Hypercoagulable Workup in Cryptogenic Stroke: What to Test, and When

There is a significant percentage of ischemic strokes, particularly in younger people, with etiologies that remain elusive despite standard workup. One dilemma in managing such patients is deciding whether they may have an underlying hypercoagulable condition that would lead to consideration of anticoagulation. Previous guidelines have focused on primary thrombophilia, but acquired conditions exceed genetic causes, and a stepwise approach to exclude such conditions before pursuing primary thrombophilia testing is important to improve diagnostic accuracy. To date, we have not encountered any algorithm in the medical literature that advises exclusion of secondary prothrombotic states prior to considering primary hypercoagulable disorders. This report proposes a methodical approach to screening the basic stroke workup for acquired hypercoagulable states before consideration of primary thromboembolic conditions. These recommendations are informed by the authors' experience at tertiary stroke centers and the current literature.