Spinal cord herniation into associated pseudomeningocele after brachial plexus avulsion injury: case report.

Objective: Posttraumatic spinal cord herniation is a rare condition. We describe a case of spinal cord herniation into an associated pseudomeningocele after a brachial plexus avulsion injury.

Clinical Presentation: A 33-year-old man began to develop progressive Horner's syndrome 14 years after a brachial plexus avulsion injury. At a clinical presentation 17 years after that injury, sensory disturbance and a unilateral pyramidal sign were also evident. In addition to myelography and computed tomographic myelography findings, coronal magnetic resonance imaging scans clearly demonstrated herniation of the spinal cord into a large pseudomeningocele inside the C7-T1 intervertebral foramen. Another pseudomeningocele inside the T1-T2 intervertebral foramen was also noted.

Intervention: The patient underwent a C6-T2 laminectomy, during which the spinal cord was found to be herniated through a dural defect into a pseudomeningocele at the C8 root level, and a second dural defect was also shown, with an arachnoid outpouching that included an avulsed T1 root. The spinal cord herniation was reduced and the dural defects were repaired. After surgery, the patient showed no significant neurological changes, and his condition stabilized.

Conclusion: Brachial plexus root avulsions may result in the formation of pseudomeningoceles and can lead to spinal cord herniation. Coronal magnetic resonance imaging is useful to demonstrate spinal cord herniation as well as pseudomeningoceles. Surgical treatment is recommended for such cases with progressive symptoms to prevent further deterioration.