Photoparoxysmal response examples

(Top) Generalized 3 to 4 Hz spike/polyspike-waves associated with an absence. The discharge outlasts the duration of the stimulus. (Middle) Generalized polyspike discharge in a patient with symptomatic spontaneous and photically induced mainly GTCS, which are resistant to appropriate antiepileptic medication. This type of discharge is usually associated with myoclonic jerks, which did not feature in this case. Note that the discharge occurs only after eye-blinks or eye-closure and does not outlast the stimulus train. (Bottom) Typical occipital spikes time-locked to each flash of intermittent photic stimulation. The patient is a woman with idiopathic occipital epilepsy (probably a variant of Gastaut-type childhood occipital epilepsy) who never had attacks precipitated by lights (Agathonikou et al 1997). (Used with permission from: Panayiotopoulos CP. Reflex seizures and related epileptic syndromes: a clinical guide to epileptic syndromes and their treatment. Revised 2nd ed. London: Springer, 2010:497-531.)