Sleep disorders in adult-onset myotonic dystrophy type 1: a controlled polysomnographic study


A. Romigi, MD, PhD, Neurophysiopathology Department, University of Rome Tor Vergata, Policlinico Tor Vergata, Viale Oxford 81, 00133 Rome, Italy (tel.: +390620902107; fax: +390620902106; e-mail:


Background:  Sleep disturbances and excessive daytime somnolence are common and disabling features in adult-onset myotonic dystrophy type 1 (DM1).

Methods:  Our study used questionnaires, ambulatory polysomnography and the multiple sleep latency test to evaluate sleep-wake cycle and daytime sleepiness in unselected adult-onset DM1 patients. We recruited 18 patients affected by adult-onset DM1 and 18 matched controls.

Results:  Sleep efficiency was <90% in 16/18 patients, and it was significantly reduced when compared with controls. Reduced sleep efficiency was associated with abnormal respiratory events (5/18 patients) and/or periodic limb movements (11/18 patients). The Periodic Limb Movement Index was significantly increased in DM1 versus controls. A significantly lower mean MSLT sleep latency was detected in DM1 versus controls, but it did not reach pathological levels.

Conclusions:  Our controlled study demonstrated sleep alterations in unselected consecutive DM1 patients. Periodic limb movements in sleep are commonly associated with sleep disturbance in adult-onset DM1, and it may represent a marker of CNS neurodegenerative processes in DM1.