TP3-5 Structural connectivity driven stereoelectroencephalography (SEEG) electrode targeting in suspected pseudotemporal and temporal plus epilepsy

2019 ◽  
Vol 90 (3) ◽  
pp. e19.1-e19
Author(s):  
M Della Costanza ◽  
VN Vakharia ◽  
K Li ◽  
M Mancini ◽  
SB Vos ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Structural Connectivity ◽  
Posterior Part ◽  
Middle Part ◽  
Fusiform Gyrus ◽  
Angular Gyrus ◽  
Computer Assisted ◽  
Epileptogenic Zone ◽  
Whole Brain ◽  
Lingual Gyrus

ObjectivesOne third of patients with drug resistant focal mesial temporal lobe epilepsy (MTLE) fail to achieve long-term seizure freedom following temporal lobe resections. Reasons for failure may include ictal onset outside the temporal lobe (TL), termed ‘pseudotemporal lobe epilepsy’ (pTLE), with propagation from strongly connected neighboring areas or temporal plus (TL+) epilepsy, when the epileptogenic zone primarily involves the temporal lobe and also extends to neighboring regions. In such cases the perisylvian and orbito-frontal (OF) cortices, cingulum and temporo-parieto-occipital junction may be implicated. Stereoelectroencephalography (SEEG) is a procedure in which electrodes are stereotactically placed within predefined brain regions to delineate the SOZ and allows evaluation of deep anatomical structures adjacent to the TL. SEEG electrode contacts sample from a core radius of 3–5 mm. It is unclear which sub-regions of target structures should be preferentially implanted to optimally detect the network involved in seizure onset and rapid propagation. Using normalized average group templates of structural connectivity from patients with hippocampal sclerosis (HS), we determine the greatest connectivity to critical sub-regions and based upon this propose optimal locations for SEEG targeting.DesignObservational cross-sectional study.SubjectsTwelve patients with HS (6 right) that had undergone SEEG and pre-operative diffusion imaging were identified from a prospectively maintained database.MethodsWhole brain connectomes with 10 million tracts were generated using cortical seed regions derived from whole brain GIF parcellations. Normalized group templates were generated separately for right and left HS patients. Orbitofrontal cortex (OF), insula (INS), cingulum (Cing) and temporo-parietal-occipital junction (supramarginal gyrus, angular gyrus, precuneus, fusiform gyrus and lingual gyrus) were segmented into surgically targetable subregions. All subregions had similar volumes. Connectivity of the amygdalohippocampal complex (AHC) was defined based on the number of streamlines terminating in the subregions of interest.ResultsLeft HS showed preferential connections to the ipsilateral: posterior part of lateral OF cortex, posterior short gyrus of anterior INS, posterior part of the posterior Cing, middle part of lingual gyrus, posterior part of precuneus and middle part of fusiform gyrus. Right HS showed preferential connections to the ipsilateral: posterior part of the lateral OF cortex, anterior long gyrus of posterior INS, posterior part of posterior Cing, anterior part of lingual gyrus and posterior part of precuneus.ConclusionsUsing whole brain connectomes we determine surgically feasible targets in sub-regions based on greatest connectivity to the AHC. We propose that SEEG targeting utilizing computer-assisted planning may improve the understanding of the overall network connectivity in order to enhance the diagnostic utility of the SEEG implantation. SEEG electrode placement within structures associated with pTLE and TL +may aid in delineating the SOZ if the correct sub-regions are targeted. This should be evaluated prospectively.

scholarly journals A-063 Viewer Engagement Modulates Activation of Social Brain Systems: Evidence from a Natural Viewing fMRI Paradigm

2020 ◽  
Vol 35 (6) ◽  
pp. 853-853
Author(s):  
Pincus J ◽  
Koirala S ◽  
Li L ◽  
Klin A ◽  
Jones W ◽  
...  
Keyword(s):  
Social Learning ◽  
Inferior Frontal Gyrus ◽  
Brain Activation ◽  
Neural Mechanisms ◽  
Fusiform Gyrus ◽  
Angular Gyrus ◽  
Stimulus Category ◽  
Social Brain ◽  
Whole Brain ◽  
Social Disability

