Intramedullary lesion expansion on magnetic resonance imaging in patients with motor complete cervical spinal cord injury

Evolution of Spinal Cord Swelling in Acute Traumatic Spinal Cord Injury

We hypothesized that the Monro-Kellie doctrine, a key principle in traumatic brain injury (TBI), also applies in traumatic spinal cord injury (TSCI). By analyzing 9986 h of intraspinal pressure (ISP) monitoring data from 79 TSCI patients, we show that concepts developed to quantify compensatory reserve in TBI may be analogously defined in TSCI, termed ISP pulse amplitude (sAMP), spinal compensatory reserve index (sRAP), and ISP waveform shape. As ISP increases beyond 15 mmHg, compensatory reserve becomes impaired (sAMP rises and sRAP becomes positive). As ISP increases beyond 20 mmHg, the morphology of the ISP waveform changes from three peaks (P1, P2, P3) with P1 dominant, to three peaks with P2 dominant, to a rounded signal. Key differences in TSCI, compared with TBI, are no plateau ISP waves, and no critical ISP beyond which sAMP decreases and sRAP becomes negative. Four factors were associated with increased spinal cord swelling or reduced spinal cord compliance: thoracic level of injury, no laminectomy, delayed surgery, and more severe injury. We also hypothesized that, as in TBI, the spinal cord maximally swells a few days after injury. Serial ultrasound scans of the injured spinal cords in 9 patients and plots of change from baseline in ISP, sAMP, and sRAP versus time in 79 patients revealed delayed maximal cord swelling within 5 days of surgery. We conclude that the spinal Monro-Kellie concept allows the spinal compensatory reserve to be quantified. Our data show that spinal compensatory reserve becomes exhausted as ISP increases above 15-20 mmHg and that there is delayed cord swelling after injury, which implies that adequate cord decompression confirmed during surgery by ultrasound may not persist postoperatively.

Trends and variation in cervical spine imaging utilization across children's hospitals for pediatric trauma

BACKGROUND

Cervical spine (c-spine) evaluation is a critical component in trauma evaluation, and although several pediatric c-spine evaluation algorithms have been developed, none have been widely implemented. Here, we assess rates of c-spine imaging use across children's hospitals, specifically temporal trends in imaging use, variation across hospitals in imaging used, and timing of magnetic resonance imaging in admitted patients.

METHODS

Data from the Children's Hospital Associations Pediatric Health Information System were abstracted from 2015 to 2020. Patients younger than 18 years seen in the emergency department with an International Classification of Diseases, Tenth Revision , code indicative of trauma and c-spine plain radiograph or computed tomography (CT) in the emergency department were included. Data visualization and descriptive statistics were used to assess rates of imaging use by age, year, hospital, injury severity, and day of service. Changes in rates of imaging use over time were evaluated via simple linear regression.

RESULTS

Across 25,238 patient encounters at 35 children's hospitals, there was an increase in use of c-spine CT from 2015 to 2020 (28.5-36.5%). There was substantial interinstitutional variation in rates of use of plain radiographs versus CT for initial evaluation of the c-spine across all age groups. Magnetic resonance imaging was obtained more than 3 days after admission in 31.5% of intensive care patients who received this imaging.

CONCLUSION

Increasing use of CT, substantial interinstitutional variation in rates of use of plain radiographs versus CT, and heterogenous timing of magnetic resonance imaging for evaluation of the pediatric c-spine demonstrate the growing need for development and implementation of an age-specific c-spine evaluation algorithm to guide judicious use of diagnostic resources.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level III.

Early surgical intervention for acute spinal cord injury: time is spine

Acute traumatic spinal cord injury (tSCI) is a devastating occurrence that significantly contributes to global morbidity and mortality. Surgical decompression with stabilization is the most effective way to minimize the damaging sequelae that follow acute tSCI. In recent years, strong evidence has emerged that supports the rationale that early surgical intervention, within 24 h following the initial injury, is associated with a better prognosis and functional outcomes. In this review, we have summarized the evidence and elaborated on the nuances of this concept. Additionally, we have reviewed further concepts that stem from "time is spine," including earlier cutoffs less than 24 h and the challenging entity of central cord syndrome, as well as the emerging concept of adequate surgical decompression. Lastly, we identify barriers to early surgical care for acute tSCI, a key aspect of spine care that needs to be globally addressed via research and policy on an urgent basis.

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.

Quantifying Intraparenchymal Hemorrhage after Traumatic Spinal Cord Injury: A Review of Methodology

Intraparenchymal hemorrhage (IPH) after a traumatic injury has been associated with poor neurological outcomes. Although IPH may result from the initial mechanical trauma, the blood and its breakdown products have potentially deleterious effects. Further, the degree of IPH has been correlated with injury severity and the extent of subsequent recovery. Therefore, accurate evaluation and quantification of IPH following traumatic spinal cord injury (SCI) is important to define treatments' effects on IPH progression and secondary neuronal injury. Imaging modalities, such as magnetic resonance imaging (MRI) and ultrasound (US), have been explored by researchers for the detection and quantification of IPH following SCI. Both quantitative and semiquantitative MRI and US measurements have been applied to objectively assess IPH following SCI, but the optimal methods for doing so are not well established. Studies in animal SCI models (rodent and porcine) have explored US and histological techniques in evaluating SCI and have demonstrated the potential to detect and quantify IPH. Newer techniques using machine learning algorithms (such as convolutional neural networks [CNN]) have also been studied to calculate IPH volume and have yielded promising results. Despite long-standing recognition of the potential pathological significance of IPH within the spinal cord, quantifying IPH with MRI or US is a relatively new area of research. Further studies are warranted to investigate their potential use. Here, we review the different and emerging quantitative MRI, US, and histological approaches used to detect and quantify IPH following SCI.

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.

Superiority of Brain and Spinal Injury Center Score for Assessing Injury Severity and Predicting Prognosis in Patients with Acute Traumatic Spinal Cord Injury

PURPOSE

The goal of this study was to evaluate the interrelationship between different magnetic resonance (MR) imaging measures and their validity in assessing the severity of acute traumatic spinal cord injury (tSCI) and predicting neurological outcomes.

METHODS

We performed a preoperative multicenter cohort study of 89 patients with acute tSCI and preoperative MR imaging within 24 h after injury. We assessed several MR imaging measures of injury, including axial grade (Brain and Spinal Injury Center [BASIC] score), sagittal grade, length of injury, maximum canal compromise (MCC), and maximum spinal cord compression (MSCC). Principal component analysis (PCA) was applied to evaluate the interrelationship between different MR imaging measures. Spearman correlation and regression analyses were applied to assess injury severity and predict neurological impairment. The severity was assessed by the American Spinal Injury Association Impairment Scale (AIS) at admission, while neurological outcome was defined by AIS grade change at 6 weeks, AIS grade and SCIM score at 1 year after surgery.

RESULTS

The PCA identified 2 clusters of MR imaging variables related to 1) measures of intrinsic cord signal abnormality (BASIC score, sagittal grade and length of injury) and 2) measures of extrinsic cord compression (MCC and MSCC). Neurological outcome and injury severity were best accounted for by MR imaging measures of intrinsic cord signal abnormalities, with the BASIC score representing the most accurate predictor of short-term and long-term neurological outcomes.

CONCLUSION

We determined the superior significance of the BASIC score in assessing injury severity, predicting early AIS improvement, AIS grade and SCIM score at 1 year compared with other MR imaging measures.

Pathophysiology, Classification and Comorbidities after Traumatic Spinal Cord Injury

The spinal cord is a conduit within the central nervous system (CNS) that provides ongoing communication between the brain and the rest of the body, conveying complex sensory and motor information necessary for safety, movement, reflexes, and optimization of autonomic function. After a spinal cord injury (SCI), supraspinal influences on the spinal segmental control system and autonomic nervous system (ANS) are disrupted, leading to spastic paralysis, pain and dysesthesia, sympathetic blunting and parasympathetic dominance resulting in cardiac dysrhythmias, systemic hypotension, bronchoconstriction, copious respiratory secretions and uncontrolled bowel, bladder, and sexual dysfunction. This article outlines the pathophysiology of traumatic SCI, current and emerging methods of classification, and its influence on sensory/motor function, and introduces the probable comorbidities associated with SCI that will be discussed in more detail in the accompanying manuscripts of this special issue.

