Interobserver and intraobserver reliability of maximum canal compromise and spinal cord compression for evaluation of acute traumatic cervical spinal cord injury

m6A-related genes of peripheral white blood cell in spinal cord injury as potential targets for prognosis and treatment

Objective

Spinal cord injury (SCI) is a destructive neurological and pathological state that causes major motor, sensory, and autonomic dysfunction. N6-methyladenosine (m6A) is a reversible RNA modification implicated in various biological processes. However, few studies have examined m6A expression in patients with SCI. We explored the prognostic value of m6A-related genes as potential biomarkers in SCI to establish a set of accurate diagnostic and prognostic prediction models.

Methods

Differentially expressed analysis and weighted gene co-expression network analysis (WGCNA) was used to explore m6a related modules and hub genes. KEGG and GO analyses was utilized to explore the potential role of these hub genes. Gene expression was verified in single-cell data. The correlation of m6A related gene with spinal cord injury severity was explored.

Results

We found 289 SCI-related and five m6A-related candidate genes with high SCI correlation and high differential expression in the publicly available dataset, GSE151371. These genes are also involved in long-chain fatty acid binding. Early SCI was accompanied by significant immune cell infiltration. Simultaneously, infiltrating immune cells and the innate immune system have a strong cellular interaction, which gradually decreases over time. The number of PPARG-positive cells also increases after SCI. The comparatively higher expression of PPARG and lower expression of AK5 in white blood cells (WBCs) correlates with severity of SCI.

Conclusion

Our integrated analysis illustrates the hub genes involved in SCI, which can be prognostic markers. Further understanding of the functions of the identified SCI hub genes may provide deeper insights into the molecular mechanisms of SCI.

Evaluation of the prognostic value of extra-parenchymal changes in traumatic spinal cord injury, assessed by magnetic resonance imaging

OBJECTIVES

To analyze the relationship between neurological progression following traumatic spinal cord injury and Spinal Cord Compression (SCC) and Spinal Ligamentous Injury (LI) by magnetic resonance imaging.

DESIGN

Retrospective observational study.

SETTING

Spinal Cord Injury Unit (A Coruña, Spain).

PARTICIPANTS

Patients were admitted for traumatic spinal cord injury between January 2010 and December 2018 with a magnetic resonance imaging examination performed during the acute phase.

INTERVENTION

Evaluation of SCC and LI by magnetic resonance imaging.

OUTCOME MEASURES

Comparisons between neurological examination at admission and discharge were made, assessing ASIA Impairment Scale (AIS) grade and motor score.

RESULTS

Data from 296 patients were collected. A relationship between SCC and LI and complete injuries were found (P < 0.001). Improvement of the AIS grade was observed in 31.6% of patients with SCC and 31.3% with LI versus 42.7% and 37.8% of subjects without these complications, respectively. Regarding motor score, patients with SCC had lower mean values at the beginning (46.9 ± 26.8 versus 61.1 ± 29.9 in the control group, P < 0.001), as well as less improvement when assessed by the percentage of change (35.1 ± 37.5% versus 49.4 ± 38.1% in the control group, P = 0.010). Similar results were obtained in cases with LI: mean motor score at admission was 45.9 ± 26.7 versus 54.9 ± 29.4 in the control group (P = 0.014) and the percentage of change was 28.5 ± 37.1% in comparison to 46.0 ± 37.5% (P = 0.001) in the controls.

CONCLUSIONS

There is a relationship between SCC and LI and complete spinal cord injury. This patient population has lower possibilities of improving their AIS grade and motor score.

Time for change? Radiologists highly concordant assessing change in stenoses on follow-up cervical spine MRI

OBJECTIVE

There is considerable variability among radiologists when grading spinal canal and foraminal stenosis on MRI. However, to date, studies have not evaluated radiologists' agreement when assessing interval change in cervical spine stenoses. The purpose of this study was to evaluate radiologists' concordance for change in cervical spine stenoses on follow-up MRIs, a major indication for these exams.

METHODS

Initial and follow-up cervical MRIs were retrospectively reviewed by three blinded radiologists. Spinal canal and foramina from C1 through T1 were rated for interval change and concordance between the blinded raters was calculated. The original MRI reports were also reviewed for specific language assessing interval change on the follow-up exams.

RESULTS

40 cervical MRI exams and 40 corresponding MRI follow-ups were assessed. Agreement for interval change in spinal canal and foraminal stenosis was near perfect amongst all readers (kappa values of 0.78-0.94). 97% of the original MRI reports used the standard severity scale. 68% of follow-up MRI reports specifically assessed for change.

DISCUSSION

Blinded radiologists had high agreement when assessing for change in spinal canal and foraminal stenosis on follow-up cervical spine MRIs. Because of inter-rater variability in stenosis grading, reports that do not emphasize change assessment, may imply change that is not truly present. For clarity and consistency in reporting of cervical spine stenoses, change assessment should be emphasized and added to structured reporting templates.

Delayed inhibition of collagen deposition by targeting bone morphogenetic protein 1 promotes recovery after spinal cord injury

Fibrotic scars appear after spinal cord injury (SCI) and are mainly composed of fibroblasts and excess extracellular matrix (ECM), including different types of collagen. The temporal and spatial distribution and role of excess collagens and ECM after SCI are not yet fully understood. Here, we identified that the procollagen type I C-terminal propeptide (PICP), a marker of collagen type I deposition, and bone morphogenetic protein 1 (BMP1), a secreted procollagen c-proteinase (PCP) for type I collagen maturation, were significantly elevatedin cerebrospinal fluid of patients with SCI compared with healthy controls, and were associated with spinal cord compression and neurological symptoms. We revealed the deposition of type I collagen in the area damaged by SCI in mice and confirmed that BMP1 was the only expressed PCP and induced collagen deposition. Furthermore, transforming growth factor-β (TGF-β), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) can activate the expression of BMP1. However, inhibition of BMP1 at the acute phase eliminated fibrotic scars in the damaged area and inhibited activation and enrichment of astrocytes, which made the damage difficult to repair and increased hematoma. Unexpectedly, knockdown of Bmp1 by adeno-associated virus or the inhibition of BMP1 biological function by specific inhibitors and monoclonal antibodies at different time points after injury led to distinct therapeutic effects. Only delayed inhibition of BMP1 improved axonal regeneration and myelin repair at the subacute stage post-injury, and led to the recovery of motor function, suggesting that scarring had a dual effect. Early inhibition of the scarring was not conducive to limiting inflammation, while excessive scar formation inhibited the growth of axons. After SCI, the collagen deposition indicators increased in both human cerebrospinal fluid and mouse spinal cord. Therefore, suppression of BMP1 during the subacute phase improves nerve function after SCI and is a potential target for scar reduction.

Prognostic and risk factors for the surgical efficacy of central spinal cord syndrome in patients with preexisting degenerative cervical spinal cord compression

OBJECTIVES

To analyze the prognostic and risk factors related to surgical treatment of central spinal cord syndrome (CSS) and to find out the optimal timing of operative management.

METHODS

From January 2011 to January 2019, a consecutive series of 128 patients with CSS confirmed by magnetic resonance imaging (MRI) were retrospectively analyzed including their clinical records and radiologic data from a prospectively maintained database in a single center.

RESULTS

According to the prognosis evaluated by the modified Japanese Orthopedic Association (mJOA), American Spinal Injury Association (ASIA) motor score (AMS), and ASIA impairment scale (AIS) grade, the overall postoperative outcome was good. Finally, it was found that surgical timing, presence of myelopathy or not at baseline, AMS at admission, and compression ratio were independent factors affecting the prognosis. Surgery as soon as possible after the occurrence of CSS is still advocated.

CONCLUSION

Cervical myelopathy at baseline, compression ratio, and AMS score on admission were independent prognostic factors for the surgical treatment of CSS. If surgical indications are clear, early surgical intervention should be actively considered.

Development of a Dynamic Nomogram for Predicting the Probability of Satisfactory Recovery after 6 Months for Cervical Traumatic Spinal Cord Injury

OBJECTIVE

Cervical traumatic spinal cord injury (CTSCI) is a seriously disabling disease that severely affects the physical and mental health of patients and imposes a huge economic burden on patients and their families. Accurate identification of the prognosis of CTSCI patients helps clinicians to design individualized treatment plans for patients. For this purpose, a dynamic nomogram was developed to predict the recovery of CTSCI patients after 6 months.

