The relationship between visual seizures and visual evoked potentials.
We have studied a patient (pt) in status epilepticus with visual seizures (szs) arising focally from the right occipital area and have recorded the visual evoked potential (VEP) to three different stimuli under three different conditions (during, between and with no szs). The pt experienced "sparkling" in the contralateral visual field as the sz and the intensity of the "sparkling" was directly related to the frequency of the ictal activity recorded on the EEG. During the szs the VEPs could still be recorded, but the amplitude of the P100 was higher on the contralateral side with pattern reversal (PR) stimuli, and with flashes (FL) the positive peak after the P100 was less evident on the ipsilateral side. Latencies to these latter two positivities were generally shorter than in normals, with much greater standard deviations ipsilaterally with FL and contralaterally with PR, especially during the actual szs. The relationship between VEP generation and visual sz phenomena is discussed.
D000328:Adult; D004569:Electroencephalography; D005074:Evoked Potentials, Visual; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D011930:Reaction Time; D012640:Seizures / Q000209:etiology / Q000503:physiopathology*; D013226:Status Epilepticus / Q000150:complications / Q000503:physiopathology*