Periodic Spikes Research Articles

Abstract 4129223: Large Language Modeling-Enabled Analysis of Atrial Fibrillation Topics and Sentiments on Social Media

Purpose: We utilized large language modeling (LLM) and automated topic modeling techniques to describe public perceptions regarding AF on Reddit, a social media platform. Methods: In this qualitative study, we curated all AF-related discussions on Reddit from 2006 to 2023 by searching for all posts and comments containing AF-related terms (“atrial fibrillation”, “afib”, and “atrial flutter”). Discussions were embedded using a state-of-the-art embedding model (BAAI/bge-base-en-v1.5). Embeddings are reduced in dimensionality using Uniform Manifold Approximation and Project and clustered using K-Means Clustering to find topics and groups. Topic and group labels are enhanced using large language models (Llama2 and GPT4, respectively). Results: We identified a total of 86,323 discussions related to AF from 38,183 unique users between April 14, 2006 and November 20, 2023. Discussions around wearables and ablations increased over time, while discussions around anticoagulation had periodic spikes. The topic modeling pipeline automatically identified 64 topics and 9 groups (Figure 1). Groups emphasized the following themes: lifestyle factors and triggers associated with AF (groups 1, 5, 7); patient experiences with management strategies including anticoagulation, rate control, pharmacological rhythm control, and ablation (groups 2, 4, 5); experiences with wearable devices (group 8); psychological burden of living with AF (group 6); and online advertisements for AF-related medications (groups 3, 9). Conclusions: Our AI-enabled topic modeling analysis revealed public perceptions about AF including triggers, experiences with different management strategies, impact of wearables, and psychological burden of the diagnosis, which may help guide potential strategies for improving shared decision making around the AF patient journey.

Exploring the use of satellite Earth observation active wildland fire hotspot data via open access web platforms

ABSTRACT Globally, managing wildland fire is increasing in complexity. Satellite Earth Observation (EO) data, specifically active fire ‘hotspot’ data, is often used to inform wildland fire management. This study explores hotspot data usage via web traffic data (‘user counts’) for the FIRMS, GWIS and EFFIS web portals between September 2019 and April 2023. Global active fire data use is characterized by multi-month periods of relatively low, stable user counts, interspersed with periodic spikes (4.1x median monthly activity) of activity broadly aligned with the North American / European fire season (late summer-fall). Users from the Americas (45%) and Europe (36%) dominate web traffic. We also examined correlative relationships between web page user counts and environmental and social variables at multiple spatial scales. Globally, the strongest relationships were found between user counts and the total number of fires, total burned area, number of fire disaster events; country population levels and internet proliferation. Notably, at a country level, the strongest (and weakest) relationships between weekly user counts and fire activity were found in a diverse range of countries suggesting that a variety of hotspot data use situations exist and further investigation is needed to better understand EO active fire data usage.

Photocatalytic and antibacterial activity properties of Ti surface treated by femtosecond laser–a prospective solution to peri-implant disease

Laser texturing seems to be a promising technique for reducing bacterial adhesion on titanium implant surfaces. This work aims to demonstrate the possibility of obtaining a functionally orientated surface of titanium implant elements with a specific architecture with specific bacteriological and photocatalytic properties. Femtosecond laser-generated surface structures, such as laser-induced periodic surface structures (LIPSS, wrinkles), grooves, and spikes on titanium, have been characterised by XRD, Raman spectroscopy, and scanning electron microscopy (SEM). The photocatalytic activity of the titanium surfaces produced was tested based on the degradation effect of methylene blue (MB). The correlation between the photocatalytic activity of TiO2 coatings and their morphology and structure has been analysed. Features related to the size, shape, and distribution of the roughness patterns were found to influence the adhesion of the bacterial strain on different surfaces. On the laser-structurised surface, the adhesion of Escherichia coli bacteria were reduced by 80% compared to an untreated reference surface.

Coupling dynamics of locally active memristor based neurons.

