Recovery of upper-extremity strength in complete and incomplete tetraplegia: a multicenter study

Implicit and explicit motor imagery ability after SCI: Moving the elbow makes the difference

Cervical spinal cord injury (SCI) causes dramatic sensorimotor deficits that restrict both activity and participation. Restoring activity and participation requires extensive upper limb rehabilitation focusing elbow and wrist movements, which can include motor imagery. Yet, it remains unclear whether MI ability is impaired or spared after SCI. We investigated implicit and explicit MI ability in individuals with C6 or C7 SCI (SCIC6 and SCIC7 groups), as well as in age- and gender-matched controls without SCI. Inspired by previous studies, implicit MI evaluations involved hand laterality judgments, hand orientation judgments (HOJT) and hand-object interaction judgments. Explicit MI evaluations involved mental chronometry assessments of physically possible or impossible movements due to the paralysis of upper limb muscles in both groups of participants with SCI. HOJT was the paradigm in which implicit MI ability profiles differed the most between groups, particularly in the SCIC6 group who had impaired elbow movements in the horizontal plane. MI ability profiles were similar between groups for explicit MI evaluations, but reflected task familiarity with higher durations in the case of unfamiliar movements in controls or attempt to perform movements which were no longer possible in persons with SCI. Present results, obtained from a homogeneous population of individuals with SCI, suggest that people with long-term SCI rely on embodied cognitive motor strategies, similar to controls. Differences found in behavioral response pattern during implicit MI mirrored the actual motor deficit, particularly during tasks that involved internal representations of affected body parts.

Impact of Upper Limb Motor Recovery on Functional Independence After Traumatic Low Cervical Spinal Cord Injury

Cervical spinal cord injury (SCI) causes devastating loss of upper limb function and independence. Restoration of upper limb function can have a profound impact on independence and quality of life. In low-cervical SCI (level C5-C8), upper limb function can be restored via reinnervation strategies such as nerve transfer surgery. The translation of recovered upper limb motor function into functional independence in activities of daily living (ADLs), however, remains unknown in low cervical SCI (i.e., tetraplegia). The objective of this study was to evaluate the association of patterns in upper limb motor recovery with functional independence in ADLs. This will then inform prioritization of reinnervation strategies focused to maximize function in patients with tetraplegia. This retrospective study performed a secondary analysis of patients with low cervical (C5-C8) enrolled in the SCI Model Systems (SCIMS) database. Baseline neurological examinations and their association with functional independence in major ADLs-i.e., eating, bladder management, and transfers (bed/wheelchair/chair)-were evaluated. Motor functional recovery was defined as achieving motor strength, in modified research council (MRC) grade, of ≥ 3 /5 at one year from ≤ 2/5 at baseline. The association of motor function recovery with functional independence at one-year follow-up was compared in patients with recovered elbow flexion (C5), wrist extension (C6), elbow extension (C7), and finger flexion (C8). A multi-variable logistic regression analysis, adjusting for known factors influencing recovery after SCI, was performed to evaluate the impact of motor function at one year on a composite outcome of functional independence in major ADLs. Composite outcome was defined as functional independence measure score of 6 or higher (complete independence) in at least two domains among eating, bladder management, and transfers. Between 1992 and 2016, 1090 patients with low cervical SCI and complete neurological/functional measures were included. At baseline, 67% of patients had complete SCI and 33% had incomplete SCI. The majority of patients were dependent in eating, bladder management, and transfers. At one-year follow-up, the largest proportion of patients who recovered motor function in finger flexion (C8) and elbow extension (C7) gained independence in eating, bladder management, and transfers. In multi-variable analysis, patients who had recovered finger flexion (C8) or elbow extension (C7) had higher odds of gaining independence in a composite of major ADLs (odds ratio [OR] = 3.13 and OR = 2.87, respectively, p < 0.001). Age 60 years (OR = 0.44, p = 0.01), and complete SCI (OR = 0.43, p = 0.002) were associated with reduced odds of gaining independence in ADLs. After cervical SCI, finger flexion (C8) and elbow extension (C7) recovery translate into greater independence in eating, bladder management, and transfers. These results can be used to design individualized reinnervation plans to reanimate upper limb function and maximize independence in patients with low cervical SCI.

Does Improvement in American Spinal Injury Association Impairment Scale Grade Correlate With Functional Recovery in All Patients With a Traumatic Spinal Cord Injury?

OBJECTIVE

The aim of the study is to determine what improvement on the American Spinal Injury Impairment Scale correlates with functional status after a traumatic spinal cord injury.

DESIGN

We performed an observational cohort study, analyzing prospective data from 168 patients with traumatic spinal cord injury admitted to a single level 1 trauma center. A multivariable analysis was performed to assess the relationship between functional status (from the Spinal Cord Independence Measure) at 1-year follow-up and American Spinal Injury Impairment Scale grade (baseline and 1-yr follow-up), while taking into account covariables describing the sociodemographic status, trauma severity, and level of neurological injury.

RESULTS

Individuals improving to at least American Spinal Injury Impairment Scale grade D had significantly higher Spinal Cord Independence Measure score compared with those not reaching American Spinal Injury Impairment Scale D (89.3 ± 15.2 vs. 52.1 ± 20.4) and were more likely to reach functional independence (68.5% vs. 3.6%), regardless of the baseline American Spinal Injury Impairment Scale grade. Higher final Spinal Cord Independence Measure was more likely with an initial American Spinal Injury Impairment Scale grade D (β = 1.504; 95% confidence interval = 0.46-2.55), and a final American Spinal Injury Impairment Scale grade D (β = 3.716; 95% CI = 2.77-4.66) or E (β = 4.422; 95% CI = 2.91-5.93).

CONCLUSIONS

Our results suggest that reaching American Spinal Injury Impairment Scale grade D or better 1 yr after traumatic spinal cord injury is highly predictive of significant functional recovery, more so than the actual improvement in American Spinal Injury Impairment Scale grade from the injury to the 1-yr follow-up.

Computer-assisted robotic device for upper limb interventions for a patient with an incomplete cervical level spinal cord injury

A man in his 50s with an incomplete cervical spinal cord injury underwent a 3-week occupational therapy programme using a computer-assisted robotic device for the upper limbs (Diego) in an acute care spinal injury unit. The patient and their partner reported their experience. Range of motion (ROM), muscle strength, pain, fatigue, independence and occupational performance are reported. Improvements occurred in upper limb ROM (shoulder and elbow), muscle strength (right elbow extensors), fatigue and functional status. Whether the results in this patient with the Diego were the same or better than standard care could not be determined. Preliminary findings suggest that the Diego was feasible for rehabilitation in an acute setting in our patient. However, it may not be suitable for all patients and a large comparative study with other therapies is needed. A limitation in the use of the Diego relates to the initial cost of the device ($A150 000).

Testing a Novel Wearable Device for Motor Recovery of the Elbow Extensor Triceps Brachii in Chronic Spinal Cord Injury

After corticospinal tract damage, reticulospinal connections to motoneurons strengthen preferentially to flexor muscles. This could contribute to the disproportionately poor recovery of extensors often seen after spinal cord injury (SCI) and stroke. In this study, we paired electrical stimulation over the triceps muscle with auditory clicks, using a wearable device to deliver stimuli over a prolonged period of time. Healthy human volunteers wore the stimulation device for ∼6 h and a variety of electrophysiological assessments were used to measure changes in triceps motor output. In contrast to previous results in the biceps muscle, paired stimulation: (1) did not increase the StartReact effect; (2) did not decrease the suppression of responses to transcranial magnetic brain stimulation (TMS) following a loud sound; (3) did not enhance muscle responses elicited by a TMS coil oriented to induce anterior-posterior current. In a second study, chronic cervical SCI survivors wore the stimulation device for ∼4 h every day for four weeks; this was compared with a four-week period without wearing the device. Functional and electrophysiological assessments were repeated at week 0, week 4, and week 8. No significant changes were observed in electrophysiological assessments after paired stimulation. Functional measurements such as maximal force and variability and speed of trajectories made during a planar reaching task also remained unchanged. Our results suggest that the triceps muscle shows less potential for plasticity than biceps; pairing clicks with muscle stimulation does not seem beneficial in enhancing triceps recovery after SCI.

