Marcadores Neurales como Indicadores de Funciones Predictivas en Pacientes con Traumatismo Cerebral Moderado a Severo / Neural Markers as Indicators of Predictive Functions in Patients with Moderate to Severe Brain Trauma

Introducción. El traumatismo encéfalo craneano moderado a severo (TEC-MS) es una condición compleja que cambia la estructura y función del cerebro, afectando a personas de distintas edades. Los problemas cognitivos y motores son la mayor causa de discapacidad en individuos con TEC-MS crónico. Sin embargo, muchas de estas dificultades no son visibles de inmediato clasificándose como una "Epidemia silenciosa". Las principales alteraciones reportadas por los pacientes tienen relación con problemas de la memoria, atención y lentitud psicomotora, los cuales tienen un impacto en su independencia y funcionalidad. Objetivo. Este estudio tiene por objetivo discutir y revisar la evidencia disponible acerca de la capacidad de los pacientes crónicos con TEC-MS para generar predicciones en diferentes niveles de procesamiento cerebral. Métodos. Para esto, utilizamos desde las neurociencias el modelo teórico del código predictivo para explicar las respuestas neurofisiológicas adquiridas bajo un paradigma de predicción auditiva. Esta información es complementada con el reporte de datos preliminares de sujetos con TEC-MS y sujetos control, con el fin de ilustrar los aspectos teóricos discutidos. Conclusiones. Esto podría contribuir a una mejor comprensión de los mecanismos neurales detrás de los déficits cognitivos en esta población, aportando una perspectiva que nos oriente al desarrollo de nuestras estrategias terapéuticas.

Background. Moderate to severe traumatic brain injury (TBI-MS) is a complex condition that changes the structure and function of the brain, affecting people of different ages. Cognitive and motor problems are the major cause of disability in individuals with chronic ECT-MS. However, many of these difficulties are not immediately visible, classifying them as a "Silent Epidemic." The main alterations reported by patients are related to problems with memory, attention and psychomotor slowness, which have an impact on their independence and functionality. Objetive. This study aims to discuss and review the available evidence about the ability of chronic ECT-MS patients to generate predictions at different levels of brain processing. Methods. For this, we use the theoretical model of the predictive code from neuroscience to explain the neurophysiological responses acquired under an auditory prediction paradigm. This information is complemented with the report of preliminary data from subjects with ECT-MS and control subjects, in order to illustrate the theoretical aspects discussed. Conclusions. This could contribute to a better understanding of the neural mechanisms behind cognitive deficits in this population, providing a perspective that guides us in the development of our therapeutic strategies.

Estudios neurofisiológicos en los trastornos del neurodesarrollo: potenciales evocados cognitivos / Neurophysiological studies in neurodevelopmental disorders: event related potentials

Resumen El trastorno por déficit de atención con hiperactividad (TDAH) y el trastorno del espectro autista (TEA) son trastornos del neurodesarrollo cuyo diagnóstico es clínico y con gran variabilidad en la presentación clínica. La posibilidad de identificar y validar biomarcadores en estos trastornos del neurodesarrollo ayudaría no sólo en su diagnóstico sino también a la hora de implementar tratamientos personalizados y mo nitorizar la respuesta al tratamiento. Exploraciones neurofisiológicas como los potenciales evocados cognitivos (PEC), son una de las herramientas más utilizadas para evaluar de forma objetiva y con una alta resolución temporal las funciones cognitivas y proporcionan información sobre los mecanismos neurobiológicos subyacen tes, por lo que constituyen una herramienta de gran utilidad para valorar las alteraciones cognitivas asociadas a los trastornos del neurodesarrollo. Se han utilizado diferentes componentes de los PEC para el estudio de los trastornos del neurodesarrollo, como el componente P300, N400 o el componente N170 como biomarcador de la disfunción social en TEA. Revisamos los principales componentes de los PEC que se han estudiado como herramientas complementarias en el diagnóstico y en la monitorización de los tratamientos en los trastornos del neurodesarrollo.

Abstract Attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are neurodevel opmental disorders whose diagnosis is clinical and with great variability in clinical presentation. The possibility of identifying and validating biomarkers in these neurodevelopmental disorders would help not only in their diagnosis, but also when implementing personalized treatments and monitori ng the response to treatment. Neurophysiologi cal examinations such as event related potentials (ERP) are one of the most widely used tools to objectively assess cognitive functions with high temporal resolution and provide information on the underlying neurobiological mechanisms, making them a very useful tool to assess cognitive alterations associated with neurodevelopmental disorders. Different components of the ERP have been used for the study of neurodevelopmental disorders, such as the P300, N400 component or the N170 component as a biomarker of social dysfunction in ASD. We review the main components of ERP that have been studied as complementary tools in the diagnosis and monitoring of treatments in neurodevelopmental disorders.

