Management of auricular transcutaneous neuromodulation and electro-acupuncture of the vagus nerve for chronic migraine: a systematic review

Abstract

BackgroundMigraine is a type of primary headache that is accompanied by symptoms such as nausea, vomiting, or sensitivity to light and sound.ObjectiveThe aim of this study was to conduct a systematic review on the effectiveness of non-invasive neuromodulation, auricular transcutaneous vagus nerve stimulation (at-VNS), and electro-ear acupuncture of the vagus nerve in patients with migraine headaches.MethodsSix databases were searched from inception to 15 June 2022 for clinical trials, in which at least one group received any form of non-invasive neuromodulation of the vagus nerve for managing migraine with outcomes collected on pain intensity and related disability. Data, including participants, interventions, blinding strategy, outcomes, and results, were extracted by two reviewers. The methodological quality was assessed with the PEDro scale, ROB, and Oxford scale.ResultsThe search identified 1,117 publications with nine trials eligible for inclusion in the review. The methodological quality scores ranged from 6 to 8 (mean: 7.3, SD: 0.8) points. Low-quality evidence suggests some positive clinical effects for the treatment of chronic migraine with 1 Hz with at-VNS and ear-electro-acupuncture compared with the control group at post-treatment. Some of the studies provided evidence of the relationship between chronic migraine and a possible positive effect as a treatment with at-VNS and the neurophysiological effects using fMRI. Six of the studies provided evidence using fMRI of the relationship between chronic migraine and a possible positive effect as a treatment with at-VNS and the neurophysiological effects. Regarding all included studies, the level of evidence with the Oxford scale was level 1 (11.17%), six studies were graded as level 2 (66.66%), and two studies were graded as level 3 (22.2%). With the PEDro score, five studies got a low methodological score < 5 and only four got a score superior to 5, being highly methodological quality studies. For ROB, most of the studies were high risk and only a few of them received a low risk of bias. The pain intensity, migraine attacks, frequency, and duration were measured by three studies with positive results at post-treatment. And only 7% reported adverse events using at-VNS. All studies reported results at a post-treatment period in their respective main outcomes. And all studies with fMRI provided strong evidence of the relationship between the Locus Coeruleus, Frontal Cortex, and other superior brain areas with the auricular branch of the Vagus nerve with at-VNS.ConclusionSome positive effects regarding the effect of non-invasive neuromodulation, auricular transcutaneous vagus nerve stimulation (at-VNS), and electro-ear acupuncture of the vagus nerve on migraine is reported in the current literature, but there are not enough data to obtain strong conclusions.Systematic review registrationThis systematic review was registered in the PROSPERO database (registration number: CRD42021265126).

Efficacy and Safety of Auricular Acupuncture for Depression

“…Besides the technique’s safety, patients in the SA group had increased rates of symptom remission between 6 weeks and 3 months, which may be associated with the delayed effects of AA treatment . We should underscore that in AA, part of the technique’s effect is attributed to stimulating the auricular branch of the vagus nerve, increasing parasympathetic activity while simultaneously decreasing sympathetic nervous system activity . This effect may lead to an improvement in depression-related symptoms .…”

Neuromodulation Techniques for Headache Management

“…Song et al [29] Decrease in number of migraine attacks. Fernandez-Hernando et al [30] External Trigeminal Nerve Stimulation NI None reported [26].…”

“…Of these, n-cNVS was approved by the Food Drug Administration (FDA) for treatment of migraines in 2018, nearly 21 years after the original technology was introduced [29]. This technique simply necessitates the placement of an electrical stimulation device on the concha or tragus of the ear with the goal of stimulating the auricular branches of the vagus nerve, providing analgesic effects [30].…”

“…However, when stratified by n-cVNS and n-aVNS, the authors found that n-aVNS did significantly reduce migraine days, suggesting that specific applications of n-VNS may be an effective therapy [29]. Another systematic review which looked at nine studies on n-aVNS similarly found that the therapy helped to reduce the number of migraine attacks [30]. However, the studies included in this review exhibited considerable variability in follow-up periods and study protocols, precluding the evaluation of the data via meta-analysis.…”

Eficácia da acupuntura auricular na qualidade do sono em indivíduos com sintomas depressivos: ensaio clínico randomizado

“…Isso envolve alternar entre estados de É importante ressaltar que, na prática da acupuntura auricular, uma parcela significativa dos efeitos da técnica tem sido atribuída à estimulação do ramo auricular do nervo vago. Este estímulo tem o efeito de aumentar a atividade do sistema nervoso parassimpático, ao mesmo tempo em que reduz a atividade do sistema nervoso simpático(118,119). A estimulação transcutânea do nervo vago auricular (taVNS) tem demonstrado segurança e eficácia em condições como epilepsia, transtornos depressivos maiores e insônia(120).…”