Superficial Siderosis: A Clinical Review

Abstract

Superficial siderosis of the central nervous system results from subpial hemosiderin deposition due to chronic low‐grade bleeding into the subarachnoid space. The confluent and marginal subpial hemosiderin is best appreciated on iron‐sensitive magnetic resonance imaging sequences. With widespread use of magnetic resonance imaging, the disorder is increasingly being recognized, including in asymptomatic individuals. Gait ataxia, often with hearing impairment is a common clinical presentation. A clinical history of subarachnoid hemorrhage is generally not present. A macrovascular pathology is generally not causative. The most common etiology is dural disease, often dural tears. Prior or less commonly ongoing symptoms of craniospinal hypovolemia may be present. Common etiologies for dural tears include disc disease and trauma, including surgical trauma. Patients with dural tears due to herniated and calcified discs often have a ventral intraspinal fluid collection due to cerebrospinal fluid leak. A precise identification of the dural tear relies on multimodality imaging. It has been speculated that chronic bleeding from fragile blood vessels around the dural tear may be the likely underlying mechanism. Surgical correction of the bleeding source is a logical therapeutic strategy. Clinical outcomes are variable, although neuroimaging evidence of successful dural tear repair is noted. The currently available data regarding use of deferiprone in patients with superficial siderosis is insufficient to recommend its routine use in patients. ANN NEUROL 2021;89:1068–1079

Superficial siderosis associated with an iatrogenic posterior fossa dural leak identified on CT cisternography

“…Such defects are most frequently seen in the spine; they may be related to spontaneous ventral dural tears adjacent to spiculated osteophytes but can also be caused by trauma, surgery, and a variety of other etiologies. 2,5,7 Dynamic CT myelography and digital subtraction myelography can be used to localize such defects. 8,9 Dural defects can also occur in the posterior fossa, sometimes after surgery for tumors, Chiari malformation repair, or other procedures requiring incision of the dura.…”

“…The most common potentially treatable etiology for SS is a dural tear. 2 One recent report described three patients developing SS after posterior fossa surgery complicated by pseudomeningoceles. 3 All patients were found to have incomplete dural closure at surgery.…”

Classical infratentorial superficial siderosis of the central nervous system: pathophysiology, clinical features and management

“…Radicular pain may also occur. Bladder and bowel dysfunction can develop in severe disease, manifesting as neurogenic bladder, constipation, urinary or faecal incontinence and reduced sensation during micturition and defaecation 4 6 28…”

Superficial siderosis and nonobstructive hydrocephalus due to subependymoma in the ventricle: An illustrative case report

“…[ 8 ] Early detection of SS is important as SS causes irreversible symptoms. [ 6 , 12 , 13 ] However, the means for the early detection of SS in intraventricular tumor follow-up have not been established. Here, we present a case of subependymoma of the lateral ventricle.…”