We studied the effects of cholinergic receptor activation on cerebral blood flow in dogs anesthetized with chloralose. Continuous measurements of cerebral blood flow, arterial and cerebral spinal fluid pressure, heart rate, and respiratory carbon dioxide tension were made during parasympathetic nerve stimulation and during intraarterial infusion of acetylcholine. Multiple samples of arterial an...

AIM To study continuously cerebral blood flow velocity in the middle cerebral artery before, during, and after tube feeding in neonates. METHOD Cerebral blood flow velocity was measured in 14 neonates using a Doppler ultrasound device. Blood pressure, respiration, and oxygen saturation were monitored. RESULTS Mean blood flow velocity decreased from 37 cm/s before feeding to 33 cm/s (P < 0.0...

This comprehensive review summarizes the evidence regarding use of cerebral autoregulation-directed therapy at the bedside and provides an evaluation of its impact on optimizing cerebral perfusion and associated functional outcomes. Multiple studies in adults and several in children have shown the feasibility of individualizing mean arterial blood pressure and cerebral perfusion pressure goals ...

BACKGROUND Thiopental and propofol are highly lipid-soluble, and their entry into the brain often is assumed to be limited by cerebral blood flow rather than by a diffusion barrier. However, there is little direct experimental evidence for this assumption. METHODS The cerebral kinetics of thiopental and propofol were examined over a range of cerebral blood flows using five and six chronically...

BACKGROUND AND PURPOSE External counterpulsation (ECP) is a novel noninvasive method used to improve the perfusion of vital organs, which may benefit ischemic stroke patients. We hypothesized that ECP may augment cerebral blood flow of ischemic stroke patients via induced hypertension. METHODS We recruited ischemic stroke patients with cerebral intracranial large artery occlusive disease and ...

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...

BACKGROUND Abnormalities in nocturnal blood pressure dipping are well known for its relationship to cardiovascular diseases. Cerebral microbleeds are frequently observed in patients with hypertension and are known to be potent risk factors for stroke. However, there are scanty reports about the relationship between nocturnal dipping and cerebral microbleeds. METHODS We recruited consecutive p...

We measured cerebral blood flow and somatosensory evoked potentials during transient focal cerebral ischemia in cats to compare the effects of four commonly used anesthetic regimens: ketamine/fentanyl/N2O (fentanyl), pentobarbital, ketamine/alpha-chloralose (alpha-chloralose), and ketamine/halothane/N2O (halothane). Six cats in each group were subjected to 60 minutes of left middle cerebral art...

AIM To measure changes in cerebral haemodynamics over the first three days of life in very preterm infants with normal brains. METHODS Eleven mechanically ventilated infants (median gestational age 26 weeks) without evidence of major abnormalities on cranial ultrasound examination were studied. Cerebral blood flow (CBF) and cerebral blood volume (CBV) were measured using near infrared spectro...

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...