Subarachnoid hemorrhage perforating into the cavum septi pellucidi

The authors discuss a 49-year-old man with a complicating subarachnoid hemorrhage that had perforated into the cavum septi pellucidi. The patient was admitted to our hospital on January 4, 1986. Three days before, he had experienced impairment of consciousness and a severe headache. After admission these complaints disappeared except for disorientation. CT scans were performed with and without contrast-medium enhancement. These scans disclosed a diffuse high-density lesion in the subarachnoid space, especially in the interhemispheric fissure. A globoid lesion showed no enhancement after contrast infusion. A left carotid angiogram showed a pea-sized saccular aneurysm on the anterior communicating artery. Neither tumor-supplying vessels nor any large aneurysm was noticed. On January 5, 1986, the aneurysm neck was clipped. During the procedure, no tumors were noticed at the interhemispheric fissure. CT scan after the operation showed the mass lesion to have decreased in both density and size, and the cavum septi pellucidi gradually appeared again. Retrospectively the mass lesion was diagnosed as a hematoma that had perforated into the cavum septi pellucidi at the time of the subarachnoid hemorrhage from the aneurysm. (author)