Superficial siderosis of central nervous system mimicking multiple sclerosis

Superficial siderosis of the central nervous system is a neurologic disorder mainly characterized by cerebellar involvement, myelopathy, neurosensory hearing loss, and possibly progressive cognitive impairment. Root avulsion due to traumatic plexus injury has been recognized as an extremely rare cause of hemosiderin deposition on leptomeninges and subpial layers of brain and spinal cord parenchyma.

A 49-year-old man presented with progressively evolving ataxia and spastic paraparesis. CSF oligoclonal bands were indicative of an underlying inflammatory process and raised the possibility of a demyelinating disorder. However, spinal cord and brain MRI revealed hemosiderin deposition along the entire neuraxis. A rigorous electrophysiologic study confirmed a functional impairment in many different levels of the nervous system.

The demonstration of CSF oligoclonal bands in the reported patient implies that inflammation might be involved in the pathogenesis of superficial siderosis. The diagnosis of this newly recognizable entity needs a high clinical suspicion, but further research is needed to fully elucidate the involved mechanisms.