Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association
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J Stroke Cerebrovasc Dis · Nov 1999
Brain acidosis, cerebral blood flow, capillary bed density, and mitochondrial function in the ischemic penumbra.
Within the ischemic penumbra, there is a heterogeneous development of cortical intracellular acidosis that is associated with selective neuronal injury. This experiment, which used a rabbit model of moderate focal cerebral ischemia, examined the time course for changes in intracellular brain pH, cortical blood flow, capillary bed density, and mitochondrial function in the ischemic penumbra. After cortical annotation of regions of intracellular acidosis in the ischemic penumbra, the animals underwent transcardiac carbon black perfusion for measurement of capillary bed density. ⋯ For example, capillary bed density in preischemic controls was 338+/-6/mm(2), whereas after 1 hour of ischemia, it measured 147+/-12/mm(2), at 3 hours 97+/-23/mm(2), and at 6 hours 92+/-16/mm(2). Mitochondrial function was reduced coinciding with the decrease in capillary bed density. These data support the hypothesis that cortical acidosis in the ischemic penumbra facilitates the development of perfusion defects that subsequently lead to mitochondrial dysfunction.
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J Stroke Cerebrovasc Dis · Jan 1999
Rebleeding during transport of patients with a ruptured intracranial aneurysm.
Although many reports have described the rebleeding risk of the ruptured aneurysm in already hospitalized patients, there are only a few reports that have addressed the incidence of rebleeding in these patients before hospitalization. To improve the prognosis of patients with a ruptured intracranial aneurysm, it seems very important to know the incidence of rebleeding before hospitalization. ⋯ The incidence of rebleeding in the prehospitalized patients with a ruptured aneurysm is supposed to by very high. Appropriate medical countermeasures for prevention of rebleeding in prehospitalized patients are crucial to decrease the overall mortality and morbidity rate of intracranial aneurysm.
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J Stroke Cerebrovasc Dis · Sep 1998
Reduced stroke risk in patients with compromised cerebral blood flow reactivity treated with superficial temporal artery to distal middle cerebral artery bypass surgery.
Extracranial-to-intracranial (EC-IC) bypass surgery for the prevention of stroke in patients with symptomatic carotid artery occlusion has nearly ended after a randomized trial showed no benefit of the procedure. Although an EC-IC bypass might benefit patients with compromised cerebrovascular hemodynamics, the randomized trial did not differentiate patients with hemodynamic from embolic etiologies. However, subsequent investigators have identified a subgroup of patients at increased stroke risk from hemodynamic compromise. ⋯ STA-MCA bypass surgery can restore cerebrovascular reserve in high-risk patients with symptomatic internal carotid artery occlusion. This was achieved with minimal perioperative complications, resulting in a subsequent reduction of stroke frequency. We suggest that the efficacy of STA-MCA bypass surgery for symptomatic carotid occlusion be re-examined prospectively using hemodynamic selection criteria.
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J Stroke Cerebrovasc Dis · Jul 1997
Increasing hospital admission rates for intracerebral hemorrhage during the last decade.
The incidence and mortality of all types of strokes, including intracerebral hemorrhages, declined during the 1970s. However, some evidence exists that these trends stabilized or reversed during the 1980s. In the present study, a large North American population was observed from 1981 to 1989 to assess changes in the annual hospital admission rates of intracerebral hemorrhage. ⋯ Hospital admission rates for intracerebral hemorrhage nearly doubled from 1981 to 1989. This change may be due to an actual increase in the annual incidence of intracerebral hemorrhage caused by mechanisms that are not yet fully understood.
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J Stroke Cerebrovasc Dis · Jul 1997
Changes in cerebral oxygen saturation with change in posture: a preliminary report.
Disease of the major vessels in the neck can disrupt autoregulation and lead to changes in the cerebral blood flow and cerebral autoregulation. These changes can be reflected by means of cerebral oxygen saturation. ⋯ Changes in regional cerebral oxygen saturation inpatients with carotid-vertebral artery disease may reflect disruption of cerebral autoregulation.