On the Operational Utility of Measures of Multichannel EEGs.
Ontology highlight
ABSTRACT:
SUBMITTER: Darmon D
PROVIDER: S-EPMC8617715 | biostudies-literature | 2021 Oct
REPOSITORIES: biostudies-literature
Publications
On the Operational Utility of Measures of Multichannel EEGs.
Darmon David D Watanabe Tomas T Cellucci Christopher C Rapp Paul E PE
Entropy (Basel, Switzerland) 20211030 11
Multichannel EEGs were obtained from healthy participants in the eyes-closed no-task condition and in the eyes-open condition (where the alpha component is typically abolished). EEG dynamics in the two conditions were quantified with two related binary Lempel-Ziv measures of the first principal component, and with three measures of integrated information, including the more recently proposed integrated synergy. Both integrated information and integrated synergy with model order p=1 had greater v ...[more]
Similar Datasets
Project description:Assessment of hypnotic susceptibility is usually obtained through the application of psychological instruments. A satisfying classification obtained through quantitative measures is still missing, although it would be very useful for both diagnostic and clinical purposes. Aiming at investigating the relationship between the cortical brain activity and the hypnotic susceptibility level, we propose the combined use of two methodologies - Recurrence Quantification Analysis and Detrended Fluctuation Analysis - both inherited from nonlinear dynamics. Indicators obtained through the application of these techniques to EEG signals of individuals in their ordinary state of consciousness allowed us to obtain a clear discrimination between subjects with high and low susceptibility to hypnosis. Finally a neural network approach was used to perform classification analysis.
| S-EPMC4085592 | biostudies-other
Project description:In longitudinal event data, a crude rate is a simple quantification of the event rate, defined as the number of events during an evaluation window, divided by the at-risk population size at the beginning or mid-time point of that window. The crude rate recently received revitalizing interest from medical researchers who aimed to improve measurement of misdiagnosis-related harms using administrative or billing data by tracking unexpected adverse events following a "benign" diagnosis. The simplicity of these measures makes them attractive for implementation and routine operational monitoring at hospital or health system level. However, relevant statistical inference procedures have not been systematically summarized. Moreover, it is unclear to what extent the temporal changes of the at-risk population size would bias analyses and affect important conclusions concerning misdiagnosis-related harms. In this article, we present statistical inference tools for using crude-rate based harm measures, as well as formulas and simulation results that quantify the deviation of such measures from those based on the more sophisticated Nelson-Aalen estimator. Moreover, we present results for a generalized multibin version of the crude rate, for which the usual crude rate is a single-bin special case. The generalized multibin crude rate is more straightforward to compute than the Nelson-Aalen estimator and can reduce potential biases of the single-bin crude rate. For studies that seek to use multibin measures, we provide simulations to guide the choice regarding number of bins. We further bolster these results using a worked example of stroke after "benign" dizziness from a large data set.
| S-EPMC8365112 | biostudies-literature
Project description:BackgroundA method for rapid detection of dengue virus using the reverse-transcription recombinase polymerase amplification (RT-RPA) was recently developed, evaluated and made ready for deployment. However, reliance solely on the evaluation performed by experienced researchers in a well-structured and well-equipped reference laboratory may overlook the potential intrinsic problems that may arise during deployment of the assay into new application sites, especially for users unfamiliar with the test. Appropriate assessment of this newly developed assay by users who are unfamiliar with the assay is, therefore, vital.MethodsAn operational utility test to elucidate the efficiency and effectiveness of the dengue RT-RPA assay was conducted among a group of researchers new to the assay. Nineteen volunteer researchers with different research experience were recruited. The participants performed the RT-RPA assay and interpreted the test results according to the protocol provided. Deviation from the protocol was identified and tabulated by trained facilitators. Post-test questionnaires were conducted to determine the user satisfaction and acceptability of the dengue RT-RPA assay.ResultsAll the participants completed the test and successfully interpreted the results according to the provided instructions, regardless of their research experience. Of the 19 participants, three (15.8%) performed the assay with no deviations and 16 (84.2%) performed the assay with only 1 to 5 deviations. The number of deviations from protocol, however, was not correlated with the user laboratory experience. The accuracy of the results was also not affected by user laboratory experience. The concordance of the assay results against that of the expected was at 89.3%. The user satisfaction towards the RT-RPA protocol and interpretation of results was 90% and 100%, respectively.ConclusionsThe dengue RT-RPA assay can be successfully performed by simply following the provided written instructions. Deviations from the written protocols did not adversely affect the outcome of the assay. These suggest that the RT-RPA assay is indeed a simple, robust and efficient laboratory method for detection of dengue virus. Furthermore, high new user acceptance of the RT-RPA assay suggests that this assay could be successfully deployed into new laboratories where RT-RPA was not previously performed.
