title: A clinical epidemiological study of 251 cases of amyotrophic lateral sclerosis in the south of Brazil.
abstract: OBJECTIVE
  To study the clinical forms of amyotrophic lateral sclerosis (ALS) and the possible presence of risk factors in order to verify if there is any difference between cases in Paraná, Brazil.
  
  
  METHODS
  We studied 251 cases, all of which fulfilled the diagnosis criteria proposed in El Escorial (WFN). Between 1977 and 2004, 157 male and 94 female patients were examined.
  
  
  RESULTS
  220 cases were classified as ALS-Spinal Onset (ALS-SO), 24 as ALS-Bulbar Onset (ALS-BO) and 7 as Familial ALS. The mean age at time of evaluation was 54.4+/-12.3 years, and symptoms had started 17.9+/-15.7 months previously. In the group studied, statistical relationships were found between heavy occupations and males; previous surgeries and females; ALS-BO and dysphagia and dysarthria in females; and ALS-SO and males, cramps, weakness, muscle atrophy, hypertonia, increased deep tendon reflex and abnormal gait.
  
  
  CONCLUSIONS
  The average age at time of evaluation was lower than that registered in the literature but similar to the Brazilian series. Domestic work and heavy occupations appear to be related to precocious perception of the symptoms by interference with daily functions. The socioeconomically higher classes seek medical care early. There was no relationship with exposure to toxic agents or trauma.
authors.affiliation: Neurology and Neuromuscular Service, Internal Medicine Department, Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, PR, Brazil. werneck@ufpr.br
authors.forename: Lineu Cesar
authors.initials: LC
authors.lastname: Werneck
authors.forename: Ruth
authors.initials: R
authors.lastname: Bezerra
authors.forename: Octavio da
authors.initials: Od
authors.lastname: Silveira Neto
authors.forename: Rosana Herminia
authors.initials: RH
authors.lastname: Scola
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000382:Agricultural Workers' Diseases / Q000453:epidemiology; D000690:Amyotrophic Lateral Sclerosis / Q000145:classification / Q000453:epidemiology* / Q000209:etiology; D001938:Brazil / Q000453:epidemiology; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology / Q000209:etiology; D016272:Occupational Health / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution; D012959:Socioeconomic Factors; D014931:Women, Working / Q000523:psychology; D016526:Workload