Superficial siderosis of the central nervous system.

We report five cases of superficial siderosis of the central nervous system. All patients developed progressive deafness and cerebellar ataxia associated with pyramidal tract signs or mental deterioration. The cerebrospinal fluid examinations usually revealed an elevated protein level, without other abnormalities. Magnetic resonance imaging typically showed a hypointense rim around the cerebral and cerebellar hemispheres, the brainstem and the spinal cord on T2-weighted images. A definite source of bleeding was only found in two patients. The literature on superficial siderosis is reviewed. The etiologies and the pathogenesis are discussed.