A Direct Comparison of Physical Versus Dihydrocapsaicin-Induced Hypothermia in a Rat Model of Traumatic Spinal Cord Injury

Spinal cord injury (SCI) is a devastating neurological condition with no effective treatment. Hypothermia induced by physical means (cold fluid) is established as an effective therapy in animal models of SCI, but its clinical translation to humans is hampered by several constraints. Hypothermia induced pharmacologically may be noninferior or superior to physically induced hypothermia for rapid, convenient systemic temperature reduction, but it has not been investigated previously in animal models of SCI. We used a rat model of SCI to compare outcomes in three groups: (1) normothermic controls; (2) hypothermia induced by conventional physical means; (3) hypothermia induced by intravenous (IV) dihydrocapsaicin (DHC). Male rats underwent unilateral lower cervical SCI and were treated after a 4-hour delay with physical cooling or IV DHC (∼0.60 mg/kg total) cooling (both 33.0 ± 1.0°C) lasting 4 hours; controls were kept normothermic. Telemetry was used to monitor temperature and heart rate during and after treatments. In two separate experiments, one ending at 48 hours, the other at 6 weeks, “blinded” investigators evaluated rats in the three groups for neurological function followed by histopathological evaluation of spinal cord tissues. DHC reliably induced systemic cooling to 32–33°C. At both the time points examined, the two modes of hypothermia yielded similar improvements in neurological function and lesion size compared with normothermic controls. Our results indicate that DHC-induced hypothermia may be comparable with physical hypothermia in efficacy, but more clinically feasible to administer than physical hypothermia.

Lateral Corticospinal Tract and Dorsal Column Damage: Predictive Relationships With Motor and Sensory Scores at Discharge From Acute Rehabilitation After Spinal Cord Injury

OBJECTIVE

To determine if lateral corticospinal tract (LCST) integrity demonstrates a significant predictive relationship with future ipsilateral lower extremity motor function (LEMS) and if dorsal column (DC) integrity demonstrates a significant predictive relationship with future light touch (LT) sensory function post spinal cord injury (SCI) at time of discharge from inpatient rehabilitation.

DESIGN

Retrospective analyses of imaging and clinical outcomes.

SETTING

University and academic hospital.

PARTICIPANTS

A total of 151 participants (N=151) with SCI.

INTERVENTIONS

Inpatient rehabilitation.

MAIN OUTCOME MEASURES

LEMS and LT scores at discharge from inpatient rehabilitation.

RESULTS

In 151 participants, right LCST spared tissue demonstrated a significant predictive relationship with right LEMS percentage recovered (β=0.56; 95% confidence interval [CI], 0.37-0.73; R=0.43; P<.001). Left LCST spared tissue demonstrated a significant predictive relationship with left LEMS percentage recovered (β=0.66; 95% CI, 0.50-0.82; R=0.51; P<.001). DC spared tissue demonstrated a significant predictive relationship with LT percentage recovered (β=0.69; 95% CI, 0.52-0.87; R=0.55; P<.001). When subgrouping the participants into motor complete vs incomplete SCI, motor relationships were no longer significant, but the sensory relationship remained significant. Those who had no voluntary motor function but recovered some also had significantly greater LCST spared tissue than those who did not recover motor function.

CONCLUSIONS

LCST demonstrated significant moderate predictive relationships with lower extremity motor function at the time of discharge from inpatient rehabilitation, in an ipsilesional manner. DC integrity demonstrated a significant moderate predictive relationship with recovered function of LT. With further development, these neuroimaging methods might be used to predict potential deficits after SCI and to provide corresponding targeted interventions.

Magnetic Resonance Imaging of the Cervical Spine: Frequency of Abnormal Findings with Relation to Age

Background: Patients with neck pain are frequently encountered in cervical spine (C-spine) magnetic resonance imaging (MRI) practice. However, the exact distribution and prevalence of cervical abnormalities are not known. Aim: The aim of this study is to evaluate the association between age, gender, and prevalence of abnormal cervical MRI findings. Methods: Records of 111 cervical MRIs were collected in 12 months from January to December 2019 from adults aged 20–89 years who were referred from neurosurgery, neurology, and orthopedic clinics. Findings were classified and analyzed using the Statistical Package for Social Science (SPSS), version 24.0 (IBM, Armonk, NY, USA). The chi-square test was used to determine the association between demographics and abnormalities using a significance of p = 0.05. Results: The majority of patients were female (72.1%). The number of abnormal incidences increased with age until it reached a peak at ages 50–59. Spondylodegenerative changes were the most frequent finding, which was present in 52.2% of the total sample, and was followed by disc bulge (25.2%). Incidences increased in lower discs, with C5–C6 being the most frequent in 65% of the total sample. Younger males in their 20s had more injuries than females of the same age. However, this rate was reversed in patients over 40, as women were the dominant gender among patients in their 40s with cervical injuries, with a rate of 81.5%. Conclusion: In our study, we found that older patients developed more C-spine injuries. Gender may play a role in the rate of incidents. However, we did not find any significant differences between men and women or between different types of abnormalities.

Traumatic cervical spinal cord injury: relationship of MRI findings to initial neurological impairment

PURPOSE

To quantify the degree of available space for the cord and cord swelling in patients following traumatic cervical spinal cord injury (TCSCI), and to assess the relationship among the available space for the cord, cord swelling, and the severity of neurological impairment.

METHODS

This study included 91 patients. The following indexes were measured by two blinded observers: maximum cord available area (CAA_max) and maximum cord swelling area (CSA_max). The American Spinal Injury Association (ASIA) impairment scale (AIS) grades were used to evaluate the extent of neurological injury. Relationship among CAA_max, CSA_max, and initial AIS grades was assessed via univariate and multivariate analyses.

RESULTS

Patients who were AIS grade A (complete injury) demonstrated significantly greater median CAA_max and CSA_max than AIS grade C or D (incomplete injury) (P < 0.01). Multivariate analysis identified only CAA_max (OR 20.88 [95% CI 1.50-291.21]; P = 0.024) and CSA_max (OR 17.84 [95% CI 1.15-276.56]; P = 0.039) were identified as independently influencing the likelihood of complete injury at the initial assessment. The classification accuracy was best for CAA_max and CSA_max; areas under the curve were 0.8998 (95% CI 0.7881-1.0000) and 0.9167 (95% CI 0.8293-1.0000), respectively.

CONCLUSION

The present study provides a novel radiologic method for identifying the severity of TCSCI with T2-weighted MRI findings. Greater available space for the cord (CAA_max > 38%) and cord swelling (CSA_max > 29%) can be used to identify patients at risk for TCSCI and both imaging characteristics are associated with an increased likelihood of severe neurological deficits.

LEVEL OF EVIDENCE

Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Meeting Proceedings for SCI 2020: Launching a Decade of Disruption in Spinal Cord Injury Research

The spinal cord injury (SCI) research community has experienced great advances in discovery research, technology development, and promising clinical interventions in the past decade. To build upon these advances and maximize the benefit to persons with SCI, the National Institutes of Health (NIH) hosted a conference February 12-13, 2019 titled "SCI 2020: Launching a Decade of Disruption in Spinal Cord Injury Research." The purpose of the conference was to bring together a broad range of stakeholders, including researchers, clinicians and healthcare professionals, persons with SCI, industry partners, regulators, and funding agency representatives to break down existing communication silos. Invited speakers were asked to summarize the state of the science, assess areas of technological and community readiness, and build collaborations that could change the trajectory of research and clinical options for people with SCI. In this report, we summarize the state of the science in each of five key domains and identify the gaps in the scientific literature that need to be addressed to move the field forward.

