title: Incidence and distribution of parkinsonism in Olmsted County, Minnesota, 1976-1990.
abstract: OBJECTIVE
  Limited information is available on the frequency and distribution of parkinsonism as a syndrome. We studied the incidence of parkinsonism and its specific types among residents of Olmsted County, MN, for the period from 1976 through 1990.
  
  
  METHODS
  We used the medical records linkage-system of the Rochester Epidemiology Project to identify all individuals whose records contained documentation of any form of parkinsonism, related neurodegenerative diseases, or tremor of any type. A nurse abstractor screened the records, and, when applicable, a neurologist reviewed them to determine the presence of parkinsonism using specified diagnostic criteria and to define the year of onset.
  
  
  RESULTS
  We found 364 incident cases of parkinsonism: 154 with PD (42%), 72 with drug-induced parkinsonism (20%), 61 unspecified (17%), 51 with parkinsonism in dementia (14%), and 26 with other causes (7%). The average annual incidence rate of parkinsonism (per 100,000 person-years) in the age group 50 to 99 years was 114.7; incidence increased steeply with age from 0.8 in the age group 0 to 29 years to 304.8 in the age group 80 to 99 years. The cumulative incidence of parkinsonism assuming no competing causes of death was 7.5% to age 90 years. PD was the most common type of parkinsonism, followed by parkinsonism in dementia in men and drug-induced parkinsonism in women. Men had higher incidence than women at all ages for all types of parkinsonism except drug-induced.
  
  
  CONCLUSIONS
  Parkinsonism is a common disease among the elderly; its incidence increases steeply with advancing age and is consistently higher in men. The distribution by type changes with age and gender.
authors.affiliation: Department of Neurology, Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Bower
authors.forename: D M
authors.initials: DM
authors.lastname: Maraganore
authors.forename: S K
authors.initials: SK
authors.lastname: McDonnell
authors.forename: W A
authors.initials: WA
authors.lastname: Rocca
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D010300:Parkinson Disease / Q000453:epidemiology*; D017678:Sex Distribution