Elderly people with human T-cell leukemia virus type 1-associated myelopathy present an early impairment in cognitive skills / Idosos com mielopatia associada ao vírus da leucemia de células T humanas tipo 1apresentam comprometimento precoce em habilidades cognitivas

Abstract Background Cerebral changes occur in individuals with human T-cell leukemia virus type 1 (HTLV-1 )-associated myelopathy (HAM) and seem to predominate in subcortical areas. Little is known about the cognitive decline in the elderly living with HTLV-1. Objective To evaluate the cognitive aging of individuals infected with HTLV-1 aged ≥ 50 years. Methods This is a cross-sectional study of former blood donors infected with HTLV-1 who have been followed in the cohort of the Interdisciplinary Research Group on HTLV-1 since 1997. The groups of study consisted of 79 HTLV-1 infected individuals aged ≥ 50 years, with 41 of them presenting symptomatic HAM and 38 being asymptomatic carriers, and 59 seronegative individuals (controls) aged ≥ 60 years. All were submitted to the P300 electrophysiological test and neuropsychological tests. Results Individuals with HAM presented delayed P300 latency in relation to the other groups, and this latency delay increased progressively with aging. The performance of this group in the neuropsychological tests was also the worst. The HTLV-1- asymptomatic group performance was similar to that of the control group. Conclusions Individuals with HAM presented cognitive decline that progressed with aging and, although HTLV-1-asymptomatic carriers appear to present cognitive aging similar to that of healthy elderly people, concern about a subclinical cognitive impairment is warranted in this population.

Resumo Antecedentes Alterações cerebrais ocorrem em indivíduos com mielopatia associada ao vírus da leucemia de células T humanas tipo 1 (HTLV-1) (HAM) e parecem predominar em áreas subcorticais. Pouco se sabe sobre o declínio cognitivo em idosos vivendo com HTLV-1. Objetivo Avaliar o envelhecimento cognitivo de indivíduos infectados pelo HTLV-1 com idade ≥ 50 anos. Métodos Trata-se de um estudo transversal com ex-doadores de sangue infectados pelo HTLV-1 acompanhados na coorte do Grupo Interdisciplinar de Pesquisa em HTLV-1 há 20 anos. Os grupos de estudo foram compostos por 79 indivíduos infectados pelo HTLV-1 com idade ≥ 50 anos, sendo que 41 apresentavam HAM e 38 eram portadores assintomáticos, e 59 indivíduos soronegativos (controles) com idade ≥ 60 anos. Todos foram submetidos ao teste eletrofisiológico P300 e testes neuropsicológicos. Resultados Indivíduos com HAM apresentaram atraso na latência do P300 em relação aos demais grupos, e esse atraso de latência aumentou progressivamente com o envelhecimento. O desempenho desse grupo nos testes neuropsicológicos também foi o pior. O desempenho do grupo HTLV-1- assintomático foi semelhante ao do grupo controle. Conclusão Indivíduos com HAM apresentaram declínio cognitivo que progrediu com o envelhecimento e, embora os portadores assintomáticos do HTLV-1 pareçam apresentar envelhecimento cognitivo semelhante ao dos idosos saudáveis, justificase a preocupação com um comprometimento cognitivo subclínico nessa população.

Effects of transcranial direct current stimulation on event-related potentials of mental rotation / 生物医学工程学杂志

There are few researches on the modulation effect of transcranial direct current stimulation(tDCS) on complex spatial cognition. Especially, the influence of tDCS on the neural electrophysiological response in spatial cognition is not yet clear. This study selected the classic spatial cognition task paradigm (three-dimensional mental rotation task) as the research object. By comparing the changes in behavior and event-related potentials in different modes of tDCS before, during and after the application of tDCS, this study analyzed the behavioral and neurophysiological effects of tDCS on mental rotation. The comparison between active-tDCS and sham-tDCS showed no statistically significant difference in behavior between different stimulation modes. Still, the changes in the amplitudes of P2 and P3 during the stimulation were statistically significant. Compared with sham-tDCS, the amplitudes of P2 and P3 in active-tDCS mode showed a greater decrease during the stimulation. This study clarifies the influence of tDCS on the event-related potentials of the mental rotation task. It shows that tDCS may improve the brain information processing efficiency during the mental rotation task. Also, this study provides a reference for an in-depth understanding and exploration of the modulation effect of tDCS on complex spatial cognition.

