Multisensory Conflict Impairs Cortico-Muscular Network Connectivity and Postural Stability: Insights from Partial Directed Coherence Analysis / 神经科学通报·英文版

Sensory conflict impacts postural control, yet its effect on cortico-muscular interaction remains underexplored. We aimed to investigate sensory conflict's influence on the cortico-muscular network and postural stability. We used a rotating platform and virtual reality to present subjects with congruent and incongruent sensory input, recorded EEG (electroencephalogram) and EMG (electromyogram) data, and constructed a directed connectivity network. The results suggest that, compared to sensory congruence, during sensory conflict: (1) connectivity among the sensorimotor, visual, and posterior parietal cortex generally decreases, (2) cortical control over the muscles is weakened, (3) feedback from muscles to the cortex is strengthened, and (4) the range of body sway increases and its complexity decreases. These results underline the intricate effects of sensory conflict on cortico-muscular networks. During the sensory conflict, the brain adaptively decreases the integration of conflicting information. Without this integrated information, cortical control over muscles may be lessened, whereas the muscle feedback may be enhanced in compensation.

Association between telomere length in the DNA of peripheral blood leukocytes and the propofol dose in anesthesia induction: an observational study

Abstract Introduction: Propofol is a widely used anesthetic and its dose is closely related to aging. Telomere length (TL) is a unique heritable trait, and emerging as a biomarker of aging, health and disease. Telomerase RNA component (TERC) plays an important role in maintaining TL. We proposed a hypothesis that propofol dose in general anesthesia can be predicted by measuring TL before operation, which greatly reduced the risk of anesthesia, especially the elderly. Methods: The association between the propofol dose in anesthesia induction and: TL in the DNA of peripheral blood leukocytes; body weight; sex; difference of the Bispectral Index (BIS) before and after anesthesia induction in patients was evaluated by multivariable linear regression analyses. The mutation at the 5'end or 3'end of TERC was detected. We recruited 100 patients of elective surgery. Results: We found that propofol dose in anesthesia induction was clearly correlated significantly with TL (r = 0.78, p < 0.001), body weight (r = 0.84, p = 0.004), sex (r = 0.83, p= 0.84, p = 0.004), sex (r = 0.83, p = 0.004), and difference of BIS before and after anesthesia induction (r = 0.85, p = 0.029). By comparing the absolute values of standardized regression coefficients (0.58, 0.21, 0.19, and 0.12) of the four variables, it can be seen that TL contributes the most to the propofol dose in anesthesia induction. However, the mutation at the 5' end or 3' end of TERC was not found. Conclusions: These findings provide preliminary evidence that the propofol dose in anesthesia induction was clearly correlated with genetically determined TL. TL may be a promising predictor of the propofol dose, which is beneficial to improve the safety of anesthesia and reduce perioperative complications.

Detección de novedad y codificación predictiva en el sistema auditivo: Impacto clínico en disfunciones auditivas y vestibulares. Revisión de la literatura / Deviance detection and predictive coding in the auditory system: Clinical impact in auditory and vestibular dysfunctions

Una propiedad fundamental de los sistemas sensoriales es su capacidad para detectar estímulos novedosos en el entorno. El sistema nervioso posee neuronas que disminuyen su respuesta a los estímulos sonoros que se repiten a lo largo del tiempo y otras neuronas que aumentan su frecuencia de disparo ante estímulos novedosos, siendo la diferencia entre ambas respuestas conocida como adaptación-específica a estímulos. En las últimas décadas, se ha propuesto que el cerebro establece, continuamente, predicciones de los estímulos novedosos y del entorno basándose en sus experiencias previas y en modelos de representación internos, teoría denominada codificación predictiva. En esta revisión, abordaremos algunos conceptos de la adaptación-específica a estímulos y codificación predictiva, centrándonos principalmente en el sistema auditivo. Por último, propondremos una explicación teórica basada en el marco de la codificación predictiva para algunas disfunciones neuropsiquiátricas, auditivas y vestibulares.

A fundamental property of sensory systems is their ability to detect novel stimuli in the environment. The nervous system possesses neurons that decrease their response to sound stimuli that are repeated over time and other neurons that increase their firing rate to novel stimuli, the difference between the two responses being known as stimulus-specific adaptation. In recent decades, it has been proposed that the brain continuously makes predictions of novel stimuli and the environment based on its previous experiences and internal representational models, a theory called predictive coding. In this review, we will address some concepts of stimulus-specific adaptation and predictive coding, focusing mainly on the auditory system. Finally, we will propose a theoretical explanation based on the predictive coding framework for some neuropsychiatric, auditory, and vestibular dysfunctions.

