Prognostic value of tissue bridges in cervical spinal cord injury: a longitudinal, multicentre, retrospective cohort study

BACKGROUND

The accuracy of prognostication in patients with cervical spinal cord injury (SCI) needs to be improved. We aimed to explore the prognostic value of preserved spinal tissue bridges-injury-spared neural tissue adjacent to the lesion-for prediction of sensorimotor recovery in a large, multicentre cohort of people with SCI.

METHODS

For this longitudinal study, we included patients with acute cervical SCI (vertebrae C1-C7) admitted to one of three trauma or rehabilitation centres: Murnau, Germany (March 18, 2010-March 1, 2021); Zurich, Switzerland (May 12, 2002-March 2, 2019); and Denver, CO, USA (Jan 12, 2010-Feb 16, 2017). Patients were clinically assessed at admission (baseline), at discharge (3 months), and at 12 months post SCI. Midsagittal tissue bridges were quantified from T2-weighted images assessed at 3-4 weeks post SCI. Fractional regression and unbiased recursive partitioning models, adjusted for age, sex, centre, and neurological level of injury, were used to assess associations between tissue bridge width and baseline-adjusted total motor score, pinprick score, and light touch scores at 3 months and 12 months. Patients were stratified into subgroups according to whether they showed better or worse predicted recovery.

FINDINGS

The cohort included 227 patients: 93 patients from Murnau (22 [24%] female); 43 patients from Zurich (four [9%] female); and 91 patients from Denver (14 [15%] female). 136 of these participants (from Murnau and Zurich) were followed up for up to 12 months. At 3 months, per preserved 1 mm of tissue bridge at baseline, patients recovered a mean of 9·3% (SD 0·9) of maximal total motor score (95% CI 7·5-11.2), 8·6% (0·8) of maximal pinprick score (7·0-10·1), and 10·9% (0·8) of maximal light touch score (9·4-12·5). At 12 months post SCI, per preserved 1 mm of tissue bridge at baseline, patients recovered a mean of 10·9% (1·3) of maximal total motor score (8·4-13·4), 5·7% (1·3) of maximal pinprick score (3·3-8·2), and 6·9% (1·4) of maximal light touch score (4·1-9·7). Partitioning models identified a tissue bridge cutoff width of 2·0 mm to be indicative of higher or lower 3-month total motor, pinprick, and light touch scores, and a cutoff of 4·0 mm to be indicative of higher and lower 12-month scores. Compared with models that contained clinical predictors only, models additionally including tissue bridges had significantly improved prediction accuracy across all three centres.

INTERPRETATION

Tissue bridges, measured in the first few weeks after SCI, are associated with short-term and long-term clinical improvement. Thus, tissue bridges could potentially be used to guide rehabilitation decision making and to stratify patients into more homogeneous subgroups of recovery in regenerative and neuroprotective clinical trials.

FUNDING

Wings for Life, International Foundation for Research in Paraplegia, EU project Horizon 2020 (NISCI grant), and ERA-NET NEURON.

Classifying clinical phenotypes of functional recovery for acute traumatic spinal cord injury. An observational cohort study

PURPOSE

Identify patient subgroups with different functional outcomes after SCI and study the association between functional status and initial ISNCSCI components.

METHODS

Using CART, we performed an observational cohort study on data from 675 patients enrolled in the Rick-Hansen Registry(RHSCIR) between 2014 and 2019. The outcome was the Spinal Cord Independence Measure (SCIM) and predictors included AIS, NLI, UEMS, LEMS, pinprick(PPSS), and light touch(LTSS) scores. A temporal validation was performed on data from 62 patients treated between 2020 and 2021 in one of the RHSCIR participating centers.

RESULTS

The final CART resulted in four subgroups with increasing totSCIM according to PPSS, LEMS, and UEMS: 1)PPSS < 27(totSCIM = 28.4 ± 16.3); 2)PPSS ≥ 27, LEMS < 1.5, UEMS < 45(totSCIM = 39.5 ± 19.0); 3)PPSS ≥ 27, LEMS < 1.5, UEMS ≥ 45(totSCIM = 57.4 ± 13.8); 4)PPSS ≥ 27, LEMS ≥ 1.5(totSCIM = 66.3 ± 21.7). The validation model performed similarly to the original model. The adjusted R-squared and F-test were respectively 0.556 and 62.2(P-value <0.001) in the development cohort and, 0.520 and 31.9(P-value <0.001) in the validation cohort.

CONCLUSION

Acknowledging the presence of four characteristic subgroups of patients with distinct phenotypes of functional recovery based on PPSS, LEMS, and UEMS could be used by clinicians early after tSCI to plan rehabilitation and establish realistic goals. An improved sensory function could be key for potentiating motor gains, as a PPSS ≥ 27 was a predictor of a good function.

Verification of the Accuracy of Cervical Spinal Cord Injury Prognosis Prediction Using Clinical Data-Based Artificial Neural Networks

BACKGROUND

In patients with cervical spinal cord injury (SCI), we need to make accurate prognostic predictions in the acute phase for more effective rehabilitation. We hypothesized that a multivariate prognosis would be useful for patients with cervical SCI.

METHODS

We made two predictive models using Multiple Linear Regression (MLR) and Artificial Neural Networks (ANNs). We adopted MLR as a conventional predictive model. Both models were created using the same 20 clinical parameters of the acute phase data at the time of admission. The prediction results were classified by the ASIA Impairment Scale. The training data consisted of 60 cases, and prognosis prediction was performed for 20 future cases (test cohort). All patients were treated in the Spinal Injuries Center (SIC) in Fukuoka, Japan.

RESULTS

A total of 16 out of 20 cases were predictable. The correct answer rate of MLR was 31.3%, while the rate of ANNs was 75.0% (number of correct answers: 12).

CONCLUSION

We were able to predict the prognosis of patients with cervical SCI from acute clinical data using ANNs. Performing effective rehabilitation based on this prediction will improve the patient's quality of life after discharge. Although there is room for improvement, ANNs are useful as a prognostic tool for patients with cervical SCI.

