In a previous report of this series1 it was shown, in agreement with Findlay2 and Rosenbloom and Cohoe,3 that in adults with myotonia congenita the urinary output of creatinine and creatine is normal. It was shown further that the creatine tolerance4 and the effects of aminoacetic acid on the metabolism of creatine in persons with this condition are similar to those observed in normal persons. Moreover, functional disturbances of the muscles, such as adventitious movements and increased resistance to passive stretch, were observed by us1 to be without effect on the metabolism of creatine. Considered together, these findings suggest that there is no essential relationship between the functional defect (myotonia) in myotonia congenita and the metabolism of creatine.
However, Poncher and Woodward,5 on the basis of their studies, recently postulated such a relationship. They observed an increase in the myotonia of 2 patients with