keyword
MENU ▼
Read by QxMD icon Read
search

HFOs

keyword
https://www.readbyqxmd.com/read/29333618/age-associated-urethral-dysfunction-in-urethane-anesthetized-rats
#1
Ryu Kimura, Minoru Miyazato, Asuka Ashikari, Takuma Oshiro, Seiichi Saito
AIMS: We aimed to investigate the age-associated changes in movement coordination between the urinary bladder and the urethra in rats. METHODS: A total of 17 female Sprague-Dawley rats were used. The rats were divided into young (3 months old) and middle-aged (12-15 months old) groups. In both groups, isovolumetric cystometry and urethral perfusion pressure (UPP) measurements were performed under urethane anesthesia. After the rhythmic bladder contractions stabilized, L-arginine, a nitric oxide (NO) substrate (100 mg/kg), was administered intravenously in both groups...
January 15, 2018: Neurourology and Urodynamics
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
#2
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...
January 6, 2018: Epilepsia
https://www.readbyqxmd.com/read/29288992/the-effect-of-increased-intracranial-eeg-sampling-rates-in-clinical-practice
#3
Kathryn A Davis, Seth P Devries, Abba Krieger, Temenuzhka Mihaylova, Daniela Minecan, Brian Litt, Joost B Wagenaar, William C Stacey
OBJECTIVE: Recent research suggests that high frequency intracranial EEG (iEEG) may improve localization of epileptic networks. This study aims to determine whether recording macroelectrode iEEG with higher sampling rates improves seizure localization in clinical practice. METHODS: 14 iEEG seizures from 10 patients recorded with >2000 Hz sampling rate were downsampled to four sampling rates: 100, 200, 500, 1000 Hz. In the 56 seizures, seizure onset time and location was marked by 5 independent, blinded EEG experts...
November 16, 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/29244226/high-frequency-oscillations-are-not-better-biomarkers-of-epileptogenic-tissues-than-spikes
#4
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 the HFOs and the 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 thirty patients...
December 15, 2017: Annals of Neurology
https://www.readbyqxmd.com/read/29175154/immature-status-epilepticus-in-vitro-models-reveal-differences-in-cholinergic-control-and-hfo-properties-of-adult-ca3-interictal-discharges-in-temporal-vs-septal-hippocampus
#5
Apostolos Mikroulis, Christos Panagiotis Lisgaras, Caterina Psarropoulou
We have earlier demonstrated that a Status Epilepticus (SE) during CNS development has long lasting effects on cholinergic neurotransmission, detectable in vitro and in vivo. In this work, we aimed to localize changes in temporal (T) vs septal (S) hippocampus and to correlate adult CA3 interictal epileptiform discharge (IED) frequency changes to those of Ripples (R) and Fast Ripples (FR) of the High Frequency Oscillations (HFOs). Spontaneous IEDs were induced by bathing slices in Mg2+-free ACSF or in 4-Aminopyridine (4-AP, 50µM) and data were analyzed separately for each model...
November 23, 2017: Neuroscience
https://www.readbyqxmd.com/read/29111591/magnetoencephalographic-imaging-of-ictal-high-frequency-oscillations-80-200%C3%A2-hz-in-pharmacologically-resistant-focal-epilepsy
#6
Jayabal Velmurugan, Srikantan S Nagarajan, Narayanan Mariyappa, Shankar G Ravi, Kandavel Thennarasu, Ravindranadh C Mundlamuri, Kenchaiah Raghavendra, Rose Dawn Bharath, Jitender Saini, Arimappamagan Arivazhagan, Jamuna Rajan, Anita Mahadevan, Malla B Rao, Parthasarathy Satishchandra, Sanjib Sinha
OBJECTIVE: Specificity of ictal high-frequency oscillations (HFOs) in identifying epileptogenic abnormality is significant, compared to the spikes and interictal HFOs. The objectives of the study were to detect and to localize ictal HFOs by magnetoencephalography (MEG) for identifying the seizure onset zone (SOZ), evaluate the cortical excitability from preictal to ictal transition, and establish HFO concordance rates with other modalities and postsurgical resection. METHODS: Sixty-seven patients with drug-resistant epilepsy had at least 1 spontaneous seizure each during MEG acquisition, and analysis was carried out on 20 seizures from 20 patients...
