Objective, physiologic, biometrically driven spinal cord stimulation trialing is a necessity—The length of the trial is not

Spinal cord stimulation (SCS) has been an important treatment modality for moderate to severe chronic pain of the trunk and/or limb since its inception in 1967. To determine candidacy for implantation, the patient undergoes a procedure known as a trial. This is a temporary application of the therapy to predict success. SCS trials were historically accomplished over a 3–7-day period, assessing patient-reported pain intensity reduction and functionality, oftentimes described as a pain intensity reduction.1 This trial has been the prerequisite to move forward with a permanent implant with most insurance companies requiring 50% or more reduction in pain during the trial period. Despite this requirement, durable benefit deficiencies occur and have been reported, with loss of efficacy being a major contributor to device removal.2, 3 It has been demonstrated in a randomized controlled trial that the SCS trial has a poor positive predictive value for success of spinal cord stimulation implant at 6 months and long-term durable outcomes, when compared to no SCS trial in a randomized controlled study.4 There may be several contributing factors including placebo effects5 programming paradigm differences between trial and permanent phases, Hawthorne effect, and/or patient desire for terminal therapy. However, the reason may be more centered on the complete reliance on a subjective measure of neural activation with nonphysiologic closed loop controlled Spinal Cord Stimulation (PCLC SCS). PCLC devices can benefit the patient by facilitating safe and effective, consistent, and timely delivery or removal of energy or article (e.g., drugs, or liquid or gas regulated as a medical device). Other benefits of PCLC devices may include improving the quality and/or accuracy of delivering the energy or article over time, reducing potential under- or overdosage, enabling safe and effective delivery of energy… Therefore, traditional poor predictability of SCS trials may represent a device limitation, lacking an objective neurophysiologic biomarker for neural activation and maintenance of a therapeutic dose. On the other hand, with PCLC SCS, we now have an objective biometric for spinal cord neural activation and the ability to target dosing: the Evoked Compound Action Potential (ECAP).7 Recently, utilizing a PCLC SCS system during the trial, measuring neural activation and responding with each delivered impulse, it was concluded one can predict the result of the trial at day 7 from a day 0 assessment, with a positive predictive value of 98%.8 This investigation serves as an extension to the durable outcomes proven in the first randomized, prospective, multicenter, double blinded, comparative, and self-selected crossover study of a PCLC SCS with a study endpoint of 36 months.9 Further, appreciating maximal therapeutic efficacy (MAE) is 1.4 times above ECAP threshold for back and lower limb pain, we now can deliver electricity at a consistent dose and confidence, significantly mitigating the placebo effect and potential for failure from inconsistent or poor neural activation.10 With PCLC, the trial now becomes more focused on therapeutic assessment of guaranteed neural activation and MAE dosing which is biometrically driven and less subjective. The recent insurance determination by some payers requiring an extended 5-day trial is the wrong answer to the question of how to improve trial predictability.11 This may increase patient risk (including infection and embolic events in certain susceptible patients) and serves as a barrier for access to care. In consideration of these limitations, the more scientific and now validated answer is biometrically driven, objective, neural activation. JEP developed concept wrote and had provided edits. TRD and JHG wrote and had provided edits. EAP provided edits. The authors acknowledge further contributions from Dr. Chau M Vu, Dr. Harjot S. Bhandal, and Dr. Jacob Wang. Jason E. Pope is a consultant for Abbott, Medtronic, Saluda, Flowonix, SpineThera, PainTEQ, Vertos, Vertiflex, SPR Therapeutics, Tersera, Aurora, Spark, Ethos, Flowonix, Biotronik, Mainstay, WISE, Boston Scientific, Thermaquil, and SpineThera; has received grant/research support from Abbott, Flowonix, Saluda, Aurora, PainTEQ, Ethos, Muse, Boston Scientific, SPR Therapeutics, Mainstay, Vertos, AIS, and Thermaquil; and is a shareholder for Vertos, SPR Therapeutics, PainTEQ, Aurora, Spark, Celeri Health, Neural Integrative Solutions, Pacific Research Institute, Thermaquil, Saluda, Abbott, SpineThera, and Axonics. Timothy R. Deer is a consultant for Abbott, Vertos, SpineThera, Saluda Medical, Cornerloc, SPR Therapeutics, PainTEQ, Spinal Simplicity, Aurora, and Biotronik; an advisory board member for Abbott, Vertos, SPR Therapeutics, and Biotronik, has a DRG Lead patent that is pending with Abbott, and has funded research with Abbott, Vertos, Saluda, Mainstay, SPR Therapeutic, Boston Scientific, and PainTEQ. DS is a consultant to Abbott, PainTEQ, Saluda, Mainstay, Surgentec, Nevro, and holds stock options with PainTEQ, Neuralace, Mainstay, Vertos, and SPR. Dr., Deer is an Editorial Board member of "Pain Practice" and a coauthor of this article. To minimize bias, they were excluded from all editorial decision-making related to the acceptance of this article for publication. Jonathon H. Goree is a consultant for Abbott, Saluda Medical, and Stratus Medical; and has received research funding from SPR Therapeutics and Mainstay Medical. MG is a consultant for Saluda, Boston Scientific, Averitas Pharmaceutical, Pacira Medical, and PainTEQ. Erika A. Petersen has received research support from Mainstay, Medtronic, Nalu, Neuros Medical, Nevro Corp, ReNeuron, SPR, Surgical Information Systems, and Saluda, as well as personal fees from Abbott Neuromodulation, Biotronik, Medtronic Neuromodulation, Nalu, Neuros Medical, Nevro, Presidio Medical, Saluda, and Vertos; and holds stock options from SynerFuse and neuro42. Data sharing not applicable to this article as no datasets were generated or analyzed during the current study.