Superficial siderosis of the central nervous system secondary to a thalamic hamartoma

A patient with radiologically evident superficial siderosis of the central nervous system secondary to a thalamic hamartoma is reported, Cerebral hama rtomas are rare, benign congenital lesions which when vascular can cause re peated subarachnoid haemorrhages, which results in deposition of iron (haem osiderin) in the leptomeninges and in the subpial layers of the brain and s pinal cord. Progressive sensorineural deafness and cerebellar ataxia, which are typical clinical manifestations of superficial siderosis, may then app ear. The importance of prompt diagnosis and treatment is highlighted. (C) 1 999 Harcourt Publishers Ltd.