Independence and upper extremity functioning after spinal cord injury: a cross-sectional study

Upper extremity functioning is important for achieving independence in activities of daily living (ADL). A better understanding of relationships between different aspects of independence in ADL after spinal cord injury (SCI) and upper extremity functioning is required to guide rehabilitation practices. To determine which aspects of independence in ADL are correlated with upper extremity functioning in individuals with cervical or thoracic SCI. A total of 25 adults (mean age 58.4 years, 72% men) with established cervical or thoracic SCI were recruited. Independence in ADL was assessed by Spinal Cord Independence Measure (SCIM-III) and upper extremity functioning by kinematic measures (movement time, smoothness, and wrist angle during drinking task), grip strength, Upper Extremity Motor and Sensory Score, Box and Block Test (BBT), Action Research Arm Test (ARAT), and Upper Extremity Basic Data Set (ISCI-Hand and ISCI-Shoulder). Spearman correlation coefficients were used for data analyses. The SCIM-self-care subscale, particularly the feeding and dressing items, correlated moderately (r ≥ 0.5) with movement time and smoothness, grip strength, ARAT, BBT, and ISCI-Hand. The SCIM-respiration/sphincter subscale and the SCIM-mobility showed very low and low correlations with upper extremity assessments. However, at item level, respiration and bed/wheelchair mobility showed moderate correlations. Independence in self-care as domain and feeding/dressing, respiration and bed/wheelchair mobility as separate items were dependent on upper extremity functioning in individuals with cervical or thoracic SCI. Movement time and smoothness along with BBT, grip strength, ARAT, and ISCI-Hand can be used as indicators of independence in ADL. These findings can provide guidance to clinical practice in selection of upper extremity assessments in the context for ADL in individuals with SCI.

Development of a Remote Version of the Graded Redefined Assessment of Strength, Sensation, and Prehension (GRASSP): Validity and Reliability

BACKGROUND

The Graded Redefined Assessment of Strength, Sensation, and Prehension (GRASSP V1.0) was developed in 2010 as a 3-domain assessment for upper extremity function after tetraplegia (domains: Strength, Sensibility, and Prehension). A remote version (rGRASSP) was created in response to the growing needs of the field of Telemedicine.

OBJECTIVE

The purpose of this study was to assess the psychometric properties of rGRASSP, establishing concurrent validity and inter-rater reliability.

METHODS

Individuals with tetraplegia (n = 61) completed 2 visits: 1 in-person and 1 remote. The first visit was completed in-person to administer the GRASSP, and the second visit was conducted remotely to administer the rGRASSP. The rGRASSP was scored both by the administrator of the rGRASSP (Examiner 1), and a second assessor (Examiner 2) to establish inter-rater reliability. Agreement between the in-person and remote GRASSP evaluations was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman agreement plots.

RESULTS

The remote GRASSP demonstrated excellent concurrent validity with the GRASSP (left hand intraclass correlation coefficient (ICC) = .96, right ICC = .96). Concurrent validity for the domains was excellent for strength (left ICC = .96, right ICC = .95), prehension ability (left ICC = .94, right ICC = .95), and prehension performance (left ICC = .92, right ICC = .93), and moderate for sensibility (left ICC = .59, right ICC = .68). Inter-rater reliability for rGRASSP total score was high (ICC = .99), and remained high for all 4 domains. Bland-Altman plots and limits of agreements support these findings.

CONCLUSIONS

The rGRASSP shows strong concurrent validity and inter-rater reliability, providing a psychometrically sound remote assessment for the upper extremity in individuals with tetraplegia.

Minimal Clinically Important Difference of Graded Redefined Assessment of Strength, Sensibility, and Prehension Version 1 in Acute Cervical Traumatic Spinal Cord Injury

The Graded Redefined Assessment of Strength, Sensibility, and Prehension Version 1 (GRASSP v1) is a validated measure of upper extremity impairment shown to be sensitive and responsive for traumatic cervical spinal cord injury (SCI) in both North American (NA) and European (EU) cohorts. The minimal clinically important difference (MCID) is the quantitative change in an assessment scale that patients perceive as being beneficial. Our aim was to establish the MCID of all subtests of the GRASSP v1 for cervical SCI. We prospectively analyzed 127 patients from NA and EU for up to six months after motor complete and incomplete cervical SCI using the GRASSP v1, Spinal Cord Independence Measure, and International Standards of Neurological Classification of Spinal Cord Injury. We used a patient global rating of change and the anchor-based method to calculate MCID of GRASSP v1 at six months post-injury. The MCID was established for the whole group, dividing the sample by "better" and "much better." Improvement in GRASSP v1 Strength and Prehension Performance scores of 13 and 3 are the MCID for the better category, and 19 and 7 are the MCID for the much better category, respectively. The MCID was also established for the motor complete and incomplete groups. Improvement in GRASSP v1 Strength and Prehension Performance scores of 12 and 6 are the MCID for the motor complete group, and 17 and 12 are the MCID for the motor incomplete group, respectively. The GRASSP v1 Strength subscore is the most sensitive for detecting meaningful clinical change in patients and is most closely related to measures of independence. Thus, use of GRASSP v1 Strength and Prehension Performance as measures of change is substantiated by this study.

Clinical electrodiagnostic evaluation for nerve transfer surgery in spinal cord injury: a new indication and clinical pearls

In this review, we highlight the important role of the clinical electrodiagnostic (EDX) evaluation after cervical spinal cord injury (SCI). Our discussion focuses on the need for timely, frequent, and accurate EDX evaluations in the context of nerve transfer surgery to restore critical upper limb functions, including elbow extension, hand opening, and hand closing. The EDX evaluation is crucial to define the extent of lower motor neuron lesions and determine candidacy for surgery. We also discuss the important role of the postoperative EDX evaluation in determining prognosis and supporting rehabilitation. We propose a practical framework for EDX evaluation in this clinical setting.

Motor Recovery Depends on Timing of Surgery in Patients With Lumbar Disk Herniation

BACKGROUND

Although approximately half of the patients undergoing lumbar disk surgery present with motor deficits, timing of surgery for radicular weakness is largely unclear.

OBJECTIVE

To evaluate the impact of surgical timing on motor recovery in patients with lumbar disk herniation (LDH) and to identify an ideal time window for intervention.

