Transdural Spinal Cord Herniation: Tips and Tricks

Transdural spinal cord herniation: A rare cause of neurologic impairment: Report of two cases and review of the literature

Introduction

Herniation of the thoracic spinal cord is a rare pathology related to the genesis of a breach in the anterior dura. Adding to the previously published cases, we report our department's experience with 2 cases of young adults who presented with transdural spinal cord herniation following spinal trauma.

Presentation of the cases

We report the cases of 2 men aged 27 and 57, with history of spinal trauma, who presented diverse clinical complaints (motor impairment, genito-sphincteric disorders, etc.). Spinal cord MRI showed an anterior displacement of the spinal cord. Both patients were operated. Peroperative findings and radiological features were concordant with transdural spinal cord herniation.

Discussion

Spinal cord herniation is a rare condition which is usually related to a misdiagnosed spinal trauma. Pathogenesis is still being debated. This condition may lead to a myelopathy potentially responsible for severe neurologic impairment, mainly presenting as a Brown-Sequard syndrome. Diagnosis is based on clinical and radiologic features on MRI. Surgical treatment is proposed when neurological signs are found. Long-term clinical and radiological monitoring is necessary for paucisymptomatic, non-operated patients.

Conclusions

Based on the described cases, we tried to review the main clinical, radiological and therapeutic features related to this condition.

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Herniation of the thoracic spinal cord is due to a breach in the anterior dura of an uncertain pathogenesis

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Transdural spinal cord herniation is a little known cause for myelopathy potentially responsible for severe neurologic impairment

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Main clinical features are related to a Brown-Sequard syndrome

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In symptomatic cases, surgical treatment may stabilize or even improve neurologic impairment

Late Cervical Spinal Cord Herniation Resulting from Post-Traumatic Brachial Plexus Avulsion Injury

BACKGROUND

Spinal cord herniation (SCH) is often described as occurring spontaneously in the thoracic spine, with few cases of cervical SCH reported as a late complication of traumatic brachial plexus avulsion. We present 2 cases of nerve root avulsion and pseudomeningocele formation, resulting in delayed cervical SCH and neurologic deterioration.

CASE DESCRIPTION

Case 1: A 37-year old man presented with progressive leg weakness 2 years after experiencing traumatic C8 and T1 root avulsions. Magnetic resonance imaging (MRI) showed previously documented C8-T1 nerve avulsions with new SCH in a T1 pseudomeningocele. A C7-T1 costotransversectomy and C4-T4 instrumented fusion were completed, allowing SCH reduction and patch graft repair of the dural defects without the need for adhesiolysis. At last follow-up, the patient's leg weakness had resolved. Case 2: A 32-year old man presented with progressive right arm numbness, weakness, and signs of myelopathy 9 years after experiencing C8 and T1 root avulsions. MRI showed previously documented root avulsions and new SCH with extensive and compressive pseudomeningocele formation. A C7 transpedicular approach with C5-T1 instrumented fusion was completed for dural repair. A large pseudomeningocele was found and drained on drilling the C7 pedicle, and adhesiolysis was required at the spinal cord avulsion site to reduce the SCH and allow patch graft repair. At last follow-up, the patient's right arm weakness was improving, although numbness persisted.

CONCLUSIONS

SCH is a rare cause of delayed neurologic deterioration after brachial plexus avulsion, with few case reports describing its occurrence. We present 2 cases of this complication and describe its successful surgical treatment through dural repair after instrumented fusion.