National Cross-Sectional Epidemiological Analysis of the Impact of Pandemic COVID-19 on Vascular Procedures in Public Health System: 521,069 Procedures Over 4 Years.

BACKGROUND: During the COVID-19 pandemic, there was a dramatic increase in healthcare demand. Resources were redirected to care patients with COVID-19. Therefore, surgical treatments were affected, including those of vascular diseases. There are no studies evaluating the whole impact of the COVID-19 pandemic, considering all types of vascular procedures, both elective and urgent, in a large country. The aim of the present study was to analyze the impact on all types of vascular procedures performed in Brazilian public hospitals during the COVID-19 pandemic. METHODS: Cross-sectional population-based analysis of publicly available data referring to vascular procedures. Surgeries 2 years before the pandemic onset (2018-2019) and 2 years during pandemic (2020-2021) were included. RESULTS: We observed a total of 521,069 procedures. Decrease was observed in elective abdominal aortic aneurysm repairs both open surgery (P = 0.001) and endovascular surgery (P < 0.001), emergency open abdominal repairs (P = 0.005), elective thoracic aortic aneurysm repairs (P = 0.007), elective open peripheral aneurysm repairs (P = 0.038), carotid endarterectomies (P < 0.001) and angioplasties (P = 0.001), open revascularizations for peripheral arterial disease (P < 0.001), surgical treatment of chronic venous disease (P < 0.001) and sympathectomies for hyperhidrosis (P < 0.001). However, there was an increase of lower limb amputations (P = 0.027) and vena cava filter placements (P = 0.005). There was a reduction of almost US$17 million in financial investments. CONCLUSIONS: The reorganization of health systems led to a significant reduction in vascular procedures and decrease in financial investments. On the other hand, there was a significant increase in the number of lower limb amputations and vena cava filter placements.

Microstates in complex and dynamical environments: Unraveling situational awareness in critical helicopter landing maneuvers.

Understanding decision-making in complex and dynamic environments is relevant for designing strategies targeting safety improvements and error rate reductions. However, studies evaluating brain dynamics in realistic situations are scarce in the literature. Given the evidence that specific microstates may be associated with perception and attention, in this work we explored for the first time the application of the microstate model in an ecological, dynamic and complex scenario. More specifically, we evaluated elite helicopter pilots during engine-failure missions in the vicinity of the so called "dead man's curve," which establishes the operational limits for a safe landing after the execution of a recovery maneuver (autorotation). Pilots from the Brazilian Air Force flew a AS-350 helicopter in a certified aerodrome and physiological sensor data were synchronized with the aircraft's flight test instrumentation. We assessed these neural correlates during maneuver execution, by comparing their modulations and source reconstructed activity with baseline epochs before and after flights. We show that the topographies of our microstate templates with 4, 5, and 6 classes resemble the literature, and that a distinct modulation characterizes decision-making intervals. Moreover, the source reconstruction result points to a differential activity in the medial prefrontal cortex, which is associated to emotional regulation circuits in the brain. Our results suggest that microstates are promising neural correlates to evaluate realistic situations, even in a challenging and intrinsically noisy environment. Furthermore, it strengthens their usage and expands their application for studying cognition under more realistic conditions.

Decreased centrality of subcortical regions during the transition to adolescence: a functional connectivity study.

Investigations of brain maturation processes are a key step to understand the cognitive and emotional changes of adolescence. Although structural imaging findings have delineated clear brain developmental trajectories for typically developing individuals, less is known about the functional changes of this sensitive development period. Developmental changes, such as abstract thought, complex reasoning, and emotional and inhibitory control, have been associated with more prominent cortical control. The aim of this study is to assess brain networks connectivity changes in a large sample of 7- to 15-year-old subjects, testing the hypothesis that cortical regions will present an increasing relevance in commanding the global network. Functional magnetic resonance imaging (fMRI) data were collected in a sample of 447 typically developing children from a Brazilian community sample who were submitted to a resting state acquisition protocol. The fMRI data were used to build a functional weighted graph from which eigenvector centrality (EVC) was extracted. For each brain region (a node of the graph), the age-dependent effect on EVC was statistically tested and the developmental trajectories were estimated using polynomial functions. Our findings show that angular gyrus become more central during this maturation period, while the caudate; cerebellar tonsils, pyramis, thalamus; fusiform, parahippocampal and inferior semilunar lobe become less central. In conclusion, we report a novel finding of an increasing centrality of the angular gyrus during the transition to adolescence, with a decreasing centrality of many subcortical and cerebellar regions.

