Evaluation of Neurophysiologic Correlates of Maximal Analgesia Using EVOKE™ Therapy: Insights from Triangle Pain Clinic

Introduction: Like pharmacotherapies (1), electroceutical therapies such as spinal cord stimulation (SCS) require optimal dosing to achieve maximal clinical effectiveness. Traditional SCS has been limited by a lack of neurophysiologic data to guide therapy optimization, often relying on trial-and-error approaches (2). These methods can lead to reduced battery life, inconsistent outcomes, and diminished therapeutic effects (2). EVOKE™ therapy addresses this by measuring neural activation through evoked compound action potentials (ECAPs), delivering stimulation that maintains consistent neural engagement with each pulse. This enables the study of optimal neural dosing in real-world settings. Here, we present objective neural metrics associated with maximal analgesic effect (MAE) achieved using EVOKE therapy across three Dutch clinics.

Methods: A total of 113 subjects with intractable trunk and/or limb pain were included in this retrospective analysis. MAE was defined at the visit with the maximum percent reduction in pain intensity [Numeric Rating Scale (NRS)] of the back and/or leg within the first twelve-months of implantation. Objective neurophysiological data that produced the MAE was analyzed.

Results: The mean MAE was 74.7%, and the pain responder (≥50% NRS improvement), and, high responder (≥80% NRS improvement) rate, was 86.7%, and 48.7%, respectively. Median out-of-clinic dose accuracy (i.e., deviation from ECAP target) was 4.9 µV (IQR 3.0-7.3 µV). Patients used their system 97% (IQR 83-98%) of the time and stimulation was above ECAP threshold 97% (IQR 66-100%) of the time. Dose ratio (estimated current at median ECAP/ECAP threshold current) was 1.3 (IQR=1.1-1.4).

Conclusion: EVOKE™ therapy supports creating neural dosing guidelines for MAE, with observed neurophysiologic metrics matching recent MAE (3) findings. These objective measures link clinical trials to real-world clinical practice by standardizing therapy and moving beyond subjective reports.
EVOKE therapy provides meaningful benefits for chronic pain in real-world use. A physiologic neural panel enables consistent neural dosing and may enhance therapeutic outcomes.