fMRI activity. A combination of two such hemodynamic brain networks shows promise as a biomarker for schizophrenia and bipolar disorder. PMID:17894392

Temporal lobe and "default" hemodynamic brain modes discriminate between schizophrenia and bipolar disorder.

PubMed

Calhoun, Vince D; Maciejewski, Paul K; Pearlson, Godfrey D; Kiehl, Kent A

2008-11-01

Schizophrenia and bipolar disorder are currently diagnosed on the basis of psychiatric symptoms and longitudinal course. The determination of a reliable, biologically-based diagnostic indicator of these diseases (a biomarker) could provide the groundwork for developing more rigorous tools for differential diagnosis and treatment assignment. Recently, methods have been used to identify distinct sets of brain regions or "spatial modes" exhibiting temporally coherent brain activity. Using functional magnetic resonance imaging (fMRI) data and a multivariate analysis method, independent component analysis, we combined the temporal lobe and the default modes to discriminate subjects with bipolar disorder, chronic schizophrenia, and healthy controls. Temporal lobe and default mode networks were reliably identified in all participants. Classification results on an independent set of individuals revealed an average sensitivity and specificity of 90 and 95%, respectively. The use of coherent brain networks such as the temporal lobe and default mode networks may provide a more reliable measure of disease state than task-correlated fMRI activity. A combination of two such hemodynamic brain networks shows promise as a biomarker for schizophrenia and bipolar disorder.

Altered functional MR imaging language activation in elderly individuals with cerebral leukoaraiosis.

PubMed

Welker, Kirk M; De Jesus, Reordan O; Watson, Robert E; Machulda, Mary M; Jack, Clifford R

2012-10-01

To test the hypothesis that leukoaraiosis alters functional activation during a semantic decision language task. With institutional review board approval and written informed consent, 18 right-handed, cognitively healthy elderly participants with an aggregate leukoaraiosis lesion volume of more than 25 cm(3) and 18 age-matched control participants with less than 5 cm(3) of leukoaraiosis underwent functional MR imaging to allow comparison of activation during semantic decisions with that during visual perceptual decisions. Brain statistical maps were derived from the general linear model. Spatially normalized group t maps were created from individual contrast images. A cluster extent threshold of 215 voxels was used to correct for multiple comparisons. Intergroup random effects analysis was performed. Language laterality indexes were calculated for each participant. In control participants, semantic decisions activated the bilateral visual cortex, left posteroinferior temporal lobe, left posterior cingulate gyrus, left frontal lobe expressive language regions, and left basal ganglia. Visual perceptual decisions activated the right parietal and posterior temporal lobes. Participants with leukoaraiosis showed reduced activation in all regions associated with semantic decisions; however, activation associated with visual perceptual decisions increased in extent. Intergroup analysis showed significant activation decreases in the left anterior occipital lobe (P=.016), right posterior temporal lobe (P=.048), and right basal ganglia (P=.009) in particpants with leukoariosis. Individual participant laterality indexes showed a strong trend (P=.059) toward greater left lateralization in the leukoaraiosis group. Moderate leukoaraiosis is associated with atypical functional activation during semantic decision tasks. Consequently, leukoaraiosis is an important confounding variable in functional MR imaging studies of elderly individuals. © RSNA, 2012.

Functional relevance of interindividual differences in temporal lobe callosal pathways: a DTI tractography study.

PubMed

Westerhausen, René; Grüner, Renate; Specht, Karsten; Hugdahl, Kenneth

2009-06-01

The midsagittal corpus callosum is topographically organized, that is, with regard to their cortical origin several subtracts can be distinguished within the corpus callosum that belong to specific functional brain networks. Recent diffusion tensor tractography studies have also revealed remarkable interindividual differences in the size and exact localization of these tracts. To examine the functional relevance of interindividual variability in callosal tracts, 17 right-handed male participants underwent structural and diffusion tensor magnetic resonance imaging. Probabilistic tractography was carried out to identify the callosal subregions that interconnect left and right temporal lobe auditory processing areas, and the midsagittal size of this tract was seen as indicator of the (anatomical) strength of this connection. Auditory information transfer was assessed applying an auditory speech perception task with dichotic presentations of consonant-vowel syllables (e.g., /ba-ga/). The frequency of correct left ear reports in this task served as a functional measure of interhemispheric transfer. Statistical analysis showed that a stronger anatomical connection between the superior temporal lobe areas supports a better information transfer. This specific structure-function association in the auditory modality supports the general notion that interindividual differences in callosal topography possess functional relevance.

Bilateral temporal lobe volume reduction parallels cognitive impairment in progressive aphasia.

PubMed

Andersen, C; Dahl, C; Almkvist, O; Ostberg, P; Julin, P; Wahlund, L O

1997-10-01

Patients with isolated aphasia in the absence of other cognitive abnormalities have been the focus of several studies during the past decade. It has been called primary progressive aphasia (PPA), and the typical features of this syndrome are marked atrophy of the left temporal lobe according to the radiological examination and a language disorder as the initial symptom. In previous studies of PPA, the selection of the patients was based mainly on linguistic symptoms. Now, when computed tomography or magnetic resonance imaging scans are part of the routine investigation of cognitive impairment and suspected dementia, the patients with lobar atrophy will be found at an earlier stage. In the present study, we used a new approach and defined the study group by selecting patients with obvious left temporal lobe atrophy, assessed by MRI, and we referred to them as patients with temporal lobe atrophy (TLA). To identify the features that distinguish TLA from other primary neurodegenerative disorders. Six patients with TLA were compared with patients with Alzheimer disease (AD), patients with frontal lobe dementia (FLD), and healthy control subjects. The investigations included magnetic resonance imaging volumetry, single photon emission computed tomography, and neuropsychologic and linguistic evaluations. In the TLA group, the mean volume of the left temporal lobe was 35% smaller than the right, while in the AD and FLD groups, the atrophy was symmetrical and bilateral. In the TLA group, the absolute volumes of the temporal lobes were significantly smaller on the left side compared with the AD and FLD groups, whereas there was no difference on the right side. The cerebral blood flow pattern in TLA was asymmetric and differed from that in the other study groups. All patients with TLA had a history of progressive Wernicke-type aphasia, ranging from 2 to 6 years. They showed primary verbal memory impairment but had preserved visuospatial functions. The clinical condition of all patients with TLA deteriorated during the study period; severe aphasia developed, and the patients exhibited signs of frontal lobe dysfunction. Serial volumetric measurements in 4 of 6 patients showed an annual 8% to 9% decrease of both left and right temporal lobes. The initial marked asymmetry in cognitive function found in patients with TLA contrasts with the general decline found in patients with AD. The bilateral degenerative process evident in patients with TLA paralleled the clinical deterioration, indicating TLA to be a non-AD lobar atrophy that develops into generalized cognitive dysfunction and dementia.

Task activation and functional connectivity show concordant memory laterality in temporal lobe epilepsy.

PubMed

Sideman, Noah; Chaitanya, Ganne; He, Xiaosong; Doucet, Gaelle; Kim, Na Young; Sperling, Michael R; Sharan, Ashwini D; Tracy, Joseph I

2018-04-01

In epilepsy, asymmetries in the organization of mesial temporal lobe (MTL) functions help determine the cognitive risk associated with procedures such as anterior temporal lobectomy. Past studies have investigated the change/shift in a visual episodic memory laterality index (LI) in mesial temporal lobe structures through functional magnetic resonance imaging (fMRI) task activations. Here, we examine whether underlying task-related functional connectivity (FC) is concordant with such standard fMRI laterality measures. A total of 56 patients with temporal lobe epilepsy (TLE) (Left TLE [LTLE]: 31; Right TLE [RTLE]: 25) and 34 matched healthy controls (HC) underwent fMRI scanning during performance of a scene encoding task (SET). We assessed an activation-based LI of the hippocampal gyrus (HG) and parahippocampal gyrus (PHG) during the SET and its correspondence with task-related FC measures. Analyses involving the HG and PHG showed that the patients with LTLE had a consistently higher LI (right-lateralized) than that of the HC and group with RTLE, indicating functional reorganization. The patients with RTLE did not display a reliable contralateral shift away from the pathology, with the mesial structures showing quite distinct laterality patterns (HG, no laterality bias; PHG, no evidence of LI shift). The FC data for the group with LTLE provided confirmation of reorganization effects, revealing that a rightward task LI may be based on underlying connections between several left-sided regions (middle/superior occipital and left medial frontal gyri) and the right PHG. The FCs between the right HG and left anterior cingulate/medial frontal gyri were also observed in LTLE. Importantly, the data demonstrate that the areas involved in the LTLE task activation shift to the right hemisphere showed a corresponding increase in task-related FCs between the hemispheres. Altered laterality patterns based on mesial temporal lobe epilepsy (MTLE) pathology manifest as several different phenotypes, varying according to side of seizure onset and the specific mesial structures involved. There is good correspondence between task LI activation and FC patterns in the setting of LTLE, suggesting that reliable visual episodic memory reorganization may require both a shift in nodal activation and a change in nodal connectivity with mesial temporal structures involved in memory. Copyright © 2018. Published by Elsevier Inc.

Disrupted Structural and Functional Networks and Their Correlation with Alertness in Right Temporal Lobe Epilepsy: A Graph Theory Study.

PubMed

Jiang, Wenyu; Li, Jianping; Chen, Xuemei; Ye, Wei; Zheng, Jinou

2017-01-01

Previous studies have shown that temporal lobe epilepsy (TLE) involves abnormal structural or functional connectivity in specific brain areas. However, limited comprehensive studies have been conducted on TLE associated changes in the topological organization of structural and functional networks. Additionally, epilepsy is associated with impairment in alertness, a fundamental component of attention. In this study, structural networks were constructed using diffusion tensor imaging tractography, and functional networks were obtained from resting-state functional MRI temporal series correlations in 20 right temporal lobe epilepsy (rTLE) patients and 19 healthy controls. Global network properties were computed by graph theoretical analysis, and correlations were assessed between global network properties and alertness. The results from these analyses showed that rTLE patients exhibit abnormal small-world attributes in structural and functional networks. Structural networks shifted toward more regular attributes, but functional networks trended toward more random attributes. After controlling for the influence of the disease duration, negative correlations were found between alertness, small-worldness, and the cluster coefficient. However, alertness did not correlate with either the characteristic path length or global efficiency in rTLE patients. Our findings show that disruptions of the topological construction of brain structural and functional networks as well as small-world property bias are associated with deficits in alertness in rTLE patients. These data suggest that reorganization of brain networks develops as a mechanism to compensate for altered structural and functional brain function during disease progression.

IMAGING OF BRAIN FUNCTION BASED ON THE ANALYSIS OF FUNCTIONAL CONNECTIVITY - IMAGING ANALYSIS OF BRAIN FUNCTION BY FMRI AFTER ACUPUNCTURE AT LR3 IN HEALTHY INDIVIDUALS.

PubMed

Zheng, Yu; Wang, Yuying; Lan, Yujun; Qu, Xiaodong; Lin, Kelin; Zhang, Jiping; Qu, Shanshan; Wang, Yanjie; Tang, Chunzhi; Huang, Yong

2016-01-01

This Study observed the relevant brain areas activated by acupuncture at the Taichong acupoint (LR3) and analyzed the functional connectivity among brain areas using resting state functional magnetic resonance imaging (fMRI) to explore the acupoint specificity of the Taichong acupoint. A total of 45 healthy subjects were randomly divided into the Taichong (LR3) group, sham acupuncture group and sham acupoint group. Subjects received resting state fMRI before acupuncture, after true (sham) acupuncture in each group. Analysis of changes in connectivity among the brain areas was performed using the brain functional connectivity method. The right cerebrum temporal lobe was selected as the seed point to analyze the functional connectivity. It had a functional connectivity with right cerebrum superior frontal gyrus, limbic lobe cingulate gyrus and left cerebrum inferior temporal gyrus (BA 37), inferior parietal lobule compared by before vs. after acupuncture at LR3, and right cerebrum sub-lobar insula and left cerebrum middle frontal gyrus, medial frontal gyrus compared by true vs. sham acupuncture at LR3, and right cerebrum occipital lobe cuneus, occipital lobe sub-gyral, parietal lobe precuneus and left cerebellum anterior lobe culmen by acupuncture at LR3 vs. sham acupoint. Acupuncture at LR3 mainly specifically activated the brain functional network that participates in visual function, associative function, and emotion cognition, which are similar to the features on LR3 in tradition Chinese medicine. These brain areas constituted a neural network structure with specific functions that had specific reference values for the interpretation of the acupoint specificity of the Taichong acupoint.

Proteomic analysis and comparison of the biopsy and autopsy specimen of human brain temporal lobe.

PubMed

He, Sizhi; Wang, Qingsong; He, Jintang; Pu, Hai; Yang, Wei; Ji, Jianguo

2006-09-01

The proteomic study on human temporal lobe can help us to understand the physiological function of CNS in normal as well as in pathological state. Proteomic tools are potent for the assessment of protein stability post mortem. In this pilot study, the human temporal lobe biopsy specimen with chronic pharmacoresistant temporal lobe epilepsy (TLE) and autopsy specimen in control were separated by 2-DE. Using MALDI-TOF-MS and MS/MS, 375 protein spots were identified which were the products of 267 genes. Six down-regulated and 23 up-regulated protein spots in the autopsy specimen were ascertained after the gel image analysis with the ImageMaster software. A number of proteins that include neurotransmitter metabolic and glycolytic enzymes, cytoprotective proteins and cytoskeleton were found decreased while the precursor of apolipoprotein A-I increased in the TLE brain. We tried several methods to prepare the protein samples and found that DNase and RNase treatment, ultracentrifugation and Amersham clean-up kit purification can improve gel separation quality. This work optimized the sample preparation method and constructed a primary protein database of human temporal lobe and found some proteins with remarkable level change probably involved in the post-mortem process and chronic pharmacoresistant TLE pathogenesis.

Frontal Lobe Involvement in a Task of Time-Based Prospective Memory

ERIC Educational Resources Information Center

McFarland, Craig P.; Glisky, Elizabeth L.

2009-01-01

Time-based prospective memory (PM) has been found to be negatively affected by aging, possibly as a result of declining frontal lobe (FL) function. Despite a clear retrospective component to PM tasks, the medial temporal lobes (MTL) are thought to play only a secondary role in successful task completion. The present study investigated the role of…

Emergence of artistic talent in frontotemporal dementia.

PubMed

Miller, B L; Cummings, J; Mishkin, F; Boone, K; Prince, F; Ponton, M; Cotman, C

1998-10-01

To describe the clinical, neuropsychological, and imaging features of five patients with frontotemporal dementia (FTD) who acquired new artistic skills in the setting of dementia. Creativity in the setting of dementia has recently been reported. We describe five patients who became visual artists in the setting of FTD. Sixty-nine FTD patients were interviewed regarding visual abilities. Five became artists in the early stages of FTD. Their history, artistic process, neuropsychology, and anatomy are described. On SPECT or pathology, four of the five patients had the temporal variant of FTD in which anterior temporal lobes are involved but the dorsolateral frontal cortex is spared. Visual skills were spared but language and social skills were devastated. Loss of function in the anterior temporal lobes may lead to the "facilitation" of artistic skills. Patients with the temporal lobe variant of FTD offer a window into creativity.

Parametric fMRI analysis of visual encoding in the human medial temporal lobe.

PubMed

Rombouts, S A; Scheltens, P; Machielson, W C; Barkhof, F; Hoogenraad, F G; Veltman, D J; Valk, J; Witter, M P

1999-01-01

A number of functional brain imaging studies indicate that the medial temporal lobe system is crucially involved in encoding new information into memory. However, most studies were based on differences in brain activity between encoding of familiar vs. novel stimuli. To further study the underlying cognitive processes, we applied a parametric design of encoding. Seven healthy subjects were instructed to encode complex color pictures into memory. Stimuli were presented in a parametric fashion at different rates, thus representing different loads of encoding. Functional magnetic resonance imaging (fMRI) was used to assess changes in brain activation. To determine the number of pictures successfully stored into memory, recognition scores were determined afterwards. During encoding, brain activation occurred in the medial temporal lobe, comparable to the results obtained by others. Increasing the encoding load resulted in an increase in the number of successfully stored items. This was reflected in a significant increase in brain activation in the left lingual gyrus, in the left and right parahippocampal gyrus, and in the right inferior frontal gyrus. This study shows that fMRI can detect changes in brain activation during variation of one aspect of higher cognitive tasks. Further, it strongly supports the notion that the human medial temporal lobe is involved in encoding novel visual information into memory.

[Dynamics of functional MRI and speech function in patients after resection of frontal and temporal lobe tumors].

PubMed

Buklina, S B; Batalov, A I; Smirnov, A S; Poddubskaya, A A; Pitskhelauri, D I; Kobyakov, G L; Zhukov, V Yu; Goryaynov, S A; Kulikov, A S; Ogurtsova, A A; Golanov, A V; Varyukhina, M D; Pronin, I N

There are no studies on application of functional MRI (fMRI) for long-term monitoring of the condition of patients after resection of frontal and temporal lobe tumors. The study purpose was to correlate, using fMRI, reorganization of the speech system and dynamics of speech disorders in patients with left hemisphere gliomas before surgery and in the early and late postoperative periods. A total of 20 patients with left hemisphere gliomas were dynamically monitored using fMRI and comprehensive neuropsychological testing. The tumor was located in the frontal lobe in 12 patients and in the temporal lobe in 8 patients. Fifteen patients underwent primary surgery; 5 patients had repeated surgery. Sixteen patients had WHO Grade II and Grade III gliomas; the others had WHO Grade IV gliomas. Nineteen patients were examined preoperatively; 20 patients were examined at different times after surgery. Speech functions were assessed by a Luria's test; the dominant hand was determined using the Annette questionnaire; a family history of left-handedness was investigated. Functional MRI was performed on an HDtx 3.0 T scanner using BrainWavePA 2.0, Z software for fMRI data processing program for all calculations >7, p<0.001. In patients with extensive tumors and recurrent tumors, activation of right-sided homologues of the speech areas cold be detected even before surgery; but in most patients, the activation was detected 3 months or more after surgery. Therefore, reorganization of the speech system took time. Activation of right-sided homologues of the speech areas remained in all patients for up to a year. Simultaneous activation of right-sided homologues of both speech areas, the Broca's and Wernicke's areas, was detected more often in patients with frontal lobe tumors than in those with temporal lobe tumors. No additional activation foci in the left hemisphere were found at the thresholds used to process fMRI data. Recovery of the speech function, to a certain degree, occurred in all patients, but no clear correlation with fMRI data was found. Complex fMRI and neuropsychological studies in 20 patients after resection of frontal and temporal lobe tumors revealed individual features of speech system reorganization within one year follow-up. Probably, activation of right-sided homologues of the speech areas in the presence of left hemisphere tumors depends not only on the severity of speech disorder but also reflects individual involvement of the right hemisphere in enabling speech function. This is confirmed by right-sided activation, according to the fMRI data, in right-sided patients without aphasia and, conversely, the lack of activation of right-sided homologues of the speech areas in several patients with severe postoperative speech disorders during the entire follow-up period.

Surgical Considerations of Intractable Mesial Temporal Lobe Epilepsy

PubMed Central

Boling, Warren W.

2018-01-01

Surgery of temporal lobe epilepsy is the best opportunity for seizure freedom in medically intractable patients. The surgical approach has evolved to recognize the paramount importance of the mesial temporal structures in the majority of patients with temporal lobe epilepsy who have a seizure origin in the mesial temporal structures. For those individuals with medically intractable mesial temporal lobe epilepsy, a selective amygdalohippocampectomy surgery can be done that provides an excellent opportunity for seizure freedom and limits the resection to temporal lobe structures primarily involved in seizure genesis. PMID:29461485

Treating autism by targeting the temporal lobes.

PubMed

Chi, Richard P; Snyder, Allan W

2014-11-01

Compelling new findings suggest that an early core signature of autism is a deficient left anterior temporal lobe response to language and an atypical over-activation of the right anterior temporal lobe. Intriguingly, our recent results from an entirely different line of reasoning and experiments also show that applying cathodal stimulation (suppressing) at the left anterior temporal lobe together with anodal stimulation (facilitating) at the right anterior temporal lobe, by transcranial direct current stimulation (tDCS), can induce some autistic-like cognitive abilities in otherwise normal adults. If we could briefly induce autistic like cognitive abilities in healthy individuals, it follows that we might be able to mitigate some autistic traits by reversing the above stimulation protocol, in an attempt to restore the typical dominance of the left anterior temporal lobe. Accordingly, we hypothesize that at least some autistic traits can be mitigated, by applying anodal stimulation (facilitating) at the left anterior temporal lobe together with cathodal stimulation (suppressing) at the right anterior temporal lobe. Our hypothesis is supported by strong convergent evidence that autistic symptoms can emerge and later reverse due to the onset and subsequent recovery of various temporal lobe (predominantly the left) pathologies. It is also consistent with evidence that the temporal lobes (especially the left) are a conceptual hub, critical for extracting meaning from lower level sensory information to form a coherent representation, and that a deficit in the temporal lobes underlies autistic traits. Copyright © 2014 Elsevier Ltd. All rights reserved.

Verbal memory outcome in patients with normal preoperative verbal memory and left mesial temporal sclerosis.

PubMed

LoGalbo, Anthony; Sawrie, Stephen; Roth, David L; Kuzniecky, Ruben; Knowlton, Robert; Faught, Edward; Martin, Roy

2005-05-01

Previous studies have shown that structural integrity (i.e., presence/absence of mesial temporal sclerosis (MTS)) of the left mesial temporal lobe is associated with verbal memory outcome following left anterior temporal lobectomy (ATL). However, the functional integrity of the left temporal lobe, as exemplified by preoperative verbal memory performance, has also been associated with verbal memory outcome following surgery. We investigated the risk of verbal memory loss in patients with known structural abnormality (i.e., left mesial temporal sclerosis by MRI) and normal preoperative verbal memory performance who undergo left ATL. Seventeen patients with left temporal lobe epilepsy, MRI-based exclusive left MTS, and normal preoperative verbal memory were identified. Normal verbal memory was defined as performance on both Acquisition (learning across trials 1-5) and Retrieval (long delayed free recall) portions of the California Verbal Learning Test (CVLT) above a T score of 40 (>16%ile). Postoperative verbal memory outcome was established by incorporating standardized regression-based (SRB) change scores. Postoperative declines across both CVLT Retrieval T scores and Acquisition T scores (average 20% and average 15% declines from baseline scores, respectively) were measured for the group. The average CVLT Retrieval SRB change score was -2.5, and the average CVLT Acquisition SRB change score was -1.0. A larger proportion of patients demonstrated postoperative declines on Retrieval scores than Acquisition scores (64.7% vs 17.6%, respectively). Even in the presence of left MTS, patients exhibiting normal presurgical verbal memory are at risk for verbal memory declines following ATL. These results suggest that the functional integrity of the left mesial temporal lobe may play an important role in the verbal memory outcome in this patient group.

Cognitive changes in people with temporal lobe epilepsy over a 13-year period.

PubMed

Mameniškienė, Rūta; Rimšienė, Justė; Puronaitė, Roma

2016-10-01

The aims of our study were to evaluate cognitive decline in people with temporal lobe epilepsy over a period of 13years and to determine what clinical and treatment characteristics may have been associated with these. Thirty-three individuals with temporal lobe epilepsy underwent the same neuropsychological assessment of verbal and nonverbal memory, attention, and executive functions using the same cognitive test battery as one used 13years ago. Long-term verbal and nonverbal memory was tested four weeks later. Results were compared with those carried out 13years earlier. There was no significant change in verbal and verbal-logical memory tests; however, nonverbal memory worsened significantly. Long-term verbal memory declined for 21.9% of participants, long-term verbal-logical memory for 34.4%, and long-term nonverbal memory for 56.3%. Worsening of working verbal and verbal-logical memory was associated with longer epilepsy duration and lower levels of patients' education; worsening of verbal delayed recall and long-term verbal-logical memory was associated with higher seizure frequency. Decline in long-term nonverbal memory had significant association with a longer duration of epilepsy. The worsening of reaction and attention inversely correlated with the symptoms of depression. Over a 13-year period, cognitive functions did not change significantly. Good seizure control and reduced symptoms of depression in this sample of people with temporal lobe epilepsy were associated with better cognitive functioning. The predictors of change of cognitive functions could be complex and require further study. Copyright © 2016 Elsevier Inc. All rights reserved.

Alteration of functional connectivity within visuospatial working memory-related brain network in patients with right temporal lobe epilepsy: a resting-state fMRI study.

PubMed

Lv, Zong-xia; Huang, Dong-Hong; Ye, Wei; Chen, Zi-rong; Huang, Wen-li; Zheng, Jin-ou

2014-06-01

This study aimed to investigate the resting-state brain network related to visuospatial working memory (VSWM) in patients with right temporal lobe epilepsy (rTLE). The functional mechanism underlying the cognitive impairment in VSWM was also determined. Fifteen patients with rTLE and 16 healthy controls matched for age, gender, and handedness underwent a 6-min resting-state functional MRI session and a neuropsychological test using VSWM_Nback. The VSWM-related brain network at rest was extracted using multiple independent component analysis; the spatial distribution and the functional connectivity (FC) parameters of the cerebral network were compared between groups. Behavioral data were subsequently correlated with the mean Z-value in voxels showing significant FC difference during intergroup comparison. The distribution of the VSWM-related resting-state network (RSN) in the group with rTLE was virtually consistent with that in the healthy controls. The distribution involved the dorsolateral prefrontal lobe and parietal lobe in the right hemisphere and the partial inferior parietal lobe and posterior lobe of the cerebellum in the left hemisphere (p<0.05, AlphaSim corrected). Between-group differences suggest that the group with rTLE had a decreased FC within the right superior frontal lobe (BA8), right middle frontal lobe, and right ventromedial prefrontal lobe compared with the controls (p<0.05, AlphaSim corrected). The regions of increased FC in rTLE were localized within the right superior frontal lobe (BA11), right superior parietal lobe, and left posterior lobe of the cerebellum (p<0.05, AlphaSim corrected). Moreover, patients with rTLE performed worse than controls in the VSWM_Nback test, and there were negative correlations between ACCmeanRT (2-back) and the mean Z-value in the voxels showing decreased or increased FC in rTLE (p<0.05). The results suggest that the alteration of the VSWM-related RSN might underpin the VSWM impairment in patients with rTLE and possibly implies a functional compensation by enlarging the FC within the ipsilateral cerebral network. Copyright © 2014 Elsevier Inc. All rights reserved.

Impaired familiarity with preserved recollection after anterior temporal-lobe resection that spares the hippocampus.

PubMed

Bowles, Ben; Crupi, Carina; Mirsattari, Seyed M; Pigott, Susan E; Parrent, Andrew G; Pruessner, Jens C; Yonelinas, Andrew P; Köhler, Stefan

2007-10-09

It is well established that the medial-temporal lobe (MTL) is critical for recognition memory. The MTL is known to be composed of distinct structures that are organized in a hierarchical manner. At present, it remains controversial whether lower structures in this hierarchy, such as perirhinal cortex, support memory functions that are distinct from those of higher structures, in particular the hippocampus. Perirhinal cortex has been proposed to play a specific role in the assessment of familiarity during recognition, which can be distinguished from the selective contributions of the hippocampus to the recollection of episodic detail. Some researchers have argued, however, that the distinction between familiarity and recollection cannot capture functional specialization within the MTL and have proposed single-process accounts. Evidence supporting the dual-process view comes from demonstrations that selective hippocampal damage can produce isolated recollection impairments. It is unclear, however, whether temporal-lobe lesions that spare the hippocampus can produce selective familiarity impairments. Without this demonstration, single-process accounts cannot be ruled out. We examined recognition memory in NB, an individual who underwent surgical resection of left anterior temporal-lobe structures for treatment of intractable epilepsy. Her resection included a large portion of perirhinal cortex but spared the hippocampus. The results of four experiments based on three different experimental procedures (remember-know paradigm, receiver operating characteristics, and response-deadline procedure) indicate that NB exhibits impaired familiarity with preserved recollection. The present findings thus provide a crucial missing piece of support for functional specialization in the MTL.

Episodic Memory and Regional Atrophy in Frontotemporal Lobar Degeneration

PubMed Central

Söderlund, Hedvig; Black, Sandra E.; Miller, Bruce L.; Freedman, Morris; Levine, Brian

2008-01-01

It has been unclear to what extent memory is affected in frontotemporal lobar degeneration (FTLD). Since patients usually have atrophy in regions implicated in memory function, the frontal and/or temporal lobes, one would expect some memory impairment, and that the degree of atrophy in these regions would be inversely related to memory function. The purposes of this study were 1) to assess episodic memory function in FTLD, and more specifically patients' ability to episodically re-experience an event, and determine its source; 2) to examine whether memory performance is related to quantified regional brain atrophy. FTLD patients (n=18) and healthy comparison subjects (n=14) were assessed with cued recall, recognition, “remember/know” (self-reported re-experiencing) and source recall, at 30 min and 24 hr after encoding. Regional gray matter volumes were assessed with high resolution structural MRI concurrently to testing. Patients performed worse than comparison subjects on all memory measures. Gray matter volume in the left medial temporal lobe was positively correlated with recognition, re-experiencing, and source recall. Gray matter volume in the left posterior temporal lobe correlated significantly with recognition, at 30 min and 24 hr, and with source recall at 30 min. Estimated familiarity at 30 min was positively correlated with gray matter volume in the left inferior parietal lobe. In summary, episodic memory deficits in FTLD may be more common than previously thought, particularly in patients with left medial and posterior temporal atrophy. PMID:17888461

Thalamo-Cortical Disruption Contributes to Short-Term Memory Deficits in Patients with Medial Temporal Lobe Damage.

PubMed

Voets, Natalie L; Menke, Ricarda A L; Jbabdi, Saad; Husain, Masud; Stacey, Richard; Carpenter, Katherine; Adcock, Jane E

2015-11-01

Short-term (STM) and long-term memory (LTM) have largely been considered as separate brain systems reflecting fronto-parietal and medial temporal lobe (MTL) functions, respectively. This functional dichotomy has been called into question by evidence of deficits on aspects of working memory in patients with MTL damage, suggesting a potentially direct hippocampal contribution to STM. As the hippocampus has direct anatomical connections with the thalamus, we tested the hypothesis that damage to thalamic nuclei regulating cortico-cortical interactions may contribute to STM deficits in patients with hippocampal dysfunction. We used diffusion-weighted magnetic resonance imaging-based tractography to identify anatomical subdivisions in patients with MTL epilepsy. From these, we measured resting-state functional connectivity with detailed cortical divisions of the frontal, temporal, and parietal lobes. Whereas thalamo-temporal functional connectivity reflected LTM performance, thalamo-prefrontal functional connectivity specifically predicted STM performance. Notably, patients with hippocampal volume loss showed thalamic volume loss, most prominent in the pulvinar region, not detected in patients with normal hippocampal volumes. Aberrant thalamo-cortical connectivity in the epileptic hemisphere was mirrored in a loss of behavioral association with STM performance specifically in patients with hippocampal atrophy. These findings identify thalamo-cortical disruption as a potential mechanism contributing to STM deficits in the context of MTL damage. © The Author 2015. Published by Oxford University Press.

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.

Cognitive and Learning Strategies for Longstanding Temporal Lobe Lesions in a Child Who Suffered from "Herpes Simplex" Virus Encephalitis: A Case Study over 10 Years

ERIC Educational Resources Information Center

van Schoor, A. N.; Naude, H.; van Rensburg, M.; Pretorius, E.; Boon, J. M.

2005-01-01

This article presents a case study indicating that "Herpes simplex" virus (HSV) encephalitis may cause permanent learning disabilities due to damage to the temporal lobes as it discusses the results of a case study extending over 10 years to determine the long-term effects on both the anatomy of the brain and the intellectual functioning of the…

Cognitive and Learning Strategies for Longstanding Temporal Lobe Lesions in a Child Who Suffered from "Herpes Simplex" Virus Encephalitis: A Case Study over 10 Years

ERIC Educational Resources Information Center

van Schoor, A. N.; Naude, H.; van Rensburg, M.; Pretorius, E.; Boon, J. M.

2004-01-01

This article presents a case study indicating that "Herpes simplex" virus (HSV) encephalitis may cause permanent learning disabilities due to damage to the temporal lobes, as it discusses the results of a case study extending over 10 years to determine the long-term effects on both the anatomy of the brain and the intellectual functioning of the…

Parietal lobe critically supports successful paired immediate and single-item delayed memory for targets.

PubMed

Krumm, Sabine; Kivisaari, Sasa L; Monsch, Andreas U; Reinhardt, Julia; Ulmer, Stephan; Stippich, Christoph; Kressig, Reto W; Taylor, Kirsten I

2017-05-01

The parietal lobe is important for successful recognition memory, but its role is not yet fully understood. We investigated the parietal lobes' contribution to immediate paired-associate memory and delayed item-recognition memory separately for hits (targets) and correct rejections (distractors). We compared the behavioral performance of 56 patients with known parietal and medial temporal lobe dysfunction (i.e. early Alzheimer's Disease) to 56 healthy control participants in an immediate paired and delayed single item object memory task. Additionally, we performed voxel-based morphometry analyses to investigate the functional-neuroanatomic relationships between performance and voxel-based estimates of atrophy in whole-brain analyses. Behaviorally, all participants performed better identifying targets than rejecting distractors. The voxel-based morphometry analyses associated atrophy in the right ventral parietal cortex with fewer correct responses to familiar items (i.e. hits) in the immediate and delayed conditions. Additionally, medial temporal lobe integrity correlated with better performance in rejecting distractors, but not in identifying targets, in the immediate paired-associate task. Our findings suggest that the parietal lobe critically supports successful immediate and delayed target recognition memory, and that the ventral aspect of the parietal cortex and the medial temporal lobe may have complementary preferences for identifying targets and rejecting distractors, respectively, during recognition memory. Copyright © 2017. Published by Elsevier Inc.

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.

Frontal lobe connectivity and cognitive impairment in pediatric frontal lobe epilepsy.

PubMed

Braakman, Hilde M H; Vaessen, Maarten J; Jansen, Jacobus F A; Debeij-van Hall, Mariette H J A; de Louw, Anton; Hofman, Paul A M; Vles, Johan S H; Aldenkamp, Albert P; Backes, Walter H

2013-03-01

Cognitive impairment is frequent in children with frontal lobe epilepsy (FLE), but its etiology is unknown. With functional magnetic resonance imaging (fMRI), we have explored the relationship between brain activation, functional connectivity, and cognitive functioning in a cohort of pediatric patients with FLE and healthy controls. Thirty-two children aged 8-13 years with FLE of unknown cause and 41 healthy age-matched controls underwent neuropsychological assessment and structural and functional brain MRI. We investigated to which extent brain regions activated in response to a working memory task and assessed functional connectivity between distant brain regions. Data of patients were compared to controls, and patients were grouped as cognitively impaired or unimpaired. Children with FLE showed a global decrease in functional brain connectivity compared to healthy controls, whereas brain activation patterns in children with FLE remained relatively intact. Children with FLE complicated by cognitive impairment typically showed a decrease in frontal lobe connectivity. This decreased frontal lobe connectivity comprised both connections within the frontal lobe as well as connections from the frontal lobe to the parietal lobe, temporal lobe, cerebellum, and basal ganglia. Decreased functional frontal lobe connectivity is associated with cognitive impairment in pediatric FLE. The importance of impairment of functional integrity within the frontal lobe network, as well as its connections to distant areas, provides new insights in the etiology of the broad-range cognitive impairments in children with FLE. Wiley Periodicals, Inc. © 2012 International League Against Epilepsy.

Syntactic structure building in the anterior temporal lobe during natural story listening.

PubMed

Brennan, Jonathan; Nir, Yuval; Hasson, Uri; Malach, Rafael; Heeger, David J; Pylkkänen, Liina

2012-02-01

The neural basis of syntax is a matter of substantial debate. In particular, the inferior frontal gyrus (IFG), or Broca's area, has been prominently linked to syntactic processing, but the anterior temporal lobe has been reported to be activated instead of IFG when manipulating the presence of syntactic structure. These findings are difficult to reconcile because they rely on different laboratory tasks which tap into distinct computations, and may only indirectly relate to natural sentence processing. Here we assessed neural correlates of syntactic structure building in natural language comprehension, free from artificial task demands. Subjects passively listened to Alice in Wonderland during functional magnetic resonance imaging and we correlated brain activity with a word-by-word measure of the amount syntactic structure analyzed. Syntactic structure building correlated with activity in the left anterior temporal lobe, but there was no evidence for a correlation between syntactic structure building and activity in inferior frontal areas. Our results suggest that the anterior temporal lobe computes syntactic structure under natural conditions. Copyright © 2010 Elsevier Inc. All rights reserved.

Dissociating the semantic function of two neighbouring subregions in the left lateral anterior temporal lobe

PubMed Central

Sanjuán, Ana; Hope, Thomas M.H.; Parker Jones, 'Ōiwi; Prejawa, Susan; Oberhuber, Marion; Guerin, Julie; Seghier, Mohamed L.; Green, David W.; Price, Cathy J.

2015-01-01

We used fMRI in 35 healthy participants to investigate how two neighbouring subregions in the lateral anterior temporal lobe (LATL) contribute to semantic matching and object naming. Four different levels of processing were considered: (A) recognition of the object concepts; (B) search for semantic associations related to object stimuli; (C) retrieval of semantic concepts of interest; and (D) retrieval of stimulus specific concepts as required for naming. During semantic association matching on picture stimuli or heard object names, we found that activation in both subregions was higher when the objects were semantically related (mug–kettle) than unrelated (car–teapot). This is consistent with both LATL subregions playing a role in (C), the successful retrieval of amodal semantic concepts. In addition, one subregion was more activated for object naming than matching semantically related objects, consistent with (D), the retrieval of a specific concept for naming. We discuss the implications of these novel findings for cognitive models of semantic processing and left anterior temporal lobe function. PMID:25496810

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 anterior temporal lobes support residual comprehension in Wernicke’s aphasia

PubMed Central

Robson, Holly; Zahn, Roland; Keidel, James L.; Binney, Richard J.; Sage, Karen; Lambon Ralph, Matthew A.

2014-01-01

Wernicke’s aphasia occurs after a stroke to classical language comprehension regions in the left temporoparietal cortex. Consequently, auditory–verbal comprehension is significantly impaired in Wernicke’s aphasia but the capacity to comprehend visually presented materials (written words and pictures) is partially spared. This study used functional magnetic resonance imaging to investigate the neural basis of written word and picture semantic processing in Wernicke’s aphasia, with the wider aim of examining how the semantic system is altered after damage to the classical comprehension regions. Twelve participants with chronic Wernicke’s aphasia and 12 control participants performed semantic animate–inanimate judgements and a visual height judgement baseline task. Whole brain and region of interest analysis in Wernicke’s aphasia and control participants found that semantic judgements were underpinned by activation in the ventral and anterior temporal lobes bilaterally. The Wernicke’s aphasia group displayed an ‘over-activation’ in comparison with control participants, indicating that anterior temporal lobe regions become increasingly influential following reduction in posterior semantic resources. Semantic processing of written words in Wernicke’s aphasia was additionally supported by recruitment of the right anterior superior temporal lobe, a region previously associated with recovery from auditory-verbal comprehension impairments. Overall, the results provide support for models in which the anterior temporal lobes are crucial for multimodal semantic processing and that these regions may be accessed without support from classic posterior comprehension regions. PMID:24519979

The anterior temporal lobes support residual comprehension in Wernicke's aphasia.

PubMed

Robson, Holly; Zahn, Roland; Keidel, James L; Binney, Richard J; Sage, Karen; Lambon Ralph, Matthew A

2014-03-01

Wernicke's aphasia occurs after a stroke to classical language comprehension regions in the left temporoparietal cortex. Consequently, auditory-verbal comprehension is significantly impaired in Wernicke's aphasia but the capacity to comprehend visually presented materials (written words and pictures) is partially spared. This study used functional magnetic resonance imaging to investigate the neural basis of written word and picture semantic processing in Wernicke's aphasia, with the wider aim of examining how the semantic system is altered after damage to the classical comprehension regions. Twelve participants with chronic Wernicke's aphasia and 12 control participants performed semantic animate-inanimate judgements and a visual height judgement baseline task. Whole brain and region of interest analysis in Wernicke's aphasia and control participants found that semantic judgements were underpinned by activation in the ventral and anterior temporal lobes bilaterally. The Wernicke's aphasia group displayed an 'over-activation' in comparison with control participants, indicating that anterior temporal lobe regions become increasingly influential following reduction in posterior semantic resources. Semantic processing of written words in Wernicke's aphasia was additionally supported by recruitment of the right anterior superior temporal lobe, a region previously associated with recovery from auditory-verbal comprehension impairments. Overall, the results provide support for models in which the anterior temporal lobes are crucial for multimodal semantic processing and that these regions may be accessed without support from classic posterior comprehension regions.

The inferior, anterior temporal lobes and semantic memory clarified: novel evidence from distortion-corrected fMRI.

PubMed

Visser, M; Embleton, K V; Jefferies, E; Parker, G J; Ralph, M A Lambon

2010-05-01

The neural basis of semantic memory generates considerable debate. Semantic dementia results from bilateral anterior temporal lobe (ATL) atrophy and gives rise to a highly specific impairment of semantic memory, suggesting that this region is a critical neural substrate for semantic processing. Recent rTMS experiments with neurologically-intact participants also indicate that the ATL are a necessary substrate for semantic memory. Exactly which regions within the ATL are important for semantic memory are difficult to detect from these methods (because the damage in SD covers a large part of the ATL). Functional neuroimaging might provide important clues about which specific areas exhibit activation that correlates with normal semantic performance. Neuroimaging studies, however, have not consistently found anterior temporal lobe activation in semantic tasks. A recent meta-analysis indicates that this inconsistency may be due to a collection of technical limitations associated with previous studies, including a reduced field-of-view and magnetic susceptibility artefacts associated with standard gradient echo fMRI. We conducted an fMRI study of semantic memory using a combination of techniques which improve sensitivity to ATL activations whilst preserving whole-brain coverage. As expected from SD patients and ATL rTMS experiments, this method revealed bilateral temporal activation extending from the inferior temporal lobe along the fusiform gyrus to the anterior temporal regions, bilaterally. We suggest that the inferior, anterior temporal lobe region makes a crucial contribution to semantic cognition and utilising this version of fMRI will enable further research on the semantic role of the ATL. 2010 Elsevier Ltd. All rights reserved.

Retrograde amnesia in patients with diencephalic, temporal lobe or frontal lesions.

PubMed

Kopelman, M D; Stanhope, N; Kingsley, D

1999-07-01

Patients with focal diencephalic, temporal lobe, or frontal lobe lesions were examined on various measures of remote memory. Korsakoff patients showed a severe impairment with a characteristic 'temporal gradient', whereas two patients with focal diencephalic damage (and anterograde amnesia) were virtually unimpaired on remote memory measures. Patients with frontal lobe pathology were severely impaired in the recall of autobiographical incidents and famous news events. Patients with temporal lobe pathology showed severe impairment but a relatively 'flat' temporal gradient, largely attributable to herpes encephalitis patients. From recognition and cued recall tasks, it is argued that there is an important retrieval component to the remote memory deficit across all the lesion groups. In general, the pattern of performance by the frontal lobe and temporal lobe groups was closely similar, and there was no evidence of any major access/storage difference between them. However, laterality comparisons across these groups indicated that the right temporal and frontal lobe regions may make a greater contribution to the retrieval of past episodic (incident and event) memories, whereas the left temporal region is more closely involved in the lexical-semantic labelling of remote memories.

Rethinking cognition and behavior in the new classification for childhood epilepsy: Examples from frontal lobe and temporal lobe epilepsies.

PubMed

Smith, Mary Lou

2016-11-01

The new approach to classification of the epilepsies emphasizes the role of dysfunction in networks in defining types of epilepsies. This paper reviews the structural and neuropsychological deficits in two types of childhood epilepsy: frontal lobe and temporal lobe epilepsy. The evidence for and against a pattern of specificity of deficits in executive function and memory associated with these two types of epilepsies is presented. The evidence varies with the methodologies used in the studies, but direct comparison of the two types of epilepsies does not suggest a clear-cut mapping of function onto structure. These findings are discussed in light of the concept of network dysfunction. The evidence supports the conceptualization of epilepsy as a network disease. Implications for future work in the neuropsychology of pediatric epilepsy are suggested. This article is part of a Special Issue entitled "The new approach to classification: Rethinking cognition and behavior in epilepsy". Copyright © 2016 Elsevier Inc. All rights reserved.

Exploring the roles of spectral detail and intonation contour in speech intelligibility: an FMRI study.

PubMed

Kyong, Jeong S; Scott, Sophie K; Rosen, Stuart; Howe, Timothy B; Agnew, Zarinah K; McGettigan, Carolyn

2014-08-01

The melodic contour of speech forms an important perceptual aspect of tonal and nontonal languages and an important limiting factor on the intelligibility of speech heard through a cochlear implant. Previous work exploring the neural correlates of speech comprehension identified a left-dominant pathway in the temporal lobes supporting the extraction of an intelligible linguistic message, whereas the right anterior temporal lobe showed an overall preference for signals clearly conveying dynamic pitch information [Johnsrude, I. S., Penhune, V. B., & Zatorre, R. J. Functional specificity in the right human auditory cortex for perceiving pitch direction. Brain, 123, 155-163, 2000; Scott, S. K., Blank, C. C., Rosen, S., & Wise, R. J. Identification of a pathway for intelligible speech in the left temporal lobe. Brain, 123, 2400-2406, 2000]. The current study combined modulations of overall intelligibility (through vocoding and spectral inversion) with a manipulation of pitch contour (normal vs. falling) to investigate the processing of spoken sentences in functional MRI. Our overall findings replicate and extend those of Scott et al. [Scott, S. K., Blank, C. C., Rosen, S., & Wise, R. J. Identification of a pathway for intelligible speech in the left temporal lobe. Brain, 123, 2400-2406, 2000], where greater sentence intelligibility was predominately associated with increased activity in the left STS, and the greatest response to normal sentence melody was found in right superior temporal gyrus. These data suggest a spatial distinction between brain areas associated with intelligibility and those involved in the processing of dynamic pitch information in speech. By including a set of complexity-matched unintelligible conditions created by spectral inversion, this is additionally the first study reporting a fully factorial exploration of spectrotemporal complexity and spectral inversion as they relate to the neural processing of speech intelligibility. Perhaps surprisingly, there was little evidence for an interaction between the two factors-we discuss the implications for the processing of sound and speech in the dorsolateral temporal lobes.

High-gamma band fronto-temporal coherence as a measure of functional connectivity in speech motor control.

PubMed

Kingyon, J; Behroozmand, R; Kelley, R; Oya, H; Kawasaki, H; Narayanan, N S; Greenlee, J D W

2015-10-01

The neural basis of human speech is unclear. Intracranial electrophysiological recordings have revealed that high-gamma band oscillations (70-150Hz) are observed in the frontal lobe during speech production and in the temporal lobe during speech perception. Here, we tested the hypothesis that the frontal and temporal brain regions had high-gamma coherence during speech. We recorded electrocorticography (ECoG) from the frontal and temporal cortices of five humans who underwent surgery for medically intractable epilepsy, and studied coherence between the frontal and temporal cortex during vocalization and playback of vocalization. We report two novel results. First, we observed high-gamma band as well as theta (4-8Hz) coherence between frontal and temporal lobes. Second, both high-gamma and theta coherence were stronger when subjects were actively vocalizing as compared to playback of the same vocalizations. These findings provide evidence that coupling between sensory-motor networks measured by high-gamma coherence plays a key role in feedback-based monitoring and control of vocal output for human vocalization. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

[Local brain activity in different motor subtypes of Parkinson's disease with fMRI].

PubMed

Hou, Ya'nan; Zhang, Jiarong; Chen, Biao; Wu, Tao

2015-02-17

To explore the changes of local brain activity in motor subtypes of Parkinson's disease (PD) with functional magnetic resonance imaging (fMRI). A total of 60 idiopathic PD and 30 age- and gender-matched normal controls were examined with resting-state fMRI from January 2013 to March 2014. All subjects gave their written informed consent for the study. The amplitude of low-frequency fluctuation (ALFF) was calculated to measure local brain activity. The PD patients were divided into two groups of tremor dominant (TD) and postural instability/gait difficulty (PIGD) (n = 30 each). All subjects gave their written in formed consent for the study.One-way ANOVA and post-hoc t-test were performed to detect the differences of local brain activity between PD and normal subjects. And the correlations were examined between ALFF, scores and levodopa dose. Compared with normal subjects, the TD group showed increased activity in bilateral cerebellums (-37, -47, -38), thalamus (-18, -17,0), pons (-3, -23, -37) and left precentral gyrus (-41, -30, 46) versus decreased activity in bilateral frontal lobes (-13, 69, 6), temporal lobes (-42, 18, -21), left insula (-32, 22, 2) and left anterior cingulated (-7, 32, -5). The PIGD group showed increased activity in right postcentral gyrus (63, -18, 39) and decreased activity in bilateral putamens (-24, 12, 3), pre-supplementary motor area (10, 10, 58), frontal lobes (15, -15, 57), temporal lobes (-39, 18, -3) and left insula (-29, 20, 11). Compared with PIGD, the TD group showed increased activity in temporal lobes, but decreased activity in frontal lobes. Additionally, ALFF in bilateral cerebellums and frontal lobes was positively correlated with TD scores while ALFF in left precentral gyrus, bilateral putamens and temporal lobes negatively correlated with TD scores. ALFF in bilateral frontal lobes and left temporal lobe was positively correlated with PIGD scores.However, in right postcentral gyrus and bilateral putamens, ALFF was negatively correlated with PIGD scores. The levodopa dose was positively correlated with frontal lobes and temporal lobe in TD and cerebellums and inferior parietal lobule in PIGD. A specific pattern of intrinsic activity in TD and PIGD may provide insights into neurophysiological mechanisms of PD motor subtypes. The changes of brain activity in TD are caused by the interaction between cerebello-thalamo-cortical circuit and basal ganglia loop while the changes in PIGD result largely from damaged basal ganglia loop.

Differences in functional connectivity between alcohol dependence and internet gaming disorder

PubMed Central

Han, Ji Won; Han, Doug Hyun; Bolo, Nicolas; Kim, BoAh; Kim, Boong Nyun; Renshaw, Perry F.

2017-01-01

Introduction Internet gaming disorder (IGD) and alcohol dependence (AD) have been reported to share clinical characteristics including craving and over-engagement despite negative consequences. However, there are also clinical factors that differ between individuals with IGD and those with AD in terms of chemical intoxication, prevalence age, and visual and auditory stimulation. Methods We assessed brain functional connectivity within the prefrontal, striatum, and temporal lobe in 15 patients with IGD and in 16 patients with AD. Symptoms of depression, anxiety, and the attention deficit hyperactivity disorder were assessed in patients with IGD and in patients with AD. Results Both AD and IGD subjects have positive functional connectivity between the dorsolateral prefrontal cortex (DLPFC), cingulate, and cerebellum. In addition, both groups have negative functional connectivity between the DLPFC and the orbitofrontal cortex. However, the AD subjects have positive functional connectivity between the DLPFC, temporal lobe and striatal areas while IGD subjects have negative functional connectivity between the DLPFC, temporal lobe and striatal areas. Conclusions AD and IGD subjects may share deficits in executive function, including problems with self-control and adaptive responding. However, the negative connectivity between the DLPFC and the striatal areas in IGD subjects, different from the connectivity observed in AD subjects, may be due to the earlier prevalence age, different comorbid diseases as well as visual and auditory stimulation. PMID:25282597

Differences in functional connectivity between alcohol dependence and internet gaming disorder.

PubMed

Han, Ji Won; Han, Doug Hyun; Bolo, Nicolas; Kim, BoAh; Kim, Boong Nyun; Renshaw, Perry F

2015-02-01

Internet gaming disorder (IGD) and alcohol dependence (AD) have been reported to share clinical characteristics including craving and over-engagement despite negative consequences. However, there are also clinical factors that differ between individuals with IGD and those with AD in terms of chemical intoxication, prevalence age, and visual and auditory stimulation. We assessed brain functional connectivity within the prefrontal, striatum, and temporal lobe in 15 patients with IGD and in 16 patients with AD. Symptoms of depression, anxiety, and the attention deficit hyperactivity disorder were assessed in patients with IGD and in patients with AD. Both AD and IGD subjects have positive functional connectivity between the dorsolateral prefrontal cortex (DLPFC), cingulate, and cerebellum. In addition, both groups have negative functional connectivity between the DLPFC and the orbitofrontal cortex. However, the AD subjects have positive functional connectivity between the DLPFC, temporal lobe and striatal areas while IGD subjects have negative functional connectivity between the DLPFC, temporal lobe and striatal areas. AD and IGD subjects may share deficits in executive function, including problems with self-control and adaptive responding. However, the negative connectivity between the DLPFC and the striatal areas in IGD subjects, different from the connectivity observed in AD subjects, may be due to the earlier prevalence age, different comorbid diseases as well as visual and auditory stimulation. Copyright © 2014 Elsevier Ltd. 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

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.

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.

The timing of associative memory formation: frontal lobe and anterior medial temporal lobe activity at associative binding predicts memory

PubMed Central

Hales, J. B.

2011-01-01

The process of associating items encountered over time and across variable time delays is fundamental for creating memories in daily life, such as for stories and episodes. Forming associative memory for temporally discontiguous items involves medial temporal lobe structures and additional neocortical processing regions, including prefrontal cortex, parietal lobe, and lateral occipital regions. However, most prior memory studies, using concurrently presented stimuli, have failed to examine the temporal aspect of successful associative memory formation to identify when activity in these brain regions is predictive of associative memory formation. In the current study, functional MRI data were acquired while subjects were shown pairs of sequentially presented visual images with a fixed interitem delay within pairs. This design allowed the entire time course of the trial to be analyzed, starting from onset of the first item, across the 5.5-s delay period, and through offset of the second item. Subjects then completed a postscan recognition test for the items and associations they encoded during the scan and their confidence for each. After controlling for item-memory strength, we isolated brain regions selectively involved in associative encoding. Consistent with prior findings, increased regional activity predicting subsequent associative memory success was found in anterior medial temporal lobe regions of left perirhinal and entorhinal cortices and in left prefrontal cortex and lateral occipital regions. The temporal separation within each pair, however, allowed extension of these findings by isolating the timing of regional involvement, showing that increased response in these regions occurs during binding but not during maintenance. PMID:21248058

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.

Right fronto-limbic atrophy is associated with reduced empathy in refractory unilateral mesial temporal lobe epilepsy.

PubMed

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

2015-11-01

Refractory mesial temporal lobe epilepsy (MTLE) is the most frequent focal epilepsy and is often accompanied by deficits in social cognition including emotion recognition, theory of mind, and empathy. Consistent with the neuronal networks that are crucial for normal social-cognitive processing, these impairments have been associated with functional changes in fronto-temporal regions. However, although atrophy in unilateral MTLE also affects regions of the temporal and frontal lobes that underlie social cognition, little is known about the structural correlates of social-cognitive deficits in refractory MTLE. In the present study, a psychometrically validated empathy questionnaire was combined with whole-brain voxel-based morphometry (VBM) to investigate the relationship between self-reported affective and cognitive empathy and gray matter volume in 55 subjects (13 patients with right MTLE, 9 patients with left MTLE, and 33 healthy controls). Consistent with the brain regions underlying social cognition, our results show that lower affective and cognitive empathy was associated with smaller volume in predominantly right fronto-limbic regions, including the right hippocampus, parahippocampal gyrus, thalamus, fusiform gyrus, inferior temporal gyrus, dorsomedial and dorsolateral prefrontal cortices, and in the bilateral midbrain. The only region that was associated with both affective and cognitive empathy was the right mesial temporal lobe. These findings indicate that patients with right MTLE are at increased risk for reduced empathy towards others' internal states and they shed new light on the structural correlates of impaired social cognition frequently accompanying refractory MTLE. In line with previous evidence from patients with neurodegenerative disease and stroke, the present study suggests that empathy depends upon the integrity of right fronto-limbic and brainstem regions and highlights the importance of the right mesial temporal lobe and midbrain structures for human empathy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Emotions induced by intracerebral electrical stimulation of the temporal lobe.

