{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,13]],"date-time":"2026-05-13T20:32:55Z","timestamp":1778704375088,"version":"3.51.4"},"reference-count":47,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2024,12,13]],"date-time":"2024-12-13T00:00:00Z","timestamp":1734048000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Neurol."],"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>Lambert\u2013Eaton myasthenic syndrome (LEMS) is an autoimmune disorder of the presynaptic neuromuscular junction associated with antibody mediated dysfunction of voltage-gated calcium channels (VGCCs). LEMS can exist as a paraneoplastic syndrome, paraneoplastic-LEMS (P-LEMS), when associated with tumors, most commonly, small cell lung carcinoma (SCLC) or as a non-paraneoplastic condition (NP-LEMS) when no malignancies are detected.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>A retrospective chart review was conducted in 3 tertiary hospitals in Saudi Arabia for patients diagnosed with LEMS between January 2010 and January 2020. Patients meeting all the following criteria were included: (1) weakness or fatigability of one or more extremity or oculo-bulbar muscles, (2) 60% or higher increment of compound muscle action potential (CMAP) amplitudes immediately following isometric exercise, and (3) positive serum P\/Q type VGCC antibodies. Clinical, laboratory, and electrophysiologic features, as well as radiologic imaging modalities performed for tumor screening were reviewed.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The study included six patients diagnosed with LEMS, split evenly between P-LEMS and NP-LEMS. Fatigability, particularly in the lower extremities, and dyspnea on exertion were commonly reported symptoms. Low CMAP amplitudes were more frequently seen in NP-LEMS as compared to P-LEMS when recorded from both abductor pollicis brevis and abductor digiti minimi muscles. An incremental response above 60% in post activation CMAPs was detected at similar rates following variable durations of isometric exercise (10, 15, and 20\u202fs). Tumor types detected in 3 patients with P-LEMS are SCLC, breast carcinoma, colon adenocarcinoma, and prostate acinar adenocarcinoma. Triple malignancy was detected in one patient.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>This is the first study to describe clinical and electrophysiologic features of LEMS in an Arab ethnic cohort. Early recognition of LEMS has a significant impact on prognosis, especially given the aggressive nature of associated cancers such as SCLC.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fneur.2024.1525155","type":"journal-article","created":{"date-parts":[[2024,12,13]],"date-time":"2024-12-13T05:10:10Z","timestamp":1734066610000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":3,"title":["Clinical presentations, electrophysiologic features, and long-term follow-up in Lambert\u2013Eaton myasthenic syndrome: a series of six patients"],"prefix":"10.3389","volume":"15","author":[{"given":"Reem M.","family":"Alhammad","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yafa","family":"Alshamlan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ruwa","family":"Alneseyan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Talal M.","family":"Al-Harbi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ali","family":"Alhijab","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mohammed H.","family":"Alanazy","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2024,12,13]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"603","DOI":"10.1212\/wnl.54.3.603","article-title":"A randomized trial of 3,4-diaminopyridine in Lambert-Eaton myasthenic syndrome","volume":"54","author":"Sanders","year":"2000","journal-title":"Neurology"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"74","DOI":"10.1177\/088307380201700123","article-title":"Lambert-Eaton myasthenic syndrome in children","volume":"17","author":"Tsao","year":"2002","journal-title":"J Child Neurol"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"NP58","DOI":"10.1177\/0883073813499970","article-title":"Long-term follow-up in infantile-onset lambert-Eaton myasthenic syndrome","volume":"29","author":"Portaro","year":"2014","journal-title":"J Child Neurol"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"1596","DOI":"10.1212\/CON.0000000000001205","article-title":"Lambert-Eaton Myasthenic syndrome and botulism","volume":"28","author":"Raja","year":"2022","journal-title":"Continuum"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"1098","DOI":"10.1016\/S1474-4422(11)70245-9","article-title":"Lambert-Eaton myasthenic syndrome: from clinical characteristics to therapeutic strategies","volume":"10","author":"Titulaer","year":"2011","journal-title":"Lancet Neurol"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"66","DOI":"10.1097\/CND.0000000000000190","article-title":"Distinguishing features of the repetitive nerve stimulation test between Lambert-Eaton Myasthenic syndrome and myasthenia gravis, 50-year reappraisal","volume":"19","author":"Oh","year":"2017","journal-title":"J Clin Neuromuscul Dis"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"S407","DOI":"10.1016\/j.jtho.2023.09.729","article-title":"P2.31-03 Lambert-Eaton Myasthenic syndrome is underrecognized in small cell lung cancer: an analysis of real-world data","volume":"18","author":"Morrell","year":"2023","journal-title":"J Thorac Oncol"},{"key":"ref8","doi-asserted-by":"publisher","first-page":"34","DOI":"10.1097\/JTO.0b013e3181c3f4f1","article-title":"Prospective study into the incidence of Lambert Eaton myasthenic syndrome in small cell lung cancer","volume":"5","author":"Payne","year":"2010","journal-title":"J Thorac Oncol Off Publ Int Assoc Study Lung Cancer"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"4276","DOI":"10.1200\/JCO.2008.17.5133","article-title":"Screening for small-cell lung cancer: a follow-up study of patients with Lambert-Eaton myasthenic syndrome","volume":"26","author":"Titulaer","year":"2008","journal-title":"J Clin Oncol Off J Am Soc Clin Oncol"},{"key":"ref10","doi-asserted-by":"publisher","first-page":"379","DOI":"10.1016\/j.ncl.2018.01.008","article-title":"Lambert-Eaton Myasthenic syndrome","volume":"36","author":"Kesner","year":"2018","journal-title":"Neurol Clin"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"27","DOI":"10.2147\/DNND.S192588","article-title":"Lambert-Eaton Myasthenic syndrome: early diagnosis is key","volume":"9","author":"Ivanovski","year":"2019","journal-title":"Degener Neurol Neuromuscul Dis"},{"key":"ref12","doi-asserted-by":"publisher","first-page":"823","DOI":"10.1111\/j.1749-6632.1998.tb11024.x","article-title":"Lambert-Eaton myasthenic syndrome (LEMS). 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