Cognitive impairment in superficial siderosis of the central nervous system: a case report.

Superficial siderosis is a rare disease characterized by cerebellar ataxia and sensorineural deafness. So far, there are only few reports on cognitive dysfunctions associated with superficial siderosis. Using a comprehensive psychometric test battery, we describe the cognitive impairments in a 65-year-old woman fulfilling the clinical and magnetic resonance imaging criteria of superficial siderosis. The neuropsychological findings included deterioration of primary and episodic memory, behavioral and linguistic changes characterized by social disinhibition, and decreased verbal fluency. These findings may correspond to the "cerebellar cognitive affective syndrome" which was suggested to occur in patients with selective cerebellar lesions. Probable mechanisms leading to the characteristic cognitive impairment in superficial siderosis are discussed.