Effect of transcranial direct current stimulation in the initial weeks post-stroke: a pilot randomized study.

OBJECTIVE: This study aimed at assessing the alterations in upper limb motor impairment and connectivity between motor areas following the post-stroke delivery of cathodal transcranial direct current stimulation sessions. METHODS: Modifications in the Fugl-Meyer Assessment scores, connectivity between the primary motor cortex of the unaffected and affected hemispheres, and between the primary motor and premotor cortices of the unaffected hemisphere were compared prior to and following six sessions of cathodal transcranial direct current stimulation application in 13 patients (active = 6; sham = 7); this modality targets the primary motor cortex of the unaffected hemisphere early after a stroke. RESULTS: Clinically relevant distinctions in Fugl-Meyer Assessment scores (≥9 points) were observed more frequently in the Sham Group than in the Active Group. Between-group differences in the alterations in Fugl-Meyer Assessment scores were not statistically significant (Mann-Whitney test, p=0.133). ROI-to-ROI correlations between the primary motor cortices of the affected and unaffected hemispheres post-therapeutically increased in 5/6 and 2/7 participants in the Active and Sham Groups, respectively. Between-group differences in modifications in connectivity between the aforementioned areas were not statistically significant. Motor performance enhancements were more frequent in the Sham Group compared to the Active Group. CONCLUSION: The results of this hypothesis-generating investigation suggest that heightened connectivity may not translate into early clinical benefits following a stroke and will be crucial in designing larger cohort studies to explore mechanisms underlying the impacts of this intervention. ClinicalTrials.gov Identifier: NCT02455427.

Mesencephalic Locomotor Region and Presynaptic Inhibition during Anticipatory Postural Adjustments in People with Parkinson's Disease.

Individuals with Parkinson's disease (PD) and freezing of gait (FOG) have a loss of presynaptic inhibition (PSI) during anticipatory postural adjustments (APAs) for step initiation. The mesencephalic locomotor region (MLR) has connections to the reticulospinal tract that mediates inhibitory interneurons responsible for modulating PSI and APAs. Here, we hypothesized that MLR activity during step initiation would explain the loss of PSI during APAs for step initiation in FOG (freezers). Freezers (n = 34) were assessed in the ON-medication state. We assessed the beta of blood oxygenation level-dependent signal change of areas known to initiate and pace gait (e.g., MLR) during a functional magnetic resonance imaging protocol of an APA task. In addition, we assessed the PSI of the soleus muscle during APA for step initiation, and clinical (e.g., disease duration) and behavioral (e.g., FOG severity and APA amplitude for step initiation) variables. A linear multiple regression model showed that MLR activity (R2 = 0.32, p = 0.0006) and APA amplitude (R2 = 0.13, p = 0.0097) explained together 45% of the loss of PSI during step initiation in freezers. Decreased MLR activity during a simulated APA task is related to a higher loss of PSI during APA for step initiation. Deficits in central and spinal inhibitions during APA may be related to FOG pathophysiology.

Advances in diffuse glial tumors diagnosis.

In recent decades, there have been significant advances in the diagnosis of diffuse gliomas, driven by the integration of novel technologies. These advancements have deepened our understanding of tumor oncogenesis, enabling a more refined stratification of the biological behavior of these neoplasms. This progress culminated in the fifth edition of the WHO classification of central nervous system (CNS) tumors in 2021. This comprehensive review article aims to elucidate these advances within a multidisciplinary framework, contextualized within the backdrop of the new classification. This article will explore morphologic pathology and molecular/genetics techniques (immunohistochemistry, genetic sequencing, and methylation profiling), which are pivotal in diagnosis, besides the correlation of structural neuroimaging radiophenotypes to pathology and genetics. It briefly reviews the usefulness of tractography and functional neuroimaging in surgical planning. Additionally, the article addresses the value of other functional imaging techniques such as perfusion MRI, spectroscopy, and nuclear medicine in distinguishing tumor progression from treatment-related changes. Furthermore, it discusses the advantages of evolving diagnostic techniques in classifying these tumors, as well as their limitations in terms of availability and utilization. Moreover, the expanding domains of data processing, artificial intelligence, radiomics, and radiogenomics hold great promise and may soon exert a substantial influence on glioma diagnosis. These innovative technologies have the potential to revolutionize our approach to these tumors. Ultimately, this review underscores the fundamental importance of multidisciplinary collaboration in employing recent diagnostic advancements, thereby hoping to translate them into improved quality of life and extended survival for glioma patients.

