Abstract
Mycotic intracranial aneurysms (MIAs) are rare infection-mediated arterial wall destructions that result in focal vessel weakness and dilatation. They commonly involve the anterior cerebral circulation, usually following hematogenous embolization from infective cardiac vegetation, and are associated with an elevated risk of rupture. MIAs arising from a posterior inferior cerebellar artery (PICA) are uncommon, and those resulting from contiguous infections are extremely rare. Here, we present a case report and review the literature on rare MIAs involving the distal PICA segment following meningitis after endoscopic endonasal transsphenoidal surgery. A 75-year-old man presented with a 2-year history of progressive visual impairment of the left eye, for which initial cranial magnetic resonance imaging suggested optic perineuritis ; however, conservative management with high-dose steroid therapy did not improve the patient's condition. He subsequently had biopsy, which confirmed an optic nerve sheath meningioma, for which optic nerve decompression via the endoscopic endonasal approach (EEA) and follow-up radiation therapy was done. He developed postoperative meningitis and subsequently had rupture of left PICA mycotic aneurysm (angiography done a month earlier demonstrated normal left PICA). Risk factors for meningitis were invasive cranial intervention, prolonged steroid use, and radiation therapy. Coil embolization was successfully performed ; however, the patient succumbed to irreversible herniation and infection. MIAs arising from the PICA following meningitis are rare, but complications following surgical intervention and rupture are associated with high morbidity and mortality. A high index of suspicion and early intervention before rupture may prevent poor outcomes.
