Non-invasive recording of deep brain activity: mobile sensors optimized with intracerebral measures

Epilepsy presurgical evaluation consists in mapping the brain regions generating pathological activities, which can be surgically resected. The current method of choice is stereotaxic electroencephalography (SEEG), an invasive procedure which involves implanting a limited number of electrodes in the brain. Thanks to 4-He Optically Pumped Magnetometers (OPMs), a new generation of mobile sensors, I will be able to record magnetic activity non-invasively across the whole brain. Compared to classical magnetoencephalography, OPMs can be placed directly on the scalp, drastically reducing the distance to the brain and opening the way to optimise spatial sampling of magnetic fields. Thus, the OptiMEG project aims to develop a personalized, non-invasive tool based on OPMs for localizing epileptic activity. I will use intracerebral (SEEG) signals recorded simultaneously with OPMs in order to learn how to retrieve the deep signals measured in SEEG from OPM. My expertise in MEG and the collaboration I have already established with clinicians at the Timone Hospital will guarantee the success of OptiMEG. The questions that I will address are: 1) Design the optimal placement of mobile OPM sensors for retrieving non-invasively activity from deep brain regions 2) Identify the signatures on the surface OPM signals of the different regions seen on the deep SEEG contacts 3) Validate the resulting signatures as biomarkers in a clinical setting The OptiMEG project will revolutionize clinical practice by retrieving activity from deep brain regions without requiring implantation of depth electrodes, with unprecedented spatial and temporal resolution. It will produce a more precise diagnostic by capturing activity across the whole brain. allow more patients to have access to epilepsy surgery, lowering risks and costs compared to SEEG. It will also bring non-invasive access to deep brain regions in other neurological pathologies and in fundamental neuroscience.