Nas últimas décadas, houve avanços significativos no diagnóstico de gliomas difusos, impulsionados pela integração de novas tecnologias. Esses avanços aprofundaram nossa compreensão da oncogênese tumoral, permitindo uma estratificação mais refinada do comportamento biológico dessas neoplasias. Esse progresso culminou na quinta edição da classificação da OMS de tumores do sistema nervoso central (SNC) em 2021. Esta revisão abrangente tem como objetivo elucidar esses avanços de forma multidisciplinar, no contexto da nova classificação. Este artigo irá explorar a patologia morfológica e as técnicas moleculares/genéticas (imuno-histoquímica, sequenciamento genético e perfil de metilação), que são fundamentais no diagnóstico, além da correlação dos radiofenótipos da neuroimagem estrutural com a patologia e a genética. Aborda sucintamente a utilidade da tractografia e da neuroimagem funcional no planejamento cirúrgico. Destacaremos o valor de outras técnicas de imagem funcional, como ressonância magnética de perfusão, espectroscopia e medicina nuclear, na distinção entre a progressão do tumor e as alterações relacionadas ao tratamento. Discutiremos as vantagens das diferentes técnicas de diagnóstico na classificação desses tumores, bem como suas limitações em termos de disponibilidade e utilização. Além disso, os crescentes avanços no processamento de dados, inteligência artificial, radiômica e radiogenômica têm grande potencial e podem em breve exercer uma influência substancial no diagnóstico de gliomas. Essas tecnologias inovadoras têm o potencial de revolucionar nossa abordagem a esses tumores. Em última análise, esta revisão destaca a importância fundamental da colaboração multidisciplinar na utilização dos recentes avanços diagnósticos, com a esperança de traduzi-los em uma melhor qualidade de vida e uma maior sobrevida.

Artificial intelligence and Big Data in neurology.

Recent advances in technology have allowed us access to a multitude of datasets pertaining to various dimensions in neurology. Together with the enormous opportunities, we also face challenges related to data quality, ethics and intrinsic difficulties related to the application of data science in healthcare. In this article we will describe the main advances in the field of artificial intelligence and Big Data applied to neurology with a focus on neurosciences based on medical images. Real-World Data (RWD) and analytics related to large volumes of information will be described as well as some of the most relevant scientific initiatives at the time of this writing.

Epidemiological analysis of 556 procedures of open thoracoabdominal aortic aneurysm repair in the Public Health System in the largest Brazilian city.

OBJECTIVE: Despite the development of endovascular procedures, open repair remains the gold standard for the treatment of aortic thoracoabdominal aneurysms and some type B dissections, with well-established good outcomes and long-term durability at high-volume centers. The present study described and analyzed public data from patients treated in the public system in a 12-year interval, in a city where more than 5 million inhabitants depend on the Public Health System. METHODS: Public data from procedures performed between 2008 and 2019 were extracted using web scraping techniques. The variables available in the database include sex, age, elective or emergency hospital admission, number of surgeries, in-hospital mortality, length of stay, and information on reimbursement values. RESULTS: A total of 556 procedures were analyzed. Of these, 60.79% patients were men, and 41.18% were 65 years of age or older. Approximately 60% had a residential address registered in the municipality. Of all surgeries, 65.83% were elective cases. There were 178 in-hospital deaths (mortality of 32%). In the elective context, there were 98 deaths 26.78% versus 80 deaths (42.10%) in the emergency context (p=0.174). Mortality was lower in the hospitals that performed more surgeries. A total of USD 3,038,753.92 was paid, an average of USD 5,406.95 for elective surgery and USD 5,074.76 for emergency surgery (p=0.536). CONCLUSION: Mortality was no different between groups, and hospitals with higher volume presented more favorable outcomes. Specialized referral centers should be considered by health policy makers.

