A child with epilepsy in whom multifocal VEPs facilitated the objective measurement of the visual field

We investigated whether visual field defects can be objectively evaluated by using multifocal visual evoked potential (multifocal VEP) in children with epilepsy in whom it is difficult to measure the visual field.

First, to determine normal waves in multifocal VEP, recording was performed by using a VERIS Junior Science (Mayo, Aichi, Japan) in 21 healthy children (21 eyes) consisting of 12 boys and nine girls aged 6 to 15 years (mean age, 11.4 years). Responses from eight sites in each subject were divided into four quadrants (superior and inferior temporal quadrants and superior and inferior nasal quadrants). In each quadrant, two response waves were grouped and averaged; peak latency and amplitude were used for assessment. In a child with epilepsy in whom kinetic or static perimetry was impossible, multifocal VEPs were recorded and compared with the peak latency and amplitude in the healthy subjects.

In the 21 healthy children, no significant differences were observed in the peak latency or amplitude among four quadrants by one-way analysis of variance. Multifocal VEPs in the child with epilepsy showed abnormal waves in the right hemivisual field, which corresponded to the lesion observed with magnetic resonance imaging.

The objective evaluation of visual field defects by using multifocal VEP may be useful in children with epilepsy in whom kinetic/static perimetry as a subjective examination is difficult.