Glutamate and its synthetic analogues N-methyl-d-aspartate (NMDA), kainate, and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) are potent dilator agents in the cerebral circulation. The close linkage between neural activity-based release and actions of glutamate on neurons and the related decrease in cerebral vascular resistance is a classic example in support of the concept of tig...

Current data and guidelines recommend treating abnormal blood lipids (ABL) to goal. This is a complex process and requires involvement from various healthcare professionals with a wide range of expertise. The model of a multidisciplinary case management approach for patients with ABL is well documented and described. This collaborative approach encompasses primary and secondary prevention acros...

oxygen therapy might increase damaged tissue oxygenation, turn on the aerobic pathway, and save neurons from death and could improve clinical outcome of the patients with stroke and head trauma. hyperbaric oxygen therapy is accompanied by some unfavorable effects. results of normobaric oxygen therapy on clinical outcomes of patients with stroke were controversial up till now.  this study was th...

Although the assessment of dynamic cerebral autoregulation (CA) based on measurements of spontaneous fluctuations in arterial blood pressure (ABP) and cerebral blood flow (CBF) is a convenient and much used method, there remains uncertainty about its reliability. We tested the effects of increasing ABP variability, provoked by a modification of the thigh cuff method, on the ability of the autor...

The brain has a high blood flow to meet its high obligatory requirement for glucose as a metabolic fuel. Indeed, glucose requirement and blood flow are directly coupled so that the increased metabolic rate during enhanced functional activity of a particular cortical area is associated with increased blood flow. Here a brief review will be given of the most important methods that can be used for...

A 70-year-old man with hydrocephalus was examined with functional magnetic resonance (fMR) imaging before and after ventriculoperitoneal shunting. Preoperatively, activation by right hand exercise revealed only a slight signal increase in the peri-rolandic area. However, 3 months after ventriculoperitoneal shunting, a significant signal increase was observed. fMR imaging may detect activity-rel...

Low frequency oscillations, which are temporally correlated in functionally related brain regions, characterize the mammalian brain, even when no explicit cognitive tasks are performed. Functional connectivity MR imaging is used to map regions of the resting brain showing synchronous, regional and slow fluctuations in cerebral blood flow and oxygenation. In this study, we use a hierarchical clu...

The results of studies utilizing the nitrous oxide technic for measuring cerebral blood flow have been reviewed and divided into three groups: (1) those in which cerebral blood flow and metabolism were normal, (2) those in which cerebral blood flow was increased, and (3) those in which cerebral blood flow and metabolism were decreased. The factors which apparently regulate and control cerebral ...

We investigated the neural substrates of a recent model of human stereodepth perception by obtaining measurements of regional cerebral blood flow (rCBF) using PET. Subjects experienced the perceptual properties of stereopsis by viewing rival-luminance stereograms displaying an identical random-dot pattern in their central portion while the backgrounds exhibited correspondent dots contrasting in...

The extreme diffusibility of hydrogen, compared with xenon or krypton, may create serious artifacts when it is used to measure local blood flow with a tissue electrode. The errors are greatest when hydrogen is given by intra-arterial slug injection, and when the electrode is within 2mm of another tissue compartment, CSF, or air. These all appear to be a consequence of intercompartmental diffus...