TY - JOUR. T1 - Temporal lobe seizure interhemispheric propagation time depends on nonepileptic cortical cerebral blood flow. AU - Weinand, M. E.. AU - Labiner, D. M.. AU - Ahern, G. L.. PY - 2001/3/24. Y1 - 2001/3/24. N2 - In some patients with epilepsy, activation of eloquent cortex using various forms of environmental stimulation and mental activity may induce seizures. The increased neuronal activity resulting from cortical stimulation may be associated with increased regional cerebral blood flow. The vascular steal theory of temporal lobe epilepsy suggests that as nonepileptogenic cortical cerebral blood flow (CBFn) increases, temporal lobe epileptogenicity increases as a result, in part, of decreasing interhemispheric propagation time (IHPT). Recently, IHPT has been shown to be a quantitative electrocorticographic measure of temporal lobe epileptogenicity. In the current study, long-term combined subdural-EEG and surface cortical cerebral blood flow (CBF) monitoring was performed to test ...
article{3b545620-2f5d-4405-9964-2753884aaa8d, abstract = {The effect of moderate hypoglycaemia (venous blood glucose 2.0 +/- 0.2 mmol/l; mean +/- SD) on regional cerebral blood flow and cerebral volume was studied in a group of ten right-handed patients with Type 1 (insulin-dependent) diabetes mellitus (age 26.0 +/- 2.4 years, duration 18.4 +/- 3.8 years) using an intravenous Xenon 133 single photon emission computed tomography technique. After 10 min of hypoglycaemia, global cerebral blood flow had increased to 55.8 +/- 4.5 ml.100 g-1.min-1 compared to the initial normoglycaemic flow of 49.5 +/- 3.7 ml.100 g-1.min-1 (p < 0.01). A further increase in global cerebral blood flow to 59.5 +/- 4.5 ml.100 g-1.min-1 (p < 0.05) occurred 15 min after normalization of the blood glucose level. The global cerebral blood flow change from before hypoglycaemia to after recovery was inversely related to the initial glucose level. No change in the relative distribution of the regional cerebral blood flow ...
Recently, short-term visual deprivation has been shown to affect a variety of non-visual processes and regional cortical activity (Sathian & Zangaladze, 2001). Surprisingly, very little is known about how such visual deprivation impacts regional cerebral blood flow velocity (CBFv) or its adaptation with the underlying neuronal activity (i.e., neurovascular coupling). The current study sought to investigate the effects of short-term (two-hour) visual deprivation on regional CBFv and neurovascular coupling. CBFv (transcranial Doppler ultrasound) was measured concurrently in the posterior cerebral artery (PCA) and the middle cerebral artery (MCA). Neurovascular coupling was assessed using established methods, consisting of two minutes of baseline (eyes closed and reading), five cycles of 40 seconds reading - 20 seconds eyes-closed (primary protocol), and five cycles of 40 seconds eyes-moving - 20 seconds eyes-closed (secondary protocol). Neurovascular coupling, using both protocols, was collected ...
J. M. Whitley, D. S. Prough, A. K. Lamb, D. D. Deal, D. S. DeWitt; REGIONAL CEREBRAL BLOOD FLOW FOLLOWING RESUSCITATION FROM HEMORRHAGIC SHOCK IN DOGS WITH A SUBDURAL MASS. Anesthesiology 1988;69(3A):A539. Download citation file:. ...
Chi, O.Z., C. Hunter, X. Liu, S.K. Chokshi and H.R. Weiss. Effects of fentanyl pretreatment on regional cerebral blood flow in focal cerebral ischemia in rats. Pharmacol. 85:153-157, 2010.. Chi, O.Z., C. Hunter, X. Liu and H.R. Weiss. The effects of isoflurane pretreatment on cerebral blood flow, capillary permeability, and oxygen consumption in focal cerebral ischemia in rats. Anesth. Analg. 110:1412-1418, 2010.. Liu, X., C. Hunter, H.R. Weiss and O.Z. Chi. Effects of blockade of ionotropic glutamate receptors on blood-brain barrier disruption in focal cerebral ischemia. Neurol. Sci. 31:699-703, 2010.. Chi, O.Z., C. Hunter, X. Liu, Y. Chi and H.R. Weiss. Effects of GABAA receptor blockade on regional cerebral blood flow and blood-brain barrier disruption in focal cerebral ischemia. J. Neurol. Sci. 301:66-70, 2011.. Chi, O.Z., C. Hunter, X. Liu and H.R. Weiss. The effects of dexmedetomidine on regional cerebral blood flow and oxygen consumption during severe hemorrhagic hypotension in rats. ...
