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Introduction: Although the 2019 severe acute respiratory syndrome coronavirus 2 infection (SARS-CoV-2, COVID-19) pandemic poses new challenges to the healthcare system to provide support for thousands of patients, there is special concern about common medical emergencies, such as stroke, that will continue to occur and will require adequate treatment. The allocation of both material and human resources to fight the pandemic cannot overshadow the care for acute stroke, a time-sensitive emergency that with an inefficient treatment will further increase mortality and long-term disability. Objective: This paper summarizes the recommendations from the Scientific Department on Cerebrovascular Diseases of the Brazilian Academy of Neurology, the Brazilian Society of Cerebrovascular Diseases and the Brazilian Society of Neuroradiology for management of acute stroke and urgent neuro-interventional procedures during the COVID-19 pandemic, including proper use of screening tools, personal protective equipment (for patients and health professionals), and patient allocation.

Background: Atrial fibrillation (AF) is a widely accepted risk for causing stroke. However, recent studies show AF as a risk factor for dementia, even without causing stroke. The mechanisms by which dementia develops in stroke-free patients with AF are still poorly understood and the association of AF with abnormal function of brain networks activities, such as the default mode network (DMN), has not been previously studied. We aimed to determine whether, in the absence of stroke and dementia, patients with AF have abnormal resting-state brain networks compared to controls without AF. Methods: Twenty-one stroke-free patients with AF and 21 age- and sex-matched controls without AF underwent brain functional magnetic resonance imaging acquired at a 3.0 Tesla scanner. During the exam, the subjects were instructed to lie still with eyes closed. At first-level analysis, connectivity of the DMN was obtained for all subjects. Second-level analysis compared the DMN connectivity between AF patients and controls with a general linear model (two-sample t test, p < 0.05, False Discovery Rate corrected, minimum of 50 contiguous voxels). Results: Patients with AF compared with controls showed decreased connectivity in regions of the DMN including the frontal lobe (left medial frontal gyrus, left superior frontal gyrus and anterior cingulate), left angular gyrus, and bilateral precuneus. Conclusions: Stroke-free patients with AF have evidence of abnormal DMN connectivity. This study adds evidence to the occurrence of cerebral dysfunction in patients with AF.

Ischemic stroke (IS) is one of the most common causes of mortality worldwide and represents 80% of all stroke cases. Previous studies have shown that some metabolites can be markers of oxidative injury to vascular endothelial cells and neuromodulation after brain ischemia. Biomarkers are small molecules that are dysregulated during diseases and that can be used to improve diagnosis and to determine prognosis, including responses to treatment. This study aims to identify if there are specific metabolites in the plasma of patients with IS in the acute and chronic stages. Currently, we have evaluated plasma samples of 21 individuals, using proton Nuclear Magnetic Resonance (1H NMR). The samples were divided into 4 groups: 6 samples from patients in the acute phase of IS (less than 24 h after the event), 6 samples from patients in the chronic phase of IS (more than 3 months after the acure event), 5 samples from healthy and agematched individuals and 4 samples from asymptomatic patients with severe internal carotid artery stenosis. Samples were evaluated using 1 H NMR spectra, recorded under the same conditions in a 600 MHz spectrometer.

Background: The role of patent foramen ovale is a field of debate and current publications have increasing controversies about the patients’ management in young undetermined stroke. Work up with echocardiography and transcranial Doppler (TCD) can aid the decision with better anatomical and functional characterization of right-to-left shunt (RLS). Medical and interventional strategy may benefit from this information. Summary: a group of experts from the Latin American participants of the Neurosonology Research Group (NSRG) of World Federation of Neurology created a task force to review literature and describe the better methodology of contrast TCD (c-TCD). All signatories of the present consensus statement have published at least one study on TCD as an author or co-author in an indexed journal. Two meetings were held while the consensus statement was being drafted, during which controversial issues were discussed and voted on by the statement signatories. The statement paper was reviewed and approved by the Executive Committee of the NSRG of the World Federation of Neurology. The main objective of this consensus statement is to establish a standardization of the c-TCD technique and its interpretation, in order to improve the informative quality of the method, resulting in expanding the application of TCD in the clinical setting. These recommendations optimize the comparison of different diagnostic methods and encourage the use of c-TCD for RLS screening and complementary diagnosis in multicenter studies.

