Application of quantitative electroencephalogram trends in the assessment of the state of brain function in patients with severe stenosis of the internal carotid artery and its predictive value for the risk of acute occlusion in the short term(report of one case) / 临床神经病学杂志

Objective To explore the application of quantitative EEG(QEEG)trends in the assessment of the state of brain function in patients with severe stenosis of the internal carotid artery and its predictive value for the risk of acute occlusion in the short term.Methods The clinical and imaging data of a case of severe left internal carotid stenosis were retrospectively analyzed,and QEEG trends were used for evaluating the state of brain function.Results It showed that rhythmicity spectrogram,amplitude-integrated EEG,fast Fourier transformation spectrogram and fast Fourier transform power spectrum in QEEG trends could quickly and visually display theta activity and amplitude at the side of severe internal carotid artery stenosis continued to increase compared with the healthy side hemisphere.Acute occlusion of the left internal carotid artery and large artery atherosclerotic cerebral infarction occurred in the patient after 3 days.Conclusion As a supplement to neuroimaging examination,QEEG trends may be helpful for rapidly diagnosing brain function damage in the early stage of patients with severe internal carotid artery stenosis who are under the ischemic attack state,and even have potential predictive values for patients with acute occlusion in the short term.

Motor imagery EEG classification and recognition based on differential entropy and convolutional neural network / 中国医学物理学杂志

To address the problem of low accuracy in multi-classification recognition of motor imagery electroencephalogram(EEG)signals,a recognition method is proposed based on differential entropy and convolutional neural network for 4-class classification of motor imagery.EEG signals are extracted into 4 frequency bands(Alpha,Beta,Theta,and Gamma)through the filter,followed by the computation of differential entropy for each frequency band.According to the spatial characteristics of brain electrodes,the data structure is reconstructed into three-dimensional EEG signal feature cube which is input into convolutional neural network for 4-class classification.The method achieves an accuracy of 95.88%on the BCI Competition IV-2a public dataset.Additionally,a 4-class classification motor imagery dataset is established in the laboratory for the same processing,and an accuracy of 94.50%is obtained.The test results demonstrate that the proposed method exhibits superior recognition performance.

Relationship among physical activity,mild depressive symptoms and frontal alpha power asymmetry in college students / 中国心理卫生杂志

Objective:To investigate the correlation among physical activity,mild depressive symptoms and frontal alpha power asymmetry in college students.Methods:Seventy college students with mild depressive symp-toms who conformed to the standard of the Self-Rating Scale for Depression(SDS)of 53-62 and 70 normal col-lege students were recruited.The frontal alpha power was measured under quiet and closed-eye state,and the total physical activity(PA)was assessed with the International Physical Activity Questionnaire.Results:The college students with mild depressive symptoms had lower Total PA scores,right frontal alpha power and frontal alpha a-symmetry(FAA)than the normal controls(P＜0.001).In college students with mild depressive symptoms,the to-tal PA scores(r=-0.29,P＜0.05)and FAA(r=-0.41,P＜0.001)were negatively correlated with SDS scores,and the total PA scores were positively correlated with FAA(r=0.34,P＜0.01).Conclusion:The college students with mild depressive symptoms may have reduced physical activity and asymmetric right lateralization of frontal alpha power.There is a correlation among depressive symptoms,physical activity and frontal alpha power a-symmetry in college students with mild depressive symptoms.

Crisis neonatales: evaluacion, diagnostico y tratamiento / Neonatal seizures: evaluation, diagnosis, and treatment

Resumen Las crisis convulsivas tienen una alta incidencia en la etapa neonatal, representando la principal manifes tación de disfunción neurológica. Ciertas condiciones fisiológicas del cerebro neonatal facilitan su aparición. Su diagnóstico puede ser un reto debido a que su semio logía no es tan clara comparado con niños mayores, y además, es necesario la confirmación por medio de EEG continuo o aEEG. Su reconocimiento oportuno es muy importante para un adecuado tratamiento y así evitar un impacto negative en el pronóstico a largo plazo. En la siguiente revisión, recapitulamos la fisiopatología, las causas y la clasificación de las crisis convulsivas neo natales, además de su correcto abordaje y las mejores opciones terapéuticas para su tratamiento dependiendo de la causa.

