Thoracic idiopathic spinal cord herniation at the vertebral body level: a subgroup with a poor prognosis?

Abstract

<jats:p content-type="fine-print">✓ The authors present two cases of thoracic idiopathic spinal cord herniation (TISCH) occurring at the vertebral body (VB) level in whom adequate surgical reduction failed to reverse symptoms. In the second case, in which TISCH occurred into a VB cavity, presentation was atypical (subacute spinal cord syndrome) and there was persistent postoperative deterioration.</jats:p> <jats:p content-type="fine-print">In both cases, adequate surgical reduction was achieved via a posterior midthoracic laminectomy, and reduction was maintained by closure of the anterior dural defect by using prosthetic material.</jats:p> <jats:p content-type="fine-print">Thoracic idiopathic spinal cord herniation occurring at a VB level may be technically well treated by surgical reduction, but the outcome appears less predictable. Herniation that occurs directly into a VB cavity may form a distinct subgroup in which the presentation is atypical and the prognosis worse.</jats:p>

Thoracic spinal cord herniation in a patient with long-standing ankylosing spondylitis

“…ISCH was first reported by Wortzman et al [16] in 1974. It was well accepted that the presence of a dural defect is considered to be a necessary condition of SCH [17,18]. Najjar et al [19] proposed that an inflammation might lead to arachnoid adhesion formation and erosion through the dura forming an idiopathic dural defect and subsequent spinal cord herniation.…”

“…Recently, Barbagallo et al [18] described two cases with SCH at the vertebral body level, where the surgical outcome was poor. In particular, he hypothesized that vertebral body level SCH occurring into a vertebral body cavity may form a distinct subgroup with both an atypical presentation and a poor prognosis.…”

Idiopathic ventral spinal cord herniation: a rare presentation of tethered cord

“…These include enlargement of the ventral dural defect, 21,25,30,33,39,44,45 primary closure of the defect with sutures, 7,18,22 and insertion of a ventral patch for duraplasty. 4,6,11,13,23 In a recent literature review, Saito et al 33 found that approximately 20% of patients with primary ventral dural closure worsened clinically after surgery, compared with 10% of patients with dural patching or widening of the dural defect. This difference is attributed to the difficulty of suturing the ventral dura from a strictly dorsal approach without excessively retracting the spinal cord.…”

“…Several other authors have also described thoracic disc herniation producing an adjacent dural defect, with subsequent cord herniation at the level of the vertebral body and not at the disc level. 1,4,10,17,26 These patients are thought to have a worse prognosis. 4 Erosion of the dura by a herniated and calcified disc has been observed just caudal to the level of spinal cord tethering.…”

“…1,4,10,17,26 These patients are thought to have a worse prognosis. 4 Erosion of the dura by a herniated and calcified disc has been observed just caudal to the level of spinal cord tethering. 23,32 Although the theory of a thoracic disc causing ventral dural weakening with subsequent cord herniation is described often, the case reported by Miyaguchi et al 26 is the only one in the literature in which a herniated disc was visualized through the ventral dural defect at surgery.…”