Heart rate variability (HRV) is an accessible and convenient means to assess the sympathetic/parasympathetic balance. Autonomic dysfunctions may reflect a pro-ictal state and occur before the seizure ...onset. Previous studies have reported HRV-based models to identify preictal states in continuous electrocardiogram (EKG) monitoring. Here, we evaluated the ability of HRV metrics extracted from daily single resting-state periods to estimate the risk of upcoming seizure(s) using probabilistic forecasts. Daily standardized 10-min vigilance-controlled EKG periods were recorded in 15 patients with drug-resistant focal epilepsy who underwent intracerebral electroencephalography (EEG). Analyses of a total of 156 periods, based on machine learning approaches, suggested that HRV features can identify preictal states with a median AUC of 0.75 0.68;0.99. Pseudoprospective daily forecasts yielded a median Brier score of 0.3 0.18;0.48. About 60% of preictal days were correctly forecasted, while false positive predictions were noticed in 24% of interictal days. Daily resting HRV seems to capture information on autonomic variations that may reflect a pro-ictal state. The method could be embedded in an ambulatory clinical seizure prediction device, but additional modalities (prodromes, EEG-based features, etc.) should be associated to improve its performance.
•HRV features from resting state can discriminate between interictal/preictal states.•Daily short EKG recordings can provide fair pseudoprospective forecasts of preictal states.•Sensitivity of HRV-based seizure prediction should be increased.•This approach could be embedded in an ambulatory clinical device.•Multimodal fusion (e.g., prodromes and EEG) could improve prediction performances.
iEDeaL Wang, Qitong; Whitmarsh, Stephen; Navarro, Vincent ...
Proceedings of the VLDB Endowment,
11/2022, Volume:
16, Issue:
3
Journal Article
Peer reviewed
Epilepsy is a chronic neurological disease, ranked as the second most burdensome neurological disorder worldwide. Detecting Interictal Epileptiform Discharges (IEDs) is among the most important ...clinician operations to support epilepsy diagnosis, rendering automatic IED detection based on electroencephalography (EEG) signals an important topic. However, most existing solutions were designed and evaluated upon artificially balanced IED datasets, which do not conform to the real-world highly imbalanced scenarios. In this work, we propose the iEDeaL framework for automatic IED detection in challenging real-world use cases. The main components of iEDeaL are the new SC neural network architecture, to efficiently detect IEDs on raw EEG series instead of extracted features, and SaSu, a novel loss function to train SC by optimizing the
F
β
-score. Experiments on two real-world imbalanced IED datasets verify the advantages of iEDeaL in offering more accurate and efficient IED detection when compared with other state-of-the-art deep learning-based and spectrogram feature-based solutions.
Neurological manifestations of coronavirus disease 19 (COVID‐19) such as encephalitis and seizures have been reported increasingly, but our understanding of COVID‐19‐related brain injury is still ...limited. Herein we describe prefrontal involvement in a patient with COVID‐19 who presented prior anosmia, raising the question of a potential trans‐olfactory bulb brain invasion.
Des troubles du sommeil tels que et l’hypersomnie ont été décrits dans l’encéphalite à anti-NMDAr. L’agrypnie, stade le plus extrême du status dissociatus, n’a jamais été rapportée.
Une patiente de ...22 ans a présenté un tableau de bradypsychie et troubles du comportement, avec des anticorps anti-NMDAr positifs associés à un tératome ovarien droit. Après une amélioration initiale des symptômes sous traitement immunomodulateur, l’évolution a été marquée par une aggravation comportementale et cognitive, avec un déficit sévère en quantité de sommeil. Deux enregistrements en vidéo-EEG avec montage polysomnographique ont mis en évidence une destruction profonde de l’architecture du sommeil avec de courtes séquences de sommeil N1, des phases de mouvements oculaires rapides non physiologiques et une hyperactivité motrice et autonomique, confirmant un tableau d’agrypnia excitata. L’identification de l’agrypnie a permis la mise en évidence d’une rechute de l’encéphalite en relation avec le développement d’un second tératome ovarien controlatéral. Une seconde ligne d’immunothérapie a permis de normaliser le sommeil et les symptômes cliniques.
L’agrypnie, forme la plus sévère du status dissociatus, correspondant à un déficit subtotal de sommeil et sa déstructuration profonde sans stade physiologique identifiable, a été observée au décours d’une rechute d’encéphalite à anti-NMDAr. Une insomnie très sévère a été rapportée à la phase aiguë de l’ENMDAr sans donnée polysomnographique disponible, et pourrait correspondre à un tableau d’agrypnie.
Les enregistrements polysomnographiques manquent cruellement à la phase aiguë des encéphalites et permettraient une meilleure compréhension de la clinique et du pronostic de ces pathologies.