METHODS

We retrospectively included 475 patients with CTSCI in our institution between March 2013 and January 2022. The outcome variable of the current study was a satisfactory recovery of patients with CTSCI at 6 months. Univariate analyses and univariate logistic regression analyses were used to assess the factors affecting the prognosis of patients with CTSCI. Subsequently, variables (P < 0.05) were included in the multivariate logistic regression analysis to evaluate these factors further. Eventually, a nomogram model was constructed according to these independent risk factors. The concordance index (C-index) and the calibration curve were utilized to assess the model's predictive ability. The discriminating capacity of the prediction model was measured by the receiver operating characteristic (ROC) area under the curve (AUC). One hundred nine patients were randomly selected from 475 patients to serve as the center's internal validation test cohort.

RESULTS

The multivariate logistic regression model further screened out six independent factors that impact the recovery of patients with CTSCI. Including admission to the American Spinal Injury Association Impairment Scale (AIS) grade, the length of high signal in the spinal cord, maximum spinal cord compression (MSCC), spinal segment fractured, admission time, and hormonal therapy within 8 h after injury. A nomogram prediction model was developed based on the six independent factors above. In the training cohort, the AUC of the nomogram that included these predictors was 0.879, while in the test cohort, it was 0.824. The nomogram C-index incorporating these predictors was 0.872 in the training cohort and 0.813 in the test cohort, while the calibration curves for both cohorts also indicated good consistency. Furthermore, this nomogram was converted into a Web-based calculator, which provided individual probabilities of recovery to be generated for individuals with CTSCI after 6 months and displayed in a graphical format.

CONCLUSION

The nomogram, including ASIA grade, the length of high signal in the spinal cord, MSCC, spinal segment fractured, admission time, and hormonal therapy within 8 h after injury, is a promising model to predict the probability of content recovery in patients with CTSCI. This nomogram assists clinicians in stratifying patients with CTSCI, enhancing evidence-based decision-making, and individualizing the most appropriate treatment.

Surgical Efficacy and Prognostic Factors for Acute Traumatic Central Cord Syndrome Without Fracture and Dislocation

This study was undertaken to evaluate the effectiveness of surgical treatment of acute traumatic central cord syndrome (ATCCS) without fracture and dislocation and explore surgical timing and factors influencing postoperative recovery of spinal cord function. We retrospectively collected the general and clinical data of 112 patients with ATCCS (American Spinal Injury Association impairment scale grade C or D) without fracture and dislocation who underwent surgical treatment in our hospital from January 2013 to August 2019. We used statistical methods to evaluate the safety of the operation and explore the timing of surgery and the factors influencing postoperative recovery of spinal cord function. The mean age of the 112 patients was 60.64±12.91 years. The Japanese Orthopaedic Association score and the American Spinal Injury Association motor score (AMS) of the 112 patients were significantly higher at final follow-up than at admission. No significant difference in recovery of spinal cord function was seen between the early operation group (≤4 days) and the late operation group (>4 days). Comparison of patients with a good prognosis vs a poor prognosis showed that age, intrahand muscle strength at admission, maximum spinal cord compression, maximum canal compromise, length of high-intensity signal in the spinal cord on sagittal T2-weighted magnetic resonance imaging, AMS, and American Spinal Injury Association injury grade D/C at admission had a significant effect on recovery of spinal cord function. Surgical treatment of ATCCS without fracture and dislocation is safe and effective. Age, admission AMS and American Spinal Injury Association impairment scale score, intrinsic hand muscle strength, maximum canal compromise, maximum spinal cord compression, and length of high-intensity signal in the spinal cord can be used to predict postoperative recovery of spinal cord function. [Orthopedics. 2022;45(6):325-332.].

Are surgical outcomes for one level anterior decompression and fusion associated with MRI parameters for degenerative cervical myelopathy?

Background

Our study is to determine the correlation between preoperative MRI parameters of spinal cord compression and the effects of anterior surgery in patients with degenerative cervical myelopathy (DCM).

Methods

24 normal subjects with no evident abnormalities were selected as group A. 79 patients with DCM underwent single-segment (C4–5/C5–6) ACDF surgery formed the operation group, and separated into group B (without high signal) and group C (with high signal) according to the absence or presence of high signal in the spinal cord on preoperative T2-weighted MRI respectively. MRI parameters (MCC, maximum canal compromise; MSCC, maximum spinal cord compression; CR, spinal cord compression rate; RCSCDS, ratio of cervical spinal cord to dura sac) were measured. The JOA score was used to evaluate cervical spinal cord function and recovery rate (RR) was used to evaluate postoperative efficacy. The relationship between preoperative MRI parameters and postoperative efficacy was analyzed.

Results

The preoperative JOA score and RR of group B were higher than that of group C. MCC and MSCC in group B were significantly lower than those in groups C. The multiple linear regression equation was the fitted postoperative JOA score = 13.371–2.940 * MCC −5.660 * RCSCDS +0.471 * preoperative JOA score. The fitted RR = 1.451–0.472 * MCC −1.313 * RCSCDS.

Conclusion

The occurrence of high signal on T2-weighted images could reflect more serious spinal cord injury. The postoperative JOA score was significantly correlated with MCC, RCSCDS, and preoperative JOA score, while RR was significantly associated with MCC and RCSCDS.

Added Value of Three-Plane Multiecho Fast Field Echo MRI Sequence in the Evaluation of Acute Spinal Trauma Using Sensitivity: A Prospective Study

Background

Multiecho fast field echo (mFFE) MRI sequence provides added value to the conventional MR imaging in evaluation of acute spinal trauma, especially for detecting spinal cord hemorrhage which is a best predictor for patient prognosis.

Objective

This study aims to evaluate the diagnostic efficacies of three-plane mFFE MRI sequence along with the conventional MRI sequences in acute spinal trauma patients using sensitivity. 

Materials and methods

This prospective study comprised of 48 patients of acute spinal trauma. The neurological deficit of acute spinal trauma patients assessed according to the American Spine Injury Association (ASIA) scale. The correlation between the various MRI findings of acute spinal cord injury and neurological deficits were compared with the Chi-square test.

Results

Of 48 patients of acute spinal trauma, 36 males and 12 females with a mean age of 38.71±1.42 [SD] years. 22 (45.8%) patients had cord edema with a mean length of was 3.45±5.52 [SD] cm. The mean percentage of spinal canal compromisation was 39.47±25.47 [SD] and spinal cord compression 18.1±24.4 [SD]. There was statistical significance between the ASIA impairment scale and spinal canal compromisation and cord compression with a p-value of 0.0005. Cord hemorrhage observed in 13 (27%), non-hemorrhagic cord contusions in 3 (6.3%), cord transection in 5 (10.4%) and epidural hematoma in 10 (20.8%) patients with an initial high grade of ASIA scale. The visibility score of three-plane mFFE sequence was higher in comparison to the single plane sagittal mFFE and short tau inversion recovery (STIR) sequences. For detection of spinal cord hemorrhage with visibility score of 2, the three-plane mFFE had sensitivity of 77% followed by 38.5% with single plane sagittal mFFE and 7.7% with sagittal STIR images. 26 (54.2%) patients showed neurological improvement in their hospital stay/follow-up period and no improvement observed in 7 (14.6%) patients of acute spinal trauma.

Conclusions

Application of three-plane mFFE sequences detects more spinal cord hemorrhages and vertebral fractures with a better visibility score as compared to the single sagittal plane mFFE and STIR sequence.

Validation of the National Institute of Neurological Disorders and Stroke Spinal Cord Injury MRI Common Data Elements Instrument

BACKGROUND AND PURPOSE

The National Institute of Neurological Disorders and Stroke common data elements initiative was created to provide a consistent method for recording and reporting observations related to neurologic diseases in clinical trials. The purpose of this study is to validate the subset of common data elements related to MR imaging evaluation of acute spinal cord injury.

MATERIALS AND METHODS

Thirty-five cervical and thoracic MR imaging studies of patients with acute spinal cord injury were evaluated independently in 2 rounds by 5 expert reviewers. Intra- and interrater agreement were calculated for 17 distinct MR imaging observations related to spinal cord injury. These included ordinal, categoric, and continuous measures related to the length and location of spinal cord hemorrhage and edema as well as spinal canal and cord measurements. Level of agreement was calculated using the interclass correlation coefficient and kappa.

RESULTS

The ordinal common data elements spinal cord injury elements for lesion center and rostral or caudal extent of edema or hemorrhage demonstrated agreement ranging from interclass correlation coefficient 0.68 to 0.99. Reproducibility ranged from 0.95 to 1.00. Moderate agreement was observed for absolute length of hemorrhage and edema (0.54 to 0.60) with good reproducibility (0.78 to 0.83). Agreement for the Brain and Spinal Injury Center score showed the lowest interrater agreement with an overall kappa of 0.27 (0.20, 0.34). For 7 of the 8 variables related to spinal cord injury, agreement improved between the first and second evaluation. Continuous diameter measures of the spinal cord and spinal canal using interclass correlation coefficient varied substantially (0.23 to 0.83).