METHODS

In a single-center observational trial, 390 patients with LDH-associated motor deficits were prospectively followed for a minimum of 12 months after nonelective microscopic disk surgery. The duration of motor deficit before surgery was documented. Motor function was graded according to the Medical Research Council (MRC) scale. Statistical analysis of motor recovery applied unbiased recursive partitioning conditional inference tree to determine cutoff times for optimal surgical intervention. The slope of recovery calculated as the change of the MRC grade over time served as the primary outcome.

RESULTS

A preoperative motor deficit of MRC ≤2/5 and the duration of paresis were identified as the most important predictors of recovery ( P < .001). Surgery within 3 days was associated with a better recovery for both severe and moderate/mild deficits ( P = .017 for MRC ≤ 2/5; P < .001 for MRC > 2/5; number needed to treat [NNT] <2). A sensitivity analysis in mild motor deficits indicated a cutoff of 8 days.

CONCLUSION

Timing of surgery is crucial for motor recovery in LDH-associated deficits. Immediate diagnosis, imaging, and referral should be aimed for to allow disk surgery within 3 days in patients with severe and moderate radicular weakness. If functionally disabling, even mild deficits may warrant decompression within a week.

Associations between upper extremity functioning and kinematics in people with spinal cord injury

Introduction

More knowledge of the relationships between kinematic measures and clinical assessments is required to guide clinical decision making and future research.

Objectives

To determine which kinematic variables obtained during a drinking task were associated with clinical assessments of upper extremity functioning in people with spinal cord injury (SCI).

Methods

In total, 25 individuals with chronic cervical (n = 17) or thoracic (n = 8) complete (n = 14) or motor incomplete (n = 11) SCI (mean age 58.4, SD 13.8) were included. Kinematic data, including movement time, smoothness and joint angles was captured with a 5-camera optoelectronic system during a unimanual drinking task. Action Research Arm Test (ARAT), Sollerman Hand Function Test (SHFT) and basic hand classification of the Upper Extremity Data Set (ISCI-Hand) were used as clinical assessments. Multiple regression analysis was used to identify kinematic variables associated with clinical assessments after controlling for potential confounding factors, such as, age, severity of SCI, sensory function, and hand surgery.

Results

Movement time, smoothness and movement pattern kinematics including trunk displacement, elbow and wrist joint angles were correlated (p < 0.05) with all three clinical scales while the velocity-related kinematics and inter-joint coordination showed low correlations. Multiple regression analysis revealed that wrist angle combined with movement time or smoothness explained 82% and 77% of the total variance in ARAT and SHFT, respectively. Wrist angle alone explained 59% of the variance in ISCI-Hand. The proprioception of the hand increased the explanatory power in the models of ARAT and SHFT. Associations between kinematics and clinical assessments in the subgroup with cervical SCI were equivalent to the whole group analyses. The number of participants in the subgroup with thoracic SCI was small and only allowed limited analysis.

Conclusions

Wrist angle, movement time, movement smoothness are the most important kinematic variables associated with upper extremity clinical assessments in people with SCI. The results are most valid for individuals with cervical SCI. All three assessments are appropriate for SCI. Further research with larger representative sample of thoracic SCI needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12984-021-00938-9.

External Validation Confirms Validity of a Simple Model to Predict Bowel Outcome After Traumatic Spinal Cord Injury

Background. The prediction of functional outcomes after spinal cord injury (SCI) is essential to plan the rehabilitation phase and the social reintegration. Recently, 2 models to predict independent and reliable bowel management 1 year after traumatic SCI have been derived and validated in 2 cohorts of patients included in the European Multicenter Study about Spinal Cord Injury (EMSCI). Objective. We aimed to validate 2 prediction models for bowel outcome after traumatic SCI in a patient sample external to EMSCI. Methods. The simplified model (based on a single predictor, the International Standards for Neurological Classification of Spinal Cord Injury [ISNCSCI] total motor score) and the full model (based on 2 predictors, the ISNCSCI total motor score and item 3a of the Spinal Cord Independence Measure) were applied to the retrospectively collected data of 111 patients with traumatic SCI. Results. The simplified and the full models showed excellent discrimination with an area under the receiver operating characteristic curve of .939 (95% confidence interval (CI) .87-1.00) and .922 (95% CI 0.85-.99), respectively. Both models displayed similar results for sensitivity and negative predictive values; however, the simplified model showed higher values for specificity, positive predictive values, and accuracy. The calibration analysis showed a partial overlap between predicted probabilities and observed proportion, with better and acceptable calibration for the simplified model. Conclusions. Using an independent sample, our study demonstrates the validity of a simple model to predict independent and reliable bowel management 1 year after traumatic SCI.

Unbiased Recursive Partitioning Enables Robust and Reliable Outcome Prediction in Acute Spinal Cord Injury

Neurological disorders usually present very heterogeneous recovery patterns. Nonetheless, accurate prediction of future clinical end-points and robust definition of homogeneous cohorts are necessary for scientific investigation and targeted care. For this, unbiased recursive partitioning with conditional inference trees (URP-CTREE) have received increasing attention in medical research, especially, but not limited to traumatic spinal cord injuries (SCIs). URP-CTREE was introduced to SCI as a clinical guidance tool to explore and define homogeneous outcome groups by clinical means, while providing high accuracy in predicting future clinical outcomes. The validity and predictive value of URP-CTREE to provide improvements compared with other more common approaches applied by clinicians has recently come under critical scrutiny. Therefore, a comprehensive simulation study based on traumatic, cervical complete spinal cord injuries provides a framework to investigate and quantify the issues raised. First, we assessed the replicability and robustness of URP-CTREE to identify homogeneous subgroups. Second, we implemented a prediction performance comparison of URP-CTREE with traditional statistical techniques, such as linear or logistic regression, and a novel machine learning method. URP-CTREE's ability to identify homogeneous subgroups proved to be replicable and robust. In terms of prediction, URP-CTREE yielded a high prognostic performance comparable to a machine learning algorithm. The simulation study provides strong evidence for the robustness of URP-CTREE, which is achieved without compromising prediction accuracy. The slightly lower prediction performance is offset by URP-CTREE's straightforward interpretation and application in clinical settings based on simple, data-driven decision rules.