Abstract Seizures have a high incidence in the neonatal stage, being the main manifestation of neurological dysfunc tion. Certain physiological conditions of the neonatal brain facilitate its appearance. Its diagnosis can be a challenging because its semiology is not as clear as in older children, furthermore, confirmation by either EEG or aEEG is necessary. Its timely recognition is very im portant for adequate treatment and thus avoid a nega tive impact on the long-term outcome. In the following review, we recapitulate the pathophysiology, causes, and classification of neonatal seizures, as well as their correct approach and the best therapeutic options for their treatment depending on the cause.

NEONATAL SEIZURES: NARRATIVE REVIEW

Neonatal seizures are often complex and difcult to recognize, but can be identied through electroencephalogram (EEG) monitoring. The Brighton Collaboration has developed a scheme with ve levels of diagnostic certainty to guide treatment decisions when EEG is not available. Different seizure types are usually associated with specic underlying causes, which may require specic diagnostic and treatment approaches. Neonatal seizures require prompt management, including the stabilization of cardiovascular and respiratory function and the identication of the underlying cause. EEG monitoring is considered essential for the detection of seizures and should be performed until the neonate has been seizure-free for 12 to 24 hours. Treatment involves the use of antiseizure medication and may include pyridoxine challenge or other treatment options such as the ketogenic diet, intravenous immunoglobulin, or corticosteroids if seizures are refractory to conventional antiseizure medication. It is important to differentiate between seizures and nonepileptic motor phenomena, which can occur without obvious cause or as symptoms of drug withdrawal, electrolyte abnormalities, hypoglycemia, or infection. Neuroimaging is also considered essential for the detection of possible structural abnormalities in neonates with seizures.

Construction of an epileptic seizure prediction model using a semi-supervised method of generative adversarial and long short term memory network combined with Stockwell transform / 南方医科大学学报

OBJECTIVE@#To propose a semi-supervised epileptic seizure prediction model (ST-WGAN-GP-Bi-LSTM) to enhance the prediction performance by improving time-frequency analysis of electroencephalogram (EEG) signals, enhancing the stability of the unsupervised feature learning model and improving the design of back-end classifier.@*METHODS@#Stockwell transform (ST) of the epileptic EEG signals was performed to locate the time-frequency information by adaptive adjustment of the resolution and retaining the absolute phase to obtain the time-frequency inputs. When there was no overlap between the generated data distribution and the real EEG data distribution, to avoid failure of feature learning due to a constant JS divergence, Wasserstein GAN was used as a feature learning model, and the cost function based on EM distance and gradient penalty strategy was adopted to constrain the unsupervised training process to allow the generation of a high-order feature extractor. A temporal prediction model was finally constructed based on a bi-directional long short term memory network (Bi-LSTM), and the classification performance was improved by obtaining the temporal correlation between high-order time-frequency features. The CHB-MIT scalp EEG dataset was used to validate the proposed patient-specific seizure prediction method.@*RESULTS@#The AUC, sensitivity, and specificity of the proposed method reached 90.40%, 83.62%, and 86.69%, respectively. Compared with the existing semi-supervised methods, the propose method improved the original performance by 17.77%, 15.41%, and 53.66%. The performance of this method was comparable to that of a supervised prediction model based on CNN.@*CONCLUSION@#The utilization of ST, WGAN-GP, and Bi-LSTM effectively improves the prediction performance of the semi-supervised deep learning model, which can be used for optimization of unsupervised feature extraction in epileptic seizure prediction.

