keyword
MENU ▼
Read by QxMD icon Read
search

fast ripple

keyword
https://www.readbyqxmd.com/read/29753620/oh-surprise-fast-ripples-on-scalp-eeg
#1
EDITORIAL
Jean Gotman
No abstract text is available yet for this article.
April 30, 2018: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/29701700/using-the-transient-response-of-wo%C3%A2-nanoneedles-under-pulsed-uv-light-in-the-detection-of-nh%C3%A2-and-no%C3%A2
#2
Oriol Gonzalez, Tesfalem G Welearegay, Xavier Vilanova, Eduard Llobet
Here we report on the use of pulsed UV light for activating the gas sensing response of metal oxides. Under pulsed UV light, the resistance of metal oxides presents a ripple due to light-induced transient adsorption and desorption phenomena. This methodology has been applied to tungsten oxide nanoneedle gas sensors operated either at room temperature or under mild heating (50 °C or 100 °C). It has been found that by analyzing the rate of resistance change caused by pulsed UV light, a fast determination of gas concentration is achieved (ten-fold improvement in response time)...
April 26, 2018: Sensors
https://www.readbyqxmd.com/read/29673547/visual-and-semi-automatic-non-invasive-detection-of-interictal-fast-ripples-a-potential-biomarker-of-epilepsy-in-children-with-tuberous-sclerosis-complex
#3
Danilo Bernardo, Hiroki Nariai, Shaun A Hussain, Raman Sankar, Noriko Salamon, Darcy A Krueger, Mustafa Sahin, Hope Northrup, E Martina Bebin, Joyce Y Wu
OBJECTIVES: We aim to establish that interictal fast ripples (FR; 250-500 Hz) are detectable on scalp EEG, and to investigate their association to epilepsy. METHODS: Scalp EEG recordings of a subset of children with tuberous sclerosis complex (TSC)-associated epilepsy from two large multicenter observational TSC studies were analyzed and compared to control children without epilepsy or any other brain-based diagnoses. FR were identified both by human visual review and compared with semi-automated review utilizing a deep learning-based FR detector...
April 3, 2018: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/29555850/electrophysiological-evidence-for-the-development-of-a-self-sustained-large-scale-epileptic-network-in-the-kainate-mouse-model-of-temporal-lobe-epilepsy
#4
Laurent Sheybani, Gwenaël Birot, Alessandro Contestabile, Margitta Seeck, Jozsef Zoltan Kiss, Karl Schaller, Christoph M Michel, Charles Quairiaux
Most research on focal epilepsy focuses on mechanisms of seizure generation in the primary epileptic focus (EF). However, neurological deficits that are not directly linked to seizure activity and that may persist after focus removal are frequent. The recruitment of remote brain regions of an epileptic network (EN) is recognized as a possible cause, but a profound lack of experimental evidence exists concerning their recruitment and the type of pathological activities they exhibit. We studied the development of epileptic activities at the large-scale in male mice of the kainate model of unilateral temporal lobe epilepsy using high-density surface EEG and multiple-site intracortical recordings...
April 11, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/29532041/progress-and-remaining-challenges-in-the-application-of-high-frequency-oscillations-as-biomarkers-of-epileptic-brain
#5
Fatemeh Khadjevand, Jan Cimbalnik, Gregory A Worrell
High-frequency oscillations (HFOs: 100 - 600 Hz) have been widely proposed as biomarkers of epileptic brain tissue. In addition, HFOs over a broader range of frequencies spanning 30 - 2000 Hz are potential biomarkers of both physiological and pathological brain processes. The majority of the results from humans with focal epilepsy have focused on HFOs recorded directly from the brain with intracranial EEG (iEEG) in the high gamma (65 - 100 Hz), ripple (100 - 250 Hz), and fast ripple (250 - 600 Hz) frequency ranges...
