Efficacy of prefrontal-occipital transcranial direct current stimulation for refractory chronic migraine

Introduction: Patients with chronic migraine (CM) frequently demonstrate resistance to conventional medical therapies, likely attributable to the multifactorial pathophysiology underlying their pain. Transcranial direct current stimulation (tDCS) has recently emerged as a promising non-invasive neuromodulation technique for migraine prophylaxis. In this study, we evaluate the efficacy of a tDCS protocol in treating CM patients, both with and without medication-overuse headache (MOH). Method: Thirty patients diagnosed with chronic migraine (CM) underwent treatment with tDCS (2 mA, 20 min/session) targeting the anodal right dorsolateral prefrontal cortex (DLPFC) and cathodal occipital region for three days each week over two weeks, followed by once-weekly sessions for an additional six weeks. Results: The tDCS demonstrated significant efficacy in pain reduction for CM patients, regardless of MOH comorbidity. After eight weeks, tDCS had significantly reduced severe migraine days (VAS score > 7), awakening migraine episodes, and mean headache intensity and duration. The maximum effects were observed for headache duration and the number of severe headache days. A reduction of more than 50% in the mean headache duration was achieved in 80% of participants. Similarly, 70% of patients demonstrated >50% decrease in severe headache days (VAS >7). Treatment was well-tolerated, with no serious adverse effects reported during the study period. Conclusion: TDCS appears to be an effective, well-tolerated, non-invasive treatment for CM patients, including cases with MOH. The significant reductions in headache duration, intensity, and frequency suggest that tDCS may be a valuable option for those resistant to standard medical therapies. Trial registration: Iranian Registry of Clinical Trials IRCT20140624018213N2. Registered 17 June 2026. Retrospectively registered.