November 7, 2017: Epilepsia
https://www.readbyqxmd.com/read/29093566/hypertension-induces-additional-cardiometabolic-impairments-and-attenuates-aerobic-exercise-training-adaptations-in-fructose-fed-ovariectomized-rats
#7
Janaina de O Brito-Monzani, Iris Callado Sanches, Nathalia Bernardes, Kátia Ponciano, Ivana C Moraes-Silva, Maria-Cláudia Irigoyen, Susana Llesuy, Kátia De Angelis
We tested whether hypertension favors the development of additional cardiometabolic changes in fructose-fed ovariectomized rats and how it affects aerobic exercise training (ET) effects. All rats received fructose in drinking water (10%) beginning at weaning, were ovariectomized at 10 weeks of age and divided into the normotensive sedentary (NFOS) and trained (NFOT) and hypertensive sedentary (HFOS) and trained (HFOT) groups. ET was performed on a treadmill. Arterial pressure (AP) was directly recorded; heart rate and AP variabilities were analyzed...
November 2, 2017: Hypertension Research: Official Journal of the Japanese Society of Hypertension
https://www.readbyqxmd.com/read/29062105/resection-of-high-frequency-oscillations-predicts-seizure-outcome-in-the-individual-patient
#8
Tommaso Fedele, Sergey Burnos, Ece Boran, Niklaus Krayenbühl, Peter Hilfiker, Thomas Grunwald, Johannes Sarnthein
High frequency oscillations (HFOs) are recognized as biomarkers for epileptogenic brain tissue. A remaining challenge for epilepsy surgery is the prospective classification of tissue sampled by individual electrode contacts. We analysed long-term invasive recordings of 20 consecutive patients who subsequently underwent epilepsy surgery. HFOs were defined prospectively by a previously validated, automated algorithm in the ripple (80-250 Hz) and the fast ripple (FR, 250-500 Hz) frequency band. Contacts with the highest rate of ripples co-occurring with FR over several five-minute time intervals designated the HFO area...
October 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29060055/a-novel-hfo-based-method-for-unsupervised-localization-of-the-seizure-onset-zone-in-drug-resistant-epilepsy
#9
Paige M Murphy, Adam J von Paternos, Sabato Santaniello
High frequency oscillations (HFOs) are potential biomarkers of epileptic areas. In patients with drug-resistant epilepsy, HFO rates tend to be higher in the seizure onset zone (SOZ) than in other brain regions and the resection of HFO-generating areas positively correlates with seizure-free surgery outcome. Nonetheless, the development of robust unsupervised HFO-based tools for SOZ localization remains challenging. Current approaches predict the SOZ by processing small samples of intracranial EEG (iEEG) data and applying patient-specific thresholds on the HFO rate...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28983917/influence-of-the-location-and-type-of-epileptogenic-lesion-on-scalp-interictal-epileptiform-discharges-and-high-frequency-oscillations
#10
Carolina Cuello-Oderiz, Nicolas von Ellenrieder, François Dubeau, Jean Gotman
OBJECTIVE: To increase the diagnostic power of scalp electroencephalography (EEG) by investigating whether lesion type and location influence the morphology of interictal epileptic discharges (IEDs) and the likelihood that IEDs and high-frequency oscillations (HFOs) are present. METHODS: We studied EEG activity in epilepsy patients with lesional epilepsy. Lesions were classified by type and by location (region and depth). We marked a maximum of 50 IEDs during deep non-rapid eye movement sleep...
October 6, 2017: Epilepsia
https://www.readbyqxmd.com/read/28981957/the-role-of-high-frequency-oscillations-in-epilepsy-surgery-planning
#11
REVIEW
David Gloss, Sarah J Nevitt, Richard Staba
BACKGROUND: Epilepsy is a serious brain disorder characterized by recurrent unprovoked seizures. Approximately two-thirds of seizures can be controlled with antiepileptic medications (Kwan 2000). For some of the others, surgery can completely eliminate or significantly reduce the occurrence of disabling seizures. Localization of epileptogenic areas for resective surgery is far from perfect, and new tools are being investigated to more accurately localize the epileptogenic zone (the zone of the brain where the seizures begin) and improve the likelihood of freedom from postsurgical seizures...
