NEUROMODULATION
Spinal cord
stimulation
Spinal cord stimulation (SCS) is an implanted neuromodulation treatment used to reduce chronic pain. In selected people with persistent CRPS, it may be considered after a broader rehabilitation and pain-management approach has not provided sufficient relief.
SCS is intended to change how pain signals are processed. It does not remove the original injury, reverse every feature of CRPS, or guarantee restoration of function.
THE KEY POINT
PAIN MODULATION
A successful implant is not the same thing as curing CRPS.
Neuromodulation can reduce pain for some patients and may make rehabilitation or daily activity easier. The magnitude and durability of benefit vary substantially.
01
It is usually tested first
A temporary stimulation trial helps assess whether the individual patient experiences meaningful benefit.
02
Results can change over time
Long-term CRPS data show that the analgesic advantage of conventional SCS can diminish.
03
Device choice matters
Conventional SCS and dorsal root ganglion stimulation target pain differently and do not have identical evidence.
WHAT IS SPINAL CORD STIMULATION?
An implanted system designed to modulate pain signals.
SCS uses thin electrical leads placed in the epidural space and connected to a pulse generator. Electrical stimulation is programmed to alter the transmission and perception of pain. Modern systems can use different stimulation patterns and may or may not produce a tingling sensation called paresthesia.
01
Leads
Thin insulated electrodes are positioned near neural structures involved in the pain pathway. Their location depends on the painful region and the stimulation strategy.
02
Pulse generator
A small implanted device supplies electrical stimulation. Some systems are rechargeable; others use a battery that eventually requires replacement.
03
Programming
The stimulation settings can be adjusted over time. Programming is part of treatment, not simply a one-time technical step after implantation.
04
Rehabilitation still matters
Pain reduction can create an opportunity for movement and functional restoration, but an implanted device does not replace rehabilitation or broader CRPS care.
WHERE NEUROMODULATION FITS
SCS is generally considered as one part of a wider CRPS strategy.
01
Confirm the diagnosis and reassess the pain pattern
Make sure another treatable condition is not better explaining the current symptoms.
02
Review rehabilitation and non-implant options
Functional restoration, medication and appropriate interventions are usually considered before permanent neuromodulation.
03
Evaluate whether the goals are realistic
The goal may be lower pain, better sleep, improved walking or hand use, reduced medication burden, or greater participation in rehabilitation.
04
Use a trial to gather individual evidence
A temporary trial can show whether stimulation produces enough meaningful benefit to justify considering a permanent implant.
WHAT THE CRPS EVIDENCE SHOWS
Conventional SCS can reduce pain, but benefit is not guaranteed or necessarily permanent.
The classic randomized CRPS-I trial compared SCS plus physical therapy with physical therapy alone. It demonstrated an early analgesic benefit in selected chronic patients, while later follow-up showed that the difference between the randomized groups became smaller over time.
LANDMARK RANDOMIZED TRIAL
What changed between the early results and five years?
In the original trial, 36 patients were assigned to SCS plus physical therapy and 18 to physical therapy alone. Permanent implantation occurred only after a successful test stimulation.
01
EARLY FOLLOW-UP
Pain reduction favored SCS
The randomized trial reported clinically meaningful pain reduction with SCS plus physical therapy compared with physical therapy alone, although functional improvement was more limited.
02
FIVE YEARS
The randomized-group advantage was no longer significant
At five years, the SCS plus physical therapy group and physical-therapy-only group had similar results on the principal measured outcomes, indicating a reduction in the comparative treatment effect over time.
03
PATIENT EXPERIENCE
Satisfaction could remain high despite diminishing effect
Among patients who still had an implant at five years, 95% reported that they would undergo the treatment again for the same result.
HOW TO READ THIS
“It helped” and “the effect stayed equally strong forever” are not the same statement.
Long-term expectations should include the possibility of loss of efficacy, reprogramming, revision, additional treatment or eventual explantation.
CONVENTIONAL SCS VS DRG STIMULATION
Both are neuromodulation, but they do not target the nervous system in the same way.
Dorsal root ganglion stimulation (DRG-S) targets a more focal neural structure near the sensory nerve root. The strongest head-to-head randomized evidence applies to lower-limb CRPS or causalgia and should not automatically be generalized to every body region.
CONVENTIONAL SCS
Spinal cord stimulation
Leads are positioned to stimulate the dorsal column region. It has the longest history of use in CRPS and the longest randomized follow-up.
