Prognostic value of VEPs in young children with acute onset of cortical blindness.

Visual evoked potentials (VEPs) were recorded in 32 children (ages 4 months to 5 years) who were clinically diagnosed as being cortically blind. None of the children had visual or neurologic abnormalities prior to the precipitating insult which included surgery (N = 15), trauma (N = 3), infectious disease (N = 5), hypoxia (N = 3), and other causes (N = 6). VEPs were recorded during the acute stage of cortical blindness in all children and were repeated in 24 of them. Either flash or pattern stimulation was used, depending upon the age and visual status of the child. All but one of the children who had normal flash VEPs while cortically blind, recovered normal visual function. All patients with abnormal VEPs had permanent visual impairment or blindness and all but one of those with absent VEPs remained blind. The recovery period was highly variable, ranging from 5 days to 3 years. Thus, flash VEPs recorded during the period of blindness were useful in predicting visual outcome, regardless of etiology. Repeat studies using pattern VEPs were valuable in monitoring recovery in many of these patients.