Development of Reaching, Grasping & Manipulation indicators to advance the quality of spinal cord injury rehabilitation: SCI-High Project

OBJECTIVE

To describe the development of structure, process, and outcome indicators aimed to advance the quality of Reaching, Grasping & Manipulation (RG&M) rehabilitation for Canadians living with spinal cord injury or disease (SCI/D).

METHOD

Upper extremity rehabilitation experts developed a framework of indicators for evaluation of RG&M rehabilitation quality. A systematic search of the literature identified potential upper extremity indicators that influence RG&M outcomes. A Driver diagram summarized factors influencing upper extremity outcomes to inform the selection of structure and process indicators. Psychometric properties, clinical utility, and feasibility of potential upper extremity measures were considered when selecting outcome indicators.

RESULTS

The selected structure indicator is the number of occupational and physical therapists with specialized certification, education, training and/or work experience in upper extremity therapy related to RG&M at a given SCI/D rehabilitation center. The process indicator is the total hours of upper extremity therapies related to RG&M and the proportion of this time allocated to neurorestorative therapy for each individual with tetraplegia receiving therapy. The outcome indicators are the Graded Redefined Assessment of Strength, Sensation and Prehension (GRASSP) strength and Spinal Cord Independence Measure III (SCIM III) Self-Care subscores implemented at rehabilitation admission and discharge, and SCIM III Self-Care subscore only at 18 months post-admission.

CONCLUSION

The selected indicators align with current practice, will direct the timing of routine assessments, and enhance the volume and quality of RG&M therapy delivered, with the aim to ultimately increase the proportion of individuals with tetraplegia achieving improved upper extremity function by 18 months post-rehabilitation.

Predictive Value of Midsagittal Tissue Bridges on Functional Recovery After Spinal Cord Injury

Background

The majority of patients with spinal cord injury (SCI) have anatomically incomplete lesions and present with preserved tissue bridges, yet their outcomes vary.

Objective

To assess the predictive value of the anatomical location (ventral/dorsal) and width of preserved midsagittal tissue bridges for American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade conversion and SCI patient stratification into recovery-specific subgroups.

Methods

This retrospective longitudinal study includes 70 patients (56 men, age: 52.36 ± 18.58 years) with subacute (ie, 1 month) SCI (45 tetraplegics, 25 paraplegics), 1-month neuroimaging data, and 1-month and 12-month clinical data. One-month midsagittal T2-weighted scans were used to determine the location and width of tissue bridges. Their associations with functional outcomes were assessed using partial correlation and unbiased recursive partitioning conditional inference tree (URP-CTREE).

Results

Fifty-seven (81.4%) of 70 patients had tissue bridges (2.53 ± 2.04 mm) at 1-month post-SCI. Larger ventral (P = .001, r = 0.511) and dorsal (P < .001, r = 0.546) tissue bridges were associated with higher AIS conversion rates 12 months post-SCI (n = 39). URP-CTREE analysis identified 1-month ventral tissue bridges as predictors of 12-month total motor scores (0.4 mm cutoff, P = .008), recovery of upper extremity motor scores at 12 months (1.82 mm cutoff, P = .002), 12-month pin-prick scores (1.4 mm cutoff, P = .018), and dorsal tissue bridges at 1 month as predictors of 12-month Spinal Cord Independence Measure scores (0.5 mm cutoff, P = .003).

Conclusions

Midsagittal tissue bridges add predictive value to baseline clinical measures for post-SCI recovery. Based on tissue bridges’ width, patients can be classified into subgroups of clinical recovery profiles. Midsagittal tissue bridges provide means to optimize patient stratification in clinical trials.

Tissue bridges predict neuropathic pain emergence after spinal cord injury

OBJECTIVE

To assess associations between preserved spinal cord tissue quantified by the width of ventral and dorsal tissue bridges and neuropathic pain development after spinal cord injury.

METHODS

This retrospective longitudinal study includes 44 patients (35 men; mean (SD) age, 50.05 (18.88) years) with subacute (ie, 1 month) spinal cord injury (25 patients with neuropathic pain, 19 pain-free patients) and neuroimaging data who had a follow-up clinical assessment at 12 months. Widths of tissue bridges were calculated from midsagittal T2-weighted images and compared across groups. Regression analyses were used to identify relationships between these neuroimaging measures and previously assessed pain intensity and pin-prick score.

RESULTS

Pin-prick score of the 25 patients with neuropathic pain increased from 1 to 12 months (Δmean=10.08, 95% CI 2.66 to 17.50, p=0.010), while it stayed similar in pain-free patients (Δmean=2.74, 95% CI -7.36 to 12.84, p=0.576). They also had larger ventral tissue bridges (Δmedian=0.80, 95% CI 0.20 to 1.71, p=0.008) at 1 month when compared with pain-free patients. Conditional inference tree analysis revealed that ventral tissue bridges' width (≤2.1 or >2.1 mm) at 1 month is the strongest predictor for 12 months neuropathic pain intensity (1.90±2.26 and 3.83±1.19, p=0.042) and 12 months pin-prick score (63.84±28.26 and 92.67±19.43, p=0.025).

INTERPRETATION

Larger width of ventral tissue bridges-a proxy for spinothalamic tract function-at 1 month post-spinal cord injury is associated with the emergence and maintenance of neuropathic pain and increased pin-prick sensation. Spared ventral tissue bridges could serve as neuroimaging biomarkers of neuropathic pain and might be used for prediction and monitoring of pain outcomes and stratification of patients in interventional trials.

Prediction of independence in bowel function after spinal cord injury: validation of a logistic regression model

STUDY DESIGN

Retrospective analysis of prospectively collected data.

OBJECTIVES

Recently, logistic regression models were developed to predict independence in bowel function 1 year after spinal cord injury (SCI) on a multicenter European SCI (EMSCI) dataset. Here, we evaluated the external validity of these models against a prospectively accrued North American SCI dataset.

SETTING

Twenty-five SCI centers in the United States and Canada.

