Metric properties of the ASIA motor score: Subscales improve correlation with functional activities11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated

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.

Effects of early mobilization within 48 hours of injury in patients with incomplete cervical spinal cord injury

OBJECTIVE

To investigate the effects of early mobilization within 48 h of injury on motor function and walking ability in patients with incomplete cervical spinal cord injury (SCI).

DESIGN

A retrospective observational study.

SETTING

Intensive care unit or high care unit of a university hospital emergency center.

PARTICIPANTS

Of 224 patients with SCI having American Spinal Injury Association impairment scale grades C and D, 158 consecutive patients hospitalized for at least 3 weeks after injury were included.

INTERVENTIONS

Patients were categorized into two groups: an early mobilization group in which patients were mobilized within 48 h of injury and a delayed mobilization group in which they were mobilized after 48 h of injury.

OUTCOME MEASURES

The upper extremity motor score (UEMS), lower extremity motor score (LEMS), and Walking Index for Spinal Cord Injury II (WISCI II) were compared using propensity score matching analysis.

RESULTS

Of the 158 patients who met the eligibility criteria, 32 were matched between the groups. There was a significant difference in the change in LEMS from the initial assessment to the assessment 2 weeks postoperatively in the early mobilization group (median 9 points vs. 3 points, p < 0.05). There were no significant differences in UEMS or WISCI II.

CONCLUSION

Early mobilization within 48 h may improve lower extremity motor function in patients with acute incomplete cervical SCI.

Can the Initial Parameters of Functional Scales Predict Recovery in Patients with Complete Spinal Cord Injury? A Retrospective Cohort Study

Regaining greater independence in performing daily activities constitutes a priority for people with tetraplegia following spinal cord injury (SCI). The highest expectations are connected with the improvement of hand function. Therefore, it is so important for the clinician to identify reliable and commonly applicable prognostic factors for functional improvement. The aim of this study was to conduct an analysis to assess the impact of initial functional factors on the clinical improvement in patients during early neurological rehabilitation (ENR). This study assessed 38 patients with complete SCI aged 17-78 who underwent ENR in 2012-2022. The analysis included the motor score from the AIS (MS), the Barthel Index (BI) and the SCIM scale values at the beginning of the ENR program and after its completion. During ENR, patients achieved a statistically significant improvement in MS, BI and SCIM. The initial MS and the level of neurological injury constituted the predictors of functional improvement during ENR. Significant statistical relationships were observed primarily in the correlations between the initial MS and BI, and the increase in the analyzed functional scales of SCI patients. Higher initial MS may increase the chances of a greater and faster functional improvement during ENR.

Construct validity of the international standards to document remaining autonomic function after spinal cord injury (ISAFSCI) (1st edition)

STUDY DESIGN

Observational study.

OBJECTIVES

To assess the construct validity of the International Standards to Document Remaining Autonomic Function after Spinal Cord Injury (ISAFSCI) (2012 1st Edition).

SETTING

Two Canadian spinal cord injury (SCI) centers.

METHODS

Data were collected between 2011-2014. Assessments included the ISAFSCI, standardized measures of autonomic function and a clinical examination. Construct validity of ISAFSCI was assessed by testing a priori hypotheses on expected ISAFSCI responses to standard measures (convergent hypotheses) and clinical variables (clinical hypotheses).

RESULTS

Forty-nine participants with an average age of 45 ± 12 years were included, of which 42 (85.7%) were males, 37 (77.6%) had a neurological level of injury at or above T6, and 23 (46.9%) were assessed as having motor and sensory complete SCI. For the six General Autonomic Function component hypotheses, two hypotheses (1 clinical, 1 convergent) related to autonomic control of blood pressure and one clinical hypothesis for temperature regulation were statistically significant. In terms of the Lower Urinary Tract, Bowel and Sexual Function component of the ISAFSCI, all the hypotheses (5 convergent, 3 clinical) were statistically significant except for the hypotheses on female sexual items (2 convergent, 2 clinical), likely due to small sample size.

CONCLUSION

The construct validity of ISAFSCI (2012 1st Edition) for the General Autonomic Function component was considered to be weak while it was much stronger for the Lower Urinary Tract, Bowel and Sexual Function component based on a priori hypotheses. These results can inform future psychometric studies of the ISAFSCI (2021 2nd Edition).

Exoskeleton-based training improves walking independence in incomplete spinal cord injury patients: results from a randomized controlled trial

BACKGROUND

In recent years, ambulatory lower limb exoskeletons are being gradually introduced into the clinical practice to complement walking rehabilitation programs. However, the clinical evidence of the outcomes attained with these devices is still limited and nonconclusive. Furthermore, the user-to-robot adaptation mechanisms responsible for functional improvement are still not adequately unveiled. This study aimed to (1) assess the safety and feasibility of using the HANK exoskeleton for walking rehabilitation, and (2) investigate the effects on walking function after a training program with it.

METHODS

A randomized controlled trial was conducted including a cohort of 23 patients with less than 1 year since injury, neurological level of injury (C2-L4) and severity (American Spinal Cord Injury Association Impairment Scale [AIS] C or D). The intervention was comprised of 15 one-hour gait training sessions with lower limb exoskeleton HANK. Safety was assessed through monitoring of adverse events, and pain and fatigue through a Visual Analogue Scale. LEMS, WISCI-II, and SCIM-III scales were assessed, along with the 10MWT, 6MWT, and the TUG walking tests (see text for acronyms).

RESULTS

No major adverse events were reported. Participants in the intervention group (IG) reported 1.8 cm (SD 1.0) for pain and 3.8 (SD 1.7) for fatigue using the VAS. Statistically significant differences were observed for the WISCI-II for both the "group" factor (F = 16.75, p < 0.001) and "group-time" interactions (F = 8.87; p < 0.01). A post-hoc analysis revealed a statistically significant increase of 3.54 points (SD 2.65, p < 0.0001) after intervention for the IG but not in the CG (0.7 points, SD 1.49, p = 0.285). No statistical differences were observed between groups for the remaining variables.

CONCLUSIONS

The use of HANK exoskeleton in clinical settings is safe and well-tolerated by the patients. Patients receiving treatment with the exoskeleton improved their walking independence as measured by the WISCI-II after the treatment.

Neurological recovery after early versus delayed surgical decompression for acute traumatic spinal cord injury

The aim of this study was to determine whether early surgical treatment results in better neurological recovery 12 months after injury than late surgical treatment in patients with acute traumatic spinal cord injury (tSCI). Patients with tSCI requiring surgical spinal decompression presenting to 17 centres in Europe were recruited. Depending on the timing of decompression, patients were divided into early (≤ 12 hours after injury) and late (> 12 hours and < 14 days after injury) groups. The American Spinal Injury Association neurological (ASIA) examination was performed at baseline (after injury but before decompression) and at 12 months. The primary endpoint was the change in Lower Extremity Motor Score (LEMS) from baseline to 12 months. The final analyses comprised 159 patients in the early and 135 in the late group. Patients in the early group had significantly more severe neurological impairment before surgical treatment. For unadjusted complete-case analysis, mean change in LEMS was 15.6 (95% confidence interval (CI) 12.1 to 19.0) in the early and 11.3 (95% CI 8.3 to 14.3) in the late group, with a mean between-group difference of 4.3 (95% CI -0.3 to 8.8). Using multiply imputed data adjusting for baseline LEMS, baseline ASIA Impairment Scale (AIS), and propensity score, the mean between-group difference in the change in LEMS decreased to 2.2 (95% CI -1.5 to 5.9). Compared to late surgical decompression, early surgical decompression following acute tSCI did not result in statistically significant or clinically meaningful neurological improvements 12 months after injury. These results, however, do not impact the well-established need for acute, non-surgical tSCI management. This is the first study to highlight that a combination of baseline imbalances, ceiling effects, and loss to follow-up rates may yield an overestimate of the effect of early surgical decompression in unadjusted analyses, which underpins the importance of adjusted statistical analyses in acute tSCI research.

