Detection of isolated occipital lobe anomalies during early childhood.

The authors report two children with isolated occipital lobe anomalies detected by visual evoked potentials (VEPs) and confirmed by MRI and CT scanning. Both had a markedly asymmetrical occipital distribution of flash and pattern VEPs. One child had acuity reduced to 6/36, and testing on confrontation suggested an homonymous hemianopia. The second child was visually inattentive to one side during infancy. Neither child had band atrophy of the optic disc or an afferent pupillary defect. Isolated abnormalities of the occipital lobes are difficult to detect by clinical examination during infancy and early childhood. Recording VEPs from a horizontal array of occipital electrodes can be helpful in detecting subtle occipital lobe abnormalities.