Diffuse superficial siderosis of the central nervous system: four case reports and review of the literature

Introduction. Diffuse superficial siderosis of the central nervous system (CNS) is a rare condition due to hemosiderin deposits in the subpial layers of the brain and spinal cord. The source of chronic or recurrent bleeding into the subarachnoid space is detected in only 50 % of cases. The most characteristic symptoms are cerebellar ataxia and sensorineural hearing impairment. T-2 -weighted gradient echo magnetic resonance imaging constitutes the diagnostic method of choice. Case reports. We report four patients of diffuse superficial siderosis of the CNS associated to cerebral amyloid angiopathy, oral anticoagulation, schwannoma VIII, and without known source of bleeding in one case. Two patients developed cerebellar ataxia, three of them present transient focal neurological episodes, one dementia and, the last one, the diffuse superficial siderosis of the CNS is a radiological finding. No clinical progression was observed during follow-up (2-11 years) in three of them. The patient with cerebral amyloid angiopathy progresses to dementia. Conclusions. Transient focal neurological episodes were the most common symptom in our cases of diffuse superficial siderosis of the CNS. The natural history of this condition is not very known and may be regarded as a radiological finding.