Flash and pattern-reversal visual evoked potential abnormalities in infants and children with cerebral blindness.

Visual evoked potentials (VEPs) were recorded of 60 infants and children with cerebral blindness, aged between six weeks and 10 years, and compared with age-matched normative data. Every patient had abnormal VEPs. 18 had absent flash and pattern VEPs and 13 had atypical or atypical and asymmetrical flash and pattern VEPs. Of the remaining 29, most had greater abnormality of pattern than of flash VEPs and greater abnormalities over parietal and temporal than occipital areas. Eight patients had normal occipital responses to flash and five others had delayed responses with normal morphology. One had normal occipital responses to pattern stimuli. All of these had abnormal late occipital responses or abnormal responses over the parietal and temporal areas. It is recommended that visual assessments using VEPs employ both flash and pattern stimuli, that pre-occipital as well as occipital recordings be made and that tracings be compared with age-specific normative data.