Clinical,electrophysiological and imaging features of frontal opercular epilepsy / 临床神经病学杂志

Objective To summarize the clinical,electrophysiological and imaging features of frontal opercular epilepsy.Methods A retrospective analysis was conducted on 5 cases with frontal opercular epilepsy,who were treated at the Department of Functional Neurology,Shenzhen Second People's Hospital from December 2020 to December 2022.Among these cases,4 cases were underwent stereotactic-EEG(SEEG)guided radiofrequency thermocoagulation.The clinical,electrophysiological,and imaging characteristics of these 5 cases were summarized.Results The 5 cases had an onset age ranging from 2 to 17 years and a disease duration ranging from 1 to 20 years.All of them experienced daily seizures,especially at night.The seizure duration was less than 30 seconds,and consciousness recovered rapidly.Among the cases,3 exhibited hypermotor seizures of typeⅠorⅡ,characterized by body turning along the horizontal body axis.Two of them experienced laughter during the seizures,while 1 showed a fearful expression.The remaining 2 cases presented with symmetric tonic seizures,involving the facial muscles.One case reported indescribable aura,and 2 cases had autonomic symptoms.During the interictal period,all 5 cases showed epileptic discharges predominantly in the frontal region on EEG,with lateralization value present in only 2 cases.During the ictal period,4 cases demonstrated general low volatility and fast activity(LVFA),while 1 case showed low-frequency rhythmic sharp and slow waves originating from the lesioned side.Four cases underwent SEEG,which revealed seizure starting from the frontal operculum and adjacent electrodes with LVFA,rapidly spreading to the insula,insular opercular,and medial frontal lobe.Positive changes were observed in the MRI of 4 cases,including 2 cases with possible cortical dysplasia,1 case with tuberous sclerosis,and 1 case with encephalomalacia foci.All 4 cases underwent SEEG guided radiofrequency thermocoagulation,resulting in seizure frequency reduction.Conclusions Frontal opercular epilepsy is mainly characterized by hypermotor seizure with body turning along the horizontal body axis or symmetric tonic seizure.These seizure may be accompanied by emotional symptom or facial muscle tonic,but aura and autonomic symptom are less common.The lateralization value of EEG is limited in frontal opercular epilepsy.SEEG indicates early involvement of the insula,insular opercular,and medial frontal lobe.

The postictal generalized EEG suppression and its significance in sudden unexpected death in epilepsy / 中国神经精神疾病杂志

Sudden unexpected death in epilepsy(SUDEP)is the leading cause of accidental death in epileptic patients.The postictal generalized EEG suppression(PGES)is related to SUDEP.The age,seizure type,tonic seizure/tonic muscle contraction,ictal and post-ictal respiratory dysfunction and autonomic dysregulation is associated with PGES with significant individual variation.Progressive slowing of clonic phase(PSCP)in generalized tonic-clonic seizures(GTCS)is an independent predictor of the onset and prolongation of PGES.

Characteristics and research progress of resting-state EEG microstates in patients with schizophrenia / 四川精神卫生

The purpose of this article is to identify the characteristics and research progress of resting-state EEG microstates in patients with schizophrenia， in order to provide references for clinical research of schizophrenia from the perspective of neuroelectrophysiology. In September 2022， literature was retrieved from CNKI， Wanfang Data Knowledge Service Platform and PubMed database， and 27 studies meeting the requirements were finally included. Previous studies have demonstrated that patients with schizophrenia show increased presence of microstate class C and decreased presence of microstate class D in resting-state recordings， and the two commonly EEG microstate classes have been suggested as a potential endophenotype for schizophrenia. Although the correlation between psychiatric symptoms and resting-state EEG microstate abnormalities in patients with schizophrenia remains unclear， the altered resting-state EEG microstates in patients before and after treatment have undoubtedly validated its clinical significance.

Discussion on safety and related pharmacological mechanism of compound anshen essential oil in relieving sleep disorders / 中国药理学通报

