Myxedema myopathy: a case report.

A classical case of myxedema, demonstrating the typical Hoffmann syndrome (muscle weakness, hypertrophy, pseudomyotonic phenomena) and the usual rise in serum creatine phosphokinase (CPK), is discussed. Assuming that there is a CPK loss in the muscle fiber, the pseudomyotonic phenomena may be due to an increase in ADP, which in turn inhibits the calcium pump. Furthermore, light-microscopic and electron-microscopic findings are reported.