Central sleep apnea in multiple sclerosis: a pilot study

Purpose: The purpose of the present study is to investigate sleep-disordered breathing and symptoms of sleepiness in a consecutive clinical cohort of multiple sclerosis (MS) patients. Methods: Twenty-one (16 females) community-dwelling adults aged 18–75 years with MS and an Expanded Disability Status Scale score between 2 and 6 were recruited consecutively from an academic teaching hospital MS clinic. Participants performed a home sleep study (ResMed ApneaLink Plus) to objectively quantify sleep-disordered breathing. Subjective sleepiness and its impact were assessed using the Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, and Functional Outcomes of Sleep Questionnaire. Results: Three (one female) of the 19 participants who completed home overnight testing had central sleep apnea (median apnea-hypopnea index = 15 [range = 8–36] events/h sleep, median nadir SaO₂ = 88 % [range = 81–88]). There were no cases of obstructive sleep apnea. Thirty-three percent of participants reported excessive daytime sleepiness, and 71% reported poor sleep quality. Conclusions: Home sleep testing was well tolerated, and a high proportion of central rather than obstructive sleep apnea was observed in a clinical MS sample. Possible reasons include brainstem or spinal cord lesions from MS affecting the control of breathing. Poor sleep quality and daytime sleepiness were common in this group.