Diagnosis support of major depressive disorder using event-related potentials during affective priming tasks.

Major Depressive Disorder (MDD) is a global problem. Currently, the most common diagnosis is based on criteria susceptible to the subjectivity of the patient and the clinician. A possible solution to this problem is to look for diagnostic biomarkers that can accurately and early detect this mental condition. Some researchers have focused on electroencephalogram (EEG) analysis to identify biomarkers. In this study we used a dataset composed of EEG recordings from 24 subjects with MDD and 29 healthy controls (HC), during the execution of affective priming tasks with three different emotional stimuli (images): fear, sadness, and happiness. We investigated abnormalities in depressed patients using a novel technique, by directly comparing Event-Related Potential (ERP) waveforms to find statistically significant differences between the MMD and HC groups. Compared to the control group (healthy subjects), we found out that for the emotions fear and happiness there is a decrease in cortical activity at temporal regions in MDD patients. Just the opposite, for the emotion sadness, an increase in MDD brain activity occurs in frontal and occipital regions. Our findings suggest that emotions regulate the attentional control of cognitive processing and are promising for clinical application in diagnosing patients with MDD more objectively.

Increased Delta and Theta Power Density in Sickle Cell Disease Individuals with Chronic Pain Secondary to Hip Osteonecrosis: A Resting-State Eeg Study.

PURPOSE: Identify the presence of a dysfunctional electroencephalographic (EEG) pattern in individuals with sickle cell disease (SCD) and hip osteonecrosis, and assess its potential associations with depression, anxiety, pain severity, and serum levels of brain-derived neurotrophic factor (BDNF). METHODS: In this cross-sectional investigation, 24 SCD patients with hip osteonecrosis and chronic pain were matched by age and sex with 19 healthy controls. Resting-state EEG data were recorded using 32 electrodes for both groups. Power spectral density (PSD) and peak alpha frequency (PAF) were computed for each electrode across Delta, Theta, Alpha, and Beta frequency bands. Current Source Density (CSD) measures were performed utilizing the built-in Statistical nonparametric Mapping Method of the LORETA-KEY software. RESULTS: Our findings demonstrated that SCD individuals exhibited higher PSD in delta and theta frequency bands when compared to healthy controls. Moreover, SCD individuals displayed increased CSD in delta and theta frequencies, coupled with decreased CSD in the alpha frequency within brain regions linked to pain processing, motor function, emotion, and attention. In comparison to the control group, depression symptoms, and pain intensity during hip abduction were positively correlated with PSD and CSD in the delta frequency within the parietal region. Depression symptoms also exhibited a positive association with PSD and CSD in the theta frequency within the same region, while serum BDNF levels showed a negative correlation with CSD in the alpha frequency within the left insula. CONCLUSION: This study indicates that individuals with SCD experiencing hip osteonecrosis and chronic pain manifest a dysfunctional EEG pattern characterized by the persistence of low-frequency PSD during a resting state. This dysfunctional EEG pattern may be linked to clinical and biochemical outcomes, including depression symptoms, pain severity during movement, and serum BDNF levels.

Comparison of subject-independent and subject-specific EEG-based BCI using LDA and SVM classifiers.

Motor imagery brain-computer interface (MI-BCI) is one of the most used paradigms in EEG-based brain-computer interface (BCI). The current state-of-the-art in BCI involves tuning classifiers to subject-specific training data, acquired over several sessions, in order to perform calibration prior to actual use of the so-called subject-specific BCI system (SS-BCI). Herein, the goal is to provide a ready-to-use system requiring minimal effort for setup. Thus, our challenge was to design a subject-independent BCI (SI-BCI) to be used by any new user without the constraint of individual calibration. Outcomes from other studies with the same purpose were used to undertake comparisons and validate our findings. For the EEG signal processing, we used a combination of the delta (0.5-4 Hz), alpha (8-13 Hz), and beta+gamma (13-40 Hz) bands at a stage prior to feature extraction. Next, we extracted features from the 27-channel EEG using common spatial pattern (CSP) and performed binary classification (MI of right- and left-hand) with linear discriminant analysis (LDA) and support vector machine (SVM) classifiers. These analyses were done for both the SS-BCI and SI-BCI models. We employed "leave-one-subject-out" (LOSO) arrangement and 10-fold cross-validation to evaluate our SI-BCI and SS-BCI systems, respectively. Compared with other two studies, our work was the only one that showed higher accuracy for the LDA classifier in SI-BCI as compared to SS-BCI. On the other hand, LDA accuracy was lower than accuracy achieved with SVM in both conditions (SI-BCI and SS-BCI). Our SS-BCI accuracy reached 76.85% using LDA and 94.20% using SVM and for SI-BCI we got 80.30% with LDA and 83.23% with SVM. We conclude that SI-BCI may be a feasible and relevant option, which can be used in scenarios where subjects are not able to submit themselves to long training sessions or to fast evaluation of the so called "BCI illiteracy." Comparatively, our strategy proved to be more efficient, giving us the best result for SI-BCI when faced against the classification performances of other three studies, even considering the caveat that different datasets were used in the comparison of the four studies.