CONCLUSIONS

Agreement was more consistent for the ordinal measures of spinal cord injury than continuous measures. Good to excellent agreement on length and location of spinal cord hemorrhage and edema can be achieved with ordinal measures alone.

Postoperative changes in spinal cord signal intensity in patients with spinal cord injury without major bone injury: comparison between preoperative and postoperative magnetic resonance images

OBJECTIVE

Although increased signal intensity (ISI) on MRI is observed in patients with cervical spinal cord injury (SCI) without major bone injury, alterations in ISI have not been evaluated. The association between postoperative ISI and surgical outcomes remains unclear. This study elucidated whether or not the postoperative classification and alterations in MRI-based ISI of the spinal cord reflected the postoperative symptom severity and surgical outcomes in patients with SCI without major bone injury.

METHODS

One hundred consecutive patients with SCI without major bone injury (79 male and 21 female) with a mean age of 55 years (range 20-87 years) were included. All patients were treated with laminoplasty and underwent MRI pre- and postoperatively (mean 12.5 ± 0.8 months). ISI was classified into three groups on the basis of sagittal T2-weighted MRI: grade 0, none; grade 1, light (obscure); and grade 2, intense (bright). The neurological statuses were evaluated according to the Japanese Orthopaedic Association (JOA) scoring system and the American Spinal Injury Association Impairment Scale (AIS).

RESULTS

Preoperatively, 8 patients had grade 0 ISI, 49 had grade 1, and 43 had grade 2; and postoperatively, 20 patients had grade 0, 24 had grade 1, and 56 had grade 2. The postoperative JOA scores and recovery rate (RR) decreased significantly with increasing postoperative ISI grade. The postoperative ISI grade tended to increase with the postoperative AIS grade. Postoperative grade 2 ISI was observed in severely paralyzed patients. The postoperative ISI grade improved in 23 patients (23%), worsened in 25 (25%), and remained unchanged in 52 (52%). Patients with an improved ISI grade had a better RR than those with a worsened ISI grade.

CONCLUSIONS

Postoperative ISI reflected postoperative symptom severity and surgical outcomes. Alterations in ISI were seen postoperatively in 48 patients (48%) and were associated with surgical outcomes.

Relationship between Machine-Learning Image Classification of T2-Weighted Intramedullary Hypointensity on 3 Tesla Magnetic Resonance Imaging and Clinical Outcome in Dogs with Severe Spinal Cord Injury

Early prognostic information in cases of severe spinal cord injury can aid treatment planning and stratification for clinical trials. Analysis of intraparenchymal signal change on magnetic resonance imaging has been suggested to inform outcome prediction in traumatic spinal cord injury. We hypothesized that intraparenchymal T₂-weighted hypointensity would be associated with a lower potential for functional recovery and a higher risk of progressive neurological deterioration in dogs with acute, severe, naturally occurring spinal cord injury. Our objectives were to: 1) demonstrate capacity for machine-learning criteria to identify clinically relevant regions of hypointensity and 2) compare clinical outcomes for cases with and without such regions. A total of 95 dogs with complete spinal cord injury were evaluated. An image classification system, based on Speeded-Up Robust Features (SURF), was trained to recognize individual axial T₂-weighted slices that contained hypointensity. The presence of such slices in a given transverse series was correlated with a lower chance of functional recovery (odds ratio [OR], 0.08; confidence interval [CI], 0.02-0.38; p < 10^-3) and with a higher risk of neurological deterioration (OR, 0.14; 95% CI, 0.05-0.42; p < 10^-3). Identification of intraparenchymal T₂-weighted hypointensity in severe, naturally occurring spinal cord injury may be assisted by an image classification tool and is correlated with functional recovery.

Assessment of degenerative cervical stenosis on T2-weighted MR imaging: sensitivity to change and reliability of mid-sagittal and axial plane metrics

STUDY DESIGN

A retrospective cross-sectional study.

OBJECTIVE

To assess the sensitivity to change and reliability of various mid-sagittal and axial plane metrics in the assessment of patients with single-level degenerative cervical stenosis on T2-weighted MR imaging.

SETTING

A diagnostic MR imaging facility in Sydney (Australia).

METHODS

We retrospectively reviewed T2-weighted MR images of 85 consecutive patients (48 M and 37 F) with single-level degenerative cervical stenosis. Canal compromise and cord compression were evaluated using three mid-sagittal plane metrics (M₁, M₂, and M₃) and two axial plane metrics (M₄ and M₅), at the level of stenosis and nonstenotic cephalad and caudal levels (controls). Sensitivity to change (SC) for each metric was evaluated as the percentage deviation of the measured value from the estimated normal value based on cephalad and caudal controls. Reliability for each metric was evaluated using intraclass correlation coefficients.

RESULTS

Degenerative cervical stenosis showed a bimodal distribution peaking at C5-6 (n = 32) and C3-4 (n = 29) levels. The changes in the canal and cord geometry along the rostrocaudal axis were inconsistent. Across all individual subjects (reflecting a range of stenosis severity), M₃ (-32.87% ± 10.60%) was more sensitive to change compared with M₁ (16.64% ± 16.48%) and M₂ (-23.95% ± 11.12%). Similarly, M₄ (-24.62% ± 12.17%) was more sensitive to change compared with M₅ (-6.71% ± 11.08%). The level of reliability was "moderate" to "excellent" for mid-sagittal plane measurements, and "poor" to "excellent" for axial plane measurements.

CONCLUSION

Changes in canal dimensions in the mid-sagittal plane and cord shape in the axial plane are sensitive indicators of degenerative cervical stenosis on T2-weighted MR images.

Prognostic utility of magnetic resonance imaging (MRI) in predicting neurological outcomes in patients with acute thoracolumbar spinal cord injury

PURPOSE

Utility of MRI for predicting neurological outcomes in acute cervical spinal cord injury (SCI) is well established but its value in thoracolumbar (TL) SCI needs to be evaluated.

METHODS

Seventy-six patients operated for acute TL spinal injuries between January 2014 and March 2016 were reviewed to obtain demographic details, neurology at admission and at the final follow-up. Patients were divided based on the neurology at presentation into group 1 (ASIA A), group 2 (ASIA B, C, D) and group 3 (normal neurology). Preoperative MRI and CT scans were evaluated to measure parameters like osseus canal compromise, spinal cord compression (SCC), spinal cord swelling, length of cord swelling (LOS), length of edema (LOE) and the presence of hemorrhage. The MRI parameters were compared between the groups for their predictive value of neurology on admission and at the final follow-up.

RESULTS

Of the 38 patients in group 1, six patients recovered by 1 grade, nine patients recovered by 2 grades and there was no recovery in 23 (60.5%) patients. Among group 2 patients, nine (40.9%) out of 22 recovered to ASIA E neurology. On univariate analysis, SCC (P = 0.009), LOS (P = 0.021) and length of edema (P = 0.002) were associated with complete neurological deficit at presentation. However, on multivariate regression analysis only LOE was significant (P = 0.007) in predicting neurology at admission and at follow-up.

CONCLUSION

Greater the rostrocaudal LOE, worse is the neurology at presentation, and it is associated with poor neurological recovery at follow-up. These slides can be retrieved under Electronic Supplementary Material.

Congenital Cervical Spine Stenosis in a Multicenter Global Cohort of Patients With Degenerative Cervical Myelopathy: An Ambispective Report Based on a Magnetic Resonance Imaging Diagnostic Criterion

BACKGROUND

Congenital spinal stenosis (CSS) of the cervical spine is a risk factor for acute spinal cord injury and development of degenerative cervical myelopathy (DCM).

OBJECTIVE

To develop magnetic resonance imaging (MRI)-based criteria to diagnose preexisting CSS and evaluate differences between patients with and without CSS.

METHODS

A secondary analysis of international prospectively collected data between 2005 and 2011 was conducted. We examined the data of 349 surgical DCM patients and 27 controls. Spinal canal and cord anteroposterior diameters were measured at noncompressed sites to calculate spinal cord occupation ratio (SCOR). Torg-Pavlov ratios and spinal canal diameters from radiographs were correlated with SCOR. Clinical and MRI factors were compared between patients with and without CSS. Surgical outcomes were also assessed.

RESULTS

Calculation of SCOR was feasible in 311/349 patients. Twenty-six patients with CSS were identified (8.4%). Patients with CSS were younger than patients without CSS (P = .03) and had worse baseline severity as measured by the modified Japanese Orthopedic Association score (P = .04), Nurick scale (P = .05), and Neck Disability Index (P < .01). CSS patients more commonly had T2 cord hyperintensity changes (P = .09, ns) and worse SF-36 Physical Component scores (P = .06, ns). SCOR correlated better with Torg-Pavlov ratio and spinal canal diameter at C3 than C5. Patients with SCOR ≥ 65% were also younger but did not differ in baseline severity.