METHODS

Two logistic regression models developed by the EMSCI group were applied to data for 277 patients derived from three prospective multicenter SCI studies based in North America. External validation was evaluated for both models by assessing their discrimination, calibration, and clinical utility. Discrimination and calibration were assessed using ROC curves and calibration curves, respectively, while clinical utility was assessed using decision curve analysis.

RESULTS

The simplified logistic regression model, which used baseline total motor score as the predictor, demonstrated the best performance, with an area under the ROC curve of 0.869 (95% confidence interval: 0.826-0.911), a sensitivity of 75.5%, and a specificity of 88.5%. Moreover, the model was well calibrated across the full range of observed probabilities and displayed superior clinical benefit on the decision curve.

CONCLUSIONS

A logistic regression model using baseline total motor score as a predictor of independent bowel function 1 year after SCI was successfully validated against an external dataset. These findings provide evidence supporting the use of this model to enhance the care for individuals with SCI.

Serum albumin as a predictor of neurological recovery after spinal cord injury: a replication study

STUDY DESIGN

This was a secondary analysis on an observational cohort study.

OBJECTIVE

To determine if serum albumin significantly associates with long-term neurological outcome (i.e., 1-year post-injury) in a contemporary cohort of individuals with spinal cord injury.

SETTING

Six rehabilitation centers across the United States.

METHODS

A secondary analysis of neurological outcomes and serum albumin concentrations was performed on data from the Spinal Cord Injury Rehabilitation study. Data was accessed from the Archive of Data on Disability to Enable Policy and research (ADDEP). The primary analysis applied unbiased recursive partitioning to examine the relationship between serum albumin, injury severity, and long-term outcomes. The analysis is accessible via https://rpubs.com/AnhKhoaVo/586028 .

RESULTS

Serum albumin concentration was significantly associated with lower extremity motor scores (LEMS) and American Spinal Injury Association Impairment Scale (AIS) grade at admission to rehabilitation. Serum albumin concentrations alone were also significantly associated with change of LEMS and marked recovery (improvement of at least 2 AIS grades and/or recovery to walking) at 1-year post injury. However, after adjusting for admission to rehabilitation LEMS and AIS grade, serum albumin was not significant.

CONCLUSION

The current study partially confirms our previous observations that serum albumin concentrations are associated with neurological outcome after spinal cord injury. As a crude prognostic biomarker, serum albumin concentration could be useful in cases where injury severity cannot be accurately assessed.

Bowel Outcome Prediction After Traumatic Spinal Cord Injury: Longitudinal Cohort Study

Background. Predicting functional outcomes after traumatic spinal cord injury (SCI) is essential for counseling, rehabilitation planning, and discharge. Moreover, the outcome prognosis is crucial for patient stratification when designing clinical trials. However, no valid prediction rule is currently available for bowel outcomes after a SCI. Objective. To generate a model for predicting the achievement of independent, reliable bowel management at 1 year after traumatic SCI. Methods. We performed multivariable logistic regression analyses of data for 1250 patients with traumatic SCIs that were included in the European Multicenter Study about Spinal Cord Injury. The resulting model was prospectively validated on data for 186 patients. As potential predictors, we evaluated age, sex, and variables from the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) and the Spinal Cord Independence Measure (SCIM), measured within 40 days of the injury. A positive outcome at 1 year post-SCI was assessed with item 7 of the SCIM. Results. The model relied on a single predictor, the ISNCSCI total motor score—that is, the sum of muscle strengths in 5 key muscle groups in each limb. The area under the receiver operating characteristics curve (aROC) was 0.837 (95% CI: 0.815-0.859). The prospective validation confirmed high predictive power: aROC = 0.817 (95% CI: 0.754-0.881). Conclusions. We generated a valid model for predicting independent, reliable bowel management at 1 year after traumatic SCI. Its application could improve counseling, optimize patient-tailored rehabilitation planning, and become crucial for appropriate patient stratification in future clinical trials.

Unbiased Recursive Partitioning to Stratify Patients with Acute Traumatic Spinal Cord Injuries: External Validity in an Observational Cohort Study

Clinical trials of novel therapies for acute spinal cord injury (SCI) are challenging because variability in spontaneous neurologic recovery can make discerning actual treatment effects difficult. Unbiased Recursive Partitioning regression with Conditional Inference Trees (URP-CTREE) is a novel approach developed through analyses of a large European SCI database (European Multicenter Study about Spinal Cord Injury). URP-CTREE uses early neurologic impairment to predict achieved motor recovery, with potential to optimize clinical trial design by optimizing patient stratification and decreasing sample sizes. We performed external validation to determine how well a previously reported URP-CTREE model stratified patients into distinct homogeneous subgroups and predicted subsequent neurologic recovery in an independent cohort. We included patients with acute cervical SCI level C4-C6 from a prospective registry at a quaternary care center from 2004-2018 (n = 101) and applied the URP-CTREE model and evaluated Upper Extremity Motor Score (UEMS) recovery, considered correctly predicted when final UEMS scores were within a pre-specified threshold of 9 points from median; sensitivity analyses evaluated the effect of timing of baseline neurological examination. We included 101 patients, whose mean times from injury baseline and follow-up examinations were 6.1 days (standard deviation [SD] 17) and 235.0 days (SD 71), respectively. Median UEMS recovery was 7 points (interquartile range 2-12). One of the predictor variables was not statistically significant in our sample; one group did not fit progressively improving UEMS scores, and three of five groups had medians that were not significantly different from adjacent groups. Overall accuracy was 75%, but varied from 82% among participants whose examinations occurred at <12 h, to 64% at 12-24 h, and 58% at >24 h. A previous URP-CTREE model had limited ability to stratify an independent into homogeneous subgroups. Overall accuracy was promising, but may be sensitive to timing of baseline neurological examinations. Further evaluation of external validity in incomplete injuries, influence of timing of baseline examinations, and investigation of additional stratification strategies is warranted.

