Acute Hyperoxia Improves Spinal Cord Oxygenation and Circulatory Function Following Cervical Spinal Cord Injury in Rats.

Spinal cord injury is associated with spinal vascular disruptions that result in spinal ischemia and tissue hypoxia. This study evaluated the therapeutic efficacy of normobaric hyperoxia on spinal cord oxygenation and circulatory function at the acute stage of cervical spinal cord injury. Adult male Sprague Dawley rats underwent dorsal cervical laminectomy or cervical spinal cord contusion. At 1-2 days after spinal surgery, spinal cord oxygenation was monitored in anesthetized and spontaneously breathing rats through optical recording of oxygen sensor foils placed on the cervical spinal cord and pulse oximetry. The arterial blood pressure, heart rate, blood gases, and peripheral oxyhemoglobin saturation were also measured under hyperoxic (50% O2) and normoxic (21% O2) conditions. The results showed that contused animals had significantly lower spinal cord oxygenation levels than uninjured animals during normoxia. Peripheral oxyhemoglobin saturation, arterial oxygen partial pressure, and mean arterial blood pressure are significantly reduced following cervical spinal cord contusion. Notably, spinal oxygenation of contused rats could be improved to a level comparable to uninjured animals under hyperoxia. Furthermore, acute hyperoxia elevated blood pressure, arterial oxygen partial pressure, and peripheral oxyhemoglobin saturation. These results suggest that normobaric hyperoxia can significantly improve spinal cord oxygenation and circulatory function in the acute phase after cervical spinal cord injury. We propose that adjuvant normobaric hyperoxia combined with other hemodynamic optimization strategies may prevent secondary damage after spinal cord injury and improve functional recovery.

Influence of the timing of surgery for cervical spinal cord injury without bone injury in the elderly: A retrospective multicenter study.

BACKGROUND: Although previous studies have demonstrated the advantages of early surgery for traumatic spinal cord injury (SCI), the appropriate surgical timing for cervical SCIs (CSCIs) without bone injury remains controversial. Here, we investigated the influence of relatively early surgery within 48 h of injury on the neurological recovery of elderly patients with CSCI and no bone injury. METHODS: In this retrospective multicenter study, we reviewed data from 159 consecutive patients aged ≥65 years with CSCI without bone injury who underwent surgery in participating centers between 2010 and 2020. Patients were followed up for at least 6 months following CSCI. We divided patients into relatively early (≤48 h after CSCI, n = 24) and late surgery (>48 h after CSCI, n = 135) groups, and baseline characteristics and neurological outcomes were compared between them. Multivariate analysis was performed to identify factors associated with neurological recovery. RESULTS: The relatively early surgery group demonstrated a lower prevalence of cardiac disease, poorer baseline American Spinal Injury Association (ASIA) impairment scale grade, and lower baseline ASIA motor score (AMS) than those of the late surgery group (P < 0.030, P < 0.001, and P < 0.001, respectively). Although the AMS was lower in the relatively early surgery group at 6 months following injury (P = 0.001), greater improvement in this score from baseline to 6-months post injury was observed (P = 0.010). Multiple linear regression analysis revealed that relatively early surgery did not affect postoperative improvement in AMS, rather, lower baseline AMS was associated with better AMS improvement (P < 0.001). Delirium (P = 0.006), pneumonia (P = 0.030), and diabetes mellitus (P = 0.039) negatively influenced postoperative improvement. CONCLUSIONS: Although further validation by future studies is required, relatively early surgery did not show a positive influence on neurological recovery after CSCI without bone injury in the elderly.

Role of magnetic resonance imaging features in diagnosing and localization of disc rupture related to cervical spinal cord injury without radiographic abnormalities.

