Enhancing evidence for surgical treatment of refractory migraine suggestions on literature and study design

Dear Editor, We read with interest the recent systematic review and meta-analysis on surgical interventions for refractory migraine in the International Journal of Surgery[1]. The review compared nerve decompression, occipital nerve stimulation (ONS), and nasal surgeries, showing that surgery generally reduced headache intensity and improved Migraine Disability Assessment (MIDAS) scores. ONS demonstrated sustained benefits, while nerve decompression effectively alleviated pain and disability. As migraine is now recognized as a neurological disorder, targeted interventions are crucial for relieving suffering. We appreciate the authors’ comprehensive work, but would like to offer two comments that may help further strengthen the evidence presented. First, regarding the completeness of the literature. In our independent literature search, we identified a prospective cohort study published on Neuromodulation by Al-Kaisy[2] that was not included in the review. This study enrolled patients with migraine unresponsive to medication, employed spinal cord stimulation targeting the occipital nerve as the main surgical intervention, and systematically assessed headache severity, attack frequency, and quality of life. These features fully matched the inclusion criteria of the review and did not meet any exclusion criteria. We believe that including this study would enrich the evidence base. On the one hand, it provides prospective clinical data that further support the effectiveness of ONS in refractory migraine. On the other hand, its results are consistent with prior findings, thereby enhancing the robustness and credibility of the review’s conclusions. Second, regarding control group design, most studies in the review used self-controlled designs, limiting the ability to distinguish true surgical effects from placebo or natural migraine progression[3]. In other surgical fields, for example, randomized controlled trials of transurethral procedures for benign prostatic hyperplasia[4] have successfully included watchful waiting arms, which allow investigators to distinguish genuine treatment effects from natural progression or nonspecific improvements. Similarly, trials of paper patching for traumatic tympanic membrane perforation[5] and anterior cruciate ligament reconstruction[6] have incorporated observation or delayed surgery groups as comparators. Adopting similar comparator designs in migraine surgery would strengthen efficacy assessments and support evidence-based recommendations. Notably, in the field of acupuncture research for migraine, sham acupuncture has been widely adopted as a control condition in randomized controlled trials. Although sham needling may not be entirely inert, its use allows investigators to control for placebo responses and to better distinguish the specific effects of acupuncture from nonspecific improvements. For example, Liu[7]and Sun et al[8] included several clinical studies on acupuncture for migraine in which sham acupuncture was used as a control group. The use of sham acupuncture as a comparator did not diminish the scientific value of these trials, which were still considered high-level evidence and were incorporated into systematic reviews. This methodological framework illustrates the importance of incorporating appropriate comparator groups in interventional studies. By analogy, future surgical trials for refractory migraine could also benefit from adopting delayed surgery or sham surgical controls, which would similarly improve the rigor of efficacy assessment and provide more reliable evidence for clinical practice. In conclusion, acknowledging omitted studies and promoting rigorous control group designs are essential for advancing the evidence base. Expanding literature inclusion and incorporating comparator groups beyond self-control will improve future systematic reviews and trials, ultimately guiding clinical practice and patient care. We thank the authors and the journal for their contribution and hope our comments encourage further methodological refinement in surgical research for refractory migraine. To ensure this article complies with AI transparency requirements, we have conducted a self-assessment and declaration in accordance with the TITAN Guidelines 2025[9].