TY - JOUR. T1 - Cerebral blood flow autoregulation is impaired in schizophrenia. T2 - A pilot study. AU - Ku, Hsiao Lun. AU - Wang, Jiunn Kae. AU - Lee, Hsin-Chien. AU - Lane, Timothy Joseph. AU - Liu, I-Chao. AU - Chen, Yung Chan. AU - Lee, Yao Tung. AU - Lin, I Cheng. AU - Lin, Chia Pei. AU - Hu, Chaur-Jong. AU - Chi, Nai-Fang. PY - 2017/10. Y1 - 2017/10. N2 - Patients with schizophrenia have a higher risk of cardiovascular diseases and higher mortality from them than does the general population; however, the underlying mechanism remains unclear. Impaired cerebral autoregulation is associated with cerebrovascular diseases and their mortality. Increased or decreased cerebral blood flow in different brain regions has been reported in patients with schizophrenia, which implies impaired cerebral autoregulation. This study investigated the cerebral autoregulation in 21 patients with schizophrenia and 23 age- and sex-matched healthy controls. None of the participants had a history of cardiovascular ...
Changes in cerebral blood flow are an essential feature of Alzheimers disease and have been linked to apolipoprotein E-genotype and cerebral amyloid-deposition. These factors could be interdependent or influence cerebral blood flow via different mechanisms. We examined apolipoprotein E-genotype, amyloid beta-deposition, and cerebral blood flow in amnestic mild cognitive impairment using pseudo-continuous arterial spin labeling MRI in 27 cognitively normal elderly and 16 amnestic mild cognitive impairment participants. Subjects underwent Pittsburgh Compound B (PiB) positron emission tomography and apolipoprotein E-genotyping. Global cerebral blood flow was lower in apolipoprotein E ɛ4-allele carriers (apolipoprotein E4+) than in apolipoprotein E4- across all subjects (including cognitively normal participants) and within the group of cognitively normal elderly. Global cerebral blood flow was lower in subjects with mild cognitive impairment compared with cognitively normal. Subjects with ...
Progressive loss of brain tissue is seen in some patients with schizophrenia and might be caused by increased levels of glutamate and resting cerebral blood flow (rCBF) alterations. Animal studies suggest that normalization of glutamate levels decreases rCBF and prevents structural changes in hippocampus. However, the relationship between glutamate and rCBF in anterior cingulate cortex (ACC) of humans has not been studied in the absence of antipsychotics and illness chronicity. Ketamine is a non-competitive N-Methyl-D-Aspartate receptor antagonist that transiently induces schizophrenia-like symptoms and neurobiological disturbances in healthy volunteers (HV). Here, we used S-ketamine challenge to assess if glutamate levels were associated with rCBF in anterior cingulate cortex (ACC) in 25 male HV. Second, we explored if S-ketamine changed neural activity as reflected by rCBF alterations in thalamus and accumbens that are connected with ACC. Glutamatergic metabolites were measured in ACC with magnetic
Definition of Cerebrovascular circulation with photos and pictures, translations, sample usage, and additional links for more information.
