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

Phrenic nerve paralysis and phrenic nerve reconstruction surgery

Phrenic nerve injury results in paralysis of the diaphragm muscle, the primary generator of an inspiratory effort, as well as a stabilizing muscle involved in postural control and spinal alignment. Unilateral deficits often result in exertional dyspnea, orthopnea, and sleep-disordered breathing, whereas oxygen or ventilator dependency can occur with bilateral paralysis. Common etiologies of phrenic injuries include cervical trauma, iatrogenic injury in the neck or chest, and neuralgic amyotrophy. Many patients have no identifiable etiology and are considered to have idiopathic paralysis. Diagnostic evaluation requires radiographic and pulmonary function testing, as well as electrodiagnostic assessment to quantitate the nerve deficit and determine the extent of denervation atrophy. Treatment for symptomatic diaphragm paralysis has traditionally been limited. Medical therapies and nocturnal positive airway pressure may provide some benefit. Surgical repair of the nerve injury to restore functional diaphragmatic activity, termed phrenic nerve reconstruction, is a safe and effective alternative to static repositioning of the diaphragm (diaphragm plication), in properly selected patients. Phrenic nerve reconstruction has increasingly become a standard surgical treatment for diaphragm paralysis due to phrenic nerve injury. A multidisciplinary approach at specialty referral centers combining diagnostic evaluation, surgical treatment, and rehabilitation is required to achieve optimal long-term outcomes.

Late-Onset Post-Traumatic Spinal Cord Herniation as a Rare and Overlooked Cause of Late Neurologic Deterioration After Penetrating Injury to the Thoracic Spine: A Case Report and Review of the Literature

BACKGROUND AND CASE DESCRIPTION

We report a case of an 18-year-old patient who presented with late progressive deterioration of neurologic condition 8 weeks after a penetrating injury to the back. Investigations revealed a dorsally located post-traumatic spinal cord herniation. Urgent exploration, decompression, and repair were performed. We reviewed the literature and found only 19 similar cases previously reported. Pathophysiology and presentations were variable and even poorly understood.

CONCLUSIONS

Late-onset post-traumatic spinal cord herniation is a potentially curable cause of neurologic deterioration after spinal trauma and should be considered in all cases with late neurologic deterioration after spinal trauma.

Radiological data of brachial plexus avulsion injury associated spinal cord herniation (BPAI-SCH) and comparison to anterior thoracic spinal cord herniation (ATSCH)

Spinal cord herniation (SCH) is a rare cause of myelopathy. When reported, SCH has most commonly been described as occurring spontaneously in the thoracic spine, and being idiopathic in nature (anterior thoracic spinal cord herniation, ATSCH) [1–3]. Several theories have been proposed to explain its occurrence, including congenital, inflammatory, and traumatic etiologies alike [1–4]. Even more rarely, SCH has been described to occur in the cervical spine in association with brachial plexus avulsion injuries (BPAI-SCH). In our accompanying article, “Late Cervical Spinal Cord Herniation Resulting from Post-Traumatic Brachial Plexus Avulsion Injury,” two cases of BPAI-SCH are presented and discussed in the context of the reviewed literature [5]. Here, pertinent accompanying follow-up data was collected and is presented for the cases, including postoperative radiographic outcome imaging. Furthermore, a table is presented comparing and contrasting ATSCH to BPAI-SCH. Although the two phenomena have been previously grouped together, this table highlights ATSCH and BPAI-SCH as distinct entities; more specifically, BPAI-SCH is a separate, long-term complicating feature of BPAI. This supplementary data helps treating physicians by increasing awareness and knowledge of BPAI-SCH as a distinct entity from ATSCH and cause of delayed neurological deterioration.

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Myelopathy due to spinal cord herniation (SCH) is rare.

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Brachial plexus avulsion injury associated SCH (BPAI-SCH) is a unique type of SCH.

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Follow-up data for a case of BPAI-SCH treatment is presented.

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BPAI-SCH is compared and contrasted with more common SCH subtypes.

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BPAI-SCH recognition and treatment is essential for patient improvement.