| S-EPMC5896040 | biostudies-literature
Project description:BackgroundCatastrophic disruptions in care delivery threaten the operational efficiency and potentially the validity of clinical research efforts, in particular randomized clinical trials. Most recently, the COVID-19 pandemic affected essentially all aspects of care delivery and clinical research conduct. While consensus statements and clinical guidance documents have detailed potential mitigation measures, few real-world experiences detailing clinical trial adaptations to the COVID-19 pandemic exist, particularly among, large, global registrational cardiovascular trials.MethodsWe outline the operational impact of COVID-19 and resultant mitigation measures in the Dapagliflozin Evaluation to Improve the LIVEs of Patients with Preserved Ejection Fraction Heart Failure (DELIVER) trial, one of the largest and most globally diverse experiences with COVID-19 of any cardiovascular clinical trial to date. Specifically, we address the needed coordination between academic investigators, trial leadership, clinical sites, and the supporting sponsor to ensure the safety of participants and trial staff, to maintain the fidelity of trial operations, and to prospectively adapt statistical analyses plans to evaluate the impact of COVID-19 and the pandemic at large on trial participants. These discussions included key operational issues such as ensuring delivery of study medications, adaptations to study visits, enhanced COVID-19 related endpoint adjudication, and protocol and analytical plan revisions.ConclusionOur findings may have important implications for establishing consensus on prospective contingency planning in future clinical trials.Clinicaltrialgov: NCT03619213.ClinicaltrialGOV: NCT03619213.
| S-EPMC10200275 | biostudies-literature
Project description:(1) Background: The correlations between brain connectivity abnormality and psychiatric disorders have been continuously investigated and progressively recognized. Brain connectivity signatures are becoming exceedingly useful for identifying patients, monitoring mental health disorders, and treatment. By using electroencephalography (EEG)-based cortical source localization along with energy landscape analysis techniques, we can statistically analyze transcranial magnetic stimulation (TMS)-invoked EEG signals, for obtaining connectivity among different brain regions at a high spatiotemporal resolution. (2) Methods: In this study, we analyze EEG-based source localized alpha wave activity in response to TMS administered to three locations, namely, the left motor cortex (49 subjects), left prefrontal cortex (27 subjects), and the posterior cerebellum, or vermis (27 subjects) by using energy landscape analysis techniques to uncover connectivity signatures. We then perform two sample t-tests and use the (5 × 10-5) Bonferroni corrected p-valued cases for reporting six reliably stable signatures. (3) Results: Vermis stimulation invoked the highest number of connectivity signatures and the left motor cortex stimulation invoked a sensorimotor network state. In total, six out of 29 reliable, stable connectivity signatures are found and discussed. (4) Conclusions: We extend previous findings to localized cortical connectivity signatures for medical applications that serve as a baseline for future dense electrode studies.
| S-EPMC10146617 | biostudies-literature
Project description:BackgroundTraditional, trans-cervical thyroidectomy results in the presence of a neck scar, which has been shown to correlate with lower quality of life and lower patient satisfaction. Transoral thyroid surgery (TOTS) has been utilized as an alternative approach to avoid a cutaneous incision and scar by accessing the neck and thyroid through the oral cavity. This study was designed to evaluate patient preference through health-state utility scores for TOTS as compared to conventional trans-cervical thyroidectomy.MethodsIn this cross-sectional study, patient preferences were elicited for TOTS and trans-cervical thyroidectomy with the use of an online survey. Respondents were asked to consider 4 hypothetical health scenarios involving thyroid surgery with varying approaches. Health-state utility scores were elicited using visual analog scale and standard gamble exercises.ResultsOverall, 516 respondents completed the survey, of whom 261 (50.6%) were included for analysis, with a mean age of 41.5 years (SD 14.9 years), including 171 (65.5%) females. Health utility scores were similar for TOTS and conventional transcervical techniques. Statistically significant differences in the standard gamble utility score were noted for gender and ethnicity across all scenarios. Comparisons of visual analog score utilities were not statistically significant based on respondent demographics.ConclusionPreferences for TOTS and trans-cervical thyroidectomy did not significantly differ in the current study. Females and white ethnicity indicated stronger preference for a TOTs approach compared to males and other ethnicities, respectively. Some literature suggests certain types of patients who might prefer minimally invasive thyroidectomy more so than other patients-in keeping with the current findings of this study.
| S-EPMC9989232 | biostudies-literature
Project description:We here study a network of synaptic relations mingling excitatory and inhibitory neuron nodes that displays oscillations quite similar to electroencephalogram (EEG) brain waves, and identify abrupt variations brought about by swift synaptic mediations. We thus conclude that corresponding changes in EEG series surely come from the slowdown of the activity in neuron populations due to synaptic restrictions. The latter happens to generate an imbalance between excitation and inhibition causing a quick explosive increase of excitatory activity, which turns out to be a (first-order) transition among dynamic mental phases. Moreover, near this phase transition, our model system exhibits waves with a strong component in the so-called delta-theta domain that coexist with fast oscillations. These findings provide a simple explanation for the observed delta-gamma and theta-gamma modulation in actual brains, and open a serious and versatile path to understand deeply large amounts of apparently erratic, easily accessible brain data.
