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P279 Distribution of single unit activity patterns in subthalamic nucleus of Parkinsonian patients
Abstracts / Clinical Neurophysiology 128 (2017) e178–e303
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. Keywords: Brain, EEG, Sex hormone doi:10.1016/j.clinph.2017.07.285
P278 The EEG alpha response is affected by changes in sex hormone levels in two phases of menstrual cycle—Gulsum Akdeniz 1, Emine Feyza Yurt 1, Gulsen Yilmaz 1, Gamze Dogan 2 (1 Ankara Yildirim Beyazit University, School of Medicine, Ankara, Turkey, 2 Hacettepe University, School of Medicine, Ankara, Turkey) Objectives: It is known that sex hormones affect the brain in women. However, there are not enough studies that explain the relationship between sex hormone fluctuations during menstrual cycle and brain waves. Our aim in this study is to show the effects of sex hormone fluctuations on the EEG alpha response in menstrual phase and follicular phase. Methods: EEG recordings on resting state was performed in 11 healthy volunteer women in two different phases (menstrual and follicular). The alpha power values were analyzed by artifact-free 45 epochs lasting 2 s. Blood samples of volunteers were drawn simultaneously and estradiol, progesterone, FSH and LH were analyzed with electrochemiluminesence immunoassay method. The assessment of alpha power values and its relationship with hormone levels were performed in two phases of menstrual cycle. Results: The highest difference between the mean power value in the menstrual phase (46.06) and the follicular phase (36.08) was obtained from the parietal region of the brain. At the same time, the lowest difference between the mean power value (41.06) in the menstrual phase and the follicular phase (39.37) was obtained from the occipital region of the brain. Estrodiol, progesterone, FSH, LH mean levels were 30.2 pg/ml; 0.17 ng/ml; 6.7 mIU/ml; 5.43 mIU/ml in the menstrual cycle and 123.9 pg/ml; 0.23 ng/ml; 7.3 mIU/ml; 17.12 mIU/ml in the follicular phase, respectively. Conclusion: We found that increased estradiol levels in response to the elevation of LH levels in blood during follicular phase resulted in a decrease in the power of the alpha waves from the parietal region. Sex hormone fluctuations in menstrual cycle has minimal effect on the EEG alpha response in occipital region. Keywords: EEG, Brain, Sex hormone doi:10.1016/j.clinph.2017.07.286
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P279 Distribution of single unit activity patterns in subthalamic nucleus of Parkinsonian patients—Elena Belova 1, Artem Nezvinskiy 1, Ulia Semenova 1, Svetlana Usova 1, Valentin Popov 2, Anna Gamaleya 2, Alexey Tomskiy 2, Alexey Sedov 1 (1 Semenov Institute of Chemical Physics, Laboratory of Human Cell Neurophysiology, Moscow, Russia, 2 Burdenko Neurosurgery Institute, Department of Functional Neurosurgery, Moscow, Russia) Objectives: Subthalamic nucleus (STN) is the main target for surgery treatment of Parkinson’s disease (PD) patients. The aim of the study was to characterize spontaneous single unit activity in subthalamic nucleus of PD patients and to search for the possible correlations between characteristics of neuronal activity and clinical phenotype. Methods: We have analyzed single unit activity of 493 cells registered in subthalamic nucleus of 9 patients (3 males and 6 females) with PD (56.8 ± 4.8 yrs, UPDRS III score in off-state 52.0 ± 12.2), that were undergoing bilateral DBS surgery at Burdenko Neurosurgery Center in 2015–2017. For each neuron we determined several characteristics: firing rate, coefficient of variation (CV), mean and median interspike interval (ISI), asymmetry index (AI), burst characteristics. We also have performed spectral analysis of oscillations in the spiketrains. Results: We have identified three different patterns of neuronal activity: tonic regular activity (AI > 0.7, CV < 0.85) was present in 5–16% of neurons, tonic irregular activity (AI > 0.7, CV > 0.85)? in 5–25% of neurons, burst-like activity (AI < 0.7)? in 55–90% of neurons. There was unevenness in pattern distribution across STN: tonic neurons were located mainly in ventral part of STN, irregular neurons also were met more frequently in ventral segments of STN. Unlike tonic units, burst-like neurons were distributed more evenly, however, there is a tendency in AI scores of bursts-like neurons to increase with increasing distance from STN entrance. Spectral analysis have shown that beta oscillation activity was observed mainly in dorsal STN segment whereas gamma oscillation activity was seen predominantly in ventral part of STN. We found that characteristics of tonic regular neurons varied significantly across examined patients. We haven’t found any clear correlations between characteristics of different types of neurons and clinical symptoms of PD (UPDRS score, bradykinesia, rigidity or tremor scores). Significance: The unevenness of neuronal activity patterns and oscillations of STN could be used for choosing optimal location of DBS electrodes in PD patients. Keywords: Subthalamic nucleus, Parkinson’s disease, Microelectrode recording doi:10.1016/j.clinph.2017.07.287
P280 Dynamical changes associated with interictal epileptic spikes: An in vivo study using multimodal recording in rats— Lemya Araf-Yemmi, Cristian Arnal-Real, Mahdi Mahmoudzadeh, Fabrice Wallois (INSERM U1105, GRAMFC, Université de Picardie Jules Verne, CHU SUD, Medicine, Amiens, France) The mechanisms of neuronal hypersynchronization during Interictal Epileptic Spikes (IES) remain unsolved. IES’s multimodal analysis figure out the dynamic of the neurovascular unit considering the interactions between the neuronal, vascular networks and the extra cellular space occurring around the IES. To evaluate these multiscale interactions, a multimodal approach is developed in epileptic rats with Penicillin-G-induced IES. Changes