Brain-like dynamics require third-order or higher-order complexity. In order to investigate the coupling neuromorphic behaviors of identical third-order memristive neurons, this paper begins with the aim of exploring two identical neuron based dynamics under distinct operating regimes and coupling strengths. Without coupling, the single neuron can exhibit resting states, periodic spikes, or chaos depending on the bias condition. The uncoupled resting neurons can be activated by resistive coupling, inducing inhomogeneous resting states (static Smale paradox) and inhomogeneous spikes (dynamic Smale paradox) due to the edge of chaos regime. Considering the single neuron at the periodic spikes or chaotic states, the coupled neurons can mimic shocking oscillation death, non-periodic asynchronization, and periodic synchronization via the Hopf bifurcation theory. From the above analyses, an artificial ring neural network is constructed using 100 memristive neurons and resistive synapses to further study the coupled mechanism, generating exotic spatiotemporal patterns such as chimera death, amplitude chimera, solitary states, and asynchronization because of symmetry breaking. This sheds new light on exploring exotic spatiotemporal patterns of networks based on memristive neurons from the perspective of the nonlinear circuit theory.

Temporal lobe epilepsy page: Role of temporal lobe structures and subjacent pathology in the intracranial ictal onset pattern in pediatric patients with temporal lobe epilepsy: A stereo-electroencephalogram analysis

ObjectiveTo determine the intracranial ictal onset and early spread patterns in pediatric patients with Temporal lobe epilepsy and its possible association with histopathology, temporal structure involved, mesial structural pathology, and possible implication in postsurgical outcome. MethodsA descriptive, retrospective, cross-sectional study was carried out in a group of children from Children’s Wisconsin between 2016 and 2022. ResultsThis study showed a strong association between ictal onset patterns and underlying histology (p < 0.05). Low-Frequency High Amplitude periodic spikes were seen only in patients with HS (20.6 %). A strong statistically significant association was found between different ictal onset patterns and the temporal lobe structure involved in the ictal onset (p < 0.001). Seizures with ictal onset consisting of Slow Potential Shift with superimposed Low Voltage Fast Activity arise from the Inferior Temporal Lobe or Middle Temporal Gyrus in a more significant proportion of seizures than those that originated from mesial temporal structures (Difference of proportion; p < 0.05). Low Voltage Fast Activity periodic spikes as an ictal pattern were seen in a patient with seizures arising outside the mesial temporal structure. The most frequent early spread pattern observed was Low Voltage Fast Activity (89.4 %); this pattern did not depend on the type of mesial structure pathology. Ictal onset patterns were associated with postsurgical outcomes (p < 0.001). The ictal onset pattern depends on the histopathology in the ictal onset zone and the temporal lobe structure involved in the ictal onset (p = 0.001). ConclusionsIntracranial ictal onset patterns in TEMPORAL LOBE EPILEPSY depend on underlying histology and the temporal lobe structure involved in its onset.

Systematic review of seizure-onset patterns in stereo-electroencephalography: Current state and future directions

ObjectiveIncreasing evidence suggests that the seizure-onset pattern (SOP) in stereo-electroencephalography (SEEG) is important for localizing the “true” seizure onset. Specifically, SOPs with low-voltage fast activity (LVFA) are associated with seizure-free outcome (Engel I). However, several classifications and various terms corresponding to the same pattern have been reported, challenging its use in clinical practice. MethodFollowing the Preferred Reporting Items of Systematic reviews and Meta-Analyses (PRISMA) guideline, we performed a systematic review of studies describing SOPs along with accompanying figures depicting the reported SOP in SEEG. ResultsOf 1799 studies, 22 met the selection criteria. Among the various SOPs, we observed that the terminology for low frequency periodic spikes exhibited the most variability, whereas LVFA is the most frequently used term of this pattern. Some SOP terms were inconsistent with standard EEG terminology. Finally, there was a significant but weak association between presence of LVFA and seizure-free outcome. ConclusionDivergent terms were used to describe the same SOPs and some of these terms showed inconsistencies with the standard EEG terminology. Additionally, our results confirmed the link between patterns with LVFA and seizure-free outcomes. However, this association was not strong. SignificanceThese results underline the need for standardization of SEEG terminology.

