Superficial siderosis

Abstract

A history of prior subarachnoid hemorrhage is often absent in patients with superficial siderosis (SS). A past history of trauma is common. Prior intradural surgery may be an additional risk factor. Xanthochromia or the presence of red blood cells in the CSF is a common finding. Only rarely does angiography demonstrate the bleeding source. The presence of a fluid-filled collection in the spinal canal is a common finding on MRI and is likely related to the SS. With longitudinally extensive cavities, a dynamic CT myelogram may help localize the defect and direct the site of laminectomy. Surgical repair of a dural defect, if present, should be considered. Surgical correction of bleeding should be documented by CSF examination months after surgery. Friable vessels in the dural defect are a possible source of the chronic bleeding.