The association between language and recognition of facial emotional expressions in elderly individuals. / Associação entre linguagem e o reconhecimento de expressões faciais de emoções em idosos.

PURPOSE: To check the association between a good performance of language and the recognition of facial emotional expressions in elderly individuals. METHODS: Transversal study performed with 118 elderly individuals from the primary care services of health of a city in the state of São Paulo. Sociodemographic data were collected, regarding the performance of language through the domain of Addenbrooke Cognitive Examination - Revised and Recognition of Facial Emotional Expressions. The sample was divided in thirds according to the performance of language: T1 = the best, T2 = average, and T3 = the worst. The groups T1xT3 were compared regarding the performance of recognition of facial expressions of anger, disgust, fear, happiness, sadness, and surprise, and for the intensities of 40%, 60%, 80%, and 100%. The association of independent variables over the performance of language was analyzed through logistic regression. The multivariate model was built from the results of the univariate analyses and has included the continuous variables by emotion and by intensity. Age and schooling associated to the performance of language in the univariate model were included in the multivariate model in order to adjust association analyses. RESULTS: The sample was mainly female (84.7%), with an average age of 70.5 years old, and 3.5 schooling years. The variables associated to the best performance of language in comparative analysis of T1 and T3 were: surprise (OR = 1.485, IC 95% 1.194 - 1.846), and disgust (OR = 1.143, IC 95% 1.005 - 1.300). CONCLUSION: The recognition of facial emotional expressions of surprise and disgust were shown as important factors associated to the good performance of language.

OBJETIVO: Verificar a associação entre o bom desempenho de linguagem e o reconhecimento de expressões faciais de emoções em idosos. MÉTODO: Estudo transversal realizado com 118 idosos dos serviços de atenção primária à saúde de um município paulista. Foram coletados dados sociodemográficos, de desempenho da linguagem pelo domínio do Exame Cognitivo de Addenbrooke - Revisado e de Reconhecimento de Expressões Faciais de Emoções. A amostra foi dividida em tercis de acordo com o desempenho na linguagem: T1 = melhor, T2 = mediano e T3 = pior. Os grupos T1xT3 foram comparados em relação ao desempenho no reconhecimento de expressões faciais de raiva, nojo, medo, alegria, tristeza e surpresa e para as intensidades 40%, 60%, 80% e 100%. A associação das variáveis independentes sobre o desempenho de linguagem foi analisada por meio de regressão logística. O modelo multivariado foi construído a partir dos resultados das análises univariadas e incluiu as variáveis contínuas por emoção e por intensidade. Idade e escolaridade, associadas ao desempenho de linguagem no modelo univariado, foram incluídas no modelo multivariado para ajustar as análises de associação. RESULTADOS: A amostra era predominantemente feminina (84,7%), com idade média de 70,5 anos e 3,5 anos de escolaridade. As variáveis ​​associadas ao melhor desempenho de linguagem na análise comparativa de T1 e T3 foram: surpresa (OR= 1,485, IC 95% 1,194 ­ 1,846) e nojo (OR= 1,143, IC 95% 1,005 ­ 1,300). CONCLUSÃO: O reconhecimento de expressões faciais das emoções surpresa e nojo mostraram-se importantes fatores associados ao bom desempenho da linguagem.

Early Schizophrenia and Bipolar Disorder Patients Display Reduced Neural Prepulse Inhibition.

BACKGROUND: Altered sensorimotor gating has been demonstrated by Prepulse Inhibition (PPI) tests in patients with psychosis. Recent advances in signal processing methods allow assessment of neural PPI through electroencephalogram (EEG) recording during acoustic startle response measures (classic muscular PPI). Simultaneous measurements of muscular (eye-blink) and neural gating phenomena during PPI test may help to better understand sensorial processing dysfunctions in psychosis. In this study, we aimed to assess simultaneously muscular and neural PPI in early bipolar disorder and schizophrenia patients. METHOD: Participants were recruited from a population-based case-control study of first episode psychosis. PPI was measured using electromyography (EMG) and EEG in pulse alone and prepulse + pulse with intervals of 30, 60, and 120 ms in early bipolar disorder (n = 18) and schizophrenia (n = 11) patients. As control group, 15 socio-economically matched healthy subjects were recruited. All subjects were evaluated with Rating Scale, Hamilton Rating Scale for Depression, and Young Mania Rating Scale questionnaires at recruitment and just before PPI test. Wilcoxon ranked sum tests were used to compare PPI test results between groups. RESULTS: In comparison to healthy participants, neural PPI was significantly reduced in PPI 30 and PPI60 among bipolar and schizophrenia patients, while muscular PPI was reduced in PPI60 and PPI120 intervals only among patients with schizophrenia. CONCLUSION: The combination of muscular and neural PPI evaluations suggested distinct impairment patterns among schizophrenia and bipolar disorder patients. Simultaneous recording may contribute with novel information in sensory gating investigations.

