Association of superficial siderosis of the central nervous system and low pressure headache: a case report

Superficial siderosis is a rare condition caused by deposition of haemosiderin in the central nervous system (CNS) due to repeated chronic or slow sub-arachnoid or intraventricular haemorraghe.

We report a case of a 59- year old man with a three year history of progressive unsteady gait, limb incoordination and slurred speech associated with hearing loss. Additionally he had been suffering from posturally depended headaches for the last 10 years. Clinical examination showed a cerebellar syndrome with predominant ataxia and oculomotor signs. There were no signs of metabolic disease such as hypothyroidism, celiac disease, mitochondrial disease, or paraneoplastic cerebellar degeneration. Cerebrospinal fluid (CSF) examination revealed low CSF pressure with mild xanthochromia and blood-brain barrier disturbance. Additionally, high levels of transferring and ferritin were found in the CSF. T2*-weighted MRI sequences demonstrated a dark, hypointensive rim on the cerebellum and brainstem, which was identified as haemosiderin deposition so the diagnosis of superficial siderosis of the CNS could be made. A bleeding source causing the haemosiderin deposition could not be identified by digital substraction angiography of the head and spine. For further investigation a dynamic myelography was performed which identified a fluid filled epidural cavity ventral to the spinal cord, reaching from C5 to T6 with dorsomedial disc herniation right below the fluid filled cavity. However, the exact site of the CSF leakage could not be identified. Upon disc surgery, intradural inspection showed no dural lesion, but instead two circumscribed ventral adhesions were found between the pial surface of the medulla and the adjacent dura exactly at the level of the herniated disc. After microsurgical exstirpation of the herniated disc and adjacent dural coverage the postural headache completely subsided.

We suggest that CSF leakage resulting in the clinical picture of low pressure headache can cause chronic bleeding into the CSF leading to a superficial siderosis of the CNS. In our case a disc herniation was thought to be the place of CSF leakage. Whether the intervention can stop the progression of the superficial siderosis remains to be shown.