BCI system with lower-limb robot improves rehabilitation in spinal cord injury patients through short-term training: a pilot study

In the recent years, the increasing applications of brain-computer interface (BCI) in rehabilitation programs have enhanced the chances of functional recovery for patients with neurological disorders. We presented and validated a BCI system with a lower-limb robot for short-term training of patients with spinal cord injury (SCI). The cores of this system included: (1) electroencephalogram (EEG) features related to motor intention reported through experiments and used to drive the robot; (2) a decision tree to determine the training mode provided for patients with different degrees of injuries. Seven SCI patients (one American Spinal Injury Association Impairment Scale (AIS) A, three AIS B, and three AIS C) participated in the short-term training with this system. All patients could learn to use the system rapidly and maintained a high intensity during the training program. The strength of the lower limb key muscles of the patients was improved. Four AIS A/B patients were elevated to AIS C. The cumulative results indicate that clinical application of the BCI system with lower-limb robot is feasible and safe, and has potentially positive effects on SCI patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11571-022-09801-6.

Limb accelerations during sleep are related to measures of strength, sensation, and spasticity among individuals with spinal cord injury

BACKGROUND

To evaluate the relationship between measures of neuromuscular impairment and limb accelerations (LA) collected during sleep among individuals with chronic spinal cord injury (SCI) to provide evidence of construct and concurrent validity for LA as a clinically meaningful measure.

METHODS

The strength (lower extremity motor score), sensation (summed lower limb light touch scores), and spasticity (categorized lower limb Modified Ashworth Scale) were measured from 40 adults with chronic (≥ 1 year) SCI. Demographics, pain, sleep quality, and other covariate or confounding factors were measured using self-report questionnaires. Each participant then wore ActiGraph GT9X Link accelerometers on their ankles and wrist continuously for 1-5 days to measure LA from movements during sleep. Regression models with built-in feature selection were used to determine the most relevant LA features and the association to each measure of impairment.

RESULTS

LA features were related to measures of impairment with models explaining 69% and 73% of the variance (R²) in strength and sensation, respectively, and correctly classifying 81.6% (F1-score = 0.814) of the participants into spasticity categories. The most commonly selected LA features included measures of power and frequency (frequency domain), movement direction (correlation between axes), consistency between movements (relation to recent movements), and wavelet energy (signal characteristics). Rolling speed (change in angle of inclination) and movement smoothness (median crossings) were uniquely associated with strength. When LA features were included, an increase of 72% and 222% of the variance was explained for strength and sensation scores, respectively, and there was a 34% increase in spasticity classification accuracy compared to models containing only covariate features such as demographics, sleep quality, and pain.

CONCLUSION

LA features have shown evidence of having construct and concurrent validity, thus demonstrating that LA are a clinically-relevant measure related to lower limb strength, sensation, and spasticity after SCI. LA may be useful as a more detailed measure of impairment for applications such as clinical prediction models for ambulation.

Sclerostin Concentration and Bone Biomarker Trends in Patients with Spinal Cord Injury: A Prospective Study

Patients with spinal cord injury (SCI) experience a high osteoporosis incidence, which increases fracture risk. Recently, a sclerostin antibody was introduced as a target biomarker to treat osteoporosis. We aimed to determine the serum concentration of sclerostin and factors affecting its concentration over time. This was a prospective cross-sectional study. The inclusion criteria were (1) SCI patients with a grade 3 modified functional ambulatory category score (FAC—patients requiring firm continuous support) and (2) patients whose injury occurred >1 month ago. The exclusion criterion was a history of osteoporosis medication administration within 6 months. The collected data included bone biomarkers (carboxy-terminal collagen crosslinks (CTX), procollagen type 1 intact N-terminal propeptide, and sclerostin), clinical data (FAC, lower extremity motor score), body mass index, SCI duration, and hip bone mineral density (BMD). This study recruited 62 patients with SCI. Sclerostin levels significantly correlated with age, CTX level, and hip BMD. SCI duration was negatively correlated with sclerostin levels. Lower extremity motor scores were not significantly correlated with sclerostin levels. The acute SCI state showed a higher sclerostin level than the chronic SCI state. Sclerostin showed a significant relationship with CTX. In conclusion, age and BMD affect sclerostin concentration in patients with SCI.

Admission Prevalence and Risk Factors of Deep Vein Thrombosis in Patients with Spinal Cord Injury Complicated with Cervical Fractures

The purpose of this study was to investigate the prevalence of deep vein thrombosis (DVT) and to clarify the risk factors of DVT in patients with acute spinal cord injury (SCI) complicated with cervical fractures at admission. From January 2018 to December 2021, a total of 175 patients with acute SCI complicated with cervical fractures in our hospital were retrospectively analyzed. Duplex ultrasound was used to diagnose the DVT. All patients' medical record data, including demographic variables, medical history, and laboratory results, were collected. The patients were divided into DVT group and non-DVT group according to ultrasound results. The prevalence of DVT was determined and risk factors of DVT were identified. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic value of different factors. The prevalence of DVT at admission was 21.71%(38/175), including one (2.63%) with central DVT, thirty-two (84.21%) with peripheral DVT and five (13.16%) with mixed DVT. The multivariate analysis revealed that decreased lower extremity muscle strength, time from injury to admission, and D-dimer were risk factors for DVT at admission. The diagnostic value of D-dimer was the highest among these risk factors. In conclusion, in patients with acute SCI complicated with cervical fractures, the risk of DVT at admission is very high. Decreased lower extremity muscle strength, time from injury to admission, and D-dimer are risk factors for DVT. Moreover, D-dimer has the highest diagnostic value among these risk factors.

Time-to-enrollment in clinical trials investigating neurological recovery in chronic spinal cord injury: observations from a systematic review and ClinicalTrials.gov database

Currently, large numbers of clinical trials are performed to investigate different forms of experimental therapy for patients suffering from chronic spinal cord injury (SCI). However, for the enrollment process, there are different views on how the time period between injury and interventions should be determined. Herein, we sought to evaluate the impact of time-to-enrollment in chronic SCI clinical trials. A data set comprising 957 clinical studies from clinicalTrials.gov was downloaded and analyzed focusing on the eligibility criteria for post-injury time-to-enrollment. We also aggregated individual patient data from nine clinical trials of regenerative interventions for chronic SCI selected by a systematic literature search from 1990 to 2018. Characteristics of the studies were assessed and compared by dividing into three groups based on time-to-enrollment (group 1 ≤ 12 months, group 2 = 12–23 months and group 3 ≥ 24 months). In ClinicalTrials.gov registry, 445 trials were identified for chronic SCI where 87% (385) were unrestricted in the maximum post-injury time for trial eligibility. From systematic literature search, nine studies and 156 patients (group 1 = 30, group 2 = 55 and group 3 = 71) were included. The range of time-to-enrollment was 0.5 to 321 months in those studies. We also observed various degrees of motor and sensory improvement in between three time-to-enrollment groups. Our results indicate that enrolling wide ranges of time-to-enrollment in a group may present imprecise outcomes. Clinical trial designs should consider appropriate post-injury time frames to evaluate therapeutic benefit.

