Cerebrovascular diseases
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Cerebrovascular diseases · Jan 2014
Review Meta AnalysisHead position and cerebral blood flow velocity in acute ischemic stroke: a systematic review and meta-analysis.
Patients with acute ischemic stroke (AIS) have impaired vasomotor reactivity, especially in the affected cerebral hemisphere, such that they may depend directly on systemic blood pressure to maintain perfusion to vulnerable 'at risk' penumbral tissue. As the sitting up position may affect cerebral perfusion by decreasing cerebral blood flow (CBF) in salvageable tissue, positioning AIS patients with their head in a lying flat position could increase CBF through collateral circulation or gravitational force. We wished to quantify the effect of different head positions on mean flow velocity (MFV) by transcranial Doppler ultrasonography (TCD) in AIS patients to assess the potential for benefit (or harm) of head positioning in a clinical trial. ⋯ In AIS patients, MFV increased significantly in the side affected by the stroke but not in the unaffected side when they were positioned in a lying flat head position at 0 or 15° compared to an upright head position at 30°. The clinical significance of these findings is now undergoing further randomized evaluation in the international multicenter Head Position in Acute Stroke Trial (HeadPoST).
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Cerebrovascular diseases · Jan 2014
Review Meta AnalysisHead position and cerebral blood flow velocity in acute ischemic stroke: a systematic review and meta-analysis.
Patients with acute ischemic stroke (AIS) have impaired vasomotor reactivity, especially in the affected cerebral hemisphere, such that they may depend directly on systemic blood pressure to maintain perfusion to vulnerable 'at risk' penumbral tissue. As the sitting up position may affect cerebral perfusion by decreasing cerebral blood flow (CBF) in salvageable tissue, positioning AIS patients with their head in a lying flat position could increase CBF through collateral circulation or gravitational force. We wished to quantify the effect of different head positions on mean flow velocity (MFV) by transcranial Doppler ultrasonography (TCD) in AIS patients to assess the potential for benefit (or harm) of head positioning in a clinical trial. ⋯ In AIS patients, MFV increased significantly in the side affected by the stroke but not in the unaffected side when they were positioned in a lying flat head position at 0 or 15° compared to an upright head position at 30°. The clinical significance of these findings is now undergoing further randomized evaluation in the international multicenter Head Position in Acute Stroke Trial (HeadPoST).
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Cerebrovascular diseases · Jan 2014
ReviewThrombolysis in acute stroke patients with cerebral small vessel disease.
Thrombolytic treatment is of proven benefit in acute ischemic stroke. The term cerebral small vessel disease (SVD) refers to a group of pathological processes affecting the small arteries, arterioles, venules and capillaries of the brain, and encompasses both ischemic and hemorrhagic lesions. Lacunar stroke, an expression of SVD, is associated with an unfavorable long-term prognosis for an increased risk of death, recurrent stroke and cognitive dysfunction. Nonetheless, the efficacy and safety of intravenous thrombolysis in patients with lacunar stroke has been debated for two main reasons. First, among all ischemic stroke subtypes, lacunar strokes have been considered the most benign. Second, the efficacy of a pharmacological reperfusion has been questioned given the absence of a clear demonstration of thrombosis. Intracerebral hemorrhage (ICH) remains the most devastating and unpredictable complication related to thrombolysis, and neuroimaging evidence of SVD is nowadays recognized as one of the risk factors for thrombolysis-related ICH. ⋯ The studies herein reviewed show that thrombolysis is an effective treatment in acute lacunar stroke, and that the presence of cerebral SVD increases the risk of ICH during thrombolysis but does not represent an absolute exclusion criterion. In the future, it can be assumed that the use of MRI on a routine basis might lead to a better quantitative definition of SVD and its correlates, permitting a step forward in thrombolysis decision making.
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Cerebrovascular diseases · Jan 2014
Review Meta AnalysisBlood markers of coagulation, fibrinolysis, endothelial dysfunction and inflammation in lacunar stroke versus non-lacunar stroke and non-stroke: systematic review and meta-analysis.
The cause of cerebral small vessel disease is not fully understood, yet it is important, accounting for about 25% of all strokes. It also increases the risk of having another stroke and contributes to about 40% of dementias. Various processes have been implicated, including microatheroma, endothelial dysfunction and inflammation. A previous review investigated endothelial dysfunction in lacunar stroke versus mostly non-stroke controls while another looked at markers of inflammation and endothelial damage in ischaemic stroke in general. We have focused on blood markers between clinically evident lacunar stroke and other subtypes of ischaemic stroke, thereby controlling for stroke in general. ⋯ Lacunar stroke is an important stroke subtype. More studies comparing lacunar stroke to non-lacunar stroke specifically, rather than to non-stroke controls, are needed. Prospective studies with measurements taken well after the acute event are more likely to be helpful in determining pathogenesis. The available data in this review were limited and do not exclude the possibility that peripheral inflammatory processes including endothelial dysfunction are associated with lacunar stroke and cerebral small vessel disease.
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Cerebrovascular diseases · Jan 2014
Review Meta AnalysisBlood markers of coagulation, fibrinolysis, endothelial dysfunction and inflammation in lacunar stroke versus non-lacunar stroke and non-stroke: systematic review and meta-analysis.
The cause of cerebral small vessel disease is not fully understood, yet it is important, accounting for about 25% of all strokes. It also increases the risk of having another stroke and contributes to about 40% of dementias. Various processes have been implicated, including microatheroma, endothelial dysfunction and inflammation. A previous review investigated endothelial dysfunction in lacunar stroke versus mostly non-stroke controls while another looked at markers of inflammation and endothelial damage in ischaemic stroke in general. We have focused on blood markers between clinically evident lacunar stroke and other subtypes of ischaemic stroke, thereby controlling for stroke in general. ⋯ Lacunar stroke is an important stroke subtype. More studies comparing lacunar stroke to non-lacunar stroke specifically, rather than to non-stroke controls, are needed. Prospective studies with measurements taken well after the acute event are more likely to be helpful in determining pathogenesis. The available data in this review were limited and do not exclude the possibility that peripheral inflammatory processes including endothelial dysfunction are associated with lacunar stroke and cerebral small vessel disease.