SCS Neurophysiology Study
Research type
Research Study
Full title
Evaluation of Neurophysiological Characteristics of the Spinal Cord During Spinal Cord Stimulation Procedures
IRAS ID
331029
Contact name
Dave Mugan
Contact email
Sponsor organisation
Saluda Medical Europe Ltd
Duration of Study in the UK
3 years, 0 months, 1 days
Research summary
Spinal Cord Stimulation (SCS) has now been used clinically for more than 60 years(Sweet and Wepsic 1968). Additionally, mechanisms of SCS have been studied in preclinical models since the 1990’s(Meyerson et al. 1995). Despite this there is still significant uncertainty and conflicting opinions on the exact working mechanisms of SCS(Sdrulla, Guan, and Raja 2018). The use of real-time neurophysiological recordings during SCS procedures and SCS therapy is still a relatively new innovation in the SCS field(Parker et al. 2012; Mekhail et al. 2019) and the technologies that enable the recording of in-vivo neurophysiological data offer opportunities to explore some of the mechanistic underpinnings of SCS therapy. In this study we will use a system which we have used previously in the study centre to identify for the first time in human subjects a post-synaptic dorsal column fibre tract (manuscript under review). We have additionally published findings related to the interactions between patient perception of stimulation induced sensation intensity, evoked neurophysiological signals (Evoked Compound Action Potentials – ECAPs) and stimulation frequency(Gmel et al. 2021). With this new protocol we aim to further characterise the neurophysiological responses of the spinal cord in patients scheduled to undergo routine SCS surgical procedures. Specifically, we will take intra-operative recordings from 2 distinct groups of patients, those being stimulation naïve patients undergoing implantation of SCS for the first time, and patients who have experienced long-term failure (loss of efficacy – LOE) of SCS.
In the context of our study, and lacking a universally agreed definition, we will define LOE as:
LOE describes the phenomenon in some SCS treated patients who had a documented improvement in the intensity of pain in the region targeted by the SCS system for at least 6-months but then lost effect for reasons that could not be attributed to one of the factors listed below, and in whom multiple reprogramming attempts* have been made to recover effectiveness to no avail.• SCS lead migration.
• SCS system failure (e.g., hardware failure).
• Patient compliance (e.g., turned stimulation off).
• New pathology that is significantly contributing to the pain condition in the opinion of the investigator (e.g., new disc protrusion).
• Worsening of existing pathology that is significantly contributing to the pain condition in the opinion of the investigator (e.g., advancing spondylolisthesis).
• Improved physical functioning that causes ‘new pain’ associated with increased activity in the opinion of the investigator.
• New or changed psychosocial factors that could induce a secondary gain condition (e.g., workplace compensation for injury proceedings).
* Reprogramming changes should include:
• Use of lower intensity stimulation (i.e., amplitudes of 0.5 – 3.5mA).
• Targeting of anatomy of T9 body, T9/T10 disc, and T10 body.
• Evaluation during a period of no stimulation (deactivated device).REC name
East Midlands - Derby Research Ethics Committee
REC reference
23/EM/0285
Date of REC Opinion
9 Jan 2024
REC opinion
Further Information Favourable Opinion