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

Overview

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.

Interventions

• Device MEG OPM
  The OPM MEG sensor (FYNA Research device) is a new sensor technology for MEG (magnetoencephalography). It consists of 48 detectors (helium-4 magnetometers) that are positioned on the patient's head using a support system that can be adjusted to fit the size of their head. The patient goes to the MEG center at CERMEP (patients included in Lyon) or INS (patients included in Marseille), changes clothes, and removes any makeup. Metal-free clothing designed for MEG is provided. The tracking coils are
• Device MEG SQUID
  The MEG SQUID is the classical MEG (magnetoencephalography). It consists of a set of sensors placed in a rigid helmet, in contact with the head. The patient goes to the MEG center at CERMEP (patients included in Lyon) or INS (patients included in Marseille), changes clothes, and removes any makeup. Metal-free clothing designed for MEG is provided. The tracking coils are put in place. The patient is then placed in the MEG, and their positioning and comfort are checked again. The OPM MEG acquisit

Primary outcome measures

• Percentage of cases in which the location of epileptic foci identified by MEG OPM confirmed the location identified by pre-surgical assessment (EEG, SEEG, MRI, PET-FDG) when surgery was successful, one year after its completion (composite outcome) [Time frame: 1 year after surgery (18 months after inclusion)]

Secondary outcome measures (10)

• Percentage of cases in which the location of epileptic foci identified by MEG OPM differs from the location identified by conventional pre-surgical assessment (EEG, SEEG, MRI) when surgery was unsuccessful, 1 year after surgery. [Time frame: 1 year after surgery (18 months after inclusion)]
• Percentage of congruence between the location of the epileptic focus determined by OPM MEG source modeling and the area of seizure onset estimated by SEEG. [Time frame: 3 months after inclusion (Day of the SEEG Exploration)]
• Percentage of congruence between the location of the epileptic focus determined by OPM MEG source modeling and the location of the epileptic focus determined by SQUID MEG source modeling. [Time frame: Day of the MEG visit (day of inclusion)]
• Percentage of cases in which the location of epileptic foci identified by MEG SQUID confirmed the location identified by conventional pre-surgical assessment (EEG, SEEG, MRI) when surgery was successful, one year after its completion. [Time frame: 1 year after surgery (18 months after inclusion)]
• Percentage of cases in which the location of epileptic foci identified by MEG SQUID confirmed the location identified by conventional pre-surgical assessment (EEG, SEEG, MRI, PET-FDG) when surgery was successful, one year after its completion. [Time frame: 1 year after surgery (18 months after inclusion)]
• Percentage of congruence between the area modeled in MEG OPM and the area of seizure onset estimated in MEG SQUID [Time frame: Day of the MEG visit (Day of inclusion)]
• Percentage of congruence between the location of the epileptogenic zone determined by MRI and the location modeled by OPM MEG [Time frame: Day of the MEG visit (day of inclusion)]
• Proportion of congruence between the location of a hypometabolic focus in FDG PET and the location of epileptic foci modeled by MEG OPM [Time frame: Day of the MEG visit (day of inclusion)]
• Description of adverse events that occurred and were related to the performance of the MEG OPM examination [Time frame: From date of inclusion until the end of the study (54 months after inclusion)]
• Evaluation of patient comfort during OPM MEG recordings using a Likert scale [Time frame: Day of the MEG visit (day of inclusion)]

Eligibility criteria

Inclusion criteria

• Patients aged 6 to 65
• 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

• Patients who have undergone routine prolonged scalp video EEG recording showing interictal paroxysmal abnormalities
• Patients motivated to participate effectively in the project
• Patients who have signed an informed consent form to participate in the study

Exclusion criteria

• 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.
• 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
• Pregnant women, breastfeeding women, or women who have given birth within the last 6 months.
• Patients under guardianship, curatorship, or judicial protection
• Patients deprived of their liberty
• Patients not affiliated with a social security system or beneficiaries of such a system

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Diagnostic

Study locations

France · 3 centers

• Hôpital Femme-Mère-Enfant, Hospices Civils de Lyon, Service Explorations Fonctionnelles Pé — Bron
• Hôpital Neurologique, Hospices Civils de Lyon, Service Explorations Fonctionnelles Neurolo — Bron
• Hôpital de la Timone, AP-HM Service d'Epileptologie et Rythmologie Cérébrale — Marseille

Identifiers

NCT: NCT07281222 · 69HCL24_0886 · 2025-A02262-47

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