Superficial siderosis of the central nervous system--diagnosis by magnetic resonance imaging.

Superficial siderosis of the central nervous system is a rare disorder characterized by the deposition of haemosiderin in the leptomeninges, cranial nerves and spinal cord. The clinical features include sensorineural deafness, ataxia and pyramidal tract signs. We describe two cases demonstrating the characteristic findings on magnetic resonance imaging of widespread peripheral low signal on T2-weighted images.