Your new experience awaits. Try the new design now and help us make it even better

ORIGINAL RESEARCH article

Front. Neurol.

Sec. Neuromuscular Disorders and Peripheral Neuropathies

Volume 16 - 2025 | doi: 10.3389/fneur.2025.1667540

Epidemiological Analysis of Lambert-Eaton Myasthenic Syndrome in Türkiye: Insights from a Nationwide Electronic Health Database

Provisionally accepted
Berin  InanBerin Inan1*Bilgin  OZTURKBilgin OZTURK1Naim  AtaNaim Ata2Suayip  BirinciSuayip Birinci3Erdal  ErogluErdal Eroglu1Omer  KaradasOmer Karadas1Ersin  TanErsin Tan4Zeki  OdabasiZeki Odabasi1
  • 1Department of Neurology, Gulhane Medical Faculty, University of Health Sciences, Ankara, Türkiye
  • 2General Directorate of the Health Information Systems, Republic of Türkiye Ministry of Health, Ankara, Türkiye
  • 3Deputy Health Minister, Republic of Türkiye Ministry of Health, Ankara, Türkiye
  • 4Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Türkiye

The final, formatted version of the article will be published soon.

Lambert-Eaton myasthenic syndrome (LEMS) is a rare autoimmune disorder of the neuromuscular junction, with limited large-scale epidemiological data. In this study, we aimed to determine the epidemiological profile of LEMS in Türkiye, and to assess associated malignancies, mortality, and prescription rates of pyridostigmine and amifampridine. We identified LEMS cases through a retrospective review of clinical records for individuals with a G73.1 code entry in the national healthcare database between 2015 and 2024. Confirmed cases were classified as autoimmune (A-LEMS) or paraneoplastic (P-LEMS). Demographic, clinical, and prescription data were analyzed, and incidence and prevalence rates were calculated using official census data. A total of 159 LEMS cases were confirmed. The median age at diagnosis was 60 years, and 55.3% of the patients were female. P-LEMS accounted for 59.7% of cases, with small cell lung cancer (SCLC) present in 55.8% of these. Annual incidence of LEMS ranged from 0.09 to 0.30 per million, and the overall 2024 prevalence was 1.11 per million. A-LEMS had a higher prevalence than P-LEMS in 2024, likely due to its lower mortality (23.4% vs. 58.9%). P-LEMS was more common in older males and predominantly associated with SCLC. Pyridostigmine was prescribed to 65.4% of patients, and amifampridine to 24.5%, with both treatments more frequently used in A-LEMS. This is the first nationwide epidemiological study of LEMS in Türkiye, revealing lower incidence and prevalence rates than in other countries. This study provides valuable large-scale epidemiological data, enriching the global understanding of this rare disorder.

Keywords: Lambert-Eaton Myasthenic Syndrome, Epidemiology, Incidence, Prevalence, Autoimmune, Paraneoplastic, Small Cell Lung Cancer

Received: 16 Jul 2025; Accepted: 04 Aug 2025.

Copyright: © 2025 Inan, OZTURK, Ata, Birinci, Eroglu, Karadas, Tan and Odabasi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Berin Inan, Department of Neurology, Gulhane Medical Faculty, University of Health Sciences, Ankara, Türkiye

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.