Visual evoked potentials.

Pattern reversal evoked potentials (PVEPs) are a noninvasive procedure that are useful for detecting lesions of the visual pathways. This article reviews anatomy of the visual pathway and the testing protocols for fullfield and hemifield PVEP and flash (goggle) visual evoked potentials (FVEP). Criteria for evaluation of normal and abnormal responses and clinical correlates are discussed. We conclude with a brief discussion of recording visual evoked potentials (VEPs) from subdural or depth electrodes to localize primary visual cortex in patients, with a parieto-occipital seizure focus, who are undergoing evaluation for epilepsy surgery.