Impact of correction factors in human brain lesion-behavior inference.

PubMed

Sperber, Christoph; Karnath, Hans-Otto

2017-03-01

Statistical voxel-based lesion-behavior mapping (VLBM) in neurological patients with brain lesions is frequently used to examine the relationship between structure and function of the healthy human brain. Only recently, two simulation studies noted reduced anatomical validity of this method, observing the results of VLBM to be systematically misplaced by about 16 mm. However, both simulation studies differed from VLBM analyses of real data in that they lacked the proper use of two correction factors: lesion size and "sufficient lesion affection." In simulation experiments on a sample of 274 real stroke patients, we found that the use of these two correction factors reduced misplacement markedly compared to uncorrected VLBM. Apparently, the misplacement is due to physiological effects of brain lesion anatomy. Voxel-wise topographies of collateral damage in the real data were generated and used to compute a metric for the inter-voxel relation of brain damage. "Anatomical bias" vectors that were solely calculated from these inter-voxel relations in the patients' real anatomical data, successfully predicted the VLBM misplacement. The latter has the potential to help in the development of new VLBM methods that provide even higher anatomical validity than currently available by the proper use of correction factors. Hum Brain Mapp 38:1692-1701, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Anatomo-clinical overlapping maps (AnaCOM): a new method to create anatomo-functional maps from neuropsychological tests and structural MRI scan of subjects with brain lesions

NASA Astrophysics Data System (ADS)

Kinkingnehun, Serge R. J.; du Boisgueheneuc, Foucaud; Golmard, Jean-Louis; Zhang, Sandy X.; Levy, Richard; Dubois, Bruno

2004-04-01

We have developed a new technique to analyze correlations between brain anatomy and its neurological functions. The technique is based on the anatomic MRI of patients with brain lesions who are administered neuropsychological tests. Brain lesions of the MRI scans are first manually segmented. The MRI volumes are then normalized to a reference map, using the segmented area as a mask. After normalization, the brain lesions of the MRI are segmented again in order to redefine the border of the lesions in the context of the normalized brain. Once the MRI is segmented, the patient's score on the neuropsychological test is assigned to each voxel in the lesioned area, while the rest of the voxels of the image are set to 0. Subsequently, the individual patient's MRI images are superimposed, and each voxel is reassigned the average score of the patients who have a lesion at that voxel. A threshold is applied to remove regions having less than three overlaps. This process leads to an anatomo-functional map that links brain areas to functional loss. Other maps can be created to aid in analyzing the functional maps, such as one that indicates the 95% confidence interval of the averaged scores for each area. This anatomo-clinical overlapping map (AnaCOM) method was used to obtain functional maps from patients with lesions in the superior frontal gyrus. By finding particular subregions more responsible for a particular deficit, this method can generate new hypotheses to be tested by conventional group methods.

Predicting Outcome after Pediatric Traumatic Brain Injury by Early Magnetic Resonance Imaging Lesion Location and Volume

PubMed Central

Smitherman, Emily; Hernandez, Ana; Stavinoha, Peter L.; Huang, Rong; Kernie, Steven G.; Diaz-Arrastia, Ramon

2016-01-01

Abstract Brain lesions after traumatic brain injury (TBI) are heterogeneous, rendering outcome prognostication difficult. The aim of this study is to investigate whether early magnetic resonance imaging (MRI) of lesion location and lesion volume within discrete brain anatomical zones can accurately predict long-term neurological outcome in children post-TBI. Fluid-attenuated inversion recovery (FLAIR) MRI hyperintense lesions in 63 children obtained 6.2±5.6 days postinjury were correlated with the Glasgow Outcome Scale Extended-Pediatrics (GOS-E Peds) score at 13.5±8.6 months. FLAIR lesion volume was expressed as hyperintensity lesion volume index (HLVI)=(hyperintensity lesion volume / whole brain volume)×100 measured within three brain zones: zone A (cortical structures); zone B (basal ganglia, corpus callosum, internal capsule, and thalamus); and zone C (brainstem). HLVI-total and HLVI-zone C predicted good and poor outcome groups (p<0.05). GOS-E Peds correlated with HLVI-total (r=0.39; p=0.002) and HLVI in all three zones: zone A (r=0.31; p<0.02); zone B (r=0.35; p=0.004); and zone C (r=0.37; p=0.003). In adolescents ages 13–17 years, HLVI-total correlated best with outcome (r=0.5; p=0.007), whereas in younger children under the age of 13, HLVI-zone B correlated best (r=0.52; p=0.001). Compared to patients with lesions in zone A alone or in zones A and B, patients with lesions in all three zones had a significantly higher odds ratio (4.38; 95% confidence interval, 1.19–16.0) for developing an unfavorable outcome. PMID:25808802

Reliability of a novel, semi-quantitative scale for classification of structural brain magnetic resonance imaging in children with cerebral palsy.

PubMed

Fiori, Simona; Cioni, Giovanni; Klingels, Katrjin; Ortibus, Els; Van Gestel, Leen; Rose, Stephen; Boyd, Roslyn N; Feys, Hilde; Guzzetta, Andrea

2014-09-01

To describe the development of a novel rating scale for classification of brain structural magnetic resonance imaging (MRI) in children with cerebral palsy (CP) and to assess its interrater and intrarater reliability. The scale consists of three sections. Section 1 contains descriptive information about the patient and MRI. Section 2 contains the graphical template of brain hemispheres onto which the lesion is transposed. Section 3 contains the scoring system for the quantitative analysis of the lesion characteristics, grouped into different global scores and subscores that assess separately side, regions, and depth. A larger interrater and intrarater reliability study was performed in 34 children with CP (22 males, 12 females; mean age at scan of 9 y 5 mo [SD 3 y 3 mo], range 4 y-16 y 11 mo; Gross Motor Function Classification System level I, [n=22], II [n=10], and level III [n=2]). Very high interrater and intrarater reliability of the total score was found with indices above 0.87. Reliability coefficients of the lobar and hemispheric subscores ranged between 0.53 and 0.95. Global scores for hemispheres, basal ganglia, brain stem, and corpus callosum showed reliability coefficients above 0.65. This study presents the first visual, semi-quantitative scale for classification of brain structural MRI in children with CP. The high degree of reliability of the scale supports its potential application for investigating the relationship between brain structure and function and examining treatment response according to brain lesion severity in children with CP. © 2014 Mac Keith Press.

[Processes of logical thought in a case of cerebral vascular lesion].

PubMed

Blanco Men ndez, R; Aguado Balsas, A M

Reasoning and logical thought processes have traditionally been attributed to frontal lobe function or,on the other hand, have been considered as diffuse functions of the brain. However, there is today evidence enough about the possibility to find dissociations in thought processes, depending on logical structure of the experimental tasks and referring to different areas of the brain, frontal and post rolandic ones. To study possible dissociations between thought structures corresponding to categorical and relational logic, on one hand, and propositional logic on the other hand. The case of a brain injured patient with vascular etiology, localized in left frontal parietal cortex, is presented. A specific battery of reasoning tests has been administered. . A differential performance at some reasoning experimental tasks has been found depending on such logical conceptual structures. The possibility of establishing dissociations among certain logical thought and intelectual functions depending on localization of possible brain lesion (frontal versus temporal) is discussed.

Application of radiosurgical techniques to produce a primate model of brain lesions

PubMed Central

Kunimatsu, Jun; Miyamoto, Naoki; Ishikawa, Masayori; Shirato, Hiroki; Tanaka, Masaki

2015-01-01

Behavioral analysis of subjects with discrete brain lesions provides important information about the mechanisms of various brain functions. However, it is generally difficult to experimentally produce discrete lesions in deep brain structures. Here we show that a radiosurgical technique, which is used as an alternative treatment for brain tumors and vascular malformations, is applicable to create non-invasive lesions in experimental animals for the research in systems neuroscience. We delivered highly focused radiation (130–150 Gy at ISO center) to the frontal eye field (FEF) of macaque monkeys using a clinical linear accelerator (LINAC). The effects of irradiation were assessed by analyzing oculomotor performance along with magnetic resonance (MR) images before and up to 8 months following irradiation. In parallel with tissue edema indicated by MR images, deficits in saccadic and smooth pursuit eye movements were observed during several days following irradiation. Although initial signs of oculomotor deficits disappeared within a month, damage to the tissue and impaired eye movements gradually developed during the course of the subsequent 6 months. Postmortem histological examinations showed necrosis and hemorrhages within a large area of the white matter and, to a lesser extent, in the adjacent gray matter, which was centered at the irradiated target. These results indicated that the LINAC system was useful for making brain lesions in experimental animals, while the suitable radiation parameters to generate more focused lesions need to be further explored. We propose the use of a radiosurgical technique for establishing animal models of brain lesions, and discuss the possible uses of this technique for functional neurosurgical treatments in humans. PMID:25964746

Proton spectroscopy in the narcoleptic syndrome. Is there evidence of a brainstem lesion?

PubMed

Ellis, C M; Simmons, A; Lemmens, G; Williams, S C; Parkes, J D

1998-02-01

There is controversy regarding the relationship of structural or biochemical brainstem lesions to "idiopathic" narcolepsy. Most cases of the narcoleptic syndrome are considered to be idiopathic because no structural lesion is detectable, although some cases of secondary narcolepsy are known to be associated with no structural brainstem lesions. Using proton spectroscopy, we determined levels of ventral pontine metabolite pools in 12 normal subjects and 12 subjects with idiopathic narcolepsy. REM sleep is generated in ventral pontine areas. Proton spectroscopy was used to study levels of N-acetyl aspartate (NAA) as a marker of cell mass, creatine and phosphocreatine (Cr + PCr), and choline (Cho). The intensity of the peaks, as determined by the area under the peak (AUP), was measured. The AUP correlates with the quantity of chemical present. In this study, the ratios of NAA to Cr + PCr were similar in normal subjects and in narcoleptic subjects with idiopathic narcolepsy. No differences in measured metabolic ratio were observed in subjects who slept during the scan procedure compared with those who remained awake. Subjects with "symptomatic" narcolepsy accompanied by an obvious structural brain lesion were not studied. Proton spectroscopy of the brain initiates a new kind of neurochemistry, allowing the noninvasive study of metabolic pools in the living human brain without the use of any kind of tracer or radioactive molecule. In this study, there was no evidence of cell loss in the ventral pontine areas of subjects with the narcoleptic syndrome.

A simulator for evaluating methods for the detection of lesion-deficit associations

NASA Technical Reports Server (NTRS)

Megalooikonomou, V.; Davatzikos, C.; Herskovits, E. H.

2000-01-01

Although much has been learned about the functional organization of the human brain through lesion-deficit analysis, the variety of statistical and image-processing methods developed for this purpose precludes a closed-form analysis of the statistical power of these systems. Therefore, we developed a lesion-deficit simulator (LDS), which generates artificial subjects, each of which consists of a set of functional deficits, and a brain image with lesions; the deficits and lesions conform to predefined distributions. We used probability distributions to model the number, sizes, and spatial distribution of lesions, to model the structure-function associations, and to model registration error. We used the LDS to evaluate, as examples, the effects of the complexities and strengths of lesion-deficit associations, and of registration error, on the power of lesion-deficit analysis. We measured the numbers of recovered associations from these simulated data, as a function of the number of subjects analyzed, the strengths and number of associations in the statistical model, the number of structures associated with a particular function, and the prior probabilities of structures being abnormal. The number of subjects required to recover the simulated lesion-deficit associations was found to have an inverse relationship to the strength of associations, and to the smallest probability in the structure-function model. The number of structures associated with a particular function (i.e., the complexity of associations) had a much greater effect on the performance of the analysis method than did the total number of associations. We also found that registration error of 5 mm or less reduces the number of associations discovered by approximately 13% compared to perfect registration. The LDS provides a flexible framework for evaluating many aspects of lesion-deficit analysis.

Brain lesion correlates of fatigue in individuals with traumatic brain injury.

PubMed

Schönberger, Michael; Reutens, David; Beare, Richard; O'Sullivan, Richard; Rajaratnam, Shantha M W; Ponsford, Jennie

2017-10-01

The purpose of this study was to investigate the neurological correlates of both subjective fatigue as well as objective fatigability in individuals with traumatic brain injury (TBI). The study has a cross-sectional design. Participants (N = 53) with TBI (77% male, mean age at injury 38 years, mean time since injury 1.8 years) underwent a structural magnetic resonance imaging (MRI) scan and completed the Fatigue Severity Scale (FSS), while a subsample (N = 36) was also tested with a vigilance task. While subjective fatigue (FSS) was not related to measures of brain lesions, multilevel analyses showed that a change in the participants' decision time was significantly predicted by grey matter (GM) lesions in the right frontal lobe. The time-dependent development of the participants' error rate was predicted by total brain white matter (WM) lesion volumes, as well as right temporal GM and WM lesion volumes. These findings could be explained by decreased functional connectivity of attentional networks, which results in accelerated exhaustion during cognitive task performance. The disparate nature of objectively measurable fatigability on the one hand and the subjective experience of fatigue on the other needs further investigation.

A Generative Probabilistic Model and Discriminative Extensions for Brain Lesion Segmentation--With Application to Tumor and Stroke.

PubMed

Menze, Bjoern H; Van Leemput, Koen; Lashkari, Danial; Riklin-Raviv, Tammy; Geremia, Ezequiel; Alberts, Esther; Gruber, Philipp; Wegener, Susanne; Weber, Marc-Andre; Szekely, Gabor; Ayache, Nicholas; Golland, Polina

2016-04-01

We introduce a generative probabilistic model for segmentation of brain lesions in multi-dimensional images that generalizes the EM segmenter, a common approach for modelling brain images using Gaussian mixtures and a probabilistic tissue atlas that employs expectation-maximization (EM), to estimate the label map for a new image. Our model augments the probabilistic atlas of the healthy tissues with a latent atlas of the lesion. We derive an estimation algorithm with closed-form EM update equations. The method extracts a latent atlas prior distribution and the lesion posterior distributions jointly from the image data. It delineates lesion areas individually in each channel, allowing for differences in lesion appearance across modalities, an important feature of many brain tumor imaging sequences. We also propose discriminative model extensions to map the output of the generative model to arbitrary labels with semantic and biological meaning, such as "tumor core" or "fluid-filled structure", but without a one-to-one correspondence to the hypo- or hyper-intense lesion areas identified by the generative model. We test the approach in two image sets: the publicly available BRATS set of glioma patient scans, and multimodal brain images of patients with acute and subacute ischemic stroke. We find the generative model that has been designed for tumor lesions to generalize well to stroke images, and the extended discriminative -discriminative model to be one of the top ranking methods in the BRATS evaluation.

Plasticity during Early Brain Development Is Determined by Ontogenetic Potential.

PubMed

Krägeloh-Mann, Ingeborg; Lidzba, Karen; Pavlova, Marina A; Wilke, Marko; Staudt, Martin

2017-04-01

Two competing hypotheses address neuroplasticity during early brain development: the "Kennard principle" describes the compensatory capacities of the immature developing CNS as superior to those of the adult brain, whereas the "Hebb principle" argues that the young brain is especially sensitive to insults. We provide evidence that these principles are not mutually exclusive. Following early brain lesions that are unilateral, the brain can refer to homotopic areas of the healthy hemisphere. This potential for reorganization is unique to the young brain but available only when, during ontogenesis of brain development, these areas have been used for the functions addressed. With respect to motor function, ipsilateral motor tracts can be recruited, which are only available during early brain development. Language can be reorganized to the right after early left hemispheric lesions, as the representation of the language network is initially bilateral. However, even in these situations, compensatory capacities of the developing brain are found to have limitations, probably defined by early determinants. Thus, plasticity and adaptivity are seen only within ontogenetic potential; that is, axonal or cortical structures cannot be recruited beyond early developmental possibilities. The young brain is probably more sensitive and vulnerable to lesions when these are bilateral. This is shown here for bilateral periventricular white matter lesions that clearly have an impact on cortical architecture and function, thus probably interfering with early network building. Georg Thieme Verlag KG Stuttgart · New York.

Quantitative phase and texture angularity analysis of brain white matter lesions in multiple sclerosis

NASA Astrophysics Data System (ADS)

Baxandall, Shalese; Sharma, Shrushrita; Zhai, Peng; Pridham, Glen; Zhang, Yunyan

2018-03-01

Structural changes to nerve fiber tracts are extremely common in neurological diseases such as multiple sclerosis (MS). Accurate quantification is vital. However, while nerve fiber damage is often seen as multi-focal lesions in magnetic resonance imaging (MRI), measurement through visual perception is limited. Our goal was to characterize the texture pattern of the lesions in MRI and determine how texture orientation metrics relate to lesion structure using two new methods: phase congruency and multi-resolution spatial-frequency analysis. The former aims to optimize the detection of the `edges and corners' of a structure, and the latter evaluates both the radial and angular distributions of image texture associated with the various forming scales of a structure. The radial texture spectra were previously confirmed to measure the severity of nerve fiber damage, and were thus included for validation. All measures were also done in the control brain white matter for comparison. Using clinical images of MS patients, we found that both phase congruency and weighted mean phase detected invisible lesion patterns and were significantly greater in lesions, suggesting higher structure complexity, than the control tissue. Similarly, multi-angular spatial-frequency analysis detected much higher texture across the whole frequency spectrum in lesions than the control areas. Such angular complexity was consistent with findings from radial texture. Analysis of the phase and texture alignment may prove to be a useful new approach for assessing invisible changes in lesions using clinical MRI and thereby lead to improved management of patients with MS and similar disorders.

An automatic quantification system for MS lesions with integrated DICOM structured reporting (DICOM-SR) for implementation within a clinical environment

NASA Astrophysics Data System (ADS)

Jacobs, Colin; Ma, Kevin; Moin, Paymann; Liu, Brent

2010-03-01

Multiple Sclerosis (MS) is a common neurological disease affecting the central nervous system characterized by pathologic changes including demyelination and axonal injury. MR imaging has become the most important tool to evaluate the disease progression of MS which is characterized by the occurrence of white matter lesions. Currently, radiologists evaluate and assess the multiple sclerosis lesions manually by estimating the lesion volume and amount of lesions. This process is extremely time-consuming and sensitive to intra- and inter-observer variability. Therefore, there is a need for automatic segmentation of the MS lesions followed by lesion quantification. We have developed a fully automatic segmentation algorithm to identify the MS lesions. The segmentation algorithm is accelerated by parallel computing using Graphics Processing Units (GPU) for practical implementation into a clinical environment. Subsequently, characterized quantification of the lesions is performed. The quantification results, which include lesion volume and amount of lesions, are stored in a structured report together with the lesion location in the brain to establish a standardized representation of the disease progression of the patient. The development of this structured report in collaboration with radiologists aims to facilitate outcome analysis and treatment assessment of the disease and will be standardized based on DICOM-SR. The results can be distributed to other DICOM-compliant clinical systems that support DICOM-SR such as PACS. In addition, the implementation of a fully automatic segmentation and quantification system together with a method for storing, distributing, and visualizing key imaging and informatics data in DICOM-SR for MS lesions improves the clinical workflow of radiologists and visualizations of the lesion segmentations and will provide 3-D insight into the distribution of lesions in the brain.

Assessment of the structural brain network reveals altered connectivity in children with unilateral cerebral palsy due to periventricular white matter lesions.

PubMed

Pannek, Kerstin; Boyd, Roslyn N; Fiori, Simona; Guzzetta, Andrea; Rose, Stephen E

2014-01-01

Cerebral palsy (CP) is a term to describe the spectrum of disorders of impaired motor and sensory function caused by a brain lesion occurring early during development. Diffusion MRI and tractography have been shown to be useful in the study of white matter (WM) microstructure in tracts likely to be impacted by the static brain lesion. The purpose of this study was to identify WM pathways with altered connectivity in children with unilateral CP caused by periventricular white matter lesions using a whole-brain connectivity approach. Data of 50 children with unilateral CP caused by periventricular white matter lesions (5-17 years; manual ability classification system [MACS] I = 25/II = 25) and 17 children with typical development (CTD; 7-16 years) were analysed. Structural and High Angular Resolution Diffusion weighted Images (HARDI; 64 directions, b = 3000 s/mm(2)) were acquired at 3 T. Connectomes were calculated using whole-brain probabilistic tractography in combination with structural parcellation of the cortex and subcortical structures. Connections with altered fractional anisotropy (FA) in children with unilateral CP compared to CTD were identified using network-based statistics (NBS). The relationship between FA and performance of the impaired hand in bimanual tasks (Assisting Hand Assessment-AHA) was assessed in connections that showed significant differences in FA compared to CTD. FA was reduced in children with unilateral CP compared to CTD. Seven pathways, including the corticospinal, thalamocortical, and fronto-parietal association pathways were identified simultaneously in children with left and right unilateral CP. There was a positive relationship between performance of the impaired hand in bimanual tasks and FA within the cortico-spinal and thalamo-cortical pathways (r(2) = 0.16-0.44; p < 0.05). This study shows that network-based analysis of structural connectivity can identify alterations in FA in unilateral CP, and that these alterations in FA are related to clinical function. Application of this connectome-based analysis to investigate alterations in connectivity following treatment may elucidate the neurological correlates of improved functioning due to intervention.

Validation of voxel-based morphometry (VBM) based on MRI

NASA Astrophysics Data System (ADS)

Yang, Xueyu; Chen, Kewei; Guo, Xiaojuan; Yao, Li

2007-03-01

Voxel-based morphometry (VBM) is an automated and objective image analysis technique for detecting differences in regional concentration or volume of brain tissue composition based on structural magnetic resonance (MR) images. VBM has been used widely to evaluate brain morphometric differences between different populations, but there isn't an evaluation system for its validation until now. In this study, a quantitative and objective evaluation system was established in order to assess VBM performance. We recruited twenty normal volunteers (10 males and 10 females, age range 20-26 years, mean age 22.6 years). Firstly, several focal lesions (hippocampus, frontal lobe, anterior cingulate, back of hippocampus, back of anterior cingulate) were simulated in selected brain regions using real MRI data. Secondly, optimized VBM was performed to detect structural differences between groups. Thirdly, one-way ANOVA and post-hoc test were used to assess the accuracy and sensitivity of VBM analysis. The results revealed that VBM was a good detective tool in majority of brain regions, even in controversial brain region such as hippocampus in VBM study. Generally speaking, much more severity of focal lesion was, better VBM performance was. However size of focal lesion had little effects on VBM analysis.

78 FR 17917 - Medical Waivers for Merchant Mariner Credential Applicants With a History of Seizure Disorders

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-25

... structural brain lesion). (1) If a mariner is determined to be low-risk for seizure recurrence, does not... penetrating head injury; (b) Intracerebral hemorrhage of any etiology, including stroke and trauma; (c) Brain... hemorrhage; (f) Post-operative brain surgery with significant brain hemorrhage; or (g) Brain tumor. (4) Under...

Exercise training reinstates cortico-cortical sensorimotor functional connectivity following striatal lesioning: Development and application of a subregional-level analytic toolbox for perfusion autoradiographs of the rat brain

NASA Astrophysics Data System (ADS)

Peng, Yu-Hao; Heintz, Ryan; Wang, Zhuo; Guo, Yumei; Myers, Kalisa; Scremin, Oscar; Maarek, Jean-Michel; Holschneider, Daniel

2014-12-01

Current rodent connectome projects are revealing brain structural connectivity with unprecedented resolution and completeness. How subregional structural connectivity relates to subregional functional interactions is an emerging research topic. We describe a method for standardized, mesoscopic-level data sampling from autoradiographic coronal sections of the rat brain, and for correlation-based analysis and intuitive display of cortico-cortical functional connectivity (FC) on a flattened cortical map. A graphic user interface “Cx-2D” allows for the display of significant correlations of individual regions-of-interest, as well as graph theoretical metrics across the cortex. Cx-2D was tested on an autoradiographic data set of cerebral blood flow (CBF) of rats that had undergone bilateral striatal lesions, followed by 4 weeks of aerobic exercise training or no exercise. Effects of lesioning and exercise on cortico-cortical FC were examined during a locomotor challenge in this rat model of Parkinsonism. Subregional FC analysis revealed a rich functional reorganization of the brain in response to lesioning and exercise that was not apparent in a standard analysis focused on CBF of isolated brain regions. Lesioned rats showed diminished degree centrality of lateral primary motor cortex, as well as neighboring somatosensory cortex--changes that were substantially reversed in lesioned rats following exercise training. Seed analysis revealed that exercise increased positive correlations in motor and somatosensory cortex, with little effect in non-sensorimotor regions such as visual, auditory, and piriform cortex. The current analysis revealed that exercise partially reinstated sensorimotor FC lost following dopaminergic deafferentation. Cx-2D allows for standardized data sampling from images of brain slices, as well as analysis and display of cortico-cortical FC in the rat cerebral cortex with potential applications in a variety of autoradiographic and histologic studies.

Cocaine Abuse, Traumatic Brain Injury, and Preexisting Brain Lesions as Risk Factors for Bupropion-Associated Psychosis.

PubMed

Barman, Rajdip; Kumar, Sanjeev; Pagadala, Bhuvaneshwar; Detweiler, Mark B

2017-08-01

Bupropion is generally considered safe and is widely used both as a monotherapy and as an augmentation agent for the treatment of major depression. Concerns have been raised about bupropion's propensity to precipitate new psychosis and worsen existing psychotic symptoms, although the mechanism is poorly understood. Three cases are reported in which bupropion use was associated with psychosis. The aim of the study was to explore the risk factors and possible mechanisms of psychosis in each case. Case 1 describes the interaction of cocaine abuse sensitization in a patient who developed psychosis with a lower dosage of bupropion. Cases 2 and 3 discuss the role of traumatic brain injury and structural brain lesions in increasing the risk of psychosis when using bupropion. Cocaine abuse, traumatic brain injury, and preexisting brain lesions appear to be risk factors for developing psychosis in persons taking bupropion. In such cases, clinicians should carefully assess the risks and benefits and closely monitor patients for symptoms of psychosis.

Mapping causal functional contributions derived from the clinical assessment of brain damage after stroke

PubMed Central

Zavaglia, Melissa; Forkert, Nils D.; Cheng, Bastian; Gerloff, Christian; Thomalla, Götz; Hilgetag, Claus C.

2015-01-01

Lesion analysis reveals causal contributions of brain regions to mental functions, aiding the understanding of normal brain function as well as rehabilitation of brain-damaged patients. We applied a novel lesion inference technique based on game theory, Multi-perturbation Shapley value Analysis (MSA), to a large clinical lesion dataset. We used MSA to analyze the lesion patterns of 148 acute stroke patients together with their neurological deficits, as assessed by the National Institutes of Health Stroke Scale (NIHSS). The results revealed regional functional contributions to essential behavioral and cognitive functions as reflected in the NIHSS, particularly by subcortical structures. There were also side specific differences of functional contributions between the right and left hemispheric brain regions which may reflect the dominance of the left hemispheric syndrome aphasia in the NIHSS. Comparison of MSA to established lesion inference methods demonstrated the feasibility of the approach for analyzing clinical data and indicated its capability for objectively inferring functional contributions from multiple injured, potentially interacting sites, at the cost of having to predict the outcome of unknown lesion configurations. The analysis of regional functional contributions to neurological symptoms measured by the NIHSS contributes to the interpretation of this widely used standardized stroke scale in clinical practice as well as clinical trials and provides a first approximation of a ‘map of stroke’. PMID:26448908

Mapping causal functional contributions derived from the clinical assessment of brain damage after stroke.

PubMed

Zavaglia, Melissa; Forkert, Nils D; Cheng, Bastian; Gerloff, Christian; Thomalla, Götz; Hilgetag, Claus C

2015-01-01

Lesion analysis reveals causal contributions of brain regions to mental functions, aiding the understanding of normal brain function as well as rehabilitation of brain-damaged patients. We applied a novel lesion inference technique based on game theory, Multi-perturbation Shapley value Analysis (MSA), to a large clinical lesion dataset. We used MSA to analyze the lesion patterns of 148 acute stroke patients together with their neurological deficits, as assessed by the National Institutes of Health Stroke Scale (NIHSS). The results revealed regional functional contributions to essential behavioral and cognitive functions as reflected in the NIHSS, particularly by subcortical structures. There were also side specific differences of functional contributions between the right and left hemispheric brain regions which may reflect the dominance of the left hemispheric syndrome aphasia in the NIHSS. Comparison of MSA to established lesion inference methods demonstrated the feasibility of the approach for analyzing clinical data and indicated its capability for objectively inferring functional contributions from multiple injured, potentially interacting sites, at the cost of having to predict the outcome of unknown lesion configurations. The analysis of regional functional contributions to neurological symptoms measured by the NIHSS contributes to the interpretation of this widely used standardized stroke scale in clinical practice as well as clinical trials and provides a first approximation of a 'map of stroke'.

White matter reorganization after surgical resection of brain tumors and vascular malformations.

PubMed

Lazar, M; Alexander, A L; Thottakara, P J; Badie, B; Field, A S

2006-01-01

Diffusion tensor imaging (DTI) and white matter tractography (WMT) are promising techniques for estimating the course, extent, and connectivity patterns of the white matter (WM) structures in the human brain. In this study, DTI and WMT were used to evaluate WM tract reorganization after the surgical resection of brain tumors and vascular malformations. Pre- and postoperative DTI data were obtained in 6 patients undergoing surgical resection of brain lesions. WMT using a tensor deflection algorithm was used to reconstruct WM tracts adjacent to the lesions. Reconstructed tracts included corticospinal tracts, the corona radiata, superior longitudinal and inferior fronto-occipital fasciculi, cingulum bundles, and the corpus callosum. WMT revealed a series of tract alteration patterns including deviation, deformation, infiltration, and apparent tract interruption. In general, the organization of WM tracts appeared more similar to normal anatomy after resection, with either disappearance or reduction of the deviation, deformation, or infiltration present preoperatively. In patients whose lesions were associated with corticospinal tract involvement, the WMT reconstructions showed that the tract was preserved during surgery and improved in position and appearance, and this finding correlated with improvement or preservation of motor function as determined by clinical assessment. WMT is useful for appreciating the complex relationships between specific WM structures and the anatomic distortions created by brain lesions. Further studies with intraoperative correlation are necessary to confirm these initial findings and to determine WMT utility for presurgical planning and evaluation of surgical treatments.

Insults to the Developing Brain and Impact on Neurodevelopmental Outcome

ERIC Educational Resources Information Center

Adams-Chapman, Ira

2009-01-01

Premature infants have a disproportionately increased risk for brain injury based on several mechanisms including intraventricular hemorrhage, ischemia and the vulnerability of developing neuronal progenitor cells. Injury to the developing brain often results in neurologic abnormalities that can be correlated with a structural lesion; however more…

Distribution and severity of hypoxic-ischaemic lesions on brain MRI following therapeutic cooling: selective head versus whole body cooling.

PubMed

Sarkar, Subrata; Donn, Steven M; Bapuraj, Jayapalli R; Bhagat, Indira; Barks, John D

2012-09-01

Whole body cooling (WBC) cools different parts of the brain uniformly, and selective head cooling (SHC) cools the superficial brain more than the deeper brain structures. In this study, the authors hypothesised that the hypoxic-ischaemic lesions on brain MRI following cooling would differ between modalities of cooling. To compare the frequency, distribution and severity of hypoxic-ischaemic lesions on brain MRI between SHC or WBC. In a single centre retrospective study, 83 infants consecutively cooled using either SHC (n=34) or WBC (n=49) underwent brain MRI. MRI images were evaluated by a neuroradiologist, who was masked to clinical parameters and outcomes, using a basal ganglia/watershed (BG/W) scoring system. Higher scores (on a scale of 0 to 4) were given for more extensive injury. The score has been reported to be predictive of neuromotor and cognitive outcome at 12 months. The two groups were similar for severity of depression as assessed by a history of an intrapartum sentinel event, Apgar scores, initial blood pH and base deficit and early neurological examination. However, abnormal MRI was more frequent in the SHC group (SHC 25 of 34, 74% vs WBC 22 of 49, 45%; p=0.0132, OR 3.4, 95% CI 1.3 to 8.8). Infants from the SHC group also had more severe hypoxic-ischaemic lesions (median BG/W score: SHC 2 vs WBC 0, p=0.0014). Hypoxic-ischaemic lesions on brain MRI following therapeutic cooling were more frequent and more severe with SHC compared with WBC.

How does the interaction of presumed timing, location and extent of the underlying brain lesion relate to upper limb function in children with unilateral cerebral palsy?

PubMed

Mailleux, Lisa; Klingels, Katrijn; Fiori, Simona; Simon-Martinez, Cristina; Demaerel, Philippe; Locus, Marlies; Fosseprez, Eva; Boyd, Roslyn N; Guzzetta, Andrea; Ortibus, Els; Feys, Hilde

2017-09-01

Upper limb (UL) function in children with unilateral cerebral palsy (CP) vary largely depending on presumed timing, location and extent of brain lesions. These factors might exhibit a complex interaction and the combined prognostic value warrants further investigation. This study aimed to map lesion location and extent and assessed whether these differ according to presumed lesion timing and to determine the impact of structural brain damage on UL function within different lesion timing groups. Seventy-three children with unilateral CP (mean age 10 years 2 months) were classified according to lesion timing: malformations (N = 2), periventricular white matter (PWM, N = 42) and cortical and deep grey matter (CDGM, N = 29) lesions. Neuroanatomical damage was scored using a semi-quantitative MRI scale. UL function was assessed at body function and activity level. CDGM lesions were more pronounced compared to PWM lesions (p = 0.0003). Neuroanatomical scores were correlated with a higher degree to UL function in the CDGM group (r s  = -0.39 to r s  = -0.84) compared to the PWM group (r rb  = -0.42 to r s  = -0.61). Regression analysis found lesion location and extent to explain 75% and 65% (p < 0.02) respectively, of the variance in AHA performance in the CDGM group, but only 24% and 12% (p < 0.03) in the PWM group. In the CDGM group, lesion location and extent seems to impact more on UL function compared to the PWM group. In children with PWM lesions, other factors like corticospinal tract (re)organization and structural connectivity may play an additional role. Copyright © 2017 European Paediatric Neurology Society. All rights reserved.

Dominant hemisphere lateralization of cortical parasympathetic control as revealed by frontotemporal dementia

PubMed Central

Guo, Christine C.; Sturm, Virginia E.; Zhou, Juan; Gennatas, Efstathios D.; Trujillo, Andrew J.; Hua, Alice Y.; Crawford, Richard; Stables, Lara; Kramer, Joel H.; Rankin, Katherine; Levenson, Robert W.; Rosen, Howard J.; Miller, Bruce L.; Seeley, William W.

2016-01-01

The brain continuously influences and perceives the physiological condition of the body. Related cortical representations have been proposed to shape emotional experience and guide behavior. Although previous studies have identified brain regions recruited during autonomic processing, neurological lesion studies have yet to delineate the regions critical for maintaining autonomic outflow. Even greater controversy surrounds hemispheric lateralization along the parasympathetic–sympathetic axis. The behavioral variant of frontotemporal dementia (bvFTD), featuring progressive and often asymmetric degeneration that includes the frontoinsular and cingulate cortices, provides a unique lesion model for elucidating brain structures that control autonomic tone. Here, we show that bvFTD is associated with reduced baseline cardiac vagal tone and that this reduction correlates with left-lateralized functional and structural frontoinsular and cingulate cortex deficits and with reduced agreeableness. Our results suggest that networked brain regions in the dominant hemisphere are critical for maintaining an adaptive level of baseline parasympathetic outflow. PMID:27071080

Simulation of spread and control of lesions in brain.

PubMed

Thamattoor Raman, Krishna Mohan

2012-01-01

A simulation model for the spread and control of lesions in the brain is constructed using a planar network (graph) representation for the central nervous system (CNS). The model is inspired by the lesion structures observed in the case of multiple sclerosis (MS), a chronic disease of the CNS. The initial lesion site is at the center of a unit square and spreads outwards based on the success rate in damaging edges (axons) of the network. The damaged edges send out alarm signals which, at appropriate intensity levels, generate programmed cell death. Depending on the extent and timing of the programmed cell death, the lesion may get controlled or aggravated akin to the control of wild fires by burning of peripheral vegetation. The parameter phase space of the model shows smooth transition from uncontrolled situation to controlled situation. The simulations show that the model is capable of generating a wide variety of lesion growth and arrest scenarios.

Laser technique for anatomical-functional study of the medial prefrontal cortex of the brain

NASA Astrophysics Data System (ADS)

Sanchez-Huerta, Laura; Hernandez, Adan; Ayala, Griselda; Marroquin, Javier; Silva, Adriana B.; Khotiaintsev, Konstantin S.; Svirid, Vladimir A.; Flores, Gonzalo; Khotiaintsev, Sergei N.

1999-05-01

The brain represents one of the most complex systems that we know yet. In its study, non-destructive methods -- in particular, behavioral studies play an important role. By alteration of brain functioning (e.g. by pharmacological means) and observation of consequent behavior changes an important information on brain organization and functioning is obtained. For inducing local alterations, permanent brain lesions are employed. However, for correct results this technique has to be quasi-non-destructive, i.e. not to affect the normal brain function. Hence, the lesions should be very small, accurate and applied precisely over the structure (e.g. the brain nucleus) of interest. These specifications are difficult to meet with the existing techniques for brain lesions -- specifically, neurotoxical, mechanical and electrical means because they result in too extensive damage. In this paper, we present new laser technique for quasi-non- destructive anatomical-functional mapping in vivo of the medial prefrontal cortex (MPFC) of the rat. The technique is based on producing of small-size, well-controlled laser- induced lesions over some areas of the MPFC. The anesthetized animals are subjected to stereotactic surgery and certain points of the MPFC are exposed the confined radiation of the 10 W cw CO2 laser. Subsequent behavioral changes observed in neonatal and adult animals as well as histological data prove effectiveness of this technology for anatomical- functional studies of the brain by areas, and as a treatment method for some pathologies.

Voxel-based lesion-symptom mapping of stroke lesions underlying somatosensory deficits

PubMed Central

Meyer, Sarah; Kessner, Simon S.; Cheng, Bastian; Bönstrup, Marlene; Schulz, Robert; Hummel, Friedhelm C.; De Bruyn, Nele; Peeters, Andre; Van Pesch, Vincent; Duprez, Thierry; Sunaert, Stefan; Schrooten, Maarten; Feys, Hilde; Gerloff, Christian; Thomalla, Götz; Thijs, Vincent; Verheyden, Geert

2015-01-01

The aim of this study was to investigate the relationship between stroke lesion location and the resulting somatosensory deficit. We studied exteroceptive and proprioceptive somatosensory symptoms and stroke lesions in 38 patients with first-ever acute stroke. The Erasmus modified Nottingham Sensory Assessment was used to clinically evaluate somatosensory functioning in the arm and hand within the first week after stroke onset. Additionally, more objective measures such as the perceptual threshold of touch and somatosensory evoked potentials were recorded. Non-parametric voxel-based lesion-symptom mapping was performed to investigate lesion contribution to different somatosensory deficits in the upper limb. Additionally, structural connectivity of brain areas that demonstrated the strongest association with somatosensory symptoms was determined, using probabilistic fiber tracking based on diffusion tensor imaging data from a healthy age-matched sample. Voxels with a significant association to somatosensory deficits were clustered in two core brain regions: the central parietal white matter, also referred to as the sensory component of the superior thalamic radiation, and the parietal operculum close to the insular cortex, representing the secondary somatosensory cortex. Our objective recordings confirmed findings from clinical assessments. Probabilistic tracking connected the first region to thalamus, internal capsule, brain stem, postcentral gyrus, cerebellum, and frontal pathways, while the second region demonstrated structural connections to thalamus, insular and primary somatosensory cortex. This study reveals that stroke lesions in the sensory fibers of the superior thalamocortical radiation and the parietal operculum are significantly associated with multiple exteroceptive and proprioceptive deficits in the arm and hand. PMID:26900565

MRI assessment of whole-brain structural changes in aging.

PubMed

Guo, Hui; Siu, William; D'Arcy, Ryan Cn; Black, Sandra E; Grajauskas, Lukas A; Singh, Sonia; Zhang, Yunting; Rockwood, Kenneth; Song, Xiaowei

2017-01-01

One of the central features of brain aging is the accumulation of multiple age-related structural changes, which occur heterogeneously in individuals and can have immediate or potential clinical consequences. Each of these deficits can coexist and interact, producing both independent and additive impacts on brain health. Many of the changes can be visualized using MRI. To collectively assess whole-brain structural changes, the MRI-based Brain Atrophy and Lesion Index (BALI) has been developed. In this study, we validate this whole-brain health assessment approach using several clinical MRI examinations. Data came from three independent studies: the Alzheimer's Disease Neuroimaging Initiative Phase II (n=950; women =47.9%; age =72.7±7.4 years); the National Alzheimer's Coordinating Center (n=722; women =55.1%; age =72.7±9.9 years); and the Tianjin Medical University General Hospital Research database on older adults (n=170; women =60.0%; age =62.9±9.3 years). The 3.0-Tesla MRI scans were evaluated using the BALI rating scheme on the basis of T1-weighted (T1WI), T2-weighted (T2WI), T2-weighted fluid-attenuated inversion recovery (T2-FLAIR), and T2*-weighted gradient-recalled echo (T2*GRE) images. Atrophy and lesion changes were commonly seen in each MRI test. The BALI scores based on different sequences were highly correlated (Spearman r 2 >0.69; P <0.00001). They were associated with age ( r 2 >0.29; P <0.00001) and differed by cognitive status ( χ 2 >26.48, P <0.00001). T2-FLAIR revealed a greater level of periventricular ( χ 2 =29.09) and deep white matter ( χ 2 =26.65, P <0.001) lesions than others, but missed revealing certain dilated perivascular spaces that were seen in T2WI ( P <0.001). Microhemorrhages occurred in 15.3% of the sample examined and were detected using only T2*GRE. The T1WI- and T2WI-based BALI evaluations consistently identified the burden of aging and dementia-related decline of structural brain health. Inclusion of additional MRI tests increased lesion differentiation. Further research is to integrate MRI tests for a clinical tool to aid the diagnosis and intervention of brain aging.

Diagnosis of reversible causes of coma.

PubMed

Edlow, Jonathan A; Rabinstein, Alejandro; Traub, Stephen J; Wijdicks, Eelco F M

2014-12-06

Because coma has many causes, physicians must develop a structured, algorithmic approach to diagnose and treat reversible causes rapidly. The three main mechanisms of coma are structural brain lesions, diffuse neuronal dysfunction, and, rarely, psychiatric causes. The first priority is to stabilise the patient by treatment of life-threatening conditions, then to use the history, physical examination, and laboratory findings to identify structural causes and diagnose treatable disorders. Some patients have a clear diagnosis. In those who do not, the first decision is whether brain imaging is needed. Imaging should be done in post-traumatic coma or when structural brain lesions are probable or possible causes. Patients who do not undergo imaging should be reassessed regularly. If CT is non-diagnostic, a checklist should be used use to indicate whether advanced imaging is needed or evidence is present of a treatable poisoning or infection, seizures including non-convulsive status epilepticus, endocrinopathy, or thiamine deficiency. Copyright © 2014 Elsevier Ltd. All rights reserved.

Assessment of the structural brain network reveals altered connectivity in children with unilateral cerebral palsy due to periventricular white matter lesions

PubMed Central

Pannek, Kerstin; Boyd, Roslyn N.; Fiori, Simona; Guzzetta, Andrea; Rose, Stephen E.

2014-01-01

Background Cerebral palsy (CP) is a term to describe the spectrum of disorders of impaired motor and sensory function caused by a brain lesion occurring early during development. Diffusion MRI and tractography have been shown to be useful in the study of white matter (WM) microstructure in tracts likely to be impacted by the static brain lesion. Aim The purpose of this study was to identify WM pathways with altered connectivity in children with unilateral CP caused by periventricular white matter lesions using a whole-brain connectivity approach. Methods Data of 50 children with unilateral CP caused by periventricular white matter lesions (5–17 years; manual ability classification system [MACS] I = 25/II = 25) and 17 children with typical development (CTD; 7–16 years) were analysed. Structural and High Angular Resolution Diffusion weighted Images (HARDI; 64 directions, b = 3000 s/mm2) were acquired at 3 T. Connectomes were calculated using whole-brain probabilistic tractography in combination with structural parcellation of the cortex and subcortical structures. Connections with altered fractional anisotropy (FA) in children with unilateral CP compared to CTD were identified using network-based statistics (NBS). The relationship between FA and performance of the impaired hand in bimanual tasks (Assisting Hand Assessment—AHA) was assessed in connections that showed significant differences in FA compared to CTD. Results FA was reduced in children with unilateral CP compared to CTD. Seven pathways, including the corticospinal, thalamocortical, and fronto-parietal association pathways were identified simultaneously in children with left and right unilateral CP. There was a positive relationship between performance of the impaired hand in bimanual tasks and FA within the cortico-spinal and thalamo-cortical pathways (r2 = 0.16–0.44; p < 0.05). Conclusion This study shows that network-based analysis of structural connectivity can identify alterations in FA in unilateral CP, and that these alterations in FA are related to clinical function. Application of this connectome-based analysis to investigate alterations in connectivity following treatment may elucidate the neurological correlates of improved functioning due to intervention. PMID:25003031

Single-Dose Versus Fractionated Stereotactic Radiotherapy for Brain Metastases

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

Kim, Yeon-Joo; Cho, Kwan Ho, E-mail: kwancho@ncc.re.kr; Kim, Joo-Young

2011-10-01

Purpose: To evaluate the efficacy of stereotactic radiotherapy in patients with brain metastases by comparing two different treatment regimens, single-dose radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT). Methods and Materials: Between November 2003 and December 2008, 98 patients with brain metastases were included. Fifty-eight patients were treated with SRS, and forty were treated with FSRT. Fractionated stereotactic radiotherapy was used for large lesions or lesions located near critical structures. The median doses were 20 Gy for the SRS group and 36 Gy in 6 fractions for the FSRT group. Results: With a median follow-up period of 7 months, the medianmore » survival was 7 months for all patients, with a median of 6 months for the SRS group and 8 months for the FSRT group (p = 0.89). Local progression-free survival (LPFS) rates at 6 months and 1 year were 81% and 71%, respectively, for the SRS group and 97% and 69%, respectively, for the FSRT group (p = 0.31). Despite the fact that FSRT was used for large lesions and lesions in adverse locations, LPFS was not inferior to SRS. Toxicity was more frequently observed in the SRS group than in the FSRT group (17% vs. 5%, p = 0.05). Conclusions: Because patients treated with FSRT exhibited similar survival times and LPFS rates with a lower risk of toxicity in comparison to those treated with SRS, despite the fact that FSRT was used for large lesions and lesions in adverse locations, we find that FSRT can particularly be beneficial for patients with large lesions or lesions located near critical structures. Further investigation is warranted to determine the optimal dose/fractionation.« less

Locally adaptive MR intensity models and MRF-based segmentation of multiple sclerosis lesions

NASA Astrophysics Data System (ADS)

Galimzianova, Alfiia; Lesjak, Žiga; Likar, Boštjan; Pernuš, Franjo; Špiclin, Žiga

2015-03-01

Neuroimaging biomarkers are an important paraclinical tool used to characterize a number of neurological diseases, however, their extraction requires accurate and reliable segmentation of normal and pathological brain structures. For MR images of healthy brains the intensity models of normal-appearing brain tissue (NABT) in combination with Markov random field (MRF) models are known to give reliable and smooth NABT segmentation. However, the presence of pathology, MR intensity bias and natural tissue-dependent intensity variability altogether represent difficult challenges for a reliable estimation of NABT intensity model based on MR images. In this paper, we propose a novel method for segmentation of normal and pathological structures in brain MR images of multiple sclerosis (MS) patients that is based on locally-adaptive NABT model, a robust method for the estimation of model parameters and a MRF-based segmentation framework. Experiments on multi-sequence brain MR images of 27 MS patients show that, compared to whole-brain model and compared to the widely used Expectation-Maximization Segmentation (EMS) method, the locally-adaptive NABT model increases the accuracy of MS lesion segmentation.

Evidence for a double dissociation of articulatory rehearsal and non-articulatory maintenance of phonological information in human verbal working memory.

PubMed

Trost, Sarah; Gruber, Oliver

2012-01-01

Recent functional neuroimaging studies have provided evidence that human verbal working memory is represented by two complementary neural systems, a left lateralized premotor-parietal network implementing articulatory rehearsal and a presumably phylogenetically older bilateral anterior-prefrontal/inferior-parietal network subserving non-articulatory maintenance of phonological information. In order to corroborate these findings from functional neuroimaging, we performed a targeted behavioural study in patients with very selective and circumscribed brain lesions to key regions suggested to support these different subcomponents of human verbal working memory. Within a sample of over 500 neurological patients assessed with high-resolution structural magnetic resonance imaging, we identified 2 patients with corresponding brain lesions, one with an isolated lesion to Broca's area and the other with a selective lesion bilaterally to the anterior middle frontal gyrus. These 2 patients as well as groups of age-matched healthy controls performed two circuit-specific verbal working memory tasks. In this way, we systematically assessed the hypothesized selective behavioural effects of these brain lesions on the different subcomponents of verbal working memory in terms of a double dissociation. Confirming prior findings, the lesion to Broca's area led to reduced performance under articulatory rehearsal, whereas the non-articulatory maintenance of phonological information was unimpaired. Conversely, the bifrontopolar brain lesion was associated with impaired non-articulatory phonological working memory, whereas performance under articulatory rehearsal was unaffected. The present experimental neuropsychological study in patients with specific and circumscribed brain lesions confirms the hypothesized double dissociation of two complementary brain systems underlying verbal working memory in humans. In particular, the results demonstrate the functional relevance of the anterior prefrontal cortex for non-articulatory maintenance of phonological information and, in this way, provide further support for the evolutionary-based functional-neuroanatomical model of human working memory. Copyright © 2012 S. Karger AG, Basel.

Neonatal neuroimaging: going beyond the pictures.

PubMed

Ramenghi, Luca A; Rutherford, Mary; Fumagalli, Monica; Bassi, Laura; Messner, Hubert; Counsell, Serena; Mosca, Fabio

2009-10-01

The cerebral ultrasound has been used many years for the diagnosis of brain lesions in term and preterm newborns. Major improvements were obtained by the combination of different imaging modalities such as Magnetic Resonance Imaging with the Diffusion Weighted Imaging (DWI) and the new quantitative Diffusion Tensor Imaging (DTI). The clinical use of MRI has been validated over some years especially to depict the perinatal asphyxia lesions in term newborns, but its use in order to diagnose the typical diseases of preterm babies is very recent and useful in identifying a marker able to predict neurological outcome. The imaging correlates for motor impairment are well recognized (periventricular white matter cavitations), but no any imaging correlate for cognitive impairment and neurobehavioral disorders. While DWI has been used in term newborns to identify the ischemic areas with restricted diffusion, it may be also used to characterize brain development in preterm infants with the Apparent Diffusion Coefficient (ADC) and may allow us to detect abnormalities responsible for the non-motor impairments. Recent datas showed that in infants without focal lesions higher ADC values in WM were associated with poorer neurodevelopmental assessment at 2 years. The DTI also allows to detect the Fractional Anisotropy (FA) that measures the microstructure. DTI can also be used to map the WM tracts in the immature brain and may be applied to understand the normal development or the response of the brain to injury. Some WM regions in the preterm brain have a lower FA suggesting that widespread WM abnormalities are present in preterms even in the absence of focal lesions. The complexity of the developing brain can be explained by the new tractography that can assess the connectivity of different WM regions and the association between structure and function, such as optic radiations microstructure and visual assessment score. Technological advances in neonatal brain imaging have made a major contribution to understand the neurobehavioral disorders of the developing brain that have the origin in the early structural cerebral organization and maturation.

Neuropsychological and structural brain lesions in multiple sclerosis: a regional analysis.

PubMed

Swirsky-Sacchetti, T; Mitchell, D R; Seward, J; Gonzales, C; Lublin, F; Knobler, R; Field, H L

1992-07-01

Quantified lesion scores derived from MRI correlate significantly with neuropsychological testing in patients with multiple sclerosis (MS). Variables used to reflect disease severity include total lesion area (TLA), ventricular-brain ratio, and size of the corpus callosum. We used these general measures of cerebral lesion involvement as well as specific ratings of lesion involvement by frontal, temporal, and parieto-occipital regions to quantify the topographic distribution of lesions and consequent effects upon cognitive function. Lesions were heavily distributed in the parieto-occipital regions bilaterally. Neuropsychological tests were highly related to all generalized measures of cerebral involvement, with TLA being the best predictor of neuropsychological deficit. Mean TLA for the cognitively impaired group was 28.30 cm2 versus 7.41 cm2 for the cognitively intact group (p less than 0.0001). Multiple regression analyses revealed that left frontal lobe involvement best predicted impaired abstract problem solving, memory, and word fluency. Left parieto-occipital lesion involvement best predicted deficits in verbal learning and complex visual-integrative skills. Analysis of regional cerebral lesion load may assist in understanding the particular pattern and course of cognitive deficits in MS.

Safety of multiple stereotactic radiosurgery treatments for multiple brain lesions.

PubMed

Hillard, Virany H; Shih, Lynn L; Chin, Shing; Moorthy, Chitti R; Benzil, Deborah L

2003-07-01

Stereotactic radiosurgery (SRS) is a widely used therapy for multiple brain lesions, and studies have clearly established the safety and efficacy of single-dose SRS. However, as patient survival has increased, the recurrence of tumors and the development of metastases to new sites within the brain have made it desirable to repeat treatments over time. The cumulative toxicity of multi-isocenter, multiple treatments has not been well defined. We have retrospectively studied 10 patients who received multiple SRS treatments for multiple brain lesions to assess the cumulative toxicity of these treatments. In a retrospective review of all patients treated with SRS using the X-knife (Radionics, Burlington, MA) at Westchester Medical Center/New York Medical College between December 1995 and December 2000, 10 patients were identified who received at least two treatments to at least 3 isocenters and had a minimum follow-up period of 6 months. Image fusion technique was used to determine cumulative doses to targeted lesions, whole brain and critical brain structures. Toxicities and complications were identified by chart and radiological review. The average of the maximum doses (cGy) to a point within the whole brain was 2402 (range 1617-3953); to the brainstem, 1059 (range 48-4126); to the right optic nerve, 223 (range 14-1012); to the left optic nerve, 159 (range 17-475); and to the optic chiasm, 219 (range 15-909). There were no focal neurological toxicities, including visual disturbances, cranial nerve palsies, or ataxia in any of the 10 patients. There were also no global toxicities, including cognitive decline or secondary tumors. Only one patient developed seizures that were difficult to control in association with radiation necrosis. Multiple SRS treatments at the cumulative doses used in our study are a safe therapy for patients with multiple brain lesions.

[3D FSPGR (fast spoiled gradient echo) magnetic resonance imaging in the diagnosis of focal cortical dysplasia in children].

PubMed

Alikhanov, A A; Sinitsyn, V E; Perepelova, E M; Mukhin, K Iu; Demushkina, A A; Omarova, M O; Piliia, S V

2001-01-01

Small dysplastic lesions of the cerebral cortex are often missed by conventional MRI methods. The identification of subtle structural abnormalities by traditional multiplanar rectilinear slices is often limited by the complex convolutional pattern of the brain. We used a method of FSPGR (fast spoiled gradient-echo) of three-dimensional MRI data that improves the anatomical display of the sulcal structure of the hemispheric convexities. It also reduces the asymmetric sampling of gray-white matter that may lead to false-positive results. We present 5 from 12 patients with dysplastic cortical lesions in whom conventional two-dimensional and three-dimensional MRI with multiplanar reformatting was initially considered normal. Subsequent studies using 3D FSPGR identified various types of focal cortical dysplasia in all. These results indicate that an increase in the detection of subtle focal dysplastic lesions may be accomplished when one improves the anatomical display of the brain sulcal structure by performing 3D FSPGR.

Correlating Cognitive Decline with White Matter Lesion and Brain Atrophy MRI Measurements in Alzheimer’s Disease

PubMed Central

Bilello, Michel; Doshi, Jimit; Nabavizadeh, S. Ali; Toledo, Jon B.; Erus, Guray; Xie, Sharon X.; Trojanowski, John Q.; Han, Xiaoyan; Davatzikos, Christos

2015-01-01

Background Vascular risk factors are increasingly recognized as risks factors for Alzheimer’s disease (AD) and early conversion from mild cognitive impairment (MCI) to dementia. While neuroimaging research in AD has focused on brain atrophy, metabolic function or amyloid deposition, little attention has been paid to the effect of cerebrovascular disease to cognitive decline. Objective To investigate the correlation of brain atrophy and white matter lesions with cognitive decline in AD, MCI, and control subjects. Methods Patients with AD and MCI, and healthy subjects were included in this study. Subjects had a baseline MRI scan, and baseline and follow-up neuropsychological battery (CERAD). Regional volumes were measured, and white matter lesion segmentation was performed. Correlations between rate of CERAD score decline and white matter lesion load and brain structure volume were evaluated. In addition, voxel-based correlations between baseline CERAD scores and atrophy and white matter lesion measures were computed. Results CERAD rate of decline was most significantly associated with lesion loads located in the fornices. Several temporal lobe ROI volumes were significantly associated with CERAD decline. Voxel-based analysis demonstrated strong correlation between baseline CERAD scores and atrophy measures in the anterior temporal lobes. Correlation of baseline CERAD scores with white matter lesion volumes achieved significance in multilobar subcortical white matter. Conclusion Both baseline and declines in CERAD scores correlate with white matter lesion load and gray matter atrophy. Results of this study highlight the dominant effect of volume loss, and underscore the importance of small vessel disease as a contributor to cognitive decline in the elderly. PMID:26402108

Correlating Cognitive Decline with White Matter Lesion and Brain Atrophy Magnetic Resonance Imaging Measurements in Alzheimer's Disease.

PubMed

Bilello, Michel; Doshi, Jimit; Nabavizadeh, S Ali; Toledo, Jon B; Erus, Guray; Xie, Sharon X; Trojanowski, John Q; Han, Xiaoyan; Davatzikos, Christos

2015-01-01

Vascular risk factors are increasingly recognized as risks factors for Alzheimer's disease (AD) and early conversion from mild cognitive impairment (MCI) to dementia. While neuroimaging research in AD has focused on brain atrophy, metabolic function, or amyloid deposition, little attention has been paid to the effect of cerebrovascular disease to cognitive decline. To investigate the correlation of brain atrophy and white matter lesions with cognitive decline in AD, MCI, and control subjects. Patients with AD and MCI, and healthy subjects were included in this study. Subjects had a baseline MRI scan, and baseline and follow-up neuropsychological battery (CERAD). Regional volumes were measured, and white matter lesion segmentation was performed. Correlations between rate of CERAD score decline and white matter lesion load and brain structure volume were evaluated. In addition, voxel-based correlations between baseline CERAD scores and atrophy and white matter lesion measures were computed. CERAD rate of decline was most significantly associated with lesion loads located in the fornices. Several temporal lobe ROI volumes were significantly associated with CERAD decline. Voxel-based analysis demonstrated strong correlation between baseline CERAD scores and atrophy measures in the anterior temporal lobes. Correlation of baseline CERAD scores with white matter lesion volumes achieved significance in multilobar subcortical white matter. Both baseline and declines in CERAD scores correlate with white matter lesion load and gray matter atrophy. Results of this study highlight the dominant effect of volume loss, and underscore the importance of small vessel disease as a contributor to cognitive decline in the elderly.

The effect of claustrum lesions on human consciousness and recovery of function.

PubMed

Chau, Aileen; Salazar, Andres M; Krueger, Frank; Cristofori, Irene; Grafman, Jordan

2015-11-01

Crick and Koch proposed that the claustrum plays a crucial role in consciousness. Their proposal was based on the structure and connectivity of the claustrum that suggested it had a role in coordinating a set of diverse brain functions. Given the few human studies investigating this claim, we decided to study the effects of claustrum lesions on consciousness in 171 combat veterans with penetrating traumatic brain injuries. Additionally, we studied the effects of claustrum lesions and loss of consciousness on long-term cognitive abilities. Claustrum damage was associated with the duration, but not frequency, of loss of consciousness, indicating that the claustrum may have an important role in regaining, but not maintaining, consciousness. Total brain volume loss, but not claustrum lesions, was associated with long-term recovery of neurobehavioral functions. Our findings constrain the current understanding of the neurobehavioral functions of the claustrum and its role in maintaining and regaining consciousness. Copyright © 2015 Elsevier Inc. All rights reserved.

Lesion symptom map of cognitive-postural interference in multiple sclerosis.

PubMed

Ruggieri, Serena; Fanelli, Fulvia; Castelli, Letizia; Petsas, Nikolaos; De Giglio, Laura; Prosperini, Luca

2018-04-01

To investigate the disease-altered structure-function relationship underlying the cognitive-postural interference (CPI) phenomenon in multiple sclerosis (MS). We measured postural sway of 96 patients and 48 sex-/age-matched healthy controls by force platform in quiet standing (single-task (ST)) while performing the Stroop test (dual-task (DT)) to estimate the dual-task cost (DTC) of balance. In patient group, binary T2 and T1 lesion masks and their corresponding lesion volumes were obtained from magnetic resonance imaging (MRI) of brain. Normalized brain volume (NBV) was also estimated by SIENAX. Correlations between DTC and lesion location were determined by voxel-based lesion symptom mapping (VLSM) analyses. Patients had greater DTC than controls ( p < 0.001). Among whole brain MRI metrics, only T1 lesion volume correlated with DTC ( r = -0.27; p < 0.01). However, VLSM analysis did not reveal any association with DTC using T1 lesion masks. By contrast, we found clusters of T2 lesions in distinct anatomical regions (anterior and superior corona radiata, bilaterally) to be correlated with DTC ( p < 0.01 false discovery rate (FDR)-corrected). A multivariable stepwise regression model confirmed findings from VLSM analysis. NBV did not contribute to fit the model. Our findings suggest that the CPI phenomenon in MS can be explained by disconnection along specific areas implicated in task-switching abilities and divided attention.

Brain Barrier Disruption and Region-Specific Neuronal Degeneration during Necrotizing Enterocolitis in Preterm Pigs.

PubMed

Brunse, Anders; Abbaspour, Afrouz; Sangild, Per Torp

2018-06-06

Necrotizing enterocolitis (NEC) increases the risk of brain injury and impaired neurodevelopment. Rapid brain maturation prior to birth may explain why preterm brains are particularly vulnerable to serious infections. Using pigs as models, we hypothesized that preterm birth was associated with altered blood-cerebrospinal fluid (CSF) barrier (BCSFB) function and cerebral structural deficits, and that NEC was associated with systemic inflammation, BCSFB disruption, and neuroinflammation. First, cesarean-delivered preterm and term pigs (n = 43-44) were euthanized at birth to investigate BCSFB function and markers of brain structural maturation, or on day 5 to measure markers of blood-brain barrier maturation in the hippocampus and striatum (experiment 1). Next, preterm pigs (n = 162) were fed increasing volumes of infant formula to assess NEC lesions, systemic inflammation, BCSFB permeability, cerebral histopathology, hippocampal micro-glial density, and cytokine levels on day 5 (experiments 2 and 3). In experiment 1, preterm newborns had increased CSF-plasma ratios of albumin and raffinose, reduced CSF glucose levels, as well as increased cerebral hydration and reduced white matter myelination compared with term animals. We observed lower hippocampal (but not striatal) perivascular astrocyte coverage for the first 5 days after preterm birth, accompanied by altered cell junction protein levels. In experiments 2 and- 3, piglets with severe NEC lesions showed reduced blood thrombocytes and increased plasma C-reactive protein and interleukin-6 levels. NEC was associated with increased CSF-plasma albumin and raffinose ratios, reduced CSF leukocyte numbers, and increased cerebral hydration. In the hippocampus, NEC was associated with pyramidal neuron loss and increased interleukin-6 levels. In the short term, NEC did not affect cerebral myelination or microglia density. In conclusion, altered BCSFB properties and brain structural deficits were observed in pigs after preterm birth. Acute gastrointestinal NEC lesions were associated with systemic inflammation, increased BCSFB permeability and region-specific neuronal damage. The results demonstrate the importance of early interventions against NEC to prevent brain injury in preterm infants. © 2018 S. Karger AG, Basel.

Processing verbal morphology in patients with congenital left-hemispheric brain lesions.

PubMed

Knecht, Marion; Lidzba, Karen

2016-01-01

The goal of this study was to test whether children, teenagers and adults with congenital left-hemispheric brain lesions master the regularities of German verbal inflectional morphology. Thirteen patients and 35 controls without brain damage participated in three experiments. A grammaticality judgment task, a participle inflection task and a nonce-verb inflection task revealed significant differences between patients and controls. In addition, a main effect of verb type could be observed as patients and controls made more mistakes with irregular than with regular verbs. The findings indicate that the congenitally damaged brain not only has difficulties with complex syntactic structures during language development, as reported by earlier studies, but also has persistent deficits on the morphological level. These observations suggest that the plasticity of the developing brain cannot fully compensate for congenital brain damage which affects regions associated with language functions. Copyright © 2016 Elsevier Inc. All rights reserved.

The influence of acceleration loading curve characteristics on traumatic brain injury.

PubMed

Post, Andrew; Blaine Hoshizaki, T; Gilchrist, Michael D; Brien, Susan; Cusimano, Michael D; Marshall, Shawn

2014-03-21

To prevent brain trauma, understanding the mechanism of injury is essential. Once the mechanism of brain injury has been identified, prevention technologies could then be developed to aid in their prevention. The incidence of brain injury is linked to how the kinematics of a brain injury event affects the internal structures of the brain. As a result it is essential that an attempt be made to describe how the characteristics of the linear and rotational acceleration influence specific traumatic brain injury lesions. As a result, the purpose of this study was to examine the influence of the characteristics of linear and rotational acceleration pulses and how they account for the variance in predicting the outcome of TBI lesions, namely contusion, subdural hematoma (SDH), subarachnoid hemorrhage (SAH), and epidural hematoma (EDH) using a principal components analysis (PCA). Monorail impacts were conducted which simulated falls which caused the TBI lesions. From these reconstructions, the characteristics of the linear and rotational acceleration were determined and used for a PCA analysis. The results indicated that peak resultant acceleration variables did not account for any of the variance in predicting TBI lesions. The majority of the variance was accounted for by duration of the resultant and component linear and rotational acceleration. In addition, the components of linear and rotational acceleration characteristics on the x, y, and z axes accounted for the majority of the remainder of the variance after duration. Copyright © 2014 Elsevier Ltd. All rights reserved.

PREDICTING APHASIA TYPE FROM BRAIN DAMAGE MEASURED WITH STRUCTURAL MRI

PubMed Central

Yourganov, Grigori; Smith, Kimberly G.; Fridriksson, Julius; Rorden, Chris

2015-01-01

Chronic aphasia is a common consequence of a left-hemisphere stroke. Since the early insights by Broca and Wernicke, studying the relationship between the loci of cortical damage and patterns of language impairment has been one of the concerns of aphasiology. We utilized multivariate classification in a cross-validation framework to predict the type of chronic aphasia from the spatial pattern of brain damage. Our sample consisted of 98 patients with five types of aphasia (Broca’s, Wernicke’s, global, conduction, and anomic), classified based on scores on the Western Aphasia Battery. Binary lesion maps were obtained from structural MRI scans (obtained at least 6 months poststroke, and within 2 days of behavioural assessment); after spatial normalization, the lesions were parcellated into a disjoint set of brain areas. The proportion of damage to the brain areas was used to classify patients’ aphasia type. To create this parcellation, we relied on five brain atlases; our classifier (support vector machine) could differentiate between different kinds of aphasia using any of the five parcellations. In our sample, the best classification accuracy was obtained when using a novel parcellation that combined two previously published brain atlases, with the first atlas providing the segmentation of grey matter, and the second atlas used to segment the white matter. For each aphasia type, we computed the relative importance of different brain areas for distinguishing it from other aphasia types; our findings were consistent with previously published reports of lesion locations implicated in different types of aphasia. Overall, our results revealed that automated multivariate classification could distinguish between aphasia types based on damage to atlas-defined brain areas. PMID:26465238

Predicting aphasia type from brain damage measured with structural MRI.

PubMed

Yourganov, Grigori; Smith, Kimberly G; Fridriksson, Julius; Rorden, Chris

2015-12-01

Chronic aphasia is a common consequence of a left-hemisphere stroke. Since the early insights by Broca and Wernicke, studying the relationship between the loci of cortical damage and patterns of language impairment has been one of the concerns of aphasiology. We utilized multivariate classification in a cross-validation framework to predict the type of chronic aphasia from the spatial pattern of brain damage. Our sample consisted of 98 patients with five types of aphasia (Broca's, Wernicke's, global, conduction, and anomic), classified based on scores on the Western Aphasia Battery (WAB). Binary lesion maps were obtained from structural MRI scans (obtained at least 6 months poststroke, and within 2 days of behavioural assessment); after spatial normalization, the lesions were parcellated into a disjoint set of brain areas. The proportion of damage to the brain areas was used to classify patients' aphasia type. To create this parcellation, we relied on five brain atlases; our classifier (support vector machine - SVM) could differentiate between different kinds of aphasia using any of the five parcellations. In our sample, the best classification accuracy was obtained when using a novel parcellation that combined two previously published brain atlases, with the first atlas providing the segmentation of grey matter, and the second atlas used to segment the white matter. For each aphasia type, we computed the relative importance of different brain areas for distinguishing it from other aphasia types; our findings were consistent with previously published reports of lesion locations implicated in different types of aphasia. Overall, our results revealed that automated multivariate classification could distinguish between aphasia types based on damage to atlas-defined brain areas. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ventromedial prefrontal cortex modulates fatigue after penetrating traumatic brain injury

PubMed Central

Pardini, Matteo; Krueger, Frank; Raymont, Vanessa; Grafman, Jordan

2010-01-01

Background: Fatigue is a common and disabling symptom in neurologic disorders including traumatic penetrating brain injury (PBI). Despite fatigue's prevalence and impact on quality of life, its pathophysiology is not understood. Studies on effort perception in healthy subjects, animal behavioral paradigms, and recent evidence in different clinical populations suggest that ventromedial prefrontal cortex could play a significant role in fatigue pathophysiology in neurologic conditions. Methods: We enrolled 97 PBI patients and 37 control subjects drawn from the Vietnam Head Injury Study registry. Fatigue was assessed with a self-report questionnaire and a clinician-rated instrument; lesion location and volume were evaluated on CT scans. PBI patients were divided in 3 groups according to lesion location: a nonfrontal lesion group, a ventromedial prefrontal cortex lesion (vmPFC) group, and a dorso/lateral prefrontal cortex (d/lPFC) group. Fatigue scores were compared among the 3 PBI groups and the healthy controls. Results: Individuals with vmPFC lesions were significantly more fatigued than individuals with d/lPFC lesions, individuals with nonfrontal lesions, and healthy controls, while these 3 latter groups were equally fatigued. VmPFC volume was correlated with fatigue scores, showing that the larger the lesion volume, the higher the fatigue scores. Conclusions: We demonstrated that ventromedial prefrontal cortex lesion (vmPFC) plays a critical role in penetrating brain injury–related fatigue, providing a rationale to link fatigue to different vmPFC functions such as effort and reward perception. The identification of the anatomic and cognitive basis of fatigue can contribute to developing pathophysiology-based treatments for this disabling symptom. GLOSSARY AAL = Automated Anatomic Labeling; ANOVA = analysis of variance; BDI = Beck Depression Inventory; d/lPFC = dorso/lateral prefrontal cortex; DSM-IV = Diagnostic and Statistical Manual of Mental Disorders, 4th edition; NBRS = Neurobehavioral Rating Scale; NF = nonfrontal lesion; PBI = penetrating brain injury; ROI = region of interest; SCID-I = Structured Clinical Interview for DSM-IV, Axis I; VHIS = Vietnam Head Injury Study; vmPFC = ventromedial prefrontal cortex lesion. PMID:20194914

Visual recognition and visually guided action after early bilateral lesion of occipital cortex: a behavioral study of a 4.6-year-old girl.

PubMed

Amicuzi, Ileana; Stortini, Massimo; Petrarca, Maurizio; Di Giulio, Paola; Di Rosa, Giuseppe; Fariello, Giuseppe; Longo, Daniela; Cannatà, Vittorio; Genovese, Elisabetta; Castelli, Enrico

2006-10-01

We report the case of a 4.6-year-old girl born pre-term with early bilateral occipital damage. It was revealed that the child had non-severely impaired basic visual abilities and ocular motility, a selective perceptual deficit of figure-ground segregation, impaired visual recognition and abnormal navigating through space. Even if the child's visual functioning was not optimal, this was the expression of adaptive anatomic and functional brain modifications that occurred following the early lesion. Anatomic brain structure was studied with anatomic MRI and Diffusor Tensor Imaging (DTI)-MRI. This behavioral study may provide an important contribution to understanding the impact of an early lesion of the visual system on the development of visual functions and on the immature brain's potential for reorganisation related to when the damage occurred.

[Complex stimulation of the locomotor and psycholingual develop- ment of children with perinatal lesions of the central nervous system].

PubMed

Skvortsov, I A; Khavkhun, L A; Ustinova, E V; I'lin, L B

1989-01-01

In 121 children with perinatal CNS damage a combined therapy was performed including, besides routine drug treatment, imitation stimulation of age-matched posture-++-tonic attitudes and motor skills, metameric reflexotherapy aimed at the CNS region lesioned, magnetotherapy, electric laser puncture targeted at correction of dysfunctioning brain structures. Treatment efficiency was controlled by the brain "development profile" derived from formalized neurological and neuropsychological investigations, and electroneuromyography. The efficiency of the therapy was considerably decreased by the 3rd semester of life.

Effects of Focal Basal Ganglia Lesions on Timing and Force Control

ERIC Educational Resources Information Center

Aparicio, P.; Diedrichsen, J.; Ivry, R.B.

2005-01-01

Studies of basal ganglia dysfunction in humans have generally involved patients with degenerative disorders, notably Parkinson's disease. In many instances, the performance of these patients is compared to that of patients with focal lesions of other brain structures such as the cerebellum. In the present report, we studied the performance of…

SU-F-T-613: Multi-Lesion Cranial SRS VMAT Plan Quality

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

Ballangrud, A; Kuo, L; Happersett, L

Purpose: Cranial SRS VMAT plans must have steep dose gradient around each target to reduce dose to normal brain. This study reports on the correlation between gradient index (GI=V50%/V100%), target size and target dose heterogeneity index (HI=PTV Dmax/prescription dose) for multi-lesion cranial SRS VMAT plans. Methods: VMAT plans for 10 cranial cases with 3 to 6 lesions (total 39 lesions) generated in Varian Eclipse V11.0.47 with a fine-tuned AAA beam model and 0.125 cm dose grid were analyzed. One or two iso centers were used depending on the spatial distribution of lesions. Two to nine coplanar and non-coplanar arcs weremore » used per isocenter. Conformity index (CI= V100%/VPTV), HI, and GI were determined for each lesion. Dose to critical structures were recorded. Results: Lesion size ranged from 0.05–11.00 cm3. HI ranged from 1.2–1.4, CI ranged from 1.0–2.8 and GI from 3.1–8.4. Maximum dose to brainstem, chiasm, lenses, optic nerves and eyes ranged from 120–1946 cGy, 47–463 cGy, 9–121 cGy, 14–512 cGy, and 17–294 cGy, respectively. Brain minus PTV (Brain-PTV) V7Gy was in the range 1.1–6.5%, and Brain-PTV Dmean was in the range 94–324 cGy. Conclusion: This work shows that a GI < 5 can be achieved for lesions > 0.4cc. For smaller lesions, GI increases rapidly. GI is lower when HI is increased. Based on this study, recommend HI is 1.4, and recommended GI is for volumes <0.1cc GI<9, 0.1–0.4cc GI<6, 0.4–0.1.0cc GI<5, and for volumes >1.0cc GI<4. CI is < 1.3 for all lesions except for targets < 0.1cc. Cranial SRS VMAT plans must be optimized to lower the GI to reduce the dose to normal brain tissue.« less

Brain single photon emission computed tomography in neonates

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

Denays, R.; Van Pachterbeke, T.; Tondeur, M.

1989-08-01

This study was designed to rate the clinical value of ({sup 123}I)iodoamphetamine (IMP) or ({sup 99m}Tc) hexamethyl propylene amine oxyme (HM-PAO) brain single photon emission computed tomography (SPECT) in neonates, especially in those likely to develop cerebral palsy. The results showed that SPECT abnormalities were congruent in most cases with structural lesions demonstrated by ultrasonography. However, mild bilateral ventricular dilatation and bilateral subependymal porencephalic cysts diagnosed by ultrasound were not associated with an abnormal SPECT finding. In contrast, some cortical periventricular and sylvian lesions and all the parasagittal lesions well visualized in SPECT studies were not diagnosed by ultrasound scans.more » In neonates with subependymal and/or intraventricular hemorrhage the existence of a parenchymal abnormality was only diagnosed by SPECT. These results indicate that ({sup 123}I)IMP or ({sup 99m}Tc)HM-PAO brain SPECT shows a potential clinical value as the neurodevelopmental outcome is clearly related to the site, the extent, and the number of cerebral lesions. Long-term clinical follow-up is, however, mandatory in order to define which SPECT abnormality is associated with neurologic deficit.« less

Brain anomalies in velo-cardio-facial syndrome

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

Mitnick, R.J.; Bello, J.A.; Shprintzen, R.J.

Magnetic resonance imaging of the brain in 11 consecutively referred patients with velo-cardio-facial syndrome (VCF) showed anomalies in nine cases including small vermis, cysts adjacent to the frontal horns, and small posterior fossa. Focal signal hyperintensities in the white matter on long TR images were also noted. The nine patients showed a variety of behavioral abnormalities including mild development delay, learning disabilities, and characteristic personality traits typical of this common multiple anomaly syndrome which has been related to a microdeletion at 22q11. Analysis of the behavorial findings showed no specific pattern related to the brain anomalies, and the patients withmore » VCF who did not have detectable brain lesions also had behavioral abnormalities consistent with VCF. The significance of the lesions is not yet known, but the high prevalence of anomalies in this sample suggests that structural brain abnormalities are probably common in VCF. 25 refs.« less

Comparative brain stem lesions on MRI of acute disseminated encephalomyelitis, neuromyelitis optica, and multiple sclerosis.

PubMed

Lu, Zhengqi; Zhang, Bingjun; Qiu, Wei; Kang, Zhuang; Shen, Liping; Long, Youming; Huang, Junqi; Hu, Xueqiang

2011-01-01

Brain stem lesions are common in patients with acute disseminated encephalomyelitis (ADEM), neuromyelitis optica (NMO), and multiple sclerosis (MS). To investigate comparative brain stem lesions on magnetic resonance imaging (MRI) among adult patients with ADEM, NMO, and MS. Sixty-five adult patients with ADEM (n = 17), NMO (n = 23), and MS (n = 25) who had brain stem lesions on MRI were enrolled. Morphological features of brain stem lesions among these diseases were assessed. Patients with ADEM had a higher frequency of midbrain lesions than did patients with NMO (94.1% vs. 17.4%, P<0.001) and MS (94.1% vs. 40.0%, P<0.001); patients with NMO had a lower frequency of pons lesions than did patients with MS (34.8% vs. 84.0%, P<0.001) and ADEM (34.8% vs. 70.6%, P = 0.025); and patients with NMO had a higher frequency of medulla oblongata lesions than did patients with ADEM (91.3% vs. 35.3%, P<0.001) and MS (91.3% vs. 36.0%, P<0.001). On the axial section of the brain stem, the majority (82.4%) of patients with ADEM showed lesions on the ventral part; the brain stem lesions in patients with NMO were typically located in the dorsal part (91.3%); and lesions in patients with MS were found in both the ventral (44.0%) and dorsal (56.0%) parts. The lesions in patients with ADEM (100%) and NMO (91.3%) had poorly defined margins, while lesions of patients with MS (76.0%) had well defined margins. Brain stem lesions in patients with ADEM were usually bilateral and symmetrical (82.4%), while lesions in patients with NMO (87.0%) and MS (92.0%) were asymmetrical or unilateral. Brain stem lesions showed various morphological features among adult patients with ADEM, NMO, and MS. The different lesion locations may be helpful in distinguishing these diseases.

Comparative Brain Stem Lesions on MRI of Acute Disseminated Encephalomyelitis, Neuromyelitis Optica, and Multiple Sclerosis

PubMed Central

Kang, Zhuang; Shen, Liping; Long, Youming; Huang, Junqi; Hu, Xueqiang

2011-01-01

Background Brain stem lesions are common in patients with acute disseminated encephalomyelitis (ADEM), neuromyelitis optica (NMO), and multiple sclerosis (MS). Objectives To investigate comparative brain stem lesions on magnetic resonance imaging (MRI) among adult patients with ADEM, NMO, and MS. Methods Sixty-five adult patients with ADEM (n = 17), NMO (n = 23), and MS (n = 25) who had brain stem lesions on MRI were enrolled. Morphological features of brain stem lesions among these diseases were assessed. Results Patients with ADEM had a higher frequency of midbrain lesions than did patients with NMO (94.1% vs. 17.4%, P<0.001) and MS (94.1% vs. 40.0%, P<0.001); patients with NMO had a lower frequency of pons lesions than did patients with MS (34.8% vs. 84.0%, P<0.001) and ADEM (34.8% vs. 70.6%, P = 0.025); and patients with NMO had a higher frequency of medulla oblongata lesions than did patients with ADEM (91.3% vs. 35.3%, P<0.001) and MS (91.3% vs. 36.0%, P<0.001). On the axial section of the brain stem, the majority (82.4%) of patients with ADEM showed lesions on the ventral part; the brain stem lesions in patients with NMO were typically located in the dorsal part (91.3%); and lesions in patients with MS were found in both the ventral (44.0%) and dorsal (56.0%) parts. The lesions in patients with ADEM (100%) and NMO (91.3%) had poorly defined margins, while lesions of patients with MS (76.0%) had well defined margins. Brain stem lesions in patients with ADEM were usually bilateral and symmetrical (82.4%), while lesions in patients with NMO (87.0%) and MS (92.0%) were asymmetrical or unilateral. Conclusions Brain stem lesions showed various morphological features among adult patients with ADEM, NMO, and MS. The different lesion locations may be helpful in distinguishing these diseases. PMID:21853047

Stereotaxic 18F-FDG PET and MRI templates with three-dimensional digital atlas for statistical parametric mapping analysis of tree shrew brain.

PubMed

Huang, Qi; Nie, Binbin; Ma, Chen; Wang, Jing; Zhang, Tianhao; Duan, Shaofeng; Wu, Shang; Liang, Shengxiang; Li, Panlong; Liu, Hua; Sun, Hua; Zhou, Jiangning; Xu, Lin; Shan, Baoci

2018-01-01

Tree shrews are proposed as an alternative animal model to nonhuman primates due to their close affinity to primates. Neuroimaging techniques are widely used to study brain functions and structures of humans and animals. However, tree shrews are rarely applied in neuroimaging field partly due to the lack of available species specific analysis methods. In this study, 10 PET/CT and 10 MRI images of tree shrew brain were used to construct PET and MRI templates; based on histological atlas we reconstructed a three-dimensional digital atlas with 628 structures delineated; then the digital atlas and templates were aligned into a stereotaxic space. Finally, we integrated the digital atlas and templates into a toolbox for tree shrew brain spatial normalization, statistical analysis and results localization. We validated the feasibility of the toolbox by simulated data with lesions in laterodorsal thalamic nucleus (LD). The lesion volumes of simulated PET and MRI images were (12.97±3.91)mm 3 and (7.04±0.84)mm 3 . Statistical results at p<0.005 showed the lesion volumes of PET and MRI were 13.18mm 3 and 8.06mm 3 in LD. To our knowledge, we report the first PET template and digital atlas of tree shrew brain. Compared to the existing MRI templates, our MRI template was aligned into stereotaxic space. And the toolbox is the first software dedicated for tree shrew brain analysis. The templates and digital atlas of tree shrew brain, as well as the toolbox, facilitate the use of tree shrews in neuroimaging field. Copyright © 2017 Elsevier B.V. All rights reserved.

Dorsal brain stem syndrome: MR imaging location of brain stem tegmental lesions in neonates with oral motor dysfunction.

PubMed

Quattrocchi, C C; Longo, D; Delfino, L N; Cilio, M R; Piersigilli, F; Capua, M D; Seganti, G; Danhaive, O; Fariello, G

2010-09-01

The anatomic extent of brain stem damage may provide information about clinical outcome and prognosis in children with hypoxic-ischemic encephalopathy and oral motor dysfunction. The aim of this study was to retrospectively characterize the location and extent of brain stem lesions in children with oral motor dysfunction. From January 2005 to August 2009, 43 infants hospitalized at our institution were included in the study because of a history of hypoxic-ischemic events. Of this group, 14 patients showed oral motor dysfunction and brain stem tegmental lesions detected at MR imaging. MR imaging showed hypoxic-ischemic lesions in supra- and infratentorial areas. Six of 14 patients revealed only infratentorial lesions. Focal symmetric lesions of the tegmental brain stem were always present. The lesions appeared hyperintense on T2-weighted images and hypointense on IR images. We found a strong association (P < .0001) between oral motor dysfunction and infratentorial lesions on MR imaging. Oral motor dysfunction was associated with brain stem tegmental lesions in posthypoxic-ischemic infants. The MR imaging examination should be directed to the brain stem, especially when a condition of prolonged gavage feeding is necessary in infants.

Does the regulation of local excitation-inhibition balance aid in recovery of functional connectivity? A computational account.

PubMed

Vattikonda, Anirudh; Surampudi, Bapi Raju; Banerjee, Arpan; Deco, Gustavo; Roy, Dipanjan

2016-08-01

Computational modeling of the spontaneous dynamics over the whole brain provides critical insight into the spatiotemporal organization of brain dynamics at multiple resolutions and their alteration to changes in brain structure (e.g. in diseased states, aging, across individuals). Recent experimental evidence further suggests that the adverse effect of lesions is visible on spontaneous dynamics characterized by changes in resting state functional connectivity and its graph theoretical properties (e.g. modularity). These changes originate from altered neural dynamics in individual brain areas that are otherwise poised towards a homeostatic equilibrium to maintain a stable excitatory and inhibitory activity. In this work, we employ a homeostatic inhibitory mechanism, balancing excitation and inhibition in the local brain areas of the entire cortex under neurological impairments like lesions to understand global functional recovery (across brain networks and individuals). Previous computational and empirical studies have demonstrated that the resting state functional connectivity varies primarily due to the location and specific topological characteristics of the lesion. We show that local homeostatic balance provides a functional recovery by re-establishing excitation-inhibition balance in all areas that are affected by lesion. We systematically compare the extent of recovery in the primary hub areas (e.g. default mode network (DMN), medial temporal lobe, medial prefrontal cortex) as well as other sensory areas like primary motor area, supplementary motor area, fronto-parietal and temporo-parietal networks. Our findings suggest that stability and richness similar to the normal brain dynamics at rest are achievable by re-establishment of balance. Copyright © 2016 Elsevier Inc. All rights reserved.

Comprehensive Analysis of Human Endogenous Retrovirus Group HERV-W Locus Transcription in Multiple Sclerosis Brain Lesions by High-Throughput Amplicon Sequencing

PubMed Central

Schmitt, Katja; Richter, Christin; Backes, Christina; Meese, Eckart; Ruprecht, Klemens

2013-01-01

Human endogenous retroviruses (HERVs) of the HERV-W group comprise hundreds of loci in the human genome. Deregulated HERV-W expression and HERV-W locus ERVWE1-encoded Syncytin-1 protein have been implicated in the pathogenesis of multiple sclerosis (MS). However, the actual transcription of HERV-W loci in the MS context has not been comprehensively analyzed. We investigated transcription of HERV-W in MS brain lesions and white matter brain tissue from healthy controls by employing next-generation amplicon sequencing of HERV-W env-specific reverse transcriptase (RT) PCR products, thus revealing transcribed HERV-W loci and the relative transcript levels of those loci. We identified more than 100 HERV-W loci that were transcribed in the human brain, with a limited number of loci being predominantly transcribed. Importantly, relative transcript levels of HERV-W loci were very similar between MS and healthy brain tissue samples, refuting deregulated transcription of HERV-W env in MS brain lesions, including the high-level-transcribed ERVWE1 locus encoding Syncytin-1. Quantitative RT-PCR likewise did not reveal differences in MS regarding HERV-W env general transcript or ERVWE1- and ERVWE2-specific transcript levels. However, we obtained evidence for interindividual differences in HERV-W transcript levels. Reporter gene assays indicated promoter activity of many HERV-W long terminal repeats (LTRs), including structurally incomplete LTRs. Our comprehensive analysis of HERV-W transcription in the human brain thus provides important information on the biology of HERV-W in MS lesions and normal human brain, implications for study design, and mechanisms by which HERV-W may (or may not) be involved in MS. PMID:24109235

Australian Cerebral Palsy Child Study: protocol of a prospective population based study of motor and brain development of preschool aged children with cerebral palsy.

PubMed

Boyd, Roslyn N; Jordan, Rachel; Pareezer, Laura; Moodie, Anne; Finn, Christine; Luther, Belinda; Arnfield, Evyn; Pym, Aaron; Craven, Alex; Beall, Paula; Weir, Kelly; Kentish, Megan; Wynter, Meredith; Ware, Robert; Fahey, Michael; Rawicki, Barry; McKinlay, Lynne; Guzzetta, Andrea

2013-06-11

Cerebral palsy (CP) results from a static brain lesion during pregnancy or early life and remains the most common cause of physical disability in children (1 in 500). While the brain lesion is static, the physical manifestations and medical issues may progress resulting in altered motor patterns. To date, there are no prospective longitudinal studies of CP that follow a birth cohort to track early gross and fine motor development and use Magnetic Resonance Imaging (MRI) to determine the anatomical pattern and likely timing of the brain lesion. Existing studies do not consider treatment costs and outcomes. This study aims to determine the pathway(s) to motor outcome from diagnosis at 18 months corrected age (c.a.) to outcome at 5 years in relation to the nature of the brain lesion (using structural MRI). This prospective cohort study aims to recruit a total of 240 children diagnosed with CP born in Victoria (birth years 2004 and 2005) and Queensland (birth years 2006-2009). Children can enter the study at any time between 18 months to 5 years of age and will be assessed at 18, 24, 30, 36, 48 and 60 months c.a. Outcomes include gross motor function (GMFM-66 & GMFM-88), Gross Motor Function Classification System (GMFCS); musculoskeletal development (hip displacement, spasticity, muscle contracture), upper limb function (Manual Ability Classification System), communication difficulties using Communication and Symbolic Behaviour Scales-Developmental Profile (CSBS-DP), participation using the Paediatric Evaluation of Disability Inventory (PEDI), parent reported quality of life and classification of medical and allied health resource use and determination of the aetiology of CP using clinical evaluation combined with MRI. The relationship between the pathways to motor outcome and the nature of the brain lesion will be analysed using multiple methods including non-linear modelling, multilevel mixed-effects models and generalised estimating equations. This protocol describes a large population-based study of early motor development and brain structure in a representative sample of preschool aged children with CP, using direct clinical assessment. The results of this study will be published in peer reviewed journals and presented at relevant international conferences. Australia and New Zealand Clinical Trials Register (ACTRN1261200169820).

