Visual evoked potentials in school children: A comparative study of transient and steady-state methods with pattern reversal and flash stimulation

Objective: Flash visual evoked potentials (VEPs) are commonly used in pedia trics, because children are sometimes uncooperative. We performed a compara tive study of transient and steady-state VEPs with pattern reversal (PR) an d flash (light-emitting diode, LED) stimulation. Methods: We recorded VEPs in 15 boys and 17 girls (aged 6-12 years) using 4 different stimulus conditions. The latency and amplitude of transient VEPs (T-VEPs) were measured. Steady-state VEPs (S-VEPs) were Fourier analyzed, and both the phase and amplitude of the major components were obtained. Results: The mean P100 latency of LED T-VEPs was longer and had a greater v ariability than that of PR T-VEPs. The LED T-VEPs had an amplitude of about double that of PR T-VEPs. The first harmonic response in the LED and secon d harmonic in PR were the major components of S-VEPs. The phases of PR and LED S-VEPs had narrow angular dispersions and amplitudes showed marked inte rsubject variability. Sex and age had no significant effect on both T-VEPs and S-VEPs. Conclusions: Reproducible VEPs with 4 stimulus conditions can be obtained i n school children. T-VEPs and S-VEPs are clinically useful because these me thods provide complementary information. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.