Efficacy of Early (≤ 24 Hours), Late (25-72 Hours), and Delayed (>72 Hours) Surgery with Magnetic Resonance Imaging-Confirmed Decompression in American Spinal Injury Association Impairment Scale Grades C and D Acute Traumatic Central Cord Syndrome Caused by Spinal Stenosis

The therapeutic significance of timing of decompression in acute traumatic central cord syndrome (ATCCS) caused by spinal stenosis remains unsettled. We retrospectively examined a homogenous cohort of patients with ATCCS and magnetic resonance imaging (MRI) evidence of post-treatment spinal cord decompression to determine whether timing of decompression played a significant role in American Spinal Injury Association (ASIA) motor score (AMS) 6 months following trauma. We used the t test, analysis of variance, Pearson correlation coefficient, and multiple regression for statistical analysis. During a 19-year period, 101 patients with ATCCS, admission ASIA Impairment Scale (AIS) grades C and D, and an admission AMS of ≤95 were surgically decompressed. Twenty-four of 101 patients had an AIS grade C injury. Eighty-two patients were males, the mean age of patients was 57.9 years, and 69 patients had had a fall. AMS at admission was 68.3 (standard deviation [SD] 23.4); upper extremities (UE) 28.6 (SD 14.7), and lower extremities (LE) 41.0 (SD 12.7). AMS at the latest follow-up was 93.1 (SD 12.8), UE 45.4 (SD 7.6), and LE 47.9 (SD 6.6). Mean number of stenotic segments was 2.8, mean canal compromise was 38.6% (SD 8.7%), and mean intramedullary lesion length (IMLL) was 23 mm (SD 11). Thirty-six of 101 patients had decompression within 24 h, 38 patients had decompression between 25 and 72 h, and 27 patients had decompression >72 h after injury. Demographics, etiology, AMS, AIS grade, morphometry, lesion length, surgical technique, steroid protocol, and follow-up AMS were not statistically different between groups treated at different times. We analyzed the effect size of timing of decompression categorically and in a continuous fashion. There was no significant effect of the timing of decompression on follow-up AMS. Only AMS at admission determined AMS at follow-up (coefficient = 0.31; 95% confidence interval [CI]:0.21; p = 0.001). We conclude that timing of decompression in ATCCS caused by spinal stenosis has little bearing on ultimate AMS at follow-up.

The influence of conventional T2 MRI indices in predicting who will walk outside one year after spinal cord injury

CONTEXT/OBJECTIVE

Magnetic resonance imaging (MRI) indices of spinal cord damage are predictive of future motor function after spinal cord injury (SCI): hyperintensity length, midsagittal tissue bridges, and Brain and Spinal Injury Center (BASIC) scores. Whether these indices are predictive of outdoor walking after SCI is unknown. The primary purpose was to see if these MRI indices predict the ability to walk outdoors one-year after SCI. The secondary purpose was to determine if MRI indices provide additional predictive value if initial lower extremity motor scores are available.

DESIGN

Retrospective. Clinical T₂-weighted MRIs were used to quantify spinal cord damage. Three MRI indices were calculated: midsagittal ventral tissue bridges, hyperintensity length, BASIC scores.

SETTING

Academic hospital.

PARTICIPANTS

129 participants with cervical SCI.

INTERVENTIONS

Inpatient rehabilitation.

OUTCOMES MEASURES

One year after SCI, participants self-reported their outdoor walking ability.

RESULTS

Midsagittal ventral tissue bridges, hyperintensity length, and BASIC scores significantly correlated with outdoor walking ability (R = 0.34, P < 0.001; R = -0.25, P < 0.01; Rs = -0.35, P < 001, respectively). Using midsagittal ventral tissue bridges and hyperintensity length, the final adjusted R² for model 1 = 0.19. For model 2, the adjusted R² using motor scores alone = 0.81 and MRI variables were non-significant. All five participants with observable intramedullary hemorrhage reported they were unable to walk one block outdoors.

CONCLUSIONS

The MRI indices were significant predictors of outdoor walking ability, but when motor scores were available, this was the strongest predictor and neither midsagittal tissue bridges nor hyperintensity length contributed additional value. MRI indices may be a quick and convenient supplement to physical examination when motor testing is unavailable.

Adult Spinal Cord Injury without Major Bone Injury: Effects of Surgical Decompression and Predictors of Neurological Outcomes in American Spinal Injury Association Impairment Scale A, B, or C

The cervical spine can be injured even in the absence of radiographic abnormality, and the best surgical treatment for adult spinal cord injury without bone injury is debated. The aim of this study was to retrospectively investigate the effect of surgical decompression for severe adult spinal cord injury without major bone injury and to establish predictors of good neurological outcome. We analyzed 11 patients who underwent surgical decompression in severe adult spinal cord injury without major bone injury patients classified as American Spinal Injury Association Impairment Scale (AIS) grade A, B, or C. Neurological assessments were performed using AIS at preoperative and postoperative 1-year follow-up. Radiological evaluations were performed using cervical magnetic resonance imaging (MRI) at preoperative. Seven cases were classified as AIS grade A; two cases as AIS grade B; and two cases as AIS grade C. Five of 11 (45.5%) patients showed improved neurological grade 1-year postoperatively. Intramedullary lesion length (IMLL) (p = 0.047) and compression rate (p = 0.045) had the most powerful effect on AIS grade conversion. This study shows that the fate of the injured spinal cord is determined at the time of the injury, but adequate decompression may have limited contribution to the recovery of neurological function. Compression rate and IMLL on MRI can be used as a predictor of neurological recovery.

Trends in Demographics and Markers of Injury Severity in Traumatic Cervical Spinal Cord Injury

Over the past four decades, there have been progressive changes in the epidemiology of traumatic spinal cord injury (tSCI). We assessed trends in demographic and injury-related variables in traumatic cervical spinal cord injury (tCSCI) patients over an 18-year period at a single Level I trauma center. We included all magnetic resonance imaging-confirmed tCSCI patients ≥15 years of age for years 2001-2018. Among 1420 patients, 78.3% were male with a mean age 51.5 years. Etiology included falls (46.9%), motor vehicle collisions (MVCs; 34.2%), and sports injuries (10.9%). Median American Spinal Injury Association (ASIA) Motor Score (AMS) was 44, complete tCSCI was noted in 29.6% of patients, fracture dislocations were noted in 44.7%, and median intramedullary lesion length (IMLL) was 30.8 mm (complete injuries 56.3 mm and incomplete injuries 27.4 mm). Over the study period, mean age and proportion of falls increased (p < 0.001) whereas proportion attributable to MVCs and sports injuries decreased (p < 0.001). Incomplete injuries, AMS, and the proportion of patients with no fracture dislocations increased whereas complete injuries decreased significantly. IMLL declined (p = 0.17) and proportion with hematomyelia did not change significantly. In adjusted regression models, increase in age and decreases in prevalence of MVC mechanism and complete injuries over time remained statistically significant. Changes in demographic and injury-related characteristics of tCSCI patients over time may help explain the observed improvement in outcomes. Further, improved clinical outcomes and drop in IMLL may reflect improvements in initial risk assessment and pre-hospital management, advances in healthcare delivery, and preventive measures including public education.

Axial MRI biomarkers of spinal cord damage to predict future walking and motor function: a retrospective study

Study design

Retrospective.

Objectives

Primary: to assess if axial damage ratios are predictors of future walking after spinal cord injury (SCI), and if they add any predictive value if initial neurological impairment grades are available. Secondary: to determine if lateral spinal cord regions are predictors of future lower extremity motor scores (LEMS).

Setting

University/hospital.

Methods

Axial T₂-weighted MRIs were used. Axial damage ratios and non-damaged lateral cord volumes were calculated. Each participant answered at 1 year after SCI, “Are you able to walk for 150 feet? (45.72 meters)” For the secondary aim, right and left LEMS were used.