STUDY DESIGN: A retrospective study. OBJECTIVE: Traumatic cervical spinal cord injury (TSCI) is often associated with disc rupture. It was reported that high signal of disc and anterior longitudinal ligament (ALL) rupture on magnetic resonance imaging (MRI) were the typical signs of ruptured disc. However, for TSCI with no fracture or dislocation, there is still difficult to diagnose disc rupture. The purpose of this study was to investigate the diagnostic efficiency and localization method of different MRI features for cervical disc rupture in patient with TSCI but no any signs of fracture or dislocation. SETTING: Affiliated hospital of University in Nanchang, China. METHODS: Patients who had TSCI and underwent anterior cervical surgery between June 2016 and December 2021 in our hospital were included. All patients received X-ray, CT scan, and MRI examinations before surgery. MRI findings such as prevertebral hematoma, high-signal SCI, high-signal posterior ligamentous complex (PLC), were recorded. The correlation between preoperative MRI features and intraoperative findings was analyzed. Also, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of these MRI features in diagnosing the disc rupture were calculated. RESULTS: A total of 140 consecutive patients, 120 males and 20 females with an average age of 53 years were included in this study. Of these patients, 98 (134 cervical discs) were intraoperatively confirmed with cervical disc rupture, but 59.1% (58 patients) of them had no definite evidence of an injured disc on preoperative MRI (high-signal disc or ALL rupture signal). For these patients, the high-signal PLC on preoperative MRI had the highest diagnostic rate for disc rupture based on intraoperative findings, with a sensitivity of 97%, specificity of 72%, PPV of 84% and NPV of 93%. Combined high-signal SCI with high-signal PLC had higher specificity (97%) and PPV (98%), and a lower FPR (3%) and FNR (9%) for the diagnosis of disc rupture. And combination of three MRI features (prevertebral hematoma, high-signal SCI and PLC) had the highest accuracy in diagnosing traumatic disc rupture. For the localization of the ruptured disc, the level of the high-signal SCI had the highest consistency with the segment of the ruptured disc. CONCLUSION: MRI features, such as prevertebral hematoma, high-signal SCI and PLC, demonstrated high sensitivities for diagnosing cervical disc rupture. High-signal SCI on preoperative MRI could be used to locate the segment of ruptured disc.

The Dose-Response Relationship Between Age and Tracheostomy in Patients with Traumatic Cervical Spinal Cord Injury: A Restricted Cubic Spline Function Analysis.

OBJECTIVE: To investigate the continuous relationship between age and tracheostomy in patients with traumatic cervical spinal cord injury (TCSCI). METHODS: This study comprised 689 TCSCI patients in total. The logistic regression and restricted cubic spline analysis was applied to analyze the possible dose-response relationship between age and tracheostomy. The subgroup analysis was performed for the American Spinal Injury Association (ASIA) grade and neurological level of injury. RESULTS: The proportion of patients with the age ≥60 was significantly higher in the tracheostomy group than in the non-tracheostomy group (42.2% vs. 19.6%; P < 0.001). Age ≥60 was independently associated with tracheostomy (total: odds ratio = 3.560, 95% confidence interval: 1.892-6.697; P < 0.001) after adjusting for gender, smoking history, dislocation, respiratory complications, ASIA grade, neurological level of injury, preexisting lung disease, brain injury, and thoracic injury. After the relationship was presented in the subgroup analysis, the restricted cubic spline revealed a nonlinear relationship between age and tracheostomy (P-overall < 0.001 and P-nonlinear = 0.021). CONCLUSIONS: Age and tracheostomy present a dose-response relationship in patients with TCSCI. This finding could help physicians bring assistance in the early identification of tracheostomy and rationalize the allocation of medical resources.

Efficacy of a machine learning-based approach in predicting neurological prognosis of cervical spinal cord injury patients following urgent surgery within 24 h after injury.

We aimed to develop a machine learning (ML) model for predicting the neurological outcomes of cervical spinal cord injury (CSCI). We retrospectively analyzed 135 patients with CSCI who underwent surgery within 24 h after injury. Patients were assessed with the American Spinal Injury Association Impairment Scale (AIS; grades A to E) 6 months after injury. A total of 34 features extracted from demographic variables, surgical factors, laboratory variables, neurological status, and radiological findings were analyzed. The ML model was created using Light GBM, XGBoost, and CatBoost. We evaluated Shapley Additive Explanations (SHAP) values to determine the variables that contributed most to the prediction models. We constructed multiclass prediction models for the five AIS grades and binary classification models to predict more than one-grade improvement in AIS 6 months after injury. Of the ML models used, CatBoost showed the highest accuracy (0.800) for the prediction of AIS grade and the highest AUC (0.90) for predicting improvement in AIS. AIS grade at admission, intramedullary hemorrhage, longitudinal extent of intramedullary T2 hyperintensity, and HbA1c were identified as important features for these prediction models. The ML models successfully predicted neurological outcomes 6 months after injury following urgent surgery in patients with CSCI.

Predicting the Role of Preoperative Intramedullary Lesion Length and Early Decompressive Surgery in ASIA Impairment Scale Grade Improvement Following Subaxial Traumatic Cervical Spinal Cord Injury.