Apolipoprotein E ε4 allele impairs cortical activity in healthy aging and Alzheimer's disease.

AIM: To investigate the influence of apolipoprotein E (APOE) genotype on cortical activity, using the event-related potential P300 in healthy older adults and individuals with Alzheimer's disease (AD). METHODS: A cohort of 37 healthy older adults and 48 with AD participated in this study and completed an auditory oddball task using electroencephalographic equipment with 21 channels (10-20 system). APOE genotyping was obtained by real-time PCR. RESULTS: AD presented increased P300 latency and lower P300 amplitude, compared to healthy older adults. AD APOE ε4 carriers presented increased P300 latency in F3 (420.7 ± 65.8 ms), F4 (412.0 ± 49.0 ms), C4 (413.0 ± 41.1 ms) and P3 (420.4 ± 55.7 ms) compared to non-carriers (F3 = 382.5 ± 56.8 ms, p < 0.01; F4 = 372.2 ± 56.7 ms, p < 0.01; C4 = 374.2 ± 51.7 ms, p < 0.01; P3 = 384.4 ± 44.4 ms, p < 0.01). Healthy older adults APOE ε4 carriers presented lower Fz amplitude (2.6 ± 1.5 µV) compared to non-carriers (4.9 ± 2.9 µV; p = 0.02). Linear regression analysis showed that being a carrier of APOE ε4 allele remained significantly associated with P300 latency even after adjusting for sex, age, and cognitive grouping. APOE ε4 allele increases P300 latency (95% CI 0.11-0.98; p = 0.02). CONCLUSION: APOE ε4 allele negatively impacts cortical activity in both healthy older adults and AD individuals.

Association between psychosocial and functional factors and language and verbal fluency performance in older adults / Associação entre fatores psicossociais e funcionais e desempenho de idosos em linguagem e fluência verbal

ABSTRACT Purpose: to identify psychosocial and functional factors associated with language and verbal fluency performance in older adults. Methods: a study conducted with 149 older adults registered in a primary health care service in a city in inland São Paulo. Instruments such as a sociodemographic questionnaire, the Addenbrooke Cognitive Examination-Revised (verbal fluency and language domains), Geriatric Depression Scale, Perceived Stress Scale, Medical Outcomes Study, WHOQOL-OLD, and Instrumental Activities of Daily Living Scale, were used. Participants were divided into tertiles, according to their language and verbal fluency performance: T1 = best performance, T2 = median performance, and T3 = worst performance. Groups T1 and T3 were compared, and a binary regression was conducted to analyze the factors associated with the best language and verbal fluency performance. Results: higher educational attainment, higher income, and better functioning were the factors associated with the best language performance comparing T1 and T3, while higher educational attainment and better functioning were associated with the best verbal fluency. Conclusion: educational attainment and functioning proved to be important factors associated with good language and verbal fluency performance, while income was associated only with good language performance.

RESUMO Objetivo: identificar fatores psicossociais e funcionais associados ao desempenho de idosos em linguagem e fluência verbal. Métodos: estudo realizado com 149 idosos cadastrados no serviço de atenção primária à saúde de uma cidade do interior de São Paulo. Foram utilizados um questionário de caracterização sociodemográfica, Exame Cognitivo de Addenbrooke - Revisado (domínios de fluência verbal e de linguagem), Escala de Depressão Geriátrica, Escala de Estresse Percebido, Medical Outcomes Study, WHOQOL-OLD e Escala de Atividades Instrumentais da Vida Diária. Os participantes foram divididos em tercis de acordo com o desempenho em linguagem e fluência verbal: T1 = melhor desempenho, T2 = desempenho mediano e T3 = pior desempenho. Foram comparados os grupos T1 e T3 e realizada uma regressão binária para analisar os fatores associados ao melhor desempenho em linguagem e fluência verbal. Resultados: as variáveis associadas ao melhor desempenho de linguagem comparando T1 e T3 foram: maior escolaridade, maior renda e melhor funcionalidade. Para a melhor fluência verbal, os fatores associados foram: maior escolaridade e melhor funcionalidade. Conclusão: a escolaridade e a funcionalidade mostraram-se importantes fatores associados ao bom desempenho da linguagem e da fluência verbal, enquanto a renda mostrou-se associada apenas ao bom desempenho de linguagem.