Factores asociados a epilepsia farmacorresistente en niños atendidos en un hospital de referencia nacional / Factors associated with drug-resistant epilepsy in children treated at a national referral hospital

Antecedentes: Según la Organización Mundial de la Salud (OMS) cerca de 70 millones de personas en el mundo padecen epilepsia. Los países de medianos y bajos ingresos presentan 70-80% de los casos; se estima que afecta 4-13% de los niños hasta los 16 años, de los cuales la epilepsia farmacorresistente (EFR) se desarrolla en 10-23%. Objetivo: Determinar factores de riesgo asociados a EFR en pacientes pediátricos atendidos en Hospital María, Especialidades Pediátricas (HMEP), Tegucigalpa, marzo 2017-marzo 2022. Métodos: Estudio de casos-controles. A partir del total de pacientes menores de 18 años con diagnóstico de epilepsia atendidos en el Servicio de Neurología HMEP, se definió Caso como pacientes con diagnóstico de EFR y Controles como pacientes con epilepsia no farmacorresistente (ENFR). A partir de expedientes clínicos, se evaluaron factores sociodemográficos, antecedentes personales y familiares, factores clínicos, estudios de imagen y electroencefalograma. El estudio fue aprobado por el Comité de Ética Institucional. Resultados: Se analizaron 81 casos y 162 controles. La edad más afectada en casos fue preescolar (35.8%), en controles fue edad escolar (41.4%). El sexo masculino presentó similar distribución en ambos grupos (51.8% y 51.2%). La procedencia rural fue más frecuente en los casos que en controles (58.0% versus 48.8%). Se identificaron los siguientes factores asociados a EFR: Antecedentes familiares de epilepsia (ORa 2.32, IC95%1.22­4.41, p=0.01), alteración focal en examen físico (ORa 2.23, IC95%1.10­4.55, p=0.02), neurodesarrollo anormal (ORa 2.78, IC95%1.18­6.54, p=0.02). Discusión: El control adecuado de las crisis epilépticas incide directamente en la calidad de vida y sobrevida de los pacientes. La identificación correcta de los niños con epilepsia con los factores asociados identificados en este estudio, que coinciden con lo descrito internacionalmente, permitirá hacer un mejor tamizaje y priorizar la referencia temprana a un neurólogo pediatra contribuyendo a mejorar la calidad de vida de los pacientes...(AU)

Estimulación de nervio vago en epilepsia refractaria y callosotomía previa sin mejoría. Reporte de caso / Vagus nerve stimulation in refractory epilepsy and previous callosotomy without vimprovement. Case report / Estimulação do nervo vago em epilepsia refratária e calosotomia prévia sem melhora. Relato de caso

La epilepsia refractaria tanto generalizada como focal, es una patología sumamente incapacitante, para el tratamiento de la misma se ha establecido a la callosotomía desde hace décadas como primera línea quirúrgica para su control, la cual puede presentar efectos secundarios importantes como síndrome de desconexión y pérdida de memoria, sin embargo, existen pacientes que no responden a la callosotomía y necesitan nuevas líneas de tratamiento, buscando en la estimulación de nervio vago una respuesta a su condición. Descripción del caso de estudio. Se presenta el caso de paciente masculino de 24 años de edad con antecedente patológico de convulsiones tipo tónico clónicas generalizadas confirmadas por video electroencefalograma de 24 horas, de predominio nocturno de 13 años de evolución, es sometido a 2 regímenes farmacológicos antiepilépticos diferentes en un período de 7 años de duración, posteriormente diagnosticado con epilepsia refractaria, por lo que se realiza callosotomía sin control de su cuadro clínico, el mismo año se realiza estimulación de nervio vago, presentando resultados favorables en su evolución. Conclusión. Luego de evidenciar el presente caso de estudio se concluye que el tratamiento de epilepsia refractaria con la colocación de un estimulador de nervio vago izquierdo asociado a un correcto régimen FAE es una alternativa muy eficaz para considerar en estos pacientes.