BACKGROUND: Traumatic cervical spinal cord injury (TCSCI) is a disabling condition with uncertain neurologic recovery. Clinical and preclinical studies have suggested early surgical decompression and other measures of neuroprotection improve neurologic outcome. We investigated the role of intramedullary lesion length (IMLL) on preoperative magnetic resonance imaging (MRI) and the effect of early cervical decompressive surgery on ASIA impairment scale (AIS) grade improvement following TCSCI. METHODS: In this retrospective study, we investigated 34 TCSCI patients who were admitted over a 12-year period, from January 1, 2008 to January 31, 2020. We studied the patient demographics, mode of injury, IMLL and timing of surgical decompression. The IMLL is defined as the total length of edema and contusion/hemorrhage within the cord. Short tau inversion recovery (STIR) sequences or T2-weighted MR imaging with fat saturation increases the clarity of edema and depicts abnormalities in the spinal cord. All patients included had confirmed adequate spinal cord decompression with cervical fixation and a follow-up of at least 6 months. RESULTS: Of the 34 patients, 16 patients were operated on within 24 hours (early surgery group) and 18 patients were operated on more than 24 hours after trauma (delayed surgery group). In the early surgery group, 13 (81.3%) patients had improvement of at least one AIS grade, whereas in the delayed surgery group, AIS grade improvement was seen in only in 8 (44.5%) patients (early vs. late surgery; odds ratio [OR] = 1.828; 95% confidence interval [CI]: 1.036-3.225). In multivariate regression analysis coefficients, the timing of surgery and intramedullary edema length on MRI were the most significant factors in improving the AIS grade following cervical SCI. Timing of surgery as a unique variance predicted AIS grade improvement significantly (p < 0.001). The mean IMLL was 41.47 mm (standard deviation [SD]: 18.35; range: 20-87 mm). IMLL was a predictor of AIS grade improvement on long-term outcome in bivariate analysis (p < 0.001). This study suggests that patients who had IMLL of less than 30 mm had a better chance of grade conversion irrespective of the timing of surgery. Patients with an IMLL of 31 to 60 mm had chances of better grade conversion after early surgery. A longer IMLL predicts lack of improvement (p < 0.05). If the IMLL is greater than 61 mm, the probability of nonconversion of AIS grade is higher, even if the patient is operated on within 24 hours of trauma. CONCLUSION: Surgical decompression within 24 hours of trauma and shorter preoperative IMLL are significantly associated with improved neurologic outcome, reflected by better AIS grade improvement at 6 months' follow-up. The IMLL on preoperative MRI can reliably predict outcome after 6 months. The present study suggests that patients have lesser chances of AIS grade improvement when the IMLL is ≥61 mm.

Incidence and risk factors of pneumonia following acute traumatic cervical spinal cord Injury.

OBJECTIVES: To elucidate the incidence and risk factors for pneumonia after acute traumatic cervical spinal cord injury (CSCI). DESIGN: Retrospective cohort study.Setting: Spinal injuries center in Japan.Participants: Of 184 individuals who were admitted within 2 weeks after acute traumatic cervical spinal injuries, 167 individuals who met the criteria were included in this study.Interventions: The occurrence of pneumonia, degree of dysphagia using the Dysphagia Severity Scale, patient age, history of smoking, presence of tracheostomy, vital capacity, level of injury, and the American Spinal Injury Association Impairment Scale (AIS) 2 weeks after injury were assessed.Outcomes: Incidence of pneumonia were analyzed. Moreover, the risk factors of pneumonia were evaluated using logistic regression analysis. RESULTS: From the 167 individuals who met the criteria, 30 individuals (18%) had pneumonia; in 26 (87%) of these individuals, pneumonia was aspiration related, defined as Dysphagia Severity Scale ≤ 4. The median occurrence of aspiration pneumonia was 11.5 days after injury. A logistic regression analysis revealed that severe AIS and severe Dysphagia Severity Scale scores were significant risk factors of pneumonia after CSCI. CONCLUSIONS: It was highly likely that the pneumonias following CSCI were related to aspiration based on the Dysphagia Severity Scale. In addition, most of the patients developed aspiration pneumonia within 1 month after injury. Aspiration and severe paralysis were significant risk factors for pneumonia. The treatment of dysphagia in the acute phase should be considered an important indicator to prevent pneumonia.

Significance of the neurological level of injury as a prognostic predictor for motor complete cervical spinal cord injury patients.

