TRANSCUTANEOUS OCCIPITAL NERVE STIMULATION AND TRANSCRANIAL DIRECT CURRENT STIMULATION IN CHRONIC MIGRAINE: A PILOT COMPARISON OF THERAPEUTIC AND ELECTROPHYSIOLOGICAL EFFECTS

Background: Management of chronic migraine (CM) is often challenging. There is a need for more effective and better-tolerated preventive therapies. Among non-invasive neurostimulation procedures, transcutaneous occipital nerve stimulation (tONS) would act via central pain modulation, while transcranial direct current stimulation (tDCS) would modify cortical excitability that is abnormal in CM. Objectives: In this pilot trial we compared the clinical effects of tDCS and tONS in refractory CM and their ability to modify nociception and cortical responsiveness. Methods: Forty-three CM patients (17 with history of drug overuse) applied either 2mA tDCS during 2 months (N¼20, cathode over visual cortex, anode over left DLPFC), or tONS during 3 months (N¼23, Cefaly Kit ArnoldTM), both in daily 20 min-sessions. Visual evoked potentials (VEP), nociceptive blink reflexes (nBR) and quantitative sensory testing were recorded before and after treatment. Results: During the last stimulation month, total headache days decreased in both groups ( 16.4% for tDCS, 17% for tONS, p<0.05). Migraine days were reduced by 21.4% (p¼0.06) and 22% (p