[Juvenile cerebral infarction associated with heparin cofactor II abnormality. A case report].

A 15-year-old woman with a history of transient dysarthria two years before, suddenly developed weakness of right upper extremity, right facial palsy, and dysarthria. She was admitted to our hospital on the third day. She had no hypertension, heart murmur and oedema. On neurological examination, she had mild right hemiparesis including face muscles and mild dysarthria. The right knee jerk was brisk with no Babinski's sign. Ataxia and sensory disturbance were not present. T2-weighted MRI showed a hyperintensity at the posterior limb of the left internal capsule. Cerebral angiography was unremarkable. Ultracardiography and 24-hour electrocardiography were normal. Laboratory data revealed no inflammatory findings, liver dysfunction, hyperglycemia and hyperlipidemia. Antinuclear and anticardiolipin antibodies were negative. Prothrombin time was normal, but activated partial thromboplastin time was slightly prolonged (35.4 sec, normal 25.2-34.4). Protein C, protein S and antithrombin III were normal. Heparin cofactor II (HC II) activity was decreased (44%) with normal HC II antigen (79%) and so she was diagnosed as heparin cofactor II deficiency type II (heparin cofactor II abnormality). Her father manifesting thromboangitis obliterans also had low HC II activity with normal HC II antigen. However, on her genetic analysis, we didn't detect any mutations in the coding region of HC II gene. Until now she has no recurrence of cerebrovascular attacks. On the basis of these results, we suspect that HC II deficiency was a possible risk factor of cerebral infarction in this case because she was so young and had no general risk factors except for HC II. No stroke associated with HC II deficiency type II has been reported up to date. This case is worth considering etiologies of juvenile cerebral infarction.