Sleep Stage Transition of Sleep Onset Rapid Eye Movement Periods Suggesting REM Dysregulation in Narcolepsy

Abstract

Objectives: Narcolepsy diagnosis is often complicated, using relatively simple criteria that rely on sleep onset rapid eye movement periods (SOREMP) and average sleep latency in the multiple sleep latency test (MSLT). Therefore, the main goal of this study was to gain a new perspective on narcolepsy diagnosis and explore the role of rapid eye movement (REM) dysregulation by examining the progression of sleep stage transitions leading to SOREMP.Methods: From 2008 to 2022, 109 patients diagnosed with narcolepsy who underwent polysomnography and MSLT were included. Comprehensive data on clinical features, polysomnography, and MSLT findings were collected. For the MSLT, we not only considered SOREMP and mean sleep latency but also the sleep stage transition preceding SOREMP, the presence of N3, and the average SOREMP duration.Results: Among the 109 patients enrolled in the study, 59 were diagnosed with narcolepsy type 1 (NT1) and 50 with narcolepsy type 2 (NT2). We observed a high frequency of transitions in the MSLT of waking to REM (W-R) in patients with NT1. Moreover, the occurrence of W-R was associated with a higher number of SOREMPs. The temporal distribution of the MSLT results revealed a significant correlation; W-R occurrences were more frequent during the third nap.Conclusions: W-R occurrence was frequent in patients with NT1, indicating more pronounced REM dysregulation than in patients with NT2.