Objective: To investigate the usefulness of the combination of neurological findings and magnetic resonance imaging (MRI) as a prognostic predictor in patients with motor complete cervical spinal cord injury (CSCI) in the acute phase.Design: A cross-sectional analysisSetting: Department of Orthopaedic Surgery, Spinal Injuries CenterParticipants/Methods: Forty-two patients with an initial diagnosis of motor complete CSCI (AIS A, n = 29; AIS B, n = 13) within 72 h after injury were classified into the recovery group (Group R) and the non-recovery group (Group N), based on the presence or absence of motor recovery (conversion from AIS A/B to C/D) at three months after injury, respectively. The Neurological Level of Injury (NLI) at the initial diagnosis was investigated and the presumptive primary injured segment of the spinal cord was inferred from MRI performed at the initial diagnosis. We investigated whether or not the difference between the presumptive primary injured segment and the NLI exceeded one segment. The presence of a difference between the presumptive primary injured segment and the NLI was compared between Groups R and N.Results: The number of cases with the differences between the presumptive primary injured segment and the NLI was significantly higher in Group N than in Group R.Conclusion: The presence of differences between the presumptive primary injured segment and the NLI might be a poor improving prognostic predictor for motor complete CSCI. The NLI may be useful for predicting the recovery potential of patients with motor complete CSCI when combined with the MRI findings.

Proposal of a Management Algorithm to Predict the Need for Expansion Duraplasty in American Spinal Injury Association Impairment Scale Grades A-C Traumatic Cervical Spinal Cord Injury Patients.

Expansion duraplasty to reopen effaced subarachnoid space and improve spinal cord perfusion, autoregulation, and spinal pressure reactivity index (sPRX) has been advocated in patients with traumatic cervical spinal cord injury (tCSCI). We designed this study to identify candidates for expansion duraplasty, based on the absence of cerebrospinal fluid (CSF) interface around the spinal cord on magnetic resonance imaging (MRI), in the setting of otherwise adequate bony decompression. Over a 61-month period, 104 consecutive American Spinal Injury Association Impairment Scale (AIS) grades A-C patients with tCSCI had post-operative MRI to assess the adequacy of surgical decompression. Their mean age was 53.4 years, and 89% were male. Sixty-one patients had falls, 31 motor vehicle collisions, 11 sport injuries, and one an assault. The AIS grade was A in 56, B in 18, and C in 30 patients. Fifty-four patients had fracture dislocations; there was no evidence of skeletal injury in 50 patients. Mean intramedullary lesion length (IMLL) was 46.9 (standard deviation = 19.4) mm. Median time from injury to decompression was 17 h (interquartile range 15.2 h). After surgery, 94 patients had adequate decompression as judged by the presence of CSF anterior and posterior to the spinal cord, whereas 10 patients had effacement of the subarachnoid space at the injury epicenter. In two patients whose decompression was not definitive and post-operative MRI indicated inadequate decompression, expansion duraplasty was performed. Candidates for expansion duraplasty (i.e., those with inadequate decompression) were significantly younger (p < 0.0001), were AIS grade A (p < 0.0016), had either sport injuries (six patients) or motor vehicle collisions (three patients) (p < 0.0001), had fracture dislocation (p = 0.00016), and had longer IMLL (p = 0.0097). In regression models, patients with sport injuries and inadequate decompression were suitable candidates for expansion duraplasty (p = 0.03). Further, 9.6% of patients failed bony decompression alone and either did (2) or would have (8) benefited from expansion duraplasty.

Does surgery improve neurological outcomes in older individuals with cervical spinal cord injury without bone injury? A multicenter study.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVES: To investigate the neurological outcomes of older individuals treated with surgery versus conservative treatment for cervical spinal cord injury (CSCI) without bone injury. SETTING: Thirty-three medical institutions in Japan. METHODS: This study included 317 consecutive persons aged ≥65 years with CSCI without bone injury in participating institutes between 2010 and 2020. The participants were followed up for at least 6 months after the injury. Individuals were divided into surgery (n = 114) and conservative treatment (n = 203) groups. To compare neurological outcomes and complications between the groups, propensity score matching of the baseline factors (characteristics, comorbidities, and neurological function) was performed. RESULTS: After propensity score matching, the surgery and conservative treatment groups comprised 89 individuals each. Surgery was performed at a median of 9.0 (3-17) days after CSCI. Baseline factors were comparable between groups, and the standardized difference in the covariates in the matched cohort was <10%. The American Spinal Injury Association (ASIA) impairment scale grade and ASIA motor score (AMS) 6 months after injury and changes in the AMS from baseline to 6 months after injury were not significantly different between groups (P = 0.63, P = 0.24, and P = 0.75, respectively). Few participants who underwent surgery demonstrated perioperative complications such as dural tear (1.1%), surgical site infection (2.2%), and C5 palsy (5.6%). CONCLUSION: Conservative treatment is suggested to be a more favorable option for older individuals with CSCI without bone injuries, but this finding requires further validation.

