ALS Incidence, Prevalence: New Global Data


The review highlights variation in estimates of ALS incidence and prevalence around the world and points to lack of registries in some areas that cause “gaps” in reporting.


Amyotrophic lateral sclerosis (ALS) is a rare neurodegenerative disorder that affects upper and lower motor neurons.

Although the epidemiology of ALS has been investigated for many years, a comprehensive picture of the variability of the global burden of this disease is lacking.

After a literature search for relevant studies reporting estimates of prevalence, incidence and/or mortality of ALS published between 2010 and 2021, the authors included 140 in the review.


Most studies were conducted in Europe (48 reported incidence, 29 reported prevalence) and North America (17 reported incidence, 16 reported prevalence).

In Europe, the overall average annual crude incidence ranged from 1.11 per 100,000 person-years in Serbia to 5.55 per 100,000 person-years in Denmark.

Of the prevalence studies in Europe, point prevalence overall ranged from 3.44 per 100,000 population in Malta to 10.80 per 100,000 population in Italy.

In North America, the average annual crude incidence ranged from 0.50 to 3.29 per 100,000 person-years. The point prevalence ranged from 2.00 per 100,000 to 11.80 per 100,000.

Possible reasons for variability in estimates include differences in case ascertainment, coverage, and representativeness of target populations, as well as genetic and/or environmental factors within and across regions. It’s unlikely major differences are a result of differing diagnostic criteria, as most studies used the same criteria.


Accessing multiple data sources may improve case capture and disease surveillance in ALS, the investigators note. “This has the potential to greatly strengthen the reliability and validity of estimates of ALS incidence and prevalence worldwide,” they write.


The study was carried out by Christina Wolfson, PhD, Research Institute of the McGill University Health Centre and the Department of Medicine, Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec, Canada, and colleagues. It was published online June 12 in Neurology.


In certain cases, there was a lack of methodologic detail, and some relevant studies may not have been identified. The authors did not conduct formal assessment for publication bias, so published studies may not be reflective of all relevant studies. Adequate clinical and research resources were not always readily available, resulting in gaps in information concerning the epidemiology of ALS in some areas (for example, South America and Africa).


The study received funding from the Public Health Agency of Canada The authors report no relevant disclosures.

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