Fatigue and sleep disturbance in multiple sclerosis

Considering the association of sleep disturbance and fatigue in multiple sclerosis (MS), we investigated the presence of sleep disturbances that may be related to fatigue by using objective and subjective measures. We included 27 MS patients with fatigue, 10 MS patients without fatigue and 13 controls. The Pittsburgh sleep quality index score showed significant differences between patient groups and controls. Beck depression inventory scores were significantly higher in fatigued than non-fatigued patients. Comparison of patient groups and controls revealed significant differences for time in bed, sleep efficiency index, sleep continuity index, wake time after sleep onset, total arousal index and periodic limb movement arousal index. Our study confirms that MS causes sleep fragmentation in terms of both macro and microstructure. Fatigue in MS could be partially explained by disruption of sleep microstructure, poor subjective sleep quality and depression.