Non-invasive Vagus Nerve Stimulation for the Prevention of Migraines

Key Inclusion Criteria: * Between the ages of 18 and 75 years * Been previously diagnosed with migraine (with or without aura), in accordance with the ICHD-3 criteria * Experiences between 8 to 20 headaches days per month (during the last 3 months), with at least 5 of them being migraine days * Onset of migraine at age 50 years or younger * Agrees to refrain from initiating or changing any prophylactic medications for indications other than migraine Key Exclusion Criteria: * Concomitant medical condition that will require oral or injectable steroids during the study * Currently on a stable regime of more than 1 migraine preventative therapy * Other significant pain problem (e.g., cancer pain, fibromyalgia, other head or facial pain disorder) * Known or suspected severe cardiac disease (e.g., symptomatic coronary artery disease, prior myocardial infarction, congestive heart failure) * Known or suspected cerebrovascular disease * Previous cervical vagotomy * Currently implanted with an electrical and/or neurostimulator device * Been implanted with metal cervical spine hardware or has a metallic implant near the nVNS stimulation site * Known history or suspicion of secondary headache * Currently using marijuana (including medical marijuana) or has used marijuana (including medical marijuana) or cannabidiol oil within the last 6 months * Currently takes simple analgesics or NSAIDs \>15 days per month or triptans, ergots, or combined analgesics \>10 days per month for headaches or other body pain * Currently takes prescription opioids more than 2 days per month for headaches or body pain * Failed an adequate trial (2 months or greater) of at least 3 classes of a drug therapy for migraine prevention * Surgery for migraine prevention * Undergone nerve block (occipital or other) in the head or neck within the last 3 months * Received Botox or CGRP mAb injections within the last 6 months * Pregnant or thinking of becoming pregnant during the study period, or of childbearing years and unwilling to use an accepted form of birth control * Previously used gammaCore