MTL-P300 as a marker of the epileptogenic zone and hippocampal functionality in the presurgical evaluation of temporal lobe epilepsy: a systematic review / MTL-P300 como um marcador da zona epileptogênica e da funcionalidade hipocampal na avaliação pré-operatória da epilepsia do lobo temporal: revisão sistemática

Abstract Background In the past twenty years, there has been an increasing interest among neuroscientists and physicians in mapping the cortical areas involved in the epileptogenic zone (EZ) through event-related potentials (ERPs) that enable the evaluation of the functional preservation of these areas. The present review is an update on publications on this topic. Objective To investigate the accuracy of the cognitive evoked of the medial temporal lobe P300 (MTL-P300) potential in detecting the EZ in temporal lobe epilepsy (TLE). Methods The systematic review of articles on the PubMed, Embase and Lilacs databases was conducted between February and December 2020. Articles published in English from 1985 to December 2020 were included. Additional studies were identified by searching the references of the selected studies and review articles. The studies were included for the following reasons: in-depth intracranial electroencephalography (iEEG) analysis of hippocampal activity; investigations of patients with TLE; and correlations between regarding the ERP results obtained in the temporal regions (MTL-P300) and the EZ. Results In the three studies analyzed, the authors were able to define the laterality of the EZ during the preoperative investigation through the MTL-P300 results. The sensitivity of this method was of ~ 70% to 80%, and the specificity between 70% and 94.7%. One of the limitations of the present review was the low number of studies. Conclusion There is evidence that the reduced amplitude of the MTL-P300 has high specificity in identifying the EZ, and this is a good marker for diagnosis in unilateral TLE. The low sensitivity and negative likelihood ratios negative that a normal MTL-P300 response does not exclude the epileptogenicity of the hippocampus.

Resumo Antecedentes Nos últimos 20 anos, tem havido um crescente interesse de neurocientistas e médicos em mapear áreas corticais envolvidas na zona epileptogênica (ZE) por meio de potenciais relacionados a eventos (PREs), que permitem avaliar a preservação funcional dessas áreas. Esta revisão é uma atualização das publicações sobre esse tema. Objetivo Investigar a acurácia do potencial evocado cognitivo do lobo temporal medial P300 (medial temporal lobe P300, MTL-P300, em inglês) na detecção da ZE em casos de epilepsias do lobo temporal (ELT). Métodos A revisão sistemática de artigos nas bases de dados PubMed, Embase e Lilacs foi realizada entre fevereiro e dezembro de 2020. Foram incluídos artigos publicados em inglês de 1985 a dezembro de 2020. Estudos adicionais foram identificados por meio de busca nas referências dos estudos selecionados e artigos de revisão. Os estudos foram incluídos pelas seguintes razões: análise detalhada por meio de eletroencefalografia intracraniana (iEEG) da atividade hipocampal; investigações de pacientes com ELT; e correlações entre os resultados de ERP obtidos nas regiões temporais (MTL-P300) e na ZE. Resultados Nos três estudos analisados, os autores foram capazes de definir a lateralidade da ZE durante a investigação pré-operatória por meio dos resultados do MTL-P300. A sensibilidade deste método foi de 70% a 80%, e a especificidade, entre 70% e 94.7%. Uma das limitações desta revisão foi o baixo número de estudos. Conclusão Há evidências de que a amplitude reduzida do MTL-P300 tem alta especificidade na identificação da ZE, e este é um bom marcador para o diagnóstico na ELT unilateral. A baixa sensibilidade e a razão de verossimilhança negativa indicam que a resposta MTL-P300 normal não exclui a epileptogenicidade do hipocampo.

Is there a change in P300 evoked potential after 6 months in cochlear implant users?

Abstract Objective: There are few studies on long-latency auditory evoked potential (P300) in people with hearing loss who use a cochlear implant. Central auditory system evaluation with behavioral and electrophysiological tests is believed to help understand the neuroplasticity mechanisms involved in auditory functioning after cochlear implant surgery. This study investigated the electrophysiological processing of cortical level acoustic signals in a group of 21 adult individuals with postlingual bilateral severe-to-profound hearing loss who were submitted to cochlear implant surgery. Methods: Data were collected in three phases: pre-cochlear implant surgery, at cochlear implant activation, and 6 months after surgery. P300 measures were also registered during all phases. Tone-burst and speech stimuli were used to elicit P300 and were presented in free field. Results: Mean P3 component latency with tone-burst and speech stimuli were 352.9 and 321.9 ms in the pre-cochlear implant phase, 364.9 and 368.7 ms in the activation phase, 336.2 and 343.6 ms 6 months after the surgery. The P3 component mean latency values using tone-burst at activation were significantly different from those 6 months after cochlear implant. They were also significantly different using speech, between pre-cochlear implant and activation phases. Lower P3 component latency occurred 6 months after cochlear implant activation with tone-burst and pre-cochlear implant with speech stimulus. There was a weak correlation between mean P3 component latency with speech stimulus and time of hearing loss. There was no difference in amplitude between phases or in the comparison with the other variables. Conclusion: There were changes in P3 component latency during the period assessed, for both speech and pure-tone stimuli, with increased latency in the activation phase and similar lower results in the two other phases, Pre-CI and 6 months after CI use. Mean amplitude measures did not vary in the three phases.

Does gender influence P300 latency and mini mental state examination score in type 2 diabetes mellitus patients?