Refractory epilepsy, both generalized and focal, is an extremely disabling pathology. For its treatment, callosotomy has been established for decades as the first surgical line for its control, which can present important side effects such as disconnection and loss syndrome. by heart, however, there are patients who do not respond to callosotomy and need new lines of treatment, looking for an answer to their condition in vagus nerve stimulation. Description of the case study. We present the case of a 24-year-old male patient with a pathological history of generalized tonic-clonic seizures confirmed by a 24-hour video electroencephalogram, predominantly nocturnal for 13 years, undergoing 2 different antiepileptic pharmacological mechanisms over a period of 7 years in duration, later diagnosed with refractory epilepsy, for which callosotomy was performed without control of its clinical picture, the same year vagus nerve stimulation was performed, presenting favorable results in its evolution. Conclution. After evidencing the present case study, it is concluded that the treatment of refractory epilepsy with the placement of a left vagus nerve stimulator associated with a correct AED regimen is a very effective alternative to consider in these patients.

A epilepsia refratária, tanto generalizada quanto focal, é uma patologia extremamente incapacitante. Para seu tratamento, a calosotomia se estabeleceu há décadas como a primeira linha cirúrgica para seu controle, que pode apresentar importantes efeitos colaterais como desconexão e síndrome de perda., há pacientes que não respondem à calosotomia e precisam de novas linhas de tratamento, buscando resposta para sua condição na estimulação do nervo vago. Descrição do estudo de caso. Apresentamos o caso de um doente do sexo masculino, 24 anos, com antecedentes patológicos de crises tónico-clónicas generalizadas confirmadas por videoeletroencefalograma de 24 horas, predominantemente nocturnas há 13 anos, submetido a 2 mecanismos farmacológicos antiepilépticos diferentes ao longo de 7 anos de duração, posteriormente diagnosticada com epilepsia refratária, para a qual foi realizada calosotomia sem controle de seu quadro clínico, no mesmo ano foi realizada estimulação do nervo vago, apresentando resultados favoráveis em sua evolução. Conclusão. Depois de evidenciar o presente estudo de caso, conclui-se que o tratamento da epilepsia refratária com a colocação de um estimulador de nervo vago esquerdo associado a um esquema correto de DEA é uma alternativa muito eficaz a ser considerada nesses pacientes.

Modulation of brain waves in spinal cord injury patients with pain: cross-sectional analysis / Modulação de ondas cerebrais em pacientes com lesão medular e dor: uma análise transversal / Modulación de ondas cerebrales en pacientes con lesión de médula espinal y dolor: un análisis transversal

ABSTRACT: Objective: This study aimed to describe the encephalographic electrical rhythm pattern of the Alpha wave in patients with traumatic spinal cord injury in the thoracic spine. Methodology: This is a cross-sectional observational study conducted from January to March 2022. A total of 20 patients with traumatic spinal cord injury were included in the study and divided into two groups, with pain symptoms and without pain symptoms. Both groups were submitted for evaluation for population characterization, identification of the presence of pain and the possible presence of signs and symptoms of central sensitization and quantitative electroencephalographic examination. Results: Comparing them, it was possible to observe a reduction of 38.7% (2.69µV; 95%CI 1.28 to 4.09) in the Alpha 2 wave (10-12 Hz) in the group with pain symptoms. This alteration was identified in the parietal lobe, mainly in PZ. Conclusion: We observed a selective reduction of Alpha 2 waves, mainly in the parietal region (PZ), in spinal cord injury patients with pain compared to spinal cord injury patients without pain. Level of Evidence III; Diagnostic Studies.

RESUMO: Objetivo: O objetivo deste estudo foi descrever o padrão do ritmo eletroencefalográfico da onda Alfa em pacientes com lesão medular traumática na coluna torácica. Metodologia: Trata-se de um estudo observacional transversal, realizado no período de janeiro a março de 2022. No total 20 pacientes com lesão medular traumática foram incluídos no estudo e divididos em dois grupos, com sintomas de dor e sem sintomas de dor. Ambos os grupos foram submetidos a avaliação para caracterização populacional, identificação de presença de dor e possível presença de sinais e sintomas de sensibilização central e ao exame Eletroencefalográfico quantitativo. Resultados: Ao compará-los foi possível constatar uma redução de 38,7% (2.69µV; 95%IC 1,28 to 4.09) da onda Alfa 2 (10-12 Hz) do grupo com sintomas de dor. Essa alteração foi identificada no lobo parietal, principalmente em PZ. Conclusão: Observamos uma redução seletiva de ondas Alfa 2, principalmente na região parietal (PZ), em pacientes com lesão medular com dor em relação aos pacientes lesão medular sem dor. Nível de Evidência III; Estudo diagnóstico.

