Single Neurons Responses During Visual Recognition in Epileptic Patients

Study Overview
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Brief Summary
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The purpose is to evaluate specific capacities of face detection of individual neurons by comparison with their capacity of object detection in medial temporal lobe and ventral temporal cortex in epileptic patients. Secondary purpose is to evaluate specific capacities of detection of known faces of individual neurons by comparison with their capacity of detection of unknown faces in medial temporal lobe and ventral temporal cortex in epileptic patients.

Detailed Description
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In this interventional study, patients explored with mixed intracerebral electrodes (micro and macro-contacts) will be presented sets of images (objects, unknown faces, famous faces). Spikes and Multi-Unit-Activity will be recorded and analyzed and compared between conditions.

Official Title
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Study of Cerebral Mechanisms of Visual Recognition With Single-unit Recordings of Intra-cerebral Neurons in Epileptic Patients

Conditions
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Epilepsy

Intervention / Treatment
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* Procedure: Implantation of mixed intracerebral electrodes
* Behavioral: Face detection
* Behavioral: Face individualization


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient with temporal or occipito-temporal drug-resistant partial epilepsy, symptomatic, needing surgical treatment Patient having signed informed consent Patient affiliated to social security Patient having undergone preliminary medical examination Exclusion Criteria: Persons under legal protection or incapable to consent Persons deprived of liberty by juridical or administrative decision Patient with severe visual disorders of neurological or ophthalmological origin Patients with infection risk according to doctor or surgeon Women without effective contraception Pregnant or breast-feeding women

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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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Epileptic patient<br>micro-electrode recordings interventions: Implantation of mixed intracerebral electrodes Face detection Face individualization | Procedure: Implantation of mixed intracerebral electrodes<br>* 5 macro electrodes with micro electrodes are implanted in internal temporal structures (amygdala, anterior and posterior hippocampus, rhinal cortex, posterior para-hippocampal gyrus). Each electrode has 8 microcontacts, each recording the activity of 0 to 3 neurons (activity of 0 to 120 neurons/patient).<br>Behavioral: Face detection<br>* Visualization of images of 60 unknown faces and 60 objects that are not faces (object, house, scene, animal, plant, word, letter…). Each image is showed for 500 ms and separated from following image by black screen of 1500 ms. In order to keep patient attention on image, patient will be asked to push a button at color change of fixation cross in the centre of image.<br>Behavioral: Face individualization<br>* Visualization of images of celebrities (persons known by patient), showed randomly. Each image is showed for 500 ms and separated from following image by black screen of 1500 ms. In order to keep patient attention on image, patient will be asked to push a button at color change of fixation cross in the centre of image. Several celebrities are showed, with for each the presentation of 60 images different from that celebrity. 1 to 3 celebrities are showed (60 to 180 total images).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of action potential (Difference of neuronal activity) generated successively by visual presentation of 60 photography of different unknown faces and 60 different objects | Activity (number of action potential) is recorded for each neuron before and after visualization of each image. | after electrode implantation, up to 12 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of action potential (Difference of neuronal activity) generated by visual presentation of 60 photography of a known target face (familiar) and 60 photography of unknown faces (non familiar) | Activity (number of action potential) is recorded for each neuron before and after visualization of each image. | after electrode implantation, up to 12 days |