Generalized Epileptic Seizure Induced by the Stroboscopic Effect of Helicopter Blades.

BACKGROUND: The stroboscopic effect made by helicopter blades passing through rays of sunlight is known as a factor that can induce an epileptic seizure.CASE REPORT: We report a case of inaugural tonic-clonic generalized seizure while refueling an NH 90 helicopter by an aeronautical technician standing under the rotating main rotor on a sunny day at a South of France naval air station. The stroboscopic effect of the helicopter blades was identified as one of the factors involved in the induction of this seizure.DISCUSSION: This aeronautical factor identified here during ground hot refueling must be considered for patients predisposed to epileptic seizures who are being evacuated by helicopter, but also for the medical screening of flight members. This is even more important within the military aeronautical environment, justifying electroencephalogram testing implementation on initial aeronautical medical evaluation in France.Corgie L, Huiban N, Quesnel L, Brocq F-X, Boulard J-F, Monteil M. Generalized epileptic seizure induced by the stroboscopic effect of helicopter blades. Aerosp Med Hum Perform. 2019; 90(10):891-895.

Stroboscopic light effects during electronic dance music festivals and photosensitive epilepsy: a cohort study and case report.

OBJECTIVES: Electronic dance music (EDM) concerts are becoming increasingly popular. Strong stroboscopic light effects are commonly part of these shows, and may provoke seizures in individuals with photosensitive epilepsy. This study aims to examine the risk of epileptic seizures during EDM concerts. SETTING: 28 EDM concerts taking place in The Netherlands. PARTICIPANTS: We describe a young man who experienced a seizure during an EDM concert, and who later showed a positive electroencephalographic provocation test during exposure to video footage of the same concert. Subsequently, we performed a cohort study of 400 343 visitors to EDM concerts, divided in those exposed (concert occurring in darkness) versus unexposed (concert in daylight) to stroboscopic light effects. RESULTS: In total, 400 343 EDM concert visitors were included: 241 543 (representing 2 222 196 person hours) in the exposed group and 158 800 (representing 2 334 360 person hours) in the control group. The incidence density ratio of epileptic seizures in exposed versus unexposed individuals was 3.5 (95% CI: 1.7 to 7.8; p<0.0005). Less than one-third of cases occurred during use of ecstasy or similar stimulant drugs. CONCLUSION: Stroboscopic light effects during EDM concerts occurring in darkness probably more than triple the risk of epileptic seizures. Concert organisers and audience should warn against the risk of seizures and promote precautionary measures in susceptible individuals.

The effect of various levels of stroboscopic illumination on the growth of guinea pig eyes.

BACKGROUND: The aim was to investigate various levels of stroboscopic illumination effect on the growth of guinea pig eyes. METHODS: Thirty-six two-week-old guinea pigs were randomised to one of three treatment groups (n = 12 for each). Two stroboscopic-reared groups were raised with a duty diurnal cycle of 50 per cent at a flash rate of 0.5 Hz. Illumination intensity varied between zero-to-250 lux or zero-to-500 lux during each cycle in each group, respectively. The third control group was exposed to 250 lux illumination. Refraction and biometric measurements were taken for each animal prior to and after two, four, six and eight weeks of treatment. Finally, retinal microstructure was examined. RESULTS: There was significant correlation between refractive errors and axial elongation. After eight weeks of treatment, illumination with flickering light 0-250 lux caused a larger myopic shift with increased axial length than illumination of continuous 250 lux. Stroboscopic illumination with zero-to-500 lux caused a further myopic shift and longer axial length than stroboscopic illumination with zero-to-250 lux. In animals raised in flickering light of zero-to-250 lux or zero-to-500 lux for eight weeks, the outer segment disc membranes in photoreceptor layers were found deformed and detached. CONCLUSION: Chronic exposure to low-frequency temporally modulated illumination-induced histological damage in the retina and induced exaggerated axial length elongation.