PubMed

Meletti, Stefano; Tassi, Laura; Mai, Roberto; Fini, Nicola; Tassinari, Carlo Alberto; Russo, Giorgio Lo

2006-01-01

To assess the quality and frequency of emotions induced by intracerebral electrical stimulation of the temporal lobe. Behavioral responses were obtained by electrical stimulation in 74 patients undergoing presurgical video-stereo-EEG monitoring for drug-resistant epilepsy. Intracerebral electrical stimulation was performed by delivering trains of electrical stimuli of alternating polarity; the intensity could vary from 0.2 to 3 mA. Stimulation frequency was 1 Hz or 50 Hz. Nine hundred thirty-eight stimulation procedures were performed. Seventy-nine emotional responses (ERs) were obtained (8.4%). Of these, 67 were "fear responses." Sad feelings were evoked 3 times, happy-pleasant feelings 9 times. Anger and disgust were never observed. The following variables affected the incidence of ER: (a) Anatomical site of stimulation. ERs (always fear) were maximal at the amygdala (12%) and minimal for lateral neocortical stimulation (3%, p < 0.01). (b) Pathology. Stimulation of a temporal lobe with hippocampal sclerosis was associated with a lower frequency of ERs compared with stimulation of a temporal lobe with no evidence of atrophy in the medial temporal structures. (c) Stimulation frequency. ERs were 12% at 50 Hz versus 6.0% at 1 Hz (p < 0.01). (d) Gender. In women fear responses were 16% compared with 3% in men (p < 0.01). There were no gender differences when analyzing nonemotional responses. These data confirm the role of the medial temporal lobe region in the expression of emotions, especially fear-related behaviors. Fear was observed more frequently in the absence of medial temporal sclerosis, supporting the hypothesis that emotional behaviors induced by stimulation are positive phenomena, strictly related to the physiological function of these regions. Further investigations should address why women express fear behaviors more frequently than men.

Identification of environmental sounds and melodies in syndromes of anterior temporal lobe degeneration.

PubMed

Golden, Hannah L; Downey, Laura E; Fletcher, Philip D; Mahoney, Colin J; Schott, Jonathan M; Mummery, Catherine J; Crutch, Sebastian J; Warren, Jason D

2015-05-15

Recognition of nonverbal sounds in semantic dementia and other syndromes of anterior temporal lobe degeneration may determine clinical symptoms and help to define phenotypic profiles. However, nonverbal auditory semantic function has not been widely studied in these syndromes. Here we investigated semantic processing in two key nonverbal auditory domains - environmental sounds and melodies - in patients with semantic dementia (SD group; n=9) and in patients with anterior temporal lobe atrophy presenting with behavioural decline (TL group; n=7, including four cases with MAPT mutations) in relation to healthy older controls (n=20). We assessed auditory semantic performance in each domain using novel, uniform within-modality neuropsychological procedures that determined sound identification based on semantic classification of sound pairs. Both the SD and TL groups showed comparable overall impairments of environmental sound and melody identification; individual patients generally showed superior identification of environmental sounds than melodies, however relative sparing of melody over environmental sound identification also occurred in both groups. Our findings suggest that nonverbal auditory semantic impairment is a common feature of neurodegenerative syndromes with anterior temporal lobe atrophy. However, the profile of auditory domain involvement varies substantially between individuals. Copyright © 2015. Published by Elsevier B.V.

[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.

Verbal memory after temporal lobe epilepsy surgery in children: Do only mesial structures matter?

PubMed

Law, Nicole; Benifla, Mony; Rutka, James; Smith, Mary Lou

2017-02-01

Previous findings have been mixed regarding verbal memory outcome after left temporal lobectomy in children, and there are few studies comparing verbal memory change after lateral versus mesial temporal lobe resections. We compared verbal memory outcome associated with sparing or including the mesial structures in children who underwent left or right temporal lobe resection. We also investigated predictors of postsurgical verbal memory change. We retrospectively assessed verbal memory change approximately 1 year after unilateral temporal lobe epilepsy surgery using a list learning task. Participants included 23 children who underwent temporal lobe surgery with sparing of the mesial structures (13 left), and 40 children who had a temporal lobectomy that included resection of mesial structures (22 left). Children who underwent resection from the left lateral and mesial temporal lobe were the only group to show decline in verbal memory. Furthermore, when we considered language representation in the left temporal resection group, patients with left language representation and spared mesial structures showed essentially no change in verbal memory from preoperative to follow-up, whereas those with left language representation and excised mesial structures showed a decline. Postoperative seizure status had no effect on verbal memory change in children after left temporal lobe surgery. Finally, we found that patients with intact preoperative verbal memory experienced a significant decline compared to those with below average preoperative verbal memory. Our findings provide evidence of significant risk factors for verbal memory decline in children, specific to left mesial temporal lobe epilepsy. Children who undergo left temporal lobe surgery that includes mesial structures may be most vulnerable for verbal memory decline, especially when language representation is localized to the left hemisphere and when preoperative verbal memory is intact. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Interictal mood and personality disorders in temporal lobe epilepsy and juvenile myoclonic epilepsy.

PubMed Central

Perini, G I; Tosin, C; Carraro, C; Bernasconi, G; Canevini, M P; Canger, R; Pellegrini, A; Testa, G

1996-01-01

BACKGROUND: Mood disorders have been described as the commonest psychiatric disorders in patients with temporal lobe epilepsy. Secondary depression in temporal lobe epilepsy could be interpreted either as an adjustment reaction to a chronic disease or as a limbic dysfunction. To clarify this issue, a controlled study of psychiatric disorders was conducted in different forms of epileptic and non-epileptic chronic conditions. METHODS: Twenty outpatients with temporal lobe epilepsy, 18 outpatients with juvenile myoclonic epilepsy--a primary generalised seizure disorder--20 matched type I diabetic patients, and 20 matched normal controls were assessed by a structured interview (SADS) and by self rating scales (Beck depression inventory (BDI) and the state and trait anxiety scales STAIX1 and STAIX2). RESULTS: Sixteen (80%) patients with temporal lobe epilepsy fulfilled the criteria for a psychiatric diagnosis at the SADS interview with a significantly higher frequency than patients with juvenile myoclonic epilepsy (22%) and diabetic patients (10%) (P < 0.0001). The most frequent disorder in temporal lobe epilepsy was a mood disorder: 11 (55%) patients with temporal lobe epilepsy had depression compared with three patients with juvenile myoclonic epilepsy and two diabetic patients (P < 0.001). Eight patients with temporal lobe epilepsy with an affective disorder also had a comorbid personality or anxiety disorder. Patients with temporal lobe epilepsy scored significantly higher on BDI, STAIX1, and STAIX2 than the three control groups (P < 0.001, P < 0.01, P < 0.001). CONCLUSIONS: Patients with temporal lobe epilepsy have a higher incidence of affective and personality disorders, often in comorbidity, than patients with juvenile myoclonic epilepsy and diabetic patients suggesting that these psychiatric disorders are not an adjustment reaction to a chronic disease but rather reflect a limbic dysfunction. PMID:8971108

[Study based on ICA of "dorsal attention network" in patients with temporal lobe epilepsy].

PubMed

Yang, Zhigen; Wang, Huinan; Zhang, Zhiqiang; Zhong, Yuan; Chen, Zhili; Lu, Guangming

2010-02-01

Many functional magnetic resonance imaging (fMRI) studies have revealed the deactivation phenomenon of default mode network in the patients with epilepsy; however, nearly not any of the reports has focused on the dorsal attention network of epilepsy. In this paper, independent component analysis (ICA) was used to isolate the dorsal attention network of 16 patients with temporal lobe epilepsy (TLE) and of 20 healthy normals; and a goodness-of-fit analysis was applied at the individual subject level to choose the interesting component. Intra-group analysis and inter-group analysis were performed. The results indicated that the dorsal attention network included bilateral intraparietal sulcus, middle frontal gyrus, human frontal eye field, posterior lobe of right cerebellum, etc. The TLE group showed decreased functional connectivity in most of the dorsal attention regions with the predominance in the bilateral intraparietal sulcus, middle frontal gyrus, and posterior lobe of right cerebellum. These data suggested that the intrinsic organization of the brain function might be disrupted in TLE. In addition, the decrease of goodness-of-fit scores suggests that activity in the dorsal attention network may ultimately prove a sensitive biomarker for TLE.

Visual interhemispheric communication and callosal connections of the occipital lobes.

PubMed

Berlucchi, Giovanni

2014-07-01

Callosal connections of the occipital lobes, coursing in the splenium of the corpus callosum, have long been thought to be crucial for interactions between the cerebral hemispheres in vision in both experimental animals and humans. Yet the callosal connections of the temporal and parietal lobes appear to have more important roles than those of the occipital callosal connections in at least some high-order interhemispheric visual functions. The partial intermixing and overlap of temporal, parietal and occipital callosal connections within the splenium has made it difficult to attribute the effects of splenial pathological lesions or experimental sections to splenial components specifically related to select cortical areas. The present review describes some current contributions from the modern techniques for the tracking of commissural fibers within the living human brain to the tentative assignation of specific visual functions to specific callosal tracts, either occipital or extraoccipital. Copyright © 2013 Elsevier Ltd. All rights reserved.

Multiple anatomical systems embedded within the primate medial temporal lobe: implications for hippocampal function.

PubMed

Aggleton, John P

2012-08-01

A review of medial temporal lobe connections reveals three distinct groupings of hippocampal efferents. These efferent systems and their putative memory functions are: (1) The 'extended-hippocampal system' for episodic memory, which involves the anterior thalamic nuclei, mammillary bodies and retrosplenial cortex, originates in the subicular cortices, and has a largely laminar organisation; (2) The 'rostral hippocampal system' for affective and social learning, which involves prefrontal cortex, amygdala and nucleus accumbens, has a columnar organisation, and originates from rostral CA1 and subiculum; (3) The 'reciprocal hippocampal-parahippocampal system' for sensory processing and integration, which originates from the length of CA1 and the subiculum, and is characterised by columnar, connections with reciprocal topographies. A fourth system, the 'parahippocampal-prefrontal system' that supports familiarity signalling and retrieval processing, has more widespread prefrontal connections than those of the hippocampus, along with different thalamic inputs. Despite many interactions between these four systems, they may retain different roles in memory which when combined explain the importance of the medial temporal lobe for the formation of declarative memories. Copyright © 2011 Elsevier Ltd. All rights reserved.

Quantitative Evaluation of Medial Temporal Lobe Morphology in Children with Febrile Status Epilepticus: Results of the FEBSTAT Study.

PubMed

McClelland, A C; Gomes, W A; Shinnar, S; Hesdorffer, D C; Bagiella, E; Lewis, D V; Bello, J A; Chan, S; MacFall, J; Chen, M; Pellock, J M; Nordli, D R; Frank, L M; Moshé, S L; Shinnar, R C; Sun, S

2016-12-01

The pathogenesis of febrile status epilepticus is poorly understood, but prior studies have suggested an association with temporal lobe abnormalities, including hippocampal malrotation. We used a quantitative morphometric method to assess the association between temporal lobe morphology and febrile status epilepticus. Brain MR imaging was performed in children presenting with febrile status epilepticus and control subjects as part of the Consequences of Prolonged Febrile Seizures in Childhood study. Medial temporal lobe morphologic parameters were measured manually, including the distance of the hippocampus from the midline, hippocampal height:width ratio, hippocampal angle, collateral sulcus angle, and width of the temporal horn. Temporal lobe morphologic parameters were correlated with the presence of visual hippocampal malrotation; the strongest association was with left temporal horn width (P < .001; adjusted OR, 10.59). Multiple morphologic parameters correlated with febrile status epilepticus, encompassing both the right and left sides. This association was statistically strongest in the right temporal lobe, whereas hippocampal malrotation was almost exclusively left-sided in this cohort. The association between temporal lobe measurements and febrile status epilepticus persisted when the analysis was restricted to cases with visually normal imaging findings without hippocampal malrotation or other visually apparent abnormalities. Several component morphologic features of hippocampal malrotation are independently associated with febrile status epilepticus, even when complete hippocampal malrotation is absent. Unexpectedly, this association predominantly involves the right temporal lobe. These findings suggest that a spectrum of bilateral temporal lobe anomalies are associated with febrile status epilepticus in children. Hippocampal malrotation may represent a visually apparent subset of this spectrum. © 2016 by American Journal of Neuroradiology.

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.

Magnitude of Cerebral Asymmetry at Rest: Covariation with Baseline Cardiovascular Activity

ERIC Educational Resources Information Center

Foster, Paul S.; Harrison, David W.

2006-01-01

The cerebral regulation of cardiovascular functioning varies along both a lateral and a longitudinal axis. The parasympathetic and sympathetic nervous systems are lateralized to the left and right cerebral hemispheres, respectively. Further, the frontal lobes are known to be inhibitory in nature, whereas the temporal lobes are excitatory. However,…

Crossed aphasia following cerebral infarction in a right-handed patient with atypical cerebral language dominance.

PubMed

Tan, Xiaoping; Guo, Yang; Dun, Saihong; Sun, Hongzan

2018-05-18

Crossed aphasia (CA), usually referred to as an acquired language disturbance, is caused by a lesion in the cerebral hemisphere ipsilateral to the dominant hand, and the exact mechanism is not clear. The development of handedness is influenced by education and training and the impact of habitualization, while language is more susceptible to the impact of speech habits, and it is not absolutely accurate to judge cerebral language dominance by the degree of hand preference. We describe a case of CA after right hemispheric stroke in a right-handed patient with atypical language dominance and attempt to analyze the mechanism of CA based on functional imaging methods, including arterial spin labeling (ASL) and positron emission tomography/magnetic resonance imaging (PET-MRI). Brain MRI at 24 h after admission showed a large cerebral infarction in the right cerebral hemisphere, including the posteroinferior part of Broca's area in the right frontal lobe, the right temporal lobe, and the right occipital lobe. The patient exhibited a non-fluent aphasia on a standard language test (the Aphasia Battery of Chinese [ABC]) performed on the 7th day after onset. Thus, atypical language dominance was suspected. One week after admission, ASL imaging showed high perfusion in the infarct core zone and low perfusion in the left cerebellar hemisphere. Two months later, PET/MRI demonstrated low metabolism in the posterior frontal lobe, temporal lobe, temporal occipital junction area, and the right basal ganglia. The findings suggest that the patient has right-sided cerebral language dominance, or that both hemispheres have linguistic functions. Not all patients show linguistic capabilities on the side opposite hand preference. The language dominance should be predicted by a combination of clinical manifestations and functional imaging techniques.

Disentangling the cognitive components supporting Austin Maze performance in left versus right temporal lobe epilepsy.

PubMed

Hocking, Julia; Thomas, Hannah J; Dzafic, Ilvana; Williams, Rebecca J; Reutens, David C; Spooner, Donna M

2013-12-01

Neuropsychological tests requiring patients to find a path through a maze can be used to assess visuospatial memory performance in temporal lobe pathology, particularly in the hippocampus. Alternatively, they have been used as a task sensitive to executive function in patients with frontal lobe damage. We measured performance on the Austin Maze in patients with unilateral left and right temporal lobe epilepsy (TLE), with and without hippocampal sclerosis, compared to healthy controls. Performance was correlated with a number of other neuropsychological tests to identify the cognitive components that may be associated with poor Austin Maze performance. Patients with right TLE were significantly impaired on the Austin Maze task relative to patients with left TLE and controls, and error scores correlated with their performance on the Block Design task. The performance of patients with left TLE was also impaired relative to controls; however, errors correlated with performance on tests of executive function and delayed recall. The presence of hippocampal sclerosis did not have an impact on maze performance. A discriminant function analysis indicated that the Austin Maze alone correctly classified 73.5% of patients as having right TLE. In summary, impaired performance on the Austin Maze task is more suggestive of right than left TLE; however, impaired performance on this visuospatial task does not necessarily involve the hippocampus. The relationship of the Austin Maze task with other neuropsychological tests suggests that differential cognitive components may underlie performance decrements in right versus left TLE. © 2013.

On the definition and interpretation of voice selective activation in the temporal cortex

PubMed Central

Bethmann, Anja; Brechmann, André

2014-01-01

Regions along the superior temporal sulci and in the anterior temporal lobes have been found to be involved in voice processing. It has even been argued that parts of the temporal cortices serve as voice-selective areas. Yet, evidence for voice-selective activation in the strict sense is still missing. The current fMRI study aimed at assessing the degree of voice-specific processing in different parts of the superior and middle temporal cortices. To this end, voices of famous persons were contrasted with widely different categories, which were sounds of animals and musical instruments. The argumentation was that only brain regions with statistically proven absence of activation by the control stimuli may be considered as candidates for voice-selective areas. Neural activity was found to be stronger in response to human voices in all analyzed parts of the temporal lobes except for the middle and posterior STG. More importantly, the activation differences between voices and the other environmental sounds increased continuously from the mid-posterior STG to the anterior MTG. Here, only voices but not the control stimuli excited an increase of the BOLD response above a resting baseline level. The findings are discussed with reference to the function of the anterior temporal lobes in person recognition and the general question on how to define selectivity of brain regions for a specific class of stimuli or tasks. In addition, our results corroborate recent assumptions about the hierarchical organization of auditory processing building on a processing stream from the primary auditory cortices to anterior portions of the temporal lobes. PMID:25071527

Activations in temporal areas using visual and auditory naming stimuli: A language fMRI study in temporal lobe epilepsy.

PubMed

Gonzálvez, Gloria G; Trimmel, Karin; Haag, Anja; van Graan, Louis A; Koepp, Matthias J; Thompson, Pamela J; Duncan, John S

2016-12-01

Verbal fluency functional MRI (fMRI) is used for predicting language deficits after anterior temporal lobe resection (ATLR) for temporal lobe epilepsy (TLE), but primarily engages frontal lobe areas. In this observational study we investigated fMRI paradigms using visual and auditory stimuli, which predominately involve language areas resected during ATLR. Twenty-three controls and 33 patients (20 left (LTLE), 13 right (RTLE)) were assessed using three fMRI paradigms: verbal fluency, auditory naming with a contrast of auditory reversed speech; picture naming with a contrast of scrambled pictures and blurred faces. Group analysis showed bilateral temporal activations for auditory naming and picture naming. Correcting for auditory and visual input (by subtracting activations resulting from auditory reversed speech and blurred pictures/scrambled faces respectively) resulted in left-lateralised activations for patients and controls, which was more pronounced for LTLE compared to RTLE patients. Individual subject activations at a threshold of T>2.5, extent >10 voxels, showed that verbal fluency activated predominantly the left inferior frontal gyrus (IFG) in 90% of LTLE, 92% of RTLE, and 65% of controls, compared to right IFG activations in only 15% of LTLE and RTLE and 26% of controls. Middle temporal (MTG) or superior temporal gyrus (STG) activations were seen on the left in 30% of LTLE, 23% of RTLE, and 52% of controls, and on the right in 15% of LTLE, 15% of RTLE, and 35% of controls. Auditory naming activated temporal areas more frequently than did verbal fluency (LTLE: 93%/73%; RTLE: 92%/58%; controls: 82%/70% (left/right)). Controlling for auditory input resulted in predominantly left-sided temporal activations. Picture naming resulted in temporal lobe activations less frequently than did auditory naming (LTLE 65%/55%; RTLE 53%/46%; controls 52%/35% (left/right)). Controlling for visual input had left-lateralising effects. Auditory and picture naming activated temporal lobe structures, which are resected during ATLR, more frequently than did verbal fluency. Controlling for auditory and visual input resulted in more left-lateralised activations. We hypothesise that these paradigms may be more predictive of postoperative language decline than verbal fluency fMRI. Copyright © 2016 Elsevier B.V. All rights reserved.

Episodic memory, semantic memory, and amnesia.

PubMed

Squire, L R; Zola, S M

1998-01-01

Episodic memory and semantic memory are two types of declarative memory. There have been two principal views about how this distinction might be reflected in the organization of memory functions in the brain. One view, that episodic memory and semantic memory are both dependent on the integrity of medial temporal lobe and midline diencephalic structures, predicts that amnesic patients with medial temporal lobe/diencephalic damage should be proportionately impaired in both episodic and semantic memory. An alternative view is that the capacity for semantic memory is spared, or partially spared, in amnesia relative to episodic memory ability. This article reviews two kinds of relevant data: 1) case studies where amnesia has occurred early in childhood, before much of an individual's semantic knowledge has been acquired, and 2) experimental studies with amnesic patients of fact and event learning, remembering and knowing, and remote memory. The data provide no compelling support for the view that episodic and semantic memory are affected differently in medial temporal lobe/diencephalic amnesia. However, episodic and semantic memory may be dissociable in those amnesic patients who additionally have severe frontal lobe damage.

Temporal lobe structures and facial emotion recognition in schizophrenia patients and nonpsychotic relatives.

PubMed

Goghari, Vina M; Macdonald, Angus W; Sponheim, Scott R

2011-11-01

Temporal lobe abnormalities and emotion recognition deficits are prominent features of schizophrenia and appear related to the diathesis of the disorder. This study investigated whether temporal lobe structural abnormalities were associated with facial emotion recognition deficits in schizophrenia and related to genetic liability for the disorder. Twenty-seven schizophrenia patients, 23 biological family members, and 36 controls participated. Several temporal lobe regions (fusiform, superior temporal, middle temporal, amygdala, and hippocampus) previously associated with face recognition in normative samples and found to be abnormal in schizophrenia were evaluated using volumetric analyses. Participants completed a facial emotion recognition task and an age recognition control task under time-limited and self-paced conditions. Temporal lobe volumes were tested for associations with task performance. Group status explained 23% of the variance in temporal lobe volume. Left fusiform gray matter volume was decreased by 11% in patients and 7% in relatives compared with controls. Schizophrenia patients additionally exhibited smaller hippocampal and middle temporal volumes. Patients were unable to improve facial emotion recognition performance with unlimited time to make a judgment but were able to improve age recognition performance. Patients additionally showed a relationship between reduced temporal lobe gray matter and poor facial emotion recognition. For the middle temporal lobe region, the relationship between greater volume and better task performance was specific to facial emotion recognition and not age recognition. Because schizophrenia patients exhibited a specific deficit in emotion recognition not attributable to a generalized impairment in face perception, impaired emotion recognition may serve as a target for interventions.

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.

Abnormal behavior in children with temporal lobe epilepsy and ganglioglioma.

PubMed

Guimarães, Catarina A; Franzon, Renata C; Souza, Elisabete A P; Schmutzler, Kátia M R S; Montenegro, Maria Augusta; Queiroz, Luciano de S; Cendes, Fernando; Guerreiro, Marilisa M

2004-10-01

Temporal lobe epilepsy in childhood is characterized by great clinical, electroencephalographic, and etiological diversity. The prognosis after temporal lobe epilepsy surgery in childhood is usually good, with most patients achieving complete seizure control. However, in some children behavior deteriorates postoperatively. We report two girls (2 and 6 years of age) with refractory seizures due to temporal lobe ganglioglioma. They exhibited aggression and hyperactivity since the beginning of their epilepsy. In both patients, behavioral disturbances worsened postoperatively, despite complete seizure control. Patients and parents should be advised about possible behavioral disturbances after epilepsy surgery, especially in the presence of a temporal lobe developmental tumor, even when seizure control is achieved postoperatively.

Hurst Exponent Analysis of Resting-State fMRI Signal Complexity across the Adult Lifespan

PubMed Central

Dong, Jianxin; Jing, Bin; Ma, Xiangyu; Liu, Han; Mo, Xiao; Li, Haiyun

2018-01-01

Exploring functional information among various brain regions across time enables understanding of healthy aging process and holds great promise for age-related brain disease diagnosis. This paper proposed a method to explore fractal complexity of the resting-state functional magnetic resonance imaging (rs-fMRI) signal in the human brain across the adult lifespan using Hurst exponent (HE). We took advantage of the examined rs-fMRI data from 116 adults 19 to 85 years of age (44.3 ± 19.4 years, 49 females) from NKI/Rockland sample. Region-wise and voxel-wise analyses were performed to investigate the effects of age, gender, and their interaction on complexity. In region-wise analysis, we found that the healthy aging is accompanied by a loss of complexity in frontal and parietal lobe and increased complexity in insula, limbic, and temporal lobe. Meanwhile, differences in HE between genders were found to be significant in parietal lobe (p = 0.04, corrected). However, there was no interaction between gender and age. In voxel-wise analysis, the significant complexity decrease with aging was found in frontal and parietal lobe, and complexity increase was found in insula, limbic lobe, occipital lobe, and temporal lobe with aging. Meanwhile, differences in HE between genders were found to be significant in frontal, parietal, and limbic lobe. Furthermore, we found age and sex interaction in right parahippocampal gyrus (p = 0.04, corrected). Our findings reveal HE variations of the rs-fMRI signal across the human adult lifespan and show that HE may serve as a new parameter to assess healthy aging process. PMID:29456489

Temporal plus epilepsy is a major determinant of temporal lobe surgery failures.

PubMed

Barba, Carmen; Rheims, Sylvain; Minotti, Lorella; Guénot, Marc; Hoffmann, Dominique; Chabardès, Stephan; Isnard, Jean; Kahane, Philippe; Ryvlin, Philippe

2016-02-01

Reasons for failed temporal lobe epilepsy surgery remain unclear. Temporal plus epilepsy, characterized by a primary temporal lobe epileptogenic zone extending to neighboured regions, might account for a yet unknown proportion of these failures. In this study all patients from two epilepsy surgery programmes who fulfilled the following criteria were included: (i) operated from an anterior temporal lobectomy or disconnection between January 1990 and December 2001; (ii) magnetic resonance imaging normal or showing signs of hippocampal sclerosis; and (iii) postoperative follow-up ≥ 24 months for seizure-free patients. Patients were classified as suffering from unilateral temporal lobe epilepsy, bitemporal epilepsy or temporal plus epilepsy based on available presurgical data. Kaplan-Meier survival analysis was used to calculate the probability of seizure freedom over time. Predictors of seizure recurrence were investigated using Cox proportional hazards model. Of 168 patients included, 108 (63.7%) underwent stereoelectroencephalography, 131 (78%) had hippocampal sclerosis, 149 suffered from unilateral temporal lobe epilepsy (88.7%), one from bitemporal epilepsy (0.6%) and 18 (10.7%) from temporal plus epilepsy. The probability of Engel class I outcome at 10 years of follow-up was 67.3% (95% CI: 63.4-71.2) for the entire cohort, 74.5% (95% CI: 70.6-78.4) for unilateral temporal lobe epilepsy, and 14.8% (95% CI: 5.9-23.7) for temporal plus epilepsy. Multivariate analyses demonstrated four predictors of seizure relapse: temporal plus epilepsy (P < 0.001), postoperative hippocampal remnant (P = 0.001), past history of traumatic or infectious brain insult (P = 0.022), and secondary generalized tonic-clonic seizures (P = 0.023). Risk of temporal lobe surgery failure was 5.06 (95% CI: 2.36-10.382) greater in patients with temporal plus epilepsy than in those with unilateral temporal lobe epilepsy. Temporal plus epilepsy represents a hitherto unrecognized prominent cause of temporal lobe surgery failures. In patients with temporal plus epilepsy, anterior temporal lobectomy appears very unlikely to control seizures and should not be advised. Whether larger resection of temporal plus epileptogenic zones offers greater chance of seizure freedom remains to be investigated. © 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.

The Representation of Object-Directed Action and Function Knowledge in the Human Brain

PubMed Central

Chen, Quanjing; Garcea, Frank E.; Mahon, Bradford Z.

2016-01-01

The appropriate use of everyday objects requires the integration of action and function knowledge. Previous research suggests that action knowledge is represented in frontoparietal areas while function knowledge is represented in temporal lobe regions. Here we used multivoxel pattern analysis to investigate the representation of object-directed action and function knowledge while participants executed pantomimes of familiar tool actions. A novel approach for decoding object knowledge was used in which classifiers were trained on one pair of objects and then tested on a distinct pair; this permitted a measurement of classification accuracy over and above object-specific information. Region of interest (ROI) analyses showed that object-directed actions could be decoded in tool-preferring regions of both parietal and temporal cortex, while no independently defined tool-preferring ROI showed successful decoding of object function. However, a whole-brain searchlight analysis revealed that while frontoparietal motor and peri-motor regions are engaged in the representation of object-directed actions, medial temporal lobe areas in the left hemisphere are involved in the representation of function knowledge. These results indicate that both action and function knowledge are represented in a topographically coherent manner that is amenable to study with multivariate approaches, and that the left medial temporal cortex represents knowledge of object function. PMID:25595179

Quantifying interictal metabolic activity in human temporal lobe epilepsy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henry, T.R.; Mazziotta, J.C.; Engel, J. Jr.

1990-09-01

The majority of patients with complex partial seizures of unilateral temporal lobe origin have interictal temporal hypometabolism on (18F)fluorodeoxyglucose positron emission tomography (FDG PET) studies. Often, this hypometabolism extends to ipsilateral extratemporal sites. The use of accurately quantified metabolic data has been limited by the absence of an equally reliable method of anatomical analysis of PET images. We developed a standardized method for visual placement of anatomically configured regions of interest on FDG PET studies, which is particularly adapted to the widespread, asymmetric, and often severe interictal metabolic alterations of temporal lobe epilepsy. This method was applied by a singlemore » investigator, who was blind to the identity of subjects, to 10 normal control and 25 interictal temporal lobe epilepsy studies. All subjects had normal brain anatomical volumes on structural neuroimaging studies. The results demonstrate ipsilateral thalamic and temporal lobe involvement in the interictal hypometabolism of unilateral temporal lobe epilepsy. Ipsilateral frontal, parietal, and basal ganglial metabolism is also reduced, although not as markedly as is temporal and thalamic metabolism.« less

Distinct anatomical subtypes of the behavioural variant of frontotemporal dementia: a cluster analysis study.

PubMed

Whitwell, Jennifer L; Przybelski, Scott A; Weigand, Stephen D; Ivnik, Robert J; Vemuri, Prashanthi; Gunter, Jeffrey L; Senjem, Matthew L; Shiung, Maria M; Boeve, Bradley F; Knopman, David S; Parisi, Joseph E; Dickson, Dennis W; Petersen, Ronald C; Jack, Clifford R; Josephs, Keith A

2009-11-01

The behavioural variant of frontotemporal dementia is a progressive neurodegenerative syndrome characterized by changes in personality and behaviour. It is typically associated with frontal lobe atrophy, although patterns of atrophy are heterogeneous. The objective of this study was to examine case-by-case variability in patterns of grey matter atrophy in subjects with the behavioural variant of frontotemporal dementia and to investigate whether behavioural variant of frontotemporal dementia can be divided into distinct anatomical subtypes. Sixty-six subjects that fulfilled clinical criteria for a diagnosis of the behavioural variant of frontotemporal dementia with a volumetric magnetic resonance imaging scan were identified. Grey matter volumes were obtained for 26 regions of interest, covering frontal, temporal and parietal lobes, striatum, insula and supplemental motor area, using the automated anatomical labelling atlas. Regional volumes were divided by total grey matter volume. A hierarchical agglomerative cluster analysis using Ward's clustering linkage method was performed to cluster the behavioural variant of frontotemporal dementia subjects into different anatomical clusters. Voxel-based morphometry was used to assess patterns of grey matter loss in each identified cluster of subjects compared to an age and gender-matched control group at P < 0.05 (family-wise error corrected). We identified four potentially useful clusters with distinct patterns of grey matter loss, which we posit represent anatomical subtypes of the behavioural variant of frontotemporal dementia. Two of these subtypes were associated with temporal lobe volume loss, with one subtype showing loss restricted to temporal lobe regions (temporal-dominant subtype) and the other showing grey matter loss in the temporal lobes as well as frontal and parietal lobes (temporofrontoparietal subtype). Another two subtypes were characterized by a large amount of frontal lobe volume loss, with one subtype showing grey matter loss in the frontal lobes as well as loss of the temporal lobes (frontotemporal subtype) and the other subtype showing loss relatively restricted to the frontal lobes (frontal-dominant subtype). These four subtypes differed on clinical measures of executive function, episodic memory and confrontation naming. There were also associations between the four subtypes and genetic or pathological diagnoses which were obtained in 48% of the cohort. The clusters did not differ in behavioural severity as measured by the Neuropsychiatric Inventory; supporting the original classification of the behavioural variant of frontotemporal dementia in these subjects. Our findings suggest behavioural variant of frontotemporal dementia can therefore be subdivided into four different anatomical subtypes.

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

The role of the anterior temporal lobes in the comprehension of concrete and abstract words: rTMS evidence

PubMed Central

Pobric, Gorana; Lambon Ralph, Matthew A.; Jefferies, Elizabeth

2009-01-01

Conceptual knowledge allows us to bring meaning to our world. Studies of semantic dementia (SD) patients and some functional neuroimaging studies indicate that the anterior temporal lobes, bilaterally, are a core neural substrate for the formation of conceptual representations. The majority of SD patients (who have circumscribed atrophy of the anterior temporal lobes) have better comprehension of concrete than abstract words. However, this finding remains controversial, as some individual SD patients have exhibited reverse imageability effects, i.e., relative preservation of abstract knowledge. This would imply that the anterior temporal lobes are particularly crucial for processing sensory aspects of semantic knowledge, which are an important part of concrete but not abstract concepts. To adjudicate on this debate, we used offline, low-frequency, repetitive transcranial magnetic stimulation to disrupt neural processing temporarily in the left or right temporal poles (TPs). We examined this effect using a synonym judgement task, comprising high, medium and low imageability items, which we have previously employed with a case-series of SD patients. The time required to make semantic decisions was slowed considerably, particularly for low imageability items, consistent with the pattern we observed in SD. These results confirm that both TPs make a critical contribution to semantic processing, even for abstract concepts that do not have strong sensory representations. PMID:19303592

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.

Encoding and immediate retrieval tasks in patients with epilepsy: A functional MRI study of verbal and visual memory.

PubMed

Saddiki, Najat; Hennion, Sophie; Viard, Romain; Ramdane, Nassima; Lopes, Renaud; Baroncini, Marc; Szurhaj, William; Reyns, Nicolas; Pruvo, Jean Pierre; Delmaire, Christine

2018-05-01

Medial lobe temporal structures and more specifically the hippocampus play a decisive role in episodic memory. Most of the memory functional magnetic resonance imaging (fMRI) studies evaluate the encoding phase; the retrieval phase being performed outside the MRI. We aimed to determine the ability to reveal greater hippocampal fMRI activations during retrieval phase. Thirty-five epileptic patients underwent a two-step memory fMRI. During encoding phase, subjects were requested to identify the feminine or masculine gender of faces and words presented, in order to encourage stimulus encoding. One hour after, during retrieval phase, subjects had to recognize the word and face. We used an event-related design to identify hippocampal activations. There was no significant difference between patients with left temporal lobe epilepsy, patients with right temporal lobe epilepsy and patients with extratemporal lobe epilepsy on verbal and visual learning task. For words, patients demonstrated significantly more bilateral hippocampal activation for retrieval task than encoding task and when the tasks were associated than during encoding alone. Significant difference was seen between face-encoding alone and face retrieval alone. This study demonstrates the essential contribution of the retrieval task during a fMRI memory task but the number of patients with hippocampal activations was greater when the two tasks were taken into account. Copyright © 2018. Published by Elsevier Masson SAS.

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.

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.

Neuropsychology Outcomes Following Trephine Epilepsy Surgery: The Inferior Temporal Gyrus Approach for Amygdalohippocampectomy in Medically Refractory Mesial Temporal Lobe Epilepsy.

PubMed

Schoenberg, Mike R; Clifton, William E; Sever, Ryan W; Vale, Fernando L

2018-06-01

Surgery is indicated in cases of mesial temporal lobe epilepsy(MTLE) that are refractory to medical management. The inferior temporal gyrus (ITG) approach provides access to the mesial temporal lobe (MTL) structures with minimal tissue disruption. Reported neuropsychology outcomes following this approach are limited. To report neuropsychological outcomes using an ITG approach to amygdalohippocampectomy (AH) in patients with medically refractory MTLE based on a prospective design. Fifty-four participants had Engel class I/II outcome following resection of MTL using the ITG approach. All participants had localization-related epilepsy confirmed by long-term surface video-electroencephalography and completed pre/postsurgical evaluations that included magnetic resonance imaging (MRI), Wada test or functional MRI, and neuropsychology assessment. Clinical semiology/video-electroencephalography indicated that of the 54 patients, 28 (52%) had left MTLE and 26 (48%) had right MTLE. Dominant hemisphere resections were performed on 23 patients (43%), nondominant on 31(57%). Twenty-nine (29) had pathology-confirmed mesial temporal sclerosis (MTS). Group level analyses found declines in verbal memory for patients with language-dominant resections (P < .05). No significant decline in neuropsychological measures occurred for patients with MTS. Participants without MTS who underwent a language-dominant lobe resection exhibited a significant decline in verbal and visual memory (P < .05). Nondominant resection participants did not exhibit significant change in neuropsychology scores (P > .05). Neuropsychology outcomes of an ITG approach for selective mesial temporal resection are comparable to other selective AH techniques showing minimal adverse cognitive effects. These data lend support to the ITG approach for selective AH as an option for MTLE.

Nonvisual spatial navigation fMRI lateralizes mesial temporal lobe epilepsy in a patient with congenital blindness.

PubMed

Toller, Gianina; Adhimoolam, Babu; Grunwald, Thomas; Huppertz, Hans-Jürgen; König, Kristina; Jokeit, Hennric

2015-01-01

Nonvisual spatial navigation functional magnetic resonance imaging (fMRI) may help clinicians determine memory lateralization in blind individuals with refractory mesial temporal lobe epilepsy (MTLE). We report on an exceptional case of a congenitally blind woman with late-onset left MTLE undergoing presurgical memory fMRI. To activate mesial temporal structures despite the lack of visual memory, the patient was requested to recall familiar routes using nonvisual multisensory and verbal cues. Our findings demonstrate the diagnostic value of a nonvisual fMRI task to lateralize MTLE despite congenital blindness and may therefore contribute to the risk assessment for postsurgical amnesia in rare cases with refractory MTLE and accompanying congenital blindness.

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.

Structural and functional changes during epileptogenesis in the mouse model of medial temporal lobe epilepsy.

PubMed

Dietrich, Yvan; Eliat, Pierre-Antoine; Dieuset, Gabriel; Saint-Jalmes, Herve; Pineau, Charles; Wendling, Fabrice; Martin, Benoit

2016-08-01

An important issue in epilepsy research is to understand the structural and functional modifications leading to chronic epilepsy, characterized by spontaneous recurrent seizures, after initial brain insult. To address this issue, we recorded and analyzed electroencephalography (EEG) and quantitative magnetic resonance imaging (MRI) data during epileptogenesis in the in vivo mouse model of Medial Temporal Lobe Epilepsy (MTLE, kainate). Besides, this model of epilepsy is a particular form of drug-resistant epilepsy. The results indicate that high-field (4.7T) MRI parameters (T2-weighted; T2-quantitative) allow to detect the gradual neuro-anatomical changes that occur during epileptogenesis while electrophysiological parameters (number and duration of Hippocampal Paroxysmal Discharges) allow to assess the dysfunctional changes through the quantification of epileptiform activity. We found a strong correlation between EEG-based markers (invasive recording) and MRI-based parameters (non-invasive) periodically computed over the `latent period' that spans over two weeks, on average. These results indicated that both structural and functional changes occur in the considered epilepsy model and are considered as biomarkers of the installation of epilepsy. Additionally, such structural and functional changes can also be observed in human temporal lobe epilepsy. Interestingly, MRI imaging parameters could be used to track early (day-7) structural changes (gliosis, cell loss) in the lesioned brain and to quantify the evolution of epileptogenesis after traumatic brain injury.

Emotion recognition and social cognition in temporal lobe epilepsy and the effect of epilepsy surgery.

PubMed

Amlerova, Jana; Cavanna, Andrea E; Bradac, Ondrej; Javurkova, Alena; Raudenska, Jaroslava; Marusic, Petr

2014-07-01

The abilities to identify facial expression from another person's face and to attribute mental states to others refer to preserved function of the temporal lobes. In the present study, we set out to evaluate emotion recognition and social cognition in presurgical and postsurgical patients with unilateral refractory temporal lobe epilepsy (TLE). The aim of our study was to investigate the effects of TLE surgery and to identify the main risk factors for impairment in these functions. We recruited 30 patients with TLE for longitudinal data analysis (14 with right-sided and 16 with left-sided TLE) and 74 patients for cross-sectional data analysis (37 with right-sided and 37 with left-sided TLE) plus 20 healthy controls. Besides standard neuropsychological assessment, we administered an analog of the Ekman and Friesen test and the Faux Pas Test to assess emotion recognition and social cognition, respectively. Both emotion recognition and social cognition were impaired in the group of patients with TLE, irrespective of the focus side, compared with healthy controls. The performance in both tests was strongly dependent on the intelligence level. Beyond intelligence level, earlier age at epilepsy onset, longer disease duration, and history of early childhood brain injury predicted social cognition problems in patients with TLE. Epilepsy surgery within the temporal lobe seems to have neutral effect on patients' performances in both domains. However, there are a few individual patients who appear to be at risk of postoperative decline, even when seizure freedom is achieved following epilepsy surgery. Copyright © 2014 Elsevier Inc. All rights reserved.

Spatial and Temporal Episodic Memory Retrieval Recruit Dissociable Functional Networks in the Human Brain

ERIC Educational Resources Information Center

Ekstrom, Arne D.; Bookheimer, Susan Y.

2007-01-01

Imaging, electrophysiological studies, and lesion work have shown that the medial temporal lobe (MTL) is important for episodic memory; however, it is unclear whether different MTL regions support the spatial, temporal, and item elements of episodic memory. In this study we used fMRI to examine retrieval performance emphasizing different aspects…

Functional MR imaging or Wada test: which is the better predictor of individual postoperative memory outcome?

PubMed

Dupont, Sophie; Duron, Emmanuelle; Samson, Séverine; Denos, Marisa; Volle, Emmanuelle; Delmaire, Christine; Navarro, Vincent; Chiras, Jacques; Lehéricy, Stéphane; Samson, Yves; Baulac, Michel

2010-04-01

To retrospectively determine whether blood oxygen level-dependent functional magnetic resonance (MR) imaging can aid prediction of postoperative memory changes in epileptic patients after temporal lobe surgery. This study was approved by the local ethics committee, and informed consent was obtained from all patients. Data were analyzed from 25 patients (12 women, 13 men; age range, 19-52 years) with refractory epilepsy in whom temporal lobe surgery was performed after they underwent preoperative functional MR imaging, the Wada test, and neuropsychological testing. The functional MR imaging protocol included three different memory tasks (24-hour delayed recognition, encoding, and immediate recognition). Individual activations were measured in medial temporal lobe (MTL) regions of both hemispheres. The prognostic accuracy of functional MR imaging for prediction of postoperative memory changes was compared with the accuracy of the Wada test and preoperative neuropsychological testing by using a backward multiple regression analysis. An equation that was based on left functional MR imaging MTL activation during delayed recognition, side of the epileptic focus, and preoperative global verbal memory score was used to correctly predict worsening of verbal memory in 90% of patients. The right functional MR imaging MTL activation did not substantially correlate with the nonverbal memory outcome, which was only predicted by using the preoperative nonverbal global score. Wada test data were not good predictors of changes in either verbal or nonverbal memory. Findings suggest that functional MR imaging activation during a delayed-recognition task is a better predictor of individual postoperative verbal memory outcome than is the Wada test. RSNA, 2010

Jazz, guitar, and neurosurgery: the Pat Martino case report.

PubMed

Galarza, Marcelo; Isaac, Claire; Pellicer, Olga; Mayes, Andrew; Broks, Paul; Montaldi, Daniela; Denby, Christine; Simeone, Frederick

2014-01-01

We present the case of a professional jazz guitarist with temporal lobe epilepsy secondary to an arteriovenous cerebral malformation. The patient underwent a left temporal lobectomy in 1980. After surgery, he presented with severe retrograde amnesia and complete loss of musical interest and capabilities. The patient's musical abilities recovered over time, and he regained his previous virtuoso status. In 2007, his medical history, neuropsychologic functions, and structural magnetic resonance imaging study were examined and revealed a remarkable degree of recovery of memory and musical abilities in the context of extensive temporal lobe resection. The neuropsychologic findings and neuroanatomic features of the magnetic resonance imaging study were analyzed to try to understand the high degree of recovery of both long-term memory and musical processing abilities in this musician. This case reveals the possibility of an unusual degree of cerebral plasticity and reorganization. Additionally, it emphasizes the question of musical virtuosity. This report shows that the musical capabilities of professional musicians, in specific cases, can completely recover even when much of the left temporal lobe has been removed. Copyright © 2014 Elsevier Inc. All rights reserved.

Structural correlates of impaired working memory in hippocampal sclerosis.

PubMed

Winston, Gavin P; Stretton, Jason; Sidhu, Meneka K; Symms, Mark R; Thompson, Pamela J; Duncan, John S

2013-07-01

Temporal lobe epilepsy (TLE) has been considered to impair long-term memory, whilst not affecting working memory, but recent evidence suggests that working memory is compromised. Functional MRI (fMRI) studies demonstrate that working memory involves a bilateral frontoparietal network the activation of which is disrupted in hippocampal sclerosis (HS). A specific role of the hippocampus to deactivate during working memory has been proposed with this mechanism faulty in patients with HS. Structural correlates of disrupted working memory in HS have not been explored. We studied 54 individuals with medically refractory TLE and unilateral HS (29 left) and 28 healthy controls. Subjects underwent 3T structural MRI, a visuospatial n-back fMRI paradigm and diffusion tensor imaging (DTI). Working memory capacity assessed by three span tasks (digit span backwards, gesture span, motor sequences) was combined with performance in the visuospatial paradigm to give a global working memory measure. Gray and white matter changes were investigated using voxel-based morphometry and voxel-based analysis of DTI, respectively. Individuals with left or right HS performed less well than healthy controls on all measures of working memory. fMRI demonstrated a bilateral frontoparietal network during the working memory task with reduced activation of the right parietal lobe in both patient groups. In left HS, gray matter loss was seen in the ipsilateral hippocampus and parietal lobe, with maintenance of the gray matter volume of the contralateral parietal lobe associated with better performance. White matter integrity within the frontoparietal network, in particular the superior longitudinal fasciculus and cingulum, and the contralateral temporal lobe, was associated with working memory performance. In right HS, gray matter loss was also seen in the ipsilateral hippocampus and parietal lobe. Working memory performance correlated with the gray matter volume of both frontal lobes and white matter integrity within the frontoparietal network and contralateral temporal lobe. Our data provide further evidence that working memory is disrupted in HS and impaired integrity of both gray and white matter is seen in functionally relevant areas. We suggest this forms the structural basis of the impairment of working memory, indicating widespread and functionally significant structural changes in patients with apparently isolated HS. Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.

Structural correlates of impaired working memory in hippocampal sclerosis

PubMed Central

Winston, Gavin P; Stretton, Jason; Sidhu, Meneka K; Symms, Mark R; Thompson, Pamela J; Duncan, John S

2013-01-01

Purpose: Temporal lobe epilepsy (TLE) has been considered to impair long-term memory, whilst not affecting working memory, but recent evidence suggests that working memory is compromised. Functional MRI (fMRI) studies demonstrate that working memory involves a bilateral frontoparietal network the activation of which is disrupted in hippocampal sclerosis (HS). A specific role of the hippocampus to deactivate during working memory has been proposed with this mechanism faulty in patients with HS. Structural correlates of disrupted working memory in HS have not been explored. Methods: We studied 54 individuals with medically refractory TLE and unilateral HS (29 left) and 28 healthy controls. Subjects underwent 3T structural MRI, a visuospatial n-back fMRI paradigm and diffusion tensor imaging (DTI). Working memory capacity assessed by three span tasks (digit span backwards, gesture span, motor sequences) was combined with performance in the visuospatial paradigm to give a global working memory measure. Gray and white matter changes were investigated using voxel-based morphometry and voxel-based analysis of DTI, respectively. Key Findings: Individuals with left or right HS performed less well than healthy controls on all measures of working memory. fMRI demonstrated a bilateral frontoparietal network during the working memory task with reduced activation of the right parietal lobe in both patient groups. In left HS, gray matter loss was seen in the ipsilateral hippocampus and parietal lobe, with maintenance of the gray matter volume of the contralateral parietal lobe associated with better performance. White matter integrity within the frontoparietal network, in particular the superior longitudinal fasciculus and cingulum, and the contralateral temporal lobe, was associated with working memory performance. In right HS, gray matter loss was also seen in the ipsilateral hippocampus and parietal lobe. Working memory performance correlated with the gray matter volume of both frontal lobes and white matter integrity within the frontoparietal network and contralateral temporal lobe. Significance: Our data provide further evidence that working memory is disrupted in HS and impaired integrity of both gray and white matter is seen in functionally relevant areas. We suggest this forms the structural basis of the impairment of working memory, indicating widespread and functionally significant structural changes in patients with apparently isolated HS. PMID:23614459

Expertise with artificial non-speech sounds recruits speech-sensitive cortical regions

PubMed Central

Leech, Robert; Holt, Lori L.; Devlin, Joseph T.; Dick, Frederic

2009-01-01

Regions of the human temporal lobe show greater activation for speech than for other sounds. These differences may reflect intrinsically specialized domain-specific adaptations for processing speech, or they may be driven by the significant expertise we have in listening to the speech signal. To test the expertise hypothesis, we used a video-game-based paradigm that tacitly trained listeners to categorize acoustically complex, artificial non-linguistic sounds. Before and after training, we used functional MRI to measure how expertise with these sounds modulated temporal lobe activation. Participants’ ability to explicitly categorize the non-speech sounds predicted the change in pre- to post-training activation in speech-sensitive regions of the left posterior superior temporal sulcus, suggesting that emergent auditory expertise may help drive this functional regionalization. Thus, seemingly domain-specific patterns of neural activation in higher cortical regions may be driven in part by experience-based restructuring of high-dimensional perceptual space. PMID:19386919

Spontaneous brain activity in chronic smokers revealed by fractional amplitude of low frequency fluctuation analysis: a resting state functional magnetic resonance imaging study.

PubMed

Chu, Shuilian; Xiao, Dan; Wang, Shuangkun; Peng, Peng; Xie, Teng; He, Yong; Wang, Chen

2014-01-01

Nicotine is primarily rsponsible for the highly addictive properties of cigarettes. Similar to other substances, nicotine dependence is related to many important brain regions, particular in mesolimbic reward circuit. This study was to further reveal the alteration of brain function activity during resting state in chronic smokers by fractional amplitude of low frequency fluctuation (fALFF) based on functional magnetic resonance imaging (fMRI), in order to provide the evidence of neurobiological mechanism of smoking. This case control study involved twenty healthy smokers and nineteen healthy nonsmokers recruited by advertisement. Sociodemographic, smoking related characteristics and fMRI images were collected and the data analyzed. Compared with nonsmokers, smokers showed fALFF increased significantly in the left middle occipital gyrus, left limbic lobe and left cerebellum posterior lobe but decreases in the right middle frontal gyrus, right superior temporal gyrus, right extra nuclear, left postcentral gyrus and left cerebellum anterior lobe (cluster size >100 voxels). Compared with light smokers (pack years ≤ 20), heavy smokers (pack years >20) showed fALFF increased significantly in the right superior temporal gyrus, right precentral gyrus, and right occipital lobe/cuneus but decreased in the right/left limbic lobe/cingulate gyrus, right/left frontal lobe/sub gyral, right/left cerebellum posterior lobe (cluster size >50 voxels). Compared with nonsevere nicotine dependent smokers (Fagerstrőm test for nicotine dependence, score ≤ 6), severe nicotine dependent smokers (score >6) showed fALFF increased significantly in the right/left middle frontal gyrus, right superior frontal gyrus and left inferior parietal lobule but decreased in the left limbic lobe/cingulate gyrus (cluster size >25 voxels). In smokers during rest, the activity of addiction related regions were increased and the activity of smoking feeling, memory, related regions were also changed. The resting state activity changes in many regions were associated with the cumulative amount of nicotine intake and the severity of nicotine dependence.

Brain networks governing the golf swing in professional golfers.

PubMed

Kim, Jin Hyun; Han, Joung Kyue; Kim, Bung-Nyun; Han, Doug Hyun

2015-01-01

Golf, as with most complex motor skills, requires multiple different brain functions, including attention, motor planning, coordination, calculation of timing, and emotional control. In this study we assessed the correlation between swing components and brain connectivity from the cerebellum to the cerebrum. Ten female golf players and 10 age-matched female controls were recruited. In order to determine swing consistency among participants, the standard deviation (SD) of the mean swing speed time and the SD of the mean swing angle were assessed over 30 swings. Functional brain connectivity was assessed by resting state functional MRI. Pro-golfers showed greater positive left cerebellum connectivity to the occipital lobe, temporal lobe, parietal lobe and both frontal lobes compared to controls. The SD of play scores was positively correlated with the SD of the impact angle. Constant swing speed and back swing angle in professional golfers were associated with functional connectivity (FC) between the cerebellum and parietal and frontal lobes. In addition, the constant impact angle in professional golfers was associated with improved golf scores and additional FC of the thalamus.

The Representation of Object-Directed Action and Function Knowledge in the Human Brain.

PubMed

Chen, Quanjing; Garcea, Frank E; Mahon, Bradford Z

2016-04-01

The appropriate use of everyday objects requires the integration of action and function knowledge. Previous research suggests that action knowledge is represented in frontoparietal areas while function knowledge is represented in temporal lobe regions. Here we used multivoxel pattern analysis to investigate the representation of object-directed action and function knowledge while participants executed pantomimes of familiar tool actions. A novel approach for decoding object knowledge was used in which classifiers were trained on one pair of objects and then tested on a distinct pair; this permitted a measurement of classification accuracy over and above object-specific information. Region of interest (ROI) analyses showed that object-directed actions could be decoded in tool-preferring regions of both parietal and temporal cortex, while no independently defined tool-preferring ROI showed successful decoding of object function. However, a whole-brain searchlight analysis revealed that while frontoparietal motor and peri-motor regions are engaged in the representation of object-directed actions, medial temporal lobe areas in the left hemisphere are involved in the representation of function knowledge. These results indicate that both action and function knowledge are represented in a topographically coherent manner that is amenable to study with multivariate approaches, and that the left medial temporal cortex represents knowledge of object function. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Diffusion tensor tractography detection of functional pathway for the spread of epileptiform activity between temporal lobe and Rolandic region.

PubMed

Bhardwaj, Ratan D; Mahmoodabadi, Sina Zarei; Otsubo, Hiroshi; Snead, O Carter; Rutka, James T; Widjaja, Elysa

2010-02-01

The aim of the study was to assess the connectivity between magnetoencephalographic (MEG) dipoles in the temporal lobe and Rolandic region in children with temporal lobe epilepsy using diffusion tensor imaging (DTI) tractography. Six pediatric patients with intractable focal epilepsy had MEG performed, which showed MEG dipoles over both temporal and Rolandic regions in a unilateral hemisphere. DTI tractography was performed on each patient. Six control subjects were studied for comparison. Two volumes of interest (VOIs) that encompassed the MEG dipoles were drawn, one placed in temporal lobe and the other in Rolandic region. Similar VOIs were placed in the contralateral side in the patients and on both sides in controls. Fractional anisotropy (FA) and trace of the external capsules were compared between patients and controls. In all patients, a tractography pathway traversing through the external capsule, connecting the temporal and Rolandic MEG dipoles, was visualized. However, on the contralateral hemisphere in each patient, there was no evidence of a similar fiber tract. There was no corresponding tractography pathway identified in either hemisphere within the controls. There were no significant differences in FA and trace between the seizure focus side and contralateral side in the patients. There was no significant difference in FA, but a difference in trace between patients and controls. We have found aberrant tractography pathway traversing through the external capsule, connecting two distant foci of epileptiform activity. Chronic interictal epileptogenic discharge could play a causal role in the de novo organization of these tracts.

Multi-voxel patterns of visual category representation during episodic encoding are predictive of subsequent memory

PubMed Central

Kuhl, Brice A.; Rissman, Jesse; Wagner, Anthony D.

