Stroke at moderate altitude

To know the clinical profile, presence of various risk factors for stroke at moderate altitude and to study its relationship with hypertension and polycythemia at moderate altitude.

We analyzed the data of 100 patients, consecutively admitted to a hospital situated at an moderate altitude of 2200 meters MSL of Sub-Himalayan ranges and studied the age, gender, geographical distribution, clinical features and presence of various risk factors in relation to stroke. This is not only the first study conducted in Himachal Pradesh but also first study in India to be conducted at moderate altitude (2000-3000 meters MSL).

Males outnumbered females (66% males, 34% females) with rural predominance (73% rural, 27% urban). Cerebral infarction (69%) was more common but primary intracerebral haemorrhage (26%) was more common than found in the West. Hypertension (62%) and smoking (60%) were most common risk factors present and polycythemia was not a significant risk factor at this altitude.

Incidence of stroke was found to be lower than the study conducted at low altitude. incidence of various types of stroke was similar to other Indian studies. The combination of opposite effects of decreased hypertension and increased haematocrit could not be demonstrated at this altitude and smoking was more common than in other studies and other risk factors prevalent were same as that for low altitude.