MISCELLANEOUS PAIN RESEARCH © JCM Ltd

30 MINUTES OF ELECTRO-ACUPUNCTURE OPTIMAL FOR PAIN RELIEF
A team from the USA has found that the duration of electro-acupuncture treatment can affect its analgesic effect. Healthy volunteers were randomised to receive 0, 20, 30 or 40 minutes of electro-acupuncture stimulation (alternating 2/100 Hz at 5mA). Using a cold pain threshold test, the investigators found that 30 min of stimulation resulted in the most significant hypoalgesic effect, which was sustained for at least 60 minutes after stimulation. (The impact of asynchronous electroacupuncture stimulation duration on cold thermal pain threshold. Anesth Analg. 2009 Sep;109(3):932-5).

ACUPUNCTURE FOR BREAST CANCER DRUG PAIN
A preliminary trial by an American team has found acupuncture to be a promising way of treating arthralgia in women receiving aromatase inhibitors (AIs) for breast cancer. Twelve patients were provided with electro-acupuncture (EA) twice a week for two weeks, followed by six weekly treatments. Acupuncture was based on the TCM diagnosis of bi syndrome, with electrostimulation of needles around the painful joints. From baseline to the end of intervention patients reported reductions in pain severity (from 5.3 to 1.9), stiffness (from 6.9 to 2.4), and joint symptom interference (from 4.7 to 0.8). They considered joint symptoms ‘very much better’ and also reported a significant decrease in fatigue (from 4.4 to 1.9) and anxiety (from 7.1 to 4.8). No infection or development/worsening of lymphoedema was observed. (Feasibility trial of electroacupuncture for aromatase inhibitor-related arthralgia in breast cancer survivors. Integr Cancer Ther. 2009 Jun;8(2):123-9).

NEW MODEL FOR ACUPUNCTURE ANALGESIA
An Australian author has presented a new model for acupuncture anaesthesia. According to his hypothesis, C fibre tactile afferent axons bifurcate at acupuncture points and then diverge, running along acupuncture meridians, to subsequently communicate with Merkel cells. These are sensory cells which are essential for light touch responses. Each Merkel cell is intimately associated with an afferent C fibre terminal, forming a structure known as a Merkel cell-neurone complex or Merkel disc. This functions as a sensory mechanoreceptor in the epidermis, capable of responding to light touch. The author proposes that acupuncture disrupts the bifurcation of C fibre tactile afferent axons, preventing neural transmission between Merkel cells as well as central communication with the spinal cord. The hypothesis was tested using an electrical circuit model which successfully predicted the observed 103 reduction in skin resistance at acupuncture points. (The cutaneous intrinsic visceral afferent nervous system: a new model for acupuncture analgesia. J Theor Biol. 2009 Dec 21;261(4):637-42).

ACUPUNCTURE REDUCES POSTOPERATIVE PAEDIATRIC PAIN
American clinicians have carried out a nonrandomised pilot study to determine the feasibility of acupuncture for acute postoperative pain control in hospitalised children. 20 patients (aged 7 months to 18 years) who had undergone a variety of surgical interventions received two 10 to 15-minute sessions of acupuncture 24-48 hours apart. The treatment was found to be highly acceptable (of 27 patients approached, four refused, and of 23 patients enrolled, 20 patients completed the study), well-tolerated and without adverse events. In follow-up interviews, 70% of both parents and patients believed acupuncture helped the child's pain. Eighty-five percent of parents said they would pay for acupuncture if not covered by insurance. In posterior spinal fusion patients, the mean pain scores (0-10) immediately before, 4, and 24 hours after acupuncture were: 3.7, 1.7, and 3.1, respectively after the first acupuncture session and 3.7, 2.2, and 3.1 after the second session. In the other surgical cohort, the mean pain scores immediately before, 4, and 24 hours after the first session of acupuncture were 2.5, 0.3, and 1.6. The authors conclude that that acupuncture may be a potentially useful adjunctive tool for acute paediatric postoperative pain management. (Using acupuncture for acute pain in hospitalized children. Pediatr Crit Care Med. 2009 Feb 27. [Epub ahead of print]).