This study sought to determine the degree of agreement between asymmetries of neuropsychological functioning and nine methods of quantifying asymmetries of regional cerebral blood flow.. The regional cerebral blood flow methods combined three markers of cerebral blood flow asymmetry (percent hemispheric difference, maximum percent probe-pair asymmetry, and number of probe-pair asymmetries) with three indexes of regional cerebral blood flow (fast compartment flow, initial slope index, and initial slope). Eleven patients with left hemispheric ischemic strokes and 13 with right hemispheric ischemic strokes were studied with the xenon-133 inhalation technique and neuropsychological tests.. Blind clinical judgments of neuropsychological asymmetry significantly correlated with all nine methods of cerebral blood flow asymmetry determination; correlations ranged from -0.42 to -0.77. Clinical judgment of asymmetry of neuropsychological functioning accurately predicted the hemisphere of lower flow in ...
TY - JOUR. T1 - Frontotemporal cerebral blood flow change during executive and declarative memory tasks in schizophrenia. T2 - A positron emission tomography study. AU - Ragland, John D. AU - Gur, Ruben C.. AU - Glahn, David C.. AU - Censits, David M.. AU - Smith, Robin J.. AU - Lazarev, Mark G.. AU - Alavi, Abass. AU - Gur, Raquel E.. PY - 1998/7. Y1 - 1998/7. N2 - Schizophrenia affects prefrontal and temporal-limbic networks. These regions were examined by contrasting regional cerebral blood flow (rCBF) during executive (Wisconsin Card Sorting Test [WCST]), and declarative memory tasks (Paired Associate Recognition Test [PART]). The tasks, and a resting baseline, were administered to 15 patients with schizophrenia and 15 healthy controls during 10 min positron emission tomography 15O-water measures of rCBF. Patients were worse on both tasks. Controls activated inferior frontal, occipitotemporal, and temporal pole regions for both tasks. Similar results were obtained for controls matched to ...
Hypoxia increases cerebral blood flow (CBF), but it is unknown whether this increase is uniform across all brain regions. We used H215O positron emission tomography imaging to measure absolute blood flow in 50 regions of interest across the human brain (n = 5) during normoxia and moderate hypoxia. PCO2 was kept constant (44 Torr) throughout the study to avoid decreases in CBF associated with the hypocapnia that normally occurs with hypoxia. Breathing was controlled by mechanical ventilation. During hypoxia (inspired PO2 = 70 Torr), mean end-tidal PO2 fell to 45 ᠶ.3 Torr (means ᠓D). Mean global CBF increased from normoxic levels of 0.39 ᠰ.13 to 0.45 ᠰ.13 ml/g during hypoxia. Increases in regional CBF were not uniform and ranged from 9.9 ᠸ.6% in the occipital lobe to 28.9 ᠱ0.3% in the nucleus accumbens. Regions of interest that were better perfused during normoxia generally showed a greater regional CBF response. Phylogenetically older regions of the brain tended to show larger ...
Although it is now well documented (6, 8) that pial as well as intracerebral vessels are amply supplied with sympathetic adrenergic nerves which, as shown for pial arteries, fulfill ultra-structural...
Four major, interdependent mechanisms are involved in the control of cerebral blood flow: metabolic coupling: neural control, involving both extrinsic and intrinsic neural pathways: Pco2 and autoregulation. Although this division may be somewhat artificial and these control mechanisms probably operate in concert, it is useful to consider each separately. Metabolic Control Local cerebral blood flow (CBF) is regionally heterogeneous. The varied pattern of CBF is neither random nor related to the anatomic organization of the cerebral vasculature or to known differences in the innervation patterns of the cerebral vessels. Neuronal activity is the principal energy-consuming process in the brain. Local cerebral blood flow adjusts to the level of energy generation; therefore, it is the activity in the neuronal circuits that is the major determinant of variations and regional patterns of cerebral blood flow. Normally there is exquisite coupling between the regional cerebral metabolic demand for oxygen ...
Oak Za Chi, Hwu Meei Wei, Dorene A. OHara, Arabinda K. Sinha, Harvey R. Weiss; Effects of Pentobarbital and Isoflurane on Regional Cerebral Oxygen Extraction and Consumption with Middle Cerebral Artery Occlusion in Rats. Anesthesiology 1993;79(2):299-305. Download citation file:. ...
