Investigation of Trigeminal SEP with Scalp and Deep Electrodes

A special technique for stimulating and recording trigeminal so­matosensory evoked potential (SEP) is described. Eleven healthy subjects and seven patients with chronically implanted deep electrodes have been investigated. Characteristic polyphasic waves were repeatedly observed. The recording of somatosensory evoked potential following trigeminal stimulation is a more difficult tech­nique. This paper describes data in control subjects with scalp electrodes and data on patients with electrodes in the nucleus ventralis posteromedialis and cortical white matter. Depth recording may provide useful information about the origin, nature, and properties of trigeminal SEP.