Associação entre linguagem e o reconhecimento de expressões faciais de emoções em idosos / The association between language and recognition of facial emotional expressions in elderly individuals

RESUMO Objetivo Verificar a associação entre o bom desempenho de linguagem e o reconhecimento de expressões faciais de emoções em idosos. Método Estudo transversal realizado com 118 idosos dos serviços de atenção primária à saúde de um município paulista. Foram coletados dados sociodemográficos, de desempenho da linguagem pelo domínio do Exame Cognitivo de Addenbrooke - Revisado e de Reconhecimento de Expressões Faciais de Emoções. A amostra foi dividida em tercis de acordo com o desempenho na linguagem: T1 = melhor, T2 = mediano e T3 = pior. Os grupos T1xT3 foram comparados em relação ao desempenho no reconhecimento de expressões faciais de raiva, nojo, medo, alegria, tristeza e surpresa e para as intensidades 40%, 60%, 80% e 100%. A associação das variáveis independentes sobre o desempenho de linguagem foi analisada por meio de regressão logística. O modelo multivariado foi construído a partir dos resultados das análises univariadas e incluiu as variáveis contínuas por emoção e por intensidade. Idade e escolaridade, associadas ao desempenho de linguagem no modelo univariado, foram incluídas no modelo multivariado para ajustar as análises de associação. Resultados A amostra era predominantemente feminina (84,7%), com idade média de 70,5 anos e 3,5 anos de escolaridade. As variáveis ​​associadas ao melhor desempenho de linguagem na análise comparativa de T1 e T3 foram: surpresa (OR= 1,485, IC 95% 1,194 - 1,846) e nojo (OR= 1,143, IC 95% 1,005 - 1,300). Conclusão O reconhecimento de expressões faciais das emoções surpresa e nojo mostraram-se importantes fatores associados ao bom desempenho da linguagem.

ABSTRACT Purpose To check the association between a good performance of language and the recognition of facial emotional expressions in elderly individuals. Methods Transversal study performed with 118 elderly individuals from the primary care services of health of a city in the state of São Paulo. Sociodemographic data were collected, regarding the performance of language through the domain of Addenbrooke Cognitive Examination - Revised and Recognition of Facial Emotional Expressions. The sample was divided in thirds according to the performance of language: T1 = the best, T2 = average, and T3 = the worst. The groups T1xT3 were compared regarding the performance of recognition of facial expressions of anger, disgust, fear, happiness, sadness, and surprise, and for the intensities of 40%, 60%, 80%, and 100%. The association of independent variables over the performance of language was analyzed through logistic regression. The multivariate model was built from the results of the univariate analyses and has included the continuous variables by emotion and by intensity. Age and schooling associated to the performance of language in the univariate model were included in the multivariate model in order to adjust association analyses. Results The sample was mainly female (84.7%), with an average age of 70.5 years old, and 3.5 schooling years. The variables associated to the best performance of language in comparative analysis of T1 and T3 were: surprise (OR = 1.485, IC 95% 1.194 - 1.846), and disgust (OR = 1.143, IC 95% 1.005 - 1.300). Conclusion The recognition of facial emotional expressions of surprise and disgust were shown as important factors associated to the good performance of language.

Classification of Patients with Alzheimer's Disease and Dementia with Lewy Bodies using Resting EEG Selected Features at Sensor and Source Levels: A Proof-of-Concept Study.

BACKGROUND: Early differentiation between Alzheimer's disease (AD) and Dementia with Lewy Bodies (DLB) is important for accurate prognosis, as DLB patients typically show faster disease progression. Cortical neural networks, necessary for human cognitive function, may be disrupted differently in DLB and AD patients, allowing diagnostic differentiation between AD and DLB. OBJECTIVE: This proof-of-concept study assessed whether the application of machine learning techniques to data derived from resting-state electroencephalographic (rsEEG) rhythms (discriminant sensor power, 19 electrodes) and source connectivity (between five cortical regions of interest) allowed differentiation between DLB and AD. METHODS: Clinical, demographic, and rsEEG datasets from DLB patients (N=30), AD patients (N=30), and control seniors (NOld, N=30), matched for age, sex, and education, were taken from our international database. Individual (delta, theta, alpha) and fixed (beta) rsEEG frequency bands were included. The rsEEG features for the classification task were computed at both sensor and source levels. The source level was based on eLORETA freeware toolboxes for estimating cortical source activity and linear lagged connectivity. Fluctuations of rsEEG recordings (band-pass waveform envelopes of each EEG rhythm) were also computed at both sensor and source levels. After blind feature reduction, rsEEG features served as input to support vector machine (SVM) classifiers. Discrimination of individuals from the three groups was measured with standard performance metrics (accuracy, sensitivity, and specificity). RESULTS: The trained SVM two-class classifiers showed classification accuracies of 97.6% for NOld vs. AD, 99.7% for NOld vs. DLB, and 97.8% for AD vs. DLB. Three-class classifiers (AD vs. DLB vs. NOld) showed classification accuracy of 94.79%. CONCLUSION: These promising preliminary results should encourage future prospective and longitudinal cross-validation studies using higher resolution EEG techniques and harmonized clinical procedures to enable the clinical application of these machine learning techniques.