Reconstructing Nanohydroxyapatite Prosthesis Based on CT-Scanning Data and Its Application in Spinal Injury

This study investigated the nanohydroxyapatite (nHA) prosthesis application effect based on CT-scanning data in spinal injury. This study chose 26 spinal injury patients treated in our hospital from September 2017 to September 2018, who were randomly divided into two groups. nHA prosthesis based on CT-scanning data was implanted in the nHA group, whereas titanium mesh was implanted in the titanium mesh group. Consequently, osteoblasts were cultured to test the biological activity of nHA and titanium alloy. In cell tests, we found osteoblasts could better adhere to nHA, and proliferation and activity were higher when planted on nHA material. After surgical treatment, all patients' spinal symptoms (VAS score, JOA score, and Cobb angle) had improved and did not cause obvious inflammatory foreign body reactions. During a two-year follow-up, the fusion time and support settlement in the nHA group was lower, and the vertebral fusion rate and ASIA score were higher than those in the titanium mesh group. Thus, CT-scanning data could further improve the vertebral fusion rate in the nHA group. Consequentially, nHA prosthesis based on CT-scanning data is a better choice for spinal injury therapy.

Reliability and validity of the international standards for neurological classification of spinal cord injury in patients with non-traumatic spinal cord lesions

STUDY DESIGN

Prospective, observational study.

OBJECTIVES

The International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) represent the gold standard for the assessment of patients with spinal cord injury (SCI) and their measurement properties have been evaluated in patients with traumatic lesions. Albeit the ISNCSCI are widely used also for the assessment and prognosis of patients with non-traumatic SCI, a validation of this grading system in this sample has never been performed. Therefore, the aim of this study is to evaluate the measurement properties of the ISNCSCI in a population of persons with non-traumatic SCI.

SETTING

Three Italian rehabilitation hospitals.

METHODS

The sample included 140 patients with non-traumatic SCI of different etiology, level and grade, for a total of 169 evaluations performed by two examiners. Cronbach's Alpha was used to evaluate the internal consistency of the ISNCSCI various components. The agreement between two examiners of each center in the definition of different components was used to assess the inter-rater reliability. The construct validity was evaluated through the correlation of the ISNCSCI with the Spinal Cord Independence Measure (SCIM).

RESULTS

The ISNCSCI showed substantial internal consistency, and substantial inter-rater agreement for AIS grade, cumulative motor and sensory scores. The motor scores for upper and lower extremity showed fair to moderate correlation with SCIM self-care and motility subscores, respectively. The ISNCSCI total motor score correlated with the total SCIM score.

CONCLUSIONS

Our study demonstrates that the ISNCSCI are a valid and reliable tool for the assessment of patients with non-traumatic SCI.

Natural History of Isolated Below-Knee Vein Thrombosis in Patients with Spinal Cord Injury

In the general population, serial imaging is recommended over anticoagulant therapy for below-knee deep vein thrombosis (BKDVT). However, no clinical trial in Asian patients with spinal cord injury and BKDVT has been performed. Therefore, we evaluated the natural course of BKDVT in patients with acute spinal cord injury. We retrospectively analyzed inpatients with spinal cord injury with BKDVT between 2016 and 2020. All patients underwent inpatient rehabilitation treatment and duplex ultrasonographic examination of both the lower extremities at follow-up. After screening 172 patients with acute spinal cord injury for deep vein thrombosis using duplex ultrasound, 27 patients with below-the-knee deep vein thrombosis were included in this study. The mean lower-extremity motor score (median, interquartile range) was 66.0, 54.0-74.5. Sixteen patients received a non-vitamin K antagonist oral anticoagulant (NOAC) for anticoagulation. None of the patients had proximal propagation according to the follow-up duplex ultrasonography. BKDVT disappearance was not significantly different between the NOAC treatment and non-treatment groups. Asian patients with spinal cord injury have a low incidence of venous thromboembolism and favorable natural history of BKDVT. We recommend serial imaging over anticoagulant therapy for BKDVT in these patients.

Incidence and degrees of neurologic decline following thoracic costotransversectomy

BACKGROUND CONTEXT

Thoracic costotransversectomies (TCT) are amongst the most invasive spine procedures performed. Of greatest concern to the patient and surgeon is the risk of iatrogenic neurologic injury associated with these procedures. Most available studies limit their assessment of neurologic function to nonspecific scales such as the broader ASIA scoring system of A to E and have not comprehensively described the rates of iatrogenic injury following these procedures by looking more precisely with ASIA motor scoring (0-100) which allows for more in-depth analysis.

PURPOSE

The purpose of this study is to investigate the rates and degree of iatrogenic neurologic decline following TCT and subsequent rates and degree of motor recovery.

STUDY DESIGN/SETTING

Retrospective medical record review at a single institution.

PATIENT SAMPLE

Around 116 consecutive patients undergoing TCT operations.

OUTCOME MEASURES

Neurological changes from preprocedure to final follow-up assessed by lower extremity motor score.

METHODS

A retrospective chart review of patients undergoing TCT between May 2008 and April 2018 was carried out. Clinical, surgical, and intraoperative neuromonitoring data were collected. Patients who demonstrated an initial postoperative decline in lower extremity motor scores (LEMS) were followed through their final follow up to assess recovery.

RESULTS

Around 116 patients underwent TCT between T2 and T12 between May 2008 and April 2018. Seven (6.0%) patients demonstrated an immediate postoperative decline as defined by a drop of more than 4 points (mean 15.1; range 5-50) in motor score. All patients who demonstrated an initial postoperative motor score decline returned to within 4 LEMS points of their preoperative LEMS by final follow up. IOMN changes were noted only in half of all monitored patients who were noted to have a decline.

CONCLUSIONS

In our series, 6.0% of patients undergoing TCT experienced an initial decline in motor score with 94.0% demonstrating an unchanged or improved examination compared to preoperative exam. In our series, all patients who exhibited a decline recovered to within 4 points of the preoperative motor score within the first year postoperatively.

A comparison of monoaxial pedicle screw versus polyaxial pedicle screw in short-segment posterior fixation for the treatment of thoracolumbar fractured vertebra

Background

Posterior pedicle screw fixation had been applied to maintain spinal stability and avoid further nerve damage in thoracolumbar fracture. This study aimed to evaluate the efficacy of short-segment posterior fixation with monoaxial pedicle screws versus polyaxial pedicle screws in treating thoracolumbar fracture.

Methods

A total of 75 patients with thoracolumbar fracture who underwent short-segment posterior fixation with monoaxial pedicle screw (group A) or polyaxial pedicle screw (group B) were retrospectively enrolled. The patient demographic and radiological data were analyzed between the two groups.

