Evaluating brain mechanisms of combined vagus nerve stimulation and mindfulness training for migraine: A randomized 2 × 2 factorial clinical trial protocol

BACKGROUND: Migraine is a major cause of disability and efficacious interventions are needed. In this mechanistic study, we investigate the combined, and potentially synergistic, effects of a multimodal intervention combining Mindfulness-Based Stress Reduction (MBSR) and transcutaneous auricular Vagal Nerve Stimulation (taVNS) for migraine. METHODS: We utilize a modified double-blinded, placebo-controlled, 2 × 2 factorial randomized longitudinal design to assess the effects of an 8-week MBSR intervention with concomitant Respiratory-gated Auricular Vagal Afferent Nerve Stimulation (RAVANS) taVNS on migraine pathophysiology primary outcomes. We will enroll 150 patients with migraine (4-20 headache days/month). After a run-in month of daily diaries, we expect to randomly assign N = 96 participants to one of four treatment groups: (1) MBSR+RAVANS taVNS, (2) MBSR+Sham taVNS, (3) Nature Education Control (NEC) + RAVANS taVNS, or (4) NEC + Sham taVNS. Before and after intervention, participants have three in-person assessments (a 7 T MRI scan, an autonomic/sensory testing (AST) visit, and a 3 T PET-MRI scan). The primary outcomes for this study assess (1) central sensitization (brainstem/cortical response to trigeminal sensory afference), (2) autonomic dysfunction (High Frequency-Heart Rate Variability (HF-HRV) response to stressors), and (3) neuroinflammation (PET[11C]PBR28 signal). RESULTS: Funded by NIH (P01AT009965), registered (NCT03592329). Final longitudinal outcomes will be collected by May 2025. CONCLUSION: This mechanistic study is designed to investigate both independent and synergistic neurobiological effects of MBSR and RAVANS taVNS interventions on three distinct pathophysiological mechanisms of migraine. This research will elucidate the mechanistic and potentially synergistic effects of behavioral interventions (e.g., mindfulness) and device-based treatments (e.g., taVNS) for migraine.