scholarly journals Plasticity of Corticospinal Neural Control after Locomotor Training in Human Spinal Cord Injury

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Maria Knikou

Spinal lesions substantially impair ambulation, occur generally in young and otherwise healthy individuals, and result in devastating effects on quality of life. Restoration of locomotion after damage to the spinal cord is challenging because axons of the damaged neurons do not regenerate spontaneously. Body-weight-supported treadmill training (BWSTT) is a therapeutic approach in which a person with a spinal cord injury (SCI) steps on a motorized treadmill while some body weight is removed through an upper body harness. BWSTT improves temporal gait parameters, muscle activation patterns, and clinical outcome measures in persons with SCI. These changes are likely the result of reorganization that occurs simultaneously in supraspinal and spinal cord neural circuits. This paper will focus on the cortical control of human locomotion and motor output, spinal reflex circuits, and spinal interneuronal circuits and how corticospinal control is reorganized after locomotor training in people with SCI. Based on neurophysiological studies, it is apparent that corticospinal plasticity is involved in restoration of locomotion after training. However, the neural mechanisms underlying restoration of lost voluntary motor function are not well understood and translational neuroscience research is needed so patient-orientated rehabilitation protocols to be developed.

2001 ◽  
Vol 19 (4) ◽  
pp. 702-710
Author(s):  
Renata Teles Vieira ◽  
Rafaela Machado de Gusmão Oliveira ◽  
Camila Alves Nogueira Barros ◽  
Leonardo Caixeta

Objetivo. O objetivo deste trabalho foi realizar uma revisão de literatura sobre o uso do treino locomotor em pacientes portadores de lesão medular incompleta, a fim de verificar os seus efeitos para a marcha destes pacientes. Método. Foi realizada uma busca utilizando os bancos de dados medline, scielo e bvs a partir dos descritores: body weight-support treadmill training (suporte parcial de peso com treinamento em esteira), locomotor training (treino locomotor), spinal cord injury (lesão medular), gait (marcha). Todos os artigos coletados nos últimos 18 anos foram analisados. Discussão. A lesão medular é uma grave síndrome neurológica que causa diversos comprometimentos, inclusive da marcha. Para aperfeiçoar este processo, deu-se início à prática de reabilitação na esteira com suporte de peso corporal. A ampla utilização desta técnica de reabilitação deve-se a maior facilidade para o treino da marcha, a satisfação dos pacientes durante o tratamento e, principalmente, aos bons resultados gerados. Conclusão. Um número significante de estudos mostrou que o treino de marcha com suporte de peso corporal é um meio seguro e confiável, e que surgiu para inovar a reabilitação funcional da marcha. Não há evidência científica para afirmar que o treino locomotor com suporte de peso seja um método superior a outras terapias.


2017 ◽  
Vol 23 (6) ◽  
pp. 649-663 ◽  
Author(s):  
Karen Minassian ◽  
Ursula S. Hofstoetter ◽  
Florin Dzeladini ◽  
Pierre A. Guertin ◽  
Auke Ijspeert

The ability of dedicated spinal circuits, referred to as central pattern generators (CPGs), to produce the basic rhythm and neural activation patterns underlying locomotion can be demonstrated under specific experimental conditions in reduced animal preparations. The existence of CPGs in humans is a matter of debate. Equally elusive is the contribution of CPGs to normal bipedal locomotion. To address these points, we focus on human studies that utilized spinal cord stimulation or pharmacological neuromodulation to generate rhythmic activity in individuals with spinal cord injury, and on neuromechanical modeling of human locomotion. In the absence of volitional motor control and step-specific sensory feedback, the human lumbar spinal cord can produce rhythmic muscle activation patterns that closely resemble CPG-induced neural activity of the isolated animal spinal cord. In this sense, CPGs in humans can be defined by the activity they produce. During normal locomotion, CPGs could contribute to the activation patterns during specific phases of the step cycle and simplify supraspinal control of step cycle frequency as a feedforward component to achieve a targeted speed. Determining how the human CPGs operate will be essential to advance the theory of neural control of locomotion and develop new locomotor neurorehabilitation paradigms.


