A Brazilian multicentre study on the clinical and epidemiological profiles of 1116 patients with amyotrophic lateral sclerosis and its phenotypic variants

Abstract

Objective: We conducted a multicentre, cross-sectional analysis of Brazilian patients with amyotrophic lateral sclerosis (ALS) and its phenotypic variants. We describe and compare their clinical and epidemiological data. Methods: We collected data from 1,116 patients who visited seven rehabilitation hospitals in the SARAH network from 1 January 2009 to 20 March 2020. This representative sample of patients was from 308 cities in 25 states from the country's five regions. Results: The median age at onset was 55 years, and we found a significant linear correlation between the age at onset and the Municipal Human Development Index (MHDI) but not survival time. We found a four-year difference using a cutoff value of 0.750 (p < 0.001). There was a male predominance, with a 1.2:1 sex ratio. The median time from onset to diagnosis was 17.6 months, and the most common phenotypic presentations were spinal-onset and bulbar-onset ALS (62.7% and 14.7%, respectively). In total, 12.9% of the patients had familial ALS, likely due to the overrepresentation of ALS type 8 patients in our population. Conclusions: In general, our numbers are consistent with most international series and with those of other Brazilian cohorts. When patients were analyzed according to their MHDI a considerable delay in symptom onset was found, suggesting the possibility of an environmental effect on these patients. Brazil has a longer diagnostic delay which is similar to other less-developed countries. This is a substantial concern and should be a priority for health authorities and neurology societies.

Keywords:

• Amyotrophic lateral sclerosis
• motor neuron diseases
• epidemiology
• Brazil

Acknowledgments

The authors thank Marcelo Barboza Anzanel from the Statistics Department of SARAH-Rio de Janeiro Hospital and Rodrigo Souza Freitas from the DATASUS (Ministry of Health) for all the support provided for this project.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Data availability statement

Clinical and epidemiological data were obtained from the medical records of the SARAH Network of Rehabilitation Hospitals. Information about mortality was provided by DATASUS.