Embolic stroke of undetermined source (ESUS) is an important group of cryptogenic strokes that are in evidence due recent ongoing trials. We reviewed medical records at discharge from the stroke unit of all patients who met ESUS criteria and attended our institution between February 2016 and July 2017. Among 550 stroke patients, 51 had ESUS. We found that hypertension (60%), diabetes mellitus (34%), and smoking (36%) were the most prevalent risk factors. The mean National Institutes of Health Stroke Scale (NIHSS) scores were 7 at admission and 4 at discharge, while median scores on the modified Rankin scale were 0 and 2 at admission and discharge, respectively. Our sample had similar ages, risk factors prevalence and NIHSS scores at admission and discharge when compared with European and North American cohorts. Although a small cohort, our study suggests that the ESUS population is similar in countries with different health financing. RESUMO Acidentes vasculares cerebrais (AVC) embólicos de fonte indeterminada (ESUS) é um grupo importante de pacientes com AVC criptogênico que estão em evidência devido a recentes ensaios clínicos. Foram revisados os prontuários médicos na alta da unidade de AVC de todos os pacientes que preencheram os critérios para ESUS atendidos em nossa instituição entre fevereiro de 2016 e julho de 2017. Entre 550 AVCs, 51 eram pacientes com ESUS. Hipertensão (60%), diabetes mellitus (34%) e tabagismo (36%) foram os fatores de risco mais prevalentes. Os escores médios do National Institutes of Health Stroke Scale (NIHSS) foram 7 na admissão e 4 na alta, enquanto os escores médios na escala de Rankin modificada (mRs) foram 0 e 2 na admissão e alta, respectivamente. Nossa amostra teve idade, prevalência de fatores de risco, escores NIHSS na admissão e alta, quando comparados com coortes europeias e norte-americanas semelhantes. Apesar de ser uma pequena coorte, nosso estudo sugere que a população ESUS é semelhante em países com diferentes níveis de financiamento em saúde.

Background Cognitive deficits in patients with asymptomatic carotid stenosis have been reported. The ultimate mechanism of cognitive deficits remains unclear and might be related to subtle structural brain damage. Aims The aim of the present study was to evaluate the presence of subtle white and grey matter abnormalities associated with asymptomatic carotid stenosis. Methods Twenty-five patients with asymptomatic ≥70%/occlusion carotid stenosis and 25 healthy controls, matched for gender and age, underwent 3 Tesla brain magnetic resonance imaging. Gray and white matter macrostructural abnormalities were evaluated with voxel-based morphometry using spm8 software. White matter microstructural abnormalities were evaluated with diffusion tensor images with the Diffusion Toolbox package and tract-based spatial statistics from FMRIB Software Library. Results We observed significant macro- and microstructural white matter abnormalities, and these findings were diffuse and symmetrical in both hemispheres. In contrast, gray matter atrophy was observed in the areas corresponding to the anterior circulation of the hemisphere ipsilateral to the carotid stenosis. Conclusions Patients with asymptomatic carotid stenosis have different patterns of gray and white matter abnormalities. While the white matter damage is diffuse, the gray matter atrophy is localized in the territory of anterior circulation ipsilateral to the stenosis. The role of asymptomatic carotid stenosis in the gray matter damage must be further investigated with longitudinal studies and comparison with neuropsychological evaluation.

