Dynamometry testing in spinal cord injury

Persons with a spinal cord injury (SCI) demonstrate strength deficits that can limit their functional ability to perform activities of daily living. For a specific lesion level, performance of functional activities is related to the level of muscle strength. Consequently, in clinical practice, we need reliable measures of muscle strength to determine mobility and self-care ability. Muscle-strength testing is used to document recovery or loss of motor function early in SCI, as well as measure improvements in strength in chronic SCI. We also need such measures for research purposes to determine the efficacy of clinical trials. Several methods are available for testing muscle strength of persons with SCI, such as handheld, handgrip, and isokinetic dynamometers. This article provides an overview of muscle-contraction definitions and testing methodologies and discusses the reliability of these testing methods and dynamometry devices.     

Basic concepts of activity-based interventions for improved recovery of motor function after spinal cord injury

Roy RR, Harkema SJ, Edgerton VR. Basic concepts of activity-based interventions for improved recovery of motor function after spinal cord injury. Spinal cord injury (SCI) is a devastating condition that affects a large number of individuals. Historically, the recovery process after an SCI has been slow and with limited success. Recently, a number of advances have been made in the strategies used for rehabilitation, resulting in marked improved recovery, even after a complete SCI. Several rehabilitative interventions, that is, assisted motor training, spinal cord epidural stimulation, and/or administration of pharmacologic agents, alone or in combination, have produced remarkable recovery in motor function in both humans and animals. The success with each of these interventions appears to be related to the fact that the spinal cord is smart, in that it can use ensembles of sensory information to generate appropriate motor responses without input from supraspinal centers, a property commonly referred to as central pattern generation. This ability of the spinal cord reflects a level of automaticity, that is, the ability of the neural circuitry of the spinal cord to interpret complex sensory information and to make appropriate decisions to generate successful postural and locomotor tasks. Herein, we provide a brief review of some of the neurophysiologic rationale for the success of these interventions.     

Spinal cord control of movement: implications for locomotor rehabilitation following spinal cord injury

In recent years, our understanding of the spinal cord's role in movement control has been greatly advanced. Research suggests that body weight support (BWS) walking and functional electrical stimulation (FES), techniques that are used by physical therapists, have potential to improve walking function in individuals with spinal cord injury (SCI), perhaps long after the stage of spontaneous recovery. Walking is one of the most desired goals of people with SCI; however, we are obligated to be judicious in our claims of locomotor recovery. There are few controlled studies that compare outcomes of BWS training or FES with those of conventional interventions, and access to services using BWS training or FES may be restricted under managed care.     

Physical rehabilitation as an agent for recovery after spinal cord injury

The initial level of injury and severity of volitional motor and clinically detectable sensory impairment has been considered the most reliable for predicting neurologic recovery of function after spinal cord injury (SCI). This consensus implies a limited expectation for physical rehabilitation interventions as important in the facilitation of recovery of function. The development of pharmacologic and surgical interventions has always been pursued with the intent of altering the expected trajectory of recovery after SCI, but only recently physical rehabilitation strategies have been considered to improve recovery beyond the initial prognosis. This article reviews the recent literature reporting emerging activity-based therapies that target recovery of standing and walking based on activity-dependent neuroplasticity. A classification scheme for physical rehabilitation interventions is also discussed to aid clinical decision making.     

Immobilization impairs recovery after spinal cord injury

The effect of immobilization on motor recovery was studied in adult rats after subtotal spinal cord section. Anesthetized rats underwent three-quarter section of the cord, sparing the left lateral funiculus. After surgery, half the rats were placed in immobilization tubes for three to four weeks; the others were allowed free mobility. Hindlimb motor function was graded at various times in the two groups. In contrast to the marked recovery observed in mobile animals, the immobilized rats with similar cord lesions showed no significant motor recovery during the period of immobilization. Immobilized rats without cord lesions showed minimal transient deficits. In conclusion, hindlimb activity appears to be a necessary condition for motor recovery after subtotal spinal cord injury.     

