We tested the hypothesis that blood flow through cerebral collateral vessels is lower in stroke-prone spontaneously hypertensive rats (SHRSP) than in normotensive Wistar-Kyoto rats (WKY) after occlusion of the middle cerebral artery and during maximal vasodilatation. Cerebral blood flow, measured with microspheres, was similar in adult male SHRSP and WKY under control conditions. In both strain...

Because melatonin is a cerebral vasoconstrictor agent, we tested whether it could shift the lower limit of cerebral blood flow autoregulation to a lower pressure level, by improving the cerebrovascular dilatory reserve, and thus widen the security margin. Cerebral blood flow and cerebrovascular resistance were measured by hydrogen clearance in the frontal cortex of adult male Wistar rats. The c...

BACKGROUND Vasovagal syncope is usually associated with a sudden drop of blood pressure and/or heart rate. However, occasionally the symptoms of syncope induced by orthostatic stress testing are not associated with obvious haemodynamic changes. The mechanisms of syncope in these patients are not clear. AIM To evaluate changes in cerebral blood flow velocities during orthostatic stress testing...

This pilot study was designed to determine the feasibility of measuring cerebral blood flow noninvasively after an intravenous bolus of indocyanine green using near-infrared spectroscopy and pulse dye-densitometry. Feasibility aside, this study did not attempt to validate the measured values of cerebral blood flow against an established method of measurement. Twelve healthy volunteers were inve...