First-in-Man Intrathecal Application of Neurite Growth-Promoting Anti-Nogo-A Antibodies in Acute Spinal Cord Injury

Background. Neutralization of central nervous system neurite growth inhibitory factors, for example, Nogo-A, is a promising approach to improving recovery following spinal cord injury (SCI). In animal SCI models, intrathecal delivery of anti-Nogo-A antibodies promoted regenerative neurite growth and functional recovery. Objective. This first-in-man study assessed the feasibility, safety, tolerability, pharmacokinetics, and preliminary efficacy of the human anti-Nogo-A antibody ATI355 following intrathecal administration in patients with acute, complete traumatic paraplegia and tetraplegia. Methods. Patients (N = 52) started treatment 4 to 60 days postinjury. Four consecutive dose-escalation cohorts received 5 to 30 mg/2.5 mL/day continuous intrathecal ATI355 infusion over 24 hours to 28 days. Following pharmacokinetic evaluation, 2 further cohorts received a bolus regimen (6 intrathecal injections of 22.5 and 45 mg/3 mL, respectively, over 4 weeks). Results. ATI355 was well tolerated up to 1-year follow-up. All patients experienced ≥1 adverse events (AEs). The 581 reported AEs were mostly mild and to be expected following acute SCI. Fifteen patients reported 16 serious AEs, none related to ATI355; one bacterial meningitis case was considered related to intrathecal administration. ATI355 serum levels showed dose-dependency, and intersubject cerebrospinal fluid levels were highly variable after infusion and bolus injection. In 1 paraplegic patient, motor scores improved by 8 points. In tetraplegic patients, mean total motor scores increased, with 3/19 gaining >10 points, and 1/19 27 points at Week 48. Conversion from complete to incomplete SCI occurred in 7/19 patients with tetraplegia. Conclusions. ATI335 was well tolerated in humans; efficacy trials using intrathecal antibody administration may be considered in acute SCI.

The Graded and Redefined Assessment of Strength, Sensibility, and Prehension Version 2 Provides Interval Measure Properties

The Graded and Redefined Assessment of Strength, Sensibility and Prehension (GRASSP) is a valid, reliable, and responsive outcome measure to evaluate upper limb function in individuals with tetraplegia. GRASSP generates ordinal total scores; therefore, applicability as an interval level measurement requires testing of its measurement properties. This study examined the metric characteristics with Rasch Analysis to derive interval level scales of the respective GRASSP subtests. The GRASSP was recorded within 10 days, and at 1, 3, 6, and 12 months after cervical spinal cord injury (SCI). Rasch analysis was performed for each GRASSP subscale to assess the following metric assumptions: absence of local item dependency (LID), unidimensionality, monotonicity, item and model fit, reliability, and absence of differential item functioning (DIF) for side (left and right) and examination stage. If these assumptions could not be met, adjustments were undertaken to achieve a good fit to the Rasch model. Seventy-seven individuals with cervical SCI were included (n = 154 arms). Stacking the data for the side (left and right) resulted in a total of 614 observations, which were based on the repeated measurements. With minor adjustments, the GRASSP subscales showed good reliability, item fit, and ordered response options. Local item dependencies were found in the strength and sensibility subscales. Redundancies among some measurement items allowed shortening of the subscales without reasonable loss of reliability. Absence of DIF for the examination stage supported robustness of the subscales over time. The modified GRASSP, now Version 2, subtest scores can be applied as interval level measurements, and the reduction of items within subscales allows for shorter assessment times in clinical studies without degrading metric properties.

Rho Inhibitor VX-210 in Acute Traumatic Subaxial Cervical Spinal Cord Injury: Design of the SPinal Cord Injury Rho INhibition InvestiGation (SPRING) Clinical Trial

Traumatic spinal cord injury (SCI) is associated with a lifetime of disability stemming from loss of motor, sensory, and autonomic functions; these losses, along with increased comorbid sequelae, negatively impact health outcomes and quality of life. Early decompression surgery post-SCI can enhance patient outcomes, but does not directly facilitate neural repair and regeneration. Currently, there are no U.S. Food and Drug Administration-approved pharmacological therapies to augment motor function and functional recovery in individuals with traumatic SCI. After an SCI, the enzyme, Rho, is activated by growth-inhibitory factors and regulates events that culminate in collapse of the neuronal growth cone, failure of axonal regeneration, and, ultimately, failure of motor and functional recovery. Inhibition of Rho activation is a potential treatment for injuries such as traumatic SCI. VX-210, an investigational agent, inhibits Rho. When administered extradurally after decompression (corpectomy or laminectomy) and stabilization surgery in a phase 1/2a study, VX-210 was well tolerated. Here, we describe the design of the SPRING trial, a multicenter, phase 2b/3, randomized, double-blind, placebo-controlled clinical trial to evaluate the efficacy and safety of VX-210 (NCT02669849). A subset of patients with acute traumatic cervical SCI is currently being enrolled in the United States and Canada. Medical, neurological, and functional changes are evaluated at 6 weeks and at 3, 6, and 12 months after VX-210 administration. Efficacy will be assessed by the primary outcome measure, change in upper extremity motor score at 6 months post-treatment, and by secondary outcomes that include question-based and task-based evaluations of functional recovery.

Use of optical motion capture for the analysis of normative upper body kinematics during functional upper limb tasks: A systematic review

Quantifying three-dimensional upper body kinematics can be a valuable method for assessing upper limb function. Considering that kinematic model characteristics, performed tasks, and reported outcomes are not consistently standardized and exhibit significant variability across studies, the purpose of this review was to evaluate the literature investigating upper body kinematics in non-disabled individuals via optical motion capture. Specific objectives were to report on the kinematic model characteristics, performed functional tasks, and kinematic outcomes, and to assess whether kinematic protocols were assessed for validity and reliability. Five databases were searched. Studies using anatomical and/or cluster marker sets, along with optical motion capture, and presenting normative data on upper body kinematics were eligible for review. Information extracted included model characteristics, performed functional tasks, kinematic outcomes, and validity or reliability testing. 804 publication records were screened and 20 reviewed based on the selection criteria. Thirteen studies described their kinematic protocols adequately for reproducibility, and 8 studies followed International Society of Biomechanics standards for quantifying upper body kinematics. Six studies assessed their protocols for validity or reliability. While a substantial number of studies have adequately reported their protocols, more systematic work is needed to evaluate the validity and reliability of existing protocols.

Considerations and recommendations for selection and utilization of upper extremity clinical outcome assessments in human spinal cord injury trials

Study design

This is a focused review article.

