Reflex Sympathetic Dystrophy Syndrome
Complex Regional Pain Syndrome

RSD(S)-CRPS Advisory
SCS Systems Offer Advantages in CRPS Treatment
Spinal Cord Stimulator Systems Offer Advantages in CRPS Treatment
By Joshua P. Prager, MD, MS

In April, 2004, the Food and Drug Administration (FDA) approved the first rechargeable
spinal cord stimulator (SCS) system. This system, called Precision™, produced by
Advanced Bionics, is the first in a new generation of SCS systems that offers a
significant improvement in stimulation to people with CRPS. In early 2005, Advanced
Neuromodulation Systems rechargeable system, the Eon™, was approved and shortly
thereafter Medtronic, the largest producer of neurostimulator systems, received FDA
approval for its Restore™ System. This article will briefly review the use of SCS for
treatment of CRPS and then describe the potential of the new systems in improving care
and outcomes.

SCS as Part of the CRPS Treatment Algorithm
In 1995, the International Association for the Study of Pain (IASP) brought together a
group of international experts to address treatment of CRPS. This was one of four
meetings the IASP has held in the last two decades regarding various aspects of CRPS.
Stanton-Hicks published results of the 1995 meeting as a treatment algorithm, which
indicates that the mainstay of CRPS/RSD treatment is physical therapy, and that nerve
blocks or SCS as adjuvant treatment are important for patients who are not adequately
progressing with physical therapy alone. The important point of this article is that SCS
can significantly enhance CRPS treatment by facilitating physical therapy as part of the
entire rehabilitation process.

Stanton-Hicks suggested that the beneficial effect of SCS relates not only to pain relief,
but it also to inhibits or modulates the sympathetic outflow to the region where the
tingling produced by the stimulation is experienced.

There have been numerous studies of SCS for the treatment of CRPS. These studies have
been both retrospective and prospective randomized. In 1982, Broseta reported the use of
SCS for CRPS-2 patients with 72 percent having experienced excellent results. Barolat
reported a 73 percent success rate of pain in 18 patients with CRPS-1. Kumar discussed
12 patients treated with SCS for CRPS. Robaina compared SCS with TENS in 35 patients
with late-stage CRPS-1; 66 percent of patients reported good results with SCS,
experiencing rapid relief of pain and reduction in swelling. Bennett examined not only the
effect of SCS on CRPS, but also looked at the effect of different lead arrays. He found
that patient satisfaction was markedly improved with dual octapolar leads as opposed to
traditional quadripolar leads.

There have been four prospective studies published of spinal cord stimulation in CRPS.
The first, Calvillo in 1998, examined 31 patients with CRPS affecting the upper extremity
with a significant reduction in pain scores compared to baseline. Oakley and Weiner
observed statistically significant reduction in pain and an 80 percent success rate with
SCS for CRPS. The largest prospective study in CRPS was that of Kemler , in the New
England Journal of Medicine in 2000; 54 patients with CRPS-1 of one extremity were
randomized to SCS plus physical therapy or physical therapy alone. A significantly greater
number of patients with SCS plus physical therapy had a much improved global perceived
effect than the physical therapy group alone. Most recently, Kemler published a two-year
followup of the randomized trial. The mean pain score in the 24 implanted SCS patients
was significantly reduced compared to those receiving physical therapy alone; 63 of the
SCS patients reported improvement in their global perceived effect.

Thus, there is significant literature demonstrating the success with SCS in treating CRPS.
This brief discussion above was not meant to thoroughly review or evaluate this
literature, but merely to call attention to its presence and provide a reference list where
one can review this information in greater detail.

Rechargeability and its Implication toward the Treatment of CRPS with SCS
The advent of rechargeability, being able to recharge the SCS battery, creates new
opportunities. Previously, when a battery failed, the entire pulse generator needed to be
replaced, which required expensive surgery and was uncomfortable for the patient.
Rechargeability may significantly reduce the need to replace internal pulse generators.

Many CRPS patients with SCS systems have needed to use a lot of power to achieve the
pain relief necessary to function. In order to reduce the need to replace the internal pulse
generator, patients have often rationed the amount of stimulation by either reducing the
power or turning the unit off some of the time. Thus, both patient and physician have
attempted to manage the battery while compromising treatment. Rechargeability offers
the opportunity to manage the patient instead of managing the battery.

Bennett notes that large arrays produce greater satisfaction than traditional quadripolar
leads. Rechargeability offers the opportunity to use many contacts simultaneously, which
uses a significantly greater amount of energy. Previously, this increased power
consumption would have been prohibitive in some patients. Rechargeability allows the use
of a greater number of electrodes at a given time to provide better coverage with

There are some reports that increased frequency improves stimulation in patients with
CRPS. Although this not been well documented, it is important to note that higher
frequency produces higher energy consumption. Higher frequency potentially
compromises battery life. Thus, rechargeability provides an opportunity to fully utilize the
potential of any system without needing to worry about battery failure.