Population-based analysis of the epidemiology of the surgical correction of hyperhidrosis in 1,216 patients over 11 years: a cross-sectional study.

BACKGROUND: Endoscopic thoracic sympathectomy is the definitive surgical treatment for hyperhidrosis and a nationwide study has suggested that cultural and socioeconomic factors play a role in the numbers of operations performed. Thus, there is a need to evaluate local data in order to understand the local epidemiology and trends in hyperhidrosis treatment. OBJECTIVE: To study the epidemiology of sympathectomy for treating hyperhidrosis in São Paulo, the largest city in Brazil. DESIGN AND SETTING: Population-based retrospective cross-sectional study. METHODS: Data on sympathectomies for treating hyperhidrosis between 2008 and 2018 were assessed from the database of the Municipal Health Department of São Paulo, Brazil. RESULTS: 65.29% of the patients were female, 66.2% were aged between 20 and 39 years and 37.59% had registered with addresses outside São Paulo. 1,216 procedures were performed in the city of São Paulo from 2008 to 2018, and 78.45% of them were in only two public hospitals. The number of procedures significantly declined over the years (P = 0.001). 71.63% of the procedures were associated with 2-3 days of hospital stay, only 78 intensive care unit days were billed and we did not observe any intra-hospital death. CONCLUSION: The profile of patients operated on in São Paulo (young women) is similar to that described in other populations. Sympathectomy is a very safe procedure, with no mortality in our series. There was a decreasing trend in the number of surgeries over the years.

Varicose Vein Stripping in 66,577 patients in 11 years in public hospitals in São Paulo.

OBJECTIVES: The aim of this study was to evaluate the epidemiology of varicose vein stripping in Brazil's largest city, São Paulo. METHODS: Open and anonymous data regarding varicose vein surgeries between 2008 and 2018 were evaluated from the TabNet platform of the Municipal Health Secretary of São Paulo, Brazil. RESULTS: Most patients were female and adults. A total of 66,577 varicose vein surgeries were performed in public hospitals and outpatient clinics in São Paulo, with a statistically significant increase for both unilateral (p=0.003) and bilateral (p<0.001) procedures. Since 2016, unilateral procedures have been performed more frequently than bilateral procedures. Most procedures were associated with same-day (54.8%) or next-day (32%) discharge. The in-hospital mortality rate was 0.0045%. The total amount reimbursed was $20,693,437.94, corresponding to a mean value of $310.82 per procedure. CONCLUSION: Surgeries to treat chronic vein disease totaled 66,577 in 11 years, demanding $20,693,437.94 from the public health system. The majority of treated patients were female, over 40 years of age, and local residents. Procedure rates have increased over the years. The in-hospital mortality rate was very low (0.0045%).

Comparative analysis of somatostatin analog uptake between successfully irradiated and non-irradiated meningiomas.

OBJECTIVE: To evaluate whether there is a significant difference in somatostatin analog uptake in meningiomas treated or not with radiation therapy. METHODS: A cross-sectional study was performed comparing measurements of somatostatin analog (68Ga-DOTATATE) uptake in two independent groups of ten patients each - one consisting of patients with meningiomas previously treated with radiation therapy and another comprising patients who had never been submitted to radiation therapy. All patients underwent PET/CT and MRI scans in an interval shorter than 24 hours between exams. RESULTS: A total of 32 meningiomas from 20 patients were analyzed, all presenting significant somatostatin analog uptake in different degrees. The uptake levels of somatostatin analog were similar between the lesions treated or not with radiation therapy, and the mean values of SUVmax were 27.62 and 24.82, respectively (p=0.722). For SUVmean, the values were 16.20 and 14.82, respectively (p=0.822). CONCLUSION: Comparative analysis between the groups showed no significant differences in degree of somatostatin analog uptake in successfully irradiated and non-irradiated meningiomas.

Cerebral Responses to Stationary Emotional Stimuli Measured by fMRI in Women with Persistent Postural-Perceptual Dizziness.

