"Plugged" Anterior Inferior Cerebellar Artery Aneurysm Causing Facial Palsy, Hearing Loss, and Subarachnoid Hemorrhage Treated by a Translabyrinthine Approach.

Buqing Liang,Ethan A Benardete,Thomas Brammeier,Jason Huang

doi:10.7759/cureus.12282

Abstract

Anterior inferior cerebellar artery (AICA) aneurysms are rare, less than 1%-2% of all intracranial aneurysms. Aneurysms of the distal AICA are even less common and can present with hearing loss and facial paralysis because of their relationship with the internal auditory canal (IAC). A 65-year-old male was followed for fluctuating left facial weakness and left-sided hearing loss for over a year. Serial magnetic resonance imaging (MRI) scans showed a mass near the left IAC, thought to be a vestibular schwannoma. Just prior to his next clinic visit, the patient deteriorated suddenly from a subarachnoid hemorrhage. Cerebral angiography revealed a 5.5 mm saccular aneurysm at the distal left AICA, which was clip ligated via a translabyrinthine (TL) approach. The patient had a good functional outcome (modified Rankin Scale [mRS] 1) after 30 days despite persistent left facial weakness. Stable obliteration of the aneurysm was demonstrated by cerebral angiography postoperatively. Distal AICA aneurysms are rare and can have a similar presentation to tumors in the cerebellar pontine angle. Because of the unique anatomy of the distal AICA, open clip ligation via a TL approach is an effective method to secure these aneurysms.

Highlights

Anterior inferior cerebellar artery (AICA) aneurysms are rare and comprise less than 1%-2% of all intracranial aneurysms [1,2,3,4,5,6]
We describe a patient who presented with acute facial weakness and hearing loss and was found to have a mass in the internal auditory canal (IAC), thought to be a small vestibular schwannoma (VS), a common cause of hearing loss
Much later, when the patient suffered a subarachnoid hemorrhage (SAH), it became clear that the lesion was a distal AICA aneurysm

Summary

Introduction

Anterior inferior cerebellar artery (AICA) aneurysms are rare and comprise less than 1%-2% of all intracranial aneurysms [1,2,3,4,5,6]. MRI, Magnetic resonance imaging; IAC, internal auditory canal; SAH, subarachnoid hemorrhage One week before his scheduled clinic follow-up, the patient was found unconscious at home (Hunt and Hess Grade 4). An external ventricular drain was placed, and digital subtraction angiography (DSA) revealed a saccular left distal AICA aneurysm measuring 5.5 mm x 3 mm x 3 mm with a wide neck (Figure 3). Follow-up DSA revealed total occlusion of the aneurysm with patent proximal AICA and distal AICA filling retrograde from collaterals (Figure 3). During his ICU stay, the patient was extubated, weaned from ventricular drainage, and returned to normal consciousness and full strength except for persistent left facial weakness. His left facial nerve paralysis persisted at one-year follow-up (House-Brackmann V)

Discussion

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