Classification and regression tree (CART) model to assist clinical prediction for tracheostomy in patients with traumatic cervical spinal cord injury: a 7-year study of 340 patients.

OBJECTIVE: To develop a classification and regression tree (CART) model to predict the need of tracheostomy in patients with traumatic cervical spinal cord injury (TCSCI) and to quantify scores of risk factors to make individualized clinical assessments. METHODS: The clinical characteristics of patients with TCSCI admitted to our hospital from January 2014 to December 2020 were retrospectively analyzed. The demographic characteristics (gender, age, smoking history), mechanism of injury, injury characteristics (ASIA impairment grades, neurological level of impairment, injury severity score), preexisting lung disease and preexisting medical conditions were statistically analyzed. The risk factors of tracheostomy were analyzed by univariate logistic regression analysis (ULRA) and multiple logistic regression analysis (MLRA). The CART model was established to predict tracheostomy. RESULTS: Three hundred and forty patients with TCSCI met the inclusion criteria, in which 41 patients underwent the tracheostomy. ULRA and MLRA showed that age > 50, ISS > 16, NLI > C5 and AIS A were significantly associated with tracheostomy. The CART model showed that AIS A and NLI > C5 were at the first and second decision node, which had a significant influence on the decision of tracheostomy. The final scores for tracheostomy from CART algorithm, composed of age, ISS, NLI and AIS A with a sensitivity of 0.78 and a specificity of 0.96, could also predict tracheostomy. CONCLUSION: The establishment of CART model provided a certain clinical guidance for the prediction of tracheostomy in TCSCI. Quantifications of risk factors enable accurate prediction of individual patient risk of need for tracheostomy.

Timing of tracheostomy in acute traumatic spinal cord injury: A systematic review and meta-analysis.

BACKGROUND: Patients with acute traumatic cervical or high thoracic level spinal cord injury (SCI) typically require mechanical ventilation (MV) during their acute admission. Placement of a tracheostomy is preferred when prolonged weaning from MV is anticipated. However, the optimal timing of tracheostomy placement in patients with acute traumatic SCI remains uncertain. We systematically reviewed the literature to determine the effects of early versus late tracheostomy or prolonged intubation in patients with acute traumatic SCI on important clinical outcomes. METHODS: Six databases were searched from their inception to January 2020. Conference abstracts from relevant proceedings and the gray literature were searched to identify additional studies. Data were obtained by two independent reviewers to ensure accuracy and completeness. The quality of observational studies was evaluated using the Newcastle Ottawa Scale. RESULTS: Seventeen studies (2,804 patients) met selection criteria, 14 of which were published after 2009. Meta-analysis showed that early tracheostomy was not associated with decreased short-term mortality (risk ratio [RR], 0.84; 95% confidence interval [CI], 0.39-1.79; p = 0.65; n = 2,072), but was associated with a reduction in MV duration (mean difference [MD], 13.1 days; 95% CI, -6.70 to -21.11; p = 0.0002; n = 855), intensive care unit length of stay (MD, -10.20 days; 95% CI, -4.66 to -15.74; p = 0.0003; n = 855), and hospital length of stay (MD, -7.39 days; 95% CI, -3.74 to -11.03; p < 0.0001; n = 423). Early tracheostomy was also associated with a decreased incidence of ventilator-associated pneumonia and tracheostomy-related complications (RR, 0.86; 95% CI, 0.75-0.98; p = 0.02; n = 2,043 and RR, 0.64; 95% CI, 0.48-0.84; p = 0.001; n = 812 respectively). The majority of studies ranked as good methodologic quality on the Newcastle Ottawa Scale. CONCLUSION: Early tracheostomy in patients with acute traumatic SCI may reduce duration of mechanical entilation, length of intensive care unit stay, and length of hospital stay. Current studies highlight the lack of high-level evidence to guide the optimal timing of tracheostomy in acute traumatic SCI. Future research should seek to understand whether early tracheostomy improves patient comfort, decreases duration of sedation, and improves long-term outcomes. LEVEL OF EVIDENCE: Systematic Review, level III.

Risk Factors for Tracheostomy after Traumatic Cervical Spinal Cord Injury: A 10-Year Study of 456 Patients.

