Acupuncture mechanisms for clinically relevant long-term effects--reconsideration and a hypothesis
TL;DR: It is drawn that clinically relevant long-term pain relieving effects of acupuncture (>6 months) can be seen in a proportion of patients with nociceptive pain and the mechanisms behind such effects are considered in this paper.
Abstract: From the author's direct involvement in clinical research, the conclusion has been drawn that clinically relevant long-term pain relieving effects of acupuncture (>6 months) can be seen in a proportion of patients with nociceptive pain. The mechanisms behind such effects are considered in this paper. From the existing experimental data some important conclusions can be drawn: 1. Much of the animal research only represents short-term hypoalgesia probably induced by the mechanisms behind stress-induced analgesia (SIA) and the activation of diffuse noxious inhibitory control (DNIC). 2. Almost all experimental acupuncture research has been performed with electro-acupuncture (EA) even though therapeutic acupuncture is mostly gentle manual acupuncture (MA). 3. Most of the experimental human acupuncture pain threshold (PT) research shows only fast and very short-term hypoalgesia, and, importantly, PT elevation in humans does not predict the clinical outcome. 4. The effects of acupuncture may be divided into two main components--acupuncture analgesia and therapeutic acupuncture. A hypothesis on the mechanisms of therapeutic acupuncture will include: 1. Peripheral events that might improve tissue healing and give rise to local pain relief through axon reflexes, the release of neuropeptides with trophic effects, dichotomising nerve fibres and local endorphins. 2. Spinal mechanisms, for example, gate-control, long-term depression, propriospinal inhibition and the balance between long-term depression and long-term potentiation. 3. Supraspinal mechanisms through the descending pain inhibitory system, DNIC, the sympathetic nervous system and the HPA-axis. Is oxytocin also involved in the long-term effects? 4. Cortical, psychological, "placebo" mechanisms from counselling, reassurance and anxiety reduction.
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TL;DR: Experimental PsychologyIts Scope and Method is illustrated by Jean-François Le Ny, G. Oléron and César Florés.
Abstract: Experimental Psychology Its Scope and Method. IV. Learning and Memory. By Jean-Francois Le Ny, G. De Montpellier, G. Oleron and Cesar Flores. Translated by Louise Elkington. Edited by P. Fraisse and Jean Piaget. Pp. viii + 376. (Routledge and Kegan Paul: London, April 1970.) 80s.
991 citations
TL;DR: There is consistent evidence that acupuncture provides additional benefit to treatment of acute migraine attacks only or to routine care, and available studies suggest that acupuncture is at least as effective as, or possibly more effective than, prophylactic drug treatment, and has fewer adverse effects.
Abstract: BACKGROUND: Acupuncture is often used for migraine prophylaxis but its effectiveness is still controversial. This review (along with a companion review on'Acupuncture for tension-type headache') represents an updated version of a Cochrane review originally published in Issue 1, 2001, of The Cochrane Library. OBJECTIVES: To investigate whether acupuncture is a) more effective than no prophylactic treatment/routine care only; b) more effective than'sham' (placebo) acupuncture; and c) as effective as other interventions in reducing headache frequency in patients with migraine. SEARCH STRATEGY: The Cochrane Pain, Palliative& Supportive Care Trials Register, CENTRAL, MEDLINE, EMBASE and the Cochrane Complementary Medicine Field Trials Register were searched to January 2008. SELECTION CRITERIA: We included randomized trials with a post-randomization observation period of at least 8 weeks that compared the clinical effects of an acupuncture intervention with a control (no prophylactic treatment or routine care only), a sham acupuncture intervention or another intervention in patients with migraine. DATA COLLECTION AND ANALYSIS: Two reviewers checked eligibility; extracted information on patients, interventions, methods and results; and assessed risk of bias and quality of the acupuncture intervention. Outcomes extracted included response (outcome of primary interest), migraine attacks, migraine days, headache days and analgesic use. Pooled effect size estimates were calculated using a random-effects model. MAIN RESULTS: Twenty-two trials