Abstract: 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.
Lynskey. J. V, Belanger. A, Jung. R,. (2008). Activity-dependent plasticity in spinal cord injury.
Journal of Rehabilitation. 45(2): 229–240.
Abstract: Purpose Osteoporosis is a severe complication of spinal cord injury (SCI). Many exercise modalities are used to slow bone loss, yet their efficacy is equivocal. This study examined the effect of activity-based therapy (ABT) targeting the lower extremities on bone health in individuals with SCI. Methods: Thirteen men and women with SCI underwent 6 months of ABT. At baseline and after 3 and 6 months of training, blood samples were obtained to assess bone formation and participants underwent dual- energy X-ray absorptiometry (DEXA) scans to obtain total body and regional estimates of bone mineral density (BMD). Results: Results demonstrated significant increases in spine and decreases in total hip BMD from 0 to 6 months of training. BMD at the bilateral distal femur and proximal declined but was not different versus baseline. Conclusions: Chronic activity-based therapy in this study did not reverse bone loss typically observed soon after injury, yet reductions in BMD were significantly slower and less than the expected magnitude of decline in lower extremity BMD in persons with recent SCI.
Astorino. T. A., Harness. E. T., Witzke. K. A. Effect of chronic activity-based therapy on bone mineral density and bone turnover in persons with spinal cord injury. (2013). European Journal of Applied Physiolology. (12): 3027–3037.
Abstract: Randomized controlled trial of exercise training in persons with spinal cord injury.
Objective: The purpose of this study was to examine the effects of 9 months of twice-weekly exercise training on strength, arm ergometry performance, and indices of psychological well- being and quality of life. Methods: Thirty-four men and women with traumatic spinal cord injury (C4 - L1; ASIA A - D) volunteered to participate, and were randomized into exercise and control groups for a duration of 9 months. Results: At baseline, there were no significant differences between groups in submaximal arm ergometry performance, muscle strength, or psychological well-being. Following training, the EX group had significant increases in submaximal arm ergometry power output and significant increases in upper body muscle strength, no significant changes occurred in CON. Participants in EX reported significantly less pain, stress and depression after training, and scored higher than CON in indices of satisfaction with physical function, level of perceived health and overall quality of life. Conclusions: These results demonstrate that long-term twice-weekly exercise training in this population is feasible, and results in significant gains in both physical and psychological wellbeing.
Hicks. A. L., Martin. K. A., Ditor. D. S., Latimer. A. E., Craven. C., Bugaresti. J., McCartney. N. Long-term exercise training in persons with spinal cord injury: effects on strength, arm ergometry performance and psychological well-being. (2003). Spinal Cord 41, 34–43.
Abstract: This was a prospective cross-sectional study for people with chronic SCI.
Objectives: To evaluate the intensity level and nature of physical activity in community-dwelling individuals living with SCI, and explore the relation between descriptive individual variables (e.g. lesion level), secondary complications, and participation in physical activity. Methods: Forty-nine subjects with SCI who used a manual wheelchair for primary mode of mobility completed the physical activity recall assessment for people with spinal cord injury. Results: Approximately 50% of reported physical activity among individuals with SCI is due to activities of daily living. The amount of physical activity was not related to lesion level, age, BMI, or waistline size. Greater heavy intensity activity was related to lower levels of pain and fatigue and higher levels of self efficacy while higher amounts of mild intensity activity and total activity were related to less depressive symptoms. Conclusion: Activities of daily living are a large component for physical activity among individuals with SCI. It appears that greater physical activity is associated with less secondary complications (pain, fatigue and depression) in individuals with SCI.
Tawashy. A., Eng. J. J., Lin. K. H., Tang. P. F., Hung. C. Physical activity is related to lower levels of pain, fatigue, and depression in individuals with spinal cord injury: A correlational study. (2009). Spinal Cord. 47(4): 301–306.