This study investigated whether the nitric oxide synthase inhibitor NG-nitro-L-arginine-methyl ester (L-NAME) would alter blood flow and oxygen balance in the ischemic cerebrocortex of isoflurane-anesthetized Long-Evans rats.. Fifteen minutes after middle cerebral artery occlusion, L-NAME (1.5 mg/min per kilogram) was infused intravenously to the L-NAME group (n = 14), and normal saline was given to the control group (n = 14) for 45 minutes. In each group, regional cerebral blood flow was determined with [14C]iodoantipyrine, and arterial and venous oxygen saturations were determined by microspectrophotometry.. In both groups regional cerebral blood flow of the ischemic cortex was significantly lower than that of the contralateral cortex ([mean +/- SD] 55 +/- 13 versus 110 +/- 29 mL/min per 100 g in the control group and 35 +/- 13 versus 90 +/- 24 mL/min per 100 g in the L-NAME group). Compared with the blood flow in the ischemic cortex of the control group, L-NAME significantly reduced ischemic ...
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 blood flow and metabolism are reviewed and discussed.. ...
3) with the assumption that the large and small vessel Hcts are equal.12. Strictly, recirculation effects should be recognized and removed from the curves. In reality, unless there is significant BBB permeability or areas of very low flow, recirculation effects may be ignored and actually lead to improved estimates of plasma volume that are less sensitive to contrast agent delivery rates (ie, CBF). In low-flow regions, if the tracer does not complete its first passage within the time given for the measurement (usually about 25-30 seconds), it will be undercounted and vp will be underestimated. Because of this result, some authors writing about ischemia have used the term "perfused CBV".13 This may account for the discrepancies seen in between PWI and C15O PET estimates of CBV in ischemia.14 In fact, in the extreme, one would prefer to image as late after injection as possible; when the contrast agent concentration is changing slowly, it more closely approximates a steady-state or "blood pool" ...
The Windkessel properties of the vasculature are known to play a significant role in buffering arterial pulsations, but their potential importance in dampening low-frequency fluctuations in cerebral blood flow has not been clearly examined. In this study, we quantitatively assessed the contribution of arterial Windkessel (peripheral compliance and resistance) in the dynamic cerebral blood flow response to relatively large and acute changes in blood pressure. Middle cerebral artery flow velocity (MCA(V); transcranial Doppler) and arterial blood pressure were recorded from 14 healthy subjects. Low-pass-filtered pressure-flow responses (,0.15 Hz) during transient hypertension (intravenous phenylephrine) and hypotension (intravenous sodium nitroprusside) were fitted to a two-element Windkessel model. The Windkessel model was found to provide a superior goodness of fit to the MCA(V) responses during both hypertension and hypotension (R² = 0.89 ± 0.03 and 0.85 ± 0.05, respectively), with a ...
We used H(2)15O positron emission tomography (PET) to measure age-related changes in regional cerebral blood flow (rCBF) during a verbal recognition memory task. Twelve young adults (20 to 29 years) and 12 older adults (62 to 79 years) participated. Separate PET scans were conducted during Encoding, Baseline, and Retrieval conditions. Each of the conditions involved viewing a series of 64 words and making a two-choice response manually. The complete reaction time (RT) distributions in each task condition were characterized in terms of an ex-Gaussian model (convolution of exponential and Gaussian functions). Parameter estimates were obtained for the mean of the exponential component (tau), representing a task-specific decision process and the mean of the Gaussian component (mu) representing residual sensory coding and response processes. Independently of age group, both tau and mu were higher in the Encoding and Retrieval conditions than in the Baseline condition, and tau was higher during ...
All inhaled anesthetics increase cerebral blood flow and decrease cerebral metabolic rate for oxygen (CMRO2). Nitrous oxide, however, will increase CMRO2. Nitrous oxide, as well as inhaled anesthetics, causes cerebral vasodilation. However, if the patients blood pressure drops, the increase in cerebral blood flow will be attenuated or abolished because volatile anesthetics inhibit autoregulation. Isoflurane causes the least cerebral vasodilation, maintaining autoregulation better than other volatile anesthetics. Isoflurane also has no effect on cerebrospinal fluid (CSF) production and decreases resistance to CSF absorption. Desflurane increases CSF production without significantly effecting CSF reabsorption. ...