Characteristics Analysis of Influence of Multiple Parameters of Mixed Sea Waves on Delay–Doppler Map in Global Navigation Satellite System Reflectometry

Feature capture and recognition of sea wave components in radar systems especially in global navigation satellite system reflectometry (GNSS-R) using signal processing approaches or computer simulative methods has become a research hotspot in recent years. At the same time, parameter inversion of marine phenomena from the discovered characteristics plays a significant role in monitoring and forewarning the different components of sea waves. This paper aims to investigate the impact of multiple parameters, such as the wind speed, directionality variable, wave amplitude, wave length, and directions of sea wave components, on the delay waveform of the delay–Doppler map (DDM). Two types of wind waves and the 2-D sinusoidal sea surface are chosen to be analyzed. By comparing and analyzing the discrepancy of delay waveforms under different conditions, it can be concluded that the increased MSS which arises from the increase in the roughness of the sea surface can lead to the difference in the peak value or trial edges exhibited in delay waveforms. The values of delay waveforms at zero chip along the increasing direction of long-crest wind waves exhibit the periodic spikes shape, which is the opposite of the short-crest wind waves, and the fluctuation of the periodic profiles decreases with the increase in the amplitude of waves. The results and conclusions can provide a foundation for the parameter inversion, tracking, and early warning of anomalous formations of waves in bistatic radar configuration.

Moving beyond the mean: an analysis of faecal corticosterone metabolites shows substantial variability both within and across white-tailed deer populations.

Glucocorticoid (GC) levels have significant impacts on the health and behaviour of wildlife populations and are involved in many essential body functions including circadian rhythm, stress physiology and metabolism. However, studies of GCs in wildlife often focus on estimating mean hormone levels in populations, or a subset of a population, rather than on assessing the entire distribution of hormone levels within populations. Additionally, explorations of population GC data are limited due to the tradeoff between the number of individuals included in studies and the amount of data per individual that can be collected. In this study, we explore patterns of GC level distributions in three white-tailed deer (Odocoileus virginianus) populations using a non-invasive, opportunistic sampling approach. GC levels were assessed by measuring faecal corticosterone metabolite levels ('fCMs') from deer faecal samples throughout the year. We found both population and seasonal differences in fCMs but observed similarly shaped fCM distributions in all populations. Specifically, all population fCM cumulative distributions were found to be very heavy-tailed. We developed two toy models of acute corticosterone elevation in an effort to recreate the observed heavy-tailed distributions. We found that, in all three populations, cumulative fCM distributions were better described by an assumption of large, periodic spikes in corticosterone levels every few days, as opposed to an assumption of random spikes in corticosterone levels. The analyses presented in this study demonstrate the potential for exploring population-level patterns of GC levels from random, opportunistically sampled data. When taken together with individual-focused studies of GC levels, such analyses can improve our understanding of how individual hormone production scales up to population-level patterns.

Mathematical Modeling of Periodic Outbreaks with Waning Immunity: A Possible Long-Term Description of COVID-19

The COVID-19 pandemic is still ongoing, even if the emergency is over, and we now have enough data to analyze the outbreak over a long timeline. There is evidence that the outbreak alternates periods of high and low infections. Retrospectively, this can help in understanding the nature of an appropriate mathematical model for this dramatic infection. The periodic behavior may be the consequence of time-dependent coefficients related to seasonal effects and specific political actions, or an intrinsic feature of the model. The present paper relies on the assumption that the periodic spikes are an intrinsic feature of the disease, and, as such, it should be properly reflected in the mathematical model. Based on the concept of waning immunity proposed for other pathologies, we introduce a new model with (i) a compartment for weakly immune people subject to immunity booster, represented by a non-linear term; (ii) discrimination between individuals infected/vaccinated for the first time, and individuals already infected/vaccinated, undergoing to new infections/doses. We analyze some preliminary properties of our model, called SIRW2, and provide a proof-of-concept that it is capable of reproducing qualitatively the long-term oscillatory behavior of COVID-19 infection.