Segmental motor recovery after cervical spinal cord injury relates to density and integrity of corticospinal tract projections

Cervical spinal cord injury (SCI) causes extensive impairments for individuals which may include dextrous hand function. Although prior work has focused on the recovery at the person-level, the factors determining the recovery of individual muscles are poorly understood. Here, we investigate the muscle-specific recovery after cervical spinal cord injury in a retrospective analysis of 748 individuals from the European Multicenter Study about Spinal Cord Injury (NCT01571531). We show associations between corticospinal tract (CST) sparing and upper extremity recovery in SCI, which improves the prediction of hand muscle strength recovery. Our findings suggest that assessment strategies for muscle-specific motor recovery in acute spinal cord injury are improved by accounting for CST sparing, and complement person-level predictions.

Derivation and Validation of a Clinical Prediction Rule for Upper Limb Functional Outcomes After Traumatic Cervical Spinal Cord Injury

IMPORTANCE

Traumatic cervical spinal cord injury (SCI) can result in debilitating paralysis. Following cervical SCI, accurate early prediction of upper limb recovery can serve an important role in guiding the appropriateness and timing of reconstructive therapies.

OBJECTIVE

To develop a clinical prediction rule to prognosticate upper limb functional recovery after cervical SCI.

DESIGN, SETTING, AND PARTICIPANTS

This prognostic study was a retrospective review of a longitudinal cohort study including patients enrolled in the National SCI model systems (SCIMS) database in US. Eligible patients were 15 years or older with tetraplegia (neurological level of injury C1-C8, American Spinal Cord Injury Association [ASIA] impairment scale [AIS] A-D), with early (within 1 month of SCI) and late (1-year follow-up) clinical examinations from 2011 to 2016. The data analysis was conducted from September 2021 to June 2022.

MAIN OUTCOMES AND MEASURES

The primary outcome was a composite of dependency in eating, bladder management, transfers, and locomotion domains of functional independence measure at 1-year follow-up. Each domain ranges from 1 to 7 with a lower score indicating greater functional dependence. Composite dependency was defined as a score of 4 or higher in at least 3 chosen domains. Multivariable logistic regression was used to predict the outcome based on early neurological variables. Discrimination was quantified using C statistics, and model performance was internally validated with bootstrapping and 10-fold cross-validation. The performance of the prediction score was compared with AIS grading. Data were split into derivation (2011-2014) and temporal-validation (2015-2016) cohorts.

RESULTS

Among 2373 patients with traumatic cervical SCI, 940 had complete 1-year outcome data (237 patients [25%] aged 60 years or older; 753 men [80%]). The primary outcome was present in 118 patients (13%), which included 92 men (78%), 83 (70%) patients who were younger than 60 years, and 73 (62%) patients experiencing AIS grade A SCI. The variables significantly associated with the outcome were age (age 60 years or older: OR, 2.31; 95% CI, 1.26-4.19), sex (men: OR, 0.60; 95% CI, 0.31-1.17), light-touch sensation at C5 (OR, 0.44; 95% CI, 0.44-1.01) and C8 (OR, 036; 95% CI, 0.24-0.53) dermatomes, and motor scores of the elbow flexors (C5) (OR, 0.74; 95% CI, 0.60-0.89) and wrist extensors (C6) (OR, 0.61; 95% CI, 0.49-0.75). A multivariable model including these variables had excellent discrimination in distinguishing dependent from independent patients in the temporal-validation cohort (C statistic, 0.90; 95% CI, 0.88-0.93). A clinical prediction score (range, 0 to 45 points) was developed based on these measures, with higher scores increasing the probability of dependency. The discrimination of the prediction score was significantly higher than from AIS grading (change in AUC, 0.14; 95% CI, 0.10-0.18; P < .001).

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that this prediction rule may help prognosticate upper limb function following cervical SCI. This tool can be used to set patient expectations, rehabilitation goals, and aid decision-making regarding the appropriateness and timing for upper limb reconstructive surgeries.

Spontaneous Motor Recovery after Cervical Spinal Cord Injury: Issues for Nerve Transfer Surgery Decision Making

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To quantify spontaneous upper extremity motor recovery between 6 and 12 months after spinal cord injury (SCI) to help guide timing of nerve transfer surgery to improve upper limb function in cervical SCI.

SETTING

Nineteen European SCI rehabilitation centers.

METHODS

Data was extracted from the European Multicenter Study of SCI database for individuals with mid-level cervical SCI (N = 268). Muscle function grades at 6 and 12 months post-SCI were categorized for analysis.

RESULTS

From 6 to 12 months after SCI, spontaneous surgically-relevant recovery was limited. Of all limbs (N = 263) with grade 0-2 elbow extension at 6 months, 4% regained grade 4-5 and 11% regained grade 3 muscle function at 12 months. Of all limbs (N = 380) with grade 0-2 finger flexion at 6 months, 3% regained grade 4-5 and 5% regained grade 3 muscle function at 12 months.

CONCLUSION

This information supports early (6 month) post-injury surgical consultation and evaluation. With this information, individuals with SCI can more fully engage in preference-based decision-making about surgical intervention versus continued rehabilitation and spontaneous recovery to gain elbow extension and/or hand opening and closing.

Intermittent theta burst stimulation modulates biceps brachii corticomotor excitability in individuals with tetraplegia

BACKGROUND

Intermittent theta burst stimulation (iTBS) is a form of repetitive transcranial magnetic stimulation (TMS) that can increase corticomotor excitability of hand muscles in individuals with spinal cord injury (SCI). The objective of this study was to determine the effect of iTBS on the corticomotor excitability of the biceps brachii in individuals with tetraplegia.

METHODS

Ten individuals with low cervical SCI (C5-C8) and ten nonimpaired individuals completed three independent sessions. Motor evoked potentials (MEPs) served as our measure of corticomotor excitability and were collected before and after iTBS. MEPs were normalized by the electromyography corresponding to maximum voluntary contraction and analyzed using linear mixed effects models to determine the effect of iTBS (active or sham) on normalized MEPs (nMEPs). iTBS effects were compared to a ratio of active and resting motor thresholds as a measurement of corticomotor conductance potential.

RESULTS

Relative to sham, active iTBS increased nMEPs over time (p < 0.001) in individuals with SCI, but not nonimpaired individuals (p = 0.915). The amplitude of nMEPs were correlated with the biceps corticomotor conductance potential (p < 0.001), with nMEPs decreasing as the ratio increased at different rates after sham or active iTBS.

CONCLUSIONS

Preliminary results suggest that iTBS increases biceps corticomotor excitability in individuals with tetraplegia with effects that may be predicted by corticomotor conductance potential. Clinical trial registration NCT03277521 Registered on clinicaltrials.gov on August 24, 2017.

Surgery to Restore Upper Extremity Function in Tetraplegia-Preferences for Early and Frequent Access to Information

INTRODUCTION

People with cervical spinal cord injury (SCI) identify improving upper extremity (UE) function as a top priority. In addition to comprehensive rehabilitation, UE surgeries, including nerve and tendon transfers, enhance function. However, barriers exist to disseminating information about surgical options to enhance UE function.

OBJECTIVE

To assess the experiences and preferences of people with cervical SCI and their caregivers in accessing information about surgery to enhance UE function.

DESIGN

Prospective cohort study. Participants were followed for 24 months and completed up to three interviews.

SETTING

Tertiary care at academic and affiliated Veterans Administration Health Care Centers.

PARTICIPANTS

Adults with cervical SCI (n=35) ages 18 to 80 years with mid-cervical SCI American Spinal Injury Association Impairment Scale A, B, or C (at least six months post-injury) and their caregivers (n=23) were eligible to participate. Participants were enrolled in three groups: nerve transfer, tendon transfer, or no UE reconstructive surgery.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Semi-structured interviews about surgical knowledge and experiences.

RESULTS

Data were analyzed and three themes were identified. First, providing information about UE surgical options early post-injury was recommended. The acute or inpatient rehabilitation phases of recovery were the preferred times to receive surgical information. Second, challenges with information dissemination were identified. Participants learned about UE surgery through independent research, medical provider interactions, or peers. Third, peers were identified as valuable resources for SCI needs and surgical information.

CONCLUSIONS

Following cervical SCI, information about UE reconstructive surgeries should be a standard component of education during rehabilitation. An increased understanding of the reconstructive options available to improve UE function is necessary to educate stakeholders. Future research is needed to support the development of strategies to effectively present surgical information to individuals with SCI and healthcare providers. This article is protected by copyright. All rights reserved.

