Daytime continuous polysomnography predicts MSLT results in hypersomnias of central origin

Abstract

SUMMARYIn the diagnostic work-up of hypersomnias of central origin, the complaint of excessive daytime sleepiness should be objectively confirmed by MSLT findings. Indeed, the features and diagnostic utility of spontaneous daytime sleep at 24 h continuous polysomnography (PSG) have never been investigated. We compared daytime PSG features to MSLT data in 98 consecutive patients presenting with excessive daytime sleepiness and with a final diagnosis of narcolepsy with cataplexy ⁄ hypocretin deficiency (n = 39), narcolepsy without cataplexy (n = 7), idiopathic hypersomnia without long sleep time (n = 19), and ÔhypersomniaÕ with normal sleep latency at MSLT (n = 33). Daytime sleep time was significantly higher in narcolepsy-cataplexy but similar in the other groups. Receiver operating characteristics (ROC) curves showed that the number of naps during daytime PSG predicted a mean sleep latency £8 min at MSLT with an area under the curve of 0.67 ± 0.05 (P = 0.005). The number of daytime sleep-onset REM periods (SOREMPs) in spontaneous naps strikingly predicted the scheduled occurrence of two or more SOREMPs at MSLT, with an area under the ROC curve of 0.93 ± 0.03 (P < 10 )12 ). One spontaneous SOREMP during daytime had a sensitivity of 96% with specificity of 74%, whereas two SOREMPs had a sensitivity of 75%, with a specificity of 95% for a pathological REM sleep propensity at MSLT. The features of spontaneous daytime sleep well correlated with MSLT findings. Notably, the occurrence of multiple spontaneous SOREMPs during daytime clearly identified patients with narcolepsy, as well as during the MSLT.

Sleep-stage transitions during polysomnographic recordings as diagnostic features of type 1 narcolepsy

“…Many studies have found that in narcolepsy, REM latency from sleep onset is reduced; thus, it is not surprising that SOREMP-like features are found not only at sleep onset but also when patients wake up at night and fall asleep again. SOREMPs have been shown to be predictive of narcolepsy in 24-h continuous sleep recording studies, and this test has been proposed as a valid alternative to the MSLT [37,38]. One possible confounding factor for this feature could have been that REM sleep propensity is strongly regulated by the circadian clock, peaking in the early morning hours (including in narcolepsy).…”

Actigraphic assessment of sleep/wake behavior in central disorders of hypersomnolence

“…Recently, several studies attempted a more naturalistic approach by comparing the features of spontaneous daytime sleep at 24-hour continuous polysomnography versus MSLT results, in the context of central disorders of hypersomnolence [8,9]. These studies emphasized the utility of prolonged recordings performed under conditions more similar to usual life habits of patients.…”

Test-Retest Reliability of the Multiple Sleep Latency Test in Narcolepsy without Cataplexy and Idiopathic Hypersomnia

“…Recognizing this need, some investigators have advocated for continuous daytime polysomnography, ad libitum sleep polysomnography, or changes to the MSLT scoring criteria. 9,12,33 Similar to the MSLT, however, these alternatives are time and labor intensive. More cost-effective measures are needed, in addition to identification of a biomarker with diagnostic and therapeutic significance.…”