Abstract Objective Engagement is critical for social learning—information that does not engage cognition, even when looked at, will go unprocessed and unlearned. Consequently, atypical engagement can contribute to social disability. Despite its importance, the neural mechanisms underlying engagement remain unknown, largely because no studies have successfully quantified the individualized ways that viewers engage with the world. This study uses patterns of eye-blinking—a novel measure of engagement (Shultz, Klin, Jones, 2011)—to examine how a viewer’s own engagement with social stimuli (e.g. faces) modulates activation of social brain systems. Method Simultaneous functional MRI and eye-tracking data were collected while children (n = 12, ages 8–12) watched naturalistic social videos of children interacting. Eye-fixation and blink patterns were used to identify moments when viewers looked at a face and were ‘highly engaged’ or ‘less engaged’ with those faces. Whole-brain analyses compared brain activation in response to each condition of interest (‘highly engaging faces’, ‘less engaging faces’). Results Whole-brain analyses (z = 2.3, cluster corrected at p < .05) reveal increased activation in bilateral occipital cortex, left middle temporal gyrus, bilateral posterior cingulate, left orbitofrontal cortex and inferior frontal gyrus, right angular gyrus, and right fusiform gyrus, when viewing faces perceived as ‘highly engaging’ versus ‘less engaging’. Conclusion Findings suggest that even when viewing the same stimulus category (e.g. faces), one’s own engagement with the stimulus modulates brain activation, even in canonical face processing areas like the fusiform gyrus. Insights into the neural mechanisms of engagement can inform future understanding of social disability and interventions for social learning.

scholarly journals Synaptic Reshaping and Neuronal Outcomes in the Temporal Lobe Epilepsy

2021 ◽  
Vol 22 (8) ◽  
pp. 3860
Author(s):  
Elisa Ren ◽  
Giulia Curia
Keyword(s):  
Animal Models ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Current Knowledge ◽  
Focal Epilepsy ◽  
Ex Vivo ◽  
Hippocampal Sclerosis ◽  
Control Group ◽  
Epileptogenic Zone ◽  
Epileptiform Discharges

Temporal lobe epilepsy (TLE) is one of the most common types of focal epilepsy, characterized by recurrent spontaneous seizures originating in the temporal lobe(s), with mesial TLE (mTLE) as the worst form of TLE, often associated with hippocampal sclerosis. Abnormal epileptiform discharges are the result, among others, of altered cell-to-cell communication in both chemical and electrical transmissions. Current knowledge about the neurobiology of TLE in human patients emerges from pathological studies of biopsy specimens isolated from the epileptogenic zone or, in a few more recent investigations, from living subjects using positron emission tomography (PET). To overcome limitations related to the use of human tissue, animal models are of great help as they allow the selection of homogeneous samples still presenting a more various scenario of the epileptic syndrome, the presence of a comparable control group, and the availability of a greater amount of tissue for in vitro/ex vivo investigations. This review provides an overview of the structural and functional alterations of synaptic connections in the brain of TLE/mTLE patients and animal models.

scholarly journals Cerebral trauma-induced dyschromatopsia in the left hemifield: case presentation

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yoko Mase ◽  
Yoshitsugu Matsui ◽  
Eriko Uchiyama ◽  
Hisashi Matsubara ◽  
Masahiko Sugimoto ◽  
...  
Keyword(s):  
Visual Field ◽  
Color Vision ◽  
Temporal Lobe ◽  
Fusiform Gyrus ◽  
Ganglion Cell Complex ◽  
Automated Perimetry ◽  
Subjective Symptoms ◽  
Anterior Temporal Lobe ◽  
Case Presentation ◽  
Cerebral Trauma

Abstract Background Acquired color anomalies caused by cerebral trauma are classified as either achromatopsias or dyschromatopsias (Zeki, Brain 113:1721–1777, 1990). The three main brain regions stimulated by color are V1, the lingual gyrus, which was designated as human V4 (hV4), and the fusiform gyrus, designated as V4α. (Zeki, Brain 113:1721–1777, 1990). An acquired cerebral color anomaly is often accompanied by visual field loss (hemi- and quadrantanopia), facial agnosia, prosopagnosia, visual agnosia, and anosognosia depending on the underlying pathology (Bartels and Zeki, Eur J Neurosci 12:172–193, 2000), (Meadows, Brain 97:615–632, 1974), (Pearman et al., Ann Neurol 5:253–261, 1979). The purpose of this study was to determine the characteristics of a patient who developed dyschromatopsia following a traumatic injury to her brain. Case presentation The patient was a 24-year-old woman who had a contusion to her right anterior temporal lobe. After the injury, she noticed color distortion and that blue objects appeared green in the left half of the visual field. Although conventional color vision tests did not detect any color vision abnormalities, short wavelength automated perimetry (SWAP) showed a decrease in sensitivity consistent with a left hemi-dyschromatopsia. Magnetic resonance imaging (MRI) detected abnormalities in the right fusiform gyrus, a part of the anterior temporal lobe. At follow-up 14 months later, subjective symptoms had disappeared, but the SWAP abnormalities persisted and a thinning of the sectorial ganglion cell complex (GCC) was detected. Conclusion The results indicate that although the subjective symptoms resolved early, a reduced sensitivity of SWAP remained and the optical coherence tomography (OCT) showed GCC thinning. We conclude that local abnormalities in the anterior section of fusiform gyrus can cause mild cerebral dyschromatopsia without other symptoms. These findings indicate that it is important to listen to the symptoms of the patient and perform appropriate tests including the SWAP and OCT at the early stage to objectively prove the presence of acquired cerebral color anomaly.