Results

In total, 145 participants were selected. Individuals that could walk had smaller ratios than those that were unable. Walking and axial damage ratios were negatively correlated. A 0.374 ratio cut-off showed optimal sensitivity/specificity. When initial neurological grades were used, axial damage ratios did not add predictive value. Forty-two participants had LEMS available and were included for the secondary aim. Right cord regions and right LEMS were positively correlated and left regions and left LEMS, but these variables were also correlated with each other.

Conclusions

Axial damage ratios were significant predictors of walking ability 1 year after SCI. However, this measure did not add predictive value over initial neurological grades. Lateral cord regions correlated with same-side LEMS, but the opposite was also found, calling this biomarker’s specificity into question. Axial damage ratios may be useful in predicting walking after SCI if initial neurological grades are unavailable.

Sponsorship

This research was funded by a National Institutes of Health award, National Institute of Child Health and Development—NIH R03HD094577.

Improved Functional Recovery in Rat Spinal Cord Injury Induced by a Drug Combination Administered with an Implantable Polymeric Delivery System

Spinal cord injury (SCI) is an incurable condition, in which a cascade of cellular and molecular events triggered by inflammation and excitotoxicity impairs endogenous regeneration, namely remyelination and axonal outgrowth. We designed a treatment solution based on an implantable biomaterial (electrospun poly (l-lactic acid) [PLLA]) loaded with ibuprofen and triiodothyronine (T3) to counteract inflammation, thus improving endogenous regeneration. In vivo efficacy was tested by implanting the drug-loaded PLLA in the rat model of T8 contusion SCI. We observed the expected recovery of locomotion beginning on day 7. In PLLA-implanted rats (i.e., controls), the recovery stabilized at 21 days post-lesion (DPL), after which no further improvement was observed. On the contrary, in PLLA + ibuprofen (Ibu) + T3 (PLLA-Ibu-T3) rats a further recovery and a significant treatment effect were observed, also confirmed by the gait analysis on 49 DPL. Glutamate release at 24 h and 8 DPL was reduced in PLLA-Ibu-T3- compared to PLLA-implanted rats, such as the estimated lesion volume at 60 DPL. The myelin- and 200-neurofilament-positive area fraction was higher in PLLA-Ibu-T3-implanted rats, where the percentage of astrocytes was significantly reduced. The implant of a PLLA electrospun scaffold loaded with Ibu and T3 significantly improves the endogenous regeneration, leading to an improvement of functional locomotion outcome in the SCI.

Window of opportunity for surgical decompression in patients with acute traumatic cervical spinal cord injury

OBJECTIVE

The objective of this prospective study was to determine the optimal timing for surgical decompression (SD) in patients with acute traumatic cervical spinal cord injury (tSCI) within the first 24 hours of injury.

METHODS

In successive patients with fracture and/or dislocation of the subaxial cervical spine and American Spinal Injury Association Impairment Scale (AIS) grades A-C, receiver operating characteristic curve analysis was used to determine the optimal timing for SD within the first 24 hours of cervical tSCI to obtain a neurological recovery of at least two AIS grades. Multivariate logistic regression was used to model significant neurological recovery with time to SD, degree of spinal canal compromise (SCC), and severity of injury.

RESULTS

In this cohort of 64 patients, the optimal timing for SD to obtain a significant neurological improvement was within 4 hours of injury (95% confidence interval 4-9 hours). Increasing the delay from injury to SD or the degree of SCC significantly reduced the likelihood of significant neurological improvement. Due to the strong correlation with SCC, the severity of injury was a marginally significant predictor of neurological recovery.

CONCLUSIONS

These findings indicate that in patients with acute cervical tSCI and AIS grades A-C, the optimal timing for SD is within the first 4-9 hours of injury, depending on the degree of SCC and the severity of injury. Further studies are required to better understand the interrelationships among the timing of SD, injury severity, and degree of SCC in these patients.

Efficacy of Ultra-Early (< 12 h), Early (12-24 h), and Late (>24-138.5 h) Surgery with Magnetic Resonance Imaging-Confirmed Decompression in American Spinal Injury Association Impairment Scale Grades A, B, and C Cervical Spinal Cord Injury

In cervical traumatic spinal cord injury (TSCI), the therapeutic effect of timing of surgery on neurological recovery remains uncertain. Additionally, the relationship between extent of decompression, imaging biomarker evidence of injury severity, and outcome is incompletely understood. We investigated the effect of timing of decompression on long-term neurological outcome in patients with complete spinal cord decompression confirmed on postoperative magnetic resonance imaging (MRI). American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade conversion was determined in 72 AIS grades A, B, and C patients 6 months after confirmed decompression. Thirty-two patients underwent decompressive surgery ultra-early (< 12 h), 25 underwent decompressive surgery early (12-24 h), and 15 underwent decompressive surgery late (> 24-138.5 h) after injury. Age, gender, injury mechanism, intramedullary lesion length (IMLL) on MRI, admission ASIA motor score, and surgical technique were not statistically different among groups. Motor complete patients (p = 0.009) and those with fracture dislocations (p = 0.01) tended to be operated on earlier. Improvement of one grade or more was present in 55.6% of AIS grade A, 60.9% of AIS grade B, and 86.4% of AIS grade C patients. Admission AIS motor score (p = 0.0004) and pre-operative IMLL (p = 0.00001) were the strongest predictors of neurological outcome. AIS grade improvement occurred in 65.6%, 60%, and 80% of patients who underwent decompression ultra-early, early, and late, respectively (p = 0.424). Multiple regression analysis revealed that IMLL was the only significant variable predictive of AIS grade conversion to a better grade (odds ratio, 0.908; confidence interval [CI], 0.862-0.957; p < 0.001). We conclude that in patients with post-operative MRI confirmation of complete decompression following cervical TSCI, pre-operative IMLL, not the timing of surgery, determines long-term neurological outcome.

SCING-Spinal Cord Injury Neuroprotection with Glyburide: a pilot, open-label, multicentre, prospective evaluation of oral glyburide in patients with acute traumatic spinal cord injury in the USA

INTRODUCTION

Acute traumatic spinal cord injury (tSCI) is a devastating neurological disorder with no pharmacological neuroprotective strategy proven effective to date. Progressive haemorrhagic necrosis (PHN) represents an increasingly well-characterised mechanism of secondary injury after tSCI that negatively impacts neurological outcomes following acute tSCI. Preclinical studies evaluating the use of the Food and Drug Administration-approved sulfonylurea receptor 1-transient receptor potential melastatin 4 channel blocker glyburide in rodent models have shown reduced secondary microhaemorrhage formation and the absence of capillary fragmentation, the pathological hallmark of PHN.

METHODS AND ANALYSIS

In this initial phase multicentre open-label pilot study, we propose to enrol 10 patients with acute cervical tSCI to primarily assess the feasibility, and safety of receiving oral glyburide within 8 hours of injury. Secondary objectives include pharmacokinetics and preliminary evaluations on neurological recovery as well as blood and MRI-based injury biomarkers. Analysis will be performed using the descriptive and non-parametric statistics.

ETHICS AND DISSEMINATION

Glyburide has been shown as an effective neuroprotective agent in preclinical tSCI models and in the treatment of ischaemic stroke with the additional risk of a hypoglycaemic response. Given the ongoing secondary injury and the traumatic hyperglycaemic stress response seen in patients with tSCI, glyburide; thus, offers an appealing neuroprotective strategy to supplement standard of care treatment. The study protocol was approved by the Ohio State University Biomedical Institutional Review Board. The protocol was amended in February 2017 with changes related to study feasibility and patient recruitment. Specifically, the route of administration was changed to the oral form to allow for streamlined and rapid drug administration, and the injury-to-drug time window was extended to 8 hours in an effort to further enhance enrolment. Participants or legally authorised representatives are informed about the trial and its anticipated risks orally and in written form using an approved informed consent form prior to inclusion. The findings of this study will be disseminated to the participants and to academic peers through scientific conferences and peer-reviewed journal publications.

TRIAL REGISTRATION NUMBERS

NCT02524379 and 2014H0335.

