Browsing by Author "Sungurtekin, Ü"

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Visual evoked potentials in pregnancy
    Yilmaz, H; Erkin, EF; Mavioglu, H; Sungurtekin, Ü
    Pregnancy is a period when the estrogen/progesterone ratio rises considerably because of the passage of estrogen from the placenta. These changes in the level of estrogen during pregnancy increase the sensitivity of the central nervous system to cathecholamines. As a result, the sensitivity of the receptors in both the visual cortex and the inner plexiform layer of the retina to dopamine increases, and transmission in the optic pathways becomes faster. Inspired by this knowledge, we studied monocular pattern-reversal visual evoked potentials (PRVEPs) in both eyes of 30 pregnant women in the first trimester and 30 healthy nonpregnant women in the reproductive age. Mean P-100 latency of pregnant women was significantly shorter than mean P-100 latency of nonpregnant women (p<0.001). Mean P-100 amplitude values were higher in pregnant women, although not statistically significant (p>0.05). Plasma estrogen and progesterone levels of pregnant women showed a negative correlation with PRVEP latencies, but a positive correlation with PRVEP amplitudes. In conclusion, this study supports the impression that changes in the levels of sex steroids affect the formation of PRVEPs by their actions on the central nervous system. The increase in estrogen during pregnancy seems to facilitate neural transmission in the optic pathways. Rise in the estrogen-progesterone level might be responsible for the shorter PRVEPs latencies in pregnant women.
  • No Thumbnail Available
    Item
    Changes in pattern reversal evoked potentials during menstrual cycle
    Yilmaz, H; Erkin, EE; Mavioglu, H; Sungurtekin, Ü
    Hormonal changes that occur during the menstrual cycle of women influence the visual function of females. Estrogen is reported to cause a decrease in the visual transmission time by increasing the sensitivity of receptors in the optic pathways to dopamine. The aim of this study was to search if pattern reversal evoked potentials (PRVEPs) changed during the different phases of the menstrual cycle. PRVEPs of both eyes of 30 healthy women were recorded in 4 different phases of the menstrual cycle, namely, menstrual, follicular, ovulatory and luteal. The highest mean PRVEP latency and the lowest mean P-100 amplitude were recorded during the menstrual phase. The mean PRVEP latency recorded during the ovulatory phase (when estrogen level rises to 3-5 times that of other phases' without an increase in progesterone levels) was statistically significantly shorter than that of other phases' (p < 0.05). Although not statistically significant, the mean P-100 amplitude recorded during the ovulatory phase was higher than the ether phases. Looking at these results, sex steroids seemed to affect the generation of PRVEPs. The significant decrease in PRVEP latencies when estrogen levels peaked was thought to be due to facilitating effect of estrogen on the neural transmission of the visual pathways.
  • No Thumbnail Available
    Item
    Recurrent interstitial pregnancy
    Sungurtekin, Ü; Uyar, Y
    As a rare form of ectopic pregnancy, interstitial pregnancy threatens the future fertility of the patient. Methods of management include observation only, medical treatment with methotrexate either systemically or locally, or surgery either with laparotomy or laparoscopy. We present the case of a woman with recurrent interstitial pregnancy. Treatment with methotrexate was successful in her first interstitial pregnancy, however the second necessitated laparotomy. Selection of patients for treatment with methotrexate and the importance of subsequent tubal investigation are emphasized.