Revealing the complex self-assembly behaviour of sodium deoxycholate in aqueous solution.

HYPOTHESIS: Sodium deoxycholate is a natural bile salt produced by animals and fulfilling important physiological processes. It is also used as dispersive surfactant and building block for self-assembled architectures in biology and material science. Although long debated, the study of its self-assembly in water is hereto incomplete and the models of the known aggregates are still controversial. This background suggests a complex scenario likely missing of additional mesophases. EXPERIMENTS: Electron and optical microscopy techniques were crossed with SAXS data for the research. FINDINGS: Novel rod, sponge, vesicle, lamellae, nanotube phases and reversible transitions among them arise at conditions (concentration, pH, temperature, ionic strength, ionic composition) fitting the physiological working environment of sodium deoxycholate. These findings enlarge the perspective towards different directions. The integration of the previous literature with this work removes any interpretative contradiction since all the structures cover the entire spectrum of phases expected for surfactants, thus being explained according to the Israelachvili's scheme. It is not trivial that a single molecule can show such a high structural variability. This fact highlights a very versatile system. Probably it is not a coincidence that it occurs in a multitasking biomolecule. These results furnish fundamental knowledge to clarify the bile salts' role in vivo.

Highly Hydrophilic and Lipophilic Derivatives of Bile Salts.

Lipophilicity of 15 derivatives of sodium cholate, defined by the octan-1-ol/water partition coefficient (log P), has been theoretically determined by the Virtual log P method. These derivatives bear highly hydrophobic or highly hydrophilic substituents at the C3 position of the steroid nucleus, being linked to it through an amide bond. The difference between the maximum value of log P and the minimum one is enlarged to 3.5. The partition coefficient and the critical micelle concentration (cmc) are tightly related by a double-logarithm relationship (VirtuallogP=-(1.00±0.09)log(cmcmM)+(2.79±0.09)), meaning that the Gibbs free energies for the transfer of a bile anion from water to either a micelle or to octan-1-ol differ by a constant. The equation also means that cmc can be used as a measurement of lipophilicity. The demicellization of the aggregates formed by three derivatives of sodium cholate bearing bulky hydrophobic substituents has been studied by surface tension and isothermal titration calorimetry. Aggregation numbers, enthalpies, free energies, entropies, and heat capacities, ΔCP,demic, were obtained. ΔCP,demic, being positive, means that the interior of the aggregates is hydrophobic.

Efficacy of Physical Exercise on Cortical Activity Modulation in Mild Cognitive Impairment: A Systematic Review.

OBJECTIVE: To investigate the effects of physical exercise on cortical activity measured via electroencephalogram (EEG) in individuals with mild cognitive impairment (MCI). DATA SOURCES: PubMed, Web of Science, PsycINFO, and SciELO databases were searched using: "physical exercise," "physical activity," "physical therapy," "exercise," "training," "electroencephalogram," "electroencephalography," "EEG," "mild cognitive impairment," "cognitive dysfunction," and "MCI." The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement was followed and the Physiotherapy Evidence Database scale was used to assess the risk of bias of each study. STUDY SELECTION: Original articles, sample including individuals with MCI, physical exercise intervention, use of EEG to measure cortical activity. DATA EXTRACTION: Sample characteristics, physical exercise protocol characteristics, results related to effects of physical exercise on parameters derived from EEG signals, strengths, limitations, and conclusions of the studies were selected by 2 investigators. DATA SYNTHESIS: A total of 365 articles were identified in electronic databases. After the selection stage, 7 studies were included. Although there was a large spectrum of type of exercise (aerobic, resistance, multimodal, exergames, combined exercise with cognitive training), all exercise protocols altered cortical activity in patients with MCI. An exercise session (acute response) causes power reduction of delta band and increases complexity and P300 amplitude in resting-state EEG. After an intervention with an exercise program (chronic response), there was a reduction in the power of delta and theta bands and an increase in beta and alpha bands, as well an increase in complexity in resting-state EEG. CONCLUSIONS: Physical exercise seems to play a role in cortical activity in patients with MCI, suggesting neural plasticity in such individuals.

