Self-reported reduced sleep quality and excessive daytime sleepiness in facioscapulohumeral muscular dystrophy

Facioscapulohumeral muscular dystrophy (FSHD) causes weakness and secondary associations, such as respiratory complications and pain, that can be linked to abnormal sleep patterns. Limited studies have focused on sleep in FSHD. The purpose of this study was to identify the prevalence of, and clinical features associated with, self-reported lowered sleep quality (SQ) and excessive daytime sleepiness (DS) in a large group of participants with FSHD.

We conducted a prospective survey of individuals with self-reported FSHD enrolled in the FSHD Society Registry. The survey consisted of demographic and clinical characteristics, the Pittsburgh Sleep Quality Index (PSQI), and the Epworth Sleepiness Scale. Descriptive statistics were evaluated, and associations between clinical characteristics and SQ and DS were explored using one-way analysis of variance tests. Small effect size was identified as 0.01 ≥ η²  > 0.06, medium was 0.06 ≥ η²  > 0.14, and large was 0.14 ≥ η² .

Six hundred ninety individuals responded to the survey, equally distributed between men and women, and spanning the age range from under 12 to 74 years of age or older. Sixty-six percent of the respondents showed reduced SQ (PSQI > 5) (n = 392; 95% confidence interval [CI], 62.4-70.0), and 15% showed excessive DS (>10) (n = 89; 95% CI, 12.2-17.9). There was a significant association between SQ and DS. Nocturnal pain had a large significant effect on lowering SQ (P < .001, η²  = 0.192). Factors including age and gender had minor effects on SQ.

Physicians should monitor sleep quality of patients with FSHD as a routine part of care, with special attention to potentially modifiable factors. Future research should address the physiological effects of pain in sleep.