CONCLUSION

SCOR ≥ 70% is an effective criterion to diagnose CSS. CSS patients develop myelopathy at a younger age and have greater impairment and disability than other patients with DCM. Despite this, CSS patients have comparable duration of symptoms, MRI presentations, and surgical outcomes to DCM patients without CSS.

Differences in clinical outcomes between traumatic cervical myelopathy and degenerative cervical myelopathy: A comparative study of cervical spinal cord injury without major bone injury and cervical spondylotic myelopathy

A comparative study to examine the surgical outcomes of traumatic cervical myelopathy (TCM) patients was designed. The study aim was to compare the surgical outcomes between TCM and degenerative cervical myelopathy (DCM) and to characterize the preoperative symptoms and postoperative residual symptoms in TCM patients. One hundred consecutive patients with TCM (81 men, 19 women; mean age, 57.7 years; range, 31-79 years) and 100 consecutive patients with DCM (88 men, 12 women; mean age, 58.4 years; range, 36-78 years) were included in this study. All patients were treated by laminoplasty. The pre- and postoperative neurological statuses were evaluated according to the Japanese Orthopaedic Association (JOA) scoring system for cervical myelopathy. The recovery rate (RR) of each function was compared between the two groups. The mean preoperative JOA scores of motor function of the upper extremity in the TCM and DCM groups were 1.9 and 2.3, respectively (P < 0.01). After surgery, the mean RRs of motor function of the upper extremity in the TDM and DCM groups were 36.4% and 55.7%, respectively (P < 0.01) and in the lower extremity were 32.3% and 46.5%, respectively (P < 0.05). The RR for sensory function of the lower extremity was significantly lower in TCM patients than in DCM patients (39.6 vs 68.2, respectively; P < 0.0001). Motor function impairments of the upper and lower extremities and sensory function impairments of the lower extremities after surgery were more persistent in the TCM group than in the DCM group.

Risk Factors for Poor Prognosis of Cervical Spinal Cord Injury with Subaxial Cervical Spine Fracture-Dislocation After Surgical Treatment: A CONSORT Study

BACKGROUND The objective of the study was to identify risk factors for poor prognosis of cervical spinal cord injury (SCI) with subaxial cervical fracture-dislocation after surgical treatment. MATERIAL AND METHODS A total of 60 cervical SCI patients with subaxial cervical fracture-dislocation were primarily included in the study from April 2013 to April 2018. All the enrolled subjects received surgical treatment. The enrolled patients with complete follow-up record were divided into 2 groups based on the neural function prognosis: a non-functional restoration group and a functional restoration group. Multivariate regression analysis was performed to identify independent risk factors for poor prognosis of SCI after surgical treatment. RESULTS Fifty-five subjects were included in this study, and the follow-up time ranged from 8.5 to 44.5 months. A total of 25 subjects were categorized into the non-functional restoration group and 30 subjects into the functional restoration group. According to the results of multivariate regression analysis, time from injury to operation (more than 3.8 days), subaxial cervical injury classification (SLIC, score more than 7.5), and maximum spinal cord compression (MSCC, more than 55.8%) are independent risk factors for poor prognosis of SCI after surgical treatment (p<0.05), with AUCs of 0.95 (time from injury to operation), 0.91 (SLIC score), and 0.96 (MSCC). CONCLUSIONS Time from injury to operation (more than 3.8 days), SLIC score (more than 7.5), and MSCC (more than 55.8%) are independent risk factors for poor prognosis of SCI with subaxial cervical fracture-dislocation after surgical treatment.

MR T2 image classification in adult patients of cervical spinal cord injury without radiographic abnormality: A predictor of surgical outcome

OBJECTIVES

Although patients with cervical spinal cord injury without radiographic abnormality (SCIWORA) present increased signal intensity (ISI) on magnetic resonance imaging (MRI), its degree has not been examined. This study evaluated the clinical effectiveness of MRI-based ISI in adult patients of SCIWORA. Its predictive value for symptom severity was also evaluated.

PATIENTS AND METHODS

One-hundred consecutive SCIWORA patients who had undergone expansive laminoplasty were enrolled. Among them, 79 were male and 21 were female. The mean age was 55 years (range 20-87). All patients underwent MRI in the acute phase, and ISI was classified into three groups based on sagittal T2-weighted MRI: Grade 0, none; Grade 1, light (obscure); and Grade 2, intense (bright). The pre- and postoperative neurological status was evaluated using the Japanese Orthopaedic Association scoring system for cervical myelopathy (JOA score) and the ASIA impairment scale (AIS).

RESULTS

Preoperative MRI showed Grade 0 in 8 patients, Grade 1 in 49 patients, and Grade 2 in 43 patients. There were no differences in age and gender among three groups. The pre- and postoperative JOA scores decreased significantly with an increasing ISI grade. The recovery rate of JOA score decreased with the ISI grade. The ISI grade tended to increase with the pre- and postoperative AIS grades. ISI Grade 2 on MRI was observed in severely paralyzed cases.

CONCLUSIONS

MRI-based ISI classification is correlated with preoperative symptom severity in adult patients with SCIWORA and can be a predictor of surgical outcome.

Prophylactic enlargement of the thecal sac volume by spinal expansion duroplasty in patients with unresectable malignant intramedullary tumors and metastases prior to radiotherapy

Unresectable malignant intramedullary tumors and metastases usually require radiotherapy which intensifies spinal cord edema and might result in neurological decline. Spinal expansion duroplasty before radiotherapy enlarges the intrathecal volume and might thus prevent neurological deficits. The study aims to evaluate the clinical course of patients undergoing expansion duroplasty. This retrospective analysis (2007-2016) included all patients with unresectable intramedullary tumors who underwent spinal expansion duroplasty. To assess the degree of preoperative cord enlargement, we calculated the "diameter ratio": diameter of the spinal cord below and above the tumor / diameter of the tumor × 2. The presence of perimedullary cerebrospinal fluid (CSF) at the affected levels was analyzed on the preoperative magnetic resonance imaging (MRI). We recorded the occurrence of neurological deficits, wound breakdown, and CSF fistula. We screened 985 patients, 11 of which were included. Eight patients had an intramedullary metastasis, three patients a spinal malignant glioma. A diameter ratio ≤ 0.8 representing a significant preoperative intramedullary enlargement was seen in 10 cases (90.9%). Postoperative imaging was available in 9 patients, demonstrating successful decompression in 8 of the 9 patients (88.9%). The postoperative course was uneventful in 9 patients (81.8%). Mean overall survival was 13.4 (SD 16.2) months. Spinal expansion duroplasty prior to radiotherapy is a previously undescribed concept. Despite neoadjuvant radiation, no wound breakdown or CSF fistula occurred. In unresectable intramedullary tumors and metastases, spinal expansion duroplasty seems to be a safe procedure with the potential to prevent neurological decline due to radiation-induced cord swelling.

Predictive Values of Magnetic Resonance Imaging Features for Tracheostomy in Traumatic Cervical Spinal Cord Injury

Objective

To evaluate the magnetic resonance (MR) imaging features that have a statistically significant association with the need for a tracheostomy in patients with cervical spinal cord injury (SCI) during the acute stage of injury.

Methods

This study retrospectively reviewed the clinical data of 130 patients with cervical SCI. We analyzed the factors believed to increase the risk of requiring a tracheostomy, including the severity of SCI, the level of injury as determined by radiological assessment, three quantitative MR imaging parameters, and eleven qualitative MR imaging parameters.

Results

Significant differences between the non-tracheostomy and tracheostomy groups were determined by the following five factors on multivariate analysis : complete SCI (p=0.007), the radiological level of C5 and above (p=0.038), maximum canal compromise (MCC) (p=0.010), lesion length (p=0.022), and osteophyte formation (p=0.015). For the MCC, the cut-off value was 46%, and the risk of requiring a tracheostomy was three times higher at an interval between 50–60% and ten times higher between 60–70%. For lesion length, the cut-off value was 20 mm, and the risk of requiring a tracheostomy was two times higher at an interval between 20–30 mm and fourteen times higher between 40–50 mm.

Conclusion

The American Spinal Injury Association grade A, a radiological injury level of C5 and above, an MCC ≥50%, a lesion length ≥20 mm, and osteophyte formation at the level of injury were considered to be predictive values for requiring tracheostomy intervention in patients with cervical SCI.