Results

A total of 63 patients with an average age of 44.7±11.5 years were finally recruited in this study. There were no significant differences in age, gender, fracture level, thoracolumbar injury classification and severity scale (TLISS) score, American Spinal Injury Association (ASIA) score, Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification, and hospital stay between the two groups (P>0.05). At the last follow-up, the prevertebral height ratio and normal-to-injured vertebral height ratio were significantly decreased in group A compared to group B (P=0.027 and P=0.007, respectively).

Conclusions

Short-segment posterior fixation with monoaxial or polyaxial pedicle screw for fractured thoracolumbar vertebra can restore injured vertebral height. Compared with polyaxial pedicle screw, monoaxial pedicle screw endows stronger leverage which is more beneficial for restoring injured vertebral height and recovery of the damaged endplate in thoracolumbar short-segment posterior fixation.

Baseline-adjusted proportional odds models for the quantification of treatment effects in trials with ordinal sum score outcomes

Background

Sum scores of ordinal outcomes are common in randomized clinical trials. The approaches routinely employed for assessing treatment effects, such as t-tests or Wilcoxon tests, are not particularly powerful in detecting changes in relevant parameters or lack the ability to incorporate baseline information. Hence, tailored statistical methods are needed for the analysis of ordinal outcomes in clinical research.

Methods

We propose baseline-adjusted proportional odds logistic regression models to overcome previous limitations in the analysis of ordinal outcomes in randomized clinical trials. For the validation of our method, we focus on common ordinal sum score outcomes of neurological clinical trials such as the upper extremity motor score, the spinal cord independence measure, and the self-care subscore of the latter. We compare the statistical power of our models to other conventional approaches in a large simulation study of two-arm randomized clinical trials based on data from the European Multicenter Study about Spinal Cord Injury (EMSCI, ClinicalTrials.gov Identifier: NCT01571531). We also use the new method as an alternative analysis of the historical Sygen®clinical trial.

Results

The simulation study of all postulated trial settings demonstrated that the statistical power of the novel method was greater than that of conventional methods. Baseline adjustments were more suited for the analysis of the upper extremity motor score compared to the spinal cord independence measure and its self-care subscore.

Conclusions

The proposed baseline-adjusted proportional odds models allow the global treatment effect to be directly interpreted. This clear interpretation, the superior statistical power compared to the conventional analysis approaches, and the availability of open-source software support the application of this novel method for the analysis of ordinal outcomes of future clinical trials.

Assessment of postoperative outcomes in spinal epidural abscess following surgical decompression

BACKGROUND CONTEXT

A spinal epidural abscess (SEA) is a serious condition that may be managed with antibiotics alone or with decompressive surgery combined with antibiotics.

PURPOSE

The objectives of this study were to assess the clinical outcomes of SEA after surgical management and to identify the patient-level factors that are associated with outcomes following surgical decompression and removal of SEA.

STUDY DESIGN/SETTING

Retrospective chart review analysis.

PATIENT SAMPLE

An analysis of 154 consecutive patients who initially presented to a tertiary-care, academic medical center with SEA, and were subsequently treated with surgery between 2010 and 2015 was performed.

OUTCOME MEASURES

Postoperative predischarge American Spinal Injury Association Impairment Scale (AIS) scores, 6-month follow-up encounter AIS scores, need for revision surgery, and mortality during SEA surgery were the primary outcomes.Physiological Measures: AIS scores.

METHOD

Fisher's exact and Wilcoxon rank-sum tests were used to assess the associations between patient-level factors and surgical outcomes. Moreover, an interactive, predictive model for postoperative predischarge AIS score was developed using a proportional odds regression model. There was no funding secured for this study and there is no conflict of interest-associated biases.

RESULTS

One hundred fifty-four patients (mean age of 58 years) were treated using surgical decompression in addition to antibiotics. The majority of patients were Caucasian (81%) and male (61%). No intraoperative mortality was reported. A second SEA surgery was performed in 8% of patients. A comparison of the preoperative and postoperative predischarge AIS scores showed that 49% of patients maintained a score of E or improved, while 45% remained at their preoperative status and 6% worsened. Among a subset of patients (n=36; 23%) for whom a 6-month follow-up encounter occurred, 75% maintained an AIS score of E or improved, 19% remained at their preoperative status, and 6% worsened. Both the presence and longer duration of preoperative paresis was associated with an increased risk of remaining at the same AIS score or worsening at the predischarge encounter (both p< .001). A predictive model for predischarge AIS scores was developed based on several patient characteristics.

CONCLUSIONS

Surgical decompression can contribute to improving or maintaining AIS scores in a high percentage of SEA patients. The presence and duration of preoperative paresis are prognostic for poorer outcomes and suggest that rapid surgical intervention before paresis develops may lead to improved postoperative outcomes. Our modeling tool enables an estimation of probabilities of patients' predischarge condition.

Implementation and initial outcomes of a spinal cord injury home care program at a large veterans affairs medical center

OBJECTIVES

Describe an interdisciplinary spinal cord injury home care program (SCIHCP), sample demographics for the veteran participants, and initial impact of SCIHCP on health care utilization and mortality.

DESIGN

Retrospective review.

SETTING

SCIHCP of the Spinal Cord Injury Center, VA North Texas Health Care System (VANTHCS).

PARTICIPANTS

Patients with SCI/D enrolled in the SCIHCP during January 6, 2006 through January 9, 2012, whose injury occurred at least one year prior to enrollment(n = 125).

MAIN OUTCOME MEASURES

VANTHCS hospital admissions, length of stay (LOS), and emergency department (ED) visits evaluated one year before and one year after SCIHCP enrollment; mortality evaluated one-year post-enrollment.

RESULTS

There were no significant changes in number of ED visits, number of hospital admissions, or LOS over time. More home care visits and more mental health comorbidities predicted more hospital admissions. Older patients and those with more mental health comorbidities were more likely to experience increases in LOS. These prediction models were significant after adjusting for injury level, age, race, time since SCI, and number of medical comorbidities. More home care visits were associated with lower likelihood of mortality post-enrollment.

CONCLUSIONS

Inpatient and ED utilization did not change one year after enrollment, but more SCIHCP visits predicted more hospital admissions and lower likelihood of mortality in the post-evaluation year. The support, education, and care continuity SCIHCP generates might be related to increased inpatient access and lower mortality rate. Veterans with increased mental health comorbidities used inpatient services more, and might need additional support.

Prognostic validity of a clinical trunk control test for independence and walking in individuals with spinal cord injury

Objective: The objective of the present work was to determine the prognostic validity of the trunk control test for walking and independence in individuals with SCI.Design: A cohort, prospective study was carried out in all individuals with sub-acute SCI.Setting: All inpatients at the Mexico City based National Rehabilitation Institute (INR).Participants: Ninety individuals with a clinical diagnosis of sub-acute SCI, American Spinal Injury Association Impairment Scale (AIS) A-D, and that have not participated in a rehabilitation program were included. Thirty-five individuals had good initial trunk control and the remaining 55 had poor trunk control. All individuals participated in a standard rehabilitation program subsequently.Interventions: N/AOutcome Measures: The trunk control test was performed at baseline. At 1, 3, 6, 9 and 12 months after the first evaluation, walking and independence were assessed.Results: Survival Analysis revealed that 62.5% and 100% individuals with good trunk control at baseline assessment were respectively walking and independent in ADL at 12 months and 14% and 48% individuals with poor trunk control were walking and independent in ADL. Cox regression analysis revealed that individuals with good trunk control were 4.6 times more likely to walk independently at 12 months and 2.9 times more likely to be independent in activities of daily living.Conclusion: The present study revealed that the trunk control test is useful for providing a prognosis of independence and walking at 1 year in individuals with SCI, independently of the neurologic level and the severity of the injury.