DOES ACUPUNCTURE RELIEVE PAIN?
A systematic review carried out in Denmark and published in the BMJ has concluded that pain relief with acupuncture is minimal and mainly due to placebo effect. However, an accompanying editorial mitigates this seemingly negative result, explaining that interpreting the effects of sham acupuncture may be essential in understanding acupuncture’s true analgesic effect. The systematic review assessed the analgesic effect of acupuncture and 'placebo acupuncture' compared with usual care in 13 trials (3025 patients), which had three treatment arms (acupuncture, placebo acupuncture and no acupuncture). The pooled results showed that on a 100-mm visual analog pain scale, the effect of placebo acupuncture corresponded to a 10mm reduction in pain, while true acupuncture added a further 4mm reduction. The authors conclude that the analgesic effect of acupuncture is too small to be clinically relevant and is difficult to distinguish from bias due to incomplete blinding, while placebo acupuncture seems to be relatively effective. They interpret this as meaning that the analgesic effect of acupuncture is, to large degree, a placebo effect caused by the psychological impact of the treatment ritual. (Acupuncture treatment for pain: systematic review of randomised clinical trials with acupuncture, placebo acupuncture, and no acupuncture groups. BMJ. 2009 Jan 27;338:a3115). In an accompanying editorial, Adrian White (Peninsula Medical School, Universities of Exeter and Plymouth) and Mike Cummings (British Medical Acupuncture Society) suggest instead that the small but significant difference between needling at traditional point locations, and what they term sham rather than placebo acupuncture, may in fact represent a physiological difference between two active treatments. They take issue with other aspects of the review, including its search restriction of papers by trial methodology, rather than clinical condition, which is an unusual approach in systematic reviews. In addition, they point out that, because the analysis covers such a broad range of pain conditions, "it cannot directly inform clinical decisions about patients with particular conditions". They add that "the overall effect size of acupuncture in relation to usual care may be clinically relevant for musculoskeletal conditions, particularly in view of the limited treatment options and acupuncture’s safety record and patient preference.” Their recommendations for future research include definition of optimum parameters and response variables for acupuncture, comparison of optimal acupuncture with best existing treatments for different conditions and the elucidation of the mechanisms of sham techniques. (Does acupuncture relieve pain? BMJ. 2009 Jan 27;338:a2760).

ACUPUNCTURE BENEFITS PROSTATE PAIN
Acupuncture treatment is more than twice as likely as sham treatment to improve men’s symptoms of chronic prostatitis/chronic pelvic pain syndrome. Malaysian researchers randomised 89 patients to ten weeks of twice-weekly 30-minute true or sham acupuncture sessions. The patients were scored on the NIH Chronic Prostatitis Symptom Index (NIH-CPSI). Response to treatment was defined as a minimum six-point decrease from baseline to week ten in NIH-CPSI total score. 73% participants responded in the acupuncture group compared with 47% of sham group participants. This level of response was maintained 24 weeks after completing therapy by 32% of the acupuncture group and 13% of the sham group. Participants receiving acupuncture were thus 2.4-fold more likely to experience long-term benefit than were participants receiving sham acupuncture. (Acupuncture versus sham acupuncture for chronic prostatitis/chronic pelvic pain. Am J Med. 2008 Jan;121(1):79.e1-7).

AMBULANCE ACUPRESSURE REDUCES BROKEN ARM PAIN
Applying acupressure to Baihui DU-20 and Hegu L.I.-4 while in transit to hospital effectively reduces pain and anxiety in patients with distal radial fractures. Acupressure was performed in the ambulance on a group of 32 patients either at true acupressure points or at sham points. Vital signs, and pain and anxiety scores were recorded before and after the acupressure treatment. At the hospital, patients in the true points group had significantly lower pain and anxiety scores. (Prehospital analgesia with acupressure at the Baihui and Hegu points in patients with radial fractures: a prospective, randomized, double-blind trial. Am J Emerg Med. 2007 Oct;25(8):887-93).

AUDIT OF ACUPUNCTURE FOR MUSCULOSKELETAL PAIN
A retrospective audit of case histories, carried out in a Spanish primary care pain treatment unit, has concluded that acupuncture is effective in treating musculoskeletal pain. Electronically stored case histories of 5981 patients who sought acupuncture treatment for non-oncological pain at the unit, over a nine-year period, were reviewed. The primary outcome measure was the ‘success rate’, defined as an improvement of least 50% on the Global Assessment Index, which consists of five variables: pain intensity, pain frequency, consumption of analgesics, level of incapacity, and sleep disorders caused by pain. The majority (84.5%) of patients treated were women, mean age 58.8 years, who attended because of pain present for over three months (88.8%), mainly affecting the lower back (58.8%). The mean success rate was found to be 79.7%, with the highest rates (93%) being achieved in patients with headache. Pain decreased by an average of 67% from baseline. There was a reduction of 7.1 euros in the mean weekly expenditure on analgesics per patient. Patients suffering from acute or sub-acute pain showed higher success rates than did those with chronic pain. The authors conclude that acupuncture is effective in treating musculoskeletal pain, presents no severe adverse events and considerably reduces consumption of analgesic and anti-inflammatory drugs. (Effectiveness of acupuncture and related techniques in treating nononcological pain in primary healthcare-an audit. Acupunct Med. 2007 Jun;25(1-2):41-6).