scholarly journals Multi-scale image analysis and prediction of visual field defects after selective amygdalohippocampectomy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bastian David ◽  
Jasmine Eberle ◽  
Daniel Delev ◽  
Jennifer Gaubatz ◽  
Conrad C. Prillwitz ◽  
...  
Keyword(s):  
Visual Field ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Diffusion Tensor ◽  
Global Network ◽  
Visual Field Defects ◽  
Whole Brain ◽  
Network Analyses ◽  
Postoperative Mri ◽  
Selective Amygdalohippocampectomy

AbstractSelective amygdalohippocampectomy is an effective treatment for patients with therapy-refractory temporal lobe epilepsy but may cause visual field defect (VFD). Here, we aimed to describe tissue-specific pre- and postoperative imaging correlates of the VFD severity using whole-brain analyses from voxel- to network-level. Twenty-eight patients with temporal lobe epilepsy underwent pre- and postoperative MRI (T1-MPRAGE and Diffusion Tensor Imaging) as well as kinetic perimetry according to Goldmann standard. We probed for whole-brain gray matter (GM) and white matter (WM) correlates of VFD using voxel-based morphometry and tract-based spatial statistics, respectively. We furthermore reconstructed individual structural connectomes and conducted local and global network analyses. Two clusters in the bihemispheric middle temporal gyri indicated a postsurgical GM volume decrease with increasing VFD severity (FWE-corrected p < 0.05). A single WM cluster showed a fractional anisotropy decrease with increasing severity of VFD in the ipsilesional optic radiation (FWE-corrected p < 0.05). Furthermore, patients with (vs. without) VFD showed a higher number of postoperative local connectivity changes. Neither in the GM, WM, nor in network metrics we found preoperative correlates of VFD severity. Still, in an explorative analysis, an artificial neural network meta-classifier could predict the occurrence of VFD based on presurgical connectomes above chance level.

scholarly journals Localization of epileptogenic zone in temporal lobe epilepsy by ictal scalp EEG

Seizure ◽  
2002 ◽  
Vol 11 (3) ◽  
pp. 163-168 ◽  
Author(s):  
Yuzo Sakai ◽  
Hiromi Nagano ◽  
Ayumi Sakata ◽  
Sachiko Kinoshita ◽  
Naotaka Hamasaki ◽  
...  
Keyword(s):  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Epileptogenic Zone ◽  
Scalp Eeg

Surgical treatment of bilateral temporal lobe pharmacoresistant epilepsy

2020 ◽  
pp. 60-82
Author(s):  
Igor Sergeevich Trifonov ◽  
Mikhail Vladimirovich Sinkin ◽  
Elena Vladimirovna Grigoryeva ◽  
Rashid Abdurakhmanovich Navruzov
Keyword(s):  
Surgical Treatment ◽  
Temporal Lobe ◽  
Clinical Picture ◽  
Clinical Manifestations ◽  
Epileptogenic Zone ◽  
Pharmacoresistant Epilepsy ◽  
Modern Methods ◽  
Selection For ◽  
Selection Of Patients ◽  
Selection Of

Surgical treatment of bilateral temporal lobe pharmacoresistant epilepsy is associated with some difficulties: particularly, the lack of stereotypical clinical picture in the same patient and controversial data on modern methods of diagnostics — all these statements make identifying epileptogenic zone more difficult and lack of clear criteria for the selection of patients for surgical treatment. In this review, issues of aetiology, pathogenesis, clinical manifestations and criteria for the selection for surgical treatment suggested by different authors are presented.

