Acupuncture research
Traditional Chinese acupuncture and placebo (sham) acupuncture are differentiated by their effects on mu-opioid receptors (MORs).
06/07/09 20:45
Traditional Chinese acupuncture and placebo (sham) acupuncture are differentiated by their effects on mu-opioid receptors (MORs).
by: Richard E. Harris, Jon-Kar Zubieta, J">David J. Scott, Vitaly Napadow, Richard H. Gracely, J">Daniel J. Clauw
NeuroImage (09 June 2009)
Department of Anesthesiology, University of Michigan, Ann Arbor, MI 48109, USA.
Controversy remains regarding the mechanisms of acupuncture analgesia. A prevailing theory, largely unproven in humans, is that it involves the activation of endogenous opioid antinociceptive systems and mu-opioid receptors (MORs). This is also a neurotransmitter system that mediates the effects of placebo-induced analgesia. This overlap in potential mechanisms may explain the lack of differentiation between traditional acupuncture and either non-traditional or sham acupuncture in multiple controlled clinical trials. We compared both short- and long-term effects of traditional Chinese acupuncture (TA) versus sham acupuncture (SA) treatment on in vivo MOR binding availability in chronic pain patients diagnosed with fibromyalgia (FM). Patients were randomized to receive either TA or SA treatment over the course of 4 weeks. Positron emission tomography (PET) with (11)C-carfentanil was performed once during the first treatment session and then repeated a month later following the eighth treatment. Acupuncture therapy evoked short-term increases in MOR binding potential, in multiple pain and sensory processing regions including the cingulate (dorsal and subgenual), insula, caudate, thalamus, and amygdala. Acupuncture therapy also evoked long-term increases in MOR binding potential in some of the same structures including the cingulate (dorsal and perigenual), caudate, and amygdala. These short- and long-term effects were absent in the sham group where small reductions were observed, an effect more consistent with previous placebo PET studies. Long-term increases in MOR BP following TA were also associated with greater reductions in clinical pain. These findings suggest that divergent MOR processes may mediate clinically relevant analgesic effects for acupuncture and sham acupuncture.
Published 30 June 2009 in Neuroimage.
by: Richard E. Harris, Jon-Kar Zubieta, J">David J. Scott, Vitaly Napadow, Richard H. Gracely, J">Daniel J. Clauw
NeuroImage (09 June 2009)
Department of Anesthesiology, University of Michigan, Ann Arbor, MI 48109, USA.
Controversy remains regarding the mechanisms of acupuncture analgesia. A prevailing theory, largely unproven in humans, is that it involves the activation of endogenous opioid antinociceptive systems and mu-opioid receptors (MORs). This is also a neurotransmitter system that mediates the effects of placebo-induced analgesia. This overlap in potential mechanisms may explain the lack of differentiation between traditional acupuncture and either non-traditional or sham acupuncture in multiple controlled clinical trials. We compared both short- and long-term effects of traditional Chinese acupuncture (TA) versus sham acupuncture (SA) treatment on in vivo MOR binding availability in chronic pain patients diagnosed with fibromyalgia (FM). Patients were randomized to receive either TA or SA treatment over the course of 4 weeks. Positron emission tomography (PET) with (11)C-carfentanil was performed once during the first treatment session and then repeated a month later following the eighth treatment. Acupuncture therapy evoked short-term increases in MOR binding potential, in multiple pain and sensory processing regions including the cingulate (dorsal and subgenual), insula, caudate, thalamus, and amygdala. Acupuncture therapy also evoked long-term increases in MOR binding potential in some of the same structures including the cingulate (dorsal and perigenual), caudate, and amygdala. These short- and long-term effects were absent in the sham group where small reductions were observed, an effect more consistent with previous placebo PET studies. Long-term increases in MOR BP following TA were also associated with greater reductions in clinical pain. These findings suggest that divergent MOR processes may mediate clinically relevant analgesic effects for acupuncture and sham acupuncture.
Published 30 June 2009 in Neuroimage.
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Minimal acupuncture is not a valid placebo control in randomised controlled trials of acupuncture: a physiologist's perspective
25/05/09 14:39
Abstract
Placebo-control of acupuncture is used to evaluate and distinguish between the specific effects and
the non-specific ones. During 'true' acupuncture treatment in general, the needles are inserted into
acupoints and stimulated until deqi is evoked. In contrast, during placebo acupuncture, the needles
are inserted into non-acupoints and/or superficially (so-called minimal acupuncture). A sham
acupuncture needle with a blunt tip may be used in placebo acupuncture. Both minimal acupuncture
and the placebo acupuncture with the sham acupuncture needle touching the skin would evoke
activity in cutaneous afferent nerves. This afferent nerve activity has pronounced effects on the
functional connectivity in the brain resulting in a 'limbic touch response'. Clinical studies showed
that both acupuncture and minimal acupuncture procedures induced significant alleviation of
migraine and that both procedures were equally effective. In other conditions such as low back pain
and knee osteoarthritis, acupuncture was found to be more potent than minimal acupuncture and
conventional non-acupuncture treatment. It is probable that the responses to 'true' acupuncture
and minimal acupuncture are dependent on the aetiology of the pain. Furthermore, patients and
healthy individuals may have different responses. In this paper, we argue that minimal acupuncture
is not valid as an inert placebo-control despite its conceptual brilliance.
Full article is available from: http://www.cmjournal.org/content/4/1/1
Placebo-control of acupuncture is used to evaluate and distinguish between the specific effects and
the non-specific ones. During 'true' acupuncture treatment in general, the needles are inserted into
acupoints and stimulated until deqi is evoked. In contrast, during placebo acupuncture, the needles
are inserted into non-acupoints and/or superficially (so-called minimal acupuncture). A sham
acupuncture needle with a blunt tip may be used in placebo acupuncture. Both minimal acupuncture
and the placebo acupuncture with the sham acupuncture needle touching the skin would evoke
activity in cutaneous afferent nerves. This afferent nerve activity has pronounced effects on the
functional connectivity in the brain resulting in a 'limbic touch response'. Clinical studies showed
that both acupuncture and minimal acupuncture procedures induced significant alleviation of
migraine and that both procedures were equally effective. In other conditions such as low back pain
and knee osteoarthritis, acupuncture was found to be more potent than minimal acupuncture and
conventional non-acupuncture treatment. It is probable that the responses to 'true' acupuncture
and minimal acupuncture are dependent on the aetiology of the pain. Furthermore, patients and
healthy individuals may have different responses. In this paper, we argue that minimal acupuncture
is not valid as an inert placebo-control despite its conceptual brilliance.
Full article is available from: http://www.cmjournal.org/content/4/1/1