Superficial Siderosis : Importance of Susceptibility MRI Imaging

Key Points of Superficial Siderosis:

• ​It is due to hemosiderin deposition in the subpial layers of the brain and spinal cord.
  
• The hemosiderin deposition is a consequence of recurrent and persistent bleeding into the subarachnoid space.
  
• The classic clinical presentation of SS includes adult-onset slowly progressive gait (less commonly appendicular) ataxia with cerebellar dysarthria and sensorineural hearing impairment. The bleeding source may be not be detected despite extensive neuroimaging
  

Imaging Hallmarks:

• Ferritin and Hemosiderin deposits appear hypointense on T2W, blooms on GRE and SWI.
• Located around the cerebellum, brainstem, interhemispheric fissure, cortical sulci, basal cisterns, along cranial nerves II, V, VII, and VIII & spinal cord.
• Cerebellar and Spinal cord atrophy may present.

What next:

• Screen entire spine with MRI.
• The surgical treatment of SS depends on early identification of the bleeding source.
• CT myelogram, dynamic CT myelogram, or digital substraction myelogram can identify a dural defect.

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Reference: AJNR: Neuroimaging in Superficial Siderosis: An In-Depth Look