Crosswalk sign that reads don't stop at seronegative MG

When your patients test negative for acetylcholine receptor (AChR) antibodies,

Look Out For Lambert-eaton myasthenic syndrome (LEMS)

Learn More

Uncover LEMS with anti-voltage-gated calcium channel (VGCC) antibody testing

Anti-VGCC antibody testing can help identify LEMS and support timely treatment.

Ophthalmic signs and symptoms coupled with autonomic dysfunction could help distinguish LEMS1

Ophthalmologists are uniquely positioned to recognize LEMS. Learn how you can spot the signs.

Could your patient’s symptoms indicate LEMS?

LEMS is an underrecognized autoimmune neuromuscular disorder that results in progressive, debilitating muscle weakness and fatigue. The disorder diminishes patients’ physical function and severely impairs activities of daily living.2

LEMS is estimated to affect at least

individuals in
the United States3-6

While LEMS is a rare disease, the number of patients with LEMS may be significantly higher, as LEMS is frequently misdiagnosed as other conditions, such as MG.6,7

of LEMS CASES are also ASSOCIATED WITH AN UNDERLYING cancer6,8-10

It is critical to diagnose LEMS early to help treat patients’ neuromuscular symptoms and to swiftly detect any associated malignancy.11

It is vital to properly identify LEMS early.11 See how you can diagnose LEMS.
Infographic explaining LEMS is a disorder of the neuromuscular junction

LEMS is a disorder of the neuromuscular junction

LEMS occurs when voltage-gated calcium channel (VGCC) antibodies disrupt acetylcholine (ACh) release from presynaptic motor terminals.12

  • In patients with LEMS, autoantibodies target voltage-gated calcium channels on the presynaptic motor neuron, reducing calcium influx during an action potential12
  • Reduced intracellular calcium limits presynaptic vesicle fusion and release of ACh12
  • Reduced ACh release decreases activation of postsynaptic ACh receptors, impairing neuromuscular transmission12
  • Reduced neuromuscular transmission results in diminished muscle contraction and muscle weakness12

MG is caused by autoantibodies attacking the acetylcholine receptors (AChR) or associated proteins (MuSK, LRP4) on the postsynaptic muscle, leading to impaired neuromuscular transmission.13

MuSK, muscle-specific kinase; LRP4, low-density lipoprotein receptor-related protein 4.

References: 1. Costello F, Lee MS. Lambert-Eaton myasthenic syndrome shaping patient journeys through eye care. MedEdicus. February 11, 2025. Accessed March 23, 2026. https://www.aao.org/Assets/8830465b-c692-42a5-b9e3-bd3625aa0c1c/638775743511930000/march-2025-eyenet-supplement-pdf?inline=1. 2. Harms L, Sieb J-P, Williams AE, et al. Long-term disease history, clinical symptoms, health status, and healthcare utilization in patients suffering from Lambert Eaton myasthenic syndrome: results of a patient interview survey in Germany. J Med Econ. 2012;15(3):521-530. 3. American Cancer Society website. Key statistics for lung cancer. Accessed May 6, 2026. https://www.cancer.org/cancer/types/lung-cancer/about/key-statistics.html 4. American Lung Association website. Lung cancer trends brief: prevalence and incidence. Accessed May 18, 2026. https://www.lung.org/research/trends-in-lung-disease/lung-cancer-trends-brief/lung-cancer-prevalence-and-incidence-(1). 5. Payne M, Bradbury P, Lang B, et al. Prosepctive study into the incidence of Lambert Eaton myasthenic syndrome in small cell lung cancer. J Thoracic Oncol. 2010;5(1);34-38. 6. Titulaer MJ, Lang B, Verschuuren JJ. Lambert-Eaton myasthenic syndrome: from clinical characteristics to therapeutic strategies. Lancet Neurol. 2011;10(12):1098-1107. 7. Titulaer MJ, Lang B, Verschuuren JJ. Lambert-Eaton myasthenic syndrome: from clinical characteristics to therapeutic strategies. Lancet Neurol. 2011;10(12):1098-1107. (appendix 1) 8. Kesner VG, Oh SJ, Dimachkie MM, Barohn RJ. Lambert-Eaton myasthenic syndrome. Neurol Clin. 2018;36(2):379-394. 9. Wirtz PW, Smallegange TM, Wintzen AR, Verschuuren JJ. Differences in clinical features between the Lambert-Eaton myasthenic syndrome with and without cancer: an analysis of 227 published cases. Clin Neurol Neurosurg. 2002;104(4):359-363. 10. Titulaer MJ, Wirtz PW, Willems LNA, et al. Screening for small-cell lung cancer: a follow-up study of patients with Lambert-Eaton myasthenic syndrome. J Clin Oncol. 2008; 26(26):4276-4281. 11. Ivanovski T, Miralles F. Lambert-Eaton myasthenic syndrome: early diagnosis is key. Degener Neurol Neuromuscul Dis. 2019;9:27-37. 12. Tarr TB, Wipf P, Meriney SD. Synaptic pathophysiology and treatment of Lambert-Eaton myasthenic syndrome. Mol Neurobiol. 2015;52(1):456-463. 13. Vinciguerra C, Bevilaqua L, Lupica A, et al. Diagnosis and management of seronegative myasthenia gravis: lights and shadows. Brain Sci. 2023;13(1286):1-13.