Stroke; a journal of cerebral circulation
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Clinical Trial
Old microbleeds are a potential risk factor for cerebral bleeding after ischemic stroke: a gradient-echo T2*-weighted brain MRI study.
T2*-weighted gradient-echo MRI is known to detect old microbleeds (MBs), considered indicative of microangiopathy. MBs might be a potential risk factor for early cerebral bleeding (CB) after ischemic stroke. Therefore, we assessed the impact of MBs on the occurrence of CB after cerebral infarction. ⋯ Although the pathogenesis of CB after ischemic stroke is multifactorial, the increased observation of CB in patients with MBs suggests that the associated vascular vulnerability contributes to CB.
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Clinical Trial
Functional walk tests in individuals with stroke: relation to perceived exertion and myocardial exertion.
Functional walk tests such as the 6- and 12-Minute Walk Test (ie, 6MWT and 12MWT, respectively) are submaximal measures used to determine functional capacity in individuals with compromised ability. The purpose of this study was to determine the relationship between these walk tests and measures of exertion (perceived and myocardial), in addition to impairment in individuals with stroke. The relationship among the 6MWT, 12MWT, and the more traditionally assessed measure of self-paced gait speed (generally assessed over a short distance, eg, 10 m) was also evaluated. ⋯ Stroke-specific impairments are the major limitations to the distance walked in individuals with stroke. If the functional walk test is used to assess performance of an individual over time (eg, in response to an intervention), we recommend that both exertion (eg, increase in RPP or HR) and distance be measured.
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Few studies have assessed the overall importance of genetic factors on stroke risk, and the results have been contradictory. We used a large, population-based twin register and nationwide registries of death and hospitalization with long-term follow-up to estimate the effect of genetic factors on the risk of stroke. ⋯ The observed increased risk of stroke death and stroke hospitalization in monozygotic compared with dizygotic co-twins suggests that genetic factors increase the risk of stroke and that the size of this effect is moderate.
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Hemorrhagic transformation (HT) is a major complication of intra-arterial (IA) thrombolytic therapy. Identifying significant predictors of hemorrhage after thrombolysis would be useful in guiding patient selection for IA treatment. ⋯ In this large series of IA thrombolysis, rates of HT were similar to those demonstrated in prior series and clinical trials. Higher NIHSS score, longer time to recanalization, lower platelet count, and higher glucose level were independent predictors of any HT.
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Potassium channels or nitric oxide or both are major mediators of acidosis-induced dilation in the cerebral circulation. However, these contributions depend on a variety of factors such as species and vessel location. The present study was designed to clarify whether potassium channels and endothelial nitric oxide are involved in acidosis-induced dilation of isolated rat cerebral arterioles. ⋯ Endothelial nitric oxide and smooth muscle ATP-sensitive potassium channels contribute to acidosis-induced dilation of rat cerebral arterioles. Endothelial damage caused by pathological conditions such as subarachnoid hemorrhage or traumatic brain injury may contribute to reduced blood flow despite injury-induced cerebral acidosis.