Background: P300 event-related potentials (ERPs) is an electrophysiologic marker of cognitive ability which closely reflects cognitive functions. Type 2 Diabetes mellitus (T2DM) causes many complications. Diabetes mellitus-induced damage to the central nervous system is a key focus of research. Latest magnetic resonance imaging evidence suggested that the changes in anatomy of brain is more rapidly seen in males than in females. This study was carried out to study the gender variations in P300 latency and Mini Mental State Examination (MMSE). Aim and Objective: To study the influence of gender on MMSE score as well as P300 ERP. Materials and Methods: 30 diagnosed Type 2 Diabetics aged above 40 years, with more than 2 years duration of diabetes were included in this study. MMSE questionnaire was administered to each diabetic and P300 was recorded using RMS EMG EP MARK 2 machine in all the diabetics. Results: The P300 ERP of male diabetics was prolonged significantly with mean ± standard deviation (SD) of (347.01 ± 31.55) whereas female diabetics had a mean ± SD of (318.26 ± 28.22; P = 0.014) and no significant difference was found between the mean MMSE scores of male diabetics (26.06 ± 1.38) and female diabetics (26.13 ± 1.30). Conclusion: The change in P300 ERP is swifter in males when compared with females in the middle to old age. Compared to MMSE, P300 Latency is a sensitive electrophysiological tool for diagnosing early cognitive deterioration in T2DM.

Potencial de disparidad o Mismatch negativity y P3a en pacientes con esquizofrenia / Mismatch negativity and P3a in patients with Schizophrenia

Resumen Antecedentes: la esquizofrenia es una enfermedad crónica que genera gran discapacidad, para la cual se han reportado biomarcadores potenciales, pero sin suficiente validez clínica. El mismatch negativity (MMN) y el P3a son potenciales relacionados con eventos que han demostrado ser indicadores neurofisiológicos del procesamiento auditivo pre-atencional y potenciales biomarcadores. Objetivo: evaluar el MMN y P3a en pacientes con diagnóstico de esquizofrenia y su relación con variables sociodemográficas y clínicas. Método: estudio cuantitativo transversal de 23 sujetos con esquizofrenia (ESQ) y 22 controles sanos (SN). Las amplitudes promedio y latencias del MMN/P3a para la condición infrecuente en duración y frecuencia fueron obtenidas mediante un paradigma oddball auditivo en un EEG de 32 canales. Resultados: se encontraron diferencias para la condición frecuencia en la amplitud del MMN (p=0.046; CI 95% 0.009; 0.87) y la amplitud del P3a (p=0.042; CI 95% 0.025; 1.24) entre los grupos; la amplitud del MMN fue menor en el grupo ESQ (-0.36 DE 0.51 µV) en comparación con los participantes del grupo de SN (-0.81 DE 0.89 µV), mientras que la amplitud del P3a fue menor en el grupo SN (0.18 DE 0.97 µV) versus el grupo ESQ (0.82 DE 1.05 µV). En relación con las variables sociodemográficas y clínicas, las asociaciones con el P3a fueron moderadas y con el MMN débiles. Conclusiones: la reducción de la amplitud del MMN a la condición frecuencia exhibe mayor utilidad que el P3a como medida de alta estabilidad en pacientes con esquizofrenia, lo que reitera su posible uso como biomarcador.

Abstract Background: schizophrenia is a chronic disease that generates great disability, which currently has potential biomarkers but without sufficient clinical validity. Mismatch negativity (MMN) and P3a are event-related potentials that have been shown to be neurophysiological indicators of pre-attentional auditory processing and potential biomarkers. Objective: to evaluate MMN and P3a in patients with a diagnosis of schizophrenia and their relationship with sociodemographic and clinical variables. Method: a quantitative cross-sectional study of 23 subjects with schizophrenia and 22 healthy controls was performed. The average amplitudes and latencies of the MMN/P3a for the condition infrequent in duration and infrequent in frequency were obtained using an auditory oddball paradigm on a 32-channel EEG. Results: differences were found for the frequency condition in the amplitude of the MMN (p=0.046; 95% CI 0.009; 0.87) and the amplitude of the P3a (p=0.042; 95% CI 0.025; 1.24) between the groups; MMN amplitude was lower in schizophrenia (-0.36 SD 0.51 µV) compared to healthy controls (-0.81 SD 0.89 µV), while P3a amplitude was lower in healthy controls (0.18 SD 0.97 µV) versus the group with schizophrenia (0.82 SD 1.05 µV). In regard to sociodemographic and clinical variables, the associations with P3a were moderate, and showed weak MMN. Conclusions: MMN amplitude reduction to the frequency condition exhibits greater utility than P3a as a measure of high stability in schizophrenia, restating its potential use as a biomarker.

