The American Society of Pain and Neuroscience has published the first comprehensive guidelines on physiologic closed-loop controlled spinal cord stimulation for chronic pain. They establish formal definitions, review current evidence, and provide consensus recommendations for clinical implementation.
The guidelines, published in the Journal of Pain Research, define physiologic closed-loop controlled (PCLC) systems as technology that incorporates sensors, actuators, and control algorithms and dynamically adjusts electrical stimulation in real time on a pulse-to-pulse basis, using physiologic-measuring sensors to maintain consistent neural activation. This definition received a Grade A recommendation with Level I-A evidence. The document also aligns with recent U.S. Food and Drug Administration technical guidance for medical devices using physiologic closed-loop control.
The guidelines synthesize data from multiple clinical trials, including the pivotal EVOKE study, which demonstrated superior outcomes for PCLC compared with open-loop systems. At 36 months, 77.6% of patients with PCLC achieved at least 50% pain reduction vs 49.3% in the open-loop group (P < .001).
Key findings showed that PCLC systems measured and adjusted stimulation in real time using evoked compound action potentials (ECAPs), maintaining consistent neural activation despite positional changes. The guidelines confirm the safety and efficacy of PCLC spinal cord stimulation (SCS) with high-certainty recommendations:
- PCLC SCS is safe and efficacious for treating back and leg pain.
- The technology demonstrates superiority over open-loop systems (Grade A, Level I-A).
- It provides measurable improvements in sleep, quality of life, function, and mood.
- Neural activation can be precisely measured and adjusted on a pulse-by-pulse basis.
Regarding surgical technique, the guideline authors emphasize the importance of proper lead spacing for optimal measurement and stimulation. Equidistance between leads and neural activation mapping are recommended over traditional paresthesia mapping.
The guidelines also address patient selection, stating that while criteria are similar to traditional SCS, PCLC systems offer advantages in predicting long-term efficacy. A study cited in the guidelines found a 98.4% positive predictive value when assessing ECAP generation, stability, and functional improvement as early as day 0 of the trial period.
Looking ahead, the guideline authors outline several research priorities, including:
- Understanding patient characteristics affecting outcomes
- Expanding indications beyond back and leg pain
- Developing prescription guidelines specific to PCLC therapy
- Investigating remote programming capabilities
- Evaluating cost-effectiveness.
The guidelines will be updated regularly through a living systematic review process. Specifically, literature reviews will be conducted at minimum every 2 years to incorporate new evidence.
PCLC SCS allows for the objective measurement of neural activation, enabling therapy to be refined based on physiologic responses.
The development of these guidelines was supported by an unrestricted educational grant from Saluda Medical, with all consensus statements finalized by nonbiased committee members following strict conflict-of-interest protocols.