Zifkin B G, Kasteleijn-Nolst Trenité D
Epilepsy Clinic, Montréal Neurological Hospital and Institute, Canada.
Epileptic Disord. 2000 Sep;2(3):129-36.
Reflex epilepsy of the visual system is charecterised by seizures precipitated by visual stimuli. EEG responses to intermittent photic stimulation depend on the age and sex of the subject and on how stimulation is performed: abnormalities are commonest in children and adolescents, especially girls. Only generalised paroxysmal epileptiform discharges are clearly linked to epilepsy. Abnormal responses may occur in asymptomatic subjects, especially children. Photosensitivity has an important genetic component. Some patients are sensitive to patterns, suggesting an occipital trigger for these events. Myoclonus and generalised convulsive and nonconvulsive seizures may be triggered by visual stimuli. Partial seizures occur less often and can be confused with migraine. Although usually idiopathic, photosensitive epilepsy may occur in degenerative diseases and some patients with photosensitive partial seizures have brain lesions. Sunlight and video screens, including television, video games, and computer displays, are the commonest environmental triggers of photosensitive seizures. Outbreaks of triggered seizures have occurred when certain flashing or patterned images have been broadcast. There are regulations to prevent this in some countries only. Pure photosensitive epilepsy has a good prognosis. There is a role for treatment with and without antiepileptic drugs, but photosensitivity usually does not disappear spontaneously, and then typically in the third decade.
视觉系统反射性癫痫的特点是由视觉刺激诱发癫痫发作。脑电图对间歇性光刺激的反应取决于受试者的年龄和性别以及刺激的方式：异常在儿童和青少年中最为常见，尤其是女孩。只有全身性阵发性癫痫样放电与癫痫有明确关联。异常反应可能出现在无症状受试者中，尤其是儿童。光敏性有重要的遗传因素。一些患者对图案敏感，提示这些事件有枕叶触发因素。肌阵挛、全身性惊厥性和非惊厥性癫痫发作可能由视觉刺激触发。部分性癫痫发作较少见，可能与偏头痛混淆。虽然光敏性癫痫通常为特发性，但也可能发生于退行性疾病，一些光敏性部分性癫痫患者有脑部病变。阳光和视频屏幕，包括电视、电子游戏和电脑显示器，是光敏性癫痫发作最常见的环境触发因素。当播放某些闪烁或有图案的图像时，会引发癫痫发作的爆发。只有一些国家有相关规定来预防这种情况。单纯性光敏性癫痫预后良好。使用或不使用抗癫痫药物治疗都有作用，但光敏性通常不会自发消失，一般在第三个十年才会消失。
