Electrophysiologic investigation of the anterior temporal and frontal lobes: sphenoidal and intraorbital electrodes

The authors have evaluated the interest of sphenoidal electrodes in detection of internal temporal spikes, and intra-orbital electrodes in the detection of orbito-frontal spikes. From a study of 26 patients, 21 with sphenoidal electrodes, 3 with intra-orbital electrodes and 2 with both electrodes, they observed the sensitivity and specificity of such electrodes in detecting spikes with no traduction upon extra-cranial electrodes, or with an unsuspected traduction as spikes at a distance from deep electrodes, or spikes on 2 foci, or bisynchronous discharges. Sphenoidal and intra-oribital electrodes constitute a non-invasive method that provides excellent information in the exploration of the mesiobasal cerebral face. Indications for the use of such a method are complex absences without EEG traduction or with an unsuspected traduction and without abnormalities on CT scan, in the context of functional surgery of epilepsy.