The nature of the narcoleptic sleep attack

Abstract

Sixteen male and 18 female adult narcoleptics were studied during sleep attacks by means of electro-oculograms, electroencephalograms, electromyograms, electrocardiograms, and respirograms. Twenty-four of the patients gave a history of cataplexy. Of these 24, the sleep episodes of 20 were characterized by the immediate onset of fullblown rapid eye movement [REM] sleep. Only one of the 10 patients without cataplexy showed a sleep-onset REM episode. Of the remaining 9, 7 showed sleep recordings identical with the sleep recordings of 4 normal control subjects, all characterized by typical non-rapid eye movement [NREM] sleep tracings containing sleep spindles and tonic electromyographic potentials. A proposal is made for the redefinition of narcolepsy in which the narcoleptic sleep attack is identified as a REM sleep episode and the other components of the narcoleptic tetrad are also seen as manifestations of the REM process. A necessary condition for the diagnosis is the establishment of the sleep-onset REM episode by laboratory test or, inferentially, by finding a history of cataplexy. Patients giving a history of sleep attacks, but failing to show sleep-onset REM periods should be relegated to another diagnostic category.