Clinical efficacy of wrist-ankle acupuncture for postherpetic neuralgia and its effects on serum levels of NaV1.7 and CGRP

To observe the clinical efficacy of wrist-ankle acupuncture for postherpetic neuralgia (PHN) and its effects on serum levels of voltage-gated sodium channel 1.7 (NaV1.7) and calcitonin gene-related peptide (CGRP).

A total of 90 PHN patients were randomized into a wrist-ankle acupuncture group (45 cases, 2 cases dropped out) and a western medication group (45 cases, 1 case dropped out, 1 case was discontinued). In the western medication group, the topical 5% lidocaine gel plaster was used locally. In the wrist-ankle acupuncture group, wrist-ankle acupuncture was applied 30 min each time, once a day, 5-day treatment was as one course, with 2-day interval between courses. The treatments lasted for 4 weeks in both groups. The scores of visual analogue scale (VAS), Pittsburgh sleep quality index (PSQI), self-rating anxiety scale (SAS), and self-rating depression scale (SDS) were observed before treatment, after 2 and 4 weeks of treatment, and in the follow-up of 4 weeks after treatment completion. The serum levels of NaV1.7 and CGRP were measured before and after 4 weeks of treatment. The use of rescue analgesics and the occurrence of adverse reactions were recorded, and the clinical efficacy was evaluated after 4 weeks of treatment.

Compared with those before treatment, the scores of VAS, PSQI, SAS and SDS were decreased after 2 and 4 weeks of treatment, and in follow-up (P<0.05). After 4 weeks of treatment and in follow-up, the above scores in the wrist-ankle acupuncture group were lower than those in the western medication group (P<0.05). After 4 weeks of treatment, the serum levels of NaV1.7 and CGRP were decreased compared with those before treatment (P<0.05), and the serum levels of NaV1.7 and CGRP in the wrist-ankle acupuncture group were lower than those in the western medication group (P<0.05). During the trial, 5 cases in the wrist-ankle acupuncture group and 11 cases in the western medication group required rescue analgesics, with no statistical difference between the two groups (P>0.05). The incidence of adverse reactions was 9.3% in the wrist-ankle acupuncture group, which was lower than 27.9% in the western medication group (P<0.05). The total effective rate in the wrist-ankle acupuncture group was 90.7%(39/43), that of the western medication group was 83.7%(36/43), there was no statistical difference between the two groups (P>0.05).

Wrist-ankle acupuncture can effectively treat PHN, reduce pain, improve sleep quality and relieve negative emotions. Its mechanism may relate to the down-regulation of serum NaV1.7 and CGRP levels.