Stroke; a journal of cerebral circulation
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Review Comparative Study
Definition of initial grading, specific events, and overall outcome in patients with aneurysmal subarachnoid hemorrhage. A survey.
Scientific communication in medicine can be effective only if reports are based on unequivocal criteria for clinical conditions or specific diagnoses. ⋯ Reports about subarachnoid hemorrhage require closer scrutiny before publication to ascertain whether the conclusions about specific outcome events are based on unequivocal criteria.
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Comparative Study
Mechanisms of vasodilation of cerebral vessels induced by the potassium channel opener nicorandil in canine in vivo experiments.
Nicorandil, a potent antianginal agent characterized as a potassium channel opener, could produce cerebrovascular dilation in in vitro studies. Our aim was to investigate the pharmacologic response to the topical application of nicorandil on the vasomotor tone of pial vessels in vivo. To elucidate its mechanism, we also studied the inhibitory action of methylene blue and glibenclamide against nicorandil-induced vasodilation. ⋯ Our in vivo study demonstrates that topical application of nicorandil dilates both pial arterioles and venules in a concentration-dependent manner and suggests that the mechanisms of such actions are most likely due to both cyclic GMP-mediated vascular smooth muscle dilation and the regulation of K+ flux.
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Comparative Study
Therapeutic time window and dose response of the beneficial effects of ketamine in experimental head injury.
The aim of this study was to determine the time and dose response of the therapeutic effects of the N-methyl-D-aspartate receptor antagonist ketamine in experimental head injury. ⋯ We conclude that 180 mg/kg IP ketamine was effective in ameliorating neurological dysfunction after head trauma in rats when the administration time was delayed for 1 hour to 2 hours but not after 4 hours. When given at 1 hour after head trauma, ketamine at 120 mg/kg but not 60 mg/kg is effective in reducing neurological damage after head trauma.
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Transcranial Doppler sonography (TCD) can evaluate noninvasively the blood flow velocities and patency of the main trunk of the middle cerebral artery (MCA). Using TCD we evaluated MCA patency and patterns of flow through the circle of Willis in patients with acute stroke. ⋯ TCD allows early differentiation of patency and natural history of MCA thromboembolic events. This may have important implications in the decision for thrombolytic therapy.
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Randomized Controlled Trial Clinical Trial
The impact of microemboli during cardiopulmonary bypass on neuropsychological functioning.
Microemboli have been implicated in the etiology of neuropsychological deficits after cardiopulmonary bypass. This study examined the incidence of high-intensity transcranial signals (microemboli) and their relation to changes in neuropsychological performance after surgery. ⋯ These data suggest that neuropsychological deficits after routine cardiopulmonary bypass are related to the number of microemboli delivered during surgery. Furthermore, the numbers of microemboli may be reduced by including a 40-microns filter on the arterial line.