In both arms, Myasthenia Muscular Score (MMS), activities of Daily Living Scale (ADLS), MGFA Clinical Classification and MGFA Post-Intervention Status as well as prednisone and azathioprine side effects will be monthly assessed by a senior neurologist who will be blind for treatment group. A second physician, who is aware of the patient's therapeutic group, will then prescribe prednisone dose and tapering for a month, according to MGFA Post-Intervention Status.