Atherosclerotic disease has been associated with increased risk of severe neurovascular consequences including transient ischemic attacks, ischemic strokes, and even mortality. Following the onset of carotid stenosis, the brain undergoes different compensatory mechanisms to provide adequate perfusion in order to maintain brain metabolism. In this study, we employed near-infrared spectroscopy (NIRS) to better comprehend how carotid stenosis affects cerebral hemodynamics, both at rest and during activity. Eighteen patients diagnosed with atherosclerotic disease were recruited for a protocol consisting of resting state and vasoreactivity testing performed with breath holding. Although the breath holding challenge induced global vasodilation in all patients, the extent of dilation varied according to the level of stenosis. Patients diagnosed with carotid stenosis have impaired hemodynamic response, with a median 77% vasoreactivity in the hemisphere ipsilateral to the stenotic vessel when compared to the healthy hemisphere. Hemodynamics of these patients differed at rest, with 33% fewer network links in the hemisphere ipsilateral to the stenosis than the healthy hemisphere. On the other hand, hemodynamic patterns were more heterogeneous with patients diagnosed with a carotid occlusion, which correlates with the opening of collateral circulation. Overall, our results suggest that NIRS can open new directions to the investigation of the effects of cerebrovascular atherosclerotic disease.

Background and Purpose: The prognostic significance of interictal epileptiform discharges (IED) and periodic patterns (PP) after ischemic stroke has not been assessed. We sought to test whether IED and PP, detected on standard Electroencephalography (EEG) performed during the acute phase of ischemic stroke are associated with a worse functional outcome. Methods: One-hundred-fifty-seven patients 18 years or older with a diagnosis of acute ischemic stroke presenting within 72 h from stroke onset were prospectively enrolled and followed. Patients with a pre-stroke history of seizures or epilepsy, previous debilitating neurological disease or conditions that precluded the performance of EEG were excluded. Interpretation was performed by a blinded board certified neurophysiologist. IED and PP (grouped as epileptiform activity [EA]) were defined according to proposed guidelines. Univariable and multivariable analyses were used to identify predictors of outcome (modified Rankin Scale dichotomized ≤2 vs. ≥3) at 3 months. Results: In the univariable analysis, admission NIHSS (OR 1.20, 95% CI 1.12-1.28, p = 0.001), age (OR 1.03, 95% CI 1.01-1.05, p = 0.02), and presence of EA (OR 2.94, 95% CI 1.51-5.88, p = 0.001) were significantly associated with the outcome at 3 months. In the multivariable analysis, only admission NIHSS (OR 1.19, 95% CI 1.11-1.28, p < 0.001) and the presence of EA (OR 2.27, 95% CI 1.04-5.00, p = 0.04) were independently associated with the prognosis. Significance: The importance of EEG in the prognosis of acute ischemic stroke warrants additional research, examining the role of medication therapy on the outcome and the occurrence of seizures for those patients with specific EEG patterns.

Computed tomography (CT) images are routinely used to assess ischemic brain stroke in the acute phase. They can provide important clues about whether to treat the patient by thrombolysis with tissue plasminogen activator. However, in the acute phase, the lesions may be difficult to detect in the images using standard visual analysis. The objective of the present study was to determine if texture analysis techniques applied to CT images of stroke patients could differentiate between normal tissue and affected areas that usually go unperceived under visual analysis. We performed a pilot study in which texture analysis, based on the gray level co-occurrence matrix, was applied to the CT brain images of 5 patients and of 5 control subjects and the results were compared by discriminant analysis. Thirteen regions of interest, regarding areas that may be potentially affected by ischemic stroke, were selected for calculation of texture parameters. All regions of interest for all subjects were classified as lesional or non-lesional tissue by an expert neuroradiologist. Visual assessment of the discriminant analysis graphs showed differences in the values of texture parameters between patients and controls, and also between texture parameters for lesional and non-lesional tissue of the patients. This suggests that texture analysis can indeed be a useful tool to help neurologists in the early assessment of ischemic stroke and quantification of the extent of the affected areas.

Differently from previous studies that used Transcranial Doppler (TCD) and functional MRI (fMRI) for cerebral vasomotor reactivity (CVR) assessment in patients with carotid stenosis (CS), we assessed CVR using an identical stimulus, the Breath-Holding Test (BHT). We included 15 patients with CS and 7 age-matched controls to verify whether fMRI responded differently to BHT between groups and to calculate the agreement rate between tests. For TCD, impaired CVR was defined when the mean percentage increase on middle cerebral artery velocities was ≤31% on 3 consecutive 30-s apnea intercalated by 4-min normal breathing intervals. For fMRI, the percent variation on blood oxygen level-dependent (BOLD) signal intensity in the lentiform nucleus (LN) ipsilateral to the CS (or both LNs for controls) from baseline breathing to apnea was measured. The Euclidian differences between the series of each subject and the series of controls and patients classified it into normal or impaired CVR. We found different percent variations on BOLD-signal intensities between groups (P=0.032). The agreement was good in Controls (85.7%; κ=0.69) and overall (77.3%; κ=0.54). We conclude that BHT was feasible for CVR assessment on fMRI and elicited different BOLD responses in patients and controls, with a good overall agreement between the tests.

