Insomnia is frequent in amyotrophic lateral sclerosis at the time of diagnosis

Abstract

Sleep-disordered breathing and sleep-related symptoms are frequent in patients with severe amyotrophic lateral sclerosis (ALS). We aimed to describe sleep quality, sleep structure, and the occurrence of sleep-disordered breathing in patients with early ALS, at the time of initial evaluation in a tertiary care center. Sleep-related symptoms were collected using questionnaires, the Pittsburgh Sleep quality Index (PSQI), and the Epworth Sleepiness Scale. Sleep was studied by inpatient overnight polysomnography. Fourteen men and 13 women (age 66 ± 12 years, ALSFRS-R 39 ± 6) were included, among which 12 patients had disease with bulbar onset. Eighteen (69%) patients complained of insomnia, fifteen of which (55%) reported poor sleep quality (PSQI > 5). No patient had an Epworth Sleepiness Scale > 10. Respiratory and polysomnography characteristics were similar between patients with poor or good sleep quality. Sleep efficiency and REM sleep duration were normal relative to normative values, while wake after sleep onset was increased. Fifteen patients had obstructive sleep apnea syndrome (8 mild, 3 moderate, and 4 severe). No patient had central apnea syndrome. Insomnia was highly prevalent in patients with early ALS, independent of respiratory impairment. Poor sleep quality was strongly associated with insomnia.