Spinal Cord Herniation: Why Anterior Thoracic?

Abstract

Background: Spinal cord herniation and thoracic anterior adhesion syndrome make up the two extremes of a rare condition; characterized by anterior dural adhesion or protrusion of the spinal cord through the arachnoideal and dural membrane into the extradural space, respectively. Summary:We present the main features of the condition by our case series and forward a hypothesis for the consistent anterior, mid-thoracic localization. We surmise the role of an anterior pulling force by the Hofmann (meningo-vertebral) ligaments; acting when the physiologic thoracic kyphosis suddenly increases. The traction may tear the anterior dura; resulting in a dural defect; it allows the nipping/ protrusion of the spinal cord. Key messages:Because the spinal cord compression syndrome caused by adhesion or herniation of the spinal cord may be surgically treatable; the recognition of the condition is essential. The pathogenetic traction effect of the Hofmann ligament in the affected level may have surgical an prognostic implications.

Pathophysiology and Grading of the Ventral Displacement of Dorsal Spinal Cord Spectrum

“…Despite several studies being conducted, the pathogenesis of these conditions still remains unclear. One study reports that the traction force generated by the anteriorly-placed Hoffman ligaments along with normal physiological kyphosis with normal ventral motion secondary to cardiac pulsations and pulmonary actions at that level, and the biomechanical impact of flexion extension movements on the thoracic spinal cord tend to pull the cord, causing VDDSC and subsequently leading to cord adhesion and herniation (more commonly in the thoracic level) [ 2 5 10 ]. This keeps the cord in contact with the ventral dura.…”

“…Rarely, a persistent neuroenteric canal associated with anterior spina bifida, anterior meningomyeloceles, or dorsal neuroenteric cysts leads to varying severity of VDDSC; these are considered congenital causes of VDDSC [ 6 10 15 ].…”