Transcranial static magnetic field stimulation (tSMS) of the visual cortex decreases experimental photophobia

BackgroundTranscranial static magnetic field stimulation (tSMS) reduces cortical excitability in humans.MethodsThe objective of this study was to determine whether tSMS over the occipital cortex is effective in reducing experimental photophobia. In a sham-controlled double-blind crossover study, tSMS (or sham) was applied for 10 minutes with a cylindrical magnet on the occiput of 20 healthy subjects. We assessed subjective discomfort induced by low-intensity and high-intensity visual stimuli presented in a dark room before, during and after tSMS (or sham).ResultsCompared to sham, tSMS significantly reduced the discomfort induced by high-intensity light stimuli.ConclusionsThe visual cortex may contribute to visual discomfort in experimental photophobia, providing a rationale for investigating tSMS as a possible treatment for photophobia in migraine.