Aim To study the hypnotic effect and safety of compound anshen essential oil. Methods Gas chromatograph-mass spectrometer (GC-MS) was used to analyze the main active components of compound anshen essential oil. The mouse model of insomnia was established by intraperitoneal injection of para-chloro-phenyl alanine ( PC PA ) , combined with pentobarbital sodium sleep experiment and EEG characteristic monitoring in rats to study the hypnotic effect and mechanism. The safety of compound anshen essential oil was evaluated by acute toxicity test, skin irritation/allergy test and 90-day repeated administration toxicity test. The clinical effect and safety were evaluated by using the sleep monitoring technology for micro-motion sensitive mattress. Results Four components, including Atractylone (34.61%), (+) -Limonene (17.80%) , Linalool (11.63%), and Ocimene (11.67%) , were detected as the main active components of compound anshen essential oil. Compound anshen essential oil in-halation administration for seven days could effectively reduce the autonomic activity of insomnia mice, shorten the sleep latency (P <0.05) , improve the sleep duration, increase of neurotransmitters such as 5-hydroxy tryptamine (5-HT) and -γ-aminobutyric acid (GABA) in brain of mice with insomnia, and the medium dose group had better hypnotic effect. There was no death or adverse reaction in the safety evaluation test. The sleep balance index of 10 subjects with difficulty in falling a-sleep significantly increased (P <0.05), sleep latency was significantly shortened (P <0.05) , total sleep duration and sleep efficiency were improved, and no ad¬verse reactions were found after using the compound anshen essential oil for two days. Conclusions The compound anshen essential oil developed by the research team is safe and effective in relieving sleep disorders, which may be closely related to the co-regulation of the levels of neurotransmitters such as 5-HT and GABA by the four main active components.

A Clinical Correlation of EEG Changes in Relation to Ischaemic Stroke on its Prognosis as per Location

Background : Stroke is a common, potentially devastating disease with potential high morbidity and mortality. EEG (Electro-encephalogram), functional representation of electrical activity of brain, changes are closely tied to CBF (Cerebral Blood Flow). Thus EEG is useful to establish the location of Ischaemic CVA (Cerebro-vascular accident). It can also prognosticate Ischaemic stroke. Aims & Objectives : (1) To assess the grade and severity of clinical manifestations in acute ischaemic stroke patients by clinical scoring following admission. (2) To obtain EEG findings of ischaemic stroke patients following admission and after 1 month. (3) To assess the morbidity of ischaemic stroke patients by Modified Rankin Scale after 1 month. (4) To correlate EEG changes according to the clinical outcome and according to the site of involvement of ischaemic stroke. Materials and Methods : 90 Patients were selected during the study period as per the inclusion and exclusion criteria. Clinical scoring was done by NIHSS (National Institute of Health Scoring System). CT (Computed Tomography) scan of brain and MRI (Magnetic Resonance Imaging) Brain with DWI (Diffusion Weighted Image) extension was done. EEG findings on admission of morbidity was done by Modified Rankin Score on follow up after 1 month was noted. EEG findings after 1 month was noted on follow up. Assessment Clinical correlation was compared with EEG changes. All the data were collected and analysed by statistical software SPSS version 20. Results : The mean MRS (Modified Rankin Score) after 1 month for abnormal EEG on admission was 4.50 in comparison to score of 3.36 in case of normal EEG. The p value of this association was 0.003 and was considered significant. Conclusions : Normal EEG and focal slowing of EEG was mostly noted in MCA (Middle Cerebral Artery) and PCA (Posterior Cerebral Artery) infarcts involving the cortical region. Those with normal EEG findings had good clinical outcome in comparison to those with abnormal findings in EEG

Fusión de datos multimodales de neurociencias generados en estudios EEG-fMRI, un análisis temático / Fusion of Multimodal Neuroscience Data Generated in EEG-fMRI Studies, a Thematic Analysis

La actividad cerebral tiene múltiples atributos, entre ellos los eléctricos, metabólicos, hemodinámicos y hormonales. Los métodos modernos para estudiar las funciones cerebrales como el PET (Tomografía por Emisión de Positrones), fMRI (Imagen de Resonancia Magnética Funcional) y MEG (Magnetoencefalograma) son ampliamente utilizados por los científicos. Sin embargo, el EEG es una herramienta utilizada para la investigación y diagnóstico debido a su bajo costo, simplicidad de uso, movilidad y la posibilidad de monitoreo a largo tiempo de adquisición. Para detectar e interpretar las características relevantes de estas señales, se describe cada proceso por su escala temporal (EEG) y espacial (fMRI). La presente investigación se enfoca en realizar una revisión bibliográfica sobre la integración de datos multimodales EEG-fMRI que propicie valorar su importancia para el desarrollo de algoritmos de fusión y su uso en el contexto cubano. Para ello se analizaron documentos con altos índices de citas en la literatura, donde se destacan autores precursores de los temas en análisis. Los estudios multimodales EEG-fMRI generan múltiples datos temporales y espaciales con alto valor para la medicina basada en evidencia. La integración de los mismos provee un valor agregado en la búsqueda de nuevos métodos diagnósticos, aplicando minería de datos, Deep learning y algoritmos de fusión. En este trabajo se pone de relieve la existencia de baja resolución temporal de fMRI y por otro lado la baja resolución espacial de EEG, por lo que la integración de ambos estudios aumentaría la calidad de su información(AU)

