HEMATOLOGIC DISORDERS ASSOCIATED WITH ISCHEMIC STROKE

Hematological disorders underlie a small proportion of all ischemic st rokes. The association of these coagulation abnormalities with ischemi c stroke is not always clear. The etiology of stroke still remains unc ertain in a large number of cases and proper screening for coagulation abnormalities and the discovery of new coagulation disorders will pro bably increase the rate of strokes attributable to these causes. Since large case-control studies with unselected and consecutive stroke pat ients from different ethnic origins have not yet been performed to det ermine the role of coagulation abnormalities in ischemic stroke, our k nowledge is dependent on case reports and small series of mostly young er patients. Extensive hematologic evaluation of unselected stroke pat ients will likely yield little useful information and be too expensive . Every stroke patient needs a careful evaluation, and in selected cas es, this should include coagulation parameters. Patients with unexplai ned strokes after a careful evaluation, previous thrombotic episodes, or a positive family history for thrombosis, are good candidates for f urther coagulation studies. As long as the hypercoagulable state persi sts, both arterial and venous thromboembolic recurrences can be expect ed. Many of these patients may benefit from anticoagulants. In patient s with hereditary coagulation disorders, studies should be extended to close relatives. Since some coagulation tests are fairly expensive, p rovide only equivocal data, and are not widely available, we advise a step-by-step approach starting with the patient and family history.