Reduced Muscle Activity of the Upper Extremity in Individuals with Spinal Cord Injuries

Compromised physical ability due to musculoskeletal impairment among spinal cord injury (SCI) patients is known to negatively affect their quality of life. It is essential to comprehensively understand the muscle strength of the upper extremity among patients with SCI to enhance muscle function and capacity to engage in an active lifestyle. The objective of this study was to evaluate the muscle strength of 15 upper extremity muscles among patients with SCI and compare the relative weakness of individual muscles to the control group. Seven male patients with SCI with ASIA impairment scale D and E and 33 males in the control group participated in this study. Each participant performed maximal voluntary contraction of individual muscles, and the electromyography data were recorded. The results showed that the majority of the upper extremity muscles (12 out of 15) showed considerable weakness (24 to 53%) relative to the control group. Furthermore, the relative strength (ranking) of individual muscles among 15 upper extremity muscles was different between patients with SCI and the control group. This information would be useful to the selective strengthening of specific muscles as an intensive rehabilitation effort and prevent overuse and adverse injuries due to excessive muscle training.

Stimulation Parameters Used During Repetitive Transcranial Magnetic Stimulation for Motor Recovery and Corticospinal Excitability Modulation in SCI: A Scoping Review

There is a growing interest in non-invasive stimulation interventions as treatment strategies to improve functional outcomes and recovery after spinal cord injury (SCI). Repetitive transcranial magnetic stimulation (rTMS) is a neuromodulatory intervention which has the potential to reinforce the residual spinal and supraspinal pathways and induce plasticity. Recent reviews have highlighted the therapeutic potential and the beneficial effects of rTMS on motor function, spasticity, and corticospinal excitability modulation in SCI individuals. For this scoping review, we focus on the stimulation parameters used in 20 rTMS protocols. We extracted the rTMS parameters from 16 published rTMS studies involving SCI individuals and were able to infer preliminary associations between specific parameters and the effects observed. Future investigations will need to consider timing, intervention duration and dosage (in terms of number of sessions and number of pulses) that may depend on the stage, the level, and the severity of the injury. There is a need for more real vs. sham rTMS studies, reporting similar designs with sufficient information for replication, to achieve a significant level of evidence regarding the use of rTMS in SCI.

Characterizing Natural Recovery of People With Initial Motor Complete Tetraplegia

OBJECTIVE

To determine the differences in neurologic recovery in persons with initial cervical American Spinal Cord Injury Association Impairment Scale (AIS) grades A and B over time.

DESIGN

Retrospective analysis of data from people with traumatic cervical spinal cord injury (SCI) enrolled in the National Spinal Cord Injury Model Systems (SCIMS) database from 2011-2019.

SETTING

SCIMS centers.

PARTICIPANTS

Individuals (N=187) with traumatic cervical (C1-C7 motor level) SCI admitted with initial AIS grade A and B injuries within 30 days of injury, age 16 years or older, upper extremity motor score (UEMS) ≤20 on both sides, and complete neurologic data at admission and follow-up between 6 months and 2 years.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Conversion in AIS grades, UEMS and lower extremity motor scores (LEMS), and sensory scores.

RESULTS

Mean time to initial and follow-up examinations were 16.1±7.3 days and 377.5±93.4 days, respectively. Conversion from an initial cervical AIS grades A and B to motor incomplete status was 13.4% and 50.0%, respectively. The mean UEMS change for people with initial AIS grades A and B did not differ (7.8±6.5 and 8.8±6.1; P=.307), but people with AIS grade B experienced significantly higher means of LEMS change (2.3±7.4 and 8.8±13.9 (P≤.001). The increased rate of conversion to motor incomplete status from initial AIS grade B appears to be the primary driving factor of increased overall motor recovery. Individuals with initial AIS grade B had greater improvement in sensory scores.

CONCLUSIONS

While UEMS recovery is similar in persons with initial AIS grades A and B, the rate of conversion to motor incomplete status, LEMS, and sensory recovery are significantly different. This information is important for clinical as well as research considerations.

Optimizing the timing of peripheral nerve transfers for functional re-animation in cervical spinal cord injury: a conceptual framework

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

Plasticity in Cervical Motor Circuits following Spinal Cord Injury and Rehabilitation

Simple Summary

Spinal cord injury results in a decreased quality of life and impacts hundreds of thousands of people in the US alone. This review discusses the underlying cellular mechanisms of injury and the concurrent therapeutic hurdles that impede recovery. It then describes the phenomena of neural plasticity—the nervous system’s ability to change. The primary focus of the review is on the impact of cervical spinal cord injury on control of the upper limbs. The neural plasticity that occurs without intervention is discussed, which shows new connections growing around the injury site and the involvement of compensatory movements. Rehabilitation-driven neural plasticity is shown to have the ability to guide connections to create more normal functions. Various novel stimulation and recording technologies are outlined for their role in further improving rehabilitative outcomes and gains in independence. Finally, the importance of sensory input, an often-overlooked aspect of motor control, is shown in driving neural plasticity. Overall, this review seeks to delineate the historical and contemporary research into neural plasticity following injury and rehabilitation to guide future studies.

Abstract

Neuroplasticity is a robust mechanism by which the central nervous system attempts to adapt to a structural or chemical disruption of functional connections between neurons. Mechanical damage from spinal cord injury potentiates via neuroinflammation and can cause aberrant changes in neural circuitry known as maladaptive plasticity. Together, these alterations greatly diminish function and quality of life. This review discusses contemporary efforts to harness neuroplasticity through rehabilitation and neuromodulation to restore function with a focus on motor recovery following cervical spinal cord injury. Background information on the general mechanisms of plasticity and long-term potentiation of the nervous system, most well studied in the learning and memory fields, will be reviewed. Spontaneous plasticity of the nervous system, both maladaptive and during natural recovery following spinal cord injury is outlined to provide a baseline from which rehabilitation builds. Previous research has focused on the impact of descending motor commands in driving spinal plasticity. However, this review focuses on the influence of physical therapy and primary afferent input and interneuron modulation in driving plasticity within the spinal cord. Finally, future directions into previously untargeted primary afferent populations are presented.

Evaluation of Functional Independence in Cervical Spinal Cord Injury: Implications for Surgery to Restore Upper Limb Function

PURPOSE

To help individuals make informed choices regarding the optimal type and timing of restorative surgical treatment for cervical spinal cord injury (SCI), more precise information is needed on their ability to perform activities of daily living. The goal of this work was to describe functional independence achieved by individuals with differing levels of cervical SCI.

METHODS

Using the comprehensive European Multicenter Study of Spinal Cord Injury dataset, analysis was undertaken of individuals with traumatic SCI, motor-level C5-C8. Data on feeding, bladder management, and transfers (bed to wheelchair) were compared between individuals with different levels of injury. Subgroup analyses of symmetrical and asymmetrical SCI and between complete and incomplete SCI were performed. The impact of age, sex, and time postinjury on functional independence was ascertained.

RESULTS

Data were available for individuals with symmetrical (n = 204) and asymmetrical (n = 95) patterns of SCI. Independence with feeding, urinary function, and transfer ability was increased in individuals with strong finger flexion. Unexpectedly, the presence of strong elbow extension did not uniformly result in the ability to transfer independently. There was no change in any of the analyzed activities between 6 and 12 months postinjury.

CONCLUSIONS

People with cervical SCI who gain finger flexion have greater independence with feeding, urinary, and transfer activities. Restoration of finger flexion should be a reconstructive priority for individuals with midcervical-level SCI.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

Characterizing Natural Recovery after Traumatic Spinal Cord Injury

The predominant tool used to predict outcomes after traumatic spinal cord injury (SCI) is the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI), in association with the American Spinal Injury Association (ASIA) Impairment Scale (AIS). These measures have evolved based on analyses of large amounts of longitudinal neurological recovery data published in numerous separate studies. This article reviews and synthesizes published data on neurological recovery from multiple sources, only utilizing data in which the sacral sparing definition was applied for determination of completeness. Conversion from a complete to incomplete injury is more common in tetraplegia than paraplegia. The majority of AIS conversion and motor recovery occurs within the first 6-9 months, with the most rapid rate of motor recovery occurring in the first three months after injury. Motor score changes, as well as recovery of motor levels, are described with the initial strength of muscles as well as the levels of the motor zone of partial preservation influencing the prognosis. Total motor recovery is greater for patients with initial AIS B than AIS A, and greater after initial AIS C than with motor complete injuries. Older age has a negative impact on neurological and functional recovery after SCI; however, the specific age (whether >50 or >65 years) and underlying reasons for this impact are unclear. Penetrating injury is more likely to lead to a classification of a neurological complete injury compared with blunt trauma and reduces the likelihood of AIS conversion at one year. There are insufficient data to support gender having a major effect on neurological recovery after SCI.

