Subjective-objective sleepiness discrepancy in adult-onset myotonic dystrophy type 1

Study Objectives: Excessive daytime sleepiness (EDS) in myotonic dystrophy type 1 is mostly of central origin but it may coexist with sleep-related breathing disorders. However, there is no consensus on the sleep protocols to be used, assessments vary, and only a minority of patients are regularly tested or are on treatment for EDS. Our study presents data on self-reported and objective EDS in adult-onset myotonic dystrophy type 1. Methods: Sixty-three patients with adult-onset DM1 were subjected to EDS-sleep assessments (polysomnography, Multiple Sleep Latency Test, Epworth Sleepiness Scale). Correlation coefficients were computed to assess the relationship between sleep and sleepiness test results, fatigue, and quality of life. Results: 33% and 48% of patients had EDS based, respectively, on the Epworth Sleepiness Scale and the Multiple Sleep Latency Test, with a low concordance between these tests (k = 0.19). Thirteen patients (20%) displayed 2 or more sleep-onset rapid eye movement periods on Multiple Sleep Latency Test. Patients having EDS by Multiple Sleep Latency Test had a shorter disease duration (P < .05), higher total sleep time and sleep efficiency and lower wake after sleep onset on polysomnography. Patients with self-reported EDS reported significantly higher fatigue score compared with patients without EDS (P < .05). No other difference was found in demographic, clinical, and respiratory features. Conclusions: EDS test results are contradictory, making treatment options difficult. Combining quantitative tests and self-reported scales may facilitate physicians in planning EDS care with patients and families. © 2021 American Academy of Sleep Medicine. All rights reserved.