Spinal cord stimulation gives significant improvement in pain relief for
chronic pain sufferers
6 Oct 2006
An international multicentre study presented at the annual meeting of the
European Federation of the International Association for the Study of Pain
(IASP) Chapters (EFIC) shows that neurostimulation in combination with
conventional medical management is significantly more effective than
conventional medical management alone for patients suffering from persistent
leg and back pain despite anatomically successful spine surgery.
Initial results of the trial, known as the PROCESS study (for
prospective, randomized, controlled, multicentre study to evaluate the
effectiveness and cost-effectiveness of spinal cord stimulation), were
presented by principal investigator Dr Kumar. The new data — the first to be
released from the PROCESS study — indicate that for a group of patients with
chronic back and leg pain, spinal chord stimulation (SCS) plus conventional
medical management (CMM) provides a significantly greater improvement in
pain relief, quality of life, functional capacity, and treatment
satisfaction than CMM alone after six months of treatment.
"Patients with severe and persistent pain after anatomically successful
spine surgery represent one of the most difficult treatment problems in
clinical practice, the real-world setting of our trial," said Dr Krishna
Kumar chairman of the neurosurgery department at the University of
Saskatchewan's Regina General Hospital in Canada. "Our findings show that
spinal cord stimulation offers patients in this situation a treatment option
that can relieve their pain to a significantly greater degree than
conventional medical management alone — and, as a result, restore their
quality of life and functional capacity as well."
Professor Per Hansson, world renowned pain physician and researcher from
the Karolinska Institute in Stockholm Sweden said, "Today, many physicians
are unaware of the possible benefits of Neurostimulation in patients for
whom pharmacological management has not adequately controlled their pain.
The results of this study challenge the present status quo of endless
poly-pharmacy with minor if any pain relief and considerable cognitive and
other side effects when promising alternatives exist".
EFIC President Professor Serdar Erdine, chairman of the pain department
at Istanbul Medical University, commented, "EFIC has a long standing
commitment to supporting and presenting clinical research at our congresses.
We are happy that these results were presented at the European Forum of the
More than 500,000 patients undergo spine surgery for chronic pain each
year in Europe alone, and in the majority of cases the surgery successfully
relieves the pain. According to published reports, however, some patients
continue to experience disabling pain after recovering from surgery. These
patients are sometimes diagnosed with failed back surgery syndrome (FBSS).
In the PROCESS study, 48 percent of the SCS patients experienced a 50
percent or greater improvement in leg pain as assessed by a visual analog
scale (VAS) — the study's primary endpoint — compared with 9 percent of the
CMM-only patients (p=0.0001).
The PROCESS study, the largest of its kind undertaken to date, enrolled
100 patients from 12 academic medical centres in Australia, Belgium, Canada,
Israel, Italy, Spain, Switzerland, and the United Kingdom who were randomly
assigned to receive CMM with or without SCS for a period of 24 months. Its
primary endpoint was a reduction in leg pain of 50 percent or greater on a
100-point VAS. Secondary endpoints included health-related quality of life
as assessed by two standard questionnaires; functional capacity as assessed
by a standard disability index; and patient satisfaction. All endpoints were
evaluated at six months.
To qualify for study enrollment, which ended in June 2005, patients were
required to have chronic neuropathic pain — predominantly in one or both
legs, with a leg pain VAS score of 50 or greater — following at least one
spine surgery. At baseline (the beginning of the study), patients had an
average leg pain VAS score of 75, and an average of 4.7 years had elapsed
since their last spine surgery. Fourteen (29%) of the 48 patients who
received a stimulator had a complication that required additional surgery.
Funded by Medtronic, Inc. (NYSE: MDT) (Medtronic Europe Sarl), the study
was designed and supervised by an independent steering committee. All SCS
patients in the study received Medtronic Synergy (r) neurostimulation