Abstract
A case of acute severe neurologic deterioration following a craniotomy performed for
a left frontotemporal arachnoid cyst is reported here. Early postoperative cranial
computed tomography (CT) showed a large right parietal intracerebral hematoma which
was removed immediately, resulting in neurologic improvement. Surgical and histopathologic
observations revealed venous angioma as the cause of the hemorrhage which was not
detected on the preoperative cranial CT. Six months postoperatively, the patient developed
subdural hematoma over the left cerebral hemisphere with no evidence of trauma.
