[Isaacs syndrome: long-term improvement with intravenous polyvalent immunoglobulins].

A 35 year-old man developed a syndrome with muscle cramp, myokimia, generalized, fasciculations, excessive sweating, sleep disorders and severe impairment. It was a syndrome of continuous muscle fiber activity--or Isaacs syndrome--with central disorders (this may be called "Maladie de Morvan"). Previous reports have suggested that Isaac's syndrome might be an autoimmune disorder. Moreover, high doses intravenous immunoglobulins were given resulting in a substantial improvement six months after the onset of this treatment.