Effects of Green Light Exposure on Epileptic Spikes in Patients With Refractory Epilepsy

The trial is designed to detect (1) change in spike frequency on EEG before and after exposure to low intensity green light, and (2) presence or absence of neurologic/systemic symptoms referable to exposure of the pre-selected duration, intensity, and band of green light. Our primary aim is to determine whether prolonged exposure (120 minutes) to a narrow band of green light (520-540 nm) at low intensities (1-10 cd/m2) alters the pattern of electrical activity in the cortex of epilepsy patients. The primary outcome measure for this aim will be the fraction of patients in which the number of epileptiform discharges (spikes or sharp waves) decrease, per recording, in response to green light exposure, as determined by spike frequency detected via scalp EEG before and after green light exposure. The investigators anticipate that the primary outcome measures of safety and tolerability will not differ from the previously established measures of green light exposure for migraine (Noseda et al. 2016). The investigators will use only low intensities (1-10 cd/m2) of green light which is well tolerated in adults and children (Main et al. 2000). In addition, given limited experience with conventional green light exposure in epilepsy, the investigators predict that post-exposure to green light, patients will have an improvement on the post-exposure EEG (decreased spike frequency).