OBJECTIVES: To explore the difference between tracheostomy and non-tracheostomy and identify the risk factors associated with the need for tracheostomy after traumatic cervical spinal cord injury (TCSCI). METHODS: The demographic and injury characteristics of 456 TCSCI patients, treated in the Xinqiao Hospital from 2010 to 2019, were retrospective analyzed. Patients were divided into the tracheostomy group (n = 63) and the non-tracheostomy group (n = 393). Variables included were age, gender,smoking history, mechanism of injury, concomitant injury, American Spinal Injury Association (ASIA) Impairment Scale, the neurological level of injury, Cervical Spine Injury Severity Score (CSISS), surgery, and length of stay in ICU and hospital. SPSS 25.0 (SPSS, Chicago, IL) was used for statistical analysis and ROC curve drawing. Chi-square analysis was applied to find out the difference of variables between the tracheostomy and non-tracheostomy groups. Univariate logistic regression analysis (ULRA) and multiple logistic regression analysis (MLRA) were used to identify risk factors for tracheostomy. The area under the ROC curve (AUC) was used to evaluate the performance of these risk factors. RESULTS: Of 456 patients who met the inclusion criteria, 63 (13.8%) underwent tracheostomy. There were differences in age (χ2 = 6.615, P = 0.032), mechanism of injury (χ2 = 9.87, P = 0.036), concomitant injury (χ2 = 6.131, P = 0.013),ASIA Impairment Scale (χ2 = 123.08, P < 0.01), the neurological level of injury (χ2 = 34.74, P < 0.01), and CSISS (χ2 = 19.612, P < 0.01) between the tracheostomy and non-tracheostomy groups. Smoking history, CSISS ≥ 7, AIS A and, NLI ≥ C5 were identified as potential risk factors for tracheostomy by ULRA. Smoking history (OR = 2.960, 95% CI: 1.524-5.750, P = 0.001), CSISS ≥ 7 (OR = 4.599, 95% CI: 2.328-9.085, P = 0.000), AIS A (OR = 14.213, 95% CI: 6.720-30.060, P = 0.000) and NLI ≥ C5 (OR = 8.312, 95% CI: 1.935-35.711, P = 0.004) as risk factors for tracheostomy were determined by MLRA. The AUC for the risk factors of tracheostomy after TCSCI was 0.858 (95% CI: 0.810-0.907). CONCLUSIONS: Smoking history, CSISS ≥ 7, AIS A and, NLI ≥ C5 were identified as risk factors needing of tracheostomy in patients with TCSCI. These risk factors may be important to assist the clinical decision of tracheostomy.

Optimizing the Timing of Peripheral Nerve Transfers for Functional Re-Animation in Cervical Spinal Cord Injury: A Conceptual Framework.

Loss of upper extremity function following spinal cord injury (SCI) can have devastating consequences on quality of life. Peripheral nerve transfer surgery aims to restore motor control of upper extremities following cervical SCI and is poised to revolutionize surgical management in this population. The surgery involves dividing an expendable donor nerve above the level of the spinal lesion and coapting it to a recipient nerve arising from the lesional or infralesional segment of the injured cord. In order to maximize outcomes in this complex patient population, refinements in surgical technique need to be integrated with principles of spinal cord medicine and basic science. Deciding on the ideal timing of nerve transfer surgery is one aspect of care that is critical to maximizing recovery and has received very little attention to date in the literature. This complex topic is reviewed, with a focus on expectations for spontaneous recovery within upper motor neuron components of the injury, balanced against the need for expeditious re-innervation for lower motor neuron elements of the injury. The discussion also considers the case of a patient with C6 motor complete SCI in whom myotomes without electrodiagnostic evidence of denervation spontaneously improved by 6 months post-injury, thereby adjusting the surgical plan. The relevant concepts are integrated into a clinical algorithm with recommendations that consider maximal opportunity for spontaneous clinical improvement post-injury while avoiding excessive delays that may adversely affect patient outcomes.

Management of patients with cervical spine trauma in the emergency department: a systematic critical appraisal of guidelines with a view to developing standardized strategies for clinical practice.

Several guidelines on the evaluation of patients with suspected cervical spine trauma in the Emergency Department (ED) exist. High heterogeneity between different guidelines has been reported. Aim of this study was to find areas of agreement and disagreement between guidelines, to identify topics in which further research is needed and to provide an evidence-based cervical spine trauma algorithm for ED physicians. The three most relevant guidelines published on cervical spine trauma in the last 10 years were selected screening websites of the main scientific societies and through the comparison of a normalized Google Scholar and SCOPUS citation index. We compared the selected guidelines through seven a-priori defined questions. In case of disagreement between the guidelines or if the quality of evidence appeared low, evidence from published systematic reviews on the topic was added to build an evidence-based algorithm for approach to spinal trauma in the ED. The three selected guidelines were: NICE 2016, Eastern Association for the Surgery of Trauma 2009 and American Association of Neurological Surgeons and Congress of Neurological Surgeons 2013. We found complete agreement on one question, partial agreement for one questions, no agreement for two questions, while agreement was not assessable for 3 questions. The agreement between different guidelines and the evidence on which recommendations are based is low. An attempt to build an evidence-based algorithm has been made. More studies are needed on many topics.