Differences in Physical Performance Measures Among Patients With Unilateral Lower-Limb Amputations Classified as Functional Level K3 Versus K4

OBJECTIVE

To determine whether differences in physical function, assessed via self-report questionnaires and physical performance tests, exist between individuals with lower-limb loss using a prosthetic device classified as a K3 versus a K4 functional level.

DESIGN

Cross-sectional study.

SETTING

A university physical therapy amputee clinic.

PARTICIPANTS

Participants (N=55) were included if they (1) were aged ≥18 years with a unilateral transfemoral or transtibial amputation; (2) were classified as K3 or K4 functional level; (3) completed all relevant outcome measures; and (4) were currently using a prosthesis.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Locomotor Capabilities Index (LCI), Prosthetic Evaluation Questionnaire-Mobility Section (PEQ-MS), Timed Up and Go (TUG), 10-Meter Walk Test (10MWT), Amputee Mobility Predictor (AMPPRO), and 6-Minute Walk Test (6MWT). K level was determined by group consensus based on a standardized clinical evaluation.

RESULTS

After controlling for covariates, patients classified as K3 had slower TUG times (P=.002) and self-selected and fast gait speeds (P<.001), lower AMPPRO scores (P<.001), and walked shorter distances during the 6MWT (P=.003) when compared with patients classified as K4. No significant between-group differences for the LCI or PEQ-MS were found.

CONCLUSIONS

Clinicians involved in prosthetic prescription may consider including the TUG, 10MWT, AMPPRO, and 6MWT during their clinical evaluations to help differentiate between individuals of higher functional mobility. The LCI and PEQ-MS may be less useful in classifying individuals as K3 versus K4 because of a ceiling effect.

Effects of anterior weight-shifting methods on sitting balance in wheelchair-dependent patients with spinal cord injury

[Purpose] This study aimed to compare changes in the center of pressure between healthy subjects and patients with spinal cord injury and to provide basic information to these patients for improving their sitting balance. [Subjects and Methods] A total of 12 healthy subjects without histories of neurological or psychiatric disorders and 12 patients with spinal cord injuries were recruited. In all subjects, a change in the center of pressure during the performance of the modified functional reach test was measured using a Force Sensing Array system while the subjects were seated in a wheelchair. In the spinal cord injury group, the change in the center of pressure was highest when subjects reached forward while holding a gym ball. [Results] In the spinal cord injury group, the change in the center of pressure was highest when subjects reached forward while holding a gym ball. A significant correlation between forward reaching of the upper limbs with shoulders at 90° flexion and a change in the center of pressure was found. [Conclusion] Our findings suggest that the combination of functional reaching and the change in the center of pressure assessment is novel enough to be attempted to achieve sitting balance control in patients with spinal cord injury. The findings can provide clinical interventions that contribute to the improvement in the balance ability of wheelchair-dependent individuals.

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.

Gait training after spinal cord injury: safety, feasibility and gait function following 8 weeks of training with the exoskeletons from Ekso Bionics

STUDY DESIGN

Prospective quasi-experimental study, pre- and post-design.

OBJECTIVES

Assess safety, feasibility, training characteristics and changes in gait function for persons with spinal cord injury (SCI) using the robotic exoskeletons from Ekso Bionics.

SETTING

Nine European rehabilitation centres.

METHODS

Robotic exoskeleton gait training, three times weekly over 8 weeks. Time upright, time walking and steps in the device (training characteristics) were recorded longitudinally. Gait and neurological function were measured by 10 Metre Walk Test (10 MWT), Timed Up and Go (TUG), Berg Balance Scale (BBS), Walking Index for Spinal Cord Injury (WISCI) II and Lower Extremity Motor Score (LEMS).

RESULTS

Fifty-two participants completed the training protocol. Median age: 35.8 years (IQR 27.5-52.5), men/women: N = 36/16, neurological level of injury: C1-L2 and severity: AIS A-D (American Spinal Injury Association Impairment Scale). Time since injury (TSI) < 1 year, N = 25; > 1 year, N = 27. No serious adverse events occurred. Three participants dropped out following ankle swelling (overuse injury). Four participants sustained a Category II pressure ulcer at contact points with the device but completed the study and skin normalized. Training characteristics increased significantly for all subgroups. The number of participants with TSI < 1 year and gait function increased from 20 to 56% (P = 0.004) and 10MWT, TUG, BBS and LEMS results improved (P < 0.05). The number of participants with TSI > 1 year and gait function, increased from 41 to 44% and TUG and BBS results improved (P < 0.05).

CONCLUSIONS

Exoskeleton training was generally safe and feasible in a heterogeneous sample of persons with SCI. Results indicate potential benefits on gait function and balance.

Cervical Spondylodiscitis: Presentation, Timing, and Surgical Management in 59 Patients

BACKGROUND

Cervical spondylodiscitis is thought to carry a significant risk for rapid neurologic deterioration with a poor response to nonsurgical management.

METHODS

A retrospective surgical case series of the acute surgical management of cervical spondylodiscitis is reviewed to characterize the neurologic presentation and postoperative neurologic course in a relatively uncommon disease.

RESULTS

Fifty-nine patients were identified (mean age, 59 years [range, 18-83 years; SD ± 13.2 years]) from a single-institution neurosurgical database. The most common levels of radiographic cervical involvement were C4-C5, C5-C6, and C6-C7, in descending order. Overall, statistically significant clinical improvement was noted after surgery (P < 0.05). Spinal cord hyperintensity on T2-weighted magnetic resonance imaging was significantly associated with a worse preoperative neurologic grade (P = 0.036), but did not correlate with a relatively worse neurologic outcome by discharge. No significant difference was noted between potential preoperative predictors (organism cultured, presence of epidural abscess, tobacco use, early surgery within 24 hours of clinical presentation) and preoperative American Spinal Injury Association injury scale, with the exception of the duration between symptom onset and surgical intervention. A negative correlation between increased preoperative duration of symptoms and magnitude in motor improvement was observed. Relative to anteroposterior decompression and fusion, anterior treatment alone demonstrated a relatively greater effect in neurologic improvement.

CONCLUSIONS

Cervical spondylodiscitis is a rare disease that typically manifests with preoperative motor deficits. Surgery was associated with a significant improvement in motor score by hospital discharge. Significant predictors of neurologic improvement were not observed. Prolonged symptomatic duration was correlated with a significantly lower likelihood of motor score improvement.

