37. Difficulties of motion-onset VEP examination in children

Abstract

Introduction In our previous papers (for review see Kuba et al., Vision Res., 2007, 47, 189–202) we have shown that in adults the motion-onset visual evoked potentials (M-VEPs) represent a useful diagnostic tool in neuro-opthalmology because they enable to test quite selectively the magnocellular system/dorsal stream function. In adults robust M-VEPs with low variability and typical shape with dominant negative N160 peak can be acquired easily, however, it is difficult to record and evaluate this type of VEPs in children. The M-VEPs go through very long maturation (up to 18 years of age) accompanied by gradual shortening of main negative peak latencies and also by age dependent shape development (Langrova et al., Vision Res., 2006, 46, 536–544). Moreover, they are unidentifiable to standard moving stimuli in some children. To understand better this problem, we tested 30 normal children aged 7–12 years. Methods We performed the set of standard stimuli used in our lab (https://www.lfhk.cuni.cz/elf) for examination of adults – low contrast translation motion (TM) and expansion/contraction motion (EXCOM). Results Reliable VEPs were detected in 77% of children to TM and in 83% of children to EXCOM. The dominant peak of the VEPs was negative in all TM VEPs and in 80% of EXCOM VEPs (positive in 20%). In both VEP types there was large inter-individual latency variability (in the range of 176–268 ms in TM and 176–290 ms in EXCOM). When a high contrast TM stimulus (non-optimal “magno” stimulus) was used, the M-VEP latencies shortened and amplitudes increased in majority of subjects. In contrast to adults, M-VEPs to peripheral stimulation (outside central 20°) were detectable only in 43% of children. Conclusions Our findings show that maturation of motion perception in children is rather inter-individually variable, which makes a diagnostic use of M-VEPs in children quite complicated. Acknowledgement Supported by the project PRVOUK - P37/07.