- Broader stimulation field
- Multiple waveform options depending on the system
- Long-term CRPS evidence shows possible loss of effect
- Trial stimulation usually precedes permanent implantation
DRG-S
Dorsal root ganglion stimulation
Leads target selected dorsal root ganglia, allowing more focal stimulation of specific painful regions—particularly relevant to focal lower-extremity pain.
- More anatomically targeted stimulation
- Less variation in stimulation with body position in the ACCURATE trial
- Superior treatment success to conventional SCS in the ACCURATE lower-limb population
- Evidence base is newer and more location-specific
ACCURATE RANDOMIZED COMPARATIVE TRIAL
DRG stimulation vs conventional SCS in lower-extremity CRPS / causalgia
3 MONTHS
81.2%
DRG treatment success
vs 55.7% with conventional SCS
12 MONTHS
74.2%
DRG treatment success
vs 53.0% with conventional SCS
Important: These percentages come from a specific randomized trial population with lower-extremity CRPS or causalgia and a defined study endpoint. They are not universal success rates for every patient, device, pain location or clinical setting.
THE TRIAL PHASE
One advantage of neuromodulation is that benefit can usually be tested before permanent implantation.
During a stimulation trial, temporary leads are connected to an external device. The clinical team and patient then evaluate whether pain relief and practical improvements are meaningful enough to justify a permanent system.
01
Define success before the trial begins
Decide what will be measured: pain intensity, sleep, walking, hand use, sitting tolerance, ability to participate in therapy or another patient-specific goal.
02
Place temporary leads
Leads are introduced into the epidural space or positioned for DRG stimulation and connected to an external pulse generator for a limited evaluation period.
03
Evaluate more than a single pain score
Many programs use approximately 50% pain relief as an important benchmark, but functional change, medication use, sleep and patient goals can also matter.
04
Decide whether permanent implantation is justified
A positive trial does not guarantee the same result years later. It provides patient-specific information that can improve the quality of the decision.
DO NOT ASK ONLY
“Did my pain fall by 50%?”
The better question is whether the trial produced a change that would matter in your actual life and whether that benefit is worth accepting the risks and maintenance of an implanted device.
Did I sleep better?
Could I move more?
Could I tolerate rehabilitation better?
Did medication use change?
Was the stimulation itself acceptable?
PATIENT SELECTION
The best candidate is not simply the person with the highest pain score.
Neuromodulation assessment usually looks at diagnosis, previous treatment, pain distribution, medical risks, psychological factors, rehabilitation goals and the patient’s ability to manage an implanted system.
01
Clear diagnosis
The team should be confident about the CRPS diagnosis and understand whether another condition is contributing to the pain.
02
Persistent clinically important pain
Implantable neuromodulation is generally considered for chronic pain that remains significant despite a broader treatment program.
03
Realistic goals
Treatment goals should be measurable and broader than the expectation that the device will make CRPS disappear completely.
04
Psychological readiness
Screening can identify depression, anxiety, unrealistic expectations, coping issues or other factors that should be addressed as part of care—not used simply as a label.
05
Ability to manage the system
Patients need to understand charging if applicable, programming, activity restrictions, follow-up visits and when to contact the implanting team.
06
A plan beyond the implant
If the device reduces pain, the next question is how that window of relief will be used to improve function, independence and quality of life.
RISKS & LONG-TERM REALITIES
An implanted system creates both surgical and device-related risks.
Complications can range from relatively manageable hardware problems to infection, bleeding or neurological injury. Some complications require revision surgery or removal of the system.
01
Infection
Infection can occur during the trial or after implantation. Significant device infection may require removal.
02
Lead migration or breakage
Leads can move or fail, changing stimulation coverage or causing loss of benefit. Revision may be required.
03
Generator or hardware problems
Batteries, connectors or the implanted pulse generator can eventually require replacement or revision.
04
Bleeding & neurological injury
Epidural bleeding and neurological injury are uncommon but potentially serious risks because leads are placed close to the spinal canal and neural structures.
05
Uncomfortable stimulation
Some stimulation patterns can produce unwanted paresthesia or changes in stimulation with movement and posture.
06
Loss of efficacy
A device that works initially can become less effective over time, requiring reprogramming, revision, another strategy or explantation.
07
Future procedures & imaging
MRI compatibility and precautions depend on the specific implanted system. Future procedures should be discussed with the device team.