Combining transcranial magnetic stimulation with action observation therapy better improves the neurological functioning of stroke survivors / 中华物理医学与康复杂志

Objective:To observe any effect of combining repetitive transcranial magnetic stimulation (rTMS) under the guidance of event related potentials (ERPs) with action observation therapy (AOT) on the cognitive and motor functioning of stroke survivors in the recovery period.Methods:Ninety stroke survivors were randomly divided into a control group, an rTMS group and an rTMS+ AOT group, each of 30. All three groups were given conventional rehabilitation treatment (including the training of waist, upper and lower limb function, balance, walking, memory, attention, orientation, spatial perception and executive ability). The rTMS group also received one session of ERP-based rTMS daily five times a week. The rTMS+ AOT group was given the same rTMS combined with AOT twice a day, five times a week. Before and after 4 weeks of treatment, the Mini-mental State Examination (MMSE), the Montreal Cognitive Assessment Scale (MOCA), the Fugl-Meyer assessment scale (FMA), the Berg Balance Scale (BBS) and the modified Barthel index (MBI) were used to evaluate each subject′s cognitive and motor ability and their skill in the activities of daily living.Results:After the treatment, the average MMSE, MOCA, FMA, BBS and MBI scores of all groups had improved significantly, but the average MMSE, MOCA, upper limb FMA and MBI scores of the rTMS group were then significantly higher than the control group′s averages. And the average scores of the rTMS+ AOT group were significantly better than those of the other two groups.Conclusion:Combining rTMS guided by ERPs with AOT can effectively improve the cognitive functioning, motor control and balance of stroke survivors, and improve their ability in the activities of daily living.

Clinical study of acupuncture combined with medication for the elderly with Alzheimer disease / 针灸推拿医学（英文版）

Objective: To observe the impact of mind-regulating acupuncture plus donepezil on the cognitive ability, mean cerebral blood flow velocity, event-related potential P300, and activities of daily living (ADL) in the aged patients with Alzheimer disease (AD).Methods: Sixty senile AD patients were divided into a treatment group and a control group following the envelope method for random allocation, with 30 cases in each group. Based on the conventional treatment of the internal medicine, the control group received oral donepezil, and the treatment group received oral donepezil plus mind-regulating acupuncture. After 4-week treatment, the two groups were evaluated by the mini-mental state examination (MMSE), Alzheimer disease assessment scale-cognitive part (ADAS-Cog), and ADL; changes in P300 and the mean cerebral blood flow velocity were also observed.Results: Before treatment, there were no significant differences in the scores of MMSE, ADAS-Cog, or ADL between the two groups (P>0.05). The MMSE score increased after treatment in both groups and was notably higher in the treatment group than in the control group, showing intra-group and inter-group statistical significance (P<0.05). After treatment, the ADAS-Cog and ADL scores dropped in both groups and were markedly lower in the treatment group than in the control group, also showing intra-group and inter-group statistical significance (P<0.05). Compared with the same group before treatment, the latency of P300 was shortened and the amplitude was extended in both groups, all with statistical significance (P<0.05); the latency was shorter and the amplitude was larger in the treatment group than in the control group after treatment, presenting significant between-group differences (P<0.05). The mean blood flow velocity accelerated after the intervention in both groups, and the differences were statistically significant (P<0.05); the improvement in the treatment group was more notable than that in the control group (P<0.05).Conclusion: Mind-regulating acupuncture plus donepezil can regulate the latency and amplitude of P300, increase cerebral blood flow, and improve the learning and memory abilities of AD patients.

The value of event-related potential P300 for diagnosing cognitive impairment after stroke / 中华物理医学与康复杂志

Objective:To observe the utility of event-related potential P300 in diagnosing post-stroke cognitive impairment.Methods:Forty-nine stroke survivors at high risk of cognitive impairment formed the observation group, while 54 healthy volunteers were the control group. General clinical data and Montreal Cognitive Assessment Scale (MoCA) scores were compiled for all of the subjects, and the two groups′ P300 latencies, amplitudes and mean reaction times (MRTs) were compared. A total MoCA score <26 (corrected for education level) was taken as the diagnostic criterion for cognitive impairment. The receiver operating characteristics (ROC) curve was employed to analyze the diagnostic efficacy of P300 for post-stroke cognitive impairment and determine the diagnostic cutoff.Results:(1) The average MoCA score, P300 latency and P300 MRT of the observation group were all significantly different from the control group′s averages. There was, however, no significant difference between the two groups′ median P300 amplitudes. (2) According to the ROC curve analysis, the diagnostic limit of P300 latency was 376.50ms. With the area under the curve 0.795, sensitivity was 70.8% and specificity was 78.9%. The diagnosis cut-off value of P300 MRT was 423.35ms, with the area under the curve 0.695, giving a sensitivity of 80.0% and a specificity of 52.6%.Conclusions:Event-related potential P300 has useful efficacy in diagnosing post-stroke cognitive impairment.