Spinal cord injury: A multisystem physiological impairment/dysfunction

Spinal cord injury (SCI) is a complex disease that affects not only sensory and motor pathways below the neurological level of injury (NLI) but also all the organs and systems situated below this NLI. This multisystem impairment implies comprehensive management in dedicated SCI specialized centers, by interdisciplinary and multidisciplinary teams, able to treat not only the neurological impairment, but also all the systems and organs affected. After a brief history of the Spinal Cord Medicine, the author describes how to determine the level and severity of a SCI based on the International Standards for Neurological Classification of Spinal Cord Injury and the prognosis factors of recovery. This article provides also a review of the numerous SCI-related impairments (except for urinary, sexual problems and pain treated separately in this issue), their principles of management and related complications.

[Upper limb motor and functional recovery in patients with tetraplegia]

OBJECTIVE

To study the recovery of the upper limb motor function and functional independence in patients with cervical spinal cord injury.

MATERIAL AND METHODS

The study included 49 patients with subacute tetraplegia, mean age 33±14.8 years, 42 men and 7 women, admitted to the Preodolenie Rehabilitation Center. The follow-up was up to 2 years. The clinical and functional states were assessed after 3, 6, 12 and more than 12 months after spinal injury, using the ASIA neurological standard scale, the motor subscale of Functional Independence Scale (FIM) and short form of Van Lieshout Test (VLT). All patients received continuous rehabilitation courses that included physiotherapy, occupational therapy, social support, psychological rehabilitation.

RESULTS

Upper limb motor recovery occurred in the first 6 months after spinal cord injury at 5±3.9 points (ASIA), while in 49% patients motor level decreased by one segment of the spinal cord, in 8% patients completeness of spinal cord injury improved. The improvement of functional independence was found during the first 12 months: according to FIM, in the period of 3-6 months by 18±11.1 points, in the period of 6-12 months by 8±8.1 points; according to VLT in the period of 3-6 months by 19±14.4 points, in the period of 6-12 months by 5.6±6.02 points.

CONCLUSIONS

Upper limb motor recovery mostly occurs in the first 6 months while the functional independence improvement lasts during the first 12 months after a spinal cord injury.

[Comparative analysis of functional independence predictors in patients with cervical tetraplegia]

Purpose of the study was to investigate clinical predictors of functional independence in patients with cervical tetraplegia at different periods after a spinal cord injury (SCI).

MATERIAL AND METHODS

190 patients (151 men and 39 women) with an SCI from 3 months to 6 years old were included in a retrospective study. The average age was 27 years. The examination was carried out using the international standard for neurological classification of spinal cord injury (ASIA) with the definition of motor score ASIA for the upper extremity (ASIA _{upper extremity}), neurological (NL) and motor levels (ML), and the completeness of spinal cord injury (AIS). Functional assessment was performed using the FIM motor subscale. The study of neuromuscular conduction of the median nerves - according to stimulation electroneuromyography (SENMG). The degree of functional independence was assessed as a severe disability with FIM less than 42 points, mild and moderate - FIM 42 points or more.

RESULTS

Using logistic regression analysis, it was found that in the first 6 months after SCI, the main predictors are ASIA_{upper extremity} (AUC=0.84; X²=3.32; p=0.06) and NL (AUC=0.80; X²=2.96; p=0.09). When observed in the first 12 months, ASIA_{upper extremity} (AUC=0.86) remains the leading predictor. Moreover, pronounced functional limitations can be predicted using predictors of ASIA_{upper extremity} in 84.4% and completeness of injury (AIS) in 81.2% of cases, moderate and mild limitations - ASIA_{upper extremity} in 81.4%, NL in 86.0% and functional tenodesis (FT) in 100% of cases. In the long-term period (more than 12 months), the exceptional predictive power of the predictor ASIA_{upper extremity} (AUC=0.92) is noted both in the prediction of severe (82.5%) cases and moderate and mild functional disorders (91.8% of cases). In addition, in the SCI long-term period, the predictor AIS plays a significant role in severe disorders (in 82.5% of cases), and NL (88.2%) and FT (100%) - in moderate and mild disorders. The boundaries between functional groups according to functional independence in groups of 12 months and more than 12 months after SMT are presented: ASIA_{upper extremity} 22.4 and 22.6 points, ML more than 6.5 and the presence of FT with a ML of more than 5.6, respectively. At the same time, the results of SENMG showed low predictive significance.

CONCLUSION

Motor score ASIA_{upper extremity} is a leading predictor in all periods after SCI, while completeness of spinal cord injury (AIS) more accurately predicts pronounced functional limitations, and ML and FT predict moderate functional limitations. The FT, a neurological level of C6 and higher, a motor score ASIA _{upper extremity} of more than 22 points are criteria for achieving moderate functional independence.

Distinct Corticospinal and Reticulospinal Contributions to Voluntary Control of Elbow Flexor and Extensor Muscles in Humans with Tetraplegia

Humans with cervical spinal cord injury (SCI) often recover voluntary control of elbow flexors and, to a much lesser extent, elbow extensor muscles. The neural mechanisms underlying this asymmetrical recovery remain unknown. Anatomical and physiological evidence in animals and humans indicates that corticospinal and reticulospinal pathways differentially control elbow flexor and extensor motoneurons; therefore, it is possible that reorganization in these pathways contributes to the asymmetrical recovery of elbow muscles after SCI. To test this hypothesis, we examined motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation over the arm representation of the primary motor cortex, maximal voluntary contractions, the StartReact response (a shortening in reaction time evoked by a startling stimulus), and the effect of an acoustic startle cue on MEPs elicited by cervicomedullary stimulation (CMEPs) on biceps and triceps brachii in males and females with and without chronic cervical incomplete SCI. We found that SCI participants showed similar MEPs and maximal voluntary contractions in biceps but smaller responses in triceps compared with controls, suggesting reduced corticospinal inputs to elbow extensors. The StartReact and CMEP facilitation was larger in biceps but similar to controls in triceps, suggesting enhanced reticulospinal inputs to elbow flexors. These findings support the hypothesis that the recovery of biceps after cervical SCI results, at least in part, from increased reticulospinal inputs and that the lack of these extra inputs combined with the loss of corticospinal drive contribute to the pronounced weakness found in triceps.SIGNIFICANCE STATEMENT Although a number of individuals with cervical incomplete spinal cord injury show limited functional recovery of elbow extensors compared with elbow flexor muscles, to date, the neural mechanisms underlying this asymmetrical recovery remain unknown. Here, we provide for the first time evidence for increased reticulospinal inputs to biceps but not triceps brachii and loss of corticospinal drive to triceps brachii in humans with tetraplegia. We propose that this reorganization in descending control contributes to the asymmetrical recovery between elbow flexor and extensor muscles after cervical spinal cord injury.

Hand Reconstruction in Children with Spinal Cord Injury

Comprehensive programs for children who sustain traumatic spinal cord injury should incorporate optimizing hand and upper extremity function along with the other traditional pillars of rehabilitation. Children's smaller anatomy, open growth plates, and future skeletal growth, combined with the age-related psychosocial impact of these injuries, require protocols suited to these age-related issues. There is a role for surgical reconstruction, as is the case for adults with traumatic tetraplegia, and surgical outcomes are equally beneficial and long lasting. Strict adherence to surgical indications, and surgical strategies and protocols that incorporate their age-related challenges, are the keys to successful management.

Magnetic Resonance Imaging of Trunk Musculature and Intervertebral Discs in Patients with Spinal Cord Injury with Thoracolumbar Vertebral Fractures: A Prospective Study

Study Design

This study is a prospective clinical study.

Purpose

This study aims to evaluate the characteristics of trunk musculature and intervertebral discs by using magnetic resonance imaging in patients with spinal cord injuries (SCIs) with thoracic and lumbar fractures.

