Data Builds the Case for Acupuncture in Pain Management

Acupuncture has been used for more than 2,000 years throughout Asia and is an important component of Traditional Chinese Medicine (TCM). Based on the concept of qi – the vital energy in the body that flows along well-defined meridians, acupuncture is thought to restore any imbalance in the energy flow responsible for health. These concepts have evolved to take on a neurological model, based on evidence that acupuncture needles stimulate nerve endings and alter brain function, particularly the intrinsic pain inhibitory mechanisms.¹ Functional magnetic resonance imaging (fMRI) data has shown that acupuncture may stimulate gene expression of neuropeptides.²

In the United States, the popularity of acupuncture has grown since a 1998 NIH consensus report showed its efficacy as an analgesic for postoperative dental pain and treatment of postoperative and chemotherapy-induced nausea and vomiting.³ Many hospitals now incorporate acupuncture into a comprehensive treatment plan and insurance companies are more likely to cover the cost of treatment.⁴

In fact, an estimated 1.5% of the US population has received acupuncture treatment for chronic pain at least once, often in addition to established therapeutic regimens.⁵ Acupuncture is one of several nonpharmacological interventions used to help manage chronic pain and numerous clinical trials and reviews on its use have been published. A recent review, however, points out that variations in study designs and inconclusive results have created uncertainty about its place in clinical pain practice.⁶

Here, we look at two subsets of studies which have demonstrated measurable effects of acupuncture, showing it to be a viable addition to the clinician’s armamentarium for the management of patients with migraine or neuropathies that commonly result during and after chemotherapy.

Recent studies demonstrate the potential role for acupuncture in treating and managing patients with migraine and headache pain.

Acupuncture for Migraine

Migraine is notoriously difficult to treat due to medication side effects and exacerbations of pain. Numerous studies have shown acupuncture to be a safe and readily available therapy for the chronic disorder, however, and evidence is accumulating showing acupuncture’s measurable effects on the duration and frequency of migraine attacks.

In a recent review, Ivan Urits, MD, of Beth Israel Deaconess Medical Center-Harvard Medical School, and his colleagues provided an overview of the current research investigating the effectiveness of acupuncture in treating migraine.⁴

In their view, three studies stand out for expanding the potential role for acupuncture in treating and managing patients with migraine. In one study, proton magnetic resonance spectroscopy imaging was used to examine the neurochemical response to acupuncture treatment. Two brain metabolites were found to significantly increase after acupuncture therapy:

• N-acetylaspartate (NAA) – a marker of neural functionality
• Creatine – a marker of energy metabolism

The metabolite increase correlated with a post-treatment decrease in headache intensity score.⁷

Another study on the ability of ear acupuncture to prevent chronic migraine found that, after 1 month of treatment, the average reduction in migraine days per month was 6.31 ±4.64 days.⁸

The third was a retrospective review of 21,209 patients diagnosed from 2000 to 2012. In this study, the acupuncture cohort (n=1948) had lower medical expenditures, lower depression risk, and lower anxiety risk compared with the non-acupuncture group. An analysis of 13 years of follow-up data supported the decrease in incidence of depression and anxiety in the acupuncture cohort.⁹

Despite these and other promising results, the authors concluded that further investigation is needed to ensure that acupuncture will continue to have a positive outcome on patients.

Acupuncture to Reduce Chemotherapy Induced Peripheral Neuropathy

Chemotherapy drugs are neurotoxic and damage peripheral nerves and can lead to chemotherapy-induced peripheral neuropathy (CIPN). Symptoms are predominantly sensory rather than motor and may include nerve pain in the arms and legs, loss of sensation, and numbness, typically in a symmetrical glove-and-stocking distribution. The prevalence of CIPN is 68.1% in the first month of chemotherapy and declines to 30% at 6 months or more.¹⁰

The pathophysiological mechanism of CIPN has not been totally discovered. Neurotoxic drugs induce axonal poly neuropathy in several ways, including by damaging microtubules, interfering with microtubule-related axonal transport, causing mitochondrial disability, changing the release of pain mediators, and causing cytotoxic effects on DNA.¹¹ According to TCM, the pathogenesis of CIPN is a deficiency of qi and blood, qi stagnation, and blood stasis, which lead to the malnourishment of tendons and vessels and stasis in channels and collaterals.¹²

CIPN significantly affects the quality of life for patients with cancer. Reducing the dose of chemotherapy drugs or stopping them temporarily is a general management strategy for CIPN, and there are no therapeutic options available for its prevention. Tricyclic antidepressants (TCAs), selective serotonin norepinephrine reuptake inhibitors (SNRIs), pregabalin, and gabapentin have been recommended for treatment, but current ASCO guidelines for CIPN treatment recommend only duloxetine.¹³

Acupuncture has been shown to be safe and effective in treating cancer-related symptoms and other peripheral neuropathies. Its efficacy in the treatment of CIPN has been tested; however, the evidence has, so far, been inconclusive, primarily due to a lack of RCTs to investigate its therapeutic effectiveness. New studies have been published that aim to provide more data.

A recent pilot study by Somayeh Iravani, MD, of Beijing University of Chinese Medicine, and colleagues compared a 12-session acupuncture regimen over 4 weeks with taking a 300-mg table of vitamin B1 and 900 mg of gabapentin each day for 4 weeks.¹⁴ At the end of the treatment period and after 4 weeks of follow-up, symptom severity decreased significantly in both groups (P <0.001), with a significantly higher reduction in the acupuncture group (P <0.001) than the vitamin B1/gabapentin group (P = 0.03). In addition, the acupuncture group showed higher overall satisfaction with the treatment. The nerve conduction study in the acupuncture group improved significantly (P <0.05), while improvement was not observed in the vitamin B1/gabapentin group.¹⁴

Another review of 386 patients with cancer from six RCTs showed that acupuncture led to significant improvements in pain scores and nervous system symptoms, but no significant change in nerve conduction velocity.¹⁵ Lastly, a study of 4 weeks of acupuncture in Korean women with peripheral neuropathy after chemotherapy for breast cancer showed improvement in pain and sensory neuropathy, as well as physical functioning and general health perception. These effects lasted for at least 1 month after treatment.¹⁶

In another study that assessed the results of three clinical trials which included 203 participants, two of the trials determined acupuncture to be effective in alleviating CIPN pain and improving quality of life, but the third trial found no benefit of acupuncture in pain, symptoms, or quality of life.¹⁵ The paper’s authors, led by K Li, MD, of the University of British Columbia, Vancouver, BC, concluded in that, “The evidence is insufficient for the treatment of prevention of CIPN. Further research is needed to evaluate the effects of acupuncture in the treatment of CIPN. Given that acupuncture is considered safe and might provide relief for patients, it can be considered at the clinician’s discretion.”¹⁷

Practical Takeaway

At this point, the evidence base for the effectiveness of acupuncture to help manage certain pain conditions, such as migraine and chemotherapy-induced peripheral neuropathy, is growing but still somewhat inconclusive.