Sleep Dysfunction in Multiple System Atrophy

Abstract

Sleep disorders in multiple system atrophy (MSA) are common manifestation and include reduced and fragmented sleep, excessive daytime sleepiness, REM sleep behaviour disorder (RBD), and sleep-disordered breathing. Of these, RBD is the most common (affecting 90%-100% of patients with MSA) and is regarded as a red flag for MSA. RBD, as well as stridor during sleep, may be the initial manifestation of the disease, occurring several years before the waking motor and dysautonomic onset. Sleep disorders occur in both MSA with predominant parkinsonism (MSA-P) and MSA with predominant cerebellar ataxia (MSA-C). Treatment strategies in patients with MSA presenting difficulties in initiating and maintaining sleep need to be highly individualized. Clonazepam has been found to be successful in treating RBD symptoms at the dose of 0.25 to 2.0mg given approximately 30min before bedtime. In case of comorbid obstructive sleep apnea, zopiclone (at the dose from 3.75 to 7.5mg each night) or melatonin (with a recommended dose of 3 to 12mg at bedtime) may be alternative treatments. An increased survival in MSA patients with stridor may be obtained both with continuous positive airway pressure (CPAP) and tracheostomy. Since tracheostomy is an invasive surgical procedure, not easily accepted by the patient, CPAP therapy should be considered first. However, tracheostomy is first indicated when stridor is present during wakefulness because of the high risk of respiratory failure and death. In MSA, obstructive sleep apnea (OSA) occurs more frequently than central sleep apnea, ranging from 15% to 37% of the cases. CPAP is an effective treatment for eliminating obstructive sleep apnea in MSA patients, even if the adaptation to the device may be difficult in advanced cases.