Title: The Effect of Cranial Electrotherapy Stimulation (CES) on Pain
Associated with Fibromyalgia
Authors:
Randall C. Cork, M.D., Ph.D.,
Department of
Anesthesiology, LSU Health Sciences Center, Shreveport, LA
Patrick Wood, M.D., Department of
Anesthesiology, LSU Health Sciences Center , Shreveport, LA
Norbert Ming M.D., Department of
Anesthesiology, LSU Health Sciences Center, Shreveport, LA
Clifton Shepherd M.D., Department of
Anesthesiology, LSU Health Sciences Center, Shreveport, LA
James Eddy M.D., Department of
Anesthesiology, LSU Health Sciences Center, Shreveport, LA
Larry Price Ph.D., Texas State
University, San Marcos, TX |
|
Oswestry Score:
The Oswestry
Disability Questionnaire
9
assesses functional impairment by scoring how much the activities of
daily living are affected by disability. In this case, the disability
is pain. Patients are asked to rate from 0 to 5 the magnitude of their
pain and the impact of their pain on the following activities: Tying
shoes and putting on socks, lifting, walking, sitting, standing,
sleeping, sexual function, social life, and traveling. Points are
summed to form the Oswestry Score.
Following the baseline
tests, the subjects were taught how to use the CES unit, and they were
instructed to use it every day for 1 hour over a 3-week period. At the
end of 3 weeks, the subjects returned to the Pain Clinic, and all the
above tests were repeated. At that time, the key to the blinding was
broken, and the patients in the Sham Group were given the option to
receive CES for an additional three weeks. Those who elected to do so
returned to clinic after the three-week period and were re-tested.
Data were analyzed
with repeated-measures analysis of variance, with
least-significant-difference a posteriori testing. Significance was
defined as p<0.05. The primary variable to be assessed was pain
intensity (0-5). Assuming a standard deviation of 0.2, a difference of
0.1 in this measurement is detectable with a sample size of 35 in each
group, resulting in a calculated power of 82.0%.
Results
A
total of 74 patients were studied, 39 in the CES Group and 35 in the
Sham Group. Following the unblinding at 3 weeks, 23 patients in the Sham Group elected to cross over to active treatment for
three weeks. Of the 74 patients, 70 were female. Average age was 53
(min 22 yrs, max 75 yrs); average duration of symptoms was 7.3 years
(min 1 yr, max 21 yrs).
All measurements are graphically depicted in the accompanying Figures
3-5, 7-8. There were no differences detected at baseline between the
CES Group and the Sham Group for any of the measurements. The Pain
Intensity Score, the Tenderpoint Score, and the POMS Score were all
significantly less in the CES Group compared to the Sham Group at 3
weeks (p<0.01). For those patients in the Sham Group who elected to
receive treatment with CES over the subsequent 3-week period, all
measurements except the Oswestry Score were significantly improved
over baseline (p<0.001).
Figure 3: Pain intensity as a numerical scale
reported by patients based on a scale of 0-5, where 0 represents no
pain, and 5 represents the maximum
pain imaginable. The pain intensity reported by the CES Group was
significantly less at three weeks, compared to the Sham Group
(p<0.01). However, after crossover, the Sham Group showed a
significant decrease in pain intensity after receiving cranial
electrotherapy stimulation (CES) for the subsequent three weeks
(p<0.001). All values are means ± standard error of the mean (sem). |