2012-01-01

Successful encoding of episodic memories is thought to depend on contributions from prefrontal and temporal lobe structures. Neural processes that contribute to successful encoding have been extensively explored through univariate analyses of neuroimaging data that compare mean activity levels elicited during the encoding of events that are subsequently remembered vs. those subsequently forgotten. Here, we applied pattern classification to fMRI data to assess the degree to which distributed patterns of activity within prefrontal and temporal lobe structures elicited during the encoding of word-image pairs were diagnostic of the visual category (Face or Scene) of the encoded image. We then assessed whether representation of category information was predictive of subsequent memory. Classification analyses indicated that temporal lobe structures contained information robustly diagnostic of visual category. Information in prefrontal cortex was less diagnostic of visual category, but was nonetheless associated with highly reliable classifier-based evidence for category representation. Critically, trials associated with greater classifier-based estimates of category representation in temporal and prefrontal regions were associated with a higher probability of subsequent remembering. Finally, consideration of trial-by-trial variance in classifier-based measures of category representation revealed positive correlations between prefrontal and temporal lobe representations, with the strength of these correlations varying as a function of the category of image being encoded. Together, these results indicate that multi-voxel representations of encoded information can provide unique insights into how visual experiences are transformed into episodic memories. PMID:21925190

Distinct medial temporal networks encode surprise during motivation by reward versus punishment

PubMed Central

Murty, Vishnu P.; LaBar, Kevin S.; Adcock, R. Alison

2016-01-01

Adaptive motivated behavior requires predictive internal representations of the environment, and surprising events are indications for encoding new representations of the environment. The medial temporal lobe memory system, including the hippocampus and surrounding cortex, encodes surprising events and is influenced by motivational state. Because behavior reflects the goals of an individual, we investigated whether motivational valence (i.e., pursuing rewards versus avoiding punishments) also impacts neural and mnemonic encoding of surprising events. During functional magnetic resonance imaging (fMRI), participants encountered perceptually unexpected events either during the pursuit of rewards or avoidance of punishments. Despite similar levels of motivation across groups, reward and punishment facilitated the processing of surprising events in different medial temporal lobe regions. Whereas during reward motivation, perceptual surprises enhanced activation in the hippocampus, during punishment motivation surprises instead enhanced activation in parahippocampal cortex. Further, we found that reward motivation facilitated hippocampal coupling with ventromedial PFC, whereas punishment motivation facilitated parahippocampal cortical coupling with orbitofrontal cortex. Behaviorally, post-scan testing revealed that reward, but not punishment, motivation resulted in greater memory selectivity for surprising events encountered during goal pursuit. Together these findings demonstrate that neuromodulatory systems engaged by anticipation of reward and punishment target separate components of the medial temporal lobe, modulating medial temporal lobe sensitivity and connectivity. Thus, reward and punishment motivation yield distinct neural contexts for learning, with distinct consequences for how surprises are incorporated into predictive mnemonic models of the environment. PMID:26854903

Distinct medial temporal networks encode surprise during motivation by reward versus punishment.

PubMed

Murty, Vishnu P; LaBar, Kevin S; Adcock, R Alison

2016-10-01

Adaptive motivated behavior requires predictive internal representations of the environment, and surprising events are indications for encoding new representations of the environment. The medial temporal lobe memory system, including the hippocampus and surrounding cortex, encodes surprising events and is influenced by motivational state. Because behavior reflects the goals of an individual, we investigated whether motivational valence (i.e., pursuing rewards versus avoiding punishments) also impacts neural and mnemonic encoding of surprising events. During functional magnetic resonance imaging (fMRI), participants encountered perceptually unexpected events either during the pursuit of rewards or avoidance of punishments. Despite similar levels of motivation across groups, reward and punishment facilitated the processing of surprising events in different medial temporal lobe regions. Whereas during reward motivation, perceptual surprises enhanced activation in the hippocampus, during punishment motivation surprises instead enhanced activation in parahippocampal cortex. Further, we found that reward motivation facilitated hippocampal coupling with ventromedial PFC, whereas punishment motivation facilitated parahippocampal cortical coupling with orbitofrontal cortex. Behaviorally, post-scan testing revealed that reward, but not punishment, motivation resulted in greater memory selectivity for surprising events encountered during goal pursuit. Together these findings demonstrate that neuromodulatory systems engaged by anticipation of reward and punishment target separate components of the medial temporal lobe, modulating medial temporal lobe sensitivity and connectivity. Thus, reward and punishment motivation yield distinct neural contexts for learning, with distinct consequences for how surprises are incorporated into predictive mnemonic models of the environment. Copyright © 2016 Elsevier Inc. All rights reserved.

Complementary Hemispheric Asymmetries in Object Naming and Recognition: A Voxel-Based Correlational Study

ERIC Educational Resources Information Center

Acres, K.; Taylor, K. I.; Moss, H. E.; Stamatakis, E. A.; Tyler, L. K.

2009-01-01

Cognitive neuroscientific research proposes complementary hemispheric asymmetries in naming and recognising visual objects, with a left temporal lobe advantage for object naming and a right temporal lobe advantage for object recognition. Specifically, it has been proposed that the left inferior temporal lobe plays a mediational role linking…

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.

Right anterior temporal lobe dysfunction underlies theory of mind impairments in semantic dementia.

PubMed

Irish, Muireann; Hodges, John R; Piguet, Olivier

2014-04-01

Semantic dementia is a progressive neurodegenerative disorder characterized by the amodal and profound loss of semantic knowledge attributable to the degeneration of the left anterior temporal lobe. Although traditionally conceptualized as a language disorder, patients with semantic dementia display significant alterations in behaviour and socioemotional functioning. Recent evidence points to an impaired capacity for theory of mind in predominantly left-lateralized cases of semantic dementia; however, it remains unclear to what extent semantic impairments contribute to these deficits. Further the neuroanatomical signature of such disturbance remains unknown. Here, we sought to determine the neural correlates of theory of mind performance in patients with left predominant semantic dementia (n=11), in contrast with disease-matched cases with behavioural-variant frontotemporal dementia (n=10) and Alzheimer's disease (n=10), and healthy older individuals (n=14) as control participants. Participants completed a simple cartoons task, in which they were required to describe physical and theory of mind scenarios. Irrespective of subscale, patients with semantic dementia exhibited marked impairments relative to control subjects; however, only theory of mind deficits persisted when we covaried for semantic comprehension. Voxel-based morphometry analyses revealed that atrophy in right anterior temporal lobe structures, including the right temporal fusiform cortex, right inferior temporal gyrus, bilateral temporal poles and amygdalae, correlated significantly with theory of mind impairments in the semantic dementia group. Our results point to the marked disruption of cognitive functions beyond the language domain in semantic dementia, not exclusively attributable to semantic processing impairments. The significant involvement of right anterior temporal structures suggests that with disease evolution, the encroachment of pathology into the contralateral hemisphere heralds the onset of social cognitive deficits in this syndrome.

A Novel Functional Magnetic Resonance Imaging Paradigm for the Preoperative Assessment of Auditory Perception in a Musician Undergoing Temporal Lobe Surgery.

PubMed

Hale, Matthew D; Zaman, Arshad; Morrall, Matthew C H J; Chumas, Paul; Maguire, Melissa J

2018-03-01

Presurgical evaluation for temporal lobe epilepsy routinely assesses speech and memory lateralization and anatomic localization of the motor and visual areas but not baseline musical processing. This is paramount in a musician. Although validated tools exist to assess musical ability, there are no reported functional magnetic resonance imaging (fMRI) paradigms to assess musical processing. We examined the utility of a novel fMRI paradigm in an 18-year-old left-handed pianist who underwent surgery for a left temporal low-grade ganglioglioma. Preoperative evaluation consisted of neuropsychological evaluation, T1-weighted and T2-weighted magnetic resonance imaging, and fMRI. Auditory blood oxygen level-dependent fMRI was performed using a dedicated auditory scanning sequence. Three separate auditory investigations were conducted: listening to, humming, and thinking about a musical piece. All auditory fMRI paradigms activated the primary auditory cortex with varying degrees of auditory lateralization. Thinking about the piece additionally activated the primary visual cortices (bilaterally) and right dorsolateral prefrontal cortex. Humming demonstrated left-sided predominance of auditory cortex activation with activity observed in close proximity to the tumor. This study demonstrated an fMRI paradigm for evaluating musical processing that could form part of preoperative assessment for patients undergoing temporal lobe surgery for epilepsy. Copyright © 2017 Elsevier Inc. All rights reserved.

Early metabolic crisis-related brain atrophy and cognition in traumatic brain injury.

PubMed

Wright, Matthew J; McArthur, David L; Alger, Jeffry R; Van Horn, Jack; Irimia, Andrei; Filippou, Maria; Glenn, Thomas C; Hovda, David A; Vespa, Paul

2013-09-01

Traumatic brain injury often results in acute metabolic crisis. We recently demonstrated that this is associated with chronic brain atrophy, which is most prominent in the frontal and temporal lobes. Interestingly, the neuropsychological profile of traumatic brain injury is often characterized as 'frontal-temporal' in nature, suggesting a possible link between acute metabolic crisis-related brain atrophy and neurocognitive impairment in this population. While focal lesions and diffuse axonal injury have a well-established role in the neuropsychological deficits observed following traumatic brain injury, no studies to date have examined the possible contribution of acute metabolic crisis-related atrophy in the neuropsychological sequelae of traumatic brain injury. In the current study we employed positron emission tomography, magnetic resonance imaging, and neuropsychological assessments to ascertain the relationship between acute metabolic crisis-related brain atrophy and neurocognitive outcome in a sample of 14 right-handed traumatic brain injury survivors. We found that acute metabolic crisis-related atrophy in the frontal and temporal lobes was associated with poorer attention, executive functioning, and psychomotor abilities at 12 months post-injury. Furthermore, participants with gross frontal and/or temporal lobe atrophy exhibited numerous clinically significant neuropsychological deficits in contrast to participants with other patterns of brain atrophy. Our findings suggest that interventions that reduce acute metabolic crisis may lead to improved functional outcomes for traumatic brain injury survivors.

Epilepsy, hippocampal sclerosis and febrile seizures linked by common genetic variation around SCN1A

PubMed Central

Kasperavičiūtė, Dalia; Catarino, Claudia B.; Matarin, Mar; Leu, Costin; Novy, Jan; Tostevin, Anna; Leal, Bárbara; Hessel, Ellen V. S.; Hallmann, Kerstin; Hildebrand, Michael S.; Dahl, Hans-Henrik M.; Ryten, Mina; Trabzuni, Daniah; Ramasamy, Adaikalavan; Alhusaini, Saud; Doherty, Colin P.; Dorn, Thomas; Hansen, Jörg; Krämer, Günter; Steinhoff, Bernhard J.; Zumsteg, Dominik; Duncan, Susan; Kälviäinen, Reetta K.; Eriksson, Kai J.; Kantanen, Anne-Mari; Pandolfo, Massimo; Gruber-Sedlmayr, Ursula; Schlachter, Kurt; Reinthaler, Eva M.; Stogmann, Elisabeth; Zimprich, Fritz; Théâtre, Emilie; Smith, Colin; O’Brien, Terence J.; Meng Tan, K.; Petrovski, Slave; Robbiano, Angela; Paravidino, Roberta; Zara, Federico; Striano, Pasquale; Sperling, Michael R.; Buono, Russell J.; Hakonarson, Hakon; Chaves, João; Costa, Paulo P.; Silva, Berta M.; da Silva, António M.; de Graan, Pierre N. E.; Koeleman, Bobby P. C.; Becker, Albert; Schoch, Susanne; von Lehe, Marec; Reif, Philipp S.; Rosenow, Felix; Becker, Felicitas; Weber, Yvonne; Lerche, Holger; Rössler, Karl; Buchfelder, Michael; Hamer, Hajo M.; Kobow, Katja; Coras, Roland; Blumcke, Ingmar; Scheffer, Ingrid E.; Berkovic, Samuel F.; Weale, Michael E.; Delanty, Norman; Depondt, Chantal; Cavalleri, Gianpiero L.; Kunz, Wolfram S.

2013-01-01

Epilepsy comprises several syndromes, amongst the most common being mesial temporal lobe epilepsy with hippocampal sclerosis. Seizures in mesial temporal lobe epilepsy with hippocampal sclerosis are typically drug-resistant, and mesial temporal lobe epilepsy with hippocampal sclerosis is frequently associated with important co-morbidities, mandating the search for better understanding and treatment. The cause of mesial temporal lobe epilepsy with hippocampal sclerosis is unknown, but there is an association with childhood febrile seizures. Several rarer epilepsies featuring febrile seizures are caused by mutations in SCN1A, which encodes a brain-expressed sodium channel subunit targeted by many anti-epileptic drugs. We undertook a genome-wide association study in 1018 people with mesial temporal lobe epilepsy with hippocampal sclerosis and 7552 control subjects, with validation in an independent sample set comprising 959 people with mesial temporal lobe epilepsy with hippocampal sclerosis and 3591 control subjects. To dissect out variants related to a history of febrile seizures, we tested cases with mesial temporal lobe epilepsy with hippocampal sclerosis with (overall n = 757) and without (overall n = 803) a history of febrile seizures. Meta-analysis revealed a genome-wide significant association for mesial temporal lobe epilepsy with hippocampal sclerosis with febrile seizures at the sodium channel gene cluster on chromosome 2q24.3 [rs7587026, within an intron of the SCN1A gene, P = 3.36 × 10−9, odds ratio (A) = 1.42, 95% confidence interval: 1.26–1.59]. In a cohort of 172 individuals with febrile seizures, who did not develop epilepsy during prospective follow-up to age 13 years, and 6456 controls, no association was found for rs7587026 and febrile seizures. These findings suggest SCN1A involvement in a common epilepsy syndrome, give new direction to biological understanding of mesial temporal lobe epilepsy with hippocampal sclerosis with febrile seizures, and open avenues for investigation of prognostic factors and possible prevention of epilepsy in some children with febrile seizures. PMID:24014518

Monitoring fractional anisotropy in developing rabbit brain using MR diffusion tensor imaging at 3T

NASA Astrophysics Data System (ADS)

Jao, Jo-Chi; Yang, Yu-Ting; Hsiao, Chia-Chi; Chen, Po-Chou

2016-03-01

The aim of this study was to investigate the factional anisotropy (FA) in various regions of developing rabbit brain using magnetic resonance diffusion tensor imaging (MR DTI) at 3 T. A whole-body clinical MR imaging (MRI) scanner with a 15-channel high resolution knee coil was used. An echo-planar-imaging (EPI)-DTI pulse sequence was performed. Five 5 week-old New Zealand white (NZW) rabbits underwent MRI once per week for 24 weeks. After scanning, FA maps were obtained. ROIs (regions of interests) in the frontal lobe, parietal & temporal lobe, and occipital lobe were measured. FA changes with time were evaluated with a linear regression analysis. The results show that the FA values in all lobes of the brain increased linearly with age. The ranking of FA values was FA(frontal lobe) < FA(parietal & temporal lobe) > FA(occipital lobe). There was significant difference (p < 0.05) among these lobes. FA values are associated with the nerve development and brain functions. The FA change rate could be a biomarker to monitor the brain development. Understanding the FA values of various lobes during development could provide helpful information to diagnosis the abnormal syndrome earlier and have a better treatment and prognosis. This study established a brain MR-DTI protocol for rabbits to investigate the brain anatomy during development using clinical MRI. This technique can be further applied to the pre-clinical diagnosis, treatment, prognosis and follow-up of brain lesions.

A Combined Study of SLC6A15 Gene Polymorphism and the Resting-State Functional Magnetic Resonance Imaging in First-Episode Drug-Naive Major Depressive Disorder.

PubMed

Wang, Lijuan; Liu, Zhifen; Cao, Xiaohua; Li, Jianying; Zhang, Aixia; Sun, Ning; Yang, Chunxia; Zhang, Kerang

2017-09-01

The SLC6A15 gene has been identified as a novel candidate gene for major depressive disorder (MDD). However, the mechanism underlying the effects of how the SLC6A15 gene affects functional brain activity of patients with MDD remains unknown. In the present study, we investigated the effect of the SLC6A15 gene polymorphism, rs1545843, on resting-state brain function in MDD with the imaging genomic technology and the regional homogeneity (ReHo) method. Sixty-seven MDD patients and 44 healthy controls underwent functional magnetic resonance imaging scans and genotyping. The differences in ReHo between genotypes were initially tested using the student's t test. We then performed a 2 × 2 (genotypes × disease status) analysis of variance to identify the main effects of genotypes, disease status, and their interactions in MDD. MDD patients with A+ genotypes showed decreased ReHo in the medial cingulum compared with MDD patients with the GG genotype. This was in contrast to normal controls with A+ genotypes who showed increased ReHo in the posterior cingulum and the frontal, temporal, and parietal lobes and decreased ReHo in the left corpus callosum, compared with controls with the GG genotypes. The main effect of disease was found in the frontal, parietal, and temporal lobes. The main effect of genotypes was found in the left corpus callosum and the frontal lobe. There was no interaction between rs1545843 genotypes and disease status. We found that the left corpus callosum ReHo was positively correlated with total scores of the Hamilton Depression Scale (HAMD) (p = 0.021), so as was the left inferior parietal gyrus ReHo with cognitive disorder (p = 0.02). In addition, the right middle temporal gyrus had a negative correlation with retardation (p = 0.049). We observed an association between the SLC6A15 rs1545843 and resting-state brain function of the corpus callosum, cingulum and the frontal, parietal, and temporal lobes in MDD patients, which may be involved in the pathogenesis of MDD.

Impairments in Precision, Rather than Spatial Strategy, Characterize Performance on the Virtual Morris Water Maze: A Case Study

PubMed Central

Kolarik, Branden S.; Shahlaie, Kiarash; Hassan, Abdul; Borders, Alyssa A.; Kaufman, Kyle C.; Gurkoff, Gene; Yonelinas, Andy P.; Ekstrom, Arne D.

2015-01-01

Damage to the medial temporal lobes produces profound amnesia, greatly impairing the ability of patients to learn about new associations and events. While studies in rodents suggest a strong link between damage to the hippocampus and the ability to navigate using distal landmarks in a spatial environment, the connection between navigation and memory in humans remains less clear. Past studies on human navigation have provided mixed findings about whether patients with damage to the medial temporal lobes can successfully acquire and navigate new spatial environments, possibly due, in part, to issues related to patient demographics and characterization of medial temporal lobe damage. Here, we report findings from a young, high functioning patient who suffered severe medial temporal lobe damage. Although the patient is densely amnestic, her ability to acquire and utilize new, but coarse, spatial “maps” appears largely intact. Specifically, a novel computational analysis focused on the precision of her spatial search revealed a significant deficit in spatial precision rather than spatial search strategy. These findings argue that an intact hippocampus in humans is not necessary for representing multiple external landmarks during spatial navigation of new environments. We suggest instead that the human hippocampus may store and represent complex high-resolution bindings of features in the environment as part of a larger role in perception, memory, and navigation. PMID:26593960

Targeting deficiencies in mitochondrial respiratory complex I and functional uncoupling exerts anti-seizure effects in a genetic model of temporal lobe epilepsy and in a model of acute temporal lobe seizures.

PubMed

Simeone, Kristina A; Matthews, Stephanie A; Samson, Kaeli K; Simeone, Timothy A

2014-01-01

Mitochondria actively participate in neurotransmission by providing energy (ATP) and maintaining normative concentrations of reactive oxygen species (ROS) in both presynaptic and postsynaptic elements. In human and animal epilepsies, ATP-producing respiratory rates driven by mitochondrial respiratory complex (MRC) I are reduced, antioxidant systems are attenuated and oxidative damage is increased. We report that MRCI-driven respiration and functional uncoupling (an inducible antioxidant mechanism) are reduced and levels of H2O2 are elevated in mitochondria isolated from KO mice. Experimental impairment of MRCI in WT hippocampal slices via rotenone reduces paired-pulse ratios (PPRs) at mossy fiber-CA3 synapses (resembling KO PPRs), and exacerbates seizure-like events in vitro. Daily treatment with AATP [a combination therapy composed of ascorbic acid (AA), alpha-tocopherol (T), sodium pyruvate (P) designed to synergistically target mitochondrial impairments] improved mitochondrial functions, mossy fiber PPRs, and reduced seizure burden index (SBI) scores and seizure incidence in KO mice. AATP pretreatment reduced severity of KA-induced seizures resulting in 100% protection from the severe tonic-clonic seizures in WT mice. These data suggest that restoration of bioenergetic homeostasis in the brain may represent a viable anti-seizure target for temporal lobe epilepsy. Copyright © 2013 Elsevier Inc. All rights reserved.

Left or right? Lateralizing temporal lobe epilepsy by dynamic amygdala fMRI.

PubMed

Ives-Deliperi, Victoria; Butler, James Thomas; Jokeit, Hennric

2017-05-01

In this case series, the findings of 85 functional MRI studies employing a dynamic fearful face paradigm are reported. Previous findings have shown the paradigm to generate bilateral amygdala activations in healthy subjects and unilateral activations in patients with MTLE, in the contralateral hemisphere to seizure origin. Such findings suggest ipsilateral limbic pathology and offer collateral evidence in lateralizing MTLE. The series includes 60 patients with TLE, 12 patients with extra-temporal lobe epilepsy, and 13 healthy controls. Functional MRI studies using a 1.5T scanner were conducted over a three-year period at a single epilepsy center and individual results were compared with EEG findings. In the cohort of unilateral TLE patients, lateralized activations of the amygdala were concordant with EEG findings in 76% of patients (77% lTLE, 74% rTLE). The differences in the mean lateralized indices of the lTLE, rTLE, and healthy control groups were all statistically significant. Lateralized amygdala activations were concordant with EEG findings in only 31% of the 12 patients with extra-temporal lobe epilepsy and bilateral amygdala activations were generated in all but one of the healthy control subjects. This case series further endorses the utility of the dynamic fearful face functional MRI paradigm using the widely available 1.5T as an adjunctive investigation to lateralize TLE. Copyright © 2017 Elsevier Inc. All rights reserved.

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

Determinants of Autobiographical Memory in Patients with Unilateral Temporal Lobe Epilepsy or Excisions

ERIC Educational Resources Information Center

St-Laurent, Marie; Moscovitch, Morris; Levine, Brian; McAndrews, Mary Pat

2009-01-01

Patients with unilateral temporal lobe epilepsy from hippocampal origin and patients with unilateral surgical excision of an epileptic focus located in the medial temporal lobe were compared to healthy controls on a version of the Autobiographical Interview (AI) adapted to assess memory for event-specific and generic personal episodes. For both…

Material-Specific Lateralization of Working Memory in the Medial Temporal Lobe

ERIC Educational Resources Information Center

Wagner, Dylan D.; Sziklas, Viviane; Garver, Krista E.; Jones-Gotman, Marilyn

2009-01-01

Mnemonic deficits in patients with medial temporal lobe (MTL) damage arising from temporal lobe epilepsy (TLE) are traditionally constrained to long-term episodic memory, sparing short-term and working memory (WM). This view of WM as being independent of MTL structures has recently been challenged by a small number of patient and neuroimaging…

Autobiographical memory of the recent past following frontal cortex or temporal lobe excisions.

PubMed

Thaiss, Laila; Petrides, Michael

2008-08-01

Previous research has raised questions regarding the necessity of the frontal cortex in autobiographical memory and the role that it plays in actively retrieving contextual information associated with personally relevant events. Autobiographical memory was studied in patients with unilateral excisions restricted to the frontal cortex or temporal lobe involving the amygdalo-hippocampal region and in normal controls using an event-sampling method. We examined accuracy of free recall, use of strategies during retrieval and memory for specific aspects of the autobiographical events, including temporal order. Patients with temporal lobe excisions were impaired in autobiographical recall. By contrast, patients with frontal cortical excisions exhibited normal autobiographical recall but were less likely to use temporal order spontaneously to organize event retrieval. Instruction to organize retrieval by temporal order failed to improve recall in temporal lobe patients and increased the incidence of plausible intrusion errors in left temporal patients. In contrast, patients with frontal cortical excisions now surpassed control subjects in recall of autobiographical events. Furthermore, the retrieval accuracy for the temporal order of diary events was not impaired in these patients. In a subsequent cued recall test, temporal lobe patients were impaired in their memory for the details of the diary events and their context. In conclusion, a basic impairment in autobiographical memory (including memory for temporal context) results from damage to the temporal lobe and not the frontal cortex. Patients with frontal excisions fail to use organizational strategies spontaneously to aid retrieval but can use these effectively if instructed to do so.

Decreasing Temporal Lobe Dose With Five-Field Intensity-Modulated Radiotherapy for Treatment of Pituitary Macroadenomas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parhar, Preeti K.; Duckworth, Tamara; Shah, Parinda

2010-10-01

Purpose: To compare temporal lobe dose delivered by three pituitary macroadenoma irradiation techniques: three-field three-dimensional conformal radiotherapy (3D-CRT), three-field intensity-modulated radiotherapy (3F IMRT), and a proposed novel alternative of five-field IMRT (5F IMRT). Methods and Materials: Computed tomography-based external beam radiotherapy planning was performed for 15 pituitary macroadenoma patients treated at New York University between 2002 and 2007 using: 3D-CRT (two lateral, one midline superior anterior oblique [SAO] beams), 3F IMRT (same beam angles), and 5F IMRT (same beam angles with additional right SAO and left SAO beams). Prescription dose was 45 Gy. Target volumes were: gross tumor volume (GTV)more » = macroadenoma, clinical target volume (CTV) = GTV, and planning target volume = CTV + 0.5 cm. Structure contouring was performed by two radiation oncologists guided by an expert neuroradiologist. Results: Five-field IMRT yielded significantly decreased temporal lobe dose delivery compared with 3D-CRT and 3F IMRT. Temporal lobe sparing with 5F IMRT was most pronounced at intermediate doses: mean V25Gy (% of total temporal lobe volume receiving {>=}25 Gy) of 13% vs. 28% vs. 29% for right temporal lobe and 14% vs. 29% vs. 30% for left temporal lobe for 5F IMRT, 3D-CRT, and 3F IMRT, respectively (p < 10{sup -7} for 5F IMRT vs. 3D-CRT and 5F IMRT vs. 3F IMRT). Five-field IMRT plans did not compromise target coverage, exceed normal tissue dose constraints, or increase estimated brain integral dose. Conclusions: Five-field IMRT irradiation technique results in a statistically significant decrease in the dose to the temporal lobes and may thus help prevent neurocognitive sequelae in irradiated pituitary macroadenoma patients.« less

Functional and structural brain correlates of theory of mind and empathy deficits in schizophrenia.

PubMed

Benedetti, Francesco; Bernasconi, Alessandro; Bosia, Marta; Cavallaro, Roberto; Dallaspezia, Sara; Falini, Andrea; Poletti, Sara; Radaelli, Daniele; Riccaboni, Roberta; Scotti, Giuseppe; Smeraldi, Enrico

2009-10-01

Patients affected by schizophrenia show deficits in social cognition, with abnormal performance on tasks targeting theory of mind (ToM) and empathy (Emp). Brain imaging studies suggested that ToM and Emp depend on the activation of brain networks mainly localized at the superior temporal lobe and temporo-parietal junction. Participants included 24 schizophrenia patients and 20 control subjects. We used brain blood oxygen level dependent fMRI to study the neural responses to tasks targeting ToM and Emp. We then studied voxel-based morphometry of grey matter in areas where diagnosis influenced functional activation to both tasks. Outcomes were analyzed in the context of the general linear model, with global grey matter volume as nuisance covariate for structural MRI. Patients showed worse performance on both tasks. We found significant effects of diagnosis on neural responses to the tasks in a wide cluster in right posterior superior temporal lobe (encompassing BA 22-42), in smaller clusters in left temporo-parietal junction and temporal pole (BA 38 and 39), and in a white matter region adjacent to medial prefrontal cortex (BA 10). A pattern of double dissociation of the effects of diagnosis and task on neural responses emerged. Among these areas, grey matter volume was found to be reduced in right superior temporal lobe regions of patients. Functional and structural abnormalities were observed in areas affected by the schizophrenic process early in the illness course, and known to be crucial for social cognition, suggesting a biological basis for social cognition deficits in schizophrenia.

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.

Voxel-Based Morphometry and fMRI Revealed Differences in Brain Gray Matter in Breastfed and Milk Formula-Fed Children.

PubMed

Ou, X; Andres, A; Pivik, R T; Cleves, M A; Snow, J H; Ding, Z; Badger, T M

2016-04-01

Infant diets may have significant impact on brain development in children. The aim of this study was to evaluate brain gray matter structure and function in 8-year-old children who were predominantly breastfed or fed cow's milk formula as infants. Forty-two healthy children (breastfed: n = 22, 10 boys and 12 girls; cow's milk formula: n = 20, 10 boys and 10 girls) were studied by using structural MR imaging (3D T1-weighted imaging) and blood oxygen level-dependent fMRI (while performing tasks involving visual perception and language functions). They were also administered standardized tests evaluating intelligence (Reynolds Intellectual Assessment Scales) and language skills (Clinical Evaluation of Language Fundamentals). Total brain gray matter volume did not differ between the breastfed and cow's milk formula groups. However, breastfed children had significantly higher (P < .05, corrected) regional gray matter volume measured by voxel-based morphometry in the left inferior temporal lobe and left superior parietal lobe compared with cow's milk formula-fed children. Breastfed children showed significantly more brain activation in the right frontal and left/right temporal lobes on fMRI when processing the perception task and in the left temporal/occipital lobe when processing the visual language task than cow's milk formula-fed children. The imaging findings were associated with significantly better performance for breastfed than cow's milk formula-fed children on both tasks. Our findings indicated greater regional gray matter development and better regional gray matter function in breastfed than cow's milk formula-fed children at 8 years of age and suggested that infant diets may have long-term influences on brain development in children. © 2016 by American Journal of Neuroradiology.

Reversible dyscognition in patients with a unilateral, middle fossa arachnoid cyst revealed by using a laptop based neuropsychological test battery (CANTAB).

PubMed

Torgersen, Johan; Helland, Christian; Flaatten, Hans; Wester, Knut

2010-11-01

The aim of this study was to evaluate and validate the Cambridge Neuropsychological Test Automated Battery (CANTAB) in a Norwegian group of patients undergoing surgery for middle fossa arachnoid cysts (AC). We also wanted to assess health related quality of life (HRQOL) in these patients to see if it could be improved by decompression of the AC. Adult patients (>18 years) with unilateral middle fossa AC and no previous history of neurological disease, head injury, or a psychiatric disorder were eligible for inclusion. We used four tests from CANTAB to assess the level of neuropsychological performance: paired associate learning (PAL) and delayed matching to sample (DMS) assessed temporal lobe functions, while Stockings of Cambridge (SOC) and intra-extra dimensional (IED) shift focused on frontal lobe functions. Patients with postoperative cerebral complications were reported, but excluded from neuropsychological follow-up. In addition to the CANTAB data, pre- and postoperative clinical and radiological data were collected. HRQOL was assessed using Short Form 36 (SF-36) pre- and postoperatively. We found significant improvement in the two temporal tests assessing memory, but no improvement in the two frontal tests assessing executive function. HRQOL was significantly reduced preoperatively in two of eight SF-36 domains and improved significantly in four domains postoperatively. CANTAB facilitates detection of cognitive improvements after decompression of the cyst in patients with AC in the middle fossa. The improvements were detected on the tests sensitive to temporal lobe problems only, not on the tests more sensitive to frontal lobe affection. This establishes construct validity for CANTAB for the first time in this population.

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.

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.

Craniopharyngioma in the Temporal Lobe: A Case Report

PubMed Central

Baik, Seung Kug; Kim, Sang-Pyo; Kim, Il-Man; Sevick, Robert J.

2004-01-01

Herein, we report on an unusual case of craniopharyngioma arising in the temporal lobe with no prior history of surgery and with no connection to the craniopharyngeal duct. MR images showed a cystic tumor with a small solid portion. To the best of our knowledge, this is the first case of a craniopharyngioma occurring in the temporal lobe. PMID:15064562

Successful decoding of famous faces in the fusiform face area.

PubMed

Axelrod, Vadim; Yovel, Galit

2015-01-01

What are the neural mechanisms of face recognition? It is believed that the network of face-selective areas, which spans the occipital, temporal, and frontal cortices, is important in face recognition. A number of previous studies indeed reported that face identity could be discriminated based on patterns of multivoxel activity in the fusiform face area and the anterior temporal lobe. However, given the difficulty in localizing the face-selective area in the anterior temporal lobe, its role in face recognition is still unknown. Furthermore, previous studies limited their analysis to occipito-temporal regions without testing identity decoding in more anterior face-selective regions, such as the amygdala and prefrontal cortex. In the current high-resolution functional Magnetic Resonance Imaging study, we systematically examined the decoding of the identity of famous faces in the temporo-frontal network of face-selective and adjacent non-face-selective regions. A special focus has been put on the face-area in the anterior temporal lobe, which was reliably localized using an optimized scanning protocol. We found that face-identity could be discriminated above chance level only in the fusiform face area. Our results corroborate the role of the fusiform face area in face recognition. Future studies are needed to further explore the role of the more recently discovered anterior face-selective areas in face recognition.

Displaced aggression predicts switching deficits in people with temporal lobe epilepsy.

PubMed

Gul, Amara; Ahmad, Hira

2014-12-01

This study examined the relationship between task-switching abilities and displaced aggression in people with temporal lobe epilepsy (PWE). Participants (35 PWE and 35 healthy controls) performed emotion and gender classification switching tasks. People with temporal lobe epilepsy showed larger switch costs than controls. This result reflected task-switching deficits in PWE. People with temporal lobe epilepsy reported higher anger rumination, revenge planning, and behavioral displaced aggression compared with controls. Displaced aggression was a significant predictor of the task switch costs. It is suggested that displaced aggression is a significant marker of task-switching deficits. Copyright © 2014 Elsevier Inc. All rights reserved.

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.

Sex differences in verbal and nonverbal learning before and after temporal lobe epilepsy surgery.

PubMed

Berger, Justus; Oltmanns, Frank; Holtkamp, Martin; Bengner, Thomas

2017-01-01

Women outperform men in a host of episodic memory tasks, yet the neuroanatomical basis for this effect is unclear. It has been suggested that the anterior temporal lobe might be especially relevant for sex differences in memory. In the current study, we investigated whether temporal lobe epilepsy (TLE) has an influence on sex effects in learning and memory and whether women and men with TLE differ in their risk for memory deficits after epilepsy surgery. 177 patients (53 women and 41 men with left TLE, 42 women and 41 men with right TLE) were neuropsychologically tested before and one year after temporal lobe resection. We found that women with TLE had better verbal, but not figural, memory than men with TLE. The female advantage in verbal memory was not affected by temporal lobe resection. The same pattern of results was found in a more homogeneous subsample of 84 patients with only hippocampal sclerosis who were seizure-free after surgery. Our findings challenge the concept that the anterior temporal lobe plays a central role in the verbal memory advantage for women. Copyright © 2016 Elsevier Inc. All rights reserved.

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.

Auditory temporal processing in patients with temporal lobe epilepsy.

PubMed

Lavasani, Azam Navaei; Mohammadkhani, Ghassem; Motamedi, Mahmoud; Karimi, Leyla Jalilvand; Jalaei, Shohreh; Shojaei, Fereshteh Sadat; Danesh, Ali; Azimi, Hadi

2016-07-01

Auditory temporal processing is the main feature of speech processing ability. Patients with temporal lobe epilepsy, despite their normal hearing sensitivity, may present speech recognition disorders. The present study was carried out to evaluate the auditory temporal processing in patients with unilateral TLE. The present study was carried out on 25 patients with epilepsy: 11 patients with right temporal lobe epilepsy and 14 with left temporal lobe epilepsy with a mean age of 31.1years and 18 control participants with a mean age of 29.4years. The two experimental and control groups were evaluated via gap-in-noise and duration pattern sequence tests. One-way ANOVA was run to analyze the data. The mean of the threshold of the GIN test in the control group was observed to be better than that in participants with LTLE and RTLE. Also, it was observed that the percentage of correct responses on the DPS test in the control group and in participants with RTLE was better than that in participants with LTLE. Patients with TLE have difficulties in temporal processing. Difficulties are more significant in patients with LTLE, likely because the left temporal lobe is specialized for the processing of temporal information. Copyright © 2016 Elsevier Inc. All rights reserved.

Dose–Volume Relationships Associated With Temporal Lobe Radiation Necrosis After Skull Base Proton Beam Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDonald, Mark W., E-mail: markmcdonaldmd@gmail.com; Indiana University Health Proton Therapy Center, Bloomington, Indiana; Linton, Okechukwu R.

Purpose: We evaluated patient and treatment parameters correlated with development of temporal lobe radiation necrosis. Methods and Materials: This was a retrospective analysis of a cohort of 66 patients treated for skull base chordoma, chondrosarcoma, adenoid cystic carcinoma, or sinonasal malignancies between 2005 and 2012, who had at least 6 months of clinical and radiographic follow-up. The median radiation dose was 75.6 Gy (relative biological effectiveness [RBE]). Analyzed factors included gender, age, hypertension, diabetes, smoking status, use of chemotherapy, and the absolute dose:volume data for both the right and left temporal lobes, considered separately. A generalized estimating equation (GEE) regression analysis evaluatedmore » potential predictors of radiation necrosis, and the median effective concentration (EC50) model estimated dose–volume parameters associated with radiation necrosis. Results: Median follow-up time was 31 months (range 6-96 months) and was 34 months in patients who were alive. The Kaplan-Meier estimate of overall survival at 3 years was 84.9%. The 3-year estimate of any grade temporal lobe radiation necrosis was 12.4%, and for grade 2 or higher radiation necrosis was 5.7%. On multivariate GEE, only dose–volume relationships were associated with the risk of radiation necrosis. In the EC50 model, all dose levels from 10 to 70 Gy (RBE) were highly correlated with radiation necrosis, with a 15% 3-year risk of any-grade temporal lobe radiation necrosis when the absolute volume of a temporal lobe receiving 60 Gy (RBE) (aV60) exceeded 5.5 cm{sup 3}, or aV70 > 1.7 cm{sup 3}. Conclusions: Dose–volume parameters are highly correlated with the risk of developing temporal lobe radiation necrosis. In this study the risk of radiation necrosis increased sharply when the temporal lobe aV60 exceeded 5.5 cm{sup 3} or aV70 > 1.7 cm{sup 3}. Treatment planning goals should include constraints on the volume of temporal lobes receiving higher dose. The EC50 model provides suggested dose–volume temporal lobe constraints for conventionally fractionated high-dose skull base radiation therapy.« less

Improved Diagnostic Accuracy of Alzheimer's Disease by Combining Regional Cortical Thickness and Default Mode Network Functional Connectivity: Validated in the Alzheimer's Disease Neuroimaging Initiative Set.

PubMed

Park, Ji Eun; Park, Bumwoo; Kim, Sang Joon; Kim, Ho Sung; Choi, Choong Gon; Jung, Seung Chai; Oh, Joo Young; Lee, Jae-Hong; Roh, Jee Hoon; Shim, Woo Hyun

2017-01-01

To identify potential imaging biomarkers of Alzheimer's disease by combining brain cortical thickness (CThk) and functional connectivity and to validate this model's diagnostic accuracy in a validation set. Data from 98 subjects was retrospectively reviewed, including a study set (n = 63) and a validation set from the Alzheimer's Disease Neuroimaging Initiative (n = 35). From each subject, data for CThk and functional connectivity of the default mode network was extracted from structural T1-weighted and resting-state functional magnetic resonance imaging. Cortical regions with significant differences between patients and healthy controls in the correlation of CThk and functional connectivity were identified in the study set. The diagnostic accuracy of functional connectivity measures combined with CThk in the identified regions was evaluated against that in the medial temporal lobes using the validation set and application of a support vector machine. Group-wise differences in the correlation of CThk and default mode network functional connectivity were identified in the superior temporal ( p < 0.001) and supramarginal gyrus ( p = 0.007) of the left cerebral hemisphere. Default mode network functional connectivity combined with the CThk of those two regions were more accurate than that combined with the CThk of both medial temporal lobes (91.7% vs. 75%). Combining functional information with CThk of the superior temporal and supramarginal gyri in the left cerebral hemisphere improves diagnostic accuracy, making it a potential imaging biomarker for Alzheimer's disease.

Regional homogeneity changes in prelingually deafened patients: a resting-state fMRI study

NASA Astrophysics Data System (ADS)

Li, Wenjing; He, Huiguang; Xian, Junfang; Lv, Bin; Li, Meng; Li, Yong; Liu, Zhaohui; Wang, Zhenchang

2010-03-01

Resting-state functional magnetic resonance imaging (fMRI) is a technique that measures the intrinsic function of brain and has some advantages over task-induced fMRI. Regional homogeneity (ReHo) assesses the similarity of the time series of a given voxel with its nearest neighbors on a voxel-by-voxel basis, which reflects the temporal homogeneity of the regional BOLD signal. In the present study, we used the resting state fMRI data to investigate the ReHo changes of the whole brain in the prelingually deafened patients relative to normal controls. 18 deaf patients and 22 healthy subjects were scanned. Kendall's coefficient of concordance (KCC) was calculated to measure the degree of regional coherence of fMRI time courses. We found that regional coherence significantly decreased in the left frontal lobe, bilateral temporal lobes and right thalamus, and increased in the postcentral gyrus, cingulate gyrus, left temporal lobe, left thalamus and cerebellum in deaf patients compared with controls. These results show that the prelingually deafened patients have higher degree of regional coherence in the paleocortex, and lower degree in neocortex. Since neocortex plays an important role in the development of auditory, these evidences may suggest that the deaf persons reorganize the paleocortex to offset the loss of auditory.

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

Dietary influences on cognitive function with aging: from high-fat diets to healthful eating.

PubMed

Parrott, Matthew D; Greenwood, Carol E

2007-10-01

Human epidemiologic studies provide convincing evidence that dietary patterns practiced during adulthood are important contributors to age-related cognitive decline and dementia risk. Diets high in fat, especially trans and saturated fats, adversely affect cognition, while those high in fruits, vegetables, cereals, and fish are associated with better cognitive function and lower risk of dementia. While the precise physiologic mechanisms underlying these dietary influences are not completely understood, modulation of brain insulin activity and neuroinflammation likely contribute. Not surprisingly, deficits in cognitive functions, especially those dependent on the medial temporal lobes, are apparent in type 2 diabetes mellitus (T2DM). Special care in food selection at meals should be exercised by those with T2DM since ingestion of rapidly absorbed, high-glycemic index carbohydrate foods further impairs medial temporal lobe function, with food-induced increases in oxidative stress and cytokine release likely explaining the association between food ingestion and reduction in cognitive function in those with T2DM.

Functional neuroimaging and presenting psychiatric features in frontotemporal dementia

PubMed Central

Mendez, M F; McMurtray, A; Chen, A K; Shapira, J S; Mishkin, F; Miller, B L

2006-01-01

Background Frontotemporal dementia (FTD) is a behavioural syndrome caused by degeneration of the frontal and anterior temporal lobes. Behavioural disturbances include psychiatric features. Whether patients with FTD present with psychiatric features varies with the initial neuroanatomical variability of FTD. Objective To identify presenting psychiatric changes not part of diagnostic criteria of FTD and contrast them with the degree of hemispheric asymmetry and frontal and temporal hypoperfusion on single photon emission computed tomography (SPECT) imaging. Methods 74 patients who met consensus criteria for FTD were evaluated at a two year follow up. All had brain SPECT on initial presentation. Results of an FTD psychiatric checklist were contrasted with ratings of regional hypoperfusion. Results The regions of predominant hypoperfusion did not correlate with differences on FTD demographic variables but were associated with presenting psychiatric features. Dysthymia and anxiety were associated with right temporal hypoperfusion. “Moria” or frivolous behaviour also occurred with temporal lobe changes, especially on the right. The only significant frontal lobe feature was the presence of a peculiar physical bearing in association with right frontal hypoperfusion. Conclusions Patients with FTD may present with psychiatric changes distinct from the behavioural diagnostic criteria for this disorder. Early temporal involvement is associated with frivolous behaviour and right temporal involvement is associated with emotional disturbances. In contrast, those with right frontal disease may present with alterations in non‐verbal behaviour. PMID:16043457

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.

Towards a functional organization of episodic memory in the medial temporal lobe

PubMed Central

Eichenbaum, Howard; Sauvage, Magdalena; Fortin, Norbert; Komorowski, Robert; Lipton, Paul

2011-01-01

Here we describe a model of medial temporal lobe organization in which parallel “what” and “where” processing streams converge within the hippocampus to represent events in the spatio-temporal context in which they occurred; this circuitry also mediates the retrieval of context from event cues and vice versa, which are prototypes of episodic recall. Evidence from studies in animals are reviewed in support of this model, including experiments that distinguish characteristics of episodic recollection from familiarity, neuropsychological and recording studies that have identified a key role for the hippocampus in recollection and in associating events with the context in which they occurred, and distinct roles for parahippocampal region areas in separate “what” and “where” information processing that contributes to recollective and episodic memory. PMID:21810443

Towards a functional organization of episodic memory in the medial temporal lobe.

PubMed

Eichenbaum, Howard; Sauvage, Magdalena; Fortin, Norbert; Komorowski, Robert; Lipton, Paul

2012-08-01

Here we describe a model of medial temporal lobe organization in which parallel "what" and "where" processing streams converge within the hippocampus to represent events in the spatio-temporal context in which they occurred; this circuitry also mediates the retrieval of context from event cues and vice versa, which are prototypes of episodic recall. Evidence from studies in animals are reviewed in support of this model, including experiments that distinguish characteristics of episodic recollection from familiarity, neuropsychological and recording studies that have identified a key role for the hippocampus in recollection and in associating events with the context in which they occurred, and distinct roles for parahippocampal region areas in separate "what" and "where" information processing that contributes to recollective and episodic memory. Copyright © 2011 Elsevier Ltd. All rights reserved.

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.

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.

Direct Exploration of the Role of the Ventral Anterior Temporal Lobe in Semantic Memory: Cortical Stimulation and Local Field Potential Evidence From Subdural Grid Electrodes

PubMed Central

Shimotake, Akihiro; Matsumoto, Riki; Ueno, Taiji; Kunieda, Takeharu; Saito, Satoru; Hoffman, Paul; Kikuchi, Takayuki; Fukuyama, Hidenao; Miyamoto, Susumu; Takahashi, Ryosuke; Ikeda, Akio; Lambon Ralph, Matthew A.

2015-01-01

Semantic memory is a crucial higher cortical function that codes the meaning of objects and words, and when impaired after neurological damage, patients are left with significant disability. Investigations of semantic dementia have implicated the anterior temporal lobe (ATL) region, in general, as crucial for multimodal semantic memory. The potentially crucial role of the ventral ATL subregion has been emphasized by recent functional neuroimaging studies, but the necessity of this precise area has not been selectively tested. The implantation of subdural electrode grids over this subregion, for the presurgical assessment of patients with partial epilepsy or brain tumor, offers the dual yet rare opportunities to record cortical local field potentials while participants complete semantic tasks and to stimulate the functionally identified regions in the same participants to evaluate the necessity of these areas in semantic processing. Across 6 patients, and utilizing a variety of semantic assessments, we evaluated and confirmed that the anterior fusiform/inferior temporal gyrus is crucial in multimodal, receptive, and expressive, semantic processing. PMID:25491206

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 functional neuroanatomy of verbal memory in Alzheimer's disease: [18F]-Fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) correlates of recency and recognition memory.

PubMed

Staffaroni, Adam M; Melrose, Rebecca J; Leskin, Lorraine P; Riskin-Jones, Hannah; Harwood, Dylan; Mandelkern, Mark; Sultzer, David L

2017-09-01

The objective of this study was to distinguish the functional neuroanatomy of verbal learning and recognition in Alzheimer's disease (AD) using the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word Learning task. In 81 Veterans diagnosed with dementia due to AD, we conducted a cluster-based correlation analysis to assess the relationships between recency and recognition memory scores from the CERAD Word Learning Task and cortical metabolic activity measured using [ 18 F]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET). AD patients (Mini-Mental State Examination, MMSE mean = 20.2) performed significantly better on the recall of recency items during learning trials than of primacy and middle items. Recency memory was associated with cerebral metabolism in the left middle and inferior temporal gyri and left fusiform gyrus (p < .05 at the corrected cluster level). In contrast, recognition memory was correlated with metabolic activity in two clusters: (a) a large cluster that included the left hippocampus, parahippocampal gyrus, entorhinal cortex, anterior temporal lobe, and inferior and middle temporal gyri; (b) the bilateral orbitofrontal cortices (OFC). The present study further informs our understanding of the disparate functional neuroanatomy of recency memory and recognition memory in AD. We anticipated that the recency effect would be relatively preserved and associated with temporoparietal brain regions implicated in short-term verbal memory, while recognition memory would be associated with the medial temporal lobe and possibly the OFC. Consistent with our a priori hypotheses, list learning in our AD sample was characterized by a reduced primacy effect and a relatively spared recency effect; however, recency memory was associated with cerebral metabolism in inferior and lateral temporal regions associated with the semantic memory network, rather than regions associated with short-term verbal memory. The correlates of recognition memory included the medial temporal lobe and OFC, replicating prior studies.

Neural Correlates of Subliminal Language Processing.

PubMed

Axelrod, Vadim; Bar, Moshe; Rees, Geraint; Yovel, Galit

2015-08-01

Language is a high-level cognitive function, so exploring the neural correlates of unconscious language processing is essential for understanding the limits of unconscious processing in general. The results of several functional magnetic resonance imaging studies have suggested that unconscious lexical and semantic processing is confined to the posterior temporal lobe, without involvement of the frontal lobe-the regions that are indispensable for conscious language processing. However, previous studies employed a similarly designed masked priming paradigm with briefly presented single and contextually unrelated words. It is thus possible, that the stimulation level was insufficiently strong to be detected in the high-level frontal regions. Here, in a high-resolution fMRI and multivariate pattern analysis study we explored the neural correlates of subliminal language processing using a novel paradigm, where written meaningful sentences were suppressed from awareness for extended duration using continuous flash suppression. We found that subjectively and objectively invisible meaningful sentences and unpronounceable nonwords could be discriminated not only in the left posterior superior temporal sulcus (STS), but critically, also in the left middle frontal gyrus. We conclude that frontal lobes play a role in unconscious language processing and that activation of the frontal lobes per se might not be sufficient for achieving conscious awareness. © The Author 2014. Published by Oxford University Press.

[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.

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

Decreased expression of thyroid receptor-associated protein 220 in temporal lobe tissue of patients with refractory epilepsy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li Jinmei; Wang Xuefeng; Xi Zhiqin

2006-10-06

Purpose: TRAP220 (thyroid hormone receptor-associated protein) functions as a coactivator for nuclear receptors and stimulates transcription by recruiting the TRAP mediator complex to hormone responsive promoter regions. Thus, TRAP220 enhances the function of thyroid/steroid hormone receptors such as thyroid hormone and oestrogen receptors. This study investigated the expression of TRAP220 mRNA and protein level in epileptic brains comparing with human control. Methods: We examined the expression of TRAP220 mRNA and protein levels in temporal lobes from patients with chronic pharmacoresistant epilepsy who have undergone surgery. Results: Expression of TRAP220 mRNA and protein was shown to be decreased significantly in themore » temporal cortex of the patients with epilepsy. Conclusions: Our work showed that a decrease in TRAP220 mRNA and protein levels may be involved in the pathophysiology of epilepsy and may be associated with impairment of the brain caused by frequent seizures.« less

The Role of White Matter Hyperintensities and Medial Temporal Lobe Atrophy in Age-Related Executive Dysfunctioning

ERIC Educational Resources Information Center

Oosterman, Joukje M.; Vogels, Raymond L. C.; van Harten, Barbera; Gouw, Alida A.; Scheltens, Philip; Poggesi, Anna; Weinstein, Henry C.; Scherder, Erik J. A.

2008-01-01

Various studies support an association between white matter hyperintensities (WMH) and deficits in executive function in nondemented ageing. Studies examining executive functions and WMH have generally adopted executive function as a phrase including various functions such as flexibility, inhibition, and working memory. However, these functions…

Focal epilepsy recruiting a generalised network of juvenile myoclonic epilepsy: a case report.

PubMed

Khaing, Myo; Lim, Kheng-Seang; Tan, Chong-Tin

2014-09-01

We report a patient with juvenile myoclonic epilepsy who subsequently developed temporal lobe epilepsy, which gradually became clinically dominant. Video telemetry revealed both myoclonic seizures and temporal lobe seizures. The temporal lobe seizures were accompanied by a focal recruiting rhythm with rapid generalisation on EEG, in which the ictal EEG pattern during the secondary generalised phase was morphologically similar to the ictal pattern during myoclonic seizures. The secondary generalised seizures of the focal epilepsy responded to sodium valproate, similar to the myoclonic epilepsy. In this rare case of coexistent Juvenile Myoclonic Epilepsy and Temporal lobe epilepsy, the possibility of focal epilepsy recruiting a generalised epileptic network was proposed and discussed.

Working memory for conjunctions relies on the medial temporal lobe.

PubMed

Olson, Ingrid R; Page, Katie; Moore, Katherine Sledge; Chatterjee, Anjan; Verfaellie, Mieke

2006-04-26

A prominent theory of hippocampal function proposes that the hippocampus is importantly involved in relating or binding together separate pieces of information to form an episodic representation. This hypothesis has only been applied to studies of long-term memory because the paradigmatic view of the hippocampus is that it is not critical for short-term forms of memory. However, relational processing is important in many working memory tasks, especially tasks using visual stimuli. Here, we test the hypothesis that the medial temporal lobes are important for relational memory even over short delays. The task required patients with medial temporal lobe amnesia and controls to remember three objects, locations, or object-location conjunctions over 1 or 8 s delays. The results show that working memory for objects and locations was at normal levels, but that memory for conjunctions was severely impaired at 8 s delays. Additional analyses suggest that the hippocampus per se is critical for accurate conjunction working memory. We propose that the hippocampus is critically involved in memory for conjunctions at both short and long delays.

Working Memory for Conjunctions Relies on the Medial Temporal Lobe

PubMed Central

Olson, Ingrid R.; Page, Katie; Moore, Katherine Sledge; Chatterjee, Anjan; Verfaellie, Mieke

2006-01-01

A prominent theory of hippocampal function proposes that the hippocampus is importantly involved in relating or binding together separate pieces of information to form an episodic representation. This hypothesis has only been applied to studies of long-term memory because the paradigmatic view of the hippocampus is that it is not critical for short-term forms of memory. However, relational processing is important in many working memory tasks, especially tasks using visual stimuli. Here, we test the hypothesis that the medial temporal lobes are important for relational memory even over short delays. The task required patients with medial temporal lobe amnesia and controls to remember three objects, locations, or object-location conjunctions over 1 or 8 s delays. The results show that working memory for objects and locations was at normal levels, but that memory for conjunctions was severely impaired at 8 s delays. Additional analyses suggest that the hippocampus per se is critical for accurate conjunction working memory. We propose that the hippocampus is critically involved in memory for conjunctions at both short and long delays. PMID:16641239

Abnormal functional network connectivity among resting-state networks in children with frontal lobe epilepsy.

PubMed

Widjaja, E; Zamyadi, M; Raybaud, C; Snead, O C; Smith, M L

2013-12-01

Epilepsy is considered a disorder of neural networks. The aims of this study were to assess functional connectivity within resting-state networks and functional network connectivity across resting-state networks by use of resting-state fMRI in children with frontal lobe epilepsy and to relate changes in resting-state networks with neuropsychological function. Fifteen patients with frontal lobe epilepsy and normal MR imaging and 14 healthy control subjects were recruited. Spatial independent component analysis was used to identify the resting-state networks, including frontal, attention, default mode network, sensorimotor, visual, and auditory networks. The Z-maps of resting-state networks were compared between patients and control subjects. The relation between abnormal connectivity and neuropsychological function was assessed. Correlations from all pair-wise combinations of independent components were performed for each group and compared between groups. The frontal network was the only network that showed reduced connectivity in patients relative to control subjects. The remaining 5 networks demonstrated both reduced and increased functional connectivity within resting-state networks in patients. There was a weak association between connectivity in frontal network and executive function (P = .029) and a significant association between sensorimotor network and fine motor function (P = .004). Control subjects had 79 pair-wise independent components that showed significant temporal coherence across all resting-state networks except for default mode network-auditory network. Patients had 66 pairs of independent components that showed significant temporal coherence across all resting-state networks. Group comparison showed reduced functional network connectivity between default mode network-attention, frontal-sensorimotor, and frontal-visual networks and increased functional network connectivity between frontal-attention, default mode network-sensorimotor, and frontal-visual networks in patients relative to control subjects. We found abnormal functional connectivity within and across resting-state networks in children with frontal lobe epilepsy. Impairment in functional connectivity was associated with impaired neuropsychological function.

Behaviors induced or disrupted by complex partial seizures.

PubMed

Leung, L S; Ma, J; McLachlan, R S

2000-09-01

We reviewed the neural mechanisms underlying some postictal behaviors that are induced or disrupted by temporal lobe seizures in humans and animals. It is proposed that the psychomotor behaviors and automatisms induced by temporal lobe seizures are mediated by the nucleus accumbens. A non-convulsive hippocampal afterdischarge in rats induced an increase in locomotor activity, which was suppressed by the injection of dopamine D(2) receptor antagonist in the nucleus accumbens, and blocked by inactivation of the medial septum. In contrast, a convulsive hippocampal or amygdala seizure induced behavioral hypoactivity, perhaps by the spread of the seizure into the frontal cortex and opiate-mediated postictal depression. Mechanisms underlying postictal psychosis, memory disruption and other long-term behavioral alterations after temporal lobe seizures, are discussed. In conclusion, many of the changes of postictal behaviors observed after temporal lobe seizures in humans may be found in animals, and the basis of the behavioral change may be explained as a change in neural processing in the temporal lobe and the connecting subcortical structures.

