Superficial siderosis of the central nervous system many years after neurosurgical procedures.(Short Report)

Recurrent haemorrhage into the subarachnoid space causes superficial siderosis, which clinically manifests as cerebellar ataxia, sensorineural hearing loss, and myelopathy. Two patients developed clinical, radiological, and biochemical evidence of superficial siderosis many years after surgery. One had two posterior fossa operations, a left temporal craniectomy, and radiotherapy for a presumed brain tumour before developing clinical evidence of superficial sidersosis 37 years later. The other had small bilateral subdural collections from recurrent shunt revisions following posterior fossa surgery for a Chiari malformation, and then developed deafness and ataxia. The first patient currently has the longest recorded delay between presumed subarachnoid bleeding and clinical manifestations of superficial siderosis. Both patients provide further evidence that superficial siderosis of the central nervous system, a progressive neurodegenerative vascular condition, may be a delayed complication of neurosurgical procedures.

Recurrent or persistent haemorrhage into the subarachnoid space causes superficial siderosis of the central nervous system (CNS). This rare condition results in the triad of cerebellar ataxia, sensorineural hearing loss, and a myelopathy. (1) The diagnosis has only been made during life since 1965. An abundance of microglia and Bergmann glia in the molecular layer of the cerebellum, and susceptible glial ensheathment of the eighth cranial nerve are thought to account for the prominence of ataxia and deafness in superficial siderosis. (2) The usual sources of the subarachnoid bleeding are dural abnormalities, vascular lesions, and tumours. (3-6) Nowadays the diagnosis can be confirmed with magnetic resonance imaging (MRI) of brain, which provides evidence of haemosiderin in the form of a rim of hypointensity around the brain stem on T2 weighted images. (1)

We report two patients who each had had several neurosurgical procedures and in whom the delay in symptom onset followed by a slowly progressive course eventually led to the diagnosis of superficial siderosis of the CNS.

CASE REPORTS Case 1

An eight year old boy presented in June 1962 with a four month history of right sided incoordination. An exploratory …