A Case of Overlap Myasthenic Syndrome

ABSTRACT

Myasthenia gravis (MG) differs from the Lambert-Eaton syndrome (LES) clinically, electrophysiologically, and therapeutically. However. There had been a few reports documenting the coexistence of MG and LES in the same patient, which is termed as "overlap myasthenic syndrome". We had studied a patient who had showed all the clinical characteristics of MG including positive response to pyridostigmin. Unlike the usual response in MG, there had been an abnormal incremental responses at post-exercise and high rate stimulation with abnormal decremental responses at low-rate stimulation in repetitive nerve stimulation test, which satisfies the diagnostic criteria of both MG as LES.