Australian Cerebral Palsy Child Study: protocol of a prospective population based study of motor and brain development of preschool aged children with cerebral palsy

PubMed Central

2013-01-01

Background Cerebral palsy (CP) results from a static brain lesion during pregnancy or early life and remains the most common cause of physical disability in children (1 in 500). While the brain lesion is static, the physical manifestations and medical issues may progress resulting in altered motor patterns. To date, there are no prospective longitudinal studies of CP that follow a birth cohort to track early gross and fine motor development and use Magnetic Resonance Imaging (MRI) to determine the anatomical pattern and likely timing of the brain lesion. Existing studies do not consider treatment costs and outcomes. This study aims to determine the pathway(s) to motor outcome from diagnosis at 18 months corrected age (c.a.) to outcome at 5 years in relation to the nature of the brain lesion (using structural MRI). Methods This prospective cohort study aims to recruit a total of 240 children diagnosed with CP born in Victoria (birth years 2004 and 2005) and Queensland (birth years 2006–2009). Children can enter the study at any time between 18 months to 5 years of age and will be assessed at 18, 24, 30, 36, 48 and 60 months c.a. Outcomes include gross motor function (GMFM-66 & GMFM-88), Gross Motor Function Classification System (GMFCS); musculoskeletal development (hip displacement, spasticity, muscle contracture), upper limb function (Manual Ability Classification System), communication difficulties using Communication and Symbolic Behaviour Scales-Developmental Profile (CSBS-DP), participation using the Paediatric Evaluation of Disability Inventory (PEDI), parent reported quality of life and classification of medical and allied health resource use and determination of the aetiology of CP using clinical evaluation combined with MRI. The relationship between the pathways to motor outcome and the nature of the brain lesion will be analysed using multiple methods including non-linear modelling, multilevel mixed-effects models and generalised estimating equations. Discussion This protocol describes a large population-based study of early motor development and brain structure in a representative sample of preschool aged children with CP, using direct clinical assessment. The results of this study will be published in peer reviewed journals and presented at relevant international conferences. Trial registration Australia and New Zealand Clinical Trials Register (ACTRN1261200169820) PMID:23758951

Minimally Invasive Transsulcal Resection of Intraventricular and Periventricular Lesions Through a Tubular Retractor System: Multicentric Experience and Results.

PubMed

Eliyas, Javed Khader; Glynn, Ryan; Kulwin, Charles G; Rovin, Richard; Young, Ronald; Alzate, Juan; Pradilla, Gustavo; Shah, Mitesh V; Kassam, Amin; Ciric, Ivan; Bailes, Julian

2016-06-01

Conventional approaches to deep-seated cerebral lesions range from biopsy to transcortical or transcallosal resection. Although the former does not reduce tumor burden, the latter are more invasive and associated with greater potential for irreparable injury to normal brain. Disconnection syndrome, hemiparesis, hemianesthesia, or aphasia is not uncommon after such surgery, especially when lesion is large. By contrast, the transsulcal parafascicular approach uses naturally existing corridors and a tubular retractor to minimize brain injury. A retrospective review of patients undergoing minimally invasive transsulcal parafascicular resection of ventricular and periventricular lesions, across 5 independent centers, was conducted. Twenty patients with lesions located in the lateral ventricle (n = 9), the third ventricle (n = 6) and periventricular region (n = 4) are described in this report. Average age was 64 years (8 male/12 female). The average depth from cortical surface was 4.37 cm. A 13.5-mm-diameter tubular retractor (BrainPath [NICO Corporation, Indianapolis, Indiana, USA]) of differing lengths was used, aided by neuronavigation. Gross total resection was obtained in 17 patients. Pathologies included colloid cyst, subependymoma, glioma, meningioma, central neurocytoma, lymphoma, and metastasis. Three patients experienced transient morbidity: memory loss (2), hemiparesis (1). One patient died 3 months postoperatively as a result of unrelated pulmonary illness. Follow-up ranged from 6 to 27 months (average, 12 months). This technique is safe and effective for the treatment of intraventricular and periventricular lesions. Surgery-related morbidity is minimal and often transient. Lesions are satisfactorily resected and residuum occurs only when the neoplasm involves vital structures. The tubular retractor minimizes trauma to brain incident in the surgeon's path. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Random motor generation in a finger tapping task: influence of spatial contingency and of cortical and subcortical hemispheric brain lesions

PubMed Central

Annoni, J.; Pegna, A.

1997-01-01

OBJECTIVE—To test the hypothesis that, during random motor generation, the spatial contingencies inherent to the task would induce additional preferences in normal subjects, shifting their performances farther from randomness. By contrast, perceptual or executive dysfunction could alter these task related biases in patients with brain damage.
METHODS—Two groups of patients, with right and left focal brain lesions, as well as 25 right handed subjects matched for age and handedness were asked to execute a random choice motor task—namely, to generate a random series of 180 button presses from a set of 10 keys placed vertically in front of them.
RESULTS—In the control group, as in the left brain lesion group, motor generation was subject to deviations from theoretical expected randomness, similar to those when numbers are generated mentally, as immediate repetitions (successive presses on the same key) are avoided. However, the distribution of button presses was also contingent on the topographic disposition of the keys: the central keys were chosen more often than those placed at extreme positions. Small distances were favoured, particularly with the left hand. These patterns were influenced by implicit strategies and task related contingencies.
 By contrast, right brain lesion patients with frontal involvement tended to show a more square distribution of key presses—that is, the number of key presses tended to be more equally distributed. The strategies were also altered by brain lesions: the number of immediate repetitions was more frequent when the lesion involved the right frontal areas yielding a random generation nearer to expected theoretical randomness. The frequency of adjacent key presses was increased by right anterior and left posterior cortical as well as by right subcortical lesions, but decreased by left subcortical lesions.
CONCLUSIONS—Depending on the side of the lesion and the degree of cortical-subcortical involvement, the deficits take on a different aspect and direct repetions and adjacent key presses have different patterns of alterations. Motor random generation is therefore a complex task which seems to necessitate the participation of numerous cerebral structures, among which those situated in the right frontal, left posterior, and subcortical regions have a predominant role.

 PMID:9408109

Intranasally administered mesenchymal stem cells promote a regenerative niche for repair of neonatal ischemic brain injury.

PubMed

Donega, Vanessa; Nijboer, Cora H; van Tilborg, Geralda; Dijkhuizen, Rick M; Kavelaars, Annemieke; Heijnen, Cobi J

2014-11-01

Previous work from our group has shown that intranasal MSC-treatment decreases lesion volume and improves motor and cognitive behavior after hypoxic-ischemic (HI) brain damage in neonatal mice. Our aim was to determine the kinetics of MSC migration after intranasal administration, and the early effects of MSCs on neurogenic processes and gliosis at the lesion site. HI brain injury was induced in 9-day-old mice and MSCs were administered intranasally at 10days post-HI. The kinetics of MSC migration were investigated by immunofluorescence and MRI analysis. BDNF and NGF gene expression was determined by qPCR analysis following MSC co-culture with HI brain extract. Nestin, Doublecortin, NeuN, GFAP, Iba-1 and M1/M2 phenotypic expression was assessed over time. MRI and immunohistochemistry analyses showed that MSCs reach the lesion site already within 2h after intranasal administration. At 12h after administration the number of MSCs at the lesion site peaks and decreases significantly at 72h. The number of DCX(+) cells increased 1 to 3days after MSC administration in the SVZ. At the lesion, GFAP(+)/nestin(+) and DCX(+) expression increased 3 to 5days after MSC-treatment. The number of NeuN(+) cells increased within 5days, leading to a dramatic regeneration of the somatosensory cortex and hippocampus at 18days after intranasal MSC administration. Interestingly, MSCs expressed significantly more BDNF gene when exposed to HI brain extract in vitro. Furthermore, MSC-treatment resulted in the resolution of the glial scar surrounding the lesion, represented by a decrease in reactive astrocytes and microglia and polarization of microglia towards the M2 phenotype. In view of the current lack of therapeutic strategies, we propose that intranasal MSC administration is a powerful therapeutic option through its functional repair of the lesion represented by regeneration of the cortical and hippocampal structure and decrease of gliosis. Copyright © 2014. Published by Elsevier Inc.

Lesion network localization of criminal behavior

PubMed Central

Darby, R. Ryan; Horn, Andreas; Fox, Michael D.

2018-01-01

Following brain lesions, previously normal patients sometimes exhibit criminal behavior. Although rare, these cases can lend unique insight into the neurobiological substrate of criminality. Here we present a systematic mapping of lesions with known temporal association to criminal behavior, identifying 17 lesion cases. The lesion sites were spatially heterogeneous, including the medial prefrontal cortex, orbitofrontal cortex, and different locations within the bilateral temporal lobes. No single brain region was damaged in all cases. Because lesion-induced symptoms can come from sites connected to the lesion location and not just the lesion location itself, we also identified brain regions functionally connected to each lesion location. This technique, termed lesion network mapping, has recently identified regions involved in symptom generation across a variety of lesion-induced disorders. All lesions were functionally connected to the same network of brain regions. This criminality-associated connectivity pattern was unique compared with lesions causing four other neuropsychiatric syndromes. This network includes regions involved in morality, value-based decision making, and theory of mind, but not regions involved in cognitive control or empathy. Finally, we replicated our results in a separate cohort of 23 cases in which a temporal relationship between brain lesions and criminal behavior was implied but not definitive. Our results suggest that lesions in criminals occur in different brain locations but localize to a unique resting state network, providing insight into the neurobiology of criminal behavior. PMID:29255017

Expanded Endoscopic Endonasal Approaches to Skull Base Meningiomas

PubMed Central

Prosser, J. Drew; Vender, John R.; Alleyne, Cargill H.; Solares, C. Arturo

2012-01-01

Anterior cranial base meningiomas have traditionally been addressed via frontal or frontolateral approaches. However, with the advances in endoscopic endonasal treatment of pituitary lesions, the transphenoidal approach is being expanded to address lesions of the petrous ridge, anterior clinoid, clivus, sella, parasellar region, tuberculum, planum, olfactory groove, and crista galli regions. The expanded endoscopic endonasal approach (EEEA) has the advantage of limiting brain retraction and resultant brain edema, as well as minimizing manipulation of neural structures. Herein, we describe the techniques of transclival, transphenoidal, transplanum, and transcribiform resections of anterior skull base meningiomas. Selected cases are presented. PMID:23730542

A systematic review and meta-analysis of structural magnetic resonance imaging studies investigating cognitive and social activity levels in older adults.

PubMed

Anatürk, M; Demnitz, N; Ebmeier, K P; Sexton, C E

2018-06-22

Population aging has prompted considerable interest in identifying modifiable factors that may help protect the brain and its functions. Collectively, epidemiological studies show that leisure activities with high mental and social demands are linked with better cognition in old age. The extent to which socio-intellectual activities relate to the brain's structure is, however, not yet fully understood. This systematic review and meta-analysis summarizes magnetic resonance imaging studies that have investigated whether cognitive and social activities correlate with measures of gray and white matter volume, white matter microstructure and white matter lesions. Across eighteen included studies (total n = 8429), activity levels were associated with whole-brain white matter volume, white matter lesions and regional gray matter volume, although effect sizes were small. No associations were found for global gray matter volume and the evidence concerning white matter microstructure was inconclusive. While the causality of the reviewed associations needs to be established, our findings implicate socio-intellectual activity levels as promising targets for interventions aimed at promoting healthy brain aging. Copyright © 2018. Published by Elsevier Ltd.

An object-based approach for detecting small brain lesions: application to Virchow-Robin spaces.

PubMed

Descombes, Xavier; Kruggel, Frithjof; Wollny, Gert; Gertz, Hermann Josef

2004-02-01

This paper is concerned with the detection of multiple small brain lesions from magnetic resonance imaging (MRI) data. A model based on the marked point process framework is designed to detect Virchow-Robin spaces (VRSs). These tubular shaped spaces are due to retraction of the brain parenchyma from its supplying arteries. VRS are described by simple geometrical objects that are introduced as small tubular structures. Their radiometric properties are embedded in a data term. A prior model includes interactions describing the clustering property of VRS. A Reversible Jump Markov Chain Monte Carlo algorithm (RJMCMC) optimizes the proposed model, obtained by multiplying the prior and the data model. Example results are shown on T1-weighted MRI datasets of elderly subjects.

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.

Lesions causing freezing of gait localize to a cerebellar functional network

PubMed Central

Fasano, Alfonso; Laganiere, Simon E.; Lam, Susy; Fox, Michael D.

2016-01-01

Objective Freezing of gait is a disabling symptom in Parkinson’s disease and related disorders, but the brain regions involved in symptom generation remain unclear. Here we analyze brain lesions causing acute onset freezing of gait to identify regions causally involved in symptom generation. Methods Fourteen cases of lesion-induced freezing of gait were identified from the literature and lesions were mapped to a common brain atlas. Because lesion-induced symptoms can come from sites connected to the lesion location, not just the lesion location itself, we also identified brain regions functionally connected to each lesion location. This technique, termed lesion network mapping, has been recently shown to identify regions involved in symptom generation across a variety of lesion-induced disorders. Results Lesion location was heterogeneous and no single region could be considered necessary for symptom generation. However, over 90% (13/14) of lesions were functionally connected to a focal area in the dorsal medial cerebellum. This cerebellar area overlapped previously recognized regions that are activated by locomotor tasks, termed the cerebellar locomotor region. Connectivity to this region was specific to lesions causing freezing of gait compared to lesions causing other movement disorders (hemichorea or asterixis). Interpretation Lesions causing freezing of gait are located within a common functional network characterized by connectivity to the cerebellar locomotor region. These results based on causal brain lesions complement prior neuroimaging studies in Parkinson’s disease patients, advancing our understanding of the brain regions involved in freezing of gait. PMID:28009063

Diagnostic Value of 68Ga PSMA-11 PET/CT Imaging of Brain Tumors-Preliminary Analysis.

PubMed

Sasikumar, Arun; Joy, Ajith; Pillai, M R A; Nanabala, Raviteja; Anees K, Muhammed; Jayaprakash, P G; Madhavan, Jayaprakash; Nair, Suresh

2017-01-01

To evaluate the feasibility of using Ga PSMA-11 PET/CT for imaging brain lesions and its comparison with F-FDG. Ten patients with brain lesions were included in the study. Five patients were treated cases of glioblastoma with suspected recurrence. F-FDG and Ga PSMA-11 brain scans were done for these patients. Five patients were sent for assessing the nature (primary lesion/metastasis) of space occupying lesion in brain. They underwent whole body F-FDG PET/CT scan and a primary site elsewhere in the body was ruled out. Subsequently they underwent Ga PSMA-11 brain PET/CT imaging. Target to background ratios (TBR) for the brain lesions were calculated using contralateral cerebellar uptake as background. In five treated cases of glioblastoma with suspected recurrence the findings of Ga PSMA-11 PET/CT showed good correlation with that of F-FDG PET/CT scan. Compared to the F-FDG, Ga PSMA-11 PET/CT showed better visualization of the recurrent lesion (presence/absence) owing to its significantly high TBR. Among the five cases evaluated for lesion characterization glioma and atypical meningioma patients showed higher SUVmax in the lesion with Ga PSMA-11 than with F-FDG and converse in cases of lymphoma. TBR was better with Ga PSMA PET/CT in all cases. Ga PSMA-11 PET/CT brain imaging is a potentially useful imaging tool in the evaluation of brain lesions. Absence of physiological uptake of Ga PSMA-11 in the normal brain parenchyma results in high TBR values and consequently better visualization of metabolically active disease in brain.

Gender effects on age-related changes in brain structure.

PubMed

Xu, J; Kobayashi, S; Yamaguchi, S; Iijima, K; Okada, K; Yamashita, K

2000-01-01

Previous reports have suggested that brain atrophy is associated with aging and that there are gender differences in brain atrophy with aging. These reports, however, neither exclude silent brain lesions in "healthy subjects" nor divide the brain into subregions. The aim of this study is to clarify the effect of gender on age-related changes in brain subregions by MR imaging. A computer-assisted system was used to calculate the brain matter area index (BMAI) of various regions of the brain from MR imaging of 331 subjects without brain lesions. There was significantly more brain atrophy with aging in the posterior parts of the right frontal lobe in male subjects than there was in female subjects. Age-related atrophy in the middle part of the right temporal lobe, the left basal ganglia, the parietal lobe, and the cerebellum also was found in male subjects, but not in female subjects. In the temporal lobe, thalamus, parieto-occipital lobe, and cerebellum, brain volume in the left hemisphere is significantly smaller than in the right hemisphere; sex and age did not affect the hemisphere differences of brain volume in these regions. The effect of gender on brain atrophy with aging varied in different subregions of the brain. There was more brain atrophy with aging in male subjects than in female subjects.

Dynamical Signatures of Structural Connectivity Damage to a Model of the Brain Posed at Criticality.

PubMed

Haimovici, Ariel; Balenzuela, Pablo; Tagliazucchi, Enzo

2016-12-01

Synchronization of brain activity fluctuations is believed to represent communication between spatially distant neural processes. These interareal functional interactions develop in the background of a complex network of axonal connections linking cortical and subcortical neurons, termed the human "structural connectome." Theoretical considerations and experimental evidence support the view that the human brain can be modeled as a system operating at a critical point between ordered (subcritical) and disordered (supercritical) phases. Here, we explore the hypothesis that pathologies resulting from brain injury of different etiologies are related to this model of a critical brain. For this purpose, we investigate how damage to the integrity of the structural connectome impacts on the signatures of critical dynamics. Adopting a hybrid modeling approach combining an empirical weighted network of human structural connections with a conceptual model of critical dynamics, we show that lesions located at highly transited connections progressively displace the model toward the subcritical regime. The topological properties of the nodes and links are of less importance when considered independently of their weight in the network. We observe that damage to midline hubs such as the middle and posterior cingulate cortex is most crucial for the disruption of criticality in the model. However, a similar effect can be achieved by targeting less transited nodes and links whose connection weights add up to an equivalent amount. This implies that brain pathology does not necessarily arise due to insult targeted at well-connected areas and that intersubject variability could obscure lesions located at nonhub regions. Finally, we discuss the predictions of our model in the context of clinical studies of traumatic brain injury and neurodegenerative disorders.

Studying variability in human brain aging in a population-based German cohort-rationale and design of 1000BRAINS.

PubMed

Caspers, Svenja; Moebus, Susanne; Lux, Silke; Pundt, Noreen; Schütz, Holger; Mühleisen, Thomas W; Gras, Vincent; Eickhoff, Simon B; Romanzetti, Sandro; Stöcker, Tony; Stirnberg, Rüdiger; Kirlangic, Mehmet E; Minnerop, Martina; Pieperhoff, Peter; Mödder, Ulrich; Das, Samir; Evans, Alan C; Jöckel, Karl-Heinz; Erbel, Raimund; Cichon, Sven; Nöthen, Markus M; Sturma, Dieter; Bauer, Andreas; Jon Shah, N; Zilles, Karl; Amunts, Katrin

2014-01-01

The ongoing 1000 brains study (1000BRAINS) is an epidemiological and neuroscientific investigation of structural and functional variability in the human brain during aging. The two recruitment sources are the 10-year follow-up cohort of the German Heinz Nixdorf Recall (HNR) Study, and the HNR MultiGeneration Study cohort, which comprises spouses and offspring of HNR subjects. The HNR is a longitudinal epidemiological investigation of cardiovascular risk factors, with a comprehensive collection of clinical, laboratory, socioeconomic, and environmental data from population-based subjects aged 45-75 years on inclusion. HNR subjects underwent detailed assessments in 2000, 2006, and 2011, and completed annual postal questionnaires on health status. 1000BRAINS accesses these HNR data and applies a separate protocol comprising: neuropsychological tests of attention, memory, executive functions and language; examination of motor skills; ratings of personality, life quality, mood and daily activities; analysis of laboratory and genetic data; and state-of-the-art magnetic resonance imaging (MRI, 3 Tesla) of the brain. The latter includes (i) 3D-T1- and 3D-T2-weighted scans for structural analyses and myelin mapping; (ii) three diffusion imaging sequences optimized for diffusion tensor imaging, high-angular resolution diffusion imaging for detailed fiber tracking and for diffusion kurtosis imaging; (iii) resting-state and task-based functional MRI; and (iv) fluid-attenuated inversion recovery and MR angiography for the detection of vascular lesions and the mapping of white matter lesions. The unique design of 1000BRAINS allows: (i) comprehensive investigation of various influences including genetics, environment and health status on variability in brain structure and function during aging; and (ii) identification of the impact of selected influencing factors on specific cognitive subsystems and their anatomical correlates.

Computed microtomography visualization and quantification of mouse ischemic brain lesion by nonionic radio contrast agents

PubMed Central

Dobrivojević, Marina; Bohaček, Ivan; Erjavec, Igor; Gorup, Dunja; Gajović, Srećko

2013-01-01

Aim To explore the possibility of brain imaging by microcomputed tomography (microCT) using x-ray contrasting methods to visualize mouse brain ischemic lesions after middle cerebral artery occlusion (MCAO). Methods Isolated brains were immersed in ionic or nonionic radio contrast agent (RCA) for 5 days and subsequently scanned using microCT scanner. To verify whether ex-vivo microCT brain images can be used to characterize ischemic lesions, they were compared to Nissl stained serial histological sections of the same brains. To verify if brains immersed in RCA may be used afterwards for other methods, subsequent immunofluorescent labeling with anti-NeuN was performed. Results Nonionic RCA showed better gray to white matter contrast in the brain, and therefore was selected for further studies. MicroCT measurement of ischemic lesion size and cerebral edema significantly correlated with the values determined by Nissl staining (ischemic lesion size: P=0.0005; cerebral edema: P=0.0002). Brain immersion in nonionic RCA did not affect subsequent immunofluorescent analysis and NeuN immunoreactivity. Conclusion MicroCT method was proven to be suitable for delineation of the ischemic lesion from the non-infarcted tissue, and quantification of lesion volume and cerebral edema. PMID:23444240

Computed microtomography visualization and quantification of mouse ischemic brain lesion by nonionic radio contrast agents.

PubMed

Dobrivojević, Marina; Bohaček, Ivan; Erjavec, Igor; Gorup, Dunja; Gajović, Srećko

2013-02-01

To explore the possibility of brain imaging by microcomputed tomography (microCT) using x-ray contrasting methods to visualize mouse brain ischemic lesions after middle cerebral artery occlusion (MCAO). Isolated brains were immersed in ionic or nonionic radio contrast agent (RCA) for 5 days and subsequently scanned using microCT scanner. To verify whether ex-vivo microCT brain images can be used to characterize ischemic lesions, they were compared to Nissl stained serial histological sections of the same brains. To verify if brains immersed in RCA may be used afterwards for other methods, subsequent immunofluorescent labeling with anti-NeuN was performed. Nonionic RCA showed better gray to white matter contrast in the brain, and therefore was selected for further studies. MicroCT measurement of ischemic lesion size and cerebral edema significantly correlated with the values determined by Nissl staining (ischemic lesion size: P=0.0005; cerebral edema: P=0.0002). Brain immersion in nonionic RCA did not affect subsequent immunofluorescent analysis and NeuN immunoreactivity. MicroCT method was proven to be suitable for delineation of the ischemic lesion from the non-infarcted tissue, and quantification of lesion volume and cerebral edema.

High frequency of silent brain infarcts associated with cognitive deficits in an economically disadvantaged population.

PubMed

Squarzoni, Paula; Tamashiro-Duran, Jaqueline H; Duran, Fabio L S; Leite, Claudia C; Wajngarten, Mauricio; Scazufca, Marcia; Menezes, Paulo R; Lotufo, Paulo A; Alves, Tania C T F; Busatto, Geraldo F

2017-08-01

Using magnetic resonance imaging, we aimed to assess the presence of silent brain vascular lesions in a sample of apparently healthy elderly individuals who were recruited from an economically disadvantaged urban region (São Paulo, Brazil). We also wished to investigate whether the findings were associated with worse cognitive performance. A sample of 250 elderly subjects (66-75 years) without dementia or neuropsychiatric disorders were recruited from predefined census sectors of an economically disadvantaged area of Sao Paulo and received structural magnetic resonance imaging scans and cognitive testing. A high proportion of individuals had very low levels of education (4 years or less, n=185; 21 with no formal education). The prevalence of at least one silent vascular-related cortical or subcortical lesion was 22.8% (95% confidence interval, 17.7-28.5), and the basal ganglia was the most frequently affected site (63.14% of cases). The subgroup with brain infarcts presented significantly lower levels of education than the subgroup with no brain lesions as well as significantly worse current performance in cognitive test domains, including memory and attention (p<0.002). Silent brain infarcts were present at a substantially high frequency in our elderly sample from an economically disadvantaged urban region and were significantly more prevalent in subjects with lower levels of education. Covert cerebrovascular disease significantly contributes to cognitive deficits, and in the absence of magnetic resonance imaging data, this cognitive impairment may be considered simply related to ageing. Emphatic attention should be paid to potentially deleterious effects of vascular brain lesions in poorly educated elderly individuals from economically disadvantaged environments.

Decreased integration and information capacity in stroke measured by whole brain models of resting state activity.

PubMed

Adhikari, Mohit H; Hacker, Carl D; Siegel, Josh S; Griffa, Alessandra; Hagmann, Patric; Deco, Gustavo; Corbetta, Maurizio

2017-04-01

While several studies have shown that focal lesions affect the communication between structurally normal regions of the brain, and that these changes may correlate with behavioural deficits, their impact on brain's information processing capacity is currently unknown. Here we test the hypothesis that focal lesions decrease the brain's information processing capacity, of which changes in functional connectivity may be a measurable correlate. To measure processing capacity, we turned to whole brain computational modelling to estimate the integration and segregation of information in brain networks. First, we measured functional connectivity between different brain areas with resting state functional magnetic resonance imaging in healthy subjects (n = 26), and subjects who had suffered a cortical stroke (n = 36). We then used a whole-brain network model that coupled average excitatory activities of local regions via anatomical connectivity. Model parameters were optimized in each healthy or stroke participant to maximize correlation between model and empirical functional connectivity, so that the model's effective connectivity was a veridical representation of healthy or lesioned brain networks. Subsequently, we calculated two model-based measures: 'integration', a graph theoretical measure obtained from functional connectivity, which measures the connectedness of brain networks, and 'information capacity', an information theoretical measure that cannot be obtained empirically, representative of the segregative ability of brain networks to encode distinct stimuli. We found that both measures were decreased in stroke patients, as compared to healthy controls, particularly at the level of resting-state networks. Furthermore, we found that these measures, especially information capacity, correlate with measures of behavioural impairment and the segregation of resting-state networks empirically measured. This study shows that focal lesions affect the brain's ability to represent stimuli and task states, and that information capacity measured through whole brain models is a theory-driven measure of processing capacity that could be used as a biomarker of injury for outcome prediction or target for rehabilitation intervention. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Causal functional contributions and interactions in the attention network of the brain: an objective multi-perturbation analysis.

PubMed

Zavaglia, Melissa; Hilgetag, Claus C

2016-06-01

Spatial attention is a prime example for the distributed network functions of the brain. Lesion studies in animal models have been used to investigate intact attentional mechanisms as well as perspectives for rehabilitation in the injured brain. Here, we systematically analyzed behavioral data from cooling deactivation and permanent lesion experiments in the cat, where unilateral deactivation of the posterior parietal cortex (in the vicinity of the posterior middle suprasylvian cortex, pMS) or the superior colliculus (SC) cause a severe neglect in the contralateral hemifield. Counterintuitively, additional deactivation of structures in the opposite hemisphere reverses the deficit. Using such lesion data, we employed a game-theoretical approach, multi-perturbation Shapley value analysis (MSA), for inferring functional contributions and network interactions of bilateral pMS and SC from behavioral performance in visual attention studies. The approach provides an objective theoretical strategy for lesion inferences and allows a unique quantitative characterization of regional functional contributions and interactions on the basis of multi-perturbations. The quantitative analysis demonstrated that right posterior parietal cortex and superior colliculus made the strongest positive contributions to left-field orienting, while left brain regions had negative contributions, implying that their perturbation may reverse the effects of contralateral lesions or improve normal function. An analysis of functional modulations and interactions among the regions revealed redundant interactions (implying functional overlap) between regions within each hemisphere, and synergistic interactions between bilateral regions. To assess the reliability of the MSA method in the face of variable and incomplete input data, we performed a sensitivity analysis, investigating how much the contribution values of the four regions depended on the performance of specific configurations and on the prediction of unknown performances. The results suggest that the MSA approach is sensitive to categorical, but insensitive to gradual changes in the input data. Finally, we created a basic network model that was based on the known anatomical interactions among cortical-tectal regions and reproduced the experimentally observed behavior in visual orienting. We discuss the structural organization of the network model relative to the causal modulations identified by MSA, to aid a mechanistic understanding of the attention network of the brain.

Limitations on the Developing Preterm Brain: Impact of Periventricular White Matter Lesions on Brain Connectivity and Cognition

ERIC Educational Resources Information Center

Pavlova, Marina A.; Krageloh-Mann, Ingeborg

2013-01-01

Brain lesions to the white matter in peritrigonal regions, periventricular leukomalacia, in children who were born prematurely represent an important model for studying limitations on brain development. The lesional pattern is of early origin and bilateral, that constrains the compensatory potential of the brain. We suggest that (i) topography and…

Cohort Study of Multiple Brain Lesions in Sport Divers: Role of a Patent Foramen Ovale

NASA Technical Reports Server (NTRS)

Knauth, Michael; Ries, Stefan; Pohimann, Stefan; Kerby, Tina; Forstring, Michael; Daffertshofer, Michael; Hennerici,Michael; Sartor, Klaus

1997-01-01

To investigate the role of a patent foramen ovale in the pathogenesis of multiple brain lesions acquired by sport divers in the absence of reported decompression symptoms. Design: Prospective double blind cohort study. . Setting Diving clubs around Heidelberg and departments of neuroradiology and neurology. Subjects: 87 sport divers with a minimum of 160 scuba dives (dives with self contained underwater breathing apparatus). Main outcome measures: Presence of multiple brain lesions visualised by cranial magnetic resonance imaging and presence and size of patent foramen ovale as documented by echocontrast transcranial Doppler ultrasonograhy. Results: 25 subjects were found to have a right-to-left shunt, 13 with a patent foramen ovale of high haemodynamic relevance. A total of 41 brain lesions were detected in 11 divers. There were seven brain lesions in seven divers without a right-to-left shunt and 34 lesions in four divers with a right-to-left shunt Multiple brain lesions occurred exclusively in three divers with a large patent foramen ovale (P=0.004). Conclusions: Multiple brain lesions in sport divers were associated with presence of a large patent foramen ovale. This association suggests paradoxical gas embolism as the pathological mechanism. A patent foramen ovale of high haemodynamic relevance seems to be an important risk factor for developing multiple brain lesions in sport divers.

CB2 cannabinoid receptors modulate HIF-1α and TIM-3 expression in a hypoxia-ischemia mouse model.

PubMed

Kossatz, Elk; Maldonado, Rafael; Robledo, Patricia

2016-12-01

The role of CB2 cannabinoid receptors (CB 2 R) in global brain lesions induced by hypoxia-ischemia (HI) insult is still unresolved. The aim of this study was to evaluate the involvement of CB 2 R in the behavioural and biochemical underpinnings related to brain damage induced by HI in adult mice, and the mechanisms involved. CB 2 R knockout (KO) mice and wild-type littermates (WT) underwent permanent ligation of the left common carotid artery and hypoxia. Behavioural measurements in the rotarod, beam walking, object recognition, open field, and Irwin tests were carried out 24h, 72h and 7 days. In KO mice, more extensive brain injury was observed. Behavioural deficits in the Irwin test were observed in both genotypes; while WT mice showed progressive recovery by day 7, KO mice did not. Only KO mice showed alterations in motor learning, coordination and balance, and did not recover over time. A higher expression of microglia and astrocytes was observed in several brain areas of lesioned WT and KO mice. The possible alteration of the inflammatory-related factors HIF-1α and TIM-3 was evaluated in these animals. In both genotypes, HIF-1α and TIM-3 expression was observed in lesioned areas associated with activated microglia. However, the expression levels of these proteins were exacerbated in KO mice in several lesioned and non-lesioned brain structures. Our results indicate that CB 2 R may have a crucial neuroprotective role following HI insult through the modulation of the inflammatory-related HIF-1α/TIM-3 signalling pathway in microglia. Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.

Effects of brain lesions on moral agency: ethical dilemmas in investigating moral behavior.

PubMed

Christen, Markus; Müller, Sabine

2015-01-01

Understanding how the "brain produces behavior" is a guiding idea in neuroscience. It is thus of no surprise that establishing an interrelation between brain pathology and antisocial behavior has a long history in brain research. However, interrelating the brain with moral agency--the ability to act in reference to right and wrong--is tricky with respect to therapy and rehabilitation of patients affected by brain lesions. In this contribution, we outline the complexity of the relationship between the brain and moral behavior, and we discuss ethical issues of the neuroscience of ethics and of its clinical consequences. First, we introduce a theory of moral agency and apply it to the issue of behavioral changes caused by brain lesions. Second, we present a typology of brain lesions both with respect to their cause, their temporal development, and the potential for neural plasticity allowing for rehabilitation. We exemplify this scheme with case studies and outline major knowledge gaps that are relevant for clinical practice. Third, we analyze ethical pitfalls when trying to understand the brain-morality relation. In this way, our contribution addresses both researchers in neuroscience of ethics and clinicians who treat patients affected by brain lesions to better understand the complex ethical questions, which are raised by research and therapy of brain lesion patients.

Application of a data-mining method based on Bayesian networks to lesion-deficit analysis

NASA Technical Reports Server (NTRS)

Herskovits, Edward H.; Gerring, Joan P.

2003-01-01

Although lesion-deficit analysis (LDA) has provided extensive information about structure-function associations in the human brain, LDA has suffered from the difficulties inherent to the analysis of spatial data, i.e., there are many more variables than subjects, and data may be difficult to model using standard distributions, such as the normal distribution. We herein describe a Bayesian method for LDA; this method is based on data-mining techniques that employ Bayesian networks to represent structure-function associations. These methods are computationally tractable, and can represent complex, nonlinear structure-function associations. When applied to the evaluation of data obtained from a study of the psychiatric sequelae of traumatic brain injury in children, this method generates a Bayesian network that demonstrates complex, nonlinear associations among lesions in the left caudate, right globus pallidus, right side of the corpus callosum, right caudate, and left thalamus, and subsequent development of attention-deficit hyperactivity disorder, confirming and extending our previous statistical analysis of these data. Furthermore, analysis of simulated data indicates that methods based on Bayesian networks may be more sensitive and specific for detecting associations among categorical variables than methods based on chi-square and Fisher exact statistics.

Isolated brain stem lesion in children: is it acute disseminated encephalomyelitis or not?

PubMed

Alper, G; Sreedher, G; Zuccoli, G

2013-01-01

Isolated brain stem lesions presenting with acute neurologic findings create a major diagnostic dilemma in children. Although the brain stem is frequently involved in ADEM, solitary brain stem lesions are unusual. We performed a retrospective review in 6 children who presented with an inflammatory lesion confined to the brain stem. Two children were diagnosed with connective tissue disorder, CNS lupus, and localized scleroderma. The etiology could not be determined in 1, and clinical features suggested monophasic demyelination in 3. In these 3 children, initial lesions demonstrated vasogenic edema; all showed dramatic response to high-dose corticosteroids and made a full clinical recovery. Follow-up MRI showed complete resolution of lesions, and none had relapses at >2 years of follow-up. In retrospect, these cases are best regarded as a localized form of ADEM. We conclude that though ADEM is typically a disseminated disease with multifocal lesions, it rarely presents with monofocal demyelination confined to the brain stem.

Air pollution, cognitive deficits and brain abnormalities: a pilot study with children and dogs.

PubMed

Calderón-Garcidueñas, Lilian; Mora-Tiscareño, Antonieta; Ontiveros, Esperanza; Gómez-Garza, Gilberto; Barragán-Mejía, Gerardo; Broadway, James; Chapman, Susan; Valencia-Salazar, Gildardo; Jewells, Valerie; Maronpot, Robert R; Henríquez-Roldán, Carlos; Pérez-Guillé, Beatriz; Torres-Jardón, Ricardo; Herrit, Lou; Brooks, Diane; Osnaya-Brizuela, Norma; Monroy, Maria E; González-Maciel, Angelica; Reynoso-Robles, Rafael; Villarreal-Calderon, Rafael; Solt, Anna C; Engle, Randall W

2008-11-01

Exposure to air pollution is associated with neuroinflammation in healthy children and dogs in Mexico City. Comparative studies were carried out in healthy children and young dogs similarly exposed to ambient pollution in Mexico City. Children from Mexico City (n: 55) and a low polluted city (n:18) underwent psychometric testing and brain magnetic resonance imaging MRI. Seven healthy young dogs with similar exposure to Mexico City air pollution had brain MRI, measurement of mRNA abundance of two inflammatory genes cyclooxygenase-2, and interleukin 1 beta in target brain areas, and histopathological evaluation of brain tissue. Children with no known risk factors for neurological or cognitive disorders residing in a polluted urban environment exhibited significant deficits in a combination of fluid and crystallized cognition tasks. Fifty-six percent of Mexico City children tested showed prefrontal white matter hyperintense lesions and similar lesions were observed in dogs (57%). Exposed dogs had frontal lesions with vascular subcortical pathology associated with neuroinflammation, enlarged Virchow-Robin spaces, gliosis, and ultrafine particulate matter deposition. Based on the MRI findings, the prefrontal cortex was a target anatomical region in Mexico City children and its damage could have contributed to their cognitive dysfunction. The present work presents a groundbreaking, interdisciplinary methodology for addressing relationships between environmental pollution, structural brain alterations by MRI, and cognitive deficits/delays in healthy children.

Cholinergic modulation of event-related oscillations (ERO)

PubMed Central

Sanchez-Alavez, Manuel; Robledo, Patricia; Wills, Derek N.; Havstad, James; Ehlers, Cindy L.

2014-01-01

The cholinergic system in the brain modulates patterns of activity involved in general arousal, attention processing, memory and consciousness. In the present study we determined the effects of selective cholinergic lesions of the medial septum area (MS) or nucleus basalis magnocellularis (NBM) on amplitude and phase characteristics of event related oscillations (EROs). A time–frequency based representation was used to determine ERO energy, phase synchronization across trials, recorded within a structure (phase lock index, PLI), and phase synchronization across trials, recorded between brain structures (phase difference lock index, PDLI), in the frontal cortex (Fctx), dorsal hippocampus (DHPC) and central amygdala (Amyg). Lesions in MS produced: (1) decreases in ERO energy in delta, theta, alpha, beta and gamma frequencies in Amyg, (2) reductions in gamma ERO energy and PLI in Fctx, (3) decreases in PDLI between the Fctx–Amyg in the theta, alpha, beta and gamma frequencies, and (4) decreases in PDLI between the DHPC–Amyg and Fctx–DHPC in the theta frequency bands. Lesions in NBM resulted in: (1) increased ERO energy in delta and theta frequency bands in Fctx, (2) reduced gamma ERO energy in Fctx and Amyg, (3) reductions in PLI in the theta, beta and gamma frequency ranges in Fctx, (4) reductions in gamma PLI in DHPC and (5) reduced beta PLI in Amyg. These studies suggest that the MS cholinergic system can alter phase synchronization between brain areas whereas the NBM cholinergic system modifies phase synchronization/phase resetting within a brain area. PMID:24594019

Origins of serotonin innervation of forebrain structures

NASA Technical Reports Server (NTRS)

Kellar, K. J.; Brown, P. A.; Madrid, J.; Bernstein, M.; Vernikos-Danellis, J.; Mehler, W. R.

1977-01-01

The tryptophan hydroxylase activity and high-affinity uptake of (3H) serotonin ((3H)5-HT) were measured in five discrete brain regions of rats following lesions of the dorsal or median raphe nuclei. Dorsal raphe lesions reduced enzyme and uptake activity in the striatum only. Median raphe lesions reduced activities in the hippocampus, septal area, frontal cortex, and, to a lesser extent, in the hypothalamus. These data are consistent with the suggestion that the dorsal and median raphe nuclei are the origins of two separate ascending serotonergic systems - one innervating striatal structures and the other mesolimbic structures, predominantly. In addition, the data suggest that measurements of high-affinity uptake of (3H)5-HT may be a more reliable index of innervation than either 5-HT content or tryptophan hydroxylase activity.

Relationship between somatosensory deficit and brain somatosensory system after early brain lesion: A morphometric study.

PubMed

Perivier, Maximilien; Delion, Matthieu; Chinier, Eva; Loustau, Sebastien; Nguyen, Sylvie; Ter Minassian, Aram; Richard, Isabelle; Dinomais, Mickael

2016-05-01

Cerebral Palsy (CP) is a group of permanent motor disorders due to non-progressive damage to the developing brain. Poor tactile discrimination is common in children with unilateral CP. Previous findings suggest the crucial role of structural integrity of the primary (S1) and secondary (S2) somatosensory areas located in the ipsilesional hemisphere for somatosensory function processing. However, no focus on the relationship between structural characteristics of ipsilesional S1 and S2 and tactile discrimination function in paretic hands has been proposed. Using structural MRI and a two-point discrimination assessment (2 PD), we explore this potential link in a group of 21 children (mean age 13 years and 7 months) with unilateral CP secondary to a periventricular white matter injury (PWMI) or middle cerebral artery infarct (MCA). For our whole sample there was a significant negative correlation between the 2 PD and the gray matter volume in the ipsilesional S2 (rho = -0.50 95% confidence interval [-0.76, -0.08], one-tailed p-value = 0.0109) and in the ipsilesional S1 (rho = -0.57, 95% confidence interval [-0.81, -0.19], one-tailed p-value = 0.0032). When studying these relationships with regard to the lesion types, we found these correlations were non-significant in the patients with PWMI but stronger in patients with MCA. According to our results, the degree of sensory impairment is related to the spared gray matter volume in ipsilesional S1 and S2 and is marked after an MCA stroke. Our work contributes to a better understanding of why some patients with CP have variable somatosensory deficit following an early brain lesion. Copyright © 2015 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

Sudden Onset of Brain Metastasis despite the Use of Vemurafenib for Another Metastatic Lesion in Malignant Melanoma Patients.

PubMed

Imafuku, Keisuke; Yoshino, Koji; Yamaguchi, Kei; Tsuboi, Satoshi; Ohara, Kuniaki; Hata, Hiroo

2017-01-01

Vemurafenib is an inhibitor of the BRAF mutation and has been approved by the Food and Drug Administration as a treatment option for patients with unresectable melanoma without brain metastasis. In the literature, vemurafenib has been reported to be also effective against brain metastasis. We encountered 3 cases with brain metastasis on vemurafenib therapy. In these cases, vemurafenib was clinically effective against metastatic lesions other than those in the brain. The brain lesions developed after the metastatic lesion had occurred. Therefore, we assume that the melanomas of the patients acquired resistance against vemurafenib. The brain metastases were treated with the cyberknife. Patients 1 and 2 without LDH elevation are still alive, but patient 3 with abnormal LDH elevation died despite the treatment. We need to carefully follow patients on vemurafenib therapy because brain metastasis can suddenly occur even if the metastatic lesion has decreased clinically. The therapeutic effect of vemurafenib against brain metastasis is poor in cases with LDH elevation.

The structural basis of moderate disability after traumatic brain damage

PubMed Central

Adams, J; Graham, D; Jennett, B

2001-01-01

The objective was to discover the nature of brain damage in survivors of head injury who are left with moderate disability. Macroscopic and microscopic examination was carried out on the brains of 20 persons who had died long after a head injury that had been treated in a neurosurgical unit. All had become independent but had various disabilities (moderate disability on the Glasgow outcome scale) Most deaths had been sudden, which had led to their referral from forensic pathologists. Post-traumatic epilepsy was a feature in 75%. An intracranial haematoma had been evacuated in 75%, and in 11 of the 15 with epilepsy. Diffuse axonal injury was found in six patients, five of the mildest type (grade 1) and one of grade 2. No patient had diffuse thalamic damage but one had a small focal ischaemic lesion in the thalamus. No patient had severe ischaemic brain damage, but three had moderate lesions which were bilateral in only one. No patient had severe cortical contusions. In conclusion, the dominant lesion was focal damage from an evacuated intracranial haematoma. Severe diffuse damage was not found, with diffuse axonal injury only mild and thalamic damage in only one patient.

 PMID:11561038

Visual navigation in adolescents with early periventricular lesions: knowing where, but not getting there.

PubMed

Pavlova, Marina; Sokolov, Alexander; Krägeloh-Mann, Ingeborg

2007-02-01

Visual navigation in familiar and unfamiliar surroundings is an essential ingredient of adaptive daily life behavior. Recent brain imaging work helps to recognize that establishing connectivity between brain regions is of importance for successful navigation. Here, we ask whether the ability to navigate is impaired in adolescents who were born premature and suffer congenital bilateral periventricular brain damage that might affect the pathways interconnecting subcortical structures with cortex. Performance on a set of visual labyrinth tasks was significantly worse in patients with periventricular leukomalacia (PVL) as compared with premature-born controls without lesions and term-born adolescents. The ability for visual navigation inversely relates to the severity of motor disability, leg-dominated bilateral spastic cerebral palsy. This agrees with the view that navigation ability substantially improves with practice and might be compromised in individuals with restrictions in active spatial exploration. Visual navigation is negatively linked to the volumetric extent of lesions over the right parietal and frontal periventricular regions. Whereas impairments of visual processing of point-light biological motion are associated in patients with PVL with bilateral parietal periventricular lesions, navigation ability is specifically linked to the frontal lesions in the right hemisphere. We suggest that more anterior periventricular lesions impair the interrelations between the right hippocampus and cortical areas leading to disintegration of neural networks engaged in visual navigation. For the first time, we show that the severity of right frontal periventricular damage and leg-dominated motor disorders can serve as independent predictors of the visual navigation disability.

Added value of high-b-value (b = 3000 s/mm2) diffusion-weighted imaging at 3 T in relation to fluid-attenuated inversion recovery images for the evaluation of cortical lesions in inflammatory brain diseases.

PubMed

Iwashita, Koya; Hirai, Toshinori; Kitajima, Mika; Shigematsu, Yoshinori; Uetani, Hiroyuki; Iryo, Yasuhiko; Azuma, Minako; Hayashida, Eri; Ando, Yukio; Murakami, Ryuji; Yamashita, Yasuyuki

2013-01-01

The purpose of this study was to determine how the gray-to-white matter contrast in healthy subjects changes on high-b-value diffusion-weighted imaging (DWI) acquired at 3 T and evaluate whether high-b-value DWI at 3 T is useful for the detection of cortical lesions in inflammatory brain diseases. Ten healthy volunteers underwent DWI at b = 1000, 2000, 3000, 4000, and 5000 s/mm(2) on a 3-T MRI unit. On DW images, 1 radiologist performed region-of-interest measurements of the signal intensity of 8 gray matter structures. The gray-to-white matter contrast ratio (GWCR) was calculated. Ten patients with inflammatory cortical lesions were also included. All patients underwent conventional MRI and DWI at b = 1000 and 3000 s/mm(2). Using a 4-point grading system, 2 radiologists independently assessed the presence of additional information on DW images compared with fluid-attenuated inversion recovery images. Interobserver agreement was assessed by κ statistics. In the healthy subjects, the b value increased as the GWCR decreased in all evaluated gray matter structures. On DW images acquired at b = 3000 s/mm(2), mean GWCR was less than 1.0 in 7 of 8 structures. For both reviewers, DWI at b = 3000 s/mm(2) yielded significantly more additional information than did DWI at b = 1000 s/mm(2) (P < 0.05). Interobserver agreement for DWI at b = 1000 s/mm(2) and b = 3000 s/mm(2) was fair (κ = 0.35) and excellent (κ = 1.0), respectively. At 3-T DWI, the gray-to-white matter contrast in most gray matter structures reverses at b = 3000 s/mm. In the evaluation of cortical lesions in patients with inflammatory brain diseases, 3-T DWI at b = 3000 s/mm was more useful than b = 1000 s/mm(2).

Network localization of neurological symptoms from focal brain lesions

PubMed Central

Prasad, Sashank; Liu, Hesheng; Liu, Qi; Pascual-Leone, Alvaro; Caviness, Verne S.; Fox, Michael D.

2015-01-01

A traditional and widely used approach for linking neurological symptoms to specific brain regions involves identifying overlap in lesion location across patients with similar symptoms, termed lesion mapping. This approach is powerful and broadly applicable, but has limitations when symptoms do not localize to a single region or stem from dysfunction in regions connected to the lesion site rather than the site itself. A newer approach sensitive to such network effects involves functional neuroimaging of patients, but this requires specialized brain scans beyond routine clinical data, making it less versatile and difficult to apply when symptoms are rare or transient. In this article we show that the traditional approach to lesion mapping can be expanded to incorporate network effects into symptom localization without the need for specialized neuroimaging of patients. Our approach involves three steps: (i) transferring the three-dimensional volume of a brain lesion onto a reference brain; (ii) assessing the intrinsic functional connectivity of the lesion volume with the rest of the brain using normative connectome data; and (iii) overlapping lesion-associated networks to identify regions common to a clinical syndrome. We first tested our approach in peduncular hallucinosis, a syndrome of visual hallucinations following subcortical lesions long hypothesized to be due to network effects on extrastriate visual cortex. While the lesions themselves were heterogeneously distributed with little overlap in lesion location, 22 of 23 lesions were negatively correlated with extrastriate visual cortex. This network overlap was specific compared to other subcortical lesions (P < 10−5) and relative to other cortical regions (P < 0.01). Next, we tested for generalizability of our technique by applying it to three additional lesion syndromes: central post-stroke pain, auditory hallucinosis, and subcortical aphasia. In each syndrome, heterogeneous lesions that themselves had little overlap showed significant network overlap in cortical areas previously implicated in symptom expression (P < 10−4). These results suggest that (i) heterogeneous lesions producing similar symptoms share functional connectivity to specific brain regions involved in symptom expression; and (ii) publically available human connectome data can be used to incorporate these network effects into traditional lesion mapping approaches. Because the current technique requires no specialized imaging of patients it may prove a versatile and broadly applicable approach for localizing neurological symptoms in the setting of brain lesions. PMID:26264514

Network localization of neurological symptoms from focal brain lesions.

PubMed

Boes, Aaron D; Prasad, Sashank; Liu, Hesheng; Liu, Qi; Pascual-Leone, Alvaro; Caviness, Verne S; Fox, Michael D

2015-10-01

A traditional and widely used approach for linking neurological symptoms to specific brain regions involves identifying overlap in lesion location across patients with similar symptoms, termed lesion mapping. This approach is powerful and broadly applicable, but has limitations when symptoms do not localize to a single region or stem from dysfunction in regions connected to the lesion site rather than the site itself. A newer approach sensitive to such network effects involves functional neuroimaging of patients, but this requires specialized brain scans beyond routine clinical data, making it less versatile and difficult to apply when symptoms are rare or transient. In this article we show that the traditional approach to lesion mapping can be expanded to incorporate network effects into symptom localization without the need for specialized neuroimaging of patients. Our approach involves three steps: (i) transferring the three-dimensional volume of a brain lesion onto a reference brain; (ii) assessing the intrinsic functional connectivity of the lesion volume with the rest of the brain using normative connectome data; and (iii) overlapping lesion-associated networks to identify regions common to a clinical syndrome. We first tested our approach in peduncular hallucinosis, a syndrome of visual hallucinations following subcortical lesions long hypothesized to be due to network effects on extrastriate visual cortex. While the lesions themselves were heterogeneously distributed with little overlap in lesion location, 22 of 23 lesions were negatively correlated with extrastriate visual cortex. This network overlap was specific compared to other subcortical lesions (P < 10(-5)) and relative to other cortical regions (P < 0.01). Next, we tested for generalizability of our technique by applying it to three additional lesion syndromes: central post-stroke pain, auditory hallucinosis, and subcortical aphasia. In each syndrome, heterogeneous lesions that themselves had little overlap showed significant network overlap in cortical areas previously implicated in symptom expression (P < 10(-4)). These results suggest that (i) heterogeneous lesions producing similar symptoms share functional connectivity to specific brain regions involved in symptom expression; and (ii) publically available human connectome data can be used to incorporate these network effects into traditional lesion mapping approaches. Because the current technique requires no specialized imaging of patients it may prove a versatile and broadly applicable approach for localizing neurological symptoms in the setting of brain lesions. © 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.

Obesity and Structural Brain Integrity in Older Women: The Women’s Health Initiative Magnetic Resonance Imaging Study

PubMed Central

Gaussoin, Sarah A.; Wassertheil-Smoller, Sylvia; Limacher, Marian; Casanova, Ramon; Yaffe, Kristine; Resnick, Susan M.; Espeland, Mark A.

2016-01-01

Background: Midlife obesity has been linked to age-related brain atrophy and risk of dementia, but the relationships are less clear for older individuals. These associations may be explained by changes in appetite or metabolism in the dementia prodrome; thus, prospective studies with adequate follow-up are needed. We examined the associations that obesity (body mass index, BMI) and change in BMI over an average of 6.6 (1.0–9.1) years have with global and regional brain and white matter lesion volumes in a sample of 1,366 women aged 65–80. Methods: Least square means for regional brain volumes and white matter lesion loads for women grouped by BMI and changes in BMI were generated from multivariable linear models with and without adjustment for demographic and health covariates. Results: Both global obesity and increase in BMI were associated with lower cerebrospinal fluid and higher specific brain volumes (ps < .05), after controlling for diabetes and other cerebrovascular disease risk factors. Obesity, but not change in BMI, predicted lower lesion loads for the total, parietal, and occipital white matter (ps < .05). Conclusions: Obesity in this cohort is associated with less brain atrophy and lower ischemic lesion loads. The findings are consistent with our previous report of worse cognitive performance in association with weight loss (probably not due to frailty) in this cohort and in line with the idea of the “obesity paradox” as differences in dementia risk vary across time, whereby midlife obesity seems to be a predictor of dementia, whereas weight loss seems to be a better predictor at older ages. PMID:26961581

Brain lesions in septic shock: a magnetic resonance imaging study.

PubMed

Sharshar, Tarek; Carlier, Robert; Bernard, Francis; Guidoux, Céline; Brouland, Jean-Philippe; Nardi, Olivier; de la Grandmaison, Geoffroy Lorin; Aboab, Jérôme; Gray, Françoise; Menon, David; Annane, Djillali

2007-05-01

Understanding of sepsis-induced brain dysfunction remains poor, and relies mainly on data from animals or post-mortem studies in patients. The current study provided findings from magnetic resonance imaging of the brain in septic shock. Nine patients with septic shock and brain dysfunction [7 women, median age 63 years (interquartile range 61-79 years), SAPS II: 48 (44-56), SOFA: 8 (6-10)] underwent brain magnetic resonance imaging including gradient echo T1-weighted, fluid-attenuated inversion recovery (FLAIR), T2-weighted and diffusion isotropic images, and mapping of apparent diffusion coefficient. Brain imaging was normal in two patients, showed multiple ischaemic strokes in two patients, and in the remaining patients showed white matter lesions at the level of the centrum semiovale, predominating around Virchow-Robin spaces, ranging from small multiple areas to diffuse lesions, and characterised by hyperintensity on FLAIR images. The main lesions were also characterised by reduced signal on diffusion isotropic images and increased apparent diffusion coefficient. The lesions of the white matter worsened with increasing duration of shock and were correlated with Glasgow Outcome Score. This preliminary study showed that sepsis-induced brain lesions can be documented by magnetic resonance imaging. These lesions predominated in the white matter, suggesting increased blood-brain barrier permeability, and were associated with poor outcome.

Association Between Traumatic Brain Injury-Related Brain Lesions and Long-term Caregiver Burden.

PubMed

Guevara, Andrea Brioschi; Demonet, Jean-Francois; Polejaeva, Elena; Knutson, Kristine M; Wassermann, Eric M; Grafman, Jordan; Krueger, Frank

2016-01-01

To investigate the association between traumatic brain injury (TBI)-related brain lesions and long-term caregiver burden in relation to dysexecutive syndrome. National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland. A total of 256 participants: 105 combat veterans with TBI, 23 healthy control combat veterans (HCv), and 128 caregivers. Caregiver burden assessed by the Zarit Burden Interview at 40 years postinjury. Participants with penetrating TBI were compared with HCv on perceived caregiver burden and neuropsychological assessment measures. Data of computed tomographic scans (overlay lesion maps of participants with a penetrating TBI whose caregivers have a significantly high burden) and behavioral statistical analyses were combined to identify brain lesions associated with caregiver burden. Burden was greater in caregivers of veterans with TBI than in caregivers of HCv. Caregivers of participants with lesions affecting cognitive and behavioral indicators of dysexecutive syndrome (ie, left dorsolateral prefrontal cortex and dorsal anterior cingulate cortex) showed greater long-term burden than caregivers of participants with lesions elsewhere in the brain. The TBI-related brain lesions have a lasting effect on long-term caregiver burden due to cognitive and behavioral factors associated with dysexecutive syndrome.

The medial frontal cortex contributes to but does not organize rat exploratory behavior.

PubMed

Blankenship, Philip A; Stuebing, Sarah L; Winter, Shawn S; Cheatwood, Joseph L; Benson, James D; Whishaw, Ian Q; Wallace, Douglas G

2016-11-12

Animals use multiple strategies to maintain spatial orientation. Dead reckoning is a form of spatial navigation that depends on self-movement cue processing. During dead reckoning, the generation of self-movement cues from a starting position to an animal's current position allow for the estimation of direction and distance to the position movement originated. A network of brain structures has been implicated in dead reckoning. Recent work has provided evidence that the medial frontal cortex may contribute to dead reckoning in this network of brain structures. The current study investigated the organization of rat exploratory behavior subsequent to medial frontal cortex aspiration lesions under light and dark conditions. Disruptions in exploratory behavior associated with medial frontal lesions were consistent with impaired motor coordination, response inhibition, or egocentric reference frame. These processes are necessary for spatial orientation; however, they are not sufficient for self-movement cue processing. Therefore it is possible that the medial frontal cortex provides processing resources that support dead reckoning in other brain structures but does not of itself compute the kinematic details of dead reckoning. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Deep Learning for Brain MRI Segmentation: State of the Art and Future Directions.

PubMed

Akkus, Zeynettin; Galimzianova, Alfiia; Hoogi, Assaf; Rubin, Daniel L; Erickson, Bradley J

2017-08-01

Quantitative analysis of brain MRI is routine for many neurological diseases and conditions and relies on accurate segmentation of structures of interest. Deep learning-based segmentation approaches for brain MRI are gaining interest due to their self-learning and generalization ability over large amounts of data. As the deep learning architectures are becoming more mature, they gradually outperform previous state-of-the-art classical machine learning algorithms. This review aims to provide an overview of current deep learning-based segmentation approaches for quantitative brain MRI. First we review the current deep learning architectures used for segmentation of anatomical brain structures and brain lesions. Next, the performance, speed, and properties of deep learning approaches are summarized and discussed. Finally, we provide a critical assessment of the current state and identify likely future developments and trends.

Is the spatial distribution of brain lesions associated with closed-head injury in children predictive of subsequent development of posttraumatic stress disorder?

NASA Technical Reports Server (NTRS)

Herskovits, Edward H.; Gerring, Joan P.; Davatzikos, Christos; Bryan, R. Nick

2002-01-01

PURPOSE: To determine whether there is an association between the spatial distributions of lesions detected at magnetic resonance (MR) imaging of the brain in children, adolescents, and young adults after closed-head injury (CHI) and development of the reexperiencing symptoms of posttraumatic stress disorder (PTSD). MATERIALS AND METHODS: Data obtained in 94 subjects without a history of PTSD as determined by parental interview were analyzed. MR images were obtained 3 months after CHI. Lesions were manually delineated and registered to the Talairach coordinate system. Mann-Whitney analysis of lesion distribution and PTSD status at 1 year (again, as determined by parental interview) was performed, consisting of an analysis of lesion distribution versus the major symptoms of PTSD: reexperiencing, hyperarousal, and avoidance. RESULTS: Of the 94 subjects, 41 met the PTSD reexperiencing criterion and nine met all three PTSD criteria. Subjects who met the reexperiencing criterion had fewer lesions in limbic system structures (eg, the cingulum) on the right than did subjects who did not meet this criterion (Mann-Whitney, P =.003). CONCLUSION: Lesions induced by CHI in the limbic system on the right may inhibit subsequent manifestation of PTSD reexperiencing symptoms in children, adolescents, and young adults. Copyright RSNA, 2002.

Psychological problems, self-esteem and body dissatisfaction in a sample of adolescents with brain lesions: A comparison with a control group.

PubMed

Pastore, Valentina; Colombo, Katia; Maestroni, Deborah; Galbiati, Susanna; Villa, Federica; Recla, Monica; Locatelli, Federica; Strazzer, Sandra

2015-01-01

This study aims to describe psychological problems, self-esteem difficulties and body dissatisfaction in a sample of adolescents with acquired brain lesions and to compare them with an age- and gender-matched control group. In an experimental design, the psychological profile of 26 adolescents with brain lesions of traumatic or vascular aetiology, aged 12-18 years, was compared with that of 18 typically-developing subjects. Moreover, within the clinical group, patients with TBI were compared with patients with vascular lesions. The psychological and adaptive profile of the adolescents was assessed by a specific protocol, including CBCL, VABS, RSES, EDI-2 and BES. Adolescents with brain lesions showed more marked psychological problems than their healthy peers; they also presented with a greater impairment of adaptive skills and a lower self-esteem. No significant differences were found between patients with traumatic lesions and patients with vascular lesions. Adolescents with acquired brain lesions were at higher risk to develop psychological and behavioural difficulties. Furthermore, in the clinical sample, some variables such as the long hospitalization and isolation from family and peers were associated to a greater psychological burden than the aetiology of the brain damage.

Structural Brain Damage and Upper Limb Kinematics in Children with Unilateral Cerebral Palsy.

PubMed

Mailleux, Lisa; Simon-Martinez, Cristina; Klingels, Katrijn; Jaspers, Ellen; Desloovere, Kaat; Demaerel, Philippe; Fiori, Simona; Guzzetta, Andrea; Ortibus, Els; Feys, Hilde

2017-01-01

Background: In children with unilateral cerebral palsy (uCP) virtually nothing is known on the relation between structural brain damage and upper limb (UL) kinematics quantified with three-dimensional movement analysis (3DMA). This explorative study aimed to (1) investigate differences in UL kinematics between children with different lesion timings, i.e., periventricular white matter (PWM) vs. cortical and deep gray matter (CDGM) lesions and (2) to explore the relation between UL kinematics and lesion location and extent within each lesion timing group. Methods: Forty-eight children (age 10.4 ± 2.7 year; 29 boys; 21 right-sided; 33 PWM; 15 CDGM) underwent an UL 3DMA during a reach-to-grasp task. Spatiotemporal parameters [movement duration, (timing of) maximum velocity, trajectory straightness], the Arm Profile Score (APS) and Arm Variable Scores (AVS) were extracted. The APS and AVS refer to the total amount of movement pathology and movement deviations of the wrist, elbow, shoulder, scapula and trunk respectively. Brain lesion location and extent were scored based on FLAIR-images using a semi-quantitative MRI-scale. Results: Children with CDGM lesions showed more aberrant spatiotemporal parameters ( p < 0.03) and more movement pathology (APS, p = 0.003) compared to the PWM group, mostly characterized by increased wrist flexion ( p = 0.01). In the CDGM group, moderate to high correlations were found between lesion location and extent and duration, timing of maximum velocity and trajectory straightness ( r = 0.53-0.90). Lesion location and extent were further moderately correlated with distal UL movement pathology (wrist flexion/extension, elbow pronation/supination, elbow flexion/extension; r = 0.50-0.65) and with the APS ( r = 0.51-0.63). In the PWM group, only a few and low correlations were observed, mostly between damage to the PLIC and higher AVS of elbow flexion/extension, shoulder elevation and trunk rotation ( r = 0.35-0.42). Regression analysis revealed damage to the temporal lobe with lesion timing as interactor (27%, p = 0.002) and the posterior limb of the internal capsule (PLIC) (7%, p = 0.04) as the strongest predictors, explaining 34% of the variance in APS. Conclusion: UL kinematic deviations are more influenced by lesion location and extent in children with later (CDGM) versus earlier lesions (PWM), except for proximal movement pathology. Damage to the PLIC is a significant predictor for UL movement pathology irrespective of lesion timing.

Alterations of brain grey matter density and olfactory bulb volume in patients with olfactory loss after traumatic brain injury.

PubMed

Han, Pengfei; Winkler, Nicole; Hummel, Cornelia; Hähner, Antje; Gerber, Johannes; Hummel, Thomas

2018-04-27

Olfactory loss and traumatic brain injury (TBI) both lead to anatomical brain alterations in humans. Little research has been done on the structural brain changes for TBI patients with olfactory loss. Using voxel-based morphometry, the grey matter (GM) density was examined for twenty-two TBI patients with hyposmia, twenty-four TBI patients with anosmia, and twenty-two age-matched controls. Olfactory bulb (OB) volumes were measured by manual segmentation of acquired T2 weighted coronal slices using a standardized protocol. Brain lesions in the olfactory relevant areas were also examined for TBI patients. Results showed that patients with anosmia have more frequent lesions in the OB, orbitofrontal cortex (OFC) and the temporal lobe pole, as compared to patients with hyposmia. GM density in the primary olfactory area was decreased in both groups of patients. In addition, compared to controls, patients with anosmia showed GM density reduction in several secondary olfactory eloquent regions, including the gyrus rectus, medial OFC, anterior cingulate cortex, insula, and cerebellum. However, patients with hyposmia showed a lesser degree of GM reduction compared to healthy controls. Smaller OB volumes were found for patients with olfactory loss as compared to controls. TBI patients with anosmia had the smallest OB volumes which were caused by the lesions for OB. In addition, post-TBI duration was negatively correlated with GM density in the secondary olfactory areas in patients with hyposmia, but was positively correlated with GM density in the frontal and temporal gyrus in patients with anosmia. The GM density and OB volume reduction among TBI patients with olfactory loss was largely depend on the location and severity of brain lesions in olfactory relevant regions. Longer post-TBI duration had an impact on brain GM density changes, which indicate a decreased olfactory function in patients with hyposmia and possible compensatory mechanisms in patients with anosmia.

Cortical venous disease severity in MELAS syndrome correlates with brain lesion development.

PubMed

Whitehead, M T; Wien, M; Lee, B; Bass, N; Gropman, A

2017-08-01

MELAS syndrome is a mitochondrial disorder typified by recurrent stroke-like episodes, seizures, and progressive brain injury. Abnormal mitochondria have been found in arterial walls implicating a vasculogenic etiology. We have observed abnormal cortical vein T2/FLAIR signal in MELAS patients, potentially representing wall thickening and sluggish flow. We sought to examine the relationship of hyperintense veins and brain lesions in MELAS. Imaging databases at two children's hospitals were searched for brain MRIs from MELAS patients. Artifact, sedated exams, and lack of 2D-T2/FLAIR sequences were exclusion criteria. Each exam was assigned a venous score based on number of T2/FLAIR hyperintense veins: 1 = <10, 2 = 10 to 20, 3 = >20. Cumulative brain lesions and venous score in MELAS and aged-matched normal exams were compared by Mann-Whitney test. A total of 106 exams from 14 unique MELAS patients (mean 16 ± 3 years) and 30 exams from normal aged-matched patients (mean 15 ± 3 years) were evaluated. Median venous score between MELAS and control patients significantly differed (3 versus 1; p < 0.001). In the MELAS group, venous score correlated with presence (median = 3) or absence (median = 1) of cumulative brain lesions. In all 8 MELAS patients who developed lesions, venous hyperintensity was present prior to, during, and after lesion onset. Venous score did not correlate with brain lesion acuity. Abnormal venous signal correlates with cumulative brain lesion severity in MELAS syndrome. Cortical venous stenosis, congestion, and venous ischemia may be mechanisms of brain injury. Identification of cortical venous pathology may aid in diagnosis and could be predictive of lesion development.

Acute Methanol Poisoning: Prevalence and Predisposing Factors of Haemorrhagic and Non-Haemorrhagic Brain Lesions.

PubMed

Zakharov, Sergey; Kotikova, Katerina; Vaneckova, Manuela; Seidl, Zdenek; Nurieva, Olga; Navratil, Tomas; Caganova, Blazena; Pelclova, Daniela

2016-08-01

The purpose was to study the prevalence and predisposing factors of brain lesions in survivors of acute methanol poisoning. Clinical data on 106 patients with methanol poisoning were collected during the Czech mass poisoning outbreak. Of 83 survivors, in 46 (55%) patients, follow-up examinations including magnetic resonance imaging of brain (MR) were performed 3-8 and 24-28 months after discharge from the hospital. Of 46 patients with a median age of 49 (interquartile range, 35-57) years, 24 (52%) patients had a total of 40 abnormal brain findings with haemorrhagic lesions detected in 15 (33%) and non-haemorrhagic lesions found in 9 (19%) patients. The patients with haemorrhagic brain lesions were more acidemic (lower arterial blood pH, higher base deficit) and had higher glycaemia and lactacidaemia on admission than those without haemorrhages (all p < 0.05). Thirteen of 32 (41%) of patients with systemic anticoagulation and 2 of 14 (14%) of patients without it had haemorrhagic lesions (p = 0.080). Bleeding complications during the treatment occurred in 4 of 15 (27%) patients, and 5 of 15 (33%) patients had conditions predisposing to haemorrhage in the group with haemorrhagic lesions. In three cases with a series of computer tomography (CT)/MR performed during hospitalization, the necrotic lesions in the brain remained non-haemorrhagic during hospitalization and haemorrhagic lesions were detected on the follow-up MR examinations only. No association between brain haemorrhages and systemic anticoagulation during dialysis was found: brain haemorrhages might occur in severely poisoned patients treated without systemic anticoagulation, whereas treatment with high doses of heparin might not lead to brain haemorrhages. © 2016 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

Cerebellar Growth Impairment Characterizes School-Aged Children Born Preterm without Perinatal Brain Lesions.

PubMed

Pieterman, K; White, T J; van den Bosch, G E; Niessen, W J; Reiss, I K M; Tibboel, D; Hoebeek, F E; Dudink, J

2018-05-01

Infants born preterm are commonly diagnosed with structural brain lesions known to affect long-term neurodevelopment negatively. Yet, the effects of preterm birth on brain development in the absence of intracranial lesions remain to be studied in detail. In this study, we aim to quantify long term consequences of preterm birth on brain development in this specific group. Neonatal cranial sonography and follow-up T1-weighted MR imaging and DTI were performed to evaluate whether the anatomic characteristics of the cerebrum and cerebellum in a cohort of school-aged children (6-12 years of age) were related to gestational age at birth in children free of brain lesions in the perinatal period. In the cohort consisting of 36 preterm (28-37 weeks' gestational age) and 66 term-born infants, T1-weighted MR imaging and DTI at 6-12 years revealed a reduction of cerebellar white matter volume (β = 0.387, P < .001), altered fractional anisotropy of cerebellar white matter (β = -0.236, P = .02), and a reduction of cerebellar gray and white matter surface area (β = 0.337, P < .001; β = 0.375, P < .001, respectively) in relation to birth age. Such relations were not observed for the cerebral cortex or white matter volume, surface area, or diffusion quantities. The results of our study show that perinatal influences that are not primarily neurologic are still able to disturb long-term neurodevelopment, particularly of the developing cerebellum. Including the cerebellum in future neuroprotective strategies seems therefore essential. © 2018 by American Journal of Neuroradiology.

The hubs of the human connectome are generally implicated in the anatomy of brain disorders.

PubMed

Crossley, Nicolas A; Mechelli, Andrea; Scott, Jessica; Carletti, Francesco; Fox, Peter T; McGuire, Philip; Bullmore, Edward T

2014-08-01

Brain networks or 'connectomes' include a minority of highly connected hub nodes that are functionally valuable, because their topological centrality supports integrative processing and adaptive behaviours. Recent studies also suggest that hubs have higher metabolic demands and longer-distance connections than other brain regions, and therefore could be considered biologically costly. Assuming that hubs thus normally combine both high topological value and high biological cost, we predicted that pathological brain lesions would be concentrated in hub regions. To test this general hypothesis, we first identified the hubs of brain anatomical networks estimated from diffusion tensor imaging data on healthy volunteers (n = 56), and showed that computational attacks targeted on hubs disproportionally degraded the efficiency of brain networks compared to random attacks. We then prepared grey matter lesion maps, based on meta-analyses of published magnetic resonance imaging data on more than 20 000 subjects and 26 different brain disorders. Magnetic resonance imaging lesions that were common across all brain disorders were more likely to be located in hubs of the normal brain connectome (P < 10(-4), permutation test). Specifically, nine brain disorders had lesions that were significantly more likely to be located in hubs (P < 0.05, permutation test), including schizophrenia and Alzheimer's disease. Both these disorders had significantly hub-concentrated lesion distributions, although (almost completely) distinct subsets of cortical hubs were lesioned in each disorder: temporal lobe hubs specifically were associated with higher lesion probability in Alzheimer's disease, whereas in schizophrenia lesions were concentrated in both frontal and temporal cortical hubs. These results linking pathological lesions to the topological centrality of nodes in the normal diffusion tensor imaging connectome were generally replicated when hubs were defined instead by the meta-analysis of more than 1500 task-related functional neuroimaging studies of healthy volunteers to create a normative functional co-activation network. We conclude that the high cost/high value hubs of human brain networks are more likely to be anatomically abnormal than non-hubs in many (if not all) brain disorders. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain.

Injured Brain Regions Associated with Anxiety in Vietnam Veterans

PubMed Central

Knutson, Kristine M.; Rakowsky, Shana T.; Solomon, Jeffrey; Krueger, Frank; Raymont, Vanessa; Tierney, Michael C.; Wassermann, Eric M.; Grafman, Jordan

2013-01-01

Anxiety negatively affects quality of life and psychosocial functioning. Previous research has shown that anxiety symptoms in healthy individuals are associated with variations in the volume of brain regions, such as the amygdala, hippocampus, and the bed nucleus of the stria terminalis. Brain lesion data also suggests the hemisphere damaged may affect levels of anxiety. We studied a sample of 182 male Vietnam War veterans with penetrating brain injuries, using a semi-automated voxel-based lesion-symptom mapping (VLSM) approach. VLSM reveals significant associations between a symptom such as anxiety and the location of brain lesions, and does not require a broad, subjective assignment of patients into categories based on lesion location. We found that lesioned brain regions in cortical and limbic areas of the left hemisphere, including middle, inferior and superior temporal lobe, hippocampus, and fusiform regions, along with smaller areas in the inferior occipital lobe, parahippocampus, amygdala, and insula, were associated with increased anxiety symptoms as measured by the Neurobehavioral Rating Scale (NRS). These results were corroborated by similar findings using Neuropsychiatric Inventory (NPI) anxiety scores, which supports these regions’ role in regulating anxiety. In summary, using a semi-automated analysis tool, we detected an effect of focal brain damage on the presentation of anxiety. We also separated the effects of brain injury and war experience by including a control group of combat veterans without brain injury. We compared this control group against veterans with brain lesions in areas associated with anxiety, and against veterans with lesions only in other brain areas. PMID:23328629

Ischemic brain injury in cerebral amyloid angiopathy

PubMed Central

van Veluw, Susanne J; Greenberg, Steven M

2016-01-01

Cerebral amyloid angiopathy (CAA) is a common form of cerebral small vessel disease and an important risk factor for intracerebral hemorrhage and cognitive impairment. While the majority of research has focused on the hemorrhagic manifestation of CAA, its ischemic manifestations appear to have substantial clinical relevance as well. Findings from imaging and pathologic studies indicate that ischemic lesions are common in CAA, including white-matter hyperintensities, microinfarcts, and microstructural tissue abnormalities as detected with diffusion tensor imaging. Furthermore, imaging markers of ischemic disease show a robust association with cognition, independent of age, hemorrhagic lesions, and traditional vascular risk factors. Widespread ischemic tissue injury may affect cognition by disrupting white-matter connectivity, thereby hampering communication between brain regions. Challenges are to identify imaging markers that are able to capture widespread microvascular lesion burden in vivo and to further unravel the etiology of ischemic tissue injury by linking structural magnetic resonance imaging (MRI) abnormalities to their underlying pathophysiology and histopathology. A better understanding of the underlying mechanisms of ischemic brain injury in CAA will be a key step toward new interventions to improve long-term cognitive outcomes for patients with CAA. PMID:25944592

Finding the imposter: brain connectivity of lesions causing delusional misidentifications.

PubMed

Darby, R Ryan; Laganiere, Simon; Pascual-Leone, Alvaro; Prasad, Sashank; Fox, Michael D

2017-02-01

SEE MCKAY AND FURL DOI101093/AWW323 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Focal brain injury can sometimes lead to bizarre symptoms, such as the delusion that a family member has been replaced by an imposter (Capgras syndrome). How a single brain lesion could cause such a complex disorder is unclear, leading many to speculate that concurrent delirium, psychiatric disease, dementia, or a second lesion is required. Here we instead propose that Capgras and other delusional misidentification syndromes arise from single lesions at unique locations within the human brain connectome. This hypothesis is motivated by evidence that symptoms emerge from sites functionally connected to a lesion location, not just the lesion location itself. First, 17 cases of lesion-induced delusional misidentifications were identified and lesion locations were mapped to a common brain atlas. Second, lesion network mapping was used to identify brain regions functionally connected to the lesion locations. Third, regions involved in familiarity perception and belief evaluation, two processes thought to be abnormal in delusional misidentifications, were identified using meta-analyses of previous functional magnetic resonance imaging studies. We found that all 17 lesion locations were functionally connected to the left retrosplenial cortex, the region most activated in functional magnetic resonance imaging studies of familiarity. Similarly, 16 of 17 lesion locations were functionally connected to the right frontal cortex, the region most activated in functional magnetic resonance imaging studies of expectation violation, a component of belief evaluation. This connectivity pattern was highly specific for delusional misidentifications compared to four other lesion-induced neurological syndromes (P < 0.0001). Finally, 15 lesions causing other types of delusions were connected to expectation violation (P < 0.0001) but not familiarity regions, demonstrating specificity for delusion content. Our results provide potential neuroanatomical correlates for impaired familiarity perception and belief evaluation in patients with delusional misidentifications. More generally, we demonstrate a mechanism by which a single lesion can cause a complex neuropsychiatric syndrome based on that lesion's unique pattern of functional connectivity, without the need for pre-existing or hidden pathology. © 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.

Minds on replay: musical hallucinations and their relationship to neurological disease.

PubMed

Golden, Erin C; Josephs, Keith A

2015-12-01

The phenomenon of musical hallucinations, in which individuals perceive music in the absence of an external auditory stimulus, has been described sparingly in the literature through small case reports and series. Musical hallucinations have been linked to multiple associated conditions, including psychiatric and neurologic disease, brain lesions, drug effect, and hearing impairment. This study aimed to review the demographics of subjects with musical hallucinations and to determine the prevalence of neurological disorders, particularly neurodegenerative disease. Through the Mayo medical record, 393 subjects with musical hallucinations were identified and divided into five categories based on comorbid conditions that have been associated with musical hallucinations: neurological, psychiatric, structural, drug effect and not otherwise classifiable. Variables, including hearing impairment and the presence of visual and other auditory hallucinations, were evaluated independently in all five groups. The mean age at onset of the hallucinations was 56 years, ranging from 18 to 98 years, and 65.4% of the subjects were female. Neurological disease and focal brain lesions were found in 25% and 9% of the total subjects, respectively. Sixty-five subjects were identified with a neurodegenerative disorder, with the Lewy body disorders being the most common. Visual hallucinations were more common in the group with neurological disease compared to the psychiatric, structural, and not otherwise classifiable groups (P < 0.001), whereas auditory hallucinations were more common in the psychiatric group compared to all other groups (P < 0.001). Structural lesions associated with musical hallucinations involved both hemispheres with a preference towards the left, and all but two included the temporal lobe. Hearing impairment was common, particularly in the not otherwise classifiable category where 67.2% had documented hearing impairment, more than in any other group (P < 0.001). Those with an underlying neurodegenerative disorder or isolated hearing impairment tended to hear more persistent music, which was often religious and patriotic compared to those with a structural lesion, where more modern music was heard, and those with psychiatric disorders where music was mood-congruent. This case series shows that musical hallucinations can occur in association with a wide variety of conditions, of which neurological disease and brain lesions represent a substantial proportion, and that Lewy body disorders are the most commonly associated neurodegenerative diseases. A future prospective study would be helpful to further delineate an association between musical hallucinations and neurodegenerative disease. © 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.

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.

Brain atrophy and lesion load measures over 1 year relate to clinical status after 6 years in patients with clinically isolated syndromes.

PubMed

Di Filippo, M; Anderson, V M; Altmann, D R; Swanton, J K; Plant, G T; Thompson, A J; Miller, D H

2010-02-01

Conventional MRI lesion measures modestly predict long term disability in some clinically isolated syndrome (CIS) studies. Brain atrophy suggests neuroaxonal loss in multiple sclerosis (MS) with the potential to reflect disease progression to a greater extent than lesion measures. To investigate whether brain atrophy and lesion load, during the first year in patients presenting with CIS, independently predict clinical outcome (development of MS and disability at 6 years). 99 patients presenting with CIS were included in the study. T1 gadolinium enhanced and T2 weighted brain MRI was acquired at baseline and approximately 1 year later. Percentage brain atrophy rate between baseline and follow-up scans was analysed using SIENA. Mean annual brain atrophy rates were -0.38% for all patients, -0.50% in patients who had developed MS at 6 years and -0.26% in those who had not. Brain atrophy rate (p = 0.005) and baseline T2 lesion load (p<0.001) were independent predictors of clinically definite MS. While brain atrophy rate was a predictor of Expanded Disability Status Scale (EDSS) score in a univariate analysis, only 1 year T2 lesion load change (p = 0.007) and baseline gadolinium enhancing lesion number (p = 0.03) were independent predictors of EDSS score at the 6 year follow-up. T1 lesion load was the only MRI parameter which predicted Multiple Sclerosis Functional Composite score at the 6 year follow-up. The findings confirm that brain atrophy occurs during the earliest phases of MS and suggest that 1 year longitudinal measures of MRI change, if considered together with baseline MRI variables, might help to predict clinical status 6 years after the first demyelinating event in CIS patients, better than measurements such as lesion or brain volumes on baseline MRI alone.

Scan-stratified case-control sampling for modeling blood-brain barrier integrity in multiple sclerosis.

PubMed

Pomann, Gina-Maria; Sweeney, Elizabeth M; Reich, Daniel S; Staicu, Ana-Maria; Shinohara, Russell T

2015-09-10

Multiple sclerosis (MS) is an immune-mediated neurological disease that causes morbidity and disability. In patients with MS, the accumulation of lesions in the white matter of the brain is associated with disease progression and worse clinical outcomes. Breakdown of the blood-brain barrier in newer lesions is indicative of more active disease-related processes and is a primary outcome considered in clinical trials of treatments for MS. Such abnormalities in active MS lesions are evaluated in vivo using contrast-enhanced structural MRI, during which patients receive an intravenous infusion of a costly magnetic contrast agent. In some instances, the contrast agents can have toxic effects. Recently, local image regression techniques have been shown to have modest performance for assessing the integrity of the blood-brain barrier based on imaging without contrast agents. These models have centered on the problem of cross-sectional classification in which patients are imaged at a single study visit and pre-contrast images are used to predict post-contrast imaging. In this paper, we extend these methods to incorporate historical imaging information, and we find the proposed model to exhibit improved performance. We further develop scan-stratified case-control sampling techniques that reduce the computational burden of local image regression models, while respecting the low proportion of the brain that exhibits abnormal vascular permeability. Copyright © 2015 John Wiley & Sons, Ltd.

Limitations on the developing preterm brain: impact of periventricular white matter lesions on brain connectivity and cognition.

PubMed

Pavlova, Marina A; Krägeloh-Mann, Ingeborg

2013-04-01

Brain lesions to the white matter in peritrigonal regions, periventricular leukomalacia, in children who were born prematurely represent an important model for studying limitations on brain development. The lesional pattern is of early origin and bilateral, that constrains the compensatory potential of the brain. We suggest that (i) topography and severity of periventricular lesions may have a long-term predictive value for cognitive and social capabilities in preterm birth survivors; and (ii) periventricular lesions may impact cognitive and social functions by affecting brain connectivity, and thereby, the dissociable neural networks underpinning these functions. A further pathway to explore is the relationship between cerebral palsy and cognitive outcome. Restrictions caused by motor disability may affect active exploration of surrounding and social participation that may in turn differentially impinge on cognitive development and social cognition. As an outline for future research, we underscore sex differences, as the sex of a preterm newborn may shape the mechanisms by which the developing brain is affected.

High-definition fiber tractography of the human brain: neuroanatomical validation and neurosurgical applications.

PubMed

Fernandez-Miranda, Juan C; Pathak, Sudhir; Engh, Johnathan; Jarbo, Kevin; Verstynen, Timothy; Yeh, Fang-Cheng; Wang, Yibao; Mintz, Arlan; Boada, Fernando; Schneider, Walter; Friedlander, Robert

2012-08-01

High-definition fiber tracking (HDFT) is a novel combination of processing, reconstruction, and tractography methods that can track white matter fibers from cortex, through complex fiber crossings, to cortical and subcortical targets with subvoxel resolution. To perform neuroanatomical validation of HDFT and to investigate its neurosurgical applications. Six neurologically healthy adults and 36 patients with brain lesions were studied. Diffusion spectrum imaging data were reconstructed with a Generalized Q-Ball Imaging approach. Fiber dissection studies were performed in 20 human brains, and selected dissection results were compared with tractography. HDFT provides accurate replication of known neuroanatomical features such as the gyral and sulcal folding patterns, the characteristic shape of the claustrum, the segmentation of the thalamic nuclei, the decussation of the superior cerebellar peduncle, the multiple fiber crossing at the centrum semiovale, the complex angulation of the optic radiations, the terminal arborization of the arcuate tract, and the cortical segmentation of the dorsal Broca area. From a clinical perspective, we show that HDFT provides accurate structural connectivity studies in patients with intracerebral lesions, allowing qualitative and quantitative white matter damage assessment, aiding in understanding lesional patterns of white matter structural injury, and facilitating innovative neurosurgical applications. High-grade gliomas produce significant disruption of fibers, and low-grade gliomas cause fiber displacement. Cavernomas cause both displacement and disruption of fibers. Our HDFT approach provides an accurate reconstruction of white matter fiber tracts with unprecedented detail in both the normal and pathological human brain. Further studies to validate the clinical findings are needed.

Correlation of neurocognitive function and brain lesion load on magnetic resonance imaging in systemic lupus erythematosus.

PubMed

Roldan, Paola C; Jung, Rex E; Sibbitt, Wilmer L; Qualls, Clifford R; Flores, Ranee A; Roldan, Carlos A

2018-06-13

Neurocognitive dysfunction and brain injury on magnetic resonance imaging (MRI) are common in patients with systemic lupus erythematosus (SLE) and are associated with increased morbidity and mortality. However, brain MRI is expensive, is restricted by payers, and requires high expertise. Neurocognitive assessment is an easily available, safe, and inexpensive clinical tool that may select patients needing brain MRI. In this cross-sectional and controlled study, 76 SLE patients (69 women, age 37 ± 12 years) and 26 age and gender-matched healthy subjects (22 women, age 34 ± 11 years) underwent assessment of attention, memory, processing speed, executive function, motor function, and global neurocognitive function. All subjects underwent brain MRI with T1-weighted, fluid-attenuated inversion recovery (FLAIR), and diffusion-weighted imaging. Hemispheric and whole brain lesion load in cm 3 were determined using semi-automated methods. Neurocognitive z-scores in all clinical domains were significantly lower and whole brain and right and left hemispheres brain lesion load were significantly greater in patients than in controls (all p ≤ 0.02). There was significant correlation between neurocognitive z-scores in all domains and whole brain lesion load: processing speed (r = - 0.46; p < 0.0001), attention (r = - 0.42; p < 0.001), memory (r = - 0.40; p = 0.0004), executive function (r = - 0.25; p = 0.03), motor function (r = - 0.25; p = 0.05), and global neurocognitive function (r = - 0.38; p = 0.006). Similar correlations were found for brain hemisphere lesion loads (all p ≤ 0.05). These correlations were strengthened when adjusted for glucocorticoid therapy and SLE disease activity index. Finally, global neurocognitive z-score and erythrosedimentation rate were the only independent predictors of whole brain lesion load (both p ≤ 0.007). Neurocognitive measures and brain lesion load are worse in SLE patients than in controls. In SLE patients, neurocognitive z-scores correlate negatively with and independently predict brain lesion load. Therefore, neurocognitive testing may be an effective clinical tool to select patients needing brain MRI.

Enhancement of matrix metalloproteinases 2 and 9 accompanied with neurogenesis following collagen glycosaminoglycan matrix implantation after surgical brain injury.

PubMed

Hsu, Wei-Cherng; Yu, Chun-Hsien; Kung, Woon-Man; Huang, Kuo-Feng

2018-06-01

Surgical brain injury may result in irreversible neurological deficits. Our previous report showed that partial regeneration of a traumatic brain lesion is achieved by implantation of collagen glycosaminoglycan (CGM). Matrix metalloproteinases (MMPs) may play an important role in neurogenesis but there is currently a lack of studies displaying the relationship between the stimulation of MMPs and neurogenesis after collagen glycosaminoglycan implantation following surgical brain trauma. The present study was carried out to further examine the expression of MMP2 and MMP9 after implantation of collagen glycosaminoglycan (CGM) following surgical brain trauma. Using the animal model of surgically induced brain lesion, we implanted CGM into the surgical trauma. Rats were thus divided into three groups: (1) sham operation group: craniotomy only; (2) lesion (L) group: craniotomy + surgical trauma lesion; (3) lesion + CGM (L + CGM) group: CGM implanted following craniotomy and surgical trauma lesion. Cells positive for SOX2 (marker of proliferating neural progenitor cells) and matrix metalloproteinases (MMP2 and MMP9) in the lesion boundary zone were assayed and analyzed by immunofluorescence and ELISA commercial kits, respectively. Our results demonstrated that following implantation of CGM after surgical brain trauma, significant increases in MMP2 + /SOX2 + cells and MMP9 + /SOX2 + cells were seen within the lesion boundary zone in the L + CGM group. Tissue protein concentrations of MMP2 and MMP9 also increased after CGM scaffold implantation. These findings suggest that implantation of a CGM scaffold alone after surgical brain trauma can enhance the expression of MMP2 and MMP9 accompanied by neurogenesis.

