printer-friendly version (PDF) - Reflex Sympathetic Dystrophy ...

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 (1).
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 inhibits or modulates
the sympathetic outflow to the region where the tingling produced
by the stimulation is experienced (2).
SCS and CRPS
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 (3). Barolat (4) reported a 73 percent success
rate of pain in 18 patients with CRPS-1. Kumar (5) discussed
12 patients treated with SCS for CRPS. Robaina (6) 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 (7)
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 (8) in
1998, examined 31 patients with CRPS affecting the upper
extremity with a significant reduction in pain scores compared
to baseline. Oakley and Weiner (9) 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 (10), 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 (11) published
a two-year follow up 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 (12) 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 stimulation.
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 (13) in their
discussion of SCS, indicate that when SCS leads are placed
closer together the result is deeper penetration of the spinal
Rechargeability offers the opportunity to manage the
patient instead of managing the battery.
T H E PA I N P R A C T I T I O N E R | V O L U M E 16 , N U M B E R 1 | 69