[Recurring consciousness disturbance with elevation of endogenous benzodiazepine-like activity]

A 63-year-old man had recurrent spontaneous attacks of consciousness disturbance without toxic, metabolic, or structural brain damage. Interictal electroencephalography showed 14 Hz spindle wave-like activity; ictal electroencephalography revealed faster basic activity. Flumazenil, a benzodiazepine antagonist, promptly resolved the attacks. The endogenous benzodiazepine-like activities in plasma and cerebrospinal fluid (measured in the courtesy of P. Schoch Ph. D, F. Hoffmann-La Roche Ltd, Basel, Switzerland) increased in the interictal period and increased more strikingly in the ictal period. These findings and the clinical effects of flumazenil suggest an involvement of an endogenous benzodiazepine-like activity in the pathogenesis of the attacks in this patient, as same as in a case reported by Tinuper et al (1992).