A case of progressing pseudoaneurysm formation after intermittent minor leak from an aneurysm

• Main Authors: Hiroyuki Matsumoto, Daisuke Izawa, Hirokazu Nishiyama, Naotsugu Toki
• Format: Article
• Language: English
• Published: Elsevier 2021-09-01
• Series: Interdisciplinary Neurosurgery
• Subjects: Pseudoaneurysm; Minor leak; Coil embolization; Oculomotor palsy
• Online Access: http://www.sciencedirect.com/science/article/pii/S2214751921001043

Background: Intracranial pseudoaneurysm formation due to a ruptured aneurysm is rare. We present a rare case of a pseudoaneurysm that likely formed after an intermittent minor leak from a cerebral aneurysm and caused hemiparesis and oculomotor nerve palsy as a mass effect sign. Case description: An 88-year-old woman presented with left hemiparesis and right oculomotor palsy, which had gradually progressed for 6 months. Imaging findings revealed that the mass lesion extended from the right suprasellar cistern to the right cerebral peduncle. Angiography demonstrated a saccular true aneurysm on the right internal carotid artery, and contrast medium was leaking from a portion of the aneurysmal dome. The mass lesion was speculated to be a partially thrombosed pseudoaneurysm and treated with coil embolization for a true aneurysm. The pseudoaneurysm gradually diminished and disappeared 6 months after coil embolization, and the symptoms also completely improved. Conclusion: In this case, intermittent minor leaks may have had some effect on the formation and growth of the pseudoaneurysm.