Where and When to Cut? Fluorescein Guidance for Brain Stem and Spinal Cord Tumor Surgery-Technical Note.

PubMed

Molina, Eric Suero; Stummer, Walter

2017-12-29

Spinal cord and brain stem lesions require a judicious approach with an optimized trajectory due to a clustering of functions on their surfaces. Intraoperative mapping helps locate function. To confidently locate such lesions, neuronavigation alone lacks the desired accuracy and is of limited use in the spinal cord. To evaluate the clinical value of fluoresceins for initial delineation of such critically located lesions. We evaluated fluorescein guidance in the surgical resection of lesions with blood-brain barrier disruption demonstrating contrast enhancement in magnet resonance imaging in the spinal cord and in the brain stem in 3 different patients. Two patients harbored a diffuse cervical and thoracic spinal cord lesion, respectively. Another patient suffered metastatic lesions in the brain stem and at the floor of the fourth ventricle. Low-dose fluorescein (4 mg/kg body weight) was applied after anesthesia induction and visualized using the Zeiss Pentero 900 Yellow560 filter (Carl Zeiss, Oberkochen, Germany). Fluorescein was helpful for locating lesions and for defining the best possible trajectory. During resection, however, we found unspecific propagation of fluorescein within the brain stem up to 6 mm within 3 h after application. As these lesions were otherwise distinguishable from surrounding tissue, monitoring resection was not an issue. Fluorescein guidance is a feasible tool for defining surgical entry zones when aiming for surgical removal of spinal cord and brain stem lesions. Unselective fluorescein extravasation cautions against using such methodology for monitoring completeness of resection. Providing the right timing, a window of pseudoselectivity could increase fluoresceins' clinical value in these cases. © Congress of Neurological Surgeons 2017.

Lower gingival squamous cell carcinoma with brain metastasis during long-term cetuximab treatment: A case report.

PubMed

Naruse, Tomofumi; Tokuhisa, Mitsuko; Yanamoto, Souichi; Sakamoto, Yuki; Okuyama, Kohei; Tsuchihashi, Hiroki; Umeda, Masahiro

2018-05-01

Long-term cetuximab treatment can lead to acquired resistance, and tumor progression and/or new lesions often occur. The present report describes a case of lower gingival squamous cell carcinoma with brain metastasis during long-term cetuximab treatment in a 60-year-old man, including findings of an immunohistochemical study. The resected primary tumors, biopsy of the lung metastasis before administration of cetuximab, and brain metastasis specimens mediated by cetuximab were immunohistochemically examined. Histologically, the metastatic brain lesion showed hyperkeratinizing tumor cells with deeply stained irregular nuclei with necrotizing tumor cells, and a decrease in cell density was exhibited in part of the tumor nest. Moreover, the brain lesion was less malignant compared with the primary tumor and metastatic lung lesions. Immunohistochemically, the metastatic brain lesions showed low expression of epidermal growth factor receptor (EGFR) and high expression of N-cadherin compared with the primary tumor and metastatic lung lesions. These results suggest that acquired resistance to cetuximab may be associated with low EGFR expression and increased epithelial-to-mesenchymal transition potential.

Medical Imaging Lesion Detection Based on Unified Gravitational Fuzzy Clustering

PubMed Central

Vianney Kinani, Jean Marie; Gallegos Funes, Francisco; Mújica Vargas, Dante; Ramos Díaz, Eduardo; Arellano, Alfonso

2017-01-01

We develop a swift, robust, and practical tool for detecting brain lesions with minimal user intervention to assist clinicians and researchers in the diagnosis process, radiosurgery planning, and assessment of the patient's response to the therapy. We propose a unified gravitational fuzzy clustering-based segmentation algorithm, which integrates the Newtonian concept of gravity into fuzzy clustering. We first perform fuzzy rule-based image enhancement on our database which is comprised of T1/T2 weighted magnetic resonance (MR) and fluid-attenuated inversion recovery (FLAIR) images to facilitate a smoother segmentation. The scalar output obtained is fed into a gravitational fuzzy clustering algorithm, which separates healthy structures from the unhealthy. Finally, the lesion contour is automatically outlined through the initialization-free level set evolution method. An advantage of this lesion detection algorithm is its precision and its simultaneous use of features computed from the intensity properties of the MR scan in a cascading pattern, which makes the computation fast, robust, and self-contained. Furthermore, we validate our algorithm with large-scale experiments using clinical and synthetic brain lesion datasets. As a result, an 84%–93% overlap performance is obtained, with an emphasis on robustness with respect to different and heterogeneous types of lesion and a swift computation time. PMID:29158887

Nuclear microscopy in Alzheimer's disease

NASA Astrophysics Data System (ADS)

Makjanic, Jagoda; Watt, Frank

1999-04-01

The elemental composition of the two types of brain lesions which characterise Alzheimer's disease (AD) has been the subject of intense scrutiny over the last decade, ever since it was proposed that inorganic trace elements, particularly aluminium, might be implicated in the pathogenesis of the disease. The major evidence for this involvement was the detection of aluminium in the characteristic lesions of the AD brain; neuritic plaques and neurofibrillary tangles (NFTs). Using the powerful combination of Particle-Induced X-ray Emission (PIXE), Rutherford Backscattering Spectrometry (RBS) and Scanning Transmission Ion Microscopy (STIM), it is possible to image and analyse structures in brain sections without recourse to chemical staining. Previous results on elemental composition of senile plaques indicated the absence of aluminium at the 15 parts per million level. We have more recently focused on the analysis of neurofibrillary tangles (NFTs), destructive structural defects within neurons. Imaging and analysis of neurons in brain tissue presented a greater challenge due to the small dimensional size compared with the plaques. We describe the methodology and the results of imaging and analysing neurons in brain tissue sections using Nuclear Microscopy. Our results show that aluminium is not present in either neurons or surrounding tissue in unstained sections at the 20 ppm level, but can be observed in stained sections. We also report elemental concentrations showing significant elevations of phosphorus, sulphur, chlorine, iron and zinc.

Proton MRS of the peritumoral brain.

PubMed

Chernov, Mikhail F; Kubo, Osami; Hayashi, Motohiro; Izawa, Masahiro; Maruyama, Takashi; Usukura, Masao; Ono, Yuko; Hori, Tomokatsu; Takakura, Kintomo

2005-02-15

Long-echo (TR: 2000 ms, TE: 136 ms) proton MRS of the cerebral tissue in the vicinity to intracranial lesion was done in 15 patients, mainly with parenchymal brain tumors. Significant decrease of N-acetylaspartate (NAA) (P<0.001) and more frequent presence of lactate (P<0.01) comparing with distant normal white matter were found in the perilesional brain tissue. The level of NAA in the perilesional brain tissue had negative associations with presence of lactate in the lesion (P<0.05), excess of lactate in the lesion compared to perilesional brain (P<0.01), grade of the perilesional edema (P<0.01) and patient's age (P<0.05). Multivariate analysis disclosed that identification of lactate in the lesion is associated with lower relative NAA content in the perilesional brain tissue, independently on the presence or absence of any other factor, including brain edema (P<0.001). In patients with lobar lesions who had at least one epileptic seizure during course of their disease the relative NAA content in the perilesional brain was significantly lower, comparing with those who were seizure-free (P<0.05). Therefore, lactate diffused from the tumor, or other metabolites secreted by lactate-producing neoplasm, should be considered as important contributors to the neuronal dysfunction in the surrounding brain. Decrease of NAA in the vicinity to intracranial lesions may reflect neuronal alteration responsible for associated epilepsy.

Focal brain lesions induced with ultraviolet irradiation.

PubMed

Nakata, Mariko; Nagasaka, Kazuaki; Shimoda, Masayuki; Takashima, Ichiro; Yamamoto, Shinya

2018-05-22

Lesion and inactivation methods have played important roles in neuroscience studies. However, traditional techniques for creating a brain lesion are highly invasive, and control of lesion size and shape using these techniques is not easy. Here, we developed a novel method for creating a lesion on the cortical surface via 365 nm ultraviolet (UV) irradiation without breaking the dura mater. We demonstrated that 2.0 mWh UV irradiation, but not the same amount of non-UV light irradiation, induced an inverted bell-shaped lesion with neuronal loss and accumulation of glial cells. Moreover, the volume of the UV irradiation-induced lesion depended on the UV light exposure amount. We further succeeded in visualizing the lesioned site in a living animal using magnetic resonance imaging (MRI). Importantly, we also observed using an optical imaging technique that the spread of neural activation evoked by adjacent cortical stimulation disappeared only at the UV-irradiated site. In summary, UV irradiation can induce a focal brain lesion with a stable shape and size in a less invasive manner than traditional lesioning methods. This method is applicable to not only neuroscientific lesion experiments but also studies of the focal brain injury recovery process.

Imaging of mild traumatic brain injury using 57Co and 99mTc HMPAO SPECT as compared to other diagnostic procedures.

PubMed

Audenaert, Kurt; Jansen, Hugo M L; Otte, Andreas; Peremans, Kathelijne; Vervaet, Myriam; Crombez, Roger; de Ridder, Leo; van Heeringen, Cees; Thirot, Joel; Dierckx, Rudi; Korf, Jaap

2003-10-01

Traumatic brain injury (TBI) is usually assessed with the Glasgow Coma Scale (GCS), CT and EEG. TBI can result from either the primary mechanical impact or secondary (ischemic) brain damage, in which calcium (Ca) plays a pivotal role. This study was undertaken to compare the applicability of SPECT using 57Co as a Ca-tracer in patients with mild traumatic brain injury. 8 patients with mild TBI (GCS 15) were clinically examined and studied with EEG, neuropsychological testing (NPT) and SPECT within 2 days post-TBI. After i.v.-administration of 37 MBq (1 mCi) 57Co (effective radiation dose 0.34 mSv x MBq(-1); 1.24 rem x mCi(-1); physical half-life 270 days, biological half-life 37.6 h), single-headed SPECT (12 h pi) was performed, consecutively followed by standard 925 MBq (25 mCi) Tc-99m HMPAO SPECT. In 6 of the 8 patients, baseline NPT and SPECT showed focal abnormalities in the affected frontal and temporal brain regions, which were in good topographical accordance. CT and EEG did not detect (structural) lesions in any of these cases. Single-headed 57Co-SPECT is able to show the site and extent of brain damage in patients with mild TBI, even in the absence of structural lesions. It may confirm and localize NPT findings. The predictive value of 57Co-SPECT should be assessed in larger patient series.

Topographic distribution of brain iron deposition and small cerebrovascular lesions in amyotrophic lateral sclerosis and in frontotemporal lobar degeneration: a post-mortem 7.0-tesla magnetic resonance imaging study with neuropathological correlates.

PubMed

De Reuck, Jacques; Devos, David; Moreau, Caroline; Auger, Florent; Durieux, Nicolas; Deramecourt, Vincent; Pasquier, Florence; Maurage, Claude-Alain; Cordonnier, Charlotte; Leys, Didier; Bordet, Regis

2017-12-01

Amyotrophic lateral sclerosis (ALS) is associated with frontotemporal lobar degeneration (FTLD) in 15% of the cases. A neuropathological continuity between ALS and FTLD-TDP is suspected. The present post-mortem 7.0-tesla magnetic resonance imaging (MRI) study compares the topographic distribution of iron (Fe) deposition and the incidence of small cerebrovascular lesions in ALS and in FTLD brains. Seventy-eight post-mortem brains underwent 7.0-tesla MRI. The patients consisted of 12 with ALS, 38 with FTLD, and 28 controls. Three ALS brains had minor FTLD features. Three coronal sections of a cerebral hemisphere were submitted to T2 and T2* MRI sequences. The amount of Fe deposition in the deep brain structures and the number of small cerebrovascular lesions was determined in ALS and the subtypes of FTLD compared to control brains, with neuropathological correlates. A significant increase of Fe deposition was observed in the claustrum, caudate nucleus, globus pallidus, thalamus, and subthalamic nucleus of the FTLD-FUS and FTLD-TDP groups, while in the ALS one, the Fe increase was only observed in the caudate and the subthalamic nuclei. White matter changes were only significantly more severe in the FTLD compared to those in ALS and in controls brains. Cortical micro-bleeds were increased in the frontal and temporal lobes of FTLD as well as of ALS brains compared to controls. Cortical micro-infarcts were, on the other hand, more frequent in the control compared to the ALS and FTLD groups. The present study supports the assumption of a neuropathological continuity between ALS and FTLD and illustrates the favourable vascular risk profile in these diseases.

The frontal lobe and aggression

PubMed Central

Séguin, Jean R.

2014-01-01

Frontal lesions often lead to psychosocial problems. It is not surprising that frontal lobe dysfunctions have been proposed to underlie antisocial behaviour in individuals without apparent lesions. However, physical aggression and violence have never been systematically related to acquired lesions. Whereas, traditional neuropsychological testing identifies problems in cognitive and emotional information processing, recent brain-imaging studies have revealed both the frontal structural and functional underpinnings of antisocial behaviour. Careful characterization of antisocial behaviour subtypes seems to indicate that cognitive-neuropsychological function is systematically poor in physical aggression and hyperactivity. Recent refinements point to biological and genetic moderators of that association. PMID:24976846

Brain networks of temporal preparation: A multiple regression analysis of neuropsychological data.

PubMed

Triviño, Mónica; Correa, Ángel; Lupiáñez, Juan; Funes, María Jesús; Catena, Andrés; He, Xun; Humphreys, Glyn W

2016-11-15

There are only a few studies on the brain networks involved in the ability to prepare in time, and most of them followed a correlational rather than a neuropsychological approach. The present neuropsychological study performed multiple regression analysis to address the relationship between both grey and white matter (measured by magnetic resonance imaging in patients with brain lesion) and different effects in temporal preparation (Temporal orienting, Foreperiod and Sequential effects). Two versions of a temporal preparation task were administered to a group of 23 patients with acquired brain injury. In one task, the cue presented (a red versus green square) to inform participants about the time of appearance (early versus late) of a target stimulus was blocked, while in the other task the cue was manipulated on a trial-by-trial basis. The duration of the cue-target time intervals (400 versus 1400ms) was always manipulated within blocks in both tasks. Regression analysis were conducted between either the grey matter lesion size or the white matter tracts disconnection and the three temporal preparation effects separately. The main finding was that each temporal preparation effect was predicted by a different network of structures, depending on cue expectancy. Specifically, the Temporal orienting effect was related to both prefrontal and temporal brain areas. The Foreperiod effect was related to right and left prefrontal structures. Sequential effects were predicted by both parietal cortex and left subcortical structures. These findings show a clear dissociation of brain circuits involved in the different ways to prepare in time, showing for the first time the involvement of temporal areas in the Temporal orienting effect, as well as the parietal cortex in the Sequential effects. Copyright © 2016 Elsevier Inc. All rights reserved.

Detection of small human cerebral cortical lesions with MRI under different levels of Gaussian smoothing: applications in epilepsy

NASA Astrophysics Data System (ADS)

Cantor-Rivera, Diego; Goubran, Maged; Kraguljac, Alan; Bartha, Robert; Peters, Terry

2010-03-01

The main objective of this study was to assess the effect of smoothing filter selection in Voxel-Based Morphometry studies on structural T1-weighted magnetic resonance images. Gaussian filters of 4 mm, 8 mm or 10 mm Full Width at High Maximum are commonly used, based on the assumption that the filter size should be at least twice the voxel size to obtain robust statistical results. The hypothesis of the presented work was that the selection of the smoothing filter influenced the detectability of small lesions in the brain. Mesial Temporal Sclerosis associated to Epilepsy was used as the case to demonstrate this effect. Twenty T1-weighted MRIs from the BrainWeb database were selected. A small phantom lesion was placed in the amygdala, hippocampus, or parahippocampal gyrus of ten of the images. Subsequently the images were registered to the ICBM/MNI space. After grey matter segmentation, a T-test was carried out to compare each image containing a phantom lesion with the rest of the images in the set. For each lesion the T-test was repeated with different Gaussian filter sizes. Voxel-Based Morphometry detected some of the phantom lesions. Of the three parameters considered: location,size, and intensity; it was shown that location is the dominant factor for the detection of the lesions.

Neurosarcoidosis associated with hypersomnolence treated with corticosteroids and brain irradiation

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

Rubinstein, I.; Gray, T.A.; Moldofsky, H.

1988-07-01

Narcoleptic features developed in a young man with CNS sarcoidosis. This was associated with a structural lesion in the hypothalamus as demonstrated on CT scans of the head. The diagnosis of narcolepsy was established by compatible clinical history and the Multiple Sleep Latency Test. Treatment with high-dose corticosteroids was ineffective, but when the low-dose, whole-brain irradiation was added, complete resolution of the narcoleptic features ensued.

The treatment of extensive scalp lesions combining electrons with intensity-modulated photons.

PubMed

Chan, Maria F; Song, Yulin; Burman, Chandra; Chui, Chen S; Schupak, Karen

2006-01-01

This study was to investigate the feasibility and potential benefits of combining electrons with intensity modulated photons (IMRT+e) for patients with extensive scalp lesions. A case of a patient with an extensive scalp lesion, in which the target volume covered the entire front half of the scalp, is presented. This approach incorporated the electron dose into the inverse treatment planning optimization. The resulting doses to the planning target volume (PTV) and relevant critical structures were compared. Thermoluminescent dosimeters (TLD), diodes, and GAFCHROMIC EBT films were used to verify the accuracy of the techniques. The IMRT+e plan produced a superior dose distribution to the patient as compared to the IMRT plan in terms of reduction of the dose to the brain with the same dose conformity and homogeneity in the target volumes. This study showed that IMRT+e is a viable treatment modality for extensive scalp lesions patients. It provides a feasible alternative to existing treatment techniques, resulting in improved homogeneity of dose to the PTV compared to conventional electron techniques and a decrease in dose to the brain compared to photon IMRT alone.

Reinforcement of the Brain's Rich-Club Architecture Following Early Neurodevelopmental Disruption Caused by Very Preterm Birth

PubMed Central

Karolis, Vyacheslav R.; Froudist-Walsh, Sean; Brittain, Philip J.; Kroll, Jasmin; Ball, Gareth; Edwards, A. David; Dell'Acqua, Flavio; Williams, Steven C.; Murray, Robin M.; Nosarti, Chiara

2016-01-01

The second half of pregnancy is a crucial period for the development of structural brain connectivity, and an abrupt interruption of the typical processes of development during this phase caused by the very preterm birth (<33 weeks of gestation) is likely to result in long-lasting consequences. We used structural and diffusion imaging data to reconstruct the brain structural connectome in very preterm-born adults. We assessed its rich-club organization and modularity as 2 characteristics reflecting the capacity to support global and local information exchange, respectively. Our results suggest that the establishment of global connectivity patterns is prioritized over peripheral connectivity following early neurodevelopmental disruption. The very preterm brain exhibited a stronger rich-club architecture than the control brain, despite possessing a relative paucity of white matter resources. Using a simulated lesion approach, we also investigated whether putative structural reorganization takes place in the very preterm brain in order to compensate for its anatomical constraints. We found that connections between the basal ganglia and (pre-) motor regions, as well as connections between subcortical regions, assumed an altered role in the structural connectivity of the very preterm brain, and that such alterations had functional implications for information flow, rule learning, and verbal IQ. PMID:26742566

In Vivo Characterization of Traumatic Brain Injury Neuropathology with Structural and Functional Neuroimaging

PubMed Central

LEVINE, BRIAN; FUJIWARA, ESTHER; O’CONNOR, CHARLENE; RICHARD, NADINE; KOVACEVIC, NATASA; MANDIC, MARINA; RESTAGNO, ADRIANA; EASDON, CRAIG; ROBERTSON, IAN H.; GRAHAM, SIMON J.; CHEUNG, GORDON; GAO, FUQIANG; SCHWARTZ, MICHAEL L.; BLACK, SANDRA E.

2007-01-01

Quantitative neuroimaging is increasingly used to study the effects of traumatic brain injury (TBI) on brain structure and function. This paper reviews quantitative structural and functional neuroimaging studies of patients with TBI, with an emphasis on the effects of diffuse axonal injury (DAI), the primary neuropathology in TBI. Quantitative structural neuroimaging has evolved from simple planometric measurements through targeted region-of-interest analyses to whole-brain analysis of quantified tissue compartments. Recent studies converge to indicate widespread volume loss of both gray and white matter in patients with moderate-to-severe TBI. These changes can be documented even when patients with focal lesions are excluded. Broadly speaking, performance on standard neuropsychological tests of speeded information processing are related to these changes, but demonstration of specific brain-behavior relationships requires more refined experimental behavioral measures. The functional consequences of these structural changes can be imaged with activation functional neuroimaging. Although this line of research is at an early stage, results indicate that TBI causes a more widely dispersed activation in frontal and posterior cortices. Further progress in analysis of the consequences of TBI on neural structure and function will require control of variability in neuropathology and behavior. PMID:17020478

SU-G-IeP1-07: Inaccuracy of Lesion Blood Flow Quantification Related to the Proton Density Reference Image in Arterial Spin Labeling MRI of Brain Tumors

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

Jen, M; Johnson, J; Hou, P

Purpose: Cerebral blood flow quantification in arterial spin labeling (ASL) MRI requires an estimate of the equilibrium magnetization of blood, which is often obtained by a set of proton density (PD) reference image. Normally, a constant blood-brain partition coefficient is assumed across the brain. However, this assumption may not be valid for brain lesions. This study aimed to evaluate the impact of lesion-related PD variations on ASL quantification in patients with brain tumors. Methods: MR images for posttreatment evaluation of 42 patients with brain tumors were retrospectively analyzed. These images were acquired on a 3T MRI scanner, including T2-weighted FLAIR,more » 3D pseudo-continuous ASL and post-contrast T1-weighted images. Anatomical images were coregistered with ASL images using the SPM software. Regions of interest (ROIs) of the enhancing and FLAIR lesions were manually drawn on the coregistered images. ROIs of the contralateral normal appearing tissues were also determined, with the consideration of approximating coil sensitivity patterns in lesion ROIs. Relative lesion blood flow (lesion/contralateral tissue) was calculated from both the CBF map (dependent on the PD) and the ΔM map for comparison. Results: The signal intensities in both enhancing and FLAIR lesions were significantly different than contralateral tissues on the PD reference image (p<0.001). The percent signal difference ranged from −15.9 to 19.2%, with a mean of 5.4% for the enhancing lesion, and from −2.8 to 22.9% with a mean of 10.1% for the FLAIR lesion. The high/low lesion-related PD signal resulted in inversely proportional under-/over-estimation of blood flow in both enhancing and FLAIR lesions. Conclusion: Significant signal differences were found between lesions and contralateral tissues in the PD reference image, which introduced errors in blood flow quantification in ASL. The error can be up to 20% in individual patients with an average of 5- 10% for the group of patients with brain tumors.« less

Behavioral consequences of selective damage to frontal pole and posterior cingulate cortices

PubMed Central

Mansouri, Farshad A.; Buckley, Mark J.; Mahboubi, Majid; Tanaka, Keiji

2015-01-01

Frontal pole cortex (FPC) and posterior cingulate cortex (PCC) have close neuroanatomical connections, and imaging studies have shown coactivation or codeactivation of these brain regions during performance of certain tasks. However, they are among the least well-understood regions of the primate brain. One reason for this is that the consequences of selective bilateral lesions to either structure have not previously been studied in any primate species. We studied the effects of circumscribed bilateral lesions to FPC or PCC on monkeys’ ability to perform an analog of Wisconsin Card Sorting Test (WCST) and related tasks. In contrast to lesions in other prefrontal regions, neither posttraining FPC nor PCC lesions impaired animals’ abilities to follow the rule switches that frequently occurred within the WCST task. However, FPC lesions were not without effect, because they augmented the ability of animals to adjust cognitive control after experiencing high levels of conflict (whereas PCC lesions did not have any effect). In addition, FPC-lesioned monkeys were more successful than controls or PCC-lesioned animals at remembering the relevant rule across experimentally imposed distractions involving either an intervening secondary task or a surprising delivery of free reward. Although prefrontal cortex posterior to FPC is specialized for mediating efficient goal-directed behavior to maximally exploit reward opportunities from ongoing tasks, our data led us to suggest that FPC is, instead, specialized for disengaging executive control from the current task and redistributing it to novel sources of reward to explore new opportunities/goals. PMID:26150522

Treatment of Five or More Brain Metastases With Stereotactic Radiosurgery

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

Hunter, Grant K.; Suh, John H.; Reuther, Alwyn M.

2012-08-01

Purpose: To examine the outcomes of patients with five or more brain metastases treated in a single session with stereotactic radiosurgery (SRS). Methods and Materials: Sixty-four patients with brain metastases treated with SRS to five or more lesions in a single session were reviewed. Primary disease type, number of lesions, Karnofsky performance score (KPS) at SRS, and status of primary and systemic disease at SRS were included. Patients were treated using dosing as defined by Radiation Therapy Oncology Group Protocol 90-05, with adjustments for critical structures. We defined prior whole-brain radiotherapy (WBRT) as WBRT completed >1 month before SRS andmore » concurrent WBRT as WBRT completed within 1 month before or after SRS. Kaplan-Meier estimates and Cox proportional hazard regression were used to determine which patient and treatment factors predicted overall survival (OS). Results: The median OS after SRS was 7.5 months. The median KPS was 80 (range, 60-100). A KPS of {>=}80 significantly influenced OS (median OS, 4.8 months for KPS {<=}70 vs. 8.8 months for KPS {>=}80, p = 0.0097). The number of lesions treated did not significantly influence OS (median OS, 6.6 months for eight or fewer lesions vs. 9.9 months for more than eight, p = nonsignificant). Primary site histology did not significantly influence median OS. On multivariate Cox modeling, KPS and prior WBRT significantly predicted for OS. Whole-brain radiotherapy before SRS compared with concurrent WBRT significantly influenced survival, with a risk ratio of 0.423 (95% confidence interval 0.191-0.936, p = 0.0338). No significant differences were observed when no WBRT was compared with concurrent WBRT or when the no WBRT group was compared with prior WBRT. A KPS of {<=}70 predicted for poorer outcomes, with a risk ratio of 2.164 (95% confidence interval 1.157-4.049, p = 0.0157). Conclusions: Stereotactic radiosurgery to five or more brain lesions is an effective treatment option for patients with metastatic cancer, especially for patients previously treated with WBRT. A KPS of {>=}80 predicts for an improved outcome.« less

Lesion segmentation from multimodal MRI using random forest following ischemic stroke.

PubMed

Mitra, Jhimli; Bourgeat, Pierrick; Fripp, Jurgen; Ghose, Soumya; Rose, Stephen; Salvado, Olivier; Connelly, Alan; Campbell, Bruce; Palmer, Susan; Sharma, Gagan; Christensen, Soren; Carey, Leeanne

2014-09-01

Understanding structure-function relationships in the brain after stroke is reliant not only on the accurate anatomical delineation of the focal ischemic lesion, but also on previous infarcts, remote changes and the presence of white matter hyperintensities. The robust definition of primary stroke boundaries and secondary brain lesions will have significant impact on investigation of brain-behavior relationships and lesion volume correlations with clinical measures after stroke. Here we present an automated approach to identify chronic ischemic infarcts in addition to other white matter pathologies, that may be used to aid the development of post-stroke management strategies. Our approach uses Bayesian-Markov Random Field (MRF) classification to segment probable lesion volumes present on fluid attenuated inversion recovery (FLAIR) MRI. Thereafter, a random forest classification of the information from multimodal (T1-weighted, T2-weighted, FLAIR, and apparent diffusion coefficient (ADC)) MRI images and other context-aware features (within the probable lesion areas) was used to extract areas with high likelihood of being classified as lesions. The final segmentation of the lesion was obtained by thresholding the random forest probabilistic maps. The accuracy of the automated lesion delineation method was assessed in a total of 36 patients (24 male, 12 female, mean age: 64.57±14.23yrs) at 3months after stroke onset and compared with manually segmented lesion volumes by an expert. Accuracy assessment of the automated lesion identification method was performed using the commonly used evaluation metrics. The mean sensitivity of segmentation was measured to be 0.53±0.13 with a mean positive predictive value of 0.75±0.18. The mean lesion volume difference was observed to be 32.32%±21.643% with a high Pearson's correlation of r=0.76 (p<0.0001). The lesion overlap accuracy was measured in terms of Dice similarity coefficient with a mean of 0.60±0.12, while the contour accuracy was observed with a mean surface distance of 3.06mm±3.17mm. The results signify that our method was successful in identifying most of the lesion areas in FLAIR with a low false positive rate. Copyright © 2014 Elsevier Inc. All rights reserved.

Mapping higher-order relations between brain structure and function with embedded vector representations of connectomes.

PubMed

Rosenthal, Gideon; Váša, František; Griffa, Alessandra; Hagmann, Patric; Amico, Enrico; Goñi, Joaquín; Avidan, Galia; Sporns, Olaf

2018-06-05

Connectomics generates comprehensive maps of brain networks, represented as nodes and their pairwise connections. The functional roles of nodes are defined by their direct and indirect connectivity with the rest of the network. However, the network context is not directly accessible at the level of individual nodes. Similar problems in language processing have been addressed with algorithms such as word2vec that create embeddings of words and their relations in a meaningful low-dimensional vector space. Here we apply this approach to create embedded vector representations of brain networks or connectome embeddings (CE). CE can characterize correspondence relations among brain regions, and can be used to infer links that are lacking from the original structural diffusion imaging, e.g., inter-hemispheric homotopic connections. Moreover, we construct predictive deep models of functional and structural connectivity, and simulate network-wide lesion effects using the face processing system as our application domain. We suggest that CE offers a novel approach to revealing relations between connectome structure and function.

Imaging of Traumatic Brain Injury.

PubMed

Bodanapally, Uttam K; Sours, Chandler; Zhuo, Jiachen; Shanmuganathan, Kathirkamanathan

2015-07-01

Imaging plays an important role in the management of patients with traumatic brain injury (TBI). Computed tomography (CT) is the first-line imaging technique allowing rapid detection of primary structural brain lesions that require surgical intervention. CT also detects various deleterious secondary insults allowing early medical and surgical management. Serial imaging is critical to identifying secondary injuries. MR imaging is indicated in patients with acute TBI when CT fails to explain neurologic findings. However, MR imaging is superior in patients with subacute and chronic TBI and also predicts neurocognitive outcome. Copyright © 2015 Elsevier Inc. All rights reserved.

Diagnostic performance of brain MRI in pharmacovigilance of natalizumab-treated MS patients.

PubMed

Wattjes, Mike P; Wijburg, Martijn T; Vennegoor, Anke; Witte, Birgit I; Roosendaal, Stefan D; Sanchez, Esther; Liu, Yaou; Martins Jarnalo, Carine O; Richert, Nancy D; Uitdehaag, Bernard Mj; Barkhof, Frederik; Killestein, Joep

2016-08-01

In natalizumab-treated multiple sclerosis (MS) patients, magnetic resonance imaging (MRI) is considered as a sensitive tool in detecting both MS disease activity and progressive multifocal leukoencephalopathy (PML). To investigate the performance of neuroradiologists using brain MRI in detecting new MS lesions and asymptomatic PML lesions and in differentiating between MS and PML lesions in natalizumab-treated MS patients. The secondary aim was to investigate interrater variability. In this retrospective diagnostic study, four blinded neuroradiologists assessed reference and follow-up brain MRI scans of 48 natalizumab-treated MS patients with new asymptomatic PML lesions (n = 21) or new MS lesions (n = 20) or no new lesions (n = 7). Sensitivity and specificity for detection of new lesions in general (MS and PML lesions), MS and PML lesion differentiation, and PML detection were determined. Interrater agreement was calculated. Overall sensitivity and specificity for the detection of new lesions, regardless of the nature of the lesions, were 77.4% and 89.3%, respectively; for PML-MS lesion differentiation, 74.2% and 84.7%, respectively; and for asymptomatic PML lesion detection, 59.5% and 91.7%, respectively. Interrater agreement for the tested categories was fair to moderate. The diagnostic performance of trained neuroradiologists using brain MRI in pharmacovigilance of natalizumab-treated MS patients is moderately good. Interrater agreement among trained readers is fair to moderate. © The Author(s), 2015.

Lesions of entorhinal cortex produce a calpain-mediated degradation of brain spectrin in dentate gyrus. I. Biochemical studies.

PubMed

Seubert, P; Ivy, G; Larson, J; Lee, J; Shahi, K; Baudry, M; Lynch, G

1988-09-06

Lesions of the rat entorhinal cortex cause extensive synaptic restructuring and perturbation of calcium regulation in the dentate gyrus of hippocampus. Calpain is a calcium-activated protease which has been implicated in degenerative phenomena in muscles and in peripheral nerves. In addition, calpain degrades several major structural neuronal proteins and has been proposed to play a critical role in the morphological changes observed following deafferentation. In this report we present evidence that lesions of the entorhinal cortex produce a marked increase in the breakdown of brain spectrin, a substrate for calpain, in the dentate gyrus. Two lines of evidence indicate that this effect is due to calpain activation: (i) the spectrin breakdown products observed following the lesion are indistinguishable from calpain-generated spectrin fragments in vitro; and (ii) their appearance can be reduced by prior intraventricular in fusion of leupeptin, a calpain inhibitor. Levels of spectrin breakdown products are increased as early as 4 h post-lesion, reach maximal values at 2 days, and remain above normal to some degree for at least 27 days. In addition, a small but significant increase in spectrin proteolysis is also observed in the hippocampus contralateral to the lesioned side in the first week postlesion. At 2 days postlesion the total spectrin immunoreactivity (native polypeptide plus breakdown products) increases by 40%, suggesting that denervation of the dentate gyrus produces not only an increased rate of spectrin degradation but also an increased rate of spectrin synthesis. These results indicate that calpain activation and spectrin degradation are early biochemical events following deafferentation and might well participate in the remodelling of postsynaptic structures. Finally, the magnitude of the observed effects as well as the stable nature of the breakdown products provide a sensitive assay for neuronal pathology.

Interleukin-6 -174 and -572 genotypes and the volume of deep gray matter in preterm infants.

PubMed

Reiman, Milla; Parkkola, Riitta; Lapinleimu, Helena; Lehtonen, Liisa; Haataja, Leena

2009-01-01

Preterm infants have smaller cerebral and cerebellar volumes at term compared with term born infants. Perinatal factors leading to the reduction in volumes are not well known. IL-6 -174 and -572 genotypes partly regulate individual immunologic responses and have also been connected with deviant neurologic development in preterm infants. Our hypothesis was that IL-6 -174 and -572 genetic polymorphisms are associated with brain lesions and regional brain volumes in very low birth weight or in very preterm infants. DNA was genotyped for IL-6 -174 and -572 polymorphisms (GG/GC/CC). Study infants (n = 175) were categorized into three groups according to the most pathologic brain finding in ultrasound examinations until term. The brain MRI performed at term was analyzed for regional brain volumes. Analyzed IL-6 genotypes did not show statistically significant association with structural brain lesions. However, IL-6 -174 CC and -572 GG genotypes associated with reduced volume of one brain region, the combined volume of basal ganglia and thalami, both in univariate and in multivariate analyses (p = 0.009, 0.009, respectively). The association of IL-6 -174 and -572 genetic polymorphisms with smaller volumes in deep gray matter provides us new ways to understand the processes leading to neurologic impairments in preterm infants.

Syringe Port: A Convenient, Safe, and Cost-Effective Tubular Retractor for Transportal Removal of Deep-Seated Lesions of the Brain.

PubMed

Singh, Harnarayan; Patir, Rana; Vaishya, Sandeep; Miglani, Rahul; Kaur, Amandeep

2018-06-01

Minimally invasive transportal resection of deep intracranial lesions has become a widely accepted surgical technique. Many disposable, mountable port systems are available in the market for this purpose, like the ViewSite Brain Access System. The objective of this study was to find a cost-effective substitute for these systems. Deep-seated brain lesions were treated with a port system made from disposable syringes. The syringe port could be inserted through minicraniotomies placed and planned with navigation. All deep-seated lesions like ventricular tumours, colloid cysts, deep-seated gliomas, and basal ganglia hemorrhages were treated with this syringe port system and evaluated for safety, operative site hematomas, and blood loss. 62 patients were operated on during the study period from January 2015 to July 2017, using this innovative syringe port system for deep-seated lesions of the brain. No operative site hematoma or contusions were seen along the port entry site and tract. Syringe port is a cost-effective and safe alternative to the costly disposable brain port systems, especially for neurosurgical setups in developing countries for minimally invasive transportal resection of deep brain lesions. Copyright © 2018 Elsevier Inc. All rights reserved.

Differential DNA damage in response to the neonatal and adult excitotoxic hippocampal lesion in rats.

PubMed

Khaing, Z Z; Weickert, C S; Weinberger, D R; Lipska, B K

2000-12-01

We examined the developmental profile of excitotoxin-induced nuclear DNA fragmentation using the transferase dUTP nick-end labelling (TUNEL) technique, as a marker of DNA damage and cell death in rats with neonatal and adult excitotoxic lesions of the ventral hippocampus. We hypothesized that infusion of neurotoxin may result in a differential pattern of cell death in neonatally and adult lesioned rats, both in the infusion site and in remote brain regions presumably involved in mediating behavioural changes observed in these animals. Brains of rats lesioned at 7 days of age and in adulthood were collected at several survival times 1-21 days after the lesion. In the lesioned neonates 1-3 days postlesion, marked increases in TUNEL-positive cells occurred in the ventral hippocampus, the site of neurotoxin infusion, and in a wide surrounding area. Adult lesioned brains showed more positive cells than controls only at the infusion site. In the lesioned neonates, TUNEL-labelled cells were also present in the striatum and nucleus accumbens 1 day postlesion but not at later survival times. Our findings indicate that cell death in remote regions is more prominent in immature than adult brains, that it may lead to distinct alterations in development of these brain regions, and thus may be responsible for functional differences between neonatally and adult lesioned rats.

Finding the imposter: brain connectivity of lesions causing delusional misidentifications

PubMed Central

Darby, R Ryan; Laganiere, Simon; Pascual-Leone, Alvaro; Prasad, Sashank; Fox, Michael D

2017-01-01

Abstract See McKay and Furl (doi:10.1093/aww323) for a scientific commentary on this article. Focal brain injury can sometimes lead to bizarre symptoms, such as the delusion that a family member has been replaced by an imposter (Capgras syndrome). How a single brain lesion could cause such a complex disorder is unclear, leading many to speculate that concurrent delirium, psychiatric disease, dementia, or a second lesion is required. Here we instead propose that Capgras and other delusional misidentification syndromes arise from single lesions at unique locations within the human brain connectome. This hypothesis is motivated by evidence that symptoms emerge from sites functionally connected to a lesion location, not just the lesion location itself. First, 17 cases of lesion-induced delusional misidentifications were identified and lesion locations were mapped to a common brain atlas. Second, lesion network mapping was used to identify brain regions functionally connected to the lesion locations. Third, regions involved in familiarity perception and belief evaluation, two processes thought to be abnormal in delusional misidentifications, were identified using meta-analyses of previous functional magnetic resonance imaging studies. We found that all 17 lesion locations were functionally connected to the left retrosplenial cortex, the region most activated in functional magnetic resonance imaging studies of familiarity. Similarly, 16 of 17 lesion locations were functionally connected to the right frontal cortex, the region most activated in functional magnetic resonance imaging studies of expectation violation, a component of belief evaluation. This connectivity pattern was highly specific for delusional misidentifications compared to four other lesion-induced neurological syndromes (P < 0.0001). Finally, 15 lesions causing other types of delusions were connected to expectation violation (P < 0.0001) but not familiarity regions, demonstrating specificity for delusion content. Our results provide potential neuroanatomical correlates for impaired familiarity perception and belief evaluation in patients with delusional misidentifications. More generally, we demonstrate a mechanism by which a single lesion can cause a complex neuropsychiatric syndrome based on that lesion’s unique pattern of functional connectivity, without the need for pre-existing or hidden pathology. PMID:28082298

Spectrum of MRI brain lesion patterns in neuromyelitis optica spectrum disorder: a pictorial review.

PubMed

Wang, Kevin Yuqi; Chetta, Justin; Bains, Pavit; Balzer, Anthony; Lincoln, John; Uribe, Tomas; Lincoln, Christie M

2018-06-01

Neuromyelitis optica is a neurotropic autoimmune inflammatory disease of the central nervous system traditionally thought to exclusively involve the optic nerves and spinal cord. With the discovery of the disease-specific aquaporin-4 antibody and the increasing recognition of clinical and characteristic imaging patterns of brain involvement in what is now termed neuromyelitis optica spectrum disorder (NMOSD), MRI now plays a greater role in diagnosis of NMOSD based on the 2015 consensus criteria and in distinguishing it from other inflammatory disorders, particularly multiple sclerosis (MS). Several brain lesion patterns are highly suggestive of NMOSD, whereas others may serve as red flags. Specifically, long corticospinal lesions, hemispheric cerebral white matter lesions and periependymal lesions in the diencephalon, dorsal brainstem and white matter adjacent to lateral ventricles are typical of NMOSD. In contrast, juxtacortical, cortical, or lesions perpendicularly oriented to the surface of the lateral ventricle suggests MS as the diagnosis. Ultimately, a strong recognition of the spectrum of MRI brain findings in NMOSD is essential for accurate diagnosis, and particularly in differentiating from MS. This pictorial review highlights the spectrum of characteristic brain lesion patterns that may be seen in NMOSD and further delineates findings that may help distinguish it from MS.

Secondary brain injuries in thalamus and hippocampus after focal ischemia caused by mild, transient extradural compression of the somatosensori cortex in the rat.

PubMed

Holmberg, Per; Liljequist, Sture; Wägner, Anna

2009-02-01

The development and distribution of secondary brain lesions, subsequent to ischemic stroke, are of considerable clinical interest but so far only a limited number of studies have investigated the distribution and development of these secondary lesions in detail. In this study, we used an animal model of focal ischemia caused by extradural compression of the sensorimotor cortex. This paradigm of focal ischemia was shown to produce a consistent pattern of secondary lesions located distally from the primary lesion. Functionally the primary brain lesion produced a transient neurological deficit, which was evaluated by daily beam walking tests. Morphological changes were assessed in parallel after the ischemic event using Fluoro-Jade (FJ) staining as a marker of neuronal cell death. Secondary brain lesions were observed in the thalamus as well as in the hippocampus. The first sign of the slowly developing secondary brain lesions was present on day 3 with subsequent lesions being identified until day 16 after the primary ischemia. In addition to the identification of neuronal cell death by the FJ assays, immunostaining for parvalbumin (PA), a marker of GABAergic interneurons, revealed a loss of PA-staining in the pyramidal layer of CA1 on day 3, thus showing a similar time pattern for loss of PA-staining as for the loss of FJ stained cells. Based upon our present results, we suggest that the current animal model of focal ischemia represents a valuable tool for studies concerning the development of secondary remote brain lesions and their association to impaired motor and cognitive functions.

Expression of Antigen Processing and Presenting Molecules in Brain Metastasis of Breast Cancer

PubMed Central

Liu, Yan; Komohara, Yoshihiro; Domenick, Natalie; Ohno, Masasuke; Ikeura, Maki; Hamilton, Ronald L.; Horbinski, Craig; Wang, Xinhui; Ferrone, Soldano; Okada, Hideho

2012-01-01

Defects in human leukocyte antigen (HLA) class I antigen processing machinery (APM) component expression can have a negative impact on the clinical course of tumors and the response to T-cell-based immunotherapy. Since brain metastases of breast cancer are of increasing clinical significance, the APM component expression levels and CD8+ T-cell infiltration patterns were analyzed in primary breast and metastatic brain lesions of breast cancer by immunohistochemistry. Comparison of unpaired 50 primary and 33 brain metastases showed lower expression of β2-microgloblin, transporter associated with antigen processing (TAP) 1, TAP2 and calnexin in the brain lesions. Although no significant differences were found in APM component scores between primary breast and brain lesions in 15 paired cases, primary breast lesions of which patients eventually developed brain metastases showed lower levels of β2-microgloblin, TAP1 and calnexin compared with breast lesions without known brain metastases. The extent of CD8+ T cell infiltration was significantly higher in the lesions without metastasis compared with the ones with brain metastases, and was positively associated with the expression of TAP1 and calnexin. Furthermore, mouse tumor cells stably transfected with silencing hairpin (sh)RNA for TAP1 demonstrated a decreased susceptibility to cytotoxic T lymphocytes (CTL) in vitro and enhanced spontaneous brain metastasis in vivo. These data support the functional significance of TAP1 expression in tumor cells. Taken together, our data suggest that patients with low or defective TAP1 or calnexin in primary breast cancers may be at higher risks for developing brain metastasis due to the defects in T cell-based immunosurveillance. PMID:22065046

Lesion registration for longitudinal disease tracking in an imaging informatics-based multiple sclerosis eFolder

NASA Astrophysics Data System (ADS)

Ma, Kevin; Liu, Joseph; Zhang, Xuejun; Lerner, Alex; Shiroishi, Mark; Amezcua, Lilyana; Liu, Brent

2016-03-01

We have designed and developed a multiple sclerosis eFolder system for patient data storage, image viewing, and automatic lesion quantification results stored in DICOM-SR format. The web-based system aims to be integrated in DICOM-compliant clinical and research environments to aid clinicians in patient treatments and data analysis. The system needs to quantify lesion volumes, identify and register lesion locations to track shifts in volume and quantity of lesions in a longitudinal study. In order to perform lesion registration, we have developed a brain warping and normalizing methodology using Statistical Parametric Mapping (SPM) MATLAB toolkit for brain MRI. Patients' brain MR images are processed via SPM's normalization processes, and the brain images are analyzed and warped according to the tissue probability map. Lesion identification and contouring are completed by neuroradiologists, and lesion volume quantification is completed by the eFolder's CAD program. Lesion comparison results in longitudinal studies show key growth and active regions. The results display successful lesion registration and tracking over a longitudinal study. Lesion change results are graphically represented in the web-based user interface, and users are able to correlate patient progress and changes in the MRI images. The completed lesion and disease tracking tool would enable the eFolder to provide complete patient profiles, improve the efficiency of patient care, and perform comprehensive data analysis through an integrated imaging informatics system.

Reading Development in Typically Developing Children and Children With Prenatal or Perinatal Brain Lesions: Differential School Year and Summer Growth.

PubMed

Demir-Lira, Özlem Ece; Levine, Susan C

2016-01-01

Summer slide, uneven growth of academic skills over the calendar year, captures the fact that the learning gains children make over the school year do not continue at the same pace over the summer, when children are typically not in school. We compared growth of reading skills during the school year and over the summer months in children with pre-or perinatal brain lesion (PL) and typically-developing (TD) children from varying socioeconomic status (SES) backgrounds as a new way to probe the role of structured environmental support in functional plasticity for reading skills in children with PL. Results showed that children with PL performed lower than TD children on both reading decoding and reading comprehension. Group differences were primarily driven by children with larger lesions and children with right hemisphere lesions (RH). For reading comprehension, children with RH showed greater growth during the school year but more slide during the summer months than both TD children and children with left hemisphere lesions, implicating a particularly strong role of structured input in supporting reading comprehension in this group. TD children from lower SES backgrounds fell behind their TD peers from higher SES backgrounds on decoding and reading comprehension, but did not show differential patterns of school year and summer growth. Overall, results highlight the importance of considering the role of a host of factors interacting at multiple levels of analyses, including biological and environmental, in influencing developmental trajectories of typically and atypically-developing children.

Examining Neural Correlates of Psychopathology Using a Lesion-Based Approach.

PubMed

Calamia, Matthew; Markon, Kristian E; Sutterer, Matthew J; Tranel, Daniel

2018-06-22

Studies of individuals with focal brain damage have long been used to expand understanding of the neural basis of psychopathology. However, most previous studies were conducted using small sample sizes and relatively coarse methods for measuring psychopathology or mapping brain-behavior relationships. Here, we examined the factor structure and neural correlates of psychopathology in 232 individuals with focal brain damage, using their responses to the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF). Factor analysis and voxel-based lesion symptom mapping were used to examine the structure and neural correlates of psychopathology in this sample. Consistent with existing MMPI-2-RF literature, separate internalizing, externalizing, and psychotic symptom dimensions were found. In addition, a somatic dimension likely reflecting neurological symptoms was identified. Damage to the medial temporal lobe, including the hippocampus, was associated with scales related to both internalizing problems and psychoticism. Damage to the medial temporal lobe and orbitofrontal cortex was associated with both a general distrust of others and beliefs that one is being personally targeted by others. These findings provide evidence for the critical role of dysfunction in specific frontal and temporal regions in the development of psychopathology. Copyright © 2018. Published by Elsevier Ltd.

On the role of general system theory for functional neuroimaging.

PubMed

Stephan, Klaas Enno

2004-12-01

One of the most important goals of neuroscience is to establish precise structure-function relationships in the brain. Since the 19th century, a major scientific endeavour has been to associate structurally distinct cortical regions with specific cognitive functions. This was traditionally accomplished by correlating microstructurally defined areas with lesion sites found in patients with specific neuropsychological symptoms. Modern neuroimaging techniques with high spatial resolution have promised an alternative approach, enabling non-invasive measurements of regionally specific changes of brain activity that are correlated with certain components of a cognitive process. Reviewing classic approaches towards brain structure-function relationships that are based on correlational approaches, this article argues that these approaches are not sufficient to provide an understanding of the operational principles of a dynamic system such as the brain but must be complemented by models based on general system theory. These models reflect the connectional structure of the system under investigation and emphasize context-dependent couplings between the system elements in terms of effective connectivity. The usefulness of system models whose parameters are fitted to measured functional imaging data for testing hypotheses about structure-function relationships in the brain and their potential for clinical applications is demonstrated by several empirical examples.

Characterisation of tissue-type metabolic content in secondary progressive multiple sclerosis: a magnetic resonance spectroscopic imaging study.

PubMed

Marshall, Ian; Thrippleton, Michael J; Bastin, Mark E; Mollison, Daisy; Dickie, David A; Chappell, Francesca M; Semple, Scott I K; Cooper, Annette; Pavitt, Sue; Giovannoni, Gavin; Wheeler-Kingshott, Claudia A M Gandini; Solanky, Bhavana S; Weir, Christopher J; Stallard, Nigel; Hawkins, Clive; Sharrack, Basil; Chataway, Jeremy; Connick, Peter; Chandran, Siddharthan

2018-05-30

Proton magnetic resonance spectroscopy yields metabolic information and has proved to be a useful addition to structural imaging in neurological diseases. We applied short-echo time Spectroscopic Imaging in a cohort of 42 patients with secondary progressive multiple sclerosis (SPMS). Linear modelling with respect to brain tissue type yielded metabolite levels that were significantly different in white matter lesions compared with normal-appearing white matter, suggestive of higher myelin turnover (higher choline), higher metabolic rate (higher creatine) and increased glial activity (higher myo-inositol) within the lesions. These findings suggest that the lesions have ongoing cellular activity that is not consistent with the usual assumption of 'chronic' lesions in SPMS, and may represent a target for repair therapies.

The connective tissue component of the caprine arthritis-encephalitis syndrome.

PubMed Central

Crawford, T. B.; Adams, D. S.; Sande, R. D.; Gorham, J. R.; Henson, J. B.

1980-01-01

The gross and microscopic connective tissue lesions in 12 goats with caprine arthritis-encephalitis (CAE) are described, including those from which a virus (CAEV) was isolated. Lesions were most often associated with synovial-lined structures including joints, tendon sheaths, and bursae, and were typified by synovial cell proliferations, subsynovial mononuclear cell infiltration, the presence of fibrin, fibrinous concretions, necrosis, and mineralization. Extrasynovial lesions were located in kidneys, vessels, and brain. The inflammatory infiltrates in these organs were predominantly mononuclear. Amyloid was also found in liver, spleen, and kidney. Microbiologic techniques failed to demonstrate any bacteria, mycoplasma, or chlamydia in the lesions. Images Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 1 Figure 2 Figure 3 Figure 4 PMID:7406019

Brain lesion-pattern analysis in patients with olfactory dysfunctions following head trauma

PubMed Central

Lötsch, Jörn; Ultsch, Alfred; Eckhardt, Maren; Huart, Caroline; Rombaux, Philippe; Hummel, Thomas

2016-01-01

The presence of cerebral lesions in patients with neurosensory alterations provides a unique window into brain function. Using a fuzzy logic based combination of morphological information about 27 olfactory-eloquent brain regions acquired with four different brain imaging techniques, patterns of brain damage were analyzed in 127 patients who displayed anosmia, i.e., complete loss of the sense of smell (n = 81), or other and mechanistically still incompletely understood olfactory dysfunctions including parosmia, i.e., distorted perceptions of olfactory stimuli (n = 50), or phantosmia, i.e., olfactory hallucinations (n = 22). A higher prevalence of parosmia, and as a tendency also phantosmia, was observed in subjects with medium overall brain damage. Further analysis showed a lower frequency of lesions in the right temporal lobe in patients with parosmia than in patients without parosmia. This negative direction of the differences was unique for parosmia. In anosmia, and also in phantosmia, lesions were more frequent in patients displaying the respective symptoms than in those without these dysfunctions. In anosmic patients, lesions in the right olfactory bulb region were much more frequent than in patients with preserved sense of smell, whereas a higher frequency of carriers of lesions in the left frontal lobe was observed for phantosmia. We conclude that anosmia, and phantosmia, are the result of lost function in relevant brain areas whereas parosmia is more complex, requiring damaged and intact brain regions at the same time. PMID:26937377

Neuropsychology and the neurochemical lesion: evolution, applications and extensions.

PubMed

Hartman, D E

1988-01-01

The evolution of neuropsychology into a method for neurotoxic damage detection is reviewed. When neuropsychology is transformed into "neuropsychological toxicology", fundamental philosophical assumptions of the field are altered; the search for brain-behavior relationships must extend from structural damage into the analysis of neurochemical systems. The complementary relationship of human neuropsychology to basic toxicological and animal research is discussed. The great numbers of human "natural experiments" whose employment, medical history or substance abuse subjects them to contact with neurotoxic substances, suggest that there is a great need for expanded human investigations involving neuropsychological testing procedures in the service of research and clinical identification of neurotoxic syndromes. Further, it is argued that neurobehavioral procedures originally developed to detect industrial neurotoxic exposure will prove additionally useful assessing other brain-behavior disruptions mediated by neurochemistry or neurotoxicity rather than structural lesion. These frontiers include physical or emotional illness, substance abuse, effects of abused or prescription drugs as well as little-researched areas deserving of closer study, e.g., allergens or biotoxic exposure.

Cerebral perfusion abnormalities in therapy-resistant epilepsy in childhood: comparison between EEG, MRI and 99Tcm-ECD brain SPET.

PubMed

Vattimo, A; Burroni, L; Bertelli, P; Volterrani, D; Vella, A

1996-01-01

We performed 99Tcm-ethyl cysteinate dimer (ECD) interictal single photon emission tomography (SPET) in 26 children with severe therapy-resistant epilepsy. All the children underwent a detailed clinical examination, an electroencephalogram (EEG) investigation and brain magnetic resonance imaging (MRI). In 21 of the 26 children, SPET demonstrated brain blood flow abnormalities, in 13 cases in the same territories that showed EEG alterations. MRI showed structural lesions in 6 of the 26 children, while SPET imaging confirmed these abnormalities in only 5 children. The lesion not detected on SPET was shown to be 3 mm thick on MRI. Five symptomatic patients had normal SPET. In one of these patients, the EEG findings were normal and MRI revealed a small calcific nodule (4 mm thick); in the others, the EEG showed non-focal but diffuse abnormalities. These data confirm that brain SPET is sensitive in detecting and localizing hypoperfused areas that could be associated with epileptic foci in this group of patients, even when the MRI image is normal.

Analysis of brain and spinal cord lesions to occult brain damage in seropositive and seronegative neuromyelitis optica.

PubMed

Sun, Jie; Sun, Xianting; Zhang, Ningnannan; Wang, Qiuhui; Cai, Huanhuan; Qi, Yuan; Li, Ting; Qin, Wen; Yu, Chunshui

2017-09-01

According to aquaporin-4 antibody (AQP4-Ab), neuromyelitis optica (NMO) can be divided into seropositive and seronegative subgroups. The purpose of this study was to a) compare the distribution of spinal cord and brain magnetic resonance imaging (MRI) lesions between seropositive and seronegative NMO patients; b) explore occult brain damage in seropositive and seronegative NMO patients; and c) explore the contribution of visible lesions to occult grey and white matter damage in seropositive and seronegative NMO patients. Twenty-two AQP4-Ab seropositive and 14 seronegative NMO patients and 30 healthy controls were included in the study. Two neuroradiologists independently measured the brain lesion volume (BLV) and the length of spinal cord lesion (LSCL) and recorded the region of brain lesions. The normal-appearing grey matter volume (NAGM-GMV) and white matter fractional anisotropy (NAWM-FA) were calculated for each subject to evaluate occult brain damage. The seropositive patients displayed more extensive damage in the spinal cord than the seronegative patients, and the seronegative group had a higher proportion of patients with brainstem lesions (28.57%) than the seropositive group (4.55%, P=0.064). Both NMO subgroups exhibited reduced NAGM-GMV and NAWM-FA compared with the healthy controls. NAGM-GMV was negatively correlated with LSCL in the seropositive group (r s =-0.444, P=0.044) and with BLV in the seronegative group (r s =-0.768, P=0.002). NAWM-FA was also negatively correlated with BLV in the seropositive group (r s =-0.682, P<0.001). Our findings suggest that the occult brain damage in these two NMO subgroups may be due to different mechanisms, which need to be further clarified. Copyright © 2017 Elsevier B.V. All rights reserved.

Does placental inflammation relate to brain lesions and volume in preterm infants?

PubMed

Reiman, Milla; Kujari, Harry; Maunu, Jonna; Parkkola, Riitta; Rikalainen, Hellevi; Lapinleimu, Helena; Lehtonen, Liisa; Haataja, Leena

2008-05-01

To evaluate the association between histologic inflammation of placenta and brain findings in ultrasound examinations and regional brain volumes in magnetic resonance imaging in very-low-birth-weight (VLBW) or in very preterm infants. VLBW or very preterm infants (n = 121) were categorized into 3 groups according to the most pathologic brain finding on ultrasound examinations until term. The brain magnetic resonance imaging performed at term was analyzed for regional brain volumes. The placentas were analyzed for histologic inflammatory findings. Histologic chorioamnionitis on the fetal side correlated to brain lesions in univariate but not in multivariate analyses. Low gestational age was the only significant risk factor for brain lesions in multivariate analysis (P < .0001). Histologic chorioamnionitis was not associated with brain volumes in multivariate analyses. Female sex, low gestational age, and low birth weight z score correlated to smaller volumes in total brain tissue (P = .001, P = .0002, P < .0001, respectively) and cerebellum (P = .047, P = .003, P = .001, respectively). In addition, low gestational age and low-birth-weight z score correlated to a smaller combined volume of basal ganglia and thalami (P = .0002). Placental inflammation does not appear to correlate to brain lesions or smaller regional brain volumes in VLBW or in very preterm infants at term age.

Micro-computed tomography in murine models of cerebral cavernous malformations as a paradigm for brain disease.

PubMed

Girard, Romuald; Zeineddine, Hussein A; Orsbon, Courtney; Tan, Huan; Moore, Thomas; Hobson, Nick; Shenkar, Robert; Lightle, Rhonda; Shi, Changbin; Fam, Maged D; Cao, Ying; Shen, Le; Neander, April I; Rorrer, Autumn; Gallione, Carol; Tang, Alan T; Kahn, Mark L; Marchuk, Douglas A; Luo, Zhe-Xi; Awad, Issam A

2016-09-15

Cerebral cavernous malformations (CCMs) are hemorrhagic brain lesions, where murine models allow major mechanistic discoveries, ushering genetic manipulations and preclinical assessment of therapies. Histology for lesion counting and morphometry is essential yet tedious and time consuming. We herein describe the application and validations of X-ray micro-computed tomography (micro-CT), a non-destructive technique allowing three-dimensional CCM lesion count and volumetric measurements, in transgenic murine brains. We hereby describe a new contrast soaking technique not previously applied to murine models of CCM disease. Volumetric segmentation and image processing paradigm allowed for histologic correlations and quantitative validations not previously reported with the micro-CT technique in brain vascular disease. Twenty-two hyper-dense areas on micro-CT images, identified as CCM lesions, were matched by histology. The inter-rater reliability analysis showed strong consistency in the CCM lesion identification and staging (K=0.89, p<0.0001) between the two techniques. Micro-CT revealed a 29% greater CCM lesion detection efficiency, and 80% improved time efficiency. Serial integrated lesional area by histology showed a strong positive correlation with micro-CT estimated volume (r(2)=0.84, p<0.0001). Micro-CT allows high throughput assessment of lesion count and volume in pre-clinical murine models of CCM. This approach complements histology with improved accuracy and efficiency, and can be applied for lesion burden assessment in other brain diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

Some Problems for Representations of Brain Organization Based on Activation in Functional Imaging

ERIC Educational Resources Information Center

Sidtis, John J.

2007-01-01

Functional brain imaging has overshadowed traditional lesion studies in becoming the dominant approach to the study of brain-behavior relationships. The proponents of functional imaging studies frequently argue that this approach provides an advantage over lesion studies by observing normal brain activity in vivo without the disruptive effects of…

[Right extremities pain caused by a malacia lesion in the left putamen:a resting functional magnetic resonance imaging of the marginal division of the human brain].

PubMed

Chen, Zhi-Ye; Ma, Lin

2014-04-01

To explore the role of marginal division of the human brain in the pain modulation. Resting functional magnetic resonance imaging was applied in a patient with right extremities pain caused by a malacia lesion in the left putamen and in 8 healthy volunteers. Marginal division was defined using manual drawing on structure images, and was applied to the computation of fuctional connectivity maps. The functional connectivities in the left marginal division showed an evident decrease in the patient when compared with healthy controls. These connectivities were mainly located in the bilateral head of caudate nucleus, putamen, and left globus pallidus. The marginal division may be involved in the pain modulation.

Pathology of non-thermal irreversible electroporation (N-TIRE)-induced ablation of the canine brain.

PubMed

Rossmeisl, John H; Garcia, Paulo A; Roberston, John L; Ellis, Thomas L; Davalos, Rafael V

2013-01-01

This study describes the neuropathologic features of normal canine brain ablated with non-thermal irreversible electroporation (N-TIRE). The parietal cerebral cortices of four dogs were treated with N-TIRE using a dose-escalation protocol with an additional dog receiving sham treatment. Animals were allowed to recover following N-TIRE ablation and the effects of treatment were monitored with clinical and magnetic resonance imaging examinations. Brains were subjected to histopathologic and ultrastructural assessment along with Bcl-2, caspase-3, and caspase-9 immunohistochemical staining following sacrifice 72 h post-treatment. Adverse clinical effects of N-TIRE were only observed in the dog treated at the upper energy tier. MRI and neuropathologic examinations indicated that N-TIRE ablation resulted in focal regions of severe cytoarchitectural and blood-brain-barrier disruption. Lesion size correlated to the intensity of the applied electrical field. N-TIRE-induced lesions were characterized by parenchymal necrosis and hemorrhage; however, large blood vessels were preserved. A transition zone containing parenchymal edema, perivascular inflammatory cuffs, and reactive gliosis was interspersed between the necrotic focus and normal neuropil. Apoptotic labeling indices were not different between the N-TIRE-treated and control brains. This study identified N-TIRE pulse parameters that can be used to safely create circumscribed foci of brain necrosis while selectively preserving major vascular structures.

Cerebral Metastases of Lung Cancer Mimicking Multiple Ischaemic Lesions - A Case Report and Review of Literature.

PubMed

Zacharzewska-Gondek, Anna; Maksymowicz, Hanna; Szymczyk, Małgorzata; Sąsiadek, Marek; Bladowska, Joanna

2017-01-01

Restricted diffusion that is found on magnetic resonance diffusion-weighted imaging (DWI) typically indicates acute ischaemic stroke. However, restricted diffusion can also occur in other diseases, like metastatic brain tumours, which we describe in this case report. A 57-year-old male, with a diagnosis of small-cell cancer of the right lung (microcellular anaplastic carcinoma), was admitted with focal neurological symptoms. Initial brain MRI revealed multiple, disseminated lesions that were hyperintense on T2-weighted images and did not enhance after contrast administration; notably, some lesions manifested restricted diffusion on DWI images. Based on these findings, disseminated ischaemic lesions were diagnosed. On follow-up MRI that was performed after 2 weeks, we observed enlargement of the lesions; there were multiple, disseminated, sharply outlined, contrast-enhancing, oval foci with persistent restriction of diffusion. We diagnosed the lesions as disseminated brain metastases due to lung cancer. To our knowledge, this is the first description of a patient with brain metastases that were characterised by restricted diffusion and no contrast enhancement. Multiple, disseminated brain lesions, that are characterised by restricted diffusion on DWI, typically indicate acute or hyperacute ischemic infarcts; however, they can also be due to hypercellular metastases, even if no contrast enhancement is observed. This latter possibility should be considered particularly in patients with cancer.

MRI and histopathologic study of a novel cholesterol-fed rabbit model of xanthogranuloma.

PubMed

Chen, Yuanxin; Hamilton, Amanda M; Parkins, Katie M; Wang, Jian-Xiong; Rogers, Kem A; Zeineh, Michael M; Rutt, Brian K; Ronald, John A

2016-09-01

To develop a rabbit model of xanthogranuloma based on supplementation of dietary cholesterol. The aim of this study was to analyze the xanthogranulomatous lesions using magnetic resonance imaging (MRI) and histological examination. Rabbits were fed a low-level cholesterol (CH) diet (n = 10) or normal chow (n = 5) for 24 months. In vivo brain imaging was performed on a 3T MR system using fast imaging employing steady state acquisition, susceptibility-weighted imaging, spoiled gradient recalled, T1 -weighted inversion recovery imaging and T1 relaxometry, PD-weighted and T2 -weighted spin-echo imaging and T2 relaxometry, iterative decomposition of water and fat with echo asymmetry and least-squares estimation, ultrashort TE MRI (UTE-MRI), and T2* relaxometry. MR images were evaluated using a Likert scale for lesion presence and quantitative analysis of lesion size, ventricular volume, and T1 , T2 , and T2* values of lesions was performed. After imaging, brain specimens were examined using histological methods. In vivo MRI revealed that 6 of 10 CH-fed rabbits developed lesions in the choroid plexus. Region-of-interest analysis showed that for CH-fed rabbits the mean lesion volume was 8.5 ± 2.6 mm(3) and the volume of the lateral ventricle was significantly increased compared to controls (P < 0.01). The lesions showed significantly shorter mean T2 values (35 ± 12 msec, P < 0.001), longer mean T1 values (1581 ± 146 msec, P < 0.05), and shorter T2* values (22 ± 13 msec, P < 0.001) compared to adjacent brain structures. The ultrashort T2* components were visible using UTE-MRI. Histopathologic evaluation of lesions demonstrated features of human xanthogranuloma. Rabbits fed a low-level CH diet develop sizable intraventricular masses that have similar histopathological features as human xanthogranuloma. Multiparametric MRI techniques were able to provide information about the complex composition of these lesions. J. Magn. Reson. Imaging 2016;44:673-682. © 2016 International Society for Magnetic Resonance in Medicine.

Hyperintense White Matter Lesions in 50 High-Altitude Pilots with Neurologic Decompression Sickness

DTIC Science & Technology

2012-12-01

Environ Med 2004 ; 75 : 969 – 72 . 4. Bartzokis G, Tishler TA, Shin IS, Lu PH, Cummings JL . Brain ferritin iron as a risk factor for...Coyle T, Lancaster J, et al. Can structural MRI indices of cerebral integrity track cognitive trends in executive control function during normal...Digital brain atlases . Trends Neurosci 1995 ; 18 : 210 – 1 . 28. Miura K, Soyama Y, Morikawa Y, Nishijo M, Nakanishi Y, et al

Lesion characteristics driving right-hemispheric language reorganization in congenital left-hemispheric brain damage.

PubMed

Lidzba, Karen; de Haan, Bianca; Wilke, Marko; Krägeloh-Mann, Ingeborg; Staudt, Martin

2017-10-01

Pre- or perinatally acquired ("congenital") left-hemispheric brain lesions can be compensated for by reorganizing language into homotopic brain regions in the right hemisphere. Language comprehension may be hemispherically dissociated from language production. We investigated the lesion characteristics driving inter-hemispheric reorganization of language comprehension and language production in 19 patients (7-32years; eight females) with congenital left-hemispheric brain lesions (periventricular lesions [n=11] and middle cerebral artery infarctions [n=8]) by fMRI. 16/17 patients demonstrated reorganized language production, while 7/19 patients had reorganized language comprehension. Lesions to the insular cortex and the temporo-parietal junction (predominantly supramarginal gyrus) were significantly more common in patients in whom both, language production and comprehension were reorganized. These areas belong to the dorsal stream of the language network, participating in the auditory-motor integration of language. Our data suggest that the integrity of this stream might be crucial for a normal left-lateralized language development. Copyright © 2017. Published by Elsevier Inc.

Neurochemical and behavioral consequences of striatal injection of 5,7-dihydroxytryptamine.

PubMed

Ludwig, Verena; Schwarting, Rainer K W

2007-05-15

It is known that central serotonin (5HT) is involved in anxiety, but the behavioral results of many studies have been inconsistent. A prevalent research approach is to destroy 5HT neurotoxically. Such lesions were mostly generated by injecting 5,7-dihydroxytryptamine into ventricles or raphé nuclei, leading to rather global losses of 5HT in the brain. However, there is evidence for differential effects of 5HT in different brain structures regarding anxiety. Therefore, we decided to study the effects of injecting 5,7-dihydroxytryptamine into the forebrain. We chose the ventral striatum as the site of injection, since there is evidence that 5HT may be involved in anxiety there. We administered the neurotoxin bilaterally in adult rats, and analyzed neurochemical and behavioral consequences in three experiments. The first one showed that the toxin dose-dependently (10-50 microg) depleted 5HT in the ventral striatum, neostriatum, frontal cortex, and amygdala. Besides 5HT, dopamine was also partly depleted there. This dopaminergic lesion was prevented in a second experiment, where rats were pre-treated systemically with the dopamine reuptake inhibitor nomifensine. In the final experiment, the functional consequences of such 5HT lesions were tested, which yielded moderate anxiogenic effects in the elevated plus maze and in the open field. Also, there were lesion effects on aversively motivated ultrasonic vocalization during an active avoidance test. In contrast, active avoidance performance itself and general activity in the open field were not affected. Lesion effects became discernible there when challenging rats with MDMA. The psycho-stimulatory effectiveness of this drug, which acts largely via the availability of 5HT in the brain, was reduced to degrees that depended on the size of 5HT lesion. These results are discussed with respect to factors such as severity of lesion, anatomical specificity, and the role of 5HT in anxiety.

Searching for the elusive neural substrates of body part terms: a neuropsychological study.

PubMed

Kemmerer, David; Tranel, Daniel

2008-06-01

Previous neuropsychological studies suggest that, compared to other categories of concrete entities, lexical and conceptual aspects of body part knowledge are frequently spared in brain-damaged patients. To further investigate this issue, we administered a battery of 12 tests assessing lexical and conceptual aspects of body part knowledge to 104 brain-damaged patients with lesions distributed throughout the telencephalon. There were two main outcomes. First, impaired oral naming of body parts, attributable to a disturbance of the mapping between lexical-semantic and lexical-phonological structures, was most reliably and specifically associated with lesions in the left frontal opercular and anterior/inferior parietal opercular cortices and in the white matter underlying these regions (8 patients). Also, 1 patient with body part anomia had a left occipital lesion that included the "extrastriate body area" (EBA). Second, knowledge of the meanings of body part terms was remarkably resistant to impairment, regardless of lesion site; in fact, we did not uncover a single patient who exhibited significantly impaired understanding of the meanings of these terms. In the 9 patients with body part anomia, oral naming of concrete entities was evaluated, and this revealed that 4 patients had disproportionately worse naming of body parts relative to other types of concrete entities. Taken together, these findings extend previous neuropsychological and functional neuroimaging studies of body part knowledge and add to our growing understanding of the nuances of how different linguistic and conceptual categories are operated by left frontal and parietal structures.

Searching for the Elusive Neural Substrates of Body Part Terms: A Neuropsychological Study

PubMed Central

Kemmerer, David; Tranel, Daniel

2010-01-01

Previous neuropsychological studies suggest that, compared to other categories of concrete entities, lexical and conceptual aspects of body part knowledge are frequently spared in brain-damaged patients. To further investigate this issue, we administered a battery of 12 tests assessing lexical and conceptual aspects of body part knowledge to 104 brain-damaged patients with lesions distributed throughout the telencephalon. There were two main outcomes. First, impaired oral naming of body parts, attributable to a disturbance of the mapping between lexical-semantic and lexical-phonological structures, was most reliably and specifically associated with lesions in the left frontal opercular and anterior/inferior parietal opercular cortices, and in the white matter underlying these regions (8 patients). Also, one patient with body part anomia had a left occipital lesion that included the “extrastriate body area” (EBA). Second, knowledge of the meanings of body part terms was remarkably resistant to impairment, regardless of lesion site; in fact, we did not uncover a single patient who exhibited significantly impaired understanding of the meanings of these terms. In the 9 patients with body part anomia, oral naming of concrete entities was evaluated, and this revealed that 4 patients had disproportionately worse naming of body parts relative to other types of concrete entities. Taken together, these findings extend previous neuropsychological and functional neuroimaging studies of body part knowledge, and add to our growing understanding of the nuances of how different linguistic and conceptual categories are operated by left frontal and parietal structures. PMID:18608319

Multimodal Characterization of the Late Effects of Traumatic Brain Injury: A Methodological Overview of the Late Effects of Traumatic Brain Injury Project.

PubMed

Edlow, Brian L; Keene, C Dirk; Perl, Daniel P; Iacono, Diego; Folkerth, Rebecca D; Stewart, William; Mac Donald, Christine L; Augustinack, Jean; Diaz-Arrastia, Ramon; Estrada, Camilo; Flannery, Elissa; Gordon, Wayne A; Grabowski, Thomas J; Hansen, Kelly; Hoffman, Jeanne; Kroenke, Christopher; Larson, Eric B; Lee, Patricia; Mareyam, Azma; McNab, Jennifer A; McPhee, Jeanne; Moreau, Allison L; Renz, Anne; Richmire, KatieRose; Stevens, Allison; Tang, Cheuk Y; Tirrell, Lee S; Trittschuh, Emily H; van der Kouwe, Andre; Varjabedian, Ani; Wald, Lawrence L; Wu, Ona; Yendiki, Anastasia; Young, Liza; Zöllei, Lilla; Fischl, Bruce; Crane, Paul K; Dams-O'Connor, Kristen

2018-05-03

Epidemiological studies suggest that a single moderate-to-severe traumatic brain injury (TBI) is associated with an increased risk of neurodegenerative disease, including Alzheimer's disease (AD) and Parkinson's disease (PD). Histopathological studies describe complex neurodegenerative pathologies in individuals exposed to single moderate-to-severe TBI or repetitive mild TBI, including chronic traumatic encephalopathy (CTE). However, the clinicopathological links between TBI and post-traumatic neurodegenerative diseases such as AD, PD, and CTE remain poorly understood. Here, we describe the methodology of the Late Effects of TBI (LETBI) study, whose goals are to characterize chronic post-traumatic neuropathology and to identify in vivo biomarkers of post-traumatic neurodegeneration. LETBI participants undergo extensive clinical evaluation using National Institutes of Health TBI Common Data Elements, proteomic and genomic analysis, structural and functional magnetic resonance imaging (MRI), and prospective consent for brain donation. Selected brain specimens undergo ultra-high resolution ex vivo MRI and histopathological evaluation including whole-mount analysis. Co-registration of ex vivo and in vivo MRI data enables identification of ex vivo lesions that were present during life. In vivo signatures of postmortem pathology are then correlated with cognitive and behavioral data to characterize the clinical phenotype(s) associated with pathological brain lesions. We illustrate the study methods and demonstrate proof of concept for this approach by reporting results from the first LETBI participant, who despite the presence of multiple in vivo and ex vivo pathoanatomic lesions had normal cognition and was functionally independent until her mid-80s. The LETBI project represents a multidisciplinary effort to characterize post-traumatic neuropathology and identify in vivo signatures of postmortem pathology in a prospective study.

Real-Time Ultrasound-Guided Catheter Navigation for Approaching Deep-Seated Brain Lesions: Role of Intraoperative Neurosonography with and without Fusion with Magnetic Resonance Imaging.

PubMed

Manjila, Sunil; Karhade, Aditya; Phi, Ji Hoon; Scott, R Michael; Smith, Edward R

2017-01-01

Brain shift during the exposure of cranial lesions may reduce the accuracy of frameless stereotaxy. We describe a rapid, safe, and effective method to approach deep-seated brain lesions using real-time intraoperative ultrasound placement of a catheter to mark the dissection trajectory to the lesion. With Institutional Review Board approval, we retrospectively reviewed the radiographic, pathologic, and intraoperative data of 11 pediatric patients who underwent excision of 12 lesions by means of this technique. Full data sets were available for 12 lesions in 11 patients. Ten lesions were tumors and 2 were cavernous malformations. Lesion locations included the thalamus (n = 4), trigone (n = 3), mesial temporal lobe (n = 3), and deep white matter (n = 2). Catheter placement was successful in all patients, and the median time required for the procedure was 3 min (range 2-5 min). There were no complications related to catheter placement. The median diameter of surgical corridors on postresection magnetic resonance imaging was 6.6 mm (range 3.0-12.1 mm). Use of real-time ultrasound guidance to place a catheter to aid in the dissection to reach a deep-seated brain lesion provides advantages complementary to existing techniques, such as frameless stereotaxy. The catheter insertion technique described here provides a quick, accurate, and safe method for reaching deep-seated lesions. © 2017 S. Karger AG, Basel.

Extensive brain masses and cavitary lung lesions associated with toxoplasmosis and acquired immunodeficiency syndrome.

PubMed

Ayoade, Folusakin; Todd, John; Al-Delfi, Firas; King, John

2017-10-01

Toxoplasmosis is an important cause of enhancing brain lesions in patients with acquired immunodeficiency syndrome (AIDS), and it is typically associated with low CD4-lymphocyte counts. Extensive toxoplasma encephalitis when the CD4-lymphocyte count is above 100 cells/µl is unusual. Cavitary lung lesions are also not typically associated with toxoplasmosis. Here, we present a case of toxoplasmosis associated with extensive brain masses and cavitary lung lesions, both of which improved with directed toxoplasmosis therapy, in an AIDS patient with a CD4 cell count of 120 cells/µl.

Preoperative magnetic resonance and intraoperative ultrasound fusion imaging for real-time neuronavigation in brain tumor surgery.

PubMed

Prada, F; Del Bene, M; Mattei, L; Lodigiani, L; DeBeni, S; Kolev, V; Vetrano, I; Solbiati, L; Sakas, G; DiMeco, F

2015-04-01

Brain shift and tissue deformation during surgery for intracranial lesions are the main actual limitations of neuro-navigation (NN), which currently relies mainly on preoperative imaging. Ultrasound (US), being a real-time imaging modality, is becoming progressively more widespread during neurosurgical procedures, but most neurosurgeons, trained on axial computed tomography (CT) and magnetic resonance imaging (MRI) slices, lack specific US training and have difficulties recognizing anatomic structures with the same confidence as in preoperative imaging. Therefore real-time intraoperative fusion imaging (FI) between preoperative imaging and intraoperative ultrasound (ioUS) for virtual navigation (VN) is highly desirable. We describe our procedure for real-time navigation during surgery for different cerebral lesions. We performed fusion imaging with virtual navigation for patients undergoing surgery for brain lesion removal using an ultrasound-based real-time neuro-navigation system that fuses intraoperative cerebral ultrasound with preoperative MRI and simultaneously displays an MRI slice coplanar to an ioUS image. 58 patients underwent surgery at our institution for intracranial lesion removal with image guidance using a US system equipped with fusion imaging for neuro-navigation. In all cases the initial (external) registration error obtained by the corresponding anatomical landmark procedure was below 2 mm and the craniotomy was correctly placed. The transdural window gave satisfactory US image quality and the lesion was always detectable and measurable on both axes. Brain shift/deformation correction has been successfully employed in 42 cases to restore the co-registration during surgery. The accuracy of ioUS/MRI fusion/overlapping was confirmed intraoperatively under direct visualization of anatomic landmarks and the error was < 3 mm in all cases (100 %). Neuro-navigation using intraoperative US integrated with preoperative MRI is reliable, accurate and user-friendly. Moreover, the adjustments are very helpful in correcting brain shift and tissue distortion. This integrated system allows true real-time feedback during surgery and is less expensive and time-consuming than other intraoperative imaging techniques, offering high precision and orientation. © Georg Thieme Verlag KG Stuttgart · New York.

Disconnection mechanism and regional cortical atrophy contribute to impaired processing of facial expressions and theory of mind in multiple sclerosis: a structural MRI study.

PubMed

Mike, Andrea; Strammer, Erzsebet; Aradi, Mihaly; Orsi, Gergely; Perlaki, Gabor; Hajnal, Andras; Sandor, Janos; Banati, Miklos; Illes, Eniko; Zaitsev, Alexander; Herold, Robert; Guttmann, Charles R G; Illes, Zsolt

2013-01-01

Successful socialization requires the ability of understanding of others' mental states. This ability called as mentalization (Theory of Mind) may become deficient and contribute to everyday life difficulties in multiple sclerosis. We aimed to explore the impact of brain pathology on mentalization performance in multiple sclerosis. Mentalization performance of 49 patients with multiple sclerosis was compared to 24 age- and gender matched healthy controls. T1- and T2-weighted three-dimensional brain MRI images were acquired at 3Tesla from patients with multiple sclerosis and 18 gender- and age matched healthy controls. We assessed overall brain cortical thickness in patients with multiple sclerosis and the scanned healthy controls, and measured the total and regional T1 and T2 white matter lesion volumes in patients with multiple sclerosis. Performances in tests of recognition of mental states and emotions from facial expressions and eye gazes correlated with both total T1-lesion load and regional T1-lesion load of association fiber tracts interconnecting cortical regions related to visual and emotion processing (genu and splenium of corpus callosum, right inferior longitudinal fasciculus, right inferior fronto-occipital fasciculus, uncinate fasciculus). Both of these tests showed correlations with specific cortical areas involved in emotion recognition from facial expressions (right and left fusiform face area, frontal eye filed), processing of emotions (right entorhinal cortex) and socially relevant information (left temporal pole). Thus, both disconnection mechanism due to white matter lesions and cortical thinning of specific brain areas may result in cognitive deficit in multiple sclerosis affecting emotion and mental state processing from facial expressions and contributing to everyday and social life difficulties of these patients.

Lateralization of Egocentric and Allocentric Spatial Processing after Parietal Brain Lesions

ERIC Educational Resources Information Center

Iachini, Tina; Ruggiero, Gennaro; Conson, Massimiliano; Trojano, Luigi

2009-01-01

The purpose of this paper was to verify whether left and right parietal brain lesions may selectively impair egocentric and allocentric processing of spatial information in near/far spaces. Two Right-Brain-Damaged (RBD), 2 Left-Brain-Damaged (LBD) patients (not affected by neglect or language disturbances) and eight normal controls were submitted…

Celecoxib-induced gastrointestinal, liver and brain lesions in rats, counteraction by BPC 157 or L-arginine, aggravation by L-NAME

PubMed Central

Drmic, Domagoj; Kolenc, Danijela; Ilic, Spomenko; Bauk, Lara; Sever, Marko; Zenko Sever, Anita; Luetic, Kresimir; Suran, Jelena; Seiwerth, Sven; Sikiric, Predrag

2017-01-01

AIM To counteract/reveal celecoxib-induced toxicity and NO system involvement. METHODS Celecoxib (1 g/kg b.w. ip) was combined with therapy with stable gastric pentadecapeptide BPC 157 (known to inhibit these lesions, 10 μg/kg, 10 ng/kg, or 1 ng/kg ip) and L-arginine (100 mg/kg ip), as well as NOS blockade [N(G)-nitro-L-arginine methyl ester (L-NAME)] (5 mg/kg ip) given alone and/or combined immediately after celecoxib. Gastrointestinal, liver, and brain lesions and liver enzyme serum values in rats were assessed at 24 h and 48 h thereafter. RESULTS This high-dose celecoxib administration, as a result of NO system dysfunction, led to gastric, liver, and brain lesions and increased liver enzyme serum values. The L-NAME-induced aggravation of the lesions was notable for gastric lesions, while in liver and brain lesions the beneficial effect of L-arginine was blunted. L-arginine counteracted gastric, liver and brain lesions. These findings support the NO system mechanism(s), both NO system agonization (L-arginine) and NO system antagonization (L-NAME), that on the whole are behind all of these COX phenomena. An even more complete antagonization was identified with BPC 157 (at both 24 h and 48 h). A beneficial effect was evident on all the increasingly negative effects of celecoxib and L-NAME application and in all the BPC 157 groups (L-arginine + BPC 157; L-NAME + BPC 157; L-NAME + L-arginine + BPC 157). Thus, these findings demonstrated that BPC 157 may equally counteract both COX-2 inhibition (counteracting the noxious effects of celecoxib on all lesions) and additional NOS blockade (equally counteracting the noxious effects of celecoxib + L-NAME). CONCLUSION BPC 157 and L-arginine alleviate gastrointestinal, liver and brain lesions, redressing NSAIDs’ post-surgery application and NO system involvement. PMID:28839430

Celecoxib-induced gastrointestinal, liver and brain lesions in rats, counteraction by BPC 157 or L-arginine, aggravation by L-NAME.

PubMed

Drmic, Domagoj; Kolenc, Danijela; Ilic, Spomenko; Bauk, Lara; Sever, Marko; Zenko Sever, Anita; Luetic, Kresimir; Suran, Jelena; Seiwerth, Sven; Sikiric, Predrag

2017-08-07

To counteract/reveal celecoxib-induced toxicity and NO system involvement. Celecoxib (1 g/kg b.w. ip) was combined with therapy with stable gastric pentadecapeptide BPC 157 (known to inhibit these lesions, 10 μg/kg, 10 ng/kg, or 1 ng/kg ip) and L-arginine (100 mg/kg ip), as well as NOS blockade [N(G)-nitro-L-arginine methyl ester (L-NAME)] (5 mg/kg ip) given alone and/or combined immediately after celecoxib. Gastrointestinal, liver, and brain lesions and liver enzyme serum values in rats were assessed at 24 h and 48 h thereafter. This high-dose celecoxib administration, as a result of NO system dysfunction, led to gastric, liver, and brain lesions and increased liver enzyme serum values. The L-NAME-induced aggravation of the lesions was notable for gastric lesions, while in liver and brain lesions the beneficial effect of L-arginine was blunted. L-arginine counteracted gastric, liver and brain lesions. These findings support the NO system mechanism(s), both NO system agonization (L-arginine) and NO system antagonization (L-NAME), that on the whole are behind all of these COX phenomena. An even more complete antagonization was identified with BPC 157 (at both 24 h and 48 h). A beneficial effect was evident on all the increasingly negative effects of celecoxib and L-NAME application and in all the BPC 157 groups (L-arginine + BPC 157; L-NAME + BPC 157; L-NAME + L-arginine + BPC 157). Thus, these findings demonstrated that BPC 157 may equally counteract both COX-2 inhibition (counteracting the noxious effects of celecoxib on all lesions) and additional NOS blockade (equally counteracting the noxious effects of celecoxib + L-NAME). BPC 157 and L-arginine alleviate gastrointestinal, liver and brain lesions, redressing NSAIDs' post-surgery application and NO system involvement.

Intraoperative Squash and Touch Preparation Cytology of Brain Lesions Stained with H+E and Diff-Quik™: A 20-Year Retrospective Analysis and Comparative Literature Review.

PubMed

Hamasaki, Makoto; Chang, Karen H F; Nabeshima, Kazuki; Tauchi-Nishi, Pamela S

2018-01-01

Squash preparation (SP) is a rapid technique for the intraoperative assessment of brain lesions. Only a few studies have employed touch preparation (TP) cytology and Diff-QuikTM (DQ) staining in conjunction with SP. Our study aimed to assess the diagnostic efficacy of SP of brain lesions at our institution, ascertain the additional effect of TP and DQ staining, examine factors affecting the sensitivity and specificity of our methods, and compare our findings with those of previous investigations. Our database was searched for all SP/TP of brain lesions examined from January 1996 to December 2016. During this 20-year study period, our search revealed 400 brain lesions diagnosed by SP/TP cytology. There were 338 (84.5%) neoplasms and 62 (15.5%) nonneoplastic lesions. The most common neoplasms were glioblastoma multiforme (24.6%), metastatic cancer (18.3%), meningioma (16.9%), astrocytoma (11.5%), lymphoma (8.3%), oligoastrocytoma (3.3%), and pituitary adenoma (3.3%). There was discordance between the SP/TP and histological diagnoses in 19/338 (5.6%) cases, i.e., 12 misclassifications of tumor subtype and 7 sampling errors. No false-positive cases were detected. Brain SP/TP stained with H+E/DQ demonstrated high sensitivity (97.9%), specificity (100%), and overall diagnostic accuracy (95.3%). The combined methods, in particular, aided in the diagnosis of brain tumors prone to smearing artifacts and certain metastatic malignancies. © 2017 S. Karger AG, Basel.

Microarray RNA expression analysis of cerebral white matter lesions reveals changes in multiple functional pathways.