Clinico-Radiographic Discordance: An Evidence-Based Commentary on the Management of Degenerative Cervical Spinal Cord Compression in the Absence of Symptoms or With Only Mild Symptoms of Myelopathy

STUDY DESIGN

Narrative review with commentary.

OBJECTIVES

The growing use of magnetic resonance imaging (MRI) often leaves clinicians faced with scenarios where imaging findings are inconsistent with the clinical picture. This is particularly relevant for degenerative cervical spinal cord compression (CSCC). In this article, we provide a focused narrative literature review to address whether (1) surgery should be offered to asymptomatic patients with CSCC and (2) should MRI spinal cord signal changes influence clinical decisions for a patient with mild myelopathy from CSCC?

METHODS

Illustrative cases are presented with expert commentary which is supplemented by a focused literature review.

RESULTS

The literature suggests that CSCC from degenerative pathology is a common incidental radiographic finding. For those without symptoms of myelopathy, the short-term risk of progression is low. There is a lack of evidence to support surgery for asymptomatic individuals with CSCC who have no risk factors for progression. For these patients, the authors suggest non-operative management that includes education on the symptoms of myelopathy, clinical follow-up within 6 to 12 months, and avoidance of high-risk activities. Conversely, symptomatic patients have a notable risk of progression. Surgical intervention improves neurological function and quality of life regardless of severity. The authors support surgery as an option for all patients with mild myelopathy who are appropriate operative candidates. Intramedullary signal change on MRI has not been shown to reliably predict progression.

CONCLUSIONS

While MRI technologies are under evolution, we advise that surgical decisions for patients with CSCC should rely on clinical assessment and not imaging findings.

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.

Traumatic subaxial cervical facet subluxation and dislocation: epidemiology, radiographic analyses, and risk factors for spinal cord injury

BACKGROUND CONTEXT

Distractive flexion injuries (DFIs) of the subaxial cervical spine are major contributors to spinal cord injury (SCI). Prompt assessment and early intervention of DFIs associated with SCI are crucial to optimize patient outcome; however, neurologic examination of patients with subaxial cervical injury is often difficult, as patients commonly present with reduced levels of consciousness. Therefore, it is important to establish potential associations between injury epidemiology and radiographic features, and neurologic involvement.

PURPOSE

The aims of this study were to describe the epidemiology and radiographic features of DFIs presenting to a major Australian tertiary hospital and to identify those factors predictive of SCI. The agreement and repeatability of radiographic measures of DFI severity were also investigated.

STUDY DESIGN/SETTING

This is a combined retrospective case-control and reliability-agreement study.

PATIENT SAMPLE

Two hundred twenty-six patients (median age 40 years [interquartile range = 34]; 72.1% male) who presented with a DFI of the subaxial cervical spine between 2003 and 2013 were reviewed.

OUTCOME MEASURES

The epidemiology and radiographic features of DFI, and risk factors for SCI were identified. Inter- and intraobserver agreement of radiographic measurements was evaluated.

METHODS

Medical records, radiographs, and computed tomography and magnetic resonance imaging scans were examined, and the presence of SCI was evaluated. Radiographic images were analyzed by two consultant spinal surgeons, and the degree of vertebral translation, facet apposition, spinal canal occlusion, and spinal cord compression were documented. Multivariable logistic regression models identified epidemiology and radiographic features predictive of SCI. Intraclass correlation coefficients (ICCs) examined inter- and intraobserver agreement of radiographic measurements.

RESULTS

The majority of patients (56.2%) sustained a unilateral (51.2%) or a bilateral facet (48.8%) dislocation. The C6-C7 vertebral level was most commonly involved (38.5%). Younger adults were over-represented among motor-vehicle accidents, whereas falls contributed to a majority of DFIs sustained by older adults. Greater vertebral translation, together with lower facet apposition, distinguished facet dislocation from subluxation. Dislocation, bilateral facet injury, reduced Glasgow Coma Scale, spinal canal occlusion, and spinal cord compression were predictive of neurologic deficit. Radiographic measurements demonstrated at least a "moderate" agreement (ICC>0.4), with most demonstrating an "almost perfect" reproducibility.

CONCLUSIONS

This large-scale cohort investigation of DFIs in the cervical spine describes radiographic features that distinguish facet dislocation from subluxation, and associates highly reproducible anatomical and clinical indices to the occurrence of concomitant SCI.

Acute Thoracolumbar Spinal Cord Injury: Relationship of Cord Compression to Neurological Outcome

BACKGROUND

Spinal cord injury in the cervical spine is commonly accompanied by cord compression and urgent surgical decompression may improve neurological recovery. However, the extent of spinal cord compression and its relationship to neurological recovery following traumatic thoracolumbar spinal cord injury is unclear. The purpose of this study was to quantify maximum cord compression following thoracolumbar spinal cord injury and to assess the relationship among cord compression, cord swelling, and eventual clinical outcome.

METHODS

The medical records of patients who were 15 to 70 years of age, were admitted with a traumatic thoracolumbar spinal cord injury (T1 to L1), and underwent a spinal surgical procedure were examined. Patients with penetrating injuries and multitrauma were excluded. Maximal osseous canal compromise and maximal spinal cord compression were measured on preoperative mid-sagittal computed tomography (CT) scans and T2-weighted magnetic resonance imaging (MRI) by observers blinded to patient outcome. The American Spinal Injury Association (ASIA) Impairment Scale (AIS) grades from acute hospital admission (≤24 hours of injury) and rehabilitation discharge were used to measure clinical outcome. Relationships among spinal cord compression, canal compromise, and initial and final AIS grades were assessed via univariate and multivariate analyses.

RESULTS

Fifty-three patients with thoracolumbar spinal cord injury were included in this study. The overall mean maximal spinal cord compression (and standard deviation) was 40% ± 21%. There was a significant relationship between median spinal cord compression and final AIS grade, with grade-A patients (complete injury) exhibiting greater compression than grade-C and D patients (incomplete injury) (p < 0.05). Multivariate logistic regression identified mean spinal cord compression as independently influencing the likelihood of complete spinal cord injury (p < 0.01).

CONCLUSIONS

Traumatic thoracolumbar spinal cord injury is commonly accompanied by substantial cord compression. Greater cord compression is associated with an increased likelihood of severe neurological deficits (complete injury) following thoracolumbar spinal cord injury.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Multivariate Analysis of MRI Biomarkers for Predicting Neurologic Impairment in Cervical Spinal Cord Injury

BACKGROUND AND PURPOSE

Acute markers of spinal cord injury are essential for both diagnostic and prognostic purposes. The goal of this study was to assess the relationship between early MR imaging biomarkers after acute cervical spinal cord injury and to evaluate their predictive validity of neurologic impairment.

MATERIALS AND METHODS

We performed a retrospective cohort study of 95 patients with acute spinal cord injury and preoperative MR imaging within 24 hours of injury. The American Spinal Injury Association Impairment Scale was used as our primary outcome measure to define neurologic impairment. We assessed several MR imaging features of injury, including axial grade (Brain and Spinal Injury Center score), sagittal grade, length of injury, maximum canal compromise, and maximum spinal cord compression. Data-driven nonlinear principal component analysis was followed by correlation and optimal-scaled multiple variable regression to predict neurologic impairment.

RESULTS

Nonlinear principal component analysis identified 2 clusters of MR imaging variables related to 1) measures of intrinsic cord signal abnormality and 2) measures of extrinsic cord compression. Neurologic impairment was best accounted for by MR imaging measures of intrinsic cord signal abnormality, with axial grade representing the most accurate predictor of short-term impairment, even when correcting for surgical decompression and degree of cord compression.

CONCLUSIONS

This study demonstrates the utility of applying nonlinear principal component analysis for defining the relationship between MR imaging biomarkers in a complex clinical syndrome of cervical spinal cord injury. Of the assessed imaging biomarkers, the intrinsic measures of cord signal abnormality were most predictive of neurologic impairment in acute spinal cord injury, highlighting the value of axial T2 MR imaging.

Return to Play after Cervical Spine Injuries: A Consensus of Opinion

Study Design Survey. Objective Sports-related spinal cord injury (SCI) represents a growing proportion of total SCIs but lacks evidence or guidelines to guide clinical decision-making on return to play (RTP). Our objective is to offer the treating physician a consensus analysis of expert opinion regarding RTP that can be incorporated with the unique factors of a case for clinical decision-making. Methods Ten common clinical scenarios involving neurapraxia and stenosis, atlantoaxial injury, subaxial injury, and general cervical spine injury were presented to 25 spine surgeons from level 1 trauma centers for whom spine trauma is a significant component of their practice. We evaluated responses to questions about patient RTP, level of contact, imaging required for a clinical decision, and time to return for each scenario. The chi-square test was used for statistical analysis, with p < 0.05 considered significant. Results Evaluation of the surgeons' responses to these cases showed significant consensus regarding return to high-contact sports in cases of cervical cord neurapraxia without symptoms or stenosis, surgically repaired herniated disks, and nonoperatively healed C1 ring or C2 hangman's fractures. Greater variability was found in recommendations for patients showing persistent clinical symptomatology. Conclusion This survey suggests a consensus among surgeons for allowing patients with relatively normal imaging and resolution of symptoms to return to high-contact activities; however, patients with cervical stenosis or clinical symptoms continue to be a challenge for management. This survey may serve as a basis for future clinical trials and consensus guidelines.

