Hypnose et douleur – Hypnosis and pain

Please welcome Pierre
Rainville, our first guest speaker. Hypnosis. Hypnosis and pain.
Hypnosis fascinates, hypnosis worries, maybe hypnosis scares you.
Maybe you’re skeptical about the potential of using hypnosis
in the medical field. Hypnosis certainly arouses healthy skepticism
but also a fascination that it

deserves our attention. In medicine,
some researchers, some doctors claim to be able to operate without
general anaesthesia. Maybe have you ever attended
hypnosis shows where the participants are lined up on the stage
and seem to act, seem to lose their free will, and act under the control of
the hypnotist, who thus takes possession of their spirit and their action, as
if they lost their ability to control of their own actions.
What part of this is myth and what part is the reality in the phenomena observed
under hypnosis? Medical hypnosis finds its roots in the practice of Dr Franz
Anton Mesmer, a Viennese doctor who will develop a whole ritual, a whole
procedure for magnetizing his patients and produce clinical effects that, for
example, lead to convulsions, loss of consciousness, but which
otherwise seems to bring some benefits for relieving
pain, improving mood, or treatment of melancholy. Doctor
Mesmer will propose a theory of animal magnetism, a universal fluid
that he channels through these magnetization procedures, to
produce beneficial effects at the clinical level.
These procedures, this therapeutic ritual that Mesmer developed expands,
is exported to other European countries, and arrives in Paris where the King Louis XVI
worries about the growing popularity of a
practice which appears questionable to him. The King will appoint a Royal commission of inquiry,
which will be made up of imminent scientists of the time:
Antoine Lavoisier, Benjamin Franklin, who was Minister of Representatives of
United States in Europe at the time. And these commissioners will submit the procedure to an
examination, a rigorous and systematic examination, and so will submit
some patients to Mesmer’s magnetizing procedure, with help
from a collaborator of Mesmer’s, Mr. Decelon, who practices hypnosis,
who practice Mesmerism, or animal magnetism, in Paris. So some
patients are going to be submitted to this magnetization procedure and the
Commissioners will see that indeed certain effects are
observable: seizures, loss of conscience, and some patients that
actually report a relief from their symptoms at the mood level, at
pain level. Some effects are not confirmed
but several effects like these are actually confirmed. The Commissioners will
then submit other participants to same procedure without telling
them they were subject to the magnetization procedure. Here, the
participants show no effect. The Commissioners will
conclude that the procedure for magnetization is likely
ineffective here, to produce the clinical effects they had observed
in the first group. But the Commissioners will not stop to the
simple examination of the presence or absence of a magnetization procedure. They
will add a third group to whom they will say that they will do this
magnetization without actually proceeding to the magnetization. This
third group will show similar effects to the first group, and so the
simple belief of being exposed to magnetism seems sufficient for
produce clinical effects. In their report, the Commissioners
will report clinical effects, tangible clinical effects, on the condition
of consciousness, seizures, relief of certain symptoms.
However, they conclude that the animal magnetism theory
is a pseudo theory, is not a scientific theory, and so
this pseudoscience is invalidated by the demonstration that the
magnetization procedure has no effect on the patients. They will conclude that it is the
patient’s belief that he is experiencing the magnetization procedure that is the
mechanism by which the effects are produced, and in their conclusions,
they will even suggest that it’s the patients’ imagination which is at play. Today,
studying the imaginary is possible using the methods of
modern neuroscience. Neuroimaging allows us to examine the activity of the
brain in different contexts, where the participants are invited to imagine
different things. And in the field of pain, we will apply a
painful stimulation, for example dipping the hand into a hot water tray,
we will be able to measure motor reflexes, we will be able to measure the
body’s response to this stimulation, for example the increase of the cardiac
rhythm, but we will also be able to measure the brain activity in
response to this stimulation. And these studies have shown that there is an activation
pattern, which is very reproducible, which is associated with the experience of
pain and that includes not only sensory regions of the brain but
also includes regions that are involved in the regulation of
emotions. When we examine this activation pattern in subjects in good
health, who are once again submitted to the pain procedure,
the hand immersion in a hot water tray, and that we suggested to these
participants that they can imagine that pain is like the sound of a radio, and
we can simply lower the volume of the radio to decrease the sound intensity.
These participants, in the brain on the right, show a decrease in
the activity evoked by the painful stimulus. In a second condition, we
suggested to the participants that they will perceive the pain normally, but
that this pain will be accompanied a feeling of well-being that spreads
from their hand to their arm, and to their whole experience. In this second
condition, once again, the brain on the right shows an activation
decrease, but not in the sensory regions,
rather in the frontal regions of the brain, which are associated with the
regulation of emotions and of cognition. So these two neuroimaging
studies show us that hypno- analgesia can produce a decrease
in brain response to painful stimulation, but in addition that the choice of
words, what is suggested to imagine, will have an impact on the regions that will be
more or less affected by the hypnotic procedure. In the field of
clinical research, this time, there had been for the past twenty years a large
number of studies showing that hypno-analgesia can be used in
surgical context to decrease pain. So you see here the bottom curve,
which represents the group that is submitted to the hypnotic procedure during
a surgery, so there is general anesthesia and hypnosis, as you can see,
permit to diminish, or at least to control participants’ pain,
compared to two other control groups, in which hypnosis
was not used. Not only is the pain less
intense, but in addition the duration of the procedure seems shortened by
the hypnotic intervention. So there are definitely some facts that
corroborate the potential benefits of hypnosis to control pain, but
there are still some myths, some obstacles, to the use of hypnosis
in a clinical setting. One of these myths is very well-represented by
the hypnosis done in performances, this loss Of control that make us a little
reluctant to participate in hypnotic procedures.
For the past twenty years, there is much interest in neuroscience
to understand the consciousness, to understand free will, to
understand how our brain produces actions that we think are
willful, how we feel our actions as willful. In the
context of hypnosis, we recently examined the brain activity in response
to hypnotic suggestions and we have asked participants to evaluate their
feelings of automaticity, so the feeling that their answer was produced
automatically without their willful control. The brain activity was modulated in certain areas, that we know from
previous studies are involved in our willful actions. The activity in these same
regions were altered, and this alteration predicted
what each participant would answer after each scan, in terms of
an increase of their feelings of automaticity. Therefore, the standardized
hypnotic procedure, here, produced a change in the
participant’s brain areas that we know are involved in the willful action,
in the perception that we act willfully.
So it seems that hypnosis seems to alter this perception that we
have of our willful control, and so gives this impression of
control by an external agent. For two centuries we can say that we have progressed in our understanding of
phenomenon of hypnosis. Certainly, the commissioners of this Royal Commission
investigated by king Louis XVI would have probably liked the
todays’ neuroimaging methods to study the patients’ imagination
and see how it worked in response to
hypnotic suggestions. Medial hypnosis, today, can certainly
produce clinical benefits that depend on these psychological and neurophysiological
principles, that reflects the activation of the endogenous mechanisms of
pain control in our brain, and which can, when they are
used by competent clinicians, people or healthcare professionals
who have been trained in hypnosis, can certainly contribute to better
pain treatment. Thank you.

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