| Although not being part of the diagnostic criteria for narcolepsy, disturbed nocturnal sleep (DNS) has been well documented as a common feature in narcolepsy. The relationship between DNS and EDS has not been well documented. For the diagnosis of narcolepsy, shortened nocturnal SOREMP has been included in the diagnostic criteria for narcolepsy, while other features including sleep stage transition and related power spectral analysis in both nocturnal and daytime naps were being investigated as additional discriminatory features assisting in the diagnosis of narcolepsy. In our study, the case notes and sleep study results of 109 patients (mean age 27.1 14.3 at baseline) with narcolepsy were analyzed, in which 65 of them had Multiple Sleep Latency Test (MSLT), Epworth Sleepiness Scale and BMI measured at both the baseline and follow up. The mean follow-up duration was 7.7 5.8 years (range 1-21 years). Fifty-five patients (50.5% of 109) had cataplexy at baseline. Six (11.1%) out of the 54 patients, who did not have cataplexy at baseline, developed cataplexy at follow up. Patients with cataplexy (type I) had a significantly shorter sleep latency and REM latency and MSL at the baseline but not with in other sleep parameters. Those subjects with subjective insomnia complaints, including difficulty in maintaining sleep and early morning wakening (but not difficulty in initiating sleep), had a shorter MSL at baseline. Baseline MSL was significantly correlated with WASO, REM latency and percentage of REM sleep. At follow up, the patients with cataplexy had a lower sleep efficiency, more WASO and more subjective complaint of early morning wakening. The early morning wakening was associated with more EDS (both in MSL and ESS score). |