Evaluation of the FYNA Research OPM MEG Device for Locating Epileptic Foci as Part of Pre-surgical Assessment of Epilepsy

Brief Summary

The success of epilepsy surgery depends largely on the reliability of the preoperative localization of the epileptogenic zone. The conventional method for determining the area to be removed is based on a complex assessment involving an electroencephalogram (EEG) coupled with simultaneous video recording of seizures (video SEEG), a brain MRI, and a fluorodeoxyglucose positron emission tomography scan (PET-FDG). At present, epilepsy surgery cannot cure all patients. Since the prognosis for surgery depends primarily on the ability to delineate the epileptogenic zone, it is essential to develop new diagnostic approaches that can accurately detect epileptic foci. MEG (magnetoencephalography) is a non-invasive brain mapping technique based on the magnetic fields created by neuronal activity. Numerous studies have shown that it is a highly effective technique for locating epileptic foci, and more accurate than EEG. However, MEG remains relatively uncommon (three centers in France) because current conventional systems (MEG SQUID) are difficult to use, expensive, require significant structural constraints for installation, and are not very sensitive (sensors are distant from the scalp). Mag4Health has developed a new MEG device, the "MEG FYNA Research", which records brain magnetic activity using 48 or 96 sensors (4He optical pumping magnetometers, or "OPMs"). Compared to conventional MEG (SQUID MEG), this OPM MEG technology is more compact, less expensive, more sensitive, and allows the sensors to be placed directly on the scalp. The EPI-OPM study is a prospective, uncontrolled, bicenter clinical investigation that aims to evaluate the diagnostic performance of this device. The main objective is to assess the value of the OPM MEG device for localizing the epileptogenic zone compared to the reference method in epileptic patients undergoing epilepsy surgery. Patients (children and adults) will be enrolled at the Lyon University Hospital and the Marseille University Hospital. Each patient will undergo an OPM MEG examination and a SQUID MEG examination (SQUID MEG only for patients in Lyon), in addition to the clinical procedures performed as part of routine care: intracranial EEG recording (SEEG) and MRI if necessary, followed by surgery to resect the epileptic focus. The performance of the OPM MEG device in locating epileptic foci will be validated by surgical results and invasive EEG recordings. The localization of epileptic foci using the OPM MEG system will be compared with that obtained using the SQUID MEG system (conventional MEG) and other pre-surgical assessment tests carried out as part of routine care. Finally, we will describe tolerance to the recordings and assess overall comfort and feasibility using appropriate questionnaires.