title: Cerebrovascular stroke at high altitude.
abstract: OBJECTIVE
  To asses the high altitude as a risk factor for cerebrovascular stroke in people residing at a height greater than 15,000 feet above sea level.
  
  
  METHODS
  A case control study.
  
  
  METHODS
  The study was conducted at Military Hospital, Rawalpindi from June 2000 to May 2001.
  
  
  METHODS
  Four thousand persons between the ages of 20-40 years, residing at the height of 15,000 feet or above, were studied for occurrence of stroke. All cases of stroke referred from Northern areas of Pakistan, with positive CT scan, were included in the study. They were then investigated at Military Hospital, Rawalpindi to find out any other risk factor for stroke. During the same period four thousand persons living at Rawalpindi (height-2,000 ft) in same age group were also observed as control group.
  
  
  RESULTS
  Ten patients suffered from stroke at high altitude while just one case had stroke in indexed age group at lower heights (p-value<0.05). Relative risk was 10 times greater at high altitude.
  
  
  CONCLUSIONS
  High altitude is a risk factor for stroke in persons residing at altitudes of over 15,000 ft.
authors.affiliation: Department of Medicine, Military Hospital, Rawalpindi, Pakistan. asifniazh@hotmail.com
authors.forename: Asif
authors.initials: A
authors.lastname: Niaz
authors.forename: Shaista
authors.initials: S
authors.lastname: Nayyar
mesh_terms: D000328:Adult; D000531:Altitude; D016022:Case-Control Studies; D006801:Humans; D008297:Male; D010154:Pakistan / Q000453:epidemiology; D012307:Risk Factors; D020521:Stroke / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology*; D014057:Tomography, X-Ray Computed