Needling the pain and comforting the brain: Acupuncture in the treatment of chronic migraine

Chronic migraine (CM) is a disabling complication of migraine. Prevalence is high, disease-related burden is great, and medical and psychiatric comorbidity is considerable. Treatment has been unsatisfactory and rigorous trials specifically targeting CM are rare. Topiramate and botulinum neurotoxin are the only pharmacological treatments that have been proven effective in randomized, placebo-controlled trials (1–6); however, the therapeutic gain (against placebo) is only modest (Table 1). New or complementary therapeutic modalities for CM treatment are needed. Acupuncture is a widely used, non-pharmacological treatment for migraine. Although its use is still controversial, a recent Cochrane systematic review found acupuncture to be as effective as, or possibly more effective than, preventive migraine agents (7). A beneficial effect of acupuncture in migraine prophylaxis was demonstrated in a prospective randomized trial for CM (8). In a 12-week treatment period, a significantly larger decrease in the mean monthly number of moderate/ severe headache days was observed in the acupuncture group compared with the topiramate group ( 10.5 vs. 7.8 days per 4 weeks, p< 0.01). Significant differences favoring acupuncture across multiple efficacy end points, including mean change of headache days, Migraine Disability Assessment Scores (MIDAS), Hospital Anxiety and Depression Scale (HADS) scores, Short Form 36 (SF-36) scores, Beck Depression Inventory II (BDI-II) scores, mean days of acute medication use, 50% reduction in monthly moderate/severe headache days, 50% reduction in monthly headache days, and safety end points were also observed. In the context of the topiramate studies (1,9) and the Phase III Research Evaluating Migraine Prophylaxis Therapy (PREEMPT) trials (4–6), similar beneficial effects were also observed in patients who were overusing acute medications. Does this study identify an alternative choice for CM patients? Probably yes, but the reasons behind the positive effect could be complex. The study was designed according to the guidelines for trials of the prophylactic treatment of CM (10) and had a clearly defined acupuncture treatment procedure following the Standards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA) recommendations (11), making it possible to replicate the study and provide a basis for comparisons across disciplines. The acupoints chosen are classic acupuncture sites, which correspond to the dermatomal distribution of trigeminocervical complexes: V1 dermatome [Cuanzhu (BL 2) and Yintang (EX-HN 3)], V2 dermatome [Taiyang (EX-HN 5)], and C2 dermatome [Fengchi (GB-20)]. Traditionally, acupuncture has had its own diagnostic system and the acupoints are individualized and tailored for headaches over different meridians. In this study, the benefits from individualized acupuncture are limited by the fixed-site approach. However, even with this trade-off, the acupuncture arm still outweighed the topiramate group. The positive results of this trial seem to provide a rational mechanism linking the intervention with the pathophysiology of migraine; that is, modulating the trigeminal sensory system. While this hypothesis is possible, a second thought is required to interpret the data. The investigators provided several reasons to justify the choice of topiramate as the active comparator instead of control with sham acupuncture; however, none could offset the putatively higher placebo effect caused by the needling procedure in comparison