Unique image findings around "kissing" distal anterior cerebral artery aneurysms in addition to perianeurysmal edema: A case report.

Background: Some aneurysms cause edema formation in the surrounding brain parenchyma and are thought to reflect various phenomena occurring in the aneurysm. Some authors highlighted perianeurysmal edema (PAE) as a finding that indicates higher risk of rupture of the aneurysm. On the other hand, there are no reports of image changes in the surrounding brain parenchyma of aneurysm other than edema formation.

Case Description: We describe a 63-year-old man with unique signal change in the surrounding brain parenchyma of "kissing" distal anterior cerebral artery aneurysms completely different from PAE. The large and partially thrombosed aneurysm presented well-defined signal change surrounding brain parenchyma in addition to PAE. Intraoperative findings revealed the signal change as a space of retaining serous fluid. Drain the fluid and clipping was made for the both anterior cerebral artery aneurysms. The postoperative course was uneventful and his headache was improved the day after the surgery. The perianeurysmal signal change was also disappeared immediately after the surgery except for the PAE.

Conclusion: This case demonstrates a rare phenomenon of signal change around the aneurysm, and there is a possibility that the unique finding exists as an early manifestation of intracerebral hematoma associated with aneurysm rupture.