Excitatory and inhibitory mechanisms of photosensitivity

Objective: Photosensitivity or photoparoxysmal response (PPR) is a highly heritable electroencephalographic trait characterized by an abnormal EEG reaction to intermittent photic stimulation (IPS), consisting of spikes, spike-waves, and intermittent slow waves. The knowledge concerning the pathophysiology of human photosensitivity is still limited. Methods: Phosphene threshold by a paired-pulse TMS (ISI=50 ms), suppression of visual perception by a single-pulse TMS (40–180 stimulus onset asynchrony, 75% of stimulator output, perception of letter trigrams, 25 ms exposition), threshold of motor evoked potentials (…