Læknablaðið : fylgirit - 01.05.1978, Page 132

Vinterberg H. , Donde R. , Andersen R.B. ,
Kommunehospitalet, Copenhagen, Denmark.
By means of a newly developed apparatus that
gives an electric impulse, wbich cannot be felt,
we have given TNS to patients with R.A. , and
by using a double blind cross-over design, we
have found significant pain relief.
Transcutaneous electro-stimulation has already
been used for many years on an empirical basis
as an alternative to pharmacological and surgical
therapy. But not until 1965, when Melzac and
Wall proposed their "spinal gate control theory",
did we get a developed theoretical, though still
partly hypothetical, explanation of the clinically
observed pain relief.
Briefly, gate control theory holds that the pain
impulse that goes to the spinal medulla via thin
C- and A-delta-fibers, is impeded at the synapses
in the dorsal column when the thick, non - pain
conducting, myelinized A-fibers are stimulated
simultaneously. In this way the pain impulse is
hindered from reaching the higher levels of the
central nervous system. Increased activity in
the thick fibers thus tends to "close the gate"
for pain impulses. It should therefore be poss-
ible to reduce pain by means of selective
stimulation of the thick myelinized fibers, which
have a threshold for electro-stimulation that is
significantly lower than that of the thin fibers.
In the past ten years several clinical studies
have been conducted based on Gate control
theory. Two studies from 1974 should be men-
tioned. Shealy and Maurer published a study on
750 patients with acute- or chronic pain.
In patients with acute pain 807o achieved excellent
control of pain. In those with chronic pain, 297o
found TNS so satisfactory that it sufficed as the
only treatment, and another 6Ö7o obtained partial
pain relief.
TRANSCU TANEOUS NERVE STIM-
ULATION (TNS) ON PATIENTS
WITH RHEUMATOED ARTHRITIS
(R.A.) A DOUBLE BLIND
CROSS-OVER TRIAL
In Augustinssons study of 73 consecutive patients
ít was found that 337o achieved complete pain relief
and 19% partial relief. These and all other studies
known to us have in their methology been open
studies.
The applied electro-stimulation could be felt by
the patients.
Recently came on the market a Danish developed
stimulator "Perator", which gives a modulated,
high-frequency electric impulse which cannot be
felt. A controlled investigation of double blind
cross-over design is then possible.
The purpose of our study has been to find
out if this apparatus can provide pain relief.
This is a preliminary study carried out on a
group of patients with a well defined joint disease
accompanied by chronic pain. We have not found
any comparative studies in the literature.
The subjects consisted of 14 consecutive
patients with R.A. , 11 women and 3 men between
the ages of 45 and 74, the average age being 60.
Only patients with both wrist-joints involved were
included. All patients were classified according
to the criteria of the American Rheumatism
Association and assessed clinically using Lansbury’s
index. Fig. 1 shows the classifications and length
of sickness in months. As seropositive were
considered patients with Waaler-Rose-titers of
40 or more and/or RA Latex-fixation-titers of
32 or over.
Method. The study was blind for both
patients and investigators. It was carried out on
a double blind cross-over design in the following
manner: On the first day, after randomizing, one
half of the patients received active treatment
while the other half received placebo treatment
with the same set-up, but without any generator
SYGDOMSVARIGHED LANSBURY'
GENNEMSNIT I MDR.INDEX
8 CLASSICAL 127 mdr. 79
12 SEROPOS.
ANTAL .14 4 DEFINITE (6-24o) (8-97)
2 SERONEG. 1 CLASSICAL 1 DEFINITE l8o mdr. (l8o) 73 (57-88)
130