Brain activity has multiple attributes, including electrical, metabolic, hemodynamic, and hormonal. Modern methods for studying brain functions such as PET (Positron Emission Tomography), fMRI (Functional Magnetic Resonance Imaging), and MEG (Magnetoencephalogram) are widely used by scientists. However, the EEG is a tool used for research and diagnosis due to its low cost, simplicity of use, mobility and the possibility of long-term monitoring of acquisition. To detect and interpret the relevant characteristics of these signals, each process is described by its temporal (EEG) and spatial (fMRI) scale. The present research focuses on conducting a bibliographic review on the integration of multimodal EEG-fMRI data that favors assessing its importance for the development of fusion algorithms and their use in the Cuban context. For this, documents with high rates of citations in the literature were analyzed, where precursor authors of the topics under analysis stand out. Multimodal EEG-fMRI studies generate multiple temporal and spatial data with high value for evidence-based medicine. Their integration provides added value in the search for new diagnostic methods, applying data mining, Deep learning and fusion algorithms. This work highlights the existence of low temporal resolution of fMRI and, on the other hand, the low spatial resolution of EEG, so the integration of both studies would increase the quality of their information(AU)

Correlation of Clinical Profile and Electroencephalographic Finding in Hypoxic-Ischemic Encephalopathy in a Tertiary Care Hospital: A Single-Center Experience from Bangladesh

Background: Perinatal asphyxia and resultant hypoxic-ischemic encephalopathy (HIE) is not an uncommon phenomenon in a developing country, like Bangladesh. Electroencephalogram (EEG) is regarded as an effective prognostic tool. Correlation of clinical profiles and EEG findings of HIE patients arenot commonly observed in Bangladesh. The aim of the study was to observe the clinical profile and EEG changes in different stages of hypoxic-ischemic encephalopathy and compare them in a tertiary care hospital.Material & Methods:This is a cross-sectional observational study conducted for a period of six months in Dhaka Medical College Hospital, Dhaka. Sarnat and Sarnat score was used to classify HIE. 20 asphyxiated neonates without HIE were selected as the control group (group II) while 30asphyxiated neonates with HIE, were selected as the case group (group I) by purposive sampling. Clinical profiles, EEG findings, and immediate outcomes were observed and compared between the two groups.Results:73.3% patients were delivered at term and 30% patients were delivered at home in group I. 70% patients’ delivery were conducted by doctor in group I and 75% in group II. 63.3% patients had meconium stain in group I and 25% in group II, which was found significant. 46.7% had prolong labor in group I and 20% in group II, 40% had premature ruptured membrane (PROM) in group I and 40% in group II. Hypothermia, weak primitive reflexes, hypotonia, lethargy and seizure were significantly higher in group I. Changes in EEG correlated between the two groups and was found significant. Also, patients in group I, needed prolong hospital stay.Conclusions:The clinical profiles and EEG changes in patients with hypoxic ischemic encephalopathy was concluded that there is significant association with meconium stain, seizure, hypothermia, weak primitive reflexes, lethargic, miosis, hypotonia, poor APGAR score, burst suppression & SET findings in EEG and prolonged hospital stay in prenatal asphyxia with hypoxic ischemic encephalopathy.

