Harvard Medical School, Massachusetts General Hospital, and Beth Israel Deaconess Medical Center (Boston) researchers find acupuncture effective for the treatment of carpal tunnel syndrome, an entrapment neuropathy affecting the arm, wrist, and hand. Results were published in Brain, a journal founded in 1878 that is dedicated to the publication of landmark findings in both clinical neurology and translational neuroscience. Additional members of the research team hailed from Logan University (Missouri), Korean Institute of Oriental Medicine (Daejeon, South Korea), Spaulding Rehabilitation Hospital (Medford, Massachusetts), and Harvard Vanguard Medical Associates (Boston, Massachusetts).

The research team used subjective and objective instruments to measure patient outcomes. The Boston Carpal Tunnel Syndrome Questionnaire assessed pain and paraesthesia. Nerve conduction studies assessed median nerve improvements. Brain imaging data using fMRIs (functional magnetic resonance imaging) was used to measure somatotopic arrangements. Somatotopy maps the correspondence of specific points on the body to specific areas of the brain and other areas of the central nervous system.

In a landmark finding, the researchers find that acupuncture "may improve median nerve function at the wrist by somatotopically distinct neuroplasticity in the primary somatosensory cortex following therapy." Essentially, acupuncture elicits measurable improvements in brain areas correlated with positive patient outcomes for patients with carpal tunnel syndrome. The researchers add that somatotopic improvements elicited by acupuncture "can predict long-term clinical outcomes for carpal tunnel syndrome."

True acupuncture (verum acupuncture) produced improvements in the median nerve that were directly correlated with reductions of fractional anisotropy (i.e., MRI scans measured specific improvements in white matter fiber tracts of the brain that regulate positive patient outcomes for carpal tunnel patients). This discovery reveals an important neurophysiological mechanism activated by acupuncture stimulation. Acupuncture produces positive patient outcomes in the wrist by improving specific areas of the brain.

Fake acupuncture (sham acupuncture), used as a control, did not produce results in the brain correlated with median nerve improvements, as measured by MRIs. This dispels a great mystery. Medical procedures often produce short-term placebo effects, including sham acupuncture. However, the long-term clinical benefits of true acupuncture are quantifiable in terms of improvements in specific areas of the brain. In other words, sham acupuncture is only capable of producing minor short-term placebo benefits because it does not produce the central nervous system improvements produced by true acupuncture.

True acupuncture produces superior patient neurophysiological outcomes in the wrist and brain over sham acupuncture. True acupuncture produces quantifiable improvements in median nerve conduction and digit cortical separation distances. The researchers discovered that interdigit cortical separation distances are predictive of long-term symptomatic improvements achievable with true acupuncture (and not with sham acupuncture). The results are published in the research entitled Rewiring the primary somatosensory cortex in carpal tunnel syndrome with acupuncture. Results were based on comparative outcomes of baseline to acupuncture treatments (16 sessions over 8 weeks).

Li et al. and Wang et al. confirm that acupuncture is effective for the treatment of carpal tunnel syndrome. Li et al. find that acupuncture produces a 95.2% total effective rate. Wang et al. find that acupuncture produces an 86.67% total effective rate for the treatment of carpal tunnel syndrome.

Let’s take a look at both studies. Shandong University of Traditional Chinese Medicine researchers (Li et al.) find acupuncture effective for the treatment of carpal tunnel syndrome, producing a 95.2% total effective rate. The results are published in a research paper entitled Acupuncture in Treating Carpal Tunnel Syndrome: a Study of 21 Cases. A total of 21 patients with carpal tunnel syndrome were treated and evaluated in this study.

The patients were diagnosed with carpal tunnel syndrome between November 2013 and September 2014. There were 9 males and 12 females participating in the study. The youngest patient was 25 years of age, the oldest was 72. The shortest course of the disease was 1 week, the longest was 2 years. In a breakdown of etiologies, 5 cases of CTS were caused by carpometacarpal joint ganglion cysts, 9 were caused by repetitive strain injuries, and 7 by wrist sprains. The primary acupoints selected for all patients were the following:
TB4 (Yangchi)
SI5 (Yanggu)
LI5 (Yangxi)
LI4 (Hegu)
LI11 (Quchi)
TB5 (Waiguan)
Ashi

Additional acupoints were administered based on individual symptoms. For finger paresthesia, the following acupoints were added:
Sifeng
Shixuan

For atrophy of the thenar muscles, the following acupoints were added:
LU10 (Yuji)
PC8 (Laogong)
SI3 (Houxi)

For wrist pain, the following acupoints were added:
PC7 (Daling)
SI6 (Yanglao)
LU7 (Lieque)

For pain radiating to the forearm, the following acupoints were added:
LI10 (Shousanli)
PC3 (Quze)

Treatment commenced with patients in a sitting position, with the arms, wrists, and fingers relaxed and the palms facing downwards. After disinfection of the acupoint sites, a 0.30 mm x 40 mm disposable filiform needle was inserted into each acupoint. TB4 was pierced to a depth of 10–15 mm with the triple acupuncture technique. SI5, LI5, LI4, TB5, LU10, PC8, SI3, PC7, SI6, and Ashi points were perpendicularly needled to a depth of 10–15 mm. For Sifeng points, needles were inserted rapidly to a depth of 3–6mm and then immediately withdrawn. LI11, LI10 and PC3 were pierced to a depth of 15–25 mm. Next, 3–5 Shixuan points were selected and were needled with the bleeding technique. Shixuan (translated as 10 dispersions) acupoints are located on the fingers, 0.1 cun distal to the fingernails. Each hand has ten Shixuan acupoints.

