When the lateral striate arteries of baboons are occluded, an immediate cessation of blood flow followed by a transient, minimal restitution of flow occurs in that vascular distribution. These findings are evident from serial xenon/computed tomography cerebral blood flow imaging. In our study, infarction consistently accompanied arterial occlusion for 6 hours or more. The xenon/computed tomogra...

Background: Nitric oxide synthase (NOS) activity is increased during hypertension and cerebral ischemia. NOS inactivation reduces stroke-induced cerebral injuries, but little is known about its role in blood-brain barrier (BBB) disruption and cerebral edema formation during stroke in acute hypertension. Here, we investigated the role of NOS inhibition in progression of edema formation and BBB d...

Autoregulation of cerebral blood flow (constant perfusion despite variations in blood pressure) was studied in 15 control subjects and in 24 patients with cerebral vascular lesions. Thirteen patients were studied within the first 2 days of an episode of cerebral ischemia ("acute" group); 11 were studied from 15 days to several months after an ischemic episode ("chronic" group). Measurements of ...

introduction : cerebral autoregulation (ca) and mean cerebral blood flow velocity in males and females are still under controversy. the present study was scheduled to address the effect of sex on these parameters. materials and methods : the present study was interventional and performed on 30 healthy volunteers (15 males aging from 20-30 yrs and mean age of 23.9±3 years old and 15 females agin...

introduction:amphetamines are central nervous system (cns) stimulant substances and amphetamine abuse is considered a growing problem in our country. previous studies revealed destructive effects of amphetamines on metabolism, perfusion and structure of brain. the aim of current study was evaluating regional cerebral blood flow (rcbf) disturbances in methamphetamine (ma) abusers using brain per...

We studied the response of cerebral blood flow to acute step decreases in arterial blood pressure noninvasively and nonpharmacologically in 10 normal volunteers during normocapnia, hypocapnia, and hypercapnia. The step (approximately 20 mm Hg) was induced by rapidly deflating thigh blood pressure cuffs following a 2-minute inflation above systolic blood pressure. Instantaneous arterial blood pr...

Background: The reactions of the whole organism that occur under the action of accelerations of rectilinear and rotational motion are factors that have a systemic effect on the cerebral blood flow. The use of hurdling performance in the structure of human physical activity can have a significant impact on the tone of the brain vessels, their elasticity and venous outflow in the development of f...

A utoregulation and Hyperemia of Cerebral Blood Flow as Evaluated by Thermal Diffusion • A thermal diffusion flow probe gave a quantitative dynamic recording of cerebral blood flow (CBF) during bleeding and transfusion in experimental animals. Autoregulation was readily demonstrated in nine of 12 animals and was found only with gradual hypotension. After autoregulation was lost, no increase in ...

Collateral circulation provides an alternative route for blood flow to reach ischemic tissue during a stroke. Blood flow through the cerebral collaterals is a critical predictor of clinical prognosis after stroke and response to recanalization, but data on collateral dynamics and collateral therapeutics are lacking. Here, we investigate the efficacy of a novel approach to collateral blood flow ...

The pattern of blood flow leaving the cranium via the lateral sinuses and internal jugular veins is significantly altered by head rotation. This effect is documented in the baboon and macaque monkey by Doppler flow recording and by angiography. This phenomenon may affect the validity of cerebral blood flow data determined by venous sampling and may have significance in angiographic interpretati...