The Effect of Learning English on P300 in Children

Abstract Introduction Learning a second language is an essential task in today's world, and is experienced by many children. The cognitive auditory-evoked potential (P300) is related to cognitive activity, attention and concentration, enabling the investigation of the effect of a second language on the central auditory pathway. Objective To analyze the effects of learning English on P300 latency and amplitude in children and to correlate them with age, time of exposure to English, and time in class. Method An observational, descriptive, cross-sectional and quantitative study, in which 33 children, aged between 5 and 9 years and 11 months, of both genders participated, 14 of them in the process of learning English (study group) and 19 without this experience (control group). All subjects had their P300 evaluated using the Intelligent Hearing Systems (IHS, Miami, FL, US) Smart EP equipment. A total of 300 binaural stimuli were used in 75 dBnHL, as well as 240 frequent and 60 rare stimuli, using the pairs /ba/ and /di/ respectively. Results There was a statistically significant difference regarding P300 latency between the groups, and children exposed to English classes had lower latency in this component. No statistical difference was found between P300 amplitudes. No correlation was observed regarding age, time of exposure to English, time in class, and electrophysiological responses. Conclusion The Children exposed to English classes had the most stimulating auditory pathway, because their P300 had lower latency, being a resource for the speech therapy clinic.

Application of event-related potential in Alzheimer's disease and mild cognitive impairment / 中华行为医学与脑科学杂志

Alzheimer's disease (AD) is one of the major diseases that harmful to healthy elderly, and mild cognitive impairment (MCI) is the early clinical stage of AD. There is a lag in the clinical diagnosis of both diseases. An objective and reliable auxiliary diagnostic method is urgently needed to provide early diagnosis and differential indicators for AD and MCI, to predict the probability of individuals suffering from AD and MCI transforming into AD, and to reduce the overall incidence of AD and reduce the huge medical and economic burden for the country and society. Event-related potential is widely used in AD and MCI, and the resolution at the millisecond level can truly reflect the time course of cognitive processing and the degree of impairment of cognitive function in patients. In this study, we investigated the differences in the amplitude and latency of ERP components in healthy elderly, MCI and AD patients, and the correlation between ERP components and cognitive impairment. Early N170 and P200 showed high sensitivity and specificity in differentiating MCI from healthy elderly or MCI from AD. The late perception-related ERPs also showed high sensitivity and specificity in differentiating healthy elderly from MCI/AD. The differences in ERPs between MCI and AD may be related to the etiology, the degree of disease progression and the site of brain damage. The specific brain mechanism still need to be further explored and will be the focus of future research. With the progress of the research, the relationship between the specific ERP manifestations and the mechanism of brain injury as well as the impairment of cognitive function will be more clear. It is believed that the application of ERP in clinical will bring more benefits to AD and its early clinical MCI.

Behavioral and Electrophysiological Assessment of Adults Who Underwent Cochlear Implantation After Hearing Aid Experience

Abstract Introduction Cochlear implantation has been considered a viable option to restore hearing perception in adults with severe to profound postlingual hearing loss. Objectives To analyze behavioral hearing responses and P300 latency and amplitude measurements in adults with bilateral sensorineural hearing loss at two phases, first when they were using hearing aids (HAs) and, then, after 12 months of cochlear implant (CI) use. The associationbetweenbehavioral and electrophysiological evaluationswas explored, as it is believed that the study of auditory processing with different hearing devices can contribute to future CI adjustments and fittings, especially for patients who cannot give subjective feedback (such as small children and individuals with multiple disabilities). Methods Prospective comparative study (Ethical approval 11489/2014). Twelve adults were assessed, 7 males and 5 females, in the 22 to 76 years old age range, who had undergone CI surgery after HA experience. Results The analyses showed an improvement of hearing thresholds when patients started using CIs. Comparing data from P300 latency measurements, there was an increase of the P300 wave post-CI at Cz and Fz. Regarding the amplitude, P300 mean values decreased at Cz, but increased at Fz. There was no significant correlation between behavioral and electrophysiological assessment and the variables age, gender, auditory deprivation, and electronic device used. Conclusion There was a significant improvement of hearing thresholds after twelve months of CI experience. The mean latency values of P300 after 12 months of CI use increased at Cz and Fz, while mean amplitude values decreased at Cz and increased at Fz.

Morfología de los potenciales evocados auditivos de latencia tardía P300 y su rol en la evaluación de la conducta suicida / Morphology of auditory evoked potentials, and its role in the evaluation of suicidal behavior

El suicidio es un problema de salud a nivel mundial, siendo la conducta suicida uno de los predictores de mortalidad por suicidio; sin embargo, su valoración aún sigue siendo compleja. Aunque la cantidad de literatura que ha abordado distintas perspectivas de la conducta suicida es abundante, se requiere ahondar en nuevos métodos que permitan una valoración rápida y objetiva de ésta, proporcionando a los clínicos y pacientes, un sistema de evaluación que registre los cambios de estados emocionales de manera dinámica. El objetivo de este manuscrito fue proporcionar una visión general de la morfología de los potenciales evocados auditivos de latencia tardía p300 y su rol en la evaluación de la conducta suicida.