An unusual case of complicated temporal lobe abscess following tympanomastoidectomy

PubMed Central

Yin, Tuanfang; Ren, Jihao; Lu, Yongde; Chen, Xing; Wang, Yaowen; Huang, Fengying

2013-01-01

We report a unusual case of complicated temporal lobe abscess following tympanomastoidectomy in a 26-year-old Chinese man here. The patient complained of binaural recurrent purulent discharge accompanied by hearing loss more than 10 years, then he received a right tympanomastoidectomy three months ago, but 3 weeks after surgery, he started to experience fierce headache and nausea and so on. The CT and MRI suggested the diagnosis of right temporal lobe abscess and then right temporal lobe abscess was excised. The patient was successfully treated with a right temporal lobe abscess resection and a radical right mastoidectomy. Although the cerebral abscess following radical tympanomastoidectomy are extremely rare, we should pay attention to it. we suggest the main reasons was still suffering from purulent discharge in the ear after the first tympanomastoidectomy, the granulation and cholesteatoma failed to completely remove during the first operation. and even resulted in substantial bone defect. It is well-known that good drainage is a key to reduce intra-cranial complications. PMID:23826430

Translational Advancement of Somatostatin Gene Delivery for Disease Modification and Cognitive Sparing in Intractable Epilepsy

DTIC Science & Technology

2014-09-01

delivery persistently reduces seizure severity in a rat model of temporal lobe epilepsy ," Session number: 314, Session title: Non-pharmacological...delivery persistently reduces seizure severity in a rat model of temporal lobe epilepsy Location: WCC Hall A-C Presentation time: Monday, Nov 17, 2014...therapeutic potential administered prior to last-resort neurosurgical resections in pharmacoresistant cases of temporal lobe epilepsy . Disclosures: G. Natarajan

JaK/STAT Inhibition to Prevent Post-Traumatic Epileptogenesis

DTIC Science & Technology

2013-07-01

temporal lobe epilepsy (TLE), a frequently medically intractable and permanent epilepsy syndrome. Unlike many TLE models, which cause global brain injury...addresses the FY10 PRMRP topic area of Epilepsy . Traumatic Brain Injury (TBI) is a well-established etiology of temporal lobe epilepsy (TLE), a...is one of the most common causes of temporal lobe epilepsy (TLE). Changes in inhibitory signaling after CCI include hilar inhibitory neuron loss

MRI anatomy of schizophrenia.

PubMed

McCarley, R W; Wible, C G; Frumin, M; Hirayasu, Y; Levitt, J J; Fischer, I A; Shenton, M E

1999-05-01

Structural magnetic resonance imaging (MRI) data have provided much evidence in support of our current view that schizophrenia is a brain disorder with altered brain structure, and consequently involving more than a simple disturbance in neurotransmission. This review surveys 118 peer-reviewed studies with control group from 1987 to May 1998. Most studies (81%) do not find abnormalities of whole brain/intracranial contents, while lateral ventricle enlargement is reported in 77%, and third ventricle enlargement in 67%. The temporal lobe was the brain parenchymal region with the most consistently documented abnormalities. Volume decreases were found in 62% of 37 studies of whole temporal lobe, and in 81% of 16 studies of the superior temporal gyrus (and in 100% with gray matter separately evaluated). Fully 77% of the 30 studies of the medial temporal lobe reported volume reduction in one or more of its constituent structures (hippocampus, amygdala, parahippocampal gyrus). Despite evidence for frontal lobe functional abnormalities, structural MRI investigations less consistently found abnormalities, with 55% describing volume reduction. It may be that frontal lobe volume changes are small, and near the threshold for MRI detection. The parietal and occipital lobes were much less studied; about half of the studies showed positive findings. Most studies of cortical gray matter (86%) found volume reductions were not diffuse, but more pronounced in certain areas. About two thirds of the studies of subcortical structures of thalamus, corpus callosum and basal ganglia (which tend to increase volume with typical neuroleptics), show positive findings, as do almost all (91%) studies of cavum septi pellucidi (CSP). Most data were consistent with a developmental model, but growing evidence was compatible also with progressive, neurodegenerative features, suggesting a "two-hit" model of schizophrenia, for which a cellular hypothesis is discussed. The relationship of clinical symptoms to MRI findings is reviewed, as is the growing evidence suggesting structural abnormalities differ in affective (bipolar) psychosis and schizophrenia.

Epilepsy in multiple sclerosis: The role of temporal lobe damage.

PubMed

Calabrese, M; Castellaro, M; Bertoldo, A; De Luca, A; Pizzini, F B; Ricciardi, G K; Pitteri, M; Zimatore, S; Magliozzi, R; Benedetti, M D; Manganotti, P; Montemezzi, S; Reynolds, R; Gajofatto, A; Monaco, S

2017-03-01

Although temporal lobe pathology may explain some of the symptoms of multiple sclerosis (MS), its role in the pathogenesis of seizures has not been clarified yet. To investigate the role of temporal lobe damage in MS patients suffering from epilepsy, by the application of advanced multimodal 3T magnetic resonance imaging (MRI) analysis. A total of 23 relapsing remitting MS patients who had epileptic seizures (RRMS/E) and 23 disease duration matched RRMS patients without any history of seizures were enrolled. Each patient underwent advanced 3T MRI protocol specifically conceived to evaluate grey matter (GM) damage. This includes grey matter lesions (GMLs) identification, evaluation of regional cortical thickness and indices derived from the Neurite Orientation Dispersion and Density Imaging model. Regional analysis revealed that in RRMS/E, the regions most affected by GMLs were the hippocampus (14.2%), the lateral temporal lobe (13.5%), the cingulate (10.0%) and the insula (8.4%). Cortical thinning and alteration of diffusion metrics were observed in several regions of temporal lobe, in insular cortex and in cingulate gyrus of RRMS/E compared to RRMS ( p< 0.05 for all comparisons). Compared to RRMS, RRMS/E showed more severe damage of temporal lobe, which exceeds what would be expected on the basis of the global GM damage observed.

Neurobiological markers of exercise-related brain plasticity in older adults

PubMed Central

Voss, Michelle W.; Erickson, Kirk I.; Prakash, Ruchika Shaurya; Chaddock, Laura; Kim, Jennifer S.; Alves, Heloisa; Szabo, Amanda; White, Siobhan M.; Wójcicki, Thomas R.; Mailey, Emily L.; Olson, Erin A.; Gothe, Neha; Potter, Vicki V.; Martin, Stephen A.; Pence, Brandt D.; Cook, Marc D.; Woods, Jeffrey A.; McAuley, Edward; Kramer, Arthur F.

2012-01-01

The current study examined how a randomized one-year aerobic exercise program for healthy older adults would affect serum levels of brain-derived neurotrophic factor (BDNF), insulin-like growth factor type 1 (IGF-1), and vascular endothelial growth factor (VEGF) - putative markers of exercise-induced benefits on brain function. The study also examined whether (a) change in the concentration of these growth factors was associated with alterations in functional connectivity following exercise, and (b) the extent to which pre-intervention growth factor levels were associated with training-related changes in functional connectivity. In 65 participants (mean age = 66.4), we found that although there were no group-level changes in growth factors as a function of the intervention, increased temporal lobe connectivity between the bilateral parahippocampus and the bilateral middle temporal gyrus was associated with increased BDNF, IGF-1, and VEGF for an aerobic walking group but not for a non-aerobic control group, and greater pre-intervention VEGF was associated with greater training-related increases in this functional connection. Results are consistent with animal models of exercise and the brain, but are the first to show in humans that exercise-induced increases in temporal lobe functional connectivity are associated with changes in growth factors and may be augmented by greater baseline VEGF. PMID:23123199

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

Is less always better? Keyhole and standard subtemporal approaches: evaluation of temporal lobe retraction and surgical volume with and without zygomatic osteotomy in a cadaveric model.

PubMed

Ercan, Serdar; Scerrati, Alba; Wu, Phengfei; Zhang, Jun; Ammirati, Mario

2017-07-01

OBJECTIVE The subtemporal approach is one of the surgical routes used to reach the interpeduncular fossa. Keyhole subtemporal approaches and zygomatic arch osteotomy have been proposed in an effort to decrease the amount of temporal lobe retraction. However, the effects of these modified subtemporal approaches on temporal lobe retraction have never been objectively validated. METHODS A keyhole and a classic subtemporal craniotomy were executed in 4 fresh-frozen silicone-injected cadaver heads. The target was defined as the area bordered by the superior cerebellar artery, the anterior clinoid process, supraclinoid internal carotid artery, and the posterior cerebral artery. Once the target was fully visualized, the authors evaluated the amount of temporal lobe retraction by measuring the distance between the base of the middle fossa and the temporal lobe. In addition, the volume of the surgical and anatomical corridors was assessed as well as the surgical maneuverability using navigation and 3D moldings. The same evaluation was conducted after a zygomatic osteotomy was added to the two approaches. RESULTS Temporal lobe retraction was the same in the two approaches evaluated while the surgical corridor and the maneuverability were all greater in the classic subtemporal approach. CONCLUSIONS The zygomatic arch osteotomy facilitates the maneuverability and the surgical volume in both approaches, but the temporal lobe retraction benefit is confined to the lateral part of the middle fossa skull base and does not result in the retraction necessary to expose the selected target.

[Successful treatment with anti-epileptic-drug of an 83-year-old man with musical hallucinosis].

PubMed

Futamura, Akinori; Katoh, Hirotaka; Kawamura, Mitsuru

2014-05-01

An 83-year-old man with 3 years symptomatic hearing loss suddenly experienced musical hallucinosis. He heard children's songs, folk songs, military songs, and the Japanese national anthem for seven months every day. He sometime had paroxysmal nausea, dull headaches and depressive mood. On examination he had no psychosis or neurological symptoms except sensorineural hearing loss in both ears. MRI brain imaging and electroencephalography showed no significant abnormalities, however ¹²³I-IMP brain SPECT showed decreased activity in the right temporal lobe and increased activity in the left temporal and parietal lobes. Late phase ¹²³I-iomazenil brain SPECT showed decreased accumulation in the right temporal lobe compared to the early phase. This indicates right temporal lobe epilepsy. He was diagnosed with epilepsy because of paroxysmal nausea and headache and the laterality of ¹²³I-IMP brain SPECT and ¹²³I-iomazenil brain SPECT. The musical hallucinosis was much reduced by carbamazepine 200mg per day. Nine months after beginning carbamazepine we detected decreased activity in the right temporal lobe and increased activity in left temporal and parietal lobes was improved. We do not believe he had epileptogenic musical hallucinosis because his musical hallusinosis was neither paroxysmal nor lateral. We diagnosed auditory Charles Bonnet syndrome with onset 3 years after sensorineural hearing loss due to reversible epileptic like discharge in temporal and parietal lobes. There is no established treatment for musical hallucinosis, but anti-epileptic drugs may be of some help.

From learning to forgetting: behavioral, circuitry, and molecular properties define the different functional states of the recognition memory trace.

PubMed

Romero-Granados, Rocío; Fontán-Lozano, Angela; Delgado-García, José María; Carrión, Angel M

2010-05-01

Neuropsychological analyses of amnesic patients, as well as lesion experiments, indicate that the temporal lobe is essential for the encoding, storage, and expression of object recognition memory (ORM). However, temporal lobe structures directly involved in the consolidation and reconsolidation of these memories are not yet well-defined. We report here that systemic administration of a protein synthesis inhibitor before or up to 4 h after training or reactivation sessions impairs consolidation and reconsolidation of ORM, without affecting short-term memory. We have also observed that ORM reconsolidation is sensitive to protein synthesis inhibition, independently of the ORM trace age. Using bdnf and egr-1 gene expression analysis, we defined temporal lobe areas related to consolidation and reconsolidation of ORM. Training and reactivation 21 days after ORM acquisition sessions provoked changes in bdnf mRNA in somatosensory, perirhinal, and hippocampal cortices. Reactivation 2 days after the training session elicited changes in bdnf and egr-1 mRNA in entorhinal and prefrontal cortices, while reactivation 9 days post-training provoked an increase in egr-1 transcription in somatosensory and entorhinal cortices. The differences in activated circuits and in the capacity to recall the memory trace after 9 or 21 days post-training suggest that memory trace suffers functional changes in this period of time. All these results indicate that the functional state of the recognition memory trace, from acquisition to forgetting, can be specifically defined by behavioral, circuitry, and molecular properties. 2009 Wiley-Liss, Inc.

Measuring the effects of aging and sex on regional brain stiffness with MR elastography in healthy older adults

PubMed Central

Arani, Arvin; Murphy, Matthew C; Glaser, Kevin J; Manduca, Armando; Lake, David S; Kruse, Scott; Jack, Clifford R; Ehman, Richard; Huston, John

2015-01-01

Changes in tissue composition and cellular architecture have been associated with neurological disease, and these in turn can affect biomechanical properties. Natural biological factors such as aging and an individual’s sex also affect underlying tissue biomechanics in different brain regions. Understanding the normal changes is necessary before determining the efficacy of stiffness imaging for neurological disease diagnosis and therapy monitoring. The objective of this study was to evaluate global and regional changes in brain stiffness as a function of age and sex, using improved MRE acquisition and processing that has been shown to provide median stiffness values that are typically reproducible to within 1% in global measurements and within 2% for regional measurements. Furthermore, this is the first study to report the effects of age and sex over the entire cerebrum volume and over the full frontal, occipital, parietal, temporal, deep gray matter/white matter (insula, deep gray nuclei and white matter tracts), and cerebellum volumes. In 45 volunteers, we observed a significant linear correlation between age and brain stiffness in the cerebrum (P<.0001), frontal lobes (P<.0001), occipital lobes (P=.0005), parietal lobes (P=.0002), and the temporal lobes (P<.0001) of the brain. No significant linear correlation between brain stiffness and age was observed in the cerebellum (P=.74), and the sensory-motor regions (P=.32) of the brain, and a weak linear trend was observed in the deep gray matter/white matter (P=.075). A multiple linear regression model predicted an annual decline of 0.011±0.002 kPa in cerebrum stiffness with a theoretical median age value (76 years old) of 2.56±0.08 kPa. Sexual dimorphism was observed in the temporal (P=.03) and occipital (P=.001) lobes of the brain, but no significant difference was observed in any of the other brain regions (P>.20 for all other regions). The model predicted female occipital and temporal lobes to be 0.23 kPa and 0.09 kPa stiffer than males of the same age, respectively. This study confirms that as the brain ages, there is softening; however, the changes are dependent on region. In addition, stiffness effects due to sex exist in the occipital and temporal lobes. PMID:25698157

Altered Brain Activation During Action Imitation and Observation in Schizophrenia: A Translational Approach to Investigating Social Dysfunction in Schizophrenia

PubMed Central

Thakkar, Katharine N.; Peterman, Joel S.; Park, Sohee

2015-01-01

Objective Social impairments are a key feature of schizophrenia, but their underlying mechanisms are poorly understood. Imitation, a process through which we understand the minds of others, involves the so-called mirror neuron system, a network comprising the inferior parietal lobe, inferior frontal gyrus, and posterior superior temporal sulcus. The authors examined mirror neuron system function in schizophrenia. Method Sixteen medicated schizophrenia patients and 16 healthy comparison subjects performed an action imitation/ observation task during functional MRI. Participants saw a video of a moving hand or spatial cue and were instructed to either execute finger movements associated with the stimulus or simply observe. Activation in the mirror neuron system was measured during imitative versus nonimitative actions and observation of a moving hand versus a moving spatial cue. These contrasts were compared across groups. Results Activation in the mirror neuron system was less specific for imitation in schizophrenia. Relative to healthy subjects, patients had reduced activity in the posterior superior temporal sulcus during imitation and greater activity in the posterior superior temporal sulcus and inferior parietal lobe during nonimitative action. Patients also showed reduced activity in these regions during action observation. Mirror neuron system activation was related to symptom severity and social functioning in patients and to schizotypal syndrome in comparison subjects. Conclusions Given the role of the inferior parietal lobe and posterior superior temporal sulcus in imitation and social cognition, impaired imitative ability in schizophrenia may stem from faulty perception of biological motion and transformations from perception to action. These findings extend our understanding of social dysfunction in schizophrenia. PMID:24626638

Neural circuitry of emotional face processing in autism spectrum disorders.

PubMed

Monk, Christopher S; Weng, Shih-Jen; Wiggins, Jillian Lee; Kurapati, Nikhil; Louro, Hugo M C; Carrasco, Melisa; Maslowsky, Julie; Risi, Susan; Lord, Catherine

2010-03-01

Autism spectrum disorders (ASD) are associated with severe impairments in social functioning. Because faces provide nonverbal cues that support social interactions, many studies of ASD have examined neural structures that process faces, including the amygdala, ventromedial prefrontal cortex and superior and middle temporal gyri. However, increases or decreases in activation are often contingent on the cognitive task. Specifically, the cognitive domain of attention influences group differences in brain activation. We investigated brain function abnormalities in participants with ASD using a task that monitored attention bias to emotional faces. Twenty-four participants (12 with ASD, 12 controls) completed a functional magnetic resonance imaging study while performing an attention cuing task with emotional (happy, sad, angry) and neutral faces. In response to emotional faces, those in the ASD group showed greater right amygdala activation than those in the control group. A preliminary psychophysiological connectivity analysis showed that ASD participants had stronger positive right amygdala and ventromedial prefrontal cortex coupling and weaker positive right amygdala and temporal lobe coupling than controls. There were no group differences in the behavioural measure of attention bias to the emotional faces. The small sample size may have affected our ability to detect additional group differences. When attention bias to emotional faces was equivalent between ASD and control groups, ASD was associated with greater amygdala activation. Preliminary analyses showed that ASD participants had stronger connectivity between the amygdala ventromedial prefrontal cortex (a network implicated in emotional modulation) and weaker connectivity between the amygdala and temporal lobe (a pathway involved in the identification of facial expressions, although areas of group differences were generally in a more anterior region of the temporal lobe than what is typically reported for emotional face processing). These alterations in connectivity are consistent with emotion and face processing disturbances in ASD.

Individual variation in the propensity for prospective thought is associated with functional integration between visual and retrosplenial cortex.

PubMed

Villena-Gonzalez, Mario; Wang, Hao-Ting; Sormaz, Mladen; Mollo, Giovanna; Margulies, Daniel S; Jefferies, Elizabeth A; Smallwood, Jonathan

2018-02-01

It is well recognized that the default mode network (DMN) is involved in states of imagination, although the cognitive processes that this association reflects are not well understood. The DMN includes many regions that function as cortical "hubs", including the posterior cingulate/retrosplenial cortex, anterior temporal lobe and the hippocampus. This suggests that the role of the DMN in cognition may reflect a process of cortical integration. In the current study we tested whether functional connectivity from uni-modal regions of cortex into the DMN is linked to features of imaginative thought. We found that strong intrinsic communication between visual and retrosplenial cortex was correlated with the degree of social thoughts about the future. Using an independent dataset, we show that the same region of retrosplenial cortex is functionally coupled to regions of primary visual cortex as well as core regions that make up the DMN. Finally, we compared the functional connectivity of the retrosplenial cortex, with a region of medial prefrontal cortex implicated in the integration of information from regions of the temporal lobe associated with future thought in a prior study. This analysis shows that the retrosplenial cortex is preferentially coupled to medial occipital, temporal lobe regions and the angular gyrus, areas linked to episodic memory, scene construction and navigation. In contrast, the medial prefrontal cortex shows preferential connectivity with motor cortex and lateral temporal and prefrontal regions implicated in language, motor processes and working memory. Together these findings suggest that integrating neural information from visual cortex into retrosplenial cortex may be important for imagining the future and may do so by creating a mental scene in which prospective simulations play out. We speculate that the role of the DMN in imagination may emerge from its capacity to bind together distributed representations from across the cortex in a coherent manner. Copyright © 2017 Elsevier Ltd. All rights reserved.

Auditory connections and functions of prefrontal cortex

PubMed Central

Plakke, Bethany; Romanski, Lizabeth M.

2014-01-01

The functional auditory system extends from the ears to the frontal lobes with successively more complex functions occurring as one ascends the hierarchy of the nervous system. Several areas of the frontal lobe receive afferents from both early and late auditory processing regions within the temporal lobe. Afferents from the early part of the cortical auditory system, the auditory belt cortex, which are presumed to carry information regarding auditory features of sounds, project to only a few prefrontal regions and are most dense in the ventrolateral prefrontal cortex (VLPFC). In contrast, projections from the parabelt and the rostral superior temporal gyrus (STG) most likely convey more complex information and target a larger, widespread region of the prefrontal cortex. Neuronal responses reflect these anatomical projections as some prefrontal neurons exhibit responses to features in acoustic stimuli, while other neurons display task-related responses. For example, recording studies in non-human primates indicate that VLPFC is responsive to complex sounds including vocalizations and that VLPFC neurons in area 12/47 respond to sounds with similar acoustic morphology. In contrast, neuronal responses during auditory working memory involve a wider region of the prefrontal cortex. In humans, the frontal lobe is involved in auditory detection, discrimination, and working memory. Past research suggests that dorsal and ventral subregions of the prefrontal cortex process different types of information with dorsal cortex processing spatial/visual information and ventral cortex processing non-spatial/auditory information. While this is apparent in the non-human primate and in some neuroimaging studies, most research in humans indicates that specific task conditions, stimuli or previous experience may bias the recruitment of specific prefrontal regions, suggesting a more flexible role for the frontal lobe during auditory cognition. PMID:25100931

Neural connectivity of the anterior body of the fornix in the human brain: diffusion tensor imaging study.

PubMed

Jang, Sung Ho; Kwon, Hyeok Gyu

2014-01-24

A few studies have reported on the neural connectivity of the fornix in the human brain, however, little is known about the neural connectivity of the anterior body of the fornix. In this study, we used diffusion tensor imaging in investigation of the neural connectivity of the anterior body of the fornix in normal subjects. Forty healthy subjects were recruited for this study. A seed region of interest was placed on the anterior body of the fornix using the FMRIB Software Library. Connectivity was defined as the incidence of connection between the anterior body of the fornix and any neural structure of the brain at the threshold of 5, 25, and 50 streamlines. In all subjects, the anterior body of the fornix showed 100% connectivity to the anterior commissure and hypothalamus at thresholds of 5, 25, and 50. On the other hand, regarding the thresholds of 5, 25, and 50, the anterior body of the fornix showed connectivity to the septal forebrain region (53.8, 23.8, and 15.0%), frontal lobe via anterior commissure (41.3,12.5, and 10.0%), medial temporal lobe (85.0,66.3, and 62.5%), lateral temporal lobe (75.0, 56.3, and 35.0%), occipital lobe (21.3, 5.0, and 1.3%), frontal lobe via septum pellucidum (28.8, 13.8, and 8.8%), tegmentum of midbrain (7.5, 5.0, and 0%), tectum of midbrain (2.5,0, and 0%), and tegmentum of pons (5.0,0, and 0%). The anterior body of the fornix showed high connectivity with the anterior commissure and hypothalamus, and brain areas relevant to cholinergic nuclei (the septal forebrain region and brainstem) and memory function (the medial temporal lobe). Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Semantic retrieval during overt picture description: Left anterior temporal or the parietal lobe?

PubMed

Geranmayeh, Fatemeh; Leech, Robert; Wise, Richard J S

2015-09-01

Retrieval of semantic representations is a central process during overt speech production. There is an increasing consensus that an amodal semantic 'hub' must exist that draws together modality-specific representations of concepts. Based on the distribution of atrophy and the behavioral deficit of patients with the semantic variant of fronto-temporal lobar degeneration, it has been proposed that this hub is localized within both anterior temporal lobes (ATL), and is functionally connected with verbal 'output' systems via the left ATL. An alternative view, dating from Geschwind's proposal in 1965, is that the angular gyrus (AG) is central to object-based semantic representations. In this fMRI study we examined the connectivity of the left ATL and parietal lobe (PL) with whole brain networks known to be activated during overt picture description. We decomposed each of these two brain volumes into 15 regions of interest (ROIs), using independent component analysis. A dual regression analysis was used to establish the connectivity of each ROI with whole brain-networks. An ROI within the left anterior superior temporal sulcus (antSTS) was functionally connected to other parts of the left ATL, including anterior ventromedial left temporal cortex (partially attenuated by signal loss due to susceptibility artifact), a large left dorsolateral prefrontal region (including 'classic' Broca's area), extensive bilateral sensory-motor cortices, and the length of both superior temporal gyri. The time-course of this functionally connected network was associated with picture description but not with non-semantic baseline tasks. This system has the distribution expected for the production of overt speech with appropriate semantic content, and the auditory monitoring of the overt speech output. In contrast, the only left PL ROI that showed connectivity with brain systems most strongly activated by the picture-description task, was in the superior parietal lobe (supPL). This region showed connectivity with predominantly posterior cortical regions required for the visual processing of the pictorial stimuli, with additional connectivity to the dorsal left AG and a small component of the left inferior frontal gyrus. None of the other PL ROIs that included part of the left AG were activated by Speech alone. The best interpretation of these results is that the left antSTS connects the proposed semantic hub (specifically localized to ventral anterior temporal cortex based on clinical neuropsychological studies) to posterior frontal regions and sensory-motor cortices responsible for the overt production of speech. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

The Cognitive Neuroscience of Human Memory Since H.M

PubMed Central

Squire, Larry R.; Wixted, John T.

2011-01-01

Work with patient H.M., beginning in the 1950s, established key principles about the organization of memory that inspired decades of experimental work. Since H.M., the study of human memory and its disorders has continued to yield new insights and to improve understanding of the structure and organization of memory. Here we review this work with emphasis on the neuroanatomy of medial temporal lobe and diencephalic structures important for memory, multiple memory systems, visual perception, immediate memory, memory consolidation, the locus of long-term memory storage, the concepts of recollection and familiarity, and the question of how different medial temporal lobe structures may contribute differently to memory functions. PMID:21456960

Effects of decompressive surgery on prognosis and cognitive deficits in herpes simplex encephalitis.

PubMed

Midi, Ipek; Tuncer, Nese; Midi, Ahmet; Mollahasanoglu, Aynur; Konya, Deniz; Sav, Aydin

2007-01-01

Herpes simplex encephalitis (HSE) is a serious viral infection with a high rate of mortality. The most commonly seen complications are behavioral changes, seizures and memory deficits. We report the case of a 37-year-old man with HSE in the right temporal lobe and a severe midline shift who was treated with acyclovir. The patient underwent anterior temporal lobe resection. Although HSE can cause permanent cognitive deficits, in this case, early surgical intervention minimized any deficit, as determined by detailed neuropsychological examination. Surgical decompression is indicated as early as possible in severe cases. This case report emphasizes the effect of surgical decompression for HSE on cognitive function, which has rarely been mentioned before.

Painful Heat Reveals Hyperexcitability of the Temporal Pole in Interictal and Ictal Migraine States

PubMed Central

Moulton, E. A.; Becerra, L.; Maleki, N.; Pendse, G.; Tully, S.; Hargreaves, R.; Burstein, R.

2011-01-01

During migraine attacks, alterations in sensation accompanying headache may manifest as allodynia and enhanced sensitivity to light, sound, and odors. Our objective was to identify physiological changes in cortical regions in migraine patients using painful heat and functional magnetic resonance imaging (fMRI) and the structural basis for such changes using diffusion tensor imaging (DTI). In 11 interictal patients, painful heat threshold + 1°C was applied unilaterally to the forehead during fMRI scanning. Significantly greater activation was identified in the medial temporal lobe in patients relative to healthy subjects, specifically in the anterior temporal pole (TP). In patients, TP showed significantly increased functional connectivity in several brain regions relative to controls, suggesting that TP hyperexcitability may contribute to functional abnormalities in migraine. In 9 healthy subjects, DTI identified white matter connectivity between TP and pulvinar nucleus, which has been related to migraine. In 8 patients, fMRI activation in TP with painful heat was exacerbated during migraine, suggesting that repeated migraines may sensitize TP. This article investigates a nonclassical role of TP in migraineurs. Observed temporal lobe abnormalities may provide a basis for many of the perceptual changes in migraineurs and may serve as a potential interictal biomarker for drug efficacy. PMID:20562317

Passive language mapping combining real-time oscillation analysis with cortico-cortical evoked potentials for awake craniotomy.

PubMed

Tamura, Yukie; Ogawa, Hiroshi; Kapeller, Christoph; Prueckl, Robert; Takeuchi, Fumiya; Anei, Ryogo; Ritaccio, Anthony; Guger, Christoph; Kamada, Kyousuke

2016-12-01

OBJECTIVE Electrocortical stimulation (ECS) is the gold standard for functional brain mapping; however, precise functional mapping is still difficult in patients with language deficits. High gamma activity (HGA) between 80 and 140 Hz on electrocorticography is assumed to reflect localized cortical processing, whereas the cortico-cortical evoked potential (CCEP) can reflect bidirectional responses evoked by monophasic pulse stimuli to the language cortices when there is no patient cooperation. The authors propose the use of "passive" mapping by combining HGA mapping and CCEP recording without active tasks during conscious resections of brain tumors. METHODS Five patients, each with an intraaxial tumor in their dominant hemisphere, underwent conscious resection of their lesion with passive mapping. The authors performed functional localization for the receptive language area, using real-time HGA mapping, by listening passively to linguistic sounds. Furthermore, single electrical pulses were delivered to the identified receptive temporal language area to detect CCEPs in the frontal lobe. All mapping results were validated by ECS, and the sensitivity and specificity were evaluated. RESULTS Linguistic HGA mapping quickly identified the language area in the temporal lobe. Electrical stimulation by linguistic HGA mapping to the identified temporal receptive language area evoked CCEPs on the frontal lobe. The combination of linguistic HGA and frontal CCEPs needed no patient cooperation or effort. In this small case series, the sensitivity and specificity were 93.8% and 89%, respectively. CONCLUSIONS The described technique allows for simple and quick functional brain mapping with higher sensitivity and specificity than ECS mapping. The authors believe that this could improve the reliability of functional brain mapping and facilitate rational and objective operations. Passive mapping also sheds light on the underlying physiological mechanisms of language in the human brain.

Hippocampal Networks Habituate as Novelty Accumulates

ERIC Educational Resources Information Center

Murty, Vishnu P.; Ballard, Ian C.; Macduffie, Katherine E.; Krebs, Ruth M.; Adcock, R. Alison

2013-01-01

Novelty detection, a critical computation within the medial temporal lobe (MTL) memory system, necessarily depends on prior experience. The current study used functional magnetic resonance imaging (fMRI) in humans to investigate dynamic changes in MTL activation and functional connectivity as experience with novelty accumulates. fMRI data were…

Improved Diagnostic Accuracy of Alzheimer's Disease by Combining Regional Cortical Thickness and Default Mode Network Functional Connectivity: Validated in the Alzheimer's Disease Neuroimaging Initiative Set

PubMed Central

Park, Ji Eun; Park, Bumwoo; Kim, Ho Sung; Choi, Choong Gon; Jung, Seung Chai; Oh, Joo Young; Lee, Jae-Hong; Roh, Jee Hoon; Shim, Woo Hyun

2017-01-01

Objective To identify potential imaging biomarkers of Alzheimer's disease by combining brain cortical thickness (CThk) and functional connectivity and to validate this model's diagnostic accuracy in a validation set. Materials and Methods Data from 98 subjects was retrospectively reviewed, including a study set (n = 63) and a validation set from the Alzheimer's Disease Neuroimaging Initiative (n = 35). From each subject, data for CThk and functional connectivity of the default mode network was extracted from structural T1-weighted and resting-state functional magnetic resonance imaging. Cortical regions with significant differences between patients and healthy controls in the correlation of CThk and functional connectivity were identified in the study set. The diagnostic accuracy of functional connectivity measures combined with CThk in the identified regions was evaluated against that in the medial temporal lobes using the validation set and application of a support vector machine. Results Group-wise differences in the correlation of CThk and default mode network functional connectivity were identified in the superior temporal (p < 0.001) and supramarginal gyrus (p = 0.007) of the left cerebral hemisphere. Default mode network functional connectivity combined with the CThk of those two regions were more accurate than that combined with the CThk of both medial temporal lobes (91.7% vs. 75%). Conclusion Combining functional information with CThk of the superior temporal and supramarginal gyri in the left cerebral hemisphere improves diagnostic accuracy, making it a potential imaging biomarker for Alzheimer's disease. PMID:29089831

Successful Decoding of Famous Faces in the Fusiform Face Area

PubMed Central

Axelrod, Vadim; Yovel, Galit

2015-01-01

What are the neural mechanisms of face recognition? It is believed that the network of face-selective areas, which spans the occipital, temporal, and frontal cortices, is important in face recognition. A number of previous studies indeed reported that face identity could be discriminated based on patterns of multivoxel activity in the fusiform face area and the anterior temporal lobe. However, given the difficulty in localizing the face-selective area in the anterior temporal lobe, its role in face recognition is still unknown. Furthermore, previous studies limited their analysis to occipito-temporal regions without testing identity decoding in more anterior face-selective regions, such as the amygdala and prefrontal cortex. In the current high-resolution functional Magnetic Resonance Imaging study, we systematically examined the decoding of the identity of famous faces in the temporo-frontal network of face-selective and adjacent non-face-selective regions. A special focus has been put on the face-area in the anterior temporal lobe, which was reliably localized using an optimized scanning protocol. We found that face-identity could be discriminated above chance level only in the fusiform face area. Our results corroborate the role of the fusiform face area in face recognition. Future studies are needed to further explore the role of the more recently discovered anterior face-selective areas in face recognition. PMID:25714434

Temporal Lobe Epilepsy Surgery Failures: A Review

PubMed Central

Harroud, Adil; Bouthillier, Alain; Weil, Alexander G.; Nguyen, Dang Khoa

2012-01-01

Patients with temporal lobe epilepsy (TLE) are refractory to antiepileptic drugs in about 30% of cases. Surgical treatment has been shown to be beneficial for the selected patients but fails to provide a seizure-free outcome in 20–30% of TLE patients. Several reasons have been identified to explain these surgical failures. This paper will address the five most common causes of TLE surgery failure (a) insufficient resection of epileptogenic mesial temporal structures, (b) relapse on the contralateral mesial temporal lobe, (c) lateral temporal neocortical epilepsy, (d) coexistence of mesial temporal sclerosis and a neocortical lesion (dual pathology); and (e) extratemporal lobe epilepsy mimicking TLE or temporal plus epilepsy. Persistence of epileptogenic mesial structures in the posterior temporal region and failure to distinguish mesial and lateral temporal epilepsy are possible causes of seizure persistence after TLE surgery. In cases of dual pathology, failure to identify a subtle mesial temporal sclerosis or regions of cortical microdysgenesis is a likely explanation for some surgical failures. Extratemporal epilepsy syndromes masquerading as or coexistent with TLE result in incomplete resection of the epileptogenic zone and seizure relapse after surgery. In particular, the insula may be an important cause of surgical failure in patients with TLE. PMID:22934162

Factors affecting reorganisation of memory encoding networks in temporal lobe epilepsy

PubMed Central

Sidhu, M.K.; Stretton, J.; Winston, G.P.; Symms, M.; Thompson, P.J.; Koepp, M.J.; Duncan, J.S.

2015-01-01

Summary Aims In temporal lobe epilepsy (TLE) due to hippocampal sclerosis reorganisation in the memory encoding network has been consistently described. Distinct areas of reorganisation have been shown to be efficient when associated with successful subsequent memory formation or inefficient when not associated with successful subsequent memory. We investigated the effect of clinical parameters that modulate memory functions: age at onset of epilepsy, epilepsy duration and seizure frequency in a large cohort of patients. Methods We studied 53 patients with unilateral TLE and hippocampal sclerosis (29 left). All participants performed a functional magnetic resonance imaging memory encoding paradigm of faces and words. A continuous regression analysis was used to investigate the effects of age at onset of epilepsy, epilepsy duration and seizure frequency on the activation patterns in the memory encoding network. Results Earlier age at onset of epilepsy was associated with left posterior hippocampus activations that were involved in successful subsequent memory formation in left hippocampal sclerosis patients. No association of age at onset of epilepsy was seen with face encoding in right hippocampal sclerosis patients. In both left hippocampal sclerosis patients during word encoding and right hippocampal sclerosis patients during face encoding, shorter duration of epilepsy and lower seizure frequency were associated with medial temporal lobe activations that were involved in successful memory formation. Longer epilepsy duration and higher seizure frequency were associated with contralateral extra-temporal activations that were not associated with successful memory formation. Conclusion Age at onset of epilepsy influenced verbal memory encoding in patients with TLE due to hippocampal sclerosis in the speech-dominant hemisphere. Shorter duration of epilepsy and lower seizure frequency were associated with less disruption of the efficient memory encoding network whilst longer duration and higher seizure frequency were associated with greater, inefficient, extra-temporal reorganisation. PMID:25616449

Radiosurgery in the Management of Intractable Mesial Temporal Lobe Epilepsy.

PubMed

Peñagarícano, José; Serletis, Demitre

2015-09-01

Mesial temporal lobe epilepsy (MTLE) describes recurrent seizure activity originating from the depths of the temporal lobe. MTLE patients who fail two trials of medication now require testing for surgical candidacy at an epilepsy center. For these individuals, temporal lobectomy offers the greatest likelihood for seizure-freedom (up to 80-90%); unfortunately, this procedure remains largely underutilized. Moreover, for select patients unable to tolerate open surgery, novel techniques are emerging for selective ablation of the mesial temporal structures, including stereotactic radiosurgery (SRS). We present here a review of SRS as a potential therapy for MTLE, when open surgery is not an option.

Radiosurgery for Medial Temporal Lobe Epilepsy Resulting from Mesial Temporal Sclerosis.

PubMed

Gianaris, Thomas; Witt, Thomas; Barbaro, Nicholas M

2016-01-01

Medial temporal lobe epilepsy associated with mesial temporal sclerosis (MTS) is perhaps the most well-defined epilepsy syndrome that is responsive to structural interventions such as surgery. Several minimally invasive techniques have arisen that provide additional options for the treatment of MTS while potentially avoiding many of open surgery's associated risks. By evading these risks, they also open up treatment options to patients who otherwise are poor surgical candidates. Radiosurgery is one of the most intensively studied of these alternatives and has found a growing role in the treatment of medial temporal lobe epilepsy. Copyright © 2016 Elsevier Inc. All rights reserved.

Lesion evidence for a critical role of left posterior but not frontal areas in alpha-beta power decreases during context-driven word production.

PubMed

Piai, Vitória; Rommers, Joost; Knight, Robert T

2017-09-09

Different frequency bands in the electroencephalogram are postulated to support distinct language functions. Studies have suggested that alpha-beta power decreases may index word-retrieval processes. In context-driven word retrieval, participants hear lead-in sentences that either constrain the final word ('He locked the door with the') or not ('She walked in here with the'). The last word is shown as a picture to be named. Previous studies have consistently found alpha-beta power decreases prior to picture onset for constrained relative to unconstrained sentences, localised to the left lateral-temporal and lateral-frontal lobes. However, the relative contribution of temporal versus frontal areas to alpha-beta power decreases is unknown. We recorded the electroencephalogram from patients with stroke lesions encompassing the left lateral-temporal and inferior-parietal regions or left-lateral frontal lobe and from matched controls. Individual participant analyses revealed a behavioural sentence context facilitation effect in all participants, except for in the two patients with extensive lesions to temporal and inferior parietal lobes. We replicated the alpha-beta power decreases prior to picture onset in all participants, except for in the two same patients with extensive posterior lesions. Thus, whereas posterior lesions eliminated the behavioural and oscillatory context effect, frontal lesions did not. Hierarchical clustering analyses of all patients' lesion profiles, and behavioural and electrophysiological effects identified those two patients as having a unique combination of lesion distribution and context effects. These results indicate a critical role for the left lateral-temporal and inferior parietal lobes, but not frontal cortex, in generating the alpha-beta power decreases underlying context-driven word production. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Comprehension of concrete and abstract words in semantic dementia

PubMed Central

Jefferies, Elizabeth; Patterson, Karalyn; Jones, Roy W.; Lambon Ralph, Matthew A.

2009-01-01

The vast majority of brain-injured patients with semantic impairment have better comprehension of concrete than abstract words. In contrast, several patients with semantic dementia (SD), who show circumscribed atrophy of the anterior temporal lobes bilaterally, have been reported to show reverse imageability effects, i.e., relative preservation of abstract knowledge. Although these reports largely concern individual patients, some researchers have recently proposed that superior comprehension of abstract concepts is a characteristic feature of SD. This would imply that the anterior temporal lobes are particularly crucial for processing sensory aspects of semantic knowledge, which are associated with concrete not abstract concepts. However, functional neuroimaging studies of healthy participants do not unequivocally predict reverse imageability effects in SD because the temporal poles sometimes show greater activation for more abstract concepts. We examined a case-series of eleven SD patients on a synonym judgement test that orthogonally varied the frequency and imageability of the items. All patients had higher success rates for more imageable as well as more frequent words, suggesting that (a) the anterior temporal lobes underpin semantic knowledge for both concrete and abstract concepts, (b) more imageable items – perhaps due to their richer multimodal representations – are typically more robust in the face of global semantic degradation and (c) reverse imageability effects are not a characteristic feature of SD. PMID:19586212

Temporal lobe origin is common in patients who have undergone epilepsy surgery for hypermotor seizures.

PubMed

Arain, Amir M; Azar, Nabil J; Lagrange, Andre H; McLean, Michael; Singh, Pradumna; Sonmezturk, Hasan; Konrad, Peter; Neimat, Joseph; Abou-Khalil, Bassel

2016-11-01

Hypermotor seizures are most often reported from the frontal lobe but may also have temporal, parietal, or insular origin. We noted a higher proportion of patients with temporal lobe epilepsy in our surgical cohort who had hypermotor seizures. We evaluated the anatomic localization and surgical outcome in patient with refractory hypermotor seizures who had epilepsy surgery in our center. We identified twenty three patients with refractory hypermotor seizures from our epilepsy surgery database. We analyzed demographics, presurgical evaluation including semiology, MRI, PET scan, interictal/ictal scalp video-EEG, intracranial recording, and surgical outcomes. We evaluated preoperative variables as predictors of outcome. Most patients (65%) had normal brain MRI. Intracranial EEG was required in 20 patients (86.9%). Based on the presurgical evaluation, the resection was anterior temporal in fourteen patients, orbitofrontal in four patients, cingulate in four patients, and temporoparietal in one patient. The median duration of follow-up after surgery was 76.4months. Fourteen patients (60%) had been seizure free at the last follow up while 3 patients had rare disabling seizures. Hypermotor seizures often originated from the temporal lobe in this series of patients who had epilepsy surgery. This large proportion of temporal lobe epilepsy may be the result of a selection bias, due to easier localization and expected better outcome in temporal lobe epilepsy. With extensive presurgical evaluation, including intracranial EEG when needed, seizure freedom can be expected in the majority of patients. Copyright © 2016. Published by Elsevier Inc.

Superficial Temporal Artery-Superior Cerebellar Artery Bypass with Anterior Petrosectomy.

PubMed

Hokari, Masaaki; Asaoka, Katsuyuki; Shimbo, Daisuke; Uchida, Kazuki; Itamoto, Koji

2018-06-01

Superficial temporal artery (STA) to superior cerebellar artery (SCA) bypass is associated with a relatively high risk of surgical complications, such as hematoma and/or edema caused by temporal lobe retraction. Therefore, the right side is typically used to avoid retraction of the left temporal lobe. In this report, we present a case of left STA-SCA bypass with anterior petrosectomy to avoid retraction of dominant-side temporal lobe and describe the surgical technique in detail. A 69-year-old man presented with gradual worsening of dysarthria and gait disturbance. Magnetic resonance imaging showed no signs of acute infarction, but digital subtraction angiography showed severe stenosis of basilar artery and faint flow in the distal basilar artery. On 3-dimensional computed tomography angiography, posterior communicating arteries were not visualized; we could identify the left SCA, but not the right SCA. Despite dual antiplatelet therapy, a small fresh brainstem infarct was detected 10 days after admission. To avert fatal brainstem infarction and further enlargement of the infarct, we performed left STA-SCA bypass with anterior petrosectomy to avoid retraction of the dominant-side temporal lobe. Postoperative imaging revealed no new lesions, such as infarction or temporal lobe contusional hematoma, and confirmed the patency of the bypass. Postoperative single-photon emission computed tomography demonstrated improved cerebral blood flow in the posterior circulation. The patient was transferred to another hospital for rehabilitation. This method helps minimize the risk of injury to the temporal lobe, especially that of the dominant side. Copyright © 2018. Published by Elsevier Inc.

Reduced sensitivity of the N400 and late positive component to semantic congruity and word repetition in left temporal lobe epilepsy.

PubMed

Olichney, John M; Riggins, Brock R; Hillert, Dieter G; Nowacki, Ralph; Tecoma, Evelyn; Kutas, Marta; Iragui, Vicente J

2002-07-01

We studied 14 patients with well-characterized refractory temporal lobe epilepsy (TLE), 7 with right temporal lobe epilepsy (RTE) and 7 with left temporal lobe epilepsy (LTE), on a word repetition ERP experiment. Much prior literature supports the view that patients with left TLE are more likely to develop verbal memory deficits, often attributable to left hippocampal sclerosis. Our main objectives were to test if abnormalities of the N400 or Late Positive Component (LPC, P600) were associated with a left temporal seizure focus, or left temporal lobe dysfunction. A minimum of 19 channels of EEG/EOG data were collected while subjects performed a semantic categorization task. Auditory category statements were followed by a visual target word, which were 50% "congruous" (category exemplars) and 50% "incongruous" (non-category exemplars) with the preceding semantic context. These auditory-visual pairings were repeated pseudo-randomly at time intervals ranging from approximately 10-140 seconds later. The ERP data were submitted to repeated-measures ANOVAs, which showed the RTE group had generally normal effects of word repetition on the LPC and the N400. Also, the N400 component was larger to incongruous than congruous new words, as is normally the case. In contrast, the LTE group did not have statistically significant effects of either word repetition or congruity on their ERPs (N400 or LPC), suggesting that this ERP semantic categorization paradigm is sensitive to left temporal lobe dysfunction. Further studies are ongoing to determine if these ERP abnormalities predict hippocampal sclerosis on histopathology, or outcome after anterior temporal lobectomy.

Medial Temporal Lobe Contributions to Cued Retrieval of Items and Contexts

PubMed Central

Hannula, Deborah E.; Libby, Laura A.; Yonelinas, Andrew P.; Ranganath, Charan

2013-01-01

Several models have proposed that different regions of the medial temporal lobes contribute to different aspects of episodic memory. For instance, according to one view, the perirhinal cortex represents specific items, parahippocampal cortex represents information regarding the context in which these items were encountered, and the hippocampus represents item-context bindings. Here, we used event-related functional magnetic resonance imaging (fMRI) to test a specific prediction of this model – namely, that successful retrieval of items from context cues will elicit perirhinal recruitment and that successful retrieval of contexts from item cues will elicit parahippocampal cortex recruitment. Retrieval of the bound representation in either case was expected to elicit hippocampal engagement. To test these predictions, we had participants study several item-context pairs (i.e., pictures of objects and scenes, respectively), and then had them attempt to recall items from associated context cues and contexts from associated item cues during a scanned retrieval session. Results based on both univariate and multivariate analyses confirmed a role for hippocampus in content-general relational memory retrieval, and a role for parahippocampal cortex in successful retrieval of contexts from item cues. However, we also found that activity differences in perirhinal cortex were correlated with successful cued recall for both items and contexts. These findings provide partial support for the above predictions and are discussed with respect to several models of medial temporal lobe function. PMID:23466350

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.

Seizure semiology identifies patients with bilateral temporal lobe epilepsy.

PubMed

Loesch, Anna Mira; Feddersen, Berend; Tezer, F Irsel; Hartl, Elisabeth; Rémi, Jan; Vollmar, Christian; Noachtar, Soheyl

2015-01-01

Laterality in temporal lobe epilepsy is usually defined by EEG and imaging results. We investigated whether the analysis of seizure semiology including lateralizing seizure phenomena identifies bilateral independent temporal lobe seizure onset. We investigated the seizure semiology in 17 patients in whom invasive EEG-video-monitoring documented bilateral temporal seizure onset. The results were compared to 20 left and 20 right consecutive temporal lobe epilepsy (TLE) patients who were seizure free after anterior temporal lobe resection. The seizure semiology was analyzed using the semiological seizure classification with particular emphasis on the sequence of seizure phenomena over time and lateralizing seizure phenomena. Statistical analysis included chi-square test or Fisher's exact test. Bitemporal lobe epilepsy patients had more frequently different seizure semiology (100% vs. 40%; p<0.001) and significantly more often lateralizing seizure phenomena pointing to bilateral seizure onset compared to patients with unilateral TLE (67% vs. 11%; p<0.001). The sensitivity of identical vs. different seizure semiology for the identification of bilateral TLE was high (100%) with a specificity of 60%. Lateralizing seizure phenomena had a low sensitivity (59%) but a high specificity (89%). The combination of lateralizing seizure phenomena and different seizure semiology showed a high specificity (94%) but a low sensitivity (59%). The analysis of seizure semiology including lateralizing seizure phenomena adds important clinical information to identify patients with bilateral TLE. Copyright © 2014 Elsevier B.V. All rights reserved.

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.

Autobiographical memory and patterns of brain atrophy in frontotemporal lobar degeneration.

PubMed

McKinnon, Margaret C; Nica, Elena I; Sengdy, Pheth; Kovacevic, Natasa; Moscovitch, Morris; Freedman, Morris; Miller, Bruce L; Black, Sandra E; Levine, Brian

2008-10-01

Autobiographical memory paradigms have been increasingly used to study the behavioral and neuroanatomical correlates of human remote memory. Although there are numerous functional neuroimaging studies on this topic, relatively few studies of patient samples exist, with heterogeneity of results owing to methodological variability. In this study, fronto-temporal lobar degeneration (FTLD), a form of dementia affecting regions crucial to autobiographical memory, was used as a model of autobiographical memory loss. We emphasized the separation of episodic (recollection of specific event, perceptual, and mental state information) from semantic (factual information unspecific in time and place) autobiographical memory, derived from a reliable method for scoring transcribed autobiographical protocols, the Autobiographical Interview [Levine, B., Svoboda, E., Hay, J., Winocur, G., & Moscovitch, M. Aging and autobiographical memory: Dissociating episodic from semantic retrieval. Psychology and Aging, 17, 677-689, 2002]. Patients with the fronto-temporal dementia (FTD) and mixed fronto-temporal and semantic dementia (FTD/SD) variants of FTLD were impaired at reconstructing episodically rich autobiographical memories across the lifespan, with FTD/SD patients generating an excess of generic semantic autobiographical information. Patients with progressive nonfluent aphasia were mildly impaired for episodic autobiographical memory, but this impairment was eliminated with the provision of structured cueing, likely reflecting relatively intact medial-temporal lobe function, whereas the same cueing failed to bolster the FTD and FTD/SD patients' performance relative to that of matched comparison subjects. The pattern of episodic, but not semantic, autobiographical impairment was enhanced with disease progression on 1- to 2-year follow-up testing in a subset of patients, supplementing the cross-sectional evidence for specificity of episodic autobiographical impairment with longitudinal data. This behavioral pattern covaried with volume loss in a distributed left-lateralized posterior network centered on the temporal lobe, consistent with evidence from other patient and functional neuroimaging studies of autobiographical memory. Frontal lobe volumes, however, did not significantly contribute to this network, suggesting that frontal contributions to autobiographical episodic memory may be more complex than previously appreciated.

The right hemisphere supports but does not replace left hemisphere auditory function in patients with persisting aphasia.

PubMed

Teki, Sundeep; Barnes, Gareth R; Penny, William D; Iverson, Paul; Woodhead, Zoe V J; Griffiths, Timothy D; Leff, Alexander P

2013-06-01

In this study, we used magnetoencephalography and a mismatch paradigm to investigate speech processing in stroke patients with auditory comprehension deficits and age-matched control subjects. We probed connectivity within and between the two temporal lobes in response to phonemic (different word) and acoustic (same word) oddballs using dynamic causal modelling. We found stronger modulation of self-connections as a function of phonemic differences for control subjects versus aphasics in left primary auditory cortex and bilateral superior temporal gyrus. The patients showed stronger modulation of connections from right primary auditory cortex to right superior temporal gyrus (feed-forward) and from left primary auditory cortex to right primary auditory cortex (interhemispheric). This differential connectivity can be explained on the basis of a predictive coding theory which suggests increased prediction error and decreased sensitivity to phonemic boundaries in the aphasics' speech network in both hemispheres. Within the aphasics, we also found behavioural correlates with connection strengths: a negative correlation between phonemic perception and an inter-hemispheric connection (left superior temporal gyrus to right superior temporal gyrus), and positive correlation between semantic performance and a feedback connection (right superior temporal gyrus to right primary auditory cortex). Our results suggest that aphasics with impaired speech comprehension have less veridical speech representations in both temporal lobes, and rely more on the right hemisphere auditory regions, particularly right superior temporal gyrus, for processing speech. Despite this presumed compensatory shift in network connectivity, the patients remain significantly impaired.

The right hemisphere supports but does not replace left hemisphere auditory function in patients with persisting aphasia

PubMed Central

Barnes, Gareth R.; Penny, William D.; Iverson, Paul; Woodhead, Zoe V. J.; Griffiths, Timothy D.; Leff, Alexander P.

2013-01-01

In this study, we used magnetoencephalography and a mismatch paradigm to investigate speech processing in stroke patients with auditory comprehension deficits and age-matched control subjects. We probed connectivity within and between the two temporal lobes in response to phonemic (different word) and acoustic (same word) oddballs using dynamic causal modelling. We found stronger modulation of self-connections as a function of phonemic differences for control subjects versus aphasics in left primary auditory cortex and bilateral superior temporal gyrus. The patients showed stronger modulation of connections from right primary auditory cortex to right superior temporal gyrus (feed-forward) and from left primary auditory cortex to right primary auditory cortex (interhemispheric). This differential connectivity can be explained on the basis of a predictive coding theory which suggests increased prediction error and decreased sensitivity to phonemic boundaries in the aphasics’ speech network in both hemispheres. Within the aphasics, we also found behavioural correlates with connection strengths: a negative correlation between phonemic perception and an inter-hemispheric connection (left superior temporal gyrus to right superior temporal gyrus), and positive correlation between semantic performance and a feedback connection (right superior temporal gyrus to right primary auditory cortex). Our results suggest that aphasics with impaired speech comprehension have less veridical speech representations in both temporal lobes, and rely more on the right hemisphere auditory regions, particularly right superior temporal gyrus, for processing speech. Despite this presumed compensatory shift in network connectivity, the patients remain significantly impaired. PMID:23715097

Altered resting-state functional activity in isolated pontine infarction patients with pathological laughing and crying.

PubMed

Liu, Tao; Li, Jianjun; Huang, Shixiong; Li, Changqinq; Zhao, Zhongyan; Wen, Guoqiang; Chen, Feng

2017-10-13

We used resting-state functional magnetic resonance imaging to investigate the global spontaneous neural activity involved in pathological laughing and crying after stroke. Twelve pathological laughing and crying patients with isolated pontine infarction were included, along with 12 age- and gender-matched acute isolated pontine infarction patients without pathological laughing and crying, and 12 age- and gender-matched healthy controls. We examined both the amplitude of low-frequency fluctuation and the regional homogeneity in order to comprehensively evaluate the intrinsic activity in patients with post-stroke pathological laughing and crying. In the post-stroke pathological laughing and crying group, changes in these measures were observed mainly in components of the default mode network (medial prefrontal cortex/anterior cingulate cortex, middle temporal gyrus, inferior temporal gyrus, superior frontal gyrus, middle frontal gyrus and inferior parietal lobule), sensorimotor network (supplementary motor area, precentral gyrus and paracentral lobule), affective network (medial prefrontal cortex/anterior cingulate cortex, parahippocampal gyrus, middle temporal gyrus and inferior temporal gyrus) and cerebellar lobes (cerebellum posterior lobe). We therefore speculate that when disinhibition of the volitional system is lost, increased activation of the emotional system causes pathological laughing and crying.

