UNMASKING OF TRUE MYOTONIA BY HYPOTHYROIDISM

A case with the combination of hypothyroidism and true myotonia is rep orted, in which the latter first became manifest clinically together w ith the thyroid disorder and improved with L-thyroxine therapy. The hy pothyroidism itself caused very few symptoms, and the diagnosis was no t made until examination for myotonia. The effect of each disorder on muscle function seems to be additive.