A deqi sensation was elicited at all acupoints. A TDP (Teding Diancibo Pu) heat lamp was applied to warm the acupoints. The TDP heat lamp emits far infrared radiation (2–50 micrometers).

A needle retention time of 20 minutes was observed for each acupuncture session. On week 1, the acupuncture treatments were applied once daily for 6 consecutive days. Starting at week 2, the treatments were applied every other day. Each treatment course consisted of 6 acupuncture treatments. All patients received a total of 4 treatment courses. After treatment, the treatment efficacy for each patient was categorized into 1 of 4 tiers:

Full recovery: Complete absence of symptoms. Physical movement of the upper limbs regained completely.

Significantly effective: Absence of most symptoms. Physical movement of the upper limbs regained. Discomfort reoccurs only under strenuous exercise.

Effective: Elimination of symptoms. Pain or discomfort present.

Not effective: No improvement in symptoms.

After four courses of care, the total effective rate was 95.2% with the following breakdown of improvement tiers: 66.7% fully recovered, 19.0% significantly effective, 9.5% effective, 4.8% not effective. In Traditional Chinese Medicine, carpal tunnel syndrome (CTS) falls under the Bi Zheng class of disorders. CTS is caused by weak qi and blood circulation, blood stasis, plus tendon and muscle malnourishment. Thus, researchers selected local acupuncture points to improve qi and blood circulation, including SI5, LI5, LI4, TB5, PC8, and PC7. The researchers note that the bleeding technique was applied to Shixuan points for the relief of finger paraesthesia.

Wang et al. produced similar patient outcomes by using a different acupoint prescription. Their independent investigation was published in the Journal of Clinical Acupuncture and Moxibustion. Patients receiving acupuncture had an 86.67% total effective rate for the treatment of CTS. Primary acupoints for all patients included the following:
PC7 (Daling)
PC6 (Neiguan)

Secondary acupoints included the following:
PC5 (Jianshi)
LI4 (Hegu)
PC8 (Laogong)

The patients rested in a supine position. Upon disinfection of the acupoint sites, a 0.25 mm x 40 mm filiform acupuncture needle was inserted into the acupoints with a rapid entry speed. For PC7, a mild manual stimulation was applied until a deqi sensation was achieved. For PC6, PC5, and PC8, a moderate to strong stimulation was applied until a deqi sensation was achieved. A needle retention time of 40 minutes was observed. During needle retention, the needle was manipulated every 5 minutes. Treatment was conducted once daily for 20 consecutive days. The total effective rate was 86.67% with the following breakdown of improvement tiers: 16 cases fully recovered, 6 cases significant improvements, 4 cases slight improvements, 4 no improvements.

PC6 and PC7 are mentioned in this study as particularly helpful for the treatment of CTS. PC6 is a Luo-Connecting point on the pericardium meridian. In the Zheng Jiu Da Cheng (Compendium of Acupuncture and Moxibustion), it is said that PC6 is indicated for the treatment of "swelling and spasm of the hand which is caused by the attack of wind and heat." PC7 is also on the the pericardium meridian. According to the Zhen Jiu Jia Yi Jing (Jia–Yi Classic of Acupuncture and Moxibustion), it is effective for "hand spasms, hemiparesis of upper limbs, as well as hand spasms with slight tendon convulsion."

Continuing acupuncture education investigations reveal that acupuncture is clinically effective for the treatment of carpal tunnel syndrome. The research published in the journal Brain provides insight into the neurophysiological mechanisms responsible for acupuncture’s therapeutic actions. The best way for patients with carpal tunnel syndrome to learn more and receive treatment is to contact licensed acupuncturists in their area.

References
Maeda, Y., Kim, H., Kettner, N., Kim, J., Cina, S., Malatesta, C., Gerber, J., McManus, C., Ong-Sutherland, R., Mezzacappa, P. and Libby, A., 2017. Rewiring the primary somatosensory cortex in carpal tunnel syndrome with acupuncture. Brain, 140(4), pp.914-927.

Li Q, Hou SW. Acupuncture in Treating Carpal Tunnel Syndrome: a Study of 21 Cases [J]. Shanghai Journal of Acupuncture and Moxibustion, 2015(12):1229–1229.2.

Wang W, Tang W, Chi HT et al. Acupuncture in Treating Carpal Tunnel Syndrome: a Study of 30 Cases [J]. Journal of Clinical Acupuncture and Moxibustion, 2016, 32(5):28–29.