Neurologic recovery after traumatic spinal cord injury: data from the Model Spinal Cord Injury Systems

OBJECTIVE: To present data on neurologic recovery gathered by the Model Spinal Cord Injury (SCI) Systems over a 10-year period. DESIGN: Case series. SETTING: Twenty-one Model SCI Systems. PATIENTS: A total of 3,585 individuals with traumatic SCI admitted between January 1, 1988 and December 31, 1997. MAIN OUTCOME MEASURES: Neurologic impairment category; Frankel grade; American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade; motor score. RESULTS: SCI caused by violence is more likely than SCI from nonviolent etiologies to result in a complete injury. Changes in severity of injury were similar using the older Frankel scale and the newer ASIA Impairment Scale. Individuals who were motor-complete with extended zones of sensory preservation but without sacral sparing were less likely to convert to motor-incomplete status than those with sacral sparing (13.3% vs 53.6%; p < .001). Motor score improvements at 1 year were related to severity of injury, with greater increases for better AIS grades except grade D, because of ceiling effects. Individuals with AIS grade B injuries have a mixed prognosis. CONCLUSION: Neurologic recovery after SCI is influenced by etiology and severity of injury. Multicenter studies on prognostic features such as preserved pin sensation in grade B injuries may identify subgroups with similar recovery patterns. Identification of such groups would facilitate clinical trials for neurologic recovery in acute SCI.     

Late neurologic recovery after traumatic spinal cord injury

OBJECTIVE: To present Model Spinal Cord Injury System (MSCIS) data on late neurologic recovery after 1 year after spinal cord injury (SCI). DESIGN: Longitudinal study of neurologic status as determined by annual evaluations at 1 and 5 years postinjury. SETTING: MSCIS centers contributing data on people with traumatic SCI to the National Spinal Cord Injury Statistical Center database. PARTICIPANTS: People with traumatic SCI (N=987) admitted to an MSCIS between 1988 and 1997 with 1- and 5-year follow-up examinations. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: American Spinal Injury Association (ASIA) Impairment Scale (AIS) classification, motor index scores (MIS), motor level, and neurologic level of injury (NLI), measured and compared for changes over time. RESULTS: The majority of subjects (94.4%) who had a neurologically complete injury at 1 year remained complete at 5 years postinjury, with 3.5% improving to AIS grade B, and up to 1.05% each improving to AIS grades C and D. There was a statistically significant change noted for MIS. There were no significant changes for the motor level and NLI over 4 years; however, approximately 20% of subjects improved their motor level and NLI. People with complete and incomplete injuries had similar improvements in motor level, but subjects with an incomplete injury had a greater chance of improvement in NLI and MIS. CONCLUSIONS: There was a small degree of neurologic recovery (between 1 and 5 y postinjury) after a traumatic SCI. Late conversion, between 1 and 5 years, from a neurologically complete to an incomplete injury occurred in 5.6% of cases, but in only up to 2.1% was there a conversion from motor complete to motor incomplete status. Limitations of this study included changes in the ASIA classification during the study and in the intra- and interrater reliability typically seen in longitudinal studies of the ASIA standards. Functional changes were not studied. Knowledge of the degree of late recovery may help in analyzing newer interventions to enhance recovery.     

Return to work following spinal cord injury: a review

Purpose. To review literature on return to work (RTW) and employment in persons with spinal cord injury (SCI), and present employment rates, factors influencing employment, and interventions aimed at helping people with SCI to obtain and sustain productive work.

Methods. A systematic review for 2000 – 2006 was carried out in PubMed/Medline, AMED, (ISI) Web of Science, EMBASE, CINAHL, PsycInfo and Sociological abstracts database. The keywords ‘spinal cord injuries’, ‘spinal cord disorder’, ‘spinal cord lesion’ or ‘spinal cord disease’ were cross-indexed with ‘employment’, ‘return to work’, ‘occupation’ or ‘vocational’.

Results. Out of approximately 270 hits, 110 references were used, plus 13 more found elsewhere. Among individuals with SCI working at the time of injury 21 – 67% returned to work after injury. RTW was higher in persons injured at a younger age, had less severe injuries and higher functional independence. Employment rate improved with time after SCI. Persons with SCI employed ranged from 11.5% to 74%. Individuals who sustained SCI during childhood or adolescence had higher adult employment rates. Most common reported barriers to employment were problems with transportation, health and physical limitations, lack of work experience, education or training, physical or architectural barriers, discrimination by employers, and loss of benefits. Individuals with SCI discontinue working at younger age.