RESUMEN: Objetivo: El objetivo de este estudio fue describir el patrón del ritmo electroencefalográfico de la onda Alfa en pacientes con lesión medular traumática en la columna torácica. Metodología: Se trata de un estudio observacional transversal realizado entre enero y marzo de 2022. En total, se incluyeron 20 pacientes con lesión medular traumática en el estudio, divididos en dos grupos, uno con síntomas de dolor y otro sin síntomas de dolor. Ambos grupos fueron sometidos a evaluación para caracterización poblacional, identificación de presencia de dolor y posible presencia de signos y síntomas de sensibilización central, así como al examen electroencefalográfico cuantitativo. Resultados: Al compararlos, se pudo constatar una reducción del 38,7% (2,69 µV; IC del 95%: 1,28 a 4,09) en la onda Alfa 2 (10-12 Hz) del grupo con síntomas de dolor. Esta alteración se identificó en el lóbulo parietal, principalmente en PZ. Conclusión: Observamos una reducción selectiva de las ondas Alfa 2, principalmente en la región parietal (PZ), en pacientes con lesión medular y dolor en comparación con pacientes con lesión medular sin dolor. Nivel de Evidencia III; Estudios de diagnósticos.

Levetiracetam plus Oxcarbazepine Combination Treatment Downregulates Serum Multidrug Resistance Protein 1 Levels and Upregulates Neuropeptide Y Levels in Children with Epilepsy

Abstract The aim of the present study was to investigate the usefulness of multidrug resistance protein 1 (MDR1) and neuropeptide Y (NPY) levels in predicting the efficacy of levetiracetam (LEV) plus oxcarbazepine (OXC) treatment administered to children with epilepsy and to determine their prognosis. Overall, 193 children with epilepsy admitted to the hospital were enrolled and randomly divided into two groups according to different treatment methods: group A (n = 106, treated with LEV plus OXC combination) and group B (n = 87, treated with OXC only). After treatment, compared with group B, group A exhibited a remarkably higher total effective rate and a significantly lower total adverse reaction rate. Areas under the curve for MDR1 and NPY for predicting ineffective treatment were 0.867 and 0.834, whereas those for predicting epilepsy recurrence were 0.916 and 0.829, respectively. Electroencephalography abnormalities, intracranial hemorrhage, neonatal convulsion, premature delivery, and MDR1 and NPY levels were independent risk factors for poor prognosis in children with epilepsy. Serum MDR1 and NPY levels exhibited a high predictive value for early epilepsy diagnosis, treatment efficacy assessment, and prognostication in children with epilepsy treated with LEV plus OXC combination.

Grado de concordancia en una serie de informes de electroencefalogramas ambulatorios del Departamento de Neurofisiología Clínica del Hospital de Clínicas / Coefficient of agreement in a series of reports for ambulatory electroencephalograms at the clinical neurophisiology department of Clinicas Hospital / Grau de concordância em uma série de relatórios de eletroencefalogramas ambulatoriais do Departamento de Neurofisiologia Clínica do Hospital de Clínicas

El electroencefalograma (EEG) es una técnica neurofisiológica encargada de analizar la actividad cerebral utilizada con fines diagnósticos en la epilepsia, pero también en pacientes con encefalopatías agudas y crónicas no epilépticas. Su interpretación debe realizarse por médicos especializados en el área con una formación correcta, actualizada y homogénea para evitar conclusiones disimiles y términos en desuso. Para conocer dentro de una unidad de Neurofisiología Clínica de manera objetiva cómo se interpreta un EEG y su concordancia, comparamos una serie de estudios de EEG ambulatorios a través del grado de concordancia o Kappa entre los observadores. Creemos que es importante conocer las similitudes o diferencias inter observador a fines de corregir los problemas observados y mejorar la calidad asistencial.

An electroencephalogram (EEG) is a neurophysiological technique that measures electrical activity in the brain for diagnostic purposes in epilepsy, and in patients with nonepileptic acute and chronic encelopathies. This test must be performed by physicians who are specialized in the area and have the appropriate updated and uniform training, in order to avoid dissimilar conclusions and outdated terms. We compared a series of ambulatory EEG by analyzing the Kappa or coefficient of agreement rate among observers to objectively learn how an EEG is interpreted and about agreement rates at the Neurophisiology Clinic. We believe it is important to learn about interobserver similarities and differences to allow for the correction of problems noticed and improve the quality of care. Coefficient of agreement in a series of reports for ambulatory electroencephalograms at the clinical neurophisiology department of Clinicas Hospital.

