Lambert-Eaton Myasthenic Syndrome - A Clinical Review

Lambert–Eaton myasthenic syndrome (LEMS) is a rare autoimmune condition that disrupts communication between nerves and muscles by blocking the release of acetylcholine. This clinical review highlights the disorder's signature triad of symptoms, which includes leg-heavy weakness, diminished reflexes, and autonomic issues like dry mouth. A critical aspect of the text is the link between LEMS and small-cell lung cancer, noting that the neurological symptoms often serve as a preliminary warning for an underlying tumor. Beyond LEMS, the sources compare various presynaptic disorders, such as botulism and genetic myasthenic syndromes, which share similar electrical patterns despite different causes. Diagnostic protocols emphasize a combination of antibody testing and electrophysiology to differentiate these conditions from other neuromuscular diseases. Finally, the material outlines management strategies ranging from symptomatic medications like amifampridine to long-term immunotherapy and cancer-directed treatments. This episode is based on a paper written exclusively for the Weekly Neurology Deep Dive Podcast by Amer A. Ghavanini MD PhD FRCPC.