Introduction Persistent postural-perceptual dizziness (PPPD) is a functional vestibular disorder characterized by chronic dizziness, unsteadiness, and hypersensitivity to motion. Preexisting anxiety disorders and neurotic personality traits confer vulnerability to PPPD. High anxiety during acute vertigo or dizziness incites it. A functional magnetic resonance imaging (fMRI) study of chronic subjective dizziness found unexpectedly hypoactive responses to vestibular stimulation in cortical regions that integrate threat assessment and spatial perception. Objective This fMRI study used non-moving, but emotionally charged visual stimuli to investigate the brain's activity of PPPD patients and control subjects. Methods The participants included 16 women with PPPD and 16 age-matched women who recovered completely from acute episodes of vertigo or dizziness capable of triggering PPPD. Brain responses to positive, neutral, and negative figures from the International Affective Picture System were measured with fMRI and compared between the groups. Dizziness handicap, anxiety, and depression were assessed with validated questionnaires. Results Between group analyses: Participants with PPPD showed reduced activity in anterior cingulate cortex and increased activity in left angular gyrus in response to negative versus positive stimuli, which was not observed in recovered individuals. Within group analyses: Participants with PPPD had increased activity in visuospatial areas (parahippocampal gyrus, intraparietal sulcus) in negative versus positive and negative versus neutral contrasts, whereas recovered individuals had increased activity in anxiety regions (amygdala, orbitofrontal cortex). Conclusion Patients with PPPD may be more attuned to spatial elements than to the content of emotionally charged visual stimuli.

Epidemiological Analysis of 5,595 Procedures of Endovascular Correction of Isolated Descending Thoracic Aortic Disease Over 12 Years in the Public Health System in Brazil.

OBJECTIVES: In Brazil, descending thoracic aorta disease, including aneurysms and dissections, is managed preferentially by endovascular treatment, owing to its feasibility and good results. In this study, we analyzed endovascular treatment of isolated descending thoracic aortic disease cases in the Brazilian public health system over a 12-year period. METHODS: Public data from procedures performed from 2008 to 2019 were extracted using web scraping techniques to assess procedure type frequency (elective or urgency), mortality, and governmental costs. RESULTS: A total of 5,595 procedures were analyzed, the vast majority of which were urgent procedures (61.82% vs. 38.18%). In-hospital mortality was lower for elective than for urgent surgeries (4.96 vs.10.32% p=0.008). An average of R$16,845.86 and R$20,012.04 was paid per elective and emergency procedure, respectively, with no statistical difference (p=0.095). CONCLUSION: Elective procedures were associated with lower mortality than urgent procedures. There was no statistically significant difference between elective and urgent procedures regarding costs.

Endovascular correction of isolated descending thoracic aortic disease: a descriptive analysis of 1,344 procedures over 10 years in the public health system of São Paulo.

OBJECTIVES: In Brazil, descending thoracic aorta disease (TAD), including aneurysms and dissection, are preferentially managed by endovascular treatment (TEVAR) due to the feasibility and good results of this technique. In this study, we analyzed endovascular treatment of isolated TAD (ITAD) in the public health system over a 10-year period in São Paulo, a municipality in Brazil in which more than 5 million inhabitants depend on the governmental health system. METHODS: Public data from procedures performed between 2008 and 2019 were extracted using web scraping techniques. The following types of data were analyzed: demographic data, operative technique, elective or urgent status, number of surgeries, in-hospital mortality, length of hospital stay, mean length of stay in the intensive care unit, and reimbursement values paid by the government. Trauma cases and congenital diseases were excluded. RESULTS: A total of 1,344 procedures were analyzed; most patients were male and aged ≥65 years. Most individuals had a residential address registered in the city. Approximately one-third of all surgeries were urgent cases. There were 128 in-hospital deaths (9.52%), and in-hospital mortality was lower for elective than for urgent surgeries (7.29% vs. 14.31%, p=0.031). A total of R$ 24.766.008,61 was paid; an average of R$ 17.222,98 per elective procedure and R$ 18.558,68 per urgent procedure. Urgent procedures were significantly more expensive than elective surgeries (p=0.029). CONCLUSION: Over a 10-year period, the total cost of ITAD interventions was R$ 24.766.008,61, which was paid from the governmental system. Elective procedures were associated with lower mortality and lower investment from the health system when compared to those performed in an urgent scenario.

