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

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

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.

Inclusion Criteria:

1. Patients aged 6 to 65

2. Patients suffering from partial epilepsy that has been developing for at least 2 years, drug-resistant, regardless of the presumed topographical origin or suggested cause (lesional with or without MRI abnormality) and for whom the following have been decided and planned:

   either i) a surgical procedure to resect the epileptogenic zone without prior intracranial EEG recording or ii) intracranial EEG recording necessary before a possible cortical resection procedure

3. Patients who have undergone routine prolonged scalp video EEG recording showing interictal paroxysmal abnormalities

4. Patients motivated to participate effectively in the project

5. Patients who have signed an informed consent form to participate in the study

Exclusion Criteria:

1. Patients with neurological or psychiatric disorders or a history of neurological or psychiatric disorders, sleep disorders other than epilepsy that may impact the variability or quality of the data or the cooperation and retention of the participant, which will be assessed by the principal investigator or co-investigator during the inclusion interview.

2. Patients with contraindications common to MEG and MRI examinations:

   • Metal in the body that is incompatible with the examination (pacemaker, implanted pump including insulin pump, neurostimulator, cochlear implants or other hearing devices, metal prosthesis, intracerebral/surgical clips for aneurysms, implantable defibrillators, ferromagnetic foreign bodies in the eyes or brain in the upper body, ventriculoperitoneal neurosurgical shunt valves, dental braces or steel pivots for dental root canals, ferromagnetic foreign bodies in the upper body)
   • Claustrophobia

3. Pregnant women, breastfeeding women, or women who have given birth within the last 6 months.

4. Patients under guardianship, curatorship, or judicial protection

5. Patients deprived of their liberty

6. Patients not affiliated with a social security system or beneficiaries of such a system