Correlate of Surface Electroencephalogram (EEG) With Implanted EEG Recordings (ECOG)

Study Overview
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Brief Summary
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Improve understanding of the correlation between surface EEG and implanted EEG recordings

Official Title
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Correlate of Surface Electroencephalogram (EEG) With Implanted EEG Recordings (ECOG)

Conditions
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Anesthesia

Intervention / Treatment
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* Device: EEG
* Device: ECOG


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male or Female subjects 18 years of age or older. English or Spanish Speaking Subjects who have been previously diagnosed with intractable epilepsy and require implantation of invasive electrophysiological recordings as part of their routine clinical presurgical workup. Exclusion Criteria: Patients with skin abnormalities at the planned application sites that would interfere with sensor or electrode applications. Patients with pre-existing conditions and/or co-morbidities that would prohibit them from participating in the study due to unacceptable risks to their health and well-being, as determined by the Principal Investigator (PI). Patients who the PI deems ineligible at the PI's discretion Pregnant patients

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 |
| --- | --- |
| ECOG and EEG Sensor<br>Study subjects are neurosurgical patients with medically refractory epilepsy who will have implanted with intracranial ECoG electrodes. The electrodes will be used during a period of inpatient monitoring to identify resectable seizure foci. | Device: EEG<br>* EEG will be collected with Brain Product's VAMP-16 channel EEG Monitor using the accompanying software. (Website with further specifications and product details: https://www.brainproducts.com/productdetails.php?id=15)<br>Device: ECOG<br>* ECOG will be collected with Nihon Kohden acquisition System and accompanying software and depth electrodes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Electrocardiogram (EEG) change before, during, and after anesthesia. | Patient subjective level of consciousness during and after anesthesia administration will be assessed using response to verbal stimuli, response via button press, reported subjective level of consciousness, and/or response to memory tests (i.e. demonstration of explicit memory recall). Around loss and recovery of consciousness time points (e.g. induction or emergence from anesthesia or when patient falls asleep or wakes up during 24 hour postoperative time points) level of consciousness will be assessed in brief intervals (seconds) until patient no longer responds or begins to respond. Data collected before, after, and during seizure activity if a patient loses consciousness or has diminished consciousness may also be compared. | Up to 48 hours. Specific time points are dependent on patient clinical events. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Electrocardiogram (EEG) change during any changes in consciousness. | Scalp and cortical electrical activity collected using EEG and ECOG arrays respectively will be analyzed using standard frequency-derived measures (e.g. spectrograms, Fourier analysis), nonlinear dynamical analyses (e.g. correlation dimension, entropy), network dynamics (e.g. connectivity matrices, path length), and/or machine learning. These measures will include all of the data collected from the start of the implant procedure until 24 hours after the implant procedure has ended. Data collected before, after, and during seizure activity if a patient loses consciousness or has diminished consciousness may also be compared. Reports will included characterization of electrophysiological activity before, during, and after variations in behavioral and subjectively reported consciousness. | Up to 48 hours. Specific time points are dependent on patient clinical events. | 
| Electrocardiogram (EEG) change during any seizures. | Scalp and cortical electrical activity collected using EEG and ECOG arrays respectively will be analyzed using standard frequency-derived measures (e.g. spectrograms, Fourier analysis), nonlinear dynamical analyses (e.g. correlation dimension, entropy), network dynamics (e.g. connectivity matrices, path length), and/or machine learning. Data collected before, after, and during seizure activity if a patient loses consciousness or has diminished consciousness may also be compared. Reports will include characterization and comparison of EEG and ECOG electrophysiological activity and analyses during consciousness transitions and significant time points. | Up to 48 hours. Specific time points are dependent on patient clinical events. |