Lambert-Eaton Myasthenic Syndrome.

Weakness and autonomic dysfunction in Lambert-Eaton myasthenic syndrome (LEMS) can be partially or fully controlled by 3,4-Diaminopyridine. Intravenous immunoglobulin or plasma exchange (PE) plasmapheresis) provides short-term improvement in severely affected patients. In those at risk from paraneoplastic LEMS (cigarette smokers), an intensive search for lung cancer should be undertaken, and specific tumor therapy instituted that likely will improve the neurologic deficit. Prednisolone (1.5 mg per kg of body weight administered on alternate days, maximum dosage is 100 mg) is indicated in those with paraneoplastic or nonparaneoplastic LEMS who fail to respond sufficiently to symptomatic treatment. The addition of azathioprine or cyclosporine is indicated as corticosteroid sparing medications in nonparaneoplastic LEMS. When remission or optimal improvement is judged to be present, prednisolone should be tapered to the minimum dose that effectively controls symptoms. If full withdrawal is achieved, azathioprine dose reduction is similarly initiated. In nonparaneoplastic LEMS patients failing to respond to azathioprine after 1 to 2 years of therapy, physicians should consider substituting cyclosporine.