Analysis of characteristics of photosensitivity and electroencephalography under different eye conditions of intermittent photic stimulation in epilepsy children / 临床神经病学杂志

ABSTRACT

Objective To research the characteristics of photosensitivity and EEG under different eye conditions of intermittent photic stimulation (IPS) in epilepsy children. Methods Epilepsy children showed positive under IPS were chose. The characteristics of photosensitivity and EEG under different eye conditions were analyzed. Results From 104 patients, background was normal in 101 cases (97. 1% ), background was slower in 3 cases (2. 8% ). Epileptic discharges during interictal periods was in 99 cases (95. 1% ), and generalized discharge was in 66 cases (63. 5% ), partial discharge was in 20 cases (19. 2% ), generalized discharge and partial discharge was in 13 cases (12. 5% ). Generalized discharge during IPS was in 96 cases (92. 3% ), partial discharge during IPS was in 8 cases (7. 7% ). The clinical attacking rate of IPS was significantly higher for those who showed positive in IPS in eye closure, opened, and closed condition than other patients (χ2 =4. 575,P=0. 032). Photosensitivity could increases then decreases as frequency increases, and reached highest when frequency was from 8 to 25 Hz. All of patients who generalized discharges during interval periods appeared generalized discharges during IPS, and 65. 0% patients who partial discharge during interval periods appeared generalized discharges during IPS; there was significant statistical differences (χ2 =20. 684, P<0. 001). Conclusions Photosensitivity is more common in idiopathic generalized epileptic children. The positive rate of IPS is higher under eye open or closure than eye closed, and it reaches highest when frequency is from 8 to 25 Hz. When photosensitivity happened under all three eye conditions, it is easily caused to seizure. The characteristic of discharge under IPS is strongly related to EEG of interictal periods and types of epilepsies.