DC operating points of Mott neuristor circuits

In 1960 Hewitt Crane conceptualized neuristors as electronic logic networks that could mimic action potential generation by biological neurons. In 2012 Mott memristors were presented as nano-scale electronic devices for physically constructing neuristor networks. Both the original Mott memristor model and the simplified model presented in 2020 are stiff nonlinear first-order ordinary differential equations (ODEs) that describe the voltage controlled threshold switching and current controlled negative differential resistance, attributed to a Mott insulator-to-metal phase transition. By design, a Mott neuristor contains two identical Mott memristors plus linear resistors and capacitors (no inductors), which enables alternating threshold switching by the memristors to generate periodic (AC) output voltage spikes in response to a DC current or voltage input. This paper presents a steady-state analysis of dynamic neuristor models, including four-, five-, and six-state variables (each of which is a system of first-order ODEs involving the states) based on the original phenomenological model of the Mott memristor. Specifically, it reveals the unique stable operating points that occur for applied currents or voltages below the amounts needed to induce resistive switching. These DC operating points represent the physically meaningful “OFF” states for the circuit when the neuristor does not output voltage spikes. Jacques Hadamard's mathematical criteria for a well-posed physical model (existence, uniqueness, continuity, stability) motivated the search for these DC operating points (OFF states), which are needed for efficiently initializing neuristor models before conducting dynamic neuristor simulations. The key result of our analysis is the neuristor steady-state eq. (29) which is useful for understanding neuristor OFF states as well as the role of negative-differential resistance (NDR) in the operation of the Mott memristor model and neuristor circuits. In addition to the steady-state analysis, three numerical examples of dynamic neuristor circuit operation are also given and MATLAB code for the dynamic four-state model is available for interested readers.

Road salt intrusion dynamics in an ex-urban native wetland complex

Inland freshwater wetlands throughout the northern U.S. and Canada are experiencing an increase in salinity due to road salt runoff during winter months. Salinization affects soil texture, contaminant transport, microbial activity, and plant growth in wetlands. Therefore, there is a pressing need to understand the dynamics of road salt intrusion in urbanized freshwater ecosystems. We used distributed high-resolution sensors to evaluate the dynamics of road salt intrusion into a wetland complex, Gensburg Markham Prairie (GMP), located in the ex-urban area outside Chicago, Illinois (USA). The in situ sensors measure electrical conductivity (EC), surface and groundwater level, precipitation, water temperature, and air temperature at 30-minute intervals. Water samples were collected monthly from 13 shallow groundwater wells and eight surface water locations and analyzed for Cl-, Mg2+, Na+, Ca2+, and K+. Two-years of continuous data show periodic spikes in EC during winter months, generally by an order-of-magnitude, due to intrusion of road salt applied on nearby roads. However, this behavior was not evident from monthly water samples, indicating that traditional water quality sampling methods likely miss such abrupt salt intrusion dynamics caused by rapid snowmelt runoff events. Higher levels of EC and Cl- occurred at the periphery of GMP near roadways, as well as in a preferential flow path to the interior of the wetland. Spectral analysis of EC time-series in ditches suggests that there is no correlation between salinity dynamics at super-annual timescales. This indicates that the salinity dynamics at GMP are event-driven, and the introduced solutes are rapidly exported from the site. This research supports development of improved de-icing strategies by local agencies and informs site-specific management of wetland ecosystems under anthropogenic stressors.

Stereo-Electroencephalography-Recorded Interictal Epileptiform Discharges: Activation Pattern and Its Relationship With Surgical Outcome.

Background Patients with drug-resistant epilepsy commonly undergo stereo-electroencephalography (SEEG) intracranial monitoring for surgical evaluation. Our current practice of defining the epileptogenic zone relies heavily on recognizing the seizure onset zone (SOZ), but the clinical significance of interictal epileptiform discharges (IEDs) is not well established. Methodology We retrospectively identified adult patients who underwent SEEG between January 2019 and May 2022. To study IED activation patterns, we classified IEDs as leading spikes (involved within the SOZ) and distant spikes (outside the SOZ). We calculated each patient's total number of brain subregions generating distant spikes. We correlated them with epilepsy type, duration, and surgical outcome (Engel I:good outcome and Engel II-IV: poor outcome). Results A total of 22 patients were identified during the study period, and 16 underwent surgical intervention (ablation or resection) with one-year post-surgery follow-up. The most common IED morphology was a single spike or sharp followed by periodic spikes or sharps. We found that 87% (n = 19/22) of leading spikes were activated during the first 24 hours of SEEG monitoring, whereas no activation pattern was observed for distant spikes. We found that a higher number of subregions generating distant spikes were associated with poor surgical outcomes (p = 0.002). However, we did not find any significant association between the number of subregions generating distant spikes with epilepsy duration (p = 0.67), temporal or extratemporal-onset epilepsy (p = 0.58), or the presence of an MRI lesion (p = 0.62). Conclusions IEDs involved within the SOZ were found to be activated during the first 24 hours of SEEG monitoring, which could aid in recognizing the pathological spikes and targeted mapping of the irritative zone. We also observed that a higher number of brain subregions generating IEDs outside the SOZ were associated with poor surgical outcomes, but this observation needs to be further studied with larger sample size prospective studies.

