Amyotrophic lateral sclerosis in Brazil: 1998 national survey.

Objectives: To assess the epidemiologic characteristics of amyotrophic lateral sclerosis (ALS) in Brazil in 1998.
Method: Structured Clinical Report Forms (CRFs) sent to 2,505 Brazilian neurologists from January to September 1998 to be filled with demographic and clinical data regarding any ALS patient seen at any time during that year.
Results: Five hundred and forty CRFs were returned by 168 neurologists. Data on 443 patients meeting the criteria of probable or definite ALS according to El Escorial definition were analysed: 63 probable (14.2%) and 380 definite (85. 8%). Two hundred and fifty-nine (58.5%) of the patients were male, mean age of onset was 52. Spinal onset occurred in 306 patients (69%); bulbar onset in 82 (18.5%), and both in 52 (11.7%). Twenty-six (5.9%) had a family history of ALS. Two hundred and fifty-nine (58.6%) were seen by private practitioners, and 178 (40. 2%) at a hospital clinic. Age-ajusted incidence shows a peak incidence at the 65-74 years old range.
Conclusions: The disease's characteristics are similar to those described in international studies, except for age of onset (Brazilian patients are younger). This difference is not confirmed when figures are age-adjusted.