REC2Stim as a Treatment for Refractory Epilepsy in the Primary Sensorimotor Cortex.

The investigators will include ten patients with CLE, aged 16 years and older, in whom pre-surgical chronic intracranial EEG monitoring has revealed a seizure onset in the primary sensorimotor cortex. Patients should have on average at least two seizures per day. Clinical intracranial EEG monitoring (normally 7-10 days) will be extended with two extra monitoring days, for systematic testing of different stimulation settings and their effect on interictal epileptiform EEG activity (as a surrogate marker for ictal epileptiform activity), from which site and parameters for chronic stimulation will be determined. Upon removal of the clinically implanted electrodes, a neurostimulator with sensing capabilities, Activa PC+S, will be implanted and attached to two subdural leads with electrodes covering the predefined stimulation site and the eloquent epileptogenic area. During a data collection phase, stimulation-free data will then be collected to train the seizure detection algorithm up to at least 50% sensitivity. Finally, the REC2Stim phase will be started, in which cortical stimulation is applied when seizure activity is detected. Study participation is one year. When REC2Stim turns out effective in month 10 and 11 after implantation of the neurostimulator, 2 weeks of sham stimulation will follow in month 12.