STUDIES IN DISEASES OF MUSCLE

Abstract

In contrast to progressive muscular dystrophy, in which appreciable amounts of creatine usually are excreted (Milhorat and Wolff 1 ), myasthenia gravis is associated often with little change in the metabolism of creatine and creatinine. Some observers have reported creatinuria and a diminished output of creatinine in myasthenia gravis, whereas other workers have observed patients in whom no excretion of creatine could be demonstrated and in whom the amounts of urinary creatinine appeared to be normal. The present study, which is part of an investigation on the metabolism of creatine and creatinine in the various types of muscular disease, was undertaken to determine the factors which influence the output of creatine and creatinine in myasthenia gravis. MATERIAL AND METHODS The subjects were eleven patients, five of whom were seen at regular intervals for a period of from over three to four years. During the periods of observation the patients were in