Contrast optimization in arterial spin labeling with multiple post-labeling delays for cerebrovascular assessment.

OBJECTIVE: Improving the readout for arterial spin labeling with multiple post-labeling delays (multi-PLD ASL) through a flip angle (FA) sweep towards increasing contrast-to-noise ratio for long PLD images. METHODS: Images were acquired from 20 healthy subjects and 14 patients with severe, asymptomatic carotid artery stenosis (ACAS) in a 3T MRI scanner. Multi-PLD ASL images with conventional and proposed (FA sweep) readouts were acquired. For patients, magnetic resonance angiography was used to validate the multi-PLD ASL results. Perfusion values were calculated for brain regions irrigated by the main cerebral arteries and compared by analysis of variance. RESULTS: For healthy subjects, better contrast was obtained for long PLDs when using the proposed multi-PLD method compared to the conventional. For both methods, no hemispheric difference of perfusion was observed. For patients, the proposed method facilitated the observation of delayed tissue perfusion, which was not visible for long PLD using the conventional multi-PLD ASL. CONCLUSION: We successfully assessed brain perfusion of patients with asymptomatic CAS using multi-PLD ASL with FA sweep. We were able to show subtle individual differences. Moreover, prolonged arterial transit time in patients was observed, although they were considered asymptomatic, suggesting that it may not be an adequate term to characterize them.

Clinical swallowing assessment in the diagnosis of silent aspiration / Avaliação clínica da deglutição no diagnóstico da aspiração silente

ABSTRACT Purpose: to identify, in the clinical assessment of swallowing, signs indicating silent aspiration in ischemic stroke patients. Methods: forty-six patients were assessed, 17 days being the mean time elapsed from the stroke to the swallowing assessment. The clinical assessment encompassed structural and functional aspects, oximetry monitoring, and cervical auscultation. During the videofluoroscopy examination, the patients were also monitored with pulse oximetry. In both assessments, the patients were given 100 ml of liquid. In the statistical analysis, the exact logistic regression test and odds ratio calculation were used, with a 0.05 significance level. Results: seven, out of the 46 patients, presented aspiration, which was silent in six of them. Change in the cervical auscultation, in the clinical assessment (OR: 18.8; 95% CI: 1.2 - 1000, p = 0.03), was associated with silent aspiration, as detected in the videofluoroscopy. The hawking present in the analysis of the recording (OR: 12.2; 95% CI: 1.23 - ∞, p = 0.03), was associated with possible non-silent laryngotracheal penetrations and aspirations. No change was identified regarding oxygen saturation in patients presented with silent aspiration. Conclusion: the change in cervical auscultation observed in the clinical assessment can indicate silent aspiration in patients affected by an ischemic stroke.

RESUMO Objetivo: identificar sinais na avaliação clínica da deglutição que indiquem aspiração silente em pacientes com acidente vascular cerebral isquêmico. Métodos: foram avaliados 46 pacientes. O tempo médio entre a ocorrência do acidente e a avaliação da deglutição foi de 17 dias. A avaliação clínica abarcou aspectos estruturais e funcionais, monitoração da oximetria e ausculta cervical. Durante o exame de videofluoroscopia os pacientes foram monitorados por meio da oximetria de pulso. Em ambas avaliações os pacientes ingeriram 100 ml de líquido. Na análise estatística foi utilizado o teste de regressão logística exata e o cálculo do Odds Ratio (OR), com nível de significância de 0,05. Resultados: dos 46 pacientes, sete apresentaram aspiração, sendo silente em seis. A alteração da ausculta cervical na avaliação clínica (OR: 18,8; IC 95%: 1,2 - 1000, p=0,03) associou-se à aspiração silente detectada na videofluoroscopia. O pigarro presente na análise da filmagem (OR: 12,2; IC 95%: 1,23 - ∞, p=0,03) foi associado a possíveis penetrações e aspiração laringotraqueais não silentes. Não foi identificada alteração no nível de saturação de oxigênio nos pacientes com aspiração silente. Conclusão: alteração da ausculta cervical observada na avaliação clínica pode indicar aspiração silente em pacientes acometidos por acidente vascular cerebral isquêmico.

Past, present, and future of stroke in middle-income countries: the Brazilian experience.

BACKGROUND: Stroke is one of the major public health challenges in middle-income countries. Brazil is the world's sixth largest economy but was clearly behind the milestones in the fight against stroke, which is the leading cause of death and disability in the country. Nevertheless, many initiatives are now reshaping stroke prevention, care, and rehabilitation in the country. AIMS: The present article discusses the evolution of stroke care in Brazil over the last decade. METHODS: We describe the main characteristics of stroke care before 2008; a pilot study in a Southern Brazilian city between 2008 and 2010, the Brazilian Stroke Project initiative; and the 2012 National Stroke Policy Act. RESULTS: The National Stroke Project was followed by a major increased on the number of stroke center in the country. The key elements of the 2012 National Stroke Policy Act included: definition of the requirements and levels of stroke centers; improved reimbursement for stroke care; promotion of stroke telemedicine; definition of the Line of Stroke Care (to integrate available resources and other health programs); increased funding for stroke rehabilitation; funding for training of healthcare professionals and initiatives to increase awareness about stroke within the population. CONCLUSIONS: The evolution of stroke care in Brazil over the last decade is a pathway that exemplifies the challenges that middle-income countries have to face in order to improve stroke prevention, treatment and rehabilitation. The reported Brazilian experience can be extrapolated to understand the past, present, and future of stroke care in middle-income countries.