Journal of neurotrauma
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Journal of neurotrauma · May 2017
Modulating arm swing symmetry with cognitive load: a window on rhythmic spinal locomotor networks in humans?
In healthy subjects, changes in arm swing symmetry while walking are observed when a cognitive dual task is added, with a tendency toward left-dominant arm swing as cognitive load increases. We applied a modified Stroop word/color naming paradigm to investigate this effect in spinal cord injured (SCI) patients. Six patients with cervical SCI (cSCI), 6 with thoracic injuries (tSCI; all 12 patients American Spinal Injury Association [ASIA] Injury Score [AIS]D), and 12 healthy, matched controls underwent three-dimensional 3D gait analysis while walking normally at a comfortable speed (NW) and when performing an additional congruent (CS) and incongruent (IS) Stroop task. ⋯ A larger shift in tSCI patients (NW, 15.8 ± 6.0; CS, 23.4 ± 3.8; IS, 30.7 ± 4.4) was driven by a significant reduction in right wrist trajectory (p = 0.014), whereas cSCI patients showed a small reduction in mean ASI with high variability (NW, 14.2 ± 10.7; CS, 9.3 ± 13.5; IS, 6.0 ± 12.9). The effect of the IS task on ASI compared to baseline (NW) was significantly different between tSCI (+12.5 ± 6.3) and cSCI (-8.2 ± 6.0) patients (p = 0.011). Disruption of the long propriospinal connections coordinating arm and leg movements during walking may explain the heightened sensitivity to manipulation of cognitive load in tSCI, whereas the more robust automaticity in cSCI may be attributed to impaired supraspinal inputs in the context of preserved intraspinal pathways.
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Journal of neurotrauma · May 2017
Transplants of neurotrophin-producing autologous fibroblasts promote recovery of treadmill stepping in the acute, sub-chronic, and chronic spinal cat.
Adult cats show limited spontaneous locomotor capabilities following spinal transection, but recover treadmill stepping with body-weight-supported training. Delivery of neurotrophic factors such as brain-derived neurotrophic factor (BDNF) and neurotrophic factor 3 (NT-3) can substitute for body-weight-supported training, and promotes a similar recovery in a shorter period of time. Autologous cell grafts would negate the need for the immunosuppressive agents currently used with most grafts, but have not shown functional benefits in incomplete spinal cord injury models and have never been tested in complete transection or chronic injury models. ⋯ Eleven of 12 cats with neurotrophin-producing grafts recovered plantar weight-bearing stepping at treadmill speeds from 0.3 to 0.8 m/sec within 5 weeks of grafting, whereas control cats recovered poor quality stepping at low speeds only (≤ 0.4 m/sec). Further, kinematic measures in cats with grafts were closer to pre-transection values than those for controls, and recovery was maintained up to 12 weeks post-grafting. Our results show that not only are autologous neurotrophin-producing grafts effective at promoting recovery of locomotion, but that delayed delivery of neurotrophins does not diminish the therapeutic effect, and may improve outcome.
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Journal of neurotrauma · May 2017
Review Meta AnalysisEffects of Activity-based therapy interventions on mobility, independence and quality of life for people with spinal cord injuries: a systematic review and meta-analysis.
The aim of this study was to review the literature about the effects of activity-based therapy (ABT) interventions on mobility, functional independence, and quality of life for people with a spinal cord injury (SCI). A systematic review with meta-analysis of randomized and non-randomized trials was performed, including adults with a non-progressive SCI at any level. The intervention of interest was ABT, defined as any intervention that sought to improve muscle activation or sensory function below the level of injury in the spinal cord and does not rely on compensatory mechanisms for improving function. ⋯ Compared with conventional physical interventions, there was no significant effect of ABT on lower limb mobility, independence, or quality of life; however, it had positive effects on upper limbs. In conclusion, there is evidence that ABT can improve independence and functional ability when applied to the upper limbs in people with SCI. However, it is not superior to conventional physical interventions when applied to the lower limbs.
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Journal of neurotrauma · May 2017
Randomized Controlled Trial Multicenter StudyRepetitive intermittent hypoxia and locomotor training enhances walking function in incomplete spinal cord injury subjects: A randomized, triple-blind, placebo-controlled clinical trial.
Incomplete spinal cord injuries (iSCI) leave spared synaptic pathways below the level of injury. Intermittent hypoxia (IH) elicits plasticity in the spinal cord and strengthens spared synaptic pathways, expressed as respiratory and somatic functional recovery in experimental animals and humans with iSCI. This study is a randomized, triple-blind, two-arm parallel clinical trial performed in Santiago, Chile. ⋯ We conclude that daily IH enhances walking recovery in subjects with iSCI, confirming previous findings. Moreover, 3 × wIH prolonged or enhanced daily IH-induced walking speed and endurance improvements, respectively, up to 5 weeks post-daily IH. Repetitive IH may be a safe and effective therapeutic alternative for persons with iSCI.
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Journal of neurotrauma · May 2017
ReviewSUPRASPINAL CONTROL PREDICTS LOCOMOTOR FUNCTION AND FORECASTS RESPONSIVENESS TO TRAINING AFTER SPINAL CORD INJURY.
Restoration of walking ability is an area of great interest in the rehabilitation of persons with spinal cord injury. Because many cortical, subcortical, and spinal neural centers contribute to locomotor function, it is important that intervention strategies be designed to target neural elements at all levels of the neuraxis that are important for walking ability. While to date most strategies have focused on activation of spinal circuits, more recent studies are investigating the value of engaging supraspinal circuits. ⋯ A number of clinical prediction rules and association models based on common clinical measures have been developed with the intent, respectively, to predict future walking function based on early clinical presentation, and to delineate characteristics associated with responsiveness to training. Further, a number of variables that are correlated with walking function have been identified. Not surprisingly, most of these prediction rules, association models, and correlated variables incorporate measures of volitional lower extremity strength, illustrating the important influence of supraspinal centers in the production of walking behavior in humans.