Vep latency: sex and head size.
OBJECTIVE
To investigate whether differences in visual evoked potential (VEP) latencies in a large sample of healthy subjects are influenced by different head size or sex or both.


METHODS
Black-and-white pattern-reversal checkerboard VEPs at a frequency of 2c/deg. were recorded in a group of 54 normal subjects of both sexes (age 30.15+/-9.12 years). P100 latency was measured in all subjects and the data were analyzed in the whole sample and in a selected subgroup of subjects of both sexes with comparable head size.


RESULTS
In the study group overall, the P100 latency was slightly shorter in females than males and this small difference reached only weak statistical significance (P<0.04) whereas head size differed significantly between sexes (females<males) (P<0.001). No difference was found in the P100 latency in the subgroup of the two sexes with a comparable range of head size.


CONCLUSIONS
These findings suggest that VEP latency is relatively constant in a sample of healthy subjects. The slight sex difference in P100 latencies observed in a normal sample is mainly related to the slightly smaller average head size in females than in males.


CONCLUSIONS
Head size, not sex, should be considered for VEP latency normative studies.
La Sapienza Department of Neurological Sciences, University of Rome, Viale Regina Elena 336, 00161 Rome, Italy. b.gregori@mclink.it
Bruno
B
Gregori
Stefano
S
Pro
Francesco
F
Bombelli
Maurizio
M
La Riccia
Neri
N
Accornero
D000328:Adult; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006257:Head / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology*; D012727:Sex Characteristics