Lumbar Subarachnoid-Peritoneal Shunting Deteriorates Superficial Siderosis Associated with a Dural Defect.

Superficial siderosis is a disease in which hemosiderin is deposited under the leptomeninges and subpial layers of hindbrain structures, e.g., the cerebellum, brainstem, and eighth cranial nerve. The main symptoms of superficial siderosis are cerebellar ataxia, hearing loss, cognitive decline, and myelopathy. The activities of daily living of patients with superficial siderosis are severely impaired due to the progressive symptoms. Here, we report a patient with superficial siderosis whose symptoms deteriorated after lumbar subarachnoid-peritoneal (L-P) shunt surgery. She received L-P shunt surgery based on the diagnosis of idiopathic normal pressure hydrocephalus at another hospital. The patient had a history of cervical surgery, and a dural defect was identified at the C4-5 level by a detailed magnetic resonance imaging study. We hypothesized that the L-P shunt reduced cerebrospinal pressure and increased bleeding from the fragile vessels in the dural defect, which might have increased hemosiderin deposition.