Shaping and generalization procedures in the EMG-biofeedback treatment of tension headaches

Headaches treatment with EMG biofeedback: a focused systematic review and meta-analysis

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.

Behavioral treatments of chronic tension-type headache in adults: are they beneficial?

To assess the efficacy of behavioral treatments in patients with tension headache. Medline, Cinahl, EMBASE, and the Cochrane library were searched from inception to October 2007 and reference lists were checked. We selected randomized trials evaluating behavioral treatments (e.g., relaxation, electromyographic [EMG] biofeedback, and cognitive behavioral training) in patients with tension-type headache (TTH). We assessed the risk of bias using the Delphi list and extracted data from the original reports. A qualitative analysis was carried out. We found 44 trials (2618 patients), which were included in this review, of which only 5 studies (11.4%) were considered to have low risk of bias. Most trials lacked adequate power to show statistical significant differences, but frequently, recovery/improvement rates did not reach clinical relevance. In 8 studies, relaxation treatment was compared with waiting list conditions, and in 11 studies, biofeedback was compared with waiting list conditions, both showing inconsistent results. On the basis of the available literature, we found no indications that relaxation, EMG biofeedback, or cognitive behavioral treatment is better than no treatment, waiting list, or placebo controls.

Age comparisons in acquiring biofeedback control and success in reducing headache pain

This article presents a review and archival analysis to assess age differences in acquiring biofeedback control and success in treating recurrent headache by using data from 56 studies with either adult (total N = 503) or child (total N = 98) subjects. All studies focused on treating headache with temperature biofeedback (TBF) or electromyographic (EMG) biofeedback. To standardize the varied measures across studies, we calculated each study's percent change scores for biofeedback performance and headache activity. All headache activity scores included assessments of pain intensity. We then calculated subject-weighted means of percent change for biofeedback performance and for headache activity by summing the products of each relevant percent change score and N and then dividing by the total number of subjects contributing to those sums. Results showed that both children and adults reported substantial improvements in headache activity with TBF and EMG biofeedback treatment (Ms ranged from 34% to 81%), but children showed significantly greater improvement than adults. No age differences were found in the acquisition of biofeedback control. Further analyses revealed two additional findings. First, biofeedback control and headache improvement were strongly correlated. Second, headache activity continued to decrease in the weeks following treatment, and this decrease was significantly greater for children than adults.

Hypnotic susceptibility, mood state, and cardiovascular reactivity

In this study we explored the relationship between hypnotic susceptibility measured with the Harvard Group Scale of Hypnotic Susceptibility (HGSHS) and cardiovascular parameters. After assessing their degree of hypnotic susceptibility, we induced 21 female students into happy mood states and into sad mood states. During the mood state induction we monitored blood pressure, heart rate, and cardiac vagal tone continuously. The study demonstrated a strong relationship between hypnotic susceptibility and both cardiac vagal tone and heart rate reactivity. Subjects with lower heart rate and greater vagal tone during baseline and greater heart rate increases during mood induction were more susceptible to hypnosis. Multiple regression analyses indicated that approximately 40% of the individual difference variance of hypnotic susceptibility was accounted for by baseline cardiac vagal tone and heart rate reactivity during mood state. The data demonstrate that autonomic tone, assessed by cardiac vagal tone and heart rate reactivity, are related to hypnotic susceptibility as measured by the HGSHS.

Client variables and the behavioral treatment of recurrent tension headache: a meta-analytic review

Meta-analysis revealed that in studies evaluating behavioral treatments for tension headaches, the treatment outcome has varied with the client samples (e.g., age, gender, referral source) that have been used but not with the treatment procedures (e.g., type of behavioral intervention, length of treatment, whether or not efforts were made to facilitate transfer of training) or the research designs (e.g., internal validity, explicitness of diagnostic criteria) that have been used. Mean client age proved the best predictor of treatment outcome, accounting for 30% of the outcome variance following behavior therapy. Significantly poorer outcomes have also been reported in recent studies than were reported in early studies. These findings suggest that outcomes obtained with behavioral interventions have been less dependent upon the treatment variables that have been the primary focus of research attention than upon characteristics of client samples and behavioral interventions may be less effective in reducing headache activity than has previously been assumed.