Nonawake versus Awake Placement of Spinal Cord Stimulators in Canada

Spinal cord stimulation (SCS) is a common therapeutic approach for treating intractable chronic pain. A key factor determining SCS efficacy is lead positioning to generate paresthesias in areas of perceived pain. There are two distinct approaches to confirming appropriate coverage. 1) Sedative anesthesia with local anesthetic and intraoperative patient reporting of pain coverage. 2) General anesthesia and intraoperative neurophysiological mapping. Placement guided by neuromonitoring decreases OR times, produces more accurate placement with better pain coverage, less excess paresthesias and adverse events. We aim to determine the prevalence of non-awake SCS placement with neuromonitoring in Canada, given the demonstrated benefits, and to identify possible barriers to implementation.

A structured questionnaire was designed to assess procedures for SCS implantation in Canada. The survey was distributed via email to members of the Canadian Neuromodulation Society.

14 responses were received. 36% perform SCS implantation asleep with neuromonitoring where 75% utilize CMAPs and 25% utilize SSEP collisions. 71% have access to a neurophysiologist yet 93% are at centres where neurophysiologists are used for other procedures. Barriers to utilizing neurophysiologist assisted lead placement include familiarity with the awake procedure, and lack of access and awareness.

This survey provides a summary of SCS implantation practice patterns in Canada. Although asleep SCS implantation with neuromonitoring is faster and results in more accurate placement while avoiding downsides of the awake procedure, most neurosurgeons currently do not utilize this protocol in part due to a lack of access to neurophysiologists with expertise in this area.