Professional
Formal
IVT
Lambert-Eaton myasthenic syndrome
A presynaptic neuromuscular disorder causing weakness that improves with exercise, often associated with malignancy.
Full Definition
Lambert-Eaton myasthenic syndrome (LEMS) is a rare autoimmune disorder affecting the presynaptic neuromuscular junction, characterized by muscle weakness that paradoxically improves with sustained effort. The condition results from antibodies against voltage-gated calcium channels, reducing acetylcholine release. Unlike myasthenia gravis, weakness typically affects proximal muscles first and shows post-exercise facilitation. LEMS is frequently associated with small cell lung cancer as a paraneoplastic syndrome, though idiopathic forms also occur.
Usage
Usage note: Hyphenate Lambert-Eaton; may be abbreviated as LEMS after first use.
In Context
- "Lambert-Eaton myasthenic syndrome was suspected due to the characteristic post-exercise facilitation pattern." — Diagnostic evaluation
- "Oncologic screening revealed small cell lung carcinoma underlying the Lambert-Eaton myasthenic syndrome." — Case report
Also known as
LEMS
Eaton-Lambert syndrome
Don't confuse with
myasthenia gravis
myasthenic syndrome