O eletroencefalograma (EEG) é uma técnica neurofisiológica utilizada no estudo da atividade cerebral utilizada no diagnóstico em epilepsia, mas também em pacientes com encefalopatias não epilépticas agudas e crônicas. Sua interpretação deve ser realizada por médicos especialistas na área com formação correta, atualizada e homogênea para evitar conclusões díspares e termos obsoletos. Para conhecer como um EEG e sua concordância são interpretados objetivamente dentro de uma unidade de Neurofisiologia Clínica, comparamos uma série de estudos EEG ambulatoriais através do grau de concordância ou Kappa entre observadores. Acreditamos que é importante conhecer as semelhanças ou diferenças interobservadores para corrigir os problemas observados e melhorar a qualidade do atendimento.

Epilepsy classification (ILAE Classification 2017) in resource-limited countries: A cross-sectional study on epilepsy in pediatric patients from Sudan

Background: The objective of this study is to utilize the ILAE 2017 to classify epilepsy patients and determine its applicability in Sudan. Methods: This study is a prospective, descriptive, cross-sectional research conducted in two pediatric epilepsy clinics in Khartoum State, Sudan. Results: In this cross-sectional study, 350 pediatric patients with epilepsy were included, with a mean age of 8.4 ± 4.7 years and a mean illness duration of 4.71 ± 3.91 years. The ILAE classification was applied, showing that 71.11% of patients had generalized onset seizures, 27.7% had focal onset seizures, and only 1.1% had unknown onset seizures. Among patients with focal onset seizures, 56.4% had intact awareness, while 43.6% had impaired levels of awareness. The majority of patients who had generalized onset seizures experienced motor onset seizures, with tonicclonic seizures being the most common (44.2%). Nearly all patients with unknown onset seizures experienced tonic-clonic convulsions. These findings provide insights into the prevalence and types of seizures among pediatric epilepsy patients in Sudan and can guide clinicians in developing appropriate treatment plans. Conclusion: This study highlights the importance of utilizing the latest ILAE classification 2017 in epilepsy classification and its potential utilization in resource limited areas like Sudan.

Clinical characteristics of epileptic seizure in neurofibromatosis type 1 in 15 cases / 中华儿科杂志

Objective: To summarize the clinical characteristics of epileptic seizure associated with neurofibromatosis type 1 (NF1). Methods: From January 2017 to July 2023 at Children's Hospital Capital Institute of Pediatrics, medical records of patients with both NF1 and epileptic seizure were reviewed in this case series study. The clinical characteristics, treatment and prognosis were analyzed retrospectively. Results: A total of 15 patients(12 boys and 3 girls) were collected. Café-au-lait macules were observed in all 15 patients. There were 6 patients with neurodevelopmental disorders and the main manifestations were intellectual disability or developmental delay. The age at the first epileptic seizure was 2.5 (1.2, 5.5) years. There were various seizure types, including generalized tonic-clonic seizures in 8 patients, focal motor seizures in 6 patients, epileptic spasm in 4 patients, tonic seizures in 1 patient, absence in 1 patient, generalized myoclonic seizure in 1 patient and focal to bilateral tonic-clonic seizure in 1 patient. Among 14 patients whose brain magnetic resonance imaging results were available, there were abnormal signals in corpus callosum, basal ganglia, thalamus or cerebellum in 6 patients, dilated ventricles of different degrees in 3 patients, blurred gray and white matter boundary in 2 patients, agenesis of corpus callosum in 1 patient and no obvious abnormalities in the other patients. Among 13 epilepsy patients, 8 were seizure-free with 1 or 2 antiseizure medications(ASM), 1 with drug resistant epilepsy was seizure-free after left temporal lobectomy, and the other 4 patients who have received 2 to 9 ASM had persistent seizures. One patient with complex febrile convulsion achieved seizure freedom after oral administration of diazepam on demand. One patient had only 1 unprovoked epileptic seizure and did not have another seizure without taking any ASM. Conclusions: The first epileptic seizure in NF1 patients usually occurs in infancy and early childhood, with the main seizure type of generalized tonic-clonic seizure and focal motor seizure. Some patients have intellectual disability or developmental delay. Most epilepsy patients achieve seizure freedom with ASM.