Cognition and chronic pain: an analysis on community-dwelling elderly caregivers and non-caregivers.

BACKGROUND: In recent years there has been an increasing number of elderly people who care for another elderly person in the same household. These elderly people are more susceptible to overload and the presence of chronic pain, while pain can negatively influence cognitive variables. OBJECTIVE: To compare the performance and cognitive processing of elderly caregivers and non-caregivers with and without chronic pain. METHODS: This was a cross-sectional study carried out among 149 elderly people divided into four groups that were matched according to sex, age and schooling. The tests used were a numerical pain assessment scale, the Brief Cognitive Screening Battery (BCSB), Addenbrooke's Cognitive Examination (ACER-R) and cognitive processing through event-related potentials (P300). RESULTS: Statistically significant differences between participants with and without chronic pain were found with regard to attention/orientation (p=0.045) and visual-spatial skills (p=0.017), and in the total score (p=0.033). In the pain-free group, the caregivers showed better results than the non-caregivers. There were no effects between subjects or interactions (caregiving and pain factors) either on P300 amplitude or on P300 latency. CONCLUSION: In general, it was observed that pain-free individuals presented better performance. No relationship was observed between the factors care and pain regarding cognitive performance.

Cognition and chronic pain: an analysis on community-dwelling elderly caregivers and non-caregivers / Cognição e dor crônica: uma análise em idosos cuidadores e não cuidadores residentes na comunidade

ABSTRACT Background: In recent years there has been an increasing number of elderly people who care for another elderly person in the same household. These elderly people are more susceptible to overload and the presence of chronic pain, while pain can negatively influence cognitive variables. Objective: To compare the performance and cognitive processing of elderly caregivers and non-caregivers with and without chronic pain. Methods: This was a cross-sectional study carried out among 149 elderly people divided into four groups that were matched according to sex, age and schooling. The tests used were a numerical pain assessment scale, the Brief Cognitive Screening Battery (BCSB), Addenbrooke's Cognitive Examination (ACER-R) and cognitive processing through event-related potentials (P300). Results: Statistically significant differences between participants with and without chronic pain were found with regard to attention/orientation (p=0.045) and visual-spatial skills (p=0.017), and in the total score (p=0.033). In the pain-free group, the caregivers showed better results than the non-caregivers. There were no effects between subjects or interactions (caregiving and pain factors) either on P300 amplitude or on P300 latency. Conclusion: In general, it was observed that pain-free individuals presented better performance. No relationship was observed between the factors care and pain regarding cognitive performance.

RESUMO Introdução: Nos últimos anos, observou-se crescente número de idosos que realizam o cuidado a outro idoso no mesmo domicílio. Esses idosos estão mais susceptíveis à sobrecarga e à presença de dor crônica, sendo que a dor pode influenciar negativamente as variáveis cognitivas. Objetivo: Comparar o desempenho e o processamento cognitivo de cuidadores idosos e não cuidadores com e sem dor crônica. Métodos: Estudo transversal realizado com 149 idosos, divididos em 4 grupos, pareados por sexo, idade e escolaridade. Os testes utilizados foram: escala numérica de avaliação da dor, Bateria Breve de Rastreio Cognitivo (BBRC), Addenbrooke's Cognitive Examination (ACER-R) e processamento cognitivo por meio de Potenciais Relacionados a Eventos (P300). Resultados: Foram encontradas diferenças estatisticamente significantes entre os participantes com e sem dor crônica nos domínios cognitivos atenção/orientação (p=0,045) e habilidades visual-espacial (p=0,017), bem como no escore total do instrumento ACE-R (p=0,033). No grupo sem dor foram encontradas diferenças estatísticas entre cuidadores e não cuidadores, com melhores resultados no grupo cuidador. Não houve efeitos entre os sujeitos ou interações (fatores de Cuidado e Dor) na amplitude do P300 ou na latência do P300. Conclusão: De maneira geral, observou-se que indivíduos sem dor apresentaram melhor desempenho. Não foi observada relação entre os fatores cuidado e dor no desempenho cognitivo.

Association between perceived social support and better cognitive performance among caregivers and non-caregivers.