Complex Dynamics of Coupled Neurons Through a Memristive Synapse: Extreme Multistability and Its Control With Selection of the Desired State

In this contribution, a new configuration involving the coupling of a 2D Fitzhugh-Nagumo (FN) neuron with a 3D Hindmarsh-Rose (HR) neuron via a memristive synapse is investigated. The self-excited dynamics of the coupled neurons is revealed after the analysis of the equilibria of the model. During the numerical investigation of the model, resting activity, periodic spikes, periodic and chaotic bursts are found. More interestingly, the coupled neurons display the striking and rare phenomenon of homogeneous extreme multistability. It corresponds to the coexistence of an infinite number of firing activities of the same nature but located at different levels in the phase space. Furthermore, the selection of the desired electrical activity dynamics is also underlined through the noninvasive control scheme. Finally, an electronic circuit of the coupled neuron is designed and investigated in the Pspice environment to further support the obtained results.

Comparison study of the femtosecond laser-induced surface structures on silicon at an elevated temperature.

The temperature dependency of femtosecond laser induced surface structures opens up a new scenario for studying ultrafast laser-mater interaction on the surface and a novel method for controlling the features of these structures. The shape and crystallinity of micro/nano surface structures created by femtosecond laser irradiation of n-type silicon (100) at elevated temperatures were compared in this study. Low spatial frequency laser induced periodic ripples structures (LSFL), micrometer-sized grooves, and spikes occur at room temperature as the number of pulses increases. At 400 °C, however, the grooves parallel to the polarization are the dominant structures, notwithstanding the presence of LSFL. As the temperature rises, the periodicities of LSFL increase, which we believe is due to a reduction in the oscillation of the surface plasmon polaritons due to the increased damping rate at higher temperatures. Furthermore, Raman spectra reveal that surface structures generated at 400 °C have higher crystallinity than those formed at 25 °C. Our simulations show that the better crystallinity at high temperatures is due to a slower resolidification velocity which is caused by a smaller temperature gradient and higher energy absorption. Our findings demonstrate that the features of femtosecond laser induced surface structures, such as periodicity and crystallinity, can be controlled by adjusting the substrate temperature simultaneously, paving the way for high crystallinity surface micro/nano-structures.

Focal low amplitude periodic spikes on interictal scalp EEG and intracranial EEG for localizing epileptogenic foci

Focal low amplitude periodic spikes on interictal scalp EEG and intracranial EEG for localizing epileptogenic foci

Latina mothers navigating COVID-19: Within- and between-family stress processes over time.

