Experiments With Quinine and Prostigmin in Treatment of Myotonia and Myasthenia

There is acute clinical contrast between myotonia congenita and myasthenia gravis: that of the sthenic and the asthenic; great muscles and lean ones, progressive power and progressive weakness. By Walker's1discovery of the effectiveness of prostigmin (the dimethylcarbamic ester of 3-oxyphenyltrimethylammonium methylsulfate)2in the treatment of myasthenia and the recent observation by one of us (A. W.)3that quinine abolishes myotonus, pharmacologic tools have become available with which to show also a chemical contrast between these two disorders. The value of quinine in the treatment of myotonia is further established by the following brief report of four additional cases, bringing the total number in our series up to eight. REPORT OF CASES Case 1. —A. B., a middle-aged woman, had had myotonia atrophica for six years. Myotonus most evident in grasping movements and on percussion of the tongue, was eliminated by the administration of quinine hydrochloride, 5