[Superficial siderosis of the CNS. 2 cases and a review of the literature].

Superficial siderosis of the CNS is a rare disease. The superficial deposition of haemosiderin in the cerebrum, cerebellum and spinal cord is due to chronic and recurrent subarachnoidal haemorrhage (SAH). Known sources of bleeding are vascular CNS-tumours, CSF-cavity lesions, vascular malformations, nerve root lesions and neurosurgical interventions. Detection of the source of bleeding is successful in only about 50% of cases. The clinical syndrome is characterized by sensorineural deafness, cerebellar ataxia and pyramidal signs. CSF-investigation might be indicative for SAH, while ferritin and ionic iron can be elevated in the CSF. CT is unspecific and insensitive but MR imaging of the brain and spinal cord is very sensitive and specific. The elimination of the source of bleeding alone might prevent the progression of the disease, therefore, an early and extensive search for this source is highly recommended.