Superficial siderosis.

Case 1 An elderly patient presented with insidious onset of sensorineural hearing loss. The past history was unremarkable except for insidious onset of weakness of left lower limb. Physical examination revealed left hemiparesis with upgoing left plantar. Magnetic resonance imaging (MRI) of brain revealed a large flow void in the interpeduncular cistern suggestive of aneurysm arising from the top of the basilar artery. In addition, hypointense signal was noted (prominent on T2 and FLAIR images) on the surface of both cerebral hemispheres, the pons, cerebellar folia and medulla. The final diagnosis was superficial siderosis secondary to leaking basilar artery aneurysm [Figures 1 and 2].