Gender based normative values of pattern-reversal visual evoked potentials in school age children

Background: Male and female brain develops differently. Gender is one of biological variables that influence visual evoked potentials (VEP). Some previous studies support the existence of sex related VEP difference while others not. This study is an attempt to explore if any difference exists in VEP responses between genders of children age seven to 10 years with an additional aim of documenting preliminary normative VEP data. Methods: This cross-sectional study was done on consenting children taken from parents (n=76; girls, n=41, age = 8.39±1.11years; boys, n=35, age =8.40±1.09 years). Pattern reversal VEP of these children was recorded as per standard method. Latencies of N75, P100, and N145 (ms); amplitude of P100 (μV) and ratio; interocular asymmetry (ms) of both eyes were calculated. Unpaired t-test was applied for statistical analysis. Ethical clearance was obtained prior to the study.   Result: Girls had decreased VEP latency of P100 than boys in left eye (108.15±8.42 vs. 112.71±11.17ms, p = 0.046), in right eye ( 107.71±8.52 vs. 114.46±10.98 ms, p = 0.004), and in combination of both eyes (107.92±8.07 vs. 113.58±10.36 ms, p = 0.009). Likewise, girls had decreased VEP latency of N75 than boys in right eye (67.44±6.77 vs. 71.29±8.07 ms, p = 0.027) and in combined eyes (67.23±5.19 vs. 70.14±7.31 ms, p = 0.047). A gender difference in P100 amplitude was not detected. Conclusion: Visual evoked potential differs with gender in prepubertal children aged seven to 10 years.