Detection of Spinal Dural Defect in Superficial Siderosis by Intraoperative Ultrasonography

Superficial Siderosis: A Clinical Review

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 of the central nervous system with epilepsy originating from traumatic cervical injury: illustrative case

BACKGROUND

Superficial siderosis of the central nervous system (SSCNS) is a rare condition that results from hemosiderin deposition in the brain, brainstem, cerebellum, and spinal cord as a result of chronic, repeated, and recurrent subarachnoid hemorrhage. SSCNS that originates in the spinal cord is rarely reported, and epilepsy as a manifestation of such a case has not been reported before.

OBSERVATIONS

The authors reported a rare case of SSCNS with epilepsy originating from traumatic cervical injury and presented a literature review of all reported SSCNS cases that originated in the spine. The patient was a 29-year-old man with a 16-year history of progressive headache accompanied by seizures, ataxia, and sensorineural hearing loss. He had experienced a traumatic cervical injury at age 7. Magnetic resonance imaging revealed a characteristic hypointense rim around the pons and cervical spinal cord on susceptibility-weighted imaging scans. Cerebrospinal fluid examination during a headache episode confirmed subarachnoid hemorrhage and increased intracranial pressure. Surgical exploration revealed a C6 dural defect with bone spurs inserted into the dura mater. After the patient underwent dura mater repair and shunt implantation, his symptoms disappeared completely except for hearing loss.

LESSONS

This rare case indicated that symptomatic epilepsy followed by SSCNS can be eliminated by complete repair of the cervical dura mater.