Inclusion Criteria:  male or female patients, aged between 40 and 70 years, referring to the Headache Center of the University of L'Aquila; a diagnosis of migraine with or without aura according to the International Classification of Headache Disorders, 3rd Edition (ICHD-3; https://ichd-3.org/); age at onset of migraine <50 years; migraine must have been present for at least ≥ 12 months; treated with CGRP-MAbs (erenumab, fremanezumab or galcanezumab) according to clinical practice criteria for 90-180 days since the first subcutaneous administration (this time range was chosen to ensure a stable CGRP pathway inhibition); reporting >4 monthly migraine days in the last 30 days of observation despite treatment with CGRP-MAbs; able to discriminate between migraine and tension-type headaches; written informed consent to participate in the study  Exclusion Criteria:  any migraine preventive medication other than CGRP-MAbs; secondary migraine; epilepsy or any other neurologic condition that may be worsened by transcranial electrical stimulation; metallic head implants, cardiac pacemaker or any other device that could malfunction or be displaced by electrical stimulation; pregnancy or lactation.