Effects of sleep deprivation on daytime sleepiness in primary insomnia

STUDY OBJECTIVES: This study investigated changes in MSLT scores and recovery sleep following total sleep deprivation in subjects with insomnia as compared to normal sleepers. DESIGN: Matched-groups design. SETTING: A sleep disorders center in a large medical center. PARTICIPANTS: Ten individuals with psychophysiological insomnia and ten age- and sex-matched normal sleepers served as subjects. INTERVENTIONS: Subjects underwent total sleep deprivation after baseline polysomnography and MSLT. A post-deprivation MSLT was obtained, as well as polysomnography on the recovery night and an MSLT after the recovery night. MEASUREMENTS AND RESULTS: Both groups showed significant decreases in MSLT scores following total sleep deprivation, as compared to baseline. Both groups had significantly shorter scores on a nighttime MSLT compared to a daytime MSLT. The insomnia group also showed a significant increase in total sleep time on the recovery night compared to baseline. CONCLUSIONS: The MSLT is sensitive to changes in sleepiness associated with total sleep deprivation in individuals with primary insomnia.