December 2017: Current Opinion in Biomedical Engineering
https://www.readbyqxmd.com/read/29523391/value-of-ictal-and-interictal-epileptiform-discharges-and-high-frequency-oscillations-for-delineating-the-epileptogenic-zone-in-patients-with-focal-cortical-dysplasia
#6
C Cuello-Oderiz, N von Ellenrieder, R Sankhe, A Olivier, J Hall, F Dubeau, J Gotman
OBJECTIVES: There are different neurophysiological markers of the Epileptogenic Zone (EZ), but their sensitivity and specificity for the EZ is not known in Focal Cortical Dysplasia (FCD) patients. METHODS: We studied patients with FCD who underwent stereoelectroencephalography (SEEG) and surgery. We marked in the SEEG: (a) typical and atypical interictal epileptiform patterns, (b) ictal onset patterns, and (c) rates of ripples (80-250 Hz) and fast ripples (FRs) (>250 Hz)...
June 2018: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/29508901/extrahippocampal-high-frequency-oscillations-during-epileptogenesis
#7
Lin Li, Mayur Patel, Joyel Almajano, Jerome Engel, Anatol Bragin
The current study aimed to investigate the spatial and temporal patterns of high-frequency oscillations (HFOs) in the intra-/extrahippocampal areas during epileptogenesis. Local field potentials were bilaterally recorded from hippocampus (CA1), thalamus, motor cortex, and prefrontal cortex in 13 rats before and after intrahippocampal kainic acid (KA) lesions. HFOs in the ripple (100-200 Hz) and fast ripple (250-500 Hz) ranges were detected and their rates were computed during different time periods (1-5 weeks) after KA-induced status epilepticus (SE)...
April 2018: Epilepsia
https://www.readbyqxmd.com/read/29482079/on-the-origin-of-epileptic-high-frequency-oscillations-observed-on-clinical-electrodes
#8
Mohamad Shamas, Pascal Benquet, Isabelle Merlet, Mohamad Khalil, Wassim El Falou, Anca Nica, Fabrice Wendling
OBJECTIVE: In this study we aim to identify the key (patho)physiological mechanisms and biophysical factors which impact the observability and spectral features of High Frequency Oscillations (HFOs). METHODS: In order to accurately replicate HFOs we developed virtual-brain/virtual-electrode simulation environment combining novel neurophysiological models of neuronal populations with biophysical models for the source/sensor relationship. Both (patho)physiological mechanisms (synaptic transmission, depolarizing GABAA effect, hyperexcitability) and physical factors (geometry of extended cortical sources, size and position of electrodes) were taken into account...
April 2018: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/29476870/high-frequency-oscillations-in-epileptic-rodents-are-we-doing-it-right
#9
Maxime Lévesque, Siyan Wang, Jean Gotman, Massimo Avoli
BACKGROUND: The detection of high-frequency oscillations (HFOs, ripples: 80-200 Hz, fast ripples: 250-500 Hz) is often based on considering ripples or fast ripples in isolation; overlapping ripples and fast ripples are excluded from further analysis. Here, we studied overlapping HFOs during spontaneous seizures in pilocarpine-treated animals. NEW METHOD: Spontaneous seizures (n = 6 animals) presented with either hypersynchronous- (HYP, n = 18) or low-voltage fast-onset (LVF, n = 21) pattern...
April 1, 2018: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/29453207/hippocampal-ripple-oscillations-and-inhibition-first-network-models-frequency-dynamics-and-response-to-gaba-modulators
#10
José R Donoso, Dietmar Schmitz, Nikolaus Maier, Richard Kempter
Hippocampal ripples are involved in memory consolidation, but the mechanisms underlying their generation remain unclear. Models relying on interneuron networks in the CA1 region disagree on the predominant source of excitation to interneurons: either "direct," via the Schaffer collaterals that provide feedforward input from CA3 to CA1, or "indirect," via the local pyramidal cells in CA1, which are embedded in a recurrent excitatory-inhibitory network. Here, we used physiologically constrained computational models of basket-cell networks to investigate how they respond to different conditions of transient, noisy excitation...
March 21, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/29397957/a-novel-dual-closed-loop-control-scheme-based-on-repetitive-control-for-grid-connected-inverters-with-an-lcl-filter
#11
Yun-Guang Gao, Fa-Yang Jiang, Jian-Cheng Song, Li-Jun Zheng, Fei-Yan Tian, Pu-Long Geng
Grid-connected inverters with LCL filters need high steady-state control accuracy, fast dynamic response performance, and strong robustness to guarantee the power quality. However, there are many problems in traditional control strategies that restrict improvements to control system performance, such as poor dynamic performance of traditional single-repetitive control, large ripples, low steady-state accuracy of inverter current feedback based repetitive dual-loop control or grid-current feedback based single-loop proportional-integral control...
