Long-Term Treatment of Myasthenia gravis with Alternate-Day Prednisone

Personal experience of the corticosteroid treatment of myasthenia gravis in 15 patients ranging from 15 to 71 years of age is reported. Patients had a severe illness (classes III and IV of Osserman’s clinical classification) or a moderately severe one or an incapacitating ocular form. In all of them myasthenic symptoms failed to give a satisfactory response to anticholinesterase drugs and/or a favourable course after thymectomy. Therapy consisted of alternate-day high single-dose prednisone (from 75 to 115 mg), but in some cases a small dose was given each in-between day. The starting dose was generally maintained for a 3-month period, after which a very slow and gradual reduction was made down to a maintenance dose. In the patients with more than 3 months’ treatment complete or almost complete remission occurred in 6 cases, marked improvement in 5 cases, moderate improvement in one case. Clinical improvement started between the first and the 40th day of therapy with a median on the 12th day. During the early phase of prednisone therapy 4 patients showed a slight to severe decrease in muscle strength. Eleven patients showed fluctuation in the improvement of motor performances with a mild to moderate decrease in muscle strength in off-prednisone days: this effect tended to decline with time and to disappear completely after a period of 10–60 days. Apart from a psychotic reaction observed in one patient, steroid side-effects were absent or slight.