Fatigue, excessive daytime sleepiness, and sleep-related breathing disorders in patients with myotonic dystrophies

The myotonic dystrophies are dominantly inherited multisystem disorders characterized by progressive muscle weakness, endocrine symptoms, and mild-to-moderate cognitive impairment. Many patients report chronic fatigue. Excessive daytime sleepiness (EDS) is an early and highly relevant complaint of patients with myotonic dystrophy type 1 (DM 1). Sleep-related breathing disorders are a common cause of EDS in these patients, including both obstructive sleep apnea and nocturnal alveolar hypoventilation. In DM 1, EDS can also reflect secondary CNS hypersomnia. This article outlines our current knowledge on the etiology, diagnosis, and therapy of both fatigue and EDS in patients with myotonic dystrophy. © 2011 Springer.