Superficial siderosis of the central nervous system associated with incomplete dural closure following posterior fossa surgery: report of 3 cases.

This report reviews a series of 3 patients who developed superficial siderosis following posterior fossa operations in which dural closure was incomplete. In all 3 patients, revision surgery and complete duraplasty was performed to halt the progression of superficial siderosis. Following surgery, 2 patients experienced resolution of their CSF xanthochromia while 1 patient had reduced CSF xanthochromia. In this paper the authors also review the etiology, pathophysiology, diagnosis, and treatment of this condition. The authors suggest that posterior fossa dural patency and pseudomeningocele are risk factors for the latent development of superficial siderosis and recommend that revision duraplasty be performed in patients with posterior fossa pseudomeningoceles and superficial siderosis to prevent progression of the disease.

CSF tau protein is a useful marker for effective treatment of superficial siderosis of the central nervous system: two case reports.

We report two cases of superficial siderosis (SS) of the central nervous system (CNS), which is caused by chronic haemorrhaging into the subarachnoid space with haemosiderin deposition in the superficial portion of the CNS. Patient 1 had fluid collection in the spinal canal, which was reported as the source of the chronic bleeding. Patient 2 was bleeding from thickened dura at the level of the sacral vertebrae. Both of the patients had xanthochromic cerebrospinal fluid. We surgically repaired the sources of bleeding. Subsequently the cerebrospinal fluid (CSF) cleared and their symptoms were not aggravated for about 1 year. We measured several CSF markers of SS before and after surgery. Total tau protein (CSF-t-tau), phosphorylated tau protein (CSF-p-tau), iron (CSF-iron) and ferritin (CSF-ferritin) in the CSF were highly elevated at diagnosis. After surgery, the levels of CSF-t-tau and CSF-p-tau were markedly reduced while CSF-iron and CSF-ferritin had not decreased. It is suggested that CSF-t-tau and CSF-p-tau reflected the neural damage in SS and were useful to evaluate the effectiveness of SS therapies.

Superficial siderosis.

BACKGROUND: Superficial siderosis (SS) of the CNS is caused by repeated slow hemorrhage into the subarachnoid space with resultant hemosiderin deposition in the subpial layers of the brain and spinal cord. Despite extensive investigations, the cause of bleeding is frequently undetermined. OBJECTIVES: To review the clinical and imaging features of 30 consecutive patients with SS and provide insights into the underlying causes of subarachnoid bleeding in this disabling disorder. METHODS: The authors reviewed the medical records of 30 consecutive patients with clinical and MRI evidence of SS. RESULTS: The commonest neurologic manifestations included gait ataxia and hearing impairment. A clinical history of subarachnoid hemorrhage was relatively rare. Possible predisposing conditions were identified on history in 22 patients, the commonest being a prior trauma (15 patients). In addition to the characteristic MRI findings of SS, 18 patients had abnormalities on MRI possibly related to chronic bleeding. The most common of these was the presence of a fluid-filled collection in the spinal canal seen in 14 patients. CONCLUSIONS: 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.

Spinal meningeal melanocytoma presenting with superficial siderosis of the central nervous system. Case report and review of the literature.

Meningeal melanocytoma is a benign melanocytic tumor that originates most frequently from the melanocytes in the posterior fossa or along the spinal cord. This tumor generally occurs as an extraaxial mass that compresses adjacent neural structures to produce various neurological signs. The authors describe an unusual case in which a patient with a meningeal melanocytoma located at the thoracic spinal cord presented with superficial siderosis of the central nervous system (CNS). Extensive neuroradiological studies identified the presence of a spinal cord tumor, and postsurgical histological examination revealed the meningeal melanocytoma as a bleeding source. After surgery, lumbar puncture demonstrated normalization of the patient's cerebrospinal fluid; however, no neurological improvement occurred. The neurological deficits seem irreversible. Meningeal melanocytoma is biologically benign and can be cured by complete surgical resection; therefore, this tumor should be included in the differential diagnosis of pigmented lesions of the CNS. The authors reviewed 14 cases of well-documented meningeal melanocytoma in the literature and discuss the clinical, radiological, and pathological features of the present case to emphasize the importance of early diagnosis and identification of the source of bleeding in patients with superficial siderosis.

Superficial siderosis of the brain: roles for cerebrospinal fluid circulation, iron and the hydroxyl radical.

Superficial siderosis is associated with chronic blood loss into the cerebrospinal fluid. The pattern of hemosiderin deposition and clinical signs in superficial siderosis suggest that cerebrospinal fluid is recirculated into the ventricular system. Patterns of deposition of corpora amylacea and findings in normopressure communicating hydrocephalus also support the recirculation theory. 'Free' iron with excess production of hydroxyl radicals is the probable mechanism of tissue damage. The arachnoid villus-superior saggital sinus theory of cerebrospinal fluid circulation should be abandoned.

Superficial siderosis of the central nervous system: report of three cases and review of the literature.

We present 3 cases and a review of the literature to demonstrate the current state of clinical diagnosis and therapy of superficial siderosis of the central nervous system. Typical symptoms were progressive cerebellar ataxia, spasticity and hearing loss. Repeated subarachnoid hemorrhage was indicated by persistent xanthochromia of the cerebrospinal fluid and confirmed by the presence of erythrophages, siderophages and iron-containing pigments. Deposition of free iron and hemosiderin in pial and subpial structures leads to intoxication of the central nervous system and represents the pathophysiological mechanism of superficial siderosis. Hypointensity of the marginal zones of the central nervous system on T2 weighted MR images indicates an iron-induced susceptibility effect and seems pathognomonic for superficial siderosis. In 39 of the 43 previously described cases superficial siderosis was verified by biopsy or autopsy. Today magnetic resonance imaging enables diagnosis at an early stage of the disease. Therapeutic management requires the elimination of any potential source of bleeding. In patients with unknown etiology no proofed therapy is yet available.