with 4419 participants (mean 201, median 42, range 27 to 1715) met the inclusion criteria. Sixtrials (including two large trials with 401 and 1715 patients) compared acupuncture to no prophylactic treatment or routine care only. After 3 to 4 months patients receiving acupuncture had higher response rates and fewer headaches. The only study with long-term follow up saw no evidence that effects dissipated up to 9 months after cessation of treatment. Fourteen trials compared a'true' acupuncture intervention with a variety of sham interventions. Pooled analyses did not show a statistically significant superiority for true acupuncture for any outcome in any of the time windows, but the results of single trials varied considerably. Four trials compared acupuncture to proven prophylactic drug treatment. Overall in these trials acupuncture was associated with slightly better outcomes and fewer adverse effects than prophylactic drug treatment. Two small low-quality trials comparing acupuncture with relaxation (alone or in combination with massage) could not be interpreted reliably. AUTHORS' CONCLUSIONS: In the previous version of this review, evidence in support of acupuncture for migraine prophylaxis was considered promising but insufficient. Now, with 12 additional trials, there is consistent evidence that acupuncture provides additional benefit to treatment of acute migraine attacks only or to routine care. There is no evidence for an effect of'true' acupuncture over sham interventions, though this is difficult to interpret, as exact point location could be of limited importance. Available studies suggest that acupuncture is at least as effective as, or possibly more effective than, prophylactic drug treatment, and has fewer adverse effects. Acupuncture should be considered a treatment option for patients willing to undergo this treatment.
417 citations
Cites background from "Acupuncture mechanisms for clinical..."
...It is assumed that a variable combination of peripheral effects; spinal and supraspinal mechanisms; and cortical, psychological or ’placebo’ mechanisms contribute to the clinical effects in routine care (Carlsson 2002)....
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TL;DR: Evidence is presented that this pain suppression system is mediated in part by endogenous opiatelike compounds (endorphins), and a neural model which incorporates the experimental findings is proposed and the clinical implications of the model are discussed.
Abstract: The anatomy, physiology, and pharmacology of an intrinsic neural network that monitors and modulates the activity of pain-transmitting neurons is reviewed. This system can be activated by opiate administration or by electrical stimulation of discrete brainstem sites. Evidence is presented that its pain-suppressing action is mediated in part by endogenous opiatelike compounds (endorphins). This pain suppression system is organized at three levels of the neuraxis: midbrain, medulla, and spinal cord. Activation of neurons in the midbrain periaqueductal gray matter (by electrical stimulation, opiates, and possibly psychological factors) excites neurons of the rostral medulla, some of which contain serotonin. The medullary neurons, in turn, project to and specifically inhibit the firing of trigeminal and spinal pain-transmission neurons. As part of a negative feedback loop, the output of the pain transmission neurons, i.e., pain itself, is an important factor in activating the pain-suppression system. A neural model which incorporates the experimental findings is proposed, and the clinical implications of the model are discussed.
399 citations
TL;DR: It is concluded that acupuncture could be a valuable non-pharmacological tool in patients with frequent episodic or chronic tension-type headaches with small but statistically significant benefits of acupuncture over sham.
Abstract: Background
Acupuncture is often used for tension-type headache prophylaxis but its effectiveness is still controversial. This review (along with a companion review on 'Acupuncture for migraine prophylaxis') represents an updated version of a Cochrane review originally published in Issue 1, 2001, of The Cochrane Library.
Objectives
To investigate whether acupuncture is a) more effective than no prophylactic treatment/routine care only; b) more effective than 'sham' (placebo) acupuncture; and c) as effective as other interventions in reducing headache frequency in patients with episodic or chronic tension-type headache.