Conclusions. This review confirmed low employment rates after SCI. Future research should explore interventions aimed at helping people with SCI to obtain and sustain productive work.     

Vector-mediated expression of erythropoietin improves functional outcome after cervical spinal cord contusion injury

We evaluated the therapeutic effect of erythropoietin (EPO) delivered by direct injection of a nonreplicating herpes simplex virus (HSV)-based vector coding for EPO (vEPO) in a model of cervical hemicord contusion at C7. At 1?h after spinal cord injury (SCI), either vEPO or control vector carrying a reporter gene (vC) was injected into the cord above and below the lesion. Animals injected with vEPO showed a statistically significant improvement in the ipsilateral forelimb function, as measured by open-field evaluation of motor performance, forelimb reaching in the cylinder test and misplacement in grid walk. This correlated with preservation of gray matter in the area of the lesion. There was also mild but significant improvement of hindlimb motor function measured by Basso-Beattie-Bresnahan score and computerized gait analysis in vEPO compared with control vector-injected animals. Microtubule-associated protein tau, phosphorylated and nonphosphorylated neurofilament protein and the synaptic proteins synaptophysin and PSD-95 were all significantly increased in the spinal cord of vEPO-treated animals compared with control vector-injected animals. These data suggest that gene transfer of EPO after cervical SCI by minimizing the injury size and enhancing tissue sparing preserves large-caliber axons and promotes synaptogenesis.     

Current and future therapeutic strategies for functional repair of spinal cord injury

Spinal cord injury (SCI) is one of the major disabilities dealt with in clinical rehabilitation settings and is multifactorial in that the patients suffer from motor and sensory impairments as well as many other complications throughout their lifetimes. Many clinical trials have been documented during the last two decades to restore damaged spinal cords. However, only a few pharmacological therapies used in clinical settings which still have only limited effects on the regeneration and functional recovery. This review presents recent clinical trials and recent advances in the development of strategies to restore locomotion after SCI. Several approaches toward functional recovery in SCI succeeded in acute and subacute phases in animal models.However, effective strategies against chronic phase of SCI have not been established yet. The strategy aiming to inhibit single molecule sometimes shows controversial results. In SCI, a lot of players participate in motor and sensory dysfunctions. Therefore, sufficient functional recovery may be achieved by regulating multiple targets. Regrowth of tracts connecting the brain and spinal cord, and axonal sprouting of propriospinal interneurons are fundamentally important for neuronal network working. In addition, remyelination, protection of neuronal death, inhibition of inflammation, and upregulation of beneficial influence of astrocytes are also quite crucial to supporting the axonal refining. Combination of several strategies might be useful as practical therapy. Several compounds such as a Sema3A inhibitor, estrogen, withanoside IV and their relating compounds or other neurotrophic factor-mimicking agents may be candidates for useful SCI therapeutic drugs since those have multi-effects on damaged spinal cord.     

水中活动平板训练对脊髓损伤大鼠体感、运动诱发电位及运动功能的影响

目的:探讨水中平板训练对脊髓损伤(SCI)大鼠体感诱发电位(SEP)、运动诱发电位(MEP)及运动功能的影响。方法:将成年雄性SD大鼠25只,随机分为假模组、模型对照组、水疗训练组、减重平板训练组和水中平板训练组。采用改良Allen’s打击法制作T10—11SCI模型,采用BBB评分、爬网格实验、SEP及MEP评定肢体功能及训练效果。结果:BBB评分及爬网格实验显示,水中平板训练组的大鼠后肢运动功能较其他组明显改善(P<0.05)。SEP、MEP的潜伏期,三组训练组较模型对照组均有显著缩短(P<0.05);但三组训练组之间MEP潜伏期差异无显著性意义(P>0.05)。水中平板训练组较减重平板训练组SEP、MEP波幅明显增大,差异均有显著性意义(P<0.05)。结论:三组训练对脊髓损伤大鼠SEP、MEP及运动功能均有不同程度的促进恢复作用,其中水中平板训练最为显著。     

The isolated sympathetic spinal cord: Cardiovascular and sudomotor assessment in spinal cord injury patients: A literature survey