March 2018: ISA Transactions
https://www.readbyqxmd.com/read/29396876/neuronal-oscillations-on-an-ultra-slow-timescale-daily-rhythms-in-electrical-activity-and-gene-expression-in-the-mammalian-master-circadian-clockwork
#12
REVIEW
Mino D C Belle, Casey O Diekman
Neuronal oscillations of the brain, such as those observed in the cortices and hippocampi of behaving animals and humans, span across wide frequency bands, from slow delta waves (0.1 Hz) to ultra-fast ripples (600 Hz). Here, we focus on ultra-slow neuronal oscillators in the hypothalamic suprachiasmatic nuclei (SCN), the master daily clock that operates on interlocking transcription-translation feedback loops to produce circadian rhythms in clock gene expression with a period of near 24 h (< 0.001 Hz)...
February 3, 2018: European Journal of Neuroscience
https://www.readbyqxmd.com/read/29395662/detection-of-fast-40-150-hz-oscillations-from-the-ictal-scalp-eeg-data-of-myoclonic-seizures-in-pediatric-patients
#13
Katsuhiro Kobayashi, Yuji Ohuchi, Takashi Shibata, Yoshiyuki Hanaoka, Mari Akiyama, Makio Oka, Fumika Endoh, Tomoyuki Akiyama
OBJECTIVE: We explored fast (40-150 Hz) oscillations (FOs) from the ictal scalp electroencephalogram (EEG) data of myoclonic seizures in pediatric patients to obtain insight into the pathophysiological mechanisms involved in the generation of myoclonic seizures. SUBJECTS AND METHODS: The participants were 21 children (11 boys, 10 girls; age ranging from 5 months to 17 years 2 months) with myoclonic seizures associated with generalized (poly)spike-wave bursts in the ictal EEG data...
May 2018: Brain & Development
https://www.readbyqxmd.com/read/29394328/stereotyped-high-frequency-oscillations-discriminate-seizure-onset-zones-and-critical-functional-cortex-in-focal-epilepsy
#14
Su Liu, Candan Gurses, Zhiyi Sha, Michael M Quach, Altay Sencer, Nerses Bebek, Daniel J Curry, Sujit Prabhu, Sudhakar Tummala, Thomas R Henry, Nuri F Ince
High-frequency oscillations in local field potentials recorded with intracranial EEG are putative biomarkers of seizure onset zones in epileptic brain. However, localized 80-500 Hz oscillations can also be recorded from normal and non-epileptic cerebral structures. When defined only by rate or frequency, physiological high-frequency oscillations are indistinguishable from pathological ones, which limit their application in epilepsy presurgical planning. We hypothesized that pathological high-frequency oscillations occur in a repetitive fashion with a similar waveform morphology that specifically indicates seizure onset zones...
January 30, 2018: Brain: a Journal of Neurology
https://www.readbyqxmd.com/read/29360943/spike-related-haemodynamic-responses-overlap-with-high-frequency-oscillations-in-patients-with-focal-epilepsy
#15
Karina A González Otárula, Hui Ming Khoo, Nicolás von Ellenrieder, Jeffery A Hall, François Dubeau, Jean Gotman
Simultaneous scalp EEG/functional MRI measures non-invasively haemodynamic responses to interictal epileptic discharges, which are related to the epileptogenic zone. High frequency oscillations are also an excellent indicator of this zone, but are primarily recorded from intracerebral EEG. We studied the spatial overlap of these two important markers in patients with drug-resistant epilepsy to assess if their combination could help better define the extent of the epileptogenic zone. We included patients who underwent EEG-functional MRI and later intracerebral EEG...
January 18, 2018: Brain: a Journal of Neurology
https://www.readbyqxmd.com/read/29347053/radiation-pressure-driven-ion-weibel-instability-and-collisionless-shocks
#16
A Grassi, M Grech, F Amiranoff, A Macchi, C Riconda
The Weibel instability from counterstreaming plasma flows is a basic process highly relevant for collisionless shock formation in astrophysics. In this paper we investigate, via two- and three-dimensional simulations, suitable configurations for laboratory investigations of the ion Weibel instability (IWI) driven by a fast quasineutral plasma flow launched into the target via the radiation pressure of an ultra-high-intensity laser pulse ("hole-boring" process). The use of S-polarized light at oblique incidence is found to be an optimal configuration for driving IWI, as it prevents the development of surface rippling observed at normal incidence that would lead to strong electron heating and would favor competing instabilities...
