Table 2.

Diagnosis criteria for refractory chronic migraine accepted by the European Headache Federation (2014)

1: Chronic migraine—no overuse of medication

2: Use of prophylactic medication in adequate doses for at least 3 months with each drug

3: Lack of effect (or contraindications for use) of 2 to 4 drugs from each of the following groups after appropriate treatment#

A: β-blockers: propranolol, metoprolol, atenolol, bisoprolol

B: Anticonvulsants: sodium valproate, topiramate

C: Tricyclic antidepressants: amitriptyline

D: Others: flunarizine, candesartan

E: Botulinum toxin A

4: Appropriate psychiatric treatment or other comorbidities carried out by a multidisciplinary group, if available

Adapted from [38]

^#Appropriate treatment is commonly understood as the time during which adequate doses of an indicated medication are administered, typically at least 2 months (preferably three) at the optimal dose or maximum tolerated dose, unless terminated earlier due to side effects. This concept requires the control of the factors promoting chronification [38, 39]