Hormonal influences on peripheral nerve conduction studies during an ovarian cycle

We aimed to investigate the influence of different levels of estrogen and progesteron during an ovarian cycle on peripheral nerve conduction studies and late responses, in women with regular menstrual cycle. Forty healthy volunteer women with regular menstrual cycle were included in the study. Nerve conduction studies and late responses were studied at dominant extremities during high levels of estrogen in late follicular phase, high levels of progesteron in mid luteal phase and low levels of both hormones in early follicular phase of overian cycle. Motor nerve conduction studies of median, ulnar, tibial, peroneal nerves, F wave latency, sensory nerve conduction studies of median, ulnar, radial, sural nerves, median mixed nerve condution studies and H reflexes of gastrosoleus muscle for tibial nerve were studied. In our study, there was a statistically significant difference in the median motor nerve velocities between early follicular phase and late follicular phase of the ovarian cycle (p= 0,03). There was no statistically significant difference in motor, sensory and mixed nerve conduction velocities, distal and proximal motor latencies, distal sensory latencies and CMAP and SNAP amplitudes, F wave latencies and H reflexes between phases of overian cycle, except a relatively slower median motor nerve condution velocity in late follicular phase than early follicular phase. However, this result was interpretated as an incidental finding since there was no significant difference in median nerve sensory conduction studies between three measures. The effects of estrogen and progesteron on central nervous system and electrolyte metabolism was shown in many studies. In conclusion, peripheral nerve conduction studies and late responses seem to be unaffected by hormonal differences during an ovarian cycle.