Natural history, symptoms and treatment of the narcoleptic syndrome.

This study describes the clinical features, natural history and treatment of 100 patients with narcolepsy. Over half had one or more affected relatives. Symptoms commenced in adolescence or early adult life in most patients, and remissions were uncommon. Narcolepsy occurred several times each day, often in unusual circumstances and sometimes with little warning. The mean total sleep time of narco-leptics was a little over 9 hours in each 24 hour period, as compared with under 8 in normal subjects. Cataplexy occurred in 93 patients, most commonly when subjects were tired. Attacks were similar in nature to physiological weakness with laughter, although other sudden sensory or emotional stimuli did not cause paralysis of voluntary movement nor loss of muscle tone in normal subjects. Half these patients had frequent dreams before the onset of proper sleep, and 62 had sleep paralysis. This was often frightening, with feelings of suffocation, accompanied by dreams, and of uncertain length. A minority of patients with narcolepsy had muscle aches and jerks before sleep, double vision or loss of focus during cataplexy, went sleep-walking by day, and had daytime hallucinations. Amphetamines had been given to 71 patients for periods of up to 33 years with adequate, but rarely complete, control of narcolepsy. Side effects were common and almost half these patients became tolerant, needing higher dosage to control symptoms. Three patients had a cerebrovascular accident whilst taking amphetamines. Imipramine or clomipramine had ben given in combination with amphetamines to 33 patients for periods of up to 6 years with considerable improvement in both cataplexy and sleep paralysis, and few side effects. Sustained or paroxysmal hypertension as a result of amphetamines or combined treatment did not occur.