Cyclic alternating pattern in narcolepsy patients and healthy controls after partial and total sleep deprivation.

OBJECTIVE To investigate the regulation NREM sleep at baseline and in morning recovery sleep after partial and total sleep deprivation (SD) in narcolepsy-cataplexy (NC) using cyclic alternating pattern (CAP). METHODS Daytime sleep under either increased (no sleep in the previous night) or decreased sleep pressure (allowing 4h of sleep, 23:00-3:00 h) was recorded in ten drug-free, HLA-positive, hypocretin deficient NC patients and ten age, gender and body mass index matched healthy controls. Baseline sleep was also recorded and used for comparison purposes. CAP parameters were scored and analyzed for each subject. RESULTS Narcolepsy patients had significantly lower CAP rate, CAP index, CAP time, number of CAP cycles, A1 index and number of A1 cycles in comparison to healthy controls at baseline as well as after partial and total SD. In both narcolepsy patients and healthy control subjects there was a significant decrease in these parameters after partial and total SD but the changes followed a similar pattern. CONCLUSION The persistence of baseline differences in CAP parameters between narcolepsy patients and healthy controls and their similar behavior after partial and total SD suggests similar homeostatic NREM sleep regulation but on a different level. SIGNIFICANCE CAP analysis demonstrates that NREM sleep homeostasis although altered, is functional in narcolepsy patients.