ObjectivesTo present a comprehensive approach to the assessment of the severity of the autonomic lesion in spinal cord injury (SCI) patients, with regard to the level of lesion. To discuss how to assess an isolated sympathetic spinal cord that has lost supraspinal control (sympathetically complete lesion).MethodPubMed was searched for articles related to cardiovascular (mainly cold pressor test, respiratory and postural challenges) and sudomotor (sympathetic skin responses) tests that have been used. The results of these evaluations are analysed with regard to the site of stimulation (above or below the lesion) according to three types of SCI that offer typical autonomic reactions (tetraplegics, paraplegics at T6 and at T10).ResultsNon-invasive cardiovascular and sudomotor testing allows the assessment of the isolated sympathetic spinal cord in SCI patients. Typical responses are found in relation with the level of the sympathetic lesion. Its definition would allow comparison with the somatic motor and sensory level of lesion of SCI patients and provide additional aid to the classification of those patients.ConclusionFor research purposes on the integrity of the spinal sympathetic pathways, a battery of test approach is probably needed, using a combination of stimuli above and below the lesion, evaluating both cardiovascular and sudomotor pathways.     

The impact of sacral sensory sparing in motor complete spinal cord injury

Kirshblum S, Botticello A, Lammertse DP, Marino RJ, Chiodo AE, Jha A. The impact of sacral sensory sparing in motor complete spinal cord injury.

Objective

To determine the effect of sensory sparing in motor complete persons with spinal cord injury (SCI) on completion of rehabilitation on neurologic, functional, and social outcomes reported at 1 year.

Design

Secondary analysis of longitudinal data collected by using prospective survey-based methods.

Setting

Data submitted to the National SCI Statistical Center Database.

Participants

Of persons (N=4106) enrolled in the model system with a motor complete injury (American Spinal Injury Association Impairment Scale [AIS] grade A or B) at the time of discharge between 1997 and 2007, a total of 2331 (56.8%) completed a 1-year follow-up interview (Form II) and 1284 (31.3%) had complete data for neurologic (eg, AIS grade, injury level) variables at 1 year.

Interventions

Not applicable.

Main Outcome Measures

AIS grade (A vs B) at 1 year, bladder management, hospitalizations, perceived health status, motor FIM items, Satisfaction With Life Scale, depressive symptoms, and social participation.

Results

Compared with persons with AIS grade A at discharge, persons with AIS grade B were less likely to require indwelling catheterization and be hospitalized and more likely to perceive better health, report greater functional independence (ie, self-care, sphincter control, mobility, locomotion), and report social participation in the first year postinjury. A greater portion of individuals with AIS grade B at discharge had improved neurologic recovery at 1 year postinjury than those with AIS grade A. Significant AIS group differences in 1-year outcomes related to physical health were maintained after excluding persons who improved to motor incomplete status for only bladder management and change in perceived health status. This recognition of differences between persons with motor complete injuries (AIS grade A vs B) has important ramifications for the field of SCI rehabilitation and research.     

Future directions for spinal cord injury research: recent developments and model systems contributions

Tate DG, Boninger ML, Jackson AB. Future directions for spinal cord injury research: recent developments and model systems contributions.The authors look forward and discuss future directions in spinal cord injury (SCI) from a perspective of biomedical, psychosocial and technologic research. This discussion is based both on recent developments from various fields of knowledge and, more specifically, on SCI Model Systems' research contributions to medical rehabilitation. Biomedical research, as described here, includes (1) the process of moving from the “bench to bedside” and harnessing knowledge from basic science to produce new clinical treatment options for SCI during the life span; (2) the rapid proliferation of clinical trials aimed at neurologic recovery; (3) the growth of new technologies to restore and improve function; and (4) the challenges of developing relevant outcome measures to evaluate efficacy and effectiveness of interventions. Recent progress in psychosocial research has contributed significantly to understanding of the many factors associated with disability during the life course, the importance of quality of life issues, and the value of activity, participation, and the environment in promoting successful rehabilitation outcomes following SCI. Technology and bioengineering advances are discussed in relation to access to high-quality technology; restoration and replacement of movement; and technology to enhance rehabilitation outcomes.     