Influence of Preoperative Magnetic Resonance Imaging on Surgical Decision Making for Patients with Acute Traumatic Cervical Spinal Cord Injury: A Survey Among Experienced Spine Surgeons

OBJECTIVE

Early decompression after acute spinal cord injury (SCI) is recommended. Acute care is crucial, but optimal management is unclear. The aim of this study was to investigate the role of preoperative magnetic resonance imaging (MRI) in addition to computed tomography (CT) in surgical decision making for acute cervical SCI.

METHODS

All patients with cervical SCI between 2008 and 2016 who had preoperative CT and MRI (n = 63) at the Trauma Center Murnau, Germany, were included. We administered a survey to 10 experienced spine surgeons (5 neurosurgeons, 5 trauma surgeons) regarding the surgical management. First, the surgeons were shown clinical information and CT scans. Two months later, the survey was repeated with additional MRI. Corresponding percentages of change and agreement were obtained for each rater and survey item. Finally, results from both parts of the survey were compared with the definitive treatment option (i.e., real-world decision).

RESULTS

MRI modified surgical timing in a median of 41% of patients (interquartile range 38%-56%). In almost every fifth patient (17%), no surgery would have been indicated with CT alone. The advocated surgical approach was changed in almost half of patients (median 48%, interquartile range 33%-49%). Surgically addressed levels were changed in a median of 57% of patients (interquartile range 56%-60%). MRI led to higher agreement with the real-world decision concerning addressed levels (median 35% vs. 73%), timing (median 51% vs. 57%), and approach (median 44% vs. 65%).

CONCLUSIONS

Preoperative MRI influenced surgical decision making substantially in our cohort and has become a new standard for patients with cervical SCI in our institution if medically possible.

Ulnar nerve integrity predicts 1-year outcome in cervical spinal cord injury

Background

Accurate predictors of neurological recovery after cervical spinal cord injury are needed. Particularly, to tailor adequate rehabilitation plans. However, objective and quantifiable predictors are sparse.

Methods

Within the prospective European Multicenter Study about Spinal Cord Injury (EMSCI) registry, cervical spinal cord injury patients are monitored at fixed follow up visits (2, 4, 12, 24, and 48 weeks after injury) clinically and with ulnar nerve electroneurography. Associations of ulnar nerve compound muscle action potential amplitudes (CMAP) with American Spinal Cord Injury Association (ASIA) impairment scale (AIS) grades over time were analyzed using linear mixed modeling. Applying logistic regression, the prognostic value of within 4-week ulnar nerve CMAP for 1-year AIS was analyzed. To account for missing data, (1) last observation carried forward and (2) multiple imputation methods were applied. For model derivation, our centers’ cohort (EMSCI-HD) was analyzed. For model validation the cohort of other centers (EMSCI-nonHD) was used.

Results

In the EMSCI-HD cohort, the median age (interquartile range (IQR)) was 52 (34–67) years. 58% were male. The initial AIS distribution was: A = 31%, B = 17%, C = 30%, and D = 22%). In the EMSCI-nonHD cohort, the median age was 49 (32–65) years. Compared to the EMSCI-HD cohort more patients were male (79%, p = 0.0034). The AIS distribution was: A = 33%, B = 13%, C = 21%, and D = 33%).

In complete-case mixed model analyses (EMSCI-HD: n = 114; EMSCI-nonHD: n = 508) higher ulnar nerve CMAP were associated with better AIS grades over the entire follow up period. In complete-case logistic regression (EMSCI-HD: n = 90; EMSCI-nonHD: n = 444) higher ulnar nerve CMAP was an independent predictor of better AIS grades. The odds ratio for within 4-week ulnar nerve CMAP to predict 1-year AIS grade D versus A-C in the EMSCI-HD cohort was 1.24 per millivolt (confidence interval 1.07–1.44). The model was validated in an independent cervical spinal cord injury (EMSCI-nonHD) cohort (odds ratio 1.09, confidence interval 1.03–1.17).

Conclusions

In cervical spinal cord injury, the consideration of early ulnar nerve CMAP improves prognostic accuracy, which is of particular importance in patients with clinical grading uncertainties.

Electronic supplementary material

The online version of this article (10.1186/s42466-019-0017-1) contains supplementary material, which is available to authorized users.

Extent of Spinal Cord Decompression in Motor Complete (American Spinal Injury Association Impairment Scale Grades A and B) Traumatic Spinal Cord Injury Patients: Post-Operative Magnetic Resonance Imaging Analysis of Standard Operative Approaches

Although decompressive surgery following traumatic spinal cord injury (TSCI) is recommended, adequate surgical decompression is rarely verified via imaging. We utilized magnetic resonance imaging (MRI) to analyze the rate of spinal cord decompression after surgery. Pre-operative (within 8 h of injury) and post-operative (within 48 h of injury) MRI images of 184 motor complete patients (American Spinal Injury Association Impairment Scale [AIS] grade A = 119, AIS grade B = 65) were reviewed to verify spinal cord decompression. Decompression was defined as the presence of a patent subarachnoid space around a swollen spinal cord. Of the 184 patients, 100 (54.3%) underwent anterior cervical discectomy and fusion (ACDF), and 53 of them also underwent laminectomy. Of the 184 patients, 55 (29.9%) underwent anterior cervical corpectomy and fusion (ACCF), with (26 patients) or without (29 patients) laminectomy. Twenty-nine patients (16%) underwent stand-alone laminectomy. Decompression was verified in 121 patients (66%). The rates of decompression in patients who underwent ACDF and ACCF without laminectomy were 46.8% and 58.6%, respectively. Among these patients, performing a laminectomy increased the rate of decompression (72% and 73.1% of patients, respectively). Twenty-five of 29 (86.2%) patients who underwent a stand-alone laminectomy were found to be successfully decompressed. The rates of decompression among patients who underwent laminectomy at one, two, three, four, or five levels were 58.3%, 68%, 78%, 80%, and 100%, respectively (p < 0.001). In multi-variate logistic regression analysis, only laminectomy was significantly associated with successful decompression (odds ratio 4.85; 95% confidence interval 2.2-10.6; p < 0.001). In motor complete TSCI patients, performing a laminectomy significantly increased the rate of successful spinal cord decompression, independent of whether anterior surgery was performed.

Establishing the inter-rater reliability of spinal cord damage manual measurement using magnetic resonance imaging

Study design

Retrospective study.

Objectives

To establish the inter-rater reliability in the quantitative evaluation of spinal cord damage following cervical incomplete spinal cord injury (SCI) utilizing magnetic resonance imaging (MRI). MRI was used to perform manual measurements of the cranial and caudal boundaries of edema, edema length, midsagittal tissue bridge ratio, axial damage ratio, and edema volume in 10 participants with cervical incomplete SCI.

Setting

Academic university setting.

Methods

Structural MRIs of 10 participants with SCI were collected from Northwestern University's Neuromuscular Imaging and Research Lab. All manual measures were performed using OsiriX (Pixmeo Sarl, Geneva, Switzerland). Intraclass correlation coefficients (ICC) were used to determine inter-rater reliability across seven raters of varying experience.

Results

High-to-excellent inter-rater reliability was found for all measures. ICC values for cranial/caudal levels of involvement, edema length, midsagittal tissue bridge ratio, axial damage ratio, and edema volume were 0.99, 0.98, 0.90, 0.84, and 0.93, respectively.

Conclusions

Manual MRI measures of spinal cord damage are reliable between raters. Researchers and clinicians may confidently utilize manual MRI measures to quantify cord damage. Future research to predict functional recovery following SCI and better inform clinical management is warranted.

