Superficial Siderosis

Abstract

Superficial siderosis (SS) is a rare, neurodegenerative disease that results from toxic accumulation of hemosiderin on the surface of the brain and spinal cord. The Japanese guidelines for diagnosis and classification of SS have been classified into three categories, according to the distribution of iron deposition and the clinical symptoms, as follows: "classical" type, "localized" type and "atypical" type. In "classical" type SS, patients typically present with slowly progressive and irreversible cerebellar ataxia, sensorineural hearing loss, and/or myelopathy, due to involvement of the acoustic nerve, cerebellum, and spinal cord. T2-weighted imaging (WI) or T2^* WI demonstrates characteristic linear low intensity signals along the surface of the brain and spinal cord. However, the natural history and clinical evolution of SS are poorly understood. Furthermore identification and resolution of the bleeding source do not elicit prompt clinical recovery or radiological reversal of SS in most cases. Pharmacological treatments for SS primarily include strategies that produce iron chelation. For example, deferiprone is the only treatment that crosses the blood-brain barrier and binds hemosiderin in the central nervous system.