| S-EPMC8301300 | biostudies-literature
Project description:Clinical electroencephalographic (EEG) data varies significantly depending on a number of operational conditions (e.g., the type and placement of electrodes, the type of electrical grounding used). This investigation explores the statistical differences present in two different referential montages: Linked Ear (LE) and Averaged Reference (AR). Each of these accounts for approximately 45% of the data in the TUH EEG Corpus. In this study, we explore the impact this variability has on machine learning performance. We compare the statistical properties of features generated using these two montages, and explore the impact of performance on our standard Hidden Markov Model (HMM) based classification system. We show that a system trained on LE data significantly outperforms one trained only on AR data (77.2% vs. 61.4%). We also demonstrate that performance of a system trained on both data sets is somewhat compromised (71.4% vs. 77.2%). A statistical analysis of the data suggests that mean, variance and channel normalization should be considered. However, cepstral mean subtraction failed to produce an improvement in performance, suggesting that the impact of these statistical differences is subtler.
| S-EPMC5479869 | biostudies-literature
Project description:ObjectiveQuantitatively evaluate whether screening with compressed spectral arrays (CSAs) is a practical and time-effective protocol for assisting expert review of continuous EEG (cEEG) studies in hospitalized adults.MethodsThree neurophysiologists reviewed the reported findings of the first 30 minutes of 118 cEEGs, then used CSA to guide subsequent review ("CSA-guided review" protocol). Reviewers viewed 120 seconds of raw EEG data surrounding suspicious CSA segments. The same neurophysiologists performed independent page-by-page visual interpretation ("conventional review") of all cEEGs. Independent conventional review by 2 additional, more experienced neurophysiologists served as a gold standard. We compared review times and detection rates for seizures and other pathologic patterns relative to conventional review.ResultsA total of 2,092 hours of cEEG data were reviewed. Average times to review 24 hours of cEEG data were 8 (±4) minutes for CSA-guided review vs 38 (±17) minutes for conventional review (p < 0.005). Studies containing seizures required longer review: 10 (±4) minutes for CSA-guided review vs 44 (±20) minutes for conventional review (p < 0.005). CSA-guided review was sensitive for seizures (87.3%), periodic epileptiform discharges (100%), rhythmic delta activity (97.1%), focal slowing (98.7%), generalized slowing (100%), and epileptiform discharges (88.5%).ConclusionsCSA-guided review reduces cEEG review time by 78% with minimal loss of sensitivity compared with conventional review.Classification of evidenceThis study provides Class IV evidence that screening of cEEG with CSAs efficiently and accurately identifies seizures and other EEG abnormalities as compared with standard cEEG visual interpretation.
| S-EPMC4114174 | biostudies-literature
Project description:Extracellular vesicles (EVs) transport biological content between cells to mediate physiological processes. The association between EVs and resilience, the ability to cope with stress, is unknown. Using unbiased machine learning approaches, we aimed to identify a biological profile of resilience. Twenty servicemen (27.8 ± 5.9 years) completed the Connor Davidson Resilience (CD-RISC) questionnaire and were exposed to daily physical and cognitive exertion with 48-hr sleep and caloric restriction. Blood samples from baseline and the second day of stress were analyzed for neuroendocrine biomarkers impacted by military stress. EVs were isolated from plasma and stained with antibodies associated with exosomes (CD63), microvesicles (VAMP3), and apoptotic bodies (THSD1). Individuals were separated into high (n = 10, CD-RISC > 90) and low (n = 10, CD-RISC < 79) resilience. EV features were stratified by size, then down-selected using regression trees and compared between groups. Diagnostic accuracy was assessed using receiver operating characteristic curves. Compared to low resilience, high resilience demonstrated a greater increase in variability of THSD1 local bright spot intensities among large-sized EVs in response to stress (p = 0.002, Hedges' g = 1.59). Among medium-sized EVs, high resilience exhibited a greater decrease in side scatter intensity (p = 0.014, Hedges' g = 1.17). Both features demonstrated high to moderate diagnostic accuracy for high resilience (AUC = 0.90 and 0.79). In contrast, neuroendocrine biomarker concentrations were similar between groups. The increase in variability among THSD1 + EVs in high, but not low, resilient individuals following stress may suggest high resilience is accompanied by stress-triggered apoptotic adaptations to the environment that are not detected in neuroendocrine biomarkers.
| S-EPMC8978596 | biostudies-literature