Neurological, psychological and polygraphic findings in sleep drunkenness.

Eight patients suffering from idiopathic hypersomnia with sleep drunkenness were given neurological, psychological and polygraphic investigations, and that after 4, 8 and 12 hours of nocturnal sleep. Also examined and tested were 8 controls - after 4, 8 and 0 hours of sleep during the preceding night. The patients and the controls were awakened and tested in the afternoon hours 30-45 minutes after they had fallen asleep. Under those circumstances the state of sleep drunkenness was observed in the patients in 19 instances, but only once in the controls. While experiencing sleep drunkenness the subjects were found to have prominent cerebellar signs, proprioceptive hypo- or even areflexia, signs of vestibular and, rarely, pyramidal tract involvement. Psychological tests scores and scores for the fine and gross motricity tests were substantially worse in sleep drunkenness than in wakefulness. Sleep drunkenness manifested itself in the polygraphic recordings by signs of microsleep. Pathological predisposition to the development of sleep drunkenness in hypersomniacs was found to be the most significant factor responsible for the occurrence of this state. Attention is drawn to the analogy between states of sleep drunkenness and automatic behaviour in narcoleptics and hypersomniacs as a common feature of both states. The authors believe that sleep drunkenness in idiopathic hypersomnia develops as a result of chronic relative sleep deprivation in those patients whose sleep requirements are greater than conditions of normal life can permit.