An Examination of Cognitive and Sensorimotor Processes in Patients With Epilepsy

Study Overview
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Brief Summary
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The overall goal of this project is to better understand the micro-physiology of human epilepsy and cognition using the intracranial electroencephalogram (iEEG), electrical brain stimulation, functional magnetic resonance imaging (fMRI), and histology.

Detailed Description
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The overall goal of this project is to better understand the micro-physiology of human epilepsy and cognition using iEEG, electrical brain stimulation, fMRI, and histology. Specific AIM 1: Mapping cognitive networks using intracranial electrodes, functional magnetic resonance imaging, and cognitive tasks. To identify brain areas and mechanisms involved in cognitive function we will ask participants to perform tasks while their brain activity is measured with intracranial electrodes or functional magnetic resonance imaging (fMRI). Specific AIM 2: Using microelectrodes to better understand the mechanisms of seizure genesis and spread. We will use microelectrodes to measure activity within single neurons, data that will allow us to tease apart incoming and outgoing activity to a brain area. Specific AIM 3: Using macroscale measures of brain connectivity to map functional and epileptogenic brain areas. We will measure connectivity between macroscale brain regions via variety of techniques: diffusion tensor imaging (DTI), fMRI, cortico-cortical evoked potentials (CCEP), and intracranial electrophysiology. We believe that epileptogenic and functional regions will be mutually segregated by their connectivity patterns. Specific AIM 4: Using EEG/iEEG source localization to better identify the sources of epileptiform activity. We will construct models of participants' heads via MRI and CT, which will potentially allow us to localize the neural generators of EEG and iEEG recordings. Specific AIM 5: Investigating the effects of transcranial electrical stimulation (tES) on cortical excitability and cognitive function. We will apply tES to epileptogenic and functional brain regions and evaluate the effects of this stimulation on microelectrode recordings, CCEPs, and cognitive tasks. Specific AIM 6: Studying local connectivity of epileptic brain tissue with histology. We will reserve a small portion of resected brain tissue from patients who have undergone surgical resection for histological analysis to better understand altered patterns of neural connectivity in epilepsy.

Official Title
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An Examination of Cognitive and Sensorimotor Processes in Patients With Epilepsy Using Electrophysiology, Cortical Mapping, and fMRI

Conditions
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Epilepsy

Intervention / Treatment
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* Other: fMRI
* Other: Releasing Data
* Other: Neuropsychological Testing
* Other: Additional electrode implantation
* Other: Brain stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects are selected on the basis of intractability of their seizures to medical intervention by antiepileptic drugs and following a noninvasive workup that indicates the patient would be an excellent candidate for resective surgery. Exclusion Criteria: Patient is under the age of 5

Ages Eligible for Study
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Minimum Age: 5 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: fMRI|Subjects will undergo MRI scanning to gather data about cognitive functions.|
|Other: Releasing Data|Subjects in the study will be asked to release data about their surgery, and electrostimulation to the research team for analysis.|
|Other: Neuropsychological Testing|Subjects will have a neuropsych evaluation as part of their standard of care for surgery. The research team is asking the subject to release their neuropsych evaluations for analysis.|
|Other: Additional electrode implantation|Subjects normally will have anywhere from 100-200 electrodes implanted as part of their surgery. As part of the study, we would implant additional electrodes that are able to record from smaller, more specific parts of the brain to better understand how your brain is wired.|
|Other: Brain stimulation|Subjects may be asked to undergo additional electrical brain stimulation (in addition to what is required for clinical purposes) to map brain function and epileptogenic areas. This may include extended stimulation mapping, low frequency stimulation (CCEPs), and transcranial stimulation.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| epilepsy surgical outcome | We are primarily interested in finding ways of predicting the effects of epilepsy surgery on seizure control and cognitive function. | 1 year minimum | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Epilepsy, fMRI, Electrophysiology, Cortical Mapping, Neurosurgery