Sleep and neuromuscular disease: frequency of sleep-disordered breathing in a neuromuscular disease clinic population

Abstract

We investigated 60 adult and pediatric patients (33 male, 27 female) with various neuromuscular disorders for sleep-disordered breathing in a clinic population at a local altitude of 1,500 m. Measurements included a questionnaire concerning symptoms of sleep and daytime function, a disability index, and pulmonary function tests. We used an EdenTrace monitor for 1 night to evaluate breathing during sleep and calculated mean and minimum oxygen saturation (SpO2), total apneas, hypopneas, and respiratory disturbance index (RDI). We had validated the EdenTrace II monitor prior to the study. The majority of the patients had symptoms of daytime dysfunction. The frequency of sleep-disordered breathing in this population was much higher (42% with RDI > 15) than frequencies indicated in recent population-based surveys. Spirometry revealed no positional effect in this population. Statistical analysis comparing RDI with disability index, pulmonary function tests, age, sex, body mass index, and Epworth Sleepiness Scales identified no strong correlates that could be used as predictors of sleep-disordered breathing in this population. Sleep studies using ambulatory equipment such as the EdenTrace II are an easy and effective means of identifying sleep-disordered breathing in patients with neuromuscular disorders and, given the high frequency of sleep-disordered breathing in our sample, should be performed on most patients with neuromuscular disorders if sleep-disordered breathing is to be identified early.