Effects of electroacupuncture on carpal tunnel syndrome: a clinical, electrophysiological and ultrasonographical pilot study

BACKGROUND: Carpal tunnel syndrome (CTS) is the most common compressive neuropathy and is associated with significant strain on both patients and healthcare systems. Acupuncture is one of the conservative treatments used for this syndrome, although more evidence is needed regarding the efficacy of this intervention. The aim of this pilot study was to evaluate the effects of electroacupuncture (EA) in patients with CTS through clinical, electrophysiological and ultrasonographical assessments. METHODS: Seventeen wrists, belonging to a total of 12 patients who had been diagnosed with CTS, were included. Eight EA sessions were performed (twice a week for 4 weeks). The visual analogue scale (VAS), symptom severity scale (SSS) and functional status scale (FSS) of the Boston Carpal Tunnel Questionnaire (BCTQ) were administered, median nerve conduction studies were performed and the cross-sectional area (CSA) of the median nerve was measured by ultrasound. These evaluations were made at baseline and 3-7 days after the last treatment. RESULTS: Following EA, there was a decrease in pain on the VAS scale with a median difference (MD) of -2.45 (p < 0.001), a decrease in the severity of symptoms on the SSS scale (MD -0.60; p = 0.001) and an improvement in the function of the limb on the FSS scale (MD -0.25; p = 0.02). Furthermore, there was a reduction in the CSA of the median nerve at the carpal tunnel inlet (MD -2.00 mm²; p = 0.003). No differences in any median nerve conduction study parameters were found. Side effects (observed in 8% of treatments) were all minimal and self-limiting. CONCLUSION: Although no firm conclusions can be drawn from this uncontrolled clinical trial, EA appears to be a promising treatment for CTS patients, and herein was associated with an improvement in symptoms and morphological changes in the median nerve. TRIAL REGISTRATION NUMBER: NCT04603274 (ClinicalTrials.gov).