Myotonia and flaccid dysarthria in patients with adult onset myotonic dystrophy

Background: Myotonia and weakness are the most important components of dysarthric speech in myotonic dystrophy.

Objective: To specify and quantify possible defects in speech execution in patients with adult onset myotonic dystrophy.

Methods: Studies on speech production were done on 30 mildly affected patients with myotonic dystrophy. Special attention was paid to myotonia. Because muscle activity can result in a decrease of myotonia, speech characteristics were measured before and after warm up. The possibility that warming up causes increased weakness was also assessed.

Results: As with other motor skills, a warm up effect was found in speech production, resulting in an increase in repetition rate and a decrease in variability of repetition rate. Signs of fatigue did not occur.

Conclusions: Warming up is valuable for patients with myotonic dystrophy in reducing the influence of myotonia on speech production.