Eventos paroxísticos que se confunden con epilepsia / Paroxysmal events that are confused with epilepsy

Resumen Los eventos paroxísticos no epilépticos (EPNE) se definen como episodios de aparición brusca y de breve duración que imitan a una crisis epiléptica, originados por una disfunción cerebral de origen diverso y a diferencia de la epilepsia no obedecen a una descarga neuronal excesiva. Su incidencia es mucho más elevada que la epilepsia y pueden aparecer a cualquier edad, pero son más frecuentes en los primeros años de vida. La inmadurez del sistema nervioso central en la infancia favorece que en este período las manifestaciones clínicas sean muy floridas y diferentes de otras edades. Fenómenos normales y comunes en el niño pueden también confundirse con crisis epilépticas. El primer paso para un diagnóstico correcto es establecer si este primer episodio corresponde a una crisis epiléptica o puede tratarse de un primer episodio de EPNE. Es importante seguir un protocolo de diagnóstico, valorando los antecedentes personales y familiares, sin olvidar el examen físico, analizar los posibles factores desencadenantes, los pormenores de cada episodio, si es posible un registro de los episodios, aplicar el sentido común y la experiencia y solamente proceder a los exámenes complementarios básicos como el registro EEG u otras exploraciones en caso de duda o para con firmación diagnóstica. En algunos casos se ha demostrado una base genética. Las opciones terapéuticas son escasas y la mayoría de EPNE tienen una evolución favorable.

Abstract Non-epileptic paroxysmal events (NEPE) are defined as episodes of sudden onset and short duration that mimic an epileptic seizure, caused by a brain dysfunction of diverse origin and, unlike epilepsy, are not due to excessive neuronal discharge. Its incidence is much higher than epilepsy and can appear at any age, but are more frequent in the first years of life. The immaturity of the central nervous system in childhood favors that in this period the clinical manifestations are more spectacular and different from other ages. Normal and common phenomena in children can also be confused with epileptic seizures. The first step for a correct diagnosis is to establish whether this first episode corresponds to an epileptic seizure or could be a first episode of NEPE. It is important to follow a diagnostic protocol, assessing the personal and family history, without forgetting the physical examination, analyzing the possible triggering factors, the details of each episode, if it's possible a record of the episodes, applying common sense and experience and only carrying out basic complementary tests such as EEG recording or others in case of doubt or for diagnostic confirmation. In some cases, a genetic basis has been demonstrated. Therapeutic op tions are scarce and the majority of NEPE have a favorable evolution.

EEG microstates in resting condition in young indians

Objectives: The map topography analysis gives an idea of temporal dynamics of electric fields, which is reference independent, making the results unambiguous. These topographic maps remain stable for 80 to 100 milliseconds, abruptly shifting to a new topographic map configuration and remains stable in that state are called the ‘functional microstates’ as described by Lehmann et al (1987). There has been no study done in the resting state eye closed and eye open conditions showing the microstate maps in healthy Indian subjects in resting eyes open and resting eyes closed condition using 128 channel EEG. So our study aim was to assess the microstates in resting eyes closed and eyes open condition. And to compare the microstate parameters such as mean duration, global explained variance (GEV) and time coverage between eyes closed and eyes open condition. Materials and Methods: A cross-sectional and observational study on 20 indian subjects (Mean age- 26.65 and (SD) - 2.78 years) was done on resting eyes closed and eyes open conditions. After EEG acquisition using 128 channel EEG machine, EEG was preprocessed and microstate analysis using CARTOOL software was performed on the EEG data. Results: After microstate analysis four maps topography were obtained. There was statistically non-significant difference observed in microstate maps between resting eyes closed and resting eyes open condition for the all parameters i.e. mean duration, time coverage and GEV. Conclusion: Our findings suggests that, both eyes closed and eyes open conditions were similar to each other in terms of stability and predominance of Maps

Hallazgos electroencefalográficos compatibles con encefalopatía en pacientes ingresados por covid-19 / Electroencephalographic findings compatible with encephalopathy in patients admitted for COVID-19

