Superficial Siderosis with Delayed Onset Post Syringopleural Shunting in a Later Anticoagulated Patient
Introduction and objective: Superficial siderosis of the posterior fossa and spinal cord has been most often reported following CSF cavity lesions, posterior fossa surgery, root avulsions, tumours (eg., ependymomas) and vascular anomalies. We report the first known case many years after syringopleural shunting while the patient was anticoagulated.
Methods / case history and examination: The patient presented with 12 months of progressive gait ataxia, bilateral leg weakness, lumbosacral pain and hearing impairment. Thirteen years previously, he had a syringopleural shunt placed for symptomatic idiopathic midthoracic syringomyelia. Since that procedure, unprovoked deep venous thrombosis via Factor V Leiden mutation had lead to a continuous need for warfarin.
Results / case investigations: MRI demonstrated T2 hypointense signal over the surface of the brain stem, cerebellar hemispheres and spinal cord consistent with siderosis, with no change in the known midthoracic syrinx. CSF showed xanthochromia, red blood cells, haemosiderin-laden macrophages and abnormally high levels of bilirubin and ferritin. MRI of the lumbar spine, cerebral angiography, MRA of the cord, CT of the chest and red cell scanning failed to find a bleeding mass or vascular anomaly to cause siderosis.
Discussion and conclusions: While siderosis has been reported following previous posterior fossa surgery, our case is the first known following shunting with a later need for anticoagulation. This potential complication, which can occur many years after neurosurgery, warrants recognition, and perhaps even monitoring in such patients who also develop a long-term need for anticoagulation.