Reality of Accomplishing Surgery within 24 Hours for Complete Cervical Spinal Cord Injury: Clinical Practices and Safety.

Substantial clinical data support an association between superior neurological outcomes and early (within 24 h) surgical decompression for those with traumatic cervical spinal cord injury (SCI). Despite this, much discussion persists around feasibility and safety of this time threshold, particularly for those with a complete cervical SCI. This study aims to assess clinical practices and the safety profile of early surgery across a large sample of North American trauma centers. Data were derived from the Trauma Quality Improvement Program database from 2010-2016. Adult patients with a complete cervical SCI (American Spinal Injury Association [ASIA] A) who underwent surgery were included. Patients were stratified into those receiving surgery at or before 24 h and those receiving delayed intervention. Risk-adjusted variability in surgical timing across trauma centers was investigated using mixed-effects regression. In-hospital adverse events including death, major complications, and immobility-related complications were compared between groups after propensity score matching. There were 2862 patients from 353 North American trauma centers included; 1760 (61.5%) underwent surgery within 24 h. Case-mix and hospital-level characteristics explained only 6% of the variability in surgical timing both between centers and within centers. No significant differences in adverse events were identified between groups. These findings suggest a relatively large proportion of patients are not receiving surgery within the recommended time frame, despite apparent safety. Moreover, patient and hospital-level characteristics explain little of the variability in time-to-surgery. Further knowledge translation is needed to increase the proportion of patients in whom surgery is performed before the 24-h threshold so patients might reach their greatest potential for neurological recovery.

High-flow nasal cannula oxygen therapy was effective for dysphagia associated with respiratory muscle paralysis due to cervical spinal cord injury: A case report.

RATIONALE: Respiratory muscle paralysis due to low cervical spinal cord injury (CSCI) can lead to dysphagia. Noninvasive positive airway pressure (PAP) therapy can effectively treat this type of dysphagia. High-flow nasal cannula (HFNC) oxygen therapy can generate a low level of positive airway pressure resembling PAP therapy, it may improve the dysphagia. PATIENT CONCERNS: The patient was an 87-year-old man without preexisting dysphagia. He suffered a CSCI due to a dislocated C5/6 fracture, without brain injury, and underwent emergency surgery. Postoperatively (day 2), he complained of dysphagia, and the intervention was initiated. DIAGNOSIS: Based on clinical findings, dysphagia in this case, may have arisen due to impaired coordination between breathing and swallowing, which typically occurs in patients with CSCI who have reduced forced vital capacity. INTERVENTIONS: HFNC oxygen therapy was started immediately after the surgery, and swallowing rehabilitation was started on Day 2. Indirect therapy (without food) and direct therapy (with food) were applied in stages. HFNC oxygen therapy appeared to be effective because swallowing function temporarily decreased when the HFNC oxygen therapy was changed to nasal canula oxygen therapy. OUTCOMES: Swallowing function of the patient improved and he did not develop aspiration pneumonia. LESSONS: HFNC oxygen therapy improved swallowing function in a patient with dysphagia associated with respiratory-muscle paralysis following a CSCI. It may have prolonged the apnea tolerance time during swallowing and may have improved the timing of swallowing. HFNC oxygen therapy can facilitate both indirect and direct early swallowing therapy to restore both swallowing and respiratory function.

Cervical spinal cord injury-induced neuropathic pain in male mice is associated with a persistent pro-inflammatory macrophage/microglial response in the superficial dorsal horn.