Implicit, But Not Explicit, Emotion Regulation Relieves Unpleasant Neural Responses Evoked by High-Intensity Negative Images / 神经科学通报·英文版

Evidence suggests that explicit reappraisal has limited regulatory effects on high-intensity emotions, mainly due to the depletion of cognitive resources occupied by the high-intensity emotional stimulus itself. The implicit form of reappraisal has proved to be resource-saving and therefore might be an ideal strategy to achieve the desired regulatory effect in high-intensity situations. In this study, we explored the regulatory effect of explicit and implicit reappraisal when participants encountered low- and high-intensity negative images. The subjective emotional rating indicated that both explicit and implicit reappraisal down-regulated negative experiences, irrespective of intensity. However, the amplitude of the parietal late positive potential (LPP; a neural index of experienced emotional intensity) showed that only implicit reappraisal had significant regulatory effects in the high-intensity context, though both explicit and implicit reappraisal successfully reduced the emotional neural responses elicited by low-intensity negative images. Meanwhile, implicit reappraisal led to a smaller frontal LPP amplitude (an index of cognitive cost) compared to explicit reappraisal, indicating that the implementation of implicit reappraisal consumes limited cognitive control resources. Furthermore, we found a prolonged effect of implicit emotion regulation introduced by training procedures. Taken together, these findings not only reveal that implicit reappraisal is suitable to relieve high-intensity negative experiences as well as neural responses, but also highlight the potential benefit of trained implicit regulation in clinical populations whose frontal control resources are limited.

Application of brain functional connectivity and nonlinear dynamic analysis in brain function assessment for infants with controlled infantile spasm / 中国当代儿科杂志

OBJECTIVES@#To investigate the role of brain functional connectivity and nonlinear dynamic analysis in brain function assessment for infants with controlled infantile spasm (IS).@*METHODS@#A retrospective analysis was performed on 14 children with controlled IS (IS group) who were admitted to the Department of Neurology, Anhui Provincial Children's Hospital, from January 2019 to January 2023. Twelve healthy children, matched for sex and age, were enrolled as the control group. Electroencephalogram (EEG) data were analyzed for both groups to compare the features of brain network, and nonlinear dynamic indicators were calculated, including approximate entropy, sample entropy, permutation entropy, and permutation Lempel-Ziv complexity.@*RESULTS@#Brain functional connectivity showed that compared with the control group, the IS group had an increase in the strength of functional connectivity, and there was a significant difference between the two groups in the connection strength between the Fp2 and F8 channels (P<0.05). The network stability analysis showed that the IS group had a significantly higher network stability than the control group at different time windows (P<0.05). The nonlinear dynamic analysis showed that compared with the control group, the IS group had a significantly lower sample entropy of Fz electrode (P<0.05).@*CONCLUSIONS@#Abnormalities in brain network and sample entropy may be observed in some children with controlled IS, and it is suggested that quantitative EEG analysis parameters can serve as neurological biomarkers for evaluating brain function in children with IS.

A preliminary study on a new method for evaluating brain maturation in preterm infants / 中国当代儿科杂志

OBJECTIVES@#To establish a new method for evaluating the brain maturation of preterm infants based on the features of electroencephalographic activity.@*METHODS@#A prospective study was conducted on the video electroencephalography (vEEG) and amplitude-integrated electroencephalography (aEEG) recordings within 7 days after birth of preterm infants who had a postmenstrual age (PMA) of 25-36 weeks and met the inclusion criteria. The background activity of aEEG+conventional electroencephalography (cEEG) was scored according to the features of brain maturation as a new evaluation system and was compared with the aEEG evaluation system. The correlations of the evaluation results of the two methods with gestational age (GA), PMA, and head circumference were evaluated. The intervals of the total scores of aEEG+cEEG and aEEG were calculated for preterm infants with different PMAs and were compared between groups. The consistency of the new scoring system was evaluated among different raters.@*RESULTS@#A total of 52 preterm infants were included. The total scores of aEEG+cEEG and aEEG were positively correlated with GA, PMA, and head circumference (P<0.05), and the correlation coefficient between the total scores of the two systems and PMA and GA was >0.9. The normal score intervals for aEEG+cEEG and aEEG scoring systems were determined in preterm infants with different PMAs as follows: infants with a PMA of less than 28 weeks had scores of 13.0 (11.0, 14.0) points for aEEG+cEEG and 6.0 (4.0, 7.0) points for aEEG; infants with a PMA between 28 and 29+6 weeks had scores of 16.0 (14.5, 17.0) points for aEEG+cEEG and 8.0 (6.0, 8.0) points for aEEG; infants with a PMA between 30 and 31+6 weeks had scores of 18.0 (17.0, 21.0) points for aEEG+cEEG and 9.0 (8.0, 10.0) points for aEEG; infants with between 32 and 33+6 weeks had scores of 22.0 (20.0, 24.5) points for aEEG+cEEG and 10.0 (10.0, 10.8) points for aEEG; infants with a PMA between 34 and 36 weeks had scores of 26.0 (24.5, 27.5) points for aEEG+cEEG and 11.0 (10.0, 12.0) points for aEEG. There were significant differences in the total scores of aEEG+cEEG and aEEG among the different PMA groups (P<0.05). There was a high consistency between different raters when using the scoring system to evaluate the brain maturation of preterm infants (κ=0.86).@*CONCLUSIONS@#The aEEG+cEEG scoring system established in this study can quantitatively reflect the brain maturation of preterm infants, with a good discriminatory ability between preterm infants with different PMAs and high consistency between different raters.

