Enhancing Ambulation Function in Patients with Spinal Cord Injury by Lumbar Posterior Root Muscle Stimulation

Ambulation training is an important part in the rehabilitation of spinal cord injuries (SCI). Bracing, functional electrical stimulation (FES) and body weight-supported treadmill training (BWSTT) had been applied to enhance ambulation function. However, the results were not good. The evidence for spinal central pattern generator in humans was firstly described by Dimitrijevic et al in 1998. Dimitrijevic et al demonstrated epidural spinal cord stimulation in the level of T12-S1 could elicit step-like EMG activity and locomotor synergies in paraplegic patients with complete SCI. Dimitrijevic et al further demonstrated the posterior roots muscle reflex (PRM) responses to stimulation were routed through monosynaptic pathways. In 2007, Karen and Dimitrijevic found posterior root afferents could also be depolarized by transcutaneous stimulation with moderate stimulus intensities in healthy subjects. This noninvasive approach can be applied in the clinical settings. Therefore, the purpose of this study is to apply this novel technique to improve the ambulation function in SCI patients. Our hypotheses were: (1) PRM stimulation could elicit stepping-like movement in chronic SCI patients. (2)PRM stimulation combined with body weight-supported treadmill training (BWSTT) could have enhanced benefits on improving motor control and ambulation function in chronic SCI patients. (3) PRM stimulation could elicit more coordinated response of lower limbs than FES in chronic SCI patients while combined with BWSTT. This study will be conducted in three years. In the first year, we are going to test the hypothesis (1). In the second year, hypothesis (2) will be tested. In the third year, hypothesis (3) will be tested. Each year, we will recruit 100 of SCI patients with ASIA impairment scale A, B, C and D, 25 patients in each category and 25 healthy subjects served as control. All subjects will receive PRM stimulation 30 minutes per day, 5 days a week for duration of 3 months. Clinical assessment and laboratory assessment include polyelectromyography for motor control evaluation, VICON Motion Analysis System for kinematic evaluation, and foot pressure measurement system for foot contact pattern analysis. Outcomes between before and after PRM stimulation will be compared as well as between each time of stimulation. The results in this study could provide the effects of PRM in different categories of SCI patients and establish a new treatment strategy of ambulation training in SCI patients.

Project ID:PC10001-0097
External Project ID:NSC98-2314-B182-004-MY3