Epidemiology
Lambert-Eaton myasthenic syndrome (LEMS) is a rare disease with prevalence affected by factors that determine the frequency of the associated disease process: either underlying cancer (CA-LEMS; small cell lung cancer is the most commonly associated) or autoimmune disease (NCA-LEMS). Worldwide prevalence is estimated to be 2 to 3 per million.[4][5][6] LEMS usually begins in later life, although, rarely, children may also be affected. CA-LEMS has a male predominance, with a median onset age in the 60s.[1][3] NCA-LEMS has an equal representation of males and females and a median onset age in the 50s.[7] A bimodal distribution has been described in NCA-LEMS, with a female predominance <45 years of age and male predominance >60 years of age.[7]
Use of this content is subject to our disclaimer