Most patients with myotonic dystrophy experience fatigue. Also excessive daytime sleepiness may occur, causing them to fall asleep for example while watching television or while driving as a passenger in a car. This may give the impression of lack of interest, while this is not the case.

Short naps during the day (maximum 30 minutes) may sometimes be helpful. Daytime sleepiness can sometime be helped with medication, such as modafinil (Modiodal®).

As excessive daytime sleepiness may also be the consequence of respiration problems, a consult with a respiratory specialist, familiar with muscular dystrophy, is needed to determine if breathing is compromised during sleep (see ‘Lungs‘ and ‘Centre for Home Ventilation‘).