Quantitative assessment of pilot-endured workloads during helicopter flying emergencies: an analysis of physiological parameters during an autorotation.

The procedures to be performed after sudden engine failure of a single-engine helicopter impose high workload on pilots. The maneuver to regain aircraft control and safe landing is called autorotation. The safety limits to conduct this maneuver are based on the aircraft height versus speed diagram, which is also known as "Dead Man's Curve". Flight-test pilots often use subjective methods to assess the difficulty to conduct maneuvers in the vicinity of this curve. We carried out an extensive flight test campaign to verify the feasibility of establishing quantitative physiological parameters to better assess the workload endured by pilots undergoing those piloting conditions. Eleven pilots were fully instrumented with sensors and had their physiological reactions collected during autorotation maneuvers. Our analyses suggested that physiological measurements (heart rate and electrodermal activity) can be successfully recorded and useful to capture the most effort-demanding effects during the maneuvers. Additionally, the helicopter's flight controls displacements were also recorded, as well as the pilots' subjective responses evaluated by the Handling Qualities Rate scale. Our results revealed that the degree of cognitive workload was associated with the helicopter's flight profile concerning the Height-Speed diagram and that the strain intensity showed a correlation with measurable physiological responses. Recording flight controls displacement and quantifying the pilot's subjective responses show themselves as natural effective candidates to evaluate the intensity of cognitive workload in such maneuvers.

Chronic low back pain and sick-leave: a functional magnetic resonance study.

BACKGROUND: Chronic low back pain (CLBP) represents a problem in the occupational environment, often associated with disability, sick-leave demands, loss of productivity, anxiety, depression and high socioeconomic cost. The emergence of functional neuroimaging allowed new insights into brain structure and physiology in normality and chronic pain. While occupational related aspects are recognized as important risk factors for chronicity there have not been thus far evaluated by fMRI experiments. The overall objective of this study is to compare the neuronal correlates between groups of individuals CLBP with or without sick-leave demands. METHODS: A total of 74 individuals were divided into three groups: chronic low back pain with sick-leave demands [CLBP_L]; chronic low back pain without sick-leave demands [CLBP_NL]; individuals without pain or sick-leave demands [Control]. Functional magnetic resonance imaging was used to assess brain function during moderate acute pain stimulation task (thumb controlled pressure). RESULTS: After acute painful stimulation, a higher brain response was found in the anterior cingulate and superior and medium frontal gyrus was observed in CLBP_NL vs. CLBP_L (p <  0,001) and increased brain response in the frontal pole and paracingulate region in control vs. CLBP_L (p <  0.001) during acute pain stimulation. CONCLUSION: The modulation of acute pain participates in the mechanism propagating chronic pain perception. The lower activation in the superior frontal gyrus observed in the CLBP_L group compared to CLBP_NL, reinforces the idea of an already existing activation in this area.

COVID-19 information exposure in digital media and implications for employees in the health care sector: findings from an online survey.

OBJECTIVE: To estimate coronavirus disease 2019-related information consumption and related implications for health care professionals (medical and nonmedical personnel) during the pandemic. METHODS: A cross-sectional on-line survey was distributed to employees of a major health care institution located in São Paulo, Brazil between April 3 and April 10, 2020. Data were analyzed using descriptive statistics. RESULTS: The sample comprised 2,646 respondents. Most participants (44.4%) reported excessive or almost excessive access to information about the novel coronavirus and 67.6% reported having increased their average time spent on social media. When asked how frequently they consider it was easy to determine the reliability of information, "sometimes" corresponded to 43.2% of the answers in contrast to 14.6% responding "always". Answers related to potential signs of information overload associated with the pandemic indicated that 31% of respondents felt stressed by the amount of information they had to keep up with almost every day or always. Overall, 80.0% of respondents reported having experienced at least one of the following symptoms: headache, eye twitching, restlessness or sleeping difficulty. The frequency of symptoms was higher among participants with a more negative information processing style regarding when dealing with large volumes of information relative to those with a positive information processing style. Likewise, symptoms were more frequently reported by participants who had increased their social media access relative to those reporting reduced access during the pandemic. CONCLUSION: Our survey provides a description of how health professionals consume COVID-19 related information during the pandemic, and suggests that excessive information exposure and high processing demands may impose psychological distress and affect mental health.

