Chagas disease is endemic in a region from Mexico to Argentina. In Brazil, chronic cases predominate with approximately two million infected individuals. Central nervous system involvement, triggering stroke in chagasic patients with myocardiopathy, has occurred in high incidence, usually due to cardiac emboli originating from apical aneurysm, mural thrombi and atrial fibrillation. However, the occurrence of stroke can also occur in individuals with Chagas disease (CD) even without a history of cardiopathy. This study aims to evaluate cerebral hemodynamics in individuals with serological diagnosis for CD through Transcranial Doppler(TCD) in the various chronic forms of the disease. A cross-sectional study was carried out in twelve settlements in the rural area of municipality of Umbaúba, State of Sergipe, where 617 individuals answered a questionnaire on socio-epidemiological conditions and collected blood sample for the performance of serology for Trypanosoma cruzi. There was a prevalence of 12.1% (75/617) of seropositivity for CD, 64% had a primary school level and 33.3% were illiterate, 78.7% worked in agriculture and 92% had a family income of up to one minimal salary. Of these seropositive individuals, 71 underwent clinical examination and electrocardiogram, echocardiogram, chest X-ray, and contrast-enhanced radiography of the esophagus and colon to determine the clinical form of CD. For the TCD, 96 individuals participated, 59 seropositive for CD and 37 seronegative. These individuals had a mean age of 54 ± 11 years and female sex in 62.5%. Among the chronic clinical forms of CD, 22 individuals were in the indeterminate, 17 cardiac, 16 cardiodigestive and 4 digestive forms. The values of mean velocity of the middle cerebral artery (MVMCA) and pulsatility index did not change in the individuals examined. Correlating the mean velocity of the middle cerebral artery with the age and clinical forms of Chagas disease and control, it was observed that in the cardiac and indeterminate forms and control there was a reduction of the MVMCA with the increase of the age in a similar way. However, with the cardiodigestive and digestive forms, the opposite occurred, increasing MVMCA with increasing age. No signs of microemboli were evident. The present study did not show alteration of the cerebral hemodynamics among the clinical chronic forms and control, probably due to individuals with CD being in a controlled phase of the disease, not presenting during the research symptoms or cardiac signals. / A doença de Chagas é endêmica numa região que abrange desde o México até a Argentina. No Brasil, atualmente predominam os casos crônicos com aproximadamente dois milhões de indivíduos infectados. O acometimento do sistema nervosa central, desencadeando acidente vascular cerebral (AVC) nos indivíduos chagásicos com miocardiopatia tem ocorrido em alta incidência, geralmente em decorrência de êmbolos cardíacos originados de aneurisma apical, trombos murais e fibrilação atrial. Entretanto, a ocorrência de AVC também pode advir de indivíduos com doença de Chagas (DC) mesmo sem história de cardiopatia. Este estudo tem por objetivo avaliar a hemodinâmica cerebral nos indivíduos com diagnóstico sorológico para DC por meio do Doppler Transcraniano (DTC) nas diversas formas crônicas da doença. Foi realizado um estudo transversal em doze povoados da zona rural do município de Umbaúba, Estado de Sergipe, onde 617 indivíduos responderam a um questionário sobre as condições sócio epidemiológicas e coletado amostra de sangue para realização de sorologia para Tripanosoma cruzi. Houve uma prevalência de 12,1% (75/617) de soropositividade para DC, 64% apresentavam nível de escolaridade primária e 33,3% eram analfabetos, 78,7% trabalhavam na lavoura e 92% tinham renda familiar de até um salário mínimo. Desses indivíduos soropositivos, 71 foram submetidos ao exame clínico e realização de eletrocardiograma, ecocardiograma, radiografia de tórax e radiografia contrastada de esôfago e cólon para determinar a forma clínica da DC. Para a realização do DTC, participaram 96 indivíduos, 59 soropositivos para DC e 37 soronegativos. Esses indivíduos tiveram uma média de idade de 54± 11 anos e sexo feminino em 62.5%. Dentre as formas clínicas crônicas da DC, 22 indivíduos estavam na forma indeterminada, 17 cardíaca, 16 cardiodigestiva e 4 digestiva. Os valores da velocidade média da artéria cerebral média (VMACM) e do índice de pulsatilidade não apresentaram alteração nos indivíduos examinados. Correlacionando a velocidade média da artéria cerebral média com a idade e as formas clínicas da doença de Chagas e o controle, foi observado que nas formas cardíaca, indeterminada e controle houve redução da VMACM com o aumento da idade de maneira semelhante. Entretanto com as formas cardiodigestiva e digestiva ocorreu o contrário, elevação da VMACM com o aumento da idade. Não foram evidenciados sinais de microêmbolos. O presente estudo não demonstrou alteração da hemodinâmica cerebral entre as formas crônicas clínicas e o controle, provavelmente em decorrência dos indivíduos com DC estarem numa fase controlada da doença, não apresentando durante a pesquisa sintomas ou sinais cardíacos. / Aracaju