OBJECTIVE: to identify the association between the characteristics of the support network and cognitive performance of older caregivers and compare characteristics between caregivers and non-caregivers. METHODS: we evaluated 85 older caregivers and 84 older non-caregivers registered with primary care units regarding sociodemographic characteristics, cognition, and social support. Multiple linear regression analysis was performed. RESULTS: among non-caregivers, significant associations were found between a better cognitive performance and receiving emotional/affectionate support; each one-point increase in the emotional support score and affectionate support score was related to a 0.43-point and 0.39-point increase in cognitive assessment, respectively. Among older caregivers, each one-point increase in the emotional support score was related to a 0.55-point increase in cognitive assessment. CONCLUSION: strengthening the support networks of older caregivers and encouraging satisfactory exchanges of social support can assist in improving cognitive performance, which can have a positive impact on caregivers' health.

A Systematic Review of Altered P300 Event-Related Potential in Apolipoprotein E4 (APOE4) Carriers.

BACKGROUND: Apolipoprotein ε4 allele (APOE4) is the strongest genetic risk factor for Alzheimer's disease and seems to be related to cognitive decline and damaged event-related potential P300, which is a sensitive measure to assess cognitive processing. OBJECTIVE: This research aims to critically review the existing scientific evidence regarding the association between APOE4 and P300. METHODS: A systematic review was carried out up to January 2020 on the following databases: Web of Science, Scopus and Medline/PubMed. Articles were considered for inclusion if they are original research that provided information regarding the association between APOE4 and P300, available in English, Spanish, or Portuguese, and available in full text. The methodological quality of the studies selected was evaluated using the quality assessment tool for observational cohort and cross-sectional studies recommended by Cochrane. RESULTS: Out of 993 studies, 14 met the inclusion criteria. The results obtained showed that APOE4 is related to a longer P300 latency. However, the data supplied do not allow us to confirm if this relationship also occurs in amplitude measures. Moreover, it was observed that APOE genotype may influence P300 in different ages, from younger individuals to demented older people. CONCLUSION: Evidence shows that APOE4 negatively influences cortical activities related to cognitive functions, as indicated by P300.

Association between perceived social support and better cognitive performance among caregivers and non-caregivers / Associação entre suporte social percebido e melhor desempenho cognitivo entre cuidadores e não cuidadores / Asociación entre apoyo social percibido y mejor desempeño cognitivo entre cuidadores y no cuidadores

ABSTRACT Objective: to identify the association between the characteristics of the support network and cognitive performance of older caregivers and compare characteristics between caregivers and non-caregivers. Methods: we evaluated 85 older caregivers and 84 older non-caregivers registered with primary care units regarding sociodemographic characteristics, cognition, and social support. Multiple linear regression analysis was performed. Results: among non-caregivers, significant associations were found between a better cognitive performance and receiving emotional/affectionate support; each one-point increase in the emotional support score and affectionate support score was related to a 0.43-point and 0.39-point increase in cognitive assessment, respectively. Among older caregivers, each one-point increase in the emotional support score was related to a 0.55-point increase in cognitive assessment. Conclusion: strengthening the support networks of older caregivers and encouraging satisfactory exchanges of social support can assist in improving cognitive performance, which can have a positive impact on caregivers' health.

RESUMO Objetivo: identificar a associação entre as características da rede de apoio e o desempenho cognitivo de cuidadores idosos e comparar características entre cuidadores e não cuidadores. Método: foram avaliados 85 idosos cuidadores e 84 idosos não cuidadores cadastrados em unidades da atenção primária de saúde quanto às características sociodemográficas, cognitivas e suporte social. Foi realizada análise de regressão linear múltipla. Resultados: entre os não cuidadores, foram encontradas associações significativas entre melhor desempenho cognitivo e receber apoio emocional/afetivo; cada aumento de um ponto no escore de apoio emocional e escore de suporte afetivo foi relacionado a um aumento de 0,43 pontos e 0,39 pontos na avaliação cognitiva, respectivamente. Entre os cuidadores mais velhos, cada aumento de um ponto na pontuação do apoio emocional teve relação com um aumento de 0,55 ponto na avaliação cognitiva. Conclusão: o fortalecimento das redes de apoio de cuidadores mais velhos e o incentivo a trocas satisfatórias de apoio social podem auxiliar na melhoria do desempenho cognitivo, o que pode impactar positivamente na saúde dos cuidadores.

RESUMEN Objetivo: identificar la asociación entre las características de la red de apoyo y el desempeño cognitivo de los cuidadores mayores y comparar características entre cuidadores y no cuidadores. Métodos: se evaluaron 85 cuidadores mayores y 84 no cuidadores mayores registrados en unidades de atención primaria en cuanto a características sociodemográficas, cognitivas y de apoyo social. Se realizó un análisis de regresión lineal múltiple. Resultados: entre los no cuidadores, se encontraron asociaciones significativas entre un mejor desempeño cognitivo y recibir apoyo emocional/afectivo; cada aumento de un punto en la puntuación de apoyo emocional y la puntuación de apoyo afectivo se relacionó con un aumento de 0,43 puntos y 0,39 puntos en la evaluación cognitiva, respectivamente. Entre los cuidadores mayores, cada aumento de un punto en la puntuación de apoyo emocional se relacionó con un aumento de 0,55 puntos en la evaluación cognitiva. Conclusión: el fortalecimiento de las redes de apoyo para los cuidadores mayores y el fomento de intercambios satisfactorios de apoyo social puede ayudar a mejorar el rendimiento cognitivo, lo que puede tener un impacto positivo en la salud de los cuidadores.