Neurobiological underpinnings of shame and guilt: a pilot fMRI study

PubMed Central

Michl, Petra; Meindl, Thomas; Meister, Franziska; Born, Christine; Engel, Rolf R.; Reiser, Maximilian

2014-01-01

In this study, a functional magnetic resonance imaging paradigm originally employed by Takahashi et al. was adapted to look for emotion-specific differences in functional brain activity within a healthy German sample (N = 14), using shame- and guilt-related stimuli and neutral stimuli. Activations were found for both of these emotions in the temporal lobe (shame condition: anterior cingulate cortex, parahippocampal gyrus; guilt condition: fusiform gyrus, middle temporal gyrus). Specific activations were found for shame in the frontal lobe (medial and inferior frontal gyrus), and for guilt in the amygdala and insula. This is consistent with Takahashi et al.’s results obtained for a Japanese sample (using Japanese stimuli), which showed activations in the fusiform gyrus, hippocampus, middle occipital gyrus and parahippocampal gyrus. During the imagination of shame, frontal and temporal areas (e.g. middle frontal gyrus and parahippocampal gyrus) were responsive regardless of gender. In the guilt condition, women only activate temporal regions, whereas men showed additional frontal and occipital activation as well as a responsive amygdala. The results suggest that shame and guilt share some neural networks, as well as having individual areas of activation. It can be concluded that frontal, temporal and limbic areas play a prominent role in the generation of moral feelings. PMID:23051901

Repetition Suppression and Reactivation in Auditory–Verbal Short-Term Recognition Memory

PubMed Central

D'Esposito, Mark

2009-01-01

The neural response to stimulus repetition is not uniform across brain regions, stimulus modalities, or task contexts. For instance, it has been observed in many functional magnetic resonance imaging (fMRI) studies that sometimes stimulus repetition leads to a relative reduction in neural activity (repetition suppression), whereas in other cases repetition results in a relative increase in activity (repetition enhancement). In the present study, we hypothesized that in the context of a verbal short-term recognition memory task, repetition-related “increases” should be observed in the same posterior temporal regions that have been previously associated with “persistent activity” in working memory rehearsal paradigms. We used fMRI and a continuous recognition memory paradigm with short lags to examine repetition effects in the posterior and anterior regions of the superior temporal cortex. Results showed that, consistent with our hypothesis, the 2 posterior temporal regions consistently associated with working memory maintenance, also show repetition increases during short-term recognition memory. In contrast, a region in the anterior superior temporal lobe showed repetition suppression effects, consistent with previous research work on perceptual adaptation in the auditory–verbal domain. We interpret these results in light of recent theories of the functional specialization along the anterior and posterior axes of the superior temporal lobe. PMID:18987393

Repetition suppression and reactivation in auditory-verbal short-term recognition memory.

PubMed

Buchsbaum, Bradley R; D'Esposito, Mark

2009-06-01

The neural response to stimulus repetition is not uniform across brain regions, stimulus modalities, or task contexts. For instance, it has been observed in many functional magnetic resonance imaging (fMRI) studies that sometimes stimulus repetition leads to a relative reduction in neural activity (repetition suppression), whereas in other cases repetition results in a relative increase in activity (repetition enhancement). In the present study, we hypothesized that in the context of a verbal short-term recognition memory task, repetition-related "increases" should be observed in the same posterior temporal regions that have been previously associated with "persistent activity" in working memory rehearsal paradigms. We used fMRI and a continuous recognition memory paradigm with short lags to examine repetition effects in the posterior and anterior regions of the superior temporal cortex. Results showed that, consistent with our hypothesis, the 2 posterior temporal regions consistently associated with working memory maintenance, also show repetition increases during short-term recognition memory. In contrast, a region in the anterior superior temporal lobe showed repetition suppression effects, consistent with previous research work on perceptual adaptation in the auditory-verbal domain. We interpret these results in light of recent theories of the functional specialization along the anterior and posterior axes of the superior temporal lobe.

Neurobiological underpinnings of shame and guilt: a pilot fMRI study.

PubMed

Michl, Petra; Meindl, Thomas; Meister, Franziska; Born, Christine; Engel, Rolf R; Reiser, Maximilian; Hennig-Fast, Kristina

2014-02-01

In this study, a functional magnetic resonance imaging paradigm originally employed by Takahashi et al. was adapted to look for emotion-specific differences in functional brain activity within a healthy German sample (N = 14), using shame- and guilt-related stimuli and neutral stimuli. Activations were found for both of these emotions in the temporal lobe (shame condition: anterior cingulate cortex, parahippocampal gyrus; guilt condition: fusiform gyrus, middle temporal gyrus). Specific activations were found for shame in the frontal lobe (medial and inferior frontal gyrus), and for guilt in the amygdala and insula. This is consistent with Takahashi et al.'s results obtained for a Japanese sample (using Japanese stimuli), which showed activations in the fusiform gyrus, hippocampus, middle occipital gyrus and parahippocampal gyrus. During the imagination of shame, frontal and temporal areas (e.g. middle frontal gyrus and parahippocampal gyrus) were responsive regardless of gender. In the guilt condition, women only activate temporal regions, whereas men showed additional frontal and occipital activation as well as a responsive amygdala. The results suggest that shame and guilt share some neural networks, as well as having individual areas of activation. It can be concluded that frontal, temporal and limbic areas play a prominent role in the generation of moral feelings.

Levels of processing with free and cued recall and unilateral temporal lobe epilepsy.

PubMed

Lespinet-Najib, Véronique; N'Kaoua, Bernard; Sauzéon, Hélène; Bresson, Christel; Rougier, Alain; Claverie, Bernard

2004-04-01

This study investigates the role of the temporal lobes in levels-of-processing tasks (phonetic and semantic encoding) according to the nature of recall tasks (free and cued recall). These tasks were administered to 48 patients with unilateral temporal epilepsy (right "RTLE"=24; left "LTLE"=24) and a normal group (n=24). The results indicated that LTLE patients were impaired for semantic processing (free and cued recall) and for phonetic processing (free and cued recall), while for RTLE patients deficits appeared in free recall with semantic processing. It is suggested that the left temporal lobe is involved in all aspects of verbal memory, and that the right temporal lobe is specialized in semantic processing. Moreover, our data seem to indicate that RTLE patients present a retrieval processing impairment (semantic condition), whereas the LTLE group is characterized by encoding difficulties in the phonetic and semantic condition.

Anterior temporal lobes and hippocampal formations: normative volumetric measurements from MR images in young adults.

PubMed

Jack, C R; Twomey, C K; Zinsmeister, A R; Sharbrough, F W; Petersen, R C; Cascino, G D

1989-08-01

Volumes of the right and left anterior temporal lobes and hippocampal formations were measured from magnetic resonance images in 52 healthy volunteers, aged 20-40 years. Subjects were selected by age, sex, and handedness to evaluate possible effect of these variables. Data were normalized for variation in total intracranial volume between individuals. Right-left asymmetry in the volumes of the anterior temporal lobes and hippocampal formations was a normal finding. The anterior temporal lobe of the non-dominant (right) hemisphere was larger than the left by a small (mean right-left difference, 2.3 cm3) but statistically significant amount (P less than .005) in right-handed subjects. No significant effect of age or sex was seen in normalized right or left anterior temporal lobe volume. The right hippocampal formation was larger than the left for all subjects by a small (mean right-left difference, 0.3 cm3) but statistically significant amount (P less than .001). No effect of age, sex, or handedness was seen in normalized hippocampal formation volumes.

A Method for Automatic Extracting Intracranial Region in MR Brain Image

NASA Astrophysics Data System (ADS)

Kurokawa, Keiji; Miura, Shin; Nishida, Makoto; Kageyama, Yoichi; Namura, Ikuro

It is well known that temporal lobe in MR brain image is in use for estimating the grade of Alzheimer-type dementia. It is difficult to use only region of temporal lobe for estimating the grade of Alzheimer-type dementia. From the standpoint for supporting the medical specialists, this paper proposes a data processing approach on the automatic extraction of the intracranial region from the MR brain image. The method is able to eliminate the cranium region with the laplacian histogram method and the brainstem with the feature points which are related to the observations given by a medical specialist. In order to examine the usefulness of the proposed approach, the percentage of the temporal lobe in the intracranial region was calculated. As a result, the percentage of temporal lobe in the intracranial region on the process of the grade was in agreement with the visual sense standards of temporal lobe atrophy given by the medical specialist. It became clear that intracranial region extracted by the proposed method was good for estimating the grade of Alzheimer-type dementia.

Recollection of episodic memory within the medial temporal lobe: behavioural dissociations from other types of memory.

PubMed

Easton, Alexander; Eacott, Madeline J

2010-12-31

In recent years there has been significant debate about whether there is a single medial temporal lobe memory system or dissociable systems for episodic and other types of declarative memory. In addition there has been a similar debate over the dissociability of recollection and familiarity based processes in recognition memory. Here we present evidence from recent work using episodic memory tasks in animals that allows us to explore these issues in more depth. We review studies that demonstrate triple dissociations within the medial temporal lobe, with only the hippocampal system being necessary for episodic memory. Similarly we review behavioural evidence for a dissociation in a task of episodic memory in rats where animals with lesions of the fornix are only impaired at recollection of the episodic memory, not recognition within the same trial. This work, then, supports recent models of dissociable neural systems within the medial temporal lobe but also raises questions for future investigation about the interactions of these medial temporal lobe memory systems with other structures. Copyright © 2009 Elsevier B.V. All rights reserved.

Semiautomated volumetry of the cerebrum, cerebellum-brain stem, and temporal lobe on brain magnetic resonance images.

PubMed

Hayashi, Norio; Sanada, Shigeru; Suzuki, Masayuki; Matsuura, Yukihiro; Kawahara, Kazuhiro; Tsujii, Hideo; Yamamoto, Tomoyuki; Matsui, Osamu

2008-02-01

The aim of this study was to develop an automated method of segmenting the cerebrum, cerebellum-brain stem, and temporal lobe simultaneously on magnetic resonance (MR) images. We obtained T1-weighted MR images from 10 normal subjects and 19 patients with brain atrophy. To perform automated volumetry from MR images, we performed the following three steps: (1) segmentation of the brain region; (2) separation between the cerebrum and the cerebellum-brain stem; and (3) segmentation of the temporal lobe. Evaluation was based on the correctly recognized region (CRR) (i.e., the region recognized by both the automated and manual methods). The mean CRRs of the normal and atrophic brains were 98.2% and 97.9% for the cerebrum, 87.9% and 88.5% for the cerebellum-brain stem, and 76.9% and 85.8% for the temporal lobe, respectively. We introduce an automated volumetric method for the cerebrum, cerebellum-brain stem, and temporal lobe on brain MR images. Our method can be applied to not only the normal brain but also the atrophic brain.

Anterior Temporal Lobe Connectivity Correlates with Functional Outcome after Aphasic Stroke

ERIC Educational Resources Information Center

Warren, Jane E.; Crinion, Jennifer T.; Ralph, Matthew A. Lambon; Wise, Richard J. S.

2009-01-01

Focal brain lesions are assumed to produce language deficits by two basic mechanisms: local cortical dysfunction at the lesion site, and remote cortical dysfunction due to disruption of the transfer and integration of information between connected brain regions. However, functional imaging studies investigating language outcome after aphasic…

Lateralized Spatial and Object Memory Encoding in Entorhinal and Perirhinal Cortices

ERIC Educational Resources Information Center

Bellgowan, Patrick S. F.; Buffalo, Elizabeth A.; Bodurka, Jerzy; Martin, Alex

2009-01-01

The perirhinal and entorhinal cortices are critical components of the medial temporal lobe (MTL) declarative memory system. Study of their specific functions using blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI), however, has suffered from severe magnetic susceptibility signal dropout resulting in poor…

Relationship of Temporal Lobe Volumes to Neuropsychological Test Performance in Healthy Children

ERIC Educational Resources Information Center

Wells, Carolyn T.; Mahone, E. Mark; Matson, Melissa A.; Kates, Wendy R.; Hay, Trisha; Horska, Alena

2008-01-01

Ecological validity of neuropsychological assessment includes the ability of tests to predict real-world functioning and/or covary with brain structures. Studies have examined the relationship between adaptive skills and test performance, with less focus on the association between regional brain volumes and neurobehavioral function in healthy…

Abnormal relationship between medial temporal lobe and subcortical dopamine function in people with an ultra high risk for psychosis.

PubMed

Allen, Paul; Chaddock, Christopher A; Howes, Oliver D; Egerton, Alice; Seal, Marc L; Fusar-Poli, Paolo; Valli, Isabel; Day, Fern; McGuire, Philip K

2012-09-01

Neuroimaging studies in humans have implicated both dysfunction of the medial temporal lobe (MTL) and the dopamine system in psychosis, but the relationship between them is unclear. We addressed this issue by measuring MTL activation and striatal dopaminergic function in individuals with an At Risk Mental State (ARMS) for psychosis, using functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), respectively. Thirty-four subjects (20 ARMS and 14 Controls), matched for age, gender, digit span performance, and premorbid IQ, were scanned using fMRI, while performing a verbal encoding and recognition task, and using 18F-DOPA PET. All participants were naïve to antipsychotic medication. ARMS subjects showed reduced MTL activation when encoding words and made more false alarm responses for Novel words than controls. The relationship between striatal dopamine function and MTL activation during both verbal encoding and verbal recognition was significantly different in ARMS subjects compared with controls. An altered relationship between MTL function and dopamine storage/synthesis capacity exists in the ARMS and may be related to psychosis vulnerability.

Prenatal ultrasound and MRI findings of temporal and occipital lobe dysplasia in a twin with achondroplasia.

PubMed

Pugash, D; Lehman, A M; Langlois, S

2014-09-01

Thanatophoric dysplasia, hypochondroplasia and achondroplasia are all caused by FGFR3 (fibroblast growth factor receptor 3) mutations. Neuropathological findings of temporal lobe dysplasia are found in thanatophoric dysplasia, and temporal and occipital lobe abnormalities have been described recently in brain imaging studies of children with hypochondroplasia. We describe twins discordant for achondroplasia, in one of whom the prenatal diagnosis was based on ultrasound and fetal MRI documentation of temporal and occipital lobe abnormalities characteristic of hypochondroplasia, in addition to the finding of short long bones. Despite the intracranial findings suggestive of hypochondroplasia, achondroplasia was confirmed following postnatal clinical and genetic testing. These intracranial abnormalities have not been previously described in a fetus with achondroplasia. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

Using regional homogeneity to reveal altered spontaneous activity in patients with mild cognitive impairment.

PubMed

Wang, Yumei; Zhao, Xiaochuan; Xu, Shunjiang; Yu, Lulu; Wang, Lan; Song, Mei; Yang, Linlin; Wang, Xueyi

2015-01-01

Most patients with mild cognitive impairment (MCI) are thought to be in an early stage of Alzheimer's disease (AD). Resting-state functional magnetic resonance imaging reflects spontaneous brain activity and/or the endogenous/background neurophysiological process of the human brain. Regional homogeneity (ReHo) rapidly maps regional brain activity across the whole brain. In the present study, we used the ReHo index to explore whole brain spontaneous activity pattern in MCI. Our results showed that MCI subjects displayed an increased ReHo index in the paracentral lobe, precuneus, and postcentral and a decreased ReHo index in the medial temporal gyrus and hippocampus. Impairments in the medial temporal gyrus and hippocampus may serve as important markers distinguishing MCI from healthy aging. Moreover, the increased ReHo index observed in the postcentral and paracentral lobes might indicate compensation for the cognitive function losses in individuals with MCI.

Using Regional Homogeneity to Reveal Altered Spontaneous Activity in Patients with Mild Cognitive Impairment

PubMed Central

Wang, Yumei; Zhao, Xiaochuan; Xu, Shunjiang; Yu, Lulu; Wang, Lan; Song, Mei; Yang, Linlin; Wang, Xueyi

2015-01-01

Most patients with mild cognitive impairment (MCI) are thought to be in an early stage of Alzheimer's disease (AD). Resting-state functional magnetic resonance imaging reflects spontaneous brain activity and/or the endogenous/background neurophysiological process of the human brain. Regional homogeneity (ReHo) rapidly maps regional brain activity across the whole brain. In the present study, we used the ReHo index to explore whole brain spontaneous activity pattern in MCI. Our results showed that MCI subjects displayed an increased ReHo index in the paracentral lobe, precuneus, and postcentral and a decreased ReHo index in the medial temporal gyrus and hippocampus. Impairments in the medial temporal gyrus and hippocampus may serve as important markers distinguishing MCI from healthy aging. Moreover, the increased ReHo index observed in the postcentral and paracentral lobes might indicate compensation for the cognitive function losses in individuals with MCI. PMID:25738156

Direct Exploration of the Role of the Ventral Anterior Temporal Lobe in Semantic Memory: Cortical Stimulation and Local Field Potential Evidence From Subdural Grid Electrodes.

PubMed

Shimotake, Akihiro; Matsumoto, Riki; Ueno, Taiji; Kunieda, Takeharu; Saito, Satoru; Hoffman, Paul; Kikuchi, Takayuki; Fukuyama, Hidenao; Miyamoto, Susumu; Takahashi, Ryosuke; Ikeda, Akio; Lambon Ralph, Matthew A

2015-10-01

Semantic memory is a crucial higher cortical function that codes the meaning of objects and words, and when impaired after neurological damage, patients are left with significant disability. Investigations of semantic dementia have implicated the anterior temporal lobe (ATL) region, in general, as crucial for multimodal semantic memory. The potentially crucial role of the ventral ATL subregion has been emphasized by recent functional neuroimaging studies, but the necessity of this precise area has not been selectively tested. The implantation of subdural electrode grids over this subregion, for the presurgical assessment of patients with partial epilepsy or brain tumor, offers the dual yet rare opportunities to record cortical local field potentials while participants complete semantic tasks and to stimulate the functionally identified regions in the same participants to evaluate the necessity of these areas in semantic processing. Across 6 patients, and utilizing a variety of semantic assessments, we evaluated and confirmed that the anterior fusiform/inferior temporal gyrus is crucial in multimodal, receptive, and expressive, semantic processing. © The Author 2014. Published by Oxford University Press.

[Gray matter abnormalities in developmental stuttering determined with voxel-based morphometry].

PubMed

Song, Lu-ping; Peng, Dan-ling; Jin, Zhen; Yao, Li; Ning, Ning; Guo, Xiao-juan; Zhang, Tong

2007-11-06

To investigate the differences of regional grey matter volume between adults with persistent developmental stuttering and fluent speaking adults, and to determine whether stutterers have anomalous anatomy of speech-relevant brain areas that possibly affect speech fluency. High-resolution magnetic resonance imaging (MRI) scanning was performed on 10 adults with developmental stuttering, aged 26 (21 - 35) with the onset age of 4 (3 - 7) and 12 age, sex, hand preference, and education-matched controls. The customized brain templates were created in order to improve spatial normalization and segmentation. Then automated preprocessing of MRI data was conducted using an optimized version of VBM, a fully automated unbiased and objective whole-brain MRI analysis technique. VBM analysis revealed that compared with the controls, the stuttering adults had significant clusters of locally gray matter volume increased in the superior temporal, middle temporal, precentral and postcentral gyrus, and inferior parietal lobule of the bilateral hemisphere (P < 0.001), the numbers of increased gray matter volume in the right and left hemispheres were 60,247 and 48,782 voxels respectively. The, Grey matter decrease was shown with an overall decreased gray matter volume of 32 394 voxels, mainly in the bilateral cerebella posterior lobe and dorsal part of medulla, especially inferior semi-lunar lobule, followed by cerebellar tonsil and bilateral medulla in comparison with the controls (P < 0.001). The reduction of the regional gray matter volume of bilateral cerebella and medulla is related to the neural mechanism of the controlling disorder of speech production and may be the essential cause of stuttering. Some areas with increased gray matter volume in temporal lobe, parietal lobe, and frontal lobe, may be the result of long term functional compensation for the cerebella and medulla function deficiency.

Frontal lobe atrophy is associated with small vessel disease in ischemic stroke patients.

PubMed

Chen, Yangkun; Chen, Xiangyan; Xiao, Weimin; Mok, Vincent C T; Wong, Ka Sing; Tang, Wai Kwong

2009-12-01

The pathogenesis of frontal lobe atrophy (FLA) in stroke patients is unclear. We aimed to ascertain whether subcortical ischemic changes were more associated with FLA than with parietal lobe atrophy (PLA) and temporal lobe atrophy (TLA). Brain magnetic resonance images (MRIs) from 471 Chinese ischemic stroke patients were analyzed. Lobar atrophy was defined by a widely used visual rating scale. All patients were divided into non-severe, mild-moderate, and severe atrophy of the frontal, parietal, and temporal lobe groups. The severity of white matter lesions (WMLs) was rated with the Fazekas' scale. Clinical and radiological features were compared among the groups. Subsequent logistic regressions were performed to determine the risk factors of atrophy and severe atrophy of the frontal, parietal and temporal lobes. The frequency of FLA in our cohort was 36.9% (174/471). Severe FLA occurred in 30 (6.4%) patients. Age, previous stroke, and periventricular hyperintensities (PVH) (odds ratio (OR)=1.640, p=0.039) were independent risk factors of FLA. Age and deep white matter hyperintensities (DWMH) (OR=3.634, p=0.002) were independent risk factors of severe FLA. PVH and DWMH were not independent risk factors of PLA and TLA. Frontal lobe atrophy in ischemic stroke patients may be associated with small vessel disease. The association between WMLs and FLA was predominant over atrophy of the parietal and temporal lobes, which suggests that the frontal lobe may be vulnerable to subcortical ischemic changes.

Neuromagnetic Vistas into Typical and Atypical Development of Frontal Lobe Functions

PubMed Central

Taylor, Margot J.; Doesburg, Sam M.; Pang, Elizabeth W.

2014-01-01

The frontal lobes are involved in many higher-order cognitive functions such as social cognition executive functions and language and speech. These functions are complex and follow a prolonged developmental course from childhood through to early adulthood. Magnetoencephalography (MEG) is ideal for the study of development of these functions, due to its combination of temporal and spatial resolution which allows the determination of age-related changes in both neural timing and location. There are several challenges for MEG developmental studies: to design tasks appropriate to capture the neurodevelopmental trajectory of these cognitive functions, and to develop appropriate analysis strategies to capture various aspects of neuromagnetic frontal lobe activity. Here, we review our MEG research on social and executive functions, and speech in typically developing children and in two clinical groups – children with autism spectrum disorder and children born very preterm. The studies include facial emotional processing, inhibition, visual short-term memory, speech production, and resting-state networks. We present data from event-related analyses as well as on oscillations and connectivity analyses and review their contributions to understanding frontal lobe cognitive development. We also discuss the challenges of testing young children in the MEG and the development of age-appropriate technologies and paradigms. PMID:24994980

Brain volume change and cognitive trajectories in aging.

PubMed

Fletcher, Evan; Gavett, Brandon; Harvey, Danielle; Farias, Sarah Tomaszewski; Olichney, John; Beckett, Laurel; DeCarli, Charles; Mungas, Dan

2018-05-01

Examine how longitudinal cognitive trajectories relate to brain baseline measures and change in lobar volumes in a racially/ethnically and cognitively diverse sample of older adults. Participants were 460 older adults enrolled in a longitudinal aging study. Cognitive outcomes were measures of episodic memory, semantic memory, executive function, and spatial ability derived from the Spanish and English Neuropsychological Assessment Scales (SENAS). Latent variable multilevel modeling of the four cognitive outcomes as parallel longitudinal processes identified intercepts for each outcome and a second order global change factor explaining covariance among the highly correlated slopes. We examined how baseline brain volumes (lobar gray matter, hippocampus, and white matter hyperintensity) and change in brain volumes (lobar gray matter) were associated with cognitive intercepts and global cognitive change. Lobar volumes were dissociated into global and specific components using latent variable methods. Cognitive change was most strongly associated with brain gray matter volume change, with strong independent effects of global gray matter change and specific temporal lobe gray matter change. Baseline white matter hyperintensity and hippocampal volumes had significant incremental effects on cognitive decline beyond gray matter change. Baseline lobar gray matter was related to cognitive decline, but did not contribute beyond gray matter change. Cognitive decline was strongly influenced by gray matter volume change and, especially, temporal lobe change. The strong influence of temporal lobe gray matter change on cognitive decline may reflect involvement of temporal lobe structures that are critical for late life cognitive health but also are vulnerable to diseases of aging. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Reversible Information Flow across the Medial Temporal Lobe: The Hippocampus Links Cortical Modules during Memory Retrieval

PubMed Central

Cooper, Elisa; Henson, Richard N.

2013-01-01

A simple cue can be sufficient to elicit vivid recollection of a past episode. Theoretical models suggest that upon perceiving such a cue, disparate episodic elements held in neocortex are retrieved through hippocampal pattern completion. We tested this fundamental assumption by applying functional magnetic resonance imaging (fMRI) while objects or scenes were used to cue participants' recall of previously paired scenes or objects, respectively. We first demonstrate functional segregation within the medial temporal lobe (MTL), showing domain specificity in perirhinal and parahippocampal cortices (for object-processing vs scene-processing, respectively), but domain generality in the hippocampus (retrieval of both stimulus types). Critically, using fMRI latency analysis and dynamic causal modeling, we go on to demonstrate functional integration between these MTL regions during successful memory retrieval, with reversible signal flow from the cue region to the target region via the hippocampus. This supports the claim that the human hippocampus provides the vital associative link that integrates information held in different parts of cortex. PMID:23986252

Baseline Brain Activity Changes in Patients With Single and Relapsing Optic Neuritis.

PubMed

Ren, Zhuoqiong; Liu, Yaou; Li, Kuncheng; Duan, Yunyun; Jing, Huang; Liang, Peipeng; Sun, Zheng; Zhang, Xiaojun; Mao, Bei

2018-01-01

Purpose : To investigate spontaneous brain activity amplitude alterations in single and relapsing optic neuritis (sON and rON, respectively) and their relationships with clinical variables. Methods : In total, 42 patients with sON, 35 patients with rON and 50 healthy volunteers were recruited. Resting-state functional Magnetic Resonance Imaging (rs-fMRI) scans were acquired for all participants and compared to investigate the changes in the amplitude of low-frequency fluctuations (ALFFs) among the three groups. The relationships between the ALFFs in regions with significant differences in the groups and clinical variables, including the logarithm of minimal angle of resolution (LogMAR), Expanded Disability Status Scale (EDSS) score and disease duration, were further explored. Results : Compared with healthy volunteers, the sON and rON patients showed significantly decreased ALFFs in several regions of the occipital and temporal lobes (i.e., inferior occipital gyrus and superior temporal gyrus; corrected p < 0.01 using AlphaSim). The sON patients showed significantly increased ALFFs in the left caudate and certain regions in the frontal lobes (i.e., medial frontal gyrus), whereas the rON patients showed increased ALFFs in the bilateral inferior temporal gyrus and left medial frontal gyrus (corrected p < 0.01 using AlphaSim). Significantly decreased ALFFs were observed in the right inferior parietal lobule (IPL), left posterior cingulate and precuneus in the rON patients compared with those in the sON patients (corrected p < 0.01 using AlphaSim). Significant correlations were observed between the disease duration and ALFF in the left middle temporal gyrus, left inferior occipital gyrus, right lingual gyrus and right IPL ( p < 0.05). Conclusion : Functional impairment and adaptation occurred in both the sON and rON patients. Impairment mainly involved the occipital cortex, and functional adaptions predominantly occurred in the frontal lobe. Functional damage was more severe in the rON patients than in the sON patients and correlated with the disease duration.

Prefrontal cortex afferents to the anterior temporal lobe in the Macaca fascicularis monkey.

PubMed

Mohedano-Moriano, Alicia; Muñoz-López, Mónica; Sanz-Arigita, Ernesto; Pró-Sistiaga, Palma; Martínez-Marcos, Alino; Legidos-Garcia, María Ester; Insausti, Ana María; Cebada-Sánchez, Sandra; Arroyo-Jiménez, María Del Mar; Marcos, Pilar; Artacho-Pérula, Emilio; Insausti, Ricardo

2015-12-01

The anatomical organization of the lateral prefrontal cortex (LPFC) afferents to the anterior part of the temporal lobe (ATL) remains to be clarified. The LPFC has two subdivisions, dorsal (dLPFC) and ventral (vLPFC), which have been linked to cognitive processes. The ATL includes several different cortical areas, namely, the temporal polar cortex and rostral parts of the perirhinal, inferotemporal, and anterior tip of the superior temporal gyrus cortices. Multiple sensory modalities converge in the ATL. All of them (except the rostral inferotemporal and superior temporal gyrus cortices) are components of the medial temporal lobe, which is critical for long-term memory processing. We studied the LPFC connections with the ATL by placing retrograde tracer injections into the ATL: the temporal polar (n = 3), perirhinal (areas 35 and 36, n = 6), and inferotemporal cortices (area TE, n = 5), plus one additional deposit in the posterior parahippocampal cortex (area TF, n = 1). Anterograde tracer deposits into the dLPFC (A9 and A46, n = 2), the vLPFC (A46v, n = 2), and the orbitofrontal cortex (OF; n = 2) were placed for confirmation of those projections. The results showed that the vLPFC displays a moderate projection to rostral area TE and the dorsomedial portion of the temporal polar cortex; in contrast, the dLPFC connections with the ATL were weak. By comparison, the OFC and medial frontal cortices (MFC) showed dense connectivity with the ATL, namely, A13 with the temporopolar and perirhinal cortices. All areas of the MFC projected to the temporopolar cortex, albeit with a lower intensity. The functional significance of such paucity of LPFC afferents is unknown. © 2015 Wiley Periodicals, Inc.

Neural Correlates of Subliminal Language Processing

PubMed Central

Axelrod, Vadim; Bar, Moshe; Rees, Geraint; Yovel, Galit

2015-01-01

Language is a high-level cognitive function, so exploring the neural correlates of unconscious language processing is essential for understanding the limits of unconscious processing in general. The results of several functional magnetic resonance imaging studies have suggested that unconscious lexical and semantic processing is confined to the posterior temporal lobe, without involvement of the frontal lobe—the regions that are indispensable for conscious language processing. However, previous studies employed a similarly designed masked priming paradigm with briefly presented single and contextually unrelated words. It is thus possible, that the stimulation level was insufficiently strong to be detected in the high-level frontal regions. Here, in a high-resolution fMRI and multivariate pattern analysis study we explored the neural correlates of subliminal language processing using a novel paradigm, where written meaningful sentences were suppressed from awareness for extended duration using continuous flash suppression. We found that subjectively and objectively invisible meaningful sentences and unpronounceable nonwords could be discriminated not only in the left posterior superior temporal sulcus (STS), but critically, also in the left middle frontal gyrus. We conclude that frontal lobes play a role in unconscious language processing and that activation of the frontal lobes per se might not be sufficient for achieving conscious awareness. PMID:24557638

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.

Tissue Expressions of Soluble Human Epoxide Hydrolase-2 Enzyme in Patients with Temporal Lobe Epilepsy.

PubMed

Ahmedov, Merdin Lyutviev; Kemerdere, Rahsan; Baran, Oguz; Inal, Berrin Bercik; Gumus, Alper; Coskun, Cihan; Yeni, Seher Naz; Eren, Bulent; Uzan, Mustafa; Tanriverdi, Taner

2017-10-01

We sought to simply demonstrate how levels of soluble human epoxide hydrolase-2 show changes in both temporal the cortex and hippocampal complex in patients with temporal lobe epilepsy. A total of 20 patients underwent anterior temporal lobe resection due to temporal lobe epilepsy. The control group comprised 15 people who died in traffic accidents or by falling from a height, and their autopsy findings were included. Adequately sized temporal cortex and hippocampal samples were removed from each patient during surgery, and the same anatomic structures were removed from the control subjects during the autopsy procedures. Each sample was stored at -80°C as rapidly as possible until the enzyme assay. The temporal cortex in the epilepsy patients had a significantly higher enzyme level than did the temporal cortex of the control group (P = 0.03). Correlation analysis showed that as the enzyme level increases in the temporal cortex, it also increases in the hippocampal complex (r 2  = 0.06, P = 0.00001). More important, enzyme tissue levels showed positive correlations with seizure frequency in both the temporal cortex and hippocampal complex in patients (r 2  = 0.7, P = 0.00001 and r 2  = 0.4, P = 0.003, respectively). The duration of epilepsy was also positively correlated with the hippocampal enzyme level (r 2  = 0.06, P = 0.00001). Soluble human epoxy hydrolase enzyme-2 is increased in both lateral and medial temporal tissues in temporal lobe epilepsy. Further studies should be conducted as inhibition of this enzyme has resulted in a significant decrease in or stopping of seizures and attenuated neuroinflammation in experimental epilepsy models in the current literature. Copyright © 2017 Elsevier Inc. All rights reserved.

Temporal lobe epilepsy in patients with nonlesional MRI and normal memory: an SEEG study.

PubMed

Suresh, Suraj; Sweet, Jennifer; Fastenau, Philip S; Lüders, Hans; Landazuri, Patrick; Miller, Jonathan

2015-12-01

Temporal lobe epilepsy (TLE) in the absence of MRI abnormalities and memory deficits is often presumed to have an extramesial or even extratemporal source. In this paper the authors report the results of a comprehensive stereoelectroencephalography (SEEG) analysis in patients with TLE with normal MRI images and memory scores. Eighteen patients with medically refractory epilepsy who also had unremarkable MR images and normal verbal and visual memory scores on neuropsychological testing were included in the study. All patients had seizure semiology and video electroencephalography (EEG) findings suggestive of TLE. A standardized SEEG investigation was performed for each patient with electrodes implanted into the mesial and lateral temporal lobe, temporal tip, posterior temporal neocortex, orbitomesiobasal frontal lobe, posterior cingulate gyrus, and insula. This information was used to plan subsequent surgical management. Interictal SEEG abnormalities were observed in the mesial temporal structures in 17 patients (94%) and in the temporal tip in 6 (33%). Seizure onset was exclusively from mesial structures in 13 (72%), exclusively from lateral temporal cortex and/or temporal tip structures in 2 (11%), and independently from mesial and neocortical foci in 3 (17%). No seizure activity was observed arising from any extratemporal location. All patients underwent surgical intervention targeting the temporal lobe and tailored to the SEEG findings, and all experienced significant improvement in seizure frequency with a postoperative follow-up observation period of at least 1 year. This study demonstrates 3 important findings: 1) normal memory does not preclude mesial temporal seizure onset; 2) onset of seizures exclusively from mesial temporal structures without early neocortical involvement is common, even in the absence of memory deficits; and 3) extratemporal seizure onset is rare when video EEG and semiology are consistent with focal TLE.

Cortico-hippocampal systems involved in memory and cognition: the PMAT framework.

PubMed

Ritchey, Maureen; Libby, Laura A; Ranganath, Charan

2015-01-01

In this chapter, we review evidence that the cortical pathways to the hippocampus appear to extend from two large-scale cortical systems: a posterior medial (PM) system that includes the parahippocampal cortex and retrosplenial cortex, and an anterior temporal (AT) system that includes the perirhinal cortex. This "PMAT" framework accounts for differences in the anatomical and functional connectivity of the medial temporal lobes, which may underpin differences in cognitive function between the systems. The PM and AT systems make distinct contributions to memory and to other cognitive domains, and convergent findings suggest that they are involved in processing information about contexts and items, respectively. In order to support the full complement of memory-guided behavior, the two systems must interact, and the hippocampal and ventromedial prefrontal cortex may serve as sites of integration between the two systems. We conclude that when considering the "connected hippocampus," inquiry should extend beyond the medial temporal lobes to include the large-scale cortical systems of which they are a part. © 2015 Elsevier B.V. All rights reserved.

Simulating memory outcome before right selective amygdalohippocampectomy.

PubMed

Patrikelis, Panayiotis; Lucci, Giuliana; Siatouni, Anna; Zalonis, Ioannis; Sakas, Damianos E; Gatzonis, Stylianos

2013-01-01

In this paper we present the case of a left-sided speech dominant patient with right medial temporal sclerosis (RMTS) and pharmacoresistant epilepsy who showed improved verbal memory during intracarotid amobarbital test (IAT) at his right hemisphere as compared with his own performance before the drug injection (baseline), as well as after right selective amygdalohippocampectomy. We suggest that the defective verbal memory shown by this patient is due to abnormal activity of his right hippocampus that interfered with the function of his left hippocampus. This hypothesis was demonstrated by the fact that disconnection of the two hippocampi, either by anesthetisation or by resection of the right hippocampus, disengaged the left hippocampus and, consequently improved its function. This paper main objective is twofold: first to contribute to the field of neuropsychology of epilepsy surgery by emphasising on postoperative memory outcomes in right medial temporal lobe epilepsy (RMTLE) patients, particularly those undergoing amygdalohippocampectomy, as the pattern of memory changes after resection of the right temporal lobe is less clear; second, by focusing on memory performance asymmetries during IAT, and comparatively considering them with neuropsychological memory performance, because of their possible prognostic-simulating value.

Cerebral Blood Flow and BOLD Responses to a Memory Encoding Task: A Comparison Between Healthy Young and Elderly Adults

PubMed Central

Restom, Khaled; Bangen, Katherine J.; Bondi, Mark W.; Perthen, Joanna E.; Liu, Thomas T.

2007-01-01

Functional magnetic resonance imaging (fMRI) studies of the medial temporal lobe have primarily made use of the blood oxygenation level dependent (BOLD) response to neural activity. The interpretation of the BOLD signal as a measure of medial temporal lobe function can be complicated, however, by changes in the cerebrovascular system that can occur with both normal aging and age-related diseases, such as Alzheimer's disease. Quantitative measures of the functional cerebral blood flow (CBF) response offer a useful complement to BOLD measures, and have been shown to aid in the interpretation of fMRI studies. Despite these potential advantages, the application of ASL to fMRI studies of cognitive tasks and at-risk populations has been limited. In this study, we demonstrate the application of ASL fMRI to obtain measures of the CBF and BOLD responses to the encoding of natural scenes in healthy young (mean 25 years) and elderly (mean 74 years) adults. The percent CBF increase in the medial temporal lobe was significantly higher in the older adults, whereas the CBF levels during baseline and task conditions and during a separate resting-state scan were significantly lower in the older group. The older adults also showed slightly higher values for the BOLD response amplitude and the absolute change in CBF, but the age group differences were not significant. The percent CBF and BOLD responses are consistent with an age-related increase in the cerebral metabolic rate of oxygen metabolism (CMRO2) response to memory encoding. PMID:17590353

Functional organization of the medial temporal lobe memory system following neonatal hippocampal lesion in rhesus monkeys.

PubMed

Chareyron, Loïc J; Banta Lavenex, Pamela; Amaral, David G; Lavenex, Pierre

2017-12-01

Hippocampal damage in adult humans impairs episodic and semantic memory, whereas hippocampal damage early in life impairs episodic memory but leaves semantic learning relatively preserved. We have previously shown a similar behavioral dissociation in nonhuman primates. Hippocampal lesion in adult monkeys prevents allocentric spatial relational learning, whereas spatial learning persists following neonatal lesion. Here, we quantified the number of cells expressing the immediate-early gene c-fos, a marker of neuronal activity, to characterize the functional organization of the medial temporal lobe memory system following neonatal hippocampal lesion. Ninety minutes before brain collection, three control and four adult monkeys with bilateral neonatal hippocampal lesions explored a novel environment to activate brain structures involved in spatial learning. Three other adult monkeys with neonatal hippocampal lesions remained in their housing quarters. In unlesioned monkeys, we found high levels of c-fos expression in the intermediate and caudal regions of the entorhinal cortex, and in the perirhinal, parahippocampal, and retrosplenial cortices. In lesioned monkeys, spatial exploration induced an increase in c-fos expression in the intermediate field of the entorhinal cortex, the perirhinal, parahippocampal, and retrosplenial cortices, but not in the caudal entorhinal cortex. These findings suggest that different regions of the medial temporal lobe memory system may require different types of interaction with the hippocampus in support of memory. The caudal perirhinal cortex, the parahippocampal cortex, and the retrosplenial cortex may contribute to spatial learning in the absence of functional hippocampal circuits, whereas the caudal entorhinal cortex may require hippocampal output to support spatial learning.

Music Recognition in Frontotemporal Lobar Degeneration and Alzheimer Disease

PubMed Central

Johnson, Julene K; Chang, Chiung-Chih; Brambati, Simona M; Migliaccio, Raffaella; Gorno-Tempini, Maria Luisa; Miller, Bruce L; Janata, Petr

2013-01-01

Objective To compare music recognition in patients with frontotemporal dementia, semantic dementia, Alzheimer disease, and controls and to evaluate the relationship between music recognition and brain volume. Background Recognition of familiar music depends on several levels of processing. There are few studies about how patients with dementia recognize familiar music. Methods Subjects were administered tasks that assess pitch and melody discrimination, detection of pitch errors in familiar melodies, and naming of familiar melodies. Results There were no group differences on pitch and melody discrimination tasks. However, patients with semantic dementia had considerable difficulty naming familiar melodies and also scored the lowest when asked to identify pitch errors in the same melodies. Naming familiar melodies, but not other music tasks, was strongly related to measures of semantic memory. Voxel-based morphometry analysis of brain MRI showed that difficulty in naming songs was associated with the bilateral temporal lobes and inferior frontal gyrus, whereas difficulty in identifying pitch errors in familiar melodies correlated with primarily the right temporal lobe. Conclusions The results support a view that the anterior temporal lobes play a role in familiar melody recognition, and that musical functions are affected differentially across forms of dementia. PMID:21617528

Localizing and lateralizing value of ictal flatulence.

PubMed

Strzelczyk, Adam; Nowak, Mareike; Bauer, Sebastian; Reif, Philipp S; Oertel, Wolfgang H; Knake, Susanne; Hamer, Hajo M; Rosenow, Felix

2010-02-01

Autonomic seizures have been associated with seizure onset in the temporal or insular lobe and consist of variations in blood pressure and heart rate, sweating, flushing, piloerection, hypersalivation, vomiting, spitting, and alterations in bladder and bowel functions. The aim of this study was to evaluate the localizing and lateralizing value of ictal flatulence. Medical records of patients with focal epilepsies who were monitored at the Interdisciplinary Epilepsy Center Marburg between 2006 and 2009 were reviewed for the occurrence of ictal flatulence. Clinical, electrophysiological, and imaging data were reviewed and compared with data for previously reported cases of ictal flatulence. Two patients with ictal flatulence were identified (0.6%). In both patients, ictal flatulence was associated with a seizure pattern in the temporal lobe of the dominant hemisphere. Our cases and previously reported cases point toward activation of insular cortex because of such additional autonomic symptoms as unilateral piloerection, tachycardia, profound sweating, and flushing of the face. Ictal flatulence is a rare manifestation of autonomic seizures and a localizing sign for temporal or/and insular lobe epilepsies. In general, ictal flatulence seems to have no lateralizing value. (c) 2009 Elsevier Inc. All rights reserved.

Graph theory findings in the pathophysiology of temporal lobe epilepsy

PubMed Central

Chiang, Sharon; Haneef, Zulfi

2014-01-01

Temporal lobe epilepsy (TLE) is the most common form of adult epilepsy. Accumulating evidence has shown that TLE is a disorder of abnormal epileptogenic networks, rather than focal sources. Graph theory allows for a network-based representation of TLE brain networks, and has potential to illuminate characteristics of brain topology conducive to TLE pathophysiology, including seizure initiation and spread. We review basic concepts which we believe will prove helpful in interpreting results rapidly emerging from graph theory research in TLE. In addition, we summarize the current state of graph theory findings in TLE as they pertain its pathophysiology. Several common findings have emerged from the many modalities which have been used to study TLE using graph theory, including structural MRI, diffusion tensor imaging, surface EEG, intracranial EEG, magnetoencephalography, functional MRI, cell cultures, simulated models, and mouse models, involving increased regularity of the interictal network configuration, altered local segregation and global integration of the TLE network, and network reorganization of temporal lobe and limbic structures. As different modalities provide different views of the same phenomenon, future studies integrating data from multiple modalities are needed to clarify findings and contribute to the formation of a coherent theory on the pathophysiology of TLE. PMID:24831083

Physiogenomic analysis of localized FMRI brain activity in schizophrenia.

PubMed

Windemuth, Andreas; Calhoun, Vince D; Pearlson, Godfrey D; Kocherla, Mohan; Jagannathan, Kanchana; Ruaño, Gualberto

2008-06-01

The search for genetic factors associated with disease is complicated by the complexity of the biological pathways linking genotype and phenotype. This analytical complexity is particularly concerning in diseases historically lacking reliable diagnostic biological markers, such as schizophrenia and other mental disorders. We investigate the use of functional magnetic resonance imaging (fMRI) as an intermediate phenotype (endophenotype) to identify physiogenomic associations to schizophrenia. We screened 99 subjects, 30 subjects diagnosed with schizophrenia, 13 unaffected relatives of schizophrenia patients, and 56 unrelated controls, for gene polymorphisms associated with fMRI activation patterns at two locations in temporal and frontal lobes previously implied in schizophrenia. A total of 22 single nucleotide polymorphisms (SNPs) in 15 genes from the dopamine and serotonin neurotransmission pathways were genotyped in all subjects. We identified three SNPs in genes that are significantly associated with fMRI activity. SNPs of the dopamine beta-hydroxylase (DBH) gene and of the dopamine receptor D4 (DRD4) were associated with activity in the temporal and frontal lobes, respectively. One SNP of serotonin-3A receptor (HTR3A) was associated with temporal lobe activity. The results of this study support the physiogenomic analysis of neuroimaging data to discover associations between genotype and disease-related phenotypes.

Structural MRI research in patients with nasopharyngeal carcinoma following radiotherapy: A DTI and VBM study.

PubMed

Leng, Xi; Fang, Peng; Lin, Huan; An, Jie; Tan, Xin; Zhang, Chi; Wu, Donglin; Shen, Wen; Qiu, Shijun

2017-11-01

The aim of the present study was to investigate the microstructural characteristics of the brain lobes following radiotherapy (RT) for patients with nasopharyngeal carcinoma (NPC) at distinct times. Diffusion tensor imaging (DTI) and 3D-T1-weighted imaging was performed in 70 age- and sex-matched subjects, 24 of whom were pre-treatment patients. The patients were divided into three groups, according to the time following completion of RT. Fractional anisotropy (FA) and gray matter (GM) volume were determined. The DTI data were analyzed using tract-based spatial statistics and the GM volume was analyzed using voxel-based morphometry (VBM). Compared with the pre-RT group, the mean FA values in the left parietal lobe white matter (WM) and right cerebellum decreased significantly in the post-RT 0-6 month group (P<0.05). In addition, the mean FA values in the right parietal lobe WM decreased significantly in the post-RT 6-12 month group (P<0.05), compared with the pre-RT group. The FA level in the right temporal lobe remained significantly decreased, compared with that in the pre-RT group (P<0.05) for 1 year after RT. Furthermore, compared with pre-RT group, the GM volume in the bilateral frontal lobe, right occipital lobe, left parietal lobe, right temporal lobe and left cerebellum decreased significantly in the post-RT 0-6 month group (P<0.05), and in the bilateral temporal lobe, parietal lobe, right frontal lobe and left cerebellum, the GM volume decreased significantly in the post-RT 6-12 month group (P<0.05). The GM volume in the right temporal lobe, bilateral frontal lobe and bilateral cerebellum remained significantly decreased compared with that in the pre-RT group (P<0.05) for 1 year after RT. A combination of DTI and VBM may be used to determine radiation-induced brain injury in patients treated for NPC.

Microsurgical anatomy of the transsylvian translimen insula approach to the mediobasal temporal lobe: Technical considerations and case illustration.

PubMed

Straus, David; Byrne, Richard W; Sani, Sepehr; Serici, Anthony; Moftakhar, Roham

2013-01-01

Various vascular, neoplastic, and epileptogenic pathologies occur in the mediobasal temporal region. A transsylvian translimen insula (TTI) approach can be used as an alternative to temporal transcortical approach to the mediobasal temporal region. The aim of this study was to demonstrate the surgical anatomy of the TTI approach, including the gyral, sulcal, and vascular anatomy in and around the limen insula. The use of this approach is illustrated in the resection of a complex arteriovenous malformation. The TTI approach to the mediobasal temporal region was performed on three silicone-injected cadaveric heads. The gyral, sulcal, and arterial anatomy of the limen insula was studied in six formalin-fixed injected hemispheres. The TTI approach provided access to the anterior and middle segments of the mediobasal temporal lobe region as well as allowing access to temporal horn of the lateral ventricle. Using this approach we were able to successfully resect an arteriovenous malformation of the dominant medial temporal lobe. The TTI approach provides a viable surgical route to the region of mediobasal temporal lobe region. This approach offers an advantage over the temporal transcortical route in that there is less risk of damage to optic radiations and speech area in the dominant hemisphere.

Effects of Decompressive Surgery on Prognosis and Cognitive Deficits in Herpes Simplex Encephalitis

PubMed Central

Midi, Ipek; Tuncer, Nese; Midi, Ahmet; Mollahasanoglu, Aynur; Konya, Deniz; Sav, Aydın

2007-01-01

Herpes simplex encephalitis (HSE) is a serious viral infection with a high rate of mortality. The most commonly seen complications are behavioral changes, seizures and memory deficits. We report the case of a 37-year-old man with HSE in the right temporal lobe and a severe midline shift who was treated with acyclovir. The patient underwent anterior temporal lobe resection. Although HSE can cause permanent cognitive deficits, in this case, early surgical intervention minimized any deficit, as determined by detailed neuropsychological examination. Surgical decompression is indicated as early as possible in severe cases. This case report emphasizes the effect of surgical decompression for HSE on cognitive function, which has rarely been mentioned before. PMID:18430984

Functional network changes in the hippocampus contribute to depressive symptoms in epilepsy.

PubMed

Peng, Weifeng; Mao, Lingyan; Yin, Dazhi; Sun, Wei; Wang, He; Zhang, Qianqian; Wang, Jing; Chen, Caizhong; Zeng, Mengsu; Ding, Jing; Wang, Xin

2018-06-01

Our study aimed to investigate the functional connectivity (FC) between the hippocampus and other brain regions in epilepsy patients with depressive symptoms. Epilepsy patients with and without depressive symptoms, assessed using the 17-item Hamilton Depression Rating Scale scores, were enrolled. Healthy volunteers were recruited as the control group. Resting state functional magnetic resonance imaging was performed, and the data were processed using Resting-State fMRI (DPARSFA2.0) software. The regional homogeneity (ReHo) values and the FC between the right hippocampus and other brain regions were analysed. The ReHo value of the cerebellum (particularly the left cerebellar hemisphere) was significantly lower in epilepsy patients than in healthy controls, and was lower in epilepsy patients with depressive symptoms (EP + DS group) than in those without depressive symptoms (EP-DS group, p < 0.05). Additionally, the FC between the right hippocampus and the bilateral cerebellum was significantly greater in the EP + DS group than in the EP-DS group (p < 0.05). Moreover, abnormal ReHo values in the bilateral frontal lobes, including the right anterior cingulate cortex, and changes in the FC between the right hippocampus and the bilateral frontal lobes were found in the EP + DS group. Minor changes in the FC between the temporal and parietal lobes were also found in the epilepsy patients. The functional right hippocampus-cerebellum circuit might contribute to the pathogenesis of depressive symptoms in epilepsy, with the exception of brain areas associated with emotion such as the frontal and temporal lobes. Modulating the hippocampus-cerebellum circuit is a potential therapeutic strategy for epilepsy patients with depressive symptoms. Copyright © 2018 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

What dementia reveals about proverb interpretation and its neuroanatomical correlates.

PubMed

Kaiser, Natalie C; Lee, Grace J; Lu, Po H; Mather, Michelle J; Shapira, Jill; Jimenez, Elvira; Thompson, Paul M; Mendez, Mario F

2013-08-01

Neuropsychologists frequently include proverb interpretation as a measure of executive abilities. A concrete interpretation of proverbs, however, may reflect semantic impairments from anterior temporal lobes, rather than executive dysfunction from frontal lobes. The investigation of proverb interpretation among patients with different dementias with varying degrees of temporal and frontal dysfunction may clarify the underlying brain-behavior mechanisms for abstraction from proverbs. We propose that patients with behavioral variant frontotemporal dementia (bvFTD), who are characteristically more impaired on proverb interpretation than those with Alzheimer's disease (AD), are disproportionately impaired because of anterior temporal-mediated semantic deficits. Eleven patients with bvFTD and 10 with AD completed the Delis-Kaplan Executive Function System (D-KEFS) Proverbs Test and a series of neuropsychological measures of executive and semantic functions. The analysis included both raw and age-adjusted normed data for multiple choice responses on the D-KEFS Proverbs Test using independent samples t-tests. Tensor-based morphometry (TBM) applied to 3D T1-weighted MRI scans mapped the association between regional brain volume and proverb performance. Computations of mean Jacobian values within select regions of interest provided a numeric summary of regional volume, and voxel-wise regression yielded 3D statistical maps of the association between tissue volume and proverb scores. The patients with bvFTD were significantly worse than those with AD in proverb interpretation. The worse performance of the bvFTD patients involved a greater number of concrete responses to common, familiar proverbs, but not to uncommon, unfamiliar ones. These concrete responses to common proverbs correlated with semantic measures, whereas concrete responses to uncommon proverbs correlated with executive functions. After controlling for dementia diagnosis, TBM analyses indicated significant correlations between impaired proverb interpretation and the anterior temporal lobe region (left>right). Among two dementia groups, those with bvFTD, demonstrated a greater number of concrete responses to common proverbs compared to those with AD, and this performance correlated with semantic deficits and the volume of the left anterior lobe, the hub of semantic knowledge. The findings of this study suggest that common proverb interpretation is greatly influenced by semantic dysfunction and that the use of proverbs for testing executive functions needs to include the interpretation of unfamiliar proverbs. Published by Elsevier Ltd.

Genetics Home Reference: GRN-related frontotemporal dementia

MedlinePlus

... temporal lobes . The frontal lobes are involved in reasoning, planning, judgment, and problem-solving, while the temporal ... MND. Phenotype variability in progranulin mutation carriers: a clinical, neuropsychological, imaging and genetic study. Brain. 2008 Mar; ...

Semantic and episodic memory in children with temporal lobe epilepsy: do they relate to literacy skills?

PubMed

Lah, Suncica; Smith, Mary Lou

2014-01-01

Children with temporal lobe epilepsy are at risk for deficits in new learning (episodic memory) and literacy skills. Semantic memory deficits and double dissociations between episodic and semantic memory have recently been found in this patient population. In the current study we investigate whether impairments of these 2 distinct memory systems relate to literacy skills. 57 children with unilateral temporal lobe epilepsy completed tests of verbal memory (episodic and semantic) and literacy skills (reading and spelling accuracy, and reading comprehension). For the entire group, semantic memory explained over 30% of variance in each of the literacy domains. Episodic memory explained a significant, but rather small proportion (< 10%) of variance in reading and spelling accuracy, but not in reading comprehension. Moreover, when children with opposite patterns of specific memory impairments (intact semantic/impaired episodic, intact episodic/impaired semantic) were compared, significant reductions in literacy skills were evident only in children with semantic memory impairments, but not in children with episodic memory impairments relative to the norms and to children with temporal lobe epilepsy who had intact memory. Our study provides the first evidence for differential relations between episodic and semantic memory impairments and literacy skills in children with temporal lobe epilepsy. As such, it highlights the urgent need to consider semantic memory deficits in management of children with temporal lobe epilepsy and undertake further research into the nature of reading difficulties of children with semantic memory impairments.

Cortical thickness and folding deficits in conduct-disordered adolescents

PubMed Central

Hyatt, Christopher J.; Haney-Caron, Emily; Stevens, Michael C.

2012-01-01

Background Studies of pediatric conduct disorder (CD) have described frontal and temporal lobe structural abnormalities that parallel findings in antisocial adults. The purpose of this study was to examine previously unexplored cortical thickness and folding as markers for brain abnormalities in “pure CD”-diagnosed adolescents. Based on current fronto-temporal theories, we hypothesized that CD youth would have thinner cortex or less cortical folding in temporal and frontal lobes than control subjects. Methods We obtained T1-weighted brain structure images from n=24 control and n=19 CD participants aged 12–18 years, matched by overall gender and age. We measured group differences in cortical thickness and local gyrification index (regional cortical folding measure) using surface-based morphometry with clusterwise correction for multiple comparisons. Results CD participants, when compared with controls, showed both reduced cortical thickness and folding. Thinner cortex was located primarily in posterior brain regions, including left superior temporal and parietal lobes, temporoparietal junction and paracentral lobule, right superior temporal and parietal lobes, temporoparietal junction and precuneus. Folding deficits were located mainly in anterior brain regions and included left insula, ventro- and dorsomedial prefrontal, anterior cingulate and orbitofrontal cortices, temporal lobe, right superior frontal and parietal lobes and paracentral lobule. Conclusions Our findings generally agree with previous CD volumetric studies, but here show the unique contributions of cortical thickness and folding to gray matter reductions in pure CD in different brain regions. PMID:22209639

Stimulus familiarity modulates functional connectivity of the perirhinal cortex and anterior hippocampus during visual discrimination of faces and objects

PubMed Central

McLelland, Victoria C.; Chan, David; Ferber, Susanne; Barense, Morgan D.

