Hemorrhagic Infarction following Vasospasm due to Ruptured Cerebral Aneurysms

Hemorrhagic infarction is a rare condition after vasospasm in patients with aneurysmal subarachnoid hemorrhage (SAH). Induced hypertensive therapy is being performed recently for patients with vasospasm, but this treatment risks inducing hemorrhagic infarction. It is important to study hemorrhagic infarction after vasospasm, in order to treat patients more safely with induced hypertensive therapy. 221 patients whose first computed tomographic (CT) scanning was examined within 2 weeks after SAH were investigated for this study. Symptomatic vasospasm was seen in 99 (45%), cerebral infarction in 37 (17%), and hemorrhagic infarction in 13 (6%). Hemorrhagic infarction usually occurred from day 20 to 30 after the aneurysmal rupture, and this stage corresponded with the remission stage of the vasospasm. On the CT scan, the hemorrhagic infarction was revealed as leaky hemorrhage in the low density area previously recognized in 11 cases, and massive hemorrhage with mass effect was seen in 2 cases. These findings suggest that hemorrhagic infarction after vasospasm may sometimes be fatal. The autoregulation of the cerebral blood flow in patients with vasospasm was normal or of the hypertensive type in the remission stage of vasospasm, when hemorrhagic infarction usually appeared. This finding shows that induced hypertensive therapy is ineffective in this stage. Induced hypertensive therapy, therefore, should be stopped by this stage because this treatment is not only ineffective but also has a risk of aggravating hemorrhagic infarction.