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https://www.readbyqxmd.com/read/30499503/-neurotrauma-as-a-factor-of-epileptogenesis
#1
A K Shishmanidi, S M Karpov, I A Vyshlova, A S Karpov, E M Bahadova
The presented article deals with traumatic brain injury, which can cause convulsive seizures with the subsequent development of epilepsy, which is especially characteristic of young people. The problems of classification of posttraumatic epileptic seizures, development of their mechanisms, characteristics of diagnosis, as well as the stages of epileptogenesis leading to the development of traumatic epilepsy are considered. The variants of therapy are given in view of traumatic brain injury. It is noted that the use of electrical stimulation during individual phases of paroxysmal oscillations can be an effective method in preventing the development of homeostatic plasticity that is involved in the development of epileptogenesis...
2018: Zhurnal Nevrologii i Psikhiatrii Imeni S.S. Korsakova
https://www.readbyqxmd.com/read/30497180/modulation-of-neural-oscillations-by-vagus-nerve-stimulation-in-posttraumatic-multifocal-epilepsy-case-report
#2
(no author information available yet)
The putative mechanism of vagus nerve stimulation (VNS) for medically refractory epilepsy is desynchronization of hippocampal and thalamocortical circuitry; however, the nature of the dose-response relationship and temporal dynamics is poorly understood. For greater elucidation, a study in a nonepileptic rat model was previously conducted and showed that rapid-cycle (RC) VNS achieved superior desynchrony compared to standard-cycle (SC) VNS. Here, the authors report on the first in-human analysis of the neuromodulatory dose-response effects of VNS in a patient with posttraumatic, independent, bilateral mesial temporal lobe epilepsy refractory to medications and SC-VNS who was referred as a potential candidate for a responsive neurostimulation device...
November 1, 2018: Journal of Neurosurgery
https://www.readbyqxmd.com/read/30483204/determining-the-quantitative-threshold-of-high-frequency-oscillation-distribution-to-delineate-the-epileptogenic-zone-by-automated-detection
#3
Chenxi Jiang, Xiaonan Li, Jiaqing Yan, Tao Yu, Xueyuan Wang, Zhiwei Ren, Donghong Li, Chang Liu, Wei Du, Xiaoxia Zhou, Yue Xing, Guoping Ren, Guojun Zhang, Xiaofeng Yang
Objective: We proposed an improved automated high frequency oscillations (HFOs) detector that could not only be applied to various intracranial electrodes, but also automatically remove false HFOs caused by high-pass filtering. We proposed a continuous resection ratio of high order HFO channels and compared this ratio with each patient's post-surgical outcome, to determine the quantitative threshold of HFO distribution to delineate the epileptogenic zone (EZ). Methods: We enrolled a total of 43 patients diagnosed with refractory epilepsy...
2018: Frontiers in Neurology
https://www.readbyqxmd.com/read/30472273/partial-restoration-of-physiological-up-state-activity-by-gaba-pathway-modulation-in-an-acute-brain-slice-model-of-epilepsy
#4
Anna-Lucia Koerling, Tanja Fuchsberger, Ole Paulsen, Y Audrey Hay
In addition to reducing seizures, anti-epileptic treatments should preserve physiological network activity. Here, we used a thalamocortical slice preparation displaying physiological slow oscillations to investigate the effects of anticonvulsant drugs on physiological activity and epileptiform activity in two pharmacological epilepsy models. Thus, we compared the effects of GABA pharmacology on spontaneous physiological and pathological events in slices of the mouse barrel cortex. We show that both reducing inhibition using GABAA R blockers and enhancing excitation by lowering Mg2+ concentration allow for the transition from physiological slow oscillations to epileptiform activity...
November 22, 2018: Neuropharmacology
https://www.readbyqxmd.com/read/30452374/noise-assisted-multivariate-emd-based-mean-phase-coherence-analysis-to-evaluate-phase-synchrony-dynamics-in-epilepsy-patients
#5
Sina Farahmand, Tiwalade Sobayo, David J Mogul
Spatiotemporal evolution of synchrony dynamics among neuronal populations plays an important role in decoding complicated brain function in normal cognitive processing as well as during pathological conditions such as epileptic seizures. In this paper, a non-linear analytical methodology is proposed to quantitatively evaluate the phase-synchrony dynamics in epilepsy patients. A set of finite neuronal oscillators was adaptively extracted from a multi-channel electrocorticographic (ECoG) dataset utilizing noise-assisted multivariate empirical mode de-composition (NA-MEMD)...
November 15, 2018: IEEE Transactions on Neural Systems and Rehabilitation Engineering
https://www.readbyqxmd.com/read/30441063/seizure-reduction-using-model-predictive-control
#6
Harleen K Brar, Ioannis Exarchos, Yunpeng Pan, Evangelos Theodorou, Babak Mahmoudi
This study presents a model predictive control approach for seizure reduction in a computational model of epilepsy. The differential dynamic programming (DDP) algorithm is implemented in a model predictive fashion to optimize a controller for suppressing seizures in a chaotic oscillator model. The chaotic oscillator model uses proportional-integral (PI) controller to represent the internal control mechanism that maintains stable neural activity in a healthy brain. In the pathological case, the gains of this PI controller are reduced, preventing sufficient feedback to suppress correlation increase between normal and pathological brain dynamics...
July 2018: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/30440892/emd-based-mean-phase-coherence-analysis-to-assess-instantaneous-phase-synchrony-dynamics-in-epilepsy-patients
#7
Sina Farahmand, Tiwalade Sobayo, David J Mogul
In this paper, an adaptive, non-linear, analytical methodology is proposed in order to quantitatively evaluate the instantaneous phase-synchrony dynamics in epilepsy patients. A group of finite neuronal oscillators is extracted from a multichannel electrocorticographic (ECoG) data, using the empirical mode decomposition (EMD). The instantaneous phases of the extracted oscillators are measured using the Hilbert transform in order to be utilized in the mean-phase coherence analysis. Finally, the dynamical evolution of phase-synchrony among the extracted neuronal oscillators within 1-600 Hz frequency range is assessed using eigenvalue decomposition...
July 2018: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/30440863/temporal-pattern-of-ripple-events-in-temporal-lobe-epilepsy-towards-a-pattern-based-localization-of-the-seizure-onset-zone
#8
Stefan L Sumsky, Sabato Santaniello
Ripples (80-250 Hz) are brief high-frequency oscillations that are often detected in intracranial EEG (iEEG) and are currently investigated as a potential biomarker to facilitate the Iocalization of the seizure onset zone (SOZ) in patients with drug-resistant epilepsy. While the rate and shape of these oscillations have been positively correlated with the SOZ, the temporal pattern of these oscillations in the epileptic brain still requires investigation. In this study, we investigate the temporal pattern of ripple events in five patients with temporal lobe epilepsy (TLE), which is one of the most common forms of epilepsy...
July 2018: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/30440857/using-interictal-hfos-to-improve-the-identification-of-epileptogenic-zones-in-preparation-for-epilepsy-surgery
#9
Sina Farahmand, Tiwalade Sobayo, David J Mogul
For the more than 15 million patients who have drug-resistant epilepsy, surgical resection of the region where seizure arise is often the only alternative therapy. However, the identification of this epileptogenic zone (EZ) is often imprecise. Generally, insufficient EZ identification and resection may cause seizures to continue and too much resection may lead to unnecessary neurological deficits. In this paper, an automatic high frequency oscillations (HFOs) detection method based on noise-assisted multivariate EMD (NA-MEMD) is proposed to improve the localization of the EZ for epilepsy patients...
July 2018: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/30440557/effect-of-vigilance-changes-on-the-incidence-of-high-frequency-oscillations-in-the-epileptic-brain
#10
Amir F Al-Bakri, Farid Yaghouby, Walter Besio, Lei Ding, Pradeep Modur, Sridhar Sunderam
Recent studies show that the rate of cortical high frequency oscillations (HFOs) differentiates epileptogenic tissue in individuals with epilepsy. However, HFO occurrence can vary widely with vigilance state. In this study we attempt to characterize this variation, which has implications for the choice of a suitable diagnostic baseline for spatiotemporal analysis of HFO activity. We analyzed simultaneous recordings of the scalp electroencephalogram (EEG) and the electrocorticogram (ECoG) to examine the correlation of HFO activity with vigilance state...
July 2018: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/30415633/coupled-oscillators-model-of-hyperexcitable-neuroglial-networks
#11
Firas H Farah, Vasily Grigorovsky, Berj L Bardakjian
Glial populations within neuronal networks of the brain have recently gained much interest in the context of hyperexcitability and epilepsy. In this paper, we present an oscillator-based neuroglial model capable of generating Spontaneous Electrical Discharges (SEDs) in hyperexcitable conditions. The network is composed of 16 coupled Cognitive Rhythm Generators (CRGs), which are oscillator-based mathematical constructs previously described by our research team. CRGs are well-suited for modeling assemblies of excitable cells, and in this network, each represents one of the following populations: excitatory pyramidal cells, inhibitory interneurons, astrocytes, and microglia...
September 16, 2018: International Journal of Neural Systems
https://www.readbyqxmd.com/read/30408475/detection-and-localization-of-interictal-ripples-with-magnetoencephalography-in-the-presurgical-evaluation-of-drug-resistant-insular-epilepsy
#12
Chunli Yin, Xiating Zhang, Zheng Chen, Xin Li, Siqi Wu, Peiyuan Lv, Yuping Wang
Precise noninvasive presurgical localization of insular epilepsy is important. The objective of the present study was to detect and localize interictal high-frequency oscillations (HFOs) in patients with insular epilepsy at the source levels using magnetoencephalography (MEG). We investigated whether HFOs can delineate epileptogenic areas. We analysed MEG data with new accumulated source imaging (HFOs, 80-250 Hz ripples during spikes) and conventional dipole modelling (spikes) methods for localizing epileptic foci...
November 5, 2018: Brain Research
https://www.readbyqxmd.com/read/30386286/aberrant-sensory-gating-of-the-primary-somatosensory-cortex-contributes-to-the-motor-circuit-dysfunction-in-paroxysmal-kinesigenic-dyskinesia
#13
Yo-Tsen Liu, Yi-Chieh Chen, Shang-Yeong Kwan, Chien-Chen Chou, Hsiang-Yu Yu, Der-Jen Yen, Kwong-Kum Liao, Wei-Ta Chen, Yung-Yang Lin, Rou-Shayn Chen, Kang-Yang Jih, Shu-Fen Lu, Yu-Te Wu, Po-Shan Wang, Fu-Jung Hsiao
Paroxysmal kinesigenic dyskinesia (PKD) is conventionally regarded as a movement disorder (MD) and characterized by episodic hyperkinesia by sudden movements. However, patients of PKD often have sensory aura and respond excellently to antiepileptic agents. PRRT2 mutations, the most common genetic etiology of PKD, could cause epilepsy syndromes as well. Standing in the twilight zone between MDs and epilepsy, the pathogenesis of PKD is unclear. Gamma oscillations arise from the inhibitory interneurons which are crucial in the thalamocortical circuits...
2018: Frontiers in Neurology
https://www.readbyqxmd.com/read/30318350/hexadirectional-modulation-of-theta-power-in-human-entorhinal-cortex-during-spatial-navigation
#14
Dong Chen, Lukas Kunz, Wenjing Wang, Hui Zhang, Wen-Xu Wang, Andreas Schulze-Bonhage, Peter C Reinacher, Wenjing Zhou, Shuli Liang, Nikolai Axmacher, Liang Wang
Grid cells and theta oscillations are fundamental components of the brain's navigation system. Grid cells provide animals [1, 2] and humans [3, 4] with a spatial map of the environment by exhibiting multiple firing fields arranged in a regular grid of equilateral triangles. This unique firing pattern presumably constitutes the neural basis for path integration [5-8] and may also enable navigation in visual and conceptual spaces [9-12]. Theta frequency oscillations are a prominent mesoscopic network phenomenon during navigation in both rodents and humans [13, 14] and encode movement speed [15-17], distance traveled [18], and proximity to spatial boundaries [19]...
October 22, 2018: Current Biology: CB
https://www.readbyqxmd.com/read/30302390/adaptation-and-inhibition-control-pathological-synchronization-in-a-model-of-focal-epileptic-seizure
#15
Anatoly Buchin, Cliff C Kerr, Gilles Huberfeld, Richard Miles, Boris Gutkin
Pharmacoresistant epilepsy is a common neurological disorder in which increased neuronal intrinsic excitability and synaptic excitation lead to pathologically synchronous behavior in the brain. In the majority of experimental and theoretical epilepsy models, epilepsy is associated with reduced inhibition in the pathological neural circuits, yet effects of intrinsic excitability are usually not explicitly analyzed. Here we present a novel neural mass model that includes intrinsic excitability in the form of spike-frequency adaptation in the excitatory population...
September 2018: ENeuro
https://www.readbyqxmd.com/read/30291240/electrophysiological-mechanisms-of-human-memory-consolidation
#16
Hui Zhang, Juergen Fell, Nikolai Axmacher
Consolidation stabilizes memory traces after initial encoding. Rodent studies suggest that memory consolidation depends on replay of stimulus-specific activity patterns during fast hippocampal "ripple" oscillations. Here, we measured replay in intracranial electroencephalography recordings in human epilepsy patients, and related replay to ripples. Stimulus-specific activity was identified using representational similarity analysis and then tracked during waking rest and sleep after encoding. Stimulus-specific gamma (30-90 Hz) activity during early (100-500 ms) and late (500-1200 ms) encoding is spontaneously reactivated during waking state and sleep, independent of later memory...
October 5, 2018: Nature Communications
https://www.readbyqxmd.com/read/30250863/physiological-and-pathological-high-frequency-oscillations-in-focal-epilepsy
#17
Jan Cimbalnik, Benjamin Brinkmann, Vaclav Kremen, Pavel Jurak, Brent Berry, Jamie Van Gompel, Matt Stead, Greg Worrell
Objective: This study investigates high-frequency oscillations (HFOs; 65-600 Hz) as a biomarker of epileptogenic brain and explores three barriers to their clinical translation: (1) Distinguishing pathological HFOs (pathHFO) from physiological HFOs (physHFO). (2) Classifying tissue under individual electrodes as epileptogenic (3) Reproducing results across laboratories. Methods: We recorded HFOs using intracranial EEG (iEEG) in 90 patients with focal epilepsy and 11 patients without epilepsy...
September 2018: Annals of Clinical and Translational Neurology
https://www.readbyqxmd.com/read/30242045/theta-bursts-precede-and-spindles-follow-cortical-and-thalamic-downstates-in-human-nrem-sleep
#18
Christopher E Gonzalez, Rachel A Mak-McCully, Burke Q Rosen, Sydney S Cash, Patrick Y Chauvel, Hélène Bastuji, Marc Rey, Eric Halgren
Since their discovery, slow oscillations have been observed to group spindles during non-REM sleep. Previous studies assert that the slow-oscillation downstate (DS) is preceded by slow spindles (10-12 Hz) and followed by fast spindles (12-16 Hz). Here, using both direct transcortical recordings in patients with intractable epilepsy ( n = 10, 8 female), as well as scalp EEG recordings from a healthy cohort ( n = 3, 1 female), we find in multiple cortical areas that both slow and fast spindles follow the DS. Although discrete oscillations do precede DSs, they are theta bursts (TBs) centered at 5-8 Hz...
November 14, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/30216929/ripple-oscillations-in-the-left-temporal-neocortex-are-associated-with-impaired-verbal-episodic-memory-encoding
#19
Zachary J Waldman, Liliana Camarillo-Rodriguez, Inna Chervenova, Brent Berry, Shoichi Shimamoto, Bahareh Elahian, Michal Kucewicz, Chaitanya Ganne, Xiao-Song He, Leon A Davis, Joel Stein, Sandhitsu Das, Richard Gorniak, Ashwini D Sharan, Robert Gross, Cory S Inman, Bradley C Lega, Kareem Zaghloul, Barbara C Jobst, Katheryn A Davis, Paul Wanda, Mehraneh Khadjevand, Joseph Tracy, Daniel S Rizzuto, Gregory Worrell, Michael Sperling, Shennan A Weiss
BACKGROUND: We sought to determine if ripple oscillations (80-120 Hz), detected in intracranial electroencephalogram (iEEG) recordings of patients with epilepsy, correlate with an enhancement or disruption of verbal episodic memory encoding. METHODS: We defined ripple and spike events in depth iEEG recordings during list learning in 107 patients with focal epilepsy. We used logistic regression models (LRMs) to investigate the relationship between the occurrence of ripple and spike events during word presentation and the odds of successful word recall following a distractor epoch and included the seizure onset zone (SOZ) as a covariate in the LRMs...
November 2018: Epilepsy & Behavior: E&B
https://www.readbyqxmd.com/read/30210311/alterations-of-coherent-theta-and-gamma-network-oscillations-as-an-early-biomarker-of-temporal-lobe-epilepsy-and-alzheimer-s-disease
#20
REVIEW
Valentina F Kitchigina
Alzheimer's disease (AD) and temporal lobe epilepsy (TLE) are the most common forms of neurodegenerative disorders characterized by the loss of cells and progressive irreversible alteration of cognitive functions, such as attention and memory. AD may be an important cause of epilepsy in the elderly. Early diagnosis of diseases is very important for their successful treatment. Many efforts have been done for defining new biomarkers of these diseases. Significant advances have been made in the searching of some AD and TLE reliable biomarkers, including cerebrospinal fluid and plasma measurements and glucose positron emission tomography...
2018: Frontiers in Integrative Neuroscience
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