Multidimensional Analysis of Magnetic Resonance Imaging Predicts Early Impairment in Thoracic and Thoracolumbar Spinal Cord Injury

Literature examining magnetic resonance imaging (MRI) in acute spinal cord injury (SCI) has focused on cervical SCI. Reproducible systems have been developed for MRI-based grading; however, it is unclear how they apply to thoracic SCI. Our hypothesis is that MRI measures will group as coherent multivariate principal component (PC) ensembles, and that distinct PCs and individual variables will show discriminant validity for predicting early impairment in thoracic SCI. We undertook a retrospective cohort study of 25 patients with acute thoracic SCI who underwent MRI on admission and had American Spinal Injury Association Impairment Scale (AIS) assessment at hospital discharge. Imaging variables of axial grade, sagittal grade, length of injury, thoracolumbar injury classification system (TLICS), maximum canal compromise (MCC), and maximum spinal cord compression (MSCC) were collected. We performed an analytical workflow to detect multivariate PC patterns followed by explicit hypothesis testing to predict AIS at discharge. All imaging variables loaded positively on PC1 (64.3% of variance), which was highly related to AIS at discharge. MCC, MSCC, and TLICS also loaded positively on PC2 (22.7% of variance), while variables concerning cord signal abnormality loaded negatively on PC2. PC2 was highly related to the patient undergoing surgical decompression. Variables of signal abnormality were all negatively correlated with AIS at discharge with the highest level of correlation for axial grade as assessed with the Brain and Spinal Injury Center (BASIC) score. A multiple variable model identified BASIC as the only statistically significant predictor of AIS at discharge, signifying that BASIC best captured the variance in AIS within our study population. Our study provides evidence of convergent validity, construct validity, and clinical predictive validity for the sampled MRI measures of SCI when applied in acute thoracic and thoracolumbar SCI.

Comparison of agreement of cervical spine degenerative pathology findings in magnetic resonance imaging studies

BACKGROUND CONTEXT

Magnetic resonance imaging (MRI) is often used in the evaluation of degenerative conditions of the cervical spine. However, the agreement of interpreting and reporting varying degenerative findings on cervical MRI has not been well assessed.

PURPOSE

This study aimed to compare the inter-rater and intra-rater agreement of MRI findings between common degenerative findings of the cervical spine.

STUDY DESIGN

A retrospective diagnostic study was used as study design.

PATIENT SAMPLE

The sample consisted of 48 patients who underwent routine cervical spine MRI at our institution between January 2011 and June 2012.

OUTCOME MEASURES

Reviewers evaluated each MRI study at each vertebral level for disc hydration, disc space height, central stenosis, foraminal stenosis, end plate changes, spondylolisthesis, and cord signal change.

METHODS

A panel of two orthopedic spine surgeons and four musculoskeletal radiologists independently reviewed 48 sets of T2-weighted axial and sagittal MRI sequences for a series of preselected criteria, and their findings were compared with those of the other panelists to determine inter-rater agreement. Each panelist also re-reviewed the first 10 studies to determine intra-rater agreement. Absolute inter-rater and intra-rater agreements were then calculated and compared for different findings. A modified analysis ignored disagreements between the least severe grades of findings to determine the inter-rater and intra-rater agreements of the most clinically important severity grades.

RESULTS

Absolute inter-rater agreement ranged from 54.6% to 95.0%. Disc hydration (54.6%), central stenosis (72.7%), and foraminal stenosis (73.1%) demonstrated the lowest inter-rater agreement, whereas spondylolisthesis (95.0%) and cord signal change (92.9%) demonstrated the highest agreement. The modified analysis found better inter-rater agreement, ranging from 80.9% to 95.0%. Absolute intra-rater agreement ranged from 74.2% to 94.7%. The modified analysis again found better agreement, ranging from 85.0% to 94.7%. As would be expected, overall intra-rater agreement (81.6%, 95% CI 78.9%-84.3%) was higher than inter-rater agreement (75.7%, 95% CI 74.4%-77.0%). The clinical specialty of the reviewer had no significant impact on inter- or intra-rater agreement.

CONCLUSIONS

MRI findings play an important role in the management of patients with cervical spine conditions. For this reason, consistent descriptions of these findings are essential and physicians should be aware of the relative reliability of these findings. This systematic study developed standardized grading criteria and nomenclature for common clinically significant MRI findings in the cervical spine. Even in this optimized research setting, we found significant ranges in agreement across these MRI findings. In the clinical setting, inter- and intra-rater agreements may be lower, and the range of agreements between findings may be greater. Physicians should be aware of inconsistencies inherent in the interpretation of cervical MRI findings and should be aware that some findings demonstrate lower agreement than others.

A prospective study of neurological outcome in relation to findings of imaging modalities in acute spinal cord injury

AIM

The aim was to correlate the clinical profile and neurological outcome with findings of imaging modalities in acute spinal cord injury (SCI) patients.

SUBJECTS AND METHODS

Imaging (radiographs, computed tomography [CT], and magnetic resonance imaging [MRI]) features of 25 patients of acute SCI were analyzed prospectively and correlated with clinical and neurology outcome at presentation, 3, 6 and 12 months.

RESULTS

Average initial sagittal index, Gardner's index, and regional kyphosis were 8.12 ± 3.90, 15.68 ± 4.09, 16.44 ± 2.53, respectively; and at 1-year were 4.8 ± 3.03, 12.24 ± 4.36, 12.44 ± 2.26, respectively. At presentation patients with complete SCI had significantly more compression percentage (CP) (P < 0.001), maximum canal compromise (P < 0.001), maximum spinal cord compression (P < 0.001), in comparison to incomplete SCI patients. Qualitative MRI findings; hemorrhage, cord swelling, stenosis showed a predilection toward complete SCI. Improvement in canal dimensions (P = 0.001), beck index (P = 0.008), spinal cord edema (P = 0.010) and stenosis (P = 0.001) was more significant in patients managed operatively; but it was not associated with improved neurological outcome. Cord edema was found more in incomplete SCI patients. Patients presenting with complete SCI improved neurologically to a lesser extent.

CONCLUSIONS

The present study concludes that imaging modalities in spinal cord injuries have a major role in diagnosis, directing management and predicting prognosis. Imaging findings of severe kyphotic deformities, higher canal and cord compression, lesion length, hemorrhage, and cord swelling are associated with poor initial neurological status and recovery. Quantitative and qualitative parameters measured on MRI have a significant role in predicting initial severity of neurological status and outcome. Operative intervention helps in improving few of these imaging parameters, but not ultimate neurological outcome. MRI is an excellent modality to evaluate acute SCI, and MR images obtained in the acute period significantly and usefully predict neurological outcome.

Evaluation of Traumatic Spine by Magnetic Resonance Imaging and Correlation with Neurological Recovery

Study Design

Prospective study.

Purpose

To compare magnetic resonance imaging (MRI) findings with clinical profile and neurological status of the patient and to correlate the MRI findings with neurological recovery of the patients and predict the outcome.

Overview of Literature

Previous studies have reported poor neurological recovery in patients with cord hemorrhage, as compared to cord edema in spine injury patients. High canal compromise, cord compression along with higher extent of cord injury also carries poor prognostic value.

Methods

Neurological status of patients was assessed at the time of admission and discharge in as accordance with the American Spine Injury Association (ASIA) impairment scale. Mean stay in hospital was 14.11±5.74 days. Neurological status at admission and neurological recovery at discharge was compared with various qualitative cord findings and quantitative parameters on MRI. In 27 patients, long-term follow-up was done at mean time of 285.9±43.94 days comparing same parameters.

Results

Cord edema and normal cord was associated with favorable neurological outcome. Cord contusion showed lesser neurological recovery, as compared to cord edema. Cord hemorrhage was associated with worst neurological status at admission and poor neurological recovery. Mean canal compromise (MCC), mean spinal cord compression (MSCC) and lesion length values were higher in patients presenting with ASIA A impairment scale injury and showed decreasing trends towards ASIA E impairment scale injury. Patients showing neurological recovery had lower mean MCC, MSCC, and lesion length, as compared to patients showing no neurological recovery (p<0.05).

