Subjective and polysomnographic characteristics of patients diagnosed with narcolepsy.

In order to better characterize the subjective and polysomnographic findings in patients with narcolepsy, a follow-up questionnaire was mailed to all patients diagnosed with the disorder at the Henry Ford Hospital Sleep Disorders and Research Center. The questionnaire inquired regarding the present, previous, and change in status for the constellation of narcolepsy symptoms. Memory problems, problems of daytime function, and nocturnal sleep disturbance were included among the questions related to the symptomatic constellation. By definition, all patients were symptomatic of daytime sleepiness and were diagnosed with narcolepsy only if there were two or more rapid eye movement (REM) onsets documented on the polysomnographic evaluation. A high percentage of patients reported nocturnal sleep disturbance, which was one of the symptoms with the latest reported onset. Retrospective comparison of questionnaire responses to the clinical polysomnography revealed significantly more sleep maintenance difficulties in the group of patients reporting this symptom on the questionnaire. Patients with disturbed nocturnal sleep reported taking more naps during the day, although the Multiple Sleep Latency Test (MSLT) failed to show differences in sleep latency. Interestingly, this group of patients was found to have a significantly higher number of sleep onset REM episodes on the MSLT. Finally, the findings are discussed as they compare to studies that required the presence of cataplexy as part of their inclusion criteria.