Trochlear nerve palsy associated with superficial siderosis of the central nervous system.

A 56-year-old man with superficial siderosis of the central nervous system (SSCN) presented with complaints of trochlear palsy, visual field defects, gait ataxia, and hearing loss. He had no history of trauma and there were no signs of tumors or aneurysms. T2-weighted magnetic resonance imaging demonstrated characteristic hypointensity in the meninges. We believe that SSCN should be added to the differential diagnosis of trochlear nerve palsy.