myasthenic syndrome

Thesaurus

Noun

myasthenic syndrome - a disease seen in patients with lung cancer and characterized by weakness and fatigue of hip and thigh muscles and an aching back; caused by antibodies directed against the neuromuscular junctionscarcinomatous myopathy, Eaton-Lambert syndrome, Lambert-Eaton syndromedisease of the neuromuscular junction - a disease characterized by impairment of neuromuscular junctions

myasthenic syndrome

Lam·bert-Ea·ton myasthenic syn·drome (LEMS),

(lam'bert ē'tŏn), a generalized disorder of neuromuscular transmission caused by a defect in the release of acetylcholine quanta from the presynaptic nerve terminals; often associated with small cell carcinoma of the lung, particularly in elderly men with a long history of cigarette smoking. In contrast to myasthenia gravis, weakness tends to affect solely axial muscles, girdle muscles, and less often the limb muscles; autonomic disturbances, for example, dry mouth and impotence, are common; the deep tendon reflexes are unelicitable; on motor conduction studies, responses on initial stimulation are quite low in amplitude, but they show marked posttetanic facilitation after a few seconds of exercise. Lambert-Eaton syndrome is due to loss of voltage-sensitive calcium channels located on the presynaptic motor nerve terminal. See: myasthenic syndrome. Synonym(s): carcinomatous myopathy, Eaton-Lambert syndrome, Lambert syndrome, Lambert-Eaton syndrome, myasthenic syndrome