Cathodal transcranial direct current stimulation of the visual cortex in the prophylactic treatment of migraine

Background: The purpose of this study was to determine whether transcranial direct current stimulation (tDCS) can be an effective prophylactic therapy for migraine and migraine-associated pain. Method: This painless and non-invasive method was applied for 6 weeks over the visual cortex (V1), delivered three times per week. Thirty patients were assigned to cathodal or to sham stimulation, and 26 patients participated in the final analyses (cathodal: n = 13, sham: n = 13). During the first 3 weeks both groups received only placebo stimulation. Measures of attack frequency and duration, intensity of pain and number of migraine-related days were recorded 2 months before, during and 2 months post-treatment. Results: Patients treated by cathodal tDCS showed a significant reduction in the duration of attacks, the intensity of pain and the number of migraine-related days post-treatment as compared to the baseline period, but not in the frequency of the attacks. However, compared to the sham group, only the intensity of the pain was significantly reduced post-stimulation. No patients experienced severe adverse effects. Conclusion: Our results suggest that the application of cathodal stimulation over the V1 might be an effective prophylactic therapy in migraine, at least with regard to pain control.