2014-01-01

Recent research suggests that the medial temporal lobe (MTL) is involved in perception as well as in declarative memory. Amnesic patients with focal MTL lesions and semantic dementia patients showed perceptual deficits when discriminating faces and objects. Interestingly, these two patient groups showed different profiles of impairment for familiar and unfamiliar stimuli. For MTL amnesics, the use of familiar relative to unfamiliar stimuli improved discrimination performance. By contrast, patients with semantic dementia—a neurodegenerative condition associated with anterolateral temporal lobe damage—showed no such facilitation from familiar stimuli. Given that the two patient groups had highly overlapping patterns of damage to the perirhinal cortex, hippocampus, and temporal pole, the neuroanatomical substrates underlying their performance discrepancy were unclear. Here, we addressed this question with a multivariate reanalysis of the data presented by Barense et al. (2011), using functional connectivity to examine how stimulus familiarity affected the broader networks with which the perirhinal cortex, hippocampus, and temporal poles interact. In this study, healthy participants were scanned while they performed an odd-one-out perceptual task involving familiar and novel faces or objects. Seed-based analyses revealed that functional connectivity of the right perirhinal cortex and right anterior hippocampus was modulated by the degree of stimulus familiarity. For familiar relative to unfamiliar faces and objects, both right perirhinal cortex and right anterior hippocampus showed enhanced functional correlations with anterior/lateral temporal cortex, temporal pole, and medial/lateral parietal cortex. These findings suggest that in order to benefit from stimulus familiarity, it is necessary to engage not only the perirhinal cortex and hippocampus, but also a network of regions known to represent semantic information. PMID:24624075

The right hemisphere's contribution to discourse processing: A study in temporal lobe epilepsy.

PubMed

Lomlomdjian, Carolina; Múnera, Claudia P; Low, Daniel M; Terpiluk, Verónica; Solís, Patricia; Abusamra, Valeria; Kochen, Silvia

2017-08-01

Discourse skills - in which the right hemisphere has an important role - enables verbal communication by selecting contextually relevant information and integrating it coherently to infer the correct meaning. However, language research in epilepsy has focused on single word analysis related mainly to left hemisphere processing. The purpose of this study was to investigate discourse abilities in patients with right lateralized medial temporal lobe epilepsy (RTLE) by comparing their performance to that of patients with left temporal lobe epilepsy (LTLE). 74 pharmacoresistant temporal lobe epilepsy (TLE) patients were evaluated: 34 with RTLE and 40 with LTLE. Subjects underwent a battery of tests that measure comprehension and production of conversational and narrative discourse. Disease related variables and general neuropsychological data were evaluated. The RTLE group presented deficits in interictal conversational and narrative discourse, with a disintegrated speech, lack of categorization and misinterpretation of social meaning. LTLE group, on the other hand, showed a tendency to lower performance in logical-temporal sequencing. RTLE patients showed discourse deficits which have been described in right hemisphere damaged patients due to other etiologies. Medial and anterior temporal lobe structures appear to link semantic, world knowledge, and social cognition associated areas to construct a contextually related coherent meaning. Copyright © 2017 Elsevier Inc. All rights reserved.

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.

A single subconvulsant dose of domoic acid at mid-gestation does not cause temporal lobe epilepsy in mice.

PubMed

Demars, Fanny; Clark, Kristen; Wyeth, Megan S; Abrams, Emily; Buckmaster, Paul S

2018-05-01

Harmful blooms of domoic acid (DA)-producing algae are a problem in oceans worldwide. DA is a potent glutamate receptor agonist that can cause status epilepticus and in survivors, temporal lobe epilepsy. In mice, one-time low-dose in utero exposure to DA was reported to cause hippocampal damage and epileptiform activity, leading to the hypothesis that unrecognized exposure to DA from contaminated seafood in pregnant women can damage the fetal hippocampus and initiate temporal lobe epileptogenesis. However, development of epilepsy (i.e., spontaneous recurrent seizures) has not been tested. In the present study, long-term seizure monitoring and histology was used to test for temporal lobe epilepsy following prenatal exposure to DA. In Experiment One, the previous study's in utero DA treatment protocol was replicated, including use of the CD-1 mouse strain. Afterward, mice were video-monitored for convulsive seizures from 2 to 6 months old. None of the CD-1 mice treated in utero with vehicle or DA was observed to experience spontaneous convulsive seizures. After seizure monitoring, mice were evaluated for pathological evidence of temporal lobe epilepsy. None of the mice treated in utero with DA displayed the hilar neuron loss that occurs in patients with temporal lobe epilepsy and in the mouse pilocarpine model of temporal lobe epilepsy. In Experiment Two, a higher dose of DA was administered to pregnant FVB mice. FVB mice were tested as a potentially more sensitive strain, because they have a lower seizure threshold, and some females spontaneously develop epilepsy. Female offspring were monitored with continuous video and telemetric bilateral hippocampal local field potential recording at 1-11 months old. A similar proportion of vehicle- and DA-treated female FVB mice spontaneously developed epilepsy, beginning in the fourth month of life. Average seizure frequency and duration were similar in both groups. Seizure frequency was lower than that of positive-control pilocarpine-treated mice, but seizure duration was similar. None of the mice treated in utero with vehicle or DA displayed hilar neuron loss or intense mossy fiber sprouting, a form of aberrant synaptic reorganization that develops in patients with temporal lobe epilepsy and in pilocarpine-treated mice. FVB mice that developed epilepsy (vehicle- and DA-treated) displayed mild mossy fiber sprouting. Results of this study suggest that a single subconvulsive dose of DA at mid-gestation does not cause temporal lobe epilepsy in mice. Copyright © 2018 Elsevier B.V. All rights reserved.

Temporal lobe epilepsy in a cat with a pyriform lobe oligodendroglioma and hippocampal necrosis.

PubMed

Vanhaesebrouck, An E; Posch, Barbara; Baker, Sam; Plessas, Ioannis N; Palmer, Anthony C; Constantino-Casas, Fernando

2012-12-01

A 14-year-old male domestic shorthair cat presented with an acute onset of aggressive behaviour, fear and hypersalivation. Neurological examination revealed bilateral mydriasis and left-sided facial twitching and hemiparesis. Magnetic resonance imaging (MRI) showed moderate bilateral symmetrical T2-hyperintensity along the entire hippocampus and bilateral asymmetric T2-hyperintensity in the pyriform lobes. Marked bilateral contrast enhancement of the hippocampus was evident on post-contrast T1-weighted images. The partial complex seizures were refractory to medical treatment and the cat was euthanased 4 days after admission. The clinical and MRI findings were consistent with feline hippocampal necrosis (FHN). On histopathology, neuronal necrosis and astrocytosis were present in the hippocampi and pyriform lobes. In addition, an oligodendroglioma was detected in the right pyriform lobe. Contrary to previous reports of FHN in which no underlying cause could be identified, we believe that in this case the seizure focus arose from a neoplastic lesion within the right pyriform lobe. This unique case report represents the so-called 'dual pathology' of temporal lobe epilepsy in humans, in which an extrahippocampal lesion within the temporal lobe results in hippocampal sclerosis.

Fetal alcohol syndrome and secondary schizophrenia: a unique neuropathologic study.

PubMed

Stoos, Catherine; Nelsen, Laura; Schissler, Kathryn A; Elliott, Amy J; Kinney, Hannah C

2015-04-01

We report the unique neuropathologic study of an adult brain of a patient with fetal alcohol syndrome who developed the well-recognized complication of schizophrenia in adolescence. The major finding was asymmetric formation of the lateral temporal lobes, with marked enlargement of the right superior temporal gyrus, suggesting that alcohol is preferentially toxic to temporal lobe patterning during gestation. Critical maturational changes unique to adolescence can unmask psychotic symptomatology mediated by temporal lobe pathology that has been clinically dormant since birth. Elucidating the neuropathologic basis of the secondary psychiatric disorders in fetal alcohol syndrome can help provide insight into their putative developmental origins. © The Author(s) 2014.

Plasticity of Interhemispheric Temporal Lobe White Matter Pathways Due to Early Disruption of Corpus Callosum Development in Spina Bifida

PubMed Central

Juranek, Jenifer; Romanowska-Pawliczek, Anna; Hannay, H. Julia; Cirino, Paul T.; Dennis, Maureen; Kramer, Larry A.; Fletcher, Jack M.

2016-01-01

Abstract Spina bifida myelomeningocele (SBM) is commonly associated with anomalous development of the corpus callosum (CC) because of congenital partial hypogenesis and hydrocephalus-related hypoplasia. It represents a model disorder to examine the effects of early disruption of CC neurodevelopment and the plasticity of interhemispheric white matter connections. Diffusion tensor imaging was acquired on 76 individuals with SBM and 27 typically developing individuals, aged 8–36 years. Probabilistic tractography was used to isolate the interhemispheric connections between the posterior superior temporal lobes, which typically traverse the posterior third of the CC. Early disruption of CC development resulted in restructuring of interhemispheric connections through alternate commissures, particularly the anterior commissure (AC). These rerouted fibers were present in people with SBM and both CC hypoplasia and hypogenesis. In addition, microstructural integrity was reduced in the interhemispheric temporal tract in people with SBM, indexed by lower fractional anisotropy, axial diffusivity, and higher radial diffusivity. Interhemispheric temporal tract volume was positively correlated with total volume of the CC, such that more severe underdevelopment of the CC was associated with fewer connections between the posterior temporal lobes. Therefore, both the macrostructure and microstructure of this interhemispheric tract were reduced, presumably as a result of more extensive CC malformation. The current findings suggest that early disruption in CC development reroutes interhemispheric temporal fibers through both the AC and more anterior sections of the CC in support of persistent hypotheses that the AC may serve a compensatory function in atypical CC development. PMID:26798959

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.

Peri-ictal water drinking: a rare automatic behaviour in temporal lobe epilepsy.

PubMed

Pietrafusa, Nicola; Trivisano, Marina; de Palma, Luca; Serino, Domenico; Moavero, Romina; Benvenga, Antonella; Cappelletti, Simona; Boero, Giovanni; Vigevano, Federico; La Neve, Angela; Specchio, Nicola

2015-12-01

Peri-ictal water drinking (PIWD) has been reported as the action of drinking during or within two minutes of an electroclinical seizure. It is considered a peri-ictal vegetative symptom, evident both during childhood and adulthood epilepsy. The aim of this paper was to describe the clinical and electroencephalographic features of two new adult subjects suffering from symptomatic temporal lobe epilepsy with episodes of PIWD recorded by VIDEO-EEG and to review literature data in order to better define this peculiar event during seizures, a rare and probably underestimated semiological sign. To date, 51 cases with focal epilepsy and seizures associated with PIWD have been reported. All patients presented with temporal lobe epilepsy. All cases but one had symptomatic epilepsy. Most of the patients had an involvement of the right hemisphere. Water drinking was reported as an ictal sign in the majority of patients, and less frequently was reported as postictal. We believe that PIWD might be considered a rare automatic behaviour, like other automatisms. Automatisms are more frequently described in patients with temporal lobe epilepsy. PIWD was reported also to have lateralizing significance in the non-dominant temporal lobe, however, because of its rarity, this finding remains unclear.

Two magneto-encephalographic epileptic foci did not coincide with the electrocorticographic ictal onset zone in a patient with temporal lobe epilepsy.

PubMed

Hisada, K; Morioka, T; Nishio, S; Yamamoto, T; Fukui, M

2001-12-01

To evaluate the usefulness and limitations of magneto-encephalography (MEG) for epilepsy surgery, we compared 'interictal' epileptic spike fields on MEG with ictal electrocorticography (ECoG) using invasive chronic subdural electrodes in a patient with intractable medial temporal lobe epilepsy (MTLE) associated with vitamin K deficiency intracerebral hemorrhage. A 19-year-old male with an 8-year history of refractory complex partial seizures, secondarily generalized, and right hemispheric atrophy and porencephaly in the right frontal lobe on MRI, was studied with MEG to define the interictal paroxysmal sources based on the single-dipole model. This was followed by invasive ECoG monitoring to delineate the epileptogenic zone. MEG demonstrated two paroxysmal foci, one each on the right lateral temporal and frontal lobes. Ictal ECoG recordings revealed an ictal onset zone on the right medial temporal lobe, which was different from that defined by MEG. Anterior temporal lobectomy with hippocampectomy was performed and the patient has been seizure free for two years. Our results indicate that interictal MEG does not always define the epileptogenic zone in patients with MTLE.

Variations and asymmetries in regional brain surface in the genus Homo.

PubMed

Balzeau, Antoine; Holloway, Ralph L; Grimaud-Hervé, Dominique

2012-06-01

Paleoneurology is an important field of research within human evolution studies. Variations in size and shape of an endocast help to differentiate among fossil hominin species whereas endocranial asymmetries are related to behavior and cognitive function. Here we analyse variations of the surface of the frontal, parieto-temporal and occipital lobes among different species of Homo, including 39 fossil hominins, ten fossil anatomically modern Homo sapiens and 100 endocasts of extant modern humans. We also test for the possible asymmetries of these features in a large sample of modern humans and observe individual particularities in the fossil specimens. This study contributes important new information about the brain evolution in the genus Homo. Our results show that the general pattern of surface asymmetry for the different regional brain surfaces in fossil species of Homo does not seem to be different from the pattern described in a large sample of anatomically modern H. sapiens, i.e., the right hemisphere has a larger surface than the left, as do the right frontal, the right parieto-temporal and the left occipital lobes compared with the contra-lateral side. It also appears that Asian Homo erectus specimens are discriminated from all other samples of Homo, including African and Georgian specimens that are also sometimes included in that taxon. The Asian fossils show a significantly smaller relative size of the parietal and temporal lobes. Neandertals and anatomically modern H. sapiens, who share the largest endocranial volume of all hominins, show differences when considering the relative contribution of the frontal, parieto-temporal and occipital lobes. These results illustrate an original variation in the pattern of brain organization in hominins independent of variations in total size. The globularization of the brain and the enlargement of the parietal lobes could be considered derived features observed uniquely in anatomically modern H. sapiens. Copyright © 2012 Elsevier Ltd. All rights reserved.

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.

Memory Outcomes Following Selective versus Nonselective Temporal Lobe Removal: A Systematic Review

ERIC Educational Resources Information Center

Girgis, Fady

2012-01-01

The surgical removal of brain tissue for the treatment of temporal lobe epilepsy can be either nonselective, as with an anterior temporal lobectomy (ATL), or selective, as with a selective amygdalohippocampectomy (SAH). Although seizure outcomes are similar with both procedures, cognitive and memory outcomes remain a matter of debate. This study…

Perfusion network shift during seizures in medial temporal lobe epilepsy.

PubMed

Sequeira, Karen M; Tabesh, Ali; Sainju, Rup K; DeSantis, Stacia M; Naselaris, Thomas; Joseph, Jane E; Ahlman, Mark A; Spicer, Kenneth M; Glazier, Steve S; Edwards, Jonathan C; Bonilha, Leonardo

2013-01-01

Medial temporal lobe epilepsy (MTLE) is associated with limbic atrophy involving the hippocampus, peri-hippocampal and extra-temporal structures. While MTLE is related to static structural limbic compromise, it is unknown whether the limbic system undergoes dynamic regional perfusion network alterations during seizures. In this study, we aimed to investigate state specific (i.e. ictal versus interictal) perfusional limbic networks in patients with MTLE. We studied clinical information and single photon emission computed tomography (SPECT) images obtained with intravenous infusion of the radioactive tracer Technetium- Tc 99 m Hexamethylpropyleneamine Oxime (Tc-99 m HMPAO) during ictal and interictal state confirmed by video-electroencephalography (VEEG) in 20 patients with unilateral MTLE (12 left and 8 right MTLE). Pair-wise voxel-based analyses were used to define global changes in tracer between states. Regional tracer uptake was calculated and state specific adjacency matrices were constructed based on regional correlation of uptake across subjects. Graph theoretical measures were applied to investigate global and regional state specific network reconfigurations. A significant increase in tracer uptake was observed during the ictal state in the medial temporal region, cerebellum, thalamus, insula and putamen. From network analyses, we observed a relative decreased correlation between the epileptogenic temporal region and remaining cortex during the interictal state, followed by a surge of cross-correlated perfusion in epileptogenic temporal-limbic structures during a seizure, corresponding to local network integration. These results suggest that MTLE is associated with a state specific perfusion and possibly functional organization consisting of a surge of limbic cross-correlated tracer uptake during a seizure, with a relative disconnection of the epileptogenic temporal lobe in the interictal period. This pattern of state specific shift in metabolic networks in MTLE may improve the understanding of epileptogenesis and neuropsychological impairments associated with MTLE.

1H-MR spectroscopy and diffusion tensor imaging of normal-appearing temporal white matter in patients with nasopharyngeal carcinoma after irradiation: initial experience.

PubMed

Xiong, Wei Feng; Qiu, Shi Jun; Wang, Hong Zhuo; Lv, Xiao Fei

2013-01-01

To detect radiation-induced changes of temporal lobe normal-appearing white mater (NAWM) following radiation therapy (RT) for nasopharyngeal carcinoma (NPC). Seventy-five H(1)-MR spectroscopy and diffusion-tensor imaging (DTI) examinations were performed in 55 patients before and after receiving fractionated radiation therapy (total dose; 66-75GY). We divided the dataset into six groups, a pre-RT control group and five other groups based on time after completion of RT. N-acetylaspartic acid (NAA)/choline (Cho), NAA/creatine (Cr), Cho/Cr, mean diffusibility (MD), functional anisotropy (FA), radial diffusibility (λ(⊥)), and axial diffusibility (λ(||)) were calculated. NAA/Cho and NAA/Cr decreased and λ(⊥) increased significantly within 1 year after RT compared with pre-RT. After 1 year, NAA/Cho, NAA/Cr, and λ(⊥) were not significantly different from pre-RT. In all post-RT groups, FA decreased significantly. λ(||) decreased within 9 months after RT compared with pre-RT, but was not significantly different from pre-RT more than 9 months after RT. DTI and H(1)-MR spectroscopy can be used to detect early radiation-induced changes of temporal lobe NAWM following radiation therapy for NPC. Metabolic alterations and water diffusion characteristics of temporal lobe NAWM in patients with NPC after RT were dynamic and transient. Copyright © 2012 Wiley Periodicals, Inc.

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.

Medial temporal lobe contributions to cued retrieval of items and contexts.

PubMed

Hannula, Deborah E; Libby, Laura A; Yonelinas, Andrew P; Ranganath, Charan

2013-10-01

Several models have proposed that different regions of the medial temporal lobes contribute to different aspects of episodic memory. For instance, according to one view, the perirhinal cortex represents specific items, parahippocampal cortex represents information regarding the context in which these items were encountered, and the hippocampus represents item-context bindings. Here, we used event-related functional magnetic resonance imaging (fMRI) to test a specific prediction of this model-namely, that successful retrieval of items from context cues will elicit perirhinal recruitment and that successful retrieval of contexts from item cues will elicit parahippocampal cortex recruitment. Retrieval of the bound representation in either case was expected to elicit hippocampal engagement. To test these predictions, we had participants study several item-context pairs (i.e., pictures of objects and scenes, respectively), and then had them attempt to recall items from associated context cues and contexts from associated item cues during a scanned retrieval session. Results based on both univariate and multivariate analyses confirmed a role for hippocampus in content-general relational memory retrieval, and a role for parahippocampal cortex in successful retrieval of contexts from item cues. However, we also found that activity differences in perirhinal cortex were correlated with successful cued recall for both items and contexts. These findings provide partial support for the above predictions and are discussed with respect to several models of medial temporal lobe function. Copyright © 2013 Elsevier Ltd. All rights reserved.

Different macaque models of cognitive aging exhibit task-dependent behavioral disparities.

PubMed

Comrie, Alison E; Gray, Daniel T; Smith, Anne C; Barnes, Carol A

2018-05-15

Deficits in cognitive functions that rely on the integrity of the frontal and temporal lobes are characteristic of normative human aging. Due to similar aging phenotypes and homologous cortical organization between nonhuman primates and humans, several species of macaque monkeys are used as models to explore brain senescence. These macaque species are typically regarded as equivalent models of cognitive aging, yet no direct comparisons have been made to support this assumption. Here we used adult and aged rhesus and bonnet macaques (Macaca mulatta and Macaca radiata) to characterize the effect of age on acquisition and retention of information across delays in a battery of behavioral tasks that rely on prefrontal cortex and medial temporal lobe networks. The cognitive functions that were tested include visuospatial short-term memory, object recognition memory, and object-reward association memory. In general, bonnet macaques at all ages outperformed rhesus macaques on tasks thought to rely primarily on the prefrontal cortex, and were more resilient to age-related deficits in these behaviors. On the other hand, both species were comparably impaired by age on tasks thought to preferentially engage the medial temporal lobe. Together, these results suggest that rhesus and bonnet macaques are not equivalent models of cognitive aging and highlight the value of cross-species comparisons. These observations should enable improved design and interpretation of future experiments aimed at understanding changes in cognition across the lifespan. Copyright © 2018 Elsevier B.V. All rights reserved.

Recurrent spontaneous motor seizures after repeated low-dose systemic treatment with kainate: assessment of a rat model of temporal lobe epilepsy.

PubMed

Hellier, J L; Patrylo, P R; Buckmaster, P S; Dudek, F E

1998-06-01

Human temporal lobe epilepsy is associated with complex partial seizures that can produce secondarily generalized seizures and motor convulsions. In some patients with temporal lobe epilepsy, the seizures and convulsions occur following a latent period after an initial injury and may progressively increase in frequency for much of the patient's life. Available animal models of temporal lobe epilepsy are produced by acute treatments that often have high mortality rates and/or are associated with a low proportion of animals developing spontaneous chronic motor seizures. In this study, rats were given multiple low-dose intraperitoneal (i.p.) injections of kainate in order to minimize the mortality rate usually associated with single high-dose injections. We tested the hypothesis that these kainate-treated rats consistently develop a chronic epileptic state (i.e. long-term occurrence of spontaneous, generalized seizures and motor convulsions) following a latent period after the initial treatment. Kainate (5 mg/kg per h, i.p.) was administered to rats every hour for several hours so that class III-V seizures were elicited for > or = 3 h, while control rats were treated similarly with saline. This treatment protocol had a relatively low mortality rate (15%). After acute treatment, rats were observed for the occurrence of motor seizures for 6-8 h/week. Nearly all of the kainate-treated rats (97%) had two or more spontaneous motor seizures months after treatment. With this observation protocol, the average latency for the first spontaneous motor seizure was 77+/-38 (+/-S.D.) days after treatment. Although variability was observed between rats, seizure frequency initially increased with time after treatment, and nearly all of the kainate-treated rats (91%) had spontaneous motor seizures until the time of euthanasia (i.e. 5-22 months after treatment). Therefore, multiple low-dose injections of kainate, which cause recurrent motor seizures for > or = 3 h, lead to the development of a chronic epileptic state that is characterized by (i) a latent period before the onset of chronic motor seizures, and (ii) a high but variable seizure frequency that initially increases with time after the first chronic seizure. This modification of the kainate-treatment protocol is efficient and relatively simple, and the properties of the chronic epileptic state appear similar to severe human temporal lobe epilepsy. Furthermore, the observation that seizure frequency initially increased as a function of time after kainate treatment supports the hypothesis that temporal lobe epilepsy can be a progressive syndrome.

Temporal lobe sulcal pattern and the bony impressions in the middle cranial fossa: the case of the el Sidrón (Spain) neandertal sample.

PubMed

Rosas, Antonio; Peña-Melián, Angel; García-Tabernero, Antonio; Bastir, Markus; De La Rasilla, Marco

2014-12-01

Correspondence between temporal lobe sulcal pattern and bony impressions on the middle cranial fossae (MCF) was analyzed. MCF bone remains (SD-359, SD-315, and SD-1219) from the El Sidrón (Spain) neandertal site are analyzed in this context. Direct comparison of the soft and hard tissues from the same individual was studied by means of: 1) dissection of two human heads; 2) optic (white light) surface scans; 3) computed tomography and magnetic resonance of the same head. The inferior temporal sulcus and gyrus are the features most strongly influencing MCF bone surface. The Superior temporal sulcus and middle temporal and fusiform gyri also leave imprints. Temporal lobe form differs between Homo sapiens and neandertals. A wider and larger post-arcuate fossa (posterior limit of Brodmann area 20 and the anterior portion of area 37) is present in modern humans as compared to neandertals. However other traits of the MCF surface are similar in these two large-brained human groups. A conspicuous variation is appreciated in the more vertical location of the inferior temporal gyrus in H. sapiens. In parallel, structures of the lower surface of the temporal lobe are more sagittally orientated. Grooves accommodating the fusiform and the lower temporal sulci become grossly parallel to the temporal squama. These differences can be understood within the context of a supero-lateral deployment of the lobe in H. sapiens, a pattern previously identified (Bastir et al., Nat Commun 2 (2011) 588-595). Regarding dural sinus pattern, a higher incidence of petrosquamous sinus is detected in neandertal samples. © 2014 Wiley Periodicals, Inc.

Temporal lobe volumes in patients with hippocampal sclerosis with or without cortical dysplasia.

PubMed

Diehl, B; Najm, I; LaPresto, E; Prayson, R; Ruggieri, P; Mohamed, A; Ying, Z; Lieber, M; Babb, T; Bingaman, W; Lüders, H O

2004-05-25

Recent MRI-based volume reconstruction studies in intractable temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS) suggested atrophy that extends to the adjacent neocortical areas. To study the extent of temporal lobe volume (TLV) abnormalities in patients with pathologically confirmed HS (with or without cortical dysplasia [CD]) who underwent anterior temporal lobectomy for the treatment of drug-resistant TLE. Fifty patients (right TLE: n = 24; left TLE: n = 26) were found to have HS (hippocampal cell loss of >30%). Associated neocortical CD was seen in 20 patients (43%). MRI-based TLVs and hippocampal and hemispheric volume reconstructions in all patients were compared between pathologic groups and with volumes acquired from 10 age-matched control subjects. TLVs ipsilateral to the epileptogenic zone in patients with TLE were smaller than TLVs in control subjects (p < 0.01). In patients with left TLE, TLVs ipsilateral to the epileptogenic zone were smaller than contralateral TLVs (left: 66.6 +/- 8.3 cm3, right: 74.9 +/- 10.0 cm3; p < 0.001). In patients with right TLE, there were no significant asymmetries. The contralateral TLVs (regardless of the side of surgery) were smaller in the HS + CD group than the HS group (HS + CD group: 74.9 +/- 8.6 cm3, HS group: 79.7 +/- 6.6 cm3; p < 0.05). Patients with HS + CD had a tendency to have less hippocampal atrophy and slightly smaller TLVs ipsilateral to the epileptogenic zone, accounting for significantly smaller TLV/hippocampal volume ratios compared with patients with HS alone. Drug-resistant TLE due to HS is associated with extrahippocampal temporal lobe atrophy. The presence of bilateral temporal lobe atrophy is suggestive of a more widespread (bilateral) temporal lobe involvement in patients with HS and CD.

Personal semantic memory: insights from neuropsychological research on amnesia.

PubMed

Grilli, Matthew D; Verfaellie, Mieke

2014-08-01

This paper provides insight into the cognitive and neural mechanisms of personal semantic memory, knowledge that is specific and unique to individuals, by reviewing neuropsychological research on stable amnesia secondary to medial temporal lobe damage. The results reveal that personal semantic memory does not depend on a unitary set of cognitive and neural mechanisms. Findings show that autobiographical fact knowledge reflects an experience-near type of personal semantic memory that relies on the medial temporal lobe for retrieval, albeit less so than personal episodic memory. Additional evidence demonstrates that new autobiographical fact learning likely relies on the medial temporal lobe, but the extent to which remains unclear. Other findings show that retrieval of personal traits/roles and new learning of personal traits/roles and thoughts/beliefs are independent of the medial temporal lobe and thus may represent highly conceptual types of personal semantic memory that are stored in the neocortex. Published by Elsevier Ltd.

Atypical language representation in children with intractable temporal lobe epilepsy.

PubMed

Maulisova, Alice; Korman, Brandon; Rey, Gustavo; Bernal, Byron; Duchowny, Michael; Niederlova, Marketa; Krsek, Pavel; Novak, Vilem

2016-05-01

This study evaluated language organization in children with intractable epilepsy caused by temporal lobe focal cortical dysplasia (FCD) alone or dual pathology (temporal lobe FCD and hippocampal sclerosis, HS). We analyzed clinical, neurological, fMRI, neuropsychological, and histopathologic data in 46 pediatric patients with temporal lobe lesions who underwent excisional epilepsy surgery. The frequency of atypical language representation was similar in both groups, but children with dual pathology were more likely to be left-handed. Atypical receptive language cortex correlated with lower intellectual capacity, verbal abstract conceptualization, receptive language abilities, verbal working memory, and a history of status epilepticus but did not correlate with higher seizure frequency or early seizure onset. Histopathologic substrate had only a minor influence on neuropsychological status. Greater verbal comprehension deficits were noted in children with atypical receptive language representation, a risk factor for cognitive morbidity. Copyright © 2016 Elsevier Inc. All rights reserved.

Altered cortical anatomical networks in temporal lobe epilepsy

NASA Astrophysics Data System (ADS)

Lv, Bin; He, Huiguang; Lu, Jingjing; Li, Wenjing; Dai, Dai; Li, Meng; Jin, Zhengyu

2011-03-01

Temporal lobe epilepsy (TLE) is one of the most common epilepsy syndromes with focal seizures generated in the left or right temporal lobes. With the magnetic resonance imaging (MRI), many evidences have demonstrated that the abnormalities in hippocampal volume and the distributed atrophies in cortical cortex. However, few studies have investigated if TLE patients have the alternation in the structural networks. In the present study, we used the cortical thickness to establish the morphological connectivity networks, and investigated the network properties using the graph theoretical methods. We found that all the morphological networks exhibited the small-world efficiency in left TLE, right TLE and normal groups. And the betweenness centrality analysis revealed that there were statistical inter-group differences in the right uncus region. Since the right uncus located at the right temporal lobe, these preliminary evidences may suggest that there are topological alternations of the cortical anatomical networks in TLE, especially for the right TLE.

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.

T2 hyperintense signal in patients with temporal lobe epilepsy with MRI signs of hippocampal sclerosis and in patients with temporal lobe epilepsy with normal MRI.

PubMed

Kubota, Bruno Yukio; Coan, Ana Carolina; Yasuda, Clarissa Lin; Cendes, Fernando

2015-05-01

Increased MRI T2 signal is commonly present not only in the hippocampus but also in other temporal structures of patients with temporal lobe epilepsy (TLE), and it is associated with histological abnormalities related to the epileptogenic lesion. This study aimed to verify the distribution of T2 increased signal in temporal lobe structures and its correlations with clinical characteristics of TLE patients with (TLE-HS) or without (TLE-NL) MRI signs of hippocampal sclerosis. We selected 203 consecutive patients: 124 with TLE-HS and 79 with TLE-NL. Healthy controls (N=59) were used as a comparison group/comparative group. T2 multiecho images obtained via a 3-T MRI were evaluated with in-house software. T2 signal decays were computed from five original echoes in regions of interest in the hippocampus, amygdala, and white matter of the anterior temporal lobe. Values higher than 2 standard deviations from the mean of controls were considered as abnormal. T2 signal increase was observed in the hippocampus in 78% of patients with TLE-HS and in 17% of patients with TLE-NL; in the amygdala in 13% of patients with TLE-HS and in 14% of patients with TLE-NL; and in the temporal lobe white matter in 22% of patients with TLE-HS and in 8% of patients with TLE-NL. Group analysis demonstrated a significant difference in the distribution of the T2 relaxation times of the hippocampus (ANOVA, p<0.0001), amygdala (p=0.003), and temporal lobe white matter (p<0.0001) ipsilateral to the epileptogenic zone for patients with TLE-HS compared with controls but only for the amygdala (p=0.029) and temporal lobe white matter (ANOVA, p=0.025) for patients with TLE-NL compared with controls. The average signal from the hippocampus ipsilateral to the epileptogenic zone was significantly higher in patients with no family history of epilepsy (two-sample T-test, p=0.005). Increased T2 signal occurs in different temporal structures of patients with TLE-HS and in patients with TLE-NL. The hippocampal hyperintense signal is more pronounced in patients without family history of epilepsy and is influenced by earlier seizure onset. These changes in T2 signal may be associated with structural abnormalities related to the epileptogenic zone or to the nature of the initial precipitating injury in patients with TLE. Copyright © 2015 Elsevier Inc. All rights reserved.

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.

Bringing memory fMRI to the clinic: comparison of seven memory fMRI protocols in temporal lobe epilepsy.

PubMed

Towgood, Karren; Barker, Gareth J; Caceres, Alejandro; Crum, William R; Elwes, Robert D C; Costafreda, Sergi G; Mehta, Mitul A; Morris, Robin G; von Oertzen, Tim J; Richardson, Mark P

2015-04-01

fMRI is increasingly implemented in the clinic to assess memory function. There are multiple approaches to memory fMRI, but limited data on advantages and reliability of different methods. Here, we compared effect size, activation lateralisation, and between-sessions reliability of seven memory fMRI protocols: Hometown Walking (block design), Scene encoding (block design and event-related design), Picture encoding (block and event-related), and Word encoding (block and event-related). All protocols were performed on three occasions in 16 patients with temporal lobe epilepsy (TLE). Group T-maps showed activity bilaterally in medial temporal lobe for all protocols. Using ANOVA, there was an interaction between hemisphere and seizure-onset lateralisation (P = 0.009) and between hemisphere, protocol and seizure-onset lateralisation (P = 0.002), showing that the distribution of memory-related activity between left and right temporal lobes differed between protocols and between patients with left-onset and right-onset seizures. Using voxelwise intraclass Correlation Coefficient, between-sessions reliability was best for Hometown and Scenes (block and event). The between-sessions spatial overlap of activated voxels was also greatest for Hometown and Scenes. Lateralisation of activity between hemispheres was most reliable for Scenes (block and event) and Words (event). Using receiver operating characteristic analysis to explore the ability of each fMRI protocol to classify patients as left-onset or right-onset TLE, only the Words (event) protocol achieved a significantly above-chance classification of patients at all three sessions. We conclude that Words (event) protocol shows the best combination of between-sessions reliability of the distribution of activity between hemispheres and reliable ability to distinguish between left-onset and right-onset patients. © 2015 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

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

Naming and recognizing famous faces in temporal lobe epilepsy.

PubMed

Glosser, G; Salvucci, A E; Chiaravalloti, N D

2003-07-08

To assess naming and recognition of faces of familiar famous people in patients with epilepsy before and after anterior temporal lobectomy (ATL). Color photographs of famous people were presented for naming and description to 63 patients with temporal lobe epilepsy (TLE) either before or after ATL and to 10 healthy age- and education-matched controls. Spontaneous naming of photographed famous people was impaired in all patient groups, but was most abnormal in patients who had undergone left ATL. When allowed to demonstrate knowledge of the famous faces through verbal descriptions, rather than naming, patients with left TLE, left ATL, and right TLE improved to normal levels, but patients with right ATL were still impaired, suggesting a new deficit in identifying famous faces. Naming of famous people was related to naming of other common objects, verbal memory, and perceptual discrimination of faces. Recognition of the identity of pictured famous people was more related to visuospatial perception and memory. Lesions in anterior regions of the right temporal lobe impair recognition of the identities of familiar faces, as well as the learning of new faces. Lesions in the left temporal lobe, especially in anterior regions, disrupt access to the names of known people, but do not affect recognition of the identities of famous faces. Results are consistent with the hypothesized role of lateralized anterior temporal lobe structures in facial recognition and naming of unique entities.

Dynamic imaging in mild traumatic brain injury: support for the theory of medial temporal vulnerability.

PubMed

Umile, Eric M; Sandel, M Elizabeth; Alavi, Abass; Terry, Charles M; Plotkin, Rosette C

2002-11-01

To determine whether patients with mild traumatic brain injury (TBI) and persistent postconcussive symptoms have evidence of temporal lobe injury on dynamic imaging. Case series. An academic medical center. Twenty patients with a clinical diagnosis of mild TBI and persistent postconcussive symptoms were referred for neuropsychologic evaluation and dynamic imaging. Fifteen (75%) had normal magnetic resonance imaging (MRI) and/or computed tomography (CT) scans at the time of injury. Neuropsychologic testing, positron-emission tomography (PET), and single-photon emission-computed tomography (SPECT). Temporal lobe findings on static imaging (MRI, CT) and dynamic imaging (PET, SPECT); neuropsychologic test findings on measures of verbal and visual memory. Testing documented neurobehavioral deficits in 19 patients (95%). Dynamic imaging documented abnormal findings in 18 patients (90%). Fifteen patients (75%) had temporal lobe abnormalities on PET and SPECT (primarily in medial temporal regions); abnormal findings were bilateral in 10 patients (50%) and unilateral in 5 (25%). Six patients (30%) had frontal abnormalities, and 8 (40%) had nonfrontotemporal abnormalities. Correlations between neuropsychologic testing and dynamic imaging could be established but not consistently across the whole group. Patients with mild TBI and persistent postconcussive symptoms have a high incidence of temporal lobe injury (presumably involving the hippocampus and related structures), which may explain the frequent finding of memory disorders in this population. The abnormal temporal lobe findings on PET and SPECT in humans may be analogous to the neuropathologic evidence of medial temporal injury provided by animal studies after mild TBI. Copyright 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

Anterior temporal lobes mediate semantic representation: Mimicking semantic dementia by using rTMS in normal participants

PubMed Central

Pobric, Gorana; Jefferies, Elizabeth; Ralph, Matthew A. Lambon

2007-01-01

Studies of semantic dementia and PET neuroimaging investigations suggest that the anterior temporal lobes (ATL) are a critical substrate for semantic representation. In stark contrast, classical neurological models of comprehension do not include ATL, and likewise functional MRI studies often fail to show activations in the ATL, reinforcing the classical view. Using a novel application of low-frequency, repetitive transcranial magnetic stimulation (rTMS) over the ATL, we demonstrate that the behavioral pattern of semantic dementia can be mirrored in neurologically intact participants: Specifically, we show that temporary disruption to neural processing in the ATL produces a selective semantic impairment leading to significant slowing in both picture naming and word comprehension but not to other equally demanding, nonsemantic cognitive tasks. PMID:18056637

Category Learning in the Brain

PubMed Central

Seger, Carol A.; Miller, Earl K.

2013-01-01

The ability to group items and events into functional categories is a fundamental characteristic of sophisticated thought. It is subserved by plasticity in many neural systems, including neocortical regions (sensory, prefrontal, parietal, and motor cortex), the medial temporal lobe, the basal ganglia, and midbrain dopaminergic systems. These systems interact during category learning. Corticostriatal loops may mediate recursive, bootstrapping interactions between fast reward-gated plasticity in the basal ganglia and slow reward-shaded plasticity in the cortex. This can provide a balance between acquisition of details of experiences and generalization across them. Interactions between the corticostriatal loops can integrate perceptual, response, and feedback-related aspects of the task and mediate the shift from novice to skilled performance. The basal ganglia and medial temporal lobe interact competitively or cooperatively, depending on the demands of the learning task. PMID:20572771

FMRI Is a Valid Noninvasive Alternative to Wada Testing

PubMed Central

Binder, Jeffrey R.

2010-01-01

Partial removal of the anterior temporal lobe (ATL) is a highly effective surgical treatment for intractable temporal lobe epilepsy, yet roughly half of patients who undergo left ATL resection show decline in language or verbal memory function postoperatively. Two recent studies demonstrate that preoperative fMRI can predict postoperative naming and verbal memory changes in such patients. Most importantly, fMRI significantly improves the accuracy of prediction relative to other noninvasive measures used alone. Addition of language and memory lateralization data from the intracarotid amobarbital (Wada) test did not improve prediction accuracy in these studies. Thus, fMRI provides patients and practitioners with a safe, non-invasive, and well-validated tool for making better-informed decisions regarding elective surgery based on a quantitative assessment of cognitive risk. PMID:20850386

What role does the anterior temporal lobe play in sentence-level processing? Neural correlates of syntactic processing in semantic variant primary progressive aphasia.

PubMed

Wilson, Stephen M; DeMarco, Andrew T; Henry, Maya L; Gesierich, Benno; Babiak, Miranda; Mandelli, Maria Luisa; Miller, Bruce L; Gorno-Tempini, Maria Luisa

2014-05-01

Neuroimaging and neuropsychological studies have implicated the anterior temporal lobe (ATL) in sentence-level processing, with syntactic structure-building and/or combinatorial semantic processing suggested as possible roles. A potential challenge to the view that the ATL is involved in syntactic aspects of sentence processing comes from the clinical syndrome of semantic variant primary progressive aphasia (semantic PPA; also known as semantic dementia). In semantic PPA, bilateral neurodegeneration of the ATLs is associated with profound lexical semantic deficits, yet syntax is strikingly spared. The goal of this study was to investigate the neural correlates of syntactic processing in semantic PPA to determine which regions normally involved in syntactic processing are damaged in semantic PPA and whether spared syntactic processing depends on preserved functionality of intact regions, preserved functionality of atrophic regions, or compensatory functional reorganization. We scanned 20 individuals with semantic PPA and 24 age-matched controls using structural MRI and fMRI. Participants performed a sentence comprehension task that emphasized syntactic processing and minimized lexical semantic demands. We found that, in controls, left inferior frontal and left posterior temporal regions were modulated by syntactic processing, whereas anterior temporal regions were not significantly modulated. In the semantic PPA group, atrophy was most severe in the ATLs but extended to the posterior temporal regions involved in syntactic processing. Functional activity for syntactic processing was broadly similar in patients and controls; in particular, whole-brain analyses revealed no significant differences between patients and controls in the regions modulated by syntactic processing. The atrophic left ATL did show abnormal functionality in semantic PPA patients; however, this took the unexpected form of a failure to deactivate. Taken together, our findings indicate that spared syntactic processing in semantic PPA depends on preserved functionality of structurally intact left frontal regions and moderately atrophic left posterior temporal regions, but no functional reorganization was apparent as a consequence of anterior temporal atrophy and dysfunction. These results suggest that the role of the ATL in sentence processing is less likely to relate to syntactic structure-building and more likely to relate to higher-level processes such as combinatorial semantic processing.

Aerobic Exercise and Attention Deficit Hyperactivity Disorder: Brain Research

PubMed Central

Choi, Jae Won; Han, Doug Hyun; Kang, Kyung Doo; Jung, Hye Yeon; Renshaw, Perry F.

2017-01-01

Purpose As adjuvant therapy for enhancing the effects of stimulants and thereby minimizing medication doses, we hypothesized that aerobic exercise might be an effective adjunctive therapy for enhancing the effects of methylphenidate on the clinical symptoms, cognitive function, and brain activity of adolescents with attention deficit hyperactivity disorder (ADHD). Methods Thirty-five adolescents with ADHD were randomly assigned to one of two groups in a 1/1 ratio; methylphenidate treatment + 6-wk exercise (sports-ADHD) or methylphenidate treatment + 6-wk education (edu-ADHD). At baseline and after 6 wk of treatment, symptoms of ADHD, cognitive function, and brain activity were evaluated using the Dupaul attention deficit hyperactivity disorder rating scale–Korean version (K-ARS), the Wisconsin Card Sorting Test, and 3-T functional magnetic resonance imaging, respectively. Results The K-ARS total score and perseverative errors in the sports-ADHD group decreased compared with those in the edu-ADHD group. After the 6-wk treatment period, the mean β value of the right frontal lobe in the sports-ADHD group increased compared with that in the edu-ADHD group. The mean β value of the right temporal lobe in the sports-ADHD group decreased. However, the mean β value of the right temporal lobe in the edu-ADHD group did not change. The change in activity within the right prefrontal cortex in all adolescents with ADHD was negatively correlated with the change in K-ARS scores and perseverative errors. Conclusions The current results indicate that aerobic exercise increased the effectiveness of methylphenidate on clinical symptoms, perseverative errors, and brain activity within the right frontal and temporal cortices in response to the Wisconsin card sorting test stimulation. PMID:24824770

Transport induced by mean-eddy interaction: I. Theory, and relation to Lagrangian lobe dynamics

NASA Astrophysics Data System (ADS)

Ide, Kayo; Wiggins, Stephen

2015-02-01

In this paper we develop a method for the estimation of Transport Induced by the Mean-Eddy interaction (TIME) in two-dimensional unsteady flows. The method is based on the dynamical systems approach to fluid transport and can be viewed as a hybrid combination of Lagrangian and Eulerian methods. The (Eulerian) boundaries across which we consider (Lagrangian) transport are kinematically defined by appropriately chosen streamlines of the mean flow. By evaluating the impact of the mean-eddy interaction on transport, the TIME method can be used as a diagnostic tool for transport processes that occur during a specified time interval along a specified boundary segment. We introduce two types of TIME functions: one that quantifies the accumulation of flow properties and another that measures the displacement of the transport geometry. The spatial geometry of transport is described by the so-called pseudo-lobes, and temporal evolution of transport by their dynamics. In the case where the TIME functions are evaluated along a separatrix, the pseudo-lobes have a relationship to the lobes of Lagrangian transport theory. In fact, one of the TIME functions is identical to the Melnikov function that is used to measure the distance, at leading order in a small parameter, between the two invariant manifolds that define the Lagrangian lobes. We contrast the similarities and differences between the TIME and Lagrangian lobe dynamics in detail. An application of the TIME method is carried out for inter-gyre transport in the wind-driven oceanic circulation model and a comparison with the Lagrangian transport theory is made.

[Kumagusu Minakata with temporal lobe epilepsy: a pathographic study].

PubMed

Sengoku, Akira

2006-01-01

Kumagusu Minakata (1867-1941), a Japanese genius devoted to natural history and folklore, is famous for his immense range of works (including 50 monographs in 'Nature') and his discovery of several varieties of mycetozoa. His diary and the observations of other persons reveal that he was affected by several grand mal epileptic seizures, and he complained himself of frequent déjà vu experiences which he called promnesia according to Myers. Promnesia means, for example, "I have lived through all this before, and I know what will happen this next minute." Minakata also had this rare type of aural sign. MRI analysis of his postmortem brain found evidence of right hippocampal atrophy. This result showed that he had temporal lobe epilepsy with focus of the right side, and this coincides with his déjà vu experiences which were the aura of the loss of consciousness. However, he did not notice that these were aural signs, and he also complained of memory disturbances due to frequent déjà vu. His behavioral characteristics were peculiar, and those of Dostoyevsky who also had temporal lobe epilepsy were similar. Temporal lobe epilepsies may influence behavioral patterns which control the emotions. As a positive point, some patients with temporal lobe epilepsy can exhibit their primordial mental actions and perform persistent works.

Segmentation of the thalamus based on BOLD frequencies affected in temporal lobe epilepsy.

PubMed

Morgan, Victoria L; Rogers, Baxter P; Abou-Khalil, Bassel

2015-11-01

Temporal lobe epilepsy is associated with functional changes throughout the brain, particularly including a putative seizure propagation network involving the hippocampus, insula, and thalamus. We identified a specified frequency range where functional connectivity in this network was related to duration of disease. Then, to identify specific thalamic nuclei involved in seizure propagation, we determined the subregions of the thalamus that have increased resting functional oscillations in this frequency range. Resting-state functional magnetic resonance imaging (fMRI) was acquired from 20 patients with unilateral temporal lobe epilepsy (TLE; 14 right and 6 left) and 20 healthy controls who were each age and gender matched to a specific patient. Wavelet-based fMRI connectivity mapping across the network was computed at each frequency to determine those frequencies where connectivity significantly decreases with duration of disease consistent with impairment due to repeated seizures. The voxel-wise power of the spontaneous blood oxygenation fluctuations of this frequency band was computed in the thalamus of each subject. Functional connectivity was impaired in the proposed seizure propagation network over a specific range (0.0067-0.013 Hz and 0.024-0.032 Hz) of blood oxygenation oscillations. Increased power in this frequency band (<0.032 Hz) was detected bilaterally in the pulvinar and anterior nucleus of the thalamus of healthy controls, and was increased over the ipsilateral thalamus compared to the contralateral thalamus in TLE. This study identified frequencies of impaired connectivity in a TLE seizure propagation network and used them to localize the anterior nucleus and pulvinar of the thalamus as subregions most susceptible to TLE seizures. Further examinations of these frequencies in healthy and TLE subjects may provide unique information relating to the mechanism of seizure propagation and potential treatment using electrical stimulation. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

Lesion correlates of impairments in actual tool use following unilateral brain damage.

PubMed

Salazar-López, E; Schwaiger, B J; Hermsdörfer, J

2016-04-01

To understand how the brain controls actions involving tools, tests have been developed employing different paradigms such as pantomime, imitation and real tool use. The relevant areas have been localized in the premotor cortex, the middle temporal gyrus and the superior and inferior parietal lobe. This study employs Voxel Lesion Symptom Mapping to relate the functional impairment in actual tool use with extent and localization of the structural damage in the left (LBD, N=31) and right (RBD, N=19) hemisphere in chronic stroke patients. A series of 12 tools was presented to participants in a carousel. In addition, a non-tool condition tested the prescribed manipulation of a bar. The execution was scored according to an apraxic error scale based on the dimensions grasp, movement, direction and space. Results in the LBD group show that the ventro-dorsal stream constitutes the core of the defective network responsible for impaired tool use; it is composed of the inferior parietal lobe, the supramarginal and angular gyrus and the dorsal premotor cortex. In addition, involvement of regions in the temporal lobe, the rolandic operculum, the ventral premotor cortex and the middle occipital gyrus provide evidence of the role of the ventral stream in this task. Brain areas related to the use of the bar largely overlapped with this network. For patients with RBD data were less conclusive; however, a trend for the involvement of the temporal lobe in apraxic errors was manifested. Skilled bar manipulation depended on the same temporal area in these patients. Therefore, actual tool use depends on a well described left fronto-parietal-temporal network. RBD affects actual tool use, however the underlying neural processes may be more widely distributed and more heterogeneous. Goal directed manipulation of non-tool objects seems to involve very similar brain areas as tool use, suggesting that both types of manipulation share identical processes and neural representations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hierarchical Processing of Auditory Objects in Humans

PubMed Central

Kumar, Sukhbinder; Stephan, Klaas E; Warren, Jason D; Friston, Karl J; Griffiths, Timothy D

2007-01-01

This work examines the computational architecture used by the brain during the analysis of the spectral envelope of sounds, an important acoustic feature for defining auditory objects. Dynamic causal modelling and Bayesian model selection were used to evaluate a family of 16 network models explaining functional magnetic resonance imaging responses in the right temporal lobe during spectral envelope analysis. The models encode different hypotheses about the effective connectivity between Heschl's Gyrus (HG), containing the primary auditory cortex, planum temporale (PT), and superior temporal sulcus (STS), and the modulation of that coupling during spectral envelope analysis. In particular, we aimed to determine whether information processing during spectral envelope analysis takes place in a serial or parallel fashion. The analysis provides strong support for a serial architecture with connections from HG to PT and from PT to STS and an increase of the HG to PT connection during spectral envelope analysis. The work supports a computational model of auditory object processing, based on the abstraction of spectro-temporal “templates” in the PT before further analysis of the abstracted form in anterior temporal lobe areas. PMID:17542641

Déjà Experiences in Temporal Lobe Epilepsy

PubMed Central

Illman, Nathan A.; Butler, Chris R.; Souchay, Celine; Moulin, Chris J. A.

2012-01-01

Historically, déjà vu has been linked to seizure activity in temporal lobe epilepsy, and clinical reports suggest that many patients experience the phenomenon as a manifestation of simple partial seizures. We review studies on déjà vu in epilepsy with reference to recent advances in the understanding of déjà vu from a cognitive and neuropsychological standpoint. We propose a decoupled familiarity hypothesis, whereby déjà vu is produced by an erroneous feeling of familiarity which is not in keeping with current cognitive processing. Our hypothesis converges on a parahippocampal dysfunction as the locus of déjà vu experiences. However, several other temporal lobe structures feature in reports of déjà vu in epilepsy. We suggest that some of the inconsistency in the literature derives from a poor classification of the various types of déjà experiences. We propose déjà vu/déjà vécu as one way of understanding déjà experiences more fully. This distinction is based on current models of memory function, where déjà vu is caused by erroneous familiarity and déjà vécu by erroneous recollection. Priorities for future research and clinical issues are discussed. PMID:22957231

Déjà experiences in temporal lobe epilepsy.

PubMed

Illman, Nathan A; Butler, Chris R; Souchay, Celine; Moulin, Chris J A

2012-01-01

Historically, déjà vu has been linked to seizure activity in temporal lobe epilepsy, and clinical reports suggest that many patients experience the phenomenon as a manifestation of simple partial seizures. We review studies on déjà vu in epilepsy with reference to recent advances in the understanding of déjà vu from a cognitive and neuropsychological standpoint. We propose a decoupled familiarity hypothesis, whereby déjà vu is produced by an erroneous feeling of familiarity which is not in keeping with current cognitive processing. Our hypothesis converges on a parahippocampal dysfunction as the locus of déjà vu experiences. However, several other temporal lobe structures feature in reports of déjà vu in epilepsy. We suggest that some of the inconsistency in the literature derives from a poor classification of the various types of déjà experiences. We propose déjà vu/déjà vécu as one way of understanding déjà experiences more fully. This distinction is based on current models of memory function, where déjà vu is caused by erroneous familiarity and déjà vécu by erroneous recollection. Priorities for future research and clinical issues are discussed.

Graph theory findings in the pathophysiology of temporal lobe epilepsy.

PubMed

Chiang, Sharon; Haneef, Zulfi

2014-07-01

Temporal lobe epilepsy (TLE) is the most common form of adult epilepsy. Accumulating evidence has shown that TLE is a disorder of abnormal epileptogenic networks, rather than focal sources. Graph theory allows for a network-based representation of TLE brain networks, and has potential to illuminate characteristics of brain topology conducive to TLE pathophysiology, including seizure initiation and spread. We review basic concepts which we believe will prove helpful in interpreting results rapidly emerging from graph theory research in TLE. In addition, we summarize the current state of graph theory findings in TLE as they pertain its pathophysiology. Several common findings have emerged from the many modalities which have been used to study TLE using graph theory, including structural MRI, diffusion tensor imaging, surface EEG, intracranial EEG, magnetoencephalography, functional MRI, cell cultures, simulated models, and mouse models, involving increased regularity of the interictal network configuration, altered local segregation and global integration of the TLE network, and network reorganization of temporal lobe and limbic structures. As different modalities provide different views of the same phenomenon, future studies integrating data from multiple modalities are needed to clarify findings and contribute to the formation of a coherent theory on the pathophysiology of TLE. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Physiogenomic Analysis of Localized fMRI Brain Activity in Schizophrenia

PubMed Central

Windemuth, Andreas; Calhoun, Vince D.; Pearlson, Godfrey D.; Kocherla, Mohan; Jagannathan, Kanchana; Ruaño, Gualberto

2009-01-01

The search for genetic factors associated with disease is complicated by the complexity of the biological pathways linking genotype and phenotype. This analytical complexity is particularly concerning in diseases historically lacking reliable diagnostic biological markers, such as schizophrenia and other mental disorders. We investigate the use of functional magnetic resonance imaging (fMRI) as an intermediate phenotype (endophenotype) to identify physiogenomic associations to schizophrenia. We screened 99 subjects, 30 subjects diagnosed with schizophrenia, 13 unaffected relatives of schizophrenia patients, and 56 unrelated controls, for gene polymorphisms associated with fMRI activation patterns at two locations in temporal and frontal lobes previously implied in schizophrenia. A total of 22 single nucleotide polymorphisms (SNPs) in 15 genes from the dopamine and serotonin neurotransmission pathways were genotyped in all subjects. We identified three SNPs in genes that are significantly associated with fMRI activity. SNPs of the dopamine beta-hydroxylase (DBH) gene and of the dopamine receptor D4 (DRD4) were associated with activity in the temporal and frontal lobes, respectively. One SNP of serotonin-3A receptor (HTR3A) was associated with temporal lobe activity. The results of this study support the physiogenomic analysis of neuroimaging data to discover associations between genotype and disease-related phenotypes. PMID:18330705

Semantic Processing Impairment in Patients with Temporal Lobe Epilepsy

PubMed Central

Jaimes-Bautista, Amanda G.; Rodríguez-Camacho, Mario; Martínez-Juárez, Iris E.; Rodríguez-Agudelo, Yaneth

2015-01-01

The impairment in episodic memory system is the best-known cognitive deficit in patients with temporal lobe epilepsy (TLE). Recent studies have shown evidence of semantic disorders, but they have been less studied than episodic memory. The semantic dysfunction in TLE has various cognitive manifestations, such as the presence of language disorders characterized by defects in naming, verbal fluency, or remote semantic information retrieval, which affects the ability of patients to interact with their surroundings. This paper is a review of recent research about the consequences of TLE on semantic processing, considering neuropsychological, electrophysiological, and neuroimaging findings, as well as the functional role of the hippocampus in semantic processing. The evidence from these studies shows disturbance of semantic memory in patients with TLE and supports the theory of declarative memory of the hippocampus. Functional neuroimaging studies show an inefficient compensatory functional reorganization of semantic networks and electrophysiological studies show a lack of N400 effect that could indicate that the deficit in semantic processing in patients with TLE could be due to a failure in the mechanisms of automatic access to lexicon. PMID:26257956

Distinct and overlapping fMRI activation networks for processing of novel identities and locations of objects.