2009 ◽  
Vol 101 (2) ◽  
pp. 969-979 ◽  
Author(s):  
Monica A. Gorassini ◽  
Jonathan A. Norton ◽  
Jennifer Nevett-Duchcherer ◽  
Francois D. Roy ◽  
Jaynie F. Yang

Intensive treadmill training after incomplete spinal cord injury can improve functional walking abilities. To determine the changes in muscle activation patterns that are associated with improvements in walking, we measured the electromyography (EMG) of leg muscles in 17 individuals with incomplete spinal cord injury during similar walking conditions both before and after training. Specific differences were observed between subjects that eventually gained functional improvements in overground walking (responders), compared with subjects where treadmill training was ineffective (nonresponders). Although both groups developed a more regular and less clonic EMG pattern on the treadmill, it was only the tibialis anterior and hamstring muscles in the responders that displayed increases in EMG activation. Likewise, only the responders demonstrated decreases in burst duration and cocontraction of proximal (hamstrings and quadriceps) muscle activity. Surprisingly, the proximal muscle activity in the responders, unlike nonresponders, was three- to fourfold greater than that in uninjured control subjects walking at similar speeds and level of body weight support, suggesting that the ability to modify muscle activation patterns after injury may predict the ability of subjects to further compensate in response to motor training. In summary, increases in the amount and decreases in the duration of EMG activity of specific muscles are associated with functional recovery of walking skills after treadmill training in subjects that are able to modify muscle activity patterns following incomplete spinal cord injury.


2018 ◽  
Vol 31 (0) ◽  
Author(s):  
Jéssica Saccol Borin ◽  
Tânia Valdameri Capelari ◽  
Melissa Grigol Goldhardt ◽  
Márcia Cristina Issa ◽  
Diego Antônio Pereira Bica dos Santos ◽  
...  

Abstract Introduction: The locomotor training with body weight support has been proposed as an alternative for the rehabilitation of people with spinal cord injury, in order to develop most of the residual potential of the body. Objective: To compare the levels of muscle activation of the main muscle involved in gait during body weight-supported treadmill training and body weight-supported overground training in incomplete spinal cord injured patients. Methods: It was a prospective cross-sectional study, in which 11 incomplete injured patients were submitted to two modalities of gait with body weight support, the first one on the treadmill (two different speeds: 1 and 4km/h), and the second one with the walker on fixed floor. The electromyographical acquisition was done in the rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL) and gluteus maximus (GM). Results: There was a greater muscle activation of all muscles analyzed in the treadmill training as compared to the over groundtraining, both at 4 km/h (RF: p=0.00), (VM: p=0.00), (VL: p=0.00) e (GM: p=0.00) and at 1km/h (RF: p=0.00), (VM: p=0.00), (VL: p=0.00) e (GM: p=0.00). When comparing the two modalities of treadmill training, at 4 and 1km/h, there was no statically significant difference between them (RF: p=0.36), (VM: p=1.00), (VL: p=1.00) e (GM: p=0.16). Conclusion: The gait training with body weight support is more effective in activating the muscles involved in the gait training on treadmill compared to overground training in patients with incomplete spinal cord injury.


2014 ◽  
Vol 112 (9) ◽  
pp. 2164-2175 ◽  
Author(s):  
Andrew C. Smith ◽  
Chaithanya K. Mummidisetty ◽  
William Zev Rymer ◽  
Maria Knikou

In humans, a chronic spinal cord injury (SCI) impairs the excitability of pathways mediating early flexor reflexes and increases the excitability of late, long-lasting flexor reflexes. We hypothesized that in individuals with SCI, locomotor training will alter the behavior of these spinally mediated reflexes. Nine individuals who had either chronic clinically motor complete or incomplete SCI received an average of 44 locomotor training sessions. Flexor reflexes, elicited via sural nerve stimulation of the right or left leg, were recorded from the ipsilateral tibialis anterior (TA) muscle before and after body weight support (BWS)-assisted treadmill training. The modulation pattern of the ipsilateral TA responses following innocuous stimulation of the right foot was also recorded in 10 healthy subjects while they stepped at 25% BWS to investigate whether body unloading during walking affects the behavior of these responses. Healthy subjects did not receive treadmill training. We observed a phase-dependent modulation of early TA flexor reflexes in healthy subjects with reduced body weight during walking. The early TA flexor reflexes were increased at heel contact, progressively decreased during the stance phase, and then increased throughout the swing phase. In individuals with SCI, locomotor training induced the reappearance of early TA flexor reflexes and changed the amplitude of late TA flexor reflexes during walking. Both early and late TA flexor reflexes were modulated in a phase-dependent pattern after training. These new findings support the adaptive capability of the injured nervous system to return to a prelesion excitability and integration state.


Sign in / Sign up

Export Citation Format

Share Document