Being able to predict each patients response to a specific treatment can mean a significant improvement in socioeconomic costs, but above all in their quality of life. With the present study, the investigators aim to analyze in a combined way different clinical, biological and neuroimaging variables, which allow the clinical staff to anticipate the response to treatment with anti-CGRP monoclonal antibodies in patients with migraine.

The study consists of an initial visit coinciding with the start of treatment, a subsequent visit after 6 months of treatment and finally another after 12 months, coinciding with the end of treatment. In case of worsening after suspension, a clinical visit will be carried out at the time of worsening to evaluate the reintroduction of the drug and in case of reintroduction, a visit will be carried out after 3 months. If patients do not worsen, a visit will be made 6 months after completing treatment.

At each visit, demographic and clinical variables will be collected. In addition, 3 blood tests will be performed corresponding to the beginning of treatment, after 6 months and a month and a half from the last infiltration. Likewise, a brain MRI will be obtained prior to the start of treatment. These blood samples and neuroimaging data will be processed for subsequent analysis.

Inclusion Criteria:

• Patients aged between 18 and 65 years.
• Caucasian ethnicity.
• Patients diagnosed with migraine with and without high-frequency episodic aura (more than 8 days of migraine per month) or chronic by a neurologist expert in headaches and according to the criteria proposed in the International Classification of Headache Diseases, 3rd edition (ICHD- 3).
• Have at least one year of history of migraine.
• Patients must maintain stable preventive treatment in the previous month and not have received botulinum toxin in the month prior to starting the monoclonal antibody.
• Patients able to describe their clinical situation and the characteristics of their headache.
• Grant your informed consent.

Exclusion Criteria:

• Patients who present with another type of non-migraine headache, with the exception of headache due to excessive use of analgesic medication.
• Neurological focus in the examination.
• Pregnancy or breastfeeding period.
• Patients with cognitive deficiency or pathology that may prevent or hinder the correct completion of the study.
• Patients who require changes in preventive treatment during the first 6 months after starting treatment with monoclonal antibodies.
• Patients who present any significant adverse effect that requires withdrawal or change of anti-CGRP drug.

Patients aged between 18 and 65 years with a diagnosis of episodic or chronic migraine who, at the discretion of their neurologist and according to clinical practice guidelines and standard of care, receive treatment with monoclonal antibodies against CGRP (Galcanezumab, Fremanezumab, Eptinezumab) or its receptor (Erenumab) be included. These patients will come from 7 Headache Units in Spain belonging to the following hospitals:

• La Princesa University Hospital
• Vall d'Hebron University Hospital
• Marqués de Valdecilla University Hospital
• Valladolid University Clinical Hospital
• Donostia University Hospital
• Lozano Blesa University Clinical Hospital
• La Fe Polytechnic University Hospital

Individual participant data (IPD) will not be shared with other researchers. This decision is based on data protection and confidentiality requirements in accordance with applicable European and national regulations (including GDPR). Given that this is a multicentre observational study conducted in routine clinical practice, access to IPD is restricted to the study investigators for the purposes of the predefined analyses.

Any potential secondary use of the dataset would only be considered in fully anonymized form and subject to prior ethical approval and compliance with applicable data protection legislation.