Contrast-enhanced ultrasound to visualize hemodynamic changes after rodent spinal cord injury

OBJECTIVE

Traumatic spinal cord injury (tSCI) causes an almost complete loss of blood flow at the site of injury (primary injury) as well as significant hypoperfusion in the penumbra of the injury. Hypoperfusion in the penumbra progresses after injury to the spinal cord and is likely to be a major contributor to progressive cell death of spinal cord tissue that was initially viable (secondary injury). Neuroprotective treatment strategies seek to limit secondary injury. Clinical monitoring of the temporal and spatial patterns of blood flow within the contused spinal cord is currently not feasible. The purpose of the current study was to determine whether ultrafast contrast-enhanced ultrasound (CEUS) Doppler allows for detection of local hemodynamic changes within an injured rodent spinal cord in real time.

METHODS

A novel ultrafast CEUS Doppler technique was developed utilizing a research ultrasound platform combined with a 15-MHz linear array transducer. Ultrafast plane-wave acquisitions enabled the separation of higher-velocity blood flow in macrocirculation from low-velocity flow within the microcirculation (tissue perfusion). An FDA-approved contrast agent (microbubbles) was used for visualization of local blood flow in real time. CEUS Doppler acquisition protocols were developed to characterize tissue perfusion both during contrast inflow and during the steady-state plateau. A compression injury of the thoracic spinal cord of adult rats was induced using iris forceps.

RESULTS

High-frequency ultrasound enabled visualization of spinal cord vessels such as anterior spinal arteries as well as central arteries (mean diameter [± SEM] 145.8 ± 10.0 µm; 76.2 ± 4.5 µm, respectively). In the intact spinal cord, ultrafast CEUS Doppler confirmed higher perfusion of the gray matter compared to white matter. Immediately after compression injury of the thoracic rodent spinal cord, spinal cord vessels were disrupted in an area of 1.93 ± 1.14 mm2. Ultrafast CEUS Doppler revealed a topographical map of local tissue hypoperfusion with remarkable spatial resolution. Critical loss of perfusion, defined as less than 40% perfusion compared to the surrounding spared tissue, was seen within an area of 2.21 ± 0.6 mm2.

CONCLUSIONS

In our current report, we introduce ultrafast CEUS Doppler for monitoring of spinal vascular structure and function in real time. Development and clinical implementation of this type of imaging could have a significant impact on the care of patients with tSCI.

Impact of Admission Imaging Findings on Neurological Outcomes in Acute Cervical Traumatic Spinal Cord Injury

Variable and unpredictable spontaneous recovery can occur after acute cervical traumatic spinal cord injury (tSCI). Despite the critical clinical and interventional trial planning implications of this tSCI feature, baseline measures to predict neurologic recovery accurately are not well defined. In this study, we used data derived from 99 consecutive patients (78 male, 21 female) with acute cervical tSCIs to assess the sensitivity and specificity of various clinical and radiological factors in predicting recovery at one year after injury. Categorical magnetic resonance imaging parameters included maximum canal compromise (MCC), maximum spinal cord compression (MSCC), longitudinal length of intramedullary lesion (IML), Brain and Spinal Injury Center (BASIC) score, and a novel derived Combined Axial and Sagittal Score (CASS). Logistic regression analysis of the area under the receiver operating characteristic curve (AUC) was applied to assess the differential predictive value of individual imaging markers. Admission American Spinal Injury Association Impairment Scale (AIS) grade, presence of a spinal fracture, and central cord syndrome were predictive of AIS conversion at one year. Both BASIC and IML were stronger predictors of AIS conversion compared with MCC and MSCC (p = 0.0002 and p = 0.04). The BASIC score demonstrated the highest overall predictive value for AIS conversion at one year (AUC 0.94). We conclude that admission intrinsic cord signal findings are robust predictive surrogate markers of neurologic recovery after cervical tSCI. Direct comparison of imaging parameters in this cohort of patients indicates that the BASIC score is the single best acute predictor of the likelihood of AIS conversion.

Intramedullary Lesion Length on Postoperative Magnetic Resonance Imaging is a Strong Predictor of ASIA Impairment Scale Grade Conversion Following Decompressive Surgery in Cervical Spinal Cord Injury

BACKGROUND

Evidence indicates that, over time, patients with spinal cord injury (SCI) improve neurologically in various degrees. We sought to further investigate indicators of grade conversion in cervical SCI.

OBJECTIVE

To detect predictors of ASIA impairment scale (AIS) grade conversion in SCI following surgical decompression.

METHODS

In a retrospective study, demographics, clinical, imaging, and surgical data from 100 consecutive patients were assessed for predictors of AIS grade conversion.

RESULTS

American Spinal Injury Association motor score was 17.1. AIS grade was A in 52%, B in 29%, and C in 19% of patients. Surgical decompression took place on an average of 17.6 h following trauma (≤12 h in 51 and >12 h in 49). Complete decompression was verified by magnetic resonance imaging (MRI) in 73 patients. Intramedullary lesion length (IMLL) on postoperative MRI measured 72.8 mm, and hemorrhage at the injury epicenter was noted in 71 patients. Grade conversion took place in 26.9% of AIS grade A patients, 65.5% of AIS grade B, and 78.9% of AIS grade C. AIS grade conversion had statistical relationship with injury severity score, admission AIS grade, extent of decompression, presence of intramedullary hemorrhage, American Spinal Injury Association motor score, and IMLL. A stepwise multiple logistic regression analysis indicated IMLL was the sole and strongest indicator of AIS grade conversion (odds ratio 0.950, 95% CI 0.931-0.969). For 1- and 10-mm increases in IMLL, the model indicates 4% and 40% decreases, respectively, in the odds of AIS grade conversion.

CONCLUSION

Compared with other surrogates, IMLL remained as the only predictor of AIS grade conversion.

Lipids in the intensive care unit: Recommendations from the ESPEN Expert Group

This article summarizes the presentations given at an ESPEN Workshop on "Lipids in the ICU" held in Tel Aviv, Israel in November 2014 and subsequent discussions and updates. Lipids are an important component of enteral and parenteral nutrition support and provide essential fatty acids, a concentrated source of calories and building blocks for cell membranes. Whilst linoleic acid-rich vegetable oil-based enteral and parenteral nutrition is still widely used, newer lipid components such as medium-chain triglycerides and olive oil are safe and well tolerated. Fish oil (FO)-enriched enteral and parenteral nutrition appears to be well tolerated and confers additional clinical benefits, particularly in surgical patients, due to its anti-inflammatory and immune-modulating effects. Whilst the evidence base is not conclusive, there appears to be a potential for FO-enriched nutrition, particularly administered peri-operatively, to reduce the rate of complications and intensive care unit (ICU) and hospital stay in surgical ICU patients. The evidence for FO-enriched nutrition in non-surgical ICU patients is less clear regarding its clinical benefits and additional, well-designed large-scale clinical trials need to be conducted in this area. The ESPEN Expert Group supports the use of olive oil and FO in nutrition support in surgical and non-surgical ICU patients but considers that further research is required to provide a more robust evidence base.

Application of AOSpine Subaxial Cervical Spine Injury Classification in Simple and Complex Cases

INTRODUCTION

Cervical spine injury classification systems should be simple, easy to relate and remember, reliable guide for surgical planning, and predictor of outcome in clinical settings. We investigated whether the AOSpine subaxial cervical spine classification system predicted injury severity and neurologic outcome.

MATERIAL AND METHODS

We analyzed the relevant clinical, imaging, management, and American Spinal Injury Association (ASIA) impairment scale (AIS) grade conversion of 92 AIS grades A-C patients with cervical spine injury. We correlated morphology class with age, injury severity score (ISS), follow-up ASIA motor score (AMS), intramedullary lesion length (IMLL), and AIS grade conversion at 6 months after injury.

RESULTS

The mean age of patients was 39.3 years, 83 were men, and 69 were injured during an automobile accident or after a fall. The AOSpine class was A4 in 8, B2 in 5, B2A4 in 16, B3 in 19, and C in 44 patients. The mean ISS was 29.7 and AMS was 17.1. AIS grade was A in 48, B in 25, and C in 19 patients. Mean IMLL on postoperative magnetic resonance imaging was 72 mm: A4 = 68.1; B2A4 = 86.5; B2 = 59.3; B3 = 46.8; and C = 79.9. At a mean follow-up of 6 months, the mean AMS was 39.6. Compared to patients with class B3 injuries, those with class C injuries were significantly younger (P < 0.0001), had longer IMLL (P < 0.002), and were less likely to have AIS grade conversion to a better grade (P < 0.02).

