MYASTHENIA GRAVIS LAMBERT-EATON OVERLAP SYNDROME

Introduction: To assess whether a myasthenia gravis (MG) Lambert-Eaton overlap syndrome (MLOS) exists. Methods: Case reports that met the universally accepted diagnostic criteria for MG and Lambert-Eaton myasthenic syndrome (LEMS) were sought through a PubMed search. Fifty-five possible cases of MLOS were identified. Results: Thirty-nine cases met the diagnostic criteria for MG and LEMS. Analysis of clinical features showed that these patients have common MG and LEMS symptoms: oculo-bulbar paresis and good response to anti-cholinesterase for MG and limb weakness and decreased or absent reflexes for LEMS. All had the classical LEMS pattern in the repetitive nerve stimulation test: low compound muscle action potential amplitude and incremental response>60% with brief exercise or at high rate of stimulation. Eight patients had combined positive acetylcholine receptor antibody (AChR-ab) or muscle-specific kinase-ab and voltage-gated calcium channel-ab tests. Conclusions: A myasthenia gravis Lambert-Eaton overlap syndrome (MLOS) does exist.