The effect of transcutaneous Vagus Nerve Stimulation in migraine: an alternative treatment of chronic migraine

Abstract Context: Migraine is a disabling condition that is currently underdiagnosed and undertreated. Transcutaneous vagus nerve stimulation (VNS) is among the most researched non-invasive brain stimulation techniques for migraine control. Objectives: In this integrative review, we discuss the effects of VNS parameters (waveform, frequency, intensity, cycle, and current), central, and clinical mechanisms in auricular (taVNS) or cervical (tcVNS) transcutaneous VNS in the control of migraine pain.Methods: PubMed (National Library of Medicine), Cochrane Library, CAPES Journals (Portal of Journals of the Coordination for the Improvement of Higher Education Personnel), Virtual Health Library (VHL), and Google Scholar were searched by computer from the establishment of within the 10-year period (2011–2021). Results: Initially, a total of 10,017 articles were identified. After applying the exclusion criteria, 10,007 articles were excluded. The eligibility criteria were analyzed and only ten articles fulfilled the criteria. The most used parameters in this study for VNS were the frequencies of 1 Hz, 25 Hz, and 30 Hz. The 1 Hz stimulation caused a more significant reduction in the number of days with headache. The total stimulation time varies between studies, ranging from 2 min to 240 min, and can be repeated for a period or a single session. Studies that used a longer treatment period showed clinical results in reducing pain and analyzed the scores. Moreover, studies have shown reduced intensity or severity of pain after taVNS.Conclusions: The studies performed taVNS or tcVNS, and both methods had positive effects on migraine control, pain reduction, and migraine score.