Fast Activity Evoked by Intracranial 50 Hz Electrical Stimulation as a Marker of the Epileptogenic Zone

2015 ◽  
Vol 25 (05) ◽  
pp. 1550022 ◽  
Author(s):  
Elisa Bellistri ◽  
Ivana Sartori ◽  
Veronica Pelliccia ◽  
Stefano Francione ◽  
Francesco Cardinale ◽  
...  
Keyword(s):  
Visual Analysis ◽  
Activity Patterns ◽  
Frequency Component ◽  
High Frequency Stimulation ◽  
Computer Assisted ◽  
Epileptogenic Zone ◽  
Fast Activity ◽  
Frequency Stimulation ◽  
Definition Of ◽  
Assisted Analysis

Epilepsy is a disease characterized by aberrant connections between brain areas. The altered activity patterns generated by epileptic networks can be analyzed with intracerebral electrodes during pre-surgical stereo-electroencephalographic (EEG) monitoring in patients candidate to epilepsy surgery. The responses to high frequency stimulation (HFS) at 50Hz performed for diagnostic purposes during SEEG were analyzed with a new algorithm, to evaluate signal parameters that are masked to visual inspection and to define the boundaries of the epileptogenic network. The analysis was focused on 60–80 Hz activity that represented the largest frequency component evoked by HFS. The distribution of HFS-evoked fast activity across all (up to 162) recording contacts allowed to define different clusters of contacts that retrospectively correlated to the epileptogenic zone identified by the clinicians on the basis of traditional visual analysis. The study demonstrates that computer-assisted analysis of HFS-evoked activities may contribute to the definition of the epileptogenic network on intracranial recordings performed in a pre-surgical setting.

scholarly journals Evaluating cellularity and structural connectivity on whole brain slides using a custom-made digital pathology pipeline

2019 ◽  
Vol 311 ◽  
pp. 215-221 ◽  
Author(s):  
Thomas Roetzer ◽  
Konrad Leskovar ◽  
Nadine Peter ◽  
Julia Furtner ◽  
Martina Muck ◽  
...  
Keyword(s):  
Structural Connectivity ◽  
Digital Pathology ◽  
Whole Brain ◽  
Custom Made

scholarly journals The convergence and divergence of episodic and semantic functions across lateral parietal cortex

2020 ◽  
Author(s):  
Gina F. Humphreys ◽  
JeYoung Jung ◽  
Matthew A. Lambon Ralph
Keyword(s):  
White Matter ◽  
Semantic Memory ◽  
Parietal Cortex ◽  
Memory Retrieval ◽  
Task Difficulty ◽  
Structural Connectivity ◽  
Angular Gyrus ◽  
Episodic Retrieval ◽  
Semantic Retrieval ◽  
White Matter Connectivity

AbstractSeveral decades of neuropsychological and neuroimaging research have highlighted the importance of lateral parietal cortex (LPC) across a myriad of cognitive domains. Yet, despite the prominence of this region the underlying function of LPC remains unclear. Two domains that have placed particular emphasis on LPC involvement are semantic memory and episodic memory retrieval. From each domain, sophisticated models have been proposed as to the underlying function, as well as the more domain-general that LPC is engaged by any form of internally-directed cognition (episodic and semantic retrieval both being examples if this process). Here we directly address these alternatives using a combination of fMRI and DTI white-matter connectivity data. The results show that ventral LPC (angular gyrus) was positively engaged during episodic retrieval but disengaged during semantic memory retrieval. In addition, the level of activity negatively varied with task difficulty in the semantic task whereas episodic activation was independent of difficulty. In contrast, dorsal LPC (intraparietal sulcus) showed domain general activation that was positively correlated with task difficulty. In terms of structural connectivity, a dorsal-ventral and anterior-posterior gradient of connectivity was found to different processing networks (e.g., mid-angular gyrus (AG) connected with episodic retrieval). We propose a unifying model in which LPC as a whole might share a common underlying function (e.g., multimodal buffering) and variations across subregions arise due to differences in the underlying white matter connectivity.

scholarly journals Dynamic Properties of Simulated Brain Network Models and Empirical Resting State Data

2018 ◽  
Author(s):  
Amrit Kashyap ◽  
Shella Keilholz
Keyword(s):  
Resting State ◽  
Dynamic Properties ◽  
Brain Activity ◽  
Temporal Structure ◽  
Structural Connectivity ◽  
Network Models ◽  
Resting State Fmri ◽  
Brain Network ◽  
Dynamical Analysis ◽  
Whole Brain

AbstractBrain Network Models have become a promising theoretical framework in simulating signals that are representative of whole brain activity such as resting state fMRI. However, it has been difficult to compare the complex brain activity between simulated and empirical data. Previous studies have used simple metrics that surmise coordination between regions such as functional connectivity, and we extend on this by using various different dynamical analysis tools that are currently used to understand resting state fMRI. We show that certain properties correspond to the structural connectivity input that is shared between the models, and certain dynamic properties relate more to the mathematical description of the Brain Network Model. We conclude that the dynamic properties that gauge more temporal structure rather than spatial coordination in the rs-fMRI signal seem to provide the largest contrasts between different BNMs and the unknown empirical dynamical system. Our results will be useful in constraining and developing more realistic simulations of whole brain activity.

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