Research progress of brain-computer interface application paradigms based on rapid serial visual presentation / 生物医学工程学杂志

Rapid serial visual presentation (RSVP) is a type of psychological visual stimulation experimental paradigm that requires participants to identify target stimuli presented continuously in a stream of stimuli composed of numbers, letters, words, images, and so on at the same spatial location, allowing them to discern a large amount of information in a short period of time. The RSVP-based brain-computer interface (BCI) can not only be widely used in scenarios such as assistive interaction and information reading, but also has the advantages of stability and high efficiency, which has become one of the common techniques for human-machine intelligence fusion. In recent years, brain-controlled spellers, image recognition and mind games are the most popular fields of RSVP-BCI research. Therefore, aiming to provide reference and new ideas for RSVP-BCI related research, this paper reviewed the paradigm design and system performance optimization of RSVP-BCI in these three fields. It also looks ahead to its potential applications in cutting-edge fields such as entertainment, clinical medicine, and special military operations.

Recognition of motor imagery electroencephalogram based on flicker noise spectroscopy and weighted filter bank common spatial pattern / 生物医学工程学杂志

Due to the high complexity and subject variability of motor imagery electroencephalogram, its decoding is limited by the inadequate accuracy of traditional recognition models. To resolve this problem, a recognition model for motor imagery electroencephalogram based on flicker noise spectrum (FNS) and weighted filter bank common spatial pattern ( wFBCSP) was proposed. First, the FNS method was used to analyze the motor imagery electroencephalogram. Using the second derivative moment as structure function, the ensued precursor time series were generated by using a sliding window strategy, so that hidden dynamic information of transition phase could be captured. Then, based on the characteristic of signal frequency band, the feature of the transition phase precursor time series and reaction phase series were extracted by wFBCSP, generating features representing relevant transition and reaction phase. To make the selected features adapt to subject variability and realize better generalization, algorithm of minimum redundancy maximum relevance was further used to select features. Finally, support vector machine as the classifier was used for the classification. In the motor imagery electroencephalogram recognition, the method proposed in this study yielded an average accuracy of 86.34%, which is higher than the comparison methods. Thus, our proposed method provides a new idea for decoding motor imagery electroencephalogram.

Applications and challenges of wearable electroencephalogram signals in depression recognition and personalized music intervention / 生物医学工程学杂志

Rapid and accurate identification and effective non-drug intervention are the worldwide challenges in the field of depression. Electroencephalogram (EEG) signals contain rich quantitative markers of depression, but whole-brain EEG signals acquisition process is too complicated to be applied on a large-scale population. Based on the wearable frontal lobe EEG monitoring device developed by the authors' laboratory, this study discussed the application of wearable EEG signal in depression recognition and intervention. The technical principle of wearable EEG signals monitoring device and the commonly used wearable EEG devices were introduced. Key technologies for wearable EEG signals-based depression recognition and the existing technical limitations were reviewed and discussed. Finally, a closed-loop brain-computer music interface system for personalized depression intervention was proposed, and the technical challenges were further discussed. This review paper may contribute to the transformation of relevant theories and technologies from basic research to application, and further advance the process of depression screening and personalized intervention.