PubMed

Simpson, Julie E; Hosny, Ola; Wharton, Stephen B; Heath, Paul R; Holden, Hazel; Fernando, Malee S; Matthews, Fiona; Forster, Gill; O'Brien, John T; Barber, Robert; Kalaria, Raj N; Brayne, Carol; Shaw, Pamela J; Lewis, Claire E; Ince, Paul G

2009-02-01

White matter lesions (WML) in brain aging are linked to dementia and depression. Ischemia contributes to their pathogenesis but other mechanisms may contribute. We used RNA microarray analysis with functional pathway grouping as an unbiased approach to investigate evidence for additional pathogenetic mechanisms. WML were identified by MRI and pathology in brains donated to the Medical Research Council Cognitive Function and Ageing Study Cognitive Function and Aging Study. RNA was extracted to compare WML with nonlesional white matter samples from cases with lesions (WM[L]), and from cases with no lesions (WM[C]) using RNA microarray and pathway analysis. Functional pathways were validated for selected genes by quantitative real-time polymerase chain reaction and immunocytochemistry. We identified 8 major pathways in which multiple genes showed altered RNA transcription (immune regulation, cell cycle, apoptosis, proteolysis, ion transport, cell structure, electron transport, metabolism) among 502 genes that were differentially expressed in WML compared to WM[C]. In WM[L], 409 genes were altered involving the same pathways. Genes selected to validate this microarray data all showed the expected changes in RNA levels and immunohistochemical expression of protein. WML represent areas with a complex molecular phenotype. From this and previous evidence, WML may arise through tissue ischemia but may also reflect the contribution of additional factors like blood-brain barrier dysfunction. Differential expression of genes in WM[L] compared to WM[C] indicate a "field effect" in the seemingly normal surrounding white matter.

Mapping Common Aphasia Assessments to Underlying Cognitive Processes and Their Neural Substrates.

PubMed

Lacey, Elizabeth H; Skipper-Kallal, Laura M; Xing, Shihui; Fama, Mackenzie E; Turkeltaub, Peter E

2017-05-01

Understanding the relationships between clinical tests, the processes they measure, and the brain networks underlying them, is critical in order for clinicians to move beyond aphasia syndrome classification toward specification of individual language process impairments. To understand the cognitive, language, and neuroanatomical factors underlying scores of commonly used aphasia tests. Twenty-five behavioral tests were administered to a group of 38 chronic left hemisphere stroke survivors and a high-resolution magnetic resonance image was obtained. Test scores were entered into a principal components analysis to extract the latent variables (factors) measured by the tests. Multivariate lesion-symptom mapping was used to localize lesions associated with the factor scores. The principal components analysis yielded 4 dissociable factors, which we labeled Word Finding/Fluency, Comprehension, Phonology/Working Memory Capacity, and Executive Function. While many tests loaded onto the factors in predictable ways, some relied heavily on factors not commonly associated with the tests. Lesion symptom mapping demonstrated discrete brain structures associated with each factor, including frontal, temporal, and parietal areas extending beyond the classical language network. Specific functions mapped onto brain anatomy largely in correspondence with modern neural models of language processing. An extensive clinical aphasia assessment identifies 4 independent language functions, relying on discrete parts of the left middle cerebral artery territory. A better understanding of the processes underlying cognitive tests and the link between lesion and behavior may lead to improved aphasia diagnosis, and may yield treatments better targeted to an individual's specific pattern of deficits and preserved abilities.

Cerebral venous thrombosis with nonhemorrhagic lesions: clinical correlates and prognosis.

PubMed

Ferro, José M; Canhão, Patrícia; Bousser, Marie-Germaine; Stam, Jan; Barinagarrementeria, Fernando; Stolz, Erwin

2010-01-01

Brain imaging of patients with acute cerebral venous thrombosis often shows parenchymal hemorrhagic and nonhemorrhagic lesions. The clinical relevance of nonhemorrhagic lesions is poorly known. In the International Study on Cerebral Vein and Dural Sinus Thrombosis cohort, demographic, clinical, risk factor, prognosis and imaging findings were compared between patients with parenchymal nonhemorrhagic lesions and no hemorrhagic lesions (NHL) and (1) patients with parenchymal hemorrhagic lesions (HL) and (2) patients without brain lesions. Predictors of prognosis at the end of follow-up in the NHL group were analyzed by bivariate and Cox regression methods. We identified 147 patients (23.6%) with NHL. When compared to patients without brain lesions (n = 309), those with NHL more often presented mental status disturbances, aphasia, decreased alertness, motor deficits, seizures, occlusions of the straight sinus, deep venous system and cortical veins. Patients with NHL had a better prognosis in the acute phase and at the end of follow-up than those with HL, but a worse one than patients without brain lesions, as more NHL patients were dead or dependent (modified Rankin Scale score = 3-6) at discharge (19.7 vs. 6.5%, p < 0.001) and final follow-up (14.3 vs. 7.4%, p = 0.03). In Cox regression analysis, coma (HR = 13.7; 95% CI = 4.3-43.7) and thrombosis of the deep venous system (HR = 3.5; 95% CI = 1.4-8.7) were associated with death or dependency at the end of follow-up. Cerebral venous thrombosis patients with NHL are intermediate between patients without brain lesions and those with HL, both in initial clinical picture and prognosis. Copyright 2010 S. Karger AG, Basel.

Quantification of blood-to-brain transfer rate in multiple sclerosis

PubMed Central

Taheri, Saeid; Rosenberg, Gary A.; Ford, Corey

2016-01-01

Blood–brain barrier (BBB) disruption visualized in lesions by MRI is a major biomarker of disease activity in multiple sclerosis (MS). However, in MS, destruction occurs to a variable extent in lesions as well as in gray matter (GM) and in the normal appearing white matter (NAWM). A method to quantify the BBB disruption in lesions as well as in non-lesion areas would be useful for assessment of MS progression and treatments. The objective of this study was to quantify the BBB transfer rate (Ki) in WM lesions, in the NAWM, and in the full-brain of MS patients. Thirteen MS patients with active lesions and 10 healthy controls with age and gender matching were recruited for full-brain and WM Ki studies. Dynamic contrast-enhanced MRI (DCEMRI) scans were conducted using T1 mapping with partial inversion recovery (TAPIR), a fast T1 mapping technique, following administration of a quarter-dose of the contrast agent Gadolinium-DTPA (Gd-DTPA). The Patlak modeling technique was used to derive a voxel-based map of Ki. In all patients contrast-enhanced lesions, quantified by Ki maps, were observed. Compared with controls, patients with MS exhibited an increase in mean Ki of the full-brain (P-value<0.05) but no significant difference in mean Ki of NAWM. The identified increase in full-brain Ki of MS patients suggests a global vascular involvement associated with MS disease. The lack of observed significant decrease in Ki in NAWM suggests lower involvement of WM vasculature than full-brain vasculature in MS. Ki maps constructed from time series data acquired by DCEMRI provide additional information about BBB that could be used for evaluation of vascular involvement in MS and monitoring treatment effectiveness. PMID:25877634

A generative probabilistic model and discriminative extensions for brain lesion segmentation – with application to tumor and stroke

PubMed Central

Menze, Bjoern H.; Van Leemput, Koen; Lashkari, Danial; Riklin-Raviv, Tammy; Geremia, Ezequiel; Alberts, Esther; Gruber, Philipp; Wegener, Susanne; Weber, Marc-André; Székely, Gabor; Ayache, Nicholas; Golland, Polina

2016-01-01

We introduce a generative probabilistic model for segmentation of brain lesions in multi-dimensional images that generalizes the EM segmenter, a common approach for modelling brain images using Gaussian mixtures and a probabilistic tissue atlas that employs expectation-maximization (EM) to estimate the label map for a new image. Our model augments the probabilistic atlas of the healthy tissues with a latent atlas of the lesion. We derive an estimation algorithm with closed-form EM update equations. The method extracts a latent atlas prior distribution and the lesion posterior distributions jointly from the image data. It delineates lesion areas individually in each channel, allowing for differences in lesion appearance across modalities, an important feature of many brain tumor imaging sequences. We also propose discriminative model extensions to map the output of the generative model to arbitrary labels with semantic and biological meaning, such as “tumor core” or “fluid-filled structure”, but without a one-to-one correspondence to the hypo-or hyper-intense lesion areas identified by the generative model. We test the approach in two image sets: the publicly available BRATS set of glioma patient scans, and multimodal brain images of patients with acute and subacute ischemic stroke. We find the generative model that has been designed for tumor lesions to generalize well to stroke images, and the generative-discriminative model to be one of the top ranking methods in the BRATS evaluation. PMID:26599702

Object Recognition Memory and the Rodent Hippocampus

ERIC Educational Resources Information Center

Broadbent, Nicola J.; Gaskin, Stephane; Squire, Larry R.; Clark, Robert E.

2010-01-01

In rodents, the novel object recognition task (NOR) has become a benchmark task for assessing recognition memory. Yet, despite its widespread use, a consensus has not developed about which brain structures are important for task performance. We assessed both the anterograde and retrograde effects of hippocampal lesions on performance in the NOR…

Temporal Dissociation of Striatum and Prefrontal Cortex Uncouples Anhedonia and Defense Behaviors Relevant to Depression in 6-OHDA-Lesioned Rats.

PubMed

Matheus, Filipe C; Rial, Daniel; Real, Joana I; Lemos, Cristina; Takahashi, Reinaldo N; Bertoglio, Leandro J; Cunha, Rodrigo A; Prediger, Rui D

2016-08-01

The dorsolateral striatum (DLS) processes motor and non-motor functions and undergoes extensive dopaminergic degeneration in Parkinson's disease (PD). The nigrostriatal dopaminergic degeneration also affects other brain areas including the pre-frontal cortex (PFC), which has been associated with the appearance of anhedonia and depression at pre-motor phases of PD. Using behavioral, neurochemical, and electrophysiological approaches, we investigated the temporal dissociation between the role of the DLS and PFC in the appearance of anhedonia and defense behaviors relevant to depression in rats submitted to bilateral DLS lesions with 6-hydroxydopamine (6-OHDA; 10 μg/hemisphere). 6-OHDA induced partial dopaminergic nigrostriatal damage with no gross motor impairments. Anhedonic-like behaviors were observed in the splash and sucrose consumption tests only 7 days after 6-OHDA lesion. By contrast, defense behaviors relevant to depression evaluated in the forced swimming test and social withdrawal only emerged 21 days after 6-OHDA lesion when anhedonia was no longer present. These temporally dissociated behavioral alterations were coupled to temporal- and structure-dependent alterations in dopaminergic markers such as dopamine D1 and D2 receptors and dopamine transporter, leading to altered dopamine sensitivity in DLS and PFC circuits, evaluated electrophysiologically. These results provide the first demonstration of a dissociated involvement of the DLS and PFC in anhedonic-like and defense behaviors relevant to depression in 6-OHDA-lesioned rats, which was linked with temporal fluctuations in dopaminergic receptor density, leading to altered dopaminergic system sensitivity in these two brain structures. This sheds new light to the duality between depressive and anhedonic symptoms in PD.

Basal ganglia lesions in subacute sclerosing panencephalitis

PubMed Central

Almeida, Kelson James; Brucki, Sonia Maria Dozzi; Duarte, Maria Irma Seixas; Pasqualucci, Carlos Augusto Gonçalves; Rosemberg, Sérgio; Nitrini, Ricardo

2012-01-01

The parieto-occipital region of the brain is the most frequently and severely affected in subacute sclerosing panencephalitis (SSPE). The basal ganglia, cerebellum and corpus callosum are less commonly involved. We describe a patient with SSPE confirmed by neuropathology based on brain magnetic resonance imaging showing extensive basal ganglia involvement and no significant involvement of other cortical structures. Though rarely described in SSPE, clinicians should be aware of this involvement. SSPE should be kept in mind when changes in basal ganglia signal are seen on brain magnetic resonance imaging with or without involvement of other regions of the human brain to avoid erroneous etiological diagnosis of other pathologies causing rapidly progressive dementia. PMID:29213810

Brain vascular lesions: a clinicopathologic, immunohistochemistry, and ultrastructural approach.

PubMed

Navarrete, Marisol Galván; Hernández, Alma Dalia; Collado-Ortiz, Miguel Angel; Salinas-Lara, Citlaltepetl; Tena-Suck, Martha Lilia

2014-08-01

Brain vascular malformations are relatively common lesions that cause serious neurologic disability or death in a significant proportion of individuals bearing them. The purpose of this study was to analyze the clinicopathologic and immunohistochemistry these lesions, looking for common antibodies expressed such as CD31, CD34, CD15, factor VIII, nestin, vimentin, vascular endothelial grow factor (VEGF), vascular endothelial grow factor receptor-2 (VEGF-R2), glial fibrillar acidic protien (GFAP), and fibroblastic grow factor β (β-FGF) and ultrastructure in endothelial cells as well as in vessel walls. Fifty cases of vascular lesions were included in this study: 29 (58%) of them were arteriovenous malformations and 21 (52%) were brain cavernomas. Twenty-six (52%) patients were women and 24 (48%) men. The age range was from 13 to 68 years (mean age, 35.86 ± 15.19 years). The size of the lesions ranged between 1 and 8 cm (3 ± 1.65 cm), and parieto-occipital lesions had a bigger size. Evolution time varied from 1 month to 1 year (mean, 7.5 months). There was a significant statistical correlation between age and sex (P = -035), rupture of lesion (P = .015), brain hemorrhage (P = .033), necrosis (P = .011), hemosiderin deposit (P = .042), VEGF (P = .015), and VEGFR (P = .037), as well as localization of rupture (P = .017), loss of consciousness (P = .000), visual deficit (P = .026), hyaline vessels (P = .000), and CD31 (.009). Interactions between endothelial cells and mural cells (pericytes and vascular smooth muscle cells) in blood vessel walls have recently come into focus as central processes in the regulation of vascular formation, stabilization, remodeling, and function in brain vascular lesions. However, the molecular mechanisms that underlie the formation and growth of brain arteriovenous malformations are still poorly understood. Copyright © 2014 Elsevier Inc. All rights reserved.

Scared or scarred: Could 'dissociogenic' lesions predispose to nonepileptic seizures after head trauma?

PubMed

Popkirov, Stoyan; Carson, Alan J; Stone, Jon

2018-04-14

A history of head injury is common in patients with psychogenic nonepileptic seizures (PNES). This association has so far been interpreted as either spurious or psychologically mediated. Biased recall and misattribution could foster illness beliefs about brain damage that promote symptom production. Furthermore, the emotional impact of head injury could induce long-term changes in stress responsivity. Lastly, maladaptive cognitive-behavioural processes involving symptom modelling and aversive conditioning, known to play a role in functional neurological disorders, could contribute to the development of PNES after head trauma. Lesional effects of head injury, on the other hand, remain unexplored in the context of PNES. However, even mild traumatic brain injury without structural MRI abnormalities on routine imaging can lead to disruptions of network connectivity that correlate with short-term cognitive impairments and psychiatric symptoms. Since alterations in global functional connectivity have been demonstrated in PNES patients using imaging and electroencephalography, we hypothesize that, in some patients, TBI and the associated disruption of long-range association fibres could contribute to the individual propensity for dissociative experiences in general and PNES in particular. This possibility is explored in the context of new cognitive-behavioural models of PNES pathogenesis, and the concept of a "dissociogenic" brain lesion is introduced. Copyright © 2018 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Sensorimotor Functional and Structural Networks after Intracerebral Stem Cell Grafts in the Ischemic Mouse Brain.

PubMed

Green, Claudia; Minassian, Anuka; Vogel, Stefanie; Diedenhofen, Michael; Beyrau, Andreas; Wiedermann, Dirk; Hoehn, Mathias

2018-02-14

Past investigations on stem cell-mediated recovery after stroke have limited their focus on the extent and morphological development of the ischemic lesion itself over time or on the integration capacity of the stem cell graft ex vivo However, an assessment of the long-term functional and structural improvement in vivo is essential to reliably quantify the regenerative capacity of cell implantation after stroke. We induced ischemic stroke in nude mice and implanted human neural stem cells (H9 derived) into the ipsilateral cortex in the acute phase. Functional and structural connectivity changes of the sensorimotor network were noninvasively monitored using magnetic resonance imaging for 3 months after stem cell implantation. A sharp decrease of the functional sensorimotor network extended even to the contralateral hemisphere, persisting for the whole 12 weeks of observation. In mice with stem cell implantation, functional networks were stabilized early on, pointing to a paracrine effect as an early supportive mechanism of the graft. This stabilization required the persistent vitality of the stem cells, monitored by bioluminescence imaging. Thus, we also observed deterioration of the early network stabilization upon vitality loss of the graft after a few weeks. Structural connectivity analysis showed fiber-density increases between the cortex and white matter regions occurring predominantly on the ischemic hemisphere. These fiber-density changes were nearly the same for both study groups. This motivated us to hypothesize that the stem cells can influence, via early paracrine effect, the functional networks, while observed structural changes are mainly stimulated by the ischemic event. SIGNIFICANCE STATEMENT In recent years, research on strokes has made a shift away from a focus on immediate ischemic effects and towards an emphasis on the long-range effects of the lesion on the whole brain. Outcome improvements in stem cell therapies also require the understanding of their influence on the whole-brain networks. Here, we have longitudinally and noninvasively monitored the structural and functional network alterations in the mouse model of focal cerebral ischemia. Structural changes of fiber-density increases are stimulated in the endogenous tissue without further modulation by the stem cells, while functional networks are stabilized by the stem cells via a paracrine effect. These results will help decipher the underlying networks of brain plasticity in response to cerebral lesions and offer clues to unravelling the mystery of how stem cells mediate regeneration. Copyright © 2018 the authors 0270-6474/18/381648-14$15.00/0.

Venous or arterial blood components trigger more brain swelling, tissue death after acute subdural hematoma compared to elderly atrophic brain with subdural effusion (SDE) model rats.

PubMed

Wajima, Daisuke; Sato, Fumiya; Kawamura, Kenya; Sugiura, Keisuke; Nakagawa, Ichiro; Motoyama, Yasushi; Park, Young-Soo; Nakase, Hiroyuki

2017-09-01

Acute subdural hematoma (ASDH) is a frequent complication of severe head injury, whose secondary ischemic lesions are often responsible for the severity of the disease. We focused on the differences of secondary ischemic lesions caused by the components, 0.4ml venous- or arterial-blood, or saline, infused in the subdural space, evaluating the differences in vivo model, using rats. The saline infused rats are made for elderly atrophic brain with subdural effusion (SDE) model. Our data showed that subdural blood, both venous- and arterial-blood, aggravate brain edema and lesion development more than SDE. This study is the first study, in which different fluids in rats' subdural space, ASDH or SDE are compared with the extension of early and delayed brain damage by measuring brain edema and histological lesion volume. Blood constituents started to affect the degree of ischemia underneath the subdural hemorrhage, leading to more pronounced breakdown of the blood-brain barrier and brain damage. This indicates that further strategies to treat blood-dependent effects more efficiently are in view for patients with ASDH. Copyright © 2017 Elsevier B.V. All rights reserved.

Marking multi-channel silicon-substrate electrode recording sites using radiofrequency lesions.

PubMed

Brozoski, Thomas J; Caspary, Donald M; Bauer, Carol A

2006-01-30

Silicon-substrate multi-channel electrodes (multiprobes) have proven useful in a variety of electrophysiological tasks. When using multiprobes it is often useful to identify the site of each channel, e.g., when recording single-unit activity from a heterogeneous structure. Lesion marking of electrode sites has been used for many years. Electrolytic, or direct current (DC) lesions, have been used successfully to mark multiprobe sites in rat hippocampus [Townsend G, Peloquin P, Kloosterman F, Hetke JF, Leung LS. Recording and marking with silicon multichannel electrodes. Brain Res Brain Res Protoc 2002;9:122-9]. The present method used radio-frequency (rf) lesions to distinctly mark each of the 16 recording sites of 16-channel linear array multiprobes, in chinchilla inferior colliculus. A commercial radio-frequency lesioner was used as the current source, in conjunction with custom connectors adapted to the multiprobe configuration. In vitro bench testing was used to establish current-voltage-time parameters, as well as to check multiprobe integrity and radio-frequency performance. In in vivo application, visualization of individual-channel multiprobe recording sites was clear in 21 out of 33 sets of collicular serial-sections (i.e., probe tracks) obtained from acute experimental subjects, i.e., maximum post-lesion survival time of 2h. Advantages of the rf method include well-documented methods of in vitro calibration as well as low impact on probe integrity. The rf method of marking individual-channel sites should be useful in a variety of applications.

Expression of the plasminogen activator system and the inhibitors PAI-1 and PAI-2 in posttraumatic lesions of the CNS and brain injuries following dramatic circulatory arrests: an immunohistochemical study.

PubMed

Dietzmann, K; von Bossanyi, P; Krause, D; Wittig, H; Mawrin, C; Kirches, E

2000-01-01

Plasminogen activators as inducible extracellular serine proteases are involved in a variety of processes, such as the degradation of brain structures. In regions of brain degradation, an increase in the expression of genes encoding cytokines and proteinases has recently been demonstrated. We tested the hypothesis, whether the plasminogen activator system as well as the plasminogen activator inhibitors are expressed and possibly involved in a proteolytic cascade that breaks down the extracellular matrix as a result of ischemic or posttraumatic brain destructions. To study this supposition, we investigated immunohistochemically the expression of tPA, uPA and its receptor, the plasminogen activator inhibitors PAI-1 and PAI-2, tetranectin as well as the laminin breakdown as an event of secondary brain injury. Brain tissue from 21 autopsy cases with severe brain injuries, material from 14 ischemic infarcts and 11 controls with acute hypoxia were used. All components of the plasminogen activator system studied were over-expressed immunohistochemically in reactive astrocytes, microglia and endothelial cells around the lesion zone. Tetranectin showed an analogous distribution to the plasminogen activator system. A reduced immunoreactivity of laminin within the identical region of destruction was detected concomitant with laminin remnants in perivascular macrophages, so that a remarkable role of the plasmin cascade in the degradation of extracellular matrix proteins in the brain is taken into consideration.

Excessive disgust caused by brain lesions or temporary inactivations: Mapping hotspots of nucleus accumbens and ventral pallidum

PubMed Central

Ho, Chao-Yi; Berridge, Kent C.

2014-01-01

Disgust is a prototypical type of negative affect. In animal models of excessive disgust, only a few brain sites are known in which localized dysfunction (lesions or neural inactivations) can induce intense ‘disgust reactions’ (e.g., gapes) to a normally pleasant sensation such as sweetness. Here we aimed to map forebrain candidates more precisely to identify where either local neuronal damage (excitotoxin lesions) or local pharmacological inactivation (muscimol-baclofen microinjections) caused rats to emit excessive sensory disgust reactions to sucrose. Our study compared subregions of nucleus accumbens shell, ventral pallidum, lateral hypothalamus and adjacent extended amygdala. Results indicated the posterior half of ventral pallidum to be the only forebrain site where intense sensory disgust gapes to sucrose were induced by both lesions and temporary inactivations (this site was previously identified as a hedonic hotspot for enhancements of sweetness ‘liking’). By comparison, for the nucleus accumbens, temporary GABA inactivations in the caudal half of the medial shell also generated sensory disgust but lesions never did at any site. Further, even inactivations failed to induce disgust in the rostral half of accumbens shell (which also contains a hedonic hotspot). In other structures, neither lesions nor inactivations induced disgust as long as the posterior ventral pallidum remained spared. We conclude that the posterior ventral pallidum is an especially crucial hotspot for producing excessive sensory disgust by local pharmacological/lesion dysfunction. By comparison, the nucleus accumbens appears to segregate sites for pharmacological disgust induction and hedonic enhancement into separate posterior versus rostral halves of medial shell. PMID:25229197

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.

Vascular depression consensus report - a critical update.

PubMed

Aizenstein, Howard J; Baskys, Andrius; Boldrini, Maura; Butters, Meryl A; Diniz, Breno S; Jaiswal, Manoj Kumar; Jellinger, Kurt A; Kruglov, Lev S; Meshandin, Ivan A; Mijajlovic, Milija D; Niklewski, Guenter; Pospos, Sarah; Raju, Keerthy; Richter, Kneginja; Steffens, David C; Taylor, Warren D; Tene, Oren

2016-11-03

Vascular depression is regarded as a subtype of late-life depression characterized by a distinct clinical presentation and an association with cerebrovascular damage. Although the term is commonly used in research settings, widely accepted diagnostic criteria are lacking and vascular depression is absent from formal psychiatric manuals such as the Diagnostic and Statistical Manual of Mental Disorders, 5 th edition - a fact that limits its use in clinical settings. Magnetic resonance imaging (MRI) techniques, showing a variety of cerebrovascular lesions, including extensive white matter hyperintensities, subcortical microvascular lesions, lacunes, and microinfarcts, in patients with late life depression, led to the introduction of the term "MRI-defined vascular depression". This diagnosis, based on clinical and MRI findings, suggests that vascular lesions lead to depression by disruption of frontal-subcortical-limbic networks involved in mood regulation. However, despite multiple MRI approaches to shed light on the spatiotemporal structural changes associated with late life depression, the causal relationship between brain changes, related lesions, and late life depression remains controversial. While postmortem studies of elderly persons who died from suicide revealed lacunes, small vessel, and Alzheimer-related pathologies, recent autopsy data challenged the role of these lesions in the pathogenesis of vascular depression. Current data propose that the vascular depression connotation should be reserved for depressed older patients with vascular pathology and evident cerebral involvement. Based on current knowledge, the correlations between intra vitam neuroimaging findings and their postmortem validity as well as the role of peripheral markers of vascular disease in late life depression are discussed. The multifold pathogenesis of vascular depression as a possible subtype of late life depression needs further elucidation. There is a need for correlative clinical, intra vitam structural and functional MRI as well as postmortem MRI and neuropathological studies in order to confirm the relationship between clinical symptomatology and changes in specific brain regions related to depression. To elucidate the causal relationship between regional vascular brain changes and vascular depression, animal models could be helpful. Current treatment options include a combination of vasoactive drugs and antidepressants, but the outcomes are still unsatisfying.

Co-registration of In-Vivo Human MRI Brain Images to Postmortem Histological Microscopic Images

PubMed Central

Singh, M.; Rajagopalan, A.; Kim, T.-S.; Hwang, D.; Chui, H.; Zhang, X.-L.; Lee, A.-Y.; Zarow, C.

2009-01-01

Certain features such as small vascular lesions seen in human MRI are detected reliably only in postmortem histological samples by microscopic imaging. Co-registration of these microscopically detected features to their corresponding locations in the in-vivo images would be of great benefit to understanding the MRI signatures of specific diseases. Using non-linear Polynomial transformation, we report a method to co-register in-vivo MRIs to microscopic images of histological samples drawn off the postmortem brain. The approach utilizes digital photographs of postmortem slices as an intermediate reference to co-register the MRIs to microscopy. The overall procedure is challenging due to gross structural deformations in the postmortem brain during extraction and subsequent distortions in the histological preparations. Hemispheres of the brain were co-registered separately to mitigate these effects. Approaches relying on matching single-slices, multiple-slices and entire volumes in conjunction with different similarity measures suggested that using four slices at a time in combination with two sequential measures, Pearson correlation coefficient followed by mutual information, produced the best MRI-postmortem co-registration according to a voxel mismatch count. The accuracy of the overall registration was evaluated by measuring the 3D Euclidean distance between the locations of microscopically identified lesions on postmortem slices and their MRI-postmortem co-registered locations. The results show a mean 3D displacement of 5.1 ± 2.0 mm between the in-vivo MRI and microscopically determined locations for 21 vascular lesions in 11 subjects. PMID:19169415

Your perspective and my benefit: multiple lesion models of self-other integration strategies during social bargaining.

PubMed

Melloni, Margherita; Billeke, Pablo; Baez, Sandra; Hesse, Eugenia; de la Fuente, Laura; Forno, Gonzalo; Birba, Agustina; García-Cordero, Indira; Serrano, Cecilia; Plastino, Angelo; Slachevsky, Andrea; Huepe, David; Sigman, Mariano; Manes, Facundo; García, Adolfo M; Sedeño, Lucas; Ibáñez, Agustín

2016-11-01

Recursive social decision-making requires the use of flexible, context-sensitive long-term strategies for negotiation. To succeed in social bargaining, participants' own perspectives must be dynamically integrated with those of interactors to maximize self-benefits and adapt to the other's preferences, respectively. This is a prerequisite to develop a successful long-term self-other integration strategy. While such form of strategic interaction is critical to social decision-making, little is known about its neurocognitive correlates. To bridge this gap, we analysed social bargaining behaviour in relation to its structural neural correlates, ongoing brain dynamics (oscillations and related source space), and functional connectivity signatures in healthy subjects and patients offering contrastive lesion models of neurodegeneration and focal stroke: behavioural variant frontotemporal dementia, Alzheimer's disease, and frontal lesions. All groups showed preserved basic bargaining indexes. However, impaired self-other integration strategy was found in patients with behavioural variant frontotemporal dementia and frontal lesions, suggesting that social bargaining critically depends on the integrity of prefrontal regions. Also, associations between behavioural performance and data from voxel-based morphometry and voxel-based lesion-symptom mapping revealed a critical role of prefrontal regions in value integration and strategic decisions for self-other integration strategy. Furthermore, as shown by measures of brain dynamics and related sources during the task, the self-other integration strategy was predicted by brain anticipatory activity (alpha/beta oscillations with sources in frontotemporal regions) associated with expectations about others' decisions. This pattern was reduced in all clinical groups, with greater impairments in behavioural variant frontotemporal dementia and frontal lesions than Alzheimer's disease. Finally, connectivity analysis from functional magnetic resonance imaging evidenced a fronto-temporo-parietal network involved in successful self-other integration strategy, with selective compromise of long-distance connections in frontal disorders. In sum, this work provides unprecedented evidence of convergent behavioural and neurocognitive signatures of strategic social bargaining in different lesion models. Our findings offer new insights into the critical roles of prefrontal hubs and associated temporo-parietal networks for strategic social negotiation. © 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.

Macrostructural and Microstructural Brain Lesions Relate to Gait Pathology in Children With Cerebral Palsy.

PubMed

Meyns, Pieter; Van Gestel, Leen; Leunissen, Inge; De Cock, Paul; Sunaert, Stefan; Feys, Hilde; Duysens, Jacques; Desloovere, Kaat; Ortibus, Els

2016-10-01

Background Even though lower-limb motor disorders are core features of spastic cerebral palsy (sCP), the relationship with brain lesions remains unclear. Unraveling the relation between gait pathology, lower-limb function, and brain lesions in sCP is complex for several reasons; wide heterogeneity in brain lesions, ongoing brain maturation, and gait depends on a number of primary motor functions/deficits (eg, muscle strength, spasticity). Objective To use a comprehensive approach combining conventional MRI and diffusion tensor imaging (DTI) in children with sCP above 3 years old to relate quantitative parameters of brain lesions in multiple brain areas to gait performance. Methods A total of 50 children with sCP (25 bilateral, 25 unilateral involvement) were enrolled. The investigated neuroradiological parameters included the following: (1) volumetric measures of the corpus callosum (CC) and lateral ventricles (LVs), and (2) DTI parameters of the corticospinal tract (CST). Gait pathology and primary motor deficits, including muscle strength and spasticity, were evaluated by 3D gait analysis and clinical examination. Results In bilateral sCP (n = 25), volume of the LV and the subparts of the CC connecting frontal, (pre)motor, and sensory areas were most related to lower-limb functioning and gait pathology. DTI measures of the CST revealed additional relations with the primary motor deficits (n = 13). In contrast, in unilateral sCP, volumetric (n = 25) and diffusion measures (n = 14) were only correlated to lower-limb strength. Conclusions These results indicate that the combined influence of multiple brain lesions and their impact on the primary motor deficits might explain a large part of the gait pathology in sCP. © The Author(s) 2016.

STRUCTURAL AND CONNECTOMIC NEUROIMAGING FOR THE PERSONALIZED STUDY OF LONGITUDINAL ALTERATIONS IN CORTICAL SHAPE, THICKNESS AND CONNECTIVITY AFTER TRAUMATIC BRAIN INJURY

PubMed Central

Irimia, A.; Goh, S.-Y. M.; Torgerson, C. M.; Vespa, P. M.; Van Horn, J. D.

2014-01-01

The integration of longitudinal brain structure analysis with neurointensive care strategies continues to be a substantial difficulty facing the traumatic brain injury (TBI) research community. For patient-tailored case analysis, it remains challenging to establish how lesion profile modulates longitudinal changes in cortical structure and connectivity, as well as how these changes lead to behavioral, cognitive and neural dysfunction. Additionally, despite the clinical potential of morphometric and connectomic studies, few analytic tools are available for their study in TBI. Here we review the state of the art in structural and connectomic neuroimaging for the study of TBI and illustrate a set of recently-developed, patient-tailored approaches for the study of TBI-related brain atrophy and alterations in morphometry as well as inter-regional connectivity. The ability of such techniques to quantify how injury modulates longitudinal changes in cortical shape, structure and circuitry is highlighted. Quantitative approaches such as these can be used to assess and monitor the clinical condition and evolution of TBI victims, and can have substantial translational impact, especially when used in conjunction with measures of neuropsychological function. PMID:24844173

Differences in Brain Metabolic Impairment between Chronic Mild/Moderate TBI Patients with and without Visible Brain Lesions Based on MRI.

PubMed

Ito, Keiichi; Asano, Yoshitaka; Ikegame, Yuka; Shinoda, Jun

2016-01-01

Introduction. Many patients with mild/moderate traumatic brain injury (m/mTBI) in the chronic stage suffer from executive brain function impairment. Analyzing brain metabolism is important for elucidating the pathological mechanisms associated with their symptoms. This study aimed to determine the differences in brain glucose metabolism between m/mTBI patients with and without visible traumatic brain lesions based on MRI. Methods. Ninety patients with chronic m/mTBI due to traffic accidents were enrolled and divided into two groups based on their MRI findings. Group A comprised 50 patients with visible lesions. Group B comprised 40 patients without visible lesions. Patients underwent FDG-PET scans following cognitive tests. FDG-PET images were analyzed using voxel-by-voxel univariate statistical tests. Results. There were no significant differences in the cognitive tests between Group A and Group B. Based on FDG-PET findings, brain metabolism significantly decreased in the orbital gyrus, cingulate gyrus, and medial thalamus but increased in the parietal and occipital convexity in Group A compared with that in the control. Compared with the control, patients in Group B exhibited no significant changes. Conclusions. These results suggest that different pathological mechanisms may underlie cognitive impairment in m/mTBI patients with and without organic brain damage.

A Comparison of Four-Image Reconstruction Algorithms for 3-D PET Imaging of MDAPET Camera Using Phantom Data

NASA Astrophysics Data System (ADS)

Baghaei, H.; Wong, Wai-Hoi; Uribe, J.; Li, Hongdi; Wang, Yu; Liu, Yaqiang; Xing, Tao; Ramirez, R.; Xie, Shuping; Kim, Soonseok

2004-10-01

We compared two fully three-dimensional (3-D) image reconstruction algorithms and two 3-D rebinning algorithms followed by reconstruction with a two-dimensional (2-D) filtered-backprojection algorithm for 3-D positron emission tomography (PET) imaging. The two 3-D image reconstruction algorithms were ordered-subsets expectation-maximization (3D-OSEM) and 3-D reprojection (3DRP) algorithms. The two rebinning algorithms were Fourier rebinning (FORE) and single slice rebinning (SSRB). The 3-D projection data used for this work were acquired with a high-resolution PET scanner (MDAPET) with an intrinsic transaxial resolution of 2.8 mm. The scanner has 14 detector rings covering an axial field-of-view of 38.5 mm. We scanned three phantoms: 1) a uniform cylindrical phantom with inner diameter of 21.5 cm; 2) a uniform 11.5-cm cylindrical phantom with four embedded small hot lesions with diameters of 3, 4, 5, and 6 mm; and 3) the 3-D Hoffman brain phantom with three embedded small hot lesion phantoms with diameters of 3, 5, and 8.6 mm in a warm background. Lesions were placed at different radial and axial distances. We evaluated the different reconstruction methods for MDAPET camera by comparing the noise level of images, contrast recovery, and hot lesion detection, and visually compared images. We found that overall the 3D-OSEM algorithm, especially when images post filtered with the Metz filter, produced the best results in terms of contrast-noise tradeoff, and detection of hot spots, and reproduction of brain phantom structures. Even though the MDAPET camera has a relatively small maximum axial acceptance (/spl plusmn/5 deg), images produced with the 3DRP algorithm had slightly better contrast recovery and reproduced the structures of the brain phantom slightly better than the faster 2-D rebinning methods.

Development of a web-based DICOM-SR viewer for CAD data of multiple sclerosis lesions in an imaging informatics-based efolder

NASA Astrophysics Data System (ADS)

Ma, Kevin; Wong, Jonathan; Zhong, Mark; Zhang, Jeff; Liu, Brent

2014-03-01

In the past, we have presented an imaging-informatics based eFolder system for managing and analyzing imaging and lesion data of multiple sclerosis (MS) patients, which allows for data storage, data analysis, and data mining in clinical and research settings. The system integrates the patient's clinical data with imaging studies and a computer-aided detection (CAD) algorithm for quantifying MS lesion volume, lesion contour, locations, and sizes in brain MRI studies. For compliance with IHE integration protocols, long-term storage in PACS, and data query and display in a DICOM compliant clinical setting, CAD results need to be converted into DICOM-Structured Report (SR) format. Open-source dcmtk and customized XML templates are used to convert quantitative MS CAD results from MATLAB to DICOM-SR format. A web-based GUI based on our existing web-accessible DICOM object (WADO) image viewer has been designed to display the CAD results from generated SR files. The GUI is able to parse DICOM-SR files and extract SR document data, then display lesion volume, location, and brain matter volume along with the referenced DICOM imaging study. In addition, the GUI supports lesion contour overlay, which matches a detected MS lesion with its corresponding DICOM-SR data when a user selects either the lesion or the data. The methodology of converting CAD data in native MATLAB format to DICOM-SR and displaying the tabulated DICOM-SR along with the patient's clinical information, and relevant study images in the GUI will be demonstrated. The developed SR conversion model and GUI support aim to further demonstrate how to incorporate CAD post-processing components in a PACS and imaging informatics-based environment.

Do positive or negative stressful events predict the development of new brain lesions in people with Multiple Sclerosis?

PubMed Central

Burns, Michelle Nicole; Nawacki, Ewa; Kwasny, Mary J.; Pelletier, Daniel; Mohr, David C.

2014-01-01

Background Stressful life events have long been suspected to contribute to multiple sclerosis (MS) disease activity. The few studies examining the relationship between stressful events and neuroimaging markers have been small and inconsistent. This study examined whether different types of stressful events and perceived stress could predict development of brain lesions. Methods This was a secondary analysis of 121 patients with MS followed for 48 weeks during a randomized controlled trial comparing Stress Management Therapy for MS to a waitlist control. Patients underwent MRI’s every 8 weeks. Monthly, patients completed an interview measure assessing stressful life events, and self-report measures of perceived stress, anxiety, and depressive symptoms, which were used to predict the presence of gadolinium enhancing (Gd+) and T2 lesions on MRI’s 29–62 days later. Participants classified stressful events as positive or negative. Negative events were considered “major” if they involved physical threat or threat to the patient’s family structure, and “moderate” otherwise. Results Positive stressful events predicted decreased risk for subsequent Gd+ lesions in the control group (OR=.53 for each additional positive stressful event, 95% CI=.30–.91) and less risk for new or enlarging T2 lesions regardless of group assignment (OR=.74, 95% CI=.55–.99). Across groups, major negative stressful events predicted Gd+ lesions (OR=1.77, 95% CI=1.18–2.64) and new or enlarging T2 lesions (OR=1.57, 95% CI=1.11–2.23), while moderate negative stressful events, perceived stress, anxiety, and depressive symptoms did not. Conclusions Major negative stressful events predict increased risk for Gd+ and T2 lesions, while positive stressful events predict decreased risk. PMID:23680407

Human endogenous retrovirus W in brain lesions: Rationale for targeted therapy in multiple sclerosis.

PubMed

van Horssen, Jack; van der Pol, Susanne; Nijland, Philip; Amor, Sandra; Perron, Hervé

2016-07-01

Attempts to identify a causative agent of Multiple Sclerosis (MS) among environmental viruses have consistently failed suggesting that development of MS is a result from gene-environment interactions. A new pathogenic player within human genes, a human endogenous retrovirus (HERV) was identified from MS cells, named MS-associated retrovirus element (MSRV) and unveiled homologous multicopy HERVs (HERV-W). As independent studies revealed biological features of HERV-W on immune-mediated inflammation and on remyelinating cells, the present study characterized the presence of HERV-W envelope protein (MSRV-Env) at the cellular level, in different MS lesion stages to extend and validate previous studies. Immunohistological analysis of HERV-W envelope cellular expression in different lesion stages from a cohort of MS brains versus controls, using well-characterized and highly specific monoclonal antibodies. HERV-W envelope protein was detected in all MS brains and quite essentially in lesions. Immunohistochemistry showed dominant expression in macrophages and microglia, coinciding with areas of active demyelination, spread over the active lesions, or limited to the rim of active microglia in chronic active lesions or in few surviving astrocytes of inactive plaques. Weak expression was seen in MS normal appearing white matter. In active plaques, few lymphoid cells and astrocytes were also stained. This HERV-W expression was not observed in control brains. HERV-W was expressed in demyelinated lesions from MS brains, which were all positive for this endogenous pathogenic protein. Pronounced HERV-W immunoreactivity in active MS lesions was intimately associated with areas of active demyelination throughout the successive stages of lesion evolution in MS brains. Based on its pathogenic potential, this HERV-W (MSRV) endogenous toxin thus appears to be a novel therapeutic target in MS. It also has a unique positioning as an early and lifelong expressed pathogenic agonist, acting upstream the pathways in which dysregulated physiological effectors are usually targeted by present therapeutic strategies for MS. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Monitoring of injury induced brain regeneration of the adult zebrafish by using optical coherence tomography

NASA Astrophysics Data System (ADS)

Yuan, Zhen; Zhang, Jian

2018-02-01

The adult zebrafish has pronounced regenerative capacity of the brain, which makes it an ideal model organism of vertebrate biology for the investigation of recovery of central nervous system injuries. The aim of this study was to employ spectral-domain optical coherence tomography (SD-OCT) system for long-term in vivo monitoring of tissue regeneration using an adult zebrafish model of brain injury. Based on a 1325 nm light source and two high-speed galvo mirrors, the SD-OCT system can offer a large field of view of the three-dimensional (3D) brain structures with high imaging resolution (12 μm axial and 13 μm lateral) at video rate. In vivo experiments based on this system were conducted to monitor the regeneration process of zebrafish brain after injury during a period of 43 days. To monitor and detect the process of tissue regeneration, we performed 3D in vivo imaging in a zebrafish model of adult brain injury during a period of 43 days. The coronal and sagittal views of the injured zebrafish brain at each time point (0 days, 10 days, 20 days and 43 days postlesion) were presented to show the changes of the brain lesion in detail. In addition, the 3D SD-OCT images for an injured zebrafish brain were also reconstructed at days 0 and days 43 post-lesion. We found that SD-OCT is able to effectively and noninvasively monitor the regeneration of the adult zebrafish brain after injury in real time with high 3D spatial resolution and good penetration depth. Our findings also suggested that the adult zebrafish has the extraordinary capability of brain regeneration and is able to repair itself after brain injury.

Brain Network Theory Can Predict Whether Neuropsychological Outcomes Will Differ from Clinical Expectations.

PubMed

Warren, David E; Denburg, Natalie L; Power, Jonathan D; Bruss, Joel; Waldron, Eric J; Sun, Haoxin; Petersen, Steve E; Tranel, Daniel

2017-02-01

Theories of brain-network organization based on neuroimaging data have burgeoned in recent years, but the predictive power of such theories for cognition and behavior has only rarely been examined. Here, predictions from clinical neuropsychologists about the cognitive profiles of patients with focal brain lesions were used to evaluate a brain-network theory (Warren et al., 2014). Neuropsychologists made predictions regarding the neuropsychological profiles of a neurological patient sample (N = 30) based on lesion location. The neuropsychologists then rated the congruence of their predictions with observed neuropsychological outcomes, in regard to the "severity" of neuropsychological deficits and the "focality" of neuropsychological deficits. Based on the network theory, two types of lesion locations were identified: "target" locations (putative hubs in a brain-wide network) and "control" locations (hypothesized to play limited roles in network function). We found that patients with lesions of target locations (N = 19) had deficits of greater than expected severity that were more widespread than expected, whereas patients with lesions of control locations (N = 11) showed milder, circumscribed deficits that were more congruent with expectations. The findings for the target brain locations suggest that prevailing views of brain-behavior relationships may be sharpened and refined by integrating recently proposed network-oriented perspectives. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Oxidative Glial Cell Damage Associated with White Matter Lesions in the Aging Human Brain.

PubMed

Al-Mashhadi, Sufana; Simpson, Julie E; Heath, Paul R; Dickman, Mark; Forster, Gillian; Matthews, Fiona E; Brayne, Carol; Ince, Paul G; Wharton, Stephen B

2015-09-01

White matter lesions (WML) are common in brain aging and are associated with dementia. We aimed to investigate whether oxidative DNA damage and occur in WML and in apparently normal white matter in cases with lesions. Tissue from WML and control white matter from brains with lesions (controls lesional) and without lesions (controls non-lesional) were obtained, using post-mortem magnetic resonance imaging-guided sampling, from the Medical Research Council Cognitive Function and Ageing Study. Oxidative damage was assessed by immunohistochemistry to 8-hydroxy-2'-deoxoguanosine (8-OHdG) and Western blotting for malondialdehyde. DNA response was assessed by phosphorylated histone H2AX (γH2AX), p53, senescence markers and by quantitative Reverse transcription polymerase chain reaction (RT-PCR) panel for candidate DNA damage-associated genes. 8-OHdG was expressed in glia and endothelium, with increased expression in both WML and controls lesional compared with controls non-lesional (P < 0.001). γH2Ax showed a similar, although attenuated difference among groups (P = 0.03). Expression of senescence-associated β-galactosidase and p16 suggested induction of senescence mechanisms in glia. Oxidative DNA damage and a DNA damage response are features of WML pathogenesis and suggest candidate mechanisms for glial dysfunction. Their expression in apparently normal white matter in cases with WML suggests that white matter dysfunction is not restricted to lesions. The role of this field-effect lesion pathogenesis and cognitive impairment are areas to be defined. © 2014 The Authors. Brain Pathology published by John Wiley & Sons Ltd on behalf of International Society of Neuropathology.

Lesional perfusion abnormalities in Leigh disease demonstrated by arterial spin labeling correlate with disease activity.

PubMed

Whitehead, Matthew T; Lee, Bonmyong; Gropman, Andrea

2016-08-01

Leigh disease is a metabolic disorder of the mitochondrial respiratory chain culminating in symmetrical necrotizing lesions in the deep gray nuclei or brainstem. Apart from classic gliotic/necrotic lesions, small-vessel proliferation is also characteristic on histopathology. We have observed lesional hyperperfusion on arterial spin-labeling (ASL) sequence in children with Leigh disease. In this cross-sectional analysis, we evaluated lesional ASL perfusion characteristics in children with Leigh syndrome. We searched the imaging database from an academic children's hospital for "arterial spin labeling, perfusion, necrosis, lactate, and Leigh" to build a cohort of children for retrospective analysis. We reviewed each child's medical record to confirm a diagnosis of Leigh disease, excluding exams with artifact, technical limitations, and without ASL images. We evaluated the degree and extent of cerebral blood flow and relationship to brain lesions. Images were compared to normal exams from an aged-matche cohort. The database search yielded 45 exams; 30 were excluded. We evaluated 15 exams from 8 children with Leigh disease and 15 age-matched normal exams. In general, Leigh brain perfusion ranged from hyperintense (n=10) to hypointense (n=5). Necrotic lesions appeared hypointense/hypoperfused. Active lesions with associated restricted diffusion demonstrated hyperperfusion. ASL perfusion patterns differed significantly from those on age-matched normal studies (P=<.0001). Disease activity positively correlated with cerebral deep gray nuclei hyperperfusion (P=0.0037) and lesion grade (P=0.0256). Children with Leigh disease have abnormal perfusion of brain lesions. Hyperperfusion can be found in active brain lesions, possibly associated with small-vessel proliferation characteristic of the disease.

Monocrotaline: Histological Damage and Oxidant Activity in Brain Areas of Mice

PubMed Central

Honório Junior, José Eduardo Ribeiro; Vasconcelos, Germana Silva; Rodrigues, Francisca Taciana Sousa; Sena Filho, José Guedes; Barbosa-Filho, José Maria; Aguiar, Carlos Clayton Torres; Leal, Luzia Kalyne Almeida Moreira; Soares, Pedro Marcos Gomes; Woods, David John; Fonteles, Marta Maria de França; Vasconcelos, Silvânia Maria Mendes

2012-01-01

This work was designed to study MCT effect in histopathological analysis of hippocampus (HC) and parahippocampal cortex (PHC) and in oxidative stress (OS) parameters in brain areas such as hippocampus (HC), prefrontal cortex (PFC), and striatum (ST). Swiss mice (25–30 g) were administered a single i.p. dose of MCT (5, 50, or 100 mg/kg) or 4% Tween 80 in saline (control group). After 30 minutes, the animals were sacrificed by decapitation and the brain areas (HC, PHC, PFC, or ST) were removed for histopathological analysis or dissected and homogenized for measurement of OS parameters (lipid peroxidation, nitrite, and catalase) by spectrophotometry. Histological evaluation of brain structures of rats treated with MCT (50 and 100 mg/kg) revealed lesions in the hippocampus and parahippocampal cortex compared to control. Lipid peroxidation was evident in all brain areas after administration of MCT. Nitrite/nitrate content decreased in all doses administered in HC, PFC, and ST. Catalase activity was increased in the MCT group only in HC. In conclusion, monocrotaline caused cell lesions in the hippocampus and parahippocampal cortex regions and produced oxidative stress in the HC, PFC, and ST in mice. These findings may contribute to the neurological effects associated with this compound. PMID:23251721

Housing conditions influence motor functions and exploratory behavior following focal damage of the rat brain.

PubMed

Gornicka-Pawlak, Elzbieta; Jabłońska, Anna; Chyliński, Andrzej; Domańska-Janik, Krystyna

2009-01-01

The present study investigated influence of housing conditions on motor functions recovery and exploratory behavior following ouabain focal brain lesion in the rat. During 30 days post-surgery period rats were housed individually in standard cages (IS) or in groups in enriched environment (EE) and behaviorally tested. The EE lesioned rats showed enhanced recovery from motor impairments in walking beam task, comparing with IS animals. Contrarily, in the open field IS rats (both lesioned and control) traveled a longer distance, showed less habituation and spent less time resting at the home base than the EE animals. Unlike the EE lesioned animals, the lesioned IS rats, presented a tendency to hyperactivity in postinjury period. Turning tendency was significantly affected by unilateral brain lesion only in the EE rats. We can conclude that housing conditions distinctly affected the rat's behavior in classical laboratory tests.

3 Tesla MRI-detected brain lesions after pulmonary vein isolation for atrial fibrillation: results of the MACPAF study.

PubMed

Haeusler, Karl Georg; Koch, Lydia; Herm, Juliane; Kopp, Ute A; Heuschmann, Peter U; Endres, Matthias; Schultheiss, Heinz-Peter; Schirdewan, Alexander; Fiebach, Jochen B

2013-01-01

Left atrial catheter ablation (LACA) is an established therapeutic approach to abolish symptomatic atrial fibrillation (AF). Based on the prospective MACPAF study (clinicaltrials.gov NCT01061931) we report the rate of ischemic brain lesions postablation and their impact on cognitive function. Patients with symptomatic paroxysmal AF were randomized to LACA using the Arctic Front® or the HD Mesh Ablator® catheter. All patients underwent brain MRI at 3 Tesla, neurological, and neuropsychological examinations within 48 hours prior and after the ablation procedure. There was no clinically evident stroke in 37 patients (mean age 62.4 ± 8.4 years; 41% female; median CHADS2 score 1 [IQR 0-2]) after LACA but high-resolution diffusion-weighted imaging (DWI) detected new ischemic lesions in 15 (41%) patients after LACA. Four (27%) of the HD Mesh Ablator® patients and 11 (50%) of the Arctic Front® patients suffered a silent ischemic lesion (P = 0.19). In these 15 patients, there was a nonsignificant trend toward lower cardiac ejection fraction (P = 0.07) and AF episodes during LACA (P = 0.09), while activated clotting time levels, number of energy applications, periprocedural electrocardioversion or CHADS(2) score had no impact. Lesion volumes varied from 5 to 150 mm(3) and 1 to 5 lesions were detected per patient. However, acute brain lesions had no effect on cognitive performance immediately after LACA. Of the DWI lesions postablation 82% were not detectable on FLAIR images 6-9 months postablation. According to 3 Tesla high-resolution DWI, ischemic brain lesions after LACA were common but not associated with impaired cognitive function after the ablation procedure. © 2012 Wiley Periodicals, Inc.

White matter lesion extension to automatic brain tissue segmentation on MRI.

PubMed

de Boer, Renske; Vrooman, Henri A; van der Lijn, Fedde; Vernooij, Meike W; Ikram, M Arfan; van der Lugt, Aad; Breteler, Monique M B; Niessen, Wiro J

2009-05-01

A fully automated brain tissue segmentation method is optimized and extended with white matter lesion segmentation. Cerebrospinal fluid (CSF), gray matter (GM) and white matter (WM) are segmented by an atlas-based k-nearest neighbor classifier on multi-modal magnetic resonance imaging data. This classifier is trained by registering brain atlases to the subject. The resulting GM segmentation is used to automatically find a white matter lesion (WML) threshold in a fluid-attenuated inversion recovery scan. False positive lesions are removed by ensuring that the lesions are within the white matter. The method was visually validated on a set of 209 subjects. No segmentation errors were found in 98% of the brain tissue segmentations and 97% of the WML segmentations. A quantitative evaluation using manual segmentations was performed on a subset of 6 subjects for CSF, GM and WM segmentation and an additional 14 for the WML segmentations. The results indicated that the automatic segmentation accuracy is close to the interobserver variability of manual segmentations.

A Score to Identify Patients with Brain Metastases from Colorectal Cancer Who May Benefit from Whole-brain Radiotherapy in Addition to Stereotactic Radiosurgery/Radiotherapy.

PubMed

Rades, Dirk; Dziggel, Liesa; Blanck, Oliver; Gebauer, Niklas; Bartscht, Tobias; Schild, Steven E

2018-05-01

To design a tool to predict the probability of new cerebral lesions after stereotactic radiosurgery/radiotherapy for patients with 1-3 brain metastases from colorectal cancer. In 21 patients, nine factors were evaluated for freedom from new brain metastases, namely age, gender, Karnofsky performance score (KPS), tumor type, number, maximum total diameter of all lesions and sites of cerebral lesions, extra-cranial metastases, and time from cancer diagnosis to irradiation. Freedom from new lesions was positively associated with KPS of 90-100 (p=0.013); maximum total diameter ≤15 mm showed a trend for positive association (p=0.09). Points were assigned as: KPS 70-80=1 point, KPS 90-100=2 points, maximum diameter ≤15 mm=2 points and maximum diameter >15 mm=1 point. Six-month rates of freedom from new lesions were 29%, 45% and 100% for those with total scores of 2, 3 and 4 points, respectively, with corresponding 12-month rates of 0%, 45% and 100% (p=0.027). This study identified three risk groups regarding new brain metastases after stereotactic irradiation. Patients with 2 points could benefit from additional whole-brain radiotherapy. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Demyelinating and ischemic brain diseases: detection algorithm through regular magnetic resonance images

NASA Astrophysics Data System (ADS)

Castillo, D.; Samaniego, René; Jiménez, Y.; Cuenca, L.; Vivanco, O.; Rodríguez-Álvarez, M. J.

2017-09-01

This work presents the advance to development of an algorithm for automatic detection of demyelinating lesions and cerebral ischemia through magnetic resonance images, which have contributed in paramount importance in the diagnosis of brain diseases. The sequences of images to be used are T1, T2, and FLAIR. Brain demyelination lesions occur due to damage of the myelin layer of nerve fibers; and therefore this deterioration is the cause of serious pathologies such as multiple sclerosis (MS), leukodystrophy, disseminated acute encephalomyelitis. Cerebral or cerebrovascular ischemia is the interruption of the blood supply to the brain, thus interrupting; the flow of oxygen and nutrients needed to maintain the functioning of brain cells. The algorithm allows the differentiation between these lesions.

Thermal ablation system using high intensity focused ultrasound (HIFU) and guided by MRI

NASA Astrophysics Data System (ADS)

Damianou, C.; Ioannides, K.; HadjiSavas, V.; Milonas, N.; Couppis, A.; Iosif, D.; Komodromos, M.; Vrionides, F.

2009-04-01

In this paper magnetic resonance imaging (MRI) is investigated for monitoring lesions created by high intensity focused ultrasound (HIFU) in kidney, liver and brain in vitro and in vivo. Spherically focused transducers of 4 cm diameter, focusing at 10 cm and operating at 1 and 4 MHz were used. An MRI compatible positioning device was developed in order to scan the HIFU transducer. The MRI compatibility of the system was successfully demonstrated in a clinical high-field MRI scanner. The ability of the positioning device to accurately move the transducer thus creating discrete and overlapping lesions in biological tissue was tested successfully. A simple, cost effective, portable positioning device has been developed which can be used in virtually any clinical MRI scanner since it can be sited on the scanner's table. The propagation of HIFU can use either a lateral or superior-inferior approach. Both T1-w FSE and T2-w FSE imaged successfully lesions in kidney and liver. T1-w FSE and T2-w FSE and FLAIR shows better anatomical details in brain than T1-w FSE, but with T1-w FSE the contrast between lesion and brain is higher for both thermal and bubbly lesion. With this system we were able to create large lesions (by producing overlapping lesions). The length of the lesions in vivo brain was much higher than the length in vitro, proving that the penetration in the in vitro brain is limited by reflection due to trapped bubbles in the blood vessels.

Convergence Analysis of Micro-Lesions (CAML): An approach to mapping of diffuse lesions from carotid revascularization.

PubMed

Rosen, Allyson C; Soman, Salil; Bhat, Jyoti; Laird, Angela R; Stephens, Jeffrey; Eickhoff, Simon B; Fox, P Mickle; Long, Becky; Dinishak, David; Ortega, Mario; Lane, Barton; Wintermark, Max; Hitchner, Elizabeth; Zhou, Wei

2018-01-01

Carotid revascularization (endarterectomy, stenting) prevents stroke; however, procedure-related embolization is common and results in small brain lesions easily identified by diffusion weighted magnetic resonance imaging (DWI). A crucial barrier to understanding the clinical significance of these lesions has been the lack of a statistical approach to identify vulnerable brain areas. The problem is that the lesions are small, numerous, and non-overlapping. Here we address this problem with a new method, the Convergence Analysis of Micro-Lesions (CAML) technique, an extension of the Anatomic Likelihood Analysis (ALE). The method combines manual lesion tracing, constraints based on known lesion patterns, and convergence analysis to represent regions vulnerable to lesions as probabilistic brain atlases. Two studies were conducted over the course of 12 years in an active, vascular surgery clinic. An analysis in an initial group of 126 patients at 1.5 T MRI was cross-validated in a second group of 80 patients at 3T MRI. In CAML, lesions were manually defined and center points identified. Brains were aligned according to side of surgery since this factor powerfully determines lesion distribution. A convergence based analysis, was performed on each of these groups. Results indicated the most consistent region of vulnerability was in motor and premotor cortex regions. Smaller regions common to both groups included the dorsolateral prefrontal cortex and medial parietal regions. Vulnerability of motor cortex is consistent with previous work showing changes in hand dexterity associated with these procedures. The consistency of CAML also demonstrates the feasibility of this new approach to characterize small, diffuse, non-overlapping lesions in patients with multifocal pathologies.

Lesion studies of human emotion and feeling.

PubMed

Feinstein, Justin S

2013-06-01

The lesion method provides unique insight into how the human brain generates emotion and feeling. Recent work has explored a number of interesting topics including the dissociation of emotional experience from memory in patients with amnesia, the reliability of specific emotional deficits following focal brain damage (including fear and the amygdala), and the investigation of compensatory neural mechanisms in lesion patients. Several detailed case studies have challenged the necessary role of the insular cortex in both awareness and feeling by showing that even in rare instances of complete bilateral insula destruction, the patient remains fully sentient and capable of expressing and feeling emotion. These findings highlight the distributed nature of emotion processing in the human brain and emphasize the importance of utilizing the lesion method for elucidating brain-behavior relationships. Copyright © 2012 Elsevier Ltd. All rights reserved.

Association between MRI structural features and cognitive measures in pediatric multiple sclerosis

NASA Astrophysics Data System (ADS)

Amoroso, N.; Bellotti, R.; Fanizzi, A.; Lombardi, A.; Monaco, A.; Liguori, M.; Margari, L.; Simone, M.; Viterbo, R. G.; Tangaro, S.

2017-09-01

Multiple sclerosis (MS) is an inflammatory and demyelinating disease associated with neurodegenerative processes that lead to brain structural changes. The disease affects mostly young adults, but 3-5% of cases has a pediatric onset (POMS). Magnetic Resonance Imaging (MRI) is generally used for diagnosis and follow-up in MS patients, however the most common MRI measures (e.g. new or enlarging T2-weighted lesions, T1-weighted gadolinium- enhancing lesions) have often failed as surrogate markers of MS disability and progression. MS is clinically heterogenous with symptoms that can include both physical changes (such as visual loss or walking difficulties) and cognitive impairment. 30-50% of POMS experience prominent cognitive dysfunction. In order to investigate the association between cognitive measures and brain morphometry, in this work we present a fully automated pipeline for processing and analyzing MRI brain scans. Relevant anatomical structures are segmented with FreeSurfer; besides, statistical features are computed. Thus, we describe the data referred to 12 patients with early POMS (mean age at MRI: 15.5 +/- 2.7 years) with a set of 181 structural features. The major cognitive abilities measured are verbal and visuo-spatial learning, expressive language and complex attention. Data was collected at the Department of Basic Sciences, Neurosciences and Sense Organs, University of Bari, and exploring different abilities like the verbal and visuo-spatial learning, expressive language and complex attention. Different regression models and parameter configurations are explored to assess the robustness of the results, in particular Generalized Linear Models, Bayes Regression, Random Forests, Support Vector Regression and Artificial Neural Networks are discussed.

Brain abscess mimicking brain metastasis in breast cancer.

PubMed

Khullar, Pooja; Datta, Niloy R; Wahi, Inderjeet Kaur; Kataria, Sabeena

2016-03-01

61 year old female presented with chief complaints of headache for 30 days, fever for 10 days, altered behavior for 10 days and convulsion for 2 days. She was diagnosed and treated as a case of carcinoma of left breast 5 years ago. MRI brain showed a lobulated lesion in the left frontal lobe. She came to our hospital for whole brain radiation as a diagnosed case of carcinoma of breast with brain metastasis. Review of MRI brain scan, revealed metastasis or query infective pathology. MR spectroscopy of the lesion revealed choline: creatinine and choline: NAA (N-Acetylaspartate) ratios of ∼1.6 and 1.5 respectively with the presence of lactate within the lesion suggestive of infective pathology. She underwent left fronto temporal craniotomy and evacuation of abscess and subdural empyema. Gram stain showed gram positive cocci. After 1 month of evacuation and treatment she was fine. This case suggested a note of caution in every case of a rapidly evolving space-occupying lesion independent of the patient's previous history. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

An Epigenetic Gateway to Brain Tumor Cell Identity

PubMed Central

Mack, Stephen C.; Hubert, Christopher G.; Miller, Tyler E.; Taylor, Michael D.; Rich, Jeremy N.

2017-01-01

Precise targeting of genetic lesions alone has been insufficient to extend brain tumor patient survival. Brain cancer cells are diverse in their genetic, metabolic, and microenvironmental compositions, accounting for their phenotypic heterogeneity and disparate responses to therapy. These factors converge at the level of the epigenome, representing a unified node that can be disrupted by pharmacologic inhibition. Aberrant epigenomes define many childhood and adult brain cancers, as demonstrated by widespread changes to DNA methylation patterns, redistribution of histone marks, and disruption of chromatin structure. In this review, we describe the convergence of genetic, metabolic, and micro-environmental factors upon mechanisms of epigenetic deregulation in brain cancer. We discuss how aberrant epigenetic pathways identified in brain tumors affect cell identity, cell state, and neoplastic transformation, in addition to the potential to exploit these alterations as novel therapeutic strategies for the treatment of brain cancer. PMID:26713744

Resection of a Pediatric Thalamic Juvenile Pilocytic Astrocytoma with Whole Brain Tractography

PubMed Central

Weiner, Howard L

2017-01-01

The resection of deep-seated brain tumors has been associated with morbidity due to injury to critical neural structures during the approach. Recent technological advancements in navigation and stereotaxy, surgical planning, brain tractography and minimal-access brain ports present the opportunity to overcome such limitations. Here, we present the case of a pediatric patient with a left thalamic/midbrain juvenile pilocytic astrocytoma (JPA). The tumor displaced the corticospinal fibers posteriorly and resulted in hemiparesis. Using whole brain tractography to plan a corridor for the approach, neuronavigation, a tubular retractor and an exoscope for visualization, we obtained gross total resection of the tumor, while minimizing injury to white matter bundles, including the corticospinal fibers. We propose that surgical planning with whole brain tractography is essential for reducing morbidity while accessing deep-lying brain lesions via retractor tubes, by means of sparing critical fiber tracts. PMID:29234572

Tumor growth model for atlas based registration of pathological brain MR images

NASA Astrophysics Data System (ADS)

Moualhi, Wafa; Ezzeddine, Zagrouba

2015-02-01

The motivation of this work is to register a tumor brain magnetic resonance (MR) image with a normal brain atlas. A normal brain atlas is deformed in order to take account of the presence of a large space occupying tumor. The method use a priori model of tumor growth assuming that the tumor grows in a radial way from a starting point. First, an affine transformation is used in order to bring the patient image and the brain atlas in a global correspondence. Second, the seeding of a synthetic tumor into the brain atlas provides a template for the lesion. Finally, the seeded atlas is deformed combining a method derived from optical flow principles and a model for tumor growth (MTG). Results show that an automatic segmentation method of brain structures in the presence of large deformation can be provided.

A Comparison of Supervised Machine Learning Algorithms and Feature Vectors for MS Lesion Segmentation Using Multimodal Structural MRI

PubMed Central

Sweeney, Elizabeth M.; Vogelstein, Joshua T.; Cuzzocreo, Jennifer L.; Calabresi, Peter A.; Reich, Daniel S.; Crainiceanu, Ciprian M.; Shinohara, Russell T.

2014-01-01

Machine learning is a popular method for mining and analyzing large collections of medical data. We focus on a particular problem from medical research, supervised multiple sclerosis (MS) lesion segmentation in structural magnetic resonance imaging (MRI). We examine the extent to which the choice of machine learning or classification algorithm and feature extraction function impacts the performance of lesion segmentation methods. As quantitative measures derived from structural MRI are important clinical tools for research into the pathophysiology and natural history of MS, the development of automated lesion segmentation methods is an active research field. Yet, little is known about what drives performance of these methods. We evaluate the performance of automated MS lesion segmentation methods, which consist of a supervised classification algorithm composed with a feature extraction function. These feature extraction functions act on the observed T1-weighted (T1-w), T2-weighted (T2-w) and fluid-attenuated inversion recovery (FLAIR) MRI voxel intensities. Each MRI study has a manual lesion segmentation that we use to train and validate the supervised classification algorithms. Our main finding is that the differences in predictive performance are due more to differences in the feature vectors, rather than the machine learning or classification algorithms. Features that incorporate information from neighboring voxels in the brain were found to increase performance substantially. For lesion segmentation, we conclude that it is better to use simple, interpretable, and fast algorithms, such as logistic regression, linear discriminant analysis, and quadratic discriminant analysis, and to develop the features to improve performance. PMID:24781953

A comparison of supervised machine learning algorithms and feature vectors for MS lesion segmentation using multimodal structural MRI.

PubMed

Sweeney, Elizabeth M; Vogelstein, Joshua T; Cuzzocreo, Jennifer L; Calabresi, Peter A; Reich, Daniel S; Crainiceanu, Ciprian M; Shinohara, Russell T

2014-01-01

Machine learning is a popular method for mining and analyzing large collections of medical data. We focus on a particular problem from medical research, supervised multiple sclerosis (MS) lesion segmentation in structural magnetic resonance imaging (MRI). We examine the extent to which the choice of machine learning or classification algorithm and feature extraction function impacts the performance of lesion segmentation methods. As quantitative measures derived from structural MRI are important clinical tools for research into the pathophysiology and natural history of MS, the development of automated lesion segmentation methods is an active research field. Yet, little is known about what drives performance of these methods. We evaluate the performance of automated MS lesion segmentation methods, which consist of a supervised classification algorithm composed with a feature extraction function. These feature extraction functions act on the observed T1-weighted (T1-w), T2-weighted (T2-w) and fluid-attenuated inversion recovery (FLAIR) MRI voxel intensities. Each MRI study has a manual lesion segmentation that we use to train and validate the supervised classification algorithms. Our main finding is that the differences in predictive performance are due more to differences in the feature vectors, rather than the machine learning or classification algorithms. Features that incorporate information from neighboring voxels in the brain were found to increase performance substantially. For lesion segmentation, we conclude that it is better to use simple, interpretable, and fast algorithms, such as logistic regression, linear discriminant analysis, and quadratic discriminant analysis, and to develop the features to improve performance.

A new method for automated high-dimensional lesion segmentation evaluated in vascular injury and applied to the human occipital lobe.

PubMed

Mah, Yee-Haur; Jager, Rolf; Kennard, Christopher; Husain, Masud; Nachev, Parashkev

2014-07-01

Making robust inferences about the functional neuroanatomy of the brain is critically dependent on experimental techniques that examine the consequences of focal loss of brain function. Unfortunately, the use of the most comprehensive such technique-lesion-function mapping-is complicated by the need for time-consuming and subjective manual delineation of the lesions, greatly limiting the practicability of the approach. Here we exploit a recently-described general measure of statistical anomaly, zeta, to devise a fully-automated, high-dimensional algorithm for identifying the parameters of lesions within a brain image given a reference set of normal brain images. We proceed to evaluate such an algorithm in the context of diffusion-weighted imaging of the commonest type of lesion used in neuroanatomical research: ischaemic damage. Summary performance metrics exceed those previously published for diffusion-weighted imaging and approach the current gold standard-manual segmentation-sufficiently closely for fully-automated lesion-mapping studies to become a possibility. We apply the new method to 435 unselected images of patients with ischaemic stroke to derive a probabilistic map of the pattern of damage in lesions involving the occipital lobe, demonstrating the variation of anatomical resolvability of occipital areas so as to guide future lesion-function studies of the region. Copyright © 2012 Elsevier Ltd. All rights reserved.

Brain MRI Characteristics of Patients with Anti-N-Methyl-D-Aspartate Receptor Encephalitis and Their Associations with 2-Year Clinical Outcome.

PubMed

Zhang, T; Duan, Y; Ye, J; Xu, W; Shu, N; Wang, C; Li, K; Liu, Y

2018-05-01

Anti- N -methyl-D-aspertate receptor encephalitis is an autoimmune-mediated disease without specific brain MRI features. Our aim was to investigate the brain MR imaging characteristics of anti- N -methyl-D-aspartate receptor encephalitis and their associations with clinical outcome at a 2-year follow-up. We enrolled 53 patients with anti- N -methyl-D-aspartate receptor encephalitis and performed 2-year follow-up. Brain MRIs were acquired for all patients at the onset phase. The brain MR imaging manifestations were classified into 4 types: type 1: normal MR imaging findings; type 2: only hippocampal lesions; type 3: lesions not involving the hippocampus; and type 4: lesions in both the hippocampus and other brain areas. The modified Rankin Scale score at 2-year follow-up was assessed, and the association between the mRS and onset brain MR imaging characteristics was evaluated. Twenty-eight (28/53, 53%) patients had normal MR imaging findings (type 1), and the others (25/53, 47%) had abnormal MRI findings: type 2: 7 patients (13%); type 3: seven patients (13%); and type 4: eleven patients (21%). Normal brain MRI findings were more common in female patients ( P = .02). Psychiatric and behavioral abnormalities were more common in adults ( P = .015), and autonomic symptoms ( P = .025) were more common in pediatric patients. The presence of hippocampal lesions ( P = .008, OR = 9.584; 95% CI, 1.803-50.931) and relapse ( P = .043, OR = 0.111; 95% CI, 0.013-0.930) was associated with poor outcome. Normal brain MRI findings were observed in half of the patients. Lesions in the hippocampus were the most common MR imaging abnormal finding. The presence of hippocampal lesions is the main MR imaging predictor for poor prognosis in patients with anti- N -methyl-D-aspartate receptor encephalitis. © 2018 by American Journal of Neuroradiology.

Neurorestoration induced by the HDAC inhibitor sodium valproate in the lactacystin model of Parkinson’s is associated with histone acetylation and up-regulation of neurotrophic factors

PubMed Central

Harrison, Ian F; Crum, William R; Vernon, Anthony C; Dexter, David T

2015-01-01

Background and Purpose Histone hypoacetylation is associated with Parkinson's disease (PD), due possibly to an imbalance in the activities of enzymes responsible for histone (de)acetylation; correction of which may be neuroprotective/neurorestorative. This hypothesis was tested using the anti-epileptic drug sodium valproate, a known histone deacetylase inhibitor (HDACI), utilizing a delayed-start study design in the lactacystin rat model of PD. Experimental Approach The irreversible proteasome inhibitor lactacystin was unilaterally injected into the substantia nigra of Sprague–Dawley rats that subsequently received valproate for 28 days starting 7 days after lactacystin lesioning. Longitudinal motor behavioural testing, structural MRI and post-mortem assessment of nigrostriatal integrity were used to track changes in this model of PD and quantify neuroprotection/restoration. Subsequent cellular and molecular analyses were performed to elucidate the mechanisms underlying valproate's effects. Key Results Despite producing a distinct pattern of structural re-modelling in the healthy and lactacystin-lesioned brain, delayed-start valproate administration induced dose-dependent neuroprotection/restoration against lactacystin neurotoxicity, characterized by motor deficit alleviation, attenuation of morphological brain changes and restoration of dopaminergic neurons in the substantia nigra. Molecular analyses revealed that valproate alleviated lactacystin-induced histone hypoacetylation and induced up-regulation of brain neurotrophic/neuroprotective factors. Conclusions and Implications The histone acetylation and up-regulation of neurotrophic/neuroprotective factors associated with valproate treatment culminate in a neuroprotective and neurorestorative phenotype in this animal model of PD. As valproate induced structural re-modelling of the brain, further research is required to determine whether valproate represents a viable candidate for disease treatment; however, the results suggest that HDACIs could hold potential as disease-modifying agents in PD. PMID:26040297

Remodeling Functional Connectivity in Multiple Sclerosis: A Challenging Therapeutic Approach.

PubMed

Stampanoni Bassi, Mario; Gilio, Luana; Buttari, Fabio; Maffei, Pierpaolo; Marfia, Girolama A; Restivo, Domenico A; Centonze, Diego; Iezzi, Ennio

2017-01-01

Neurons in the central nervous system are organized in functional units interconnected to form complex networks. Acute and chronic brain damage disrupts brain connectivity producing neurological signs and/or symptoms. In several neurological diseases, particularly in Multiple Sclerosis (MS), structural imaging studies cannot always demonstrate a clear association between lesion site and clinical disability, originating the "clinico-radiological paradox." The discrepancy between structural damage and disability can be explained by a complex network perspective. Both brain networks architecture and synaptic plasticity may play important roles in modulating brain networks efficiency after brain damage. In particular, long-term potentiation (LTP) may occur in surviving neurons to compensate network disconnection. In MS, inflammatory cytokines dramatically interfere with synaptic transmission and plasticity. Importantly, in addition to acute and chronic structural damage, inflammation could contribute to reduce brain networks efficiency in MS leading to worse clinical recovery after a relapse and worse disease progression. These evidence suggest that removing inflammation should represent the main therapeutic target in MS; moreover, as synaptic plasticity is particularly altered by inflammation, specific strategies aimed at promoting LTP mechanisms could be effective for enhancing clinical recovery. Modulation of plasticity with different non-invasive brain stimulation (NIBS) techniques has been used to promote recovery of MS symptoms. Better knowledge of features inducing brain disconnection in MS is crucial to design specific strategies to promote recovery and use NIBS with an increasingly tailored approach.

Categorizing Cortical Dysplasia Lesions for Surgical Outcome Using Network Functional Connectivity

NASA Astrophysics Data System (ADS)

Bdaiwi, Abdullah Sarray

Lesion-symptom mapping is a powerful and broadly applicable approach that is used for linking neurological symptoms to specific brain regions. Traditionally, it involves identifying overlap in lesion location across patients with similar symptoms. This approach has limitations when symptoms do not localize to a single region or when lesions do not tend to overlap. In this thesis, we show that we can expand the traditional approach of lesion mapping to incorporate network effects into symptom localization without the need for specialized neuroimaging of patients. Our approach involves assessing the functional connectivity of each lesion volume with the rest of the typical healthy brain using a database of healthy pediatric brain imaging data (C-MIND), available at CCHMC. Our study included 24 subjects that had cortical dysplasia lesions and underwent surgery for seizures that did not respond to drug therapy. We tested our approach using healthy brain imaging data across all ages (2-18 years old) and using age & gender specific groupings of data. The analysis sought categorization of lesion connectivity based on five subject characteristics: gender, cortical dysplasia pathology, epilepsy syndrome, scalp EEG pattern and surgical outcome. Our primary analysis focused on surgical outcome. The results showed that there are some substantial connectivity differences in the outcome analysis. Lesions with stronger connectivity to default mode and attention/motor networks tended to result in poorer surgical outcomes. This result could be expanded with a larger set of data with the ultimate goal of allowing examination of lesions of cortical dysplasia patients and predicting their seizure outcomes.

Mapping common aphasia assessments to underlying cognitive processes and their neural substrates

PubMed Central

Lacey, Elizabeth H.; Skipper-Kallal, LM; Xing, S; Fama, ME; Turkeltaub, PE

2017-01-01

Background Understanding the relationships between clinical tests, the processes they measure, and the brain networks underlying them, is critical in order for clinicians to move beyond aphasia syndrome classification toward specification of individual language process impairments. Objective To understand the cognitive, language, and neuroanatomical factors underlying scores of commonly used aphasia tests. Methods 25 behavioral tests were administered to a group of 38 chronic left hemisphere stroke survivors and a high resolution MRI was obtained. Test scores were entered into a principal components analysis to extract the latent variables (factors) measured by the tests. Multivariate lesion-symptom mapping was used to localize lesions associated with the factor scores. Results The principal components analysis yielded four dissociable factors, which we labeled Word Finding/Fluency, Comprehension, Phonology/Working Memory Capacity, and Executive Function. While many tests loaded onto the factors in predictable ways, some relied heavily on factors not commonly associated with the tests. Lesion symptom mapping demonstrated discrete brain structures associated with each factor, including frontal, temporal, and parietal areas extending beyond the classical language network. Specific functions mapped onto brain anatomy largely in correspondence with modern neural models of language processing. Conclusions An extensive clinical aphasia assessment identifies four independent language functions, relying on discrete parts of the left middle cerebral artery territory. A better understanding of the processes underlying cognitive tests and the link between lesion and behavior may lead to improved aphasia diagnosis, and may yield treatments better targeted to an individual’s specific pattern of deficits and preserved abilities. PMID:28135902

Brain lesions in mallard ducklings from parents fed methylmercury

USGS Publications Warehouse

Heinz, G.H.; Locke, L.N.

1976-01-01

Methylmercury dicyandiamide was fed to mallard ducks at 3 ppm mercury. Mercury accumulated in the eggs to an average of 7.18 and 5.46 ppm on a wet-weight basis in 2 successive years. Mercury in the eggs is believed to have caused brain lesions in the hatched ducklings. Lesions included demyelination, neuron shrink-age, necrosis, and hemorrhage in the meninges overlying the cerebellum. Brains of dead ducklings contained an average of 6.17 and 5.19 ppm mercury on a wet-weight basis in 2 successive years.

The structure of creative cognition in the human brain

PubMed Central

Jung, Rex E.; Mead, Brittany S.; Carrasco, Jessica; Flores, Ranee A.

2013-01-01

Creativity is a vast construct, seemingly intractable to scientific inquiry—perhaps due to the vague concepts applied to the field of research. One attempt to limit the purview of creative cognition formulates the construct in terms of evolutionary constraints, namely that of blind variation and selective retention (BVSR). Behaviorally, one can limit the “blind variation” component to idea generation tests as manifested by measures of divergent thinking. The “selective retention” component can be represented by measures of convergent thinking, as represented by measures of remote associates. We summarize results from measures of creative cognition, correlated with structural neuroimaging measures including structural magnetic resonance imaging (sMRI), diffusion tensor imaging (DTI), and proton magnetic resonance spectroscopy (1H-MRS). We also review lesion studies, considered to be the “gold standard” of brain-behavioral studies. What emerges is a picture consistent with theories of disinhibitory brain features subserving creative cognition, as described previously (Martindale, 1981). We provide a perspective, involving aspects of the default mode network (DMN), which might provide a “first approximation” regarding how creative cognition might map on to the human brain. PMID:23847503

Atrophy of spared gray matter tissue predicts poorer motor recovery and rehabilitation response in chronic stroke.

PubMed

Gauthier, Lynne V; Taub, Edward; Mark, Victor W; Barghi, Ameen; Uswatte, Gitendra

2012-02-01

Although the motor deficit after stroke is clearly due to the structural brain damage that has been sustained, this relationship is attenuated from the acute to chronic phases. We investigated the possibility that motor impairment and response to constraint-induced movement therapy in patients with chronic stroke may relate more strongly to the structural integrity of brain structures remote from the lesion than to measures of overt tissue damage. Voxel-based morphometry analysis was performed on MRI scans from 80 patients with chronic stroke to investigate whether variations in gray matter density were correlated with extent of residual motor impairment or with constraint-induced movement therapy-induced motor recovery. Decreased gray matter density in noninfarcted motor regions was significantly correlated with magnitude of residual motor deficit. In addition, reduced gray matter density in multiple remote brain regions predicted a lesser extent of motor improvement from constraint-induced movement therapy. Atrophy in seemingly healthy parts of the brain that are distant from the infarct accounts for at least a portion of the sustained motor deficit in chronic stroke.

Atrophy of spared grey matter tissue predicts poorer motor recovery and rehabilitation response in chronic stroke

PubMed Central

Gauthier, Lynne V.; Taub, Edward; Mark, Victor W.; Barghi, Ameen; Uswatte, Gitendra

2011-01-01

Background and Purpose Although the motor deficit following stroke is clearly due to the structural brain damage that has been sustained, this relationship is attenuated from the acute to chronic phases. We investigated the possibility that motor impairment and response to Constraint-Induced Movement therapy (CI therapy) in chronic stroke patients may relate more strongly to the structural integrity of brain structures remote from the lesion than to measures of overt tissue damage. Methods Voxel-based morphometry (VBM) analysis was performed on MRI scans from 80 chronic stroke patients to investigate whether variations in grey matter density were correlated with extent of residual motor impairment or with CI therapy-induced motor recovery. Results Decreased grey matter density in non-infarcted motor regions was significantly correlated with magnitude of residual motor deficit. In addition, reduced grey matter density in multiple remote brain regions predicted a lesser extent of motor improvement from CI therapy. Conclusions Atrophy in seemingly healthy parts of the brain that are distant from the infarct accounts for at least a portion of the sustained motor deficit in chronic stroke. PMID:22096036

Neuroanatomical substrates of action perception and understanding: an anatomic likelihood estimation meta-analysis of lesion-symptom mapping studies in brain injured patients

PubMed Central

Urgesi, Cosimo; Candidi, Matteo; Avenanti, Alessio

2014-01-01

Several neurophysiologic and neuroimaging studies suggested that motor and perceptual systems are tightly linked along a continuum rather than providing segregated mechanisms supporting different functions. Using correlational approaches, these studies demonstrated that action observation activates not only visual but also motor brain regions. On the other hand, brain stimulation and brain lesion evidence allows tackling the critical question of whether our action representations are necessary to perceive and understand others’ actions. In particular, recent neuropsychological studies have shown that patients with temporal, parietal, and frontal lesions exhibit a number of possible deficits in the visual perception and the understanding of others’ actions. The specific anatomical substrates of such neuropsychological deficits however, are still a matter of debate. Here we review the existing literature on this issue and perform an anatomic likelihood estimation meta-analysis of studies using lesion-symptom mapping methods on the causal relation between brain lesions and non-linguistic action perception and understanding deficits. The meta-analysis encompassed data from 361 patients tested in 11 studies and identified regions in the inferior frontal cortex, the inferior parietal cortex and the middle/superior temporal cortex, whose damage is consistently associated with poor performance in action perception and understanding tasks across studies. Interestingly, these areas correspond to the three nodes of the action observation network that are strongly activated in response to visual action perception in neuroimaging research and that have been targeted in previous brain stimulation studies. Thus, brain lesion mapping research provides converging causal evidence that premotor, parietal and temporal regions play a crucial role in action recognition and understanding. PMID:24910603

Change in brain and lesion volumes after CEE therapies: the WHIMS-MRI studies.

PubMed

Coker, Laura H; Espeland, Mark A; Hogan, Patricia E; Resnick, Susan M; Bryan, R Nick; Robinson, Jennifer G; Goveas, Joseph S; Davatzikos, Christos; Kuller, Lewis H; Williamson, Jeff D; Bushnell, Cheryl D; Shumaker, Sally A

2014-02-04

To determine whether smaller brain volumes in older women who had completed Women's Health Initiative (WHI)-assigned conjugated equine estrogen-based hormone therapy (HT), reported by WHI Memory Study (WHIMS)-MRI, correspond to a continuing increased rate of atrophy an average of 6.1 to 7.7 years later in WHIMS-MRI2. A total of 1,230 WHI participants were contacted: 797 (64.8%) consented, and 729 (59%) were rescanned an average of 4.7 years after the initial MRI scan. Mean annual rates of change in total brain volume, the primary outcome, and rates of change in ischemic lesion volumes, the secondary outcome, were compared between treatment groups using mixed-effect models with adjustment for trial, clinical site, age, intracranial volumes, and time between MRI measures. Total brain volume decreased an average of 3.22 cm(3)/y in the active arm and 3.07 cm(3)/y in the placebo arm (p = 0.53). Total ischemic lesion volumes increased in both arms at a rate of 0.12 cm(3)/y (p = 0.88). Conjugated equine estrogen-based postmenopausal HT, previously assigned at WHI baseline, did not affect rates of decline in brain volumes or increases in brain lesion volumes during the 4.7 years between the initial and follow-up WHIMS-MRI studies. Smaller frontal lobe volumes were observed as persistent group differences among women assigned to active HT compared with placebo. Women with a history of cardiovascular disease treated with active HT, compared with placebo, had higher rates of accumulation in white matter lesion volume and total brain lesion volume. Further study may elucidate mechanisms that explain these findings.

Change in brain and lesion volumes after CEE therapies

PubMed Central

Espeland, Mark A.; Hogan, Patricia E.; Resnick, Susan M.; Bryan, R. Nick; Robinson, Jennifer G.; Goveas, Joseph S.; Davatzikos, Christos; Kuller, Lewis H.; Williamson, Jeff D.; Bushnell, Cheryl D.; Shumaker, Sally A.

2014-01-01

Objectives: To determine whether smaller brain volumes in older women who had completed Women's Health Initiative (WHI)-assigned conjugated equine estrogen–based hormone therapy (HT), reported by WHI Memory Study (WHIMS)-MRI, correspond to a continuing increased rate of atrophy an average of 6.1 to 7.7 years later in WHIMS-MRI2. Methods: A total of 1,230 WHI participants were contacted: 797 (64.8%) consented, and 729 (59%) were rescanned an average of 4.7 years after the initial MRI scan. Mean annual rates of change in total brain volume, the primary outcome, and rates of change in ischemic lesion volumes, the secondary outcome, were compared between treatment groups using mixed-effect models with adjustment for trial, clinical site, age, intracranial volumes, and time between MRI measures. Results: Total brain volume decreased an average of 3.22 cm3/y in the active arm and 3.07 cm3/y in the placebo arm (p = 0.53). Total ischemic lesion volumes increased in both arms at a rate of 0.12 cm3/y (p = 0.88). Conclusions: Conjugated equine estrogen–based postmenopausal HT, previously assigned at WHI baseline, did not affect rates of decline in brain volumes or increases in brain lesion volumes during the 4.7 years between the initial and follow-up WHIMS-MRI studies. Smaller frontal lobe volumes were observed as persistent group differences among women assigned to active HT compared with placebo. Women with a history of cardiovascular disease treated with active HT, compared with placebo, had higher rates of accumulation in white matter lesion volume and total brain lesion volume. Further study may elucidate mechanisms that explain these findings. PMID:24384646

Cognition and bimanual performance in children with unilateral cerebral palsy: protocol for a multicentre, cross-sectional study.

PubMed

Hoare, Brian; Ditchfield, Michael; Thorley, Megan; Wallen, Margaret; Bracken, Jenny; Harvey, Adrienne; Elliott, Catherine; Novak, Iona; Crichton, Ali

2018-05-08

Motor outcomes of children with unilateral cerebral palsy are clearly documented and well understood, yet few studies describe the cognitive functioning in this population, and the associations between the two is poorly understood. Using two hands together in daily life involves complex motor and cognitive processes. Impairment in either domain may contribute to difficulties with bimanual performance. Research is yet to derive whether, and how, cognition affects a child's ability to use their two hands to perform bimanual tasks. This study will use a prospective, cross-sectional multi-centre observational design. Children (aged 6-12 years) with unilateral cerebral palsy will be recruited from one of five Australian treatment centres. We will examine associations between cognition, bimanual performance and brain neuropathology (lesion type and severity) in a sample of 131 children. The primary outcomes are: Motor - the Assisting Hand Assessment; Cognitive - Executive Function; and Brain - lesion location on structural MRI. Secondary data collected will include: Motor - Box and Blocks, ABILHAND- Kids, Sword Test; Cognitive - standard neuropsychological measures of intelligence. We will use generalized linear modelling and structural equation modelling techniques to investigate relationships between bimanual performance, executive function and brain lesion location. This large multi-centre study will examine how cognition affects bimanual performance in children with unilateral cerebral palsy. First, it is anticipated that distinct relationships between bimanual performance and cognition (executive function) will be identified. Second, it is anticipated that interrelationships between bimanual performance and cognition will be associated with common underlying neuropathology. Findings have the potential to improve the specificity of existing upper limb interventions by providing more targeted treatments and influence the development of novel methods to improve both cognitive and motor outcomes in children with unilateral cerebral palsy. ACTRN12614000631606 ; Date of retrospective registration 29/05/2014.