Overview of Literature

Muscle atrophy is an immediate consequence of SCI and is associated with secondary complications. At present, there are limited clinical data on muscle and disc responses to fractures of the thoracic and lumbar spine.

Methods

A total of 51 patients with a mean age of 31.75±10.42 years who suffered traumatic SCI were included in this study. Complete neurological examinations (American Spinal Injury Association grading) and magnetic resonance imaging (MRI) were performed at the time of admission and at 3–6 months after injury to study the neurological status and disc and trunk parameters. The type of management (operative or conservative) was decided on the basis of clinical, radiological, and MRI evaluations, and a robust rehabilitation program was initiated.

Results

Disc parameters including disc angle, skin angle, cross-sectional area (CSA), and disc height and trunk parameters (mean trunk width, mean trunk depth, and CSA of the lumbar muscles) decreased significantly (p <0.001) during the first 3 months after SCI. However, improvements were observed in disc and muscle parameters at the 6-month follow-up, but these parameters did not return to normal levels. Neither initial neurological status (complete vs. incomplete) nor type of management (operative vs. conservative) had a significant effect on these parameters.

Conclusions

Spinal trauma leads to alterations in the morphology of the vertebral column, spinal cord, intervertebral discs, and paraspinal muscles in the initial phase of injury. The extent of these changes may determine the initial neurological deficit and subsequent recovery. Although this study did not identify any statistically significant effect of neurological status or management strategy on these parameters, rehabilitation was found to result in the improvement of these parameters in the later phase of recovery. Future studies are required to evaluate the exact causes of these alterations and the potential benefits of rehabilitation strategies and to minimize these changes.

[Funtional tenodesis as a predictor of functional outcome in patients with cervical tetraplegia]

AIM

To determine the value of functional tenodesis (FT) of the hand as a predictor of the degree of disability in patients with cervical tetraplegia (CT) at different periods after a spinal injury.

MATERIAL AND METHODS

We examined 190 patients (79% - men) with CT (92.5% of cases of traumatic origin) at the age of 27 [21.0; 36.0] years with a neurological level of C_ІІІ-D_І, and a share of complete motor damage (A - B according to AIS) 70%. The examination included determination of neurological, motor levels and completeness of spinal cord injury (according to ISNSCI), assessment of functional independence (FIM motor domain), FT of the hand, and the severity of contractures of the joints of the hand. Using logit-regression analysis, creation of contingency tables, ROC analysis, depending on the timing of spinal injury, 4 classification models were studied: Disease duration less than 6 months, assessment of the functional outcome 6 months after spinal injury (model A); disease duration less than 6 months, assessment after 12 months (model B); disease duration less than 12 months, assessment after 12 months (model C); disease duration more than 12 months, evaluation after more than 12 months (model D, primary one).

RESULTS

FT developed in the first 6 months after spinal injury in 12 (24%) patients, in 6-12 months - in 15 patients (20%), in more than 12 months - in 1 (less than 1%) patient. The incidence of joint contractures of the hand in group A (20%) and C (24%) did not have a statistical difference (χ²=0.22; p=0.64). Hand contractures in the first 6 months were observed in 20% of patients, in the first 12 months - in 24%, more than 12 months after spinal injury - in 28% of patients. In model A, the FT sensitivity was 80%, specificity was 64%, AUC - 0.65; in model B - 85%, 36%, 0.36, respectively; in model C (log-regression χ²=19.1; p was not determined) - 69%, 100%, 0.59, respectively; in model D (log-regression χ²=55.3; p was not determined) - 65%, 100%, 0.71, respectively.

CONCLUSION

FT and contracture of the joints of the hand form during the first year after the debut of CT. As a predictor of a pronounced limitation of self-care, the sensitivity of FT in the first 6 months after spinal injury was 80-85%, in the later period, the specificity of FT was 100%, and sensitivity was 65-69%; in general, the predictive power of FT was low (AUC 0.36-0.71) and increased with the assessment of the functional outcome in the period of more than 12 months after the injury.

Development of an unsupervised machine learning algorithm for the prognostication of walking ability in spinal cord injury patients

BACKGROUND CONTEXT

Traumatic spinal cord injury can have a dramatic effect on a patient's life. The degree of neurologic recovery greatly influences a patient's treatment and expected quality of life. This has resulted in the development of machine learning algorithms (MLA) that use acute demographic and neurologic information to prognosticate recovery. The van Middendorp et al. (2011) (vM) logistic regression (LR) model has been established as a reference model for the prediction of walking recovery following spinal cord injury as it has been validated within many different countries. However, an examination of the way in which these prediction models are evaluated is warranted. The area under the receiver operators curve (AUROC) has been consistently used when evaluating model performance, but it has been shown that AUROC overemphasizes the most common event resulting in an inaccurate assessment when the data are imbalanced. Furthermore, there is evidence that the use of more advanced MLA, such as an unsupervised k-means model, may show superior performance compared to LR as they can handle a larger number of features.

PURPOSE

The first objective of the study was to assess the performance of both an unsupervised MLA and LR model with complete admission neurologic information against the vM and Hicks models. Second, a comparison between the accuracy of the AUROC and the F1-score will be made to determine which method is superior for the assessment of diagnostic performance of prediction models on large-scale datasets.

STUDY DESIGN

Retrospective review of a prospective cohort study.

PATIENT SAMPLE

The Rick Hansen Spinal Cord Injury Registry (RHSCIR) was used in this study. All patients enrolled between 2004 and 2017 with complete neurologic examination and Functional Independence Measure outcome data at ≥1 year follow-up or who could walk at discharge were included. The prognostic variables included age (dichotomized at ≥65 years old); American Spinal Injury Association Impairment Scale (AIS) grade; and individual motor, light touch, and pinprick score from L2 to S1.

OUTCOME MEASURES

The Functional Independence Measure locomotor score was used to assess independent walking ability at discharge or 1-year follow-up.

METHODS

An unsupervised MLA with k=2 was chosen in order to identify a "walk" cluster and a "not walk" cluster. Model performance was assessed through the development of a receiver operating characteristic curve with associated AUROC and a precision-recall curve with associated F1-score. The study and the RHSCIR are supported by funding from Health Canada, Western Economic Diversification Canada, and the Governments of Alberta, British Columbia, Manitoba, and Ontario. These funders had no role in the study or study reporting and the authors have no conflicts of interest to report.

RESULTS

No clinically relevant differences were found between with the use of an unsupervised MLA with a greater amount of initial neurologic information compared to the established standards for any AIS classification. Although demonstrated for all separate AIS classifications, most notably, the AUROC for the vM (0.78) and Hicks models (0.76) were found to be superior to that of the new LR model (0.72); however, the vM and Hicks models had more than double the amount of false negative classifications compared to the LR. The F1-scores between these three models were also found to be different but with the vM and Hicks models being lower than the LR (0.85, 0.81, and 0.89, respectively).

CONCLUSIONS

No clinically relevant differences were found between the use of an unsupervised MLA with complete admission neurologic information compared to the previously validated standards; however, when comparing the performance of the AUROC and F1-score, the AUROC showed inaccurate prognostic performance when there was an imbalance toward a greater amount of false negatives. Importantly, the F1-score did not succumb to this imbalance. As AUROC has been used as the standard when evaluating performance of prediction models, consideration as to whether this is the most appropriate method is warranted. Future work should focus on comparing AUROC and F1-scores with other previously validated models.

Effectiveness of occupational therapy in improving activities of daily living performance in complete cervical tetraplegic patients; A quasi experimental study

OBJECTIVE

To determine the effectiveness of Occupational therapy (OT) in improving activities of daily living performance in complete cervical tetraplegic patients.

METHODS

A quasi experimental study was conducted at Paraplegic Center Peshawar from May 2018 to March 2019. Seventy two spinal cord injury patients with complete cervical tetraplegia having age 18-60 years were included in the study using non probability convenience sampling technique. A trained Occupational therapist conducted two occupational therapy sessions per day, three times a week on alternative days for a period of six weeks. Self-care portion of Spinal cord injury independence measure (SCIM) was used to collect pre and post data. Data was analyzed using SPSS version 20.

