Novel Insight Into Migraine Pathophysiolgy and Galcanezumab Mechanisms of Action

A brief overview of the study: To test the working hypothesis of the study, the investigators propose to study 60 chronic migraine (CM)/high-frequency episodic migraine (HFEM) patients in 4 visits to the Beth Israel Deaconess Medical Center (BIDMC) Comprehensive Headache Center and 2 visits to the imaging center at McLean Hospital. The first 3 visits to BIDMC Comprehensive Headache Center and the first visit to McLean Hospital will take place before treatment, whereas the 4th visit to BIDMC Comprehensive Headache Center and the second visit to McLean Hospital will take place 3 months after initiation of treatment. In these visits, the investigators will collect medical and headache history, perform a physical examination, administer and review subjects' e-diary, and perform functional and structural fMRI brain imaging (see flow chart). Overall study design: Experimental prospective study involving identification of neurological effects after treatment of CM and HFEM with galcanezumab - an anti-CGRP-monoclonal antibody (mAb). Design methodologies: Open-label treatment study comparing the effects of galcanezumab on neurological functioning and brain structure in super-responders, responders and non-responders among CM and HFEM patients. Primary goal: To determine whether galacanezumab - a drug that acts mainly outside the brain - reverses abnormal brain functioning in CM and HFEM patients. For this study, signs of abnormal brain functioning include triggering of migraine by deviation from homeostasis (prodromes, sleep deprivation, skipping meals) and abnormal sensitivity to sensory stimuli (light, noise, smell, auras). Key details of study implementation: The study includes CM and HFEM patients. The intervention is galacanezumab (Emgality™). Galcanezumab is an anti-CGRP-mAb approved by the FDA for the prophylactic treatment of migraine. Because this is not an efficacy study, the primary endpoint will not include reduction in number of migraine/headache days per month. Rather, the primary endpoints of the study will include the following: incidence of prodromes, incidence of triggers, sensitivity to light, noise and smell during and in between attacks, and incidence of aura (as determined by filling the e-diary), gray mater thickness and connectivity strength between brain areas involved in migraine (as determined by fMRI). Each patient will be scheduled to visit the headache clinic at BIDMC 4 times and the McLean Hospital Pain Imaging Center twice (a total of 6 hospital visits). Visits 1 and 6 (at BIDMC) will take 1 hour. Visits 2 and 4 (at BIDMC) will take 30 min. Visits 3 and 5 (at McLean Hospital) will take 2 hours. In addition, each patient will have to fill a daily diary for 4 months (estimated to take 5 minutes per day), and will receive a 5 minute weekly phone call from a study coordinator. Participants will undergo the following procedures: 1. Medical and Headache history at BIDMC (questionnaire filled by patients and reviewed by Drs. Ashina and Burstein) 2. Physical examination including measurements of vital signs at BIDMC (performed by Dr. Ashina). 3. E-diary education and administration by study coordinator. a. The diary e-diary will be administered in the form of a REDCap survey using an email link that participants can access from their personal computer/electronic device. 4. 2 fMRI sessions at McLean Hospital by Dr. Borsook (see attached protocol from Dr. Borsook at McLean Hospital) 5. Administration of galcanezumab by Dr. Ashina at BIDMC. 6. Self administration of galcanezumab at home McLean Hospital part of the study: Patients recruited to the study at BIDMC and deemed eligible to participate in the study (per the results of visits 1 and 2), will be referred to McLean Hospital for the fMRI scanning. All fMRI scanning will take place at McLean Hospital under the supervision of our Co-investigator Dr. David Borsook. Subjects will travel to McLean Hospital and be met by the research coordinator at McLean, Jaymin Upadhyay, to escort them to the MRI scanning area. The McLean MRI staff will review the subject's MRI safety checklist and prep the subjects for scanning.Each patient will be scanned twice, once before initiation of treatment with galcanezumab and a second time on day 115 of the study, after being on galcanezumab for about 3 months. Image acquisition will be performed with a Siemens Systems 3 Tesla MRI scanner equipped with a 32-channel head coil. For each patient, a high-resolution, T1-weighted magnetization-prepared rapid gradient-echo sequence will be acquired \[slices = 176, field of view = 220 x 220, echo time = 1.74, repetition time = 2520, flip angle = 7°, resolution = 1 x 1 mm, slice thickness = 1 mm, no gap\]. Preprocessing for the surface-based morphometric analysis will be performed using FreeSurfer (version 5.3.0) (http://surfer.nmr.mgh.harvard.edu), a semi-automated toolbox for cortical surface reconstruction and visualization Affine registration of the T1-weighted volume to Talairach space is then performed, followed by skull stripping, white matter (WM) segmentation and tessellation of the gray/white matter boundary. Visual inspection and manual correction of topological errors are carried out at each processing step. Following reconstruction of the cortical surface, brains will be inflated, averaged across patients to produce a study-specific brain, and then smoothed using a 10 mm full-width at half maximum Gaussian kernel. Each hemisphere will be parcellated into 34 distinct regions using the Desikan-Killiany atlas. A direct measure of cortical thickness will then be calculated using the shortest distance (mm) between the pial surface and gray-white matter boundary at each point or vertex of the cortical mantle.