ObjectiveThis study aimed to understand how periodic shifts in financial cutbacks and fears of contracting COVID‐19 contributed to children's externalizing behaviors due to increases in maternal stress among low‐income Latina mothers during the first 10 months of the COVID‐19 pandemic.BackgroundThe COVID‐19 pandemic caused widespread health, economic, and psychological consequences for families and children. The Latino community is particularly vulnerable to the economic and health risks of this pandemic as a consequence of systemic oppression. The family stress model suggests that these family stressors will have psychological repercussions to parents, and downstream behavioral consequences to children.MethodWe examined both the within‐ and between‐person impacts of worry surrounding contracting the virus and the economic consequences of the pandemic on maternal stress and child externalizing behaviors. Participants were 73 Latina mothers who completed assessments an average eight times across the first 10 months of the COVID‐19 pandemic. At each assessment time, the mother was asked about worries surrounding contracting the virus, economic cutbacks the family was making, her perceived stress, and her child's externalizing behaviors during a brief phone call.ResultsBetween‐families, higher economic cutbacks indirectly increased child externalizing behaviors through maternal stress. The within‐family model revealed that at assessments when mothers expressed greater worry about contracting the COVID‐19 virus, they also reported greater stress. Further, at the within‐person level, a mother's greater experience of stress was associated with greater reports of child externalizing behaviors, though the indirect association between COVID‐19 contract worry and child externalizing behaviors through maternal stress was not significant.ConclusionsAcross the first 10 months of the COVID‐19 pandemic, the children in Latino families participating in this research exhibited more externalizing behaviors among families that engaged in more financial cutbacks as a function maternal stress. However, periodic spikes in Latina mothers' fears of contracting COVID‐19 contributed to periodic spikes in stress, which predicted periodic spikes in child externalizing behaviors.ImplicationsGreater effort toward social policy that provides economic support for vulnerable families before periods of increased societal stress and greater protections for workers with limited sick leave and schedule flexibility will help promote resilience to future crises among low‐income Latino families.

The Irradiance-Based Growth of Surface Structures Induced by Nanosecond Laser Pulses on Si and Ge and Their Correlation With Plasma Ion Kinetic Energies and Densities

Abstract The laser irradiance-based surface structural growth on Si and Ge has been correlated first time with plasma parameters. The better control over plasma parameters makes manufacturing of various sized and shaped surface structures on the semiconducting materials. The effect of laser irradiances on surface morphology of Si and Ge has been explored. For this purpose, Nd: YAG laser (532 nm, 6 ns, 10 Hz) has been employed as an irradiation source at the various laser irradiances ranging from 4 to 7.1 GW/cm2 under the vacuum condition. Surface modifications of laser-ablated Si and Ge were analyzed by performing scanning electron microscope (SEM) analysis. It has been revealed that laser irradiance plays a significant role in the growth of the micro- and nanostructures on the laser-irradiated target surfaces. The surface morphology of laser-ablated Si and Ge exhibited the formation of various structures such as laser-induced periodic surface structures (LIPSS), cracks, spikes, ridges, and cones. Density and size of these structures have been found to be strongly dependent upon the laser irradiances. SEM analysis exhibits the cones formation at central ablated region of both Si and Ge. These cones become more distinct and pronounced with increasing the laser irradiance due to more energy deposition with Gaussian profile distribution at the central region. Microspikes were observed at boundaries of laser-ablated Si. Whereas, in case of Ge-ablated boundaries, wave-like ridges have been observed, which are then converted into globules at higher laser irradiances up to 7 GWcm−2. LIPSSs were seen at outer boundaries of laser-ablated Ge, whose periodicity varies with the laser irradiances. Faraday cup has been employed in order to probe the kinetic energy and density of laser-induced Si and Ge plasma ions at the similar values of laser irradiances. A correlation at similar values of laser irradiances has been established between the evaluated plasma ion parameters (kinetic energy and density of plasma ions) and observed structures for both materials. This correlation reveals the dependence of kinetic energy and density of plasma ions on the corresponding surface modification of both laser-ablated Si and Ge, as well as enables us for the better understanding of the laser-induced plasma to be used as ion source in various fields ion implantation, surface structuring, and material modification. The results of ion energies are explained by the generation of ambipolar field or self-generated electric field (SGEF) in the expanding plasma due to the charge separation and double-layer structure. The values of SGEF have also been evaluated at different laser irradiances.

Food insecurity among active duty soldiers and their families during the coronavirus disease 2019 pandemic.

