Dream Recall Frequency and Sleep in Patients with Rapid Eye Movement Sleep Behavior Disorder

ABSTRACT

OBJECTIVES: The dream recall and sleep of patients with rapid eye movement sleep behavior disorder (RBD) were not sufficiently studied. We hypothesized that RBD patients have frequent dream recall with poor sleep quality, and investigated the relationship between the dream recall frequency and sleep quality in RBD patients compared to controls. METHODS: We analyzed 81 drug naïve patients [RBD (+), 64.6±8.3 y, 57 males] and 81 age and gender matched patients with sleep disturbances without RBD [RBD (−), 63.7±7.3 y, 57 males]. All completed Pittsburgh sleep quality index (PSQI), insomnia severity index (ISI), Epworth sleepiness scale and Beck depression inventory. The 5-point rating scale was used to categorize dream recall frequency of most recent month (0=never, 4=very frequent). RESULTS: In RBD (+), dream recall frequency was much higher [frequent dreaming, 77.2% vs. 35.4%], and subjective sleep quality was much better [PSQI, 6.36±3.26 vs. 8.71±4.69]. Insomnia severity was much less in RBD (+) (ISI, 9.13±5.86) than RBD (−) (12.43±7.62). No significant differences were found in sleep parameters except lower N2 sleep % in RBD (+). The relationship between dream recall frequency and sleep was not significant in RBD (+), yet, a positive correlation was noted in RBD (−). CONCLUSIONS: RBD (+) had better sleep quality despite higher frequency of dream recall compared to RBD (−). Also dream recall was not related to their sleep quality in RBD (+), which suggests that RBD patients may have different sleep perception about their sleep and sleep quality.