Spinal Cord Reperfusion Injury: Case Report, Review of the Literature, and Future Treatment Strategies

White Cord Syndrome After Cervical Laminoplasty in an 81-Year-Old Man

White cord syndrome (WCS) shows high intramedullary signaling in T2-weighted MRI with worsening motor nerve symptoms after cervical spinal decompression surgery. It has been reported in only 13 cases. An 81-year-old man had numbness, weakness, and impaired fine motor control in both upper limbs for the previous five years. C3, C4, C6, open-door laminoplasty, and C5 laminectomy were performed. Intraoperative transcranial motor evoked potential normalization by compound muscle action potential showed an 80% reduction in amplitude in the right abductor pollicis brevis and a 96% reduction in the right abductor hallucis. Tetraplegia occurred immediately after the operation. Magnetic resonance imaging (MRI) on the day after the operation showed intramedullary T2 high signals at the C4 and C5 levels. According to Brunnstrom's staging, the upper and lower right limbs and the lower left limb were at stage two, and the upper left limb was at stage three, six months after the operation. Thirteen cases of WCS have been reported in the literature. These were thought to be caused by reperfusion due to decompression.

Case report: Medulla oblongata and cervical cord reperfusion injury after intracranial vertebral artery angioplasty and stenting

Background

White cord syndrome is an uncommon complication characterized by delayed neurologic deterioration with no other identified cause after spinal decompression surgery. Its etiology is attributed to spinal cord reperfusion injury. Here, we present the first case of an extended version of white cord syndrome, with concomitant involvement of the medulla oblongata and cervical cord reperfusion injury after intracranial vertebral artery angioplasty and stenting.

Case presentation

A 56-year-old male suffered an ischemic stroke in the right anteromedial medulla oblongata. Angiography revealed bilateral vertebral artery stenosis in the intracranial segment. We performed elective left vertebral artery angioplasty and stenting. An intraoperative flow arrest in the left VA occurred and was stopped after the withdrawal of the catheter. Several hours after the operation, the patient developed occipital headache, back neck pain, dysarthria, and worsening left-sided hemiplegia. Magnetic resonance imaging revealed hyperintensity and swelling in the medulla oblongata and cervical cord, in addition to small medullary infarction. A digital subtraction angiography revealed intact vertebrobasilar arteries and patency of the left vertebral artery, left posterior inferior cerebellar artery, and implanted stent. We considered that the reperfusion injury had caused the complication. After treatment, the patient's symptoms and neurologic deficits greatly improved. He achieved a favorable outcome at the 1-year follow-up, with normal intensity restored in the medulla oblongata and cervical cord on magnetic resonance imaging.

Conclusion

Concomitant reperfusion injury in the medulla oblongata and cervical cord secondary to vertebral artery angioplasty and stenting is extremely rare. However, this potentially devastating complication requires early recognition and prompt treatment. Maintaining the antegrade flow during vertebral artery endovascular treatment is a precaution against reperfusion injury.

Late‑onset white cord syndrome following anterior cervical discectomy and fusion: A case report

White cord syndrome refers to an emerging neurological dysfunction occurring after spinal decompression surgery with hyperenhancing changes on T2-weighted magnetic resonance imaging (T2WI). The pathophysiological mechanism is hypothesized to be an ischemia-reperfusion injury following chronic ischemic spinal cord decompression. A 54-year-old man was admitted to Jinhua Municipal Central Hospital with complaints of numbness and weakness in the extremities and swelling in the neck. MRI showed degeneration and herniation of the C4-C7 intervertebral discs. The patient underwent anterior cervical corpectomy and fusion (ACCF). On the 7th postoperative day, the patient reappeared with weakness of the limbs. Physical examination revealed paralysis. Emergency MRI suggested T2 high signal myelopathy and emergency surgery was performed following the diagnosis of white cord syndrome. Following the operation, the patient's neurological system gradually improved. The motor ability and sensory function of the extremities recovered at 7-month follow-up. Spine surgeons should be aware of this serious complication. The present case serves to provide experience for clinical treatment and diagnosis and encourage research into its pathophysiology.