To test the hypothesis that craving for alcohol in the alcohol-dependent individual is mediated by a limbic circuit involving the caudate nuclei, regional cerebral blood flow was measured with [99mTc]HMPAO SPECT during control and craving conditions in 9 alcohol-dependent subjects. In all subjects, blood flow in the head of the right caudate nucleus increased during the craving condition, and these blood flow increases were strongly correlated with the experimentally induced increases in craving for alcohol. These new findings suggest a functional role for the limbic striatum in the mediation of craving and impaired control over alcohol consumption.
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Author(s): Moore S, Hallsworth K, Jakovljevic D, Blamire A, He J, Ford G, Rochester L, Trenell M. Publication type: Conference Proceedings (inc. Abstract). Publication status: Published. Conference Name: UK Stroke Forum 2014. Year of Conference: 2014. Pages: 32-32. Print publication date: 01/11/2014. Online publication date: 01/12/2014. ISSN: 1747-4930. Publisher: Wiley-Blackwell Publishing Asia. URL: http://dx.doi.org/10.1111/ijs.12374_12. DOI: 10.1111/ijs.12374_12. Notes: 072. Series Title: International Journal of Stroke. ...
The aim of the study is to determine if regional cerebral blood flow, measured by dynamic arterial spin labeling (dASL), can be a biomarker for stage of Alzheimers disease. The study is designed to be conducted in 2 parts in participants with mild to moderate Alzheimers disease, and participants with normal cognition. Various imaging studies will be done using magnetic resonance imaging (MRI) and positron emission tomography (PET) along with neurocognitive assessments. Participants who meet the study-entry criteria will have up to 8 study visits. Repeat imaging studies may be required if the initial data are incomplete or un-interpretable. The maximum number of PET scans during the study will be limited to four ...
The aim of the study is to determine if regional cerebral blood flow, measured by dynamic arterial spin labeling (dASL), can be a biomarker for stage of Alzheimers disease. The study is designed to be conducted in 2 parts in participants with mild to moderate Alzheimers disease, and participants with normal cognition. Various imaging studies will be done using magnetic resonance imaging (MRI) and positron emission tomography (PET) along with neurocognitive assessments. Participants who meet the study-entry criteria will have up to 8 study visits. Repeat imaging studies may be required if the initial data are incomplete or un-interpretable. The maximum number of PET scans during the study will be limited to four ...
Modulation of the cholinergic neurotransmitter system results in changes in memory performance, including working memory (WM), in animals and in patients with Alzheimer disease. To identify associated changes in the functional brain response, we studied performance measures and regional cerebral blood flow (rCBF) using positron emission tomography (PET) in healthy subjects during performance of a WM task. Eight control subjects received an infusion of saline throughout the study and 13 experimental subjects received a saline infusion for the first 2 scans followed by a continuous infusion of physostigmine, an acetylcholinesterase inhibitor, for the subsequent 8 scans. rCBF was measured using H215O and PET in a sequence of 10 PET scans that alternated between rest and task scans. During task scans, subjects performed the WM task for faces. Physostigmine both improved WM efficiency, as indicated by faster reaction times, and reduced WM task-related activity in anterior and posterior regions of ...
