Amyotrophic lateral sclerosis in Brazil: Case series and review of the Brazilian literature

Our objective was to systematically analyse the first series of cases of amyotrophic lateral sclerosis (ALS) in Minas Gerais and to review the Brazilian literature about clinical studies in ALS. This was a cross-sectional and descriptive study of a consecutive series of patients with probable or defined sporadic ALS according to the Awaji criteria, followed at two referral centres of Belo Horizonte (South-east Brazil). Patients underwent full clinical assessment. Comparisons of patient subgroups according to disease duration and initial presentation were performed. A systematic review was performed about Brazilian clinical studies in ALS. Results showed that of the 61 enrolled patients the male/female ratio was 1.6:1. The mean age at onset of symptoms was 54.9 years (SD +/- 11.4). Mean age at diagnosis was 56.3 years (SD +/- 11.1). Regarding the initial form of presentation, 43 cases (70.5%) were spinal, 12 cases (19.7%) were generalized and six cases (9.8%) were bulbar. Eight studies were found in the systematic review. In conclusion, the profile of our sample was similar to other national and international series, except for fewer cases of bulbar ALS in our series. There are few clinical studies of ALS in Brazil. The national data of prevalence and incidence are still uncertain.