Abstract
Purpose: :
Previous human and animal studies have shown VEP (Visual Evoked Potential) abnormalities in newborn and infant individuals born Small for Gestational Age (SGA), with most studies showing delayed and diminished VEP responses in SGA individuals compared with controls. The current study aims to explore VEP results in older children (5-6 years of age) born SGA in order to investigate whether these VEP abnormalities persist into older ages.
Methods: :
17 children (6 boys, 11 girls) born SGA (height and/or weight less than or equal to -2 standard deviations of normal) and moderately preterm (gestational age 32+0 to 36+6 weeks) with an average age of 5 years 7 months (range 5.4 to 6.3 years) were recruited from a longitudinal study of children born SGA in Gothenburg, Sweden. Fifty-two children (31 boys, 21 girls) with normal height and weight, also born moderately preterm and included in the same study as newborns, and with a mean age of 5 years and 7 months (range 5.3 to 6.1 years) served as controls.Pattern-reversal VEPs to checks 60 min arc with a stimulus rate of 2 Hz were recorded at 1 meter distance. Two trials to each binocular, right eye and left eye stimulation were recorded. Binocular recordings were always performed first, for the second run right or left eye stimulation was chosen arbitrarily. A minimum of 30 reversals was collected for each trial if cooperation was sufficient, if attention failed; fewer reversals were accepted for each trial.
Results: :
VEP results showed no significant differences in latency (p>0.05) between children born SGA and controls for either binocular stimulation (P100 = 100.9 ms SGA vs.101.6 ms controls), right eye stimulation (P100 = 101.6 ms SGA vs.102.2 ms controls) or left eye stimulation (P100 = 100.0 ms SGA vs.102.3 ms controls). Monocular viewing conditions generally gave poorer waveforms and more unreliable results due to fading attention. VEP amplitudes were not analyzed due to the large inter-individual variability, and due to the fact that children born SGA in previous studies have been shown to have attention difficulties which could bias the outcome.
Conclusions: :
Our results suggest that children born SGA can catch up during childhood and normalize delayed VEP latencies.
Keywords: electrophysiology: clinical • visual development: infancy and childhood • clinical (human) or epidemiologic studies: outcomes/complications