Combining neuropsychological tests to improve the assessment of arithmetic difficulties in children with ADHD.

OBJECTIVE: To compare the ways of evaluating arithmetic skills in Brazilian children with ADHD by combining three validated neuropsychological tests and determining whether they are sensitive to the methylphenidate treatment. METHODS: Forty-two children (9‒12 years old) participated in the present study: 20 were children with ADHD (DSM-IV) and 22 were age-matched controls. A classification criterion was used for each test separately and one, for their combination to detect the presence of arithmetic difficulties at two time points: baseline (time 1); and when children with ADHD were taking 0.3‒0.5 mg/kg of methylphenidate (time 2). The study also assessed children's subtraction performance, combining parts of these tests. RESULTS: Separately, the tests were only sensitive to differences between groups without medication. However, by combining the three neuropsychological tests, we observed a difference and detected a reduction in arithmetic difficulties associated with the methylphenidate treatment. The same effects were found in subtraction exercises, which require a borrowing procedure. CONCLUSIONS: The present study detected arithmetic difficulties in Brazilian children with ADHD and the effects of methylphenidate. Given this improvement in sensitivity, combining tests could be a promising alternative when working with limited samples.

GeoSES: A socioeconomic index for health and social research in Brazil.

The individual's socioeconomic conditions are the most relevant to predict the quality of someone's health. However, such information is not usually found in medical records, making studies in the area difficult. Therefore, it is common to use composite indices that characterize a region socioeconomically, such as the Human Development Index (HDI). The main advantage of the HDI is its understanding and adoption on a global scale. However, its applicability is limited for health studies since its longevity dimension presents mathematical redundancy in regression models. Here we introduce the GeoSES, a composite index that summarizes the main dimensions of the Brazilian socioeconomic context for research purposes. We created the index from the 2010 Brazilian Census, whose variables selection was guided by theoretical references for health studies. The proposed index incorporates seven socioeconomic dimensions: education, mobility, poverty, wealth, income, segregation, and deprivation of resources and services. We developed the GeoSES using Principal Component Analysis and evaluated its construct, content, and applicability. GeoSES is defined at three scales: national (GeoSES-BR), Federative Unit (GeoSES-FU), and intra-municipal (GeoSES-IM). GeoSES-BR dimensions showed a good association with HDI-M (correlation above 0.85). The model with the poverty dimension best explained the relative risk of avoidable cause mortality in Brazil. In the intra-municipal scale, the model with GeoSES-IM was the one that best explained the relative risk of mortality from circulatory system diseases. By applying spatial regressions, we demonstrated that GeoSES shows significant explanatory potential in the studied scales, being a compelling complement for future researches in public health.

Evaluating SVM and MLDA in the extraction of discriminant regions for mental state prediction.

Pattern recognition methods have been successfully applied in several functional neuroimaging studies. These methods can be used to infer cognitive states, so-called brain decoding. Using such approaches, it is possible to predict the mental state of a subject or a stimulus class by analyzing the spatial distribution of neural responses. In addition it is possible to identify the regions of the brain containing the information that underlies the classification. The Support Vector Machine (SVM) is one of the most popular methods used to carry out this type of analysis. The aim of the current study is the evaluation of SVM and Maximum uncertainty Linear Discrimination Analysis (MLDA) in extracting the voxels containing discriminative information for the prediction of mental states. The comparison has been carried out using fMRI data from 41 healthy control subjects who participated in two experiments, one involving visual-auditory stimulation and the other based on bi-manual fingertapping sequences. The results suggest that MLDA uses significantly more voxels containing discriminative information (related to different experimental conditions) to classify the data. On the other hand, SVM is more parsimonious and uses less voxels to achieve similar classification accuracies. In conclusion, MLDA is mostly focused on extracting all discriminative information available, while SVM extracts the information which is sufficient for classification.