Background: Stroke is a leading cause of significant physical, cognitive, and psychiatric morbidity. One risk factor for stroke is paradoxical embolization through a patent foramen ovale (PFO). In cardiac clinical practice, power M-mode Transcranial Doppler (TCD) evaluation is the gold standard for diagnosis of PFO, or right-to-left cardiac shunt (RLS). Brain micro-embolization due to diagnostic bubble contrast echocardiography may cause neurological symptoms in patients with PFO. However, the neurocognitive effects of TCD have not been studied. Objective: The purpose of this study was to evaluate cognitive outcomes in patients who undergo routine diagnostic bubble contrast TCD. The aims of the study were (1) to determine if cognitive function declines pre- to post-TCD evaluation and, (2) to assess the relationship between cognitive function and severity of the RLS measured using the Spencer Grading System. Methods: One hundred and four participants referred to Sorensen Cardiovascular Group for diagnosis of RLS were evaluated for changes in cognitive functioning at three time points. A dual baseline (pre-test and baseline test) was administered to mitigate practice effects between the first and second administrations. All pre and post-TCD comparisons were analyzed using the baseline test and post-TCD test, controlling for the effects of practice, if present. Results: Practice effects were observed for the working memory task, with significant improvement in working memory scores occurring between the first (pre-test) and second (baseline) administrations. The main effect for shunt group (no shunt vs. moderate-to-severe shunt) and the shunt group by time interactions were not significant for processing speed, attention, or working memory, adjusting for practice effects, age, and education. Migraine did not predict group status for mood or shunt variables. Conclusion: Cardiac patients with both small and large RLS did not experience a decline in processing speed, attention, or working memory ability following TCD, suggesting that TCD-induced microemboli do not result in immediate cognitive deficits in these domains. These findings support the use of TCD for routine evaluation of PFO, even in patients with severe RLS, although findings are limited to young (30s), medically healthy, predominately Caucasian individuals assessed immediately following TCD. Results do not exclude the possibility of cognitive impairment at follow-up, on other cognitive tests, or in other cognitive domains.

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INTRODUÇÃO: Evidências relevantes acerca dos benefícios da hipotermia terapêutica provieram da utilização de técnicas de resfriamento sistêmico. Essas técnicas, no entanto, podem causar complicações graves que poderiam ser evitadas com métodos de hipotermia encefálica seletiva. O presente estudo objetiva: 1) verificar a viabilidade da hipotermia encefálica exclusiva através de um sistema de resfriamento nasofaríngeo concomitante ao de preservação da temperatura corpórea em suínos e 2) investigar os efeitos da hipotermia encefálica exclusiva nas variáveis fisiológicas sistêmicas e encefálicas. MÉTODOS: Dez suínos híbridos foram submetidos a resfriamento nasofaríngeo durante 60 minutos e subsequente reaquecimento espontâneo. Foram obtidos dados referentes a: pressão arterial média, débito cardíaco, temperatura encefálica, pressão parcial de oxigênio do tecido encefálico (PbtO2, do inglês, pressure of brain tissue O2), velocidade do fluxo sanguíneo nas artérias encefálicas, índice de resistência e índice de pulsatilidade. RESULTADOS: O resfriamento nasofaríngeo associou-se à um decréscimo gradual da temperatura encefálica, que foi mais marcante no hemisfério cerebral esquerdo (p < 0,01). Neste hemisfério, houve redução de 1,47 ± 0,86°C nos primeiros 5 minutos (p < 0,01), 2,45 ± 1,03°C aos 10 minutos e 4,45 ± 1,36°C após 1 hora (p < 0,01). A diferença entre as temperaturas cerebral sistêmica foi 4,57 ± 0,87°C (p < 0,01). As temperaturas centrais (retal, esofágica e da artéria pulmonar), assim como a hemodinâmica encefálica e sistêmica, mantiveram-se estáveis durante o procedimento. Houve diminuição significativa da PbtO2, concomitantemente ao decréscimo da temperatura encefálica. CONCLUSÕES: A indução de hipotermia encefálica exclusiva é possível através