Cervical Spinal Cord Ischemic Reperfusion Injury: A Comprehensive Narrative Review of the Literature and Case Presentation

Cervical spinal ischemic reperfusion injury (CSIRI) refers to a state of sudden neurological deterioration after surgical spinal decompression. The CSCIRI refers to a state of sudden neurological deterioration after surgical spinal decompression. The pathophysiology is hypothesized to be due to instant relief of a chronically compressed spinal cord, leading to an inflammatory cascade named ischemic reperfusion injury. Deterioration of neurological function after cervical spine decompression surgery often occurs secondary to direct cord injury, compressing hematoma, or hardware failure. Complete loss of neurological function with no organic explanation is an extremely rare complication, with only a few cases reported in the literature. We are reporting a 67-year-old male patient diagnosed with severe cervical spinal canal stenosis at level C5/6 who underwent anterior cervical discectomy and fusion (ACDF). The patient developed complete transient loss of neurological functions after the surgery and was labeled as a case of CSCIRI after excluding compressing pathology. A literature review of the CSCIRI was carried out, and ten articles were included. Due to the rarity of these cases, there is no class 1 or 2 evidence to establish management protocol nor identifiable risk factors to predict their occurrence. However, we recommend using an intra-operative neurophysiology monitor in cases with long-standing severe cervical canal stenosis with myelomalacia and managing these cases according to the acute spinal cord injury management protocol after excluding compressing pathologies.

Ischemia-Reperfusion Injury After Posterior Cervical Laminectomy

Ischemia-reperfusion injury is a rare but serious complication encountered after spinal decompression surgery. This is only the 11th case reported in the literature. There is no current mainstay of treatment; however, several therapies have been studied. This case presents a patient with myelomalacia who underwent posterior laminectomy and developed diffuse cord edema with postoperative quadriplegia. Ischemia-reperfusion injury is believed to be mediated by oxidative and nitrosative stress leading to protein degradation and lipid peroxidation. It is characterized by myelomalacia in a chronically ischemic spinal cord and hyperintensity on T2-weighted MRI after decompression. Treatment has involved steroids and rehabilitation, and outcomes have ranged from minor improvement to full recovery. Novel treatment options have shown promise in animal models.

Misdiagnosis of "White Cord Syndrome" following posterior cervical surgery for ossification of the posterior longitudinal ligament: A case report

Background:

Following decompressive cervical surgery for significant spinal cord compression/myelopathy, patients may rarely develop the “White Cord Syndrome (WCS).” This acute postoperative reperfusion injury is characterized on T2W MRI images by an increased intramedullary cord signal. However, it is a diagnosis of exclusion, and WCS can only be invoked once all other etiologies for cord injury have been ruled out.

Case Description:

A 49-year-old male, 3 days following a C3-C7 cervical laminectomy and C2-T1 fusion for extensive cord compression due to ossification of the posterior longitudinal ligament (OPLL), developed acute quadriparesis. This new deficit should have been attributed to an intraoperative iatrogenic cord injury, not the WCS.

Conclusion:

Very rarely patients sustain postoperative significant/severe new neurological deficits attributable to the WCS. Notably, the WCS is a diagnosis of exclusion, and all other etiologies (i.e. intraoperative iatrogenic surgeon-based mechanical cord injury, graft/instrumentation extrusion, failure to adequately remove/resect OPLL thus stretching cord over residual disease, other reasons for continued cord compression, including the need for secondary surgery, etc.) of cord injury must first be ruled out.

Identification of the biological function of miR-9 in spinal cord ischemia-reperfusion injury in rats

Spinal cord ischemia–reperfusion injury (SCII) is still a serious problem, and the mechanism is not fully elaborated. In the rat SCII model, qRT-PCR was applied to explore the altered expression of miR-9 (miR-9a-5p) after SCII. The biological function of miR-9 and its potential target genes based on bioinformatics analysis and experiment validation in SCII were explored next. Before the surgical procedure of SCII, miR-9 mimic and inhibitor were intrathecally infused. miR-9 mimic improved neurological function. In addition, miR-9 mimic reduced blood-spinal cord barrier (BSCB) disruption, inhibited apoptosis and decreased the expression of IL-6 and IL-1β after SCII. Gene Ontology (GO) analysis demonstrated that the potential target genes of miR-9 were notably enriched in several biological processes, such as “central nervous system development”, “regulation of growth” and “response to cytokine”. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the potential target genes of miR-9 were significantly enriched in several signaling pathways, including “Notch signaling pathway”, “MAPK signaling pathway”, “Focal adhesion” and “Prolactin signaling pathway”. We further found that the protein expression of MAP2K3 and Notch2 were upregulated after SCII while miR-9 mimic reduced the increase of MAP2K3 and Notch2 protein. miR-9 mimic or MAP2K3 inhibitor reduced the release of IL-6 and IL-1β. miR-9 mimic or si-Notch2 reduced the increase of cleaved-caspase3. Moreover, MAP2K3 inhibitor and si-Notch2 reversed the effects of miR-9 inhibitor. In conclusion, overexpression of miR-9 improves neurological outcomes after SCII and might inhibit BSCB disruption, neuroinflammation, and apoptosis through MAP2K3-, or Notch2-mediated signaling pathway in SCII.