Search methods
The Cochrane Pain, Palliative & Supportive Care Trials Register, CENTRAL, MEDLINE, EMBASE and the Cochrane Complementary Medicine Field Trials Register were searched to January 2008.
Selection criteria
We included randomized trials with a post-randomization observation period of at least 8 weeks that compared the clinical effects of an acupuncture intervention with a control (treatment of acute headaches only or routine care), a sham acupuncture intervention or another intervention in patients with episodic or chronic tension-type headache.
Data collection and analysis
Two reviewers checked eligibility; extracted information on patients, interventions, methods and results; and assessed risk of bias and quality of the acupuncture intervention. Outcomes extracted included response (at least 50% reduction of headache frequency; outcome of primary interest), headache days, pain intensity and analgesic use.
Main results
Eleven trials with 2317 participants (median 62, range 10 to 1265) met the inclusion criteria. Two large trials compared acupuncture to treatment of acute headaches or routine care only. Both found statistically significant and clinically relevant short-term (up to 3 months) benefits of acupuncture over control for response, number of headache days and pain intensity. Long-term effects (beyond 3 months) were not investigated. Six trials compared acupuncture with a sham acupuncture intervention, and five of the six provided data for meta-analyses. Small but statistically significant benefits of acupuncture over sham were found for response as well as for several other outcomes. Three of the four trials comparing acupuncture with physiotherapy, massage or relaxation had important methodological or reporting shortcomings. Their findings are difficult to interpret, but collectively suggest slightly better results for some outcomes in the control groups.
Authors' conclusions
In the previous version of this review, evidence in support of acupuncture for tension-type headache was considered insufficient. Now, with six additional trials, the authors conclude that acupuncture could be a valuable non-pharmacological tool in patients with frequent episodic or chronic tension-type headaches.
276 citations
Cites background from "Acupuncture mechanisms for clinical..."
...[MEDLINE: 15604624] Carlsson 2002 Carlsson C. Acupuncture mechanisms for clinically relevant longterm effects - reconsideration and a hypothesis....
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...It is assumed that a variable combination of peripheral effects; spinal and supraspinal mechanisms; and cortical, psychological or ’placebo’ mechanisms contribute to the clinical effects in routine care (Carlsson 2002)....
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TL;DR: The findings cast doubt on the validity of traditional acupuncture theories about point locations and indications, and the theoretical basis for traditional acupuncture practice needs to be re-evaluated.
Abstract: Objective: This study sought to determine whether sham acupuncture is as efficacious as true acupuncture, as defined by traditional acupuncture theories. Methods: A systematic review was conducted of clinical trials that used sham acupuncture controls with needle insertion at wrong points (points not indicated for the condition) or non-points (locations that are not known acupuncture points). This study used a convenience sample of 229 articles resulting from a PubMed search using the keyword “acupuncture” and limited to “clinical trials” published in English in 2005 or 2006. Studies were categorized by use of wrong points versus non-points and the use of normal insertion and stimulation versus superficial insertion or minimal stimulation. Results: Thirty-eight acupuncture trials were identified. Most studies (22/38 = 58%) found no statistically significant difference in outcomes, and most of these (13/22 = 59%) found that sham acupuncture may be as efficacious as true acupuncture, especially whe...
247 citations
References
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2,592 citations
TL;DR: Tritiated naloxone, a powerful opiate antagonist, specifically binds to an opiate receptor of mammalian brain and guinea pig intestine that closely parallels their pharmacological potency.
Abstract: Tritiated naloxone, a powerful opiate antagonist, specifically binds to an opiate receptor of mammalian brain and guinea pig intestine. Competition for the opiate receptor by various opiates and their antagonists closely parallels their pharmacological potency. The opiate receptor is confined to nervous tissue.
2,319 citations
TL;DR: This work highlights current theories about peripheral neuropathic pain and shows that progress in management is contingent on targeting treatment not at the aetiological factors or the symptoms but at the mechanisms that operate to produce the symptoms.
2,155 citations