Objectives

This review presents important features of clinical outcomes assessments (COAs) in human spinal cord injury research. Considerations for COAs by trial phase and International Classification of Functioning, Disability and Health are presented as well as strengths and recommendations for upper extremity COAs for research. Clinical trial tools and designs to address recruitment challenges are identified.

Methods

The methods include a summary of topics discussed during a two-day workshop, conceptual discussion of upper extremity COAs and additional focused literature review.

Results

COAs must be appropriate to trial phase and particularly in mid-late-phase trials, should reflect recovery vs. compensation, as well as being clinically meaningful. The impact and extent of upper vs. lower motoneuron disease should be considered, as this may affect how an individual may respond to a given therapeutic. For trials with broad inclusion criteria, the content of COAs should cover all severities and levels of SCI. Specific measures to assess upper extremity function as well as more comprehensive COAs are under development. In addition to appropriate use of COAs, methods to increase recruitment, such as adaptive trial designs and prognostic modeling to prospectively stratify heterogeneous populations into appropriate cohorts should be considered.

Conclusions

With an increasing number of clinical trials focusing on improving upper extremity function, it is essential to consider a range of factors when choosing a COA.

Sponsors

Craig H. Neilsen Foundation, Spinal Cord Outcomes Partnership Endeavor.

New Insights from Clinical Assessment of Upper Extremities in Cervical Traumatic Spinal Cord Injury

Upper extremity function has a strong impact on the quality of life in cervical spinal cord-injured patients. Upper extremity function depends on many factors, such as muscle strength, level of lesion, and extension of the cord damage in its axial axis produced by the injury. These variables can be obtained by the International Standards for Neurological Classification of Spinal Cord Injury, which is the standard for the functional evaluation of traumatic spinal cord injury (SCI) patients. The aim of this study was to describe the relationship between upper limb muscle strength, level of injury, and axial damage with the functionality of upper limb measured using the Jebsen-Taylor Hand Function Test (JTHFT) and the 9 Hole Peg Test (9HPT) in cervical SCI. Twenty-nine patients were included in this study. Our results suggest that both the JTHFT and 9HPT can be similarly used to quantify functional impairment after cervical SCI. Moreover, our data suggest that the upper extremity motor score, JTHFT, and 9HPT strongly correlate with the American Spinal Injury Association (ASIA) impairment scale (graded from A to E), but not with the lesion level. Our findings can be of great importance for the clinician or researchers whose therapeutic interventions have as a main objective to improve upper limb functionality in patients with cervical SCI. We suggest that ASIA impairment scale, ASIA motor score, and functional tests (including JTHFT and/or 9HPT) could be used as outcome measures in cervical SCI clinical trials.

Prediction of Bladder Outcomes after Traumatic Spinal Cord Injury: A Longitudinal Cohort Study

BACKGROUND

Neurogenic bladder dysfunction represents one of the most common and devastating sequelae of traumatic spinal cord injury (SCI). As early prediction of bladder outcomes is essential to counsel patients and to plan neurourological management, we aimed to develop and validate a model to predict urinary continence and complete bladder emptying 1 y after traumatic SCI.

METHODS AND FINDINGS

Using multivariate logistic regression analysis from the data of 1,250 patients with traumatic SCI included in the European Multicenter Spinal Cord Injury study, we developed two prediction models of urinary continence and complete bladder emptying 1 y after traumatic SCI and performed an external validation in 111 patients. As predictors, we evaluated age, gender, and all variables of the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) and of the Spinal Cord Independence Measure (SCIM). Urinary continence and complete bladder emptying 1 y after SCI were assessed through item 6 of SCIM. The full model relies on lower extremity motor score (LEMS), light-touch sensation in the S3 dermatome of ISNCSI, and SCIM subscale respiration and sphincter management: the area under the receiver operating characteristics curve (aROC) was 0.936 (95% confidence interval [CI]: 0.922-0.951). The simplified model is based on LEMS only: the aROC was 0.912 (95% CI: 0.895-0.930). External validation of the full and simplified models confirmed the excellent predictive power: the aROCs were 0.965 (95% CI: 0.934-0.996) and 0.972 (95% CI 0.943-0.999), respectively. This study is limited by the substantial number of patients with a missing 1-y outcome and by differences between derivation and validation cohort.

CONCLUSIONS

Our study provides two simple and reliable models to predict urinary continence and complete bladder emptying 1 y after traumatic SCI. Early prediction of bladder function might optimize counselling and patient-tailored rehabilitative interventions and improve patient stratification in future clinical trials.

Predictive Value of Upper Limb Muscles and Grasp Patterns on Functional Outcome in Cervical Spinal Cord Injury

Objective. To determine which single or combined upper limb muscles as defined by the International Standards for the Neurological Classification of Spinal Cord Injury (ISNCSCI); upper extremity motor score (UEMS) and the Graded Redefined Assessment of Strength, Sensibility, and Prehension (GRASSP), best predict upper limb function and independence in activities of daily living (ADLs) and to assess the predictive value of qualitative grasp movements (QlG) on upper limb function in individuals with acute tetraplegia. Method. As part of a Europe-wide, prospective, longitudinal, multicenter study ISNCSCI, GRASSP, and Spinal Cord Independence Measure (SCIM III) scores were recorded at 1 and 6 months after SCI. For prediction of upper limb function and ADLs, a logistic regression model and unbiased recursive partitioning conditional inference tree (URP-CTREE) were used. Results. Logistic regression and URP-CTREE revealed that a combination of ISNCSCI and GRASSP muscles (to a maximum of 4) demonstrated the best prediction (specificity and sensitivity ranged from 81.8% to 96.0%) of upper limb function and identified homogenous outcome cohorts at 6 months. The URP-CTREE model with the QlG predictors for upper limb function showed similar results. Conclusion. Prediction of upper limb function can be achieved through a combination of defined, specific upper limb muscles assessed in the ISNCSCI and GRASSP. A combination of a limited number of proximal and distal muscles along with an assessment of grasping movements can be applied for clinical decision making for rehabilitation interventions and clinical trials.

