title: Maturation of steady-state flicker VEPs in infants: fundamental and harmonic temporal response frequencies.
abstract: Transient flash VEPs allow objective assessment of visual function and are easily recorded in young infants. However, due to their high variability, they are an insensitive surrogate marker of visual development. The aim of our study was to investigate the early maturation of temporal characteristics of steady-state flicker VEPs. Data from 53 VEP sessions were analyzed in term-born infants between birth and 20 months of age. The stimulus was a square-wave modulated luminance flicker with 80% modulation depth at temporal frequencies of 4.7, 7.5, 12.5, and 19 Hz. A total of 18 healthy adults aged between 21 and 54 years served as controls. Contingent on the stimulus frequency, we found pronounced changes of the flicker VEP with age. Regression lines fit to the first harmonic VEP magnitude as a function of age between 3 and 88 weeks of age indicated increases at 7.5 (P = 0.004), 12.5 (P < 0.001), and 19 Hz (P = 0.07) and a non-significant decrease at 4.7 Hz (P = 0.3). The magnitude of the second harmonic increased for all frequencies (4.7 (P = 0.05), 7.5 (P = 0.01), 12.5 (P = 0.13), and 19 Hz (P = 0.18)). Over the whole infant age range, the flicker VEP was dominated by the first harmonic, in contrast to adults, where the response was typically shifted to a higher harmonic at low stimulus frequencies. The optimal stimulus frequency, defined as the frequency eliciting the highest magnitude for F1, shifted to higher rates with age. Due to the difference from adult responses, further developmental changes of the temporal properties must be assumed to occur after the age of 20 months. Changes in temporal characteristics of the flicker VEP with age may be useful as an indicator of visual system maturation and a useful tool to detect visual delay.
authors.affiliation: University Eye Clinic, University of Freiburg, Killianstrasse 5, 79106 Freiburg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Pieh
authors.forename: D L
authors.initials: DL
authors.lastname: McCulloch
authors.forename: U
authors.initials: U
authors.lastname: Shahani
authors.forename: H
authors.initials: H
authors.lastname: Mactier
authors.forename: M
authors.initials: M
authors.lastname: Bach
mesh_terms: D000328:Adult; D000367:Age Factors; D002657:Child Development / Q000502:physiology*; D005074:Evoked Potentials, Visual; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008027:Light; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods; D014785:Vision, Ocular / Q000502:physiology
references.citation: Exp Brain Res. 1982;47(2):159-71
references.pmid: 6811304
references.citation: Acta Psychiatr Belg. 1982 Jan-Feb;82(1):7-112
references.pmid: 6751024
references.citation: Invest Ophthalmol Vis Sci. 1991 Jul;32(8):2372-81
references.pmid: 2071348
references.citation: Doc Ophthalmol. 1999;99(1):21-39
references.pmid: 10947007
references.citation: J Clin Neurophysiol. 1992 Jul;9(3):357-72
references.pmid: 1517404
references.citation: Doc Ophthalmol. 1999;98(3):207-32
references.pmid: 10945442
references.citation: Int J Neurol. 1982-1983;16-17:144-54
references.pmid: 6765658
references.citation: Exp Neurol. 1970 Dec;29(3):405-15
references.pmid: 5492915
references.citation: Vision Res. 1983;23(10):1019-24
references.pmid: 6649418
references.citation: Neuropediatrics. 1991 May;22(2):85-91
references.pmid: 1857499
references.citation: Arch Ophthalmol. 1991 Feb;109(2):229-33
references.pmid: 1993033
references.citation: Behav Brain Res. 1983 Oct;10(1):3-13
references.pmid: 6639728
references.citation: Vision Res. 1981;21(4):549-55
references.pmid: 7269331
references.citation: Arch Ophthalmol. 1981 Apr;99(4):655-9
references.pmid: 7224936
references.citation: Optom Vis Sci. 1989 Aug;66(8):530-6
references.pmid: 2528103
references.citation: J Physiol. 1962 Jan;160:106-54
references.pmid: 14449617
references.citation: Biol Neonate. 1988;54(1):1-19
references.pmid: 3061475
references.citation: Vision Res. 1983;23(6):599-609
references.pmid: 6612999
references.citation: Dev Med Child Neurol. 1972 Aug;14(4):476-86
references.pmid: 5050620
references.citation: Electroencephalogr Clin Neurophysiol. 1987 Jan;68(1):20-7
references.pmid: 2431888
references.citation: Pediatr Neurol. 1991 Mar-Apr;7(2):111-5
references.pmid: 2059250
references.citation: Br J Ophthalmol. 1995 Mar;79(3):290-6
references.pmid: 7703212
references.citation: Electroencephalogr Clin Neurophysiol. 1986 Apr;63(4):309-16
references.pmid: 2419088
references.citation: Doc Ophthalmol. 1999;98(3):247-56
references.pmid: 10945444
references.citation: Dev Med Child Neurol. 1999 Jan;41(1):9-15
references.pmid: 10068044
references.citation: Electroencephalogr Clin Neurophysiol. 1980 Sep;49(5-6):476-89
references.pmid: 6158429
references.citation: Early Hum Dev. 2000 Feb;57(2):123-35
references.pmid: 10735459
references.citation: Vision Res. 1986;26(6):847-55
references.pmid: 3750868
references.citation: Invest Ophthalmol Vis Sci. 1978 Apr;17(4):361-5
references.pmid: 640783
references.citation: Ophthalmology. 1984 Jun;91(6):603-12
references.pmid: 6462623
references.citation: Exp Neurol. 1963 Apr;7:282-93
references.pmid: 13984937
references.citation: Vis Neurosci. 1993 Nov-Dec;10(6):1007-18
references.pmid: 8257658
references.citation: J Neurophysiol. 1978 Nov;41(6):1435-49
references.pmid: 104014
references.citation: J Comp Neurol. 1977 Mar 15;172(2):265-81
references.pmid: 838882
references.citation: Nippon Ganka Gakkai Zasshi. 1966 Oct;70(10):1511-25
references.pmid: 6009194
references.citation: Optom Vis Sci. 1997 Oct;74(10):808-15
references.pmid: 9383795
references.citation: Electroencephalogr Clin Neurophysiol. 1983 Jul;56(1):1-15
references.pmid: 6190626
references.citation: Arch Ophthalmol. 1960 Feb;63:232-42
references.pmid: 14403219
references.citation: Vision Res. 1982;22(9):1141-51
references.pmid: 7147725