Suicide is a global health problem, with suicidal behavior being one of the predictors of suicide mortality; however, its assessment is still complex. Although the amount of literature that has addressed different perspectives of suicidal behavior is abundant, it is necessary to deepen new methods that allow a rapid and objective assessment of it, providing clinicians and patients with an evaluation system that allows changes in emotional state to be recorded dynamically. The aim of this manuscript was to provide an overview of morphological patterns of auditory evoked potential P300 latency late in the assessment of suicidal behavior.

Tinnitus and event related potentials: a systematic review / Zumbido e potenciais evocados auditivos relacionados a eventos: uma revisão sistemática

Abstract Introduction Tinnitus is sound perception in the absence of a sound source. Changes in parameters of latency and amplitude on the auditory event related potentials or long latency potentials waves have been cited in tinnitus patients when compared to a control group. Objective To perform an assessment of scientific evidence that verifies the possibility of alterations in latency or amplitude of the waves of event related potentials in individuals with tinnitus. Methods By using SciELO, Lilacs, ISI Web and PubMed, scientific databases, a review was performed. Articles published in English, Portuguese, French and Spanish that correlated tinnitus with changes in event related potentials were included in this review. Results Twelve articles were located, however only eight fulfilled the criteria for inclusion. Conclusion The sample of selected studies demonstrate that the long latency auditory evoked potentials related to events between the control and tinnitus patients showed some changes in latency and or amplitude in tinnitus patients. There are changes in event-related potentials when comparing patients with tinnitus and the control group. These changes take place considering the severity of tinnitus, tinnitus site of lesion, and capacity for changes after interventions. The event related potentials can help to determine the neurotransmitter involved in tinnitus generation and evaluate tinnitus treatments.

Resumo Introdução O zumbido é a percepção de um som na ausência de uma fonte sonora. Mudanças nos parâmetros de latência e amplitude nas ondas dos potenciais evocados auditivos relacionados a eventos ou potenciais de longa latência foram citadas em pacientes com zumbido quando comparados a um grupo controle. Objetivo Realizar uma avaliação de evidências científicas que verifiquem a possibilidade de alterações na latência ou amplitude das ondas de potenciais evocados auditivos relacionados a eventos em indivíduos com zumbido. Método Foi feita uma revisão a partir dos bancos de dados científicos SciELO, Lilacs, ISI Web e PubMed. Artigos publicados em inglês, português, francês e espanhol que correlacionavam zumbido com alterações nos potenciais evocados auditivos relacionados a eventos foram incluídos. Resultados Foram localizados 12 artigos, porém apenas oito preencheram os critérios de inclusão. Conclusão A amostra de estudos selecionados demonstra que os potenciais evocados auditivos de longa latência relacionados a eventos entre os pacientes-controle e com zumbido apresentaram algumas alterações na latência e/ou amplitude nos pacientes com zumbido. Há mudanças nos potenciais relacionados a eventos ao comparar pacientes com zumbido e o grupo controle. Essas alterações consideram a gravidade do zumbido, o local da lesão do zumbido e a capacidade de alterações após as intervenções. Os potenciais evocados auditivos relacionados a eventos podem ajudar a determinar o neurotransmissor envolvido na geração do zumbido e avaliar os tratamentos para o zumbido.

Impulse Control and ERP Characteristics of Patients with Mental Disorder Caused by Traumatic Brain Injury / 法医学杂志

Objective To explore the impulse control and event-related potential （ERP） characteristics of patients with mental disorders caused by traumatic brain injury （TBI） in forensic psychiatry identification and to provide objective auxiliary indicators for forensic psychiatry identification. Methods Thirty patients （TBI group） with mental disorders caused by traumatic brain injury, who were identified as mild psychiatric impairment by judicial psychiatry, including 24 males and 6 females, as well as the thirty people in the control group participated in the study. All the participants completed Barratt Impulsiveness Scale-11 （BIS-11） and ERP induced by Go/NoGo tasks. BIS-11 and ERP data were collected and analyzed. Results The results of the BIS-11 showed that the total score and subscale scores of the TBI group were higher compared to the control group （P<0.05）. Moreover, the TBI group exhibited significantly lower NoGo-N2 amplitude and lower NoGo-P3 amplitude than the control group. The NoGo-N2 amplitude was larger than the Go-N2 amplitude, and the NoGo-P3 amplitude was larger than the Go-P3 amplitude in both groups （P<0.05）. Conclusion Traumatic brain injury could impair impulse control of mild psychiatric impairment patients, and the amplitudes of NoGo-N2 and NoGo-P3 could be important parameters to evaluate the impulse control of patients with mental disorders caused by traumatic brain injury.