PubMed

Pihlajamäki, Maija; Tanila, Heikki; Könönen, Mervi; Hänninen, Tuomo; Aronen, Hannu J; Soininen, Hilkka

2005-10-01

The ventral visual stream processes information about the identity of objects ('what'), whereas the dorsal stream processes the spatial locations of objects ('where'). There is a corresponding, although disputed, distinction for the ventrolateral and dorsolateral prefrontal areas. Furthermore, there seems to be a distinction between the anterior and posterior medial temporal lobe (MTL) structures in the processing of novel items and new spatial arrangements, respectively. Functional differentiation of the intermediary mid-line cortical and temporal neocortical structures that communicate with the occipitotemporal, occipitoparietal, prefrontal, and MTL structures, however, is unclear. Therefore, in the present functional magnetic resonance imaging (fMRI) study, we examined whether the distinction among the MTL structures extends to these closely connected cortical areas. The most striking difference in the fMRI responses during visual presentation of changes in either items or their locations was the bilateral activation of the temporal lobe and ventrolateral prefrontal cortical areas for novel object identification in contrast to wide parietal and dorsolateral prefrontal activation for the novel locations of objects. An anterior-posterior distinction of fMRI responses similar to the MTL was observed in the cingulate/retrosplenial, and superior and middle temporal cortices. In addition to the distinct areas of activation, certain frontal, parietal, and temporo-occipital areas responded to both object and spatial novelty, suggesting a common attentional network for both types of changes in the visual environment. These findings offer new insights to the functional roles and intrinsic specialization of the cingulate/retrosplenial, and lateral temporal cortical areas in visuospatial cognition.

Practice guideline summary: Use of fMRI in the presurgical evaluation of patients with epilepsy

PubMed Central

Szaflarski, Jerzy P.; Gloss, David; Binder, Jeffrey R.; Gaillard, William D.; Golby, Alexandra J.; Holland, Scott K.; Ojemann, Jeffrey; Spencer, David C.; Swanson, Sara J.; French, Jacqueline A.; Theodore, William H.

2017-01-01

Objective: To assess the diagnostic accuracy and prognostic value of functional MRI (fMRI) in determining lateralization and predicting postsurgical language and memory outcomes. Methods: An 11-member panel evaluated and rated available evidence according to the 2004 American Academy of Neurology process. At least 2 panelists reviewed the full text of 172 articles and selected 37 for data extraction. Case reports, reports with <15 cases, meta-analyses, and editorials were excluded. Results and recommendations: The use of fMRI may be considered an option for lateralizing language functions in place of intracarotid amobarbital procedure (IAP) in patients with medial temporal lobe epilepsy (MTLE; Level C), temporal epilepsy in general (Level C), or extratemporal epilepsy (Level C). For patients with temporal neocortical epilepsy or temporal tumors, the evidence is insufficient (Level U). fMRI may be considered to predict postsurgical language deficits after anterior temporal lobe resection (Level C). The use of fMRI may be considered for lateralizing memory functions in place of IAP in patients with MTLE (Level C) but is of unclear utility in other epilepsy types (Level U). fMRI of verbal memory or language encoding should be considered for predicting verbal memory outcome (Level B). fMRI using nonverbal memory encoding may be considered for predicting visuospatial memory outcomes (Level C). Presurgical fMRI could be an adequate alternative to IAP memory testing for predicting verbal memory outcome (Level C). Clinicians should carefully advise patients of the risks and benefits of fMRI vs IAP during discussions concerning choice of specific modality in each case. PMID:28077494

Evaluating executive function in patients with temporal lobe epilepsy using the frontal assessment battery.

PubMed

Agah, Elmira; Asgari-Rad, Nasima; Ahmadi, Mona; Tafakhori, Abbas; Aghamollaii, Vajiheh

2017-07-01

Previous studies have demonstrated executive dysfunction in patients with temporal lobe epilepsy (TLE). Frontal assessment battery (FAB) is a short neuropsychological tool that was developed for assessment of frontal lobe function in a clinical setting. The aim of the present study is to evaluate the clinical utility of FAB for detection of executive dysfunction in TLE patients. Forty-eight TLE patients and 48 sex and age-matched healthy controls participated in this study. Compared to healthy participants, the total FAB score was significantly lower among the TLE patients. TLE patients performed significantly worse at the mental flexibility, motor programming, sensitivity to interference and inhibitory control tasks. The duration of time has been passed since the last seizure was the only significant predictor of FAB score and patients who had a seizure less than a week before the evaluation time, had significantly lower FAB scores. The number of antiepileptic drugs (AEDs) did not influence the executive function in this study; however, sodium valproate was found to affect the mental flexibility. In conclusion, impaired executive function is common in TLE patients, and we suggest that FAB is a clinically applicable tool to monitor it. Moreover, we found that the time of the last seizure is a significant predictor of executive functioning and patients' performance may become worse up to seven days after a seizure. We also recommend that clinicians evaluate the cognitive adverse effects of AEDs especially sodium valproate, which was found to affect the mental flexibility in this study. Copyright © 2017 Elsevier B.V. All rights reserved.

Unique and shared areas of cognitive function in children with intractable frontal or temporal lobe epilepsy.

PubMed

Law, Nicole; Widjaja, Elysa; Smith, Mary Lou

2018-03-01

Previous findings have been mixed in terms of identifying a distinct pattern of neuropsychological deficits in children with frontal lobe epilepsy (FLE) and in those with temporal lobe epilepsy (TLE). The current study investigated the neuropsychological similarities and differences across these two pediatric medically intractable localization-related epilepsies. Thirty-eight children with FLE, 20 children with TLE, and 40 healthy children (HC) participated in this study. A comprehensive battery of standardized tests assessed five neuropsychological domains including intelligence, language, memory, executive function, and motor function. A principal component analysis (PCA) was used to distill our neuropsychological measures into latent components to compare between groups. Principal component analysis extracted 5 latent components: executive function (F1), verbal semantics (F2), motor (F3), nonverbal cognition/impulsivity (F4), and verbal cognition/attention (F5). The group with FLE differed from the HC group on F1, F2, F4, and F5, and had worse performance than the group with TLE on F1; the group with TLE had lower performance relative to the HC group on F2. Our findings suggest that, in comparison with neurotypically developing children, children with medically intractable FLE have more widespread neuropsychological impairments than do children with TLE. The differences between the two patient groups were greatest for the factor score most clearly related to executive function. The results provide mixed support for the concept of specificity in neuropsychological dysfunction among different subtypes of localization-related medically intractable childhood epilepsies. Copyright © 2018 Elsevier Inc. All rights reserved.

Levels of Processing with Free and Cued Recall and Unilateral Temporal Lobe Epilepsy

ERIC Educational Resources Information Center

Lespinet-Najib, Veronique; N'Kaoua, Bernard; Sauzeon, Helene; Bresson, Christel; Rougier, Alain; Claverie, Bernard

2004-01-01

This study investigates the role of the temporal lobes in levels-of-processing tasks (phonetic and semantic encoding) according to the nature of recall tasks (free and cued recall). These tasks were administered to 48 patients with unilateral temporal epilepsy (right ''RTLE''=24; left ''LTLE''=24) and a normal group (n=24). The results indicated…

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…

Postencephalitic focal retrograde amnesia after bilateral anterior temporal lobe damage.

PubMed

Tanaka, Y; Miyazawa, Y; Hashimoto, R; Nakano, I; Obayashi, T

1999-07-22

Marked retrograde amnesia with no or almost no anterograde amnesia is rare. Recently, a combination of ventrolateral prefrontal and temporopolar cortical lesions has been suggested as the cause of such isolated or focal retrograde amnesia. It is also assumed that when the right-sided cortical structures are damaged, autobiographical episodic memories are affected. To search for new anatomic substrates for focal retrograde amnesia. We performed extensive neuropsychological tests and obtained detailed neuroimages on a 43-year-old woman who showed a severe, persistent retrograde amnesia but only a limited anterograde amnesia after probable herpes simplex encephalitis. Tests of autobiographical memory revealed that she had a memory loss extending back to her childhood for both semantics and incidents; however, the ability to recall specific episodes appeared much more severely impaired than the ability to recall factual information about her past. The patient also showed profound impairments in recalling public memories; however, her scores improved nearly to a control level on forced-choice recognition memory tasks, although the recall of memories for a decade just before her illness remained mildly impaired. MRI revealed focal pathologies in the temporal poles and the anterior parts of the inferotemporal lobes on both sides, predominantly on the left, with some extension to the anterior parts of the medial temporal lobes. There was additional damage to the left insular cortex and its surrounding structures but no evidence of frontal lobe damage on MRIs or cognitive tests. A profound retrograde amnesia may be produced by damage to the bilateral temporal poles and anterior inferotemporal lobes in the absence of frontal lobe pathologies, and a dense and persistent episodic old memory loss can arise even with a relatively small lesion in the right anterior temporal lobe if it is combined with extensive damage to the left.

Lifelong Bilingualism and Neural Reserve against Alzheimer’s disease: A Review of Findings and Potential Mechanisms

PubMed Central

Gold, Brian T.

2014-01-01

Alzheimer’s disease (AD) is a progressive brain disorder that initially affects medial temporal lobe circuitry and memory functions. Current drug treatments have only modest effects on the symptomatic course of the disease. In contrast, a growing body of evidence suggests that lifelong bilingualism may delay the onset of clinical AD symptoms by several years. The purpose of the present review is to summarize evidence for bilingualism as a reserve variable against AD and discuss potential underlying neurocognitive mechanisms. Evidence is reviewed suggesting that bilingualism may delay clinical AD symptoms by protecting frontostriatal and frontoparietal executive control circuitry rather than medial temporal lobe memory circuitry. Cellular and molecular mechanisms that may contribute to bilingual cognitive reserve effects are discussed, including those that may affect neuronal metabolic functions, dynamic neuronal-glial interactions, vascular factors, myelin structure and neurochemical signaling. Future studies that may test some of these potential mechanisms of bilingual CR effects are proposed. PMID:25496781

Lifelong bilingualism and neural reserve against Alzheimer's disease: a review of findings and potential mechanisms.

PubMed

Gold, Brian T

2015-03-15

Alzheimer's disease (AD) is a progressive brain disorder that initially affects medial temporal lobe circuitry and memory functions. Current drug treatments have only modest effects on the symptomatic course of the disease. In contrast, a growing body of evidence suggests that lifelong bilingualism may delay the onset of clinical AD symptoms by several years. The purpose of the present review is to summarize evidence for bilingualism as a reserve variable against AD and discuss potential underlying neurocognitive mechanisms. Evidence is reviewed suggesting that bilingualism may delay clinical AD symptoms by protecting frontostriatal and frontoparietal executive control circuitry rather than medial temporal lobe memory circuitry. Cellular and molecular mechanisms that may contribute to bilingual cognitive reserve effects are discussed, including those that may affect neuronal metabolic functions, dynamic neuronal-glial interactions, vascular factors, myelin structure and neurochemical signaling. Future studies that may test some of these potential mechanisms of bilingual CR effects are proposed. Copyright © 2014 Elsevier B.V. All rights reserved.

Tau and β-Amyloid Are Associated with Medial Temporal Lobe Structure, Function, and Memory Encoding in Normal Aging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marks, Shawn M.; Lockhart, Samuel N.; Baker, Suzanne L.

Normal aging is associated with a decline in episodic memory and also with aggregation of the β-amyloid (Aβ) and tau proteins and atrophy of medial temporal lobe (MTL) structures crucial to memory formation. Although some evidence suggests that Aβ is associated with aberrant neural activity, the relationships among these two aggregated proteins, neural function, and brain structure are poorly understood. Using in vivo human Aβ and tau imaging, we demonstrate that increased Aβ and tau are both associated with aberrant fMRI activity in the MTL during memory encoding in cognitively normal older adults. This pathological neural activity was in turnmore » associated with worse memory performance and atrophy within the MTL. A mediation analysis revealed that the relationship with regional atrophy was explained by MTL tau. These findings broaden the concept of cognitive aging to include evidence of Alzheimer’s disease-related protein aggregation as an underlying mechanism of age-related memory impairment.« less

Multimodal imaging of language reorganization in patients with left temporal lobe epilepsy.

PubMed

Chang, Yu-Hsuan A; Kemmotsu, Nobuko; Leyden, Kelly M; Kucukboyaci, N Erkut; Iragui, Vicente J; Tecoma, Evelyn S; Kansal, Leena; Norman, Marc A; Compton, Rachelle; Ehrlich, Tobin J; Uttarwar, Vedang S; Reyes, Anny; Paul, Brianna M; McDonald, Carrie R

2017-07-01

This study explored the relationships among multimodal imaging, clinical features, and language impairment in patients with left temporal lobe epilepsy (LTLE). Fourteen patients with LTLE and 26 controls underwent structural MRI, functional MRI, diffusion tensor imaging, and neuropsychological language tasks. Laterality indices were calculated for each imaging modality and a principal component (PC) was derived from language measures. Correlations were performed among imaging measures, as well as to the language PC. In controls, better language performance was associated with stronger left-lateralized temporo-parietal and temporo-occipital activations. In LTLE, better language performance was associated with stronger right-lateralized inferior frontal, temporo-parietal, and temporo-occipital activations. These right-lateralized activations in LTLE were associated with right-lateralized arcuate fasciculus fractional anisotropy. These data suggest that interhemispheric language reorganization in LTLE is associated with alterations to perisylvian white matter. These concurrent structural and functional shifts from left to right may help to mitigate language impairment in LTLE. Copyright © 2017 Elsevier Inc. All rights reserved.

Dissecting out conscious and unconscious memory (sub)processes within the human medial temporal lobe.

PubMed

Grunwald, T; Pezer, N; Münte, T F; Kurthen, M; Lehnertz, K; Van Roost, D; Fernández, G; Kutas, M; Elger, C E

2003-11-01

The human medial temporal lobe (MTL) system mediates memories that can be consciously recollected. However, the specific natures of the individual contributions of its various subregions to conscious memory processes remain equivocal. Here we show a functional dissociation between the hippocampus proper and the parahippocampal region in conscious and unconscious memory as revealed by invasive recordings of limbic event-related brain potentials recorded during explicit and implicit word recognition: Only hippocampal and not parahippocampal neural activity exhibits a sensitivity to the implicit versus explicit nature of the recognition memory task. Moreover, only within the hippocampus proper do the neural responses to repeated words differ not only from those to new words but also from each other as a function of recognition success. By contrast parahippocampal (rhinal) responses are sensitive to repetition independent of conscious recognition. These findings thus demonstrate that it is the hippocampus proper among the MTL structures that is specifically engaged during conscious memory processes.

Recognition and identification of famous faces in patients with unilateral temporal lobe epilepsy.

PubMed

Seidenberg, Michael; Griffith, Randall; Sabsevitz, David; Moran, Maria; Haltiner, Alan; Bell, Brian; Swanson, Sara; Hammeke, Thomas; Hermann, Bruce

2002-01-01

We examined the performance of 21 patients with unilateral temporal lobe epilepsy (TLE) and hippocampal damage (10 lefts, and 11 rights) and 10 age-matched controls on the recognition and identification (name and occupation) of well-known faces. Famous face stimuli were selected from four time periods; 1970s, 1980s, 1990-1994, and 1995-1996. Differential patterns of performance were observed for the left and right TLE group across distinct face processing components. The left TLE group showed a selective impairment in naming famous faces while they performed similar to the controls in face recognition and semantic identification (i.e. occupation). In contrast, the right TLE group was impaired across all components of face memory; face recognition, semantic identification, and face naming. Face naming impairment in the left TLE group was characterized by a temporal gradient with better naming performance for famous faces from more distant time periods. Findings are discussed in terms of the role of the temporal lobe system for the acquisition, retention, and retrieval of face semantic networks, and the differential effects of lateralized temporal lobe lesions in this process.

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.

The effect of white matter hyperintensities on verbal memory: Mediation by temporal lobe atrophy.

PubMed

Swardfager, Walter; Cogo-Moreira, Hugo; Masellis, Mario; Ramirez, Joel; Herrmann, Nathan; Edwards, Jodi D; Saleem, Mahwesh; Chan, Parco; Yu, Di; Nestor, Sean M; Scott, Christopher J M; Holmes, Melissa F; Sahlas, Demetrios J; Kiss, Alexander; Oh, Paul I; Strother, Stephen C; Gao, Fuqiang; Stefanovic, Bojana; Keith, Julia; Symons, Sean; Swartz, Richard H; Lanctôt, Krista L; Stuss, Donald T; Black, Sandra E

2018-02-20

To determine the relationship between white matter hyperintensities (WMH) presumed to indicate disease of the cerebral small vessels, temporal lobe atrophy, and verbal memory deficits in Alzheimer disease (AD) and other dementias. We recruited groups of participants with and without AD, including strata with extensive WMH and minimal WMH, into a cross-sectional proof-of-principle study (n = 118). A consecutive case series from a memory clinic was used as an independent validation sample (n = 702; Sunnybrook Dementia Study; NCT01800214). We assessed WMH volume and left temporal lobe atrophy (measured as the brain parenchymal fraction) using structural MRI and verbal memory using the California Verbal Learning Test. Using path modeling with an inferential bootstrapping procedure, we tested an indirect effect of WMH on verbal recall that depends sequentially on temporal lobe atrophy and verbal learning. In both samples, WMH predicted poorer verbal recall, specifically due to temporal lobe atrophy and poorer verbal learning (proof-of-principle -1.53, 95% bootstrap confidence interval [CI] -2.45 to -0.88; and confirmation -0.66, 95% CI [-0.95 to -0.41] words). This pathway was significant in subgroups with (-0.20, 95% CI [-0.38 to -0.07] words, n = 363) and without (-0.71, 95% CI [-1.12 to -0.37] words, n = 339) AD. Via the identical pathway, WMH contributed to deficits in recognition memory (-1.82%, 95% CI [-2.64% to -1.11%]), a sensitive and specific sign of AD. Across dementia syndromes, WMH contribute indirectly to verbal memory deficits considered pathognomonic of Alzheimer disease, specifically by contributing to temporal lobe atrophy. © 2018 American Academy of Neurology.

Postoperative seizure freedom does not normalize altered connectivity in temporal lobe epilepsy.

PubMed

Maccotta, Luigi; Lopez, Mayra A; Adeyemo, Babatunde; Ances, Beau M; Day, Brian K; Eisenman, Lawrence N; Dowling, Joshua L; Leuthardt, Eric C; Schlaggar, Bradley L; Hogan, Robert Edward

2017-11-01

Specific changes in the functional connectivity of brain networks occur in patients with epilepsy. Yet whether such changes reflect a stable disease effect or one that is a function of active seizure burden remains unclear. Here, we longitudinally assessed the connectivity of canonical cognitive functional networks in patients with intractable temporal lobe epilepsy (TLE), both before and after patients underwent epilepsy surgery and achieved seizure freedom. Seventeen patients with intractable TLE who underwent epilepsy surgery with Engel class I outcome and 17 matched healthy controls took part in the study. The functional connectivity of a set of cognitive functional networks derived from typical cognitive tasks was assessed in patients, preoperatively and postoperatively, as well as in controls, using stringent methods of artifact reduction. Preoperatively, functional networks in TLE patients differed significantly from healthy controls, with differences that largely, but not exclusively, involved the default mode and temporal/auditory subnetworks. However, undergoing epilepsy surgery and achieving seizure freedom did not lead to significant changes in network connectivity, with postoperative functional network abnormalities closely mirroring the preoperative state. This result argues for a stable chronic effect of the disease on brain connectivity, with changes that are largely "burned in" by the time a patient with intractable TLE undergoes epilepsy surgery, which typically occurs years after the initial diagnosis. The result has potential implications for the treatment of intractable epilepsy, suggesting that delaying surgical intervention that may achieve seizure freedom may lead to functional network changes that are no longer reversible by the time of epilepsy surgery. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

Seizure Control and Memory Impairment Are Related to Disrupted Brain Functional Integration in Temporal Lobe Epilepsy.

PubMed

Park, Chang-Hyun; Choi, Yun Seo; Jung, A-Reum; Chung, Hwa-Kyoung; Kim, Hyeon Jin; Yoo, Jeong Hyun; Lee, Hyang Woon

2017-01-01

Brain functional integration can be disrupted in patients with temporal lobe epilepsy (TLE), but the clinical relevance of this disruption is not completely understood. The authors hypothesized that disrupted functional integration over brain regions remote from, as well as adjacent to, the seizure focus could be related to clinical severity in terms of seizure control and memory impairment. Using resting-state functional MRI data acquired from 48 TLE patients and 45 healthy controls, the authors mapped functional brain networks and assessed changes in a network parameter of brain functional integration, efficiency, to examine the distribution of disrupted functional integration within and between brain regions. The authors assessed whether the extent of altered efficiency was influenced by seizure control status and whether the degree of altered efficiency was associated with the severity of memory impairment. Alterations in the efficiency were observed primarily near the subcortical region ipsilateral to the seizure focus in TLE patients. The extent of regional involvement was greater in patients with poor seizure control: it reached the frontal, temporal, occipital, and insular cortices in TLE patients with poor seizure control, whereas it was limited to the limbic and parietal cortices in TLE patients with good seizure control. Furthermore, TLE patients with poor seizure control experienced more severe memory impairment, and this was associated with lower efficiency in the brain regions with altered efficiency. These findings indicate that the distribution of disrupted brain functional integration is clinically relevant, as it is associated with seizure control status and comorbid memory impairment.

Spatiotemporal dynamics in understanding hand—object interactions

PubMed Central

Avanzini, Pietro; Fabbri-Destro, Maddalena; Campi, Cristina; Pascarella, Annalisa; Barchiesi, Guido; Cattaneo, Luigi; Rizzolatti, Giacomo

2013-01-01

It is generally accepted that visual perception results from the activation of a feed-forward hierarchy of areas, leading to increasingly complex representations. Here we present evidence for a fundamental role of backward projections to the occipito-temporal region for understanding conceptual object properties. The evidence is based on two studies. In the first study, using high-density EEG, we showed that during the observation of how objects are used there is an early activation of occipital and temporal areas, subsequently reaching the pole of the temporal lobe, and a late reactivation of the visual areas. In the second study, using transcranial magnetic stimulation over the occipital lobe, we showed a clear impairment in the accuracy of recognition of how objects are used during both early activation and, most importantly, late occipital reactivation. These findings represent strong neurophysiological evidence that a top-down mechanism is fundamental for understanding conceptual object properties, and suggest that a similar mechanism might be also present for other higher-order cognitive functions. PMID:24043805

Alpha band event-related desynchronization underlying social situational context processing during irony comprehension: A magnetoencephalography source localization study.

PubMed

Akimoto, Yoritaka; Takahashi, Hidetoshi; Gunji, Atsuko; Kaneko, Yuu; Asano, Michiko; Matsuo, Junko; Ota, Miho; Kunugi, Hiroshi; Hanakawa, Takashi; Mazuka, Reiko; Kamio, Yoko

2017-12-01

Irony comprehension requires integration of social contextual information. Previous studies have investigated temporal aspects of irony processing and its neural substrates using psychological/electroencephalogram or functional magnetic resonance imaging methods, but have not clarified the temporospatial neural mechanisms of irony comprehension. Therefore, we used magnetoencephalography to investigate the neural generators of alpha-band (8-13Hz) event-related desynchronization (ERD) occurring from 600 to 900ms following the onset of a critical sentence at which social situational contexts activated ironic representation. We found that the right anterior temporal lobe, which is involved in processing social knowledge and evaluating others' intentions, exhibited stronger alpha ERD following an ironic statement than following a literal statement. We also found that alpha power in the left anterior temporal lobe correlated with the participants' communication abilities. These results elucidate the temporospatial neural mechanisms of language comprehension in social contexts, including non-literal processing. Copyright © 2017 Elsevier Inc. All rights reserved.

Hyperphosphorylated tau in patients with refractory epilepsy correlates with cognitive decline: a study of temporal lobe resections.

PubMed

Tai, Xin You; Koepp, Matthias; Duncan, John S; Fox, Nick; Thompson, Pamela; Baxendale, Sallie; Liu, Joan Y W; Reeves, Cheryl; Michalak, Zuzanna; Thom, Maria

2016-09-01

SEE BERNASCONI DOI101093/AWW202 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Temporal lobe epilepsy, the most prevalent form of chronic focal epilepsy, is associated with a high prevalence of cognitive impairment but the responsible underlying pathological mechanisms are unknown. Tau, the microtubule-associated protein, is a hallmark of several neurodegenerative diseases including Alzheimer's disease and chronic traumatic encephalopathy. We hypothesized that hyperphosphorylated tau pathology is associated with cognitive decline in temporal lobe epilepsy and explored this through clinico-pathological study. We first performed pathological examination on tissue from 33 patients who had undergone temporal lobe resection between ages 50 and 65 years to treat drug-refractory temporal lobe epilepsy. We identified hyperphosphorylated tau protein using AT8 immunohistochemistry and compared this distribution to Braak patterns of Alzheimer's disease and patterns of chronic traumatic encephalopathy. We quantified tau pathology using a modified tau score created specifically for analysis of temporal lobectomy tissue and the Braak staging, which was limited without extra-temporal brain areas available. Next, we correlated tau pathology with pre- and postoperative cognitive test scores and clinical risk factors including age at time of surgery, duration of epilepsy, history of secondary generalized seizures, history of head injury, handedness and side of surgery. Thirty-one of 33 cases (94%) showed hyperphosphorylated tau pathology in the form of neuropil threads and neurofibrillary tangles and pre-tangles. Braak stage analysis showed 12% of our epilepsy cohort had a Braak staging III-IV compared to an age-matched non-epilepsy control group from the literature (8%). We identified a mixture of tau pathology patterns characteristic of Alzheimer's disease and chronic traumatic encephalopathy. We also found unusual patterns of subpial tau deposition, sparing of the hippocampus and co-localization with mossy fibre sprouting, a feature of temporal lobe epilepsy. We demonstrated that the more extensive the tau pathology, the greater the decline in verbal learning (Spearman correlation, r = -0.63), recall (r = -0.44) and graded naming test scores (r = -0.50) over 1-year post-temporal lobe resection (P < 0.05). This relationship with tau burden was also present when examining decline in verbal learning from 3 months to 1 year post-resection (r = -0.54). We found an association between modified tau score and history of secondary generalized seizures (likelihood-ratio χ(2), P < 0.05) however there was no clear relationship between tau pathology and other clinical risk factors assessed. Our findings suggest an epilepsy-related tauopathy in temporal lobe epilepsy, which contributes to accelerated cognitive decline and has diagnostic and treatment implications. © 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.

Hyperphosphorylated tau in patients with refractory epilepsy correlates with cognitive decline: a study of temporal lobe resections

PubMed Central

Tai, Xin You; Koepp, Matthias; Duncan, John S.; Fox, Nick; Thompson, Pamela; Baxendale, Sallie; Liu, Joan Y. W.; Reeves, Cheryl; Michalak, Zuzanna

2016-01-01

Abstract See Bernasconi (doi:10.1093/aww202) for a scientific commentary on this article. Temporal lobe epilepsy, the most prevalent form of chronic focal epilepsy, is associated with a high prevalence of cognitive impairment but the responsible underlying pathological mechanisms are unknown. Tau, the microtubule-associated protein, is a hallmark of several neurodegenerative diseases including Alzheimer’s disease and chronic traumatic encephalopathy. We hypothesized that hyperphosphorylated tau pathology is associated with cognitive decline in temporal lobe epilepsy and explored this through clinico-pathological study. We first performed pathological examination on tissue from 33 patients who had undergone temporal lobe resection between ages 50 and 65 years to treat drug-refractory temporal lobe epilepsy. We identified hyperphosphorylated tau protein using AT8 immunohistochemistry and compared this distribution to Braak patterns of Alzheimer’s disease and patterns of chronic traumatic encephalopathy. We quantified tau pathology using a modified tau score created specifically for analysis of temporal lobectomy tissue and the Braak staging, which was limited without extra-temporal brain areas available. Next, we correlated tau pathology with pre- and postoperative cognitive test scores and clinical risk factors including age at time of surgery, duration of epilepsy, history of secondary generalized seizures, history of head injury, handedness and side of surgery. Thirty-one of 33 cases (94%) showed hyperphosphorylated tau pathology in the form of neuropil threads and neurofibrillary tangles and pre-tangles. Braak stage analysis showed 12% of our epilepsy cohort had a Braak staging III-IV compared to an age-matched non-epilepsy control group from the literature (8%). We identified a mixture of tau pathology patterns characteristic of Alzheimer’s disease and chronic traumatic encephalopathy. We also found unusual patterns of subpial tau deposition, sparing of the hippocampus and co-localization with mossy fibre sprouting, a feature of temporal lobe epilepsy. We demonstrated that the more extensive the tau pathology, the greater the decline in verbal learning (Spearman correlation, r = −0.63), recall (r = −0.44) and graded naming test scores (r = −0.50) over 1-year post-temporal lobe resection (P < 0.05). This relationship with tau burden was also present when examining decline in verbal learning from 3 months to 1 year post-resection (r = −0.54). We found an association between modified tau score and history of secondary generalized seizures (likelihood-ratio χ2, P < 0.05) however there was no clear relationship between tau pathology and other clinical risk factors assessed. Our findings suggest an epilepsy-related tauopathy in temporal lobe epilepsy, which contributes to accelerated cognitive decline and has diagnostic and treatment implications. PMID:27497924

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.

Associative episodic memory and recollective processes in childhood temporal lobe epilepsy.

PubMed

Martins, Sylvie; Guillery-Girard, Bérengère; Clochon, Patrice; Bulteau, Christine; Hertz-Pannier, Lucie; Chiron, Catherine; Eustache, Francis; Jambaqué, Isabelle

2015-03-01

While the current literature on children suffering from temporal lobe epilepsy (CTLE) mostly focuses on material-related episodic memory deficits according to seizure-onset lateralization, the present study examined associative episodic memory according to the type of information to memorize (e.g., factual, spatial, and sequential) and further investigated subjective and objective recollection. Eleven children with left temporal lobe epilepsy (LTLE), 10 children with right temporal lobe epilepsy (RTLE), among whom 9 displayed hippocampal sclerosis (HS), and 42 healthy controls completed the WHAT-WHEN-WHERE protocol (Guillery-Girard et al., 2013). Group comparisons were first conducted according to the affected side and second according to the underlying pathology. Results showed associative memory impairments in patients irrespective of the affected side. Moreover, this study revealed that HS is particularly deleterious to associative and subjective recollection in CTLE. In addition, this study emphasizes the need for assessing episodic memory in childhood TLE beyond material specificity. Copyright © 2015 Elsevier Inc. All rights reserved.

De novo 12q22.q23.3 duplication associated with temporal lobe epilepsy.

PubMed

Vari, Maria Stella; Traverso, Monica; Bellini, Tommaso; Madia, Francesca; Pinto, Francesca; Minetti, Carlo; Striano, Pasquale; Zara, Federico

2017-08-01

Temporal lobe epilepsy (TLE) is the most common form of focal epilepsy and may be associated with acquired central nervous system lesions or could be genetic. Various susceptibility genes and environmental factors are believed to be involved in the aetiology of TLE, which is considered to be a heterogeneous, polygenic, and complex disorder. Rare point mutations in LGI1, DEPDC5, and RELN as well as some copy number variations (CNVs) have been reported in families with TLE patients. We perform a genetic analysis by Array-CGH in a patient with dysmorphic features and temporal lobe epilepsy. We report a de novo duplication of the long arm of chromosome 12. We confirm that 12q22-q23.3 is a candidate locus for familial temporal lobe epilepsy with febrile seizures and highlight the role of chromosomal rearrangements in patients with epilepsy and intellectual disability. Copyright © 2017 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Exploring the Roles of Spectral Detail and Intonation Contour in Speech Intelligibility: An fMRI Study

PubMed Central

Kyong, Jeong S.; Scott, Sophie K.; Rosen, Stuart; Howe, Timothy B.; Agnew, Zarinah K.; McGettigan, Carolyn

2014-01-01

The melodic contour of speech forms an important perceptual aspect of tonal and nontonal languages and an important limiting factor on the intelligibility of speech heard through a cochlear implant. Previous work exploring the neural correlates of speech comprehension identified a left-dominant pathway in the temporal lobes supporting the extraction of an intelligible linguistic message, whereas the right anterior temporal lobe showed an overall preference for signals clearly conveying dynamic pitch information. The current study combined modulations of overall intelligibility (through vocoding and spectral inversion) with a manipulation of pitch contour (normal vs. falling) to investigate the processing of spoken sentences in functional MRI. Our overall findings replicate and extend those of Scott et al., whereas greater sentence intelligibility was predominately associated with increased activity in the left STS, the greatest response to normal sentence melody was found right superior temporal gyrus. These data suggest a spatial distinction between brain areas associated with intelligibility and those involved in the processing of dynamic pitch information in speech. By including a set of complexity-matched unintelligible conditions created by spectral inversion, this is additionally the first study reporting a fully factorial exploration of spectrotemporal complexity and spectral inversion as they relate to the neural processing of speech intelligibility. Perhaps surprisingly, there was no evidence for an interaction between the two factors—we discuss the implications for the processing of sound and speech in the dorsolateral temporal lobes. PMID:24568205

Contributions of Feature Binding During Encoding and Functional Connectivity of the Medial Temporal Lobe Structures to Episodic Memory Deficits Across the Prodromal and First-Episode Phases of Schizophrenia

PubMed Central

Haut, Kristen M.; van Erp, Theo G. M.; Knowlton, Barbara; Bearden, Carrie E.; Subotnik, Kenneth; Ventura, Joseph; Nuechterlein, Keith H.; Cannon, Tyrone D.

2014-01-01

Patients with and at risk for psychosis may have difficulty using associative strategies to facilitate episodic memory encoding and recall. In parallel studies, patients with first-episode schizophrenia (n = 27) and high psychosis risk (n = 28) compared with control participants (n = 22 and n = 20, respectively) underwent functional MRI during a remember-know memory task. Psychophysiological interaction analyses, using medial temporal lobe (MTL) structures as regions of interest, were conducted to measure functional connectivity patterns supporting successful episodic memory. During encoding, patients with first-episode schizophrenia demonstrated reduced functional coupling between MTL regions and regions involved in stimulus representations, stimulus selection, and cognitive control. Relative to control participants and patients with high psychosis risk who did not convert to psychosis, patients with high psychosis risk who later converted to psychosis also demonstrated reduced connectivity between MTL regions and auditory-verbal and visual-association regions. These results suggest that episodic memory deficits in schizophrenia are related to inefficient recruitment of cortical connections involved in associative memory formation; such deficits precede the onset of psychosis among those individuals at high clinical risk. PMID:25750836

Contributions of Feature Binding During Encoding and Functional Connectivity of the Medial Temporal Lobe Structures to Episodic Memory Deficits Across the Prodromal and First-Episode Phases of Schizophrenia.

PubMed

Haut, Kristen M; van Erp, Theo G M; Knowlton, Barbara; Bearden, Carrie E; Subotnik, Kenneth; Ventura, Joseph; Nuechterlein, Keith H; Cannon, Tyrone D

2015-03-01

Patients with and at risk for psychosis may have difficulty using associative strategies to facilitate episodic memory encoding and recall. In parallel studies, patients with first-episode schizophrenia ( n = 27) and high psychosis risk ( n = 28) compared with control participants ( n = 22 and n = 20, respectively) underwent functional MRI during a remember-know memory task. Psychophysiological interaction analyses, using medial temporal lobe (MTL) structures as regions of interest, were conducted to measure functional connectivity patterns supporting successful episodic memory. During encoding, patients with first-episode schizophrenia demonstrated reduced functional coupling between MTL regions and regions involved in stimulus representations, stimulus selection, and cognitive control. Relative to control participants and patients with high psychosis risk who did not convert to psychosis, patients with high psychosis risk who later converted to psychosis also demonstrated reduced connectivity between MTL regions and auditory-verbal and visual-association regions. These results suggest that episodic memory deficits in schizophrenia are related to inefficient recruitment of cortical connections involved in associative memory formation; such deficits precede the onset of psychosis among those individuals at high clinical risk.

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

1H and 31P spectroscopy and bioenergetics in the lateralization of seizures in temporal lobe epilepsy.

PubMed

Hetherington, Hoby P; Pan, Jullie W; Spencer, Dennis D

2002-10-01

Over the past decade, (1)H and (31)P spectroscopy measurements have demonstrated that significant metabolic alterations occur in temporal lobe epilepsy. However, to most accurately interpret these changes, metabolic heterogeneity and differences between gray and white matter must be accounted for. These alterations, decreased NAA and the ratio of phosphocreatine/inorganic phosphate, can be reversed with successful treatment of seizures. The reversibility of these two measures is consistent with the localization of NAA synthesis to neuronal mitochondria and the important role for bioenergetics in the pathophysiology of temporal lobe epilepsy. Copyright 2002 Wiley-Liss, Inc.

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.

Segmentation of the Cingulum Bundle in the Human Brain: A New Perspective Based on DSI Tractography and Fiber Dissection Study.

PubMed

Wu, Yupeng; Sun, Dandan; Wang, Yong; Wang, Yibao; Ou, Shaowu

2016-01-01

The cingulum bundle (CB) is a critical white matter fiber tract in the brain, which forms connections between the frontal lobe, parietal lobe and temporal lobe. In non-human primates, the CB is actually divided into distinct subcomponents on the basis of corticocortical connections. However, at present, no study has verified similar distinct subdivisions in the human brain. In this study, we reconstructed these distinct subdivisions in the human brain, and determined their exact cortical connections using high definition fiber tracking (HDFT) technique on 10 healthy adults and a 488-subject template from the Human Connectome Project (HCP-488). Fiber dissections were performed to verify tractography results. Five CB segments were identified. CB-I ran from the subrostral areas to the precuneus and splenium, encircling the corpus callosum (CC). CB-II arched around the splenium and extended anteriorly above the CC to the medial aspect of the superior frontal gyrus (SFG). CB-III connected the superior parietal lobule (SPL) and precuneus with the medial aspect of the SFG. CB-IV was a relatively minor subcomponent from the SPL and precuneus to the frontal region. CB-V, the para-hippocampal cingulum, stemmed from the medial temporal lobe and fanned out to the occipital lobes. Our findings not only provide a more accurate and detailed description on the associated architecture of the subcomponents within the CB, but also offer new insights into the functional role of the CB in the human brain.

Radiation-induced brain structural and functional abnormalities in presymptomatic phase and outcome prediction.

PubMed

Ding, Zhongxiang; Zhang, Han; Lv, Xiao-Fei; Xie, Fei; Liu, Lizhi; Qiu, Shijun; Li, Li; Shen, Dinggang

2018-01-01

Radiation therapy, a major method of treatment for brain cancer, may cause severe brain injuries after many years. We used a rare and unique cohort of nasopharyngeal carcinoma patients with normal-appearing brains to study possible early irradiation injury in its presymptomatic phase before severe, irreversible necrosis happens. The aim is to detect any structural or functional imaging biomarker that is sensitive to early irradiation injury, and to understand the recovery and progression of irradiation injury that can shed light on outcome prediction for early clinical intervention. We found an acute increase in local brain activity that is followed by extensive reductions in such activity in the temporal lobe and significant loss of functional connectivity in a distributed, large-scale, high-level cognitive function-related brain network. Intriguingly, these radiosensitive functional alterations were found to be fully or partially recoverable. In contrast, progressive late disruptions to the integrity of the related far-end white matter structure began to be significant after one year. Importantly, early increased local brain functional activity was predictive of severe later temporal lobe necrosis. Based on these findings, we proposed a dynamic, multifactorial model for radiation injury and another preventive model for timely clinical intervention. Hum Brain Mapp 39:407-427, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Functional imaging of semantic memory predicts postoperative episodic memory functions in chronic temporal lobe epilepsy.

PubMed

Köylü, Bülent; Walser, Gerald; Ischebeck, Anja; Ortler, Martin; Benke, Thomas

2008-08-05

Medial temporal (MTL) structures have crucial functions in episodic (EM), but also in semantic memory (SM) processing. Preoperative functional magnetic resonance imaging (fMRI) activity within the MTL is increasingly used to predict post-surgical memory capacities. Based on the hypothesis that EM and SM memory functions are both hosted by the MTL the present study wanted to explore the relationship between SM related activations in the MTL as assessed before and the capacity of EM functions after surgery. Patients with chronic unilateral left (n=14) and right (n=12) temporal lobe epilepsy (TLE) performed a standard word list learning test pre- and postoperatively, and a fMRI procedure before the operation using a semantic decision task. SM processing caused significant bilateral MTL activations in both patient groups. While right TLE patients showed asymmetry of fMRI activation with more activation in the left MTL, left TLE patients had almost equal activation in both MTL regions. Contrasting left TLE versus right TLE patients revealed greater activity within the right MTL, whereas no significant difference was observed for the reverse contrast. Greater effect size in the MTL region ipsilateral to the seizure focus was significantly and positively correlated with preoperative EM abilities. Greater effect size in the contralateral MTL was correlated with better postoperative verbal EM, especially in left TLE patients. These results suggest that functional imaging of SM tasks may be useful to predict postoperative verbal memory in TLE. They also advocate a common neuroanatomical basis for SM and EM processes in the MTL.

Family poverty affects the rate of human infant brain growth.

PubMed

Hanson, Jamie L; Hair, Nicole; Shen, Dinggang G; Shi, Feng; Gilmore, John H; Wolfe, Barbara L; Pollak, Seth D

2013-01-01

Living in poverty places children at very high risk for problems across a variety of domains, including schooling, behavioral regulation, and health. Aspects of cognitive functioning, such as information processing, may underlie these kinds of problems. How might poverty affect the brain functions underlying these cognitive processes? Here, we address this question by observing and analyzing repeated measures of brain development of young children between five months and four years of age from economically diverse backgrounds (n = 77). In doing so, we have the opportunity to observe changes in brain growth as children begin to experience the effects of poverty. These children underwent MRI scanning, with subjects completing between 1 and 7 scans longitudinally. Two hundred and three MRI scans were divided into different tissue types using a novel image processing algorithm specifically designed to analyze brain data from young infants. Total gray, white, and cerebral (summation of total gray and white matter) volumes were examined along with volumes of the frontal, parietal, temporal, and occipital lobes. Infants from low-income families had lower volumes of gray matter, tissue critical for processing of information and execution of actions. These differences were found for both the frontal and parietal lobes. No differences were detected in white matter, temporal lobe volumes, or occipital lobe volumes. In addition, differences in brain growth were found to vary with socioeconomic status (SES), with children from lower-income households having slower trajectories of growth during infancy and early childhood. Volumetric differences were associated with the emergence of disruptive behavioral problems.

Family Poverty Affects the Rate of Human Infant Brain Growth

PubMed Central

Hanson, Jamie L.; Hair, Nicole; Shen, Dinggang G.; Shi, Feng; Gilmore, John H.; Wolfe, Barbara L.; Pollak, Seth D.

2013-01-01

Living in poverty places children at very high risk for problems across a variety of domains, including schooling, behavioral regulation, and health. Aspects of cognitive functioning, such as information processing, may underlie these kinds of problems. How might poverty affect the brain functions underlying these cognitive processes? Here, we address this question by observing and analyzing repeated measures of brain development of young children between five months and four years of age from economically diverse backgrounds (n = 77). In doing so, we have the opportunity to observe changes in brain growth as children begin to experience the effects of poverty. These children underwent MRI scanning, with subjects completing between 1 and 7 scans longitudinally. Two hundred and three MRI scans were divided into different tissue types using a novel image processing algorithm specifically designed to analyze brain data from young infants. Total gray, white, and cerebral (summation of total gray and white matter) volumes were examined along with volumes of the frontal, parietal, temporal, and occipital lobes. Infants from low-income families had lower volumes of gray matter, tissue critical for processing of information and execution of actions. These differences were found for both the frontal and parietal lobes. No differences were detected in white matter, temporal lobe volumes, or occipital lobe volumes. In addition, differences in brain growth were found to vary with socioeconomic status (SES), with children from lower-income households having slower trajectories of growth during infancy and early childhood. Volumetric differences were associated with the emergence of disruptive behavioral problems. PMID:24349025

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.

Memory deficits in amyotrophic lateral sclerosis are not exclusively caused by executive dysfunction: a comparative neuropsychological study of amnestic mild cognitive impairment.

PubMed

Machts, Judith; Bittner, Verena; Kasper, Elisabeth; Schuster, Christina; Prudlo, Johannes; Abdulla, Susanne; Kollewe, Katja; Petri, Susanne; Dengler, Reinhard; Heinze, Hans-Jochen; Vielhaber, Stefan; Schoenfeld, Mircea A; Bittner, Daniel M

2014-06-30

Recent work suggests that ALS and frontotemporal dementia can occur together and share at least in part the same underlying pathophysiology. However, it is unclear at present whether memory deficits in ALS stem from a temporal lobe dysfunction, or are rather driven by frontal executive dysfunction. In this study we sought to investigate the nature of memory deficits by analyzing the neuropsychological performance of 40 ALS patients in comparison to 39 amnestic mild cognitive impairment (aMCI) patients and 40 healthy controls (HC). The neuropsychological battery tested for impairment in executive functions, as well as memory and visuo-spatial skills, the results of which were compared across study groups. In addition, we calculated composite scores for memory (learning, recall, recognition) and executive functions (verbal fluency, cognitive flexibility, working memory). We hypothesized that the nature of memory impairment in ALS will be different from those exhibited by aMCI patients. Patient groups exhibited significant differences in their type of memory deficit, with the ALS group showing impairment only in recognition, whereas aMCI patients showed short and delayed recall performance deficits as well as reduced short-term capacity. Regression analysis revealed a significant impact of executive function on memory performance exclusively for the ALS group, accounting for one fifth of their memory performance. Interestingly, merging all sub scores into a single memory and an executive function score obscured these differences. The presented results indicate that the interpretation of neuropsychological scores needs to take the distinct cognitive profiles in ALS and aMCI into consideration. Importantly, the observed memory deficits in ALS were distinctly different from those observed in aMCI and can be explained only to some extent in the context of comorbid (coexisting) executive dysfunction. These findings highlight the qualitative differences in temporal lobe dysfunction between ALS and aMCI patients, and support temporal lobe dysfunction as a mechanism underlying the distinct cognitive impairments observed in ALS.

Temporal Cerebral Microbleeds Are Associated With Radiation Necrosis and Cognitive Dysfunction in Patients Treated for Nasopharyngeal Carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Qingyu; Department of Neurology, Zengcheng People's Hospital, Guangzhou; Lin, Focai

Purpose: Radiation therapy for patients with nasopharyngeal carcinoma (NPC) may be complicated with radiation-induced brain necrosis (RN), resulting in deteriorated cognitive function. However, the underlying mechanism of this phenomenon remains unclear. This study attempts to elucidate the association between cerebral microbleeds (CMBs) and radiation necrosis and cognitive dysfunction in NPC patients treated with radiation therapy. Methods and Materials: This cross-sectional study included 106 NPC patients who were exposed to radiation therapy (78 patients with RN and 28 without RN). Sixty-six patients without discernable intracranial pathology were included as the control group. CMBs were confirmed using susceptibility-weighted magnetic resonance imaging. Cognitivemore » function was accessed using Montreal Cognitive Assessment. Patients with a total score below 26 were defined as cognitively dysfunction. Results: Seventy-seven patients (98.7%) in the RN group and 12 patients (42.9%) in the non-RN group had at least 1 CMB. In contrast, only 14 patients (21.2%) in the control group had CMBs. In patients with a history of radiation therapy, CMBs most commonly presented in temporal lobes (76.4%) followed by cerebellum (23.7%). Patients with RN had more temporal CMBs than those in the non-RN group (37.7 ± 51.9 vs 3.8 ± 12.6, respectively; P<.001). The number of temporal lobe CMBs was predictive for larger volume of brain necrosis (P<.001) in multivariate linear regression analysis. Although cognitive impairment was diagnosed in 55.1% of RN patients, only 7.1% of non-RN patients sustained cognitive impairment (P<.001). After adjusting for age, sex, education, period after radiation therapy, CMBs in other lobes, and RN volume, the number of temporal CMBs remained an independent risk factor for cognitive dysfunction (odds ratio [OR]: 1.03; 95% confidence interval [CI]: 1.01-1.04; P=.003). Conclusions: CMBs is a common radiological manifestation in NPC patients with RN. The number of temporal CMBs is independently associated with increased likelihood of cognitive dysfunction in patients with RN.« less

SU-F-J-139: Amplitude of Low Frequency Fluctuation(ALFF) and Regional Homogeneity (ReHo) Study of the Respiration Motion Control Byhypnosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Y; Li, R; Xie, Y

Purpose: Respiration control by hypnosis is a method in reducing the detriment to the healthy organs or organizations for patients during radiotherapy, especially for lung and abdomen cancer (Fig.1). It’s hypothesized that there exists alterations neurological brain activity during the hypnosis state of respiratory motion control in comparison with resting state. Methods: Thirteen healthy volunteers were organized to participate in a hypnosis experiment that consisted of two sectional scans of functional magnetic resonance imaging (fMRI), rest state condition (RSC) scanning and hypnosis state condition (HSC) scanning. In addition, the coronal section of the lung was scanned during both conditions. Duringmore » the hypnosis scan, the volunteers were under the hypnotists’ guidance to keep peace and stable respiration. To evaluate the altered physiological performance of hypnosis in the respiratory control, three conventional indicators ALFF/fALFF (0.01–0.08Hz) and ReHo, were applied to identify the difference. Results: Compared with RSC, HSC showed significant (p<0.05) higher ReHo in superior temporal gyrus, middle temporal gyrus, frontal lobe, middle occipital gyrus, parietal lobe, cerebellum anterior Lobe and lingual gyrus, and left brainstem (Fig.2). While significant lower ReHo in middle frontal gyrus, superior frontal gyrus, inferior semi-lunar lobule, sub-lobar and limbic lobe (Fig.2). As for the ALFF results, significant higher value of HSC was observed in superior temporal gyrus, middle temporal gyrus, middle occipital gyrus, middle occipital gyrus, cerebellum anterior lobe, lingual gyrus, sub-lobar, limbic lobe, and lower in cerebellum posterior lobe, inferior semi-lunar lobule, inferior parietal lobule right middle frontal gyrus, cerebellar tonsil (Fig.3). The results of fALFF were similar to ALFF (Fig.4). The above results demonstrated that most significant regions of brain were uniform between ReHo and ALFF/fALFF. Conclusion: Hypnosis is a new psychological and helpful technology for respiration control. This study provides new insights of neurological brain activity during hypnosis of respiration control. This work is supported by grants from Guangdong Innovative Research Team Program of China (Grant No. 2011S013), National 863 Programs of China (Grant Nos. 2012AA02A604 and 2015AA043203), the National High-tech R&D Program for Young Scientists by the Ministry of Science and Technology of China (Grant No. 2015AA020917)« less

Content-Specific Source Encoding in the Human Medial Temporal Lobe

ERIC Educational Resources Information Center

Awipi, T.; Davachi, L.

2008-01-01

Although the medial temporal lobe (MTL) is known to be essential for episodic encoding, the contributions of individual MTL subregions remain unclear. Data from recognition memory studies have provided evidence that the hippocampus supports relational encoding important for later episodic recollection, whereas the perirhinal cortex has been linked…

Brain Regions Underlying Word Finding Difficulties in Temporal Lobe Epilepsy

ERIC Educational Resources Information Center

Trebuchon-Da Fonseca, Agnes; Guedj, Eric; Alario, F-Xavier; Laguitton, Virginie; Mundler, Olivier; Chauvel, Patrick; Liegeois-Chauvel, Catherine

2009-01-01

Word finding difficulties are often reported by epileptic patients with seizures originating from the language dominant cerebral hemisphere, for example, in temporal lobe epilepsy. Evidence regarding the brain regions underlying this deficit comes from studies of peri-operative electro-cortical stimulation, as well as post-surgical performance.…

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…

Implications of Animal Object Memory Research for Human Amnesia

ERIC Educational Resources Information Center

Winters, Boyer D.; Saksida, Lisa M.; Bussey, Timothy J.

2010-01-01

Damage to structures in the human medial temporal lobe causes severe memory impairment. Animal object recognition tests gained prominence from attempts to model "global" human medial temporal lobe amnesia, such as that observed in patient HM. These tasks, such as delayed nonmatching-to-sample and spontaneous object recognition, for assessing…

MEG Evidence for Incremental Sentence Composition in the Anterior Temporal Lobe

ERIC Educational Resources Information Center

Brennan, Jonathan R.; Pylkkänen, Liina

2017-01-01

Research investigating the brain basis of language comprehension has associated the left anterior temporal lobe (ATL) with sentence-level combinatorics. Using magnetoencephalography (MEG), we test the parsing strategy implemented in this brain region. The number of incremental parse steps from a predictive left-corner parsing strategy that is…

Sub-Centimeter Language Organization in the Human Temporal Lobe

ERIC Educational Resources Information Center

Flinker, A.; Chang, E. F.; Barbaro, N. M.; Berger, M. S.; Knight, R. T.

2011-01-01

The human temporal lobe is well known to be critical for language comprehension. Previous physiological research has focused mainly on non-invasive neuroimaging and electrophysiological techniques with each approach requiring averaging across many trials and subjects. The results of these studies have implicated extended anatomical regions in…

Grammatical Category Ambiguity in Aphasia

ERIC Educational Resources Information Center

Goldberg, Elmera; Goldfarb, Robert

2005-01-01

This study asked whether aphasic adults show different noun/verb retrieval patterns based upon their clinical categorization as fluent or nonfluent. Participants selected either the noun or the verb meaning of target words, as presented in three contexts. The framework was that nouns (associated with temporal lobe function) are processed, stored,…

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.

Differences in visual vs. verbal memory impairments as a result of focal temporal lobe damage in patients with traumatic brain injury.

PubMed

Ariza, Mar; Pueyo, Roser; Junqué, Carme; Mataró, María; Poca, María Antonia; Mena, Maria Pau; Sahuquillo, Juan

2006-09-01

The aim of the present study was to determine whether the type of lesion in a sample of moderate and severe traumatic brain injury (TBI) was related to material-specific memory impairment. Fifty-nine patients with TBI were classified into three groups according to whether the site of the lesion was right temporal, left temporal or diffuse. Six-months post-injury, visual (Warrington's Facial Recognition Memory Test and Rey's Complex Figure Test) and verbal (Rey's Auditory Verbal Learning Test) memories were assessed. Visual memory deficits assessed by facial memory were associated with right temporal lobe lesion, whereas verbal memory performance assessed with a list of words was related to left temporal lobe lesion. The group with diffuse injury showed both verbal and visual memory impairment. These results suggest a material-specific memory impairment in moderate and severe TBI after focal temporal lesions and a non-specific memory impairment after diffuse damage.

Electrical Stimulation in Hippocampus and Entorhinal Cortex Impairs Spatial and Temporal Memory.

PubMed

Goyal, Abhinav; Miller, Jonathan; Watrous, Andrew J; Lee, Sang Ah; Coffey, Tom; Sperling, Michael R; Sharan, Ashwini; Worrell, Gregory; Berry, Brent; Lega, Bradley; Jobst, Barbara C; Davis, Kathryn A; Inman, Cory; Sheth, Sameer A; Wanda, Paul A; Ezzyat, Youssef; Das, Sandhitsu R; Stein, Joel; Gorniak, Richard; Jacobs, Joshua

2018-05-09

The medial temporal lobe (MTL) is widely implicated in supporting episodic memory and navigation, but its precise functional role in organizing memory across time and space remains elusive. Here we examine the specific cognitive processes implemented by MTL structures (hippocampus and entorhinal cortex) to organize memory by using electrical brain stimulation, leveraging its ability to establish causal links between brain regions and features of behavior. We studied neurosurgical patients of both sexes who performed spatial-navigation and verbal-episodic memory tasks while brain stimulation was applied in various regions during learning. During the verbal memory task, stimulation in the MTL disrupted the temporal organization of encoded memories such that items learned with stimulation tended to be recalled in a more randomized order. During the spatial task, MTL stimulation impaired subjects' abilities to remember items located far away from boundaries. These stimulation effects were specific to the MTL. Our findings thus provide the first causal demonstration in humans of the specific memory processes that are performed by the MTL to encode when and where events occurred. SIGNIFICANCE STATEMENT Numerous studies have implicated the medial temporal lobe (MTL) in encoding spatial and temporal memories, but they have not been able to causally demonstrate the nature of the cognitive processes by which this occurs in real-time. Electrical brain stimulation is able to demonstrate causal links between a brain region and a given function with high temporal precision. By examining behavior in a memory task as subjects received MTL stimulation, we provide the first causal evidence demonstrating the role of the MTL in organizing the spatial and temporal aspects of episodic memory. Copyright © 2018 the authors 0270-6474/18/384471-11$15.00/0.