08
Maintenance burden
Neuromodulation requires follow-up, programming, possible charging and management of future hardware or battery needs.
IMPORTANT DISTINCTION
Neuromodulation treats pain signaling. It should not automatically be described as treatment of the underlying CRPS mechanism.
A reduction in pain can be clinically valuable, but it is different from evidence that the disease process itself has been reversed. When comparing treatment options, ask what outcome each treatment is intended to change: pain perception, function, inflammation, bone metabolism, sleep, mood or another target.
QUESTIONS BEFORE A TRIAL OR IMPLANT
Make the consultation specific to your CRPS, not just to the device.
A neuromodulation consultation should explain why this approach is being proposed for your pain pattern and how success will be measured.
01
Why are you recommending conventional SCS, DRG stimulation or another waveform for my specific pain location?
02
Which outcomes will determine whether my trial is successful besides the pain score?
03
What should I realistically expect for function, sleep, medication use and quality of life?
04
What does the evidence show for patients whose CRPS resembles mine in location and duration?
05
What are your center’s rates of infection, lead revision, explantation and loss of efficacy?
06
What happens if the trial succeeds but the permanent system later loses effectiveness?
07
How will rehabilitation change if the device gives me useful pain relief?
08
What restrictions, MRI conditions, charging requirements and long-term maintenance apply to the exact device being proposed?
DECISION-MAKING RED FLAGS
Be cautious when the implant is being presented as a simple or guaranteed answer.
Neuromodulation can be a valuable treatment for selected patients. A careful decision should still include its limitations, alternatives, long-term maintenance and the possibility that benefit may decrease.
01
“This will cure your CRPS.”
The evidence supports pain modulation in selected patients, not a guaranteed cure of the syndrome.
02
No clear success criteria for the trial
You should know before the procedure what outcomes will count as meaningful enough to justify permanent implantation.
03
No discussion of revisions or loss of effect
Device maintenance, lead problems, reprogramming and diminishing benefit belong in the consent conversation.
04
The device is discussed without a rehabilitation plan
Pain relief is most useful when the team knows how it will be translated into better movement, function and daily life.
PATIENT SUPPORT
Comparing neuromodulation with other CRPS options can be difficult.
Carla Crowe, Patient Care Coordinator – California, can help you organize your questions, CRPS Support resources and practical information before you speak with the clinicians who are responsible for recommending or implanting a device.
CARLA CROWE
Patient Care Coordinator – California
COMMON QUESTIONS
Questions patients ask about SCS and CRPS
SCS is a neuromodulation treatment intended primarily to reduce pain. It should not be presented as a guaranteed cure or as proof that the underlying CRPS process has been reversed.
The temporary trial gives the patient and clinical team individual information about pain relief, function, tolerability and whether the expected benefit appears large enough to justify a permanent device.
In the ACCURATE randomized trial of lower-extremity CRPS or causalgia, DRG stimulation produced higher treatment-success rates than conventional SCS at 3 and 12 months. That result is important but applies to the population studied and should not be generalized automatically to every pain location or patient.
Yes. The classic five-year CRPS-I randomized follow-up found diminishing comparative effectiveness over time. Loss of efficacy is one of the long-term possibilities that should be discussed before implantation.
No. A trial is useful patient-specific evidence, but it cannot guarantee the same degree of benefit after permanent implantation or years later.
SOURCES & FURTHER READING
Neuromodulation decisions should include both short- and long-term evidence.
These sources include the major randomized CRPS trials, CRPS treatment guidelines and formal evidence on spinal cord stimulation.
NEW ENGLAND JOURNAL OF MEDICINE · 2000
Spinal cord stimulation in chronic CRPS-I
The landmark randomized trial of SCS plus physical therapy versus physical therapy alone.
JOURNAL OF NEUROSURGERY · 2008
Five-year final follow-up
Long-term follow-up showing diminished comparative treatment effect over time.
PAIN · 2017
The ACCURATE DRG vs SCS trial
Randomized comparative trial in lower-extremity CRPS and causalgia.
PAIN MEDICINE · 2022
CRPS Practical Diagnostic and Treatment Guidelines, 5th Edition
Multidisciplinary CRPS guideline including neuromodulation evidence.
Scientific content reviewed for this page: August 2026.
A DEVICE SHOULD SERVE A TREATMENT GOAL—NOT BECOME THE GOAL ITSELF.