Conventional SCS four-and eight-contact leads were placed relatively far apart. Oakley
and Prager in their discussion of SCS, indicate that when SCS leads are placed closer
together the result is deeper penetration of the spinal cord, which provides a stronger
effect. New lead configurations have been and will be designed specifically for
rechargeable systems because the more-effective configurations will use more energy.
Thus, once again, rechargeability provides a platform to allow for a more effective form
of stimulation that conventional primary cell internal pulse generator source would not

Cost-Effectiveness of SCS
Taylor recently reviewed the cost effectiveness of SCS for treating chronic pain.
They conclude that in the medium to long term, SCS is economically favorable compared
to other therapies for people with CRPS. Taylor indicates that pay back ranged from 15
months to five years after the SCS was implanted. The pay back period was sensitive to
the efficiency level of the battery/electrode life and the amount of patient usage. However,
this review was performed before rechargeable batteries. Considering the advantages of
rechargeability, it is possible that pay back will be shortened and that the costs of SCS
plus physical therapy will be lower than the cost of physical therapy alone. SCS initial
costs are offset by a reduction in healthcare expenditures after the implant.

The Future with Rechargeability
The release of rechargeable systems has prompted the development of many new lead
configurations that will enhance the effectiveness of SCS for the CRPS patient. New
leads and extensions are currently in development. In particular, one product that will be
available in the near future will allow four limbs to be treated simultaneously from a single-
pulse generator. For patients with advanced four-limb CRPS, this eliminates the need for
multiple systems; four limbs can be treated with a rechargeable single-pulse generator
that, despite high energy consumption, will not require frequent replacement.

Spinal cord stimulation has a demonstrated efficacy in treating patients with CRPS when
it is used in conjunction with a comprehensive rehabilitation program. Rechargeability
enhances the ability to perform stimulation without requiring as frequent internal pulse
generator battery replacements. SCS is cost effective in CRPS and future developments
will enhance its effectiveness.

Reference List
1. Stanton Hicks, M. An updated interdisciplinary clinical pathway for CRPS: Report
of an expert panel. Pain Practice 2002; 2(1):1-16.
2. Stanton-Hicks M., Spinal cord stimulation for the management of complex regional
pain syndromes. Neuromodulation 1999; 2(3):193-201.
3. Broseta J, Chronic epidural dorsal column stimulation in the treatment of
causalgia pain. Appl Neurophys 1982;45: 190-194.
4. Barolat G. Schwartzman R.,, Epidural spinal cord stimulation management of
reflex sympathetic dystrophy. Stereotact Funct Neurosurg 1999; 53:29-39.
5. Kumar K.,, Spinal cord stimulation is effective in the management of reflex
sympathetic dystrophy. Neurosurgery 1997; 40:503-508.
6. Robaina F. J.,, Transcutaneous electrical nerve stimulation and spinal cord
stimulation for pain relief in reflex sympathetic dystrophy. Stereotact Funct Neurosurg
1989; 52(1): 53-62.
7. Bennett D. S.,, Spinal cord stimulation for complex regional pain syndrome
(RSD): A retrospective multicenter experience from 1995-1998 of 100 patients.
Neuromodulation 1999;2:202-210.
8. Calvillo O,, Neuroaugmentation in treatment of complex regional pain syndrome
of the upper extremity. Acta Orthop Belg 1998; 64: 57-62.
9. Oakley, J. and Weiner, R. L., Spinal cord stimulation for complex regional pain
syndrome: A prospective study of 19 patients at two centers. Neuromodulation 1999; 2:
10. Kemler, M.A.,, Spinal cord stimulation in patients with chronic reflex dystrophy.
N Engl J Med 2000; 43:618-24.
11. Kemler, M.A., The effect of spinal cord stimulation in patients with chronic reflex
sympathetic dystrophy: Two years followup of the randomized control trial. Ann Neurol
2004; 55:13-18.
12. Bennett, D.S., ibid.
13. Oakley, J., Prager, J., Mechanism of spinal cord stimulation. Spine. 27 (22):2574-
14. Taylor, R. S., The cost effectiveness of spinal cord stimulation: A systematic review
of the literature. J Pain Symptom Manage 2004; 27 (4): 370-8.

By Joshua P. Prager, M.D., M.S.
Director, Center for the Rehabilitation of Pain Syndromes (CRPS)
Departments of Internal Medicine and Anesthesiology
David Geffen School of Medicine at UCLA

Updated 2/27/2006