Narcolepsy and Cataplexy. Clinical Features, Treatment and Cerebrospinal Fluid Findings

Clinical, EEG, and biochemical features of 20 patients with narcolepsy and one patient with the Kleine-Levin syndrome are described. The narcoleptic syndrome is a fairly common and life-long disorder which probably results from an inborn error of metabolism, whilst narcolepsy alone is of uncertain diagnostic status. In patients with the narcoleptic syndrome there is a distinctive disorder of night sleep which begins with a period of rapid eye movement and there may be a mistiming in the brain stem mechanisms of sleep, dreaming, and muscle tone. Rapid eye movement periods may not, however, occur during day sleep periods and a normal day-sleep EEG does not exclude this diagnosis. There is no effective and harmless treatment for daytime sleep attacks, but dextro-amphetamine or the less potent levoamphetamine resulted in moderate or good control of narcolepsy in most patients. Clomipramine abolished cataplexy in all and combined treatment for up to two years with amphetamines controlled both narcolepsy and cataplexy in 15 of 17 patients. Side effects of weight gain and reduced libido from clomipramine and bad temper and irritability with insomnia from amphetamines complicated therapy, but the combination did not alter blood pressure. The drugs which improve narcolepsy and cataplexy affect cerebral catecholamine and serotonin metabolism and some aspect of this may therefore be abnormal in patients with the narcoleptic syndrome. In respect of catecholamines, cerebrospinal fluid meanphenylalanine and tyrosine concentrations were normal, whilst homovanillic acid was decreased. However, individual values showed considerable variation. In respect of serotonin, tryptophan and 5-hydroxy-indole-acetic acid concentrations were normal. Cerebrospinal fluid aspartate concentration was low in patients with narcolepsy.