Optimization of Human Cortical Stimulation

Study Overview
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Brief Summary
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We will observe epileptic patients who already have electrodes implanted on the brain and are receiving high-level brain stimulation for clinical purposes while testing their motor and language function. We propose to do a limited, low-level brain stimulation to show that the signatures of local activity in the target area change as an effect of brain stimulation. The goal of this study is to understand the feasibility of a novel recurrent brain-computer interface that could eventually promote targeted functional recovery in subjects who have had a brain injury.

Detailed Description
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The subject will have already been scheduled for placement of the ECoG electrodes on the surface of the brain and who will, for all clinical purposes, subsequently receive stimulation for mapping of function of the ECoG sites. The decision to place the electrodes on the brain, the location of the electrodes and the length of time the electrodes are in are all part of clinical care. There will be two types of testing, motor and language. Motor will involve inducing stimulation to the thumb cortex and the wrist cortex. There will be a conditioning of this over 4-12 hours. Language will involve showing pictures on a computer screen and the subject will be observed whether speech is disrupted with stimulation or not.

Official Title
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U.S.-German Collaboration: Optimization of Human Cortical Stimulation

Conditions
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Epilepsy, Brain Injury

Intervention / Treatment
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* Procedure: Low-level cortical stimulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18 and older Male and Female Able to understand English for consenting and testing Referred for surgical implantation of electrodes Exclusion Criteria: Under 18 years of age Pregnant women Prisoners Mentally disabled IQ < 70 Non English Speaking Not candidates for surgical implantation of electrodes

Ages Eligible for Study
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Minimum Age: 18 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

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Epileptic Patients<br>The population of patients with medically refractory epilepsy will already have been recommended clinically for electrode grid placement on the brain and high-level stimulation to map brain function. | Procedure: Low-level cortical stimulation<br>* A couple of electrodes will be stimulated (at a lower level than the stimulation used for standard care) over a period of 4-12 hours based on the signals defined by the motor or language task.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Link EMG activity produced during a motor task to stimulation of a part of the brain | Attempt to link EMG activity produced during a motor task to stimulation of a part of the brain nearby, but distinct from, the part of the brain normally used to perform the task. | 5 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluate distribution of current from stimulation | Using mathematical models to determine if current is going to areas expected | 5 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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ECoG, Epilepsy, cortical, stimulation, Electrocorticography, electrodes, mapping