Study on the Use of Intraoperative Neurophysiological Monitoring in Spinal Cord Stimulator Trials

Details

Spinal cord stimulation (SCS) is a neuromodulation procedure that utilizes electrical stimulation via electrodes on the spinal cord for management of various chronic pain states. The most common indications for SCS placement include refractory neuropathic pain, complex regional pain syndromes (CRPS), post-laminectomy/failed back surgery syndrome, and ischemic limb pain related to peripheral vascular disease.1 Upon placing the percutaneous leads in the epidural space, the electrodes or the leads are activated with electrical currents and the patient is asked to report area of paresthesia in response to stimulation. Hypothesis This study hypothesizes that one will be able to use percutaneous SCS leads and be able to properly map the dermatomal overlap with the myotomes recorded during the procedure using CMAP. Objectives Primary Objective - To evaluate the difference between observed intraoperative neuromonitoring readings and patient reported coverage for spinal cord stimulator trials and Secondary Objective(s) - To evaluate the safety and tolerability of intraoperative neuromonitoring during spinal cord stimulator trials and via documented adverse events and patient elicited feedback on follow up questionnaires. Patient satisfaction using PGIC from one week to 6-months post procedure Change in pain intensity using NRS from baseline to 6-months post procedure Primary Study Endpoints The primary study endpoints will be the comparison between intraoperative neuromonitoring readings and patient reported coverage for spinal cord stimulator trials. This study will collect asleep tonic and sub-perception burst waveforms, as well as awake tonic and sub-perception burst waveforms. Also collected will be self-reported subject pain coverage with the subject awake and conversant. 2.5 Secondary Study Endpoints To evaluate the safety and tolerability of intraoperative neuromonitoring during spinal cord stimulator trials via documented adverse events and patient elicited feedback via NSR and PGIC. SCS Neuromonitoring: Subjects will be seen on the day of their procedure in the preoperative holding area. Once consent has been given, the patient will be taken to the OR and attached to monitors. Once the subject is sedated, the IONM specialist will place subdermal needle electrodes in various muscle groups and begin testing to obtain baseline measurements. The muscle groups that will be monitored bilaterally are as follows: upper and lower intercostals, upper and lower abdomen, iliopsoas, vastus lateralis, biceps femoris, tibialis anterior, and gastrocnemius. Transcranial electrical stimulation electrodes will also be placed in the scalp with the patient mildly anesthetized to measure SSEPs and MEPs. Once IONM baselines are obtained, SCS leads will be placed. Testing will begin with IONM with the patient under sedation. Intraoperatively, this study will employ the use of CMAP. After lead placement, the contacts of each lead will be activated with a sub-perception burst waveform and a tonic waveform. The study team will record the parameters and IONM response with the patients under sedation. Once confirmed with the IONM team, the anesthesia team will awaken the patient and cease sedation. With the patient awake, the coordinator will test the same regions while activating the same electrodes with the patient self-reporting their perceived areas of paresthesia. This will be done by asking the subject to confirm that the region being stimulated covers their region of pain. Subjects will undergo the SCS trial as part of their standard of care and will be seen for follow-up 1 week post-trial, during which the leads will be pulled. The patient will undergo SCS implant and be admitted for 24-hour postoperative observation. All follow-up visits and SCS procedures are part of standard of care. Sequence and Duration of all Study Periods Total length for participation in this study is up to 2 weeks