Introduction

Carpal tunnel syndrome is a common peripheral nerve entrapment syndrome of the upper limb and is often (mis)taken for cervical radiculopathy. Conservative options include nighttime splinting and physiotherapy for mild to moderate cases of the condition. The practice guideline by Erickson et al. (2019) we covered here does not consider acupuncture in treating carpal tunnel syndrome, unlike the current paper. Let’s find out what the conclusions were regarding acupuncture combined with physiotherapy for carpal tunnel syndrome versus physiotherapy alone.

Methods

This prospective, double-blind, randomized controlled trial included participants from 26 to 62 years who were diagnosed with mild to moderate carpal tunnel syndrome. The diagnosis was established on the following findings:

1. Pain severity of at least 4 on a Visual Analog Scale (VAS) of 0-10.
2. Clinical signs of carpal tunnel syndrome, including numbness, tingling, and pain in the median nerve distribution, nocturnal paresthesia, and positive Phalen and Tinel tests. However severe cases of carpal tunnel syndrome (including permanent numbness or pain, tendon atrophy), and cases of sensory or motor disturbance in the radial and ulnar nerve were excluded.
3. Symptoms had to persist for more than four weeks, so acute carpal tunnel syndrome cases were also excluded.

Participants were randomly assigned to two groups: physiotherapy alone and physiotherapy plus acupuncture, with 20 patients in each group.

Interventions

Physiotherapy Group:

Participants received ten sessions of physiotherapy for carpal tunnel syndrome over 4 weeks, conducted through three stages.

Stage I (4 sessions): Stretching techniques

• Transverse Ligament Traction
• Palm Fascia Stretching
• Manual Pressure on Lumbrical Muscles
• Thenar Radial Abduction Extension
• Opponens Roll Maneuver
• Guy-wire (GW) Maneuver
• Combination Maneuvers
• Operator-assisted Technique

Stage II (3 sessions): Tendon glide exercises

• From Hook-grasp in extension to Wrist flexion with relaxed fingers
• Stretching the wrist flexors
• Active and firm fist movements
• Hook grasp exercise
• Half fist exercise
• Full fist exercise
• Bending and extending each finger individually

Stage III (3 sessions):

• Neural Glide Techniques: The therapist performed shoulder depression, shoulder abduction, external rotation, and elbow extension to enhance median nerve mobility.
• Proximal and Distal Glide Mobilization: Flexion and extension of the wrist and elbow with high amplitude to mobilize neural pathways.

Physiotherapy Plus Acupuncture Group:

• In addition to physiotherapy, participants received 30-minute acupuncture sessions during each physiotherapy session.
• Acupuncture points included Tai Yin, Hegu, ASHI, and Neiguan, using sterile needles manipulated by twirling and lifting-thrusting methods, left in place for 30 minutes.

Outcome Measures

• Pain: Assessed using a Visual Analog Scale (VAS) ranging from 0 (no pain) to 10 (most severe pain).
• Disability: Evaluated using the Boston Carpal Tunnel Questionnaire (BCTQ) and the Quick Disabilities of Arm, Shoulder, and Hand (Quick-DASH) questionnaire.BCTQ includes a symptom severity scale and activities of daily living scale.Quick-DASH measures upper limb disabilities, scored from 0 (no disability) to 100 (completely disabled).
• Grip Strength: Measured using a dynamometer, recording the average force from three repetitions.
• Global Rating of Change (GRC): Patients assessed changes in their health status on a scale from -5 (completely worse) to +5 (completely better).

Results

Forty patients were included and equally randomized to the groups. All but two participants were female. The groups were comparable at baseline.

The ANOVA resulted in a significant interaction of group and time for pain and disability outcomes.

Next, the authors indicated that, considering the equal baseline measurements, at the post-test there was a significant difference between the physiotherapy group and the physiotherapy plus acupuncture group.

Both groups had a statistically significant improvement over time.

