Fluorescent Lighting and Epilepsy

Summary: Fluorescent tubes flash at twice the mains frequency (100 Hz in Europe). With aging, 50‐Hz brightness modulation appears. A survey of tubes used in our institute showed that 42% exhibited brightness modulation up to a depth of 20% or occasionally 30%. The effects of fluorescent lighting on the EEGs of 20 patients with photosensitive epilepsy have been studied. In no patient did the 100‐Hz flicker of normally functioning tubes elicit paroxysmal activity. In 8 of 13 subjects sensitive to 50 Hz, IPS paroxysmal discharges were evoked by 50‐Hz brightness modulation, but only at modulation depths of 50% or more. It is concluded that as paroxysmal activity could not be elicited by normally functioning tubes nor at those depths of modulation occurring in practice, fluorescent lighting is unlikely to present a hazard to photosensitive patients.