Impaired procedural memory in narcolepsy type 1

Abstract

Nocturnal sleep represents a time of the day where the consolidation of newly encoded procedural and explicit memories is facilitated. 1 However, under conditions of disturbed sleep, the consolidation of newly acquired memories during sleep appears dysfunctional. For example, a study involving young adults demonstrated that the consolidation of verbal memories was impaired when sleep in the post-learning night was fragmented. 2 Furthermore, reduced time in slow-wave sleep, a non-rapid eye movement (REM) sleep stage, has been linked to a less pronounced consolidation of declarative information. 3 Sleep deprivation reduces success rate on declarative and procedural memory tasks, 4,5 and a small study showed that sleep-associated consolidation of procedural memories might be impaired among patients with primary insomnia. 6 Narcolepsy is a chronic sleep disorder characterized by excessive daytime sleepiness (EDS) and disturbed nocturnal sleep. A major sleep characteristic of narcolepsy is sleep-onset REM periods (SOREMPS); however, non-REM sleep is also affected. Patients with narcolepsy often spend more time in lighter and less time in deeper non-REM sleep stages. [7][8][9] Frequent nocturnal awakenings from sleep are also highly prevalent in narcolepsy. 8,10,11 Thus, narcolepsy may interfere with sleep-dependent memory consolidation. In line with this assumption, one study found that the consolidation of procedural memories across one night of sleep was less pronounced among patients with narcolepsy than healthy controls. 12 However,

Effects of morning and evening physical exercise on subjective and objective sleep quality: an ecological study

“…The headband's technology uses the relative spectral power computed in frequency bands relevant for sleep analysis— λ (0.5–4 Hz), θ (4–8 Hz), α (8–14 Hz), and β (15–30 Hz)—to monitor EEG signals every 30 s (Arnal et al, 2020; Hochreiter & Schmidhuber, 1997). An algorithm enables automatic sleep stage analysis in two phases: feature extraction (each 30‐s epoch) and classification, which has been validated as a reliable method relative to human polysomnography scoring (Arnal et al, 2020; Asp et al, 2022; Debellemaniere et al, 2018). We extracted the time to fall asleep (SOL [min]), the total time spent in each sleep stage (NREM, REM, N1, N2, and N3 [min]), as well as the duration of each sleep stage as a percentage, the total sleep time (TST) and the WASO.…”

Sleep Stage Transitions and Sleep-Dependent Memory Consolidation in Children with Narcolepsy–Cataplexy

“…However, sleep-dependent memory consolidation, which is negatively influenced by sleep deprivation and sleep fragmentation [30], has been rarely investigated in narcoleptic patients. These studies revealed that in narcoleptic adults the sleep-dependent memory consolidation process was found to be less effective [31][32][33], suggesting that their disrupted sleep patterns hindered the complementary function of consecutive NREM-REM stages in memory consolidation [34].…”