Toward Inclusive Trial Protocols in Heterogeneous Neurological Disorders

Background. Several novel drug- and cell-based potential therapies for spinal cord injury (SCI) have either been applied or will be considered for future clinical trials. Limitations on the number of eligible patients require trials be undertaken in a highly efficient and effective manner. However, this is particularly challenging when people living with incomplete SCI (iSCI) represent a very heterogeneous population in terms of recovery patterns and can improve spontaneously over the first year after injury. Objective. The current study addresses 2 requirements for designing SCI trials: first, enrollment of as many eligible participants as possible; second, refined stratification of participants into homogeneous cohorts from a heterogeneous iSCI population. Methods. This is a retrospective, longitudinal analysis of prospectively collected SCI data from the European Multicenter study about Spinal Cord Injury (EMSCI). We applied conditional inference trees to provide a prediction-based stratification algorithm that could be used to generate decision rules for the appropriate inclusion of iSCI participants to a trial. Results. Based on baseline clinical assessments and a defined subsequent clinical endpoint, conditional inference trees partitioned iSCI participants into more homogeneous groups with regard to the illustrative endpoint, upper extremity motor score. Assuming a continuous endpoint, the conditional inference tree was validated both internally as well as externally, providing stable and generalizable results. Conclusion. The application of conditional inference trees is feasible for iSCI participants and provides easily implementable, prediction-based decision rules for inclusion and stratification. This algorithm could be utilized to model various trial endpoints and outcome thresholds.

Changes in Strength, Sensation, and Prehension in Acute Cervical Spinal Cord Injury

Objective. To investigate the internal and external responsiveness and recovery profiles of the Graded Redefined Assessment of Strength, Sensibility, and Prehension (GRASSP) instrument in revealing changes in upper limb function within the first year following cervical spinal cord injury (SCI). Method. A European prospective, longitudinal, multicenter study assessing the GRASSP at 1, 3, 6, and 12 months after cervical SCI. Subtests of GRASSP were compared to the upper extremity motor (UEMS) and light touch scores (LT) according to the International Standards of Neurological Classification of Spinal Cord Injury (ISNCSCI), the Spinal Cord Independence Measure self-care subscore (SCIM-SS), as well as a clinician-rated outcome measure (CROM) of clinical relevance. Data were analyzed for GRASSP responsiveness and recovery rate over time. Results. Seventy-four participants entered the study. GRASSP subtests proved responsive (standardized response mean [SRM] ranged from 0.79 to 1.48 for strength, 0.50 to 1.03 for prehension, and 0.14 to 0.64 for sensation) between all examination time points. In comparison, UEMS and LT showed lower responsiveness (SRM UEMS ranged from 0.69 to 1.29 and SRM LT ranged from 0.30 to −0.13). All GRASSP subtests revealed significant, moderate-to-excellent correlations with UEMS, LT, and SCIM-SS at each time point, and changes in GRASSP subtests were in accordance with the CROM. GRASSP prehension and motor recovery was largest between 1 and 3 months. Conclusion. The GRASSP showed excellent responsiveness, detecting distinct changes in strength and prehension relating to the severity of cervical SCI. It detected clinically significant changes complimentary to the ISNCSCI and SCIM-SS assessments.

Leveraging biomedical informatics for assessing plasticity and repair in primate spinal cord injury

Recent preclinical advances highlight the therapeutic potential of treatments aimed at boosting regeneration and plasticity of spinal circuitry damaged by spinal cord injury (SCI). With several promising candidates being considered for translation into clinical trials, the SCI community has called for a non-human primate model as a crucial validation step to test efficacy and validity of these therapies prior to human testing. The present paper reviews the previous and ongoing efforts of the California Spinal Cord Consortium (CSCC), a multidisciplinary team of experts from 5 University of California medical and research centers, to develop this crucial translational SCI model. We focus on the growing volumes of high resolution data collected by the CSCC, and our efforts to develop a biomedical informatics framework aimed at leveraging multidimensional data to monitor plasticity and repair targeting recovery of hand and arm function. Although the main focus of many researchers is the restoration of voluntary motor control, we also describe our ongoing efforts to add assessments of sensory function, including pain, vital signs during surgery, and recovery of bladder and bowel function. By pooling our multidimensional data resources and building a unified database infrastructure for this clinically relevant translational model of SCI, we are now in a unique position to test promising therapeutic strategies' efficacy on the entire syndrome of SCI. We review analyses highlighting the intersection between motor, sensory, autonomic and pathological contributions to the overall restoration of function. This article is part of a Special Issue entitled SI: Spinal cord injury.

Outcome of the upper limb in cervical spinal cord injury: Profiles of recovery and insights for clinical studies

BACKGROUND

Improved appreciation of recovery profiles of sensory and motor function as well as complex motor functions (prehension) after cervical spinal cord injury (SCI) will be essential to inform clinical studies to consider primary and secondary outcome measures for interventions and the optimization of dosing and timing of therapies in acute and chronic SCI.

OBJECTIVES

(1) To define the sensory, motor, and prehension recovery profiles of the upper limb and hand in acute cervical SCI and (2) to confirm the impact of AIS severity and conversion on upper limb sensorimotor recovery.

METHODS

An observational longitudinal cohort study consisting of serial testing of 53 patients with acute cervical SCI was conducted. International Standards of Neurological Classification of Spinal Cord Injury, Graded Redefined Assessment of Strength Sensibility and Prehension (GRASSP), Capabilities of Upper Extremity (CUE-Q) Questionnaire, and Spinal Cord Independence Measure III (SCIM-III) were administered at 0-10 days, 1, 3, 6, and 12 months.

ANALYSIS

Change over time was plotted using mean and standard deviation of the total and subgroups of the sample.

RESULTS

Individuals with traumatic tetraplegia show distinct patterns of recovery. Factors that distinguish homogeneous subgroups of the sample are: severity of injury (level of injury, completeness) at baseline and conversion from a complete to an incomplete injury.

CONCLUSIONS

In cervical SCI, clinical recovery can be assessed using standardized measures that distinguish levels of activity and impairment. Specific recovery profiles of the upper limb over the 1-year timecourse provide new insights and opportunity for combined analysis of recovery profiles for different clinical assessment tools of upper limb function which are meaningful to inform the design of study protocols.