CONCLUSIONS

The AOSpine subaxial cervical spine injury classification system successfully predicted injury severity (longer IMLL) and chances of neurologic recovery (AIS grade conversion) across different class subtypes.

Creation of an intramedullary cavity by hemorrhagic necrosis removal 24 h after spinal cord contusion in rats for eventual intralesional implantation of restorative materials

Intramedullary hemorrhagic necrosis occurs early after spinal cord injury at the site of injury and adjacent segments. It is considered harmful because of its potential to aggravate secondary injury, and to interfere with axonal regeneration; it might also lead to an unfavorable environment for intralesional implants. Removal of hemorrhagic necrosis has been attempted before with variable results. The invasive nature of these procedures carries the risk of exacerbating damage to the injured cord. The overall objective for this study was to test several strategies for non-damaging removal of hemorrhagic necrosis and characterize the resulting cavity looking for a space for future intralesional therapeutic implants in rats with acute cord injury. Rats were subjected to graded cord contusion, and hemorrhagic necrosis was removed after 24h. Three grades of myelotomy (extensive, medium sized, and small) were tested. Using the small surgical approach to debridement, early and late effects of the intervention were determined by histology and by analytical and behavioral analysis. Appearance and capacity of the resulting cavity were characterized. Satisfactory removal of hemorrhagic necrosis was achieved with all three surgical approaches to debridement. However, bleeding in spared cord tissue was excessive after medium sized and extensive myelotomies but similar to control injured rats after small cord surgery. Small surgical approach to debridement produced no swelling nor acute inflammation changes, nor did it affect long-term spontaneous locomotor recovery, but resulted in modest improvement of myelination in rats subjected to both moderate and severe injuries. Cavity created after intervention was filled with 10 to 15 μL of hydrogel. In conclusion, by small surgical approach to debridement, removal of hemorrhagic necrosis was achieved after acute cord contusion thereby creating intramedullary spaces without further damaging the injured spinal cord. Resulting cavities appear suitable for future intralesional placement of pro-reparative cells or other regenerative biomaterials in a clinically relevant model of spinal cord injury.

Risk factors and outcomes in thoracic stenosis with myelopathy: A single center experience

OBJECTIVE

Identify risk factors predisposing to thoracic spinal stenosis and myelopathy (TS) and address treatment options and outcomes.

METHODS

A retrospective review of our center's experience with TS over 10 years. Clinical and magnetic resonance imaging (MRI) data, surgical intervention and outcomes using Frankel and Japanese Orthopedic Association (JOA) scales were collected.

RESULTS

A total of 44 patients with TS were identified. There were 30 men and 14 women with a mean age±SD of 66±15years. Neurological performance was evaluated using the Frankel scale (A-E or 1-5), and JOA scale for myelopathy (0-11). Frankel scores (1-5) and JOA scores (0-11) on admission were 3.5±0.9 and 6.8±2.6 respectively. At follow-up, Frankel scores had improved to 4.1±0.8 (p=0.041) and JOA scores had improved to 8.3±2.4 (p=0.021). The presence on admission of increased signal from the cord on T2-weighted MRI was associated with lower Frankel and JOA scores (3.3±0.9, and 6.2±2.5 respectively) than in those with absent increased signal (4.0±0.4 and 8.6±2.1, p=0.02 and p=0.008 respectively). There were 4 complications, requiring exploration and debridement for dehiscence in 3 and an epidural hematoma in the fourth that necessitated evacuation, with a good outcome. A fifth patient underwent reoperation at the same level 18 months later for persistent stenosis.

CONCLUSION

Thoracic stenosis with myelopathy should be entertained in patients with myelopathy. Over half of our patients with TS were over the age of 70, and men outnumbered women by a ratio of 2:1. Nearly half the patients with TS had concomitant cervical and/or lumbar degenerative disease warranting surgery also. Increased signal intensity on T2-weighted MRI images correlated with lower Frankel and JOA scores compared to those without. Decompression for thoracic stenosis is associated with neurological improvement.

A Direct Comparison of Three Clinically Relevant Treatments in a Rat Model of Cervical Spinal Cord Injury

Recent preclinical studies have identified three treatments that are especially promising for reducing acute lesion expansion following traumatic spinal cord injury (SCI): riluzole, systemic hypothermia, and glibenclamide. Each has demonstrated efficacy in multiple studies with independent replication, but there is no way to compare them in terms of efficacy or safety, since different models were used, different laboratories were involved, and different outcomes were evaluated. Here, using a model of lower cervical hemicord contusion, we compared safety and efficacy for the three treatments, administered beginning 4 h after trauma. Treatment-associated mortality was 30% (3/10), 30% (3/10), 12.5% (1/8), and 0% (0/7) in the control, riluzole, hypothermia, and glibenclamide groups, respectively. For survivors, all three treatments showed overall favorable efficacy, compared with controls. On open-field locomotor scores (modified Basso, Beattie, and Bresnahan scores), hypothermia- and glibenclamide-treated animals were largely indistinguishable throughout the study, whereas riluzole-treated rats underperformed for the first two weeks; during the last four weeks, scores for the three treatments were similar, and significantly different from controls. On beam balance, hypothermia and glibenclamide treatments showed significant advantages over riluzole. After trauma, rats in the glibenclamide group rapidly regained a normal pattern of weight gain that differed markedly and significantly from that in all other groups. Lesion volumes at six weeks were: 4.8±0.7, 3.5±0.4, 3.1±0.3 and 2.5±0.3 mm³ in the control, riluzole, hypothermia, and glibenclamide groups, respectively; measurements of spared spinal cord tissue confirmed these results. Overall, in terms of safety and efficacy, systemic hypothermia and glibenclamide were superior to riluzole.

Predictors of intramedullary lesion expansion rate on MR images of patients with subaxial spinal cord injury

OBJECT

Studies of preclinical spinal cord injury (SCI) in rodents indicate that expansion of intramedullary lesions (IMLs) seen on MR images may be amenable to neuroprotection. In patients with subaxial SCI and motor-complete American Spinal Injury Association (ASIA) Impairment Scale (AIS) Grade A or B, IML expansion has been shown to be approximately 900 μm/hour. In this study, the authors investigated IML expansion in a cohort of patients with subaxial SCI and AIS Grade A, B, C, or D.

METHODS

Seventy-eight patients who had at least 2 MRI scans within 6 days of SCI were enrolled. Data were analyzed by regression analysis.

RESULTS

In this cohort, the mean age was 45.3 years (SD 18.3 years), 73 patients were injured in a motor vehicle crash, from a fall, or in sport activities, and 77% of them were men. The mean Injury Severity Score (ISS) was 26.7 (SD 16.7), and the AIS grade was A in 23 patients, B in 7, C in 7, and D in 41. The mechanism of injury was distraction in 26 patients, compression in 22, disc/osteophyte complex in 29, and Chance fracture in 1. The mean time between injury onset and the first MRI scan (Interval 1) was 10 hours (SD 8.7 hours), and the mean time to the second MRI scan (Interval 2) was 60 hours (SD 29.6 hours). The mean IML lengths of the first and second MR images were 38.8 mm (SD 20.4 mm) and 51 mm (SD 36.5 mm), respectively. The mean time from the first to the second MRI scan (Interval 3) was 49.9 hours (SD 28.4 hours), and the difference in IML lengths was 12.6 mm (SD 20.7 mm), reflecting an expansion rate of 366 μm/ hour (SD 710 μm/hour). IML expansion in patients with AIS Grades A and B was 918 μm/hour (SD 828 μm/hour), and for those with AIS Grades C and D, it was 21 μm/hour (SD 304 μm/hour). Univariate analysis indicated that AIS Grade A or B versus Grades C or D (p < 0.0001), traction (p= 0.0005), injury morphology (p < 0.005), the surgical approach (p= 0.009), vertebral artery injury (p= 0.02), age (p < 0.05), ISS (p < 0.05), ASIA motor score (p < 0.05), and time to decompression (p < 0.05) were all predictors of lesion expansion. In multiple regression analysis, however, the sole determinant of IML expansion was AIS grade (p < 0.005).

