New Methods for Evaluating Preventive Migraine Treatment

Inclusion Criteria: 1. Adults (18-65 years) 2. ≥ 1-year history of migraine with or without aura according to the International Classification of Headache Disorders (ICHD-3) diagnostic criteria 3. Known chronic migraine (headache occurring ≥ 15 days per month for \> 3 months, which on at least 8 days per month has the features of migraine headache) diagnosed before age 65 4. Eligibility for preventive migraine treatment 5. Ability to speak and read Danish Exclusion Criteria: 1. Use of onabotulinumtoxinA as preventive migraine treatment during the 4 months before inclusion 2. Use of other preventive migraine treatment except CGRP antagonists (However, participants are allowed to be on two stable preventive medication (antidepressant, calcium channel blockers, beta blockers or antiepileptic)- 2 months prior to inclusion until end of study), devices for migraine prevention such as transcranial magnetic stimulation and use of nerve blocks 3 months prior to inclusion 3. Use of opioid or barbiturate medications in the last four weeks before inclusion 4. Secondary headache disorders including medication overuse headache 5. Severe psychiatric, vascular disease, or known liver disease 6. Alcohol abuse or substance abuse 7. Current or planned pregnancy and lactation