Flicker illness: an under recognized but preventable complication of helicopter transport

Cushman JT, Floccare DJ. Prehosp Emerg Care. 2007 Jan-Mar;11(1):85-8. Division of EMS and Office of Prehospital Care, Department of Emergency Medicine, University of Rochester School of Medicine and Dentistry, Rochester

A case report of seizure due to photic stimulation from sunlight shining through spinning helicopter rotor blades is discussed. A review of photosensitive epilepsy is provided with particular emphasis on the effects and frequencies of photic stimulation required to induce symptoms. The frequencies of flashing light produced by spinning helicopter rotor blades commonly used in air medical transport range from 24 to 27 flashes per second. These frequencies are well within the range reported in the literature to produce symptoms in the laboratory setting. The literature provides only a few case reports of individuals sustaining a seizure after photic stimulation from spinning turboprop or helicopter blades. Symptoms range from mild discomfort and headache to profound spatial disorientation and seizures and may be an under recognized but preventable complication of air medical transport.