Elevated factor VIII: an unfamiliar risk factor for cerebral venous thrombosis.

An elevated factor VIII level has been shown to be an independent risk factor for venous thrombosis. However, physicians screen for this factor far less frequently than they screen for other coagulopathies. The causes of increased factor VIII levels are likely a combination of genetic and acquired variables. The authors describe a case of a healthy 48-year-old woman found to have a cerebral venous thrombosis, with her only identifiable risk factor being an elevated factor VIII level.