THE BLINK REFLEX IN THE SURVEILLANCE OF B ENZODIAZEPINE HYPNOSE

The effects of a pure benzodiazepine antagonist (Flumazenil) on the re sponses R1 and R2 of the blink reflex, psychomotor tests, and Event Re lated Potentials (ERP), in six healthy volunteers sedated with Midazol am have been compared. Measurements were made during each of four succ essive phases. Phase 0 corresponded to control recordings. Midazolam w as administered rapidly during phase 1 and slowly during phase 2. Phas e 3 corresponded to spontaneous waking once the administration of Mida zolam had been stopped. Flumazenil was administered during phase 2. As the subjects fell asleep, R1 and R2 were the last parameters to disap pear. Under the influence of Flumazenil, R1 was the first to reappear, while R2 did not recur until complete waking, and the other tests wer e unpracticable. During phase 3, R1 reappared before R2 once more, the psychomotor test responses and ERP returning only later. The modifica tions of both R1 and R2 of the blink reflex are a good criterion of th e presence of BZD in a toxic coma and a goad test to indicate the dept h of a coma or a sedation with BZD, whilst FRP since they require tire cooperation of the patient, are a test of vigilance and not of awaken ing.