RESUMEN INTRODUCCIÓN: La covid-19 afecta principalmente al aparato respiratorio, sin embargo, también se ha descrito afectación tanto directa como indirecta en el sistema nervioso central y periférico, lo cual ocasiona una gran variedad de manifestaciones neurológicas, siendo la encefalopatía una de las más frecuentemente observadas. OBJETIVO: Se busca mostrar la utilidad del video-electroencefalograma (vEEG) en el diagnóstico de encefalopatía en pacientes ingresados por covid-19, así como su valor para determinar el pronóstico de estos pacientes. MÉTODOS: Estudio observacional retrospectivo con 76 vEEG de 41 pacientes con covid-19 confirmada. Los estudios se han realizado entre los meses de marzo del 2020 y junio del 2021. Se estudió la gravedad de la enfermedad, así como sus características clínicas y neurológicas, el tratamiento farmacológico y los hallazgos electroencefalográficos según el grado de disfunción de la encefalopatía que desarrollaron estos pacientes. RESULTADOS: De los 41 pacientes, 12 (29 %) presentaron signos electroencefalográficos de disfunción cerebral leve, 15 (37 %) disfunción cerebral moderada y 14 (34 %) disfunción cerebral severa, los cuales se asociaron con una mayor mortalidad. CONCLUSIONES: En los 76 vEEG realizados a los 41 pacientes ingresados con encefalopatías asociadas con infección por covid-19, no se observó un patrón distinto a los descritos en encefalopatías de otras etiologías. El vEEG fue útil para confirmar la sospecha clínica de una disfunción cerebral en pacientes con encefalopatías asociadas con infección por covid-19 y para asignarle un grado de severidad, confirmando su beneficio como biomarcador diagnóstico y pronóstico.

ABSTRACT INTRODUCTION: COVID-19 mainly affects the respiratory system; however, both direct and indirect involvement of the central and peripheral nervous system has also been described, causing a wide variety of neurological manifestations, with encephalopathy being one of the most frequently observed neurological manifestations. OBJECTIVE: With this article we intend to show the usefulness of vEEG in the diagnosis of encephalopathy in patients referred for COVID-19 who develop this neurological complication, as well as its value in determining the prognosis of these patients. METHODS: Retrospective observational study with 76 video-electroencephalograms of 41 patients with confirmed COVID-19 infection. The studies were performed during the months of March 2020 through June 2021. Disease severity, clinical and neurological features, pharmacological treatment and electroencephalographic indings were studied according to the degree of encephalopathy dysfunction these patients developed. RESULTS: Of the 41 patients, 12 (29 %) presented electroencephalographic signs of mild cerebral dysfunction, 15 (37 %) moderate cerebral dysfunction, and 14 (34 %) severe cerebral dysfunction, which were associated with higher mortality. CONCLUSIONS: In the 76 vEEG performed in the 41 patients admitted with encephalopathies associated with COVID-19 infection, no pattern different from that described in encephalopathies of other etiologies was observed. The vEEG was useful to confirm the clinical suspicion of brain dysfunction in patients with encephalopathies associated with COVID-19 infection and to assign a degree of severity, confirming its benefit as a diagnostic and prognostic biomarker.

Silent speech of vowels in persons of different cognitive styles / Habla silenciosa de las vocales en personas de diferente estilo cognitivo

Abstract Introduction: This research measures the differences in silent speech of the vowels / a / - / u / in Spanish, in students with different cognitive styles in the Field Dependence - Independence (FDI) dimension. Method: Fifty-one (51) adults participated in the study. Electroencephalographic (EEG) signals were taken from 14 electrodes placed on the scalp in the language region located in the left hemisphere. Previously, the embedded figures test (EFT) was applied in order to classify them into dependent, intermediate and field independent persons. To analyse the EEG data, the signals were decomposed into intrinsic mode functions (IMF) and a mixed repeated measures analysis was performed. Results: It was found that the Power Spectral Density (PSD) in the vowels is independent of the cognitive style and its magnitude depends on the position of the electrodes. Conclusions: The results suggest that there are no significant differences in PSDs in the silent speech of vowels /a/-/u/ in persons of different cognitive styles. Significant differences were found in the PSDs according to the position of the 14 electrodes used. In our configuration, the silent speech of vowels can be studied using electrodes placed in premotor, motor and Wernicke areas.