RESULTS

Mean age of the participants was 30.21±13.52.Majority of the participants were (n= 61, 84.7%) male while remaining 11 (15.3%) participants were female. Pre self-care total score was 0.39±0.987 and post self-care total score was 7.17±5.536. There was significant differences (P value <0.05) between pre and post scores of feeding, upper & lower body bathing, upper & lower body dressing, grooming and total self-care scores.

CONCLUSION

Occupational therapy significantly improves activities of daily living performance in complete cervical tetraplegic spinal cord injury patients.

Highlighting discrepancies in walking prediction accuracy for patients with traumatic spinal cord injury: an evaluation of validated prediction models using a Canadian Multicenter Spinal Cord Injury Registry

BACKGROUND CONTEXT

Models for predicting recovery in traumatic spinal cord injury (tSCI) patients have been developed to optimize care. Several models predicting tSCI recovery have been previously validated, yet recent findings question their accuracy, particularly in patients whose prognoses are the least predictable.

PURPOSE

To compare independent ambulatory outcomes in AIS (ASIA [American Spinal Injury Association] Impairment Scale) A, B, C, and D patients, as well as in AIS B+C and AIS A+D patients by applying two existing logistic regression prediction models.

STUDY DESIGN

A prospective cohort study.

PARTICIPANT SAMPLE

Individuals with tSCI enrolled in the pan-Canadian Rick Hansen SCI Registry (RHSCIR) between 2004 and 2016 with complete neurologic examination and Functional Independence Measure (FIM) outcome data.

OUTCOME MEASURES

The FIM locomotor score was used to assess independent walking ability at 1-year follow-up.

METHODS

Two validated prediction models were evaluated for their ability to predict walking 1-year postinjury. Relative prognostic performance was compared with the area under the receiver operating curve (AUC).

RESULTS

In total, 675 tSCI patients were identified for analysis. In model 1, predictive accuracies for 675 AIS A, B, C, and D patients as measured by AUC were 0.730 (95% confidence interval [CI] 0.622-0.838), 0.691 (0.533-0.849), 0.850 (0.771-0.928), and 0.516 (0.320-0.711), respectively. In 160 AIS B+C patients, model 1 generated an AUC of 0.833 (95% CI 0.771-0.895), whereas model 2 generated an AUC of 0.821 (95% CI 0.754-0.887). The AUC for 515 AIS A+D patients was 0.954 (95% CI 0.933-0.975) with model 1 and 0.950 (0.928-0.971) with model 2. The difference in prediction accuracy between the AIS B+C cohort and the AIS A+D cohort was statistically significant using both models (p=.00034; p=.00038). The models were not statistically different in individual or subgroup analyses.

CONCLUSIONS

Previously tested prediction models demonstrated a lower predictive accuracy for AIS B+C than AIS A+D patients. These models were unable to effectively prognosticate AIS A+D patients separately; a failure that was masked when amalgamating the two patient populations. This suggests that former prediction models achieved strong prognostic accuracy by combining AIS classifications coupled with a disproportionately high proportion of AIS A+D patients.

Engaging cervical spinal circuitry with non-invasive spinal stimulation and buspirone to restore hand function in chronic motor complete patients

The combined effects of cervical electrical stimulation alone or in combination with the monoaminergic agonist buspirone on upper limb motor function were determined in six subjects with motor complete (AIS B) injury at C5 or above and more than one year from time of injury. Voluntary upper limb function was evaluated through measures of controlled hand contraction, handgrip force production, dexterity measures, and validated clinical assessment batteries. Repeated measure analysis of variance was used to evaluate functional metrics, EMG amplitude, and changes in mean grip strength. In aggregate, mean hand strength increased by greater than 300% with transcutaneous electrical stimulation and buspirone while a corresponding clinically significant improvement was observed in upper extremity motor scores and the action research arm test. Some functional improvements persisted for an extended period after the study interventions were discontinued. We demonstrate that, with these novel interventions, cervical spinal circuitry can be neuromodulated to improve volitional control of hand function in tetraplegic subjects. The potential impact of these findings on individuals with upper limb paralysis could be dramatic functionally, psychologically, and economically.

Descriptive pilot study of vividness and temporal equivalence during motor imagery training after quadriplegia

BACKGROUND

Motor imagery (MI) training is often used to improve physical practice (PP), and the functional equivalence between imagined and practiced movements is widely considered essential for positive training outcomes.

OBJECTIVE

We previously showed that a 5-week MI training program improved tenodesis grasp in individuals with C6-C7 quadriplegia. Here we investigated whether functional equivalence changed during the course of this training program.

METHODS

In this descriptive pilot study, we retrospectively analyzed data for 6 individuals with C6-C7 quadriplegia (spinal cord injured [SCI]) and 6 healthy age-matched controls who trained for 5 weeks in visual and kinesthetic motor imagery or visualization of geometric shapes (controls). Before training, we assessed MI ability by using the Kinesthetic and Visual Imagery Questionnaire (KVIQ). We analyzed functional equivalence by vividness measured on a visual analog scale (0-100) and MI/PP time ratios computed from imagined and physically practiced movement durations measured during MI training. These analyses were re-run considering that half of the participants with quadriplegia were good imagers and the other half were poor imagers based on KVIQ scores. To investigate generalization of training effects, we analyzed MI/PP ratios for an untrained pointing task before (3 baseline measures), immediately after, and 2 months after training.

RESULTS

During MI training, imagery vividness increased significantly. Only the good imagers evolved toward temporal equivalence during training. Good imagers were also the only participants who showed changes in temporal equivalence on the untrained pointing task.

CONCLUSION

This is the first study reporting improvement in functional equivalence during an MI training program that improved tenodesis grasp in individuals with C6-C7 quadriplegia. We recommend that clinical MI programs focus primarily on vividness and suggest that feedback about movement duration could potentially improve temporal equivalence, which could in turn lead to further improvement in PP.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

A simplified clinical prediction rule for prognosticating independent walking after spinal cord injury: a prospective study from a Canadian multicenter spinal cord injury registry

BACKGROUND CONTEXT

Traumatic spinal cord injury (SCI) is a debilitating condition with limited treatment options for neurologic or functional recovery. The ability to predict the prognosis of walking post injury with emerging prediction models could aid in rehabilitation strategies and reintegration into the community.

PURPOSE

To revalidate an existing clinical prediction model for independent ambulation (van Middendorp et al., 2011) using acute and long-term post-injury follow-up data, and to investigatethe accuracy of a simplified model using prospectively collected data from a Canadian multicenter SCI database, the Rick Hansen Spinal Cord Injury Registry (RHSCIR).

STUDY DESIGN

Prospective cohort study.

PARTICIPANT SAMPLE

The analysis cohort consisted of 278 adult individuals with traumatic SCI enrolled in the RHSCIR for whom complete neurologic examination data and Functional Independence Measure (FIM) outcome data were available.

OUTCOME MEASURES

The FIM locomotor score was used to assess independent walking ability (defined as modified or complete independence in walk or combined walk and wheelchair modality) at 1-year follow-up for each participant.

METHODS

A logistic regression (LR) model based on age and four neurologic variables was applied to our cohort of 278 RHSCIR participants. Additionally, a simplified LR model was created. The Hosmer-Lemeshow goodness of fit test was used to check if the predictive model is applicable to our data set. The performance of the model was verified by calculating the area under the receiver operating characteristic curve (AUC). The accuracy of the model was tested using a cross-validation technique. This study was supported by a grant from The Ottawa Hospital Academic Medical Organization ($50,000 over 2 years). The RHSCIR is sponsored by the Rick Hansen Institute and is supported by funding from Health Canada, Western Economic Diversification Canada, and the provincial governments of Alberta, British Columbia, Manitoba, and Ontario. ET and JP report receiving grants from the Rick Hansen Institute (approximately $60,000 and $30,000 per year, respectively). DMR reports receiving remuneration for consulting services provided to Palladian Health, LLC and Pacira Pharmaceuticals, Inc ($20,000-$30,000 annually), although neither relationship presents a potential conflict of interest with the submitted work. KEH received a grant for involvement in the present study from the Government of Canada as part of the Canada Summer Jobs Program ($3,000). JP reports receiving an educational grant from Medtronic Canada outside of the submitted work ($75,000 annually). TM reports receiving educational fellowship support from AO Spine, AO Trauma, and Medtronic; however, none of these relationships are financial in nature. All remaining authors have no conflicts of interest to disclose.