Though genetic and environmental determinants of systemic haemodynamic have been reported, surprisingly little is known about their influences on cerebral haemodynamics. We assessed the potential geographical effect on cerebral haemodynamics by comparing the individual differences in cerebral blood flow velocity (CBFv), vasomotor tone (critical closing pressure- CrCP), vascular bed resistance (resistance-area product- RAP) and cerebral autoregulation (CA) mechanism on healthy subjects and acute ischaemic stroke (AIS) patients from two countries. Participants were pooled from databases in Leicester, United Kingdom (LEI) and São Paulo, Brazil (SP) research centres. Stroke patients admitted within 48 h of ischaemic stroke onset, as well as age- and sex-matched controls were enrolled. Beat-to-beat blood pressure (BP) and bilateral mean CBFv were recorded during 5 min baseline. CrCP and RAP were calculated. CA was quantified using transfer function analysis (TFA) of spontaneous oscillations in arterial BP
Though genetic and environmental determinants of systemic haemodynamic have been reported, surprisingly little is known about their influences on cerebral haemodynamics. We assessed the potential geographical effect on cerebral haemodynamics by comparing the individual differences in cerebral blood flow velocity (CBFv), vasomotor tone (critical closing pressure- CrCP), vascular bed resistance (resistance-area product- RAP) and cerebral autoregulation (CA) mechanism on healthy subjects and acute ischaemic stroke (AIS) patients from two countries. Participants were pooled from databases in Leicester, United Kingdom (LEI) and São Paulo, Brazil (SP) research centres. Stroke patients admitted within 48 h of ischaemic stroke onset, as well as age- and sex-matched controls were enrolled. Beat-to-beat blood pressure (BP) and bilateral mean CBFv were recorded during 5 min baseline. CrCP and RAP were calculated. CA was quantified using transfer function analysis (TFA) of spontaneous oscillations in arterial BP
The goal of this study was to determine if regional cerebral blood flow (rCBF)in the left and right hemithalami or the left and right heads of the cau
TY - JOUR. T1 - Opioids and the prostanoid system in the control of cerebral blood flow in hypotensive piglets. AU - Armstead, W. M.. AU - Mirro, R.. AU - Busija, D. W.. AU - Leffler, Charles. PY - 1991/1/1. Y1 - 1991/1/1. N2 - The interaction between opioid and prostanoid mechanisms in the control of cerebral hemodynamics was investigated in the conscious hypotensive piglet. Radiomicrospheres were used to determine regional cerebral blood flow (rCBF) in piglets pretreated with the opioid receptor antagonist, naloxone, or its vehicle, saline, during normotension, hypotension, and after the administration of indomethacin, a cyclooxygenase inhibitor, during hypotension. Hemorrhage (30 ml/kg) decreased systemic arterial pressure from 68 ± 12 to 40 ± 10 mm Hg but did not decrease blood flow to any brain region. Indomethacin treatment (5 mg/kg) of hypotensive piglets decreased blood flow to all brain regions within 20 min; this decrease blood flow to all brain regions within 20 rebral vascular ...
Continuous recording of mean cerebral blood flow velocity (MCBFV) by Doppler ultrasound allows detection of low-frequency (LF) oscillations, which reflect sympathetic activity in the cerebral circulation. To establish whether the sympathetic drive to the cerebral circulation is altered in patients with compensated cirrhosis, and, if so, where alterations take place, LF oscillations of MCBFV, heart rate (RR interval) and systolic arterial pressure (SAP) were analysed in 10 patients with cirrhosis and 10 control subjects during supine rest and on stimulation of carotid baroreceptors using a neck chamber applying sinusoidal suction. Bivariate analysis was used to study the relationship between pairs of oscillations. In the case of a significant association, the delay in the appearance of the oscillation in MCBFV, SAP and RR was calculated. Baroreceptor stimulation induced significant increases in SAP LF and RR LF power in both groups, while MCBFV LF power increased only in controls. During ...
Standard techniques of cerebral blood flow (CBF) measurement provide information on both global and regional flow in patients with cerebral ischaemia or infarction. Recent availability of positron emission tomography (PET), recording oxygen and glucose metabolism, as well as blood flow and blood volume, gives a more detailed and accurate understanding of pathophysiological changes after stroke.. Changes in cerebral infarction. NON-ISCHAEMIC HEMISPHERE. Mild reduction in global CBF - perhaps due to transneuronal depression of metabolism in the unaffected hemisphere - diaschisis.. In the normal brain, cerebral blood flow to a particular part varies depending on the metabolic requirements, i.e. the supply of 02 and glucose is coupled to the tissue needs. After infarction, between areas of reduced flow and areas of luxury perfusion, lie areas of relative luxury perfusion where reduced flow exceeds the tissue requirements, i.e. uncoupling of flow and metabolism has occurred.. Studies with SPECT ...
