2022 Volume 39 Issue 4 Pages 613-619
Migraine is a neurological disease that is typically characterised by recurrent attacks of severe, unilateral, pulsating headaches associated with nausea, vomiting, photophobia, and phonophobia. Pharmacologic interventions for migraine include acute and preventive medications.
Several medications, including lomerizine, valproate acid, propranolol, amitriptyline, and verapamil, are used for migraine prophylaxis in Japan. However, substantial advances in migraine therapy mean that some individuals with migraine are refractory to guideline–based treatment.
Despite the definitions provided by the 3rd edition of the International Classification of Headache Disorders, it does not include a definition of refractoriness in migraine. A growing need of a shared definition of refractoriness has already been claimed from a multidisciplinary expert group. Though some definitions of refractory migraine (RM) have been created, it is still being debated what should be the key parameter of a definition of refractoriness (e.g., unresponsiveness to treatment, high frequency, severe disability or all of these features). Therefore, there is not enough consensus on the definition of RM.
Calcitonin gene–related peptide (CGRP) is a neuropeptide that has an important role in migraine pathophysiology and is a target for migraine preventive therapies. Monoclonal antibodies targeting CGRP (galcanezumab, fremanezumab and eptinezumab) and its receptor (erenumab) showed consistent efficacy for migraine prophylaxis with excellent safety profiles. The effects on refractory cases have also been reported, and it is expected to bring the good news to many patients who have not been effective with existing treatments, and a paradigm shift in migraine treatment is expected.
Following the widespread use of monoclonal antibodies targeting CGRP and its receptor, European headache federation proposed the definition of two subsets of difficult–to–treat migraine, resistant and refractory migraine, and considers both frequency and disability from single and frequent attacks. The definition will be expected to solve the conflicts that have limited the use of definitions which have been put forward in the past.