Gross morphology and morphometric sequelae in the hippocampus, fornix, and corpus callosum of patients with severe non-missile traumatic brain injury without macroscopically detectable lesions: a T1 weighted MRI study

PubMed Central

Tomaiuolo, F; Carlesimo, G; Di, P; Petrides, M; Fera, F; Bonanni, R; Formisano, R; Pasqualetti, P; Caltagirone, C

2004-01-01

Objective: The gross morphology and morphometry of the hippocampus, fornix, and corpus callosum in patients with severe non-missile traumatic brain injury (nmTBI) without obvious neuroradiological lesions was examined and the volumes of these structures were correlated with performance on memory tests. In addition, the predictability of the length of coma from the selected anatomical volumes was examined. Method: High spatial resolution T1 weighted MRI scans of the brain (1 mm3) and neuropsychological evaluations with standardised tests were performed at least 3 months after trauma in 19 patients. Results: In comparison with control subjects matched in terms of gender and age, volume reduction in the hippocampus, fornix, and corpus callosum of the nmTBI patients was quantitatively significant. The length of coma correlated with the volume reduction in the corpus callosum. Immediate free recall of word lists correlated with the volume of the fornix and the corpus callosum. Delayed recall of word lists and immediate recall of the Rey figure both correlated with the volume of the fornix. Delayed recall of the Rey figure correlated with the volume of the fornix and the right hippocampus. Conclusion: These findings demonstrate that in severe nmTBI without obvious neuroradiological lesions there is a clear hippocampal, fornix, and callosal volume reduction. The length of coma predicts the callosal volume reduction, which could be considered a marker of the severity of axonal loss. A few memory test scores correlated with the volumes of the selected anatomical structures. This relationship with memory performance may reflect the diffuse nature of the damage, leading to the disruption of neural circuits at multiple levels and the progressive neural degeneration occurring in TBI. PMID:15314123

Brain Regions Influencing Implicit Violent Attitudes: A Lesion-Mapping Study.

PubMed

Cristofori, Irene; Zhong, Wanting; Mandoske, Valerie; Chau, Aileen; Krueger, Frank; Strenziok, Maren; Grafman, Jordan

2016-03-02

Increased aggression is common after traumatic brain injuries and may persist after cognitive recovery. Maladaptive aggression and violence are associated with dysfunction in the prefrontal and temporal cortex, but such dysfunctional behaviors are typically measured by explicit scales and history. However, it is well known that answers on explicit scales on sensitive topics--such as aggressive thoughts and behaviors--may not reveal true tendencies. Here, we investigated the neural basis of implicit attitudes toward aggression in humans using a modified version of the Implicit Association Task (IAT) with a unique sample of 112 Vietnam War veterans who suffered penetrating brain injury and 33 healthy controls who also served in combat in Vietnam but had no history of brain injury. We hypothesized that dorsolateral prefrontal cortex (dlPFC) lesions, due to the crucial role of the dlPFC in response inhibition, could influence performance on the IAT. In addition, we investigated the causal contribution of specific brain areas to implicit attitudes toward violence. We found a more positive implicit attitude toward aggression among individuals with lesions to the dlPFC and inferior posterior temporal cortex (ipTC). Furthermore, executive functions were critically involved in regulating implicit attitudes toward violence and aggression. Our findings complement existing evidence on the neural basis of explicit aggression centered on the ventromedial prefrontal cortex. These findings highlight that dlPFC and ipTC play a causal role in modulating implicit attitudes about violence and are crucially involved in the pathogenesis of aggressive behavior. Maladaptive aggression and violence can lead to interpersonal conflict and criminal behavior. Surprisingly little is known about implicit attitudes toward violence and aggression. Here, we used a range of techniques, including voxel-based lesion-symptom mapping, to examine the causal role of brain structures underpinning implicit attitudes toward aggression in a unique sample of combat veterans with traumatic brain injury. We found that damage to the dorsolateral prefrontal cortex (dlPFC) led to a more positive implicit attitude toward violence that under most normal situations would be considered inappropriate. These results suggest that treatments aimed at increasing cognitive control using cognitive behavioral therapies dependent on the intact dlPFC could treat aggressive and violent behavior. Copyright © 2016 the authors 0270-6474/16/362757-12$15.00/0.

High-dose estrogen treatment at reperfusion reduces lesion volume and accelerates recovery of sensorimotor function after experimental ischemic stroke.

PubMed

Carpenter, Randall S; Iwuchukwu, Ifeanyi; Hinkson, Cyrus L; Reitz, Sydney; Lee, Wonhee; Kukino, Ayaka; Zhang, An; Pike, Martin M; Ardelt, Agnieszka A

2016-05-15

Estrogens have previously been shown to protect the brain against acute ischemic insults, by potentially augmenting cerebrovascular function after ischemic stroke. The current study hypothesized that treatment with sustained release of high-dose 17β-estradiol (E2) at the time of reperfusion from middle cerebral artery occlusion (MCAO) in rats would attenuate reperfusion injury, augment post-stroke angiogenesis and cerebral blood flow, and attenuate lesion volume. Female Wistar rats underwent ovariectomy, followed two weeks later by transient, two-hour right MCAO (tMCAO) and treatment with E2 (n=13) or placebo (P; n=12) pellets starting at reperfusion. E2 treatment resulted in significantly smaller total lesion volume, smaller lesions within striatal and cortical brain regions, and less atrophy of the ipsilateral hemisphere after six weeks of recovery. E2-treated animals exhibited accelerated recovery of contralateral forelimb sensorimotor function in the cylinder test. Magnetic resonance imaging (MRI) showed that E2 treatment reduced the formation of lesion cysts, decreased lesion volume, and increased lesional cerebral blood flow (CBF). K(trans), a measure of vascular permeability, was increased in the lesions. This finding, which represents lesion neovascularization, was not altered by E2 treatment. Ischemic stroke-related angiogenesis and vessel formation was confirmed with immunolabeling of brain tissue and was not altered with E2 treatment. In summary, E2 treatment administered immediately following reperfusion significantly reduced lesion size, cyst formation, and brain atrophy while improving lesional CBF and accelerating recovery of functional deficits in a rat model of ischemic stroke. Copyright © 2016 Elsevier B.V. All rights reserved.

Management strategies for neoplastic and vascular brain lesions presenting during pregnancy: A series of 29 patients.

PubMed

Pereira, Celestino Esteves; Lynch, Jose Carlos

2017-01-01

The occurrence of a brain tumor or intracranial vascular lesion during pregnancy is a rare event, but when it happens, it jeopardizes the lives of both the mother and infant. It also creates challenges of a neurosurgical, obstetric, and ethical nature. A multidisciplinary approach should be used for their care. Between 1986 and 2015, 12 pregnant women diagnosed with brain tumors and 17 women with intracranial vascular lesion underwent treatment at the Neurosurgery Department of the Servidores do Estado Hospital and Rede D'Or/São Luis. The Neurosurgery Department teamed up with Obstetrics Anesthesiology Departments in establishing the procedures. The patients' records, surgical descriptions, imaging studies, and histopathological material were reviewed. Among 12 patients presenting with brain tumors, there were neither operative mortality nor fetal deaths. Among the vascular lesions, aneurysm rupture was responsible for bleeding in 6 instances. Arteriovenous malformation was diagnosed in 7 patients. In this subgroup, the maternal and fetal mortality rates were 11.7% and 23.7%, respectively. We can assert that the association between a brain tumor and vascular lesions with pregnancy is a very unusual event, which jeopardizes both the lives of the mother and infant. It remains incompletely characterized due to the rare nature of these potentially devastating events. Knowing the exact mechanism responsible for the interaction of pregnancy and with these lesions will improve the treatment of these patients.

Severe Traumatic Brain Injury, Frontal Lesions, and Social Aspects of Language Use: A Study of French-Speaking Adults

ERIC Educational Resources Information Center

Dardier, Virginie; Bernicot, Josie; Delanoe, Anaig; Vanberten, Melanie; Fayada, Catherine; Chevignard, Mathilde; Delaye, Corinne; Laurent-Vannier, Anne; Dubois, Bruno

2011-01-01

The purpose of this study was to gain insight into the social (pragmatic) aspects of language use by French-speaking individuals with frontal lesions following a severe traumatic brain injury. Eleven participants with traumatic brain injury performed tasks in three areas of communication: production (interview situation), comprehension (direct…

Reversible Disruption of Neuronal Mitochondria by Ischemic and Traumatic Injury Revealed by Quantitative Two-Photon Imaging in the Neocortex of Anesthetized Mice

PubMed Central

Kislin, Mikhail; Sword, Jeremy; Fomitcheva, Ioulia V.; Croom, Deborah; Pryazhnikov, Evgeny; Lihavainen, Eero; Toptunov, Dmytro; Rauvala, Heikki; Ribeiro, Andre S.

2017-01-01

Mitochondria play a variety of functional roles in cortical neurons, from metabolic support and neuroprotection to the release of cytokines that trigger apoptosis. In dendrites, mitochondrial structure is closely linked to their function, and fragmentation (fission) of the normally elongated mitochondria indicates loss of their function under pathological conditions, such as stroke and brain trauma. Using in vivo two-photon microscopy in mouse brain, we quantified mitochondrial fragmentation in a full spectrum of cortical injuries, ranging from severe to mild. Severe global ischemic injury was induced by bilateral common carotid artery occlusion, whereas severe focal stroke injury was induced by Rose Bengal photosensitization. The moderate and mild traumatic injury was inflicted by focal laser lesion and by mild photo-damage, respectively. Dendritic and mitochondrial structural changes were tracked longitudinally using transgenic mice expressing fluorescent proteins localized either in cytosol or in mitochondrial matrix. In response to severe injury, mitochondrial fragmentation developed in parallel with dendritic damage signified by dendritic beading. Reconstruction from serial section electron microscopy confirmed mitochondrial fragmentation. Unlike dendritic beading, fragmentation spread beyond the injury core in focal stroke and focal laser lesion models. In moderate and mild injury, mitochondrial fragmentation was reversible with full recovery of structural integrity after 1–2 weeks. The transient fragmentation observed in the mild photo-damage model was associated with changes in dendritic spine density without any signs of dendritic damage. Our findings indicate that alterations in neuronal mitochondria structure are very sensitive to the tissue damage and can be reversible in ischemic and traumatic injuries. SIGNIFICANCE STATEMENT During ischemic stroke or brain trauma, mitochondria can either protect neurons by supplying ATP and adsorbing excessive Ca2+, or kill neurons by releasing proapoptotic factors. Mitochondrial function is tightly linked to their morphology: healthy mitochondria are thin and long; dysfunctional mitochondria are thick (swollen) and short (fragmented). To date, fragmentation of mitochondria was studied either in dissociated cultured neurons or in brain slices, but not in the intact living brain. Using real-time in vivo two-photon microscopy, we quantified mitochondrial fragmentation during acute pathological conditions that mimic severe, moderate, and mild brain injury. We demonstrated that alterations in neuronal mitochondria structural integrity can be reversible in traumatic and ischemic injuries, highlighting mitochondria as a potential target for therapeutic interventions. PMID:28077713

Do brain lesions in stroke affect basic emotions and attachment?

PubMed

Farinelli, Marina; Panksepp, Jaak; Gestieri, Laura; Maffei, Monica; Agati, Raffaele; Cevolani, Daniela; Pedone, Vincenzo; Northoff, Georg

2015-01-01

The aim of the current study was to investigate basic emotions and attachment in a sample of 86 stroke patients. We included a control group of 115 orthopedic patients (matched for age and cognitive status) without brain lesions to control for unspecific general illness effects of a traumatic recent event on basic emotions and attachment. In order to measure basic emotions and attachment style we applied the Affective Neuroscience Personality Scale (ANPS) and the Attachment Style Questionnaire (ASQ). The stroke patients showed significantly different scores in the SEEKING, SADNESS, and ANGER subscales of the ANPS as well as in the Relationship as Secondary Attachment dimension of the ASQ when compared to the control group. These differences show a pattern influenced by lesion location mainly as concerns basic emotions. Anterior, medial, left, and subcortical patients provide scores significantly lower in ANPS-SEEKING than the control group; ANPS-SADNESS scores in anterior, right, medial, and subcortical patients were significantly higher than those of the control group. ANPS-ANGER scores in posterior, right, and lateral patients were significantly higher than those in the control group; finally, the ANPS-FEAR showed slightly lower scores in posterior patients than in the control group. Minor effects on brain lesions were also individuated in the attachment style. Anterior lesion patients showed a significantly higher average score in the ASQ-Need for Approval subscale than the control group. ASQ-Confidence subscale scores differed significantly in stroke patients with lesions in medial brain regions when compared to control subjects. Scores at ANPS and ASQ subscales appear significantly more correlated in stroke patients than in the control group. Such finding of abnormalities, especially concerning basic emotions in stroke brain-lesioned patients, indicates that the effect of brain lesions may enhance the interrelation between basic emotions and attachment with respect to the control group.

Identifying relevant biomarkers of brain injury from structural MRI: Validation using automated approaches in children with unilateral cerebral palsy

PubMed Central

Dowson, Nicholas; Doecke, James; Fiori, Simona; Bradley, Andrew P.; Boyd, Roslyn N.; Rose, Stephen

2017-01-01

Previous studies have proposed that the early elucidation of brain injury from structural Magnetic Resonance Images (sMRI) is critical for the clinical assessment of children with cerebral palsy (CP). Although distinct aetiologies, including cortical maldevelopments, white and grey matter lesions and ventricular enlargement, have been categorised, these injuries are commonly only assessed in a qualitative fashion. As a result, sMRI remains relatively underexploited for clinical assessments, despite its widespread use. In this study, several automated and validated techniques to automatically quantify these three classes of injury were generated in a large cohort of children (n = 139) aged 5–17, including 95 children diagnosed with unilateral CP. Using a feature selection approach on a training data set (n = 97) to find severity of injury biomarkers predictive of clinical function (motor, cognitive, communicative and visual function), cortical shape and regional lesion burden were most often chosen associated with clinical function. Validating the best models on the unseen test data (n = 42), correlation values ranged between 0.545 and 0.795 (p<0.008), indicating significant associations with clinical function. The measured prevalence of injury, including ventricular enlargement (70%), white and grey matter lesions (55%) and cortical malformations (30%), were similar to the prevalence observed in other cohorts of children with unilateral CP. These findings support the early characterisation of injury from sMRI into previously defined aetiologies as part of standard clinical assessment. Furthermore, the strong and significant association between quantifications of injury observed on structural MRI and multiple clinical scores accord with empirically established structure-function relationships. PMID:28763455

Total target volume is a better predictor of whole brain dose from gamma stereotactic radiosurgery than the number, shape, or location of the lesions

PubMed Central

Narayanasamy, Ganesh; Smith, Adam; Van Meter, Emily; McGarry, Ronald; Molloy, Janelle A.

2013-01-01

Purpose: To assess the hypothesis that the volume of whole brain that receives a certain dose level is primarily dependent on the treated volume rather than on the number, shape, or location of the lesions. This would help a physician validate the suitability of GammaKnife® based stereotactic radiosurgery (GKSR) prior to treatment. Methods: Simulation studies were performed to establish the hypothesis for both oblong and spherical shaped lesions of various numbers and sizes. Forty patients who underwent GKSR [mean age of 54 years (range 7–80), mean number of lesions of 2.5 (range 1–6), and mean lesion volume of 4.4 cm3 (range 0.02–22.2 cm3)] were also studied retrospectively. Following recommendations of QUANTEC, the volume of brain irradiated by the 12 Gy (VB12) isodose line was measured and a power-law based relation is proposed here for estimating VB12 from the known tumor volume and the prescription dose. Results: In the simulation study on oblong, spherical, and multiple lesions, the volume of brain irradiated by 50%, 10%, and 1% of maximum dose was found to have linear, linear, and exponentially increasing dependence on the volume of the treated region, respectively. In the retrospective study on 40 GKSR patients, a similar relationship was found to predict the brain dose with a Spearman correlation coefficient >0.9. In both the studies, the volume of brain irradiated by a certain dose level does not have a statistically significant relationship (p ≥ 0.05) with the number, shape, or position of the lesions. The measured VB12 agrees with calculation to within 1.7%. Conclusions: The results from the simulation and the retrospective clinical studies indicate that the volume of whole brain that receives a certain percentage of the maximum dose is primarily dependent on the treated volume and less on the number, shape, and location of the lesions. PMID:24007147

Excessive disgust caused by brain lesions or temporary inactivations: mapping hotspots of the nucleus accumbens and ventral pallidum.

PubMed

Ho, Chao-Yi; Berridge, Kent C

2014-11-01

Disgust is a prototypical type of negative affect. In animal models of excessive disgust, only a few brain sites are known in which localized dysfunction (lesions or neural inactivations) can induce intense 'disgust reactions' (e.g. gapes) to a normally pleasant sensation such as sweetness. Here, we aimed to map forebrain candidates more precisely, to identify where either local neuronal damage (excitotoxin lesions) or local pharmacological inactivation (muscimol/baclofen microinjections) caused rats to show excessive sensory disgust reactions to sucrose. Our study compared subregions of the nucleus accumbens shell, ventral pallidum, lateral hypothalamus, and adjacent extended amygdala. The results indicated that the posterior half of the ventral pallidum was the only forebrain site where intense sensory disgust gapes in response to sucrose were induced by both lesions and temporary inactivations (this site was previously identified as a hedonic hotspot for enhancements of sweetness 'liking'). By comparison, for the nucleus accumbens, temporary GABA inactivations in the caudal half of the medial shell also generated sensory disgust, but lesions never did at any site. Furthermore, even inactivations failed to induce disgust in the rostral half of the accumbens shell (which also contains a hedonic hotspot). In other structures, neither lesions nor inactivations induced disgust as long as the posterior ventral pallidum remained spared. We conclude that the posterior ventral pallidum is an especially crucial hotspot for producing excessive sensory disgust by local pharmacological/lesion dysfunction. By comparison, the nucleus accumbens appears to segregate sites for pharmacological disgust induction and hedonic enhancement into separate posterior and rostral halves of the medial shell. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

OASIS is Automated Statistical Inference for Segmentation, with applications to multiple sclerosis lesion segmentation in MRI.

PubMed

Sweeney, Elizabeth M; Shinohara, Russell T; Shiee, Navid; Mateen, Farrah J; Chudgar, Avni A; Cuzzocreo, Jennifer L; Calabresi, Peter A; Pham, Dzung L; Reich, Daniel S; Crainiceanu, Ciprian M

2013-01-01

Magnetic resonance imaging (MRI) can be used to detect lesions in the brains of multiple sclerosis (MS) patients and is essential for diagnosing the disease and monitoring its progression. In practice, lesion load is often quantified by either manual or semi-automated segmentation of MRI, which is time-consuming, costly, and associated with large inter- and intra-observer variability. We propose OASIS is Automated Statistical Inference for Segmentation (OASIS), an automated statistical method for segmenting MS lesions in MRI studies. We use logistic regression models incorporating multiple MRI modalities to estimate voxel-level probabilities of lesion presence. Intensity-normalized T1-weighted, T2-weighted, fluid-attenuated inversion recovery and proton density volumes from 131 MRI studies (98 MS subjects, 33 healthy subjects) with manual lesion segmentations were used to train and validate our model. Within this set, OASIS detected lesions with a partial area under the receiver operating characteristic curve for clinically relevant false positive rates of 1% and below of 0.59% (95% CI; [0.50%, 0.67%]) at the voxel level. An experienced MS neuroradiologist compared these segmentations to those produced by LesionTOADS, an image segmentation software that provides segmentation of both lesions and normal brain structures. For lesions, OASIS out-performed LesionTOADS in 74% (95% CI: [65%, 82%]) of cases for the 98 MS subjects. To further validate the method, we applied OASIS to 169 MRI studies acquired at a separate center. The neuroradiologist again compared the OASIS segmentations to those from LesionTOADS. For lesions, OASIS ranked higher than LesionTOADS in 77% (95% CI: [71%, 83%]) of cases. For a randomly selected subset of 50 of these studies, one additional radiologist and one neurologist also scored the images. Within this set, the neuroradiologist ranked OASIS higher than LesionTOADS in 76% (95% CI: [64%, 88%]) of cases, the neurologist 66% (95% CI: [52%, 78%]) and the radiologist 52% (95% CI: [38%, 66%]). OASIS obtains the estimated probability for each voxel to be part of a lesion by weighting each imaging modality with coefficient weights. These coefficients are explicit, obtained using standard model fitting techniques, and can be reused in other imaging studies. This fully automated method allows sensitive and specific detection of lesion presence and may be rapidly applied to large collections of images.

Breed-Specific Magnetic Resonance Imaging Characteristics of Necrotizing Encephalitis in Dogs

PubMed Central

Flegel, Thomas

2017-01-01

Diagnosing necrotizing encephalitis, with its subcategories of necrotizing leukoencephalitis and necrotizing meningoencephalitis, based on magnetic resonance imaging alone can be challenging. However, there are breed-specific imaging characteristics in both subcategories that allow establishing a clinical diagnosis with a relatively high degree of certainty. Typical breed specific imaging features, such as lesion distribution, signal intensity, contrast enhancement, and gross changes of brain structure (midline shift, ventriculomegaly, and brain herniation) are summarized here, using current literature, for the most commonly affected canine breeds: Yorkshire Terrier, French Bulldog, Pug, and Chihuahua. PMID:29255715

Different patterns of longitudinal brain and spinal cord changes and their associations with disability progression in NMO and MS.

PubMed

Liu, Yaou; Duan, Yunyun; Huang, Jing; Ren, Zhuoqiong; Liu, Zheng; Dong, Huiqing; Weiler, Florian; Hahn, Horst K; Shi, Fu-Dong; Butzkueven, Helmut; Barkhof, Frederik; Li, Kuncheng

2018-01-01

To investigate the longitudinal spinal cord and brain changes in neuromyelitis optica (NMO) and multiple sclerosis (MS) and their associations with disability progression. We recruited 28 NMO, 22 MS, and 20 healthy controls (HC), who underwent both spinal cord and brain MRI at baseline. Twenty-five NMO and 20 MS completed 1-year follow-up. Baseline spinal cord and brain lesion loads, mean upper cervical cord area (MUCCA), brain, and thalamus volume and their changes during a 1-year follow-up were measured and compared between groups. All the measurements were also compared between progressive and non-progressive groups in NMO and MS. MUCCA decreased significantly during the 1-year follow-up in NMO not in MS. Percentage brain volume changes (PBVC) and thalamus volume changes in MS were significantly higher than NMO. MUCCA changes were significantly different between progressive and non-progressive groups in NMO, while baseline brain lesion volume and PBVC were associated with disability progression in MS. MUCCA changes during 1-year follow-up showed association with clinical disability in NMO. Spinal cord atrophy changes were associated with disability progression in NMO, while baseline brain lesion load and whole brain atrophy changes were related to disability progression in MS. • Spinal cord atrophy progression was observed in NMO. • Spinal cord atrophy changes were associated with disability progression in NMO. • Brain lesion and atrophy were related to disability progression in MS.

99mTc-HMPAO SPECT of the brain in mild to moderate traumatic brain injury patients: compared with CT--a prospective study.

PubMed

Nedd, K; Sfakianakis, G; Ganz, W; Uricchio, B; Vernberg, D; Villanueva, P; Jabir, A M; Bartlett, J; Keena, J

1993-01-01

Single photon emission computed tomography (SPECT) with Technetium-99m hexamethyl propylenamine oxime (Tc-99m-HMPAO) was used in 20 patients with mild to moderate traumatic brain injury (TBI) to evaluate the effects of brain trauma on regional cerebral blood flow (rCBF). SPECT scan was compared with CT scan in 16 patients. SPECT showed intraparenchymal differences in rCBF more often than lesions diagnosed with CT scans (87.5% vs. 37.5%). In five of six patients with lesions in both modalities, the area of involvement was relatively larger on SPECT scans than on CT scans. Contrecoup changes were seen in five patients on SPECT alone, two patients with CT alone and one patient had contrecoup lesions on CT and SPECT. Of the eight patients (50%) with skull fractures, seven (43.7%) had rCBF findings on SPECT scan and five (31.3%) demonstrated decrease in rCBF in brain underlying the fracture. All these patients with fractures had normal brain on CT scans. Conversely, extra-axial lesions and fractures evident on CT did not visualize on SPECT, but SPECT demonstrated associated changes in rCBF. Although there is still lack of clinical and pathological correlation, SPECT appears to be a promising method for a more sensitive evaluation of axial lesions in patients with mild to moderate TBI.

2q11.2 microdeletions: linking DNA structural variation to brain dysfunction and schizophrenia

PubMed Central

Karayiorgou, Maria; Simon, Tony J.; Gogos, Joseph A.

2010-01-01

Recent studies are beginning to paint a clear and consistent picture of the impairments in psychological and cognitive competencies that are associated with microdeletions in chromosome 22q11.2. These studies have highlighted a strong link between this genetic lesion and schizophrenia. Parallel studies in humans and animal models are starting to uncover the complex genetic and neural substrates altered by the microdeletion. In addition to offering a deeper understanding of the effects of this genetic lesion, these findings may guide analysis of other copy-number variants associated with cognitive dysfunction and psychiatric disorders. PMID:20485365

SPECT brain perfusion findings in mild or moderate traumatic brain injury.

PubMed

Abu-Judeh, H H; Parker, R; Aleksic, S; Singh, M L; Naddaf, S; Atay, S; Kumar, M; Omar, W; El-Zeftawy, H; Luo, J Q; Abdel-Dayem, H M

2000-01-01

The purpose of this manuscript is to present the findings in the largest series of SPECT brain perfusion imaging reported to date for mild or moderate traumatic brain injury. This is a retrospective evaluation of 228 SPECT brain perfusion-imaging studies of patients who suffered mild or moderate traumatic brain injury with or without loss of consciousness (LOC). All patients had no past medical history of previous brain trauma, neurological, or psychiatric diseases, HIV, alcohol or drug abuse. The patient population included 135 males and 93 females. The ages ranged from 11-88 years (mean 40.8). The most common complaints were characteristic of the postconcussion syndrome: headaches 139/228 (61%); dizziness 61/228 (27%); and memory problems 63/228 (28%). LOC status was reported to be positive in 121/228 (53%), negative in 41/228 (18%), and unknown for 63/228 (28%). Normal studies accounted for 52/228 (23%). For abnormal studies (176/228 or 77%) the findings were as follows: basal ganglia hypoperfusion 338 lesions (55.2%); frontal lobe hypoperfusion 146 (23.8%); temporal lobes hypoperfusion 80 (13%); parietal lobes hypoperfusion 20 (3.7%); insular and or occipital lobes hypoperfusion 28 (4.6%). Patients' symptoms correlated with the SPECT brain perfusion findings. The SPECT BPI studies in 122/228 (54%) were done early within 3 months of the date of the accident, and for the remainder, 106/228 (46%) over 3 months and less than 3 years from the date of the injury. In early imaging, 382 lesions were detected; in 92 patients (average 4.2 lesions per study) imaging after 3 months detected 230 lesions: in 84 patients (average 2.7 lesions per study). Basal ganglia hypoperfusion is the most common abnormality following mild or moderate traumatic brain injury (p = 0.006), and is more common in patients complaining of memory problem (p = 0.0005) and dizziness (p = 0.003). Early imaging can detect more lesions than delayed imaging (p = 0.0011). SPECT brain perfusion abnormalities can occur in the absence of LOC.

Correlation of brain Magnetic Resonance Imaging of spontaneously lead poisoned bald eagles (Haliaeetus leucocephalus) with histological lesions: A pilot study.

PubMed

de Francisco, Olga Nicolas; Feeney, Daniel; Armién, Anibal G; Wuenschmann, Arno; Redig, Patrick T

2016-04-01

Six bald eagles with severe, acute lead poisoning based on blood lead values were analyzed by Magnetic Resonance Imaging (MRI) of the brain and histopathology. The aims of the study were to use MRI to locate brain lesions and correlate the changes in MRI signal with the histological character of the lesions at necropsy. All of the bald eagles presented with neurologic and non-neurologic signs suggestive of severe lead poisoning and had blood lead levels in excess of 1.0 ppm. Areas of change in image intensity in the brainstem, midbrain and cerebellum were detected in the MRI scans. Histopathology confirmed the presence of all suspected lesions. The character of the lesions suggested vascular damage as the primary insult. MRI was useful for detecting lesions and defining their three-dimensional distribution and extent. Future studies are needed to evaluate the utility of MRI for detection of lesions in less severely lead poisoned eagles and determining prognosis for treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Predictors of acute and persisting ischemic brain lesions in patients randomized to carotid stenting or endarterectomy.

PubMed

Rostamzadeh, Ayda; Zumbrunn, Thomas; Jongen, Lisa M; Nederkoorn, Paul J; Macdonald, Sumaira; Lyrer, Philippe A; Kappelle, L Jaap; Mali, Willem P Th M; Brown, Martin M; van der Worp, H Bart; Engelter, Stefan T; Bonati, Leo H

2014-02-01

We investigated predictors for acute and persisting periprocedural ischemic brain lesions among patients with symptomatic carotid stenosis randomized to stenting or endarterectomy in the International Carotid Stenting Study. We assessed acute lesions on diffusion-weighted imaging 1 to 3 days after treatment in 124 stenting and 107 endarterectomy patients and lesions persisting on fluid-attenuated inversion recovery after 1 month in 86 and 75 patients, respectively. Stenting patients had more acute (relative risk, 8.8; 95% confidence interval, 4.4-17.5; P<0.001) and persisting lesions (relative risk, 4.2; 95% confidence interval, 1.6-11.1; P=0.005) than endarterectomy patients. Acute lesion count was associated with age (by trend), male sex, and stroke as the qualifying event in stenting; high systolic blood pressure in endarterectomy; and white matter disease in both groups. The rate of conversion from acute to persisting lesions was lower in the stenting group (relative risk, 0.4; 95% confidence interval, 0.2-0.8; P=0.007), and was only predicted by acute lesion volume. Stenting caused more acute and persisting ischemic brain lesions than endarterectomy. However, the rate of conversion from acute to persisting lesions was lower in the stenting group, most likely attributable to lower acute lesion volumes. Clinical Trial Registration -URL: www.isrctn.org. Unique identifier: ISRCTN25337470.

Astrocytes as gate-keepers in optic nerve regeneration--a mini-review.

PubMed

García, Dana M; Koke, Joseph R

2009-02-01

Animals that develop without extra-embryonic membranes (anamniotes--fish, amphibians) have impressive regenerative capacity, even to the extent of replacing entire limbs. In contrast, animals that develop within extra-embryonic membranes (amniotes--reptiles, birds, mammals) have limited capacity for regeneration as adults, particularly in the central nervous system (CNS). Much is known about the process of nerve development in fish and mammals and about regeneration after lesions in the CNS in fish and mammals. Because the retina of the eye and optic nerve are functionally part of the brain and are accessible in fish, frogs, and mice, optic nerve lesion and regeneration (ONR) has been extensively used as a model system for study of CNS nerve regeneration. When the optic nerve of a mouse is severed, the axons leading into the brain degenerate. Initially, the cut end of the axons on the proximal, eye-side of the injury sprout neurites which begin to grow into the lesion. Simultaneously, astrocytes of the optic nerve become activated to initiate wound repair as a first step in reestablishing the structural integrity of the optic nerve. This activation appears to initiate a cascade of molecular signals resulting in apoptotic cell death of the retinal ganglion cells axons of which make up the neural component of the optic nerve; regeneration fails and the injury is permanent. Evidence specifically implicating astrocytes comes from studies showing selective poisoning of astrocytes at the optic nerve lesion, along with activation of a gene whose product blocks apoptosis in retinal ganglion cells, creates conditions favorable to neurites sprouting from the cut proximal stump, growing through the lesion and into the distal portion of the injured nerve, eventually reaching appropriate targets in the brain. In anamniotes, astrocytes ostensibly present no such obstacle since optic nerve regeneration occurs without intervention; however, no systematic study of glial involvement has been done. In fish, vigorously growing neurites sprout from the cut axons and within a few days begin to re-enervate the brain. This review offers a new perspective on the role of glia, particularly astrocytes, as "gate-keepers;" i.e., as being permissive or inhibitory, by comparison between fish and mammals of glial function during ONR.

Assessment of the Ipsilesional Hand Function in Stroke Survivors: The Effect of Lesion Side.

PubMed

Cunha, Bianca Pinto; de Freitas, Sandra Maria Sbeghen Ferreira; de Freitas, Paulo Barbosa

2017-07-01

The aim of this study was to examine the effect of the side of brain lesion on the ipsilesional hand function of stroke survivors. Twenty-four chronic stroke survivors, equally allocated in 2 groups according to the side of brain lesion (right or left), and 12 sex- and age-matched healthy controls performed the Jebsen-Taylor Hand Function Test (JTHFT), the Nine-Hole Peg Test (9HPT), the maximum power grip strength (PwGS max ) test, and the maximum pinch grip strength (PnGS max ) test. Only the ipsilesional hand of the stroke survivors and both hands (left and right) of the controls were assessed. PwGS max and PnGS max were similar among all tested groups. Performances in JTHFT and 9HPT were affected by the brain injury. Individuals with left brain damage showed better performance in 9HPT than individuals with right brain damage, but performance in JTHFT was similar. Individuals after a brain injury have the capacity to produce maximum strength preserved when using their ipsilesional hand. However, the dexterity of their hands and digits is affected, in particular for stroke individuals with right brain lesion. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

The topograpy of demyelination and neurodegeneration in the multiple sclerosis brain

PubMed Central

Haider, Lukas; Hametner, Simon; Höftberger, Romana; Bagnato, Francesca; Grabner, Günther; Trattnig, Siegfried; Pfeifenbring, Sabine; Brück, Wolfgang

2016-01-01

Abstract Multiple sclerosis is a chronic inflammatory disease with primary demyelination and neurodegeneration in the central nervous system. In our study we analysed demyelination and neurodegeneration in a large series of multiple sclerosis brains and provide a map that displays the frequency of different brain areas to be affected by these processes. Demyelination in the cerebral cortex was related to inflammatory infiltrates in the meninges, which was pronounced in invaginations of the brain surface (sulci) and possibly promoted by low flow of the cerebrospinal fluid in these areas. Focal demyelinated lesions in the white matter occurred at sites with high venous density and additionally accumulated in watershed areas of low arterial blood supply. Two different patterns of neurodegeneration in the cortex were identified: oxidative injury of cortical neurons and retrograde neurodegeneration due to axonal injury in the white matter. While oxidative injury was related to the inflammatory process in the meninges and pronounced in actively demyelinating cortical lesions, retrograde degeneration was mainly related to demyelinated lesions and axonal loss in the white matter. Our data show that accumulation of lesions and neurodegeneration in the multiple sclerosis brain does not affect all brain regions equally and provides the pathological basis for the selection of brain areas for monitoring regional injury and atrophy development in future magnetic resonance imaging studies. PMID:26912645

Processing of Basic Speech Acts Following Localized Brain Damage: A New Light on the Neuroanatomy of Language

ERIC Educational Resources Information Center

Soroker, N.; Kasher, A.; Giora, R.; Batori, G.; Corn, C.; Gil, M.; Zaidel, E.

2005-01-01

We examined the effect of localized brain lesions on processing of the basic speech acts (BSAs) of question, assertion, request, and command. Both left and right cerebral damage produced significant deficits relative to normal controls, and left brain damaged patients performed worse than patients with right-sided lesions. This finding argues…

Deficit-Lesion Correlations in Syntactic Comprehension in Aphasia

PubMed Central

Caplan, David; Michaud, Jennifer; Hufford, Rebecca; Makris, Nikos

2015-01-01

The effects of lesions on syntactic comprehension were studied in thirty one people with aphasia (PWA). Participants were tested for the ability to parse and interpret four types of syntactic structures and elements -- passives, object extracted relative clauses, reflexives and pronouns – in three tasks – object manipulation, sentence picture matching with full sentence presentation and sentence picture matching with self-paced listening presentation. Accuracy, end-of-sentence RT and self-paced listening times for each word were measured. MR scans were obtained and analyzed for total lesion volume and for lesion size in 48 cortical areas. Lesion size in several areas of the left hemisphere was related to accuracy in particular sentence types in particular tasks and to self-paced listening times for critical words in particular sentence types. The results support a model of brain organization that includes areas that are specialized for the combination of particular syntactic and interpretive operations and the use of the meanings produced by those operations to accomplish task-related operations. PMID:26688433

Deficit-lesion correlations in syntactic comprehension in aphasia.

PubMed

Caplan, David; Michaud, Jennifer; Hufford, Rebecca; Makris, Nikos

2016-01-01

The effects of lesions on syntactic comprehension were studied in thirty-one people with aphasia (PWA). Participants were tested for the ability to parse and interpret four types of syntactic structures and elements - passives, object extracted relative clauses, reflexives and pronouns - in three tasks - object manipulation, sentence picture matching with full sentence presentation and sentence picture matching with self-paced listening presentation. Accuracy, end-of-sentence RT and self-paced listening times for each word were measured. MR scans were obtained and analyzed for total lesion volume and for lesion size in 48 cortical areas. Lesion size in several areas of the left hemisphere was related to accuracy in particular sentence types in particular tasks and to self-paced listening times for critical words in particular sentence types. The results support a model of brain organization that includes areas that are specialized for the combination of particular syntactic and interpretive operations and the use of the meanings produced by those operations to accomplish task-related operations. Copyright © 2015 Elsevier Inc. All rights reserved.

MALDI imaging mass spectrometry analysis-A new approach for protein mapping in multiple sclerosis brain lesions.

PubMed

Maccarrone, Giuseppina; Nischwitz, Sandra; Deininger, Sören-Oliver; Hornung, Joachim; König, Fatima Barbara; Stadelmann, Christine; Turck, Christoph W; Weber, Frank

2017-03-15

Multiple sclerosis is a disease of the central nervous system characterized by recurrent inflammatory demyelinating lesions in the early disease stage. Lesion formation and mechanisms leading to lesion remyelination are not fully understood. Matrix Assisted Laser Desorption Ionisation Mass Spectrometry imaging (MALDI-IMS) is a technology which analyses proteins and peptides in tissue, preserves their spatial localization, and generates molecular maps within the tissue section. In a pilot study we employed MALDI imaging mass spectrometry to profile and identify peptides and proteins expressed in normal-appearing white matter, grey matter and multiple sclerosis brain lesions with different extents of remyelination. The unsupervised clustering analysis of the mass spectra generated images which reflected the tissue section morphology in luxol fast blue stain and in myelin basic protein immunohistochemistry. Lesions with low remyelination extent were defined by compounds with molecular weight smaller than 5300Da, while more completely remyelinated lesions showed compounds with molecular weights greater than 15,200Da. An in-depth analysis of the mass spectra enabled the detection of cortical lesions which were not seen by routine luxol fast blue histology. An ion mass, mainly distributed at the rim of multiple sclerosis lesions, was identified by liquid chromatography and tandem mass spectrometry as thymosin beta-4, a protein known to be involved in cell migration and in restorative processes. The ion mass of thymosin beta-4 was profiled by MALDI imaging mass spectrometry in brain slides of 12 multiple sclerosis patients and validated by immunohistochemical analysis. In summary, our results demonstrate the ability of the MALDI-IMS technology to map proteins within the brain parenchyma and multiple sclerosis lesions and to identify potential markers involved in multiple sclerosis pathogenesis and/or remyelination. Copyright © 2016 Elsevier B.V. All rights reserved.

Atrophied Brain Lesion Volume: A New Imaging Biomarker in Multiple Sclerosis.

PubMed

Dwyer, Michael G; Bergsland, Niels; Ramasamy, Deepa P; Jakimovski, Dejan; Weinstock-Guttman, Bianca; Zivadinov, Robert

2018-06-01

Lesion accrual in multiple sclerosis (MS) is an important and clinically relevant measure, used extensively as an imaging trial endpoint. However, lesions may also shrink or disappear entirely due to atrophy. Although generally ignored or treated as a nuisance, this phenomenon may actually be an important stand-alone imaging biomarker. Therefore, we investigated the rate of brain lesion loss due to atrophy (atrophied lesion volume) in MS subtypes compared to baseline lesion volume and to new and enlarging lesion volumes, and evaluated the independent predictive value of this phenomenon for clinical disability. A total of 192 patients (18 clinically isolated syndrome, 126 relapsing-remitting MS, and 48 progressive) received 3T magnetic resonance imaging at baseline and 5 years. Lesions were quantified at baseline, and new/enlarging lesion volumes were calculated over the study interval. Atrophied lesion volume was calculated by combining baseline lesion masks with follow-up SIENAX-derived cerebrospinal fluid partial volume maps. Measures were compared between disease subgroups, and correlations with disability change (Expanded Disability Status Scale [EDSS]) were evaluated. Hierarchical regression was employed to determine the unique additive value of atrophied lesion volume. Atrophied lesion volume was different between MS subtypes (P = .02), and exceeded new lesion volume accumulation in progressive MS (298.1 vs. 75.5 mm 3 ). Atrophied lesion volume was the only significant correlate of EDSS change (r = .192 relapsing, r = .317 progressive, P < .05), and explained significant additional variance when controlling for brain atrophy and new/enlarging lesion volume (R 2 .092 vs. .045, P = .003). Atrophied lesion volume is a unique and clinically relevant imaging marker in MS, with particular promise in progressive MS. Copyright © 2018 by the American Society of Neuroimaging.

The topograpy of demyelination and neurodegeneration in the multiple sclerosis brain.

PubMed

Haider, Lukas; Zrzavy, Tobias; Hametner, Simon; Höftberger, Romana; Bagnato, Francesca; Grabner, Günther; Trattnig, Siegfried; Pfeifenbring, Sabine; Brück, Wolfgang; Lassmann, Hans

2016-03-01

Multiple sclerosis is a chronic inflammatory disease with primary demyelination and neurodegeneration in the central nervous system. In our study we analysed demyelination and neurodegeneration in a large series of multiple sclerosis brains and provide a map that displays the frequency of different brain areas to be affected by these processes. Demyelination in the cerebral cortex was related to inflammatory infiltrates in the meninges, which was pronounced in invaginations of the brain surface (sulci) and possibly promoted by low flow of the cerebrospinal fluid in these areas. Focal demyelinated lesions in the white matter occurred at sites with high venous density and additionally accumulated in watershed areas of low arterial blood supply. Two different patterns of neurodegeneration in the cortex were identified: oxidative injury of cortical neurons and retrograde neurodegeneration due to axonal injury in the white matter. While oxidative injury was related to the inflammatory process in the meninges and pronounced in actively demyelinating cortical lesions, retrograde degeneration was mainly related to demyelinated lesions and axonal loss in the white matter. Our data show that accumulation of lesions and neurodegeneration in the multiple sclerosis brain does not affect all brain regions equally and provides the pathological basis for the selection of brain areas for monitoring regional injury and atrophy development in future magnetic resonance imaging studies. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain.

Brain abscess mimicking lung cancer metastases; a case report.

PubMed

Asano, Michiko; Fujimoto, Nobukazu; Fuchimoto, Yasuko; Ono, Katsuichiro; Ozaki, Shinji; Kimura, Fumiaki; Kishimoto, Takumi

2013-01-01

A 76-year-old woman came to us because of staggering, fever, dysarthria, and appetite loss. Magnetic resonance imaging (MRI) of the brain revealed multiple masses with surrounding edema. Chest X-ray and computed tomography demonstrated a mass-like lesion in the left lung and left pleural effusion. Lung cancer and multiple brain metastases were suspected. However, the brain lesions demonstrated a high intensity through diffusion-weighted MRI. The finding was an important key to differentiate brain abscesses from lung cancer metastases. Copyright © 2013 Elsevier Inc. All rights reserved.

Is the spatial distribution of brain lesions associated with closed-head injury predictive of subsequent development of attention-deficit/hyperactivity disorder? Analysis with brain-image database

NASA Technical Reports Server (NTRS)

Herskovits, E. H.; Megalooikonomou, V.; Davatzikos, C.; Chen, A.; Bryan, R. N.; Gerring, J. P.

1999-01-01

PURPOSE: To determine whether there is an association between the spatial distribution of lesions detected at magnetic resonance (MR) imaging of the brain in children after closed-head injury and the development of secondary attention-deficit/hyperactivity disorder (ADHD). MATERIALS AND METHODS: Data obtained from 76 children without prior history of ADHD were analyzed. MR images were obtained 3 months after closed-head injury. After manual delineation of lesions, images were registered to the Talairach coordinate system. For each subject, registered images and secondary ADHD status were integrated into a brain-image database, which contains depiction (visualization) and statistical analysis software. Using this database, we assessed visually the spatial distributions of lesions and performed statistical analysis of image and clinical variables. RESULTS: Of the 76 children, 15 developed secondary ADHD. Depiction of the data suggested that children who developed secondary ADHD had more lesions in the right putamen than children who did not develop secondary ADHD; this impression was confirmed statistically. After Bonferroni correction, we could not demonstrate significant differences between secondary ADHD status and lesion burdens for the right caudate nucleus or the right globus pallidus. CONCLUSION: Closed-head injury-induced lesions in the right putamen in children are associated with subsequent development of secondary ADHD. Depiction software is useful in guiding statistical analysis of image data.

Simultaneous 11C-Methionine Positron Emission Tomography/Magnetic Resonance Imaging of Suspected Primary Brain Tumors

PubMed Central

Deuschl, Cornelius; Goericke, Sophia; Grueneisen, Johannes; Sawicki, Lino Morris; Goebel, Juliane; El Hindy, Nicolai; Wrede, Karsten; Binse, Ina; Poeppel, Thorsten; Quick, Harald; Forsting, Michael; Hense, Joerg; Umutlu, Lale; Schlamann, Marc

2016-01-01

Introduction The objective of this study was to assess the diagnostic value of integrated 11C- methionine PET/MRI for suspected primary brain tumors, in comparison to MRI alone. Material and Methods Forty-eight consecutive patients with suspected primary brain tumor were prospectively enrolled for an integrated 11C-methionine PET/MRI. Two neuro-radiologists separately evaluated the MRI alone and the integrated PET/MRI data sets regarding most likely diagnosis and diagnostic confidence on a 5-point scale. Reference standard was histopathology or follow-up imaging. Results Fifty-one suspicious lesions were detected: 16 high-grade glioma and 25 low-grade glioma. Ten non-malignant cerebral lesions were described by the reference standard. MRI alone and integrated PET/MRI each correctly classified 42 of the 51 lesions (82.4%) as neoplastic lesions (WHO grade II, III and IV) or non-malignant lesions (infectious and neoplastic lesions). Diagnostic confidence for all lesions, low-grade astrocytoma and high-grade astrocytoma (3.7 vs. 4.2, 3,1 vs. 3.8, 4.0 vs. 4,7) were significantly (p < 0.05) better with integrated PET/MRI than in MRI alone. Conclusions The present study demonstrates the high potential of integrated 11C-methionine-PET/MRI for the assessment of suspected primary brain tumors. Although integrated methionine PET/MRI does not lead to an improvement of correct diagnoses, diagnostic confidence is significantly improved. PMID:27907162

Quantitative analysis of brain magnetic resonance imaging for hepatic encephalopathy

NASA Astrophysics Data System (ADS)

Syh, Hon-Wei; Chu, Wei-Kom; Ong, Chin-Sing

1992-06-01

High intensity lesions around ventricles have recently been observed in T1-weighted brain magnetic resonance images for patients suffering hepatic encephalopathy. The exact etiology that causes magnetic resonance imaging (MRI) gray scale changes has not been totally understood. The objective of our study was to investigate, through quantitative means, (1) the amount of changes to brain white matter due to the disease process, and (2) the extent and distribution of these high intensity lesions, since it is believed that the abnormality may not be entirely limited to the white matter only. Eleven patients with proven haptic encephalopathy and three normal persons without any evidence of liver abnormality constituted our current data base. Trans-axial, sagittal, and coronal brain MRI were obtained on a 1.5 Tesla scanner. All processing was carried out on a microcomputer-based image analysis system in an off-line manner. Histograms were decomposed into regular brain tissues and lesions. Gray scale ranges coded as lesion were then brought back to original images to identify distribution of abnormality. Our results indicated the disease process involved pallidus, mesencephalon, and subthalamic regions.

Margaret Kennard (1899–1975): Not a ‘Principle’ of Brain Plasticity But a Founding Mother of Developmental Neuropsychology

PubMed Central

Dennis, Maureen

2009-01-01

According to the ‘Kennard Principle’, there is a negative linear relation between age at brain injury and functional outcome. Other things being equal, the younger the lesioned organism, the better the outcome. But the ‘Kennard Principle’ is neither Kennard’s nor a principle. In her work, Kennard sought to explain the factors that predicted functional outcome (age, to be sure, but also staging, laterality, location, and number of brain lesions, and outcome domain) and the neural mechanisms that altered the lesioned brain’s functionality. This paper discusses Kennard’s life and years at Yale (1931–1943); considers the genesis and scope of her work on early-onset brain lesions, which represents an empirical and theoretical foundation for current developmental neuropsychology; offers an historical explanation of why the ‘Kennard Principle’ emerged in the context of early 1970s work on brain plasticity; shows why uncritical belief in the ‘Kennard Principle’ continues to shape current research and practice; and reviews the continuing importance of her work. PMID:20079891

Brain extraction in partial volumes T2*@7T by using a quasi-anatomic segmentation with bias field correction.

PubMed

Valente, João; Vieira, Pedro M; Couto, Carlos; Lima, Carlos S

2018-02-01

Poor brain extraction in Magnetic Resonance Imaging (MRI) has negative consequences in several types of brain post-extraction such as tissue segmentation and related statistical measures or pattern recognition algorithms. Current state of the art algorithms for brain extraction work on weighted T1 and T2, being not adequate for non-whole brain images such as the case of T2*FLASH@7T partial volumes. This paper proposes two new methods that work directly in T2*FLASH@7T partial volumes. The first is an improvement of the semi-automatic threshold-with-morphology approach adapted to incomplete volumes. The second method uses an improved version of a current implementation of the fuzzy c-means algorithm with bias correction for brain segmentation. Under high inhomogeneity conditions the performance of the first method degrades, requiring user intervention which is unacceptable. The second method performed well for all volumes, being entirely automatic. State of the art algorithms for brain extraction are mainly semi-automatic, requiring a correct initialization by the user and knowledge of the software. These methods can't deal with partial volumes and/or need information from atlas which is not available in T2*FLASH@7T. Also, combined volumes suffer from manipulations such as re-sampling which deteriorates significantly voxel intensity structures making segmentation tasks difficult. The proposed method can overcome all these difficulties, reaching good results for brain extraction using only T2*FLASH@7T volumes. The development of this work will lead to an improvement of automatic brain lesions segmentation in T2*FLASH@7T volumes, becoming more important when lesions such as cortical Multiple-Sclerosis need to be detected. Copyright © 2017 Elsevier B.V. All rights reserved.

Impact of brain tumour location on emotion and personality: a voxel-based lesion-symptom mapping study on mentalization processes.

PubMed

Campanella, Fabio; Shallice, Tim; Ius, Tamara; Fabbro, Franco; Skrap, Miran

2014-09-01

Patients affected by brain tumours may show behavioural and emotional regulation deficits, sometimes showing flattened affect and sometimes experiencing a true 'change' in personality. However, little evidence is available to the surgeon as to what changes are likely to occur with damage at specific sites, as previous studies have either relied on single cases or provided only limited anatomical specificity, mostly reporting associations rather than dissociations of symptoms. We investigated these aspects in patients undergoing surgery for the removal of cerebral tumours. We argued that many of the problems described can be ascribed to the onset of difficulties in one or more of the different levels of the process of mentalizing (i.e. abstracting and reflecting upon) emotion and intentions, which impacts on everyday behaviour. These were investigated in terms of (i) emotion recognition; (ii) Theory of Mind; (iii) alexithymia; and (iv) self-maturity (personality disorder). We hypothesized that temporo/limbic areas would be critical for processing emotion and intentions at a more perceptual level, while frontal lobe structures would be more critical when higher levels of mentalization/abstraction are required. We administered four different tasks, Task 1: emotion recognition of Ekman faces; Task 2: the Eyes Test (Theory of Mind); Task 3: Toronto Alexithymia Scale; and Task 4: Temperament and Character Inventory (a personality inventory), both immediately before and few days after the operation for the removal of brain tumours in a series of 71 patients (age range: 18-75 years; 33 female) with lesions located in the left or right frontal, temporal and parietal lobes. Lobe-based and voxel-based analysis confirmed that tasks requiring interpretation of emotions and intentions at more basic (less mentalized) levels (Tasks 1 and 2) were more affected by temporo/insular lesions, with emotion recognition (Task 1) being maximally impaired by anterior temporal and amygdala lesions and Task 2 (found to be a 'basic' Theory of Mind task involving only limited mentalization) being mostly impaired by posterior temporoparietal lesions. Tasks relying on higher-level mentalization (Tasks 3 and 4) were maximally affected by prefrontal lesions, with the alexithymia scale (Task 3) being mostly associated with anterior/medial lesions and the self-maturity measure (Task 4) with lateral prefrontal ones. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Management strategies for neoplastic and vascular brain lesions presenting during pregnancy: A series of 29 patients

PubMed Central

Pereira, Celestino Esteves; Lynch, Jose Carlos

2017-01-01

Background: The occurrence of a brain tumor or intracranial vascular lesion during pregnancy is a rare event, but when it happens, it jeopardizes the lives of both the mother and infant. It also creates challenges of a neurosurgical, obstetric, and ethical nature. A multidisciplinary approach should be used for their care. Methods: Between 1986 and 2015, 12 pregnant women diagnosed with brain tumors and 17 women with intracranial vascular lesion underwent treatment at the Neurosurgery Department of the Servidores do Estado Hospital and Rede D’Or/São Luis. The Neurosurgery Department teamed up with Obstetrics Anesthesiology Departments in establishing the procedures. The patients’ records, surgical descriptions, imaging studies, and histopathological material were reviewed. Results: Among 12 patients presenting with brain tumors, there were neither operative mortality nor fetal deaths. Among the vascular lesions, aneurysm rupture was responsible for bleeding in 6 instances. Arteriovenous malformation was diagnosed in 7 patients. In this subgroup, the maternal and fetal mortality rates were 11.7% and 23.7%, respectively. Conclusions: We can assert that the association between a brain tumor and vascular lesions with pregnancy is a very unusual event, which jeopardizes both the lives of the mother and infant. It remains incompletely characterized due to the rare nature of these potentially devastating events. Knowing the exact mechanism responsible for the interaction of pregnancy and with these lesions will improve the treatment of these patients. PMID:28303207

Association between right-to-left shunts and brain lesions in sport divers.

PubMed

Gerriets, Tibo; Tetzlaff, Kay; Hutzelmann, Alfred; Liceni, Thomas; Kopiske, Gerrit; Struck, Niklas; Reuter, Michael; Kaps, Manfred

2003-10-01

Recent studies suggest that healthy sport divers may develop clinically silent brain damage, based on the association between a finding of multiple brain lesions on MRI and the presence of right-to-left shunt, a pathway for venous gas bubbles to enter the arterial system. We performed echocontrast transcranial Doppler sonography in 42 sport divers to determine the presence of a right-to-left shunt. Cranial MRI was carried out using a 1.5 T magnet. A lesion was counted if it was hyperintense on both T2-weighted and T2-weighted fluid attenuated inversion recovery sequences. To test the hypothesis that the occurrence of postdive arterial gas emboli is related to brain lesions on MRI, we measured postdive intravascular bubbles in a subset of 15 divers 30 min after open water scuba dives. Echocontrast transcranial Doppler sonography revealed a right-to-left shunt in 16 of the divers (38%). Only one hyperintensive lesion of the central white matter was found and that was in a diver with no evidence of a right-to-left shunt. Postdive arterial gas emboli were detected in 3 out of 15 divers; they had a right-to-left shunt, but no pathologic findings on cranial magnetic resonance imaging. Our data support the theory that right-to-left shunts can serve as a pathway for venous gas bubbles into the arterial circulation. However, we could not confirm an association between brain lesions and the presence of a right-to-left shunt in sport divers.

The significance of BRAF V600E mutation status discordance between primary cutaneous melanoma and brain metastases: The implications for BRAF inhibitor therapy.

PubMed

Hannan, Enda J; O'Leary, Donal P; MacNally, Stephen P; Kay, Elaine W; Farrell, Michael A; Morris, Patrick G; Power, Colm P; Hill, Arnold D K

2017-12-01

To compare BRAF V600E status of primary melanoma and brain metastases to assess for discordance by cross-sectional study, and to evaluate clinical implications on BRAF inhibitor therapy.Brain metastases are common in patients with advanced melanoma. Between 40% and 60% of melanomas demonstrate BRAF mutations, BRAF V600E being most common. Selective BRAF inhibitor therapy has shown improvement in outcome in patients with melanoma. It has been demonstrated that not all metastatic lesions carry the same BRAF mutation status as the primary, but the frequency in which discordance occurs remains unclear. Establishing this may have implications in the use of BRAF inhibitors in patients with melanoma brain metastases.Patients who underwent metastectomy for melanoma brain metastases were identified using our local histopathology database. A review of histology of the primary lesion and the metastasis was performed for each patient, assessing for BRAF mutation status discordance.Fourty-two patients who underwent a brain metastectomy following excision of a melanoma primary were identified over a 7-year period. Median survival was 9 months. The median Breslow thickness for the primary lesion was 3.4 mm. Six patients (14%) had discrepancy between the BRAF status of a melanoma primary and metastatic lesion. Of these 6 patients, 3 had a BRAF mutation positive primary with a BRAF mutation negative metastatic lesion, while the other 3 had a BRAF mutation negative primary with BRAF mutation positive metastasis.There is an important discordance rate in the BRAF mutation status of melanoma primaries versus brain metastases.

Social Brains in Context: Lesions Targeted to the Song Control System in Female Cowbirds Affect Their Social Network

PubMed Central

Maguire, Sarah E.; Schmidt, Marc F.; White, David J.

2013-01-01

Social experiences can organize physiological, neural, and reproductive function, but there are few experimental preparations that allow one to study the effect individuals have in structuring their social environment. We examined the connections between mechanisms underlying individual behavior and social dynamics in flocks of brown-headed cowbirds (Molothrus ater). We conducted targeted inactivations of the neural song control system in female subjects. Playback tests revealed that the lesions affected females' song preferences: lesioned females were no longer selective for high quality conspecific song. Instead, they reacted to all cowbird songs vigorously. When lesioned females were introduced into mixed-sex captive flocks, they were less likely to form strong pair-bonds, and they no longer showed preferences for dominant males. This in turn created a cascade of effects through the groups. Social network analyses showed that the introduction of the lesioned females created instabilities in the social structure: males in the groups changed their dominance status and their courtship patterns, and even the competitive behavior of other female group-mates was affected. These results reveal that inactivation of the song control system in female cowbirds not only affects individual behavior, but also exerts widespread effects on the stability of the entire social system. PMID:23650558

Social brains in context: lesions targeted to the song control system in female cowbirds affect their social network.

PubMed

Maguire, Sarah E; Schmidt, Marc F; White, David J

2013-01-01

Social experiences can organize physiological, neural, and reproductive function, but there are few experimental preparations that allow one to study the effect individuals have in structuring their social environment. We examined the connections between mechanisms underlying individual behavior and social dynamics in flocks of brown-headed cowbirds (Molothrus ater). We conducted targeted inactivations of the neural song control system in female subjects. Playback tests revealed that the lesions affected females' song preferences: lesioned females were no longer selective for high quality conspecific song. Instead, they reacted to all cowbird songs vigorously. When lesioned females were introduced into mixed-sex captive flocks, they were less likely to form strong pair-bonds, and they no longer showed preferences for dominant males. This in turn created a cascade of effects through the groups. Social network analyses showed that the introduction of the lesioned females created instabilities in the social structure: males in the groups changed their dominance status and their courtship patterns, and even the competitive behavior of other female group-mates was affected. These results reveal that inactivation of the song control system in female cowbirds not only affects individual behavior, but also exerts widespread effects on the stability of the entire social system.

Association of Deep Gray Matter Damage With Cortical and Spinal Cord Degeneration in Primary Progressive Multiple Sclerosis.

PubMed

Ruggieri, Serena; Petracca, Maria; Miller, Aaron; Krieger, Stephen; Ghassemi, Rezwan; Bencosme, Yadira; Riley, Claire; Howard, Jonathan; Lublin, Fred; Inglese, Matilde

2015-12-01

The investigation of cortical gray matter (GM), deep GM nuclei, and spinal cord damage in patients with primary progressive multiple sclerosis (PP-MS) provides insights into the neurodegenerative process responsible for clinical progression of MS. To investigate the association of magnetic resonance imaging measures of cortical, deep GM, and spinal cord damage and their effect on clinical disability. Cross-sectional analysis of 26 patients with PP-MS (mean age, 50.9 years; range, 31-65 years; including 14 women) and 20 healthy control participants (mean age, 51.1 years; range, 34-63 years; including 11 women) enrolled at a single US institution. Clinical disability was measured with the Expanded Disability Status Scale, 9-Hole Peg Test, and 25-Foot Walking Test. We collected data from January 1, 2012, through December 31, 2013. Data analysis was performed from January 21 to April 10, 2015. Cortical lesion burden, brain and deep GM volumes, spinal cord area and volume, and scores on the Expanded Disability Status Scale (score range, 0 to 10; higher scores indicate greater disability), 9-Hole Peg Test (measured in seconds; longer performance time indicates greater disability), and 25-Foot Walking Test (test covers 7.5 m; measured in seconds; longer performance time indicates greater disability). The 26 patients with PP-MS showed significantly smaller mean (SD) brain and spinal cord volumes than the 20 control group patients (normalized brain volume, 1377.81 [65.48] vs 1434.06 [53.67] cm3 [P = .003]; normalized white matter volume, 650.61 [46.38] vs 676.75 [37.02] cm3 [P = .045]; normalized gray matter volume, 727.20 [40.74] vs 757.31 [38.95] cm3 [P = .02]; normalized neocortical volume, 567.88 [85.55] vs 645.00 [42.84] cm3 [P = .001]; normalized spinal cord volume for C2-C5, 72.71 [7.89] vs 82.70 [7.83] mm3 [P < .001]; and normalized spinal cord volume for C2-C3, 64.86 [7.78] vs 72.26 [7.79] mm3 [P =.002]). The amount of damage in deep GM structures, especially with respect to the thalamus, was correlated with the number and volume of cortical lesions (mean [SD] thalamus volume, 8.89 [1.10] cm3; cortical lesion number, 12.6 [11.7]; cortical lesion volume, 0.65 [0.58] cm3; r = -0.52; P < .01). Thalamic atrophy also showed an association with cortical lesion count in the frontal cortex (mean [SD] thalamus volume, 8.89 [1.1] cm3; cortical lesion count in the frontal lobe, 5.0 [5.7]; r = -0.60; P < .01). No association was identified between magnetic resonance imaging measures of the brain and spinal cord damage. In this study, the neurodegenerative process occurring in PP-MS appeared to spread across connected structures in the brain while proceeding independently in the spinal cord. These results support the relevance of anatomical connectivity for the propagation of MS damage in the PP phenotype.

Functional recovery of the dentate gyrus after a focal lesion is accompanied by structural reorganization in the adult rat.

PubMed

Zepeda, Angélica; Aguilar-Arredondo, Andrea; Michel, Gabriela; Ramos-Languren, Laura Elisa; Escobar, Martha L; Arias, Clorinda

2013-03-01

The adult brain is highly plastic and tends to undergo substantial reorganization after injury to compensate for the lesion effects. It has been shown that such reorganization mainly relies on anatomical and biochemical modifications of the remaining cells which give rise to a network rewiring without reinstating the original morphology of the damaged region. However, few studies have analyzed the neurorepair potential of a neurogenic structure. Thus, the aim of this work was to analyze if the DG could restore its original morphology after a lesion and to establish if the structural reorganization is accompanied by behavioral and electrophysiological recovery. Using a subepileptogenic injection of kainic acid (KA), we induced a focal lesion in the DG and assessed in time (1) the loss and recovery of dependent and non dependent DG cognitive functions, (2) the anatomical reorganization of the DG using a stereological probe and immunohistochemical markers for different neuronal maturation stages and, (3) synaptic plasticity as assessed through the induction of in vivo long-term potentiation (LTP) in the mossy fiber pathway (CA3-DG). Our results show that a DG focal lesion with KA leads to a well delimited region of neuronal loss, disorganization of the structure, the loss of associated mnemonic functions and the impairment to elicit LTP. However, behavioral and synaptic plasticity expression occurs in a time dependent fashion and occurs along the morphological restoration of the DG. These results provide novel information on neural plasticity events associated to functional reorganization after damage.

Temporal lobe networks supporting the comprehension of spoken words.

PubMed

Bonilha, Leonardo; Hillis, Argye E; Hickok, Gregory; den Ouden, Dirk B; Rorden, Chris; Fridriksson, Julius

2017-09-01

Auditory word comprehension is a cognitive process that involves the transformation of auditory signals into abstract concepts. Traditional lesion-based studies of stroke survivors with aphasia have suggested that neocortical regions adjacent to auditory cortex are primarily responsible for word comprehension. However, recent primary progressive aphasia and normal neurophysiological studies have challenged this concept, suggesting that the left temporal pole is crucial for word comprehension. Due to its vasculature, the temporal pole is not commonly completely lesioned in stroke survivors and this heterogeneity may have prevented its identification in lesion-based studies of auditory comprehension. We aimed to resolve this controversy using a combined voxel-based-and structural connectome-lesion symptom mapping approach, since cortical dysfunction after stroke can arise from cortical damage or from white matter disconnection. Magnetic resonance imaging (T1-weighted and diffusion tensor imaging-based structural connectome), auditory word comprehension and object recognition tests were obtained from 67 chronic left hemisphere stroke survivors. We observed that damage to the inferior temporal gyrus, to the fusiform gyrus and to a white matter network including the left posterior temporal region and its connections to the middle temporal gyrus, inferior temporal gyrus, and cingulate cortex, was associated with word comprehension difficulties after factoring out object recognition. These results suggest that the posterior lateral and inferior temporal regions are crucial for word comprehension, serving as a hub to integrate auditory and conceptual processing. Early processing linking auditory words to concepts is situated in posterior lateral temporal regions, whereas additional and deeper levels of semantic processing likely require more anterior temporal regions.10.1093/brain/awx169_video1awx169media15555638084001. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Traumatic brain injury and hemorrhagic shock: evaluation of different resuscitation strategies in a large animal model of combined insults.

PubMed

Jin, Guang; DeMoya, Marc A; Duggan, Michael; Knightly, Thomas; Mejaddam, Ali Y; Hwabejire, John; Lu, Jennifer; Smith, William Michael; Kasotakis, Georgios; Velmahos, George C; Socrate, Simona; Alam, Hasan B

2012-07-01

Traumatic brain injury (TBI) and hemorrhagic shock (HS) are the leading causes of trauma-related mortality and morbidity. Combination of TBI and HS (TBI + HS) is highly lethal, and the optimal resuscitation strategy for this combined insult remains unclear. A critical limitation is the lack of suitable large animal models to test different treatment strategies. We have developed a clinically relevant large animal model of TBI + HS, which was used to evaluate the impact of different treatments on brain lesion size and associated edema. Yorkshire swine (42-50 kg) were instrumented to measure hemodynamic parameters and intracranial pressure. A computer-controlled cortical impact device was used to create a TBI through a 20-mm craniotomy: 15-mm cylindrical tip impactor at 4 m/s velocity, 100-ms dwell time, and 12-mm penetration depth. Volume-controlled hemorrhage was started (40% blood volume) concurrent with the TBI. After 2 h of shock, animals were randomized to one of three resuscitation groups (n = 5/group): (a) normal saline (NS); (b) 6% hetastarch, Hextend (Hex); and (c) fresh frozen plasma (FFP). Volumes of Hex and FFP matched the shed blood, whereas NS was three times the volume. After 6 h of postresuscitation monitoring, brains were sectioned into 5-mm slices and stained with TTC (2,3,5-triphenyltetrazolium chloride) to quantify the lesion size and brain swelling. Combination of 40% blood loss with cortical impact and a period of shock (2 h) resulted in a highly reproducible brain injury. Total fluid requirements were lower in the Hex and FFP groups. Lesion size and brain swelling in the FFP group (2,160 ± 202.63 mm and 22% ± 1.0%, respectively) were significantly smaller than those in the NS group (3,285 ± 130.8 mm3 and 37% ± 1.6%, respectively) (P < 0.05). Hex treatment decreased the swelling (29% ± 1.6%) without reducing the lesion size. Early administration of FFP reduces the size of brain lesion and associated swelling in a large animal model of TBI + HS. In contrast, artificial colloid (Hex) decreases swelling without reducing the actual size of the brain lesion.

Brain activation during a social attribution task in adolescents with moderate to severe traumatic brain injury.

PubMed

Scheibel, Randall S; Newsome, Mary R; Wilde, Elisabeth A; McClelland, Michelle M; Hanten, Gerri; Krawczyk, Daniel C; Cook, Lori G; Chu, Zili D; Vásquez, Ana C; Yallampalli, Ragini; Lin, Xiaodi; Hunter, Jill V; Levin, Harvey S

2011-01-01

The ability to make accurate judgments about the mental states of others, sometimes referred to as theory of mind (ToM), is often impaired following traumatic brain injury (TBI), and this deficit may contribute to problems with interpersonal relationships. The present study used an animated social attribution task (SAT) with functional magnetic resonance imaging (fMRI) to examine structures mediating ToM in adolescents with moderate to severe TBI. The study design also included a comparison group of matched, typically developing (TD) adolescents. The TD group exhibited activation within a number of areas that are thought to be relevant to ToM, including the medial prefrontal and anterior cingulate cortex, fusiform gyrus, and posterior temporal and parietal areas. The TBI subjects had significant activation within many of these same areas, but their activation was generally more intense and excluded the medial prefrontal cortex. Exploratory regression analyses indicated a negative relation between ToM-related activation and measures of white matter integrity derived from diffusion tensor imaging, while there was also a positive relation between activation and lesion volume. These findings are consistent with alterations in the level and pattern of brain activation that may be due to the combined influence of diffuse axonal injury and focal lesions.

Application of the McDonald MRI criteria in multiple sclerosis.

PubMed

Chan, Ling Ling; Sitoh, Yih Yian; Chong, June; See, Siew Ju; Umapathi, Thirugnanam N; Lim, Shih Hui; Ong, Benjamin

2007-08-01

The aim of this study was to assess the sensitivity of McDonald's magnetic resonance imaging (MRI) criteria for the diagnosis of multiple sclerosis (MS) in a group of Asian patients diagnosed with clinically definite MS, based on lesion characterisation on MRI scans. Forty-nine patients from 3 major neurological institutions were classified as having Asian- or Western-type MS based on clinical assessment. Each MRI scan was reviewed by 2 neuroradiologists for the presence and characteristics of brain and spinal lesions. The McDonald's MRI criteria were then applied and its sensitivity evaluated. Nine patients were excluded, leaving 34 females and 6 males who were dominantly Chinese (90%), with a mean age of 36.2 years. The MRI brain and spinal findings were detailed and tabulated. Statistically significant differences (P <0.01) in MRI brain findings and sensitivity of McDonald's MRI criteria were found between our Asian- and Western-type MS patients. The diagnostic yield of McDonald's MRI criteria increased by 20% when we substituted a cord for a brain lesion, and applied the substitution for enhancing cord lesions as well. The diagnosis is more likely to be made when using McDonald MRI criteria based on brain findings, in a patient who presents clinically with Western-type MS. The provision for substitution of "one brain for a spinal lesion" is helpful in Asian-type MS, where there is preponderance of spinal lesion load. Our findings suggest that minor modifications in the interpretation of McDonald's MRI criteria have significant impact on the diagnosis in patients clinically presenting as Asian-type MS, with potential bearing on their subsequent management.

Interictal Electroencephalography (EEG) Findings in Children with Epilepsy and Bilateral Brain Lesions on Magnetic Resonance Imaging (MRI).

PubMed

Zubcevic, Smail; Milos, Maja; Catibusic, Feriha; Uzicanin, Sajra; Krdzalic, Belma

2015-12-01

Neuroimaging procedures and electroencephalography (EEG) are basic parts of investigation of patients with epilepsies. The aim is to try to assess relationship between bilaterally localized brain lesions found in routine management of children with newly diagnosed epilepsy and their interictal EEG findings. Total amount of 68 patients filled criteria for inclusion in the study that was performed at Neuropediatrics Department, Pediatric Hospital, University Clinical Center Sarajevo, or its outpatient clinic. There were 33 girls (48,5%) and 35 boys (51,5%). Average age at diagnosis of epilepsy was 3,5 years. Both neurological and neuropsychological examination in the moment of making diagnosis of epilepsy was normal in 27 (39,7%) patients, and showed some kind of delay or other neurological finding in 41 (60,3%). Brain MRI showed lesions that can be related to antenatal or perinatal events in most of the patients (ventricular dilation in 30,9%, delayed myelination and post-hypoxic changes in 27,9%). More than half of patients (55,9%) showed bilateral interictal epileptiform discharges on their EEGs, and further 14,7% had other kinds of bilateral abnormalities. Frequency of bilateral epileptic discharges showed statistically significant predominance on level of p<0,05. Cross tabulation between specific types of bilateral brain MRI lesions and EEG finding did not reveal significant type of EEG for assessed brain lesions. We conclude that there exists relationship between bilaterally localized brain MRI lesions and interictal bilateral epileptiform or nonspecific EEG findings in children with newly diagnosed epilepsies. These data are suggesting that in cases when they do not correlate there is a need for further investigation of seizure etiology.

Restoring Behavior via Inverse Neurocontroller in a Lesioned Cortical Spiking Model Driving a Virtual Arm

PubMed Central

Dura-Bernal, Salvador; Li, Kan; Neymotin, Samuel A.; Francis, Joseph T.; Principe, Jose C.; Lytton, William W.

2016-01-01

Neural stimulation can be used as a tool to elicit natural sensations or behaviors by modulating neural activity. This can be potentially used to mitigate the damage of brain lesions or neural disorders. However, in order to obtain the optimal stimulation sequences, it is necessary to develop neural control methods, for example by constructing an inverse model of the target system. For real brains, this can be very challenging, and often unfeasible, as it requires repeatedly stimulating the neural system to obtain enough probing data, and depends on an unwarranted assumption of stationarity. By contrast, detailed brain simulations may provide an alternative testbed for understanding the interactions between ongoing neural activity and external stimulation. Unlike real brains, the artificial system can be probed extensively and precisely, and detailed output information is readily available. Here we employed a spiking network model of sensorimotor cortex trained to drive a realistic virtual musculoskeletal arm to reach a target. The network was then perturbed, in order to simulate a lesion, by either silencing neurons or removing synaptic connections. All lesions led to significant behvaioral impairments during the reaching task. The remaining cells were then systematically probed with a set of single and multiple-cell stimulations, and results were used to build an inverse model of the neural system. The inverse model was constructed using a kernel adaptive filtering method, and was used to predict the neural stimulation pattern required to recover the pre-lesion neural activity. Applying the derived neurostimulation to the lesioned network improved the reaching behavior performance. This work proposes a novel neurocontrol method, and provides theoretical groundwork on the use biomimetic brain models to develop and evaluate neurocontrollers that restore the function of damaged brain regions and the corresponding motor behaviors. PMID:26903796

Changes in /sup 3/H-substance P receptor binding in the rat brain after kainic acid lesion of the corpus striatum

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

Mantyh, P.W.; Hunt, S.P.

1986-06-01

Previous studies have indicated that the substantia nigra contains the highest concentration of substance P-like immunoreactivity (SPLI) in the brain. Paradoxically, it also appears to contain one of the lowest concentrations of substance P receptors in the brain. One possibility is that the massive amount of SPLI blocks the binding of the radioligand to the substance P receptor and/or down-regulates the number of substance P receptors present in this structure. Since greater than 95% of the SPLI within the substantia nigra originates from the corpus striatum, we have lesioned this area and measured the changes in substance P receptor concentrationmore » in the substantia nigra and other corpus striatal projection areas. A semiquantitative autoradiographic technique for measuring the binding of /sup 3/H-substance P to substance P receptors was used in conjunction with tritium-sensitive film. 3H-substance P binding was measured in both the corpus striatum and its projection areas after kainic acid lesion of the corpus striatum. At either 4 or 21 d after the lesion there was approximately a 90% loss of substance P receptors in the rostral striatum, a 74% loss in the globus pallidus, a 57% increase in receptor number in lamina I and II of the ipsilateral somatosensory cortex, and no apparent change in the number of receptors in the substantia nigra pars reticulata, superior colliculus, and central gray. These findings suggest that the low concentration of substance P receptors found within the substantia nigra is not due the massive SPLI innervation, since removal of greater than 95% of the SPLI had no measurable effect on the concentration of substance P receptors.« less

Voxelwise distribution of acute ischemic stroke lesions in patients with newly diagnosed atrial fibrillation: Trigger of arrhythmia or only target of embolism?

PubMed Central

Johnson, Timothy D.; Dittgen, Felix; Nichols, Thomas E.; Malzahn, Uwe; Veltkamp, Roland

2017-01-01

Objective Atrial fibrillation (AF) is frequently detected after ischemic stroke for the first time, and brain regions involved in autonomic control have been suspected to trigger AF. We examined whether specific brain regions are associated with newly detected AF after ischemic stroke. Methods Patients with acute cerebral infarctions on diffusion-weighted magnetic resonance imaging were included in this lesion mapping study. Lesions were mapped and modeled voxelwise using Bayesian Spatial Generalised Linear Mixed Modeling to determine differences in infarct locations between stroke patients with new AF, without AF and with AF already known before the stroke. Results 582 patients were included (median age 68 years; 63.2% male). AF was present in 109/582 patients [(18.7%); new AF: 39/109 (35.8%), known AF: 70/109 (64.2%)]. AF patients had larger infarct volumes than patients without AF (mean: 29.7 ± 45.8 ml vs. 15.2 ± 35.1 ml; p<0.001). Lesions in AF patients accumulated in the right central middle cerebral artery territory. Increasing stroke size predicted progressive cortical but not pontine and thalamic involvement. Patients with new AF had more frequently lesions in the right insula compared to patients without AF when stroke size was not accounted for, but no specific brain region was more frequently involved after adjustment for infarct volume. Controlled for stroke size, left parietal involvement was less likely for patients with new AF than for those without AF or with known AF. Conclusions In the search for brain areas potentially triggering cardiac arrhythmias infarct size should be accounted for. After controlling for infarct size, there is currently no evidence that ischemic stroke lesions of specific brain areas are associated with new AF compared to patients without AF. This challenges the neurogenic hypothesis of AF according to which a relevant proportion of new AF is triggered by ischemic brain lesions of particular locations. PMID:28542605

Contrast-enhanced fluid-attenuated inversion recovery vs. contrast-enhanced spin echo T1-weighted brain imaging.

PubMed

Falzone, Cristian; Rossi, Federica; Calistri, Maurizio; Tranquillo, Massimo; Baroni, Massimo

2008-01-01

In humans, contrast-enhanced fluid-attenuated inversion recovery (FLAIR) imaging plays an important role in detecting brain disease. The aim of this study was to define the clinical utility of contrast-enhanced FLAIR imaging by comparing the results with those with contrast-enhanced spin echo T1-weighted images (SE T1WI) in animals with different brain disorders. Forty-one dogs and five cats with a clinical suspicion of brain disease and 30 normal animals (25 dogs and five cats) were evaluated using a 0.2 T permanent magnet. Before contrast medium injection, spin echo T1-weighted, SE T1WI, and FLAIR sequences were acquired in three planes. SE T1WI and FLAIR images were also acquired after gadolinium injection. Sensitivity in detecting the number, location, margin, and enhancement pattern and rate were evaluated. No lesions were found in a normal animal. In affected animals, 48 lesions in 34 patients were detected in contrast-enhanced SE T1WI whereas 81 lesions in 44 patients were detected in contrast-enhanced FLAIR images. There was no difference in the characteristics of the margins or enhancement pattern of the detected lesions. The objective enhancement rate, the mean value between lesion-to-white matter ratio and lesion-to-gray matter ratio, although representing an overlap of T1 and T2 effects and not pure contrast medium shortening of T1 relaxation, was better in contrast-enhanced FLAIR images. These results suggest a superiority of contrast-enhanced FLAIR images as compared with contrast-enhanced SE T1WI in detecting enhancing brain lesions.

Hypothalamic tumors impact gray and white matter volumes in fronto-limbic brain areas.

PubMed

Özyurt, Jale; Müller, Hermann L; Warmuth-Metz, Monika; Thiel, Christiane M

2017-04-01

Patients with hypothalamic involvement of a sellar/parasellar tumor often suffer from cognitive and social-emotional deficits that a lesion in the hypothalamus cannot fully explain. It is conceivable that these deficits are partly due to distal changes in hypothalamic networks, evolving secondary to a focal lesion. Focusing on childhood-onset craniopharyngioma patients, we aimed at investigating the impact of hypothalamic lesions on gray and white matter areas densely connected to the hypothalamus, and to relate structural changes to neuropsychological deficits frequently observed in patients. We performed a voxel-based morphometric analysis based on data of 11 childhood-onset craniopharyngioma patients with hypothalamic tumor involvement, and 18 healthy controls (median age: 17.2 and 17.4 yrs.). Whole-brain analyses were used to test for volumetric differences between the groups (T-tests) and subsequent regression analyses were used to correlate neuropsychological performance with gray and white matter volumes within the patient group. Patients compared to controls had significantly reduced gray matter volumes in areas of the anterior and posterior limbic subsystems which are densely connected with the hypothalamus. In addition, a reduction in white matter volumes was observed in tracts connecting the hypothalamus to other limbic areas. Worse long-term memory retrieval was correlated with smaller gray matter volumes in the posterior cingulate cortex. Our data provide the first evidence that hypothalamic tumor involvement impacts gray and white matter volumes in limbic areas, outside the area of tumor growth. Notably, the functional range of the two limbic subsystems affected, strikingly parallels the two major domains of psychological complaints in patients i.e., deficits in episodic memory and in socio-emotional functioning. We suggest that focal hypothalamic lesions may trigger distal changes in connected brain areas, which then contribute to the impairments in cognitive, social and emotional performance often observable in patients, and not explicable by a hypothalamic lesion alone. Copyright © 2017 Elsevier Ltd. All rights reserved.

Focal stimulation of the brain by entirely extracranial means. An example of radiation controlled focal pharmacology

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

Remler, M.P.

A method for focal stimulation of the brain by entirely extracranial means is presented. A focal x ray lesion of cortex was made that reduces the blood-brain barrier in that area. Then parenteral penicillin was administered. Penicillin is primarily confined to the vascular space by the blood-brain barrier in all parts of the brain except for some leakage into the brain at higher doses. An increased concentration of penicillin is created in the irradiated cortex. The penicillin creates a focal epileptic lesion in the irradiated area. This is an example of radiation-controlled focal pharmacology in the central nervous system. (auth)

Oxidative Glial Cell Damage Associated with White Matter Lesions in the Aging Human Brain

PubMed Central

Al-Mashhadi, Sufana; Simpson, Julie E.; Heath, Paul R.; Dickman, Mark; Forster, Gillian; Matthews, Fiona E.; Brayne, Carol; Ince, Paul G.; Wharton, Stephen B.

2016-01-01

White matter lesions (WML) are common in brain aging and are associated with dementia. We aimed to investigate whether oxidative DNA damage and occur in WML and in apparently normal white matter in cases with lesions. Tissue from WML and control white matter from brains with lesions (controls lesional) and without lesions (controls non-lesional) were obtained, using post-mortem magnetic resonance imaging-guided sampling, from the Medical Research Council Cognitive Function and Ageing Study. Oxidative damage was assessed by immunohistochemistry to 8-hydroxy-2′-deoxoguanosine (8-OHdG) and Western blotting for malondialdehyde. DNA response was assessed by phosphorylated histone H2AX (γH2AX), p53, senescence markers and by quantitative Reverse transcription polymerase chain reaction (RT-PCR) panel for candidate DNA damage-associated genes. 8-OHdG was expressed in glia and endothelium, with increased expression in both WML and controls lesional compared with controls non-lesional (P < 0.001). γH2Ax showed a similar, although attenuated difference among groups (P = 0.03). Expression of senescence-associated β-galactosidase and p16 suggested induction of senescence mechanisms in glia. Oxidative DNA damage and a DNA damage response are features of WML pathogenesis and suggest candidate mechanisms for glial dysfunction. Their expression in apparently normal white matter in cases with WML suggests that white matter dysfunction is not restricted to lesions. The role of this field-effect lesion pathogenesis and cognitive impairment are areas to be defined. PMID:25311358

Effects of white matter lesions on brain perfusion in patients with mild cognitive impairment.

PubMed

Ishibashi, Masato; Kimura, Noriyuki; Aso, Yasuhiro; Matsubara, Etsuro

2018-05-01

To evaluate the effects of white matter lesions on regional cerebral blood flow in subjects with amnestic mild cognitive impairment. Seventy-five subjects with mild cognitive impairment (36 men and 39 women; mean age, 78.1 years) were included in the study. We used the Mini-Mental State Examination to assess cognitive function. All subjects underwent brain magnetic resonance imaging and 99m Tc ethylcysteinate dimer single photon emission computed tomography. Subjects were stratified based on the presence or absence of white matter lesions on magnetic resonance imaging. Statistical parametric mapping of differences in regional cerebral blood flow between the two groups were assessed by voxel-by-voxel group analysis using SPM8. Of all 75 subjects with mild cognitive impairment, 46 (61.3%) had mild to moderate white matter lesions. The prevalence of hypertension tended to be higher in subjects with white matter lesions than in those without white matter lesions. Mini-Mental State Examination scores were significantly lower in subjects with white matter lesions than in those without white matter lesions. Subjects with white matter lesions had decreased regional cerebral blood flow mainly in the frontal, parietal, and medial temporal lobes, as well as the putamen, compared to those without white matter lesions. In subjects with mild cognitive impairment, white matter lesions were associated with cognitive impairment and mainly frontal lobe brain function. Copyright © 2018 Elsevier B.V. All rights reserved.

Reproducibility of Ultrasound-Guided High Intensity Focused Ultrasound (HIFU) Thermal Lesions in Minimally-Invasive Brain Surgery

NASA Astrophysics Data System (ADS)

Zahedi, Sulmaz

This study aims to prove the feasibility of using Ultrasound-Guided High Intensity Focused Ultrasound (USg-HIFU) to create thermal lesions in neurosurgical applications, allowing for precise ablation of brain tissue, while simultaneously providing real time imaging. To test the feasibility of the system, an optically transparent HIFU compatible tissue-mimicking phantom model was produced. USg-HIFU was then used for ablation of the phantom, with and without targets. Finally, ex vivo lamb brain tissue was imaged and ablated using the USg-HIFU system. Real-time ultrasound images and videos obtained throughout the ablation process showing clear lesion formation at the focal point of the HIFU transducer. Post-ablation gross and histopathology examinations were conducted to verify thermal and mechanical damage in the ex vivo lamb brain tissue. Finally, thermocouple readings were obtained, and HIFU field computer simulations were conducted to verify findings. Results of the study concluded reproducibility of USg-HIFU thermal lesions for neurosurgical applications.

Traumatic axonal injury: the prognostic value of lesion load in corpus callosum, brain stem, and thalamus in different magnetic resonance imaging sequences.

PubMed

Moen, Kent G; Brezova, Veronika; Skandsen, Toril; Håberg, Asta K; Folvik, Mari; Vik, Anne

2014-09-01

The aim of this study was to explore the prognostic value of visible traumatic axonal injury (TAI) loads in different MRI sequences from the early phase after adjusting for established prognostic factors. Likewise, we sought to explore the prognostic role of early apparent diffusion coefficient (ADC) values in normal-appearing corpus callosum. In this prospective study, 128 patients (mean age, 33.9 years; range, 11-69) with moderate (n = 64) and severe traumatic brain injury (TBI) were examined with MRI at a median of 8 days (range, 0-28) postinjury. TAI lesions in fluid-attenuated inversion recovery (FLAIR), diffusion-weighted imaging (DWI), and T2*-weighted gradient echo (T2*GRE) sequences were counted and FLAIR lesion volumes estimated. In patients and 47 healthy controls, mean ADC values were computed in 10 regions of interests in the normal-appearing corpus callosum. Outcome measure was the Glasgow Outcome Scale-Extended (GOS-E) at 12 months. In patients with severe TBI, number of DWI lesions and volume of FLAIR lesions in the corpus callosum, brain stem, and thalamus predicted outcome in analyses with adjustment for age, Glasgow Coma Scale score, and pupillary dilation (odds ratio, 1.3-6.9; p = <0.001-0.017). The addition of Rotterdam CT score and DWI lesions in the corpus callosum yielded the highest R2 (0.24), compared to all other MRI variables, including brain stem lesions. For patients with moderate TBI only the number of cortical contusions (p = 0.089) and Rotterdam CT score (p = 0.065) tended to predict outcome. Numbers of T2*GRE lesions did not affect outcome. Mean ADC values in the normal-appearing corpus callosum did not differ from controls. In conclusion, the loads of visible TAI lesions in the corpus callosum, brain stem, and thalamus in DWI and FLAIR were independent prognostic factors in patients with severe TBI. DWI lesions in the corpus callosum were the most important predictive MRI variable. Interestingly, number of cortical contusions in MRI and CT findings seemed more important for patients with moderate TBI.

Frameless Stereotactic Insertion of Viewsite Brain Access System with Microscope-Mounted Tracking Device for Resection of Deep Brain Lesions: Technical Report

PubMed Central

Chakraborty, Shamik; Lall, Rohan; Fanous, Andrew A; Boockvar, John; Langer, David J

2017-01-01

The surgical management of deep brain tumors is often challenging due to the limitations of stereotactic needle biopsies and the morbidity associated with transcortical approaches. We present a novel microscopic navigational technique utilizing the Viewsite Brain Access System (VBAS) (Vycor Medical, Boca Raton, FL, USA) for resection of a deep parietal periventricular high-grade glioma as well as another glioma and a cavernoma with no related morbidity. The approach utilized a navigational tracker mounted on a microscope, which was set to the desired trajectory and depth. It allowed gentle continuous insertion of the VBAS directly to a deep lesion under continuous microscopic visualization, increasing safety by obviating the need to look up from the microscope and thus avoiding loss of trajectory. This technique has broad value for the resection of a variety of deep brain lesions. PMID:28331774

Frameless Stereotactic Insertion of Viewsite Brain Access System with Microscope-Mounted Tracking Device for Resection of Deep Brain Lesions: Technical Report.

PubMed

White, Tim; Chakraborty, Shamik; Lall, Rohan; Fanous, Andrew A; Boockvar, John; Langer, David J

2017-02-04

The surgical management of deep brain tumors is often challenging due to the limitations of stereotactic needle biopsies and the morbidity associated with transcortical approaches. We present a novel microscopic navigational technique utilizing the Viewsite Brain Access System (VBAS) (Vycor Medical, Boca Raton, FL, USA) for resection of a deep parietal periventricular high-grade glioma as well as another glioma and a cavernoma with no related morbidity. The approach utilized a navigational tracker mounted on a microscope, which was set to the desired trajectory and depth. It allowed gentle continuous insertion of the VBAS directly to a deep lesion under continuous microscopic visualization, increasing safety by obviating the need to look up from the microscope and thus avoiding loss of trajectory. This technique has broad value for the resection of a variety of deep brain lesions.

