Advances in Peripheral Nerve Stimulation: More Clinical Options, More Science

While neuromodulation of a peripheral nerve for pain relief is not a novel concept, the explosion of dedicated peripheral nerve stimulation (PNS) technologies has reinvigorated the field of pain medicine. The new percutaneous devices are easily placed without requiring general anesthesia or open peripheral nerve surgery, which greatly expands the pool of potential implanting physicians. The addition of ultrasound to the pain clinician’s armamentarium has improved the ability to diagnose neuropathic pain and the accurate delivery of this technology to the target neural structure. Renewed interest in this field has led to better understanding of the mechanisms involved in PNS and its clinical effect on pain and function. As a result of these advances, pain practitioners around the world are readdressing acute and chronic pain syndromes of peripheral origin with the potential for improved safety and efficacy. Countless hours of work and dedication have resulted in a much-needed supplement reviewing peripheral nerve stimulation in Pain Medicine.

The earliest forms of PNS included ayurvedic and acupuncture medicine, which established forms of peripheral stimulation as a possible treatment for numerous ailments. Modern PNS requires a deeper understanding of neuromodulation to optimize the stimulation patterns required to maximize pain relief. This PNS supplement is an ideal guide to understanding how PNS may be applied to our patient population. The initial manuscripts focus on the history of PNS and a current understanding of mechanisms of action that may explain the prolonged effects of stimulating a nerve. Later articles will focus on body region anatomy and suggested implant techniques.

The authors of these manuscripts have unique and early experience in applying various PNS technologies using both fluoroscopy and ultrasound techniques. These techniques will expand our field’s ability to treat both simple and complex acute and chronic pain syndromes. The initial studies on PNS confirmed analgesia in various neuropathic pain syndromes such as phantom pain and complex regional pain syndrome. As our techniques expand, we find that some common targets such as the lumbar medial branch nerve, which was previously an ablation target, have now become stimulation targets. We may find in the future that nerves supplying other common musculoskeletal targets will become targets for PNS, such as for the shoulder, hip, and knee joints. Severe, chronic arthritic pain may be as amenable to neuromodulation as the discrete neuropathic pain syndromes.

Furthermore, the literature supports the use of PNS of the tibial nerve for overactive bladder [1]. As Richard North showed in 1994, blocking nerves distal to pathology can in fact provide partial analgesia [2]. This lends credence to some recent case reports showing that PNS distal to the lesion may be helpful for pain [3]. If local anesthesia applied distal to a lesion is analgesic, then hopefully electricity applied distal to a lesion will work even better. As such, other peripheral targets may exist for central pain syndromes or central pathology.

As Editors, we hope this supplement serves as a foundation for modern techniques in peripheral nerve stimulation and stimulates further research establishing effectiveness in a variety of clinical populations. This collection of expert techniques will serve as a centerpiece for education and clinical management for many years to come. As PNS technologies and image guidance improve, the field of pain medicine should continue to benefit from the clinical knowledge gained from experts both treating patients with PNS systems and researching this field from animal models to clinical patient populations.

Finally, we would like to highlight and dedicate this supplement to our authors who have dedicated their lives to the betterment of pain patients. Without caring, innovative, and compassionate physicians such as yourselves, we would not be able to advance the field of peripheral nerve stimulation. We commend everyone involved in the writing, reviewing, and editing process in Pain Medicine.

Funding sources: None.

Conflicts of interest: Dr. Ottestad: scientific advisory board, consultant, and PI on one study for Bioness; consultant for SPR, Nine Continents Medical. Dr. Gulati: medical advisory board for AIS; consultant for Medtronic, SPR therapeutics, Bausch Health, Nalu Medical, Flowonix.

Supplement sponsorship: This article appears as part of the supplement entitled “Peripheral Nerve Stimulation: Update for the 21st Century” sponsored by Bioness and by SPR Therapeutics, Inc.

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