COMPONENT WAVE ANALYSIS OF FLASH VISUAL-EVOKED POTENTIALS IN PRETERM INFANTS

Waveform analysis of flash visual evoked potentials (VEPs) in neurolog ically normal preterm infants (postconceptional age 31-42 weeks) were performed using an autoregressive moving average (ARMA) model to inter pret the evoked potentials as dynamic high-order responses to natural and experimental stimulation. Averaged VEP waveforms obtained were dec omposed into 7-11 component impulse response waveforms by an ARMA comp onent wave analysis. Based on the histogram of damping frequencies of different component impulse response waveforms, the waveforms were div ided into 6 groups. All characteristic values in Group IV (6.5-12.0 Hz ), such as the energy, the percent energy and the damping time of comp onent impulse responses, changed significantly with increasing postcon ceptional age. Among the component impulse responses, neuronal network s generating impulse responses classified into Group IV appeared to be important to the developmental change of VEPs in preterm infants. The identification of an impulse response component with a dominant frequ ency which undergoes a well-identified change with age might prove to be a useful tool for discriminating between normal and abnormal change s in the VEP with age in preterm infants and could aid in the early di agnosis of abnormalities. (C) 1998 Elsevier Science Ireland Ltd.