Cerebrovascular stroke at high altitude.

Abstract

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. A case control study. The study was conducted at Military Hospital, Rawalpindi from June 2000 to May 2001. 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. 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. High altitude is a risk factor for stroke in persons residing at altitudes of over 15,000 ft.