Mukhametova, Elvira

Abstract In this study the effect of transcutaneous (tSCS) and epidural electrical spinal cord stimulation (EES) to facilitate volitional movements, balance, and non-motor functions was consecutively tested in two subjects with motor complete spinal cord injury (SCI). We hypothesized that tSCS and EES have different but complimentary effects on restoration after SCI. In both subjects tSCS demonstrated minimal improvement in volitional movements critical to initiate tSCS-enabled rehabilitation. Compared to tSCS, following EES demonstrated immediate restoration of volitional movements, while tSCS was more effective in improving balance. Continuous improvement in non-motor functions was found during tSCS-enabled and then EES-enabled rehabilitation. These results show significant difference in effect of tSCS and EES on recovery of neurologic functions and demonstrate advantages of consecutive tSCS and EES therapy of SCI. Proposed approach will help to select responsive to neuromodulation subjects and early initiate therapy, particularly for motor complete SCI with minimal effect from conventional rehabilitation.

Abstract Electrical stimulation of the cerebral cortex (ESCC) has been used to treat intractable neuropathic pain for nearly two decades, however, no standardized approach for this technique has been developed. In order to optimize targeting and validate the effect of ESCC before placing the permanent grid, we introduced initial assessment with trial stimulation, using a temporary grid of subdural electrodes. In this retrospective study we evaluate the role of electrode location on cerebral cortex in control of neuropathic pain and the role of trial stimulation in target-optimization for ESCC. Location of the temporary grid electrodes and location of permanent electrodes were evaluated in correlation with the long-term efficacy of ESCC. The results of this study demonstrate that the long-term effect of subdural pre-motor cortex stimulation is at least the same or higher compare to effect of subdural motor or combined pre-motor and motor cortex stimulation. These results also demonstrate that the initial trial stimulation helps to optimize permanent electrode positions in relation to the optimal functional target that is critical in cases when brain shift is expected. Proposed methodology and novel results open a new direction for development of neuromodulation techniques to control chronic neuropathic pain.