Electrophysiological Biomarkers in MTLE Patients.

Study Overview
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Brief Summary
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The investigators plan to enroll individuals with medical temporal lobe epilepsy who are undergoing surgical workup with clinically implanted intracranial electrodes. The study intends to administer computerized memory tasks and stimulation during the intracranial Electroencephalography (EEG) monitoring period.

Detailed Description
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This is a nonrandomized interventional trial that will apply brain stimulation via clinically implanted intracranial electrodes to subjects with medial temporal lobe epilepsy with the purpose of identifying biomarkers related to the pre-ictal state; to perform an acute parameter search to determine the stimulation pattern that most effectively modifies these biomarkers and to identify changes in memory (free recall) during asynchronous distributed multi-electrode stimulation (ADMES).

Official Title
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Electrophysiological Biomarkers During Invasive Monitoring of Mesial Temporal Lobe Epilepsy Patients.

Conditions
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Mesial Temporal Lobe Epilepsy

Intervention / Treatment
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* Device: Asynchronous distributed multi-electrode stimulation (ADMES) using an implantable neurostimulation device


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Provision of signed and dated informed consent form Male or female, aged 18-65 Diagnosed with lesional or non-lesional mesial temporal (hippocampal) seizure onset confirmed on SEEG monitoring Implanted with depth electrodes for localization of seizure onset with multiple hippocampal electrode arrays Exclusion criteria: Any patient who is unwilling or unable to provide consent Women who are pregnant Patients under 18 years Incarcerated persons

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Brain stimulation via clinically implanted electrodes<br>Brain will be stimulated in different patterns including synchronized or asynchronous current. | Device: Asynchronous distributed multi-electrode stimulation (ADMES) using an implantable neurostimulation device<br>* Participants will receive asynchronous pulses distributed across a multi-electrode array of 16 micro-electrodes and stimulating at low (theta) frequencies.<br>* Other names: ADMES;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Intracranial EEG recording: spectral power from baseline | Spectral power will be compared between baseline/sham and stimulation trials to determine if asynchronous stimulation modulates spectral power during the preictal, ictal or post ictal states. Spectral power is measured in microvolts. A change in either direction from baseline is associated with a better outcome. | Baseline, up to 6 weeks postintervention | 
| Change in Intracranial EEG recording: synchrony from baseline | Synchrony will be compared between baseline/sham and stimulation trials to determine if asynchronous stimulation modulates synchrony during the preictal, ictal or post ictal states. Synchrony is a measure of how any pair of regions communicate with one another. Synchrony is measured as the correlation [-1 to 1] between two time series. The investigators anticipate that a decrease in synchrony (correlation approaching 0) is associated with improved outcome. | Baseline, up to 6 weeks postintervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in memory during brain stimulation from baseline | Patients will be asked to recall a list of words after a 20-second delay in which they will do simple math problems to ensure long-term memory encoding. Three  1-2-hour sessions will be performed; each session will consist of 24 free recall tasks (12 during ADMES and 12 with no stimulation). The memory score will be assessed as the percentage correct out of 12. The higher the percentage recalled, the better the score. | Baseline, up to 6 weeks postintervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Epilepsy, Biomarkers