Understand · Chapter 06
Treating one nerve, instead of the whole spinal cord
If the pain comes from a single identifiable nerve, there is no reason to place hardware in the spinal canal. Peripheral nerve stimulation goes directly to the nerve — and in one form, it does its work in sixty days and then comes out entirely.
What You'll Learn
Approx. 10 min read- What peripheral nerve stimulation targets and why
- The fundamental split between temporary and permanent PNS
- How a 60-day therapy can produce relief that outlasts it
- Which platforms occupy which part of the field
- Which pain problems are well suited to PNS
- How PNS compares to SCS and DRG stimulation
The Concept
Going to the source instead of the switchboard
Spinal cord stimulation works at the level of the spinal cord, where signals from a wide region converge. Peripheral nerve stimulation works further out — at a specific named nerve, somewhere in a limb or the trunk, before the signal ever reaches the spine.
This has an obvious appeal when the pain problem is genuinely localised to one nerve's territory. There is no epidural access, no hardware in the spinal canal, and no risk profile associated with the spinal cord itself. The lead is placed near the nerve, typically under ultrasound guidance, often in an outpatient setting.
The trade-off is equally obvious. PNS treats what that nerve supplies and nothing else. It is the wrong tool for diffuse, multi-region or axial pain.
The Fundamental Split
Two entirely different propositions
The word 'PNS' covers two approaches that share a target and almost nothing else. Understanding which one is being discussed is essential.
Nothing stays behind
Temporary — up to 60 days
A fine percutaneous lead is placed without surgery, stimulation runs for up to sixty days, and then everything is removed. The therapeutic premise is that the treatment period itself produces relief that persists after the hardware is gone. This is the SPRINT system from SPR Therapeutics.
- No permanent implant
- No incision, no anesthesia required
- Removed by your treating clinician at the end of the course
- Lowest-commitment entry point in neuromodulation
Ongoing therapy
Permanent implant
A lead and a miniature pulse generator are implanted to deliver stimulation indefinitely, in the same conceptual model as spinal cord stimulation but at a peripheral target. Nalu Medical and Curonix both work in this space with battery-free designs.
- Ongoing, long-term stimulation
- Trial period before permanent placement
- Battery-free options with external power
- Revisable and removable
The Interesting Question
How can sixty days of therapy help after it stops?
This is the part of the field that patients find hardest to believe, and the scepticism is reasonable. If the device is gone, what is doing the work?
The proposed mechanism is not ongoing masking of signals, because there is nothing left to mask with. Instead, stimulation of sensory fibres — including muscle proprioceptive afferents — during the treatment period is thought to drive changes at the level of the spinal cord and brain, reducing the sensitization that had built up. Deer and colleagues described this in 2021 as peripherally induced reconditioning of the central nervous system.
The supporting evidence is real but should be understood for what it is. In a multicentre study of medial branch nerve stimulation for chronic axial back pain, four-year follow-up reported that of twenty-two patients treated for sixty days, fifteen still had clinically meaningful outcomes. In chronic post-amputation pain, a federally funded study reported that two thirds of patients had at least 50% pain reduction after eight weeks, and four of five reported relief at twelve months. These are small numbers with long follow-up, not large numbers with short follow-up.
The practical point stands regardless of mechanism: a therapy that requires no permanent implant and can be removed entirely has an unusually favourable risk-to-commitment ratio.
Why It Appeals
The advantages of a peripheral target
No spinal canal access
No epidural placement means the risks specific to the spinal canal — dural puncture, epidural haematoma — are not part of the picture.
Small hardware
Battery-free micro-generators and percutaneous leads mean substantially less implanted material than a conventional SCS system, and in the temporary form, none at all.
Lower commitment
Particularly with the 60-day approach, the decision is smaller. That makes it reasonable to try earlier in the treatment course rather than as a last step.
Fast path to therapy
Percutaneous placement in an outpatient setting, often under ultrasound guidance, without general anesthesia.
In Context
PNS compared with SCS and DRG stimulation
| Peripheral nerve stimulation | DRG stimulation | Spinal cord stimulation | |
|---|---|---|---|
| Target | A named peripheral nerve, out in the limb or trunk | A specific dorsal root ganglion in the foramen | The dorsal columns of the spinal cord |
| Coverage | That nerve's territory only | One dermatomal region, precisely | Broad — one or both legs, back, multiple areas |
| Spinal canal access | None | Yes, epidural into the foramen | Yes, epidural |
| Best suited to | Focal pain in one nerve distribution | Focal neuropathic pain, classically CRPS of a foot or lower leg | Widespread back and/or leg pain |
| Permanent implant | Optional — temporary 60-day option exists | Yes, after a trial | Yes, after a trial |
The Platforms
Who does what in this space
Temporary, 60 days
SPR Therapeutics
The SPRINT system — endura for a single lead, extensa for two. Percutaneous MicroLead placement, up to sixty days of therapy, then complete removal. The only major platform built around the temporary model.
Permanent, battery-free
Nalu Medical
A micro-IPG about the size of a paperclip with no implanted battery, powered by a wearable Therapy Disc. Randomized COMFORT data now extends to twenty-four months. Now offered within Boston Scientific's PNS portfolio.
Permanent, wireless
Curonix
The Freedom PNS system, using high frequency-electromagnetic coupling from an external transmitter to a battery-free implanted receiver. A 2024 FDA clearance extended the labeled indications to full-body use including the craniofacial region.
Good Candidates
When PNS is worth discussing
- Pain confined to one nerve's distributionWell-localised, anatomically consistent.
- A diagnostic nerve block gave temporary reliefStrong supporting evidence for the target.
- Post-surgical or post-traumatic nerve painAfter hernia repair, knee replacement, or direct injury.
- Chronic post-amputation or phantom limb painAn area with dedicated study data.
- Chronic axial back pain with a medial branch targetWhere 60-day medial branch stimulation may apply.
- You want to avoid spinal canal hardwareA legitimate preference, not an unreasonable one.
- You are not ready for a permanent implantThe temporary option exists for exactly this.
- Occipital, shoulder or knee pain in one territoryCommon focal targets, assessed individually.
PNS is generally not the right choice for diffuse pain, multi-region pain, or axial pain without an identifiable nerve target. In those situations spinal cord stimulation usually remains the better-matched therapy.
Common Questions
Questions about peripheral nerve stimulation
Take the next step in understanding your options
Read how candidacy is assessed, then discuss your history and imaging with your own clinician. This site does not arrange evaluations.