Assessment of Functional Improvement without Compensation for Human Spinal Cord Injury: Extending the Neuromuscular Recovery Scale to the Upper Extremities

The Neuromuscular Recovery Scale (NRS) is a tool for measuring functional recovery in spinal cord injured (SCI) persons based on tasks that test pre-injury functional capability. The NRS has been shown to be a valid, reliable, and responsive instrument for measuring functional recovery. The NRS has been updated to include three items measuring upper extremity function, and a new scoring mechanism has been defined. The purpose of this prospective, observational study was to explore the properties of the expanded NRS, introduce and evaluate the new scoring method, and to examine the score's relationship with other SCI outcome measures. The NRS and seven other SCI outcome measures were assessed at enrollment and after every 20 locomotor training sessions in 64 participants of the NeuroRecovery Network (NRN) of the Christopher and Dana Reeve Foundation (CDRF). The NRS exhibited a dominant first principal component that correlated strongly with the new NRS score, as well as a potential secondary component discriminating upper extremity function. The new NRS score and its empirical subscales were generally well-correlated with International Standards for the Neurological Classification of Spinal Cord Injury (ISNCSCI) motor scores and other established SCI functional measures, but exhibited substantial variability at their boundary values. The NRS score was more strongly correlated with other SCI functional measures than ISNCSCI motor scores were. The new NRS score was most responsive to change brought on by locomotor training. The expanded NRS appears to be a valuable tool in measuring functional recovery from SCI; further evaluation of its psychometric properties is warranted.

Elevated Serum Insulin-Like Growth Factor 1 Levels in Patients with Neurological Remission after Traumatic Spinal Cord Injury

After traumatic spinal cord injury, an acute phase triggered by trauma is followed by a subacute phase involving inflammatory processes. We previously demonstrated that peripheral serum cytokine expression changes depend on neurological outcome after spinal cord injury. In a subsequent intermediate phase, repair and remodeling takes place under the mediation of growth factors such as Insulin-like Growth Factor 1 (IGF-1). IGF-1 is a promising growth factor which is thought to act as a neuroprotective agent. Since previous findings were taken from animal studies, our aim was to investigate this hypothesis in humans based on peripheral blood serum. Forty-five patients after traumatic spinal cord injury were investigated over a period of three months after trauma. Blood samples were taken according to a fixed schema and IGF-1 levels were determined. Clinical data including AIS scores at admission to the hospital and at discharge were collected and compared with IGF-1 levels. In our study, we could observe distinct patterns in the expression of IGF-1 in peripheral blood serum after traumatic spinal cord injury regardless of the degree of plegia. All patients showed a marked increase of levels seven days after injury. IGF-1 serum levels were significantly different from initial measurements at four and nine hours and seven and 14 days after injury, as well as one, two and three months after injury. We did not detect a significant correlation between fracture and the IGF-1 serum level nor between the quantity of operations performed after trauma and the IGF-1 serum level. Patients with clinically documented neurological remission showed consistently higher IGF-1 levels than patients without neurological remission. This data could be the base for the establishment of animal models for further and much needed research in the field of spinal cord injury.

The effect of increased T2 signal intensity in the spinal cord on the injury severity and early neurological recovery in patients with central cord syndrome

OBJECTIVE

The aim of this paper was to compare the severity of the initial neurological injury as well as the early changes in the American Spinal Injury Association (ASIA) motor score (AMS) between central cord syndrome (CCS) patients with and without an increased T2 signal intensity in their spinal cord.

METHODS

Patients with CCS were identified and stratified based on the presence of increased T2 signal intensity in their spinal cord. The severity of the initial neurological injury and the progression of the neurological injury over the 1st week were measured according to the patient's AMS. The effect of age, sex, congenital stenosis, surgery within 24 hours, and surgery in the initial hospitalization on the change in AMS was determined using an analysis of variance.

RESULTS

Patients with increased signal intensity had a more severe initial neurological injury (AMS 57.6 vs 75.3, respectively, p = 0.01). However, the change in AMS over the 1st week was less severe in patients with an increase in T2 signal intensity (−0.85 vs −4.3, p = 0.07). Analysis of variance did not find that age, sex, Injury Severity Score, congenital stenosis, surgery within 24 hours, or surgery during the initial hospitalization affected the change in AMS.

CONCLUSIONS

The neurological injury is different between patients with and without an increased T2 signal intensity. Patients with an increased T2 signal intensity are likely to have a more severe initial neurological deficit but will have relatively minimal early neurological deterioration. Comparatively, patients without an increase in the T2 signal intensity will likely have a less severe initial injury but can expect to have a slight decline in neurological function in the 1st week.

Development and validation of a computerized algorithm for International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI)

STUDY DESIGN

Validation study.

OBJECTIVES

To describe the development and validation of a computerized application of the international standards for neurological classification of spinal cord injury (ISNCSCI).

SETTING

Data from acute and rehabilitation care.

METHODS

The Rick Hansen Institute-ISNCSCI Algorithm (RHI-ISNCSCI Algorithm) was developed based on the 2011 version of the ISNCSCI and the 2013 version of the worksheet. International experts developed the design and logic with a focus on usability and features to standardize the correct classification of challenging cases. A five-phased process was used to develop and validate the algorithm. Discrepancies between the clinician-derived and algorithm-calculated results were reconciled.

RESULTS

Phase one of the validation used 48 cases to develop the logic. Phase three used these and 15 additional cases for further logic development to classify cases with 'Not testable' values. For logic testing in phases two and four, 351 and 1998 cases from the Rick Hansen SCI Registry (RHSCIR), respectively, were used. Of 23 and 286 discrepant cases identified in phases two and four, 2 and 6 cases resulted in changes to the algorithm. Cross-validation of the algorithm in phase five using 108 new RHSCIR cases did not identify the need for any further changes, as all discrepancies were due to clinician errors. The web-based application and the algorithm code are freely available at www.isncscialgorithm.com.

CONCLUSION

The RHI-ISNCSCI Algorithm provides a standardized method to accurately derive the level and severity of SCI from the raw data of the ISNCSCI examination. The web interface assists in maximizing usability while minimizing the impact of human error in classifying SCI.

SPONSORSHIP

This study is sponsored by the Rick Hansen Institute and supported by funding from Health Canada and Western Economic Diversification Canada.

Neurological and functional recovery after thoracic spinal cord injury

OBJECTIVE

To describe neurological and functional outcomes after traumatic paraplegia.

DESIGN

Retrospective analysis of longitudinal database.

SETTING

Spinal Cord Injury Model Systems.

PARTICIPANTS

Six hundred sixty-one subjects enrolled in the Spinal Cord Injury Model Systems database, injured between 2000 and 2011, with initial neurological level of injury from T2-12. Two hundred sixty-five subjects had second neurological exams and 400 subjects had Functional Independence Measure (FIM) scores ≥6 months after injury.

OUTCOME MEASURES

American Spinal Injury Association Impairment Scale (AIS) grade, sensory level (SL), lower extremity motor scores (LEMS), and FIM.

RESULTS

At baseline, 73% of subjects were AIS A, and among them, 15.5% converted to motor incomplete. The mean SL increase for subjects with an AIS A grade was 0.33 ± 0.21; 86% remained within two levels of baseline. Subjects with low thoracic paraplegia (T10-12) demonstrated greater LEMS gain than high paraplegia (T2-9), and also had higher 1-year FIM scores, which had not been noted in earlier reports. Better FIM scores were also correlated with better AIS grades, younger age and increase in AIS grade. Ability to walk at 1 year was associated with low thoracic injury, higher initial LEMS, incomplete injury and increase in AIS grade.

