Circadian temperature and activity rhythms in unmedicated narcoleptic patients

Fifteen unmedicated narcoleptic patients with and without sleep-onset REM period (SOREMP) were compared with 16 unmedicated, age-and-sex-matched control subjects with respect to polygraphic, core body temperature and motor activity recordings. Whereas narcoleptic patients with SOREMPs had significantly more quiet wakefulness during sleep, those without SOREMPs had significantly more quiet wakefulness during daytime than the other groups. Compared with that of controls, temperature of both narcoleptic groups showed (a) less rise of temperature curve in the morning, (b) dampening of temperature amplitude, (c) phase advance of acrophase, and (d) advance of temperature minimum after sleep onset. Maximal temperature decline occurred earlier in patients with SOREMPs during naps and sleep than in the other groups. We could confirm parallels between temperature and motor activity with controls and found no change in the oscillator of narcoleptic patients. Advanced temperature minima and first REMPs relative to sleep onset and maximal temperature decline occurring nearer to sleep onset indicate a defect in the temperature-locked triggering of REM in narcoleptic patients with SOREMP and a circadian rhythm disorder.