September 2017: Physical Review. E
https://www.readbyqxmd.com/read/29336788/grey-wolf-based-control-for-speed-ripple-reduction-at-low-speed-operation-of-pmsm-drives
#17
Ali Djerioui, Azeddine Houari, Mourad Ait-Ahmed, Mohamed-Fouad Benkhoris, Aissa Chouder, Mohamed Machmoum
Speed ripple at low speed-high torque operation of Permanent Magnet Synchronous Machine (PMSM) drives is considered as one of the major issues to be treated. The presented work proposes an efficient PMSM speed controller based on Grey Wolf (GW) algorithm to ensure a high-performance control for speed ripple reduction at low speed operation. The main idea of the proposed control algorithm is to propose a specific objective function in order to incorporate the advantage of fast optimization process of the GW optimizer...
March 2018: ISA Transactions
https://www.readbyqxmd.com/read/29315516/strong-coupling-between-slow-oscillations-and-wide-fast-ripples-in-children-with-epileptic-spasms-investigation-of-modulation-index-and-occurrence-rate
#18
Yasushi Iimura, Kevin Jones, Lynne Takada, Itsuki Shimizu, Misaki Koyama, Kyoko Hattori, Yushi Okazawa, Yutaka Nonoda, Eishi Asano, Tomoyuki Akiyama, Cristina Go, Ayako Ochi, O Carter Snead, Elizabeth J Donner, James T Rutka, James M Drake, Hiroshi Otsubo
OBJECTIVE: Epileptic spasms (ES) often become drug-resistant. To reveal the electrophysiological difference between children with ES (ES+) and without ES (ES-), we compared the occurrence rate (OR) of high-frequency oscillations (HFOs) and the modulation index (MI) of coupling between slow and fast oscillations. In ES+, we hypothesized that (1) pathological HFOs are more widely distributed and (2) slow oscillations show stronger coupling with pathological HFOs than in ES-. METHODS: We retrospectively reviewed 24 children with drug-resistant multilobar onset epilepsy, who underwent intracranial video electroencephalography prior to multilobar resections...
March 2018: Epilepsia
https://www.readbyqxmd.com/read/29282211/late-ca-2-sparks-and-ripples-during-the-systolic-ca-2-transient-in-heart-muscle-cells
#19
Ewan D Fowler, Cherrie H T Kong, Jules C Hancox, Mark B Cannell
RATIONALE: The development of a refractory period for Ca2+ spark initiation after Ca2+ release in cardiac myocytes should inhibit further Ca2+ release during the action potential plateau. However, Ca2+ release sites that did not initially activate or which have prematurely recovered from refractoriness might release Ca2+ later during the action potential and alter the cell-wide Ca2+ transient. OBJECTIVE: To investigate the possibility of late Ca2+ spark (LCS) activity in intact isolated cardiac myocytes using fast confocal line scanning with improved confocality and signal to noise...
February 2, 2018: Circulation Research
https://www.readbyqxmd.com/read/29244226/high-frequency-oscillations-are-not-better-biomarkers-of-epileptogenic-tissues-than-spikes
#20
Nicolas Roehri, Francesca Pizzo, Stanislas Lagarde, Isabelle Lambert, Anca Nica, Aileen McGonigal, Bernard Giusiano, Fabrice Bartolomei, Christian-George Bénar
OBJECTIVE: High-frequency oscillations (HFOs) in intracerebral EEG (stereoelectroencephalography; SEEG) are considered as better biomarkers of epileptogenic tissues than spikes. How this can be applied at the patient level remains poorly understood. We investigated how well HFOs and spikes can predict epileptogenic regions with a large spatial sampling at the patient level. METHODS: We analyzed non-REM sleep SEEG recordings sampled at 2,048Hz of 30 patients. Ripples (Rs; 80-250Hz), fast ripples (FRs; 250-500Hz), and spikes were automatically detected...
January 2018: Annals of Neurology
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"