Resumen Introducción: La investigación mide las diferencias en el habla silenciosa de las vocales /a/-/u/ en español, en estudiantes de diferente estilo cognitivo en la dimensión Dependencia - Independencia de campo (DIC). Método: En el estudio participaron 51 adultos. Se tomaron señales electroencefalográficas (EEG), a partir de 14 electrodos dispuestos sobre el cuero cabelludo de la región del lenguaje ubicada en el hemisferio izquierdo. Previamente les fue aplicado el test de figuras enmascaradas EFT con el fin de clasificarlos en personas dependientes, intermedios e independientes de campo. Para analizar los datos del EEG se descompusieron las señales en funciones de modo intrínseco (IMF) y se realizó un análisis mixto de medidas repetidas. Resultados: Se halló que la densidad espectral de potencia (PSD) en las vocales es independiente del estilo cognitivo y su magnitud depende de la posición de los electrodos. Conclusión: Los resultados sugieren que no existen diferencias significativas en los PSD en el habla silenciosa de las vocales /a/-/u/ en las personas de diferente estilo cognitivo. Se hallaron diferencias significativas en los PSD de acuerdo con la posición de los 14 electrodos utilizados. En nuestra configuración, el habla silenciosa de las vocales puede ser estudiada mediante electrodos situados en las áreas premotora, motora y de Wernicke.

Neonatal Seizures—Perspective in Low-and Middle-Income Countries

Neonatal seizures are the commonest neurological emergency and are associated with poor neurodevelopmental outcome. While they are generally difcult to diagnose and treat, they pose a signifcant clinical challenge for physicians in low- and middle-income countries (LMIC). They are mostly provoked seizures caused by an acute brain insult such as hypoxic– ischemic encephalopathy (HIE), ischemic stroke, intracranial hemorrhage, infections of the central nervous system, or acute metabolic disturbances. Early onset epilepsy syndromes are less common. Clinical diagnosis of seizures in the neonatal period are frequently inaccurate, as clinical manifestations are difcult to distinguish from nonseizure behavior. Additionally, a high proportion of seizures are electrographic-only without any clinical manifestations, making diagnosis with EEG or aEEG a necessity. Only focal clonic and focal tonic seizures can be diagnosed clinically with adequate diagnostic certainty. Prompt diagnosis and timely treatment are important, with evidence suggesting that early treatment improves the response to antiseizure medication. The vast majority of published studies are from high-income countries, making extrapolation to LMIC impossible, thus highlighting the urgent need for a better understanding of the etiologies, comorbidities, and drug trials evaluating safety and efcacy in LMIC. In this review paper, the authors present the latest data on etiology, diagnosis, classifcation, and guidelines for the management of neonates with the emphasis on low-resource settings.

Evaluation of Mental Workload in Working Memory Tasks with Different Information Types Based on EEG / 中国医疗器械杂志

OBJECTIVE@#Exploring the effectiveness of using EEG linear and nonlinear features for accessing mental workload in different tasks.@*METHODS@#Working memory tasks with different information types and various mental loads were designed based on N-Back paradigm. EEG signals from 18 normal adults were acquired when tasks were being performed. Linear and nonlinear features of EEGs were then extracted. Indices that can effectively reflect mental workload levels were selected by using multivariate analysis of variance statistical approach.@*RESULTS@#With the increment of task load, power of frontal Theta, Theta/Alpha ratio, and sample entropies (scales>10) in parietal regions increased significantly first and decreased slightly then, while the power of central-parietal Alpha decreased significantly first and increased slightly then. No difference in power of frontal Theta, central-parietal Alpha, and sample entropies (scales>10) of parietal regions were found between verbal and object tasks, as well as between two spatial tasks. No difference of frontal Theta/Alpha ratio was found in all the four tasks.@*CONCLUSIONS@#The results can provide evidence for the mental workload evaluation in tasks with different information types.

An Adaptive Method for Detecting and Removing EEG Noise / 中国医疗器械杂志

To solve the problem of real-time detection and removal of EEG signal noise in anesthesia depth monitoring, we proposed an adaptive EEG signal noise detection and removal method. This method uses discrete wavelet transform to extract the low-frequency energy and high-frequency energy of a segment of EEG signals, and sets two sets of thresholds for the low-frequency band and high-frequency band of the EEG signal. These two sets of thresholds can be updated adaptively according to the energy situation of the most recent EEG signal. Finally, we judge the level of signal interference according to the range of low-frequency energy and high-frequency energy, and perform corresponding denoising processing. The results show that the method can more accurately detect and remove the noise interference in the EEG signal, and improve the stability of the calculated characteristic parameters.