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. Keywords: Brain, EEG, Sex hormone doi:10.1016/j.clinph.2017.07.285
P278 The EEG alpha response is affected by changes in sex hormone levels in two phases of menstrual cycle—Gulsum Akdeniz 1, Emine Feyza Yurt 1, Gulsen Yilmaz 1, Gamze Dogan 2 (1 Ankara Yildirim Beyazit University, School of Medicine, Ankara, Turkey, 2 Hacettepe University, School of Medicine, Ankara, Turkey) Objectives: It is known that sex hormones affect the brain in women. However, there are not enough studies that explain the relationship between sex hormone fluctuations during menstrual cycle and brain waves. Our aim in this study is to show the effects of sex hormone fluctuations on the EEG alpha response in menstrual phase and follicular phase. Methods: EEG recordings on resting state was performed in 11 healthy volunteer women in two different phases (menstrual and follicular). The alpha power values were analyzed by artifact-free 45 epochs lasting 2 s. Blood samples of volunteers were drawn simultaneously and estradiol, progesterone, FSH and LH were analyzed with electrochemiluminesence immunoassay method. The assessment of alpha power values and its relationship with hormone levels were performed in two phases of menstrual cycle. Results: The highest difference between the mean power value in the menstrual phase (46.06) and the follicular phase (36.08) was obtained from the parietal region of the brain. At the same time, the lowest difference between the mean power value (41.06) in the menstrual phase and the follicular phase (39.37) was obtained from the occipital region of the brain. Estrodiol, progesterone, FSH, LH mean levels were 30.2 pg/ml; 0.17 ng/ml; 6.7 mIU/ml; 5.43 mIU/ml in the menstrual cycle and 123.9 pg/ml; 0.23 ng/ml; 7.3 mIU/ml; 17.12 mIU/ml in the follicular phase, respectively. Conclusion: We found that increased estradiol levels in response to the elevation of LH levels in blood during follicular phase resulted in a decrease in the power of the alpha waves from the parietal region. Sex hormone fluctuations in menstrual cycle has minimal effect on the EEG alpha response in occipital region. Keywords: EEG, Brain, Sex hormone doi:10.1016/j.clinph.2017.07.286
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P279 Distribution of single unit activity patterns in subthalamic nucleus of Parkinsonian patients—Elena Belova 1, Artem Nezvinskiy 1, Ulia Semenova 1, Svetlana Usova 1, Valentin Popov 2, Anna Gamaleya 2, Alexey Tomskiy 2, Alexey Sedov 1 (1 Semenov Institute of Chemical Physics, Laboratory of Human Cell Neurophysiology, Moscow, Russia, 2 Burdenko Neurosurgery Institute, Department of Functional Neurosurgery, Moscow, Russia) Objectives: Subthalamic nucleus (STN) is the main target for surgery treatment of Parkinson’s disease (PD) patients. The aim of the study was to characterize spontaneous single unit activity in subthalamic nucleus of PD patients and to search for the possible correlations between characteristics of neuronal activity and clinical phenotype. Methods: We have analyzed single unit activity of 493 cells registered in subthalamic nucleus of 9 patients (3 males and 6 females) with PD (56.8 ± 4.8 yrs, UPDRS III score in off-state 52.0 ± 12.2), that were undergoing bilateral DBS surgery at Burdenko Neurosurgery Center in 2015–2017. For each neuron we determined several characteristics: firing rate, coefficient of variation (CV), mean and median interspike interval (ISI), asymmetry index (AI), burst characteristics. We also have performed spectral analysis of oscillations in the spiketrains. Results: We have identified three different patterns of neuronal activity: tonic regular activity (AI > 0.7, CV < 0.85) was present in 5–16% of neurons, tonic irregular activity (AI > 0.7, CV > 0.85)? in 5–25% of neurons, burst-like activity (AI < 0.7)? in 55–90% of neurons. There was unevenness in pattern distribution across STN: tonic neurons were located mainly in ventral part of STN, irregular neurons also were met more frequently in ventral segments of STN. Unlike tonic units, burst-like neurons were distributed more evenly, however, there is a tendency in AI scores of bursts-like neurons to increase with increasing distance from STN entrance. Spectral analysis have shown that beta oscillation activity was observed mainly in dorsal STN segment whereas gamma oscillation activity was seen predominantly in ventral part of STN. We found that characteristics of tonic regular neurons varied significantly across examined patients. We haven’t found any clear correlations between characteristics of different types of neurons and clinical symptoms of PD (UPDRS score, bradykinesia, rigidity or tremor scores). Significance: The unevenness of neuronal activity patterns and oscillations of STN could be used for choosing optimal location of DBS electrodes in PD patients. Keywords: Subthalamic nucleus, Parkinson’s disease, Microelectrode recording doi:10.1016/j.clinph.2017.07.287
P280 Dynamical changes associated with interictal epileptic spikes: An in vivo study using multimodal recording in rats— Lemya Araf-Yemmi, Cristian Arnal-Real, Mahdi Mahmoudzadeh, Fabrice Wallois (INSERM U1105, GRAMFC, Université de Picardie Jules Verne, CHU SUD, Medicine, Amiens, France) The mechanisms of neuronal hypersynchronization during Interictal Epileptic Spikes (IES) remain unsolved. IES’s multimodal analysis figure out the dynamic of the neurovascular unit considering the interactions between the neuronal, vascular networks and the extra cellular space occurring around the IES. To evaluate these multiscale interactions, a multimodal approach is developed in epileptic rats with Penicillin-G-induced IES. Changes