Effect of estrogen and progesterone on nerve conduction studies during ovarian cycle

This study aims to investigate the effects of estrogen and progesterone on nerve conduction studies (NCSs) in three different hormonal phases of the ovarian cycle.

Between April 2008 and July 2008, a total of 40 healthy volunteer women (mean age: 24.1±5.1 years; range 21 to 43 years) with regular menstrual cycles were included in this prospective study. The participants were regularly menstruating for at least one year, without any hormonal disease and without taking any medication that could lead to hormonal dysregulation. Motor and sensory conduction velocities, amplitudes, and distal latencies were analyzed at the dominant extremities within the early follicular phase (EFP), late follicular phase (LFP), and the midluteal phase (MLP).

Except for the median nerve motor conduction velocity (MCV), there were no statistically significant differences between the peripheral NCS results in the three ovarian cycle phases (p=0.033). After adjusting for multiple comparisons, a significant difference was found between the EFP and LFP (p=0.004).

Our study results showed that only median nerve MCV was affected in the menstrual cycle. However, this would be an incidental finding, or an increased sensibility of the median nerve motor fibers to ovarian steroids by an unknown mechanism. Further studies are warranted.