• At baseline, the intervention group had a 4.95 VAS score and at the post-measurement, this decreased to 1.75. In the control group, the score went from 4.75 to 2.75. The between-group difference is however only 1, and thus not clinically relevant.
• Regarding the BCTQ score, no differences were found.
• The Quick-DASH scores favored the intervention group with a statistically significant between-group difference of 10.22 at the follow-up.

Questions and thoughts

How should we look at those findings considering that acupuncture is considered an alternative treatment method? Dimitrova et al. (2017) indicated that the majority of RCTs included in their meta-analysis confirmed the effectiveness of acupuncture for carpal tunnel syndrome. However, this study was published in the Journal of Alternative and Complementary Medicine. If we instead look at the Cochrane Review by Choi et al. (2018) the authors concluded that: “Acupuncture and laser acupuncture may have little or no effect in the short term on symptoms of CTS in comparison with placebo or sham acupuncture. It is uncertain whether acupuncture and related interventions are more or less effective in relieving symptoms of CTS than corticosteroid nerve blocks, oral corticosteroids, vitamin B12, ibuprofen, splints, or when added to NSAIDs plus vitamins, as the certainty of any conclusions from the evidence is low or very low and most evidence is short term. The included studies covered diverse interventions, had diverse designs, limited ethnic diversity, and clinical heterogeneity. High‐quality randomised controlled trials (RCTs) are necessary to rigorously assess the effects of acupuncture and related interventions upon symptoms of CTS”

This study indeed added to the requirements for adding more rigorously conducted RCTs to the existing literature. However, in the absence of a true control group, still, no definite conclusions can be drawn from this study alone. When taking into consideration that the intervention group got 30 minutes of additional treatment time per session, under the supervision of a trained clinician, and received a relaxing passive intervention on top of the “standard” physiotherapy, you might see that placebo effects and relaxation effects may come into play.

For now, focusing on the proven interventions and recommendations, I suggest we hold on to the clinical practice guideline by Erickson et al. (2019) which does not even consider acupuncture for carpal tunnel syndrome.

Talk nerdy to me

Despite the absence of a true control group, the RCT was well-designed and conducted. The authors failed to include the required number of participants since 46 were necessary while only 40 were included. No drop-outs occurred and every individual completed all study procedures. Evaluators were blinded to the intervention groups and the physiotherapist delivering the intervention was blinded for the assessment.

Considering the primary outcome pain intensity, a between-group difference of 1 point was observed. This is in no case clinically relevant and thus we should refrain from interpreting the statistically significant difference.

The authors indicate that the improvements in the Quick-DASH exceeded the minimal clinically important difference (MCID) of 15.91 points. This is however not true since the between-group difference was only 10.22 points. If you look at the within-group improvement the difference between pre and post indeed exceeded the MCID in the intervention group. But that is not what an RCT is about.

No differences in grip strength were observed. The authors proposed that this could be due to the mild to moderate degrees of carpal tunnel syndrome where power could probably be less affected. Yet, since the study did not include strength training, I wonder why grip strength was even an outcome measure.

An important question when evaluating RCTs is: Apart from the intervention, were the groups treated equally? In the case of this study, we can assume they were not, since the intervention group received 30 minutes more supervised treatment time for every session.

Take home messages

This study concludes that physiotherapy for carpal tunnel syndrome combined with acupuncture offers a more effective treatment approach than physiotherapy alone, particularly in reducing pain and disability. Yet, the between-group differences are not clinically relevant, since they do not exceed the MCID. Therefore, no evidence base for adding acupuncture can be justified.

Reference

Mamipour H, Negahban H, Aval SB, Zaferanieh M, Moradi A, Kachooei AR. Effectiveness of physiotherapy plus acupuncture compared with physiotherapy alone on pain, disability and grip strength in people with carpal tunnel syndrome: A randomized clinical trial. J Bodyw Mov Ther. 2023 Jul;35:378-384. doi: 10.1016/j.jbmt.2023.04.033. Epub 2023 Apr 18. PMID: 37330796.