Distal intracranial artery pseudoaneurysm causing subdural hematoma: An illustrative case and a systematic review.

[BACKGROUND] Pseudoaneurysm arising from the distal segment of an intracranial artery is a rare cause of subdural hematoma (SDH). We report a patient diagnosed with a pseudoaneurysm of a cortical branch of the distal anterior cerebral artery (ACA) during planned middle meningeal artery embolization for SDH and present a systematic review to summarize the present literature.

[METHODS] A systematic literature search was conducted across EMBASE, MEDLINE, CINAHL, the Cochrane Library, and Scopus to identify studies reporting SDH due to pseudoaneurysms in the terminal intracranial artery segments. Details regarding clinical presentation, management, and outcomes were extracted.

[RESULTS] Twenty patients from the 18 retrospective studies and the patient from the present report were included in the review. The mean age of the patients was 49.4 years; 80.9% of the patients were males. A history of nonpenetrating head trauma was present in 11 (52.4%) patients. The most common presenting symptoms were hemiparesis and altered mental status. Catheter angiography established the diagnosis in the majority of the patients (85.7%). Angiography was performed due to a clinical/radiological suspicion for a pseudoaneurysm in 6 (28.5%) patients. In the majority of the patients (66.7%), angiography was performed for a different indication. Middle cerebral artery (15 patients, 71.4%) was the most common location of the pseudoaneurysm, followed by ACA, posterior cerebral artery, and posterior inferior cerebellar artery. Pseudoaneurysm was treated surgically in 14 patients (66.7%) and by endovascular modalities in 5 patients (23.8%). One patient undergoing endovascular treatment required surgical evacuation of SDH. The majority of the patients in both treatment groups (surgical - 72.7%, endovascular - 80%) recovered without severe disability (modified Rankin Scale ≤ 4).

[CONCLUSION] Pseudoaneurysms of distal segments of intracranial arteries are a very rare cause of SDH. A high index of suspicion is required for their identification. While a definitive diagnosis requires catheter angiography, indications to perform angiography in SDH are unclear. Pseudoaneurysms with SDH can be treated safely with both microsurgical and endovascular modalities. Microsurgery has the advantage of draining SDH at the same time. The relative efficacy of different treatment approaches and the indications for each are not yet defined.