CONCLUSION

Little neurological recovery is seen in persons with complete thoracic SCI, especially with levels above T10. Persons who are older at the time of injury have poorer functional recovery than younger persons. Conversion to a better AIS grade is associated with improvement in self-care and mobility at 1 year.

Early outcome and predictors of early outcome in patients treated surgically for central cord syndrome

OBJECT

The purpose of this study was to characterize changes in American Spinal Injury Association motor score (AMS) in the 1st week after traumatic central cord syndrome (CCS) to identify predictors of improved early outcome in patients treated with early versus delayed surgical intervention.

METHODS

All patients presenting to a regional spinal cord injury center between January 2004 and June 2009 were queried for those with a diagnosis of CCS. Patients treated conservatively were excluded. A prospectively maintained spinal cord injury database was used to track AMS throughout each patient’s hospitalization. Hospital records provided information regarding demographics, presenting neurological examination, imaging findings, comorbidities, timing and nature of surgical procedures, and length of stay (LOS) in the hospital and intensive care unit (ICU). Patients were separated into those who underwent early surgery, within 1 day of presentation (early group), and those who underwent surgery on a delayed basis (delayed group). Differences between groups were analyzed using the Student t-test and chi-square test. Predictors of outcome were identified using correlation analysis and multiple linear regression.

RESULTS

Of 426 patients in the database, 80 (18.8%) were diagnosed as having CCS, and 68 of them ultimately underwent surgical decompression. Nineteen (28%) of 68 patients underwent surgery within 1 day of presentation (early group) while the remaining 49 patients (72%) underwent surgery on a delayed basis (delayed group). The mean age in the early group was significantly younger than that of the delayed group (52 vs 59 years, p = 0.049). Other characteristics were similar between groups including sex, proportion of patients with cord edema on MRI (44% early vs 55% delayed, p = 0.47), and proportion of patients with cervical fracture (26% early vs 28% delayed, p = 0.98). Patients in the early group presented with an AMS of 62.5 versus 70.0 for the delayed group (p = 0.36). No difference in the change in AMS was seen at 7 days between the early group (-2.9 points) and the delayed group (-4.2 points) (p = 0.34). Additionally, the number of patients who had early improvement was similar between the early and delayed groups (50% vs 48%, respectively, p = 0.94). Neither time in the ICU (3.4 vs 3.4 days, p = 0.84) nor the overall LOS (10.5 vs 12.5 days, p = 0.59) was different in the early versus delayed groups, respectively. Correlation analysis and multiple linear regression demonstrated early surgery was not associated with change in AMS or AMS at Day 7. Age was identified as the only significant predictor of change in AMS and had a negative effect (coefficient = -0.34, p = 0.025).

CONCLUSIONS

Early treatment of patients with CCS remains controversial. Although some long-term neurological recovery is expected in patients with a CCS, surgeons and patients should not expect early neurological improvement with or without early operative intervention.

Surgical management in 40 consecutive patients with cervical spinal epidural abscesses: shifting toward circumferential treatment

STUDY DESIGN

Retrospective database review of a prospectively maintained neurosurgical database.

OBJECTIVE

The surgical management of cervical spinal epidural abscesses (CSEA) is reviewed examining the shift from single to staged anteroposterior decompression and stabilization.

SUMMARY OF BACKGROUND DATA

CSEA management is guided by small case series.

METHODS

A retrospective review from 1997 to 2011 was conducted for patients with the diagnostic headings: cervical epidural abscess, infection, osteomyelitis, osteodiscitis, spondylodiscitis, and abscess. Comorbidities, risk factors, surgical approach, neurologic grade, and outcomes were recorded.

RESULTS

Forty consecutive patients (mean age 53 years, age range 23-74, SD ±14, 10 female) were identified with CSEA in the operative database from 1997 to 2010. Twenty one patients had a body mass index more than 25 (53%), 6 (15%) had diabetes mellitus, 6 (15%) had a prior malignancy with 2 having prior neck irradiation, and 9 (23%) used tobacco products. The most common risk factor associated with CSEA was intravenous drug abuse, found in 10 patients (25%). The most common level of discitis involvement was C6-C7 in 12 (30%) followed by C5-C6 disc in 11 (28%) and least often at C1-C2 level in 2(5%) and C7-T1 in 2(5%). The most common neurologic grades at presentation were AIS D in 20 (50%) followed by AIS E in 9 (28%). All patients received magnetic resonance imaging identifying 17 (43%) with dorsal, 12 ventral (30%), and 11 circumferential epidural abscesses (28%). The majority of patients underwent anterior followed by posterior decompression and stabilization (n = 26, 65%); 8 (20%) underwent a ventral approach and six underwent a dorsal approach (15%). Fusion was achieved in 39 of 40 (97.5%) and not significantly influenced halo use in 10 patients.

CONCLUSIONS

In this series, patients underwent acute evacuation and spinal cord decompression, and the shift toward staged treatment did not lead to an increased periprocedural complication rate.

LEVEL OF EVIDENCE

3.

Increased spinal reflex excitability is associated with enhanced central activation during voluntary lengthening contractions in human spinal cord injury

This study of chronic incomplete spinal cord injury (SCI) subjects investigated patterns of central motor drive (i.e., central activation) of the plantar flexors using interpolated twitches, and modulation of soleus H-reflexes during lengthening, isometric, and shortening muscle actions. In a recent study of the knee extensors, SCI subjects demonstrated greater central activation ratio (CAR) values during lengthening (i.e., eccentric) maximal voluntary contractions (MVCs), compared with during isometric or shortening (i.e., concentric) MVCs. In contrast, healthy controls demonstrated lower lengthening CAR values compared with their isometric and shortening CARs. For the present investigation, we hypothesized SCI subjects would again produce their highest CAR values during lengthening MVCs, and that these increases in central activation were partially attributable to greater efficacy of Ia-α motoneuron transmission during muscle lengthening following SCI. Results show SCI subjects produced higher CAR values during lengthening vs. isometric or shortening MVCs (all P < 0.001). H-reflex testing revealed normalized H-reflexes (maximal SOL H-reflex-to-maximal M-wave ratios) were greater for SCI than controls during passive (P = 0.023) and active (i.e., 75% MVC; P = 0.017) lengthening, suggesting facilitation of Ia transmission post-SCI. Additionally, measures of spinal reflex excitability (passive lengthening maximal SOL H-reflex-to-maximal M-wave ratio) in SCI were positively correlated with soleus electromyographic activity and CAR values during lengthening MVCs (both P < 0.05). The present study presents evidence that patterns of dynamic muscle activation are altered following SCI, and that greater central activation during lengthening contractions is partly due to enhanced efficacy of Ia-α motoneuron transmission.

Increased mean arterial pressure goals after spinal cord injury and functional outcome

Introduction:

Acute spinal cord injury (SCI) is often treated with induced hypertension to enhance spinal cord perfusion. The optimal mean arterial pressure (MAP) likely varies between patients. Arbitrary goals are often set, frequently requiring vasopressors to achieve, with no clear evidence supporting this practice. We hypothesize that increased MAP goals and episodes of relative hypotension do not affect hospital outcome.

