Position Change During Sleep Period in Patients with Multiple System Atrophy

Abstract

Background and Purpose: We wanted to investigate whether patients with multiple system atrophy (MSA) change their positions less frequently compared to the controls during sleep and during the sleep period time. Methods: Fifteen MSA patients and fifteen controls were compared. They were matched in sex, age, apnea-hypopnea index (AHI), and PLMI (periodic limb movements index during sleep). Technician-attended standard polysomnography was performed. Position changes were divided into 3 categories depending on the interval between the arousal and the start of the position change. Category 1 was the position changes that initiated within 3 seconds after arousal. Category 2 was the position changes that occurred between 3 and 10 seconds of arousal and category 3 was the position change after 10 seconds of arousal. Results: As a whole, position changes are less frequent in the MSA group. Category 1 position change is decreased in stages 1 and REM in MSA group compared to the control group. The frequency of category 2 position change is also dramatically lower in the MSA group as a whole and especially with prior stages 1 and 2. Category 3 position change shows marked difference between the two groups when they are compared as position change per hour of WASO. Conclusions: Our study shows less frequent position changes during sleep in MSA patients. Longer period of wakefulness during night seems to be a compensatory mechanism for the position change.