Translational stroke research
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Clinical presentation and neurological outcome in subarachnoid hemorrhage (SAH) is highly variable. Aneurysmal SAH (aSAH) is hallmarked by sudden increase of intracranial pressure (ICP) and acute hypoperfusion contributing to early brain injury (EBI) and worse outcome, while milder or non-aneurysmal SAH with comparable amount of blood are associated with better neurological outcome, possibly due to less dramatic changes in ICP. Acute pressure dynamics may therefore be an important pathophysiological aspect determining neurological complications and outcome. ⋯ Cerebral autoregulation was disrupted initially due to the immediate ICP increase in all groups except NS10; only AB1, however, resulted in sustained impairment of autoregulation, as well as early neuronal cell loss. Rapidity and composition of hemorrhage resulted in characteristic hyperacute hemodynamic changes, with comparable hypoperfusion despite different ICP ranges. Only rapid ICP increase was associated with pronounced and early, but sustained disruption of cerebral autoregulation, possibly contributing to EBI.
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Cough reflex testing has been evaluated as a component of the clinical swallowing assessment as a means of identifying patients at risk of aspiration during swallowing. A previous study by our research group found good sensitivity and specificity of the cough reflex test for identifying patients at risk of aspiration post-stroke, yet its use did not decrease pneumonia rates, contrary to previous reports. The aim of this study was to expand on our earlier work by implementing a clinical management protocol incorporating cough reflex testing within the same healthcare setting and compare patient outcomes to those from the original study and to evaluate clinical outcomes in patients with acute stroke who were managed using the Dysphagia in Stroke Protocol (DiSP). ⋯ Previous work has suggested that simply implementing cough reflex testing in dysphagia management may not be sufficient to improve patient outcomes. The present study adds to this picture by suggesting that the true variable of influence may be the way in which the results of the test are applied to patient care. There is a strong case to support the use of a structured protocol if cough reflex testing is to be implemented in clinical practice.
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Aneurysmal subarachnoid hemorrhage (aSAH) is associated with high socio-economic burden. Prothrombotic states of early brain injury (EBI) and delayed cerebral ischemia (DCI) after aSAH determine morbidity and mortality. To understand how activated platelets might contribute to such prothrombotic states, we studied trends in coated-platelets during EBI and DCI periods. ⋯ Differences between peak coated-platelet levels and baseline levels were larger, on average for those with DCI [18.1 ± 9.6 vs. 10.6 ± 8.0; p = 0.03], MOCA < 26 [17.0 ± 7.8 vs. 10.7 ± 7.4; p = 0.05] and mRS 3-6 [24.8 ± 10.5 vs. 11.9 ± 7.6; p = 0.01]. Coated-platelet trends after aSAH predict DCI and short-term clinical outcomes. The degree of rise in coated-platelets is also associated with adverse clinical outcomes.
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Animal models are established to display the pathophysiological changes following subarachnoid hemorrhage (SAH). The aim of the present study was to determine case fatality in mouse delayed cerebral ischemia (DCI) models, to compare mortality in mouse DCI models to case fatality in human SAH patients, and to identify factors influencing mouse mortality. A systematic search of the PubMed database was performed to identify all studies that assessed mouse DCI models. ⋯ The mean overall mortality rate in mouse DCI models is significantly lower than human case fatality following aneurysmal SAH. However, time between SAH induction and evaluation is a significant variable influencing the mortality rate in mouse SAH models. Further analyses will be required to establish whether and to which extent different DCI models affect mortality and reflect human pathophysiology.
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Stroke, resulting from limited blood flow to the brain, is one of the most important causes of morbidity and mortality worldwide. Stroke is classified as ischemic, due to lack of blood flow, or hemorrhagic, due to bleeding. Because 87 % of strokes are classified as ischemic, this type will be the predominant focus of this review. ⋯ However, these approaches have not led to successful clinical outcomes. This review addresses the pathophysiology of stroke, neurogenesis after stroke, and how to stimulate these processes based on the current literature. Finally, ongoing clinical trials to improve neurological functions after stroke by enhancing neurogenesis are discussed in this review.