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

Abstract

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.

Keywords

• Pseudoaneurysm
• Minor leak
• Coil embolization
• Oculomotor palsy