Epidemiology of amyotrophic lateral sclerosis: an update of recent literature
The cause of amyotrophic lateral sclerosis (ALS) remains unknown for most of the patients with the disease. Epidemiologic studies can help describe disease burden and examine its potential risk factors, providing thereby evidence base for future mechanistic studies. With this review, we aimed to provide a summary of epidemiologic studies published during the past 18 months, which studied the incidence and risk factors for ALS. An increasing incidence and prevalence of ALS continue to be reported from different parts of the world. Several previously studied risk factors are confirmed as causally related to ALS by Mendelian randomization analysis. The previously known prognostic indicators for ALS appear to be the same across populations. Provided with the increasing number of patients diagnosed with ALS and the improved societal awareness of the disease, more resources should be allocated to the research and care of ALS. Population-based studies, especially population-based disease registers, should be the priorities in ALS research, and more data from outside Europe are needed in gaining a better global perspective of the disease.