Investigation and Modulation of the Central Mu-Opioid Mechanism in Migraine (in Vivo)

Clinical Trial: This is a phase 2, single center, three-arm, double-masked, randomized investigation and modulation of the µ-opioid and D2/D3 mechanisms in chronic migraine (in vivo). We will enroll 60 patients with Chronic Migraine divided into 3 Lab/Home-Based groups: 20 for the active unilateral M11-2 HD-tDCS group, 20 for the active bilateral M11-2 HD-tDCS group, and 20 for the sham M11-2 HD-tDCS group. Patients will complete a screening visit, baseline visit with MRI and PET session, 20 days of HD-tDCS brain stimulation treatments, as well as follow-up visits with an MRI and PET session. Observational Study Arm: 20 additional patients with low frequency EM (\<8 attacks/month) patients (that did not undergo neuromodulation) will be recruited for the study. Historical data may be used in place of recruiting new participants. Data from these 20 EM volunteers will be compared to that of CM patients at baseline; however, they will not be part of the clinical trial.