The role of microglia in thalamic reticular nucleus in acupuncture regulating cognitive deficits in insomnia rats / 针灸推拿医学（英文版）

Objective: To explore the mechanism of acupuncture in regulating cognitive deficits in insomnia rats by observing the effect of acupuncture on microglia in thalamic reticular nucleus (TRN). Methods: Thirty rats were randomly divided into a control group, a model group and an acupuncture group, with 10 rats in each group. The insomnia model was established by intraperitoneal injection of para-chlorophenylalanine (PCPA) once a day for 2 d. Rats in the control group were intraperitoneally injected with the same amount of normal saline. Rats in the acupuncture group received acupuncture at Neiguan (PC 6) and Zusanli (ST 36) for 5 consecutive days. The CLOCKLAB 2 data acquisition system was used to dynamically observe the sleep of the rats throughout the experiment. The cognition of rats was evaluated by event-related potentials (ERPs). After intervention, brain tissue was extracted. Immunofluorescence was used to test the fluorescence expression in TRN region. The concentrations of interleukin (IL)-1β and tumor necrosis factor (TNF)-α were detected by enzyme-linked immunosorbent assay. Results: After intraperitoneal injection of PCPA suspension, the spontaneous activity in light period of rats in the model group and acupuncture group increased significantly compared with the control group (both P<0.01). After acupuncture treatment, the rats in the acupuncture group had much less spontaneous activity during the light period than those in the model group (P<0.01), and the results indicated that acupuncture could effectively improve the sleep quality of insomnia rats. Compared with the control group, rats in the model group showed that the P3 latency, the average optical density of microglia, and the concentrations of IL-1β and TNF-α increased significantly (all P<0.05), and the P3 amplitude decreased significantly (P<0.01). Compared with the model group, rats in the acupuncture group presented that the P3 latency, the average optical density of microglia, and the concentrations of IL-1β and TNF-α were significantly decreased (all P<0.05), and the amplitude of P3 was significantly increased (P<0.05). Conclusion: Acupuncture possesses an ability to improve the cognitive state in insomnia rats. The mechanism may be related to inhibiting the microglial activation, diminishing the levels of pro-inflammatory mediators like IL-1β and TNF-α, and promoting the recovery of central nervous system function.

Advance in P300 Wave for Prognosis of Consciousness Disorders (review) / 中国康复理论与实践

Severe brain-injured patients would suffer severe disorders of consciousness for a long time. It is needed to prognose their brain function and outcomes. P300 wave of event-related potentials may feature as long latency and short amplitude in disorders of consciousness, which respond to the residual cognitive function. The dynamic changes of P300 wave amplitude and latency can be used to determine the recovery of cognitive function. The P300 waves induced by special stimulus may help to differentiate the vegetative state from the minimally conscious state.

Efecto de la empatía afectiva sobre el procesamiento cortical de emojis / Effect of Affective Empathy on the Cortical Processing of Emojis / Effect of Affective Empathy on the Cortical Processing of Emojis

Resumen Objetivo. Identificar las diferencias en el procesamiento cortical de emojis en personas con alta y baja empatía afectiva. Método. El estudio se llevó a cabo con 69 participantes, distribuidos en dos grupos -baja y alta empatía afectiva-, según su puntaje en el Índice de Reactividad Interpersonal. Cada participante observó emojis con expresiones de alegría, ira y neutros. Se registraron los potenciales relacionados a eventos (PRE) P100, N170 y LPP. Resultados. Se encontró una mayor amplitud del N170 en el grupo de personas con alta empatía afectiva y, en general, mayor magnitud del LPP ante emojis de ira. Conclusión. Los resultados sugieren que los emojis son procesados corticalmente de forma similar al rostro humano y que la empatía afectiva modula la codificación del emoji, pero no la atención temprana y el enganche atencional hacia estos estímulos.

Abstract Objective. The objective of this research was to identify the differences in the cortical processing of emojis in people with high and low affective empathy. Method. The study was carried out with 69 participants divided into two groups, low and high affective empathy, according to their score in the Interpersonal Reactivity Index. Each participant observed emojis with happy, neutral and angry expressions. Events related potential (ERP) P100, N170 and LPP were recorded. Results. An amplitude greater than N170 in the high affective empathy group, and a generally greater magnitude of the LPP in response to angry emoji were found. Conclusion. The results suggest that the emojis are processed cortically in a similar way to the human face and that affective empathy modulates the coding of the emoji but not the early attention and the attentional attachment to these stimuli.

Resumo Escopo. Identificar as diferencias no processamento cortical de emojis em pessoas com alta e baixa empatia afetiva. Metodologia. O estudo foi feito com 69 participantes, distribuídos em dois grupos, baixa e alta empatia afetiva, segundo sua pontuação no Índice de Reatividade Interpessoal. Cada participante observou emojis com expressões de alegria, neutrais e ira. Foram registrados os potenciais relacionados a eventos (PREs) P100, N170 e LPP. Resultados. Foi achada uma maior amplitude do N170 em um grupo de pessoas com alta empatia afetiva e, em geral, maior magnitude do LPP frente a de emoji com ira. Conclusão. Os resultados sugerem que os emojis são processados corticalmente de forma similar ao rosto humano e que a empatia afetiva modula a codificação do emoji mas não a atenção precoce e o engajamento atencional para estes estímulos.