Brainstem auditory evoked responses in different phases of menstrual cycle.
OBJECTIVE
Brainstem Auditory Evoked Potentials (BAEP) show variations with age, sex and other physiological factors. The gonadal steroids may also alter the neuronal functioning, but an electrophysiological evidence is sparse. This study was undertaken to analyze the auditory evoked response in females of the reproductive age group during four different hormonal states of the menstrual cycle.


METHODS
This was a prospective, single centered, longitudinal study. The waves of BAEP were recorded in 50 young females (of the ages of 19-36 years, who used no hormonal therapy) during four different phases of the same menstrual cycle. The peak latencies of the waves, I, II, III, IV and V, IPL I-III, I-V and III-V and the amplitude ratio, V/I were recorded and statistically analyzed.


RESULTS
A significant increase in the peak latencies of the waves, I-V in the oestrogen peak mid cycle was observed, while a significant decrease in the progesterone peak mid-luteal phase was observed. However, IPL did not show any statistically significant change in the above two phases. All the parameters did not show significant changes in the menstrual and the pre-menstrual phases.


CONCLUSIONS
The results indicated the BAEP changes in the mid follicular and the mid luteal phases of the menstrual cycle, thus suggesting the changes which were attributable to oestrogen and progesterone.
Senior Resident,  Department of Physiology, Maulana Azad Medical College ,  New Delhi, India.
Navpreet
N
Mann
Rajinder Singh
RS
Sidhu
Rashmi
R
Babbar
ABR; Estrogen; Menstrual cycle; Progesterone