de resfriamento nasofaríngeo associado a medidas de preservação da temperatura sistêmica. O resfriamento encefálico exclusivo não influencia as funções hemodinâmicas sistêmicas e encefálicas, contudo reduz significativamente a PbtO2 / INTRODUCTION: Relevant evidences for the use of therapeutic hypothermia derive from studies using whole body cooling methods. These methods can lead to serious complications. To avoid such complications, selective brain cooling methods were developed. The objective of this study was: 1) to verify the feasibility of exclusive brain hypothermia by means of nasopharyngeal cooling along with measures of systemic temperature preservation in an experimental swine model, and 2) to investigate the influence of the exclusive brain cooling on cerebral and systemic hemodynamics as well as on cerebral oxygenation. METHODS: Ten hybrid swine underwent nasopharyngeal cooling for 60 minutes, followed by spontaneous rewarming. A number of physiological variables were monitored: arterial blood pressure, cardiac output, temperature in the right and left cerebral hemispheres, pressure of brain tissue O2, cerebral blood flow velocities, resistance index, and pulsatility index. RESULTS: Nasopharyngeal cooling was associated with decrease in brain temperature, which was more significant in the left cerebral hemisphere (p < 0,01). There was a reduction of 1.47 ± 0.86°C in the first 5 minutes (p < 0.01), 2.45 ± 1.03°C within 10 min, and 4.45 ± 1.36°C after 1 hour (p < 0.01). The brain-core gradient was 4.57 ± 0.87°C (p < 0,001). Rectal, esophageal, and pulmonary artery temperatures, as well as brain and systemic hemodynamics, remained stable during the procedure. PbtO2 values significantly decreased following the brain cooling. CONCLUSION: Achievement of exclusive brain hypothermia is feasible by means of nasopharyngeal cooling associated with measures of systemic temperature preservation. Selective brain cooling does not influence both systemic and cerebral hemodynamics, except PbtO2, which decreased significantly

INTRODUÇÃO: Evidências relevantes acerca dos benefícios da hipotermia terapêutica provieram da utilização de técnicas de resfriamento sistêmico. Essas técnicas, no entanto, podem causar complicações graves que poderiam ser evitadas com métodos de hipotermia encefálica seletiva. O presente estudo objetiva: 1) verificar a viabilidade da hipotermia encefálica exclusiva através de um sistema de resfriamento nasofaríngeo concomitante ao de preservação da temperatura corpórea em suínos e 2) investigar os efeitos da hipotermia encefálica exclusiva nas variáveis fisiológicas sistêmicas e encefálicas. MÉTODOS: Dez suínos híbridos foram submetidos a resfriamento nasofaríngeo durante 60 minutos e subsequente reaquecimento espontâneo. Foram obtidos dados referentes a: pressão arterial média, débito cardíaco, temperatura encefálica, pressão parcial de oxigênio do tecido encefálico (PbtO2, do inglês, pressure of brain tissue O2), velocidade do fluxo sanguíneo nas artérias encefálicas, índice de resistência e índice de pulsatilidade. RESULTADOS: O resfriamento nasofaríngeo associou-se à um decréscimo gradual da temperatura encefálica, que foi mais marcante no hemisfério cerebral esquerdo (p < 0,01). Neste hemisfério, houve redução de 1,47 ± 0,86°C nos primeiros 5 minutos (p < 0,01), 2,45 ± 1,03°C aos 10 minutos e 4,45 ± 1,36°C após 1 hora (p < 0,01). A diferença entre as temperaturas cerebral sistêmica foi 4,57 ± 0,87°C (p < 0,01). As temperaturas centrais (retal, esofágica e da artéria pulmonar), assim como a hemodinâmica encefálica e sistêmica, mantiveram-se estáveis durante o procedimento. Houve diminuição significativa da PbtO2, concomitantemente ao decréscimo da temperatura encefálica. CONCLUSÕES: A indução de hipotermia encefálica exclusiva é possível através de resfriamento nasofaríngeo associado a medidas de preservação da temperatura sistêmica. O resfriamento encefálico exclusivo não influencia as funções hemodinâmicas sistêmicas e encefálicas, contudo reduz significativamente a PbtO2 / INTRODUCTION: Relevant evidences for the use of therapeutic hypothermia derive from studies using whole body cooling methods. These methods can lead to serious complications. To avoid such complications, selective brain cooling methods were developed. The objective of this study was: 1) to verify the feasibility of exclusive brain hypothermia by means of nasopharyngeal cooling along with measures of systemic temperature preservation in an experimental swine model, and 2) to investigate the influence of the exclusive brain cooling on cerebral and systemic hemodynamics as well as on cerebral oxygenation. METHODS: Ten hybrid swine underwent nasopharyngeal cooling for 60 minutes, followed by spontaneous rewarming. A number