Prednisone eliminates the electrophysiological decrement of myotonia congenita.
The physiological effect of corticosteroids on myotonia is not reported. We studied a 44-year-old woman with myotonia congenita whose myotonic symptoms improved on prednisone for an unrelated facial palsy. Ten-hertz repetitive stimulation showed a 46% decrement between the 7th and 20th responses at baseline. Prednisone reduced the decrement in a dose-related fashion, to 14% on 20 mg per day and to 5% on 40 mg per day. The short exercise test also improved considerably. Corticosteroids could be further investigated for symptomatic myotonia.
Chelimsky
Thomas
T
From the Department of Neurology, Case Western Reserve University and University Hospitals of Cleveland, Cleveland, Ohio.
Neal
Peggy
P
Westbrook
Edward
E