Emotional reactions in patients after frontal lobe stroke.

PubMed

Stojanović, Zlatan; Stojanović, Sanja Vukadinović

2015-09-01

Emotional reactions have been documented after tumor lesions and the other damages of the brain. The aim of this paper was to examine the correlation between frontal lobe lesions and emotional reactions in patients with stroke. The research included 118 patients after stroke. Lesion localization was defined on computed axial tomography records, whereas the area and perimeter of lesion were measured by AutoCAD 2004 software. Examinations by means of the Hamilton Rating Scale for Anxiety and Depression (HRSA and HRSD) were carried out 11-40 days after stroke. Statistic data were processed by simple linear/nonlinear regression, Cox's and the generalized linear model. A higher frequency of emotional reactions, i.e. anxiety, was determined in women after stroke (p = 0.024). A negative correlation between the lesion size and the intensity of anxiety manifestations was determined (Spearman's r = -0.297; p = 0.001). Anxiety was more frequent in patients with frontal lobe lesions in the dominant hemisphere (interaction: frontal lesion * hand dominant hemisphere, p = 0.017). Also, HRSD score values showed the tendency for lesser decline in case of greater frontal lobe lesions in relation to lesions of other regions of prosencephalon (interaction: frontal lesion * lesion area, p = 0.001). The results of this study indicate the correlation between evolutionary younger structures of the central nervous system and emotional reactions of man. Therefore, it is necessary to undertake proper early psychopharmacotherapy in the vulnerable group of patients.

Effect of intravenous gadolinium-DTPA on diffusion-weighted imaging of brain tumors: a short temporal interval assessment.

PubMed

Li, Xiang; Qu, Jin-Rong; Luo, Jun-Peng; Li, Jing; Zhang, Hong-Kai; Shao, Nan-Nan; Kwok, Keith; Zhang, Shou-Ning; Li, Yan-le; Liu, Cui-Cui; Zee, Chi-Shing; Li, Hai-Liang

2014-09-01

To determine the effect of intravenous administration of gadolinium (Gd) contrast medium (Gd-DTPA) on diffusion-weighted imaging (DWI) for the evaluation of normal brain parenchyma vs. brain tumor following a short temporal interval. Forty-four DWI studies using b values of 0 and 1000 s/mm(2) were performed before, immediately after, 1 min after, 3 min after, and 5 min after the administration of Gd-DTPA on 62 separate lesions including 15 meningioma, 17 glioma and 30 metastatic lesions. The signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and apparent diffusion coefficient (ADC) values of the brain tumor lesions and normal brain tissues were measured on pre- and postcontrast images. Statistical analysis using paired t-test between precontrast and postcontrast data were obtained on three brain tumors and normal brain tissue. The SNR and CNR of brain tumors and the SNR of normal brain tissue showed no statistical differences between pre- and postcontrast (P > 0.05). The ADC values on the three cases of brain tumors demonstrated significant initial increase on the immediate time point (P < 0.01) and decrease on following the 1 min time point (P < 0.01) after contrast. Significant decrease of ADC value was still found at 3min and 5min time point in the meningioma group (P < 0.01) with gradual normalization over time. The ADC values of normal brain tissues demonstrated significant initial elevation on the immediately postcontrast DWI sequence (P < 0.01). Contrast medium can cause a slight but statistically significant change on the ADC value within a short temporal interval after the contrast administration. The effect is both time and lesion-type dependent. © 2013 Wiley Periodicals, Inc.

miR-509 suppresses brain metastasis of breast cancer cells by modulating RhoC and TNF α

PubMed Central

Xing, Fei; Sharma, Sambad; Liu, Yin; Mo, Yin-Yuan; Wu, Kerui; Zhang, Ying-Yu; Pochampally, Radhika; Martinez, Luis A; Lo, Hui-wen; Watabe, Kounosuke

2014-01-01

The median survival time of breast cancer patients with brain metastasis is less than 6 months, and even a small metastatic lesion often causes severe neurological disabilities. Because of the location of metastatic lesions, a surgical approach is limited and most chemotherapeutic drugs are ineffective due to the blood brain barrier (BBB). Despite this clinical importance, the molecular basis of the brain metastasis is poorly understood. In this study, we have isolated RNA from samples obtained from primary breast tumors and also from brain metastatic lesions followed by microRNA profiling analysis. Our results revealed that the miR-509 is highly expressed in the primary tumors, while the expression of this microRNA is significantly decreased in the brain metastatic lesions. MicroRNA target prediction and the analysis of cytokine array for the cells ectopically expressed with miR-509 demonstrated that this microRNA was capable of modulating two genes essential for brain invasion, RhoC and TNFα that affect the invasion of cancer cells and permeability of BBB, respectively. Importantly, high levels of TNFα and RhoC-induced MMP9 were significantly correlated with brain metastasis-free survival of breast cancer patients. Furthermore, the results of our in vivo experiments indicate that miR-509 significantly suppressed the ability of cancer cells to metastasize to the brain. These findings suggest that miR-509 plays a critical role in brain metastasis of breast cancer by modulating the RhoC-TNFα network and that this miR-509 axis may represent a potential therapeutic target or serve as a prognostic tool for brain metastasis. PMID:25659578

Long-term survival in a patient with brain metastases of papillary thyroid carcinoma

PubMed Central

Guelho, Daniela; Ribeiro, Cristina; Melo, Miguel; Carrilho, Francisco

2016-01-01

We present the case of a 43-year-old woman who underwent total thyroidectomy with bilateral lymphadenectomy for a papillary thyroid carcinoma (PTC), solid variant (T4bN1bMx), with V600E BRAF mutation. After ablative therapy, she presented undetectable thyroglobulin (Tg) but progressively increasing anti-Tg antibodies (TgAbs). During follow-up, nodal, lung and brain metastases were identified. She was submitted to surgical excision of lung lesions, radiosurgery of brain metastases and five radioiodine treatments. The latest brain MRI showed no lesions, pulmonary CT showed stable micronodules and there was progressive reduction in TgAbs. This is a peculiar case of a PTC with lung and brain metastatic lesions detected through TgAbs. Initial histological and molecular study suggested a more aggressive clinical behaviour, which was eventually confirmed. Although PTC brain metastases are extremely rare and present poor prognosis, our patient presented a good response to treatment and longer survival than usually reported for similar cases. PMID:26961557

Scleroderma en coup de sabre with recurrent episodes of brain hemorrhage.

PubMed

Takahashi, Takehiro; Asano, Yoshihide; Oka, Tomonori; Miyagaki, Tomomitsu; Tamaki, Zenshiro; Nonaka, Senshu; Sato, Shinichi

2016-02-01

We report a 39-year-old man referred to our facility with linear sclerotic lesions along the several Blaschko's lines of the scalp. A year before the referral, he had had an episode of brain hemorrhage, although there was no evidence of vascular malformation or any other risk factors of brain hemorrhage for his young age. On the diagnosis of scleroderma en coup de sabre, prednisolone intake was initiated, and the skin lesions were well controlled. However, in the course of our follow up, he had another episode of brain hemorrhage, again without any evidence of cerebral vascular abnormalities. Organic intracranial abnormalities in this disease are well-documented, but there have been few reports on comorbid recurrent brain hemorrhages. We herein discuss the possible relationship of the skin lesions with the brain hemorrhages in our case, taking notice of the implication of developmental abnormalities behind these apparently independent phenomena inside and outside the cranium. © 2015 Japanese Dermatological Association.

Distinct frontal regions for processing sentence syntax and story grammar.

PubMed

Sirigu, A; Cohen, L; Zalla, T; Pradat-Diehl, P; Van Eeckhout, P; Grafman, J; Agid, Y

1998-12-01

Time is a fundamental dimension of cognition. It is expressed in the sequential ordering of individual elements in a wide variety of activities such as language, motor control or in the broader domain of long range goal-directed actions. Several studies have shown the importance of the frontal lobes in sequencing information. The question addressed in this study is whether this brain region hosts a single supramodal sequence processor, or whether separate mechanisms are required for different kinds of temporally organised knowledge structures such as syntax and action knowledge. Here we show that so-called agrammatic patients, with lesions in Broca's area, ordered word groups correctly to form a logical sequence of actions but they were severely impaired when similar word groups had to be ordered as a syntactically well-formed sentence. The opposite performance was observed in patients with dorsolateral prefrontal lesions, that is, while their syntactic processing was intact at the sentence level, they demonstrated a pronounced deficit in producing temporally coherent sequences of actions. Anatomical reconstruction of lesions from brain scans revealed that the sentence and action grammar deficits involved distinct, non-overlapping sites within the frontal lobes. Finally, in a third group of patients whose lesions encompassed both Broca's area and the prefrontal cortex, the two types of deficits were found. We conclude that sequence processing is specific to knowledge domains and involves different networks within the frontal lobes.

Different left brain regions are essential for grasping a tool compared with its subsequent use.

PubMed

Randerath, Jennifer; Goldenberg, Georg; Spijkers, Will; Li, Yong; Hermsdörfer, Joachim

2010-10-15

Tool use engages a left hemispheric network including frontal, temporal and parietal regions. Patients with left brain lesions (LBD patients) exhibit deficits when demonstrating use of a single tool (apraxia). When attempting to use a tool, some apraxic patients show errors in the preceding grasping movement. Forty-two LBD patients and 18 healthy controls grasped individual tools and demonstrated their typical use. For patients with a tool use impairment (22), lesion analysis revealed a large area of overlap in the left hemisphere, mainly in the supramarginal gyrus (SMG). For patients with erroneous grasping (12), the lesion overlay showed overlaps in the left frontal and parietal cortices, especially in the inferior frontal gyrus (IFG) and the angular gyrus (ANG). However, contrasting lesions associated with impaired grasping versus tool use impairments reveal little overlap, limited to the inferior parietal cortex. Presumably the left IFG is involved in selection processes in the context of tool use, such as choosing a functional or non-functional grasping movement depending on the task and the online information about the tool's structure and orientation. The ANG might provide this grasp related information, which is relevant for the specific action. The contribution of the SMG to tool use involves more general principals, such as integrating online and learned tool use information into the action plan for the use movement. Copyright 2010 Elsevier Inc. All rights reserved.

47-year-old man with left leg numbness.

PubMed

Mahta, Ali; Kim, Ryan Y; Saad, Ali G; Kesari, Santosh

2013-03-01

A 47-year-old white male with a history of uveitis, hypercalcemia and nephrolithiasis presented with acute onset partial seizure. On exam he had decreased sensation to light touch on his left lower extremity. A Brain MRI revealed a right frontal mass, which was initially thought to be a metastatic lesion or a primary brain tumor. However, biopsy of the lesion revealed it to be a non-caseating granulomatous lesion consistent with neurosarcoidosis.

Lesion localization of global aphasia without hemiparesis by overlapping of the brain magnetic resonance images

PubMed Central

Kim, Woo Jin; Paik, Nam-Jong

2014-01-01

Global aphasia without hemiparesis is a striking stroke syndrome involving language impairment without the typically manifested contralateral hemiparesis, which is usually seen in patients with global aphasia following large left perisylvian lesions. The objective of this study is to elucidate the specific areas for lesion localization of global aphasia without hemiparesis by retrospectively studying the brain magnetic resonance images of six patients with global aphasia without hemiparesis to define global aphasia without hemiparesis-related stroke lesions before overlapping the images to visualize the most overlapped area. Talairach coordinates for the most overlapped areas were converted to corresponding anatomical regions. Lesions where the images of more than three patients overlapped were considered significant. The overlapped global aphasia without hemiparesis related stroke lesions of six patients revealed that the significantly involved anatomical lesions were as follows: frontal lobe, sub-gyral, sub-lobar, extra-nuclear, corpus callosum, and inferior frontal gyrus, while caudate, claustrum, middle frontal gyrus, limbic lobe, temporal lobe, superior temporal gyrus, uncus, anterior cingulate, parahippocampal, amygdala, and subcallosal gyrus were seen less significantly involved. This study is the first to demonstrate the heterogeneous anatomical involvement in global aphasia without hemiparesis by overlapping of the brain magnetic resonance images. PMID:25657725

Cognitive timing: neuropsychology and anatomic basis.

PubMed

Coslett, H Branch; Shenton, Jeff; Dyer, Tamarah; Wiener, Martin

2009-02-13

We report data from 31 subjects with focal hemisphere lesions (15 left hemisphere) as well as 16 normal controls on a battery of tasks assessing the estimation, production and reproduction of time intervals ranging from 2-12 s. Both visual and auditory stimuli were employed for the estimation and production tasks. First, ANOVAs were performed to assess the effect of stimulus modality on estimation and production tasks; a significant effect of stimulus modality was observed for the production but not the estimation task. Second, accuracy was significantly different for the 2 s interval as compared to longer intervals. Subsequent analyses of the data from 4-12 s stimuli demonstrated that patients with brain lesions were more variable than controls on the estimation and reproduction tasks. Additionally, patients with brain lesions but not controls exhibited significant differences in performance on the different tasks; patients with brain lesions under-produced but over-estimated time intervals of 4-12 s but performed relatively well on the reproduction task, a pattern of performance consistent with a "fast clock". There was a significant correlation between impaired performance and lesions of the parietal lobe but there was no effect of laterality of lesion or correlation between lateral frontal lobe lesions and impairment on any task.

Language Development and Brain Magnetic Resonance Imaging Characteristics in Preschool Children With Cerebral Palsy.

PubMed

Choi, Ja Young; Choi, Yoon Seong; Park, Eun Sook

2017-05-24

The purpose of this study was to investigate characteristics of language development in relation to brain magnetic resonance imaging (MRI) characteristics and the other contributing factors to language development in children with cerebral palsy (CP). The study included 172 children with CP who underwent brain MRI and language assessments between 3 and 7 years of age. The MRI characteristics were categorized as normal, malformation, periventricular white matter lesion (PVWL), deep gray matter lesion, focal infarct, cortical/subcortical lesion, and others. Neurodevelopmental outcomes such as ambulatory status, manual ability, cognitive function, and accompanying impairments were assessed. Both receptive and expressive language development quotients (DQs) were significantly related to PVWL or deep gray matter lesion severity. In multivariable analysis, only cognitive function was significantly related to receptive language development, whereas ambulatory status and cognitive function were significantly associated with expressive language development. More than one third of the children had a language developmental discrepancy between receptive and expressive DQs. Children with cortical/subcortical lesions were at high risk for this discrepancy. Cognitive function is a key factor for both receptive and expressive language development. In children with PVWL or deep gray matter lesion, lesion severity seems to be useful to predict language development.

SU-G-BRC-14: Multi-Lesion, Multi-Rx, Brain Radiosurgery with Novel Single Isocenter Technique

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

Honig, N; Alani, S; Schlocker, A

Purpose: There is a strong trend to treat multiple brain metastases with radiosurgery rather than whole brain irradiation. This feasibility study investigates a novel planning technique for radio-surgical treatment of multiple brain lesions with differing dose prescriptions, a single isocenter, and dynamic conformal arcs. The novel technique will be compared to the well-established single-isocenter volumetric modulated arc therapy (VMAT) technique commonly used for treating brain lesions. Methods: Six patients with metastatic brain lesions were selected for a prospective treatment planning study to evaluate Interdigitating MLC Dynamic Conformal Arc (IMDCA) technique. Arcs were planned for simultaneous irradiation to maximize beam deliverymore » efficiency. To accommodate varying PTV dose prescriptions, selected arcs were re-irradiated in reverse. Beam weights were adjusted until all prescription constraints were met. The number of lesions ranged between 2 to 4 (mode = 3). For comparison, SRS VMAT plans were generated utilizing an established single-isocenter, 3 arc planning template. All plans were compared by means of Paddick conformity index (PCI), RTOG Conformity Index (RCI), gradient index (GI), and the normal brain volume receiving 10% (V10) of the highest prescription dose. The monitor units and delivery time were tabulated for each plan. Results: IMDCA achieved conformal plans (PCI = 0.72±0.03, RCI = 1.33±0.03) with steep dose fall-off (GI = 3.79±0.03) on average for all of the plans evaluated. The VMAT plans had slightly better conformity (PCI = 0.85 ± 0.03, RCI = 1.13 ± 0.03) than IMDCA, but overall worse GI (4.29 ± 0.06). IMDCA plans had lower V10% values, required 50% fewer MUs, and had 34% shorter beam delivery time on average compared to VMAT plans. Conclusion: IMDCA plans with varying dose prescriptions for multiple lesions, had comparable dosimetric coverage as VMAT plans, but were obtained with significantly lower integral dose, fewer monitor units, and quicker delivery time.« less

Intraoperative visualisation of functional structures facilitates safe frameless stereotactic biopsy in the motor eloquent regions of the brain.

PubMed

Zhang, Jia-Shu; Qu, Ling; Wang, Qun; Jin, Wei; Hou, Yuan-Zheng; Sun, Guo-Chen; Li, Fang-Ye; Yu, Xin-Guang; Xu, Ban-Nan; Chen, Xiao-Lei

2017-12-20

For stereotactic brain biopsy involving motor eloquent regions, the surgical objective is to enhance diagnostic yield and preserve neurological function. To achieve this aim, we implemented functional neuro-navigation and intraoperative magnetic resonance imaging (iMRI) into the biopsy procedure. The impact of this integrated technique on the surgical outcome and postoperative neurological function was investigated and evaluated. Thirty nine patients with lesions involving motor eloquent structures underwent frameless stereotactic biopsy assisted by functional neuro-navigation and iMRI. Intraoperative visualisation was realised by integrating anatomical and functional information into a navigation framework to improve biopsy trajectories and preserve eloquent structures. iMRI was conducted to guarantee the biopsy accuracy and detect intraoperative complications. The perioperative change of motor function and biopsy error before and after iMRI were recorded, and the role of functional information in trajectory selection and the relationship between the distance from sampling site to nearby eloquent structures and the neurological deterioration were further analyzed. Functional neuro-navigation helped modify the original trajectories and sampling sites in 35.90% (16/39) of cases to avoid the damage of eloquent structures. Even though all the lesions were high-risk of causing neurological deficits, no significant difference was found between preoperative and postoperative muscle strength. After data analysis, 3mm was supposed to be the safe distance for avoiding transient neurological deterioration. During surgery, the use of iMRI significantly reduced the biopsy errors (p = 0.042) and potentially increased the diagnostic yield from 84.62% (33/39) to 94.87% (37/39). Moreover, iMRI detected intraoperative haemorrhage in 5.13% (2/39) of patients, all of them benefited from the intraoperative strategies based on iMRI findings. Intraoperative visualisation of functional structures could be a feasible, safe and effective technique. Combined with intraoperative high-field MRI, it contributed to enhance the biopsy accuracy and lower neurological complications in stereotactic brain biopsy involving motor eloquent areas.

Nonthermal ablation in the rat brain using focused ultrasound and an ultrasound contrast agent: long-term effects

PubMed Central

McDannold, Nathan; Zhang, Yongzhi; Vykhodtseva, Natalia

2016-01-01

OBJECTIVE Thermal ablation with transcranial MRI-guided focused ultrasound (FUS) is currently under investigation as a less invasive alternative to radiosurgery and resection. A major limitation of the method is that its use is currently restricted to centrally located brain targets. The combination of FUS and a microbubble-based ultrasound contrast agent greatly reduces the ultrasound exposure level needed to ablate brain tissue and could be an effective means to increase the “treatment envelope” for FUS in the brain. This method, however, ablates tissue through a different mechanism: destruction of the microvasculature. It is not known whether nonthermal FUS ablation in substantial volumes of tissue can safely be performed without unexpected effects. The authors investigated this question by ablating volumes in the brains of normal rats. METHODS Overlapping sonications were performed in rats (n = 15) to ablate a volume in 1 hemisphere per animal. The sonications (10-msec bursts at 1 Hz for 60 seconds; peak negative pressure 0.8 MPa) were combined with the ultrasound contrast agent Optison (100 μl/kg). The rats were followed with MRI for 4–9 weeks after FUS, and the brains were examined with histological methods. RESULTS Two weeks after sonication and later, the lesions appeared as cyst-like areas in T2-weighted MR images that were stable over time. Histological examination demonstrated well-defined lesions consisting of a cyst-like cavity that remained lined by astrocytic tissue. Some white matter structures within the sonicated area were partially intact. CONCLUSIONS The results of this study indicate that nonthermal FUS ablation can be used to safely ablate tissue volumes in the brain without unexpected delayed effects. The findings are encouraging for the use of this ablation method in the brain. PMID:26848919

Effect of motor imagery in children with unilateral cerebral palsy: fMRI study.

PubMed

Chinier, Eva; N'Guyen, Sylvie; Lignon, Grégoire; Ter Minassian, Aram; Richard, Isabelle; Dinomais, Mickaël

2014-01-01

Motor imagery is considered as a promising therapeutic tool for rehabilitation of motor planning problems in patients with cerebral palsy. However motor planning problems may lead to poor motor imagery ability. The aim of this functional magnetic resonance imaging study was to examine and compare brain activation following motor imagery tasks in patients with hemiplegic cerebral palsy with left or right early brain lesions. We tested also the influence of the side of imagined hand movement. Twenty patients with clinical hemiplegic cerebral palsy (sixteen males, mean age 12 years and 10 months, aged 6 years 10 months to 20 years 10 months) participated in this study. Using block design, brain activations following motor imagery of a simple opening-closing hand movement performed by either the paretic or nonparetic hand was examined. During motor imagery tasks, patients with early right brain damages activated bilateral fronto-parietal network that comprise most of the nodes of the network well described in healthy subjects. Inversely, in patients with left early brain lesion brain activation following motor imagery tasks was reduced, compared to patients with right brain lesions. We found also a weak influence of the side of imagined hand movement. Decreased activations following motor imagery in patients with right unilateral cerebral palsy highlight the dominance of the left hemisphere during motor imagery tasks. This study gives neuronal substrate to propose motor imagery tasks in unilateral cerebral palsy rehabilitation at least for patients with right brain lesions.

Lesion Mapping the Four-Factor Structure of Emotional Intelligence

PubMed Central

Operskalski, Joachim T.; Paul, Erick J.; Colom, Roberto; Barbey, Aron K.; Grafman, Jordan

2015-01-01

Emotional intelligence (EI) refers to an individual’s ability to process and respond to emotions, including recognizing the expression of emotions in others, using emotions to enhance thought and decision making, and regulating emotions to drive effective behaviors. Despite their importance for goal-directed social behavior, little is known about the neural mechanisms underlying specific facets of EI. Here, we report findings from a study investigating the neural bases of these specific components for EI in a sample of 130 combat veterans with penetrating traumatic brain injury. We examined the neural mechanisms underlying experiential (perceiving and using emotional information) and strategic (understanding and managing emotions) facets of EI. Factor scores were submitted to voxel-based lesion symptom mapping to elucidate their neural substrates. The results indicate that two facets of EI (perceiving and managing emotions) engage common and distinctive neural systems, with shared dependence on the social knowledge network, and selective engagement of the orbitofrontal and parietal cortex for strategic aspects of emotional information processing. The observed pattern of findings suggests that sub-facets of experiential and strategic EI can be characterized as separable but related processes that depend upon a core network of brain structures within frontal, temporal and parietal cortex. PMID:26858627

Brain and lung metastasis of alveolar echinococcosis in a refugee from a hyperendemic area.

PubMed

Tappe, Dennis; Weise, David; Ziegler, Uwe; Müller, Andreas; Müllges, Wolfgang; Stich, August

2008-11-01

Alveolar echinococcosis (AE) of the liver with cerebral and pulmonary metastasis was diagnosed in a Tibetan monk who initially presented with severe headache to an emergency department in Germany. Multiple lesions with perifocal oedema and severe compression of the third ventricle were seen with computed tomography (CT) of the brain. Glioma or cerebral metastasis of a hitherto undiagnosed abdominal or pulmonary malignancy was suspected. CT scans of the lung and liver demonstrated further tumorous masses. Magnetic resonance imaging of the brain revealed the cystic nature of the cerebral lesions and the patient had a highly positive serology for AE. The echinococcal aetiology of the brain lesions was confirmed by PCR for this refugee from an area where two disease entities, AE and cystic echinococcosis, are hyperendemic.

Optical imaging of cell death in traumatic brain injury using a heat shock protein-90 alkylator

PubMed Central

Xie, B-W; Park, D; Van Beek, E R; Blankevoort, V; Orabi, Y; Que, I; Kaijzel, E L; Chan, A; Hogg, P J; Löwik, C W G M

2013-01-01

Traumatic brain injury is a major public health concern and is characterised by both apoptotic and necrotic cell death in the lesion. Anatomical imaging is usually used to assess traumatic brain injuries and there is a need for imaging modalities that provide complementary cellular information. We sought to non-invasively image cell death in a mouse model of traumatic brain injury using a near-infrared fluorescent conjugate of a synthetic heat shock protein-90 alkylator, 4-(N-(S-glutathionylacetyl) amino) phenylarsonous acid (GSAO). GSAO labels both apoptotic and necrotic cells coincident with loss of plasma membrane integrity. The optical GSAO specifically labelled apoptotic and necrotic cells in culture and did not accumulate in healthy organs or tissues in the living mouse body. The conjugate is a very effective imager of cell death in brain lesions. The optical GSAO was detected by fluorescence intensity and GSAO bound to dying/dead cells was detected from prolongation of the fluorescence lifetime. An optimal signal-to-background ratio was achieved as early as 3 h after injection of the probe and the signal intensity positively correlated with both lesion size and probe concentration. This optical GSAO offers a convenient and robust means to non-invasively image apoptotic and necrotic cell death in brain and other lesions. PMID:23348587

An age-related change in susceptibility of rat brain to encephalomyocarditis virus infection

PubMed Central

IKEGAMI, HISASHI; TAKEDA, MAKIO; DOI, KUNIO

1997-01-01

Rats were inoculated intraperitoneally (i.p.) or intracerebrally (i.c.) with 1 × 104 plaque forming units (PFU)/animal of the D variant of encephalomyocarditis virus (EMC-D) at 2, 4, 7, 14, 28 or 56 days of age for virological and histopathological examination. In the i.p.-inoculation study, neither viral replication nor lesions were detected in the animals inoculated at 28 and 56 days of age. In the animals inoculated when younger than 14 days of age, lesions were restricted to the brain although viral replication was detected in the brain, heart and pancreas. The brain lesions were characterized by acute meningoencephalitis with neuronal necrosis in the cerebral cortex, hippocampus and thalamus, and viral RNA was detected in degenerated and/or intact neurons. In the i.c.-inoculation study, similar age-related changes in susceptibility of rat brain to EMC-D infection were observed, but a minor difference was that viral replication and lesions were still detected in the hippocampus of some animals inoculated at 28 days of age. These results suggest that an age-related decrease in the susceptibility of rat brain to EMC virus infection may reflect an age-related change in the susceptibility of neurons themselves as well as in maturation of the immune system. PMID:9203984

Modeling Brain Dynamics in Brain Tumor Patients Using the Virtual Brain.

PubMed

Aerts, Hannelore; Schirner, Michael; Jeurissen, Ben; Van Roost, Dirk; Achten, Eric; Ritter, Petra; Marinazzo, Daniele

2018-01-01

Presurgical planning for brain tumor resection aims at delineating eloquent tissue in the vicinity of the lesion to spare during surgery. To this end, noninvasive neuroimaging techniques such as functional MRI and diffusion-weighted imaging fiber tracking are currently employed. However, taking into account this information is often still insufficient, as the complex nonlinear dynamics of the brain impede straightforward prediction of functional outcome after surgical intervention. Large-scale brain network modeling carries the potential to bridge this gap by integrating neuroimaging data with biophysically based models to predict collective brain dynamics. As a first step in this direction, an appropriate computational model has to be selected, after which suitable model parameter values have to be determined. To this end, we simulated large-scale brain dynamics in 25 human brain tumor patients and 11 human control participants using The Virtual Brain, an open-source neuroinformatics platform. Local and global model parameters of the Reduced Wong-Wang model were individually optimized and compared between brain tumor patients and control subjects. In addition, the relationship between model parameters and structural network topology and cognitive performance was assessed. Results showed (1) significantly improved prediction accuracy of individual functional connectivity when using individually optimized model parameters; (2) local model parameters that can differentiate between regions directly affected by a tumor, regions distant from a tumor, and regions in a healthy brain; and (3) interesting associations between individually optimized model parameters and structural network topology and cognitive performance.

Imaging Effects of Neurotrophic Factor Genes on Brain Plasticity and Repair in Multiple Sclerosis

DTIC Science & Technology

2011-07-01

focal and diffuse effects in brain (including cortical thickness and subcortical volume measures, lesion volumetry , and voxel-based morphometry and...to both focal and diffuse effects in gray and white matter, including cortical thickness and subcortical volume measures, lesion volumetry , and

Narrative discourse in children with early focal brain injury.

PubMed

Reilly, J S; Bates, E A; Marchman, V A

1998-02-15

Children with early brain damage, unlike adult stroke victims, often go on to develop nearly normal language. However, the route and extent of their linguistic development are still unclear, as is the relationship between lesion site and patterns of delay and recovery. Here we address these questions by examining narratives from children with early brain damage. Thirty children (ages 3:7-10:10) with pre- or perinatal unilateral focal brain damage and their matched controls participated in a storytelling task. Analyses focused on linguistic proficiency and narrative competence. Overall, children with brain damage scored significantly lower than their age-matched controls on both linguistic (morphological and syntactic) indices and those targeting broader narrative qualities. Rather than indicating that children with brain damage fully catch up, these data suggest that deficits in linguistic abilities reassert themselves as children face new linguistic challenges. Interestingly, after age 5, site of lesion does not appear to be a significant factor and the delays we have witnessed do not map onto the lesion profiles observed in adults with analogous brain injuries.

Poor Brain Growth in Extremely Preterm Neonates Long Before the Onset of Autism Spectrum Disorder Symptoms.

PubMed

Padilla, Nelly; Eklöf, Eva; Mårtensson, Gustaf E; Bölte, Sven; Lagercrantz, Hugo; Ådén, Ulrika

2017-02-01

Preterm infants face an increased risk of autism spectrum disorder (ASD). The relationship between autism during childhood and early brain development remains unexplored. We studied 84 preterm children born at <27 weeks of gestation, who underwent neonatal magnetic resonance imaging (MRI) at term and were screened for ASD at 6.5 years. Full-scale intelligence quotient was measured and neonatal morbidities were recorded. Structural brain morphometric studies were performed in 33 infants with high-quality MRI and no evidence of focal brain lesions. Twenty-three (27.4%) of the children tested ASD positive and 61 (72.6%) tested ASD negative. The ASD-positive group had a significantly higher frequency of neonatal complications than the ASD-negative group. In the subgroup of 33 children, the ASD infants had reduced volumes in the temporal, occipital, insular, and limbic regions and in the brain areas involved in social/behavior and salience integration. This study shows that the neonatal MRI scans of extremely preterm children, subsequently diagnosed with ASD at 6.5 years, showed brain structural alterations, localized in the regions that play a key role in the core features of autism. Early detection of these structural alterations may allow the early identification and intervention of children at risk of ASD. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Reversible lesions in the brain parenchyma in Wilson's disease confirmed by magnetic resonance imaging: earlier administration of chelating therapy can reduce the damage to the brain.

PubMed

Kozić, Duško B; Petrović, Igor; Svetel, Marina; Pekmezović, Tatjana; Ragaji, Aleksandar; Kostić, Vladimir S

2014-11-01

The aim of this study was to evaluate the resolution of brain lesions in patients with Wilson's disease during the long-term chelating therapy using magnetic resonance imaging and a possible significance of the time latency between the initial symptoms of the disease and the introduction of this therapy. Initial magnetic resonance examination was performed in 37 patients with proven neurological form of Wilson's disease with cerebellar, parkinsonian and dystonic presentation. Magnetic resonance reexamination was done 5.7 ± 1.3 years later in 14 patients. Patients were divided into: group A, where chelating therapy was initiated < 24 months from the first symptoms and group B, where the therapy started ≥ 24 months after the initial symptoms. Symmetry of the lesions was seen in 100% of patients. There was a significant difference between groups A and B regarding complete resolution of brain stem and putaminal lesions (P = 0.005 and P = 0.024, respectively). If the correct diagnosis and adequate treatment are not established less than 24 months after onset of the symptoms, irreversible lesions in the brain parenchyma could be expected. Signal abnormalities on magnetic resonance imaging might therefore, at least in the early stages, represent reversible myelinolisis or cytotoxic edema associated with copper toxicity.

Cognitive impairment in neuromyelitis optica spectrum disorders: A comparison of the Wechsler Adult Intelligence Scale-III and the Wechsler Memory Scale Revised with the Rao Brief Repeatable Neuropsychological Battery.

PubMed

Fujimori, Juichi; Nakashima, Ichiro; Baba, Toru; Meguro, Yuko; Ogawa, Ryo; Fujihara, Kazuo

2017-12-01

Approximately 55% of patients with neuromyelitis optica spectrum disorder (NMOSD) show cognitive impairment as evaluated using the Rao Brief Repeatable Neuropsychological Battery (BRBN), but this frequency appears to be higher than the frequency of specific brain lesions in NMOSD. We studied whether cognitive impairment could be observed in NMOSD patients with no or minor non-specific brain lesions. We evaluated cognitive function in 12 NMOSD and 14 MS patients using the Wechsler Adult Intelligence Scale-III (WAIS-III), the Wechsler Memory Scale-Revised (WMS-R), and the BRBN. We judged as cognitively impaired patients whose scores were below the average by 2 standard deviations or greater in 2 or more cognitive domains. Cognitive impairment was observed in 5 MS patients (35.7%) and in the only NMOSD patient (8.3%) with symptomatic brain lesions, but not in the other NMOSD patients who had no or minor non-specific brain lesions. Meanwhile, 5 NMOSD (41.7%) and 4 MS (28.6%) patients who had normal cognition according to the WAIS-III and WMS-R were assessed as cognitively impaired by the BRBN (which is not standardized for age). Cognitive function in NMOSD patients with no or mild non-specific brain lesions was preserved according to the WAIS-III and WMS-R.

Nuclear microscopy in Parkinson's disease

NASA Astrophysics Data System (ADS)

Watt, F.; Lee, T.; Thong, P. S. P.; Tang, S. M.

1995-09-01

Rats have been subjected to unilateral lesioning with the selective neurotoxin 6-OHDA in order to induce Parkinsonism. Analysis using the NUS Nuclear Microscope facility have shown that iron levels are raised by an average of 26% in the lesioned subtantia nigra region of the brain compared with the non-lesioned side. In addition the background tissue level of iron is also elevated by 31% in the lesioned side, indicating that there is a general increase in iron levels as a result of the lesioning. This result is consistent with the other observations that other diseases of the brain are frequently associated with altered iron levels (eg. progressive nuclear palsy, multiple system atrophy, Alzheimers disease, multiple sclerosis).

Nonthermal ablation with microbubble-enhanced focused ultrasound close to the optic tract without affecting nerve function.

PubMed

McDannold, Nathan; Zhang, Yong-Zhi; Power, Chanikarn; Jolesz, Ferenc; Vykhodtseva, Natalia

2013-11-01

Tumors at the skull base are challenging for both resection and radiosurgery given the presence of critical adjacent structures, such as cranial nerves, blood vessels, and brainstem. Magnetic resonance imaging-guided thermal ablation via laser or other methods has been evaluated as a minimally invasive alternative to these techniques in the brain. Focused ultrasound (FUS) offers a noninvasive method of thermal ablation; however, skull heating limits currently available technology to ablation at regions distant from the skull bone. Here, the authors evaluated a method that circumvents this problem by combining the FUS exposures with injected microbubble-based ultrasound contrast agent. These microbubbles concentrate the ultrasound-induced effects on the vasculature, enabling an ablation method that does not cause significant heating of the brain or skull. In 29 rats, a 525-kHz FUS transducer was used to ablate tissue structures at the skull base that were centered on or adjacent to the optic tract or chiasm. Low-intensity, low-duty-cycle ultrasound exposures (sonications) were applied for 5 minutes after intravenous injection of an ultrasound contrast agent (Definity, Lantheus Medical Imaging Inc.). Using histological analysis and visual evoked potential (VEP) measurements, the authors determined whether structural or functional damage was induced in the optic tract or chiasm. Overall, while the sonications produced a well-defined lesion in the gray matter targets, the adjacent tract and chiasm had comparatively little or no damage. No significant changes (p > 0.05) were found in the magnitude or latency of the VEP recordings, either immediately after sonication or at later times up to 4 weeks after sonication, and no delayed effects were evident in the histological features of the optic nerve and retina. This technique, which selectively targets the intravascular microbubbles, appears to be a promising method of noninvasively producing sharply demarcated lesions in deep brain structures while preserving function in adjacent nerves. Because of low vascularity--and thus a low microbubble concentration--some large white matter tracts appear to have some natural resistance to this type of ablation compared with gray matter. While future work is needed to develop methods of monitoring the procedure and establishing its safety at deep brain targets, the technique does appear to be a potential solution that allows FUS ablation of deep brain targets while sparing adjacent nerve structures.

Nonthermal ablation with microbubble-enhanced focused ultrasound close to the optic tract without affecting nerve function

PubMed Central

McDannold, Nathan; Zhang, Yong-Zhi; Power, Chanikarn; Jolesz, Ferenc; Vykhodtseva, Natalia

2014-01-01

Object Tumors at the skull base are challenging for both resection and radiosurgery given the presence of critical adjacent structures, such as cranial nerves, blood vessels, and brainstem. Magnetic resonance imaging–guided thermal ablation via laser or other methods has been evaluated as a minimally invasive alternative to these techniques in the brain. Focused ultrasound (FUS) offers a noninvasive method of thermal ablation; however, skull heating limits currently available technology to ablation at regions distant from the skull bone. Here, the authors evaluated a method that circumvents this problem by combining the FUS exposures with injected microbubble-based ultrasound contrast agent. These microbubbles concentrate the ultrasound-induced effects on the vasculature, enabling an ablation method that does not cause significant heating of the brain or skull. Methods In 29 rats, a 525-kHz FUS transducer was used to ablate tissue structures at the skull base that were centered on or adjacent to the optic tract or chiasm. Low-intensity, low-duty-cycle ultrasound exposures (sonications) were applied for 5 minutes after intravenous injection of an ultrasound contrast agent (Definity, Lantheus Medical Imaging Inc.). Using histological analysis and visual evoked potential (VEP) measurements, the authors determined whether structural or functional damage was induced in the optic tract or chiasm. Results Overall, while the sonications produced a well-defined lesion in the gray matter targets, the adjacent tract and chiasm had comparatively little or no damage. No significant changes (p > 0.05) were found in the magnitude or latency of the VEP recordings, either immediately after sonication or at later times up to 4 weeks after sonication, and no delayed effects were evident in the histological features of the optic nerve and retina. Conclusions This technique, which selectively targets the intravascular microbubbles, appears to be a promising method of noninvasively producing sharply demarcated lesions in deep brain structures while preserving function in adjacent nerves. Because of low vascularity—and thus a low microbubble concentration—some large white matter tracts appear to have some natural resistance to this type of ablation compared with gray matter. While future work is needed to develop methods of monitoring the procedure and establishing its safety at deep brain targets, the technique does appear to be a potential solution that allows FUS ablation of deep brain targets while sparing adjacent nerve structures. PMID:24010975

Creating Brain Lesions by Low Intensity Focused Ultrasound with Microbubbles: A Rat Study at Half MHz

PubMed Central

Huang, Yuexi; Vykhodtseva, Natalia I.; Hynynen, Kullervo

2014-01-01

Low intensity focused ultrasound was applied with microbubbles (Definity, 0.02 mL/kg) to produce brain lesions in 50 rats at 558 kHz. Burst sonications (burst length: 10 ms; pulse repetition frequency: 1 Hz; total exposure: 5 min; acoustic powers: 0.47-1.3W) generated ischemic or hemorrhagic lesions at the focal volume revealed by both MR imaging and histology. Shorter burst (2 ms) or shorter sonication time (1 min) reduced the probability of lesion production. Longer pulses (200ms, 500ms and continuous wave) caused significant near-field damages. Using microbubbles with focused ultrasound significantly reduced the acoustic power levels, therefore avoided skull heating issues and potentially can extend the treatable volume of transcranial focused ultrasound to the brain tissues close to the skull. PMID:23743099

[Pedophilia: contribution of neurology and neuroimaging techniques].

PubMed

Fonteille, V; Cazala, F; Moulier, V; Stoléru, S

2012-12-01

Pedophilia is characterized by a persistent sexual interest of an adult for prepubescent children. The development of neuroimaging techniques such as functional Magnetic Resonance Imaging (fMRI) is starting to clarify the cerebral basis of disorders of sexual behavior such as pedophilia, which had been previously suggested by case studies. To review structural and functional neuroimaging studies of pedophilia. An exhaustive consultation of PubMed and Ovid databases was conducted. We obtained 19 articles presented in the present review of the literature. Case studies have demonstrated various changes of sexual behavior in relation to brain lesions, including the late appearance in adults of a sexual attraction to prepubescent children. In most cases of pedophilia associated with brain lesions, these lesions were located in frontal or in temporal regions. Structural neuroimaging studies have compared pedophiles with healthy subjects and tried to relate pedophilia to anatomical differences between these two groups. The location of structural changes is inconsistent across studies. Recent functional neuroimaging studies have also attempted to investigate the cerebral correlates of pedophilia. Results suggest that the activation pattern found in pedophiles in response to pictures of prepubescent nude girls or boys is similar to the pattern observed in healthy subjects in response to pictures of adult nude women or men. However, regions that become more activated in patients than in healthy controls in response to the presentation of pictures of children vary across studies. Studies that have begun to investigate the cerebral correlates of pedophilia demonstrate that it is possible to explore them through neuroimaging techniques. These initial results have to be confirmed by new studies backed with objective measurements of sexual arousal such as phallometry. Copyright © 2012 L’Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

Is Neurosurgery With Adjuvant Radiotherapy an Effective Treatment Modality in Isolated Brain Involvement From Endometrial Cancer?: From Case Report to Analysis.

PubMed

Kimyon, Gunsu; Turan, Taner; Basaran, Derman; Turkmen, Osman; Karalok, Alper; Tasci, Tolga; Tulunay, Gokhan; Kose, Mehmet Faruk

2017-02-01

The aim of this study was to evaluate the treatment options and post-brain involvement survival (PBIS) of patients with isolated brain involvement from endometrial cancer (EC). The literature electronic search was conducted from 1972 to May 2016 to identify articles about isolated (without extracranial metastases) brain involvement from EC at recurrence and the initial diagnosis. Forty-eight articles were found. After comprehensive evaluation of case series and case reports, the study included 49 cases. The median age of the patients at initial diagnosis was 57 years (range, 40-77 years). Poor differentiation was determined in 36 (73.5%) patients. Thirty-five (71.4%) patients had a single brain lesion. Lesion was found in the supratentorial part of the brain in 33 (67.3%) patients. Median PBIS for all cohorts was 13 months (range, 0.25-118 months) with 2-year PBIS of 52% and 5-year PBIS of 37%. Age, tumor type, grade, disease-free interval, diagnosis time of brain lesion, localization, and number of brain lesion were not predictive of PBIS. Two-year PBIS was 77% in patients who underwent surgical resection and radiotherapy, whereas it was 19% in the surgical resection-only group, and 20% in the primary radiotherapy-only group (Ps = 0.003 and 0.001, respectively). Chemotherapy was not associated with improved PBIS. Although neuroinvasion from EC appears mostly with a disseminated disease, there is a considerable amount of patients with isolated brain involvement who would have a higher chance of curability. Surgery with radiotherapy is the rational current management option, and this improves the survival for isolated brain involvement from EC.

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…

Imaging Effects of Neurotrophic Factor Genes on Brain Plasticity and Repair in Multiple Sclerosis

DTIC Science & Technology

2012-07-01

sensitive to focal and diffuse changes in brain tissue (including cortical thickness and subcortical volume measures, lesion volumetry , and voxel-based...sensitive to both focal and diffuse effects in gray and white matter, including cortical thickness and subcortical volume measures, lesion volumetry , and

Usability and potential of geostatistics for spatial discrimination of multiple sclerosis lesion patterns.

PubMed

Marschallinger, Robert; Golaszewski, Stefan M; Kunz, Alexander B; Kronbichler, Martin; Ladurner, Gunther; Hofmann, Peter; Trinka, Eugen; McCoy, Mark; Kraus, Jörg

2014-01-01

In multiple sclerosis (MS) the individual disease courses are very heterogeneous among patients and biomarkers for setting the diagnosis and the estimation of the prognosis for individual patients would be very helpful. For this purpose, we are developing a multidisciplinary method and workflow for the quantitative, spatial, and spatiotemporal analysis and characterization of MS lesion patterns from MRI with geostatistics. We worked on a small data set involving three synthetic and three real-world MS lesion patterns, covering a wide range of possible MS lesion configurations. After brain normalization, MS lesions were extracted and the resulting binary 3-dimensional models of MS lesion patterns were subject to geostatistical indicator variography in three orthogonal directions. By applying geostatistical indicator variography, we were able to describe the 3-dimensional spatial structure of MS lesion patterns in a standardized manner. Fitting a model function to the empirical variograms, spatial characteristics of the MS lesion patterns could be expressed and quantified by two parameters. An orthogonal plot of these parameters enabled a well-arranged comparison of the involved MS lesion patterns. This method in development is a promising candidate to complement standard image-based statistics by incorporating spatial quantification. The work flow is generic and not limited to analyzing MS lesion patterns. It can be completely automated for the screening of radiological archives. Copyright © 2013 by the American Society of Neuroimaging.

Voxel-based lesion mapping of meningioma: a comprehensive lesion location mapping of 260 lesions.

PubMed

Hirayama, Ryuichi; Kinoshita, Manabu; Arita, Hideyuki; Kagawa, Naoki; Kishima, Haruhiko; Hashimoto, Naoya; Fujimoto, Yasunori; Yoshimine, Toshiki

2018-06-01

OBJECTIVE In the present study the authors aimed to determine preferred locations of meningiomas by avoiding descriptive analysis and instead using voxel-based lesion mapping and 3D image-rendering techniques. METHODS Magnetic resonance images obtained in 248 treatment-naïve meningioma patients with 260 lesions were retrospectively and consecutively collected. All images were registered to a 1-mm isotropic, high-resolution, T1-weighted brain atlas provided by the Montreal Neurological Institute (the MNI152), and a lesion frequency map was created, followed by 3D volume rendering to visualize the preferred locations of meningiomas in 3D. RESULTS The 3D lesion frequency map clearly showed that skull base structures such as parasellar, sphenoid wing, and petroclival regions were commonly affected by the tumor. The middle one-third of the superior sagittal sinus was most commonly affected in parasagittal tumors. Substantial lesion accumulation was observed around the leptomeninges covering the central sulcus and the sylvian fissure, with very few lesions observed at the frontal, parietal, and occipital convexities. CONCLUSIONS Using an objective visualization method, meningiomas were shown to be located around the middle third of the superior sagittal sinus, the perisylvian convexity, and the skull base. These observations, which are in line with previous descriptive analyses, justify further use of voxel-based lesion mapping techniques to help understand the biological nature of this disease.

Novel fingerprinting method characterises the necessary and sufficient structural connectivity from deep brain stimulation electrodes for a successful outcome

NASA Astrophysics Data System (ADS)

Fernandes, Henrique M.; Van Hartevelt, Tim J.; Boccard, Sandra G. J.; Owen, Sarah L. F.; Cabral, Joana; Deco, Gustavo; Green, Alex L.; Fitzgerald, James J.; Aziz, Tipu Z.; Kringelbach, Morten L.

2015-01-01

Deep brain stimulation (DBS) is a remarkably effective clinical tool, used primarily for movement disorders. DBS relies on precise targeting of specific brain regions to rebalance the oscillatory behaviour of whole-brain neural networks. Traditionally, DBS targeting has been based upon animal models (such as MPTP for Parkinson’s disease) but has also been the result of serendipity during human lesional neurosurgery. There are, however, no good animal models of psychiatric disorders such as depression and schizophrenia, and progress in this area has been slow. In this paper, we use advanced tractography combined with whole-brain anatomical parcellation to provide a rational foundation for identifying the connectivity ‘fingerprint’ of existing, successful DBS targets. This knowledge can then be used pre-surgically and even potentially for the discovery of novel targets. First, using data from our recent case series of cingulate DBS for patients with treatment-resistant chronic pain, we demonstrate how to identify the structural ‘fingerprints’ of existing successful and unsuccessful DBS targets in terms of their connectivity to other brain regions, as defined by the whole-brain anatomical parcellation. Second, we use a number of different strategies to identify the successful fingerprints of structural connectivity across four patients with successful outcomes compared with two patients with unsuccessful outcomes. This fingerprinting method can potentially be used pre-surgically to account for a patient’s individual connectivity and identify the best DBS target. Ultimately, our novel fingerprinting method could be combined with advanced whole-brain computational modelling of the spontaneous dynamics arising from the structural changes in disease, to provide new insights and potentially new targets for hitherto impenetrable neuropsychiatric disorders.

[A Case of Subcortical Intracerebral Hemorrhage Caused by Underlying Oligodendroglioma Diagnosed through Long-Term Follow-Up].

PubMed

Kidoguchi, Masamune; Isozaki, Makoto; Hirose, Satoshi; Kitai, Ryuhei; Kikuta, Ken-Ichiro

2017-03-01

We report on a case of an oligodendroglioma that caused intracerebral hemorrhage, which was diagnosed by long-term follow-up. An 82-year-old man with underlying hypertrophic cardiomyopathy presented with weakness in the right upper extremity. Computed tomography and magnetic resonance imaging(MRI)showed intracerebral hemorrhage and focal brain edema. Since there was a discrepancy between hematoma and focal brain edema, we first diagnosed cardiogenic cerebral embolism. Six months later, MRI results showed an improvement of the brain edema; however, the lesion developed after a year. We suspected that this lesion included a brain tumor and performed an open surgical biopsy. Pathological examination revealed that the tumor was an oligodendroglioma(World Health Organization grade 2). Because brain tumors that are complicated with intratumoral bleeding are often highly malignant and the lesions gradually increase in size, it is relatively easy to make a precise diagnosis. However, in low-grade gliomas, the intracerebral hemorrhage and brain edema may occasionally improve in the short term. We show that a case with a discrepancy between hematoma and brain edema should be followed up for at least more than a year, even when initial MRI does not reveal a brain tumor .

Intrinsic epidermoid of the brain stem: case report and review of the literature.

PubMed

Singh, Saraj K; Jain, Kapil; Jain, Vijendra Kumar

2018-03-19

Purely cystic brain stem epidermoid is a rare diagnosis among all brainstem cystic lesions. Further, it is very rare in pediatric age group. Here, we are reporting a rare case of completely cystic brain stem epidermoid in a child. The patient presented with clinical features of brain stem involvement. MRI brain was suggestive of cystic brain stem lesion. Patient went through surgical procedure. Final diagnosis of epidermoid cyst was confirmed on histopathological report. With the help of various advanced sequences of MRI like diffusion and ADC, diagnosis of epidermoid cyst can be established at unusual intracranial site also. Surgical resection of epidermoid cyst at brain stem should be attempted judiciously utilizing all modern tools of neurosurgery.

Reasoning by analogy requires the left frontal pole: lesion-deficit mapping and clinical implications.

PubMed

Urbanski, Marika; Bréchemier, Marie-Laure; Garcin, Béatrice; Bendetowicz, David; Thiebaut de Schotten, Michel; Foulon, Chris; Rosso, Charlotte; Clarençon, Frédéric; Dupont, Sophie; Pradat-Diehl, Pascale; Labeyrie, Marc-Antoine; Levy, Richard; Volle, Emmanuelle

2016-06-01

SEE BURGESS DOI101093/BRAIN/AWW092 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE  : Analogical reasoning is at the core of the generalization and abstraction processes that enable concept formation and creativity. The impact of neurological diseases on analogical reasoning is poorly known, despite its importance in everyday life and in society. Neuroimaging studies of healthy subjects and the few studies that have been performed on patients have highlighted the importance of the prefrontal cortex in analogical reasoning. However, the critical cerebral bases for analogical reasoning deficits remain elusive. In the current study, we examined analogical reasoning abilities in 27 patients with focal damage in the frontal lobes and performed voxel-based lesion-behaviour mapping and tractography analyses to investigate the structures critical for analogical reasoning. The findings revealed that damage to the left rostrolateral prefrontal region (or some of its long-range connections) specifically impaired the ability to reason by analogies. A short version of the analogy task predicted the existence of a left rostrolateral prefrontal lesion with good accuracy. Experimental manipulations of the analogy tasks suggested that this region plays a role in relational matching or integration. The current lesion approach demonstrated that the left rostrolateral prefrontal region is a critical node in the analogy network. Our results also suggested that analogy tasks should be translated to clinical practice to refine the neuropsychological assessment of patients with frontal lobe lesions. © 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.

Utility of 68Ga-PSMA-11 PET/CT in Imaging of Glioma-A Pilot Study.

PubMed

Sasikumar, Arun; Kashyap, Raghava; Joy, Ajith; Charan Patro, Kanhu; Bhattacharya, Parthasarathy; Reddy Pilaka, Venkata Krishna; Oommen, Karuna Elza; Pillai, Maroor Raghavan Ambikalmajan

2018-06-22

Imaging of gliomas remains challenging. The aim of the study was to assess the feasibility of using Ga-PSMA-11 PET/CT for imaging gliomas. Fifteen patients with glioma from 2 centers were included in the study. Ten patients were treated cases of glioblastoma with suspected recurrence. Two patients were sent for assessing the nature (primary lesion/metastasis) of space-occupying lesion in the brain; 3 patients were imaged immediately after surgery and before radiotherapy. Target-to-background ratios (TBR) for the brain lesions were calculated using contralateral cerebellar uptake as background. Among the 10 cases with suspected recurrence, scan was positive in 9, subsequent surgery was done, and histopathology proved it to be true recurrence. In the scan-negative case on follow-up, no evidence of disease could be made clinically or radiologically. Among the other cases the presence or absence of disease could be unequivocally identified on the Ga-PSMA-11 brain scan and correlated with the histopathology or other imaging. Apart from the visual assessment quantitative assessment of the lesions with TBR also showed a significantly high TBR value for those with true disease compared with those with no disease. In the evaluation of gliomas, Ga-PSMA-11 PET/CT brain imaging is a potentially useful imaging tool. The use of Ga-PSMA-11 brain PET/CT in evaluation of recurrent glioma seems promising. Absence of physiological uptake of Ga-PSMA-11 in the normal brain parenchyma results in high TBR values and consequently better visualization of glioma lesions.

Rewarding brain stimulation reverses the disruptive effect of amygdala damage on emotional learning.

PubMed

Kádár, Elisabet; Ramoneda, Marc; Aldavert-Vera, Laura; Huguet, Gemma; Morgado-Bernal, Ignacio; Segura-Torres, Pilar

2014-11-01

Intracranial self-stimulation (SS) in the lateral hypothalamus, a rewarding deep-brain stimulation, is able to improve acquisition and retention of implicit and explicit memory tasks in rats. SS treatment is also able to reverse cognitive deficits associated with aging or with experimental brain injuries and evaluated in a two-way active avoidance (2wAA) task. The main objective of the present study was to explore the potential of the SS treatment to reverse the complete learning and memory impairment caused by bilateral lesion in the lateral amygdala (LA). The effects of post-training SS, administered after each acquisition session, were evaluated on distributed 2wAA acquisition and 10-day retention in rats with electrolytic bilateral LA lesions. SS effect in acetylcholinestaresase (AchE) activity was evaluated by immunohistochemistry in LA-preserved and Central nuclei (Ce) of the amygdala of LA-damaged rats. Results showed that LA lesion over 40% completely impeded 2wAA acquisition and retention. Post-training SS in the LA-lesioned rats improved conditioning and retention compared with both the lesioned but non-SS treated and the non-lesioned control rats. SS treatment also seemed to induce a decrease in AchE activity in the LA-preserved area of the lesioned rats, but no effects were observed in the Ce. This empirical evidence supports the idea that self-administered rewarding stimulation is able to completely counteract the 2wAA acquisition and retention deficits induced by LA lesion. Cholinergic mechanisms in preserved LA and the contribution of other brain memory-related areas activated by SS could mediate the compensatory effect observed. Copyright © 2014 Elsevier B.V. All rights reserved.

Anomalous frequency-dependent ionic conductivity of lesion-laden human-brain tissue

NASA Astrophysics Data System (ADS)

Emin, David; Akhtari, Massoud; Fallah, Aria; Vinters, Harry V.; Mathern, Gary W.

2017-10-01

We study the effect of lesions on our four-electrode measurements of the ionic conductivity of (˜1 cm3) samples of human brain excised from patients undergoing pediatric epilepsy surgery. For most (˜94%) samples, the low-frequency ionic conductivity rises upon increasing the applied frequency. We attributed this behavior to the long-range (˜0.4 mm) diffusion of solvated sodium cations before encountering intrinsic impenetrable blockages such as cell membranes, blood vessels, and cell walls. By contrast, the low-frequency ionic conductivity of some (˜6%) brain-tissue samples falls with increasing applied frequency. We attribute this unusual frequency-dependence to the electric-field induced liberation of sodium cations from traps introduced by the unusually severe pathology observed in samples from these patients. Thus, the anomalous frequency-dependence of the ionic conductivity indicates trap-producing brain lesions.

Predicting the Risk of Developing New Cerebral Lesions After Stereotactic Radiosurgery or Fractionated Stereotactic Radiotherapy for Brain Metastases from Renal Cell Carcinoma.

PubMed

Rades, Dirk; Dziggel, Liesa; Blanck, Oliver; Gebauer, Niklas; Bartscht, Tobias; Schild, Steven E

2018-05-01

To create an instrument for estimating the risk of new brain metastases after stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT) alone in patients with renal cell carcinoma (RCC). In 45 patients with 1-3 brain metastases, seven characteristics were analyzed for association with freedom from new brain metastases (age, gender, performance score, number and sites of brain metastases, extra-cerebral metastasis, interval from RCC diagnosis to SRS/FSRT). Lower risk of subsequent brain lesions after RT was associated with single metastasis (p=0.043) and supratentorial involvement only (p=0.018). Scoring points were: One metastasis=1, 2-3 metastases=0, supratentorial alone=1, infratentorial with/without supratentorial=0. Scores of 0, 1 and 2 points were associated with 6-month rates of freedom from subsequent brain lesions of 25%, 74% and 92% (p=0.008). After combining groups with 1 and 2 points, 6-month rates were 25% for those with 0 points and 83% for those with 1-2 points (p=0.002). Two groups were identified with different risks of new brain metastases after SRS or FSRT alone. High-risk patients may benefit from additional whole-brain irradiation. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Chronic systemic IL-1β exacerbates central neuroinflammation independently of the blood-brain barrier integrity.

PubMed

Murta, Verónica; Farías, María Isabel; Pitossi, Fernando Juan; Ferrari, Carina Cintia

2015-01-15

Peripheral circulating cytokines are involved in immune to brain communication and systemic inflammation is considered a risk factor for flaring up the symptoms in most neurodegenerative diseases. We induced both central inflammatory demyelinating lesion, and systemic inflammation with an interleukin-1β expressing adenovector. The peripheral pro-inflammatory stimulus aggravated the ongoing central lesion independently of the blood-brain barrier (BBB) integrity. This model allows studying the role of specific molecules and cells (neutrophils) from the innate immune system, in the relationship between central and peripheral communication, and on relapsing episodes of demyelinating lesions, along with the role of BBB integrity. Copyright © 2014 Elsevier B.V. All rights reserved.

Moderate Physical Activity Mediates the Association between White Matter Lesion Volume and Memory Recall in Breast Cancer Survivors

PubMed Central

Cooke, Gillian E.; Wetter, Nathan C.; Banducci, Sarah E.; Mackenzie, Michael J.; Zuniga, Krystle E.; Awick, Elizabeth A.; Roberts, Sarah A.; Sutton, Brad P.; McAuley, Edward; Kramer, Arthur F.

2016-01-01

Increased survival rates among breast cancer patients have drawn significant attention to consequences of both the presence of cancer, and the subsequent treatment-related impact on the brain. The incidence of breast cancer and the effects of treatment often result in alterations in the microstructure of white matter and impaired cognitive functioning. However, physical activity is proving to be a successful modifiable lifestyle factor in many studies that could prove beneficial to breast cancer survivors. This study investigates the link between white matter lesion volume, moderate physical activity, and cognition in breast cancer survivors following treatment compared to non-cancer age-matched controls. Results revealed that brain structure significantly predicted cognitive function via mediation of physical activity in breast cancer survivors. Overall, the study provided preliminary evidence suggesting moderate physical activity may help reduce the treatment related risks associated with breast cancer, including changes to WM integrity and cognitive impairment. PMID:26915025

Moderate Physical Activity Mediates the Association between White Matter Lesion Volume and Memory Recall in Breast Cancer Survivors.

PubMed

Cooke, Gillian E; Wetter, Nathan C; Banducci, Sarah E; Mackenzie, Michael J; Zuniga, Krystle E; Awick, Elizabeth A; Roberts, Sarah A; Sutton, Brad P; McAuley, Edward; Kramer, Arthur F

2016-01-01

Increased survival rates among breast cancer patients have drawn significant attention to consequences of both the presence of cancer, and the subsequent treatment-related impact on the brain. The incidence of breast cancer and the effects of treatment often result in alterations in the microstructure of white matter and impaired cognitive functioning. However, physical activity is proving to be a successful modifiable lifestyle factor in many studies that could prove beneficial to breast cancer survivors. This study investigates the link between white matter lesion volume, moderate physical activity, and cognition in breast cancer survivors following treatment compared to non-cancer age-matched controls. Results revealed that brain structure significantly predicted cognitive function via mediation of physical activity in breast cancer survivors. Overall, the study provided preliminary evidence suggesting moderate physical activity may help reduce the treatment related risks associated with breast cancer, including changes to WM integrity and cognitive impairment.

Neuroanatomical dissociation for taxonomic and thematic knowledge in the human brain

PubMed Central

Schwartz, Myrna F.; Kimberg, Daniel Y.; Walker, Grant M.; Brecher, Adelyn; Faseyitan, Olufunsho K.; Dell, Gary S.; Mirman, Daniel; Coslett, H. Branch

2011-01-01

It is thought that semantic memory represents taxonomic information differently from thematic information. This study investigated the neural basis for the taxonomic-thematic distinction in a unique way. We gathered picture-naming errors from 86 individuals with poststroke language impairment (aphasia). Error rates were determined separately for taxonomic errors (“pear” in response to apple) and thematic errors (“worm” in response to apple), and their shared variance was regressed out of each measure. With the segmented lesions normalized to a common template, we carried out voxel-based lesion-symptom mapping on each error type separately. We found that taxonomic errors localized to the left anterior temporal lobe and thematic errors localized to the left temporoparietal junction. This is an indication that the contribution of these regions to semantic memory cleaves along taxonomic-thematic lines. Our findings show that a distinction long recognized in the psychological sciences is grounded in the structure and function of the human brain. PMID:21540329

The time course of syntactic activation during language processing: a model based on neuropsychological and neurophysiological data.

PubMed

Friederici, A D

1995-09-01

This paper presents a model describing the temporal and neurotopological structure of syntactic processes during comprehension. It postulates three distinct phases of language comprehension, two of which are primarily syntactic in nature. During the first phase the parser assigns the initial syntactic structure on the basis of word category information. These early structural processes are assumed to be subserved by the anterior parts of the left hemisphere, as event-related brain potentials show this area to be maximally activated when phrase structure violations are processed and as circumscribed lesions in this area lead to an impairment of the on-line structural assignment. During the second phase lexical-semantic and verb-argument structure information is processed. This phase is neurophysiologically manifest in a negative component in the event-related brain potential around 400 ms after stimulus onset which is distributed over the left and right temporo-parietal areas when lexical-semantic information is processed and over left anterior areas when verb-argument structure information is processed. During the third phase the parser tries to map the initial syntactic structure onto the available lexical-semantic and verb-argument structure information. In case of an unsuccessful match between the two types of information reanalyses may become necessary. These processes of structural reanalysis are correlated with a centroparietally distributed late positive component in the event-related brain potential.(ABSTRACT TRUNCATED AT 250 WORDS)

Focal Solute Trapping and Global Glymphatic Pathway Impairment in a Murine Model of Multiple Microinfarcts

PubMed Central

Wang, Minghuan; Ding, Fengfei; Deng, SaiYue; Guo, Xuequn; Wang, Wei

2017-01-01

Microinfarcts occur commonly in the aging brain as a consequence of diffuse embolic events and are associated with the development of vascular dementia and Alzheimer's disease. However, the manner in which disperse microscopic lesions reduce global cognitive function and increase the risk for Alzheimer's disease is unclear. The glymphatic system, which is a brain-wide perivascular network that supports the recirculation of CSF through the brain parenchyma, facilitates the clearance of interstitial solutes including amyloid β and tau. We investigated whether glymphatic pathway function is impaired in a murine model of multiple microinfarcts induced by intraarterial injection of cholesterol crystals. The analysis showed that multiple microinfarcts markedly impaired global influx of CSF along the glymphatic pathway. Although suppression of global glymphatic function was transient, resolving within 2 weeks of injury, CSF tracers also accumulated within tissue associated with microinfarcts. The effect of diffuse microinfarcts on global glymphatic pathway function was exacerbated in the mice aged 12 months compared with the 2- to 3-month-old mice. These findings indicate that glymphatic function is focally disrupted around microinfarcts and that the aging brain is more vulnerable to this disruption than the young brain. These observations suggest that microlesions may trap proteins and other interstitial solutes within the brain parenchyma, increasing the risk of amyloid plaque formation. SIGNIFICANCE STATEMENT Microinfarcts, small (<1 mm) ischemic lesions, are strongly associated with age-related dementia. However, how these microscopic lesions affect global cognitive function and predispose to Alzheimer's disease is unclear. The glymphatic system is a brain-wide network of channels surrounding brain blood vessels that allows CSF to exchange with interstitial fluid, clearing away cellular wastes such as amyloid β. We observed that, in mice, microinfarcts impaired global glymphatic function and solutes from the CSF became trapped in tissue associated with microinfarcts. These data suggest that small, disperse ischemic lesions can impair glymphatic function across the brain and trapping of solutes in these lesions may promote protein aggregation and neuroinflammation and eventually lead to neurodegeneration, especially in the aging brain. PMID:28188218

Focal Solute Trapping and Global Glymphatic Pathway Impairment in a Murine Model of Multiple Microinfarcts.

PubMed

Wang, Minghuan; Ding, Fengfei; Deng, SaiYue; Guo, Xuequn; Wang, Wei; Iliff, Jeffrey J; Nedergaard, Maiken

2017-03-15

Microinfarcts occur commonly in the aging brain as a consequence of diffuse embolic events and are associated with the development of vascular dementia and Alzheimer's disease. However, the manner in which disperse microscopic lesions reduce global cognitive function and increase the risk for Alzheimer's disease is unclear. The glymphatic system, which is a brain-wide perivascular network that supports the recirculation of CSF through the brain parenchyma, facilitates the clearance of interstitial solutes including amyloid β and tau. We investigated whether glymphatic pathway function is impaired in a murine model of multiple microinfarcts induced by intraarterial injection of cholesterol crystals. The analysis showed that multiple microinfarcts markedly impaired global influx of CSF along the glymphatic pathway. Although suppression of global glymphatic function was transient, resolving within 2 weeks of injury, CSF tracers also accumulated within tissue associated with microinfarcts. The effect of diffuse microinfarcts on global glymphatic pathway function was exacerbated in the mice aged 12 months compared with the 2- to 3-month-old mice. These findings indicate that glymphatic function is focally disrupted around microinfarcts and that the aging brain is more vulnerable to this disruption than the young brain. These observations suggest that microlesions may trap proteins and other interstitial solutes within the brain parenchyma, increasing the risk of amyloid plaque formation. SIGNIFICANCE STATEMENT Microinfarcts, small (<1 mm) ischemic lesions, are strongly associated with age-related dementia. However, how these microscopic lesions affect global cognitive function and predispose to Alzheimer's disease is unclear. The glymphatic system is a brain-wide network of channels surrounding brain blood vessels that allows CSF to exchange with interstitial fluid, clearing away cellular wastes such as amyloid β. We observed that, in mice, microinfarcts impaired global glymphatic function and solutes from the CSF became trapped in tissue associated with microinfarcts. These data suggest that small, disperse ischemic lesions can impair glymphatic function across the brain and trapping of solutes in these lesions may promote protein aggregation and neuroinflammation and eventually lead to neurodegeneration, especially in the aging brain. Copyright © 2017 the authors 0270-6474/17/372870-08$15.00/0.

Design and development of an ethnically-diverse imaging informatics-based eFolder system for multiple sclerosis patients.

PubMed

Ma, Kevin C; Fernandez, James R; Amezcua, Lilyana; Lerner, Alex; Shiroishi, Mark S; Liu, Brent J

2015-12-01

MRI has been used to identify multiple sclerosis (MS) lesions in brain and spinal cord visually. Integrating patient information into an electronic patient record system has become key for modern patient care in medicine in recent years. Clinically, it is also necessary to track patients' progress in longitudinal studies, in order to provide comprehensive understanding of disease progression and response to treatment. As the amount of required data increases, there exists a need for an efficient systematic solution to store and analyze MS patient data, disease profiles, and disease tracking for both clinical and research purposes. An imaging informatics based system, called MS eFolder, has been developed as an integrated patient record system for data storage and analysis of MS patients. The eFolder system, with a DICOM-based database, includes a module for lesion contouring by radiologists, a MS lesion quantification tool to quantify MS lesion volume in 3D, brain parenchyma fraction analysis, and provide quantitative analysis and tracking of volume changes in longitudinal studies. Patient data, including MR images, have been collected retrospectively at University of Southern California Medical Center (USC) and Los Angeles County Hospital (LAC). The MS eFolder utilizes web-based components, such as browser-based graphical user interface (GUI) and web-based database. The eFolder database stores patient clinical data (demographics, MS disease history, family history, etc.), MR imaging-related data found in DICOM headers, and lesion quantification results. Lesion quantification results are derived from radiologists' contours on brain MRI studies and quantified into 3-dimensional volumes and locations. Quantified results of white matter lesions are integrated into a structured report based on DICOM-SR protocol and templates. The user interface displays patient clinical information, original MR images, and viewing structured reports of quantified results. The GUI also includes a data mining tool to handle unique search queries for MS. System workflow and dataflow steps has been designed based on the IHE post-processing workflow profile, including workflow process tracking, MS lesion contouring and quantification of MR images at a post-processing workstation, and storage of quantitative results as DICOM-SR in DICOM-based storage system. The web-based GUI is designed to display zero-footprint DICOM web-accessible data objects (WADO) and the SR objects. The MS eFolder system has been designed and developed as an integrated data storage and mining solution in both clinical and research environments, while providing unique features, such as quantitative lesion analysis and disease tracking over a longitudinal study. A comprehensive image and clinical data integrated database provided by MS eFolder provides a platform for treatment assessment, outcomes analysis and decision-support. The proposed system serves as a platform for future quantitative analysis derived automatically from CAD algorithms that can also be integrated within the system for individual disease tracking and future MS-related research. Ultimately the eFolder provides a decision-support infrastructure that can eventually be used as add-on value to the overall electronic medical record. Copyright © 2015 Elsevier Ltd. All rights reserved.

Design and development of an ethnically-diverse imaging informatics-based eFolder system for multiple sclerosis patients

PubMed Central

Ma, Kevin C.; Fernandez, James R.; Amezcua, Lilyana; Lerner, Alex; Shiroishi, Mark S.; Liu, Brent J.

2016-01-01

Purpose MRI has been used to identify multiple sclerosis (MS) lesions in brain and spinal cord visually. Integrating patient information into an electronic patient record system has become key for modern patient care in medicine in recent years. Clinically, it is also necessary to track patients' progress in longitudinal studies, in order to provide comprehensive understanding of disease progression and response to treatment. As the amount of required data increases, there exists a need for an efficient systematic solution to store and analyze MS patient data, disease profiles, and disease tracking for both clinical and research purposes. Method An imaging informatics based system, called MS eFolder, has been developed as an integrated patient record system for data storage and analysis of MS patients. The eFolder system, with a DICOM-based database, includes a module for lesion contouring by radiologists, a MS lesion quantification tool to quantify MS lesion volume in 3D, brain parenchyma fraction analysis, and provide quantitative analysis and tracking of volume changes in longitudinal studies. Patient data, including MR images, have been collected retrospectively at University of Southern California Medical Center (USC) and Los Angeles County Hospital (LAC). The MS eFolder utilizes web-based components, such as browser-based graphical user interface (GUI) and web-based database. The eFolder database stores patient clinical data (demographics, MS disease history, family history, etc.), MR imaging-related data found in DICOM headers, and lesion quantification results. Lesion quantification results are derived from radiologists' contours on brain MRI studies and quantified into 3-dimensional volumes and locations. Quantified results of white matter lesions are integrated into a structured report based on DICOM-SR protocol and templates. The user interface displays patient clinical information, original MR images, and viewing structured reports of quantified results. The GUI also includes a data mining tool to handle unique search queries for MS. System workflow and dataflow steps has been designed based on the IHE post-processing workflow profile, including workflow process tracking, MS lesion contouring and quantification of MR images at a post-processing workstation, and storage of quantitative results as DICOM-SR in DICOM-based storage system. The web-based GUI is designed to display zero-footprint DICOM web-accessible data objects (WADO) and the SR objects. Summary The MS eFolder system has been designed and developed as an integrated data storage and mining solution in both clinical and research environments, while providing unique features, such as quantitative lesion analysis and disease tracking over a longitudinal study. A comprehensive image and clinical data integrated database provided by MS eFolder provides a platform for treatment assessment, outcomes analysis and decision-support. The proposed system serves as a platform for future quantitative analysis derived automatically from CAD algorithms that can also be integrated within the system for individual disease tracking and future MS-related research. Ultimately the eFolder provides a decision-support infrastructure that can eventually be used as add-on value to the overall electronic medical record. PMID:26564667

Graph Theoretical Framework of Brain Networks in Multiple Sclerosis: A Review of Concepts.

PubMed

Fleischer, Vinzenz; Radetz, Angela; Ciolac, Dumitru; Muthuraman, Muthuraman; Gonzalez-Escamilla, Gabriel; Zipp, Frauke; Groppa, Sergiu

2017-11-01

Network science provides powerful access to essential organizational principles of the human brain. It has been applied in combination with graph theory to characterize brain connectivity patterns. In multiple sclerosis (MS), analysis of the brain networks derived from either structural or functional imaging provides new insights into pathological processes within the gray and white matter. Beyond focal lesions and diffuse tissue damage, network connectivity patterns could be important for closely tracking and predicting the disease course. In this review, we describe concepts of graph theory, highlight novel issues of tissue reorganization in acute and chronic neuroinflammation and address pitfalls with regard to network analysis in MS patients. We further provide an outline of functional and structural connectivity patterns observed in MS, spanning from disconnection and disruption on one hand to adaptation and compensation on the other. Moreover, we link network changes and their relation to clinical disability based on the current literature. Finally, we discuss the perspective of network science in MS for future research and postulate its role in the clinical framework. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Changes in functional brain organization and behavioral correlations after rehabilitative therapy using a brain-computer interface.

PubMed

Young, Brittany M; Nigogosyan, Zack; Walton, Léo M; Song, Jie; Nair, Veena A; Grogan, Scott W; Tyler, Mitchell E; Edwards, Dorothy F; Caldera, Kristin; Sattin, Justin A; Williams, Justin C; Prabhakaran, Vivek

2014-01-01

This study aims to examine the changes in task-related brain activity induced by rehabilitative therapy using brain-computer interface (BCI) technologies and whether these changes are relevant to functional gains achieved through the use of these therapies. Stroke patients with persistent upper-extremity motor deficits received interventional rehabilitation therapy using a closed-loop neurofeedback BCI device (n = 8) or no therapy (n = 6). Behavioral assessments using the Stroke Impact Scale, the Action Research Arm Test (ARAT), and the Nine-Hole Peg Test (9-HPT) as well as task-based fMRI scans were conducted before, during, after, and 1 month after therapy administration or at analogous intervals in the absence of therapy. Laterality Index (LI) values during finger tapping of each hand were calculated for each time point and assessed for correlation with behavioral outcomes. Brain activity during finger tapping of each hand shifted over the course of BCI therapy, but not in the absence of therapy, to greater involvement of the non-lesioned hemisphere (and lesser involvement of the stroke-lesioned hemisphere) as measured by LI. Moreover, changes from baseline LI values during finger tapping of the impaired hand were correlated with gains in both objective and subjective behavioral measures. These findings suggest that the administration of interventional BCI therapy can induce differential changes in brain activity patterns between the lesioned and non-lesioned hemispheres and that these brain changes are associated with changes in specific motor functions.

A Model of Post-Traumatic Epilepsy After Penetrating Brain Injuries: Effect of Lesion Size and Metal Fragments

PubMed Central

Kendirli, M. Tansel; Rose, Dominique T.; Bertram, Edward H.

2014-01-01

Objective Penetrating brain injury (PBI) has the highest risk for inducing post-traumatic epilepsy and retained foreign materials such as bullet fragments carry the greatest risk. This study examines the potential contribution of copper, a major component of bullets, to the development of epilepsy following PBI. Methods Anesthetized adult male rats received a penetrating injury from the dorsal cortex to the ventral hippocampus from a high speed small bit drill. In one group of animals, copper wire was inserted into the lesion. Control animals had only the lesion or the lesion plus stainless steel wire (biologically inert foreign body). From 6 to up to 11 months following the injury the rats were monitored intermittently for the development of epilepsy with video-EEG. A separate set of animals was examined for possible acute seizures in the week following the injury. Results 22 of the 23 animals with copper wire developed chronic epilepsy compared to 3 of the 20 control rats (lesion and lesion with stainless steel). Copper was associated with more extensive injury. The control rats with epilepsy had larger lesions. In the acute injury group, there was no difference in the incidence of seizures (83% lesion plus stainless steel, 70% lesion plus copper). Conclusions Copper increases the risk for epilepsy and may increase damage over time, but there were no differences between the groups in the incidence of acute post-injury seizures. Lesion size may contribute to epilepsy development in lesion only animals. Copper maybe an independent risk factor for the development of epilepsy and possible secondary injury, but lesion size also contributes to the development of epilepsy. The consequences of prolonged exposure of the brain to copper observed in these animals may have clinical implications that require further evaluation. PMID:25470332

On the role of general system theory for functional neuroimaging

PubMed Central

Stephan, Klaas Enno

2004-01-01

One of the most important goals of neuroscience is to establish precise structure–function relationships in the brain. Since the 19th century, a major scientific endeavour has been to associate structurally distinct cortical regions with specific cognitive functions. This was traditionally accomplished by correlating microstructurally defined areas with lesion sites found in patients with specific neuropsychological symptoms. Modern neuroimaging techniques with high spatial resolution have promised an alternative approach, enabling non-invasive measurements of regionally specific changes of brain activity that are correlated with certain components of a cognitive process. Reviewing classic approaches towards brain structure–function relationships that are based on correlational approaches, this article argues that these approaches are not sufficient to provide an understanding of the operational principles of a dynamic system such as the brain but must be complemented by models based on general system theory. These models reflect the connectional structure of the system under investigation and emphasize context-dependent couplings between the system elements in terms of effective connectivity. The usefulness of system models whose parameters are fitted to measured functional imaging data for testing hypotheses about structure–function relationships in the brain and their potential for clinical applications is demonstrated by several empirical examples. PMID:15610393

Brain Lesions among Orally Fed and Gastrostomy-Fed Dysphagic Preterm Infants: Can Routine Qualitative or Volumetric Quantitative Magnetic Resonance Imaging Predict Feeding Outcomes?

PubMed

Kashou, Nasser H; Dar, Irfaan A; El-Mahdy, Mohamed A; Pluto, Charles; Smith, Mark; Gulati, Ish K; Lo, Warren; Jadcherla, Sudarshan R

2017-01-01

The usefulness of qualitative or quantitative volumetric magnetic resonance imaging (MRI) in early detection of brain structural changes and prediction of adverse outcomes in neonatal illnesses warrants further investigation. Our aim was to correlate certain brain injuries and the brain volume of feeding-related cortical and subcortical regions with feeding method at discharge among preterm dysphagic infants. Using a retrospective observational study design, we examined MRI data among 43 (22 male; born at 31.5 ± 0.8 week gestation) infants who went home on oral feeding or gastrostomy feeding (G-tube). MRI scans were segmented, and volumes of brainstem, cerebellum, cerebrum, basal ganglia, thalamus, and vermis were quantified, and correlations were made with discharge feeding outcomes. Chi-squared tests were used to evaluate MRI findings vs. feeding outcomes. ANCOVA was performed on the regression model to measure the association of maturity and brain volume between groups. Out of 43 infants, 44% were oral-fed and 56% were G-tube fed at hospital discharge (but not at time of the study). There was no relationship between qualitative brain lesions and feeding outcomes. Volumetric analysis revealed that cerebellum was greater ( p  < 0.05) in G-tube fed infants, whereas cerebrum volume was greater ( p  < 0.05) in oral-fed infants. Other brain regions did not show volumetric differences between groups. This study concludes that neither qualitative nor quantitative volumetric MRI findings correlate with feeding outcomes. Understanding the complexity of swallowing and feeding difficulties in infants warrants a comprehensive and in-depth functional neurological assessment.

Modern classification and outcome predictors of surgery in patients with brain arteriovenous malformations.

PubMed

Tayebi Meybodi, Ali; Lawton, Michael T

2018-02-23

Brain arteriovenous malformations (bAVM) are challenging lesions. Part of this challenge stems from the infinite diversity of these lesions regarding shape, location, anatomy, and physiology. This diversity has called on a variety of treatment modalities for these lesions, of which microsurgical resection prevails as the mainstay of treatment. As such, outcome prediction and managing strategy mainly rely on unraveling the nature of these complex tangles and ways each lesion responds to various therapeutic modalities. This strategy needs the ability to decipher each lesion through accurate and efficient categorization. Therefore, classification schemes are essential parts of treatment planning and outcome prediction. This article summarizes different surgical classification schemes and outcome predictors proposed for bAVMs.

Ability to solve riddles in patients with speech and language impairments after stroke.

PubMed

Savić, Goran

2016-01-01

Successful riddle solving requires recognition of the meaning of words, attention, concentration, memory, connectivity and analysis of riddle content, and sufficiently developed associative thinking. The aim of the study was to determine the ability to solve riddles in stroke patients who do or do not have speech and language disorders (SLDs), to determine the presence of SLDs in relation to the lesion localization, as well as to define the relationship between riddle-solving and functional impairment of a body side. The sample consisted of 88 patients. The data used included age, sex, educational level, time of stroke onset, presence of an SLD, lesion localization, and functional damage of the body side. The patients were presented with a task of solving 10 riddles. A significant SLD was present in 38.60% of the patients. Brain lesions were found distributed at 46 different brain sites. Patients with different lesion localization had different success in solving riddles. Patients with perisylvian cortex brain lesions, or patients with Wernicke and global aphasia, had the poorest results. The group with SLDs had an average success of solved riddles of 26.76% (p = 0.000). The group with right-sided functional impairments had average success of 37.14%, and the group with functional impairments of the left side of the body 56.88% (p = 0.002). Most patients with SLDs had a low ability of solving riddles. Most of the patients with left brain lesions and perisylvian cortex damage demonstrated lower ability in solving riddles in relation to patients with right hemisphere lesions.

New long-wavelength Nd:YAG laser at 1.44 micron: effect on brain.

PubMed

Martiniuk, R; Bauer, J A; McKean, J D; Tulip, J; Mielke, B W

1989-02-01

A wavelength-shifted Nd:YAG laser, tuned to coincide with the infrared absorption peak of water at 1.44 microns, was used to make lesions in normal rabbit brain. A total of 48 lesions were made with power up to 20 W, with energy up to 40 joules, and with two different spot sizes. These lesions were compared to lesions made with 1.06 microns radiation from an Nd:YAG laser under identical operating conditions. Measurements of blood-brain barrier damage and width, depth, and volume of tissue affected were obtained 30 minutes after placement of the lesions. It was found that 1.44-microns lesions produced photoevaporative tissue loss at the highest intensities used. The layer of coagulated tissue remaining after photovaporization had a mean thickness of 0.6 mm irrespective of the volume of tissue removed. There was no photovaporization in the 1.06-microns lesions. In addition, the amount of peripheral edema per unit volume of tissue coagulated was approximately half at the 1.44-microns wavelength. These findings suggest that the 1.44-microns Nd:YAG laser may be a useful surgical instrument since it combines the photoevaporative effect of the CO2 laser while maintaining the advantages of the conventional Nd:YAG laser (quartz fiber delivery and effective hemostasis).

Temporally consistent probabilistic detection of new multiple sclerosis lesions in brain MRI.

PubMed

Elliott, Colm; Arnold, Douglas L; Collins, D Louis; Arbel, Tal

2013-08-01

Detection of new Multiple Sclerosis (MS) lesions on magnetic resonance imaging (MRI) is important as a marker of disease activity and as a potential surrogate for relapses. We propose an approach where sequential scans are jointly segmented, to provide a temporally consistent tissue segmentation while remaining sensitive to newly appearing lesions. The method uses a two-stage classification process: 1) a Bayesian classifier provides a probabilistic brain tissue classification at each voxel of reference and follow-up scans, and 2) a random-forest based lesion-level classification provides a final identification of new lesions. Generative models are learned based on 364 scans from 95 subjects from a multi-center clinical trial. The method is evaluated on sequential brain MRI of 160 subjects from a separate multi-center clinical trial, and is compared to 1) semi-automatically generated ground truth segmentations and 2) fully manual identification of new lesions generated independently by nine expert raters on a subset of 60 subjects. For new lesions greater than 0.15 cc in size, the classifier has near perfect performance (99% sensitivity, 2% false detection rate), as compared to ground truth. The proposed method was also shown to exceed the performance of any one of the nine expert manual identifications.

Presence of cysts on magnetic resonance images (MRIs) in children with asperger disorder and nonverbal learning disabilities.

PubMed

Semrud-Clikeman, Margaret; Fine, Jodene

2011-04-01

The main purpose of this study was to report the existence of previously unidentified brain cysts or lesions in children with nonverbal learning disabilities, Asperger syndrome, or controls. The authors compared the incidence of cysts or lesions on magnetic resonance images (MRIs) in 28 children with nonverbal learning disability, 26 children with Asperger syndrome, and 24 typical controls for abnormalities. In this study, the authors found 25% of children previously diagnosed with nonverbal learning disability to have unsuspected brain abnormalities generally including cysts or lesions in the occipital region, compared with approximately 4% in the Asperger syndrome or control group. The cysts/lesions were found mainly in the occipital lobe, an area responsible for visual/spatial reasoning. It is appropriate to speculate that there might be a connection between anomalous brain development and skill differences among these groups.

Blood-Brain Barrier Permeability and Monocyte Infiltration in Experimental Allergic Encephalomyelitis

ERIC Educational Resources Information Center

Floris, S.; Blezer, E. L. A.; Schreibelt, G.; Dopp, E.; van der Pol, S. M. A.; Schadee-Eestermans, I. L.; Nicolay, K.; Dijkstra, C. D.; de Vries, H. E.

2004-01-01

Enhanced cerebrovascular permeability and cellular infiltration mark the onset of early multiple sclerosis lesions. So far, the precise sequence of these events and their role in lesion formation and disease progression remain unknown. Here we provide quantitative evidence that blood-brain barrier leakage is an early event and precedes massive…

Functional Topography of Early Periventricular Brain Lesions in Relation to Cytoarchitectonic Probabilistic Maps

ERIC Educational Resources Information Center

Staudt, Martin; Ticini, Luca F.; Grodd, Wolfgang; Krageloh-Mann, Ingeborg; Karnath, Hans-Otto

2008-01-01

Early periventricular brain lesions can not only cause cerebral palsy, but can also induce a reorganization of language. Here, we asked whether these different functional consequences can be attributed to topographically distinct portions of the periventricular white matter damage. Eight patients with pre- and perinatally acquired left-sided…

BRAIN MECHANISMS AND INTELLIGENCE, A QUANTITATIVE STUDY OF INJURIES TO THE BRAIN.

ERIC Educational Resources Information Center

LASHLEY, K.S.

SEVERAL EXPERIMENTS WITH RATS INVOLVING THE INFLUENCE OF CEREBRAL DESTRUCTION ON LEARNING ABILITY ARE DESCRIBED. THE TWO MAJOR EXPERIMENTS STUDY THE RETENTION OF THE MAZE HABIT AFTER CEREBRAL LESIONS AND THE INFLUENCE OF CEREBRAL LESIONS ON THE CAPACITY TO LEARN (INITIAL FORMATION OF HABITS). THEORECTICAL ANALYSIS OF THE LEARNING (BEHAVIOR)…

The impact of unilateral brain damage on anticipatory grip force scaling when lifting everyday objects.

PubMed

Eidenmüller, S; Randerath, J; Goldenberg, G; Li, Y; Hermsdörfer, J

2014-08-01

The scaling of our finger forces according to the properties of manipulated objects is an elementary prerequisite of skilled motor behavior. Lesions of the motor-dominant left brain may impair several aspects of motor planning. For example, limb-apraxia, a tool-use disorder after left brain damage is thought to be caused by deficient recall or integration of tool-use knowledge into an action plan. The aim of the present study was to investigate whether left brain damage affects anticipatory force scaling when lifting everyday objects. We examined 26 stroke patients with unilateral brain damage (16 with left brain damage, ten with right brain damage) and 21 healthy control subjects. Limb apraxia was assessed by testing pantomime of familiar tool-use and imitation of meaningless hand postures. Participants grasped and lifted twelve randomly presented everyday objects. Grip force was measured with help of sensors fixed on thumb, index and middle-finger. The maximum rate of grip force was determined to quantify the precision of anticipation of object properties. Regression analysis yielded clear deficits of anticipation in the group of patients with left brain damage, while the comparison of patient with right brain damage with their respective control group did not reveal comparable deficits. Lesion-analyses indicate that brain structures typically associated with a tool-use network in the left hemisphere play an essential role for anticipatory grip force scaling, especially the left inferior frontal gyrus (IFG) and the premotor cortex (PMC). Furthermore, significant correlations of impaired anticipation with limb apraxia scores suggest shared representations. However, the presence of dissociations, implicates also independent processes. Overall, our findings suggest that the left hemisphere is engaged in anticipatory grip force scaling for lifting everyday objects. The underlying neural substrate is not restricted to a single region or stream; instead it may rely on the intact functioning of a left hemisphere network that may overlap with the left hemisphere dominant tool-use network. Copyright © 2014 Elsevier Ltd. All rights reserved.

