scholarly journals Temporal changes of neocortical high-frequency oscillations in epilepsy

2013 ◽  
Vol 110 (5) ◽  
pp. 1167-1179 ◽  
Author(s):  
Allison Pearce ◽  
Drausin Wulsin ◽  
Justin A. Blanco ◽  
Abba Krieger ◽  
Brian Litt ◽  
...  
Keyword(s):  
High Frequency ◽  
Statistical Tests ◽  
Relative Rate ◽  
Temporal Analysis ◽  
Temporal Changes ◽  
Patient Specific ◽  
Mixed Frequency ◽  
Potential Biomarker ◽  
Before And After ◽  
Intracranial Electrodes

High-frequency (100–500 Hz) oscillations (HFOs) recorded from intracranial electrodes are a potential biomarker for epileptogenic brain. HFOs are commonly categorized as ripples (100–250 Hz) or fast ripples (250–500 Hz), and a third class of mixed frequency events has also been identified. We hypothesize that temporal changes in HFOs may identify periods of increased the likelihood of seizure onset. HFOs (86,151) from five patients with neocortical epilepsy implanted with hybrid (micro + macro) intracranial electrodes were detected using a previously validated automated algorithm run over all channels of each patient's entire recording. HFOs were characterized by extracting quantitative morphologic features and divided into four time epochs (interictal, preictal, ictal, and postictal) and three HFO clusters (ripples, fast ripples, and mixed events). We used supervised classification and nonparametric statistical tests to explore quantitative changes in HFO features before, during, and after seizures. We also analyzed temporal changes in the rates and proportions of events from each HFO cluster during these periods. We observed patient-specific changes in HFO morphology linked to fluctuation in the relative rates of ripples, fast ripples, and mixed frequency events. These changes in relative rate occurred in pre- and postictal periods up to thirty min before and after seizures. We also found evidence that the distribution of HFOs during these different time periods varied greatly between individual patients. These results suggest that temporal analysis of HFO features has potential for designing custom seizure prediction algorithms and for exploring the relationship between HFOs and seizure generation.

scholarly journals Dual mechanisms of ictal high frequency oscillations in human rhythmic onset seizures

2020 ◽  
Author(s):  
Elliot H. Smith ◽  
Edward M. Merricks ◽  
Jyun-You Liou ◽  
Camilla Casadei ◽  
Lucia Melloni ◽  
...  
Keyword(s):  
High Frequency ◽  
Activity Patterns ◽  
Field Potential ◽  
Information Theoretic ◽  
High Frequency Oscillations ◽  
Epileptiform Discharges ◽  
Before And After ◽  
Spatial Domains ◽  
Intracranial Electrodes ◽  
Seizure Localization

ABSTRACTHigh frequency oscillations (HFOs) recorded from intracranial electrodes during epileptiform discharges are a proposed biomarker of epileptic brain tissue and may also be useful for seizure forecasting, with mixed results. Despite such potential for HFOs, there is limited investigation into the spatial context of HFOs and their relationship to simultaneously recorded neuronal activity. We sought to further understand the biophysical underpinnings of ictal HFOs using unit recordings in the human neocortex and mesial temporal lobe during rhythmic onset seizures. We compare features of ictal discharges in both the seizure core and penumbra (spatial seizure domains defined by multiunit activity patterns). We report differences in spectral features, unit-local field potential coupling, and information theoretic characteristics of HFOs before and after local seizure invasion. Furthermore, we tie these timing-related differences to spatial domains of seizures, showing that penumbral discharges are widely distributed and less useful for seizure localization.

scholarly journals Dual mechanisms of ictal high frequency oscillations in rhythmic onset seizures

2020 ◽  
Author(s):  
Elliot H. Smith ◽  
Edward M. Merricks ◽  
Jyun-You Liou ◽  
Camilla Casadei ◽  
Lucia Melloni ◽  
...  
Keyword(s):  
High Frequency ◽  
Activity Patterns ◽  
Information Theoretic ◽  
High Frequency Oscillations ◽  
Epileptiform Discharges ◽  
Electrophysiological Recordings ◽  
Before And After ◽  
Spatial Domains ◽  
Intracranial Electrodes ◽  
Seizure Localization

ABSTRACTObjectiveHigh frequency oscillations (HFOs) recorded from intracranial electrodes during epileptiform discharges have been proposed as a biomarker of epileptic brain sites and may also be a useful feature for seizure forecasting, with mixed results. Currently, pathological subclasses of HFOs have been defined primarily by frequency characteristics. Despite this, there has been limited investigation into the spatial context of HFOs with recruitment of local cortex into seizure discharging. We sought to further understand the biophysical underpinnings of ictal HFOs.MethodsHere we examine ictal HFOs from multi-scale electrophysiological recordings during spontaneous human rhythmic onset seizures. We compare features of ictal discharges in both the seizure core and penumbra, as defined by multiunit activity patterns.ResultsWe show marked differences in spectral features, unit coupling, and information theoretic characteristics of HFOs during ictal discharges before and after local seizure invasion. Furthermore, we tie these timing-related differences to different spatial domains of seizures, showing that eccentric, penumbral discharges are widely distributed and less useful for seizure localization, which may explain the variable utility of HFOs in seizure localization and forecasting.InterpretationWe thus identify two distinct classes of ictal HFOs, implying two different mechanisms underlying pathological HFOs with contrasting significance for seizure localization.

