A Data Mining Study for Analysis of Acupoint Selection and Combinations in Acupuncture Treatment of Carpal Tunnel Syndrome

Carpal tunnel syndrome (CTS) is the most common compressive neuropathy of the upper limbs, affecting between 2.7% and 6.7% of the population annually. This condition results from compression of the median nerve in the carpal tunnel, causing pain, numbness, tingling, and muscle weakness in the hand. Although surgery is considered the standard treatment, acupuncture has emerged as an effective and less invasive alternative. This data mining study aimed to identify the most effective acupuncture points and their combinations for CTS treatment through systematic analysis of the scientific literature.

The researchers conducted a comprehensive search of seven electronic databases, including PubMed, Embase, Cochrane Library, and four Chinese databases, covering publications from database inception through March 2023. Clinical studies that evaluated the efficacy of acupuncture for CTS were included — both randomized controlled trials and non-randomized studies — as long as they contained more than ten patients. Exclusion criteria included reviews, protocols, animal studies, case reports, and post-surgical rehabilitation. The final analysis included 142 studies, of which 86 were randomized controlled trials and 56 were non-randomized studies, totaling 193 valid acupuncture prescriptions involving 68 different points.

Risk-of-bias assessment of the RCTs revealed that the main limitations were related to the lack of description of specific randomization methods and implementation of allocation concealment and blinding methods. The descriptive analysis results showed that the five most used points were Da-ling (PC-7) with a frequency of 14.06%, Nei-guan (PC-6) with 12.16%, He-gu (LI-4) with 7.18%, Wai-guan (TE-5) with 6.38%, and Yang-xi (LI-5) with 6.38%. The most frequently used meridians were the pericardium meridian (34.20%) and the large intestine meridian (23.13%). In terms of anatomical location, 97.31% of the points used were on the upper limbs, reflecting the local approach for this specific condition.

Analysis of special points revealed that the Shu points of the five elements and the Yuan-source points were the most used. The association rule analysis, using the Apriori algorithm, identified 11 groups of point combinations that met the established criteria of minimum support of 10% and minimum confidence of 90%. The five combinations with the highest support were centered on the PC-6–PC-7 pair, confirming these as core points in the treatment. The complex network analysis demonstrated that the core combination was 'Da-ling (PC-7) and Nei-guan (PC-6).' The exploratory factor analysis extracted 8 common factors with eigenvalues greater than 1, explaining 67.27% of the total variance, demonstrating good explanatory capacity.

The cluster analysis grouped the 22 most frequent points into 5 main clusters, providing organized patterns for point selection. From the perspective of traditional Chinese medicine, the selection of these points follows solid theoretical principles: PC-7 and PC-6 are located near the median nerve, being strategic for reducing local pressure; LI-4 has the effect of regulating qi (氣) and promoting blood circulation, addressing the pathogenesis of qi and blood stasis; and LI-5 is located at the wrist, contributing to restoring joint function. The study presents some important limitations: the variable quality of the included studies, the lack of standardization in research information, the use of subjective scales as the main evaluation criterion, and the exclusion of non-Chinese and non-English literature. The clinical implications are significant, providing data-based evidence for standardized point selection in the treatment of CTS.

The results suggest that the PC-7–PC-6 combination should be considered as the foundation of treatment, with the addition of other points according to the specific condition of the patient.