Materials and Methods:

All cervical and thoracic SCI patients treated at a level one trauma and regional SCI center over at 2.5-year period were retrospectively reviewed. Lowest and average hourly MAP was recorded for the first 72 h of hospitalization, allowing for quantification of mean MAP and the total number of episodic relative hypotensive events. These data were further compared to daily American spinal injury association motor score (AMS), which was used to determine the severity of SCI and improvement/decline during hospitalization. Patient's data were finally analyzed at theoretic MAP set points.

Results:

One hundred and five patients had complete data during the study period. At higher theoretic MAP set points (85 and 90), increased number of relative hypotensive episodes correlated with lower admission AMS (85 mmHg: <10 episodes, AMS 66.2; >50 episodes, 22.0; P < 0.001) and the need for vasopressors (P < 0.03) but showed no statistical change in AMS by hospital discharge. The need for vasopressors correlated with the number of hypotensive episodes and inversely related to admission AMS at all theoretic MAP goal set points but was not correlated with the change in AMS during the hospitalization.

Conclusions:

The frequency of relative hypotension and the need for vasopressors are progressively related to more severe SCI, as denoted by lower admission AMS. However, episodes of hypotension and the need for vasopressors did not affect the change in AMS during the acute hospitalization, regardless of theoretic MAP goal set-point. Arbitrarily elevated MAP goals may not be efficacious.

Timing in the surgical evacuation of spinal epidural abscesses

OBJECT

One often overlooked aspect of spinal epidural abscesses (SEAs) is the timing of surgical management. Limited evidence is available correlating earlier intervention with outcomes. Spinal epidural abscesses, once a rare diagnosis carrying a poor prognosis, are steadily becoming more common, with one recent inpatient meta-analysis citing an approximate incidence of 1 in 10,000 admissions with a mortality approaching 16%. One key issue of contention is the benefit of rapid surgical management of SEA to maximize outcomes. Timing of surgical management is definitely one overlooked aspect of care in spinal infections. Therefore, the authors performed a retrospective analysis in which they evaluated patients who underwent early (evacuation within 24 hours) versus delayed surgical intervention (> 24 hours) from the point of diagnosis, in an attempt to test the hypothesis that earlier surgery results in improved outcomes.

METHODS

A retrospective review of a prospectively maintained adult neurosurgical database from 2009 to 2011 was conducted for patients with the diagnostic heading: epidural abscess, infection, osteomyelitis, osteodiscitis, spondylodiscitis, and abscess. The primary end point for each patient was neurological grade, measured as an American Spinal Injury Association Impairment Scale grade using hospital inpatient records on admission and discharge. Patients were divided into early surgical (< 24 hours) and delayed surgical cohorts.

RESULTS

Eighty-seven consecutive patients were identified (25 females; mean age 55.5 years, age range 18-87 years). Fifty-four patients received surgery within 24 hours of admission (mean time from admission to incision, 11.2 hours), and 33 underwent surgery longer than 24 hours (mean 59 hours) after admission. Of the 54 patients undergoing early surgery 45 (85%) had a neurological deficit, whereas in the delayed surgical group 21 (64%) of 33 patients presented with a neurological deficit (p = 0.09). Patients in the delayed surgery cohort were significantly older by 10 years (59.6 vs 51.8 years, p = 0.01). With regard to history of prior revision, body mass index, intravenous drug abuse, tobacco use, prior radiation therapy, diabetes, chronic systemic infection, and prior osteomyelitis, there were no significant differences. There was no significant difference between early and delayed surgery groups in neurological grade on presentation, discharge, or location of epidural abscess. The most common organism isolated was Staphylococcus aureus (n = 51, 59.3%). The incidence of methicillin-resistant S. aureus was 21% (18 of 87).

CONCLUSIONS

Evacuation within 24 hours appeared to have a relative advantage over delayed surgery with regard to discharge neurological grade. However, due to a limited, variable sample size, a significant benefit could not be shown. Further subgroup analyses with larger populations are required.

Functional electrical stimulation for incomplete spinal cord injury

This case report describes the early use of functional electrical stimulation on an individual with an incomplete spinal cord injury to assist with motor recovery and a return to ambulation. A 32-year-old woman sustained a C7 burst fracture after a fall, requiring anterior cervical fixation from C6 to T1 prior to transfer to acute rehabilitation. She presented as a C8 AIS B spinal cord injury, meaning she had some sensory function spared below the level of injury but not motor function. At discharge from acute inpatient rehabilitation, she was able to ambulate household distances with supervision using a rolling walker and required a manual wheelchair for community mobility. Four months after discharge, she was ambulating in the community using a standard cane.

Reliability of surface EMG as an assessment tool for trunk activity and potential to determine neurorecovery in SCI

STUDY DESIGN

Reliability and validity study.

OBJECTIVE

This study investigates the responsiveness and reliability of the brain motor control assessment (BMCA) as a standardized neurophysiological assessment tool to: (i) characterize trunk neural activity in neurologically-intact controls; (ii) measure and quantify neurorecovery of trunk after spinal cord injury (SCI).

SETTING

Kessler Foundation Research Center, West Orange, NJ.

METHODS

A standardized BMCA protocol was performed to measure surface electromyography (sEMG) recordings for seven bilateral trunk muscles on 15 able-bodied controls during six maneuvers (inhalation, exhalation, neck flexion, jendrassik, unilateral grip). Additionally, sEMG recordings were analyzed for one chronic SCI individual before electrical stimulation (ES), after ES of the lower extremities while supine, and after active stand training using body-weight support with bilateral ES. sEMG recordings were collected on bilateral erector spinae, internal and external obliques, upper and middle trapezius, biceps and triceps. For each maneuver a voluntary response index was calculated: incorporating the magnitude of sEMG signal and a similarity index (SI), which quantifies the distribution of activity across all muscles.

RESULTS

Among all maneuvers, the SI presented reproducible assessment of trunk-motor function within (ICC: 0.860-0.997) and among (P⩾0.22) able-bodied individuals. In addition, potential changes were measured in a chronic SCI individual after undergoing two intensive ES protocols.

CONCLUSION

The BMCA provides reproducible characterization of trunk activity in able-bodied individuals, lending credence for its use in neurophysiological assessment of motor control. Additionally, the BMCA as an assessment tool to measure neurorecovery in an individual with chronic SCI after intense ES interventions was demonstrated.

Muscle activation varies with contraction mode in human spinal cord injury

INTRODUCTION

To better understand volitional force generation after chronic incomplete spinal cord injury (SCI), we examined muscle activation during single and repeated isometric, concentric, and eccentric knee extensor (KE) maximal voluntary contractions (MVCs).

METHODS

Torque and electromyographic (EMG) activity were recorded during single and repeated isometric and dynamic KE MVCs in 11 SCI subjects. Central activation ratios (CARs) were calculated for all contraction modes in SCI subjects and 11 healthy controls.

RESULTS

SCI subjects generated greater torque, KE EMG, and CARs during single eccentric vs. isometric and concentric MVCs (all P < 0.05). Torque and EMG remained similar during repeated eccentric MVCs; however, both increased during repeated isometric (>25%) and concentric (>30%) MVCs.

CONCLUSIONS

SCI subjects demonstrated greater muscle activation during eccentric MVCs vs. isometric and concentric MVCs. This pattern of activation contrasts with the decreased eccentric activation demonstrated by healthy controls. Such information may aid development of novel rehabilitation interventions.