The effects of positioning of head of bed positioning on blood flow reaching the brain can now be monitored non-invasively and continuously using a new device designed by University of Pennsylvania.
This study was performed to investigate the regulatory mechanism of cerebral blood flow of adenosine A $_{2B}$ receptor agonist in the rats, and to define whether its mechanism is mediated by adenylate cyclase, guanylate cyclase and potassium channel. In pentobarbital-anesthetized, pancuronium-par...
Cerebral blood flow and metabolism have been evaluated during exercise to elicit robust "activation" compared with during anaesthesia. It is demonstrated that physical exercise requires an approximately 20 % increase in cerebral blood flow and metabolic rate for oxygen. This reflects that low intensity exercise is associated with increasing cerebral oxygenation, while cerebral oxygenation decreases during maximal exercise, since marked hyperventilation reduces arterial carbon dioxide tension and therefore cerebral blood flow at the same time as the metabolic rate for oxygen is elevated ...
Type 2 diabetes exerts complex effects on cerebral microvasculature that may alter cerebral blood flow regulation. We found a decrease of mean BFV and an increase of CVR in type 2 diabetic patients during baseline, hypocapnia, and hypercapnia. Baseline mean BFV was negatively associated with periventricular WMH grade and volume on T2-weighted images and with A1C and inflammation markers. WMHs were also linked with uncontrolled diabetes, elevated CVR, and impaired CO2 reactivity. The relationship between WMH, uncontrolled diabetes and reduced BFV is of clinical relevance as a potential mechanism for cerebrovascular disease in elderly with type 2 diabetes.. Aging is associated with brain atrophy, changes in frontal subcortical white matter, and executive cognitive dysfunction (9). The CO2 reactivity diminishes with age, uncontrolled diabetes, and risk factors for atherosclerosis (22). In community-living elderly people, blood flow in the WMHs was lower compared with normal-appearing white matter ...
BACKGROUND: The pathophysiology of cerebral ischemia is well studied in small-animal models, which offer reproducibility and control of confounding variables-factors essential to hypothesis-testing. This presentation first highlights insights into the ischemic penumbra enabled by a multimodal experimental approach; second, discusses gene expression in ischemia; and third, confronts the challenges of neuroprotectant therapy. Summary of Review- The ischemic penumbra: Transient (2-hour) middle cerebral artery suture-occlusion in anesthetized rats gives rise to highly consistent neurological and histopathological sequelae. Autoradiographic local cerebral blood flow (LCBF) studies at 2 hours of occlusion define the penumbra as a region of intermediate CBF depression (20% to 40% of control) surrounding the densely ischemic core (5% to 20% of control) and constituting one half of the entire lesion. Local glucose metabolic rate in the acute penumbra is not reduced despite the critical CBF reduction, so ...
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Authors: Feldstein CA.. Epidemiological studies suggest an association between chronic blood pressure (BP) changes and Alzheimers disease (AD). In particular, there is growing evidence that hypertensive people that do not have their BP adequately treated and controlled in midlife are more likely to develop AD in late-life. It has been hypothesized that cerebrovascular disease is a common pathway which connects hypertension and AD in individuals with apolipoprotein E genotype through brain hypoperfusion and hypoxia. This could accelerate amyloid-β aggregation that disrupts cell-to-cell connectivity and leads to eventual brain neuron loss. Also, high BP contributes to worsen AD by raising oxidative stress and inflammatory response. Aging-related structural and functional disturbances appear to exacerbate the deleterious effect of chronic hypertension on cerebral blood flow autoregulation. There is evidence suggesting that some antihypertensive drug classes reduce the risk and progression of AD ...