Identification of disappearing brain lesions with intraoperative magnetic resonance imaging prevents surgery.

PubMed

Sutherland, Christina S; Kelly, John Jp; Morrish, William; Sutherland, Garnette R

2010-10-01

Typically, neurosurgery is performed several weeks after diagnostic imaging. In the majority of cases, histopathology confirms the diagnosis of neoplasia. In a small number of cases, a different diagnosis is established or histopathology is nondiagnostic. The frequency with which these outcomes occur has not been established. To determine the frequency and outcome of disappearing brain lesions within a group of patients undergoing surgery for suspected brain tumor. Over the past decade, 982 patients were managed in the intraoperative magnetic resonance imaging unit at the University of Calgary, Calgary, Alberta, Canada. These patients have been prospectively evaluated. In 652 patients, a brain tumor was suspected. In 6 of the 652 patients, histopathology indicated a nontumor diagnosis. In 5 patients, intraoperative images, acquired after induction of anesthesia, showed complete or nearly complete resolution of the suspected tumor identified on diagnostic magnetic resonance imaging acquired 6 ± 4 (mean ± SD) weeks previously. Anesthesia was reversed, and the surgical procedure aborted. The lesions have not progressed with 6 ± 2 years of follow-up. Intraoperative magnetic resonance imaging prevented surgery on 5 patients with disappearing lesions.

In vivo optical characterization of pediatric epileptogenic lesions

NASA Astrophysics Data System (ADS)

Lin, W.-C.; Ragheb, J.; Bhatia, S.; Johnson, Mahlon D.; Sandberg, D.; Fernandez, A.; Morrison, G.; Duchowny, M.; Jayakar, P.

2007-02-01

Epileptogenic lesions and their margins are often difficult to define intraoperatively. We hypothesize that optical spectroscopy can detect unique pathophysiological features of epileptogenic lesions in children and hence differentiate them from normal brain. This hypothesis was tested by comparing the in vivo optical and fluorescence characteristics of epileptogenic brain lesions (non-neoplastic) with those of normal brain. Patients were recruited from those receiving epilepsy surgeries at Miami Children's Hospital. Using a portable spectroscopic system, optical characterization of brain was performed intraoperatively. Fluorescence spectra were measured at 337 nm excitation, and diffuse reflectance spectra were measured between 400 and 850 nm. To date, seven epilepsy patients have been enrolled in the study. A couple interesting trends have been observed in the recorded optical spectra. First, sites within the resection zone, as defined by the intracranial electroencephalogram data, often show higher diffuse reflectance signals than normal sites do. This is especially prominent around 500 nm and between 650 and 850 nm. Secondly, several investigated sites with abnormal electroencephalogram and/or pathology show a unique blue shift in their fluorescence spectra, which is not seen in other cases.

[Evaluation of diffuse cerebral atrophy in patients with a history of traumatic brain injury and its relation to cognitive deterioration].

PubMed

Narberhaus, A; Segarra-Castells, M D; Verger-Maestre, K; Serra-Grabulosa, J M; Salgado-Pineda, P; Bartomeus-Jené, F; Mercader-Sobrequés, J M

Diffuse damage secondary to traumatic brain injury (TBI) can be studied through volumetric analysis of several structures that are sensible to this kind of injury, such as corpus callosum, ventricular system, hippocampus, basal ganglia and the volume of cerebrospinal fluid spaces. Our aim is to describe how closed head injury (CHI) occurred in early years produce diffuse damage, and how this damage affects general cognitive functioning at long term. Initially the group of subjects was composed of 27 head injured children and adolescents following paediatric moderate to severe TBI. From this initial group we selected 15 patients without focal lesion, or in case of having suffered focal lesion, this was smaller than 2,600 mm3. These subjects were assessed by means of volumetric analysis of cerebrospinal fluid spaces, corpus callosum, hippocampus and caudate nucleus, comparing the results with a matched control group. We calculated the degree of general cognitive ability of these subjects through tests of intellectual, memory, frontal lobe and motor speed functioning. This study demonstrates that early CHI produce a volume decrease in all measured structures. Corpus callosum atrophy is the factor that better explains general cognitive impairment. Diffuse damage secondary to moderate to severe peadiatric TBI has long term effects on several cerebral structures and on cognitive performance. Corpus callosum atrophy is the best predictor for general cognitive impairment, compared with other affected structures.

Primary CNS lymphoma as a cause of Korsakoff syndrome.

PubMed

Toth, Cory; Voll, Chris; Macaulay, Robert

2002-01-01

Korsakoff syndrome presents with memory dysfunction with retrograde amnesia, anterograde amnesia, limited insight into dysfunction, and confabulation. The most common etiology of Korsakoff syndrome is thiamine deficiency secondary to alcoholism. There are limited case reports of structural lesions causing Korsakoff syndrome. A 46-year-old male with a long history of alcoholism presented with a history of confusion, amnesia, and confabulation with no localizing features on neurological examination. The patient showed no clinical change with intravenous thiamine. Computed tomography of the brain revealed a heterogenous, enhancing mass lesion centered within the third ventricle, with other lesions found throughout cortical and subcortical regions. The patient was given dexamethasone i.v. without noticeable clinical improvement but with marked radiological improvement with mass reduction. Stereotactic biopsy revealed a diagnosis of primary central nervous system (CNS) lymphoma. Most patients presenting with Korsakoff syndrome have thiamine deficiency; however, mass lesions can produce an identical clinical picture. This is the first case report of a patient with primary CNS lymphoma presenting as Korsakoff syndrome.

Ten-Year Survival of a Patient Treated with Stereotactic Gamma Knife Radiosurgery for Brain Metastases from Colon Cancer with Ovarian and Lymph Node Metastases: A Case Report.

PubMed

Morinaga, Nobuhiro; Tanaka, Naritaka; Shitara, Yoshinori; Ishizaki, Masatoshi; Yoshida, Takatomo; Kouga, Hideaki; Wakabayashi, Kazuki; Fukuchi, Minoru; Tsunoda, Yoshiyuki; Kuwano, Hiroyuki

2016-01-01

Brain metastasis from colorectal cancer is infrequent and carries a poor prognosis. Herein, we present a patient alive 10 years after the identification of a first brain metastasis from sigmoid colon cancer. A 39-year-old woman underwent sigmoidectomy for sigmoid colon cancer during an emergency operation for pelvic peritonitis. The pathological finding was moderately differentiated adenocarcinoma. Eleven months after the sigmoidectomy, a metastatic lesion was identified in the left ovary. Despite local radiotherapy followed by chemotherapy, the left ovarian lesion grew, so resection of the uterus and bilateral ovaries was performed. Adjuvant chemotherapy with tegafur-uracil (UFT)/calcium folinate (leucovorin, LV) was initiated. Seven months after resection of the ovarian lesion, brain metastases appeared in the bilateral frontal lobes and were treated with stereotactic Gamma Knife radiosurgery. Cervical and mediastinal lymph node metastases were also diagnosed, and irradiation of these lesions was performed. After radiotherapy, 10 courses of oxaliplatin and infused fluorouracil plus leucovorin (FOLFOX) were administered. During FOLFOX administration, recurrent left frontal lobe brain metastasis was diagnosed and treated with stereotactic Gamma Knife radiosurgery. In this case, the brain metastases were well treated with stereotactic Gamma Knife radiosurgery, and the systemic disease arising from sigmoid colon cancer has been kept under control with chemotherapies, surgical resection, and radiotherapy.

Brain disease, connectivity, plasticity and cognitive therapy: A neurological view of mental disorders.

PubMed

Lubrini, G; Martín-Montes, A; Díez-Ascaso, O; Díez-Tejedor, E

2018-04-01

Our conception of the mind-brain relationship has evolved from the traditional idea of dualism to current evidence that mental functions result from brain activity. This paradigm shift, combined with recent advances in neuroimaging, has led to a novel definition of brain functioning in terms of structural and functional connectivity. The purpose of this literature review is to describe the relationship between connectivity, brain lesions, cerebral plasticity, and functional recovery. Assuming that brain function results from the organisation of the entire brain in networks, brain dysfunction would be a consequence of altered brain network connectivity. According to this approach, cognitive and behavioural impairment following brain damage result from disrupted functional organisation of brain networks. However, the dynamic and versatile nature of these circuits makes recovering brain function possible. Cerebral plasticity allows for functional reorganisation leading to recovery, whether spontaneous or resulting from cognitive therapy, after brain disease. Current knowledge of brain connectivity and cerebral plasticity provides new insights into normal brain functioning, the mechanisms of brain damage, and functional recovery, which in turn serve as the foundations of cognitive therapy. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Fractal dimension of EEG activity senses neuronal impairment in acute stroke.

PubMed

Zappasodi, Filippo; Olejarczyk, Elzbieta; Marzetti, Laura; Assenza, Giovanni; Pizzella, Vittorio; Tecchio, Franca

2014-01-01

The brain is a self-organizing system which displays self-similarities at different spatial and temporal scales. Thus, the complexity of its dynamics, associated to efficient processing and functional advantages, is expected to be captured by a measure of its scale-free (fractal) properties. Under the hypothesis that the fractal dimension (FD) of the electroencephalographic signal (EEG) is optimally sensitive to the neuronal dysfunction secondary to a brain lesion, we tested the FD's ability in assessing two key processes in acute stroke: the clinical impairment and the recovery prognosis. Resting EEG was collected in 36 patients 4-10 days after a unilateral ischemic stroke in the middle cerebral artery territory and 19 healthy controls. National Health Institute Stroke Scale (NIHss) was collected at T0 and 6 months later. Highuchi FD, its inter-hemispheric asymmetry (FDasy) and spectral band powers were calculated for EEG signals. FD was smaller in patients than in controls (1.447±0.092 vs 1.525±0.105) and its reduction was paired to a worse acute clinical status. FD decrease was associated to alpha increase and beta decrease of oscillatory activity power. Larger FDasy in acute phase was paired to a worse clinical recovery at six months. FD in our patients captured the loss of complexity reflecting the global system dysfunction resulting from the structural damage. This decrease seems to reveal the intimate nature of structure-function unity, where the regional neural multi-scale self-similar activity is impaired by the anatomical lesion. This picture is coherent with neuronal activity complexity decrease paired to a reduced repertoire of functional abilities. FDasy result highlights the functional relevance of the balance between homologous brain structures' activities in stroke recovery.

Advanced fiber tracking in early acquired brain injury causing cerebral palsy.

PubMed

Lennartsson, F; Holmström, L; Eliasson, A-C; Flodmark, O; Forssberg, H; Tournier, J-D; Vollmer, B

2015-01-01

Diffusion-weighted MR imaging and fiber tractography can be used to investigate alterations in white matter tracts in patients with early acquired brain lesions and cerebral palsy. Most existing studies have used diffusion tensor tractography, which is limited in areas of complex fiber structures or pathologic processes. We explored a combined normalization and probabilistic fiber-tracking method for more realistic fiber tractography in this patient group. This cross-sectional study included 17 children with unilateral cerebral palsy and 24 typically developing controls. DWI data were collected at 1.5T (45 directions, b=1000 s/mm(2)). Regions of interest were defined on a study-specific fractional anisotropy template and mapped onto subjects for fiber tracking. Probabilistic fiber tracking of the corticospinal tract and thalamic projections to the somatosensory cortex was performed by using constrained spherical deconvolution. Tracts were qualitatively assessed, and DTI parameters were extracted close to and distant from lesions and compared between groups. The corticospinal tract and thalamic projections to the somatosensory cortex were realistically reconstructed in both groups. Structural changes to tracts were seen in the cerebral palsy group and included splits, dislocations, compaction of the tracts, or failure to delineate the tract and were associated with underlying pathology seen on conventional MR imaging. Comparisons of DTI parameters indicated primary and secondary neurodegeneration along the corticospinal tract. Corticospinal tract and thalamic projections to the somatosensory cortex showed dissimilarities in both structural changes and DTI parameters. Our proposed method offers a sensitive means to explore alterations in WM tracts to further understand pathophysiologic changes following early acquired brain injury. © 2015 by American Journal of Neuroradiology.

Let thy left brain know what thy right brain doeth: Inter-hemispheric compensation of functional deficits after brain damage.

PubMed

Bartolomeo, Paolo; Thiebaut de Schotten, Michel

2016-12-01

Recent evidence revealed the importance of inter-hemispheric communication for the compensation of functional deficits after brain damage. This review summarises the biological consequences observed using histology as well as the longitudinal findings measured with magnetic resonance imaging methods in brain damaged animals and patients. In particular, we discuss the impact of post-stroke brain hyperactivity on functional recovery in relation to time. The reviewed evidence also suggests that the proportion of the preserved functional network both in the lesioned and in the intact hemispheres, rather than the simple lesion location, determines the extent of functional recovery. Hence, future research exploring longitudinal changes in patients with brain damage may unveil potential biomarkers underlying functional recovery. Copyright © 2016 Elsevier Ltd. All rights reserved.

Detaching from the negative by reappraisal: the role of right superior frontal gyrus (BA9/32)

PubMed Central

Falquez, Rosalux; Couto, Blas; Ibanez, Agustin; Freitag, Martin T.; Berger, Moritz; Arens, Elisabeth A.; Lang, Simone; Barnow, Sven

2014-01-01

The ability to reappraise the emotional impact of events is related to long-term mental health. Self-focused reappraisal (REAPPself), i.e., reducing the personal relevance of the negative events, has been previously associated with neural activity in regions near right medial prefrontal cortex, but rarely investigated among brain-damaged individuals. Thus, we aimed to examine the REAPPself ability of brain-damaged patients and healthy controls considering structural atrophies and gray matter intensities, respectively. Twenty patients with well-defined cortex lesions due to an acquired circumscribed tumor or cyst and 23 healthy controls performed a REAPPself task, in which they had to either observe negative stimuli or decrease emotional responding by REAPPself. Next, they rated the impact of negative arousal and valence. REAPPself ability scores were calculated by subtracting the negative picture ratings after applying REAPPself from the ratings of the observing condition. The scores of the patients were included in a voxel-based lesion-symptom mapping (VLSM) analysis to identify deficit related areas (ROI). Then, a ROI group-wise comparison was performed. Additionally, a whole-brain voxel-based-morphometry (VBM) analysis was run, in which healthy participant's REAPPself ability scores were correlated with gray matter intensities. Results showed that (1) regions in the right superior frontal gyrus (SFG), comprising the right dorsolateral prefrontal cortex (BA9) and the right dorsal anterior cingulate cortex (BA32), were associated with patient's impaired down-regulation of arousal, (2) a lesion in the depicted ROI occasioned significant REAPPself impairments, (3) REAPPself ability of controls was linked with increased gray matter intensities in the ROI regions. Our findings show for the first time that the neural integrity and the structural volume of right SFG regions (BA9/32) might be indispensable for REAPPself. Implications for neurofeedback research are discussed. PMID:24847230

Structural white-matter connections mediating distinct behavioral components of spatial neglect in right brain-damaged patients.

PubMed

Vaessen, Maarten J; Saj, Arnaud; Lovblad, Karl-Olof; Gschwind, Markus; Vuilleumier, Patrik

2016-04-01

Spatial neglect is a neuropsychological syndrome in which patients fail to perceive and orient to stimuli located in the space contralateral to the lesioned hemisphere. It is characterized by a wide heterogeneity in clinical symptoms which can be grouped into distinct behavioral components correlating with different lesion sites. Moreover, damage to white-matter (WM) fiber tracts has been suggested to disconnect brain networks that mediate different functions associated with spatial cognition and attention. However, it remains unclear what WM pathways are associated with functionally dissociable neglect components. In this study we examined nine patients with a focal right hemisphere stroke using a series of neuropsychological tests and diffusion tensor imaging (DTI) in order to disentangle the role of specific WM pathways in neglect symptoms. First, following previous work, the behavioral test scores of patients were factorized into three independent components reflecting perceptual, exploratory, and object-centered deficits in spatial awareness. We then examined the structural neural substrates of these components by correlating indices of WM integrity (fractional anisotropy) with the severity of deficits along each profile. Several locations in the right parietal and frontal WM correlated with neuropsychological scores. Fiber tracts projecting from these locations indicated that posterior parts of the superior longitudinal fasciculus (SLF), as well as nearby callosal fibers connecting ipsilateral and contralateral parietal areas, were associated with perceptual spatial deficits, whereas more anterior parts of SLF and inferior fronto-occipital fasciculus (IFOF) were predominantly associated with object-centered deficits. In addition, connections between frontal areas and superior colliculus were found to be associated with the exploratory deficits. Our results provide novel support to the view that neglect may result from disconnection lesions in distributed brain networks, but also extend these notions by highlighting the role of dissociable circuits in different functional components of the neglect syndrome. However these preliminary findings require replication with larger samples of patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

Craniofacial and brain abnormalities in Laron syndrome (primary growth hormone insensitivity).

PubMed

Kornreich, L; Horev, G; Schwarz, M; Karmazyn, B; Laron, Z

2002-04-01

To investigate abnormalities in the craniofacial structures and in the brain in patients with Laron syndrome. Eleven patients with classical Laron syndrome, nine untreated adults aged 36-68 years and two children aged 4 and 9 years (the latter treated by IGF-I), were studied. Magnetic resonance images of the brain were obtained in all the patients. One patient also underwent computed tomography. The maximal diameter of the maxillary and frontal sinuses was measured and compared with reference values, the size of the sphenoid sinus was evaluated in relation to the sella, and the mastoids were evaluated qualitatively (small or normal). The brain was evaluated for congenital anomalies and parenchymal lesions. In the adult untreated patients, the paranasal sinuses and mastoids were small; in six patients, the bone marrow in the base of the skull was not mature. The diploe of the calvaria was thin. On computed tomography in one adult patient, the sutures were still open. A minimal or mild degree of diffuse brain parenchymal loss was seen in ten patients. One patient demonstrated a lacunar infarct and another periventricular high signals on T2-weighted images. Two patients had cerebellar atrophy. The present study has demonstrated the important role IGF-I plays in the development of the brain and bony structures of the cranium.

White Matter Connectivity of the Thalamus Delineates the Functional Architecture of Competing Thalamocortical Systems

PubMed Central

O'Muircheartaigh, Jonathan; Keller, Simon S.; Barker, Gareth J.; Richardson, Mark P.

2015-01-01

There is an increasing awareness of the involvement of thalamic connectivity on higher level cortical functioning in the human brain. This is reflected by the influence of thalamic stimulation on cortical activity and behavior as well as apparently cortical lesion syndromes occurring as a function of small thalamic insults. Here, we attempt to noninvasively test the correspondence of structural and functional connectivity of the human thalamus using diffusion-weighted and resting-state functional MRI. Using a large sample of 102 adults, we apply tensor independent component analysis to diffusion MRI tractography data to blindly parcellate bilateral thalamus according to diffusion tractography-defined structural connectivity. Using resting-state functional MRI collected in the same subjects, we show that the resulting structurally defined thalamic regions map to spatially distinct, and anatomically predictable, whole-brain functional networks in the same subjects. Although there was significant variability in the functional connectivity patterns, the resulting 51 structural and functional patterns could broadly be reduced to a subset of 7 similar core network types. These networks were distinct from typical cortical resting-state networks. Importantly, these networks were distributed across the brain and, in a subset, map extremely well to known thalamocortico-basal-ganglial loops. PMID:25899706

Distinct brain imaging characteristics of autoantibody-mediated CNS conditions and multiple sclerosis.

PubMed

Jurynczyk, Maciej; Geraldes, Ruth; Probert, Fay; Woodhall, Mark R; Waters, Patrick; Tackley, George; DeLuca, Gabriele; Chandratre, Saleel; Leite, Maria I; Vincent, Angela; Palace, Jacqueline

2017-03-01

Brain imaging characteristics of MOG antibody disease are largely unknown and it is unclear whether they differ from those of multiple sclerosis and AQP4 antibody disease. The aim of this study was to identify brain imaging discriminators between those three inflammatory central nervous system diseases in adults and children to support diagnostic decisions, drive antibody testing and generate disease mechanism hypotheses. Clinical brain scans of 83 patients with brain lesions (67 in the training and 16 in the validation cohort, 65 adults and 18 children) with MOG antibody (n = 26), AQP4 antibody disease (n = 26) and multiple sclerosis (n = 31) recruited from Oxford neuromyelitis optica and multiple sclerosis clinical services were retrospectively and anonymously scored on a set of 29 predefined magnetic resonance imaging features by two independent raters. Principal component analysis was used to perform an overview of patients without a priori knowledge of the diagnosis. Orthogonal partial least squares discriminant analysis was used to build models separating diagnostic groups and identify best classifiers, which were then tested on an independent cohort set. Adults and children with MOG antibody disease frequently had fluffy brainstem lesions, often located in pons and/or adjacent to fourth ventricle. Children across all conditions showed more frequent bilateral, large, brainstem and deep grey matter lesions. MOG antibody disease spontaneously separated from multiple sclerosis but overlapped with AQP4 antibody disease. Multiple sclerosis was discriminated from MOG antibody disease and from AQP4 antibody disease with high predictive values, while MOG antibody disease could not be accurately discriminated from AQP4 antibody disease. Best classifiers between MOG antibody disease and multiple sclerosis were similar in adults and children, and included ovoid lesions adjacent to the body of lateral ventricles, Dawson's fingers, T1 hypointense lesions (multiple sclerosis), fluffy lesions and three lesions or less (MOG antibody). In the validation cohort patients with antibody-mediated conditions were differentiated from multiple sclerosis with high accuracy. Both antibody-mediated conditions can be clearly separated from multiple sclerosis on conventional brain imaging, both in adults and children. The overlap between MOG antibody oligodendrocytopathy and AQP4 antibody astrocytopathy suggests that the primary immune target is not the main substrate for brain lesion characteristics. This is also supported by the clear distinction between multiple sclerosis and MOG antibody disease both considered primary demyelinating conditions. We identify discriminatory features, which may be useful in classifying atypical multiple sclerosis, seronegative neuromyelitis optica spectrum disorders and relapsing acute disseminated encephalomyelitis, and characterizing cohorts for antibody discovery. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Characterizing the type and location of intracranial abnormalities in mild traumatic brain injury.

PubMed

Isokuortti, Harri; Iverson, Grant L; Silverberg, Noah D; Kataja, Anneli; Brander, Antti; Öhman, Juha; Luoto, Teemu M

2018-01-12

OBJECTIVE The incidence of intracranial abnormalities after mild traumatic brain injury (TBI) varies widely across studies. This study describes the characteristics of intracranial abnormalities (acute/preexisting) in a large representative sample of head-injured patients who underwent CT imaging in an emergency department. METHODS CT scans were systematically analyzed/coded in the TBI Common Data Elements framework. Logistic regression modeling was used to quantify risk factors for traumatic intracranial abnormalities in patients with mild TBIs. This cohort included all patients who were treated at the emergency department of the Tampere University Hospital (between 2010 and 2012) and who had undergone head CT imaging after suffering a suspected TBI (n = 3023), including 2766 with mild TBI and a reference group with moderate to severe TBI. RESULTS The most common traumatic lesions seen on CT scans obtained in patients with mild TBIs and those with moderate to severe TBIs were subdural hematomas, subarachnoid hemorrhages, and contusions. Every sixth patient (16.1%) with mild TBI had an intracranial lesion compared with 5 of 6 patients (85.6%) in the group with moderate to severe TBI. The distribution of different types of acute traumatic lesions was similar among mild and moderate/severe TBI groups. Preexisting brain lesions were a more common CT finding among patients with mild TBIs than those with moderate to severe TBIs. Having a past traumatic lesion was associated with increased risk for an acute traumatic lesion but neurodegenerative and ischemic lesions were not. A lower Glasgow Coma Scale score, male sex, older age, falls, and chronic alcohol abuse were associated with higher risk of acute intracranial lesion in patients with mild TBI. CONCLUSIONS These findings underscore the heterogeneity of neuropathology associated with the mild TBI classification. Preexisting brain lesions are common in patients with mild TBI, and the incidence of preexisting lesions increases with age. Acute traumatic lesions are fairly common in patients with mild TBI; every sixth patient had a positive CT scan. Older adults (especially men) who fall represent a susceptible group for acute CT-positive TBI.

Detection of white matter lesion regions in MRI using SLIC0 and convolutional neural network.

PubMed

Diniz, Pedro Henrique Bandeira; Valente, Thales Levi Azevedo; Diniz, João Otávio Bandeira; Silva, Aristófanes Corrêa; Gattass, Marcelo; Ventura, Nina; Muniz, Bernardo Carvalho; Gasparetto, Emerson Leandro

2018-04-19

White matter lesions are non-static brain lesions that have a prevalence rate up to 98% in the elderly population. Because they may be associated with several brain diseases, it is important that they are detected as soon as possible. Magnetic Resonance Imaging (MRI) provides three-dimensional data with the possibility to detect and emphasize contrast differences in soft tissues, providing rich information about the human soft tissue anatomy. However, the amount of data provided for these images is far too much for manual analysis/interpretation, representing a difficult and time-consuming task for specialists. This work presents a computational methodology capable of detecting regions of white matter lesions of the brain in MRI of FLAIR modality. The techniques highlighted in this methodology are SLIC0 clustering for candidate segmentation and convolutional neural networks for candidate classification. The methodology proposed here consists of four steps: (1) images acquisition, (2) images preprocessing, (3) candidates segmentation and (4) candidates classification. The methodology was applied on 91 magnetic resonance images provided by DASA, and achieved an accuracy of 98.73%, specificity of 98.77% and sensitivity of 78.79% with 0.005 of false positives, without any false positives reduction technique, in detection of white matter lesion regions. It is demonstrated the feasibility of the analysis of brain MRI using SLIC0 and convolutional neural network techniques to achieve success in detection of white matter lesions regions. Copyright © 2018. Published by Elsevier B.V.

Facial recognition in children after perinatal stroke.

PubMed

Ballantyne, A O; Trauner, D A

1999-04-01

To examine the effects of prenatal or perinatal stroke on the facial recognition skills of children and young adults. It was hypothesized that the nature and extent of facial recognition deficits seen in patients with early-onset lesions would be different from that seen in adults with later-onset neurologic impairment. Numerous studies with normal and neurologically impaired adults have found a right-hemisphere superiority for facial recognition. In contrast, little is known about facial recognition in children after early focal brain damage. Forty subjects had single, unilateral brain lesions from pre- or perinatal strokes (20 had left-hemisphere damage, and 20 had right-hemisphere damage), and 40 subjects were controls who were individually matched to the lesion subjects on the basis of age, sex, and socioeconomic status. Each subject was given the Short-Form of Benton's Test of Facial Recognition. Data were analyzed using the Wilcoxon matched-pairs signed-rank test and multiple regression. The lesion subjects performed significantly more poorly than did matched controls. There was no clear-cut lateralization effect, with the left-hemisphere group performing significantly more poorly than matched controls and the right-hemisphere group showing a trend toward poorer performance. Parietal lobe involvement, regardless of lesion side, adversely affected facial recognition performance in the lesion group. Results could not be accounted for by IQ differences between lesion and control groups, nor was lesion severity systematically related to facial recognition performance. Pre- or perinatal unilateral brain damage results in a subtle disturbance in facial recognition ability, independent of the side of the lesion. Parietal lobe involvement, in particular, has an adverse effect on facial recognition skills. These findings suggest that the parietal lobes may be involved in the acquisition of facial recognition ability from a very early point in brain development, but that there is sufficient potential to reorganize or compensate such that the residual deficits, though significant, are subtle.

Neural signatures of third-party punishment: evidence from penetrating traumatic brain injury

PubMed Central

Glass, Leila; Moody, Lara; Grafman, Jordan

2016-01-01

The ability to survive within a cooperative society depends on impartial third-party punishment (TPP) of social norm violations. Two cognitive mechanisms have been postulated as necessary for the successful completion of TPP: evaluation of legal responsibility and selection of a suitable punishment given the magnitude of the crime. Converging neuroimaging research suggests two supporting domain-general networks; a mentalizing network for evaluation of legal responsibility and a central-executive network for determination of punishment. A whole-brain voxel-based lesion-symptom mapping approach was used in conjunction with a rank-order TPP task to identify brain regions necessary for TPP in a large sample of patients with penetrating traumatic brain injury. Patients who demonstrated atypical TPP had specific lesions in core regions of the mentalizing (dorsomedial prefrontal cortex [PFC], ventromedial PFC) and central-executive (bilateral dorsolateral PFC, right intraparietal sulcus) networks. Altruism and executive functioning (concept formation skills) were significant predictors of TPP: altruism was uniquely associated with TPP in patients with lesions in right dorsolateral PFC and executive functioning was uniquely associated with TPP in individuals with lesions in left PFC. Our findings contribute to the extant literature to support underlying neural networks associated with TPP, with specific brain-behavior causal relationships confirming recent functional neuroimaging research. PMID:26276809

Oxaloacetate decreases the infarct size and attenuates the reduction in evoked responses after photothrombotic focal ischemia in the rat cortex.

PubMed

Nagy, David; Marosi, Mate; Kis, Zsolt; Farkas, Tamas; Rakos, Gabriella; Vecsei, Laszlo; Teichberg, Vivian I; Toldi, Jozsef

2009-09-01

A traumatic brain injury or a focal brain lesion is followed by acute excitotoxicity caused by the presence of abnormally high glutamate (Glu) levels in the cerebrospinal and interstitial fluids. It has recently been demonstrated that this excess Glu in the brain can be eliminated into the blood following the intravenous administration of oxaloacetate (OxAc), which, by scavenging the blood Glu, induces an enhanced and neuroprotective brain-to-blood Glu efflux. In this study, we subjected rats to a photothrombotic lesion and treated them after the illumination with a single 30-min-long administration of OxAc (1.2 mg/100 g, i.v.). Following induction of the lesion, we measured the infarct size and the amplitudes of the somatosensory evoked potentials (SEPs) as recorded from the skull surface. The photothrombotic lesion resulted in appreciably decreased amplitudes of the evoked potentials, but OxAc administration significantly attenuated this reduction, and also the infarct size assessed histologically. We suggest that the neuroprotective effects of OxAc are due to its blood Glu-scavenging activity, which, by increasing the brain-to-blood Glu efflux, reduces the excess Glu responsible for the anatomical and functional correlates of the ischemia, as evaluated by electrophysiological evoked potential (EP) measurements.

Neurologic Injury and Cerebral Blood Flow In Single Ventricles Throughout Staged Surgical Reconstruction

PubMed Central

Fogel, Mark A.; Li, Christine; Elci, Okan U.; Pawlowski, Tom; Schwab, Peter J.; Wilson, Felice; Nicolson, Susan C.; Montenegro, Lisa M.; Diaz, Laura; Spray, Thomas L.; Gaynor, J William; Fuller, Stephanie; Mascio, Christopher; Keller, Marc S.; Harris, Matthew A.; Whitehead, Kevin K.; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J.

2017-01-01

Background Single ventricle patients experience a high rate of brain injury and adverse neurodevelopmental outcome, however, the incidence of brain abnormalities throughout surgical reconstruction and its relationship with cerebral blood flow, oxygen delivery and carbon dioxide reactivity remains unknown. Methods Single ventricle patients were studied with MRI scans immediately prior to bidirectional Glenn (pre-BDG), prior to Fontan and then 3–9 months after Fontan reconstruction. Results One hundred and sixty eight consecutive subjects recruited into the project underwent 235 scans: 63 pre-BDG (mean age 4.8+1.7 months), 118 BDG (2.9+1.4 years) and 54 after Fontan (2.4+1.0 years). Non-acute ischemic white matter changes on T2 weighted imaging, focal tissue loss, and ventriculomegaly were all more commonly detected in BDG and Fontans compared to pre-BDG (P<0.05). BDG patients has significantly higher CBF than Fontan patients. The odds of discovering brain injury adjusting for surgical stage as well as 2 or more co-existing lesions within a patient all decreased (63–75% and 44% respectively) with increasing amount of cerebral blood flow (P<0.05). In general, there was no association of oxygen delivery (with the exception of ventriculomegaly in the BDG group) or carbon dioxide reactivity with neurological injury. Conclusion Significant brain abnormalities are commonly present in single ventricle patients and detection of these lesions increase as children progress through staged surgical reconstruction with multiple co-existing lesions more common earlier than later. In addition, this study demonstrated that BDG patients had greater CBF than Fontan patients and that there exists an inverse association of various indices of CBF with these brain lesions, however, CO2 reactivity, oxygen delivery (with one exception) were not associated with brain lesion development. PMID:28031423

Brain MRI lesions and atrophy are associated with employment status in patients with multiple sclerosis.

PubMed

Tauhid, Shahamat; Chu, Renxin; Sasane, Rahul; Glanz, Bonnie I; Neema, Mohit; Miller, Jennifer R; Kim, Gloria; Signorovitch, James E; Healy, Brian C; Chitnis, Tanuja; Weiner, Howard L; Bakshi, Rohit

2015-11-01

Multiple sclerosis (MS) commonly affects occupational function. We investigated the link between brain MRI and employment status. Patients with MS (n = 100) completed a Work Productivity and Activity Impairment (WPAI) (general health version) survey measuring employment status, absenteeism, presenteeism, and overall work and daily activity impairment. Patients "working for pay" were considered employed; "temporarily not working but looking for work," "not working or looking for work due to age," and "not working or looking for work due to disability" were considered not employed. Brain MRI T1 hypointense (T1LV) and T2 hyperintense (T2LV) lesion volumes were quantified. To assess lesional destructive capability, we calculated each subject's ratio of T1LV to T2LV (T1/T2). Normalized brain parenchymal volume (BPV) assessed brain atrophy. The mean (SD) age was 45.5 (9.7) years; disease duration was 12.1 (8.1) years; 75 % were women, 76 % were relapsing-remitting, and 76 % were employed. T1LV, T1/T2, Expanded Disability Status Scale (EDSS) scores, and activity impairment were lower and BPV was higher in the employed vs. not employed group (Wilcoxon tests, p < 0.05). Age, disease duration, MS clinical subtype, and T2LV did not differ between groups (p > 0.05). In multivariable logistic regression modeling, adjusting for age, sex, and disease duration, higher T1LV predicted a lower chance of employment (p < 0.05). Pearson correlations showed that EDSS was associated with activity impairment (p < 0.05). Disease duration, age, and MRI measures were not correlated with activity impairment or other WPAI outcomes (p > 0.05). We report a link between brain atrophy and lesions, particularly lesions with destructive potential, to MS employment status.

Prefrontal cortex lesions and MAO-A modulate aggression in penetrating traumatic brain injury

PubMed Central

Pardini, M.; Krueger, F.; Hodgkinson, C.; Raymont, V.; Ferrier, C.; Goldman, D.; Strenziok, M.; Guida, S.

2011-01-01

Objective: This study investigates the interaction between brain lesion location and monoamine oxidase A (MAO-A) in the genesis of aggression in patients with penetrating traumatic brain injury (PTBI). Methods: We enrolled 155 patients with PTBI and 42 controls drawn from the Vietnam Head Injury Study registry. Patients with PTBI were divided according to lesion localization (prefrontal cortex [PFC] vs non-PFC) and were genotyped for the MAO-A polymorphism linked to low and high transcriptional activity. Aggression was assessed with the aggression/agitation subscale of the Neuropsychiatric Inventory (NPI-a). Results: Patients with the highest levels of aggression preferentially presented lesions in PFC territories. A significant interaction between MAO-A transcriptional activity and lesion localization on aggression was revealed. In the control group, carriers of the low-activity allele demonstrated higher aggression than high-activity allele carriers. In the PFC lesion group, no significant differences in aggression were observed between carriers of the 2 MAO-A alleles, whereas in the non-PFC lesion group higher aggression was observed in the high-activity allele than in the low-activity allele carriers. Higher NPI-a scores were linked to more severe childhood psychological traumatic experiences and posttraumatic stress disorder symptomatology in the control and non-PFC lesion groups but not in the PFC lesion group. Conclusions: Lesion location and MAO-A genotype interact in mediating aggression in PTBI. Importantly, PFC integrity is necessary for modulation of aggressive behaviors by genetic susceptibilities and traumatic experiences. Potentially, lesion localization and MAO-A genotype data could be combined to develop risk-stratification algorithms and individualized treatments for aggression in PTBI. PMID:21422455

Characterizing Signals Within Lesions and Mapping Brain Network Connectivity After Traumatic Axonal Injury: A 7 Tesla Resting-State FMRI Study.

PubMed

Lee, Seul; Polimeni, Jonathan R; Price, Collin M; Edlow, Brian L; McNab, Jennifer A

2018-06-01

Resting-state functional magnetic resonance imaging (RS-FMRI) has been widely used to map brain functional connectivity, but it is unclear how to probe connectivity within and around lesions. In this study, we characterize RS-FMRI signal time course properties and evaluate different seed placements within and around hemorrhagic traumatic axonal injury (hTAI) lesions. RS-FMRI was performed on a 7 Tesla scanner in a patient who recovered consciousness after traumatic coma and in three healthy controls. Eleven lesions in the patient were characterized in terms of (1) temporal signal-to-noise ratio (tSNR); (2) physiological noise, through comparison of noise regressors derived from the white matter (WM), cerebrospinal fluid (CSF), and gray matter (GM); and (3) seed-based functional connectivity. Temporal SNR at the center of the lesions was 38.3% and 74.1% lower compared with the same region in the contralesional hemisphere of the patient and in the ipsilesional hemispheres of the controls, respectively. Within the lesions, WM noise was more prominent than CSF and GM noise. Lesional seeds did not produce discernable networks, but seeds in the contralesional hemisphere revealed networks whose nodes appeared to be shifted or obscured due to overlapping or nearby lesions. Single-voxel seed analysis demonstrated that placing a seed within a lesion's periphery was necessary to identify networks associated with the lesion region. These findings provide evidence of resting-state network changes in the human brain after recovery from traumatic coma. Furthermore, we show that seed placement within a lesion's periphery or in the contralesional hemisphere may be necessary for network identification in patients with hTAI.

Magnetization Transfer Ratio Relates to Cognitive Impairment in Normal Elderly

PubMed Central

Seiler, Stephan; Pirpamer, Lukas; Hofer, Edith; Duering, Marco; Jouvent, Eric; Fazekas, Franz; Mangin, Jean-Francois; Chabriat, Hugues; Dichgans, Martin; Ropele, Stefan; Schmidt, Reinhold

2014-01-01

Magnetization transfer imaging (MTI) can detect microstructural brain tissue changes and may be helpful in determining age-related cerebral damage. We investigated the association between the magnetization transfer ratio (MTR) in gray and white matter (WM) and cognitive functioning in 355 participants of the Austrian stroke prevention family study (ASPS-Fam) aged 38–86 years. MTR maps were generated for the neocortex, deep gray matter structures, WM hyperintensities, and normal appearing WM (NAWM). Adjusted mixed models determined whole brain and lobar cortical MTR to be directly and significantly related to performance on tests of memory, executive function, and motor skills. There existed an almost linear dose-effect relationship. MTR of deep gray matter structures and NAWM correlated to executive functioning. All associations were independent of demographics, vascular risk factors, focal brain lesions, and cortex volume. Further research is needed to understand the basis of this association at the tissue level, and to determine the role of MTR in predicting cognitive decline and dementia. PMID:25309438

Astrocytes, therapeutic targets for neuroprotection and neurorestoration in ischemic stroke

PubMed Central

Liu, Zhongwu; Chopp, Michael

2015-01-01

Astrocytes are the most abundant cell type within the central nervous system. They play essential roles in maintaining normal brain function, as they are a critical structural and functional part of the tripartite synapses and the neurovascular unit, and communicate with neurons, oligodendrocytes and endothelial cells. After an ischemic stroke, astrocytes perform multiple functions both detrimental and beneficial, for neuronal survival during the acute phase. Aspects of the astrocytic inflammatory response to stroke may aggravate the ischemic lesion, but astrocytes also provide benefit for neuroprotection, by limiting lesion extension via anti-excitotoxicity effects and releasing neurotrophins. Similarly, during the late recovery phase after stroke, the glial scar may obstruct axonal regeneration and subsequently reduce the functional outcome; however, astrocytes also contribute to angiogenesis, neurogenesis, synaptogenesis, and axonal remodeling, and thereby promote neurological recovery. Thus, the pivotal involvement of astrocytes in normal brain function and responses to an ischemic lesion designates them as excellent therapeutic targets to improve functional outcome following stroke. In this review, we will focus on functions of astrocytes and astrocyte-mediated events during stroke and recovery. We will provide an overview of approaches on how to reduce the detrimental effects and amplify the beneficial effects of astrocytes on neuroprotection and on neurorestoration post stroke, which may lead to novel and clinically relevant therapies for stroke. PMID:26455456

Automatic segmentation and volumetry of multiple sclerosis brain lesions from MR images

PubMed Central

Jain, Saurabh; Sima, Diana M.; Ribbens, Annemie; Cambron, Melissa; Maertens, Anke; Van Hecke, Wim; De Mey, Johan; Barkhof, Frederik; Steenwijk, Martijn D.; Daams, Marita; Maes, Frederik; Van Huffel, Sabine; Vrenken, Hugo; Smeets, Dirk

2015-01-01

The location and extent of white matter lesions on magnetic resonance imaging (MRI) are important criteria for diagnosis, follow-up and prognosis of multiple sclerosis (MS). Clinical trials have shown that quantitative values, such as lesion volumes, are meaningful in MS prognosis. Manual lesion delineation for the segmentation of lesions is, however, time-consuming and suffers from observer variability. In this paper, we propose MSmetrix, an accurate and reliable automatic method for lesion segmentation based on MRI, independent of scanner or acquisition protocol and without requiring any training data. In MSmetrix, 3D T1-weighted and FLAIR MR images are used in a probabilistic model to detect white matter (WM) lesions as an outlier to normal brain while segmenting the brain tissue into grey matter, WM and cerebrospinal fluid. The actual lesion segmentation is performed based on prior knowledge about the location (within WM) and the appearance (hyperintense on FLAIR) of lesions. The accuracy of MSmetrix is evaluated by comparing its output with expert reference segmentations of 20 MRI datasets of MS patients. Spatial overlap (Dice) between the MSmetrix and the expert lesion segmentation is 0.67 ± 0.11. The intraclass correlation coefficient (ICC) equals 0.8 indicating a good volumetric agreement between the MSmetrix and expert labelling. The reproducibility of MSmetrix' lesion volumes is evaluated based on 10 MS patients, scanned twice with a short interval on three different scanners. The agreement between the first and the second scan on each scanner is evaluated through the spatial overlap and absolute lesion volume difference between them. The spatial overlap was 0.69 ± 0.14 and absolute total lesion volume difference between the two scans was 0.54 ± 0.58 ml. Finally, the accuracy and reproducibility of MSmetrix compare favourably with other publicly available MS lesion segmentation algorithms, applied on the same data using default parameter settings. PMID:26106562

Coexistence of Multiple Sclerosis and Brain Tumor: An Uncommon Diagnostic Challenge.

PubMed

Abrishamchi, Fatemeh; Khorvash, Fariborz

2017-01-01

Nonneoplastic demyelinating processes of the brain with mass effect on magnetic resonance imaging can cause diagnostic difficulties. It requires differential diagnosis between the tumefactive demyelinating lesion and the coexistence of neoplasm. We document the case of 41-year-old woman with clinical and radiological findings suggestive of multiple sclerosis. Additional investigations confirmed the coexistence of astrocytoma. This report emphasizes the importance of considering brain tumors in the differential diagnosis of primary demyelinating disease presenting with a cerebral mass lesion.

Altered functional connectivity differs in stroke survivors with impaired touch sensation following left and right hemisphere lesions.

PubMed

Goodin, Peter; Lamp, Gemma; Vidyasagar, Rishma; McArdle, David; Seitz, Rüdiger J; Carey, Leeanne M

2018-01-01

One in two survivors experience impairment in touch sensation after stroke. The nature of this impairment is likely associated with changes associated with the functional somatosensory network of the brain; however few studies have examined this. In particular, the impact of lesioned hemisphere has not been investigated. We examined resting state functional connectivity in 28 stroke survivors, 14 with left hemisphere and 14 with right hemisphere lesion, and 14 healthy controls. Contra-lesional hands showed significantly decreased touch discrimination. Whole brain functional connectivity (FC) data was extracted from four seed regions, i.e. primary (S1) and secondary (S2) somatosensory cortices in both hemispheres. Whole brain FC maps and Laterality Indices (LI) were calculated for subgroups. Inter-hemispheric FC was greater in healthy controls compared to the combined stroke cohort from the left S1 seed and bilateral S2 seeds. The left lesion subgroup showed decreased FC, relative to controls, from left ipsi-lesional S1 to contra-lesional S1 and to distributed temporal, occipital and parietal regions. In comparison, the right lesion group showed decreased connectivity from contra-lesional left S1 and bilateral S2 to ipsi-lesional parietal operculum (S2), and to occipital and temporal regions. The right lesion group also showed increased intra-hemispheric FC from ipsi-lesional right S1 to inferior parietal regions compared to controls. In comparison to the left lesion group, those with right lesion showed greater intra-hemispheric connectivity from left S1 to left parietal and occipital regions and from right S1 to right angular and parietal regions. Laterality Indices were significantly greater for stroke subgroups relative to matched controls for contra-lesional S1 (left lesion group) and contra-lesional S2 (both groups). We provide evidence of altered functional connectivity within the somatosensory network, across both hemispheres, and to other networks in stroke survivors with impaired touch sensation. Hemisphere of lesion was associated with different patterns of altered functional connectivity within the somatosensory network and with related function was associated with different patterns of altered functional connectivity within the somatosensory network and with related functional networks.

Combining Voxel-based Lesion-symptom Mapping (VLSM) With A-tDCS Language Treatment: Predicting Outcome of Recovery in Nonfluent Chronic Aphasia.

PubMed

Campana, Serena; Caltagirone, Carlo; Marangolo, Paola

2015-01-01

Most of transcranial direct current stimulation (tDCS) studies in aphasia have already shown that significant changes in language performance could be improved by increased monitoring of the perilesional cortex in the left lesioned hemisphere with excitatory anodal tDCS (A-tDCS). However, no report to date has investigated which areas may be less predictable or may play a major role in the recovery from language impairment after brain stimulation. We investigated the relationship between the localization of damage in the left hemisphere and the amount of language recovery after A-tDCS. We conducted a Voxel-lesion mapping-symptom (VLSM) analysis on twenty non-fluent aphasics who underwent a language treatment in concomitance with left A-tDCS delivered over the left inferior frontal gyrus (IFG) and a sham condition. Significant changes in language performance before and after the two conditions were examined in three language tasks (picture description, noun and verb naming). VLSM analysis revealed that damage to distinct left hemispheric structures and, in particular, to the basal ganglia, the insula and the superior and inferior longitudinal fasciculi, resulted in lower responses to A-tDCS in all language measures. Beneficial effects after A-tDCS over the left IFG depend on the anatomical integrity of different left subcortical structures among which are the white matter language pathways. Future studies combining different approaches on larger samples of subjects will further elucidate our understanding of how the human brain responds to tDCS. Copyright © 2015 Elsevier Inc. All rights reserved.

Hoyeraal-Hreidarsson syndrome: magnetic resonance imaging findings.

PubMed

Kuwashima, Shigeko

2009-10-01

Hoyeraal-Hreidarsson syndrome (HH) has been defined as a severe variant of dyskeratosis congenita (DKC). We report here a case of a 6-year-old girl with HH who presented with bone marrow hypoplasia, skin pigmentation, nail dystrophy, growth retardation, and bilateral retinal hemorrhage. Brain MRI revealed cerebellar hypoplasia, hypoplasia of the corpus callosum, a small pituitary gland, a small brain stem, and focal long T2 lesions in the thalamus and brain stem. A brain computed tomography scan revealed intracranial calcification as well. To the best of our knowledge, a small pituitary gland and focal long T2 lesions in the thalamus and brain stem have never been reported as a feature of HH.

Brain-Only Metastases Seen on FDG PET as First Relapse of Papillary Thyroid Carcinoma Two Years Post-Thyroidectomy.

PubMed

Naddaf, Sleiman Y; Syed, Ghulam Mustafa Shah; Hadb, Abdulrahman; Al-Thaqfi, Saif

2016-09-01

We report a case of a 60-year-old man diagnosed with papillary thyroid cancer who had a relapse seen only in the brain at FDG PET on standard images. Total thyroidectomy was performed in July 2013 after initial diagnosis. Patient received I ablation in December 2013, followed by external beam radiotherapy to the neck. In September 2015, the patient presented with neurological symptoms. Brain MRI showed multiple brain metastases later confirmed on histopathology. An FDG PET/CT scan was performed to evaluate the whole body in November 2015. Multiple hypermetabolic lesions were identified in the brain with no other lesion up to mid thighs.

Bronchogenic adenocarcinoma presenting as a synchronous solitary lytic skull lesion with ischaemic stroke – case report and literature review

PubMed Central

O’Connell, David; Kaliaperumal, Chandrasekaran; Wyse, Gerald; McCarthy, Julie; Ryan, Aisling

2011-01-01

The authors describe a rare case of metastatic bronchogenic adenocarcinoma in a 55-year-old man presenting with concomittant solitary lytic skull lesion and ischaemic stroke. Metastatic bronchogenic carcinoma is known to present as lytic skull lesions. Primary brain tumours are also known to cause ischaemic brain injury. An underlying stroke risk may be exagerated by cranial tumour surgery. Patients with brain tumours are well known to be predisposed to an increased risk of developing thromboembolic disease. It is unusual to see metastatic bronchogenic adenocarcinoma presenting as ischaemic stroke with a background of concomittant cerebral metastasis. The aetio-pathogenesis of this rare occurrence is discussed with a review of literature. PMID:22669998

Synchronous glioblastoma multiforme and chondrosarcoma: A case report and review of the literature.

PubMed

Li, Charles Xin; Goldenberg, Yoni; McLean, Catriona; Savio Gomes, Keith

2018-06-01

This case report describes the rare occurrence of two individually uncommon tumours found in synchronous manner in an otherwise healthy patient with no history of malignancy. We believe this to be the first reported case of synchronous glioblastoma and chondrosarcoma. While primary rib lesions metastasising to brain are rarely reported and primary brain lesions metastasising to rib are even rarer still, there were no previous reports in the literature of synchronous brain and rib dual primary pathology that we could identify. Unrelated dual pathology, while rare, must be considered amongst the list of differential diagnoses in patients who present with multiple lesions, and highlights the importance of separate histological confirmation prior to integrated management. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of birth asphyxia on neonatal hippocampal structure and function in the spiny mouse.

PubMed

Fleiss, B; Coleman, H A; Castillo-Melendez, M; Ireland, Z; Walker, D W; Parkington, H C

2011-11-01

Studies of human neonates, and in animal experiments, suggest that birth asphyxia results in functional compromise of the hippocampus, even when structural damage is not observable or resolves in early postnatal life. The aim of this study was to determine if changes in hippocampal function occur in a model of birth asphyxia in the precocial spiny mouse where it is reported there is no major lesion or infarct. Further, to assess if, as in human infants, this functional deficit has a sex-dependent component. At 37 days gestation (term=39 days) spiny mice fetuses were either delivered immediately by caesarean section (control group) or exposed to 7.5min of in utero asphyxia causing systemic acidosis and hypoxia. At 5 days of age hippocampal function was assessed ex vivo in brain slices, or brains were collected for examination of structure or protein expression. This model of birth asphyxia did not cause infarct or cystic lesion in the postnatal day 5 (P5) hippocampus, and the number of proliferating or pyknotic cells in the hippocampus was unchanged, although neuronal density in the CA1 and CA3 was increased. Protein expression of synaptophysin, brain-derived neurotrophic factor (BDNF), and the inositol trisphosphate receptor 1 (IP(3)R1) were all significantly increased after birth asphyxia, while long-term potentiation (LTP), paired pulse facilitation (PPF), and post-tetanic potentiation (PTP) were all reduced at P5 by birth asphyxia. In control P5 pups, PPF and synaptic fatigue were greater in female compared to male pups, and after birth asphyxia PPF and synaptic fatigue were reduced to a greater extent in female vs. male pups. In contrast, the asphyxia-induced increase in synaptophysin expression and neuronal density were greater in male pups. Thus, birth asphyxia in this precocial species causes functional deficits without major structural damage, and there is a sex-dependent effect on the hippocampus. This may be a clinically relevant model for assessing treatments delivered either before or after birth to protect this vulnerable region of the developing brain. Copyright © 2011 ISDN. Published by Elsevier Ltd. All rights reserved.

Intracranial Tumor Cell Migration and the Development of Multiple Brain Metastases in Malignant Melanoma.

PubMed

Simonsen, Trude G; Gaustad, Jon-Vidar; Rofstad, Einar K

2016-06-01

A majority of patients with melanoma brain metastases develop multiple lesions, and these patients show particularly poor prognosis. To develop improved treatment strategies, detailed insights into the biology of melanoma brain metastases, and particularly the development of multiple lesions, are needed. The purpose of this preclinical investigation was to study melanoma cell migration within the brain after cell injection into a well-defined intracerebral site. A-07, D-12, R-18, and U-25 human melanoma cells transfected with green fluorescent protein were injected stereotactically into the right cerebral hemisphere of nude mice. Moribund mice were killed and autopsied, and the brain was evaluated by fluorescence imaging or histological examination. Intracerebral inoculation of melanoma cells produced multiple lesions involving all regions of the brain, suggesting that the cells were able to migrate over substantial distances within the brain. Multiple modes of transport were identified, and all transport modes were observed in all four melanoma lines. Thus, the melanoma cells were passively transported via the flow of cerebrospinal fluid in the meninges and ventricles, they migrated actively along leptomeningeal and brain parenchymal blood vessels, and they migrated actively along the surfaces separating different brain compartments. Migration of melanoma cells after initial arrest, extravasation, and growth at a single location within the brain may contribute significantly to the development of multiple melanoma brain metastases. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Reversible Holmes' tremor due to spontaneous intracranial hypotension.

PubMed

Iyer, Rajesh Shankar; Wattamwar, Pandurang; Thomas, Bejoy

2017-07-27

Holmes' tremor is a low-frequency hand tremor and has varying amplitude at different phases of motion. It is usually unilateral and does not respond satisfactorily to drugs and thus considered irreversible. Structural lesions in the thalamus and brainstem or cerebellum are usually responsible for Holmes' tremor. We present a 23-year-old woman who presented with unilateral Holmes' tremor. She also had hypersomnolence and headache in the sitting posture. Her brain imaging showed brain sagging and deep brain swelling due to spontaneous intracranial hypotension (SIH). She was managed conservatively and had a total clinical and radiological recovery. The brain sagging with the consequent distortion of the midbrain and diencephalon was responsible for this clinical presentation. SIH may be considered as one of the reversible causes of Holmes' tremor. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Surgical treatment of temporal lobe epilepsy: clinical, radiological, and histopathological findings in 178 patients.

PubMed Central

Zentner, J; Hufnagel, A; Wolf, H K; Ostertun, B; Behrens, E; Campos, M G; Solymosi, L; Elger, C E; Wiestler, O D; Schramm, J

1995-01-01

The surgical treatment of pharmacoresistant temporal lobe epilepsy is increasing rapidly. The correlation of preoperative MRI, histopathological findings, and postoperative seizure control is reported for 178 patients with chronic medically intractable temporal lobe epilepsy who were operated on between November 1987 and January 1993. Histopathologically there were distinct structural abnormalities in 97.2% of the surgical specimens. Signal abnormalities on MRI were present in 98.7% of patients with neoplastic lesions (n = 79), 76.6% of patients with non-neoplastic focal lesions (n = 55), and 69.2% of patients with Ammon's horn sclerosis (n = 39). Overall, structural abnormalities were detected by MRI in 82.7% of all patients. The mean postoperative follow up period was three years. Some 92% of the patients benefited from surgery: 103 patients (61.7%) were seizure free, 26 (15.5%) had no more than two seizures a year, and 24 (14.4%) showed a reduction of seizure frequency of at least 75%. Fourteen patients (8.4%) had a < 75% reduction of seizure frequency. The percentage of patients who were completely free of seizures after operation was 68.5% for patients with neoplastic lesions, 66.7% for Ammon's horn sclerosis, and 54.0% for patients with non-neoplastic focal lesions. By contrast, none of the patients in whom histopathological findings were normal became seizure free postoperatively. The data show that the presence of focal lesions or Ammon's horn sclerosis as determined by histopathological examination is associated with improved postoperative seizure control compared with patients without specific pathological findings. Brain MRI was very sensitive in detecting neoplasms; however, its sensitivity and specificity were limited with respect to non-neoplastic focal lesions and Ammon's horn sclerosis. Improvement of imaging techniques may provide a more precise definition of structural lesions in these cases and facilitate limited surgical resections of the epileptogenic area rather than standardised anatomical resections. Images PMID:7608662

SPET brain perfusion imaging in mild traumatic brain injury without loss of consciousness and normal computed tomography.

PubMed

Abu-Judeh, H H; Parker, R; Singh, M; el-Zeftawy, H; Atay, S; Kumar, M; Naddaf, S; Aleksic, S; Abdel-Dayem, H M

1999-06-01

We present SPET brain perfusion findings in 32 patients who suffered mild traumatic brain injury without loss of consciousness and normal computed tomography. None of the patients had previous traumatic brain injury, CVA, HIV, psychiatric disorders or a history of alcohol or drug abuse. Their ages ranged from 11 to 61 years (mean = 42). The study was performed in 20 patients (62%) within 3 months of the date of injury and in 12 (38%) patients more than 3 months post-injury. Nineteen patients (60%) were involved in a motor vehicle accident, 10 patients (31%) sustained a fall and three patients (9%) received a blow to the head. The most common complaints were headaches in 26 patients (81%), memory deficits in 15 (47%), dizziness in 13 (41%) and sleep disorders in eight (25%). The studies were acquired approximately 2 h after an intravenous injection of 740 MBq (20.0 mCi) of 99Tcm-HMPAO. All images were acquired on a triple-headed gamma camera. The data were displayed on a 10-grade colour scale, with 2-pixel thickness (7.4 mm), and were reviewed blind to the patient's history of symptoms. The cerebellum was used as the reference site (100% maximum value). Any decrease in cerebral perfusion in the cortex or basal ganglia less than 70%, or less than 50% in the medial temporal lobe, compared to the cerebellar reference was considered abnormal. The results show that 13 (41%) had normal studies and 19 (59%) were abnormal (13 studies performed within 3 months of the date of injury and six studies performed more than 3 months post-injury). Analysis of the abnormal studies revealed that 17 showed 48 focal lesions and two showed diffuse supratentorial hypoperfusion (one from each of the early and delayed imaging groups). The 12 abnormal studies performed early had 37 focal lesions and averaged 3.1 lesions per patient, whereas there was a reduction to--an average of 2.2 lesions per patient in the five studies (total 11 lesions) performed more than 3 months post-injury. In the 17 abnormal studies with focal lesions, the following regions were involved in descending frequency: frontal lobes 58%, basal ganglia and thalami 47%, temporal lobes 26% and parietal lobes 16%. We conclude that: (1) SPET brain perfusion imaging is valuable and sensitive for the evaluation of cerebral perfusion changes following mild traumatic brain injury; (2) these changes can occur without loss of consciousness; (3) SPET brain perfusion imaging is more sensitive than computed tomography in detecting brain lesions; and (4) the changes may explain a neurological component of the patient's symptoms in the absence of morphological abnormalities using other imaging modalities.

Intraoperative Magnetic Resonance Imaging of Cerebral Oxygen Metabolism During Resection of Brain Lesions.

PubMed

Stadlbauer, Andreas; Merkel, Andreas; Zimmermann, Max; Sommer, Björn; Buchfelder, Michael; Meyer-Bäse, Anke; Rössler, Karl

2017-04-01

Tissue oxygen tension is an important parameter for brain tissue viability and its noninvasive intraoperative monitoring in the whole brain is of highly clinical relevance. The purpose of this study was the introduction of a multiparametric quantitative blood oxygenation dependent magnetic resonance imaging (MRI) approach for intraoperative examination of oxygen metabolism during the resection of brain lesions. Sixteen patients suffering from brain lesions were examined intraoperatively twice (before craniotomy and after gross-total resection) via the quantitative blood oxygenation dependent technique and a 1.5-Tesla MRI scanner, which is installed in an operating room. The MRI protocol included T2*- and T2 mapping and dynamic susceptibility weighted perfusion. Data analysis was performed with a custom-made, in-house MatLab software for calculation of maps of oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO 2 ) as well as of cerebral blood volume and cerebral blood flow. Perilesional edema showed a significant increase in both perfusion (cerebral blood volume +21%, cerebral blood flow +13%) and oxygen metabolism (OEF +32%, CMRO 2  +16%) after resection of the lesions. In perilesional nonedematous tissue only, however, oxygen metabolism (OEF +19%, CMRO 2  +11%) was significantly increased, but not perfusion. No changes were found in normal brain. Fortunately, no neurovascular adverse events were observed. This approach for intraoperative examination of oxygen metabolism in the whole brain is a new application of intraoperative MRI additionally to resection control (residual tumor detection) and updating of neuronavigation (brain shift detection). It may help to detect neurovascular adverse events early during surgery. Copyright © 2017 Elsevier Inc. All rights reserved.

A standardized method for the construction of tracer specific PET and SPECT rat brain templates: validation and implementation of a toolbox.

PubMed

Vállez Garcia, David; Casteels, Cindy; Schwarz, Adam J; Dierckx, Rudi A J O; Koole, Michel; Doorduin, Janine

2015-01-01

High-resolution anatomical image data in preclinical brain PET and SPECT studies is often not available, and inter-modality spatial normalization to an MRI brain template is frequently performed. However, this procedure can be challenging for tracers where substantial anatomical structures present limited tracer uptake. Therefore, we constructed and validated strain- and tracer-specific rat brain templates in Paxinos space to allow intra-modal registration. PET [18F]FDG, [11C]flumazenil, [11C]MeDAS, [11C]PK11195 and [11C]raclopride, and SPECT [99mTc]HMPAO brain scans were acquired from healthy male rats. Tracer-specific templates were constructed by averaging the scans, and by spatial normalization to a widely used MRI-based template. The added value of tracer-specific templates was evaluated by quantification of the residual error between original and realigned voxels after random misalignments of the data set. Additionally, the impact of strain differences, disease uptake patterns (focal and diffuse lesion), and the effect of image and template size on the registration errors were explored. Mean registration errors were 0.70 ± 0.32 mm for [18F]FDG (n = 25), 0.23 ± 0.10mm for [11C]flumazenil (n = 13), 0.88 ± 0.20 mm for [11C]MeDAS (n = 15), 0.64 ± 0.28 mm for [11C]PK11195 (n = 19), 0.34 ± 0.15 mm for [11C]raclopride (n = 6), and 0.40 ± 0.13 mm for [99mTc]HMPAO (n = 15). These values were smallest with tracer-specific templates, when compared to the use of [18F]FDG as reference template (p<0.001). Additionally, registration errors were smallest with strain-specific templates (p<0.05), and when images and templates had the same size (p ≤ 0.001). Moreover, highest registration errors were found for the focal lesion group (p<0.005) and the diffuse lesion group (p = n.s.). In the voxel-based analysis, the reported coordinates of the focal lesion model are consistent with the stereotaxic injection procedure. The use of PET/SPECT strain- and tracer-specific templates allows accurate registration of functional rat brain data, independent of disease specific uptake patterns and with registration error below spatial resolution of the cameras. The templates and the SAMIT package will be freely available for the research community [corrected].

A Standardized Method for the Construction of Tracer Specific PET and SPECT Rat Brain Templates: Validation and Implementation of a Toolbox

PubMed Central

Vállez Garcia, David; Casteels, Cindy; Schwarz, Adam J.; Dierckx, Rudi A. J. O.; Koole, Michel; Doorduin, Janine

2015-01-01

High-resolution anatomical image data in preclinical brain PET and SPECT studies is often not available, and inter-modality spatial normalization to an MRI brain template is frequently performed. However, this procedure can be challenging for tracers where substantial anatomical structures present limited tracer uptake. Therefore, we constructed and validated strain- and tracer-specific rat brain templates in Paxinos space to allow intra-modal registration. PET [18F]FDG, [11C]flumazenil, [11C]MeDAS, [11C]PK11195 and [11C]raclopride, and SPECT [99mTc]HMPAO brain scans were acquired from healthy male rats. Tracer-specific templates were constructed by averaging the scans, and by spatial normalization to a widely used MRI-based template. The added value of tracer-specific templates was evaluated by quantification of the residual error between original and realigned voxels after random misalignments of the data set. Additionally, the impact of strain differences, disease uptake patterns (focal and diffuse lesion), and the effect of image and template size on the registration errors were explored. Mean registration errors were 0.70±0.32mm for [18F]FDG (n = 25), 0.23±0.10mm for [11C]flumazenil (n = 13), 0.88±0.20 mm for [11C]MeDAS (n = 15), 0.64±0.28mm for [11C]PK11195 (n = 19), 0.34±0.15mm for [11C]raclopride (n = 6), and 0.40±0.13mm for [99mTc]HMPAO (n = 15). These values were smallest with tracer-specific templates, when compared to the use of [18F]FDG as reference template (p&0.001). Additionally, registration errors were smallest with strain-specific templates (p&0.05), and when images and templates had the same size (p≤0.001). Moreover, highest registration errors were found for the focal lesion group (p&0.005) and the diffuse lesion group (p = n.s.). In the voxel-based analysis, the reported coordinates of the focal lesion model are consistent with the stereotaxic injection procedure. The use of PET/SPECT strain- and tracer-specific templates allows accurate registration of functional rat brain data, independent of disease specific uptake patterns and with registration error below spatial resolution of the cameras. The templates and the SAMIT package will be freely available for the research community. PMID:25823005

Pattern of Corticospinal Projections Defined by Brain Mapping During Resective Epilepsy Surgery in a Patient with Congenital Hemiparesis and Intractable Epilepsy.

PubMed

Yang, Chen-Ya; Chen, Hsin-Hung; Chen, Chien; Chiu, Jan-Wei; Chou, Chen-Liang; Yang, Tsui-Fen

2017-11-01

Congenital or early-onset brain structural lesions often cause contralateral hemiparesis, cognitive deficits, developmental delays, and seizures. Seizure is the most debilitating condition, as it greatly impairs quality of life in both the affected individuals and their caregivers and prevents them from active social participation. A 34-year-old man with hemiparesis and early-onset seizures since childhood owing to a congenital brain lesion developed intractable seizures in the last 2 years and was subsequently admitted for resective epileptic surgery. During the operation, we employed an innovative intraoperative neurophysiologic monitoring technique. In contrast to routine application for transcranial stimulation, we recorded compound muscle action potentials over the bilateral limb muscles simultaneously, instead of over the contralateral muscles only, to determine the patterns of the corticospinal projections. Transcranial stimulation over the bilateral hemispheres was applied before craniotomy, and direct cortical stimulation over the lesioned hemisphere was applied after craniotomy. By integrating both approaches, we could first identify the pattern of corticospinal projections before craniotomy and then accurately define the noneloquent area, which guided the resection to successfully accomplish the surgical goal. This technique is simple because no patient participation is required. We believe that it has the potential to replace conventional preoperative functional magnetic resonance imaging and transcranial magnetic stimulation in resective epilepsy surgery, particularly for young patients. Not only can it improve the safety of surgical procedures, but also it can help predict functional outcome. Copyright © 2017 Elsevier Inc. All rights reserved.

Differential Associations of Socioeconomic Status With Global Brain Volumes and White Matter Lesions in African American and White Adults: the HANDLS SCAN Study.

PubMed

Waldstein, Shari R; Dore, Gregory A; Davatzikos, Christos; Katzel, Leslie I; Gullapalli, Rao; Seliger, Stephen L; Kouo, Theresa; Rosenberger, William F; Erus, Guray; Evans, Michele K; Zonderman, Alan B

2017-04-01

The aim of the study was to examine interactive relations of race and socioeconomic status (SES) to magnetic resonance imaging (MRI)-assessed global brain outcomes with previously demonstrated prognostic significance for stroke, dementia, and mortality. Participants were 147 African Americans (AAs) and whites (ages 33-71 years; 43% AA; 56% female; 26% below poverty) in the Healthy Aging in Neighborhoods of Diversity across the Life Span SCAN substudy. Cranial MRI was conducted using a 3.0 T unit. White matter (WM) lesion volumes and total brain, gray matter, and WM volumes were computed. An SES composite was derived from education and poverty status. Significant interactions of race and SES were observed for WM lesion volume (b = 1.38; η = 0.036; p = .028), total brain (b = 86.72; η = 0.042; p < .001), gray matter (b = 40.16; η = 0.032; p = .003), and WM (b = 46.56; η = 0.050; p < .001). AA participants with low SES exhibited significantly greater WM lesion volumes than white participants with low SES. White participants with higher SES had greater brain volumes than all other groups (albeit within normal range). Low SES was associated with greater WM pathology-a marker for increased stroke risk-in AAs. Higher SES was associated with greater total brain volume-a putative global indicator of brain health and predictor of mortality-in whites. Findings may reflect environmental and interpersonal stressors encountered by AAs and those of lower SES and could relate to disproportionate rates of stroke, dementia, and mortality.

[Stereotactic biopsy in the accurate diagnosis of lesions in the brain stem and deep brain].

PubMed

Qin, F; Huang, Z C; Cai, M Q; Xu, X F; Lu, T T; Dong, Q; Wu, A M; Lu, Z Z; Zhao, C; Guo, Y

2018-06-12

Objective: To investigate the value of stereotactic biopsy in the accurate diagnosis of lesions in the brain stem and deep brain. Methods: A total of 29 consecutive patients who underwent stereotactic biopsy of brainstem and deep brain lesions between May 2012 and January 2018 were retrospectively reviewed. The Cosman-Roberts-Wells (CRW) stereotactic frame was installed under local anesthesia. Thin-layer CT and MRI scanning were performed. Target coordinates were calculated by inputting CT-MRI data into the radionics surgical planning system. The individualized puncture path was designed according to the location of the lesions and the characteristics of the image. Target distributions were as follows: 12 cases of midbrain or pons, 2 cases of internal capsule, 3 cases of thalamus, 12 cases of basal ganglia. The biopsy samples were used for further pathological and/or genetic diagnosis. Results: Twenty-eight of the 29 cases (96.6%) were diagnosed accurately by histopathology and genomic examination following stereotactic biopsy. Pathological results were as follows: 8 cases of lymphoma, 7 cases of glioma, 4 cases of demyelination, 2 cases of germ cell tumor, 2 cases of metastatic tumor, 1 cases of cerebral sparganosis, 1 case of tuberculous granuloma, 1 case of hereditary prion disease, 1 case of glial hyperplasia, 1 case of leukemia. The accurate diagnosis of one case required a combination of histopathology and genomic examination. Undefined diagnosis was still made in 1 cases (3.45%) after biopsy. After biopsy, there were 2 cases (6.9%) with symptomatic slight hemorrhage, 1 case (3.45%) with symptomatic severe hemorrhage, and 1 cass (3.45%) with permanent neurological dysfunction. No one died because of surgery or surgical complications. Conclusions: Stereotactic biopsy is fast, safe and minimally invasive. It is an ideal strategy for accurate diagnosis of lesions in brain stem and deep brain.

Brain abnormalities and neurodevelopmental delay in congenital heart disease: systematic review and meta-analysis.

PubMed

Khalil, A; Suff, N; Thilaganathan, B; Hurrell, A; Cooper, D; Carvalho, J S

2014-01-01

Studies have demonstrated an association between congenital heart disease (CHD) and neurodevelopmental delay. Neuroimaging studies have also demonstrated a high incidence of preoperative brain abnormalities. The aim of this study was to perform a systematic review to quantify the non-surgical risk of brain abnormalities and of neurodevelopmental delay in infants with CHD. MEDLINE, EMBASE and The Cochrane Library were searched electronically without language restrictions, utilizing combinations of the terms congenital heart, cardiac, neurologic, neurodevelopment, magnetic resonance imaging, ultrasound, neuroimaging, autopsy, preoperative and outcome. Reference lists of relevant articles and reviews were hand-searched for additional reports. Cohort and case-control studies were included. Studies reporting neurodevelopmental outcomes and/or brain lesions on neuroimaging in infants with CHD before heart surgery were included. Cases of chromosomal or genetic abnormalities, case reports and editorials were excluded. Between-study heterogeneity was assessed using the I(2) test. The search yielded 9129 citations. Full text was retrieved for 119 and the following were included in the review: 13 studies (n = 425 cases) reporting on brain abnormalities either preoperatively or in those who did not undergo congenital cardiac surgery and nine (n = 512 cases) reporting preoperative data on neurodevelopmental assessment. The prevalence of brain lesions on neuroimaging was 34% (95% CI, 24-46; I(2) = 0%) in transposition of the great arteries, 49% (95% CI, 25-72; I(2) = 65%) in left-sided heart lesions and 46% (95% CI, 40-52; I(2) =18.1%) in mixed/unspecified cardiac lesions, while the prevalence of neurodevelopmental delay was 42% (95% CI, 34-51; I(2) = 68.9). In the absence of chromosomal or genetic abnormalities, infants with CHD are at increased risk of brain lesions as revealed by neuroimaging and of neurodevelopmental delay. These findings are independent of the surgical risk, but it is unclear whether the time of onset is fetal or postnatal. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.

Papillary glioneuronal tumor. A case report.

PubMed

Castro Castro, Julián; Lista Martínez, Olalla; Caramés Díaz, Nuria; Conde Lorenzo, Noemi

2018-05-19

Papillary glioneuronal tumor (PGNT) is a recently described central nervous system neoplasm. In 2007, the World Health Organization classified this tumor as a grade I neuronal-glial neoplasm. Patients are usually juvenile and young adults who commonly present with headache or seizures. We report a case of a 13-year-old boy that was related to our hospital after suffering a mild head injury result of an automobile accident. Emergent CT scan showed a right hypointense temporo-occipital lesion. MRI confirmed the presence of a lesion suggestive of a primary brain tumor. The patient underwent total resection of the tumor, followed by an uneventful recovery. Pathological analysis of the lesion revealed characteristic pseudopapillary structure with astrocytes and neurons, compatible with PGNT. We discuss the clinical, Radiological and histological features of this infrequent type of tumors. Copyright © 2018 Sociedad Española de Neurocirugía. Publicado por Elsevier España, S.L.U. All rights reserved.

Structural Basis for TSC-1 TSC-2 Complex Formation

DTIC Science & Technology

2008-03-01

mental retardation and autism . Brain lesions include cerebral cortical tubers, subependymal nodules, and retinal hamartomas. Patients often develop...Rheb) (6,7). Rheb activates the mammalian target of Rapamycin ( mTOR ) and inactivates B-Raf (7). Activation of mTOR leads to increased protein...activity and activation of mTOR . Several unrelated patients with tuberous sclerosis have point mutations in the TSC2 GAP domain that influence the

Non-invasive imaging of transplanted human neural stem cells and ECM scaffold remodeling in the stroke-damaged rat brain by 19F- and diffusion-MRI

PubMed Central

Bible, Ellen; Dell’Acqua, Flavio; Solanky, Bhavana; Balducci, Anthony; Crapo, Peter; Badylak, Stephen F.; Ahrens, Eric T.; Modo, Michel

2012-01-01

Transplantation of human neural stem cells (hNSCs) is emerging as a viable treatment for stroke related brain injury. However, intraparenchymal grafts do not regenerate lost tissue, but rather integrate into the host parenchyma without significantly affecting the lesion cavity. Providing a structural support for the delivered cells appears important for cell based therapeutic approaches. The non-invasive monitoring of therapeutic methods would provide valuable information regarding therapeutic strategies but remains a challenge. Labeling transplanted cells with metal-based 1H-magnetic resonance imaging (MRI) contrast agents affects the visualization of the lesion cavity. Herein, we demonstrate that a 19F-MRI contrast agent can adequately monitor the distribution of transplanted cells, whilst allowing an evaluation of the lesion cavity and the formation of new tissue on 1H-MRI scans. Twenty percent of cells labeled with the 19F-agent were of host origin, potentially reflecting the re-uptake of label from dead transplanted cells. Both T2- and diffusion-weighted MRI scans indicated that transplantation of hNSCs suspended in a gel form of a xenogeneic extracellular matrix (ECM) bioscaffold resulted in uniformly distributed cells throughout the lesion cavity. However, diffusion MRI indicated that the injected materials did not yet establish diffusion barriers (i.e. cellular network, fiber tracts) normally found within striatal tissue. The ECM bioscaffold therefore provides an important support to hNSCs for the creation of de novo tissue and multi-nuclei MRI represents an adept method for the visualization of some aspects of this process. However, significant developments of both the transplantation paradigm, as well as regenerative imaging, are required to successfully create new tissue in the lesion cavity and to monitor this process non-invasively. PMID:22244696

A case of complex regional pain syndrome with agnosia for object orientation.

PubMed

Robinson, Gail; Cohen, Helen; Goebel, Andreas

2011-07-01

This systematic investigation of the neurocognitive correlates of complex regional pain syndrome (CRPS) in a single case also reports agnosia for object orientation in the context of persistent CRPS. We report a patient (JW) with severe long-standing CRPS who had no difficulty identifying and naming line drawings of objects presented in 1 of 4 cardinal orientations. In contrast, he was extremely poor at reorienting these objects into the correct upright orientation and in judging whether an object was upright or not. Moreover, JW made orientation errors when copying drawings of objects, and he also showed features of mirror reversal in writing single words and reading single letters. The findings are discussed in relation to accounts of visual processing. Agnosia for object orientation is the term for impaired knowledge of an object's orientation despite good recognition and naming of the same misoriented object. This defect has previously only been reported in patients with major structural brain lesions. The neuroanatomical correlates are discussed. The patient had no structural brain lesion, raising the possibility that nonstructural reorganisation of cortical networks may be responsible for his deficits. Other patients with CRPS may have related neurocognitive defects. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Time-dependent reorganization of the brain components underlying memory retention in trace eyeblink conditioning.

PubMed

Takehara, Kaori; Kawahara, Shigenori; Kirino, Yutaka

2003-10-29

Many studies have confirmed the time-limited involvement of the hippocampus in mnemonic processes and suggested that there is reorganization of the responsible brain circuitry during memory consolidation. To clarify such reorganization, we chose trace classical eyeblink conditioning, in which hippocampal ablation produces temporally graded retrograde amnesia. Here, we extended the temporal characterization of retrograde amnesia to other regions that are involved in acquisition during this task: the medial prefrontal cortex (mPFC) and the cerebellum. At a various time interval after establishing the trace conditioned response (CR), rats received an aspiration of one of the three regions. After recovery, the animals were tested for their CR retention. When ablated 1 d after the learning, both the hippocampal lesion and the cerebellar lesion group of rats exhibited a severe impairment in retention of the CR, whereas the mPFC lesion group showed only a slight decline. With an increase in interval between the lesion and the learning, the effect of the hippocampal lesion diminished and that of the mPFC lesion increased. When ablated 4 weeks after the learning, the hippocampal lesion group exhibited as robust CRs as its corresponding control group. In contrast, the mPFC lesion and the cerebellar lesion groups failed to retain the CRs. These results indicate that the hippocampus and the cerebellum, but only marginally the mPFC, constitute a brain circuitry that mediates recently acquired memory. As time elapses, the circuitry is reorganized to use mainly the mPFC and the cerebellum, but not the hippocampus, for remotely acquired memory.

Generative adversarial networks for brain lesion detection

NASA Astrophysics Data System (ADS)

Alex, Varghese; Safwan, K. P. Mohammed; Chennamsetty, Sai Saketh; Krishnamurthi, Ganapathy

2017-02-01

Manual segmentation of brain lesions from Magnetic Resonance Images (MRI) is cumbersome and introduces errors due to inter-rater variability. This paper introduces a semi-supervised technique for detection of brain lesion from MRI using Generative Adversarial Networks (GANs). GANs comprises of a Generator network and a Discriminator network which are trained simultaneously with the objective of one bettering the other. The networks were trained using non lesion patches (n=13,000) from 4 different MR sequences. The network was trained on BraTS dataset and patches were extracted from regions excluding tumor region. The Generator network generates data by modeling the underlying probability distribution of the training data, (PData). The Discriminator learns the posterior probability P (Label Data) by classifying training data and generated data as "Real" or "Fake" respectively. The Generator upon learning the joint distribution, produces images/patches such that the performance of the Discriminator on them are random, i.e. P (Label Data = GeneratedData) = 0.5. During testing, the Discriminator assigns posterior probability values close to 0.5 for patches from non lesion regions, while patches centered on lesion arise from a different distribution (PLesion) and hence are assigned lower posterior probability value by the Discriminator. On the test set (n=14), the proposed technique achieves whole tumor dice score of 0.69, sensitivity of 91% and specificity of 59%. Additionally the generator network was capable of generating non lesion patches from various MR sequences.

[High-Definition Exoscope System for Microneurosurgery:Use of an Exoscope in Combination with Tubular Retraction and Frameless Neuronavigation for Microsurgical Resection of Deep Brain Lesions].

PubMed

Nagatani, Kimihiro; Takeuchi, Satoru; Feng, Dongxia; Mori, Kentaro; Day, J Diaz

2015-07-01

The high-definition exoscope (VITOM®, Karl Storz GmbH & Co., Tuttlingen, Germany) is a new equipment that can be used as an alternative to the operating microscope in neurosurgery. Several neurosurgeons have recently reported that the exoscope allows for long working distances and great depth of field. Herein, we review reported cases of exoscope use in neurosurgery. We also describe the advantages of the exoscope compared to the operating microscope and endoscope. Furthermore, we introduce a novel technique for microsurgical resection of deep brain lesions, in which the exoscope is used along with tubular retraction and frameless neuronavigation. Before the operation, neuronavigation is registered and the surgical trajectory is planned to avoid damaging the functional cortex and eloquent white matter tracts. By using intraoperative neuronavigation, the tubular retractor (NICO BrainPath®, NICO Corporation, Indianapolis, US), which is designed to split the white matter when gently inserted, is inserted transcortically into the brain to reach the lesion, along the preplanned trajectory. After insertion, the tubular retractor is fixed in place using a self-retaining arm. This creates a narrow corridor that enables the use of the exoscope (for optimum visualization), bimanual dissection technique, and long bayoneted surgical instruments. The large focal distance of the exoscope allows it to be placed sufficiently further away from the surgical site, permitting the passage of long surgical instruments under the scope. Although obtaining surgical access to deep-seated brain lesions is challenging, we consider that this technique facilitates a safe surgical approach for lesions in deep locations.

Investigation of the usefulness of fluorescein sodium fluorescence in stereotactic brain biopsy.

PubMed

Thien, Ady; Han, Julian Xinguang; Kumar, Krishan; Ng, Yew Poh; Rao, Jai Prashanth; Ng, Wai Hoe; King, Nicolas Kon Kam

2018-02-01

Intraoperative frozen section assessment, to confirm acquisition of pathological tissues, is used in stereotactic brain biopsy to minimise sampling errors. Limitations include the dependence on dedicated neuro-oncology pathologists and an increase in operative duration. We investigated the use of intraoperative fluorescein sodium, and compared it to frozen section assessment, for confirming pathological tissue samples in the stereotactic biopsy of gadolinium-contrast-enhancing brain lesions. This prospective observational study consisted of 18 consecutive patients (12 men; median age, 63 years) who underwent stereotactic biopsy of gadolinium-contrast-enhancing brain lesions with intravenous fluorescein sodium administration. Twenty-three specimens were obtained and examined for the presence of fluorescence using a microscope with fluorescence visualisation capability. Positive and negative predictive values were calculated based on the fluorescence status of the biopsy samples with its corresponding intraoperative frozen section and definitive histopathological diagnosis. Nineteen specimens (83%) were fluorescent and four (17%) were non-fluorescent. All 19 fluorescent specimens were confirmed to be lesional on intraoperative frozen section assessment and were suitable for histopathological diagnosis. Three of the non-fluorescent specimens were confirmed to be lesional on intraoperative frozen section assessment. One non-fluorescent specimen was non-diagnostic on frozen section and histological assessments. The positive predictive value was 100% and the negative predictive value was 25%. Fluorescein sodium fluorescence is as accurate as frozen section assessment in confirming sampling of pathological tissue in the stereotactic biopsy of gadolinium-contrast-enhancing brain lesions. Fluorescein sodium fluorescence-guided stereotactic biopsy is a useful addition to the neurosurgical armamentarium.

B7-H1 shapes T-cell-mediated brain endothelial cell dysfunction and regional encephalitogenicity in spontaneous CNS autoimmunity.

PubMed

Klotz, Luisa; Kuzmanov, Ivan; Hucke, Stephanie; Gross, Catharina C; Posevitz, Vilmos; Dreykluft, Angela; Schulte-Mecklenbeck, Andreas; Janoschka, Claudia; Lindner, Maren; Herold, Martin; Schwab, Nicholas; Ludwig-Portugall, Isis; Kurts, Christian; Meuth, Sven G; Kuhlmann, Tanja; Wiendl, Heinz

2016-10-11

Molecular mechanisms that determine lesion localization or phenotype variation in multiple sclerosis are mostly unidentified. Although transmigration of activated encephalitogenic T cells across the blood-brain barrier (BBB) is a crucial step in the disease pathogenesis of CNS autoimmunity, the consequences on brain endothelial barrier integrity upon interaction with such T cells and subsequent lesion formation and distribution are largely unknown. We made use of a transgenic spontaneous mouse model of CNS autoimmunity characterized by inflammatory demyelinating lesions confined to optic nerves and spinal cord (OSE mice). Genetic ablation of a single immune-regulatory molecule in this model [i.e., B7-homolog 1 (B7-H1, PD-L1)] not only significantly increased incidence of spontaneous CNS autoimmunity and aggravated disease course, especially in the later stages of disease, but also importantly resulted in encephalitogenic T-cell infiltration and lesion formation in normally unaffected brain regions, such as the cerebrum and cerebellum. Interestingly, B7-H1 ablation on myelin oligodendrocyte glycoprotein-specific CD4 + T cells, but not on antigen-presenting cells, amplified T-cell effector functions, such as IFN-γ and granzyme B production. Therefore, these T cells were rendered more capable of eliciting cell contact-dependent brain endothelial cell dysfunction and increased barrier permeability in an in vitro model of the BBB. Our findings suggest that a single immune-regulatory molecule on T cells can be ultimately responsible for localized BBB breakdown, and thus substantial changes in lesion topography in the context of CNS autoimmunity.

Bridging Neuroanatomy, Neuroradiology and Neurology: Three-Dimensional Interactive Atlas of Neurological Disorders

PubMed Central

Nowinski, W.L.; Chua, B.C.

2013-01-01

Understanding brain pathology along with the underlying neuroanatomy and the resulting neurological deficits is of vital importance in medical education and clinical practice. To facilitate and expedite this understanding, we created a three-dimensional (3D) interactive atlas of neurological disorders providing the correspondence between a brain lesion and the resulting disorder(s). The atlas contains a 3D highly parcellated atlas of normal neuroanatomy along with a brain pathology database. Normal neuroanatomy is divided into about 2,300 components, including the cerebrum, cerebellum, brainstem, spinal cord, arteries, veins, dural sinuses, tracts, cranial nerves (CN), white matter, deep gray nuclei, ventricles, visual system, muscles, glands and cervical vertebrae (C1-C5). The brain pathology database contains 144 focal and distributed synthesized lesions (70 vascular, 36 CN-related, and 38 regional anatomy-related), each lesion labeled with the resulting disorder and associated signs, symptoms, and/or syndromes compiled from materials reported in the literature. The initial view of each lesion was preset in terms of its location and size, surrounding surface and sectional (magnetic resonance) neuroanatomy, and labeling of lesion and neuroanatomy. In addition, a glossary of neurological disorders was compiled and for each disorder materials from textbooks were included to provide neurological description. This atlas of neurological disorders is potentially useful to a wide variety of users ranging from medical students, residents and nurses to general practitioners, neuroanatomists, neuroradiologists and neurologists, as it contains both normal (surface and sectional) brain anatomy and pathology correlated with neurological disorders presented in a visual and interactive way. PMID:23859280

Bridging neuroanatomy, neuroradiology and neurology: three-dimensional interactive atlas of neurological disorders.

PubMed

Nowinski, W L; Chua, B C

2013-06-01

Understanding brain pathology along with the underlying neuroanatomy and the resulting neurological deficits is of vital importance in medical education and clinical practice. To facilitate and expedite this understanding, we created a three-dimensional (3D) interactive atlas of neurological disorders providing the correspondence between a brain lesion and the resulting disorder(s). The atlas contains a 3D highly parcellated atlas of normal neuroanatomy along with a brain pathology database. Normal neuroanatomy is divided into about 2,300 components, including the cerebrum, cerebellum, brainstem, spinal cord, arteries, veins, dural sinuses, tracts, cranial nerves (CN), white matter, deep gray nuclei, ventricles, visual system, muscles, glands and cervical vertebrae (C1-C5). The brain pathology database contains 144 focal and distributed synthesized lesions (70 vascular, 36 CN-related, and 38 regional anatomy-related), each lesion labeled with the resulting disorder and associated signs, symptoms, and/or syndromes compiled from materials reported in the literature. The initial view of each lesion was preset in terms of its location and size, surrounding surface and sectional (magnetic resonance) neuroanatomy, and labeling of lesion and neuroanatomy. In addition, a glossary of neurological disorders was compiled and for each disorder materials from textbooks were included to provide neurological description. This atlas of neurological disorders is potentially useful to a wide variety of users ranging from medical students, residents and nurses to general practitioners, neuroanatomists, neuroradiologists and neurologists, as it contains both normal (surface and sectional) brain anatomy and pathology correlated with neurological disorders presented in a visual and interactive way.

Frequency and predictors of acute ischaemic lesions on brain magnetic resonance imaging in young patients with a clinical diagnosis of transient ischaemic attack.