scholarly journals Viability of Preictal High-Frequency Oscillation Rates as a Biomarker for Seizure Prediction

2021 ◽  
Vol 14 ◽  
Author(s):  
Jared M. Scott ◽  
Stephen V. Gliske ◽  
Levin Kuhlmann ◽  
William C. Stacey
Keyword(s):  
High Frequency ◽  
Statistical Tests ◽  
Temporal Trends ◽  
Area Under The Curve ◽  
Receiver Operating Curve ◽  
High Frequency Oscillation ◽  
Seizure Prediction ◽  
Potential Biomarker ◽  
Preictal State ◽  
Better Than

Motivation: There is an ongoing search for definitive and reliable biomarkers to forecast or predict imminent seizure onset, but to date most research has been limited to EEG with sampling rates <1,000 Hz. High-frequency oscillations (HFOs) have gained acceptance as an indicator of epileptic tissue, but few have investigated the temporal properties of HFOs or their potential role as a predictor in seizure prediction. Here we evaluate time-varying trends in preictal HFO rates as a potential biomarker of seizure prediction.Methods: HFOs were identified for all interictal and preictal periods with a validated automated detector in 27 patients who underwent intracranial EEG monitoring. We used LASSO logistic regression with several features of the HFO rate to distinguish preictal from interictal periods in each individual. We then tested these models with held-out data and evaluated their performance with the area-under-the-curve (AUC) of their receiver-operating curve (ROC). Finally, we assessed the significance of these results using non-parametric statistical tests.Results: There was variability in the ability of HFOs to discern preictal from interictal states across our cohort. We identified a subset of 10 patients in whom the presence of the preictal state could be successfully predicted better than chance. For some of these individuals, average AUC in the held-out data reached higher than 0.80, which suggests that HFO rates can significantly differentiate preictal and interictal periods for certain patients.Significance: These findings show that temporal trends in HFO rate can predict the preictal state better than random chance in some individuals. Such promising results indicate that future prediction efforts would benefit from the inclusion of high-frequency information in their predictive models and technological architecture.

Аpplying of high-frequency monopolar diathermocoagulation in the treatment of chronic pulpitis

2020 ◽  
Vol 1 (12) ◽  
pp. 40-42
Author(s):  
F. Yu. Daurova ◽  
D. I. Tomaeva ◽  
S. V. Podkopaeva ◽  
Yu. A. Taptun
Keyword(s):  
Root Canal ◽  
High Frequency ◽  
Antibacterial Effect ◽  
Comparison Group ◽  
Poor Quality ◽  
Endodontic Treatment ◽  
Root Canals ◽  
The Third ◽  
Before And After

Relevance: the reason for the development of complications in endodontic treatment is poor-quality instrumental treatment root canals.Aims: a study of the animicrobial action and clinical efficacy of high-frequency monopolar diathermocoagulation in the treatment of chronic forms of pulpitis.Materials and methods: 102 patients with various chronic forms of pulpitis were divided into three groups of 34 patients each. In the first two groups, high-frequency monopolar diathermocoagulation was used in endodontic treatment in different modes. In the third group, endodontic treatment was carried out without the use of diathermocoagulation (comparison group). The root canal microflora in chronic pulpitis in vivo was studied twice-before and after diathermocoagulation.Results: it was established that high-frequency monopolar diathermocoagulation in the effect mode is 3, power is 4 (4.1 W) and effect is 4, power is 4 (5.4 W) with an exposure time of 3 seconds, it has a pronounced antibacterial effect on all presented pathogenic microflora obtained from the root canals of the teeth.

scholarly journals AB0655 RHEUMATOID ARTHRITIS ACTIVITY BEFORE AND AFTER COVID-19 LOCKDOWN PERIOD

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1360.1-1360
Author(s):  
M. Jordhani ◽  
D. Ruci ◽  
F. Skana ◽  
E. Memlika
Keyword(s):  
Rheumatoid Arthritis ◽  
Disease Activity ◽  
Musculoskeletal Diseases ◽  
Statistical Tests ◽  
Laboratory Data ◽  
World Population ◽  
Chronic Patients ◽  
Das 28 ◽  
Significant Difference ◽  
Before And After

