Using Micro-filaments to Detect Fast Ripples and Improve the Identification of the Epileptogenic Zone

Study Overview
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Brief Summary
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record fast ripples with novel intracranial electrodes with micro-tetrodes to improve the identification of epileptogenic zone (EZ) and investigate the neuronal circuits underlying brain dynamics associated with epilepsy

Detailed Description
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This study would improve the localization of the epileptogenic zone and reduce the overall duration of monitoring, especially in patients who do not experience a sufficient number of seizures during the implantation period. In addition, it would be possible to use micro-electrodes and propose a better surgical treatment to some patients whose preliminary assessment with macro-electrodes has not provided significant results. Finally, the data collected during this study will help us to further understand pathological brain activity and to describe the neuronal circuitry that gives rise to cortical signals and the relationships between them (from spindles to high frequency oscillations).

Official Title
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Using Micro-filaments to Detect Fast Ripples and Improve the Identification of the Epileptogenic Zone

Conditions
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Epilepsy, Refractory

Intervention / Treatment
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* Device: macro-micro tetrodes for intracranial recording


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: inclusion criteria is determined based on the clinical diagnosis of the refractory epilepsy and the admissibility of the patient for the stereoelectroencephalography (sEEG) procedure Exclusion Criteria: severe psychiatric disorders, severe agitation during their crisis contraindication for performing an MRI: claustrophobia, a cardiac or neural stimulator, ferromagnetic surgical clips, cochlear implants, intraocular metallic foreign body or in the nervous system, contraindication to intracerebral investigation (macro-electrodes): ongoing infection, severe associated pathology (cardiac, pulmonary, renal, hepatic), pregnant or nursing women, anti thrombotic ongoing treatment.
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: micro-macroelectrodes<br>Patients will be implanted with usually the novel intracerebral micro-macroelectrodes (instead of the regular clinical macroelectrodes). The primary and secondary outcomes will then be assessed. | Device: macro-micro tetrodes for intracranial recording<br>* novel design of tetrode micro electrodes within the standard macro intracranial electrodes used clinically for identification of the epileptogenic zone<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| evaluate the recording of fast ripples (FRs) and single neuron activity in the brain with the micro tetrodes | sum of number of single units recorded and the number of fast ripples (FRs) | 1 week after implant | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Efficiency of microelectrodes compared to macroelectrodes | proportion and quality of the FRs recorded by the macro-blocks immediately adjacent to the microelectrodes located in the EZ | 10 days after implant |