Objective: To evaluate the frequency, severity and determinants of sleep disturbances in patients with amyotrophic lateral sclerosis (ALS).
Methods: Information about night-time complaints was collected using a standardised questionnaire, the Pittsburgh Sleep Quality Index (PSQI), and the Epworth Sleepiness Scale (ESS) in a group of 100 patients with ALS and in 100 control subjects matched for age and sex. Functional disability was assessed using the ALS Functional Rating Scale-Revised (ALSFRS-R). Sleep was studied by overnight polysomnography in 12 patients.
Results: Fifty-nine patients with ALS and 36 controls reported sleep disturbances. The mean global PSQI score of patients with ALS was significantly higher than the control participants (6.82 ± 4.0 vs. 4.86 ± 3.2), and three of the seven components of PSQI in patients with ALS were significantly different from controls: 'sleep latency,' 'habitual sleep efficiency' and 'sleep disturbances.' The most commonly reported night-time complaints by patients with ALS were nocturia (54%), sleep fragmentation (48%) and nocturnal cramps (45%). Poor sleep was associated with decreased ALSFRS-R score, highest depression and ESS score. After a multivariate analysis, patients' disability and daytime somnolence remained significantly associated with sleep quality. Polysomnographic studies showed decreased sleep efficiency and fragmented sleep architecture.
Conclusion: This study demonstrated that patients with ALS have a significant poor quality of sleep, and this correlated with the severity of ALS and daytime somnolence. Increased awareness for sleep-wake problems in patients with ALS is important, as effective intervention could lead to a better management of these patients.