There are 2 published reports (Carhart et al. 2004; Herman et al. 2002) describing the effects of epidural spinal cord stimulation combined with gait training in a single subject (male with incomplete tetraplegia, 43 years old, injury level C5-C6, AIS C, 3.5 years post-injury). The subject first underwent 12 weeks of BWSTT that resulted in some significant improvements in treadmill gait parameters although overground ambulation remained limited. Subsequently, the subject underwent surgical implantation of an epidural stimulation system placed over the T10-T12 vertebral level. BWSTT and overground gait training in combination with epidural stimulation commenced after surgical healing. The combination of epidural spinal cord stimulation with gait training resulted in a substantial improvement in treadmill gait parameters as well as in overground ambulation. The subject reported a decreased sense of effort, a doubling in walking speed, and increased walking endurance when assisted by spinal cord stimulation. This was associated with improved community and indoor functional ambulation.
Another study investigated the effect of epidural spinal stimulation in combination with locomotor training in a single male subject with a motor complete spinal cord injury (23 years old, injury level C7-T1, AIS B, 3.4 years post-injury) (Harkema et al. 2011). Before implantation, the subject underwent 170 locomotor training sessions and was unable to stand or walk independently or voluntarily move his legs. A 16-electrode array was surgically placed on the dura (L1-S1 cord segments). Optimal stimulation parameters for standing and stepping were tested. With stimulation, the subject was able to maintain standing unassisted with full weight-bearing. Locomotor-like muscle activity patterns emerged when epidural stimulation was combined with body weight-supported treadmill training (but not without stimulation). At 7 months post-implantation, the subject also was able to voluntarily move the legs only with epidural stimulation.