PRACTICAL ASPECTS OF 3,4-DIAMINOPYRIDINE TREATMENT OF THE LAMBERT-EATON MYASTHENIC SYNDROME

3,4-Diaminopyridine (3,4-DAP) given alone or combined with pyridostigm ine is the recommended basic therapy in the Lambert-Eaton myasthenic s yndrome (LEMS). We present and exemplify our routine test protocol for monitoring drug introduction and treatment regimen of cholinergic dru gs in LEMS. The individual drug responses vary and no recommended stan dard doses exist. Routine electrophysiological repetitive nerve stimul ation studies recording amplitude of initial compound muscle action po tential (CMAP) in thenar muscles correlate excellently with clinical m yasthenic muscle power tests in clinically affected muscle groups. The refore repetitive clinical muscle power tests, that often are complica ted by painful myalgia and activation potentiation, can be replaced by recordings of CMAP in the introduction and clinical follow up of chol inergic drug treatment in LEMS. Also, adverse effects and other treatm ent problems from the experience of continuous treatment of 19 LEMS pa tients with 3,4-DAP for up to 10 years are presented.