Reperfusion Injury (RPI)/White Cord Syndrome (WCS) Due to Cervical Spine Surgery: A Diagnosis of Exclusion

Background:

Following acute cervical spinal cord decompression, a subset of patients may develop acute postoperative paralysis due to Reperfusion Injury (RPI)/White Cord Syndrome (WCS). Pathophysiologically, this occurs due to the immediate restoration of normal blood flow to previously markedly compressed, and under-perfused/ischemic cord tissues. On emergent postoperative MR scans, the classical findings for RPI/ WCS include new or expanded, and focal or diffuse intramedullary hyperintense cord signals consistent with edema/ischemia, swelling, and/or intrinsic hematoma. To confirm RPI/WCS, MR studies must exclude extrinsic cord pathology (e.g. extramedullary hematomas, new/residual compressive disease, new graft/vertebral fracture etc.) that may warrant additional cervical surgery to avoid permanent neurological sequelae.

Methods:

In the English literature (i.e. excluding 2 Japanese studies), 9 patients were identified with postoperative RPI/WCS following cervical surgical procedures. For 7 patients, new acute postoperative neurological deficits were appropriately attributed to MR-documented RPI/WCS syndromes (i.e. hyperintense cord signals). However, for 2 patients who neurologically worsened, MR studies demonstrated residual extrinsic disease (e.g. stenosis and OPLL) warranting additional surgery; therefore, these 2 patients did not meet the criteria for RPI/WCS.

Results:

The diagnosis of RPI/WCS is one of exclusion. It is critical to rule out residual extrinsic cord compression where secondary surgery may improve/resolve neurological deficits.

Conclusions:

Patients with acute postoperative neurological deficits following cervical spine surgery must undergo MR studies to rule out extrinsic cord pathology before being diagnosed with RPI/WCS. Notably, 2 of the 9 cases of RPI/WCS reported in the literature required additional surgery to address stenosis and OPLL, and therefore, did not have the RPI/WCS syndromes.

'White cord syndrome', a rare but disastrous complication of transient paralysis after posterior cervical decompression for severe cervical spondylotic myelopathy and spinal stenosis: A case report

Transient paralysis following spinal decompression surgery is a rare but devastating postoperative complication. Spinal cord ischemia-reperfusion injury has been identified as one of the crucial pathogenic factors contributing to the sudden neurological deterioration associated with spinal decompression surgery. 'White cord syndrome' is a characteristic imaging manifestation of spinal cord ischemia-reperfusion injury, referring to high intramedullary signal changes in the sagittal T2-weighted MRI scan with unexplained neurological deficits following surgical decompression. The present study reported on the case of a 51-year old male patient who suffered from acute left limb hemiplegic paralysis following posterior cervical laminectomy decompression for severe cervical spondylotic myelopathy and spinal stenosis, which were caused by ossification of the posterior longitudinal ligament. The patient's neurological function gradually improved after the immediate administration of high-dose methylprednisolone therapy combined with mannitol and neurotrophic drugs. At the 2-month follow-up, the intensity of the spinal cord signal on MRI had almost returned to normal and the 'white cord syndrome' had disappeared. However, the patient complained of postoperative neck swelling pain caused by cerebrospinal fluid leakage; therefore, an additional cerebrospinal fluid leakage exploration and neoplasty were performed. At 2 weeks after the second surgery, the patient's neck swelling pain was relieved and the area of cerebrospinal fluid leakage was significantly reduced. Despite the low incidence rate, surgeons should be aware of this complication, particularly when treating chronic severe cervical spinal stenosis with anterior or posterior decompression. Once transient paralysis occurs, early diagnosis and interventions are essential to reverse the neurological deficit.