• When central neurologic signs were localized to the vestibular region of the brain stem and cerebellum, a 54-year-old man experienced frequent awakenings from nocturnal sleep and daytime sleep attacks with hallucinosis. Sleep attacks were characterized by lid fluttering and closure, upward turning of the eyes, rapid eye movements, myoclonic twitching of all extremities, and loss of consciousness, lasting one or two minutes and aborted by strong sensory stimulation. At their termination, reports of hallucinoid imagery were given.
In a sleep record of 6.5 hours, there were 2.2 hours awake (34%), 4.3 hours desynchronized sleep (66%), and a complete absence of synchronized sleep. Reports of hallucinoid imagery were given after awakenings from desynchronized sleep. The findings support the hypotheses that desynchronized sleep is normally under brain stem control and that some types of narcolepsy may be pathophysiologically related to desynchronized sleep.