CONCLUSIONS

After traumatic subaxial cervical spine or spinal cord injury, patients with motor-complete injury (AIS Grade A or B) had a significantly higher rate of IML expansion than those with motor-incomplete injury (AIS Grade C or D).

Alterations of the biomarker S-100B and NSE in patients with acute vertebral spine fractures

BACKGROUND CONTEXT

Although several publications concerning the use of the biomarkers S100B and neuron-specific enolase (NSE) in vertebral spine fractures in animal experimental studies have proven their usefulness as early indicators of injury severity, there are no clinical reports on their effectiveness as indicators in patients with spinal injuries. As these biomarkers have been examined, with promising results, in patients with traumatic brain injury, there is a potential for their implementation in patients with vertebral spine fractures.

PURPOSE

To investigate the early serum measurement of S100B and NSE in patients with vertebral spine fractures compared with those in patients with acute fractures of the proximal femur.

STUDY DESIGN

Prospective longitudinal cohort study.

PATIENT SAMPLE

A cohort of 34 patients admitted over an 18-month period to a single medical center for suspected vertebral spine trauma. Twenty-nine patients were included in the control group.

OUTCOME MEASURES

S100B and NSE serum levels were assessed in different types of vertebral spine fractures.

METHODS

We included patients older than 16 years with vertebral spine fractures whose injuries were sustained within 24 hours before admission to the emergency room and who had undergone a brief neurologic examination. Spinal cord injuries (SCIs) were classified as being paresthesias, incomplete paraplegias, or complete paraplegias. Blood serum was obtained from all patients within 24 hours after the time of injury. Serum levels of S100B and NSE were statistically analyzed using Wilcoxon signed-rank test.

RESULTS

S100B serum levels were significantly higher in patients with vertebral spine fractures (p=.01). In these patients, the mean S100B serum level was 0.75 μg/L (standard deviation [SD] 1.44, 95% confidence interval [CI] 0.24, 1.25). The mean S100B serum level in control group patients was 0.14 μg/L (SD 0.11, 95% CI 0.10, 0.19). The 10 patients with neurologic deficits had significantly higher S100B serum levels compared with the patients with vertebral fractures but without neurologic deficits (p=.02). The mean S100B serum level in these patients was 1.18 μg/L (SD 1.96). In the 26 patients with vertebral spine fractures but without neurologic injury, the mean S100B serum level was 0.42 μg/L (SD 0.91, 95% CI 0.08, 0.76). The analysis revealed no significant difference in NSE levels.

CONCLUSIONS

We observed a significant correlation not only between S100B serum levels and vertebral spine fractures but also between S100B serum levels and SCIs with neurologic deficit. These results may be meaningful in clinical practice and to future studies.

Spinal cord injury: how can we improve the classification and quantification of its severity and prognosis?

The preservation of functional neural tissue after spinal cord injury (SCI) is the basis for spontaneous neurological recovery. Some injured patients in the acute phase have more potential for recovery than others. This fact is problematic for the construction of clinical trials because enrollment of subjects with variable recovery potential makes it difficult to detect effects, requires large sample sizes, and risks Type II errors. In addition, the current methods to assess injury and recovery are non-quantitative and not sensitive. It is likely that therapeutic combinations will be necessary to cause substantially improved function after SCI, thus we need highly sensitive techniques to evaluate changes in motor, sensory, autonomic and other functions. We review several emerging neurophysiological techniques with high sensitivity. Quantitative methods to evaluate residual tissue sparing after severe acute SCI have not entered widespread clinical use. This reduces the ability to correlate structural preservation with clinical outcome following SCI resulting in enrollment of subjects with varying patterns of tissue preservation and injury into clinical trials. We propose that the inclusion of additional measures of injury severity, pattern, and individual genetic characteristics may enable stratification in clinical trials to make the testing of therapeutic interventions more effective and efficient. New imaging techniques to assess tract injury and demyelination and methods to quantify tissue injury, inflammatory markers, and neuroglial biochemical changes may improve the evaluation of injury severity, and the correlation with neurological outcome, and measure the effects of treatment more robustly than is currently possible. The ability to test such a multimodality approach will require a high degree of collaboration between clinical and research centers and government research support. When the most informative of these assessments is determined, it may be possible to identify patients with substantial recovery potential, improve selection criteria and conduct more efficient clinical trials.

MRI evidence that glibenclamide reduces acute lesion expansion in a rat model of spinal cord injury

STUDY DESIGN

Experimental, controlled, animal study.

OBJECTIVES

To use non-invasive magnetic resonance imaging (MRI) to corroborate invasive studies showing progressive expansion of a hemorrhagic lesion during the early hours after spinal cord trauma and to assess the effect of glibenclamide, which blocks Sur1-Trpm4 channels implicated in post-traumatic capillary fragmentation, on lesion expansion.

SETTING

Baltimore.

METHODS

Adult female Long-Evans rats underwent unilateral impact trauma to the spinal cord at C7, which produced ipsilateral but not contralateral primary hemorrhage. In series 1 (six control rats and six administered glibenclamide), hemorrhagic lesion expansion was characterized using MRI at 1 and 24 h after trauma. In series 2, hemorrhagic lesion size was characterized on coronal tissue sections at 15 min (eight rats) and at 24 h after trauma (eight control rats and eight administered glibenclamide).

RESULTS

MRI (T2 hypodensity) showed that lesions expanded 2.3±0.33-fold (P<0.001) during the first 24 h in control rats, but only 1.2±0.07-fold (P>0.05) in glibenclamide-treated rats. Measuring the areas of hemorrhagic contusion on tissue sections at the epicenter showed that lesions expanded 2.2±0.12-fold (P<0.001) during the first 24 h in control rats, but only 1.1±0.05-fold (P>0.05) in glibenclamide-treated rats. Glibenclamide treatment was associated with significantly better neurological function (unilateral BBB scores) at 24 h in both the ipsilateral (median scores, 9 vs 0; P<0.001) and contralateral (median scores, 12 vs 2; P<0.001) hindlimbs.

CONCLUSION

MRI is an accurate non-invasive imaging biomarker of lesion expansion and is a sensitive measure of the ability of glibenclamide to reduce lesion expansion.

The Sur1-Trpm4 Channel in Spinal Cord Injury

Spinal cord injury (SCI) is a major unsolved challenge in medicine. Impact trauma to the spinal cord shears blood vessels, causing an immediate 'primary hemorrhage'. During the hours following trauma, the region of hemorrhage enlarges progressively, with delayed or 'secondary hemorrhage' adding to the primary hemorrhage, and effectively doubling its volume. The process responsible for the secondary hemorrhage that results in early expansion of the hemorrhagic lesion is termed 'progressive hemorrhagic necrosis' (PHN). PHN is a dynamic process of auto destruction whose molecular underpinnings are only now beginning to be elucidated. PHN results from the delayed, progressive, catastrophic failure of the structural integrity of capillaries. The resulting 'capillary fragmentation' is a unique, pathognomonic feature of PHN. Recent work has implicated the Sur1-Trpm4 channel that is newly upregulated in penumbral microvessels as being required for the development of PHN. Targeting the Sur1-Trpm4 channel by gene deletion, gene suppression, or pharmacological inhibition of either of the two channel subunits, Sur1 or Trpm4, yields exactly the same effects histologically and functionally, and exactly the same unique, pathognomonic phenotype - the prevention of capillary fragmentation. The potential advantage of inhibiting Sur1-Trpm4 channels using glibenclamide is a highly promising strategy for ameliorating the devastating sequelae of spinal cord trauma in humans.