SLEEP-DISORDERED BREATHING IN AMYOTROPHIC-LATERAL-SCLEROSIS

Objective: The purpose of this study was to assess sleep and breathing in patients with amyotrophic lateral sclerosis (ALS) with bulbar musc le involvement. Design: Prospective, controlled study of sleep and bre athing measured during polysomnography. Setting: University teaching h ospital and referral center, Patients: Patients with definite ALS and healthy age-matched control subjects.Interventions: Eighteen ALS patie nts and 10 age-matched control subjects underwent one night of polysom nography, Thirteen patients with ALS were studied for a second night. Results: The ALS patients had more arousals per hour (p=0.008), more s tage 1 sleep (p=0.01), and a shorter total sleep time (TST) (279+/-69 vs 331.4+/-55.9 min, mean+/-SD, p=0.04) than the control subjects. The ALS patients had mild sleep-disordered breathing with a greater apnea /hypopnea index (AHI) than the control subjects (p=0.005). On the seco nd night of polysomnography, there was an increase in TST (p=0.003) an d rapid eye movement (REM) sleep (p=0.009), an improvement in sleep ef ficiency (p=0.02), and less stage 1 sleep (p=0.04). Eight ALS patients had sleep-disordered breathing consisting of periods of hypoventilati on, predominantly during REM sleep. Conclusions: Sleep-disordered brea thing occurs in patients with ALS and is similar to patients without A LS with respiratory muscle weakness. No obstructive sleep apnea was ob served. One potential reason for its absence might be the inability of patients with respiratory muscle weakness to generate an inspiratory pressure greater than the upper airway closing pressure. This hypothes is should be addressed in future studies.