Introduction: The aim of this paper was to present an up-to-date evaluation of the efficacy of EMG-biofeedback (EMG-BFB) for primary headaches and to address possible mediators of outcome.
Evidence acquisition: PubMed, Scopus, Embase and Pedro databases were searched from inception to May 1, 2023. All randomized controlled trials (RCT) studies using an EMG-BFB to treat headache have been included in this systematic review. The current systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations and was registered in the PROSPERO database (CRD42022312827). Methodological quality was assessed through the Risk of Bias tool 2 (RoB 2). The effect sizes and 95% confidence interval (CI) were calculated by random-effect models on frequency, intensity, and duration variables. Egger regression and the Begg-Mazumdar rank correlation test were used for publication bias.
Evidence synthesis: A total of 3059 articles were identified through the database searches. 29 articles, involving 1342 participants, met the inclusion criteria for the systematic review; of them, 4 were included in the meta-analysis. Ten studies reported a significant improvement in the EMG-BFB group with respect to the control group. Meta-analyses show a reduction in the intensity of attacks in patients subjected to EMG-BFB (ES 0.21 [(95% CI=-0.02; 0.44), P value=0.07] based on 293 patients).
Conclusions: EMG-BFB represents a non-pharmacological approach to headache treatment as shown via qualitative synthesis, despite not impressive results, this technique can be particularly useful in paediatric or in adult patients who cannot undergo drug therapies. Quantitative synthesis revealed a promising effect in the intensity of headaches attacks. Moreover, no significant effect was found about the effectiveness of EMG-BFB in the reduction of frequency and durations of headache attacks. Future studies with new multimodal technologic assessment and following RCT guidelines can unmask the potentiality of EMG-BFB in the treatment of headache.