Cervical transcutaneous spinal stimulation for spinal motor mapping
Jeong‐Hoon Oh, Alexander G. Steele, Blesson Varghese, Catherine Martin, Michelle S. Scheffler, Rachel Markley, Yi‐Kai Lo, Dimitry G. Sayenko
Abstract
Transcutaneous spinal stimulation (TSS) is a promising approach to restore upper-limb (UL) functions after spinal cord injury (SCI) in humans. We sought to demonstrate the selectivity of recruitment of individual UL motor pools during cervical TSS using different electrode placements. We demonstrated that TSS delivered over the rostrocaudal and mediolateral axes of the cervical spine resulted in a preferential activation of proximal, distal, and ipsilateral UL muscles. This was revealed by changes in motor threshold intensity, maximum amplitude, and the amount of post-activation depression of the evoked responses. We propose that an arrangement of electrodes targeting specific UL motor pools may result in superior efficacy, restoring more diverse motor activities after neurological injuries and disorders, including severe SCI.