Idiopathic spinal cord herniation: Clinical review and report of three cases

Abstract

Idiopathic spinal cord herniation (ISCH) is a rare condition, of unknown pathogenesis, that primarily affects the thoracic spinal cord. It is characterized by ventral displacement of the spinal cord through a dural defect. The aim of this study was to review the literature and to present a retrospective single center experience with three cases of ISCH. The literature review analyzed a total of 78 relevant publications on ISCH, which included a total of 171 patients, supplemented with 3 patients treated at our institution. Numerous case reports have demonstrated improvement in clinical outcomes after surgery; however, follow-up is predominantly short, data are incomplete, the condition is frequently misdiagnosed, and it is difficult to predict which patients will benefit from surgery. We identified 159 cases treated with surgical management. The mean symptom duration was 54 months, and the mean follow-up 33 months. The result at follow-up was improved neurological outcome in 74%, unchanged result in 18%, and worse outcome in 8%. There were 15 cases of conservative management, with mean symptom duration 52 months and mean follow-up 33 months. The neurological outcome was unchanged in 100%. ISCH is a rare condition causing progressive thoracic myelopathy, and the natural history is unknown. There is a lack of evidence-based treatment strategies, and the majority of cases are treated with surgical management at diagnosis. Management of ISCH needs to be individualized for each patient, and clinicians should be encouraged to report new cases, standardize case reports, and ensure long-term follow-up.

Idiopathic spinal cord herniation of the cervical cord: unusual cause of proximal muscle weakness in upper limbs

“…ISCH is a recognised cause of progressive myelopathy with reported incidence of <200 cases, almost exclusively involving the thoracic spine 3. It most commonly presents as Brown-Sequard syndrome 4.…”

“…This condition was first described in 1974 by Wortzman et al 1. Around 170 cases of ISCH have been described in the literature, and all these lesions were found in the thoracic spine with the majority between the T2 and T8 vertebrae 2 3…”

Spontaneous resolution of idiopathic thoracic spinal cord herniation: case report

“…8,10 In a series of 12 patients with spinal cord herniation, 50% of the patients attained postoperative clinical improvement; however, a more recent review of 159 cases in the literature suggested a symptom improvement rate of 74% of patients. 12 Although the majority of studies have reported favorable outcomes in patients with spinal cord herniation syndromes, long-term follow-up of surgically managed patients is warranted to assess postoperative course and complications such as the recurrence of ventral cord tethering, concentric scarring, and cord swelling, which have been documented in a number of studies. 1 In cases where the condition is not clinically or radiologically progressive, conservative management has been encouraged.…”

“…1 Presently, no evidence-based guidelines on the optimal treatment modalities for spinal cord herniation exist, and patient management has been largely individualized. 12 Although the majority of patients are treated with surgical measures, precise predictive algorithms to identify patients who would benefit from surgery are lacking.…”

“…5 On axial MRI, nerve roots in the dorsal subarachnoid space are visible in spinal cord herniation, whereas nerve roots at the periphery of the cyst are visible in dorsal arachnoid cysts. 12 Computed tomography myelography is an additional imaging modality that can be used to distinguish between spinal cord herniation and subarachnoid cysts as it allows visualization of the precise relationship of the spinal cord to the ventral dura. Surgical intervention with the intent of freeing the spinal cord and repairing the dural defect has been shown to stabilize or improve neurological symptoms.…”