The concept of aphasia designates impairment in the symbolic domains of language (vocabulary, semantics, phonology, syntax and morphology) by one or more lesions in the dominant cerebral hemisphere, which may be manifest through spoken and written comprehension and production, but can not be explained by motor or sensory deficits in view of the preservation of phono-articulatory structures, and neither by generalized cognitive deficits (consciousness must be preserved)1. Stroke is the leading cause of aphasia, which may be identified in more [...]

Introduction Stroke awareness by lay people in general is poor. It has been estimated that only as much as one third of patients with acute stroke reach emergency medical services within two hours of onset of their symptoms. We aimed to assess perception of and attitude towards a person with an acute stroke by professionals working in mobile unit of emergency medical service in the city of Campinas, Brazil. Material and Methods The study was conducted during VII Stroke Workshop of Campinas in November 2007. We used an anonymous self-report questionnaire with a clinical case of an acute stroke with duration of 50 minutes. We asked two open-ended questions to gauge perception and attitude. Results One-hundred forty-nine of 205 (73%) participants answered the questionnaire; 49% were women, average age of 37 years (range 21–59). Ninety (60%) were professionals allied to medicine (nurses, health auxiliary, dentists), six (4%) were physicians, and 53 (36%) were other professionals (secretary, driver). In regard to perception, 142 of 149 (95%) had a correct perception of stroke. In regard to attitude, in general, the basic support measures have been pointed out, but only one (0.5%) mentioned an issue of time less than 3 hours for thrombolysis, four (2%) mentioned the possibility of thrombolysis, and 12 (8%) requested computed tomographic examination. Discussion It appears that professionals allied to medicine can diagnosis stroke of anterior circulation; however, they do not have thrombolytic therapy in mind, and this should be considered the default treatment for all patients with stroke within the “therapeutic window.”

WCN 2013 No: 1856 Topic: 3 — Stroke Cerebral vasoreactivity with breath holding test in Transcranial Doppler and functional MRI in patients with carotid stenosis C.R. Campos-Herrera, G.C. Beltramini, W.M. Avelar, L.M. Li. Neurology, Faculty of Medical Sciences, State University of Campinas, Brazil; ‘Gleb Wataghin’ Physics Institute, State University of Campinas

Objectives Atrial fibrillation (AF) is associated with high risk of dementia and brain atrophy in stroke-free patients, but the mechanisms underlying this association remain unclear. We aimed to examine the brain volume and connectivity of paramount cognitive brain networks in stroke-free patients with AF without dementia. Materials and Methods Twenty-six stroke-free patients with AF and 26 age and sex-matched subjects without AF were submitted to a 3-tesla brain structural and functional MRI. An extensive clinical evaluation excluded stroke, dementia, low cardiac output, carotid stenosis and metabolic diseases without optimal therapy. We used CHA2DS2-VASc score to classify the cardiovascular risk factor burden and a broad neuropsychological battery to assess the cognitive performance. Voxel based morphometry analysis of. structural MRI defined whole-brain gray and white matter volumes. Finally, we used eco-plannar MRI images to compare the differences of functional connectivity of 7 large-scale resting-state networks between AF patients and controls. Results Taking into account the history of hypertension and heart failure, AF was associated to volume decrease of the right basal frontal lobe and right inferior cerebellum. Decreased connectivity of the ventral Default Mode Network (vDMN) was observed in the AF group. No disruption of connectivity was observed in the executive, visuospatial and salience networks. Conclusion Individuals with AF without stroke or dementia have subtle reduction of gray and white matter, restricted to frontal areas and cerebellum. These patients show decreased vDMN connectivity, without other large-scale brain network disruption.