Conclusions

Cord hemorrhage, higher MCC, MSCC, and lesion length values have poor prognostic value in spine injury patients.

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).

Role of magnetic resonance imaging in predicting surgical outcome in patients with cervical spondylotic myelopathy

STUDY DESIGN

Ambispective, retrospective cohort study from prospectively collected data.

SUMMARY OF BACKGROUND DATA

Cervical spondylotic myelopathy is the commonest cause of spinal cord impairment in the elderly population worldwide. Although magnetic resonance imaging (MRI) is the primary imaging modality for confirming the diagnosis, its role in predicting surgical outcome remains unclear.

METHODS

Two hundred seventy-eight patients with 1 or more clinical signs of myelopathy were enrolled; and they underwent decompression surgery. Complete baseline clinical and MRI data were available for 102 patients. MRI parameters measured included presence/absence of signal change on T1 and T2, T2 signal quantitative factors, and anatomical measurements. A dichotomized postoperative modified Japanese Orthopedic Association (mJOA) score at 6 months was used to characterize patients with mild myelopathy (≥16) and those with substantial residual neurological impairment (<16). Univariate analysis assessed the relationship between baseline parameters and outcome. Multivariate logistic regression was conducted after a conceptual division of variables into 3 groups: T1 signal analysis, T2 signal analysis, and anatomical measurements.

RESULTS

Baseline mJOA (P<0.001; odds ratio [OR]=1.644, 95% confidence interval [95% CI]: 1.326-2.037), maximum canal compromise (MCC) (P=0.0322; OR=0.965, 95% CI: 0.934-0.997), T2 hyperintensity region of interest area (P=0.0422; OR=0.67; 95% CI: 0.456-0.986), and sagittal extent (P=0.026; OR=0.673; 95% CI: 0.475-0.954) were significantly associated with outcome univariately. The final model was comprised of T1 hypointensity (P=0.029; OR=0.242; CI: 0.068-0.866), MCC (P=0.005; OR=0.940; CI: 0.90-0.982) and baseline mJOA (P<0.001; OR=1.743; CI: 1.353-2.245), yielding an area under the receiver operating characteristic curve (AUC) of 0.845.

CONCLUSION

Baseline mJOA is a strong predictor of postsurgical outcome in cervical spondylotic myelopathy at 6 months. However, a model inclusive of MCC and T1 hypointensity assessment provides superior predictive capacity. This suggests that MRI analysis has a significant role in predicting surgical outcome.

LEVEL OF EVIDENCE

3.

Interrater and intrarater agreements of magnetic resonance imaging findings in the lumbar spine: significant variability across degenerative conditions

BACKGROUND CONTEXT

Magnetic resonance imaging (MRI) is frequently used in the evaluation of degenerative conditions in the lumbar spine. The relative interrater and intrarater agreements of MRI findings across different pathologic conditions are underexplored, as most studies are focused on specific findings.

PURPOSE

The purpose of this study was to characterize the interrater and intrarater agreements of MRI findings used to assess the degenerative lumbar spine.

STUDY DESIGN

A retrospective diagnostic study at a large academic medical center was undertaken with a panel of orthopedic surgeons and musculoskeletal radiologists to assess lumbar MRIs using standardized criteria.

PATIENT SAMPLE

Seventy-five subjects who underwent routine lumbar spine MRI at our institution were included.

OUTCOME MEASURES

Each MRI study was assessed for 10 lumbar degenerative findings using standardized criteria. Lumbar vertebral levels were assessed independently, where applicable, for a total of 52 data points collected per study.

METHODS

T2-weighted axial and sagittal MRI sequences were presented in random order to the four reviewers (two orthopedic spine surgeons and two musculoskeletal radiologists) independently to determine interrater agreement. The first 10 studies were reevaluated at the end to determine intrarater agreement. Images were assessed using standardized and pilot-tested criteria to assess disc degeneration, stenosis, and other degenerative changes. Interrater and intrarater absolute percent agreements were calculated. To highlight the most clinically important MRI disagreements, a modified agreement analysis was also performed (in which disagreements between the lowest two severity grades for applicable conditions were ignored). Fleiss kappa coefficients for interrater agreement were determined.

RESULTS

The overall absolute and modified interrater agreements were 76.9% and 93.5%, respectively. The absolute and modified intrarater agreements were 81.3% and 92.7%, respectively. Average Fleiss kappa coefficient was 0.431, suggesting moderate overall agreement. However, when stratified by condition, absolute interrater agreement ranged from 65.1% to 92.0%. Disc hydration, disc space height, and bone marrow changes exhibited the lowest absolute interrater agreements. The absolute intrarater agreement had a narrower range, from 74.5% to 91.5%. Fleiss kappa coefficients ranged from fair-to-substantial agreement (0.282-0.618).

CONCLUSIONS

Even in a study using standardized evaluation criteria, there was significant variability in the interrater and intrarater agreements of MRI in assessing different degenerative conditions of the lumbar spine. Clinicians should be aware of the condition-specific diagnostic limitations of MRI interpretation.

Prediction of prognosis in patients with cervical spinal cord injury without radiologic evidence of trauma using MRI

The purpose of this study was to investigate whether pre- to postoperative changes of increased signal intensity (ISI) of the spinal cord as seen on T2-weighted magnetic resonance imaging (MRI) reflect the surgical outcome in patients with cervical spinal cord injury without radiologic evidence of trauma (SCIWORET). In this study, 54 patients with SCIWORET who underwent expansive laminoplasty were retrospectively analyzed. All patients underwent MRI at an average of 1.9 days (range, 1-5 days) after injury and 7.9 days (range, 6-10 days) postoperatively. The pre- and postoperative range and degree of ISI were measured on computer software using the same sagittal view on T2-weighted MRI. Then, the post-preoperative ratio of range and degree of ISI were calculated. Pre- and postoperative neurologic evaluations were performed according to the criteria proposed by the Japanese Orthopedic Association (JOA). A significant negative correlation existed between the ratio of range of ISI and the recovery rate (r=-0.504, P<.01). The ratio of degree of ISI negatively correlated with the recovery rate, but this was not statistically significant. Patients were divided into 2 groups according to the ratio of degree of ISI: group A included patients with a ratio of degree of ISI of ≤1 (n=24) and group B included patients with a ratio of degree of ISI of >1 (n=30). Patients' mean recovery rate was 65.0%±6.3% in group A and 52.4%±7.4% in group B. A significant difference was found between the 2 groups (P<.001, Student's t test) when comparing recovery rate. The pre- to postoperative changes of the range and degree of ISI significantly reflected prognosis for surgical outcome in patients with SCIWORET.

Reliability of quantitative magnetic resonance imaging methods in the assessment of spinal canal stenosis and cord compression in cervical myelopathy

STUDY DESIGN

Prospective, blinded reliability study of quantitative magnetic resonance imaging (MRI) measures in patients with cervical myelopathy.

OBJECTIVE

To assess the intra- and interobserver reliability of commonly used quantitative MRI measures such as transverse area (TA) of spinal cord, compression ratio (CR), maximum canal compromise (MCC), and maximum spinal cord compression (MSCC).

SUMMARY OF BACKGROUND DATA

There is no consensus on an optimal quantitative MRI method(s) in assessing canal stenosis and cord compression.

METHODS

Seven surgeons performed measurements on 17 digital MR images, on 4 separate occasions. The degree of stenosis was evaluated by measuring TA and CR on axial T2, MCC, and MSCC on midsagittal T1- and T2-weighted MRI sequences, respectively. Statistical analyses included repeated-measures analysis of variance and intraclass correlation coefficients (ICCs).

RESULTS

The mean ± SD for intraobserver ICC was 0.88 ± 0.1 for MCC, 0.76 ± 0.08 for MSCC, 0.92 ± 0.07 for TA, and 0.82 ± 0.13 for CR. In addition, the interobserver ICC was 0.75 ± 0.04 for MCC, 0.79 ± 0.09 for MSCC, 0.80 ± 0.05 for CR, and 0.86 ± 0.03 for TA. Higher degree of canal compromise (MCC) was associated with lower modified version of Japanese Orthopaedic Association Scale score (P = 0.05). Also, a strong association was found between MSCC and lower modified version of Japanese Orthopaedic Association Scale score, greater number of steps, and longer walking time (P < 0.05).

CONCLUSION

All 4 measurement techniques demonstrated a good to moderately high degree of intra- and interobserver reliability. Highest reliability was noted in the assessment of T2-weighted sequences and axial MRI. Our results show that the measurements of MCC, MSCC, and CR are sufficiently reliable and correlate well with clinical severity of cervical myelopathy.