Weighing the value of memory loss in the surgical evaluation of left temporal lobe epilepsy: A decision analysis

PubMed Central

Akama-Garren, Elliot H.; Bianchi, Matt T.; Leveroni, Catherine; Cole, Andrew J.; Cash, Sydney S.; Westover, M. Brandon

2016-01-01

SUMMARY Objectives Anterior temporal lobectomy is curative for many patients with disabling medically refractory temporal lobe epilepsy, but carries an inherent risk of disabling verbal memory loss. Although accurate prediction of iatrogenic memory loss is becoming increasingly possible, it remains unclear how much weight such predictions should have in surgical decision making. Here we aim to create a framework that facilitates a systematic and integrated assessment of the relative risks and benefits of surgery versus medical management for patients with left temporal lobe epilepsy. Methods We constructed a Markov decision model to evaluate the probabilistic outcomes and associated health utilities associated with choosing to undergo a left anterior temporal lobectomy versus continuing with medical management for patients with medically refractory left temporal lobe epilepsy. Three base-cases were considered, representing a spectrum of surgical candidates encountered in practice, with varying degrees of epilepsy-related disability and potential for decreased quality of life in response to post-surgical verbal memory deficits. Results For patients with moderately severe seizures and moderate risk of verbal memory loss, medical management was the preferred decision, with increased quality-adjusted life expectancy. However, the preferred choice was sensitive to clinically meaningful changes in several parameters, including quality of life impact of verbal memory decline, quality of life with seizures, mortality rate with medical management, probability of remission following surgery, and probability of remission with medical management. Significance Our decision model suggests that for patients with left temporal lobe epilepsy, quantitative assessment of risk and benefit should guide recommendation of therapy. In particular, risk for and potential impact of verbal memory decline should be carefully weighed against the degree of disability conferred by continued seizures on a patient-by-patient basis. PMID:25244498

Weighing the value of memory loss in the surgical evaluation of left temporal lobe epilepsy: a decision analysis.

PubMed

Akama-Garren, Elliot H; Bianchi, Matt T; Leveroni, Catherine; Cole, Andrew J; Cash, Sydney S; Westover, M Brandon

2014-11-01

Anterior temporal lobectomy is curative for many patients with disabling medically refractory temporal lobe epilepsy, but carries an inherent risk of disabling verbal memory loss. Although accurate prediction of iatrogenic memory loss is becoming increasingly possible, it remains unclear how much weight such predictions should have in surgical decision making. Here we aim to create a framework that facilitates a systematic and integrated assessment of the relative risks and benefits of surgery versus medical management for patients with left temporal lobe epilepsy. We constructed a Markov decision model to evaluate the probabilistic outcomes and associated health utilities associated with choosing to undergo a left anterior temporal lobectomy versus continuing with medical management for patients with medically refractory left temporal lobe epilepsy. Three base-cases were considered, representing a spectrum of surgical candidates encountered in practice, with varying degrees of epilepsy-related disability and potential for decreased quality of life in response to post-surgical verbal memory deficits. For patients with moderately severe seizures and moderate risk of verbal memory loss, medical management was the preferred decision, with increased quality-adjusted life expectancy. However, the preferred choice was sensitive to clinically meaningful changes in several parameters, including quality of life impact of verbal memory decline, quality of life with seizures, mortality rate with medical management, probability of remission following surgery, and probability of remission with medical management. Our decision model suggests that for patients with left temporal lobe epilepsy, quantitative assessment of risk and benefit should guide recommendation of therapy. In particular, risk for and potential impact of verbal memory decline should be carefully weighed against the degree of disability conferred by continued seizures on a patient-by-patient basis. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

Graph theoretical analysis reveals disrupted topological properties of whole brain functional networks in temporal lobe epilepsy.

PubMed

Wang, Junjing; Qiu, Shijun; Xu, Yong; Liu, Zhenyin; Wen, Xue; Hu, Xiangshu; Zhang, Ruibin; Li, Meng; Wang, Wensheng; Huang, Ruiwang

2014-09-01

Temporal lobe epilepsy (TLE) is one of the most common forms of drug-resistant epilepsy. Previous studies have indicated that the TLE-related impairments existed in extensive local functional networks. However, little is known about the alterations in the topological properties of whole brain functional networks. In this study, we acquired resting-state BOLD-fMRI (rsfMRI) data from 26 TLE patients and 25 healthy controls, constructed their whole brain functional networks, compared the differences in topological parameters between the TLE patients and the controls, and analyzed the correlation between the altered topological properties and the epilepsy duration. The TLE patients showed significant increases in clustering coefficient and characteristic path length, but significant decrease in global efficiency compared to the controls. We also found altered nodal parameters in several regions in the TLE patients, such as the bilateral angular gyri, left middle temporal gyrus, right hippocampus, triangular part of left inferior frontal gyrus, left inferior parietal but supramarginal and angular gyri, and left parahippocampus gyrus. Further correlation analysis showed that the local efficiency of the TLE patients correlated positively with the epilepsy duration. Our results indicated the disrupted topological properties of whole brain functional networks in TLE patients. Our findings indicated the TLE-related impairments in the whole brain functional networks, which may help us to understand the clinical symptoms of TLE patients and offer a clue for the diagnosis and treatment of the TLE patients. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

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.

Grey matter correlates of susceptibility to scams in community-dwelling older adults.

PubMed

Duke Han, S; Boyle, Patricia A; Yu, Lei; Arfanakis, Konstantinos; James, Bryan D; Fleischman, Debra A; Bennett, David A

2016-06-01

Susceptibility to scams is a significant issue among older adults, even among those with intact cognition. Age-related changes in brain macrostructure may be associated with susceptibility to scams; however, this has yet to be explored. Based on previous work implicating frontal and temporal lobe functioning as important in decision making, we tested the hypothesis that susceptibility to scams is associated with smaller grey matter volume in frontal and temporal lobe regions in a large community-dwelling cohort of non-demented older adults. Participants (N = 327, mean age = 81.55, mean education = 15.30, 78.9 % female) completed a self-report measure used to assess susceptibility to scams and an MRI brain scan. Results indicated an inverse association between overall grey matter and susceptibility to scams in models adjusted for age, education, and sex; and in models further adjusted for cognitive function. No significant associations were observed for white matter, cerebrospinal fluid, or total brain volume. Models adjusted for age, education, and sex revealed seven clusters showing smaller grey matter in the right parahippocampal/hippocampal/fusiform, left middle temporal, left orbitofrontal, right ventromedial prefrontal, right middle temporal, right precuneus, and right dorsolateral prefrontal regions. In models further adjusted for cognitive function, results revealed three significant clusters showing smaller grey matter in the right parahippocampal/hippocampal/fusiform, right hippocampal, and right middle temporal regions. Lower grey matter concentration in specific brain regions may be associated with susceptibility to scams, even after adjusting for cognitive ability. Future research is needed to determine whether grey matter reductions in these regions may be a biomarker for susceptibility to scams in old age.

Practice guideline summary: Use of fMRI in the presurgical evaluation of patients with epilepsy: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology.

PubMed

Szaflarski, Jerzy P; Gloss, David; Binder, Jeffrey R; Gaillard, William D; Golby, Alexandra J; Holland, Scott K; Ojemann, Jeffrey; Spencer, David C; Swanson, Sara J; French, Jacqueline A; Theodore, William H

2017-01-24

To assess the diagnostic accuracy and prognostic value of functional MRI (fMRI) in determining lateralization and predicting postsurgical language and memory outcomes. An 11-member panel evaluated and rated available evidence according to the 2004 American Academy of Neurology process. At least 2 panelists reviewed the full text of 172 articles and selected 37 for data extraction. Case reports, reports with <15 cases, meta-analyses, and editorials were excluded. The use of fMRI may be considered an option for lateralizing language functions in place of intracarotid amobarbital procedure (IAP) in patients with medial temporal lobe epilepsy (MTLE; Level C), temporal epilepsy in general (Level C), or extratemporal epilepsy (Level C). For patients with temporal neocortical epilepsy or temporal tumors, the evidence is insufficient (Level U). fMRI may be considered to predict postsurgical language deficits after anterior temporal lobe resection (Level C). The use of fMRI may be considered for lateralizing memory functions in place of IAP in patients with MTLE (Level C) but is of unclear utility in other epilepsy types (Level U). fMRI of verbal memory or language encoding should be considered for predicting verbal memory outcome (Level B). fMRI using nonverbal memory encoding may be considered for predicting visuospatial memory outcomes (Level C). Presurgical fMRI could be an adequate alternative to IAP memory testing for predicting verbal memory outcome (Level C). Clinicians should carefully advise patients of the risks and benefits of fMRI vs IAP during discussions concerning choice of specific modality in each case. © 2017 American Academy of Neurology.

Impaired Cerebral Autoregulation Is Associated with Brain Atrophy and Worse Functional Status in Chronic Ischemic Stroke

PubMed Central

Aoi, Mikio C.; Hu, Kun; Lo, Men-Tzung; Selim, Magdy; Olufsen, Mette S.; Novak, Vera

2012-01-01

Dynamic cerebral autoregulation (dCA) is impaired following stroke. However, the relationship between dCA, brain atrophy, and functional outcomes following stroke remains unclear. In this study, we aimed to determine whether impairment of dCA is associated with atrophy in specific regions or globally, thereby affecting daily functions in stroke patients. We performed a retrospective analysis of 33 subjects with chronic infarctions in the middle cerebral artery territory, and 109 age-matched non-stroke subjects. dCA was assessed via the phase relationship between arterial blood pressure and cerebral blood flow velocity. Brain tissue volumes were quantified from MRI. Functional status was assessed by gait speed, instrumental activities of daily living (IADL), modified Rankin Scale, and NIH Stroke Score. Compared to the non-stroke group, stroke subjects showed degraded dCA bilaterally, and showed gray matter atrophy in the frontal, parietal and temporal lobes ipsilateral to infarct. In stroke subjects, better dCA was associated with less temporal lobe gray matter atrophy on the infracted side ( = 0.029), faster gait speed ( = 0.018) and lower IADL score (0.002). Our results indicate that better dynamic cerebral perfusion regulation is associated with less atrophy and better long-term functional status in older adults with chronic ischemic infarctions. PMID:23071639

Changes in flip/flop splicing of astroglial AMPA receptors in human temporal lobe epilepsy.

PubMed

Seifert, Gerald; Schröder, Wolfgang; Hinterkeuser, Stefan; Schumacher, Thekla; Schramm, Johannes; Steinhäuser, Christian

2002-01-01

Recent data suggested a role for glial cells in epilepsy. This study sought to identify and functionally characterize AMPA receptors expressed by astrocytes in human hippocampal tissue resected from patients with intractable temporal lobe epilepsy. Patch-clamp and fast application methods were combined to investigate astrocytes in situ and after fresh isolation from the stratum radiatum of the hippocampal CA1 subfield. Relying on presurgical and histopathologic analysis, we divided human specimens into two groups, Ammon's horn sclerosis (AHS) and lesion-associated epilepsy. Fast application of glutamate and kainate evoked receptor currents in all cells studied. Reversal-potential analysis revealed an intermediate Ca2+ permeability of the receptor channels that did not vary between the two groups of patients. However, preapplication of the AMPA receptor-specific modulator, cyclothiazide, disclosed differences in flip-flop splicing. This treatment considerably enhanced the receptor conductance, with potentiation being significantly stronger in cells from AHS specimens compared with lesion-associated cells, suggesting upregulation of AMPA receptor flip splice variants in astrocytes of the sclerotic tissue. Compelling evidence has been accumulated showing direct and rapid signaling between neurons and glial cells. Our data suggest that in AHS patients, neuronally released glutamate will lead to an enhanced and prolonged depolarization of astrocytes, which might be involved in seizure generation and spread in this particular condition of human temporal lobe epilepsy.

Advances in memory research: single-neuron recordings from the human medial temporal lobe aid our understanding of declarative memory.

PubMed

Viskontas, Indre V

2008-12-01

To gain a complete understanding of how the brain functions, both in illness and good health, data from multiple levels of analysis must be integrated. Technical advances have made direct recordings of neuronal activity deep inside the human brain tractable, providing a rare glimpse into cellular processes during long-term memory formation. Recent findings using intracranial recordings in the medial temporal lobe inform current neural network models of memory, and may lead to a more comprehensive understanding of the neural basis of memory-related processes. These recordings have shown that cells in the hippocampus appear to support declarative learning by distinguishing novel and familiar stimuli via changes in firing patterns. Some cells with highly selective and invariant responses have also been described, and these responses seem to represent abstract concepts such as identity, rather than superficial perceptual features of items. Importantly, however, both selective and globally responsive cells are capable of changing their preferred stimulus depending on the conscious demands of the task. Firing patterns of human medial temporal lobe neurons indicate that cells can be both plastic and stable in terms of the information that they code; although some cells show highly selective and reproducible excitatory responses when presented with a familiar object, other cells change their receptive fields in line with changes in experience and the cognitive environment.

Evidence for degraded low frequency verbal concepts in left resected temporal lobe epilepsy patients.

PubMed

Visser, M; Forn, C; Lambon Ralph, M A; Hoffman, P; Gómez Ibáñez, A; Sunajuán, Ana; Rosell Negre, P; Villanueva, V; Ávila, C

2018-06-01

According to a large neuropsychological and neuroimaging literature, the bilateral anterior temporal lobe (ATL) is a core region for semantic processing. It seems therefore surprising that semantic memory appears to be preserved in temporal lobe epilepsy (TLE) patients with unilateral ATL resection. However, recent work suggests that the bilateral semantic system is relatively robust against unilateral damage and semantic impairments under these circumstances only become apparent with low frequency specific concepts. In addition, neuroimaging studies have shown that the function of the left and right ATLs differ and therefore left or right ATL resection should lead to a different pattern of impairment. The current study investigated hemispheric differences in the bilateral semantic system by comparing left and right resected TLE patients during verbal semantic processing of low frequency concepts. Picture naming and semantic comprehension tasks with varying word frequencies were included to investigate the pattern of impairment. Left but not right TLE patients showed impaired semantic processing, which was particularly apparent on low frequency items. This indicates that, for verbal information, the bilateral semantic system is more sensitive to damage in the left compared to the right ATL, which is in line with theories that attribute a more prominent role to the left ATL due to connections with pre-semantic verbal regions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Coexistence of meningoencephalocele and hippocampal sclerosis: a new type of dual pathology.

PubMed

Martinoni, Matteo; Marucci, Gianluca; Gagliardini, Gabriele; Tinuper, Paolo; Michelucci, Roberto; Giulioni, Marco

2017-05-01

Both temporal lobe meningoencephalocele (TE) and hippocampal sclerosis (HS) are causes of drug-resistant temporal lobe epilepsy. Spontaneous TE constitutes a rare but well-known and increasingly recognised cause of refractory epilepsy. It is well known that HS may be associated with another neocortical lesion (dual pathology). Here we report for the first time a new type of dual pathology; namely, the coexistence of temporal pole meningoencephalocele and HS.

Amino acid metabolic processes in the temporal lobes assessed by proton magnetic resonance spectroscopy (1H MRS) in children with Down syndrome.

PubMed

Śmigielska-Kuzia, Joanna; Boćkowski, Leszek; Sobaniec, Wojciech; Kułak, Wojciech; Sendrowski, Krzysztof

2010-01-01

Down syndrome (DS), or trisomy 21, is one of the most common autosomal mutations. The overexpression of the β-amyloid precursor protein gene, located on chromosome 21, causes an increased production of the specific amyloid. The current study is a continuation of our earlier investigations relating to the profile of metabolic changes in the frontal lobes of DS patients as assessed by proton magnetic resonance spectroscopy ((1)H MRS). The aims of the study were the morphological assessment of the brain using magnetic resonance imaging (MRI) and the evaluation of metabolic disorders of the temporal lobes using (1)H MRS in DS children. The study group included 20 children with DS aged 3-15 years and treated in the Department of Pediatric Neurology and Rehabilitation, Medical University of Białystok. The control group included healthy children (n = 20). MRI scans of the heads of DS children were performed using a 1.5 T MR scanner under standard conditions. (1)H MRS investigations were also carried out to assess metabolic changes in the temporal lobes. Metabolites, such as N-acetylaspartate (NAA), glutamate-glutamine complex (Glx), choline (Cho), myoinositol (mI) and γ-aminobutyric acid (GABA), were determined in both temporal lobes with reference to the internal marker creatine (Cr). Results were compared with the control group.We found a statistically significant decrease in NAA/Cr, Cho/Cr, mI/Cr and GABA/Cr ratios. The Glx/Cr ratio in both temporal lobes of DS patients did not differ from the control group. Our results indicate metabolic neurotransmitter disorders in the central nervous system in children with DS.

The Temporal Lobes Differentiate between the Voices of Famous and Unknown People: An Event-Related fMRI Study on Speaker Recognition

PubMed Central

Bethmann, Anja; Scheich, Henning; Brechmann, André

2012-01-01

It is widely accepted that the perception of human voices is supported by neural structures located along the superior temporal sulci. However, there is an ongoing discussion to what extent the activations found in fMRI studies are evoked by the vocal features themselves or are the result of phonetic processing. To show that the temporal lobes are indeed engaged in voice processing, short utterances spoken by famous and unknown people were presented to healthy young participants whose task it was to identify the familiar speakers. In two event-related fMRI experiments, the temporal lobes were found to differentiate between familiar and unfamiliar voices such that named voices elicited higher BOLD signal intensities than unfamiliar voices. Yet, the temporal cortices did not only discriminate between familiar and unfamiliar voices. Experiment 2, which required overtly spoken responses and allowed to distinguish between four familiarity grades, revealed that there was a fine-grained differentiation between all of these familiarity levels with higher familiarity being associated with larger BOLD signal amplitudes. Finally, we observed a gradual response change such that the BOLD signal differences between unfamiliar and highly familiar voices increased with the distance of an area from the transverse temporal gyri, especially towards the anterior temporal cortex and the middle temporal gyri. Therefore, the results suggest that (the anterior and non-superior portions of) the temporal lobes participate in voice-specific processing independent from phonetic components also involved in spoken speech material. PMID:23112826

Medial Temporal Lobe Structures Contribute to On-Line Processing

ERIC Educational Resources Information Center

Warren, David

2009-01-01

For the last five decades, the medial temporal lobes have been generally understood to facilitate enduring representation of certain kinds of information. In particular, knowledge about the relations among items and concepts appears to rely on that region of the brain. Recent results suggest that those same structures also play a subtle role in…

Treatment of Proper Name Retrieval Deficits in an Individual with Temporal Lobe Epilepsy

ERIC Educational Resources Information Center

Minkina, Irene; Ojemann, Jeffrey G.; Grabowski, Thomas J.; Silkes, JoAnn P.; Phatak, Vaishali; Kendall, Diane L.

2013-01-01

Purpose: Studies investigating language deficits in individuals with left temporal-lobe epilepsy have consistently demonstrated impairments in proper name retrieval. The aim of this Phase I rehabilitation study was to investigate the effects of a linguistically distributed word retrieval treatment on proper name retrieval in an individual with…

Epileptic Hypergraphia: The Impact of Prolific Writing on Language Creativity

ERIC Educational Resources Information Center

Ammari, Elham H.

2012-01-01

Catalyzed academic concerns have been shown so far to tackle the issue of temporal lobe epileptic hypergraphia and the extent of its creativity. Temporal lobe epilepsy hence, (TLE) as a neurological brain disorder, has captured the attention of concerned scholars ever since. A constellation of TLE and its cohorts have baffled scientists,…

Bilateral Capacity for Speech Sound Processing in Auditory Comprehension: Evidence from Wada Procedures

ERIC Educational Resources Information Center

Hickok, G.; Okada, K.; Barr, W.; Pa, J.; Rogalsky, C.; Donnelly, K.; Barde, L.; Grant, A.

2008-01-01

Data from lesion studies suggest that the ability to perceive speech sounds, as measured by auditory comprehension tasks, is supported by temporal lobe systems in both the left and right hemisphere. For example, patients with left temporal lobe damage and auditory comprehension deficits (i.e., Wernicke's aphasics), nonetheless comprehend isolated…

Is déjà vu a symptom of temporal lobe epilepsy?

PubMed

Neppe, V M

1981-12-05

The definition and conceptualization of the déjà vu phenomenon are interpreted in various ways. The common occurrence of déjà vu is the general population stresses the need for the development of specific qualitative features which will be valuable in the diagnosis of temporal lobe epilepsy.

A Case Study of the Cognitive and Behavioral Deficits of Temporal Lobe Damage in Herpes Simplex Encephalitis.

ERIC Educational Resources Information Center

Greer, Margaret K.; And Others

1989-01-01

This case study illustrates the highly significant language difficulties, marked memory deficits, and propensity for physical aggression following temporal lobe damage brought about by herpes encephalitis, and presents the usefulness of a new diagnostic measure in delineating such a variable cognitive pattern. (Author)

Contributions of the Medial Temporal Lobe to Declarative Memory Retrieval: Manipulating the Amount of Contextual Retrieval

ERIC Educational Resources Information Center

Tendolkar, Indira; Arnold, Jennifer; Petersson, Karl Magnus; Weis, Susanne; Brockhaus-Dumke, Anke; van Eijndhoven, Philip; Buitelaar, Jan; Fernandez, Guillen

2008-01-01

We investigated how the hippocampus and its adjacent mediotemporal structures contribute to contextual and noncontextual declarative memory retrieval by manipulating the amount of contextual information across two levels of the same contextual dimension in a source memory task. A first analysis identified medial temporal lobe (MTL) substructures…

Memory, Metamemory and Their Dissociation in Temporal Lobe Epilepsy

ERIC Educational Resources Information Center

Howard, Charlotte E.; Andres, Pilar; Broks, Paul; Noad, Rupert; Sadler, Martin; Coker, Debbie; Mazzoni, Giuliana

2010-01-01

Patients with temporal-lobe epilepsy (TLE) present with memory difficulties. The aim of the current study was to determine to what extent these difficulties could be related to a metamemory impairment. Fifteen patients with TLE and 15 matched healthy controls carried out a paired-associates learning task. Memory recall was measured at intervals of…

Arousal Enhanced Memory Retention Is Eliminated Following Temporal Lobe Resection

ERIC Educational Resources Information Center

Ahs, Fredrik; Kumlien, Eva; Fredrikson, Mats

2010-01-01

The amygdala, situated in the anterior medial temporal lobe (MTL), is involved in the emotional enhancement of memory. The present study evaluated whether anterior MTL-resections attenuated arousal induced memory enhancement for pictures. Also, the effect of MTL-resections on response latencies at retrieval was assessed. Thirty-one patients with…

Distinct Roles for Medial Temporal Lobe Structures in Memory for Objects and Their Locations

ERIC Educational Resources Information Center

Buffalo, Elizabeth A.; Bellgowan, Patrick S. F.; Martin, Alex

2006-01-01

The ability to learn and retain novel information depends on a system of structures in the medial temporal lobe (MTL) including the hippocampus and the surrounding entorhinal, perirhinal, and parahippocampal cortices. Damage to these structures produces profound memory deficits; however, the unique contribution to memory of each of these…

The Consolidation of Object and Context Recognition Memory Involve Different Regions of the Temporal Lobe

ERIC Educational Resources Information Center

Balderas, Israela; Rodriguez-Ortiz, Carlos J.; Salgado-Tonda, Paloma; Chavez-Hurtado, Julio; McGaugh, James L.; Bermudez-Rattoni, Federico

2008-01-01

These experiments investigated the involvement of several temporal lobe regions in consolidation of recognition memory. Anisomycin, a protein synthesis inhibitor, was infused into the hippocampus, perirhinal cortex, insular cortex, or basolateral amygdala of rats immediately after the sample phase of object or object-in-context recognition memory…

Cortical hypoactivation during resting EEG in schizophrenics but not in depressives and schizotypal subjects as revealed by low resolution electromagnetic tomography (LORETA).

PubMed

Mientus, Susanne; Gallinat, Jürgen; Wuebben, Yvonne; Pascual-Marqui, Roberto D; Mulert, Christoph; Frick, Kurt; Dorn, Hans; Herrmann, Werner M; Winterer, Georg

2002-11-30

This study was performed in order to address the question whether the newly introduced technique of low-resolution electromagnetic tomography (LORETA) is able to detect hypofrontality in schizophrenic patients. We investigated resting EEGs of 19 unmedicated schizophrenics and 20 normal subjects. For comparison, we also investigated 19 subjects with schizotypal personality and 30 unmedicated depressive patients. A significant increase of delta activity was found in schizophrenic patients over the whole cortex, most strongly in the anterior cingulate gyrus and temporal lobe (fusiform gyrus). Both schizotypal subjects and depressive subjects showed significantly less delta, theta and beta activity in the anterior cingulum, a decrease of alpha1 activity in the right temporal lobe and a decrease of alpha2 activity in the left temporal lobe. The results suggest general cortical hypoactivation, most pronounced in the anterior cingulate and temporal lobe in schizophrenics, whereas there is evidence for a complex, frequency-dependent spatial pattern of hyperactivation in schizotypal subjects and depressive patients. The results are discussed within a neurophysiological and methodological framework.

Seizure outcomes of temporal lobe epilepsy surgery in patients with normal MRI and without specific histopathology.

PubMed

Ivanovic, Jugoslav; Larsson, Pål G; Østby, Ylva; Hald, John; Krossnes, Bård K; Fjeld, Jan G; Pripp, Are H; Alfstad, Kristin Å; Egge, Arild; Stanisic, Milo

2017-05-01

Seizure outcome following surgery in pharmacoresistant temporal lobe epilepsy patients with normal magnetic resonance imaging and normal or non-specific histopathology is not sufficiently presented in the literature. In a retrospective design, we reviewed data of 263 patients who had undergone temporal lobe epilepsy surgery and identified 26 (9.9%) who met the inclusion criteria. Seizure outcomes were determined at 2-year follow-up. Potential predictors of Engel class I (satisfactory outcome) were identified by logistic regression analyses. Engel class I outcome was achieved in 61.5% of patients, 50% being completely seizure free (Engel class IA outcome). The strongest predictors of satisfactory outcome were typical ictal seizure semiology (p = 0.048) and localised ictal discharges on scalp EEG (p = 0.036). Surgery might be an effective treatment choice for the majority of these patients, although outcomes are less favourable than in patients with magnetic resonance imaging-defined lesional temporal lobe epilepsy. Typical ictal seizure semiology and localised ictal discharges on scalp EEG were predictors of Engel class I outcome.

Decreased astroglial monocarboxylate transporter 4 expression in temporal lobe epilepsy.

PubMed

Liu, Bei; Niu, Le; Shen, Ming-Zhi; Gao, Lei; Wang, Chao; Li, Jie; Song, Li-Jia; Tao, Ye; Meng, Qiang; Yang, Qian-Li; Gao, Guo-Dong; Zhang, Hua

2014-10-01

Efflux of monocaroxylates like lactate, pyruvate, and ketone bodies from astrocytes through monocarboxylate transporter 4 (MCT4) supplies the local neuron population with metabolic intermediates to meet energy requirements under conditions of increased demand. Disruption of this astroglial-neuron metabolic coupling pathway may contribute to epileptogenesis. We measured MCT4 expression in temporal lobe epileptic foci excised from patients with intractable epilepsy and in rats injected with pilocarpine, an animal model of temporal lobe epilepsy (TLE). Cortical MCT4 expression levels were significantly lower in TLE patients compared with controls, due at least partially to MCT4 promoter methylation. Expression of MCT4 also decreased progressively in pilocarpine-treated rats from 12 h to 14 days post-administration. Underexpression of MCT4 in cultured astrocytes induced by a short hairpin RNA promoted apoptosis. Knockdown of astrocyte MCT4 also suppressed excitatory amino acid transporter 1 (EAAT1) expression. Reduced MCT4 and EAAT1 expression by astrocytes may lead to neuronal hyperexcitability and epileptogenesis in the temporal lobe by reducing the supply of metabolic intermediates and by allowing accumulation of extracellular glutamate.

Effective Connectivity from Early Visual Cortex to Posterior Occipitotemporal Face Areas Supports Face Selectivity and Predicts Developmental Prosopagnosia

PubMed Central

Garrido, Lucia; Driver, Jon; Dolan, Raymond J.; Duchaine, Bradley C.; Furl, Nicholas

2016-01-01

Face processing is mediated by interactions between functional areas in the occipital and temporal lobe, and the fusiform face area (FFA) and anterior temporal lobe play key roles in the recognition of facial identity. Individuals with developmental prosopagnosia (DP), a lifelong face recognition impairment, have been shown to have structural and functional neuronal alterations in these areas. The present study investigated how face selectivity is generated in participants with normal face processing, and how functional abnormalities associated with DP, arise as a function of network connectivity. Using functional magnetic resonance imaging and dynamic causal modeling, we examined effective connectivity in normal participants by assessing network models that include early visual cortex (EVC) and face-selective areas and then investigated the integrity of this connectivity in participants with DP. Results showed that a feedforward architecture from EVC to the occipital face area, EVC to FFA, and EVC to posterior superior temporal sulcus (pSTS) best explained how face selectivity arises in both controls and participants with DP. In this architecture, the DP group showed reduced connection strengths on feedforward connections carrying face information from EVC to FFA and EVC to pSTS. These altered network dynamics in DP contribute to the diminished face selectivity in the posterior occipitotemporal areas affected in DP. These findings suggest a novel view on the relevance of feedforward projection from EVC to posterior occipitotemporal face areas in generating cortical face selectivity and differences in face recognition ability. SIGNIFICANCE STATEMENT Areas of the human brain showing enhanced activation to faces compared to other objects or places have been extensively studied. However, the factors leading to this face selectively have remained mostly unknown. We show that effective connectivity from early visual cortex to posterior occipitotemporal face areas gives rise to face selectivity. Furthermore, people with developmental prosopagnosia, a lifelong face recognition impairment, have reduced face selectivity in the posterior occipitotemporal face areas and left anterior temporal lobe. We show that this reduced face selectivity can be predicted by effective connectivity from early visual cortex to posterior occipitotemporal face areas. This study presents the first network-based account of how face selectivity arises in the human brain. PMID:27030766

Concomitant fractional anisotropy and volumetric abnormalities in temporal lobe epilepsy: cross-sectional evidence for progressive neurologic injury.

PubMed

Keller, Simon S; Schoene-Bake, Jan-Christoph; Gerdes, Jan S; Weber, Bernd; Deppe, Michael

2012-01-01

In patients with temporal lobe epilepsy and associated hippocampal sclerosis (TLEhs) there are brain abnormalities extending beyond the presumed epileptogenic zone as revealed separately in conventional magnetic resonance imaging (MRI) and MR diffusion tensor imaging (DTI) studies. However, little is known about the relation between macroscopic atrophy (revealed by volumetric MRI) and microstructural degeneration (inferred by DTI). For 62 patients with unilateral TLEhs and 68 healthy controls, we determined volumes and mean fractional anisotropy (FA) of ipsilateral and contralateral brain structures from T1-weighted and DTI data, respectively. We report significant volume atrophy and FA alterations of temporal lobe, subcortical and callosal regions, which were more diffuse and bilateral in patients with left TLEhs relative to right TLEhs. We observed significant relationships between volume loss and mean FA, particularly of the thalamus and putamen bilaterally. When corrected for age, duration of epilepsy was significantly correlated with FA loss of an anatomically plausible route - including ipsilateral parahippocampal gyrus and temporal lobe white matter, the thalamus bilaterally, and posterior regions of the corpus callosum that contain temporal lobe fibres - that may be suggestive of progressive brain degeneration in response to recurrent seizures. Chronic TLEhs is associated with interrelated DTI-derived and volume-derived brain degenerative abnormalities that are influenced by the duration of the disorder and the side of seizure onset. This work confirms previously contradictory findings by employing multi-modal imaging techniques in parallel in a large sample of patients.

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

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

The role of the left anterior temporal lobe in exception word reading: reconciling patient and neuroimaging findings.

PubMed

Wilson, Maximiliano A; Joubert, Sven; Ferré, Perrine; Belleville, Sylvie; Ansaldo, Ana Inés; Joanette, Yves; Rouleau, Isabelle; Brambati, Simona Maria

2012-05-01

Semantic dementia (SD) is a neurodegenerative disease that occurs following the atrophy of the anterior temporal lobes (ATLs). It is characterised by the degradation of semantic knowledge and difficulties in reading exception words (surface dyslexia). This disease has highlighted the role of the ATLs in the process of exception word reading. However, imaging studies in healthy subjects have failed to detect activation of the ATLs during exception word reading. The aim of the present study was to test whether the functional brain regions that mediate exception word reading in normal readers overlap those brain regions atrophied in SD. In Study One, we map the brain regions of grey matter atrophy in AF, a patient with mild SD and surface dyslexia profile. In Study Two, we map the activation pattern associated with exception word compared to pseudoword reading in young, healthy participants using fMRI. The results revealed areas of significant activation in healthy subjects engaged in the exception word reading task in the left anterior middle temporal gyrus, in a region observed to be atrophic in the patient AF. These results reconcile neuropsychological and functional imaging data, revealing the critical role of the left ATL in exception word reading. Copyright © 2012 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.

Altered Medial Frontal and Superior Temporal Response to Implicit Processing of Emotions in Autism.

PubMed

Kana, Rajesh K; Patriquin, Michelle A; Black, Briley S; Channell, Marie M; Wicker, Bruno

2016-01-01

Interpreting emotional expressions appropriately poses a challenge for individuals with autism spectrum disorder (ASD). In particular, difficulties with emotional processing in ASD are more pronounced in contexts where emotional expressions are subtle, automatic, and reflexive-that is, implicit. In contrast, explicit emotional processing, which requires the cognitive evaluation of an emotional experience, appears to be relatively intact in individuals with ASD. In the present study, we examined the brain activation and functional connectivity differences underlying explicit and implicit emotional processing in age- and IQ-matched adults with (n = 17) and without (n = 15) ASD. Results indicated: (1) significantly reduced levels of brain activation in participants with ASD in medial prefrontal cortex (MPFC) and superior temporal gyrus (STG) during implicit emotion processing; (2) significantly weaker functional connectivity in the ASD group in connections of the MPFC with the amygdala, temporal lobe, parietal lobe, and fusiform gyrus; (3) No group difference in performance accuracy or reaction time; and (4) Significant positive relationship between empathizing ability and STG activity in ASD but not in typically developing participants. These findings suggest that the neural mechanisms underlying implicit, but not explicit, emotion processing may be altered at multiple levels in individuals with ASD. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

Visual and auditory socio-cognitive perception in unilateral temporal lobe epilepsy in children and adolescents: a prospective controlled study.

PubMed

Laurent, Agathe; Arzimanoglou, Alexis; Panagiotakaki, Eleni; Sfaello, Ignacio; Kahane, Philippe; Ryvlin, Philippe; Hirsch, Edouard; de Schonen, Scania

2014-12-01

A high rate of abnormal social behavioural traits or perceptual deficits is observed in children with unilateral temporal lobe epilepsy. In the present study, perception of auditory and visual social signals, carried by faces and voices, was evaluated in children or adolescents with temporal lobe epilepsy. We prospectively investigated a sample of 62 children with focal non-idiopathic epilepsy early in the course of the disorder. The present analysis included 39 children with a confirmed diagnosis of temporal lobe epilepsy. Control participants (72), distributed across 10 age groups, served as a control group. Our socio-perceptual evaluation protocol comprised three socio-visual tasks (face identity, facial emotion and gaze direction recognition), two socio-auditory tasks (voice identity and emotional prosody recognition), and three control tasks (lip reading, geometrical pattern and linguistic intonation recognition). All 39 patients also benefited from a neuropsychological examination. As a group, children with temporal lobe epilepsy performed at a significantly lower level compared to the control group with regards to recognition of facial identity, direction of eye gaze, and emotional facial expressions. We found no relationship between the type of visual deficit and age at first seizure, duration of epilepsy, or the epilepsy-affected cerebral hemisphere. Deficits in socio-perceptual tasks could be found independently of the presence of deficits in visual or auditory episodic memory, visual non-facial pattern processing (control tasks), or speech perception. A normal FSIQ did not exempt some of the patients from an underlying deficit in some of the socio-perceptual tasks. Temporal lobe epilepsy not only impairs development of emotion recognition, but can also impair development of perception of other socio-perceptual signals in children with or without intellectual deficiency. Prospective studies need to be designed to evaluate the results of appropriate re-education programs in children presenting with deficits in social cue processing.

Assessment of nonverbal learning and memory using the Design Learning Test.

PubMed

Foster, Paul S; Drago, Valeria; Harrison, David W

2009-05-01

The laterality of verbal and nonverbal learning and memory to the left and right temporal lobes, respectively, has received much empirical support. Researchers have often used the Rey Auditory Verbal Learning Test (RAVLT) as a measure of verbal learning and memory in these investigations. However, a precise analog of the RAVLT that uses stimuli difficult to encode verbally has not been reported. Further, although researchers have developed some measures that are essentially visuospatial analogs of the RAVLT, no correlational data have been reported attesting to the relation between the measures. The authors report the development of a nonverbal analog of the RAVLT, referred to as the Design Learning Test (DLT). Also, the authors present correlational data supporting a relation between the DLT and RAVLT, and they hope that the present study will stimulate research investigating whether the DLT is sensitive to right temporal lobe functioning.

The relationship between emotional intelligence and task-switching in temporal lobe epilepsy.

PubMed

Gul, Amara; Hussain, Imtiaz

2016-01-01

To examine the role of emotional intelligence (EI) in task-switching performance of patients with temporal lobe epilepsy (TLE). An experimental research design conducted at Sheikh Zayed Hospital, Rahim Yar Khan, Mayo and Services Hospital, Lahore, Pakistan from March 2013 to October 2014. Twenty-five patients with TLE and 25 healthy individuals from local community participated in the study. Participants completed measures of intelligence, EI, depression, anxiety, stress, and task-switching experiment. Patients and controls showed an average intelligence quotient, and normal levels of depression, anxiety, and stress. In contrast to controls, patients showed lower EI and impaired task-switching abilities. This result can be seen in the context of disintegrated white matter and cerebral connectivity in patients with TLE. Emotional intelligence was found to be a significant predictor of task-switching performance. Emotional intelligence is a potential marker of higher order cognitive functioning in patients with TLE.

Video electroencephalogram telemetry in temporal lobe epilepsy

PubMed Central

Mani, Jayanti

2014-01-01

Temporal lobe epilepsy (TLE) is the most commonly encountered medically refractory epilepsy. It is also the substrate of refractory epilepsy that gives the most gratifying results in any epilepsy surgery program, with a minimum use of resources. Correlation of clinical behavior and the ictal patterns during ictal behavior is mandatory for success at epilepsy surgery. Video electroencephalogram (EEG) telemetry achieves this goal and hence plays a pivotal role in pre-surgical assessment. The role of telemetry is continuously evolving with the advent of digital EEG technology, of high-resolution volumetric magnetic resonance imaging and other functional imaging techniques. Most of surgical selection in patients with TLE can be done with a scalp video EEG monitoring. However, the limitations of the scalp EEG technique demand invasive recordings in a selected group of TLE patients. This subset of the patients can be a challenge to the epileptologist. PMID:24791089

Postoperative recovery of hippocampal contralateral diffusivity in medial temporal lobe epilepsy.

PubMed

Thivard, Lionel; Tanguy, Marie-Laure; Adam, Claude; Clémenceau, Stéphane; Dezamis, Edouard; Lehéricy, Stéphane; Dormont, Didier; Chiras, Jacques; Baulac, Michel; Dupont, Sophie

2007-03-01

To search for a recovery after surgery of mean diffusivity (MD) values in the contralateral nonsclerotic hippocampus of patients with medial temporal lobe epilepsy (MTLE) and hippocampal sclerosis (HS). Twenty-four MTLE patients (12 right-sided and 12 left-sided MTLE) and 36 healthy volunteers were investigated using diffusion tensor imaging. A region-of-interest approach was used to measure pre- and postoperative interictal hippocampal MD values in patients. Diffusion abnormalities in contralateral nonsclerotic hippocampus recovered after surgery (p<0.0001). A subgroup of 14 patients exhibited a clear increase in MD values whereas the remaining 10 patients were stable. No significant difference was found between the two subgroups for each of the electroclinical data studied including early postoperative outcome, all patients being either seizure free or with rare persistent auras. This finding suggests that diffusion abnormalities in contralateral hippocampus may represent a functional mechanism linked to the active epileptic process.

The Ventral Anterior Temporal Lobe has a Necessary Role in Exception Word Reading.

PubMed

Ueno, Taiji; Meteyard, Lotte; Hoffman, Paul; Murayama, Kou

2018-06-06

An influential account of reading holds that words with exceptional spelling-to-sound correspondences (e.g., PINT) are read via activation of their lexical-semantic representations, supported by the anterior temporal lobe (ATL). This account has been inconclusive because it is based on neuropsychological evidence, in which lesion-deficit relationships are difficult to localize precisely, and functional neuroimaging data, which is spatially precise but cannot demonstrate whether the ATL activity is necessary for exception word reading. To address these issues, we used a technique with good spatial specificity-repetitive transcranial magnetic stimulation (rTMS)-to demonstrate a necessary role of ATL in exception word reading. Following rTMS to left ventral ATL, healthy Japanese adults made more regularization errors in reading Japanese exception words. We successfully simulated these results in a computational model in which exception word reading was underpinned by semantic activations. The ATL is critically and selectively involved in reading exception words.

Functionally defined white matter reveals segregated pathways in human ventral temporal cortex associated with category-specific processing

PubMed Central

Gomez, Jesse; Pestilli, Franco; Witthoft, Nathan; Golarai, Golijeh; Liberman, Alina; Poltoratski, Sonia; Yoon, Jennifer; Grill-Spector, Kalanit

2014-01-01

Summary It is unknown if the white matter properties associated with specific visual networks selectively affect category-specific processing. In a novel protocol we combined measurements of white matter structure, functional selectivity, and behavior in the same subjects. We find two parallel white matter pathways along the ventral temporal lobe connecting to either face-selective or place-selective regions. Diffusion properties of portions of these tracts adjacent to face- and place-selective regions of ventral temporal cortex correlate with behavioral performance for face or place processing, respectively. Strikingly, adults with developmental prosopagnosia (face blindness) express an atypical structure-behavior relationship near face-selective cortex, suggesting that white matter atypicalities in this region may have behavioral consequences. These data suggest that examining the interplay between cortical function, anatomical connectivity, and visual behavior is integral to understanding functional networks and their role in producing visual abilities and deficits. PMID:25569351

Temporal Lobe Reactions After Carbon Ion Radiation Therapy: Comparison of Relative Biological Effectiveness–Weighted Tolerance Doses Predicted by Local Effect Models I and IV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gillmann, Clarissa, E-mail: clarissa.gillmann@med.uni-heidelberg.de; Jäkel, Oliver; Heidelberg Ion Beam Therapy Center

2014-04-01

Purpose: To compare the relative biological effectiveness (RBE)–weighted tolerance doses for temporal lobe reactions after carbon ion radiation therapy using 2 different versions of the local effect model (LEM I vs LEM IV) for the same patient collective under identical conditions. Methods and Materials: In a previous study, 59 patients were investigated, of whom 10 experienced temporal lobe reactions (TLR) after carbon ion radiation therapy for low-grade skull-base chordoma and chondrosarcoma at Helmholtzzentrum für Schwerionenforschung (GSI) in Darmstadt, Germany in 2002 and 2003. TLR were detected as visible contrast enhancements on T1-weighted MRI images within a median follow-up time ofmore » 2.5 years. Although the derived RBE-weighted temporal lobe doses were based on the clinically applied LEM I, we have now recalculated the RBE-weighted dose distributions using LEM IV and derived dose-response curves with Dmax,V-1 cm³ (the RBE-weighted maximum dose in the remaining temporal lobe volume, excluding the volume of 1 cm³ with the highest dose) as an independent dosimetric variable. The resulting RBE-weighted tolerance doses were compared with those of the previous study to assess the clinical impact of LEM IV relative to LEM I. Results: The dose-response curve of LEM IV is shifted toward higher values compared to that of LEM I. The RBE-weighted tolerance dose for a 5% complication probability (TD{sub 5}) increases from 68.8 ± 3.3 to 78.3 ± 4.3 Gy (RBE) for LEM IV as compared to LEM I. Conclusions: LEM IV predicts a clinically significant increase of the RBE-weighted tolerance doses for the temporal lobe as compared to the currently applied LEM I. The limited available photon data do not allow a final conclusion as to whether RBE predictions of LEM I or LEM IV better fit better clinical experience in photon therapy. The decision about a future clinical application of LEM IV therefore requires additional analysis of temporal lobe reactions in a comparable photon-treated collective using the same dosimetric variable as in the present study.« less

The association between hemispheric specialization for language production and for spatial attention depends on left-hand preference strength.

PubMed

Zago, Laure; Petit, Laurent; Mellet, Emmanuel; Jobard, Gaël; Crivello, Fabrice; Joliot, Marc; Mazoyer, Bernard; Tzourio-Mazoyer, Nathalie

2016-12-01

Cerebral lateralization for language production and spatial attention and their relationships with manual preference strength (MPS) were assessed in a sample of 293 healthy volunteers, including 151 left-handers, using fMRI during covert sentence production (PROD) and line bisection judgment (LBJ) tasks, as compared to high- and low-level reference tasks. At the group level, we found the expected complementary hemispheric specialization (HS) with leftward asymmetries for PROD within frontal and temporal regions and rightward asymmetries for LBJ within frontal and posterior occipito-parieto-temporal regions. Individual hemispheric (HLI) and regional (frontal and occipital) lateralization indices (LI) were then calculated on the activation maps for PROD and LBJ. We found a correlation between the degree of rightward cerebral asymmetry and the leftward behavioral attentional bias recorded during LBJ task. This correlation was found when LBJ-LI was computed over the hemispheres, in the frontal lobes, but not in the occipital lobes. We then investigated whether language production and spatial attention cerebral lateralization relate to each other, and whether manual preference was a variable that impacted the complementary HS of these functions. No correlation was found between spatial and language LIs in the majority of our sample of participants, including right-handers with a strong right-hand preference (sRH, n=97) and mixed-handers (MH, n=97), indicating that these functions lateralized independently. By contrast, in the group of left-handers with a strong left-hand preference (sLH, n= 99), a negative correlation was found between language and spatial lateralization. This negative correlation was found when LBJ-LI and PROD-LI were computed over the hemispheres, in the frontal lobes and between the occipital lobes for LBJ and the frontal lobes for PROD. These findings underline the importance to include sLH in the study sample to reveal the underlying mechanisms of complementary HS. Copyright © 2015 Elsevier Ltd. All rights reserved.

Composing lexical versus functional adjectives: Evidence for uniformity in the left temporal lobe.

PubMed

Zhang, Linmin; Pylkkänen, Liina

2018-04-24

Featural information (e.g., color or shape) allows interlocutors to focus their attention on the specific items under discussion from the vast set of possibilities in the environment. Intriguingly, when they are used to modify and restrict nouns, adjectives can either carry featural information themselves (e.g., green car) or retrieve featural information from the context (e.g., somebody points at a car and claims that she has the same car or a different car). Do the processing of same/different car and green car share neural correlates? For the composition of nouns with feature-carrying adjectives, prior work revealed early compositional effects (roughly 200 ms after noun onset) in the left anterior temporal lobe. However, although we know that such effects do not extend to cases of numeral quantification, which add no conceptual features to the noun (e.g., two boats), we do not know whether they extend to functional adjectives that themselves introduce no features, but instead reference features in the context. To address this question, we measured magnetoencephalography (MEG) during the processing of five types of noun phrases (NPs): same NPs (e.g., same star), different NPs (e.g., different star), color NPs (e.g., green star), comparative NPs (e.g., larger star), and another NPs (e.g., another star). Our main finding was that between 185 to 240 ms after noun onset, same and different NPs patterned with the color NPs in their elicited left temporal lobe activity, and same NPs even trended toward higher amplitudes than the color NPs. This shows that the mechanism driving combinatory effects in the left temporal cortex does not require the input words to directly name conceptual features, as long as the words reference featural information in the context, and that overlapping neural correlates underlie the composition of featural information from both linguistic and nonlinguistic sources.

[Predictors of verbal memory decline following temporal lobe surgery].

PubMed

de Vanssay-Maigne, A; Boutin, M; Baudoin-Chial, S

2008-05-01

Verbal memory decline can occur after temporal lobe surgery, especially when the left dominant hemisphere is involved. This potential functional risk must be evaluated before surgery. Among all factors that have been identified by several studies, the side of surgery (left dominant) and high baseline memory performance have been found to be predictive of verbal memory decline. Other factors such as etiology, sex, age at surgery, age at seizure onset, and duration may influence memory decline, but the results are not clear. Our purpose was to identify, in our population of patients and among all risk factors, those that may be predictive of verbal memory decline. Logistic regression was used to examine the effect of each factor on the postoperative verbal memory index (WMS-R) in 101 patients who underwent a right (n=49) or left (n=52) anterior temporal lobe resection. In the group as a whole, 22 % of the patients demonstrated verbal memory decline of more than one standard deviation. The verbal memory decline was significantly related to surgery on the left side and a high level of verbal memory performance. These factors were significant predictors of decline. The other factors (etiology, sex, age at surgery, age at seizure onset, and duration) were not found to be predictive of this decline. Our analysis demonstrates that the patients who are most at risk of undergoing verbal memory deterioration are those who undergo left-sided temporal resection and have good memory scores preoperatively. The contradictions found in the literature about the other factors could be explained by the diversity of the tests and criteria used to assess memory decline.

Characteristic measurement for femtosecond laser pulses using a GaAs PIN photodiode as a two-photon photovoltaic receiver

NASA Astrophysics Data System (ADS)

Chen, Junbao; Xia, Wei; Wang, Ming

2017-06-01

Photodiodes that exhibit a two-photon absorption effect within the spectral communication band region can be useful for building an ultra-compact autocorrelator for the characteristic inspection of optical pulses. In this work, we develop an autocorrelator for measuring the temporal profile of pulses at 1550 nm from an erbium-doped fiber laser based on the two-photon photovoltaic (TPP) effect in a GaAs PIN photodiode. The temporal envelope of the autocorrelation function contains two symmetrical temporal side lobes due to the third order dispersion of the laser pulses. Moreover, the joint time-frequency distribution of the dispersive pulses and the dissimilar two-photon response spectrum of GaAs and Si result in different delays for the appearance of the temporal side lobes. Compared with Si, GaAs displays a greater sensitivity for pulse shape reconstruction at 1550 nm, benefiting from the higher signal-to-noise ratio of the side lobes and the more centralized waveform of the autocorrelation trace. We also measure the pulse width using the GaAs PIN photodiode, and the resolution of the measured full width at half maximum of the TPP autocorrelation trace is 0.89 fs, which is consistent with a conventional second-harmonic generation crystal autocorrelator. The GaAs PIN photodiode is shown to be highly suitable for real-time second-order autocorrelation measurements of femtosecond optical pulses. It is used both for the generation and detection of the autocorrelation signal, allowing the construction of a compact and inexpensive intensity autocorrelator.

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.

Impaired social cognition in patients with interictal epileptiform discharges in the frontal lobe.

PubMed

Hu, Ying; Jiang, Yubao; Hu, Panpan; Ma, Huijuan; Wang, Kai

2016-04-01

Patients with epilepsy frequently experience cognitive impairments, including impairments in social cognition. However, there is a lack of direct examinations of the affective and cognitive aspects of social cognition in such patients. The neural correlates remain to be identified. The present study was designed to examine the degree of impairments in different aspects of social cognition including empathy, emotion recognition, and Theory of Mind (ToM) in patients with epilepsy. In addition, we further explored factors related to the impairments, highlighting the specific importance of the frontal region. After 24-hour EEG monitoring, 53 patients with epilepsy were administered a neuropsychological battery of tests for basic intelligence assessment and then were tested with the Interpersonal Reactive Index, the "Yoni" task, the Emotion Recognition Test, the Reading the Mind in the Eyes test, and other neuropsychological tests. The clinical variables potentially affecting the ability to accomplish these tests were taken into account. We divided the patients into those having frontal lobe interictal epileptiform discharges (group with frontal IEDs) and those with seizures originating outside the frontal or temporal lobes (group with extrafrontal IEDs). Sixty healthy individuals served as controls. The group with frontal IEDs achieved the most severe deficits in emotion recognition, ToM, and cognitive empathy, while affective empathy was intact. Moreover, the performance scores of empathy in the group with frontal IEDs were selectively correlated with their executive function scores, which are believed to be associated with orbitofrontal functioning. In contrast, patients with epilepsies not originating from the frontal or temporal lobes may also be at risk of impairments in social cognition, albeit to a lesser extent. The preliminary findings suggest that patients with epilepsy, especially those having frontal lobe interictal epileptiform discharges, have associated general social cognition deficits. At the clinical level, these results are in line with previous findings regarding social cognition and the importance of the prefrontal area in the integration of cognition and affect. At the theoretical level, our findings also provide evidence for the functional independence of cognitive from affective aspects of empathy. Copyright © 2016 Elsevier Inc. All rights reserved.

Circadian organization in hemimetabolous insects.

PubMed

Tomioka, Kenji; Abdelsalam, Salaheldin

2004-12-01

The circadian system of hemimetabolous insects is reviewed in respect to the locus of the circadian clock and multioscillatory organization. Because of relatively easy access to the nervous system, the neuronal organization of the clock system in hemimetabolous insects has been studied, yielding identification of the compound eye as the major photoreceptor for entrainment and the optic lobe for the circadian clock locus. The clock site within the optic lobe is inconsistent among reported species; in cockroaches the lobula was previously thought to be a most likely clock locus but accessory medulla is recently stressed to be a clock center, while more distal part of the optic lobe including the lamina and the outer medulla area for the cricket. Identification of the clock cells needs further critical studies. Although each optic lobe clock seems functionally identical, in respect to photic entrainment and generation of the rhythm, the bilaterally paired clocks form a functional unit. They interact to produce a stable time structure within individual insects by exchanging photic and temporal information through neural pathways, in which serotonin and pigment-dispersing factor (PDF) are involved as chemical messengers. The mutual interaction also plays an important role in seasonal adaptation of the rhythm.

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.

The Interaction between Semantic and the Nonsemantic Systems in Reading: Evidence from Chinese

ERIC Educational Resources Information Center

Bi, Yanchao; Han, Zaizhu; Weekes, Brendan; Shu, Hua

2007-01-01

We report a Chinese-speaking patient WJX with left temporal lobe ischemic damage resulting in dementia. Similar to English speaking patients with this pathology, WJX showed impaired semantic system functioning together with a well preserved ability to read aloud Chinese characters including characters with unpredictable mappings between…

The Hippocampus Supports Encoding of Between-Domain Associations within Working Memory

ERIC Educational Resources Information Center

Piekema, Carinne; Kessel, Roy P. C.; Rijpkema, Mark; Fernandez, Guillen

2009-01-01

It has been established that the medial temporal lobe, including the hippocampus, is crucial for associative memory. The aim of the current functional magnetic resonance imaging (fMRI) study was to investigate whether the hippocampus is differentially activated for associations between items processed in the same neocortical region (within-domain)…

Implicit and Explicit Memory in Autism: Is Autism an Amnesic Disorder?

ERIC Educational Resources Information Center

Renner, Peggy; Klinger, Laura Grofer; Klinger, Mark R.

2000-01-01

This study examined whether children with high-functioning autism have a dissociation between explicit and implicit memory abilities characteristic of medial temporal lobe amnesic disorder. Children (N=14 and ages 6-14) with autism showed intact implicit and explicit memory abilities but did not show typical memory patterns, suggesting they used…

Contributions of Memory Circuits to Language: The Declarative/Procedural Model

ERIC Educational Resources Information Center

Ullman, Michael T.

2004-01-01

The structure of the brain and the nature of evolution suggest that, despite its uniqueness, language likely depends on brain systems that also subserve other functions. The declarative/procedural (DP) model claims that the mental lexicon of memorized word-specific knowledge depends on the largely temporal-lobe substrates of declarative memory,…

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

Episodic simulation of future events is impaired in mild Alzheimer's disease

PubMed Central

Addis, Donna Rose; Sacchetti, Daniel C.; Ally, Brandon A.; Budson, Andrew E.; Schacter, Daniel L.

2009-01-01

Recent neuroimaging studies have demonstrated that both remembering the past and simulating the future activate a core neural network including the medial temporal lobes. Regions of this network, in particular the medial temporal lobes, are prime sites for amyloid deposition and are structurally and functionally compromised in Alzheimer's disease (AD). While we know some functions of this core network, specifically episodic autobiographical memory, are impaired in AD, no study has examined whether future episodic simulation is similarly impaired. We tested the ability of sixteen AD patients and sixteen age-matched controls to generate past and future autobiographical events using an adapted version of the Autobiographical Interview. Participants also generated five remote autobiographical memories from across the lifespan. Event transcriptions were segmented into distinct details, classified as either internal (episodic) or external (non-episodic). AD patients exhibited deficits in both remembering past events and simulating future events, generating fewer internal and external episodic details than healthy older controls. The internal and external detail scores were strongly correlated across past and future events, providing further evidence of the close linkages between the mental representations of past and future. PMID:19497331

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.