Contribution of magnetic source imaging to the presurgical work-up of patients with refractory partial epilepsy

Magnetoencephalography (MEG) is a functional cerebral imaging technique that non-invasively records extracranial magnetic fields generated by the electrical activity of the brain. Magnetic source imaging (MSI) is a combination of MEG and coregistered magnetic resonance imaging (MRI) that is increasingly being used in the non-invasive presurgical evaluation of patients with refractory partial epilepsy to localize the magnetic correlate of interictal epileptiform discharges. This paper reviews the basics of MEG and MSI, briefly describes the characteristics of the MEG system installed at the ULB-Hôpital Erasme and then summarises the available data on the contribution of MSI to the presurgical work-up of refractory partial epilepsy.