P277 The effects of sex hormone fluctuations in menstrual cycle on the EEG delta response

Objectives It is clear that reproductive hormones modulate the brain activity and development in human. Studies about how the reproductive hormones fluctuations alter the brain waves during menstrual cycle are insufficient. The objective in this study to explore if reproductive hormones fluctuations in the menstrual and luteal phase of cycle alter the EEG delta response. Methods 10 healthy women participated in this study. EEG recordings on resting state and blood hormone analysis were performed in the menstrual and luteal phases. Reproductive hormone levels (estradiol, progesterone, FSH and LH) were measured with electrochemiluminescence immunoassay. The delta power values were analyzed by artifact-free 45 epochs lasting 2 s. We investigated the relationship between the hormone levels and delta power values in the two phases of menstrual cycle. Results The mean of estrodiol, progesterone, FSH and LH levels in the menstrual cycle were 26.01 pg/ml; 0.15 ng/ml; 6.33 mIU/ml and 5.28 mIU/ml, while the mean of estrodiol, progesterone, FSH and LH levels in the follicular phase were 130.7 pg/ml; 8.51 ng/ml; 3.48 mIU/ml and 7.19 mIU/ml, respectively. The mean of the delta power values in occipital region was 20.42 in menstrual phase while it was 27.21 in luteal phase. Therewithal, the mean of the delta power values in frontal region was 24.96 in menstrual phase while it was 25.42 in luteal phase. The highest difference was seen in occipital region whereas the lowest difference was in frontal region. Conclusion We obtained that increased blood levels of estradiol and progesterone in luteal phase enhance the delta power values in occipital region.