Background:The COVID-19 global pandemic has had a great impact on world population due to morbidity, mortality and restriction measures in order to stop the progression of COVID-19.Patients with rheumatic and musculoskeletic diseases, and especially rheumatoid arthritis (RA) patients, being one of the vulnerable classes of chronic patients, were recommended to follow the government’s rules1.Objectives:The aim of this study was to evaluate DAS-28-ESR in patients with rheumatoid arthritis before and after lockdown period.Methods:This is a multi-center observational study including 85 patients which were evaluated before and after lockdown for their disease activity score according to DAS-28-ESR score. They had been diagnosed with rheumatoid arthritis more than 5 years ago. A thorough physical examination was performed before and after the lockdown period. It included examination of tender and swollen joints and patient’s global health. They were completed with all required laboratory data, including erythrosedimentation rate. For a more accurate calculation, DAS-28-ESR was used in an electronic version. Patients with other inflammatory or infective diseases were excluded from the study. All data were statistically evaluated using statistical tests such as t-student test.Results:The first group (the one before lockdown) had an average DAS-28-ESR of 4.7 while after the lockdown period, the average DAS-28-ESR was 5.16.After statistically evaluating all data, it was found that there exists a significant difference between DAS-28-ESR score before and after COVID-19 lockdown (p=0.0011).Conclusion:Our study showed that lockdown period due to COVID-19 pandemic, has aggravated disease activity in patients with Rheumatoid Arthritis. This may be consequence of various causes such as physical inactivity and difficulty to follow-up or to take the medication properly.References:[1]Landewé RB, Machado PM, Kroon F, et al, EULAR provisional recommendations for the management of rheumatic and musculoskeletal diseases in the context of SARS-CoV-2, Annals of the Rheumatic Diseases 2020;79:851-858.Disclosure of Interests:None declared.

Implementation of a patient-specific tapering protocol at discharge decreases total opioid dose prescribed for 6 weeks after elective primary spine surgery

2020 ◽  
Vol 45 (6) ◽  
pp. 474-478
Author(s):  
Sarah S Joo ◽  
Oluwatobi O Hunter ◽  
Mallika Tamboli ◽  
Jody C Leng ◽  
T Kyle Harrison ◽  
...  
Keyword(s):  
Spine Surgery ◽  
Joint Replacement ◽  
Oral Morphine ◽  
Hospital Length ◽  
Opioid Consumption ◽  
Hospital Length Of Stay ◽  
Patient Specific ◽  
Opioid Dose ◽  
Before And After ◽  
Primary Spine

Background and objectivesAt our institution, we developed an individualized discharge opioid prescribing and tapering protocol for joint replacement patients and implemented the same protocol for neurosurgical spine patients. We then tested the hypothesis that this protocol will decrease the oral morphine milligram equivalent (MME) dose of opioid prescribed postdischarge after elective primary spine surgery.MethodsIn this retrospective cohort study, we identified all consecutive elective primary spine surgery cases 1 year before and after introduction of the protocol. This protocol used the patient’s prior 24-hour inpatient opioid consumption to determine discharge opioid pill count and tapering schedule. The primary outcome was total opioid dose prescribed in oral MME from discharge through 6 weeks. Secondary outcomes included in-hospital opioid consumption in MME, hospital length of stay, MME prescribed at discharge, opioid refills, and rates of minor and major adverse events.ResultsEighty-three cases comprised the final sample (45 preintervention and 38 postintervention). There were no differences in baseline characteristics. The total oral MME (median (IQR)) from discharge through 6 weeks postoperatively was 900 (420–1440) preintervention compared with 300 (112–806) postintervention (p<0.01, Mann-Whitney U test), and opioid refill rates were not different between groups. There were no differences in other outcomes.ConclusionsThis patient-specific prescribing and tapering protocol effectively decreases the total opioid dose prescribed for 6 weeks postdischarge after elective primary spine surgery. Our experience also demonstrates the potential generalizability of this protocol, which was originally designed for joint replacement patients, to other surgical populations.

scholarly journals Prediction of 3D Cardiovascular hemodynamics before and after coronary artery bypass surgery via deep learning

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Gaoyang Li ◽  
Haoran Wang ◽  
Mingzi Zhang ◽  
Simon Tupin ◽  
Aike Qiao ◽  
...  
Keyword(s):  
Deep Learning ◽  
Artery Bypass ◽  
Computational Cost ◽  
Specific Model ◽  
Arterial System ◽  
Patient Specific ◽  
Cardiovascular Hemodynamics ◽  
Before And After ◽  
Deep Learning Network ◽  
Cfd Method

AbstractThe clinical treatment planning of coronary heart disease requires hemodynamic parameters to provide proper guidance. Computational fluid dynamics (CFD) is gradually used in the simulation of cardiovascular hemodynamics. However, for the patient-specific model, the complex operation and high computational cost of CFD hinder its clinical application. To deal with these problems, we develop cardiovascular hemodynamic point datasets and a dual sampling channel deep learning network, which can analyze and reproduce the relationship between the cardiovascular geometry and internal hemodynamics. The statistical analysis shows that the hemodynamic prediction results of deep learning are in agreement with the conventional CFD method, but the calculation time is reduced 600-fold. In terms of over 2 million nodes, prediction accuracy of around 90%, computational efficiency to predict cardiovascular hemodynamics within 1 second, and universality for evaluating complex arterial system, our deep learning method can meet the needs of most situations.

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