Early rehabilitation effect for traumatic spinal cord injury

OBJECTIVE: To determine the natural course of traumatic spinal cord injury (SCI) and the effect of early rehabilitation on it. DESIGN: A retrospective, multicenter study. SETTING: Sixteen Rosai hospitals and 1 medical school. PARTICIPANTS: One hundred twenty-three SCI patients (104 men, 19 women; mean age, 48.8 +/- 17.7yr) enrolled. INTERVENTIONS: Dividing the subjects into an early rehabilitation group and a delayed group; differences were ensured by international classification of SCI. MAIN OUTCOME MEASURES: Using the American Spinal Injury Association (ASIA) classifications, the motor recovery rate (MRR) was defined as (ASIA motor score at discharge - ASIA motor score at admission)/(100 - ASIA motor score at admission). The regression lines for FIM instrument score and ASIA motor score were determined for 6 subgroups (early or delayed tetraplegia, central cord injury, paraplegia) by the MRR staging. The regression lines for physical or cognitive FIM score and ASIA motor score were also determined for 6 subgroups. RESULTS: Three stages were obtained: acute stage: 2 weeks postinjury; recovery stage: 2 weeks to 6 months postinjury; and chronic stage: more than 6 months postinjury. Regression lines showed that rehabilitation improved physical functional independence for ASIA motor score, especially in the early rehabilitation subgroups. There was no correlation between cognitive FIM score and ASIA motor score in 6 subgroups. CONCLUSION: Early SCI rehabilitation contributes to good physical activities of daily living for motor function.     

Biohybrids for spinal cord injury repair

Spinal cord injuries (SCIs) result in the loss of sensory and motor function with massive cell death and axon degeneration. We have previously shown that transplantation of spinal cord‐derived ependymal progenitor cells (epSPC) significantly improves functional recovery after acute and chronic SCI in experimental models, via neuronal differentiation and trophic glial cell support. Here, we propose an improved procedure based on transplantation of epSPC in a tubular conduit of hyaluronic acid containing poly (lactic acid) fibres creating a biohybrid scaffold. In vitro analysis showed that the poly (lactic acid) fibres included in the conduit induce a preferential neuronal fate of the epSPC rather than glial differentiation, favouring elongation of cellular processes. The safety and efficacy of the biohybrid implantation was evaluated in a complete SCI rat model. The conduits allowed efficient epSPC transfer into the spinal cord, improving the preservation of the neuronal tissue by increasing the presence of neuronal fibres at the injury site and by reducing cavities and cyst formation. The biohybrid‐implanted animals presented diminished astrocytic reactivity surrounding the scar area, an increased number of preserved neuronal fibres with a horizontal directional pattern, and enhanced coexpression of the growth cone marker GAP43. The biohybrids offer an improved method for cell transplantation with potential capabilities for neuronal tissue regeneration, opening a promising avenue for cell therapies and SCI treatment.     

Activity-dependent plasticity in spinal cord injury

The adult mammalian central nervous system (CNS) is capable of considerable plasticity, both in health and disease. After spinal neurotrauma, the degrees and extent of neuroplasticity and recovery depend on multiple factors, including the level and extent of injury, postinjury medical and surgical care, and rehabilitative interventions. Rehabilitation strategies focus less on repairing lost connections and more on influencing CNS plasticity for regaining function. Current evidence indicates that strategies for rehabilitation, including passive exercise, active exercise with some voluntary control, and use of neuroprostheses, can enhance sensorimotor recovery after spinal cord injury (SCI) by promoting adaptive structural and functional plasticity while mitigating maladaptive changes at multiple levels of the neuraxis. In this review, we will discuss CNS plasticity that occurs both spontaneously after SCI and in response to rehabilitative therapies.     

Fatigue after spinal cord injury.

OBJECTIVES: To identify variables increasing fatigue following spinal cord injury (SCI) and their functional consequences. METHODS: A search of the Medline and Reedoc databases with the keywords SCI, fatigue, intrinsic muscular fatigue, chronic fatigue, aging, training, electrostimulation, quality of life and the same words in French. RESULTS: Two kinds of fatigue are identified following SCI. Intrinsic fatigue in muscles totally or partially paralysed at the level of or below the spinal cord lesion; this peripheral fatigue is due to denervation, total or partial loss of motoneurons, or histological and metabolical changes in muscle; it is well-defined by electrophysiological technology; spasticity and spasms have little influence on its development; it is reversible in part with long term electrostimulation, but at this time, electroneuroprosthetic techniques do not reduce the excessive energetic cost to stand up and walk. Chronic fatigue appears in the long term following SCI; it is linked with aging, physiological, and psychological deconditioning; some data point to chronic fatigue after SCI similar to post-polio syndrome and chronic fatigue syndrome, which may explain the central nature of the fatigue; training programs could be useful in delaying this chronic fatigue and as a consequence, increasing the latent quality of life. CONCLUSION: Muscular intrinsic fatigue after SCI is always of a peripherical nature in muscles partially or totally paralysed. Chronic fatigue during aging greatly decreases quality of life. Both intrinsic and chronic fatigue could be anticipated by electrostimulation technique on the one hand and long term training on the other.     

