Ditte Primdahl, MD

Dr. Primdahl describes optimal multidisciplinary CA LEMS care models.

Dr. Primdahl details amifampridine (Firdapse), FDA-approved in 2018 for CA LEMS based on 2 randomized placebo-controlled studies demonstrating clinically meaningful functional improvement with a favorable safety profile.

Dr. Sen addresses the significance of the 2025 NCCN SCLC guideline update explicitly naming CA LEMS symptom recognition (proximal weakness paired with autonomic dysfunction) and recommending P/Q-type and N-type VGCC antibody testing under the neurologic workup section, with early subspecialty consultation recommended.

Dr. Sen explains how to manage discordant serologic and electrodiagnostic results without allowing disagreement between tests to paralyze decision-making.

Dr. Primdahl walks through clinical differentiation of CA LEMS from the most important diagnostic mimics encountered in SCLC.

Dr. Primdahl addresses management of seronegative CA LEMS in a patient with SCLC and a compelling clinical picture.

Dr. Sen explains VGCC antibody testing in depth.

Dr. Sen recommends against testing VGCC antibodies in isolation when CA LEMS is suspected in SCLC.

Dr. Primdahl describes the diagnostic delays and misattributions that characterize the CA LEMS journey in patients with SCLC.

Dr. Sen addresses the striking gap between CA LEMS prevalence in prospective studies (3-6% of SCLC) and real-world diagnosis rates (under 1%), citing the Drapkin et al. published dataset.

Lung cancer and neurology experts discuss the ties between cancer-associated LEMS and small cell lung cancer, diagnostic tips, and management strategies.

Dr. Primdahl describes what CA LEMS looks like clinically for oncologists with limited exposure to this diagnosis. Patients are unlikely to self-report proximal weakness in clinical terms; they more commonly describe difficulty with everyday tasks, such as climbing stairs, getting in and out of a car or chair.

Learn how subtle weakness and autonomic signs in small cell lung cancer may signal LEMS—and why early neurology referral improves outcomes.