A study on the application of cross-frequency coupling characteristics of neural oscillation in the diagnosis of mild cognitive impairment / 生物医学工程学杂志

In order to fully explore the neural oscillatory coupling characteristics of patients with mild cognitive impairment (MCI), this paper analyzed and compared the strength of the coupling characteristics for 28 MCI patients and 21 normal subjects under six different-frequency combinations. The results showed that the difference in the global phase synchronization index of cross-frequency coupling under δ-θ rhythm combination was statistically significant in the MCI group compared with the normal control group ( P = 0.025, d = 0.398). To further validate this coupling feature, this paper proposed an optimized convolutional neural network model that incorporated a time-frequency data enhancement module and batch normalization layers to prevent overfitting while enhancing the robustness of the model. Based on this optimized model, with the phase locking value matrix of δ-θ rhythm combination as the single input feature, the diagnostic accuracy of MCI patients was (95.49 ± 4.15)%, sensitivity and specificity were (93.71 ± 7.21)% and (97.50 ± 5.34)%, respectively. The results showed that the characteristics of the phase locking value matrix under the combination of δ-θ rhythms can adequately reflect the cognitive status of MCI patients, which is helpful to assist the diagnosis of MCI.

Analysis of neural fragility in epileptic zone based on stereoelectroencephalography / 生物医学工程学杂志

There are some limitations in the localization of epileptogenic zone commonly used by human eyes to identify abnormal discharges of intracranial electroencephalography in epilepsy. However, at present, the accuracy of the localization of epileptogenic zone by extracting intracranial electroencephalography features needs to be further improved. As a new method using dynamic network model, neural fragility has potential application value in the localization of epileptogenic zone. In this paper, the neural fragility analysis method was used to analyze the stereoelectroencephalography signals of 35 seizures in 20 patients, and then the epileptogenic zone electrodes were classified using the random forest model, and the classification results were compared with the time-frequency characteristics of six different frequency bands extracted by short-time Fourier transform. The results showed that the area under curve (AUC) of epileptic focus electrodes based on time-frequency analysis was 0.870 (delta) to 0.956 (high gamma), and its classification accuracy increased with the increase of frequency band, while the AUC by using neural fragility could reach 0.957. After fusing the neural fragility and the time-frequency characteristics of the γ and high γ band, the AUC could be further increased to 0.969, which was improved on the original basis. This paper verifies the effectiveness of neural fragility in identifying epileptogenic zone, and provides a theoretical reference for its further clinical application.

Research progress on attention level evaluation based on electroencephalogram signals / 生物医学工程学杂志

Attention level evaluation refers to the evaluation of people's attention level through observation or experimental testing, and its research results have great application value in education and teaching, intelligent driving, medical health and other fields. With its objective reliability and security, electroencephalogram signals have become one of the most important technical means to analyze and express attention level. At present, there is little review literature that comprehensively summarize the application of electroencephalogram signals in the field of attention evaluation. To this end, this paper first summarizes the research progress on attention evaluation; then the important methods for electroencephalogram attention evaluation are analyzed, including data preprocessing, feature extraction and selection, attention evaluation methods, etc.; finally, the shortcomings of the current development in the field of electroencephalogram attention evaluation are discussed, and the future development trend is prospected, to provide research references for researchers in related fields.

Alterations of β-γ coupling of scalp electroencephalography during epilepsy / 生物医学工程学杂志

Uncovering the alterations of neural interactions within the brain during epilepsy is important for the clinical diagnosis and treatment. Previous studies have shown that the phase-amplitude coupling (PAC) can be used as a potential biomarker for locating epileptic zones and characterizing the transition of epileptic phases. However, in contrast to the θ-γ coupling widely investigated in epilepsy, few studies have paid attention to the β-γ coupling, as well as its potential applications. In the current study, we use the modulation index (MI) to calculate the scalp electroencephalography (EEG)-based β-γ coupling and investigate the corresponding changes during different epileptic phases. The results show that the β-γ coupling of each brain region changes with the evolution of epilepsy, and in several brain regions, the β-γ coupling decreases during the ictal period but increases in the post-ictal period, where the differences are statistically significant. Moreover, the alterations of β-γ coupling between different brain regions can also be observed, and the strength of β-γ coupling increases in the post-ictal period, where the differences are also significant. Taken together, these findings not only contribute to understanding neural interactions within the brain during the evolution of epilepsy, but also provide a new insight into the clinical treatment.