Ischemic stroke associated with immune thrombocytopenia: lesion patterns and characteristics.

Although the patients with immune thrombocytopenia (ITP) have a very low platelet count, which usually causes hemorrhagic complications, they occasionally experience ischemic stroke. However, the mechanism underlying ITP-related ischemic stroke (ITP-IS) has not been fully clarified. We aim to elucidate the ITP-IS mechanism by analyzing the ischemic lesion patterns and clinical characteristics. We assessed consecutive first-ever acute ischemic stroke (AIS) patients with ITP admitted to Seoul National University Hospital between October 2002 and October 2011. The stroke lesion pattern and clinical characteristics of ITP-IS patients were analyzed. Of the 2,185 patients with first-ever AIS, seven patients (4 women) with ITP-IS were identified. Of these seven patients, 3 (43 %) who were classified as undetermined stroke etiology indicated an embolic stroke pattern, and had no remarkable atherosclerotic risk factors, no steno-occlusive lesions in their relevant artery, and no cardioembolic etiologies or conditions causing secondary ITP. Moreover, compared with the patients without ITP, the patients with ITP were younger and had lower platelet counts. Thus, we noted that ITP is a rare cause of ischemic stroke, which primarily occurs due to the development of a thromboembolism in the brain. We believe that this paradoxical mechanism of ITP-associated thrombus formation requires further investigation.