Neuromodulation of Motor and Sensory Spinal Pathways in Subjects Undergoing Epidural Spinal Cord Stimulation

Definitions and nomenclature:

Spinal cord stimulation (SCS) will be performed using a 32-electrode paddle array implanted in the dorsal epidural space along the thoracolumbar region of the spinal cord. The array will be powered by a multiple independent current-controlled (MICC) implantable pulse generator (IPG) connected to the paddle per standard of care procedures for SCS implantation. In addition, as per standard of care, motor evoked potential (MEP), somatosensory evoked potential (SSEP) and electromyography (EMG) will be performed via the IOMAX intraoperative neuromonitoring system. The SCS system will be placed for clinical purposes, i.e., treatment of chronic pain, however, the investigators will collect data at various points during the placement. The study procedures will add 15 minutes to the surgery. MUSC's Locomotion Rehabilitation Laboratory - located at the College of Health Professions Building C - houses a Biodex Pro System 4 isokinetic/isometric dynamometer. The Biodex will standardize application of passive isokinetic knee flexion/extension trials to each blinded subject for proprioceptive investigations, which will be referred to as threshold to detect passive movement (TTDPM) throughout the rest of this document. Finally, MUSC's Locomotor Energetics and Assessment Laboratory - also located at the College of Health Professions Building C - houses a dual belt Instrumental Treadmill that is coplanar with the floor and will be used during all walking events. The laboratory also has a 12-camera motion capture system that utilizes active infrared LED tracers to track kinematic positioning data and will be used during all walking events. Another tool offered by the lab is a 16-channel EMG system which utilizes surface electrodes to detect target muscle activity and will also be used during all walking events. In all, expected total duration of the study to be approximately 30 days.

Device use:

The epidural stimulator paddle and IPG are FDA-approved, commercially available devices designed to treat chronic pain of the back and lower extremities and will be used for their intended clinical purpose - electrical stimulation of dorsal column fibers to mitigate pain perception. The research use of this device, which will add approximately 15 minutes to the surgery, involves recording/stimulating from the device during the standard of care intraoperative neuromonitoring protocol. Regardless of study participation, the stimulator paddle and IPG will be implanted according to standard of care for the pre-planned SCS surgery. The IOMAX intraoperative neuromonitoring system, equipment owned by MUSC and operated by MUSC neurophysiology staff, is a commercially available device used during standard of care spinal surgical procedures, such as SCS implantation. Regardless of study participation, intraoperative neuromonitoring via IOMAX will take place according to standard of care for the pre-planned SCS surgery. The following devices are used for research purposes only. The Biodex Pro System 4, used regularly by physical rehabilitation researchers here at MUSC, is a commercially available device that will be used solely as a research tool to deliver passive isokinetic knee flexion/extension during the TTDPM. The Instrumental Treadmill, GAITRite mat, motion capture system, and MA300 EMG system are all commercially available devices that are used by MUSC researchers at the College of Health Professions to perform extensive gait analysis in subjects with various neurological deficits. Gait analysis is being performed for research purposes only, and is not standard of care for patients receiving SCS surgery.

Number of Subjects: