keyword
MENU ▼
Read by QxMD icon Read
search

fast ripple

keyword
https://www.readbyqxmd.com/read/27913322/automatic-detection-and-classification-of-high-frequency-oscillations-in-depth-eeg-signals
#1
Nisrine Jrad, Amar Kachenoura, Isabelle Merlet, Fabrice Bartolomei, Anca Nica, Arnaud Biraben, Fabrice Wendling
GOAL: Interictal High Frequency Oscillations (HFOs [30-600 Hz]) have proven to be relevant biomarkers in epilepsy. In this paper, four categories of HFOs are considered: Gamma ([30- 80 Hz]), High-Gamma ([80-120 Hz]), Ripples ([120-250 Hz]) and Fast-Ripples ([250-600 Hz]). A universal detector of the four types of HFOs is proposed. It has the advantages of i) classifying HFOs, and thus being robust to inter- and intra-subject variability; ii) rejecting artefacts, thus being specific. METHODS: Gabor atoms are tuned to cover the physiological bands...
November 29, 2016: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/27912169/non-harmonicity-in-high-frequency-components-of-the-intra-operative-corticogram-to-delineate-epileptogenic-tissue-during-surgery
#2
Evelien E Geertsema, Maryse A van 't Klooster, Nicole E C van Klink, Frans S S Leijten, Peter C van Rijen, Gerhard H Visser, Stiliyan N Kalitzin, Maeike Zijlmans
OBJECTIVE: We aimed to test the potential of auto-regressive model residual modulation (ARRm), an artefact-insensitive method based on non-harmonicity of the high-frequency signal, to identify epileptogenic tissue during surgery. METHODS: Intra-operative electrocorticography (ECoG) of 54 patients with refractory focal epilepsy were recorded pre- and post-resection at 2048Hz. The ARRm was calculated in one-minute epochs in which high-frequency oscillations (HFOs; fast ripples, 250-500Hz; ripples, 80-250Hz) and spikes were marked...
November 17, 2016: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/27900948/prediction-of-antiepileptic-drug-treatment-outcomes-using-machine-learning
#3
Sinisa Colic, Robert G Wither, Min Lang, Liang Zhang, James H Eubanks, Berj L Bardakjian
OBJECTIVE: Antiepileptic drug (AED) treatments produce inconsistent outcomes, often necessitating patients to go through several drug trials until a successful treatment can be found. This study proposes the use of machine learning techniques to predict epilepsy treatment outcomes of commonly used AEDs. APPROACH: Machine learning algorithms were trained and evaluated using features obtained from intracranial electroencephalogram (iEEG) recordings of the epileptiform discharges observed in Mecp2-deficient mouse model of the Rett Syndrome...
November 30, 2016: Journal of Neural Engineering
https://www.readbyqxmd.com/read/27896067/relationship-between-high-frequency-oscillations-and-spikes-in-a-case-of-temporal-lobe-epilepsy
#4
Vishwanath Sagi, M Steven Evans
OBJECTIVE: The aim of this case report was to study the relationship between high-frequency oscillations (HFOs), spikes, and seizures in a patient with temporal lobe epilepsy. INTRODUCTION: During intracranial electroencephalography (EEG), HFOs are thought to be a marker for the seizure onset zone (SOZ). High-frequency oscillations are classified into ripples with frequencies of 70-200 Hz and fast ripples with frequencies of 200-500 Hz. Although HFOs are thought to be a marker for the SOZ, their relationship to spikes has not been studied in detail, especially within the SOZ...
2016: Epilepsy & Behavior Case Reports
https://www.readbyqxmd.com/read/27883965/frequency-independent-characteristics-of-high-frequency-oscillations-in-epileptic-and-non-epileptic-regions
#5
Martin Pail, Pavel Řehulka, Jan Cimbálník, Irena Doležalová, Jan Chrastina, Milan Brázdil
OBJECTIVE: The purpose of the presented study is to determine whether there are frequency-independent high-frequency oscillation (HFO) parameters which may differ in epileptic and non-epileptic regions. METHODS: We studied 31 consecutive patients with medically intractable focal (temporal and extratemporal) epilepsies who were examined by either intracerebral or subdural electrodes. Automated detection was used to detect HFO. The characteristics (rate, amplitude, and duration) of HFO were statistically compared within three groups: the seizure onset zone (SOZ), the irritative zone (IZ), and areas outside the IZ and SOZ (nonSOZ/nonIZ)...
October 29, 2016: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/27882298/high-frequency-oscillations-and-high-frequency-functional-network-characteristics-in-the-intraoperative-electrocorticogram-in-epilepsy
#6
W J E M Zweiphenning, M A van 't Klooster, E van Diessen, N E C van Klink, G J M Huiskamp, T A Gebbink, F S S Leijten, P H Gosselaar, W M Otte, C J Stam, K P J Braun, G J M Zijlmans
OBJECTIVE: High frequency oscillations (HFOs; > 80 Hz), especially fast ripples (FRs, 250-500 Hz), are novel biomarkers for epileptogenic tissue. The pathophysiology suggests enhanced functional connectivity within FR generating tissue. Our aim was to determine the relation between brain areas showing FRs and 'baseline' functional connectivity within EEG networks, especially in the high frequency bands. METHODS: We marked FRs, ripples (80-250 Hz) and spikes in the electrocorticogram of 14 patients with refractory temporal lobe epilepsy...
2016: NeuroImage: Clinical
https://www.readbyqxmd.com/read/27881950/a-new-approach-of-modified-submerged-patch-clamp-recording-reveals-interneuronal-dynamics-during-epileptiform-oscillations
#7
Gareth Morris, Premysl Jiruska, John G R Jefferys, Andrew D Powell
Highlights Simultaneous epileptiform LFPs and single-cell activity can be recorded in the membrane chamber.Interneuron firing can be linked to epileptiform high frequency activity.Fast ripples, unique to chronic epilepsy, can be modeled in ex vivo tissue from TeNT-treated rats. Traditionally, visually-guided patch clamp in brain slices using submerged recording conditions has been required to characterize the activity of individual neurons. However, due to limited oxygen availability, submerged conditions truncate fast network oscillations including epileptiform activity...
2016: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/27746131/identified-cellular-correlates-of-neocortical-ripple-and-high-gamma-oscillations-during-spindles-of-natural-sleep
#8
Robert G Averkin, Viktor Szemenyei, Sándor Bordé, Gábor Tamás
Ultra-high-frequency network events in the hippocampus are instrumental in a dialogue with the neocortex during memory formation, but the existence of transient ∼200 Hz network events in the neocortex is not clear. Our recordings from neocortical layer II/III of freely behaving rats revealed field potential events at ripple and high-gamma frequencies repeatedly occurring at troughs of spindle oscillations during sleep. Juxtacellular recordings identified subpopulations of fast-spiking, parvalbumin-containing basket cells with epochs of firing at ripple (∼200 Hz) and high-gamma (∼120 Hz) frequencies detected during spindles and centered with millisecond precision at the trough of spindle waves in phase with field potential events but phase shifted relative to pyramidal cell firing...
November 23, 2016: Neuron
https://www.readbyqxmd.com/read/27721161/prospective-and-live-fast-ripple-detection-and-localization-in-the-operating-room-impact-on-epilepsy-surgery-outcomes-in-children
#9
Shaun A Hussain, Gary W Mathern, Raman Sankar, Joyce Y Wu
OBJECTIVE: Fast ripples (FR, 250-500Hz) are proposed biomarkers of the epileptogenic zone on the basis of several retrospective reports linking postoperative seizure freedom to their complete resection. There are no clinical trials or prospective reports validating the use of FR as characterized by electrocorticography (ECoG), to guide the scope of epilepsy surgery, and to inform prognosis thereafter. We set out to prospectively evaluate the utility of FR resection to predict postoperative epilepsy outcomes, and examine the feasibility of "live" intraoperative FR ascertainment...
September 23, 2016: Epilepsy Research
https://www.readbyqxmd.com/read/27647753/temperature-controlled-high-speed-afm-real-time-observation-of-ripple-phase-transitions
#10
Hirohide Takahashi, Atsushi Miyagi, Lorena Redondo-Morata, Simon Scheuring
With nanometer lateral and Angstrom vertical resolution, atomic force microscopy (AFM) has contributed unique data improving the understanding of lipid bilayers. Lipid bilayers are found in several different temperature-dependent states, termed phases; the main phases are solid and fluid phases. The transition temperature between solid and fluid phases is lipid composition specific. Under certain conditions some lipid bilayers adopt a so-called ripple phase, a structure where solid and fluid phase domains alternate with constant periodicity...
September 20, 2016: Small
https://www.readbyqxmd.com/read/27645468/load-estimator-based-hybrid-controller-design-for-two-interleaved-boost-converter-dedicated-to-renewable-energy-and-automotive-applications
#11
Mohamed Bougrine, Mohammed Benmiloud, Atallah Benalia, Emmanuel Delaleau, Mohamed Benbouzid
This paper is devoted to the development of a hybrid controller for a two-interleaved boost converter dedicated to renewable energy and automotive applications. The control requirements, resumed in fast transient and low input current ripple, are formulated as a problem of fast stabilization of a predefined optimal limit cycle, and solved using hybrid automaton formalism. In addition, a real time estimation of the load is developed using an algebraic approach for online adjustment of the hybrid controller. Mathematical proofs are provided with simulations to illustrate the effectiveness and the robustness of the proposed controller despite different disturbances...
September 16, 2016: ISA Transactions
https://www.readbyqxmd.com/read/27635628/intracranial-eeg-seizure-onset-patterns-correlate-with-high-frequency-oscillations-in-patients-with-drug-resistant-epilepsy
#12
Taissa Ferrari-Marinho, Piero Perucca, Francois Dubeau, Jean Gotman
OBJECTIVE: High-frequency oscillations (80-500Hz; HFOs) have been shown to be a specific biomarker of the seizure-onset zone. The relationship of HFOs with seizures having different intracranial electroencephalography (iEEG) morphological onsets, however, has shown significant relationships in experimental animals but has not been studied in humans. We investigated how interictal and ictal HFOs relate to different seizure-onset morphological patterns. METHODS: We analyzed the most representative seizure type of 37 patients with drug-resistant focal epilepsy who underwent iEEG for diagnostic evaluation...
September 6, 2016: Epilepsy Research
https://www.readbyqxmd.com/read/27479916/downstream-effects-of-hippocampal-sharp-wave-ripple-oscillations-on-medial-entorhinal-cortex-layer-v-neurons-in-vitro
#13
Fabian C Roth, Katinka M Beyer, Martin Both, Andreas Draguhn, Alexei V Egorov
The entorhinal cortex (EC) is a critical component of the medial temporal lobe (MTL) memory system. Local networks within the MTL express a variety of state-dependent network oscillations that are believed to organize neuronal activity during memory formation. The peculiar pattern of sharp wave-ripple complexes (SPW-R) entrains neurons by a very fast oscillation at ∼200 Hz in the hippocampal areas CA3 and CA1 and then propagates through the "output loop" into the EC. The precise mechanisms of SPW-R propagation and the resulting cellular input patterns in the mEC are, however, largely unknown...
December 2016: Hippocampus
https://www.readbyqxmd.com/read/27472542/automatic-detection-of-high-frequency-oscillations-during-epilepsy-surgery-predicts-seizure-outcome
#14
Tommaso Fedele, Maryse van 't Klooster, Sergey Burnos, Willemiek Zweiphenning, Nicole van Klink, Frans Leijten, Maeike Zijlmans, Johannes Sarnthein
OBJECTIVE: High frequency oscillations (HFOs) and in particular fast ripples (FRs) in the post-resection electrocorticogram (ECoG) have recently been shown to be highly specific predictors of outcome of epilepsy surgery. FR visual marking is time consuming and prone to observer bias. We validate here a fully automatic HFO detector against seizure outcome. METHODS: Pre-resection ECoG dataset (N=14 patients) with visually marked HFOs were used to optimize the detector's parameters in the time-frequency domain...
September 2016: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/27472539/effect-of-sampling-rate-and-filter-settings-on-high-frequency-oscillation-detections
#15
Stephen V Gliske, Zachary T Irwin, Cynthia Chestek, William C Stacey
OBJECTIVE: High Frequency Oscillations (HFOs) are being studied as a biomarker of epilepsy, yet it is unknown how various acquisition parameters at different centers affect detection and analysis of HFOs. This paper specifically quantifies effects of sampling rate (FS) and anti-aliasing filter (AAF) positions on automated HFO detection. METHODS: HFOs were detected on intracranial EEG recordings (17 patients) with 5kHz FS. HFO detection was repeated on downsampled and/or filtered copies of the EEG data, mimicking sampling rates and low-pass filter settings of various acquisition equipment...
September 2016: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/27456267/a-decrease-of-ripples-precedes-seizure-onset-in-mesial-temporal-lobe-epilepsy
#16
Cenglin Xu, Shuang Wang, Yi Wang, Kang Lin, Gang Pan, Zhenghao Xu, Jorge Gonzalez-Martinez, Feng Gao, Xiaohua Wu, Shihong Zhang, Juan C Bulacio, Imad M Najm, Jianhong Luo, Weiwei Hu, Zhaohui Wu, Norman K So, Zhong Chen
High-frequency oscillations (HFOs) are promising biomarkers for epileptic foci; however, their characteristic changes during the preictal period remain unclear. Here, the preictal HFOs were recorded and detected by an automated HFOs detection method in the mouse pilocarpine model as well as in patients with mesial temporal lobe epilepsy (mTLE) and neocortical epilepsy. A total of sixteen low-voltage fast (LVF) and fifty-three hypersynchronous-onset (HYP) seizures were recorded in ten mice. The rate of ripples (80-250Hz) decreased during 1min before the onset of LVF and HYP seizures, which was primarily due to the reduction of type II (independent of epileptiform discharges) rather than type I ripples (superimposed on epileptiform activities)...
July 22, 2016: Experimental Neurology
https://www.readbyqxmd.com/read/27450371/resection-of-ictal-high-frequency-oscillations-is-associated-with-favorable-surgical-outcome-in-pediatric-drug-resistant-epilepsy-secondary-to-tuberous-sclerosis-complex
#17
Hisako Fujiwara, James L Leach, Hansel M Greiner, Katherine D Holland-Bouley, Douglas F Rose, Todd Arthur, Francesco T Mangano
Resective epilepsy surgery can improve seizures when the epileptogenic zone (EZ) is limited to a well-defined region. High frequency oscillations (HFO) have been recognized as having a high association with the seizure onset zone. Therefore, we retrospectively identified ictal HFOs and determined their relationship to specific intracranial features of cortical tubers in children with TSC who underwent resective surgery. We identified 14 patients with drug resistant epilepsy secondary to TSC who underwent subdural grid and strip implantation for presurgical evaluation and subsequent resection with adequate post-surgical follow-up...
October 2016: Epilepsy Research
https://www.readbyqxmd.com/read/27378900/a-neuronal-network-model-for-pitch-selectivity-and-representation
#18
Chengcheng Huang, John Rinzel
Pitch is a perceptual correlate of periodicity. Sounds with distinct spectra can elicit the same pitch. Despite the importance of pitch perception, understanding the cellular mechanism of pitch perception is still a major challenge and a mechanistic model of pitch is lacking. A multi-stage neuronal network model is developed for pitch frequency estimation using biophysically-based, high-resolution coincidence detector neurons. The neuronal units respond only to highly coincident input among convergent auditory nerve fibers across frequency channels...
2016: Frontiers in Computational Neuroscience
https://www.readbyqxmd.com/read/27259671/fast-40-150hz-oscillations-are-associated-with-positive-slow-waves-in-the-ictal-eegs-of-epileptic-spasms-in-west-syndrome
#19
Katsuhiro Kobayashi, Tomoyuki Akiyama, Makio Oka, Fumika Endoh, Harumi Yoshinaga
OBJECTIVE: To elucidate the generative mechanisms of epileptic spasms (ESs) in West syndrome, we investigated the temporal relationship between scalp fast (40-150Hz) oscillations (FOs) and slow waves in the ictal electroencephalograms (EEGs) of ESs. METHODS: In 11 infants with WS, ictal FOs were detected in a bipolar montage based on spectral and waveform criteria. Their temporal distribution was analyzed in terms of the positive peaks (trough point, TT) of identical EEG data in a referential montage...
November 2016: Brain & Development
https://www.readbyqxmd.com/read/27221619/bifurcation-analysis-of-a-two-compartment-hippocampal-pyramidal-cell-model
#20
Laura A Atherton, Luke Y Prince, Krasimira Tsaneva-Atanasova
The Pinsky-Rinzel model is a non-smooth 2-compartmental CA3 pyramidal cell model that has been used widely within the field of neuroscience. Here we propose a modified (smooth) system that captures the qualitative behaviour of the original model, while allowing the use of available, numerical continuation methods to perform full-system bifurcation and fast-slow analysis. We study the bifurcation structure of the full system as a function of the applied current and the maximal calcium conductance. We identify the bifurcations that shape the transitions between resting, bursting and spiking behaviours, and which lead to the disappearance of bursting when the calcium conductance is reduced...
August 2016: Journal of Computational Neuroscience
keyword
keyword
109594
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"