A significant portion of individuals living with traumatic spinal cord injury (SCI) experiences some degree of debilitating neuropathic pain (NP). This pain remains largely intractable in a majority of cases, due in part to an incomplete understanding of its underlying mechanisms. Central sensitization, an increase in excitability of pain transmission neurons located in superficial dorsal horn (sDH), plays a key role in development and maintenance of SCI-induced NP. Resident microglia and peripheral monocyte-derived macrophages (referred to collectively as MMΦ) are involved in promoting SCI-induced DH neuron hyperexcitability. Importantly, these MMΦ consist of populations of cells that can exert pro-inflammatory or anti-inflammatory signaling within injured spinal cord. It is critical to spatiotemporally characterize this heterogeneity to understand MMΦ contribution to NP after SCI. Given that a majority of SCI cases are cervical in nature, we used a model of unilateral C5/C6 contusion that results in persistent at-level thermal hyperalgesia and mechanical allodynia, two forms of NP-related behavior, in the forepaw. The aim of this study was to characterize the sDH MMΦ response within intact cervical spinal cord segments caudal to the lesion (i.e. the location of primary afferent nociceptive input from the forepaw plantar surface). Cervical SCI promoted a persistent MMΦ response in sDH that coincided with the chronic NP phenotype. Using markers of pro- and anti-inflammatory MMΦ, we found that the MMΦ population within sDH exhibited significant heterogeneity that evolved over time post-injury, including a robust and persistent increase in pro-inflammatory MMΦ that was especially pronounced at later times. C5/C6 contusion SCI also induced below-level thermal hyperalgesia and mechanical allodynia in the hindpaw; however, we did not observe a pronounced MMΦ response in sDH of L4/L5 spinal cord, suggesting that different inflammatory cell mechanisms occurring in sDH may be involved in at-level versus below-level NP following SCI. In conclusion, our findings reveal significant MMΦ heterogeneity both within and across pain transmission locations after SCI. These data also show a prominent and persistent pro-inflammatory MMΦ response, suggesting a possible role in DH neuron hyperexcitability and NP.

Cervical spinal injury compromises caudal spinal tissue oxygenation and undermines acute intermittent hypoxia-induced phrenic long-term facilitation.

An important model of respiratory motor plasticity is phrenic long-term facilitation (pLTF), a persistent increase in phrenic burst amplitude following acute intermittent hypoxia (AIH). Moderate AIH elicits pLTF by a serotonin-dependent mechanism known as the Q pathway to phrenic motor facilitation. In contrast, severe AIH (greater hypoxemia) increases spinal adenosine accumulation and activates phrenic motor neuron adenosine 2A receptors, thereby initiating a distinct mechanism of plasticity known as the S pathway. Since the Q and S pathways interact via mutual cross-talk inhibition, the balance between spinal serotonin release and adenosine accumulation is an important pLTF regulator. Spinal injury decreases spinal tissue oxygen pressure (PtO2) caudal to injury. Since AIH is being explored as a neurotherapeutic to restore breathing ability after cervical spinal injury, we tested the hypothesis that decreased PtO2 in the phrenic motor nucleus after C2 spinal hemisection (C2Hx) undermines moderate AIH-induced pLTF, likely due to shifts in the adenosine/serotonin balance. We recorded C3/4 ventral cervical PtO2 with an optode, and bilateral phrenic nerve activity in anesthetized, paralyzed and ventilated rats, with and without C2Hx. In intact rats, PtO2 was lower during severe versus moderate AIH as expected. In chronic C2Hx rats (> 8 weeks post-injury), PtO2 was lower during baseline and moderate hypoxic episodes, approaching severe AIH levels in intact rats. After C2Hx, pLTF was blunted ipsilateral, but observed contralateral to injury. We conclude that C2Hx compromises PtO2 near the phrenic motor nucleus and undermines pLTF, presumably due to a shift in the serotonin versus adenosine balance during hypoxic episodes. These findings have important implications for optimizing AIH protocols in our efforts to restore breathing ability with therapeutic AIH in people with chronic cervical spinal injury.

COVID-19 and Acute Cervical Spinal Cord Injury-Case Report of 2 Patients: Do We Need to Rethink Our Standard Treatment Strategy?

STUDY DESIGN: This was a case series. OBJECTIVE: The authors sought to examine the high-risk population of COVID-positive patients with acute cervical spinal cord injury (SCI) in a large level 1 trauma and tertiary referral center. SUMMARY OF BACKGROUND DATA: There are limited studies regarding the surgical management of patients with acute SCI in the setting of the recent coronavirus pandemic. METHODS: The authors describe the cases of 2 patients who died from COVID-related complications after acute cervical SCI. RESULTS: Patients with SCI are at increased risk of pulmonary complications. COVID-19 infection represents a double hit in this patient population, increasing potential morbidity and mortality in the perioperative time frame. Careful consideration must be made regarding the timing of potential surgical intervention in the treatment of acute SCI. CONCLUSIONS: Nationwide database of COVID-positive patients with acute spinal cord injury should be collected and analyzed to better understand how to manage acute SCI in the COVID-19 era. The authors recommend preoperative discussion in patients with acute cervical SCI with COVID-19, specifically emphasizing the increased risk of respiratory complications and mortality.