We examined the determinants of food insecurity among active duty Army households that transitioned into food insecurity during the coronavirus disease 2019 (COVID-19) pandemic. We compared Army households that recently transitioned into marginal food insecurity with those households that remained highly food secure (n 2832) to better understand how these households differ in their resilience to food insecurity during economic downturns using data from a military installation in the USA in 2020. A US military installation in the USA. Active duty US Army soldiers. Prior to the pandemic, the prevalence of marginal food insecurity among Army households was similar to that reported for households in the general population. Marginal food insecurity among Army households increased over 1·5-fold - from 19 % to 33 % - with the onset of the pandemic. Relative to Army households with consistently high food security, the Army households that transitioned into marginal food insecurity after the onset of the pandemic were more likely to report concerns about financial insecurity and the job security of their family members. Army households, like their civilian counterparts, are vulnerable to food insecurity because of instability in their income during periods of economic uncertainty. Periods of economic uncertainty are more common for Army households because of the frequent relocations associated with military service which could lead to predictable periodic spikes in their food insecurity.

Ictal onset stereoelectroencephalography patterns in temporal lobe epilepsy: type, distribution, and prognostic value.

The aim of this study was to investigate the different ictal onset stereoelectroencephalography patterns (IOPs) in patients with drug-resistant temporal lobe epilepsy (TLE). We examined whether the IOPs relate to different TLE subtypes, MRI findings, and underlying pathologies, and we evaluated their prognostic value for predicting the surgical outcome. We retrospectively analyzed data from patients with TLE who underwent stereoelectroencephalography (SEEG) monitoring followed by surgical resection between January 2018 and January 2020. The SEEG recordings were independently analyzed by two epileptologists. Forty-five patients were included in the study, and 61seizures were analyzed. Five IOPs were identified: low voltage fast activity (LVFA; 44.3%), spike-and-wave activity (16.4%), low frequency high-amplitude periodic spikes (LFPS; 18%), a burst of high-amplitude polyspikes (8.2%), and rhythmic sharp activity at ≤ 13Hz (13.1%). Thirty-two patients were found to have a single IOP, while the other 13 patients had two or more IOPs. All five IOPs were found to occur in the medial temporal lobe epilepsy (MTLE), while four IOPs occurred in the lateral temporal lobe epilepsy (LTLE). The LFPS was a common IOP that could distinguish MTLE from LTLE (x2 = 7.046, p = 0.011). Among the MTLE patients, the LFPS was exclusively seen in cases of hippocampal sclerosis (x2 = 5.058, p = 0.038), while the LVFA was associated with nonspecific histology (x2 = 6.077, p = 0.023). The IOPs were not found to differ according to whether the MRI scans were positive or negative. After surgery, patients achieved the higher seizure-free rate at 81.8% and 77.8%, respectively, if the LFPS and LVFA were the predominant patterns. Multiple IOPs or a negative MRI did not indicate a poor prognosis. Five distinct IOPs were identified in the patients with TLE. The differences found have important clinical implications and could provide complementary information for surgical decision-making, especially in MRI-negative patients.

Seizures in autoimmune encephalitis: specific features based on a systematic comparative study.

To highlight specific characteristics of seizure semiology and EEG features associated with different subtypes of autoimmune encephalitis (AE). We systematically reviewed the seizure semiology and all the EEG recordings from patients with AE managed in a tertiary referral centre for epilepsy and a neuro-intensive care unit. Each characteristic across the different subtypes of AE was compared by post hoc analysis. We identified 66 patients with anti-neuronal antibody-mediated AE or Rasmussen's encephalitis (RE) experiencing seizures, which were the most frequent symptom at onset. Anti-NMDAR and anti-LGI1 AE accounted for the majority of patients; 41% and 24%, respectively. We isolated specific semiological features, such as early tonic-clonic seizures (TCS) in anti-NMDAR AE, early mesial temporal lobe seizures with emotional symptoms in anti-GAD AE, somatosensory seizures in RE, and a lower frequency of TCS in anti-LGI1 AE. EEG analysis also provided additional insights into distinguishing the subtypes based on: (1) generalized rhythmic delta activity, which was more sensitive than extreme delta brush in identifying anti-NMDAR AE among all subtypes; and (2) temporal interictal epileptiform activity and temporal seizures on EEG in anti-GAD AE. We identified a new EEG pattern consisting of temporal low-voltage and periodic spikes associated with ipsilateral hippocampal abnormalities on MRI, which could be a sign of inflammatory mesial temporal involvement. Specific clinical and EEG features can be useful in guiding the diagnosis of a subtype of AE with acute symptomatic seizures, particularly before the results of anti-neuronal antibody testing are available.