Training programs in spinal cord injury]

INTRODUCTION: Individualised exercise training programs in spinal cord injury (SCI) individuals are considered highly effective for improving and maintaining capacity for physical activity, as well as for reducing cardiovascular risk. However, no consensus exists on the type, intensity, and frequency of the training programs for SCI. OBJECTIVE: To review the literature about training program characteristics for SCI and describe their efficacy, limits, and results, with the aim of proposing specific recommendations. METHODS: Query using Medline and Embase databases. Ninety-nine references were found, including the following: Clinical studies examining physical endurance capacity of individuals with SCI, physiological responses to maximal exercise, or cardiovascular differences between sedentary and wheelchair-trained subjects; Articles? investigating the effects of training programmes for SCI. RESULTS: Various combinations of training intensity, duration, frequency, type, and ergometers have been proposed for SCI. Whatever the characteristics of the training program, a review of 25 cardiorespiratory training studies involving SCI subjects revealed an average improvement of 9% to 99% in VO2max, 19% to 118% in power output, and a decrease in submaximal values after 4 to 36 weeks of training. DISCUSSION - CONCLUSION: Wheelchair ergometers seems to be interesting for SCI because it mimics closely the daily motor tasks of wheelchair users and allows for adjustment of the wheelchair. Both continuous and interval training programmes are appropriate, but intermittent exercise intensities may be more beneficial since they mimic the intermittent nature of daily activity patterns. Furthermore, on the basis of the results of these studies, we recommend that training at or above 70% of maximum heart rate, for 30 minutes of rhythmic exercise, three days per week during eight weeks, will provide a sound of basis for design of an endurance exercise programme for people with SCI.     

Gait training in human spinal cord injury using electromechanical systems: effect of device type and patient characteristics

Benito-Penalva J, Edwards DJ, Opisso E, Cortes M, Lopez-Blazquez R, Murillo N, Costa U, Tormos JM, Vidal-Samsó J, Valls-Solé J, European Multicenter Study about Human Spinal Cord Injury Study Group, Medina J. Gait training in human spinal cord injury using electromechanical systems: effect of device type and patient characteristics.ObjectiveTo report the clinical improvements in spinal cord injury (SCI) patients associated with intensive gait training using electromechanical systems according to patient characteristics.DesignProspective longitudinal study.SettingInpatient SCI rehabilitation center.ParticipantsAdults with SCI (n=130).InterventionPatients received locomotor training with 2 different electromechanical devices, 5 days per week for 8 weeks.Main Outcome MeasuresLower-extremity motor score, Walking Index for Spinal Cord Injury, and 10-meter walking test data were collected at the baseline, midpoint, and end of the program. Patients were stratified according to the American Spinal Injury Association (ASIA) category, time since injury, and injury etiology. A subgroup of traumatic ASIA grade C and D patients were compared with data obtained from the European Multicenter Study about Human Spinal Cord Injury (EM-SCI).ResultsOne hundred and five patients completed the program. Significant gains in lower-limb motor function and gait were observed for both types of electromechanical device systems, to a similar degree. The greatest rate of improvement was shown in the motor incomplete SCI patients, and for patients <6 months postinjury. The positive response associated with training was not affected by injury etiology, age, sex, or lesion level. The trajectory of improvement was significantly enhanced relative to patients receiving the conventional standard of care without electromechanical systems (EM-SCI).ConclusionsThe use of electromechanical systems for intensive gait training in SCI is associated with a marked improvement in lower-limb motor function and gait across a diverse range of patients and is most evident in motor incomplete patients, and for patients who begin the regimen early in the recovery process.