NIGHT SLEEP DOES NOT PREDICT DAY SLEEP IN NARCOLEPSY

It has been suggested that the increased day sleep in narcolepsy-catap lexy is secondary to the known fragmentation and reduction of night sl eep, there being no differences in 24 h sleep totals from normals. Twe nty-two untreated patients underwent 24 h sleep wake recordings by amb ulatory monitoring. Correlations were assessed by stepwise multiple re gression between day sleep and night sleep measures. Almost no signifi cant or near significant correlations emerged. It is concluded that da y sleep in narcolepsy is based upon a different mechanism, perhaps a d iurnal ''subvigilance syndrome'' of impaired arousal mechanisms.