Comparison of cognitive performance and aspects of the care context in elderly caregivers in Brazil: A follow-up study.

Cognitive health is important for the quality of life and well-being of elderly caregivers. Cognitive impairments can negatively affect the ability to care for oneself and others. OBJECTIVE: To compare cognitive performance and aspects of the care context in elderly caregivers of older adults in a three-year follow-up investigation. METHODS: A longitudinal study was conducted of 61 elderly caregivers treated in primary care in a city in the interior of the state of São Paulo with data collected in 2014 and 2017. Sociodemographic characteristics, the care context, cognition, performance for activities of daily living, burden and depressive symptoms were collected in individual interviews. Data analysis was performed to compare categorical and continuous variables. RESULTS: Significant increases were found between baseline and follow-up for the language domain score of the cognitive evaluation (p=0.024), receipt of material support (p=0.020), time providing care (p=0.045) and dependence of elderly care recipient for basic activities of daily living (p=0.042). CONCLUSION: Elderly caregivers performed better on the domain of language, received more material/financial support, spent more time on care and reported greater dependence of the elderly care recipient.

A saúde cognitiva é importante para a qualidade de vida e bem-estar dos cuidadores idosos. O comprometimento cognitivo pode afetar negativamente a capacidade de cuidar de si e dos outros. OBJETIVO: Comparar o desempenho cognitivo e os aspectos do contexto do cuidado em idosos cuidadores de idosos em uma de acompanhamento de três anos. MÉTODOS: Trata-se de um estudo longitudinal com medidas em 2014 e 2017, realizado com 61 cuidadores idosos cadastrados na atenção primária de um município do interior do Estado de São Paulo. Características sociodemográficas, contexto do cuidado, cognição, desempenho nas atividades da vida diária, sobrecarga e sintomas depressivos foram coletados em entrevistas individuais. A análise dos dados foi realizada para comparar variáveis categóricas e contínuas. RESULTADOS: Foram encontrados aumentos significativos entre a linha de base e o acompanhamento do escore no domínio da linguagem da avaliação cognitiva (p=0,024), receber ajuda material (p=0,020), tempo de cuidado (p=0,045) e dependência do idoso em relação às atividades básicas da vida diária (p=0,042). CONCLUSÃO: Os cuidadores de idosos tiveram melhor desempenho no campo da linguagem, passaram a receber mais apoio material / financeiro, experimentaram aumentos no tempo gasto no cuidado e na dependência do idoso.

Meta-Analysis of Sensorimotor Gating Deficits in Patients With Schizophrenia Evaluated by Prepulse Inhibition Test.

Prepulse inhibition (PPI) of startle is an operational measure of sensorimotor gating that is often impaired in patients with schizophrenia. Despite the large number of studies, there is considerable variation in PPI outcomes reported. We conducted a systematic review and meta-analysis investigating PPI impairment in patients with schizophrenia compared with healthy control subjects, and examined possible explanations for the variation in results between studies. Major databases were screened for observational studies comparing healthy subjects and patients with schizophrenia for the prepulse and pulse intervals of 60 and 120 ms as primary outcomes, ie, PPI-60 and PPI-120. Standardized mean difference (SMD) and 95% confidence intervals (CI) were extracted and pooled using random effects models. We then estimated the mean effect size of these measures with random effects meta-analyses and evaluated potential PPI heterogeneity moderators, using sensitivity analysis and meta-regressions. Sixty-seven primary studies were identified, with 3685 healthy and 4290 patients with schizophrenia. The schizophrenia group showed reduction in sensorimotor gating for both PPI-60 (SMD = -0.50, 95% CI = [-0.61, -0.39]) and PPI-120 (SMD = -0.44, 95% CI = [-0.54, -0.33]). The sensitivity and meta-regression analysis showed that sample size, gender proportion, imbalance for gender, source of control group, and study continent were sources of heterogeneity (P < .05) for both PPI-60 and PPI-120 outcomes. Our findings confirm a global sensorimotor gating deficit in schizophrenia patients, with overall moderate effect size for PPI-60 and PPI-120. Methodological consistency should decrease the high level of heterogeneity of PPI results between studies.