Decreased sympathetic stimulation to the pupils in two patients with myotonic dystrophy.

Abnormalities discussed in previous papers on myotonic dystrophy suggested that there are no defects in the sympathetic nervous system, and the pupillary abnormalities were probably of peripheral origin. The pupils of two patients with myotonic dystrophy were examined and were determined to have findings suggesting a lack of preganglionic sympathetic stimulation, which has never been reported before. Other findings of Horner's syndrome such as anhidrosis and lack of sympathetic stimulation to the Muller's muscle were not present.