October 5, 2017: Cochrane Database of Systematic Reviews
https://www.readbyqxmd.com/read/28961101/low-to-high-cross-frequency-coupling-in-the-electrical-rhythms-as-biomarker-for-hyperexcitable-neuro-glial-networks-of-the-brain
#12
Vasily Grigorovsky, Berj L Bardakjian
OBJECTIVE: One of the features used in the study of hyperexcitablility are high frequency oscillations (HFOs, >80Hz). HFOs have been reported in the electrical rhythms of the brain's neuro-glial networks under physiological and pathological conditions. Cross-frequency coupling (CFC) of HFOs with low frequency rhythms was used to identify pathologic HFOs (pHFOs) (i) in the epileptogenic zones of epileptic patients, and (ii) as a biomarker for the severity of seizure-like events in genetically modified rodent models...
September 28, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28948998/bimodal-coupling-of-ripples-and-slower-oscillations-during-sleep-in-patients-with-focal-epilepsy
#13
Inkyung Song, Iren Orosz, Inna Chervoneva, Zachary J Waldman, Itzhak Fried, Chengyuan Wu, Ashwini Sharan, Noriko Salamon, Richard Gorniak, Sandra Dewar, Anatol Bragin, Jerome Engel, Michael R Sperling, Richard Staba, Shennan A Weiss
OBJECTIVE: Differentiating pathologic and physiologic high-frequency oscillations (HFOs) is challenging. In patients with focal epilepsy, HFOs occur during the transitional periods between the up and down state of slow waves. The preferred phase angles of this form of phase-event amplitude coupling are bimodally distributed, and the ripples (80-150 Hz) that occur during the up-down transition more often occur in the seizure-onset zone (SOZ). We investigated if bimodal ripple coupling was also evident for faster sleep oscillations, and could identify the SOZ...
November 2017: Epilepsia
https://www.readbyqxmd.com/read/28917017/physiological-ripples-%C3%A2-%C3%A2-100%C3%A2-hz-in-spike-free-scalp-eegs-of-children-with-and-without-epilepsy
#14
Anne H Mooij, Renee C M A Raijmann, Floor E Jansen, Kees P J Braun, Maeike Zijlmans
Pathological high frequency oscillations (HFOs, >80 Hz) are considered new biomarkers for epilepsy. They have mostly been recorded invasively, but pathological ripples (80-250 Hz) can also be found in scalp EEGs with frequent epileptiform spikes. Physiological HFOs also exist. They have been recorded invasively in hippocampus and neocortex. There are no reports of spontaneously occurring physiological HFOs recorded with scalp EEG. We aimed to study ripples in spike-free scalp EEGs. We included 23 children (6 with, 17 without epilepsy) who had an EEG without interictal epileptiform spikes recorded during sleep...
November 2017: Brain Topography
https://www.readbyqxmd.com/read/28860077/the-cs-algorithm-a-novel-method-for-high-frequency-oscillation-detection-in-eeg
#15
Jan Cimbálník, Angela Hewitt, Greg Worrell, Matt Stead
BACKGROUND: High frequency oscillations (HFOs) are emerging as potentially clinically important biomarkers for localizing seizure generating regions in epileptic brain. These events, however, are too frequent, and occur on too small a time scale to be identified quickly or reliably by human reviewers. Many of the deficiencies of the HFO detection algorithms published to date are addressed by the CS algorithm presented here. NEW METHOD: The algorithm employs novel methods for: 1) normalization; 2) storage of parameters to model human expertise; 3) differentiating highly localized oscillations from filtering phenomena; and 4) defining temporal extents of detected events...
