An Examination of Cognitive and Sensorimotor Processes in Patients With Epilepsy Using Electrophysiology, Cortical Mapping, Electrical Brain Stimulation, and fMRI

Brief Summary

Detailed Description

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/spread and human cognitive function. 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 and direct electrical stimulation on cortical excitability and cognitive function. We will apply direct electrical brain stimulation to epileptogenic and functional brain regions and evaluate the effects of this stimulation on electrode recordings, CCEPs, and cognitive tasks. Electrical stimulation may be applied with consideration of endogenous cognitive biomarkers to probe and elucidate the function of these biomarkers as they relate to cognitive function. 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.

Primary Outcomes