Increased Latency of Visual Evoked Potentials in Healthy Women during Menstruation

To evaluate the latency of visual evoked potentials (VEPs) in healthy women during and after menstruation. Pattern and flash VEPs were performed in 15 healthy women aged 18 to 25 years on the maximum bleeding day (luteal phase) and 7 days after the menstrual cycle (follicular phase). Mean latency was 119.6 msec on the maximum bleeding day and 100.8 msec one week after menstruation on pattern VEP (P < 0.001). Corresponding values for flash VEP were 124.5 msec and 112.7 msec, respectively (P < 0.001). Prolonged VEP latency on the maximum bleeding day indicates that high progesterone levels may have an inhibitory effect on optic nerve conduction velocity.