Humor plays a prominent role in our lives. Thus, understanding the cognitive and neural mechanisms of humor is particularly important. Previous studies that investigated neural substrates of humor ...used functional MRI and to a lesser extent EEG. In the present study, we conducted intracranial recording in human patients, enabling us to obtain the signal with high temporal precision from within specific brain locations. Our analysis focused on the temporal lobe and the surrounding areas, the temporal lobe was most densely covered in our recording. Thirteen patients watched a fragment of a Charlie Chaplin movie. An independent group of healthy participants rated the same movie fragment, helping us to identify the most funny and the least funny frames of the movie. We compared neural activity occurring during the most funny and least funny frames across frequencies in the range of 1–170 Hz. The most funny compared to least funny parts of the movie were associated with activity modulation in the broadband high-gamma (70−170 Hz; mostly activation) and to a lesser extent gamma band (40−69Hz; activation) and low frequencies (1−12 Hz, delta, theta, alpha bands; mostly deactivation). With regard to regional specificity, we found three types of brain areas: (I) temporal pole, middle and inferior temporal gyrus (both anterior and posterior) in which there was both activation in the high-gamma/gamma bands and deactivation in low frequencies; (II) ventral part of the temporal lobe such as the fusiform gyrus, in which there was mostly deactivation the low frequencies; (III) posterior temporal cortex and its environment, such as the middle occipital and the temporo-parietal junction, in which there was activation in the high-gamma/gamma band. Overall, our results suggest that humor appreciation might be achieved by neural activity across the frequency spectrum.
•Electrophysiological correlates of humor in the temporal lobe are shown.•Humor is mediated by high gamma/gamma activation and low frequencies deactivation.•Neural activity likely reflects cognitive mechanisms of humor appreciation.
Prediction is held to be a fundamental process underpinning perception, action, and cognition. To examine the time course of prediction error signaling, we recorded intracranial EEG activity from ...nine presurgical epileptic patients while they listened to melodies whose information theoretical predictability had been characterized using a computational model. We examined oscillatory activity in the superior temporal gyrus (STG), the middle temporal gyrus (MTG), and the pars orbitalis of the inferior frontal gyrus, lateral cortical areas previously implicated in auditory predictive processing. We also examined activity in anterior cingulate gyrus (ACG), insula, and amygdala to determine whether signatures of prediction error signaling may also be observable in these subcortical areas. Our results demonstrate that the information content (a measure of unexpectedness) of musical notes modulates the amplitude of low-frequency oscillatory activity (theta to beta power) in bilateral STG and right MTG from within 100 and 200 msec of note onset, respectively. Our results also show this cortical activity to be accompanied by low-frequency oscillatory modulation in ACG and insula—areas previously associated with mediating physiological arousal. Finally, we showed that modulation of low-frequency activity is followed by that of high-frequency (gamma) power from approximately 200 msec in the STG, between 300 and 400 msec in the left insula, and between 400 and 500 msec in the ACG. We discuss these results with respect to models of neural processing that emphasize gamma activity as an index of prediction error signaling and highlight the usefulness of musical stimuli in revealing the wide-reaching neural consequences of predictive processing.
It is unknown whether ultrasound-induced blood-brain barrier (BBB) disruption can promote epileptogenesis and how BBB integrity changes over time after sonication.
To gain more insight into the ...safety profile of ultrasound (US)-induced BBB opening, we determined BBB permeability as well as histological modifications in C57BL/6 adult control mice and in the kainate (KA) model for mesial temporal lobe epilepsy in mice after sonication with low-intensity pulsed ultrasound (LIPU). Microglial and astroglial changes in ipsilateral hippocampus were examined at different time points following BBB disruption by respectively analyzing Iba1 and glial fibrillary acidic protein immunoreactivity. Using intracerebral EEG recordings, we further studied the possible electrophysiological repercussions of a repeated disrupted BBB for seizure generation in nine non-epileptic mice.
LIPU-induced BBB opening led to transient albumin extravasation and reversible mild astrogliosis, but not to microglial activation in the hippocampus of non-epileptic mice. In KA mice, the transient albumin extravasation into the hippocampus mediated by LIPU-induced BBB opening did not aggravate inflammatory processes and histologic changes that characterize the hippocampal sclerosis. Three LIPU-induced BBB opening did not induce epileptogenicity in non-epileptic mice implanted with depth EEG electrodes.
Our experiments in mice provide persuasive evidence of the safety of LIPU-induced BBB opening as a therapeutic modality for neurological diseases.
Purpose: Analysis of the EEG signal has recently shown evidence of dynamic changes preceding ictal onset in seizures selected from patients with clear epileptogenic foci. Most of the studies were ...conducted in highly selected EEG epochs and patients. In addition, these studies relied mostly on mathematical approaches and neglected clinical and visual EEG parameters. We therefore performed a systematic comparison of a nonlinear method (the similarity measure) with classic visual inspection of the EEG and the patient's clinical state.
Methods: We analyzed the dynamics of long epochs of intracranial EEG containing 129 electroclinical and 45 electrographic seizures in 13 successive unselected patients undergoing presurgical evaluation.
Results: (a) The similarity measure detected preictal dynamical changes of the EEG signal in two thirds of the seizures whether or not a clear focus was identified, and whether seizures were electroclinical or purely electrographic. The mean duration of preictal changes was 12 min. (b) The preictal changes were correlated with various visually detectable EEG changes in 78.9% of electroclinical seizures. (c) 81.5% of the preictal dynamic changes were correlated with changes of vigilance or behavior. (d) Fluctuations of the dynamics were not necessarily followed by seizures.
Conclusions: Our results indicate that EEG dynamics frequently change before seizures. These preictal changes are most often associated with the EEG changes accompanying transitions between states of vigilance. The preictal dynamic changes may represent physiologic changes acting as facilitating factors or pathologic changes reflecting a network dysfunction.
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