Depth Cerebral Electrical Activity in Man During Hypnosis: A Brief Communication

Abstract

To the authors' knowledge, hypnosis has never been induced in epileptic patients during a depth EEG study. This neurosurgical diagnostic procedure has been routinely used in medically resistant epileptic patients for the preoperative exact delimitation of the epileptogenic lesion. It offers a unique opportunity to obtain fundamental information on the possible neurophysiological mechanisms implicated in hypnosis. Observations were carried out on 1 patient affected by medically resistant partial seizures with complex symptomatology. A chronic deep electrode study explored rbinencephalic structures as well as specific target areas of the cerebral cortex. Background electrical activity during hypnosis showed a significant decrease of slow waves and an increase of alpha and beta rhythms, with constant increase of amplitude, when compared to activity in the pre- and posthypnosis states. Focal interictal abnormalities were dramatically reduced during hypnosis.