Predictors of pulmonary complications in blunt traumatic spinal cord injury

OBJECT

Pulmonary complications are the most common acute systemic adverse events following spinal cord injury (SCI), and contribute to morbidity, mortality, and increased length of hospital stay (LOS). Identification of factors associated with pulmonary complications would be of value in prevention and acute care management. Predictors of pulmonary complications after SCI and their effect on neurological recovery were prospectively studied between 2005 and 2009 at the 9 hospitals in the North American Clinical Trials Network (NACTN).

METHODS

The authors sought to address 2 specific aims: 1) define and analyze the predictors of moderate and severe pulmonary complications following SCI; and 2) investigate whether pulmonary complications negatively affected the American Spinal Injury Association (ASIA) Impairment Scale conversion rate of patients with SCI. The NACTN registry of the demographic data, neurological findings, imaging studies, and acute hospitalization duration of patients with SCI was used to analyze the incidence and severity of pulmonary complications in 109 patients with early MR imaging and long-term follow-up (mean 9.5 months). Univariate and Bayesian logistic regression analyses were used to analyze the data.

RESULTS

In this study, 86 patients were male, and the mean age was 43 years. The causes of injury were motor vehicle accidents and falls in 80 patients. The SCI segmental level was in the cervical, thoracic, and conus medullaris regions in 87, 14, and 8 patients, respectively. Sixty-four patients were neurologically motor complete at the time of admission. The authors encountered 87 complications in 51 patients: ventilator-dependent respiratory failure (26); pneumonia (25); pleural effusion (17); acute lung injury (6); lobar collapse (4); pneumothorax (4); pulmonary embolism (2); hemothorax (2), and mucus plug (1). Univariate analysis indicated associations between pulmonary complications and younger age, sports injuries, ASIA Impairment Scale grade, ascending neurological level, and lesion length on the MRI studies at admission. Bayesian logistic regression indicated a significant relationship between pulmonary complications and ASIA Impairment Scale Grades A (p = 0.0002) and B (p = 0.04) at admission. Pulmonary complications did not affect long-term conversion of ASIA Impairment Scale grades.

CONCLUSIONS

The ASIA Impairment Scale grade was the fundamental clinical entity predicting pulmonary complications. Although pulmonary complications significantly increased LOS, they did not increase mortality rates and did not adversely affect the rate of conversion to a better ASIA Impairment Scale grade in patients with SCI. Maximum canal compromise, maximum spinal cord compression, and Acute Physiology and Chronic Health Evaluation-II score had no relationship to pulmonary complications.

A comprehensive subaxial cervical spine injury severity assessment model using numeric scores and its predictive value for surgical intervention

Multiple factors contribute to the determination for surgical intervention in the setting of cervical spinal injury, yet to date no unified classification system exists that predicts this need. The goals of this study were twofold: to create a comprehensive subaxial cervical spine injury severity numeric scoring model, and to determine the predictive value of this model for the probability of surgical intervention. In a retrospective cohort study of 333 patients, neural impairment, patho-morphology, and available spinal canal sagittal diameter post-injury were selected as injury severity determinants. A common numeric scoring trend was created; smaller values indicated less favorable clinical conditions. Neural impairment was graded from 2-10, patho-morphology scoring ranged from 2-15, and post-injury available canal sagittal diameter (SD) was measured in millimeters at the narrowest point of injury. Logistic regression analysis was performed using the numeric scores to predict the probability for surgical intervention. Complete neurologic deficit was found in 39 patients, partial deficits in 108, root injuries in 19, and 167 were neurologically intact. The pre-injury mean canal SD was 14.6 mm; the post-injury measurement mean was 12.3 mm. The mean patho-morphology score for all patients was 10.9 and the mean neurologic function score was 7.6. There was a statistically significant difference in mean scores for neural impairment, canal SD, and patho-morphology for surgical compared to nonsurgical patients. At the lowest clinical score for each determinant, the probability for surgery was 0.949 for neural impairment, 0.989 for post-injury available canal SD, and 0.971 for patho-morphology. The unit odds ratio for each determinant was 1.73, 1.61, and 1.45, for neural impairment, patho-morphology, and canal SD scores, respectively. The subaxial cervical spine injury severity determinants of neural impairment, patho-morphology, and post-injury available canal SD have well defined probability for surgical intervention when scored separately. Our data showed that each determinant alone could act as a primary predictor for surgical intervention.

Can magnetic resonance imaging reflect the prognosis in patients of cervical spinal cord injury without radiographic abnormality?

STUDY DESIGN

This is a prospective imaging study of adult patients with cervical spinal cord injury without radiographic abnormality (SCIWORA).

OBJECTIVE

The purpose of this study was to investigate the occurrence rate of intramedullary high-signal intensity (increased signal intensity [ISI]) and prevertebral hyperintensity (PVH) in patients with SCIWORA, and examine their relationship to symptom severity and surgical outcome.

SUMMARY OF BACKGROUND DATA

SCIWORA is accompanied by the presence of neurologic symptoms in the absence of positive radiographic findings before the emergence of magnetic resonance imaging (MRI). There are few reports regarding the image features on MRI in these patients.

METHODS

One-hundred consecutive patients with SCIWORA who had undergone expansive laminoplasty were enrolled. There were 79 men and 21 women; the mean age was 55 years (range, 16-87 years). All patients underwent functional x-ray and MRI in the acute phase. On MR T2-weighted imaging sagittal view, occurrence of ISI and PVH was evaluated. Range of ISI and PVH was measured relative to C3 vertebral height. Japanese Orthopaedic Association (JOA) scoring system for cervical myelopathy (JOA score), it's recovery rate, and ASIA impairment scale were used to evaluate neurological status.

RESULTS

ISI was observed in 92 patients and PVH in 90 patients on MRI preoperatively. The range of ISI and PVH tended to increase with scores on the preoperative ASIA scale. ISI and PVH were seen in all patients with ASIA A and B. There was a significant negative correlation between the range of ISI and preoperative JOA score. A significant negative correlation between the range of ISI and recovery rate of JOA score was also seen.

CONCLUSION

ISI and PVH occurred in more than 90% of patients with SCIWORA. The range of ISI significantly reflected symptom severity and prognosis for neurologic outcome.

MRI in acute and subacute post-traumatic spinal cord injury: pictorial review

STUDY DESIGN

Pictorial review.

OBJECTIVES

To illustrate MRI signs of acute and subacute injury with emphasis on evidence-based links to clinical outcome and implications for treatment.

METHODS

Description of important aspects of MRI techniques and illustration of critical MRI signs important in the assessment of spinal cord injury following trauma, in the acute and subacute stages.

CONCLUSIONS

Familiarity with cord MRI appearances has an important impact on planning the management of the acutely spinal cord injured patient and also identifying complications in the subacute phase particularly in the presence of neurological deterioration.

A novel approach to quantitatively assess posttraumatic cervical spinal canal compromise and spinal cord compression: a multicenter responsiveness study

STUDY DESIGN

Multicenter retrospective study.

OBJECTIVE

To examine whether posttraumatic cervical spinal canal compromise and spinal cord compression are responsive to changes in motor and sensory functions.

SUMMARY OF BACKGROUND DATA

The maximum canal compromise (MCC) and maximum spinal cord compression (MSCC) were developed to quantitatively assess canal stenosis and spinal cord compression using computed tomographic (CT) scan and magnetic resonance imaging (MRI) in the setting of acute spine trauma.

METHODS

We included 100 consecutive patients with acute spine trauma. Patients were classified into three groups as follows: patients with acute spine trauma without spinal cord injury (group 1), patients with incomplete spinal cord injury (group 2), and patients with complete spinal cord injury (group 3). We studied three quantitative imaging parameters given as follows: MCC using CT-based measurements, MCC using T1-MRI based measurements, and MSCC using T2-MRI based measurements.

RESULTS

There were 78 male patients and 22 female patients with ages from 17 to 82 years (mean age = 45 years). In group 1, there were no significant differences regarding the mean MRI-MCC and MSCC among the spine levels. Although most spine levels were statistically comparable regarding the CT-MCC in patients of group 1, the C7 level significantly differed from the C3 level. Comparisons among all three patient groups showed significant differences regarding the mean MRI-MCC and MSCC, but no significant differences were observed in the mean CT-MCC between groups 1 and 2, and between groups 1 and 3. Data analyses using operating characteristics of each radiologic parameter indicated that only the MRI parameters had consistently optimal cutoff points to distinguish between groups 1 and 2, and between groups 2 and 3.

CONCLUSION

Our results suggest that the MRI-based measurements of canal compromise and spinal cord compression are responsive to changes in motor and sensory functions. However, the MCC using CT-based measurements provides inconsistent results that can result in misdiagnosis in the clinical setting.