Does Acupuncture Produce Durable Analgesia in Trigeminal Neuralgia? An Updated Systematic Review and Meta-Analysis

Background/Objectives: Trigeminal neuralgia (TN) is a relapsing-remitting condition predominantly managed in primary care, where carbamazepine remains the sole recommended first-line therapy. Prior meta-analyses report end-of-treatment pain reductions with acupuncture but have not stratified results by risk of bias, audited pain outcome reporting quality, or examined whether analgesic effects persist beyond the treatment period. This updated systematic review addressed these gaps. Methods: Seven databases were searched from inception to February 2026 for randomized controlled trials comparing acupuncture against non-acupuncture controls in adults with TN (PROSPERO: CRD420251271469). End-of-treatment VAS, follow-up VAS, attack frequency, recurrence rate, and adverse events were analyzed using random-effects models with Hartung-Knapp-Sidik-Jonkman adjustment. Risk of bias was assessed with Cochrane RoB 2. Recall period specification was audited for all pain outcomes. Results: Twenty-three trials (1774 participants) were included, all from China, with one sham-controlled comparator. Fewer than 15% of VAS outcomes specified a recall period. End-of-treatment pain intensity favored acupuncture (MD = -1.49; 95% CI -1.81 to -1.16; I² = 93.1%), but the prediction interval crossed zero and significance was confined to high-risk studies (k = 16; p < 0.001). At three-month follow-up, the pooled estimate was comparable in magnitude (k = 3; MD = -1.50; I² = 47.0%) but was not robust to single-study removal. Recurrence rate favored acupuncture in both reporting studies. Acupuncture was associated with fewer adverse events than carbamazepine (RR = 0.31; I² = 0%). Conclusions: End-of-treatment estimates are compromised by risk-of-bias dependence and pervasive recall period omission. Follow-up data showed a directionally consistent but statistically fragile signal of analgesic persistence. Sham-controlled trials with prospective pain diaries and follow-up as a co-primary endpoint are needed.