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.