PubMed

Tanislav, C; Grittner, U; Fazekas, F; Thijs, V; Tatlisumak, T; Huber, R; von Sarnowski, B; Putaala, J; Schmidt, R; Kropp, P; Norrving, B; Martus, P; Gramsch, C; Giese, A K; Rolfs, A; Enzinger, C

2016-07-01

Acute lesions in patients with transient ischaemic attack (TIA) are important as they are associated with increased risk for recurrence. Characteristics associated with acute lesions in young TIA patients were therefore investigated. The sifap1 study prospectively recruited a multinational European cohort (n = 5023) of patients aged 18-55 years with acute cerebrovascular event. The detection of acute ischaemic lesions was based on diffusion-weighted imaging (DWI). The frequency of DWI lesions was assessed in 829 TIA patients who met the criteria of symptom duration <24 h and their association with demographic, clinical and imaging variables was analysed. The median age was 46 years (interquartile range 40-51 years); 45% of the patients were female. In 121 patients (15%) ≥1 acute DWI lesion was detected. In 92 patients, DWI lesions were found in the anterior circulation, mostly located in cortical-subcortical areas (n = 63). Factors associated with DWI lesions in multiple regression analysis were left hemispheric presenting symptoms [odds ratio (OR) 1.92, 95% confidence interval (CI) 1.27-2.91], dysarthria (OR 2.17, 95% CI 1.38-3.43) and old brain infarctions on MRI (territories of the middle and posterior cerebral artery: OR 2.43, 95% CI 1.42-4.15; OR 2.41, 95% CI 1.02-5.69, respectively). In young patients with a clinical TIA 15% demonstrated acute DWI lesions on brain MRI, with an event pattern highly suggestive of an embolic origin. Except for the association with previous infarctions there was no clear clinical predictor for acute ischaemic lesions, which indicates the need to obtain MRI in young individuals with TIA. © 2016 EAN.

Effects of delayed-release dimethyl fumarate on MRI measures in the phase 3 CONFIRM study.

PubMed

Miller, David H; Fox, Robert J; Phillips, J Theodore; Hutchinson, Michael; Havrdova, Eva; Kita, Mariko; Wheeler-Kingshott, Claudia A M; Tozer, Daniel J; MacManus, David G; Yousry, Tarek A; Goodsell, Mary; Yang, Minhua; Zhang, Ray; Viglietta, Vissia; Dawson, Katherine T

2015-03-17

To evaluate the effects of oral delayed-release dimethyl fumarate (DMF; also known as gastro-resistant DMF) on MRI lesion activity and load, atrophy, and magnetization transfer ratio (MTR) measures from the Comparator and an Oral Fumarate in Relapsing-Remitting Multiple Sclerosis (CONFIRM) study. CONFIRM was a 2-year, placebo-controlled study of the efficacy and safety of DMF 240 mg twice (BID) or 3 times daily (TID) in 1,417 patients with relapsing-remitting multiple sclerosis (RRMS); subcutaneous glatiramer acetate 20 mg once daily was included as an active reference comparator. The number and volume of T2-hyperintense, T1-hypointense, and gadolinium-enhancing (Gd+) lesions, as well as whole brain volume and MTR, were assessed in 681 patients (MRI cohort). DMF BID and TID produced significant and consistent reductions vs placebo in the number of new or enlarging T2-hyperintense lesions and new nonenhancing T1-hypointense lesions after 1 and 2 years of treatment and in the number of Gd+ lesions at week 24, year 1, and year 2. Lesion volumes were also significantly reduced. Reductions in brain atrophy and MTR changes with DMF relative to placebo did not reach statistical significance. The robust effects on MRI active lesion counts and total lesion volume in patients with RRMS demonstrate the ability of DMF to exert beneficial effects on inflammatory lesion activity in multiple sclerosis, and support DMF therapy as a valuable new treatment option in RRMS. This study provides Class I evidence of reduction in brain lesion number and volume, as assessed by MRI, over 2 years of delayed-release DMF treatment. © 2015 American Academy of Neurology.

Perioperative erythropoietin protects the CNS against ischemic lesions in patients after open heart surgery.

PubMed

Lakič, Nikola; Mrak, Miha; Šušteršič, Miha; Rakovec, Peter; Bunc, Matjaž

2016-12-01

The aim of this study was to establish erythropoietin as a protective factor against brain ischemia during open heart surgery. A total of 36 consecutive patients scheduled for revascularization heart surgery were included in the study. Of the patients 18 received 3 intravenous doses of recombinant human erythropoietin (rHuEpo, 24,000 IU) and 18 patients received a placebo. Magnetic resonance imaging (MRI) to detect new brain ischemic lesions was performed. Additionally, S100A, S100B, neuron-specific enolase A and B (NSE-A and B) and the concentration of antibodies against N‑methyl-D-aspartate receptors (NMDAR) to identify new neurological complications were determined. Patients who received rHuEpo showed no postoperative ischemic changes in the brain on MRI images. In the control group 5 (27.8 %) new ischemic lesions were found. The NMDAR antibody concentration, S100A, S100B and NSE showed no significant differences between the groups for new cerebral ischemia. High levels of lactate before and after external aortic compression (p = 0.022 and p = 0.048, respectively) and duration of operation could predict new ischemic lesions (p = 0.009). The addition of rHuEpo reduced the formation of lesions detectable by MRI in the brain and could be used clinically as neuroprotection in cardiac surgery.

Hand Function in Relation to Brain Lesions and Corticomotor-Projection Pattern in Children with Unilateral Cerebral Palsy

ERIC Educational Resources Information Center

Holmstrom, Linda; Vollmer, Brigitte; Tedroff, Kristina; Islam, Mominul; Persson, Jonas Ke; Kits, Annika; Forssberg, Hans; Eliasson, Ann-Christin

2010-01-01

Aim: To investigate relationships between hand function, brain lesions, and corticomotor projections in children with unilateral cerebral palsy (CP). Method: The study included 17 children (nine males, eight females; mean age 11.4 [SD 2.4] range 7-16y), with unilateral CP at Gross Motor Function Classification System level I and Manual Ability…

Causal effect of disconnection lesions on interhemispheric functional connectivity in rhesus monkeys

PubMed Central

O’Reilly, Jill X.; Croxson, Paula L.; Jbabdi, Saad; Sallet, Jerome; Noonan, MaryAnn P.; Mars, Rogier B.; Browning, Philip G.F.; Wilson, Charles R. E.; Mitchell, Anna S.; Miller, Karla L.; Rushworth, Matthew F. S.; Baxter, Mark G.

2013-01-01

In the absence of external stimuli or task demands, correlations in spontaneous brain activity (functional connectivity) reflect patterns of anatomical connectivity. Hence, resting-state functional connectivity has been used as a proxy measure for structural connectivity and as a biomarker for brain changes in disease. To relate changes in functional connectivity to physiological changes in the brain, it is important to understand how correlations in functional connectivity depend on the physical integrity of brain tissue. The causal nature of this relationship has been called into question by patient data suggesting that decreased structural connectivity does not necessarily lead to decreased functional connectivity. Here we provide evidence for a causal but complex relationship between structural connectivity and functional connectivity: we tested interhemispheric functional connectivity before and after corpus callosum section in rhesus monkeys. We found that forebrain commissurotomy severely reduced interhemispheric functional connectivity, but surprisingly, this effect was greatly mitigated if the anterior commissure was left intact. Furthermore, intact structural connections increased their functional connectivity in line with the hypothesis that the inputs to each node are normalized. We conclude that functional connectivity is likely driven by corticocortical white matter connections but with complex network interactions such that a near-normal pattern of functional connectivity can be maintained by just a few indirect structural connections. These surprising results highlight the importance of network-level interactions in functional connectivity and may cast light on various paradoxical findings concerning changes in functional connectivity in disease states. PMID:23924609

Semisupervised learning using denoising autoencoders for brain lesion detection and segmentation.

PubMed

Alex, Varghese; Vaidhya, Kiran; Thirunavukkarasu, Subramaniam; Kesavadas, Chandrasekharan; Krishnamurthi, Ganapathy

2017-10-01

The work explores the use of denoising autoencoders (DAEs) for brain lesion detection, segmentation, and false-positive reduction. Stacked denoising autoencoders (SDAEs) were pretrained using a large number of unlabeled patient volumes and fine-tuned with patches drawn from a limited number of patients ([Formula: see text], 40, 65). The results show negligible loss in performance even when SDAE was fine-tuned using 20 labeled patients. Low grade glioma (LGG) segmentation was achieved using a transfer learning approach in which a network pretrained with high grade glioma data was fine-tuned using LGG image patches. The networks were also shown to generalize well and provide good segmentation on unseen BraTS 2013 and BraTS 2015 test data. The manuscript also includes the use of a single layer DAE, referred to as novelty detector (ND). ND was trained to accurately reconstruct nonlesion patches. The reconstruction error maps of test data were used to localize lesions. The error maps were shown to assign unique error distributions to various constituents of the glioma, enabling localization. The ND learns the nonlesion brain accurately as it was also shown to provide good segmentation performance on ischemic brain lesions in images from a different database.

Visual hallucinations of autobiographic memory and asomatognosia: a case of epilepsy due to brain cysticercosis.

PubMed

Orjuela-Rojas, Juan Manuel; Ramírez-Bermúdez, Jesús; Martínez-Juárez, Iris E; Kerik, Nora Estela; Diaz Meneses, Iván; Pérez-Gay, Fernanda Juárez

2015-01-01

The current study describes the case of a woman with symptomatic epilepsy due to brain cysticercosis acquired during childhood. During her adolescence, she developed seizures characterized by metamorphopsia, hallucinations of autobiographic memory and, finally, asomatognosia. Magnetic brain imaging showed a calcified lesion in the right occipitotemporal cortex, and positron emission tomography imaging confirmed the presence of interictal hypometabolism in two regions: the right parietal cortex and the right lateral and posterior temporal cortex. We discuss the link between these brain areas and the symptoms described under the concepts of epileptogenic lesion, epileptogenic zone, functional deficit zone, and symptomatogenic zone.

Depletion of macrophages in CD11b diphtheria toxin receptor mice induces brain inflammation and enhances inflammatory signaling during traumatic brain injury.

PubMed

Frieler, Ryan A; Nadimpalli, Sameera; Boland, Lauren K; Xie, Angela; Kooistra, Laura J; Song, Jianrui; Chung, Yutein; Cho, Kae W; Lumeng, Carey N; Wang, Michael M; Mortensen, Richard M

2015-10-22

Immune cells have important roles during disease and are known to contribute to secondary, inflammation-induced injury after traumatic brain injury. To delineate the functional role of macrophages during traumatic brain injury, we depleted macrophages using transgenic CD11b-DTR mice and subjected them to controlled cortical impact. We found that macrophage depletion had no effect on lesion size assessed by T2-weighted MRI scans 28 days after injury. Macrophage depletion resulted in a robust increase in proinflammatory gene expression in both the ipsilateral and contralateral hemispheres after controlled cortical impact. Interestingly, this sizeable increase in inflammation did not affect lesion development. We also showed that macrophage depletion resulted in increased proinflammatory gene expression in the brain and kidney in the absence of injury. These data demonstrate that depletion of macrophages in CD11b-DTR mice can significantly modulate the inflammatory response during brain injury without affecting lesion formation. These data also reveal a potentially confounding inflammatory effect in CD11b-DTR mice that must be considered when interpreting the effects of macrophage depletion in disease models. Copyright © 2015 Elsevier B.V. All rights reserved.

Korsakoff syndrome from retrochiasmatic suprasellar lesions: rapid reversal after relief of cerebral compression in 4 cases.

PubMed

Savastano, Luis E; Hollon, Todd C; Barkan, Ariel L; Sullivan, Stephen E

2018-06-01

Korsakoff syndrome is a chronic memory disorder caused by a severe deficiency of thiamine that is most commonly observed in alcoholics. However, some have proposed that focal structural lesions disrupting memory circuits-in particular, the mammillary bodies, the mammillothalamic tract, and the anterior thalamus-can give rise to this amnestic syndrome. Here, the authors present 4 patients with reversible Korsakoff syndromes caused by suprasellar retrochiasmatic lesions compressing the mammillary bodies and adjacent caudal hypothalamic structures. Three of the patients were found to have large pituitary macroadenomas in their workup for memory deficiency and cognitive decline with minimal visual symptoms. These tumors extended superiorly into the suprasellar region in a retrochiasmatic position and caused significant mass effect in the bilateral mammillary bodies in the base of the brain. These 3 patients had complete and rapid resolution of amnestic problems shortly after initiation of treatment, consisting of resection in 1 case of nonfunctioning pituitary adenoma or cabergoline therapy in 2 cases of prolactinoma. The fourth patient presented with bizarre and hostile behavior along with significant memory deficits and was found to have a large cystic craniopharyngioma filling the third ventricle and compressing the midline diencephalic structures. This patient underwent cyst fenestration and tumor debulking, with a rapid improvement in his mental status. The rapid and dramatic memory improvement observed in all of these cases is probably due to a reduction in the pressure imposed by the lesions on structures contiguous to the third ventricle, rather than a direct destructive effect of the tumor, and highlights the essential role of the caudal diencephalic structures-mainly the mammillary bodies-in memory function. In summary, large pituitary lesions with suprasellar retrochiasmatic extension and third ventricular craniopharyngiomas can cause severe Korsakoff-like amnestic syndromes, probably because of bilateral pressure on or damage to mammillary bodies, anterior thalamic nuclei, or their major connections. Neuropsychiatric symptoms may rapidly and completely reverse shortly after initiation of therapy via surgical decompression of tumors or pharmacological treatment of prolactinomas. Early identification of these lesions with timely treatment can lead to a favorable prognosis for this severe neuropsychiatric disorder.

Evaluation of intraaxial enhancing brain tumors on magnetic resonance imaging: intraindividual crossover comparison of gadobenate dimeglumine and gadopentetate dimeglumine for visualization and assessment, and implications for surgical intervention.

PubMed

Kuhn, Matthew J; Picozzi, Piero; Maldjian, Joseph A; Schmalfuss, Ilona M; Maravilla, Kenneth R; Bowen, Brian C; Wippold, Franz J; Runge, Val M; Knopp, Michael V; Wolansky, Leo J; Gustafsson, Lars; Essig, Marco; Anzalone, Nicoletta

2007-04-01

The goal in this article was to compare 0.1 mmol/kg doses of gadobenate dimeglumine (Gd-BOPTA) and gadopentetate dimeglumine, also known as gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA), for enhanced magnetic resonance (MR) imaging of intraaxial brain tumors. Eighty-four patients with either intraaxial glioma (47 patients) or metastasis (37 patients) underwent two MR imaging examinations at 1.5 tesla, one with Gd-BOPTA as the contrast agent and the other with Gd-DTPA. The interval between fully randomized contrast medium administrations was 2 to 7 days. The T1-weighted spin echo and T2-weighted fast spin echo images were acquired before administration of contrast agents and T1-weighted spin echo images were obtained after the agents were administered. Acquisition parameters and postinjection acquisition times were identical for the two examinations in each patient. Three experienced readers working in a fully blinded fashion independently evaluated all images for degree and quality of available information (lesion contrast enhancement, lesion border delineation, definition of disease extent, visualization of the lesion's internal structures, global diagnostic preference) and quantitative enhancement (that is, the extent of lesion enhancement after contrast agent administration compared with that seen before its administration [hereafter referred to as percent enhancement], lesion/brain ratio, and contrast/noise ratio). Differences were tested with the Wilcoxon signed-rank test. Reader agreement was assessed using kappa statistics. Significantly better diagnostic information/imaging performance (p < 0.0001, all readers) was obtained with Gd-BOPTA for all visualization end points. Global preference for images obtained with Gd-BOPTA was expressed for 42 (50%), 52 (61.9%), and 56 (66.7%) of 84 patients (readers 1, 2, and 3, respectively) compared with images obtained with Gd-DTPA contrast in four (4.8%), six (7.1%), and three (3.6%) of 84 patients. Similar differences were noted for all other visualization end points. Significantly greater quantitative contrast enhancement (p < 0.04) was noted after administration of Gd-BOPTA. Reader agreement was good (kappa > 0.4). Lesion visualization, delineation, definition, and contrast enhancement are significantly better after administration of 0.1 mmol/kg Gd-BOPTA, potentially allowing better surgical planning and follow up and improved disease management.

A Fast Approach to Automatic Detection of Brain Lesions

PubMed Central

Koley, Subhranil; Chakraborty, Chandan; Mainero, Caterina; Fischl, Bruce; Aganj, Iman

2017-01-01

Template matching is a popular approach to computer-aided detection of brain lesions from magnetic resonance (MR) images. The outcomes are often sufficient for localizing lesions and assisting clinicians in diagnosis. However, processing large MR volumes with three-dimensional (3D) templates is demanding in terms of computational resources, hence the importance of the reduction of computational complexity of template matching, particularly in situations in which time is crucial (e.g. emergent stroke). In view of this, we make use of 3D Gaussian templates with varying radii and propose a new method to compute the normalized cross-correlation coefficient as a similarity metric between the MR volume and the template to detect brain lesions. Contrary to the conventional fast Fourier transform (FFT) based approach, whose runtime grows as O(N logN) with the number of voxels, the proposed method computes the cross-correlation in O(N). We show through our experiments that the proposed method outperforms the FFT approach in terms of computational time, and retains comparable accuracy. PMID:29082383

Magnetic resonance imaging in central nervous system sarcoidosis.

PubMed

Miller, D H; Kendall, B E; Barter, S; Johnson, G; MacManus, D G; Logsdail, S J; Ormerod, I E; McDonald, W I

1988-03-01

We performed brain MRIs on 21 patients with CNS sarcoidosis. Brain CTs were performed in 18 of these. Parenchymal lesions were seen in 17 of 21 with MRI, compared with 9 of 18 with CT. MRI detected a greater number of parenchymal lesions in cases where both CT and MRI were positive, and some lesions appeared more extensive with MRI than with CT. The most common MRI pattern was one of periventricular and multifocal white matter lesions (14 cases). Such a pattern is not specific, and other recognized causes for it were identified in four cases. It is likely, however, that sarcoid tissue causes this pattern in some cases, and confirmation was obtained from cerebral biopsy in one. In six patients, the white matter changes were indistinguishable from those seen in multiple sclerosis. Contrast-enhanced CT in two patients showed diffuse meningeal involvement not seen with MRI. MRI is the investigation of choice in detecting parenchymal changes in the brain of patients with CNS sarcoidosis and may prove useful in monitoring treatment in such cases.

[A case of pulmonary malignant melanoma mimicking lung abscess].

PubMed

Mochizuki, Hideaki; Chikui, Emiko; Tokumaru, Aya; Kato, Takayuki; Arai, Tomio; Takahashi, Hideki

2011-06-01

An 84-year-old man was admitted with paresis of the right lower limb. Hemorrhagic lesions were demonstrated in the left frontoparietal lobe and cerebellum by cranial computed tomography (CT) and magnetic resonance imaging (MRI). Chest CT revealed an ill-defined mass measuring 4 x 6 cm in the left lower lobe of the lung, although bronchoscopic examination failed to obtain pathological diagnosis. Clinical diagnosis of primary lung cancer with multiple brain metastases was made, and he underwent whole brain radiotherapy. The pulmonary and cerebral lesions mimicked abscesses during his clinical course, and he died of respiratory failure due to bilateral pneumonia three months after admission. Autopsy revealed that both the pulmonary and brain lesions were malignant melanomas, but no other melanoma lesions could be identified despite meticulous investigation. Although malignant melanoma with an unknown primary site is rare in Japan, careful evaluation of the CT and MRI findings might be the key to correct diagnosis in this case.

Functional language shift to the right hemisphere in patients with language-eloquent brain tumors.

PubMed

Krieg, Sandro M; Sollmann, Nico; Hauck, Theresa; Ille, Sebastian; Foerschler, Annette; Meyer, Bernhard; Ringel, Florian

2013-01-01

Language function is mainly located within the left hemisphere of the brain, especially in right-handed subjects. However, functional MRI (fMRI) has demonstrated changes of language organization in patients with left-sided perisylvian lesions to the right hemisphere. Because intracerebral lesions can impair fMRI, this study was designed to investigate human language plasticity with a virtual lesion model using repetitive navigated transcranial magnetic stimulation (rTMS). Fifteen patients with lesions of left-sided language-eloquent brain areas and 50 healthy and purely right-handed participants underwent bilateral rTMS language mapping via an object-naming task. All patients were proven to have left-sided language function during awake surgery. The rTMS-induced language errors were categorized into 6 different error types. The error ratio (induced errors/number of stimulations) was determined for each brain region on both hemispheres. A hemispheric dominance ratio was then defined for each region as the quotient of the error ratio (left/right) of the corresponding area of both hemispheres (ratio >1 = left dominant; ratio <1 = right dominant). Patients with language-eloquent lesions showed a statistically significantly lower ratio than healthy participants concerning "all errors" and "all errors without hesitations", which indicates a higher participation of the right hemisphere in language function. Yet, there was no cortical region with pronounced difference in language dominance compared to the whole hemisphere. This is the first study that shows by means of an anatomically accurate virtual lesion model that a shift of language function to the non-dominant hemisphere can occur.

Individualized statistical learning from medical image databases: application to identification of brain lesions.

PubMed

Erus, Guray; Zacharaki, Evangelia I; Davatzikos, Christos

2014-04-01

This paper presents a method for capturing statistical variation of normal imaging phenotypes, with emphasis on brain structure. The method aims to estimate the statistical variation of a normative set of images from healthy individuals, and identify abnormalities as deviations from normality. A direct estimation of the statistical variation of the entire volumetric image is challenged by the high-dimensionality of images relative to smaller sample sizes. To overcome this limitation, we iteratively sample a large number of lower dimensional subspaces that capture image characteristics ranging from fine and localized to coarser and more global. Within each subspace, a "target-specific" feature selection strategy is applied to further reduce the dimensionality, by considering only imaging characteristics present in a test subject's images. Marginal probability density functions of selected features are estimated through PCA models, in conjunction with an "estimability" criterion that limits the dimensionality of estimated probability densities according to available sample size and underlying anatomy variation. A test sample is iteratively projected to the subspaces of these marginals as determined by PCA models, and its trajectory delineates potential abnormalities. The method is applied to segmentation of various brain lesion types, and to simulated data on which superiority of the iterative method over straight PCA is demonstrated. Copyright © 2014 Elsevier B.V. All rights reserved.

Pusher syndrome--a frequent but little-known disturbance of body orientation perception.

PubMed

Karnath, Hans-Otto

2007-04-01

Disturbances of body orientation perception after brain lesions may specifically relate to only one dimension of space. Stroke patients with "pusher syndrome" suffer from a severe misperception of their body's orientation in the coronal (roll) plane. They experience their body as oriented 'upright' when it is in fact markedly tilted to one side. The patients use the unaffected arm or leg to actively push away from the un-paralyzed side and resist any attempt to passively correct their tilted body posture. Although pusher patients are unable to correctly determine when their own body is oriented in an upright, vertical position, they seem to have no significant difficulty in determining the orientation of the surrounding visual world in relation to their own body. Pusher syndrome is a distinctive clinical disorder occurring characteristically after unilateral left or right brain lesions in the posterior thalamus and -less frequently- in the insula and postcentral gyrus. These structures thus seem to constitute crucial neural substrates controlling human (upright) body orientation in the coronal (roll) plane. A further disturbance of body orientation that predominantly affects a single dimension of space, namely the transverse (yaw) plane, is observed in stroke patients with spatial neglect. Apparently, our brain has evolved separate neural subsystems for perceiving and controlling body orientation in different dimensions of space.

Individualized Statistical Learning from Medical Image Databases: Application to Identification of Brain Lesions

PubMed Central

Erus, Guray; Zacharaki, Evangelia I.; Davatzikos, Christos

2014-01-01

This paper presents a method for capturing statistical variation of normal imaging phenotypes, with emphasis on brain structure. The method aims to estimate the statistical variation of a normative set of images from healthy individuals, and identify abnormalities as deviations from normality. A direct estimation of the statistical variation of the entire volumetric image is challenged by the high-dimensionality of images relative to smaller sample sizes. To overcome this limitation, we iteratively sample a large number of lower dimensional subspaces that capture image characteristics ranging from fine and localized to coarser and more global. Within each subspace, a “target-specific” feature selection strategy is applied to further reduce the dimensionality, by considering only imaging characteristics present in a test subject’s images. Marginal probability density functions of selected features are estimated through PCA models, in conjunction with an “estimability” criterion that limits the dimensionality of estimated probability densities according to available sample size and underlying anatomy variation. A test sample is iteratively projected to the subspaces of these marginals as determined by PCA models, and its trajectory delineates potential abnormalities. The method is applied to segmentation of various brain lesion types, and to simulated data on which superiority of the iterative method over straight PCA is demonstrated. PMID:24607564

Iron porphyrinate Fe(TPPS) reduces brain cell damage in rats intrastriatally lesioned by quinolinate.

PubMed

González-Cortés, Carolina; Salinas-Lara, Citlaltepetl; Gómez-López, Marcos Artemio; Tena-Suck, Martha Lilia; Pérez-De La Cruz, Verónica; Rembao-Bojórquez, Daniel; Pedraza-Chaverrí, José; Gómez-Ruiz, Celedonio; Galván-Arzate, Sonia; Ali, Syed F; Santamaría, Abel

2008-01-01

It has been recently demonstrated that the reactive nitrogen species (RNS) peroxynitrite (ONOO(-)) is involved in the neurotoxic pattern produced by quinolinic acid in the rat brain [V. Pérez-De La Cruz, C. González-Cortés, S. Galván-Arzate, O.N. Medina-Campos, F. Pérez-Severiano, S.F. Ali, J. Pedraza-Chaverrí, A. Santamaría, Excitotoxic brain damage involves early peroxynitrite formation in a model of Huntington's disease in rats: protective role of iron porphyrinate 5,10,15,20-tetrakis (4-sulfonatophenyl)porphyrinate iron (III), Neuroscience 135 (2005) 463-474.]. The aim of this work was to investigate whether ONOO(-) can also be responsible for morphological alterations and inflammatory events in the same paradigm. For this purpose, we evaluated the effect of a pre-treatment with the iron porphyrinate Fe(TPPS), a well-known ONOO(-) decomposition catalyst (10 mg/kg, i.p., 120 min before lesion), on the quinolinate-induced striatal cell damage and immunoreactivities to glial-fibrilar acidic protein (GFAP), interleukin 6 (IL-6) and inducible nitric oxide synthase (iNOS), one and seven days after the intrastriatal infusion of quinolinate (240 nmol/microl) to rats. The striatal tissue from animals lesioned by quinolinate showed a significant degree of damage and enhanced immunoreactivities to GFAP, IL-6 and iNOS, both at 1 and 7 days post-lesion. Pre-treatment of rats with Fe(TPPS) significantly attenuated or prevented all these markers at both post-lesion times tested, except for GFAP immunoreactivity at 7 days post-lesion and iNOS immunoreactivity at 1 day post-lesion. Altogether, our results suggest that ONOO(-) is actively participating in triggering inflammatory events and morphological alterations in the toxic model produced by quinolinate, since the use of agents affecting its formation, such as Fe(TPPS), are effective experimental tools to reduce the brain lesions associated to excitotoxic and oxidative damage.

A special form of cerebral lacunae: expanding lacunae.

PubMed Central

Homeyer, P; Cornu, P; Lacomblez, L; Chiras, J; Derouesné, C

1996-01-01

The case of a 42 year old man with headache, blurred vision, and diplopia allowed the description of a particular form of cerebral lacunae-that is, expanding lacunae. Brain MRI showed hydrocephalus and multiple lesions in the thalamomesencephalic region. The radiological features of these lesions were similar to the histological brain coronal section of a case reported in 1983 in which expanding lacunae were related to a dilatation of the perivascular spaces and a focal segmental necrotising angiitis. The role of the lymphatic drainage of the brain is discussed to explain the dilatation of the perivascular spaces. The hypothesis of a hydrodynamic factor being responsible for the expanding character of the lacunae was suggested by the location of the lesions and the influence of various clinical events on the symptomatology. Images PMID:8708692

Therapy-induced brain reorganization patterns in aphasia.

PubMed

Abel, Stefanie; Weiller, Cornelius; Huber, Walter; Willmes, Klaus; Specht, Karsten

2015-04-01

Both hemispheres are engaged in recovery from word production deficits in aphasia. Lexical therapy has been shown to induce brain reorganization even in patients with chronic aphasia. However, the interplay of factors influencing reorganization patterns still remains unresolved. We were especially interested in the relation between lesion site, therapy-induced recovery, and beneficial reorganization patterns. Thus, we applied intensive lexical therapy, which was evaluated with functional magnetic resonance imaging, to 14 chronic patients with aphasic word retrieval deficits. In a group study, we aimed to illuminate brain reorganization of the naming network in comparison with healthy controls. Moreover, we intended to analyse the data with joint independent component analysis to relate lesion sites to therapy-induced brain reorganization, and to correlate resulting components with therapy gain. As a result, we found peri-lesional and contralateral activations basically overlapping with premorbid naming networks observed in healthy subjects. Reduced activation patterns for patients compared to controls before training comprised damaged left hemisphere language areas, right precentral and superior temporal gyrus, as well as left caudate and anterior cingulate cortex. There were decreasing activations of bilateral visuo-cognitive, articulatory, attention, and language areas due to therapy, with stronger decreases for patients in right middle temporal gyrus/superior temporal sulcus, bilateral precuneus as well as left anterior cingulate cortex and caudate. The joint independent component analysis revealed three components indexing lesion subtypes that were associated with patient-specific recovery patterns. Activation decreases (i) of an extended frontal lesion disconnecting language pathways occurred in left inferior frontal gyrus; (ii) of a small frontal lesion were found in bilateral inferior frontal gyrus; and (iii) of a large temporo-parietal lesion occurred in bilateral inferior frontal gyrus and contralateral superior temporal gyrus. All components revealed increases in prefrontal areas. One component was negatively correlated with therapy gain. Therapy was associated exclusively with activation decreases, which could mainly be attributed to higher processing efficiency within the naming network. In our joint independent component analysis, all three lesion patterns disclosed involved deactivation of left inferior frontal gyrus. Moreover, we found evidence for increased demands on control processes. As expected, we saw partly differential reorganization profiles depending on lesion patterns. There was no compensatory deactivation for the large left inferior frontal lesion, with its less advantageous outcome probably being related to its disconnection from crucial language processing pathways. © 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.

A model of posttraumatic epilepsy after penetrating brain injuries: effect of lesion size and metal fragments.

PubMed

Kendirli, M Tansel; Rose, Dominique T; Bertram, Edward H

2014-12-01

Penetrating brain injury (PBI) has the highest risk for inducing posttraumatic epilepsy, and those PBIs with retained foreign materials such as bullet fragments carry the greatest risk. This study examines the potential contribution of copper, a major component of bullets, to the development of epilepsy following PBI. Anesthetized adult male rats received a penetrating injury from the dorsal cortex to the ventral hippocampus from a high speed small bit drill. In one group of animals, copper wire was inserted into the lesion. Control animals had only the lesion or the lesion plus stainless steel wire (biologically inert foreign body). From 6 to up to 11 months following the injury the rats were monitored intermittently for the development of epilepsy with video-electroencephalography (EEG). A separate set of animals was examined for possible acute seizures in the week following the injury. Twenty-two of the 23 animals with copper wire developed chronic epilepsy, compared to three of the 20 control rats (lesion and lesion with stainless steel). Copper was associated with more extensive injury. The control rats with epilepsy had larger lesions. In the acute injury group, there was no difference in the incidence of seizures (83% lesion plus stainless steel, 70% lesion plus copper). Copper increases the risk for epilepsy and may increase damage over time, but there were no differences between the groups in the incidence of acute postinjury seizures. Lesion size may contribute to epilepsy development in lesion-only animals. Copper may be an independent risk factor for the development of epilepsy and possible secondary injury, but lesion size also contributes to the development of epilepsy. The consequences of prolonged exposure of the brain to copper observed in these animals may have clinical implications that require further evaluation. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

Accuracy for detection of simulated lesions: comparison of fluid-attenuated inversion-recovery, proton density--weighted, and T2-weighted synthetic brain MR imaging

NASA Technical Reports Server (NTRS)

Herskovits, E. H.; Itoh, R.; Melhem, E. R.

2001-01-01

OBJECTIVE: The objective of our study was to determine the effects of MR sequence (fluid-attenuated inversion-recovery [FLAIR], proton density--weighted, and T2-weighted) and of lesion location on sensitivity and specificity of lesion detection. MATERIALS AND METHODS: We generated FLAIR, proton density-weighted, and T2-weighted brain images with 3-mm lesions using published parameters for acute multiple sclerosis plaques. Each image contained from zero to five lesions that were distributed among cortical-subcortical, periventricular, and deep white matter regions; on either side; and anterior or posterior in position. We presented images of 540 lesions, distributed among 2592 image regions, to six neuroradiologists. We constructed a contingency table for image regions with lesions and another for image regions without lesions (normal). Each table included the following: the reviewer's number (1--6); the MR sequence; the side, position, and region of the lesion; and the reviewer's response (lesion present or absent [normal]). We performed chi-square and log-linear analyses. RESULTS: The FLAIR sequence yielded the highest true-positive rates (p < 0.001) and the highest true-negative rates (p < 0.001). Regions also differed in reviewers' true-positive rates (p < 0.001) and true-negative rates (p = 0.002). The true-positive rate model generated by log-linear analysis contained an additional sequence-location interaction. The true-negative rate model generated by log-linear analysis confirmed these associations, but no higher order interactions were added. CONCLUSION: We developed software with which we can generate brain images of a wide range of pulse sequences and that allows us to specify the location, size, shape, and intrinsic characteristics of simulated lesions. We found that the use of FLAIR sequences increases detection accuracy for cortical-subcortical and periventricular lesions over that associated with proton density- and T2-weighted sequences.

Use of prism adaptation in children with unilateral brain lesion: Is it feasible?

PubMed

Riquelme, Inmaculada; Henne, Camille; Flament, Benoit; Legrain, Valéry; Bleyenheuft, Yannick; Hatem, Samar M

2015-01-01

Unilateral visuospatial deficits have been observed in children with brain damage. While the effectiveness of prism adaptation for treating unilateral neglect in adult stroke patients has been demonstrated previously, the usefulness of prism adaptation in a pediatric population is still unknown. The present study aims at evaluating the feasibility of prism adaptation in children with unilateral brain lesion and comparing the validity of a game procedure designed for child-friendly paediatric intervention, with the ecological task used for prism adaptation in adult patients. Twenty-one children with unilateral brain lesion randomly were assigned to a prism group wearing prismatic glasses, or a control group wearing neutral glasses during a bimanual task intervention. All children performed two different bimanual tasks on randomly assigned consecutive days: ecological tasks or game tasks. The efficacy of prism adaptation was measured by assessing its after-effects with visual open loop pointing (visuoproprioceptive test) and subjective straight-ahead pointing (proprioceptive test). Game tasks and ecological tasks produced similar after-effects. Prismatic glasses elicited a significant shift of visuospatial coordinates which was not observed in the control group. Prism adaptation performed with game tasks seems an effective procedure to obtain after-effects in children with unilateral brain lesion. The usefulness of repetitive prism adaptation sessions as a therapeutic intervention in children with visuospatial deficits and/or neglect, should be investigated in future studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluation of the factors influencing brain language laterality in presurgical planning.

PubMed

Batouli, Seyed Amir Hossein; Hasani, Nafiseh; Gheisari, Sara; Behzad, Ebrahim; Oghabian, Mohammad Ali

2016-10-01

Brain lesions cause functional deficits, and one treatment for this condition is lesion resection. In most cases, presurgical planning (PSP) and the information from laterality indices are necessary for maximum preservation of the critical functions after surgery. Language laterality index (LI) is reliably estimated using functional magnetic resonance imaging (fMRI); however, this measure is under the influence of some external factors. In this study, we investigated the influence of a number of factors on language LI, using data from 120 patients (mean age=35.65 (±13.4) years) who underwent fMRI for PSP. Using two proposed language tasks from our previous works, brain left hemisphere was showed to be dominant for the language function, although a higher LI was obtained using the "Word Generation" task, compared to the "Reverse Word Reading". In addition, decline of LIs with age, and lower LI when the lesion invaded brain language area were observed. Meanwhile, gender, lesion side (affected hemisphere), LI calculation strategy, and fMRI analysis Z-values did not statistically show any influences on the LIs. Although fMRI is widely used to estimate language LI, it is shown here that in order to present a reliable language LI and to correctly select the dominant hemisphere of the brain, the influence of external factors should be carefully considered. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Neural signatures of third-party punishment: evidence from penetrating traumatic brain injury.

PubMed

Glass, Leila; Moody, Lara; Grafman, Jordan; Krueger, Frank

2016-02-01

The ability to survive within a cooperative society depends on impartial third-party punishment (TPP) of social norm violations. Two cognitive mechanisms have been postulated as necessary for the successful completion of TPP: evaluation of legal responsibility and selection of a suitable punishment given the magnitude of the crime. Converging neuroimaging research suggests two supporting domain-general networks; a mentalizing network for evaluation of legal responsibility and a central-executive network for determination of punishment. A whole-brain voxel-based lesion-symptom mapping approach was used in conjunction with a rank-order TPP task to identify brain regions necessary for TPP in a large sample of patients with penetrating traumatic brain injury. Patients who demonstrated atypical TPP had specific lesions in core regions of the mentalizing (dorsomedial prefrontal cortex [PFC], ventromedial PFC) and central-executive (bilateral dorsolateral PFC, right intraparietal sulcus) networks. Altruism and executive functioning (concept formation skills) were significant predictors of TPP: altruism was uniquely associated with TPP in patients with lesions in right dorsolateral PFC and executive functioning was uniquely associated with TPP in individuals with lesions in left PFC. Our findings contribute to the extant literature to support underlying neural networks associated with TPP, with specific brain-behavior causal relationships confirming recent functional neuroimaging research. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Pathological Laughing: Brain SPECT Findings.

PubMed

Morland, David; Wolff, Valérie; Blondet, Cyrille; Marescaux, Christian; Namer, Izzie Jacques

2015-09-01

We present the case of a 40-year-old man consulting for uncontrollable episodes of laughing related to emotional lability and not systematically linked to feelings of happiness. Seven months earlier he had presented a pontine ischemic stroke related to an occlusion of the basilar and left vertebral arteries. No epileptic activity or new MRI brain lesions were found. Brain perfusion SPECT performed showed marked hypoperfusion in the right frontal inferior and temporoinsular regions, suggesting a diaschisis phenomenon caused by pontine lesions and highlighted laughing regulation pathways. The patient was successfully treated with a serotonergic reuptake inhibitor, fluoxetine.

The role of rostral prefrontal cortex in prospective memory: a voxel-based lesion study.

PubMed

Volle, Emmanuelle; Gonen-Yaacovi, Gil; Costello, Angela de Lacy; Gilbert, Sam J; Burgess, Paul W

2011-07-01

Patients with lesions in rostral prefrontal cortex (PFC) often experience problems in everyday-life situations requiring multitasking. A key cognitive component that is critical in multitasking situations is prospective memory, defined as the ability to carry out an intended action after a delay period filled with unrelated activity. The few functional imaging studies investigating prospective memory have shown consistent activation in both medial and lateral rostral PFC but also in more posterior prefrontal regions and non-frontal regions. The aim of this study was to determine regions that are necessary for prospective memory performance, using the human lesion approach. We designed an experimental paradigm allowing us to assess time-based (remembering to do something at a particular time) and event-based (remembering to do something in a particular situation) prospective memory, using two types of material, words and pictures. Time estimation tasks and tasks controlling for basic attention, inhibition and multiple instructions processing were also administered. We examined brain-behaviour relationships with a voxelwise lesion method in 45 patients with focal brain lesions and 107 control subjects using this paradigm. The results showed that lesions in the right polar prefrontal region (in Brodmann area 10) were specifically associated with a deficit in time-based prospective memory tasks for both words and pictures. This deficit could not be explained by impairments in basic attention, detection, inhibition or multiple instruction processing, and there was also no deficit in event-based prospective memory conditions. In addition to their prospective memory difficulties, these polar prefrontal patients were significantly impaired in time estimation ability compared to other patients. The same region was found to be involved using both words and pictures, suggesting that right rostral PFC plays a material nonspecific role in prospective memory. This is the first lesion study showing that rostral PFC is crucial for time-based prospective memory. The findings suggest that time-based and event-based prospective memory might be supported at least in part by distinct brain regions. Two particularly plausible explanations for the deficit rest upon a possible role for polar prefrontal structures in supporting in time estimation, and/or in retrieving an intention to act. More broadly, the results are consistent with the view that the deficit of rostral patients in multitasking situations might at least in part be explained by a deficit in prospective memory. Copyright © 2011 Elsevier Ltd. All rights reserved.

[Application of diffusion tensor imaging in judging infarction time of acute ischemic cerebral infarction].

PubMed

Dai, Zhenyu; Chen, Fei; Yao, Lizheng; Dong, Congsong; Liu, Yang; Shi, Haicun; Zhang, Zhiping; Yang, Naizhong; Zhang, Mingsheng; Dai, Yinggui

2015-08-18

To evaluate the clinical application value of diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) in judging infarction time phase of acute ischemic cerebral infarction. To retrospective analysis DTI images of 52 patients with unilateral acute ischemic cerebral infarction (hyper-acute, acute and sub-acute) from the Affiliated Yancheng Hospital of Southeast University Medical College, which diagnosed by clinic and magnetic resonance imaging. Set the regions of interest (ROIs) of infarction lesions, brain tissue close to infarction lesions and corresponding contra (contralateral normal brain tissue) on DTI parameters mapping of fractional anisotropy (FA), volume ratio anisotropy (VRA), average diffusion coefficient (DCavg) and exponential attenuation (Exat), record the parameters values of ROIs and calculate the relative parameters value of infarction lesion to contra. Meanwhile, reconstruct the DTT images based on the seed points (infarction lesion and contra). The study compared each parameter value of infarction lesions, brain tissue close to infarction lesions and corresponding contra, also analysed the differences of relative parameters values in different infarction time phases. The DTT images of acute ischemic cerebral infarction in each time phase could show the manifestation of fasciculi damaged. The DCavg value of cerebral infarction lesions was lower and the Exat value was higher than contra in each infarction time phase (P<0.05). The FA and VRA value of cerebral infarction lesions were reduced than contra only in acute and sub-acute infarction (P<0.05). The FA, VRA and Exat value of brain tissue close to infarction lesions were increased and DCavg value was decreased than contra in hyper-acute infarction (P<0.05). There were no statistic differences of FA, VRA, DCavg and Exat value of brain tissue close to infarction lesions in acute and sub-acute infarction. The relative FA and VRA value of infarction lesion to contra gradually decreased from hyper-acute to sub-acute cerebral infarction (P<0.05), but there were no difference of the relative VRA value between acute and sub-acute cerebral infarction. The relative DCavg value of infarction lesion to contra in hyper-acute infarction than that in acute and sub-acute infarction (P<0.05), however there was also no difference between acute and sub-acute infarction. ROC curve showed the best diagnosis cut off value of relative FA, VRA and DCavg of infarction lesions to contra were 0.852, 0.886 and 0.541 between hyper-acute and acute cerebral infarction, the best diagnosis cut off value of relative FA was 0.595 between acute and sub-acute cerebral infarction, respectively. The FA, VRA, DCavg and Exat value have specific change mode in acute ischemic cerebral infarction of different infarction time phases, which can be combine used in judging infarction time phase of acute ischemic cerebral infarction without clear onset time, thus to help selecting the reasonable treatment protocols.

A simple brain atrophy measure improves the prediction of malignant middle cerebral artery infarction by acute DWI lesion volume.

PubMed

Beck, Christoph; Kruetzelmann, Anna; Forkert, Nils D; Juettler, Eric; Singer, Oliver C; Köhrmann, Martin; Kersten, Jan F; Sobesky, Jan; Gerloff, Christian; Fiehler, Jens; Schellinger, Peter D; Röther, Joachim; Thomalla, Götz

2014-06-01

In patients with malignant middle cerebral artery infarction (MMI) decompressive surgery within 48 h improves functional outcome. In this respect, early identification of patients at risk of developing MMI is crucial. While the acute diffusion weighted imaging (DWI) lesion volume was found to predict MMI with high predictive values, the potential impact of preexisting brain atrophy on the course of space-occupying middle cerebral artery (MCA) infarction and the development of MMI remains unclear. We tested the hypothesis that the combination of the acute DWI lesion volume with simple measures of brain atrophy improves the early prediction of MMI. Data from a prospective, multicenter, observational study, which included patients with acute middle cerebral artery main stem occlusion studied by MRI within 6 h of symptom onset, was analyzed retrospectively. The development of MMI was defined according to the European randomized controlled trials of decompressive surgery. Acute DWI lesion volume, as well as brain and cerebrospinal fluid volume (CSF) were delineated. The intercaudate distance (ICD) was assessed as a linear brain atrophy marker by measuring the hemi-ICD of the intact hemisphere to account for local brain swelling. Binary logistic regression analysis was used to identify significant predictors of MMI. Cut-off values were determined by Classification and Regression Trees analysis. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the resulting models were calculated. Twenty-one (18 %) of 116 patients developed a MMI. Malignant middle cerebral artery infarctions patients had higher National Institutes of Health Stroke Scale scores on admission and presented more often with combined occlusion of the internal carotid artery and MCA. There were no differences in brain and CSF volume between the two groups. Diffusion weighted imaging lesion volume was larger (p < 0.001), while hemi-ICD was smaller (p = 0.029) in MMI patients. Inclusion of hemi-ICD improved the prediction of MMI. Best cut-off values to predict the development of MMI were DWI lesion volume > 87 ml and hemi-ICD ≤ 9.4 mm. The addition of hemi-ICD to the decision tree strongly increased PPV (0.93 vs. 0.70) resulting in a reduction of false positive findings from 7/23 (30 %) to 1/15 (7 %), while there were only slight changes in specificity, sensitivity and NPV. The absolute number of correct classifications increased by 4 (3.4 %). The integration of hemi-ICD as a linear marker of brain atrophy, that can easily be assessed in an emergency setting, may improve the prediction of MMI by lesion volume based predictive models.

Exploring DeepMedic for the purpose of segmenting white matter hyperintensity lesions

NASA Astrophysics Data System (ADS)

Lippert, Fiona; Cheng, Bastian; Golsari, Amir; Weiler, Florian; Gregori, Johannes; Thomalla, Götz; Klein, Jan

2018-02-01

DeepMedic, an open source software library based on a multi-channel multi-resolution 3D convolutional neural network, has recently been made publicly available for brain lesion segmentations. It has already been shown that segmentation tasks on MRI data of patients having traumatic brain injuries, brain tumors, and ischemic stroke lesions can be performed very well. In this paper we describe how it can efficiently be used for the purpose of detecting and segmenting white matter hyperintensity lesions. We examined if it can be applied to single-channel routine 2D FLAIR data. For evaluation, we annotated 197 datasets with different numbers and sizes of white matter hyperintensity lesions. Our experiments have shown that substantial results with respect to the segmentation quality can be achieved. Compared to the original parametrization of the DeepMedic neural network, the timings for training can be drastically reduced if adjusting corresponding training parameters, while at the same time the Dice coefficients remain nearly unchanged. This enables for performing a whole training process within a single day utilizing a NVIDIA GeForce GTX 580 graphics board which makes this library also very interesting for research purposes on low-end GPU hardware.

[Time-organization of EEG patterns' structure in anxiety and phobic disorders].

PubMed

Sviatogor, I A; Mokhovikova, I A

2005-01-01

Thirty-five patients, aged 19-48 years (mean age 38 years) with anxiety and phobic disorders were examined. According to ICD-10 criteria--social phobia (F40.1), panic disorder (F41.0), somatoform autonomic dysfunction (F45.3) were diagnosed. Using electroencephalography data, qualitative and quantitative characteristics of the time- and spatial-organization of brain EEG activity in anxiety and phobic disorders of different severity were established. It were determined 4 types of wave interactions between EEG components, which reflected a different extent of the regulatory mechanisms lesions: 2 structures with one core component (alpha or beta), a structure with two core components and a non-organized structure.

Neuropsychological functioning and brain structure in schizophrenia.

PubMed

Crespo-Facorro, Benedicto; Barbadillo, Laura; Pelayo-Terán, José Maria; Rodríguez-Sánchez, José Manuel

2007-08-01

Cognitive deficits are core features of schizophrenia that are already evident at early phases of the illness. The study of specific relationships between cognition and brain structure might provide valuable clues about neural basis of schizophrenia and its phenomenology. The aim of this article was to review the most consistent findings of the studies exploring the relationships between cognitive deficits and brain anomalies in schizophrenia. Besides several important methodological shortcomings to bear in mind before drawing any consistent conclusion from the revised literature, we have attempted to systematically summarize these findings. Thus, this review has revealed that whole brain volume tends to positively correlate with a range of cognitive domains in healthy volunteers and female patients. An association between prefrontal morphological characteristics and general inability to control behaviour seems to be present in schizophrenia patients. Parahippocampal volume is related to semantic cognitive functions. Thalamic anomalies have been associated with executive deficits specifically in patients. Available evidence on the relationship between cognitive functions and cerebellar structure is still contradictory. Nonetheless, a larger cerebellum appears to be associated with higher IQ in controls and in female patients. Enlarged ventricles, including lateral and third ventricles, are associated with deficits in attention, executive and premorbid cognitive functioning in patients. Several of these reported findings seem to be counterintuitive according to neural basis of cognitive functioning drawn from animal, lesion, and functional imaging investigations. Therefore, there is still a great need for more methodologically stringent investigations that would help in the advance of our understanding of the cognition/brain structure relationships in schizophrenia.

Clinical presentation and treatment paradigms of brain arteriovenous malformations in patients with hereditary hemorrhagic telangiectasia.

PubMed

Gamboa, Nicholas T; Joyce, Evan J; Eli, Ilyas; Park, Min S; Taussky, Philipp; Schmidt, Richard H; McDonald, Jamie; Whitehead, Kevin J; Kalani, M Yashar S

2018-05-01

Hereditary hemorrhagic telangiectasia (HHT) is characterized by recurrent spontaneous epistaxis, mucocutaneous telangiectases, and multisystem arteriovenous malformations (AVMs). Brain AVMs typically present at birth and are identified in approximately 10-20% of patients with HHT. A retrospective review was undertaken of all HHT patients with known single or multiple brain AVMs treated at our institution. Thirty-nine patients with brain AVM(s) were diagnosed with HHT. Most patients presented with at least one Curaçao criterion. A total of 78 brain AVMs were identified in 39 patients. Two-thirds of patients had solitary brain AVMs, whereas 33% of patients harbored at least two lesions (range: 2-16). Brain AVMs of the supratentorial cerebral hemispheres comprised 83% of all lesions, whereas infratentorial lesions accounted for only 17%. Of the 55 brain AVMs assigned Spetzler-Martin grading, the majority of patients were Grade 1 (73%), and 23% and 4% were Grades 2 and 3, respectively. Patients were treated with surgery alone (51%), embolization alone (6%), embolization followed by surgery (9%), stereotactic radiosurgery (11%), stereotactic radiosurgery followed by surgery (3%), or observation (20%). Of patients who underwent genetic analysis, 62% possessed mutations in ENG (HHT type 1), whereas 38% had mutations in ACVRL1 (HHT type 2). This robust patient cohort of brain AVMs in 39 patients with HHT advances the collective understanding of this disease's varied presentation, diagnostic workup, genetic underpinnings, and available treatment options. Copyright © 2018. Published by Elsevier Ltd.

Longitudinal association between hippocampus atrophy and episodic-memory decline.

PubMed

Gorbach, Tetiana; Pudas, Sara; Lundquist, Anders; Orädd, Greger; Josefsson, Maria; Salami, Alireza; de Luna, Xavier; Nyberg, Lars

2017-03-01

There is marked variability in both onset and rate of episodic-memory decline in aging. Structural magnetic resonance imaging studies have revealed that the extent of age-related brain changes varies markedly across individuals. Past studies of whether regional atrophy accounts for episodic-memory decline in aging have yielded inconclusive findings. Here we related 15-year changes in episodic memory to 4-year changes in cortical and subcortical gray matter volume and in white-matter connectivity and lesions. In addition, changes in word fluency, fluid IQ (Block Design), and processing speed were estimated and related to structural brain changes. Significant negative change over time was observed for all cognitive and brain measures. A robust brain-cognition change-change association was observed for episodic-memory decline and atrophy in the hippocampus. This association was significant for older (65-80 years) but not middle-aged (55-60 years) participants and not sensitive to the assumption of ignorable attrition. Thus, these longitudinal findings highlight medial-temporal lobe system integrity as particularly crucial for maintaining episodic-memory functioning in older age. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Role of the Neuropathology of Alzheimer Disease in Dementia in the Oldest-Old

PubMed Central

Haroutunian, Vahram; Schnaider-Beeri, Michal; Schmeidler, James; Wysocki, Michael; Purohit, Dushyant P.; Perl, Daniel P.; Libow, Leslie S.; Lesser, Gerson T.; Maroukian, Maria; Grossman, Hillel T.

2011-01-01

Background Neuritic plaques (NPs) and neurofibrillary tangles (NFTs) in the brain, especially in the hippocampus, entorhinal cortex, and isocortex, are hallmark lesions of Alzheimer disease and dementia in the elderly. However, this association has not been extensively studied in the rapidly growing population of the very old. Objective To assess the relationship between estimates of cognitive function and NP and NFT pathologic conditions in 317 autopsied persons aged 60 to 107 years. Design We studied the relationship between severity of dementia and the density of these characteristic lesions of Alzheimer disease in young-old, middle-old, and oldest-old persons. The relationship of the severity of dementia as measured by the Clinical Dementia Rating scale to the density of NPs and NFTs was then assessed in each age group. Participants Three hundred seventeen brains of persons aged 60 years and older were selected to have either no remarkable neuropathological lesions or only NP and NFT lesions. Brains with any other neuropathological conditions, either alone or in addition to Alzheimer disease findings, were excluded. The study cohort was then stratified into the youngest quartile (aged 60–80 years), middle 2 quartiles (aged 81–89 years), and oldest quartile (aged 90–107 years). Results While the density of NPs and NFTs rose significantly by more than 10-fold as a function of the severity of dementia in the youngest-old group, significant increases in the densities of NPs and NFTs were absent in the brains of the oldest-old. This lack of difference in the densities of NPs and NFTs was due to reduced lesion densities in the brains of oldest-old persons with dementia rather than to increased density of these lesions in the brains of nondemented oldest-old persons. Conclusions These findings suggest that the neuropathological features of dementia in the oldest-old are not the same as those of cognitively impaired younger-old persons and compel a vigorous search for neuropathological indices of dementia in this most rapidly growing segment of the elderly population. PMID:18779425

Solitary tuberculous brain lesions: 24 new cases and a review of the literature.

PubMed

Psimaras, D; Bonnet, C; Heinzmann, A; Cárdenas, G; Hernández José Luis, S; Tungaria, A; Behari, S; Lacrois, D; Mokhtari, K; Karantoni, E; Sokrab Tag, E; Idris Mohamed, N; Sönmez, G; Caumes, E; Roze, E

2014-01-01

A solitary tuberculous brain lesion (STBL) can be difficult to distinguish from a glioma, metastasis or other infectious disease, especially from a pyogenic brain abscess. We analyzed the clinical characteristics, diagnostic procedures and outcomes of 24 patients with STBL diagnosed in three centers from France, India and Mexico. We also reviewed 92 STBL cases previously reported in the literature. General symptoms were found in 54% of our patients, including enlarged lymph nodes in 20%. Cerebrospinal fluid was typically abnormal, with lymphocytic pleocytosis and a high protein level. The lung CT scan was abnormal in 56% of patients, showing lymphadenopathy or pachipleuritis. Brain MRI or CT was always abnormal, showing contrast-enhanced lesions. Typically, MRI abnormalities were hypointense on T1-weighted sequences, while T2-weighted sequences showed both a peripheral hypersignal and a central hyposignal. The diagnosis was documented microbiologically or supported histologically in 71% of cases. Clinical outcome was good in 83% of cases. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Zero in the brain: A voxel-based lesion-symptom mapping study in right hemisphere damaged patients.

PubMed

Benavides-Varela, Silvia; Passarini, Laura; Butterworth, Brian; Rolma, Giuseppe; Burgio, Francesca; Pitteri, Marco; Meneghello, Francesca; Shallice, Tim; Semenza, Carlo

2016-04-01

Transcoding numerals containing zero is more problematic than transcoding numbers formed by non-zero digits. However, it is currently unknown whether this is due to zeros requiring brain areas other than those traditionally associated with number representation. Here we hypothesize that transcoding zeros entails visuo-spatial and integrative processes typically associated with the right hemisphere. The investigation involved 22 right-brain-damaged patients and 20 healthy controls who completed tests of reading and writing Arabic numbers. As expected, the most significant deficit among patients involved a failure to cope with zeros. Moreover, a voxel-based lesion-symptom mapping (VLSM) analysis showed that the most common zero-errors were maximally associated to the right insula which was previously related to sensorimotor integration, attention, and response selection, yet for the first time linked to transcoding processes. Error categories involving other digits corresponded to the so-called Neglect errors, which however, constituted only about 10% of the total reading and 3% of the writing mistakes made by the patients. We argue that damage to the right hemisphere impairs the mechanism of parsing, and the ability to set-up empty-slot structures required for processing zeros in complex numbers; moreover, we suggest that the brain areas located in proximity to the right insula play a role in the integration of the information resulting from the temporary application of transcoding procedures. Copyright © 2016 Elsevier Ltd. All rights reserved.

Structural neural correlates of multitasking: A voxel-based morphometry study.

PubMed

Zhang, Rui-Ting; Yang, Tian-Xiao; Wang, Yi; Sui, Yuxiu; Yao, Jingjing; Zhang, Chen-Yuan; Cheung, Eric F C; Chan, Raymond C K

2016-12-01

Multitasking refers to the ability to organize assorted tasks efficiently in a short period of time, which plays an important role in daily life. However, the structural neural correlates of multitasking performance remain unclear. The present study aimed at exploring the brain regions associated with multitasking performance using global correlation analysis. Twenty-six healthy participants first underwent structural brain scans and then performed the modified Six Element Test, which required participants to attempt six subtasks in 10 min while obeying a specific rule. Voxel-based morphometry of the whole brain was used to detect the structural correlates of multitasking ability. Grey matter volume of the anterior cingulate cortex (ACC) was positively correlated with the overall performance and time monitoring in multitasking. In addition, white matter volume of the anterior thalamic radiation (ATR) was also positively correlated with time monitoring during multitasking. Other related brain regions associated with multitasking included the superior frontal gyrus, the inferior occipital gyrus, the lingual gyrus, and the inferior longitudinal fasciculus. No significant correlation was found between grey matter volume of the prefrontal cortex (Brodmann Area 10) and multitasking performance. Using a global correlation analysis to examine various aspects of multitasking performance, this study provided new insights into the structural neural correlates of multitasking ability. In particular, the ACC was identified as an important brain region that played both a general and a specific time-monitoring role in multitasking, extending the role of the ACC from lesioned populations to healthy populations. The present findings also support the view that the ATR may influence multitasking performance by affecting time-monitoring abilities. © 2016 The Institute of Psychology, Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Structural and functional hallmarks of amyotrophic lateral sclerosis progression in motor- and memory-related brain regions

PubMed Central

Stoppel, Christian Michael; Vielhaber, Stefan; Eckart, Cindy; Machts, Judith; Kaufmann, Jörn; Heinze, Hans-Jochen; Kollewe, Katja; Petri, Susanne; Dengler, Reinhard; Hopf, Jens-Max; Schoenfeld, Mircea Ariel

2014-01-01

Previous studies have shown that in amyotrophic lateral sclerosis (ALS) multiple motor and extra-motor regions display structural and functional alterations. However, their temporal dynamics during disease-progression are unknown. To address this question we employed a longitudinal design assessing motor- and novelty-related brain activity in two fMRI sessions separated by a 3-month interval. In each session, patients and controls executed a Go/NoGo-task, in which additional presentation of novel stimuli served to elicit hippocampal activity. We observed a decline in the patients' movement-related activity during the 3-month interval. Importantly, in comparison to controls, the patients' motor activations were higher during the initial measurement. Thus, the relative decrease seems to reflect a breakdown of compensatory mechanisms due to progressive neural loss within the motor-system. In contrast, the patients' novelty-evoked hippocampal activity increased across 3 months, most likely reflecting the build-up of compensatory processes typically observed at the beginning of lesions. Consistent with a stage-dependent emergence of hippocampal and motor-system lesions, we observed a positive correlation between the ALSFRS-R or MRC-Megascores and the decline in motor activity, but a negative one with the hippocampal activation-increase. Finally, to determine whether the observed functional changes co-occur with structural alterations, we performed voxel-based volumetric analyses on magnetization transfer images in a separate patient cohort studied cross-sectionally at another scanning site. Therein, we observed a close overlap between the structural changes in this cohort, and the functional alterations in the other. Thus, our results provide important insights into the temporal dynamics of functional alterations during disease-progression, and provide support for an anatomical relationship between functional and structural cerebral changes in ALS. PMID:25161894

Neuroinflammation and its relationship to changes in brain volume and white matter lesions in multiple sclerosis.

PubMed

Datta, Gourab; Colasanti, Alessandro; Rabiner, Eugenii A; Gunn, Roger N; Malik, Omar; Ciccarelli, Olga; Nicholas, Richard; Van Vlierberghe, Eline; Van Hecke, Wim; Searle, Graham; Santos-Ribeiro, Andre; Matthews, Paul M

2017-11-01

Brain magnetic resonance imaging is an important tool in the diagnosis and monitoring of multiple sclerosis patients. However, magnetic resonance imaging alone provides limited information for predicting an individual patient's disability progression. In part, this is because magnetic resonance imaging lacks sensitivity and specificity for detecting chronic diffuse and multi-focal inflammation mediated by activated microglia/macrophages. The aim of this study was to test for an association between 18 kDa translocator protein brain positron emission tomography signal, which arises largely from microglial activation, and measures of subsequent disease progression in multiple sclerosis patients. Twenty-one patients with multiple sclerosis (seven with secondary progressive disease and 14 with a relapsing remitting disease course) underwent T1- and T2-weighted and magnetization transfer magnetic resonance imaging at baseline and after 1 year. Positron emission tomography scanning with the translocator protein radioligand 11C-PBR28 was performed at baseline. Brain tissue and lesion volumes were segmented from the T1- and T2-weighted magnetic resonance imaging and relative 11C-PBR28 uptake in the normal-appearing white matter was estimated as a distribution volume ratio with respect to a caudate pseudo-reference region. Normal-appearing white matter distribution volume ratio at baseline was correlated with enlarging T2-hyperintense lesion volumes over the subsequent year (ρ = 0.59, P = 0.01). A post hoc analysis showed that this association reflected behaviour in the subgroup of relapsing remitting patients (ρ = 0.74, P = 0.008). By contrast, in the subgroup of secondary progressive patients, microglial activation at baseline was correlated with later progression of brain atrophy (ρ = 0.86, P = 0.04). A regression model including the baseline normal-appearing white matter distribution volume ratio, T2 lesion volume and normal-appearing white matter magnetization transfer ratio for all of the patients combined explained over 90% of the variance in enlarging lesion volume over the subsequent 1 year. Glial activation in white matter assessed by translocator protein PET significantly improves predictions of white matter lesion enlargement in relapsing remitting patients and is associated with greater brain atrophy in secondary progressive disease over a period of short term follow-up. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Cognitive Activation by Central Thalamic Stimulation: The Yerkes-Dodson Law Revisited.

PubMed Central

Mair, Robert G.; Onos, Kristen D.; Hembrook, Jacqueline R.

2011-01-01

Central thalamus regulates forebrain arousal, influencing activity in distributed neural networks that give rise to organized actions during alert, wakeful states. Central thalamus has been implicated in working memory by the effects of lesions and microinjected drugs in this part of the brain. Lesions and drugs that inhibit neural activity have been found to impair working memory. Drugs that increase activity have been found to enhance and impair memory depending on the dose tested. Electrical deep brain stimulation (DBS) similarly enhances working memory at low stimulating currents and impairs it at higher currents. These effects are time dependent. They were observed when DBS was applied during the memory delay (retention) or choice response (retrieval) but not earlier in trials during the sample (acquisition) phase. The effects of microinjected drugs and DBS are consistent with the Yerkes-Dodson law, which describes an inverted-U relationship between arousal and behavioral performance. Alternatively these results may reflect desensitization associated with higher levels of stimulation, spread of drugs or current to adjacent structures, or activation of less sensitive neurons or receptors at higher DBS currents or drug doses. PMID:22013395

Intraoperative high-field magnetic resonance imaging, multimodal neuronavigation, and intraoperative electrophysiological monitoring-guided surgery for treating supratentorial cavernomas.

PubMed

Li, Fang-Ye; Chen, Xiao-Lei; Xu, Bai-Nan

2016-09-01

To determine the beneficial effects of intraoperative high-field magnetic resonance imaging (MRI), multimodal neuronavigation, and intraoperative electrophysiological monitoring-guided surgery for treating supratentorial cavernomas. Twelve patients with 13 supratentorial cavernomas were prospectively enrolled and operated while using a 1.5 T intraoperative MRI, multimodal neuronavigation, and intraoperative electrophysiological monitoring. All cavernomas were deeply located in subcortical areas or involved critical areas. Intraoperative high-field MRIs were obtained for the intraoperative "visualization" of surrounding eloquent structures, "brain shift" corrections, and navigational plan updates. All cavernomas were successfully resected with guidance from intraoperative MRI, multimodal neuronavigation, and intraoperative electrophysiological monitoring. In 5 cases with supratentorial cavernomas, intraoperative "brain shift" severely deterred locating of the lesions; however, intraoperative MRI facilitated precise locating of these lesions. During long-term (>3 months) follow-up, some or all presenting signs and symptoms improved or resolved in 4 cases, but were unchanged in 7 patients. Intraoperative high-field MRI, multimodal neuronavigation, and intraoperative electrophysiological monitoring are helpful in surgeries for the treatment of small deeply seated subcortical cavernomas.

Unilateral Postoperative Deep Cerebral Venous Thrombosis with Complete Recovery: A Report of 2 Cases.

PubMed

Benifla, Mony; Laughlin, Suzzanne; Tovar-Spinoza, Zulma S; Rutka, James T; Dirks, Peter B

2017-01-01

Postsurgical deep brain venous thrombosis has not been well described in children before. When approaching thalamic or intraventricular lesions, extra care should be taken to prevent injury to the internal cerebral veins (ICVs) and the vein of Galen. However, even when they are well preserved during surgery, postoperative hemodynamic changes, mainly in the first 24 h, or surgical manipulation can cause thrombosis of these veins. We report 2 children with unilateral postoperative ICV thrombosis; in 1 of the patients the vein of Galen was also thrombosed. Although both patients had altered sensorium initially, no anticoagulation therapy was given, and they both recovered well. When approaching thalamic or intraventricular lesions, extra care should be taken to prevent injury to the ICV and the vein of Galen. The surgeon should respect the deep brain venous system when approaching midline structures. Both the neurosurgeon and the neuroradiologist should be aware of this possible complication in order to make a prompt diagnosis and to offer proper treatment if needed. © 2017 S. Karger AG, Basel.

Microbiota Dysbiosis Controls the Neuroinflammatory Response after Stroke.

PubMed

Singh, Vikramjeet; Roth, Stefan; Llovera, Gemma; Sadler, Rebecca; Garzetti, Debora; Stecher, Bärbel; Dichgans, Martin; Liesz, Arthur

2016-07-13

Acute brain ischemia induces a local neuroinflammatory reaction and alters peripheral immune homeostasis at the same time. Recent evidence has suggested a key role of the gut microbiota in autoimmune diseases by modulating immune homeostasis. Therefore, we investigated the mechanistic link among acute brain ischemia, microbiota alterations, and the immune response after brain injury. Using two distinct models of acute middle cerebral artery occlusion, we show by next-generation sequencing that large stroke lesions cause gut microbiota dysbiosis, which in turn affects stroke outcome via immune-mediated mechanisms. Reduced species diversity and bacterial overgrowth of bacteroidetes were identified as hallmarks of poststroke dysbiosis, which was associated with intestinal barrier dysfunction and reduced intestinal motility as determined by in vivo intestinal bolus tracking. Recolonizing germ-free mice with dysbiotic poststroke microbiota exacerbates lesion volume and functional deficits after experimental stroke compared with the recolonization with a normal control microbiota. In addition, recolonization of mice with a dysbiotic microbiome induces a proinflammatory T-cell polarization in the intestinal immune compartment and in the ischemic brain. Using in vivo cell-tracking studies, we demonstrate the migration of intestinal lymphocytes to the ischemic brain. Therapeutic transplantation of fecal microbiota normalizes brain lesion-induced dysbiosis and improves stroke outcome. These results support a novel mechanism in which the gut microbiome is a target of stroke-induced systemic alterations and an effector with substantial impact on stroke outcome. We have identified a bidirectional communication along the brain-gut microbiota-immune axis and show that the gut microbiota is a central regulator of immune homeostasis. Acute brain lesions induced dysbiosis of the microbiome and, in turn, changes in the gut microbiota affected neuroinflammatory and functional outcome after brain injury. The microbiota impact on immunity and stroke outcome was transmissible by microbiota transplantation. Our findings support an emerging concept in which the gut microbiota is a key regulator in priming the neuroinflammatory response to brain injury. These findings highlight the key role of microbiota as a potential therapeutic target to protect brain function after injury. Copyright © 2016 the authors 0270-6474/16/367428-13$15.00/0.

Architecture of cognitive flexibility revealed by lesion mapping

PubMed Central

Barbey, Aron K.; Colom, Roberto; Grafman, Jordan

2013-01-01

Neuroscience has made remarkable progress in understanding the architecture of human intelligence, identifying a distributed network of brain structures that support goal-directed, intelligent behavior. However, the neural foundations of cognitive flexibility and adaptive aspects of intellectual function remain to be well characterized. Here, we report a human lesion study (n = 149) that investigates the neural bases of key competencies of cognitive flexibility (i.e., mental flexibility and the fluent generation of new ideas) and systematically examine their contributions to a broad spectrum of cognitive and social processes, including psychometric intelligence (Wechsler Adult Intelligence Scale), emotional intelligence (Mayer, Salovey, Caruso Emotional Intelligence Test), and personality (Neuroticism–Extraversion–Openness Personality Inventory). Latent variable modeling was applied to obtain error-free indices of each factor, followed by voxel-based lesion-symptom mapping to elucidate their neural substrates. Regression analyses revealed that latent scores for psychometric intelligence reliably predict latent scores for cognitive flexibility (adjusted R2 = 0.94). Lesion mapping results further indicated that these convergent processes depend on a shared network of frontal, temporal, and parietal regions, including white matter association tracts, which bind these areas into an integrated system. A targeted analysis of the unique variance explained by cognitive flexibility further revealed selective damage within the right superior temporal gyrus, a region known to support insight and the recognition of novel semantic relations. The observed findings motivate an integrative framework for understanding the neural foundations of adaptive behavior, suggesting that core elements of cognitive flexibility emerge from a distributed network of brain regions that support specific competencies for human intelligence. PMID:23721727

Sex differences in the functional lateralization of emotion and decision-making in the human brain

PubMed Central

Reber, Justin; Tranel, Daniel

2016-01-01

Dating back to the case of Phineas Gage, decades of neuropsychological research have shown that the ventromedial prefrontal cortex (vmPFC) is crucial to both real-world social functioning and abstract decision-making in the laboratory (e.g., Bechara et al., 1994; Damasio et al., 1994; Stuss et al., 1983). Previous research has found that the relationship between the laterality of individuals’ vmPFC lesions and neuropsychological performance is moderated by their sex, whereby there are more severe social, emotional, and decision-making impairments in men with right-sided vmPFC lesions and in women with left-sided vmPFC lesions (Tranel et al., 2005; Sutterer et al., 2015). We conducted a selective review of studies examining the effect of vmPFC lesions on emotion and decision-making, and found further evidence of sex-related differences in the lateralization of function not only in the vmPFC, but also in other neurological structures associated with decision-making and emotion. Our review suggests that both sex and laterality effects warrant more careful consideration in the scientific literature. PMID:27870462

Correlates of posttraumatic epilepsy 35 years following combat brain injury(CME)

PubMed Central

Raymont, V.; Salazar, A.M.; Lipsky, R.; Goldman, D.; Tasick, G.; Grafman, J.

2010-01-01

Background: The Vietnam Head Injury Study (VHIS) is a prospective, longitudinal follow-up of 1,221 Vietnam War veterans with mostly penetrating head injuries (PHIs). The high prevalence (45%–53%) of posttraumatic epilepsy (PTE) in this unique cohort makes it valuable for study. Methods: A standardized multidisciplinary neurologic, cognitive, behavioral, and brain imaging evaluation was conducted on 199 VHIS veterans plus uninjured controls, some 30 to 35 years after injury, as part of phase 3 of this study. Results: The prevalence of seizures (87 patients, 43.7%) was similar to that found during phase 2 evaluations 20 years earlier, but 11 of 87 (12.6%) reported very late onset of PTE after phase 2 (more than 14 years after injury). Those patients were not different from patients with earlier-onset PTE in any of the measures studied. Within the phase 3 cohort, the most common seizure type last experienced was complex partial seizures (31.0%), with increasing frequency after injury. Of subjects with PTE, 88% were receiving anticonvulsants. Left parietal lobe lesions and retained ferric metal fragments were associated with PTE in a logistic regression model. Total brain volume loss predicted seizure frequency. Conclusions: Patients with PHI carry a high risk of PTE decades after their injury, and so require long-term medical follow-up. Lesion location, lesion size, and lesion type were predictors of PTE. GLOSSARY ABLe = Analysis of Brain Lesions; AFQT = Armed Forces Qualification Test; AIR = Automated Image Registration; CHI = closed head injury; GAD = glutamic acid decarboxylase; PH1 = phase 1; PH2 = phase 2; PH3 = phase 3; PHI = penetrating head injury; PTE = posttraumatic epilepsy; TBI = traumatic brain injury; VHIS = Vietnam Head Injury Study; WAIS = Wechsler Adult Intelligence Scale. PMID:20644150

MRI evaluation and functional assessment of brain injury after hypoxic ischemia in neonatal mice.

PubMed

Adén, Ulrika; Dahlberg, Viktoria; Fredholm, Bertil B; Lai, Li-Ju; Chen, Zhengguan; Bjelke, Börje

2002-05-01

Severe perinatal asphyxia is an important cause of brain injury in the newborn infant. We examined early events after hypoxic ischemia (HI) in the 7-day-old mouse brain by MRI and related them to long-term functional effects and histopathology in the same animals at 4 to 5 weeks of age. HI was induced in 7-day-old CD1 mice by exposure to 8% oxygen for 30 minutes after occlusion of the left common carotid artery. The resulting unilateral focal lesion was evaluated in vivo by MRI (T2 maps and apparent diffusion coefficient maps) at 3, 6, and 24 hours and 5 days after hypoxia. Locomotion and sensorimotor function were analyzed after 3 weeks. Four weeks after HI, the mice were killed, and cresyl violet-stained brain sections were examined morphologically. A decrease in apparent diffusion coefficient values in cortex on the affected side was found at 3 hours after HI. T2 values were significantly increased after 6 hours and remained so for 5 days. Maximal size of the lesion was attained at 3 to 6 hours after HI and declined thereafter. Animals with MRI-detected lesions had decreased forward locomotion, performed worse than controls in the beam-walking test, and showed a unilateral hypotrophy in the cresyl violet-stained brain sections 4 weeks later. The temporal progression of the damage after HI in 7-day-old mice differs from that of the adult brain as judged by MRI. The early lesions detected by MRI were related to functional impairments for these mice in near-adult life.

Characterizing iron deposition in multiple sclerosis lesions using susceptibility weighted imaging

PubMed Central

Haacke, E. Mark; Makki, Malek; Ge, Yulin; Maheshwari, Megha; Sehgal, Vivek; Hu, Jiani; Selvan, Madeswaran; Wu, Zhen; Latif, Zahid; Xuan, Yang; Khan, Omar; Garbern, James; Grossman, Robert I.

2009-01-01

Purpose To investigate whether the variable forms of putative iron deposition seen with susceptibility weighted imaging (SWI) will lead to a set of multiple sclerosis (MS) lesion characteristics different than that seen in conventional MR imaging. Materials and Methods Twenty-seven clinically definite MS patients underwent brain scans using magnetic resonance imaging including: pre- and post-contrast T1-weighted, T2-weighted, FLAIR, and SWI at 1.5T, 3T and 4T. MS lesions were identified separately in each imaging sequence. Lesions identified in SWI were re-evaluated for their iron content using the SWI filtered phase images. Results There were a variety of new lesion characteristics identified by SWI and these were classified into six types. A total of 75 lesions were seen only with conventional imaging, 143 only with SWI and 204 by both. From the iron quantification measurements, a moderate linear correlation between signal intensity and iron content (phase) was established. Conclusion The amount of iron deposition in the brain may serve as a surrogate biomarker for different MS lesion characteristics. SWI showed many lesions missed by conventional methods and six different lesion characteristics. SWI was particularly effective at recognizing the presence of iron in MS lesions and in the basal ganglia and pulvinar thalamus. PMID:19243035

Ultrastructural blood-brain barrier alterations and edema formation in acute spinal cord trauma.

PubMed

Goodman, J H; Bingham, W G; Hunt, W E

1976-04-01

Endothelial changes leading to edema formation are examined in the primate spinal cord (Macaca mulatta) following a lesion created by a 20-gm weight falling 15 cm onto the exposed dura. Intravascular perfusion of a paraformaldehydeglutaraldehyde solution followed by carbon black provides adequate fixation of vascular structures and glial elements. Myelin is poorly preserved. Ultrastructural alterations of the blood-brain barrier consist of loss of integrity of the endothelial tight junctions. Edema caused by vascular disruption and parenchymatous extravasation of intravascular contents is observed along with glial swelling. Interglial gap junctions persist in areas of marked cellular seperation and do not impede the migration of edema fluid.

Radio-frequency lesioning in brain tissue with coagulation-dependent thermal conductivity: modelling, simulation and analysis of parameter influence and interaction.

PubMed

Johansson, Johannes D; Eriksson, Ola; Wren, Joakim; Loyd, Dan; Wårdell, Karin

2006-09-01

Radio-frequency brain lesioning is a method for reducing e.g. symptoms of movement disorders. A small electrode is used to thermally coagulate malfunctioning tissue. Influence on lesion size from thermal and electric conductivity of the tissue, microvascular perfusion and preset electrode temperature was investigated using a finite-element model. Perfusion was modelled as an increased thermal conductivity in non-coagulated tissue. The parameters were analysed using a 2(4)-factorial design (n=16) and quadratic regression analysis (n=47). Increased thermal conductivity of the tissue increased lesion volume, while increased perfusion decreased it since coagulation creates a thermally insulating layer due to the cessation of blood perfusion. These effects were strengthened with increased preset temperature. The electric conductivity had negligible effect. Simulations were found realistic compared to in vivo experimental lesions.

Acute hydrocephalus caused by intraspinal neurocysticercosis: case report

PubMed Central

2014-01-01

Background Intraspinal neurocysticercosis is an uncommon manifestation that may present as an isolated lesion. Furthermore, acute hydrocephalus caused by isolated intraspinal neurocysticercosis without concomitant cerebral involvement is extremely rare. Case presentation A 64-year-old man presented with a history of severe headache, an unsteady gait, and occasional urinary incontinence. Magnetic resonance imaging of the thoraco-lumbar spine revealed multiple, cystic, contrast-enhancing intraspinal lesions. A computed tomographic scan of the brain showed marked ventricular dilatation but no intraparenchymal lesions or intraventricular cysticercal lesions. This case of acute hydrocephalus was found to be caused by isolated intraspinal neurocysticercosis and was treated by ventriculoperitoneal shunt placement and surgical removal of the intraspinal lesions (which were histologically confirmed as neurocysticercosis), followed by administration of dexamethasone and albendazole. Conclusion Isolated spinal neurocysticercosis should be considered in the differential diagnosis of acute hydrocephalus when no explanation is found in the brain, particularly in geographical regions endemic for cysticercosis. PMID:24383427

Gastroschisis, destructive brain lesions, and placental infarction in the second trimester suggest a vascular pathogenesis.

PubMed

Folkerth, Rebecca D; Habbe, Donald M; Boyd, Theonia K; McMillan, Kristin; Gromer, Jessica; Sens, Mary Ann; Elliott, Amy J

2013-01-01

The cause and pathogenesis of gastroschisis are uncertain. We report the autopsy and placental pathology of a stillbirth at 20 gestational weeks, in which gastroschisis was accompanied by destructive lesions in the cerebral cortex and brainstem, as well as cardiac calcification, consistent with ischemic injury during the 2nd trimester. An important potential underlying mechanism explaining the fetal abnormalities is the presence of infarcts in the placenta, indicative at this gestational age of maternal vascular underperfusion. The association of gastroschisis with ischemic lesions in the brain, heart, and placenta in this case supports the concept that gastroschisis, at least in some instances, may result from vascular event(s) causing disruption of the fetal abdominal wall and resulting in the extrusion of the abdominal organs, as well as hypoxic-ischemic brain and cardiac injury.

Multiple intracranial space-occupying lesions in a renal transplant recipient from an area endemic for tuberculosis (TB): TB vs. toxoplasmosis.

PubMed

Bagchi, S; Sachdev, S S; Nalwa, A; Das, C J; Sinha, S; Suri, V; Mahajan, S; Bhowmik, D; Agarwal, S

2014-10-01

Renal transplant recipients may present with intracranial space-occupying lesions (SOLs) due to infections as well as a post-transplant lymphoproliferative disorder (PTLD). Here, we discuss a renal transplant recipient who presented with neurologic symptoms and magnetic resonance imaging (MRI) of the brain showed multiple focal SOLs. Tuberculosis (TB), toxoplasmosis, nocardiosis, fungal infections, and PTLD were considered in the differential diagnosis. MRI spectroscopy was suggestive of an infectious cause, such as toxoplasmosis or TB. Serologic tests using Toxoplasma were negative. A brain biopsy followed by immunohistochemical staining using Toxoplasma antibody demonstrated multiple intravascular cysts of toxoplasma. This case highlights the diagnostic dilemma in an immunocompromised patient with multiple focal brain lesions, especially in areas where TB is endemic. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Neurological Injury and Cerebral Blood Flow in Single Ventricles Throughout Staged Surgical Reconstruction.

PubMed

Fogel, Mark A; Li, Christine; Elci, Okan U; Pawlowski, Tom; Schwab, Peter J; Wilson, Felice; Nicolson, Susan C; Montenegro, Lisa M; Diaz, Laura; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Mascio, Christopher; Keller, Marc S; Harris, Matthew A; Whitehead, Kevin K; Bethel, Jim; Vossough, Arastoo; Licht, Daniel J

2017-02-14

Patients with a single ventricle experience a high rate of brain injury and adverse neurodevelopmental outcome; however, the incidence of brain abnormalities throughout surgical reconstruction and their relationship with cerebral blood flow, oxygen delivery, and carbon dioxide reactivity remain unknown. Patients with a single ventricle were studied with magnetic resonance imaging scans immediately prior to bidirectional Glenn (pre-BDG), before Fontan (BDG), and then 3 to 9 months after Fontan reconstruction. One hundred sixty-eight consecutive subjects recruited into the project underwent 235 scans: 63 pre-BDG (mean age, 4.8±1.7 months), 118 BDG (2.9±1.4 years), and 54 after Fontan (2.4±1.0 years). Nonacute ischemic white matter changes on T2-weighted imaging, focal tissue loss, and ventriculomegaly were all more commonly detected in BDG and Fontan compared with pre-BDG patients ( P <0.05). BDG patients had significantly higher cerebral blood flow than did Fontan patients. The odds of discovering brain injury with adjustment for surgical stage as well as ≥2 coexisting lesions within a patient decreased (63%-75% and 44%, respectively) with increasing amount of cerebral blood flow ( P <0.05). In general, there was no association of oxygen delivery (except for ventriculomegaly in the BDG group) or carbon dioxide reactivity with neurological injury. Significant brain abnormalities are commonly present in patients with a single ventricle, and detection of these lesions increases as children progress through staged surgical reconstruction, with multiple coexisting lesions more common earlier than later. In addition, this study demonstrated that BDG patients had greater cerebral blood flow than did Fontan patients and that an inverse association exists of various indexes of cerebral blood flow with these brain lesions. However, CO 2 reactivity and oxygen delivery (with 1 exception) were not associated with brain lesion development. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02135081. © 2016 American Heart Association, Inc.

CNS Langerhans cell histiocytosis: Common hematopoietic origin for LCH-associated neurodegeneration and mass lesions.

PubMed

McClain, Kenneth L; Picarsic, Jennifer; Chakraborty, Rikhia; Zinn, Daniel; Lin, Howard; Abhyankar, Harshal; Scull, Brooks; Shih, Albert; Lim, Karen Phaik Har; Eckstein, Olive; Lubega, Joseph; Peters, Tricia L; Olea, Walter; Burke, Thomas; Ahmed, Nabil; Hicks, M John; Tran, Brandon; Jones, Jeremy; Dauser, Robert; Jeng, Michael; Baiocchi, Robert; Schiff, Deborah; Goldman, Stanton; Heym, Kenneth M; Wilson, Harry; Carcamo, Benjamin; Kumar, Ashish; Rodriguez-Galindo, Carlos; Whipple, Nicholas S; Campbell, Patrick; Murdoch, Geoffrey; Kofler, Julia; Heales, Simon; Malone, Marian; Woltjer, Randy; Quinn, Joseph F; Orchard, Paul; Kruer, Michael C; Jaffe, Ronald; Manz, Markus G; Lira, Sergio A; Parsons, D Williams; Merad, Miriam; Man, Tsz-Kwong; Allen, Carl E

2018-06-15

Central nervous system Langerhans cell histiocytosis (CNS-LCH) brain involvement may include mass lesions and/or a neurodegenerative disease (LCH-ND) of unknown etiology. The goal of this study was to define the mechanisms of pathogenesis that drive CNS-LCH. Cerebrospinal fluid (CSF) biomarkers including CSF proteins and extracellular BRAFV600E DNA were analyzed in CSF from patients with CNS-LCH lesions compared with patients with brain tumors and other neurodegenerative conditions. Additionally, the presence of BRAFV600E was tested in peripheral mononuclear blood cells (PBMCs) as well as brain biopsies from LCH-ND patients, and the response to BRAF-V600E inhibitor was evaluated in 4 patients with progressive disease. Osteopontin was the only consistently elevated CSF protein in patients with CNS-LCH compared with patients with other brain pathologies. BRAFV600E DNA was detected in CSF of only 2/20 (10%) cases, both with LCH-ND and active lesions outside the CNS. However, BRAFV600E + PBMCs were detected with significantly higher frequency at all stages of therapy in LCH patients who developed LCH-ND. Brain biopsies of patients with LCH-ND demonstrated diffuse perivascular infiltration by BRAFV600E + cells with monocyte phenotype (CD14 + CD33 + CD163 + P2RY12 - ) and associated osteopontin expression. Three of 4 patients with LCH-ND treated with BRAF-V600E inhibitor experienced significant clinical and radiologic improvement. In LCH-ND patients, BRAFV600E + cells in PBMCs and infiltrating myeloid/monocytic cells in the brain is consistent with LCH-ND as an active demyelinating process arising from a mutated hematopoietic precursor from which LCH lesion CD207 + cells are also derived. Therapy directed against myeloid precursors with activated MAPK signaling may be effective for LCH-ND. Cancer 2018;124:2607-20. © 2018 American Cancer Society. © 2018 American Cancer Society.

Epilepsy, Cognition, and Behavior: The clinical picture

PubMed Central

Berg, Anne T.

2010-01-01

Although epilepsy is defined by the occurrence of spontaneous epileptic seizures, a large body of evidence indicates that epilepsy is linked to a spectrum behavioral, psychiatric, and cognitive disorders as well as to sudden death. Explanations for these associations include: (1) The effects of structural lesions which may impair the functions subserved by the regions of the brain involved in the lesion. (2) The effects of seizure activity which may begin well before a clinical seizure occurs and may persist long after it is over raising questions about what truly constitutes “interictal.” In addition, encephalopathic effects of epilepsy in infancy during critical periods in development may be particularly severe and potentially irreversible. (3) Shared mechanisms underlying seizures as well as these other disorders in the absence of structural lesions or separate diseases of the CNS. Epidemiological and clinical studies demonstrate the elevated risk of cognitive, psychiatric, and behavioral disorders not just during but also prior to the onset of epilepsy (seizures) itself. These may outlast the active phase of epilepsy as well. The mounting evidence argues strongly for the recognition of epilepsy as part of a spectrum of disorders and against the notion that even uncomplicated epilepsy can a priori be considered benign. PMID:21214534

Hyperintense white matter lesions in 50 high-altitude pilots with neurologic decompression sickness.

PubMed

McGuire, Stephen A; Sherman, Paul M; Brown, Anthony C; Robinson, Andrew Y; Tate, David F; Fox, Peter T; Kochunov, Peter V

2012-12-01

Neurologic decompression sickness (NDCS) can affect high-altitude pilots, causing variable central nervous system symptoms. Five recent severe episodes prompted further investigation. We report the hyperintense white matter (HWM) lesion imaging findings in 50 U-2 pilot volunteers, and compare 12 U-2 pilots who experienced clinical NDCS to 38 U-2 pilots who did not. The imaging data were collected using a 3T magnetic resonance imaging scanner and high-resolution (1-mm isotropic) three-dimensional fluid-attenuated inversion recovery sequence. Whole-brain and regional lesion volume and number were compared between groups. The NDCS group had significantly increased whole brain and insular volumes of HWM lesions. The intergroup difference in lesion numbers was not significant. A clinical episode of NDCS was associated with a significant increase in HWM lesion volume, especially in the insula. We postulate this to be due to hypobaric exposure rather than hypoxia since all pilots were maintained on 100% oxygen throughout the flight. Further studies will be necessary to better understand the pathophysiology underlying these lesions.

Hyperintense White Matter Lesions in 50 High-Altitude Pilots With Neurologic Decompression Sickness

PubMed Central

McGuire, Stephen A.; Sherman, Paul M.; Brown, Anthony C.; Robinson, Andrew Y.; Tate, David F.; Fox, Peter T.; Kochunov, Peter V.

2013-01-01

Introduction Neurologic decompression sickness (NDCS) can affect high-altitude pilots, causing variable central nervous system symptoms. Five recent severe episodes prompted further investigation. Methods We report the hyperintense white matter (HWM) lesion imaging findings in 50 U-2 pilot volunteers, and compare 12 U-2 pilots who experienced clinical NDCS to 38 U-2 pilots who did not. The imaging data were collected using a 3T magnetic resonance imaging scanner and high-resolution (1-mm isotropic) three-dimensional fluid-attenuated inversion recovery sequence. Whole-brain and regional lesion volume and number were compared between groups. Results The NDCS group had significantly increased whole brain and insular volumes of HWM lesions. The intergroup difference in lesion numbers was not significant. Conclusion A clinical episode of NDCS was associated with a significant increase in HWM lesion volume, especially in the insula. We postulate this to be due to hypobaric exposure rather than hypoxia since all pilots were maintained on 100% oxygen throughout the flight. Further studies will be necessary to better understand the pathophysiology underlying these lesions. PMID:23316539