Recovery of Locomotion After Spinal Cord Injury: Some Facts and Mechanisms

Abstract

After spinal cord injury (SCI), various sensorimotor functions can recover, ranging from simple spinal reflexes to more elaborate motor patterns, such as locomotion. Locomotor recovery after complete spinalization (complete SCI) must depend on the presence of spinal circuitry capable of generating the complex sequential activation of various leg muscles. This is achieved by an intrinsic spinal circuitry, termed the central pattern generator (CPG), working in conjunction with sensory feedback from the legs. After SCI, different changes in cellular and circuit properties occur spontaneously and can be promoted by pharmacological, electrical, or rehabilitation strategies. After partial SCI, hindlimb locomotor recovery can result from regeneration or sprouting of spared pathways, but also from mechanisms observed after complete SCI, namely changes within the intrinsic spinal circuitry and sensory inputs.

Supraspinal Control Predicts Locomotor Function and Forecasts Responsiveness to Training after Spinal Cord Injury

“…69,70 Beyond the ''learning'' in simple segmental reflexes described earlier, the more complex spinal circuits associated with locomotor central pattern generators also learn in response to training. 5,80,81 In particular, there is increased inhibition of polysynaptic spinal reflexes with improvements in walking, suggesting better inhibitory control of spinal circuits. 82 Adaptation and plasticity in these circuits is thought to contribute significantly to the improvements in walking function observed after locomotor training in persons with SCI.…”

Accuracy and precision of gait events derived from motion capture in horses during walk and trot

“…Kinematics of the distal limb could be of further potential (Moorman et al, 2012;Olsen et al, 2013). Motion capture and force plates have the potential to aid assessment of deficits in neuro-motor control on a spinal or supraspinal level because spatial and temporal characteristics are primarily controlled through the spinal and supra-spinal neural pathways (Martinez et al, 2012;Rossignol and Frigon, 2011). Classification of movement as normal, or abnormal, can be based on a combination of subjective clinical examination and objective analysis of gait (Keegan et al, 2012;Lord et al, 2013;Wren et al, 2011).…”

Effect of Locomotor Training in Completely Spinalized Cats Previously Submitted to a Spinal Hemisection

“…Cats recover voluntary hindlimb (HL) locomotion after various types of incomplete spinal cord injuries (iSCIs) at low thoracic levels, indicating that compensations by remnant supraspinal structures and/or the spinal cord may occur (Jiang and Drew, 1996;Brustein and Rossignol, 1998;Rossignol and Frigon, 2011). The functional plastic changes at the spinal level can be vividly demonstrated in cats completely spinalized after having been submitted 3 weeks before to a spinal hemisection.…”