EPV149 - NEXT-GENERATION CLOSED-LOOP, SPINAL CORD STIMULATION WITH DIFFERENTIAL TARGET MULTIPLEXED THERAPY (ID 454)
- David L. Cedeno, United States of America
- Ricardo Vallejo, United States of America
- Krishnan Chakravarthy, United States of America
- Andrew Will, United States of America
- Abigail Skerker, United States of America
- David Dinsmoor, United States of America
- David L. Cedeno, United States of America
Abstract
Introduction
Recent advances in spinal cord stimulation (SCS) have focused on two highly novel areas; (1) differential target, multiplexed (DTM) SCS, which has demonstrated superior pain relief, and (2) the spinal Evoked Compound Action Potential (ECAP), a bioelectrical signal used as a measure of neural activation with closed-loop (CL) SCS systems to compensate for physiologic variability.1 Simultaneous application of both approaches may allow for a new generation of neural responsive SCS that blends a science-based methodology for pain management with real-time, CL control for biophysical variation. In this study, CL DTM-SCS was explored to determine control characteristics of the system in the clinical setting.
Methods/Materials
Included here are a sample of ten subjects who underwent a DTM SCS trial using dual percutaneous 1x8 leads placed near T9. Following the trials and within the 10 days allowed per labeling, the leads were connected to an investigational neurostimulation system capable of recording ECAPs and delivering a novel CL DTM-SCS pattern.2 The stimulating electrodes and frequencies were selected for consistency with typical DTM programming paradigms. The control policy parameters and nominal charge/phase (Q/ph) of DTMBASE—one component of the DTM waveform, also used to elicit the ECAP—was selected to optimize comfort and mitigate variability in neural activation over a range of aggressor activities, such as a back arch. The Q/ph of the priming component of DTM, DTMPRIME, was programmed relative to DTMBASE. The subjects were then asked to re-perform the aggressor activities while the system was operated for a minute in both the open-loop (OL) and CL configurations. ECAP variability in both configurations was calculated to assess the capability of CL DTM-SCS to control neural activation versus OL DTM-SCS.
Results
Across the subjects, average ECAP variability—and presumably variability in neural activation with the DTM SCS—was reduced by 51% (p < 0.001) in the CL arm (3.5 µV) versus the OL arm (7.1 µV). On average, the CL DTM-SCS system modulated the stimulation Q/ph (DTMBASE and DTMPRIME) by 13% ± 10%.
Discussion
These results demonstrate the technical feasibility of CL DTM-SCS on conventional 1x8 leads, with the CL policy limiting ECAP amplitude variability by about a half versus the conventional OL configuration.
Conclusions
Potential benefits of this approach may include a more durable therapy and consistent outcomes, as well as broader SCS programming options customized for the patient. Further study is needed to characterize the chronic utility and associated clinical benefits of these methods.
References
1. Russo M, Cousins MJ, Brooker C, et al. Effective Relief of Pain and Associated Symptoms With Closed-Loop Spinal Cord Stimulation System: Preliminary Results of the Avalon Study. Neuromodulation. 2018;21(1):38-47. doi:10.1111/ner.12684
2. Chakravarthy K, Bink H, Dinsmoor D. Sensing evoked compound action potentials from the spinal cord: Novel preclinical and clinical considerations for the pain management researcher and clinician. J Pain Res. 2020;13:3269-3279. doi:10.2147/JPR.S289098
