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Association of blood pressure, penumbra as defined by MRI and recanalization in the first hours after ischemic stroke and their relation to outcome

English title Association of blood pressure, penumbra as defined by MRI and recanalization in the first hours after ischemic stroke and their relation to outcome
Applicant Mattle Heinrich
Number 110006
Funding scheme Project funding (Div. I-III)
Research institution Klinik und Poliklinik für Neurologie Inselspital
Institution of higher education University of Berne - BE
Main discipline Neurology, Psychiatry
Start/End 01.01.2006 - 31.12.2008
Approved amount 296'000.00
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Keywords (5)

blood pressure; stroke; penumbra; recanalization; outcome

Lay Summary (English)

Lead
Lay summary
Background: A transient elevation of arterial blood pressure is observed frequently in patients with acute ischemic stroke. The underlying mechanisms producing such changesare poorly understood. unclear as are their relevance and appropriate management. Mental stress, neuroendocrine factors, the Cushing reflex or the topography of the infarct have been are discussed as to have potential influences on blood pressure after ischemic strokediscussed to exert an influence on blood pressure. However, the main reason might be a locally disturbed autoregulation of Within the ischemic penumbra cerebral blood flow within the ischemic penumbra. If cerebrovascular autoregulation is lost perfusion becomes a linear function of relationship develops between blood pressurelevels and cerebral blood flow. In this case, But post stroke hypertension may represents a pathophysiological response to maintain oraim to enhancee the perfusion in the penumbra in order to save the tissue jeopardized by ischemia. From this we derive the hypothesis, that recanalization and reperfusion of the penumbra will reverse the blood pressure elevation more rapidly than this occurs with persistent occlusion of the cerebral vessel. Blood pressure course transitions in acute stroke patients have never been studied prospectively in relation to the volume of the penumbra and the recanalization of the occluded intracranial vessels. has never been studied in prospective trials. But dAata of a retrospective analysis of 149 consecutive acute stroke patients admitted to our stroke unit between January 2000 and December 2003 and treated with intra- arterial thrombolysis (IAT) suggests an association between blood pressure levels and the degree of artery occlusionvessel recanalization. Methodology: Patients Acute stroke patients with acute ischemic strokewho are admitted to our stroke unit within 6 hours of stroke onset are included in the present study. and treated with intra- arterial thrombolysis undergo cerebral angiography before treatment to assess artery occlusion as well as immediately afterwards to determine the effect of thrombolysis i.e. the recanalization of occluded vessels. They undergo aA blood pressure monitoring during 4 days after stroke onset. As a primary endpoint The blood pressure transitions after treatment and its decline since admission is compared between patients with sufficient and those with insufficientwill be analysed in relation to the size of the penumbra and the vessel recanalization as seen either on the control arteriogram performed immediately after intra- arterial thrombolysis or - if no thrombolysis is done - on MR- angiography. Besides routine laboratory analyses we will also assess renin activity and aldosterone levels in blood samples as well as steroid metabolites in the urine collected during the first 12 hours. Three months after the stroke a clinical and radiological assessment will be performed in order to define lesion size and outcome (with NIHSS, mRankin, Barthel index). Potential significance: The demonstration of an association between the size of the penumbra, vessel recanalization, endocrinological changes and blood pressure would allow insight into To know whether elevated blood pressure levels after acute ischemic stroke depend on the degree of occlusion of cerebral arteries may help to better understand the pathophysiological mechanisms of post stroke hypertension. The information gained from this study might influence the therapeutic decisions after acute stroke. To date, the optimal blood pressure management in the first hours and days after stroke is unknown.
Direct link to Lay Summary Last update: 21.02.2013

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