Stroke; a journal of cerebral circulation
-
The significance of brain temperature to outcome in cerebral ischemia is recognized. Numerous variations of depth, duration, and delay of cooling have been studied in animal models. It is important to become familiar with these studies to design appropriate clinical trials. With that in mind, a critical review of the pertinent literature is presented, taking into consideration potential limitations in translating such laboratory work to the clinical level. ⋯ Laboratory studies have shown that intraischemic hypothermia is more protective than postischemic hypothermia and more benefit is conferred with temporary occlusion than permanent occlusion models. The efficacy of postischemic hypothermia is critically dependent on the duration and depth of hypothermia and its timing relative to ischemia.
-
Critical closing pressure (CCP) is thought to be jointly influenced by intracranial pressure and cerebrovascular tone. We examined how CCP is affected by cerebral vasospasm after subarachnoid hemorrhage (SAH). ⋯ Assuming that autoregulation-related distal vasodilatation outweighs proximal vasospasm, CCP should decrease. Alternatively, CCP might have increased during vasospasm as the tension of big vessels increase, but the turbulence occurring during vasospasm may have impaired the linear relationship between pressure and FV, thus leading to a marked underestimation of CCP. In conclusion, interpretation of CCP in vasospasm is difficult and may be overshadowed by nonlinear hemodynamic effects.
-
To investigate whether the risk of recurrent ipsilateral ischemic stroke in patients with symptomatic carotid artery occlusion (CAO) is related to (1) volume flow in the contralateral internal carotid artery (ICA), basilar artery (BA), and middle cerebral arteries (MCAs), and (2) intracranial collateral flow to the symptomatic side, measured in the first 6 months after the qualifying symptoms occurred. ⋯ Recurrent ipsilateral ischemic stroke in patients with symptomatic CAO is associated with high volume flow to the brain and increased collateral PCoA flow.
-
Analysis of dynamic cerebral autoregulation (DCA) from spontaneous blood pressure fluctuations might contribute to prognosis of severe internal carotid artery stenosis, but its response to carotid recanalization has not been investigated so far. This study investigates the effect of carotid endarterectomy or stenting on various DCA parameters. ⋯ Dynamic cerebral dysautoregulation in patients with severe carotid obstruction is readily and completely remedied by carotid recanalization.
-
In several acute life-threatening diseases, the 4G-allele in the 4G/5G-promotor polymorphism in the plasminogen activator inhibitor-1 (PAI-1) gene is associated with higher PAI-1 levels and increased poor outcome, probably by promoting the formation of microthrombi. The aim of the present study was to investigate whether the PAI-1 4G/5G polymorphism is associated with the occurrence of cerebral ischemia, rebleeding, and other events, and clinical outcome after aneurysmal subarachnoid hemorrhage. ⋯ The 4G allele in the PAI-1 gene increases the risk for cerebral ischemia after aneurysmal subarachnoid hemorrhage (SAH) and probably also the risk for poor outcome. After early aneurysm occlusion, treatment aimed at enhancing fibrinolysis might be effective to prevent and treat cerebral ischemia in patients with aneurysmal SAH.