Neuronal plasticity after a human spinal cord injury: Positive and negative effects

• Published in: Experimental neurology Vol. 235; no. 1; pp. 110 - 115
• Main Author: Dietz, Volker
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2012
• Subjects: Dominance; EMG-activity; Exhausts; Feedback; Human locomotion; Humans; Leg; Load receptors; Locomotion; Locomotor activity; Motor Activity - physiology; Muscles; Neuronal dysfunction; Neuronal plasticity; Neuronal Plasticity - physiology; Neurons - physiology; Plasticity (functional); Plasticity (neural); Plasticity (spinal); Proprioception; Reflexes; Rehabilitation; robots; Sensory neurons; Spinal Cord Injuries - physiopathology; Spinal cord injury; Walking; EMG-activity; Human locomotion; Neuronal dysfunction; Neuronal plasticity; Load receptors; Spinal cord injury
• ISSN: 0014-4886; 1090-2430; 1090-2430
• DOI: 10.1016/j.expneurol.2011.04.007

In patients suffering an incomplete spinal cord injury (SCI) an improvement in walking function can be achieved by providing a functional training with an appropriate afferent input. In contrast, in immobilized incomplete and complete subjects a negative neuroplasticity leads to a neuronal dysfunction. After an SCI, neuronal centers below the level of lesion exhibit plasticity that either can be exploited by specific training paradigms or undergo a degradation of function due to the loss of appropriate input. Load- and hip-joint-related afferent inputs seem to be of crucial importance for the generation of a locomotor pattern and, consequently, the effectiveness of the locomotor training. In severely affected SCI subjects rehabilitation robots allow for a longer and more intensive training and can provide feedback information. Conversely, in severely affected chronic SCI individuals without functional training the locomotor activity in the leg muscles exhausts rapidly during assisted locomotion. This is accompanied by a shift from early to dominant late spinal reflex components. The exhaustion of locomotor activity is also observed in non-ambulatory patients with an incomplete SCI. It is assumed that in chronic SCI the patient's immobility results in a reduced input from supraspinal and peripheral sources and leads to a dominance of inhibitory drive within spinal neuronal circuitries underlying locomotor pattern and spinal reflex generation. A training with an enhancement of an appropriate proprioceptive input early after an SCI might serve as an intervention to prevent neuronal dysfunction. ► After an incomplete spinal cord injury (SCI) neuroplasticity can be exploited by a functional training. ► For a successful locomotor training of SCI subjects the provision of load and hip joint related afferent inputs is essential. ► Rehabilitation robots allow for a longer and standardized locomotor training. ► The activity of spinal reflexes can be used as marker for the neuronal function underlying locomotion. ► In severely affected SCI subjects immobility leads to a dysfunction of spinal neuronal circuits underlying locomotion.