The visual evoked potential in neonates with occipital lesions and holoprosencephaly.

Visual evoked potentials (VEPs) were studied in 4 preterm and 2 fullterm infants in whom unilateral lesions of the occipital cortex were demonstrable on cranial ultrasonography. In the neonatal period, symmetrical responses were recorded from the two hemispheres, and the VEPs only became asymmetrical at the age of 2-3 months. Evoked responses to flash stimulation were also recorded initially in an infant with complete holoprosencephaly. These findings, together with previous reports on the maturation of the VEPs in the neonatal period, suggest that the early evoked response may be subcortical rather than cortical in origin.