A 85-year-old woman was accepted to our institute with complaints of a headache and vomiting after vertigo and left ear tinnitus. Computed tomography (CT) revealed subarachnoid hemorrhage ( Figure 1 ). CT angiography identified an aneurysm at meatal loop of the left anterior inferior cerebellar artery (AICA) (Figure 2) . A surgical trapping of aneurysm was performed via retrosigmoid craniectomy. The aneurysm was covered by thinned acoustic nerve and clot was found on the surface of the

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... which penetrated the nerve (Figure 3 ). Trapping was successfully performed (Figure 4 ). Postoperative course was uneventful except for left ear hearing loss. Figure 1: Axial computed tomography scan revealed thick subarachnoid hemorrhage in the left cerebellopontine angle. Lt.