August 30, 2017: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/28750290/high-frequency-activity-overriding-cortico-cortical-evoked-potentials-reflects-altered-excitability-in-the-human-epileptic-focus
#16
Katsuya Kobayashi, Riki Matsumoto, Masao Matsuhashi, Kiyohide Usami, Akihiro Shimotake, Takeharu Kunieda, Takayuki Kikuchi, Kazumichi Yoshida, Nobuhiro Mikuni, Susumu Miyamoto, Hidenao Fukuyama, Ryosuke Takahashi, Akio Ikeda
OBJECTIVE: We aimed to clarify that high frequency activity (HFA) of cortico-cortical evoked potentials (CCEPs), elicited by single pulse electrical stimulation (SPES), reflects cortical excitability. METHODS: We recruited 16 patients with refractory partial epilepsy who had chronic subdural electrode implantation for presurgical evaluation. A repetitive SPES was given to (1) the seizure onset zone (SOZ) and (2) the control cortices (non-seizure onset zone: nSOZ)...
September 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/28748408/a-simple-statistical-method-for-the-automatic-detection-of-ripples-in-human-intracranial-eeg
#17
K Charupanit, B A Lopour
High frequency oscillations (HFOs) are a promising biomarker of epileptic tissue, but detection of these electrographic events remains a challenge. Automatic detectors show encouraging results, but they typically require optimization of multiple parameters, which is a barrier to good performance and broad applicability. We therefore propose a new automatic HFO detection algorithm, focusing on simplicity and ease of implementation. It requires tuning of only an amplitude threshold, which can be determined by an iterative process or directly calculated from statistics of the rectified filtered data (i...
July 26, 2017: Brain Topography
https://www.readbyqxmd.com/read/28702346/automatic-detection-and-visualisation-of-meg-ripple-oscillations-in-epilepsy
#18
Nicole van Klink, Frank van Rosmalen, Jukka Nenonen, Sergey Burnos, Liisa Helle, Samu Taulu, Paul Lawrence Furlong, Maeike Zijlmans, Arjan Hillebrand
High frequency oscillations (HFOs, 80-500 Hz) in invasive EEG are a biomarker for the epileptic focus. Ripples (80-250 Hz) have also been identified in non-invasive MEG, yet detection is impeded by noise, their low occurrence rates, and the workload of visual analysis. We propose a method that identifies ripples in MEG through noise reduction, beamforming and automatic detection with minimal user effort. We analysed 15 min of presurgical resting-state interictal MEG data of 25 patients with epilepsy. The MEG signal-to-noise was improved by using a cross-validation signal space separation method, and by calculating ~ 2400 beamformer-based virtual sensors in the grey matter...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28681378/update-on-the-mechanisms-and-roles-of-high-frequency-oscillations-in-seizures-and-epileptic-disorders
#19
REVIEW
Premysl Jiruska, Catalina Alvarado-Rojas, Catherine A Schevon, Richard Staba, William Stacey, Fabrice Wendling, Massimo Avoli
High-frequency oscillations (HFOs) are a type of brain activity that is recorded from brain regions capable of generating seizures. Because of the close association of HFOs with epileptogenic tissue and ictogenesis, understanding their cellular and network mechanisms could provide valuable information about the organization of epileptogenic networks and how seizures emerge from the abnormal activity of these networks. In this review, we summarize the most recent advances in the field of HFOs and provide a critical evaluation of new observations within the context of already established knowledge...
August 2017: Epilepsia
https://www.readbyqxmd.com/read/28676240/local-nmda-receptor-hypofunction-evokes-generalized-effects-on-gamma-and-high-frequency-oscillations-and-behavior
#20
Jaime Lee, Matthew R Hudson, Terence J O'Brien, Jess Nithianantharajah, Nigel C Jones
The NMDA receptor (NMDAr) hypofunction theory of schizophrenia suggests that aberrant signaling through NMDAr underlies the pathophysiology of this disease. This is commonly modeled in rodents via treatment with NMDAr antagonists, which causes a range of behavioral effects that represent endophenotypes related to schizophrenia. These drugs also disrupt high-frequency neural oscillations within the brain, also potentially relevant to disease. We studied the effect of localized NMDAr hypofunction on the generation of neural oscillations occurring both locally and in distant brain regions, and on behaviors routinely used as endophenotypes to model psychosis in rodents...
July 1, 2017: Neuroscience
keyword
keyword
43856
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"