of physiological variables were monitored: arterial blood pressure, cardiac output, temperature in the right and left cerebral hemispheres, pressure of brain tissue O2, cerebral blood flow velocities, resistance index, and pulsatility index. RESULTS: Nasopharyngeal cooling was associated with decrease in brain temperature, which was more significant in the left cerebral hemisphere (p < 0,01). There was a reduction of 1.47 ± 0.86°C in the first 5 minutes (p < 0.01), 2.45 ± 1.03°C within 10 min, and 4.45 ± 1.36°C after 1 hour (p < 0.01). The brain-core gradient was 4.57 ± 0.87°C (p < 0,001). Rectal, esophageal, and pulmonary artery temperatures, as well as brain and systemic hemodynamics, remained stable during the procedure. PbtO2 values significantly decreased following the brain cooling. CONCLUSION: Achievement of exclusive brain hypothermia is feasible by means of nasopharyngeal cooling associated with measures of systemic temperature preservation. Selective brain cooling does not influence both systemic and cerebral hemodynamics, except PbtO2, which decreased significantly

Atherosclerotic diseases including stroke are the leading causes of morbidity, mortality as well as disability in industrialized countries. Carotid endarterectomy was long considered the stan- dard approach for the treatment of atherosclerotic carotid disease, one of major causes of stroke. Over time, carotid artery stenting (CAS) has evolved as an alternative approach and is considered equivalent to surgical treatment in selected patients. Particularly in the last years, CAS has gained attention with the increasing knowledge regarding atherosclerotic plaque and cerebrovascular flow. In our study, we focused on patients undergoing CAS and evaluated structural and hemodynamic characteristics of atherosclerotic plaques together with relation to endovascular manipulation. The major part of the study includes transcranial doppler ultrasound evaluation which is able to detect flow in major cerebral arteries as well as to detect microembolizations of atherosclerotic particles during CAS. In eligible patients, we investigated the usefulness of cerebrovascular reserve (CVR) testing to predict severe hemodynamic changes in ipsilateral middle cerebral artery induced by temporary carotid occlusion during proximally protected CAS. CVR was tested by means of a breath-holding test and ophthalmic artery flow...

Measures of workload have been developed on the basis of the various definitions, some are designed to capture the multi-dimensional aspects of a unitary resource pool (Kahneman, 1973) while others are developed on the basis of multiple resource theory (Wickens, 2002). Although many theory based workload measures exist, others have often been constructed to serve the purpose of specific experimental tasks. As a result, it is likely that not every workload measure is reliable and valid for all tasks, much less each domain. To date, no single measure, systematically tested across experimental tasks, domains, and other measures is considered a universal measure of workload. Most researchers would argue that multiple measures from various categories should be applied to a given task to comprehensively assess workload. The goal for Study 1 to establish task load manipulations for two theoretically different tasks that induce distinct levels of workload assessed by both subjective and performance measures was successful. The results of the subjective responses support standardization and validation of the tasks and demands of that task for investigating workload. After investigating the use of subjective and objective measures of workload to identify a universal and comprehensive measure or set of measures, based on Study 2, it can only be concluded that not one or a set of measures exists. Arguably, it is not to say that one will never be conceived and developed, but at this time, one does not reside in the psychometric catalog. Instead, it appears that a more suitable approach is to customize a set of workload measures based on the task. The novel approach of assessing the sensitivity and comprehensive ability of conjointly utilizing subjective, performance, and physiological workload measures for theoretically different tasks within the same domain contributes to the theory by laying the foundation for improving methodology for researching workload. The applicable contribution of this project is a stepping-stone towards developing complex profiles of workload for use in closed-loop systems, such as human-robot team iv interaction. Identifying the best combination of workload measures enables human factors practitioners, trainers, and task designers to improve methodology and evaluation of system designs, training requirements, and personnel selection