RESULTS

The fitted prediction model generated 85% overall classification accuracy, 79% sensitivity, and 90% specificity. The prediction model was able to accurately classify independent walking ability (AUC 0.889, 95% confidence interval [CI] 0.846-0.933, p<.001) compared with the existing prediction model, despite the use of a different outcome measure (FIM vs. Spinal Cord Independence Measure) to qualify walking ability. A simplified, three-variable LR model based on age and two neurologic variables had an overall classification accuracy of 84%, with 76% sensitivity and 90% specificity, demonstrating comparable accuracy with its five-variable prediction model counterpart. The AUC was 0.866 (95% CI 0.816-0.916, p<.01), only marginally less than that of the existing prediction model.

CONCLUSIONS

A simplified predictive model with similar accuracy to a more complex model for predicting independent walking was created, which improves utility in a clinical setting. Such models will allow clinicians to better predict the prognosis of ambulation in individuals who have sustained a traumatic SCI.

White matter changes in corticospinal tract associated with improvement in arm and hand functions in incomplete cervical spinal cord injury: pilot case series

INTRODUCTION

This is a prospective clinical pilot case series. Improvement of arm and hand functions after spinal cord injury (SCI) is one of the major rehabilitation goals. Electrical stimulation of the primary motor cortex via transcranial direct current stimulation (tDCS) coupled with high-intensity repetitive motor training may have potential to facilitate improvement in motor function in chronic, incomplete cervical SCI. We investigated the relationship between motor recovery and changes in white matter integrity in response to treatment intervention. This study was conducted in The Institute for Rehabilitation and Research Memorial Hermann, Houston, USA.

CASE PRESENTATION

Four right-handed adults with chronic, incomplete cervical SCI (age, 36-63 years, American Spinal Injury Association Impairment Scale grade C-D) were enrolled in 10 sessions of anodal tDCS at 2 mA versus sham tDCS followed by 1 h of robotic-assisted arm training. Changes in arm and hand function were measured with Jebsen-Taylor Hand Function Test and Motor Activity Log-Amount of Use. Diffusion tension imaging was used to measure changes in fractional anisotropy (FA) of corticospinal tracts (CSTs).

DISCUSSION

After 10 sessions of treatment, we found greater improvement in hand function and hand usage in patients who received active tDCS treatment versus sham treatment. There was an overall positive change in FA values across all patients. We show changes in arm and hand function associated with changes in CST tractographic mapping to quantify the motor system components in chronic incomplete cervical SCI.

Use of an arm weight-bearing combined with upper-limb reaching apparatus to facilitate motor paralysis recovery in an incomplete spinal cord injury patient: a single case report

[Purpose] Training using an arm weight-bearing device combined with upper-limb reaching apparatus to facilitate motor paralysis recovery, named the “Reaching Robot”, as well as Repetitive Facilitation Exercise were applied to a patient with severe impairment of the shoulder and elbow due to incomplete spinal cord injury and the effects were examined. [Subjects and Methods] A 66-year-old man with incomplete spinal cord injury participated in an upper extremity rehabilitation program involving a Reaching Robot. The program was comprised of active motor suspension, continuous low amplitude neuromuscular electrical stimulation and functional vibratory stimulation, as well as Repetitive Facilitation Exercise combined with continuous low amplitude neuromuscular electrical stimulation. This protocol used a crossover design following an A₁-B₁-A₂-B₂. “A” consisted of 2 weeks of Repetitive Facilitation Exercise, and “B” consisted of 2 weeks of Reaching Robot training. [Results] Improvements were observed after all sessions. Active range of motion for shoulder flexion improved after 2 weeks of Reaching Robot sessions only. There were no adverse events. [Conclusion] Reaching Robot training for severe paretic upper-extremity after incomplete spinal cord injury was a safe and effective treatment. Reaching Robot training may be useful for rehabilitation of paretic upper-extremity after incomplete spinal cord injury.

Engaging Cervical Spinal Cord Networks to Reenable Volitional Control of Hand Function in Tetraplegic Patients

BACKGROUND

Paralysis of the upper limbs from spinal cord injury results in an enormous loss of independence in an individual's daily life. Meaningful improvement in hand function is rare after 1 year of tetraparesis. Therapeutic developments that result in even modest gains in hand volitional function will significantly affect the quality of life for patients afflicted with high cervical injury. The ability to neuromodulate the lumbosacral spinal circuitry via epidural stimulation in regaining postural function and volitional control of the legs has been recently shown. A key question is whether a similar neuromodulatory strategy can be used to improve volitional motor control of the upper limbs, that is, performance of motor tasks considered to be less "automatic" than posture and locomotion. In this study, the effects of cervical epidural stimulation on hand function are characterized in subjects with chronic cervical cord injury.

OBJECTIVE

Herein we show that epidural stimulation can be applied to the chronic injured human cervical spinal cord to promote volitional hand function.

METHODS AND RESULTS

Two subjects implanted with a cervical epidural electrode array demonstrated improved hand strength (approximately 3-fold) and volitional hand control in the presence of epidural stimulation.

CONCLUSIONS

The present data are sufficient to suggest that hand motor function in individuals with chronic tetraplegia can be improved with cervical cord neuromodulation and thus should be comprehensively explored as a possible clinical intervention.

Improvement of grasping after motor imagery in C6-C7 tetraplegia: A kinematic and MEG pilot study

PURPOSE

Grasp recovery after C6-C7-spinal cord injury (SCI) requires learning "tenodesis grasp" whereby active wrist extension elicits passive thumb-to-forefinger and finger-to-palm flexion. Evidence that motor imagery (MI) promotes upper limb function after tetraplegia is growing, but whether MI potentiates grasp recovery in C6-C7-SCI individuals who have successfully learned the "tenodesis grasp" remains unknown.

METHODS

Six chronic stable C6-C7-SCI inpatients and six healthy control participants were included. C6-C7-SCI participants imagined grasping movements and controls visualized geometric forms for 45 minutes, three times a week for five weeks. Three separate measures taken over a five week period before the intervention formed the baseline. Intervention effects were assessed immediately after the intervention and eight weeks later. Each testing session consisted of kinematic recordings during reach-to-grasp and magnetoencephalographic (MEG) recordings during wrist extension.

RESULTS

During baseline, kinematic wrist extension angle during "tenodesis grasp" and MEG contralateral sensorimotor cortex (cSMC) activity during wrist extension were stable. Moreover, SCI participants exhibited a greater number of voxels within cSMC than controls. After MI sessions, wrist extension angle increased during "tenodesis grasp" and the number of voxels within cSMC during wrist extension decreased and became similar to controls.

CONCLUSION

These findings provide further support for the use of MI to reinforce a compensatory grasping movement (tenodesis) and induce brain plasticity.

Nerve Transfers in Tetraplegia

Hand and upper extremity function is instrumental to basic activities of daily living and level of independence in cervical spinal cord injury (SCI). Nerve transfer surgery is a novel and alternate approach for restoring function in SCI. This article discusses the biologic basis of nerve transfers in SCI, patient evaluation, management, and surgical approaches. Although the application of this technique is not new; recent case reports and case series in the literature have increased interest in this field. The challenges are to improve function, achieve maximal gains in function, avoid complications, and to primum non nocere.

Nerve Transfers to Restore Upper Extremity Function in Cervical Spinal Cord Injury: Update and Preliminary Outcomes

BACKGROUND

Cervical spinal cord injury can result in profound loss of upper extremity function. Recent interest in the use of nerve transfers to restore volitional control is an exciting development in the care of these complex patients. In this article, the authors review preliminary results of nerve transfers in spinal cord injury.

METHODS

Review of the literature and the authors' cases series of 13 operations in nine spinal cord injury nerve transfer recipients was performed. Representative cases were reviewed to explore critical concepts and preliminary outcomes.

RESULTS

The nerve transfers used expendable donors (e.g., teres minor, deltoid, supinator, and brachialis) innervated above the level of the spinal cord injury to restore volitional control of missing function such as elbow extension, wrist extension, and/or hand function (posterior interosseous nerve or anterior interosseous nerve/finger flexors reinnervated). Results from the literature and the authors' patients (after a mean postsurgical follow-up of 12 months) indicate gains in function as assessed by both manual muscle testing and patients' self-reported outcomes measures.