AURICULAR ACUPUNCTURE FOR ACUTE PAIN
A randomised controlled pilot study compared the effects of standard emergency medical care to auricular acupuncture plus standard care in patients with acute pain syndromes. Eighty-seven people with a diagnosis of acute pain completed the emergency room (ER) trial. Participants in the acupuncture group experienced a 23% reduction in pain before leaving the ER, while average pain levels in participants in the standard medical care group remained unchanged. However, both groups experienced a similar reduction in pain 24 hours after treatment in the ER. (Auricular acupuncture in the treatment of acute pain syndromes: A pilot study. Mil Med. 2006 Oct;171(10):1010-4).

ACUPUNCTURE & SPINE PAIN
Acupuncture is effective in treating chronic pain following spinal cord injury (SCI) according to research carried out at the Department of Psychiatry, New Jersey Medical School. Twenty-two patients with SCI who suffered moderate to severe pain of at least six months’ duration received a course of 15 acupuncture treatments over a seven and a half week period after an equivalent assessment period without treatment. Patients were then asked about pain intensity, how much their pain interfered with activity, and how they assessed changes in their symptoms. Ten patients (46%) showed improvement in pain intensity and pain sequelae after treatment, whilst six patients (27%) reported an increase in pain that was still present 3 months after treatment. The researchers conclude that acupuncture may provide pain relief for at least a subgroup of individuals with SCI and that future research is needed to determine what part of this effect is because of acupuncture, versus nonspecific effects such as placebo effects and regression to the mean (Arch Phys Med Rehabil 2001 Nov;82(11):1578-86).

ACUPUNCTURE & PAIN
A study carried out at the Department for Family Medicine at the University of Maryland has shown that acupuncture is more effective than placebo in the treatment of postoperative oral surgery pain (Archives of Otolaryngology – Head & Neck Surgery 1999; 125(5): 567-572).

CARPAL TUNNEL SYNDROME
31 patients (36 hands) with carpal tunnel syndrome of a mean 24 months duration, with 14 hands having failed either one or two surgical release procedures, were treated by combined therapy. Primary treatment was low-level laser acupuncture and microamps TENS, and secondary treatment included regular needling and Chinese herbal formulas and supplements. Treatment was given three times a week for 4-5 weeks. After treatment 33 hands experienced either no pain or pain reduced by more than 50%, with all 14 hands that had failed surgery being successfully treated. (Journal of Alternative & Complementary Medicine 1999; 5(1): 5-26.

TENS VERSUS ACUPUNCTURE
A study has shown that transcutaneous electrical nerve stimulation (TENS) is less effective than electro-acupuncture in the treatment of chronic pain. 156 patients with chronic pain (lower back ache, osteoarthritis of the knee, and cervical spondylosis) were divided into two groups (one TENS and one electro-acupuncture) and each given fifteen treatments. In the acupuncture group, pain relief was more extensive and lasted longer than in the TENS group, especially in patients whose pain was over one year's duration (Alternat Ther Clin Pract 1996 Jul-Aug;3(4):33-5).

AURICULOPRESSURE AND PAIN RELIEF
The effect of auriculopressure on pain relief was assessed by comparing two groups of healthy students. In the first group, auriculopressure was applied to the 'toe' ear point and pressure sensitivity at the toe was measured with an algometer before and after treatment. The increase in pain threshold was statistically significant compared with a control group who received placebo stimulation at the ear (Acupunct Med 1996 May;14(1):16-8).

ACUPUNCTURE ANALGESIA
A randomised placebo-controlled single-blind study of 50 patients in Germany compared the analgesic effect of needling a single acupuncture point (on the arm) traditionally indicated for knee pain, with a simulated acupuncture treatment (control group) in postoperative knee pain following total knee replacement. The acupuncture group showed significantly greater pain relief lasting several hours. (Acupuncture against postoperative pain after total knee replacement - A placebo-controlled trial on immediate effects, Aktuelle Rheumatologie, 1995, 20/4 131-134).

ACUPUNCTURE AND WHIPLASH INJURY
A study has analysed postural changes after acupuncture treatment in a group of 15 patients with balance disorders caused by cervical torsion due to whiplash injury. The treatment consisted of 3 once-weekly sessions during which points Tianzhu BL-10 and Fengchi GB-20 were needled. Patients were given posturograhic evaluations before and just after treatment. 17 patients with the same symptoms, and treated by drugs and physiotherapy only, were used as a control. There was a significant difference in the two groups leading the authors of the study to advocate the efficacy of acupuncture for balance disorders due to cervical pathology. (Fattori B, Borsari C, Vannucci G, Casani A, Cristofani R, Bonuccelli L, Ghilardi PL, Acupuncture treatment for balance disorders following whiplash injury, Acupunct Electrother Res 1996 Jul-Dec;21(3-4):207-17).