Abstract: Many individuals with spinal cord injury (SCI) do not regain their ability to walk, even though it is a primary goal of rehabilitation. Mammals with thoracic spinal cord transection can relearn to step with their hind limbs on a treadmill when trained with sensory input associated with stepping. If humans have similar neural mechanisms for locomotion, then providing comparable training may promote locomotor recovery after SCI. We used locomotor training designed to provide sensory information associated with locomotion to improve stepping and walking in adults after SCI. Four adults with SCIs, with a mean post-injury time of 6 months, received locomotor training. Based on the American Spinal Injury Association (ASIA) Impairment Scale and neurological classification standards, subject 1 had a T5 injury classified as ASIA A, subject 2 had a T5 injury classified as ASIA C, subject 3 had a C6 injury classified as ASIA D, and subject 4 had a T9 injury classified as ASIA D. All subjects improved their stepping on a treadmill. One subject achieved over ground walking, and 2 subjects improved their over ground walking. Locomotor training using the response of the human spinal cord to sensory information related to locomotion may improve the potential recovery of walking after SCI.
Behrman. A. L., Harkema. S. J. Locomotor Training After Human Spinal Cord Injury: A Series of Case Studies. (2000). Journal of American Physical Therapy. Vol 80, Iss 7. 688-700
Abstract: Prospective cohort study. Objectives: To evaluate the efficacy of a novel functional electrical stimulation (FES) system for improving aerobic fitness in individuals with spinal cord injury (SCI). It was hypothesized that training with this FES system would in- crease peak oxygen consumption (VO2peak) and peak heart rate (HRpeak) in a sedentary adult SCI population. Participants: Volunteer participants with SCI were recruited from the national SCI outpatient and outreach service databases. Interventions: Four electrodes were placed bilaterally on the quadriceps and hamstrings muscle groups, and sub-tetanic contractions were elicited using an FES device. Training was undertaken unsupervised at home for 1 hour, 5d/wk for 8 weeks. Results: A significant increase in VO2peak and HRpeak between baseline and follow-up was observed. Conclusions: This novel form of FES is an effective method of improving aerobic fitness in an SCI population. Results are comparable to those with current FES exercise systems.
Carty. A, McCormack. K, Coughlan. G. F., Crowe. L., Caulfield. B. Increased Aerobic Fitness After Neuromuscular Electrical Stimulation Training in Adults with Spinal Cord Injury. (2012). Arch Phys Med Rehabil Vol 93
Abstract: Persons with spinal cord injury (SCI) are at a heightened risk of developing type II diabetes and cardiovascular disease. The purpose of this investigation was to conduct an analysis of metabolic, body composition, and neurological factors before and after 10 weeks of functional electrical stimulation (FES) cycling in persons with SCI. Eighteen individuals with SCI received FES cycling 2–3 times per week for 10 weeks. Body composition was analyzed by dual X-ray absorptiometry. The American Spinal Injury Association (ASIA) neurological classification of SCI test battery was used to assess motor and sensory function. An oral glucose tolerance (OGTT) and insulin- response test was performed to assess blood glucose control. Additional metabolic variables including plasma cholesterol (total-C, HDL- C, LDL-C), triglyceride, and inflammatory markers (IL-6, TNF-a, and CRP) were also measured. Total FES cycling power and work done increased with training. Lean muscle mass also increased, whereas, bone and adipose mass did not change. The ASIA motor and sensory scores for the lower extremity significantly increased with training. Blood glucose and insulin levels were lower following the OGTT after 10 weeks of training. Triglyceride levels did not change following training. However, levels of IL-6, TNF-a, and CRP were all significantly reduced.
Griffin. L,Decker. M. J., Hwang. J.Y., Wang. B, Kitchen. K, Ding. Z, Ivy. J. L. Functional electrical stimulation cycling improves body composition, metabolic and neural factors in persons with spinal cord injury. (2009). Journal of Electromyography and Kinesiology. 19, 614–622
Abstract: Spinal cord injury (SCI) can lead to paraplegia or quadriplegia. Although there are no fully restorative treatments for SCI, various rehabilitative, cellular and molecular therapies have been tested in animal models. Many of these have reached, or are approaching, clinical trials. Here, we review these potential therapies, with an emphasis on the need for reproducible evidence of safety and efficacy. Individual therapies are unlikely to provide a panacea. Rather, we predict that combinations of strategies will lead to improvements in outcome after SCI. Basic scientific research should provide a rational basis for tailoring specific combinations of clinical therapies to different types of SCI.
Thuret. S, Lawrence. D, Moon. F, Fred. H. Gage. Therapeutic interventions after spinal cord injury. (2006). Nature Reviews Neuroscience, 7, 628-643