CONCLUSIONS

Nerve transfers can provide an alternative and consistent means of reestablishing volitional control of upper extremity function in people with cervical level spinal cord injury. Early outcomes provide evidence of substantial improvements in self-reported function despite relatively subtle objective gains in isolated muscle strength. Further work to investigate the optimal timing and combination of nerve transfer operations, the combination of these with traditional treatments (tendon transfer and functional electrical stimulation), and measurement of outcomes is imperative for determining the precise role of these operations.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Clinical Trial of Human Fetal Brain-Derived Neural Stem/Progenitor Cell Transplantation in Patients with Traumatic Cervical Spinal Cord Injury

In a phase I/IIa open-label and nonrandomized controlled clinical trial, we sought to assess the safety and neurological effects of human neural stem/progenitor cells (hNSPCs) transplanted into the injured cord after traumatic cervical spinal cord injury (SCI). Of 19 treated subjects, 17 were sensorimotor complete and 2 were motor complete and sensory incomplete. hNSPCs derived from the fetal telencephalon were grown as neurospheres and transplanted into the cord. In the control group, who did not receive cell implantation but were otherwise closely matched with the transplantation group, 15 patients with traumatic cervical SCI were included. At 1 year after cell transplantation, there was no evidence of cord damage, syrinx or tumor formation, neurological deterioration, and exacerbating neuropathic pain or spasticity. The American Spinal Injury Association Impairment Scale (AIS) grade improved in 5 of 19 transplanted patients, 2 (A → C), 1 (A → B), and 2 (B → D), whereas only one patient in the control group showed improvement (A → B). Improvements included increased motor scores, recovery of motor levels, and responses to electrophysiological studies in the transplantation group. Therefore, the transplantation of hNSPCs into cervical SCI is safe and well-tolerated and is of modest neurological benefit up to 1 year after transplants. This trial is registered with Clinical Research Information Service (CRIS), Registration Number: KCT0000879.

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.

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.

Bilateral contusion-compression model of incomplete traumatic cervical spinal cord injury

Despite the increasing incidence and prevalence of cervical spinal cord injury (cSCI), we lack clinically relevant animal models that can be used to study the pathomechanisms of this injury and test new therapies. Here, we characterize a moderate cervical contusion-compression model in rats that is similar to incomplete traumatic cSCI in humans. We characterized the effects of 18-g clip-compression injury at cervical level C6 over an 8-week recovery period. Using Luxol fast blue/hematoxylin-eosin staining in combination with quantitative stereology, we determined that 18-g injury results in loss of gray matter (GM), white matter (WM), as well as in cavity formation. Magnetization transfer and T2-weighted magnetic resonance imaging were used to analyze lesion dynamics in vivo. This analysis demonstrated that both techniques are able to differentiate between the injury epicenter, subpial rim, and WM distal to the injury. Neurobehavioral assessment of locomotor function using Basso, Beattie, and Bresnahan (BBB) scoring and CatWalk revealed limited recovery from clip-compression injury at C6. Testing of forelimb function using grip strength demonstrated significant forelimb dysfunction, similar to the loss of upper-limb motor function observed in human cSCI. Sensory-evoked potentials recorded from the forelimb and Hoffman reflex recorded from the hindlimb confirmed the fore- and hindlimb deficits observed in our neurobehavioral analysis. Here, we have characterized a clip-compression model of incomplete cSCI that closely models this condition in humans. This work directly addresses the current lack of clinically relevant models of cSCI and will thus contribute to improved success in the translation of putative therapies into the clinic.

An anatomical study of the ECRL and ECRB: feasibility of developing a preoperative test for evaluating the strength of the individual wrist extensors

BACKGROUND

Tendon transfers are essential for reconstruction of hand function in tetraplegic patients. To transfer the extensor carpi radialis longus (ECRL), the extensor carpi radialis brevis (ECRB) has to be sufficiently strong. However, there is currently no reliable clinical test to individually analyse both muscles. In order to develop a reliable preoperative clinical test, the anatomy of the muscle (innervation) areas of ECRB, ECRL and brachio-radialis (BR) was examined.

METHODS

In 20 arms, the ECRB, ECRL and BR were dissected and localised. Subsequently, muscle-innervation points were mapped and categorised. A novel method, computer-assisted surgical anatomy mapping (CASAM), was used to visualise muscle areas and innervation points in a computed arm with average dimensions.

RESULTS

For both ECRL and ECRB a 100% area could be identified, a specific area in the computed average arm in which the muscle was present for all 20 arms. For the ECRL, this area was situated at 16% of the distance between the lateral epicondyle and the deltoid muscle insertion. The ECRB 100% area was 5 times bigger than that of the ECRL and was located at 40% of the distance between the lateral epicondyle and the radial styloid process. The ECRL and BR showed one to three innervation points, the ECRB one to four. In 47% of the cases, there was a combined nerve branch innervating both the ECRL and the ECRB.

CONCLUSIONS

It is feasible to develop a preoperative test; the 100% areas can be used for needle electromyography (EMG) or local anaesthetic muscle injections.

Clinical predictors of neurological outcome, functional status, and survival after traumatic spinal cord injury: a systematic review

OBJECT

The object of this study was to identify, by means of a systematic review of the literature, the acute clinical predictors of neurological outcome, functional outcome, and survival after traumatic spinal cord injury (SCI).

METHODS

A comprehensive computerized literature review search was performed, using MEDLINE, PubMed, EMBASE, CINAHL, and the Cochrane Database of Systematic Reviews. Selected articles were classified according to their level of evidence. Articles were then stratified into one of 3 domains depending on whether the primary focus was clinical prediction of 1) neurological outcome, 2) functional status, or 3) survival. For each study selected, clinical predictors related to patient demographic characteristics, injury mechanism, or neurological examination findings were extracted, and the individual relationship to outcome was defined.

RESULTS

The initial search resulted in 376 citations. After application of the inclusion and exclusion criteria and study review, 51 relevant articles were identified and graded. Of these, 25 provided predictors for neurological outcome, 22 for functional outcome, and 15 for survival, with several of the articles providing information on more than one type of outcome. All of the included studies were designated as providing Class I, II, or III levels of evidence. The severity of neurological injury (as measured by admission Americal Spinal Injury Association Impairment Scale grade, Frankel grade, or injury completeness), level of injury, and the presence of a zone of partial preservation were consistent predictors of neurological outcome. Severity of neurological injury, level of injury, reflex pattern, and age were consistent predictors of functional outcome. Finally, severity of neurological injury, level of injury, age, and the presence of multisystem trauma seen with higher-energy injury mechanisms were consistent predictors of survival.

CONCLUSIONS

On the basis on this review, the authors have identified a constellation of acute clinical features that may help to define an individual's profile for recovery and survival after SCI. This study will help to facilitate communication in the clinical realm and assist in classifying subsets of patients within future clinical studies.

Effectiveness of intense, activity-based physical therapy for individuals with spinal cord injury in promoting motor and sensory recovery: is olfactory mucosa autograft a factor?

BACKGROUND/OBJECTIVES

Rehabilitation for individuals with spinal cord injury (SCI) is expanding to include intense, activity-based, out-patient physical therapy (PT). The study's primary purposes were to (i) examine the effectiveness of intense PT in promoting motor and sensory recovery in individuals with SCI and (ii) compare recovery for individuals who had an olfactory mucosa autograft (OMA) with individuals who did not have the OMA while both groups participated in the intense PT program.

METHODS

Prospective, non-randomized, non-blinded, intervention study. Using the American Spinal Injury Association examination, motor and sensory scores for 23 (7 OMA, 6 matched control and 10 other) participants were recorded.

RESULTS

Mean therapy dosage was 137.3 total hours. The participants' total, upper and lower extremity motor scores improved significantly while sensory scores did not improve during the first 60 days and from initial to discharge examination. Incomplete SCI or paraplegia was associated with greater motor recovery. Five of 14 participants converted from motor-complete to motor-incomplete SCI. Individuals who had the OMA and participated in intense PT did not have greater sensory or greater magnitude or rate of motor recovery as compared with participants who had intense PT alone.

CONCLUSION

This study provides encouraging evidence as to the effectiveness of intense PT for individuals with SCI. Future research is needed to identify the optimal therapy dosage and specific therapeutic activities required to generate clinically meaningful recovery for individuals with SCI including those who elect to undergo a neural recovery/regenerative surgical procedure and those that elect intense therapy alone.