Myasthenia gravis and Lambert-Eaton syndrome.

Myasthenia gravis is a common autoimmune disorder characterized by the presence of pathogenic antibodies directed against the acetylcholine receptor. Patients present with variable degrees and distribution of fluctuating weakness at times life threatening. Clinical manifestations, establishment of diagnosis, the natural history of myasthenia gravis, and therapeutic options are herein reviewed. Far less common is Lambert-Eaton syndrome (the myasthenic syndrome), another autoimmune disorder due to the presence of antibodies directed against the PQ-type voltage-gated calcium channels. Clinical features and treatment options are summarized.