Authors: Feldstein CA.. Epidemiological studies suggest an association between chronic blood pressure (BP) changes and Alzheimers disease (AD). In particular, there is growing evidence that hypertensive people that do not have their BP adequately treated and controlled in midlife are more likely to develop AD in late-life. It has been hypothesized that cerebrovascular disease is a common pathway which connects hypertension and AD in individuals with apolipoprotein E genotype through brain hypoperfusion and hypoxia. This could accelerate amyloid-β aggregation that disrupts cell-to-cell connectivity and leads to eventual brain neuron loss. Also, high BP contributes to worsen AD by raising oxidative stress and inflammatory response. Aging-related structural and functional disturbances appear to exacerbate the deleterious effect of chronic hypertension on cerebral blood flow autoregulation. There is evidence suggesting that some antihypertensive drug classes reduce the risk and progression of AD ...
Firstly, is like to say that over the years Ive tried various supplements in an attempt to maximize my brain power and unlock its potential - you name it, Ive probably tried it. Lately, Ive been testing the effects of L-Arginine and the role it plays in nitric oxide production, a potent vasodilator that is imperitive to cardiovascular health. Many gentlemen seek this for the promise it shows in cases of ED, but Ive no need to stimulate blood flow to my "second brain", Im only interested in trying to increase cerebral blood flow for the sake of cognitive improvement.. Anyway, I first bought a bottle of generic L-Arginine from Sprouts, but didnt seem to get much from it. Then I read another study, and thought Id try again with a different brand. Thats when I found this product. I dont really suffer with hypertension, but after just a week of using it, my systolic blood pressure saw an average decline of 5mm/Hg. Its a subtle change, but Im not complaining - any strain I can take off my ...
By measuring brain blood flow noninvasively using arterial spin labeling (ASL) MRI, we can now begin to detect brain changes much earlier than before," said Dr. Sina Aslan, founder and president of Advance MRI and collaborator on the study. "One key region where we saw increases in brain blood flow was the anterior cingulate, indicating higher neuronal activity and metabolic rate. The anterior cingulate has been linked to superior cognition in late life.". Exercisers who improved their memory performance also showed greater increase in brain blood flow to the hippocampus, the key brain region affected by Alzheimers disease. Chapman pointed out that by using noninvasive brain imaging techniques, brain changes were identified earlier than memory improvements, implicating brain blood flow as a promising and sensitive metric of brain health gains across treatment regimens.. "Physical exercise may be one of the most beneficial and cost-effective therapies widely available to everyone to elevate ...
Aged, Aged; 80 and over, Brain/*metabolism, Carotid Stenosis/physiopathology/surgery, Cerebrovascular Circulation/*physiology, Constriction, Endarterectomy; Carotid, Female, Humans, Male, Middle Aged, Oximetry, Oxygen/*blood, Prospective Studies, Regional Blood Flow, Research Support; Non-U.S. Govt, Spectroscopy; Near-Infrared ...
In this single-center observational cohort study of 68 patients and 27 control participants, early ischemia was common in patients, but hyperemia coexisted in different brain regions. Cerebral blood volume was consistently increased, despite low cerebral blood flow. Read more.. ...
CSH is a very uncommon lesion and is distinctly unusual in the brain. This case illustrates advanced imaging findings of this rare process. We believe that the slightly increased regional cerebral blood volume and increased regional cerebral blood flow are related to hyperemia from the underlying reactive/inflammatory process. Additionally, we postulate that the flow-void-like areas on FLAIR imaging represent prominent veins, which result from the partial perivascular nature of the inflammation. Mild postcontrast enhancement likely relates to an element of breakdown at the blood-brain barrier from the same process. NAA is a marker of neuronal cell health. Decreased NAA peak is commonly seen in nonspecific neuronal loss, including ischemia, trauma, inflammation, infection, tumors, dementia, and gliosis. Choline is a marker of membrane turnover and is present to a greater degree in white matter than in gray matter. Choline is increased in tumors, inflammation, and chronic hypoxia. Lactate is not ...
Increasing brain circulation, Using Meditation To Lower Heart Rate And Improve Circulation. after running, your heart pumps more blood because your brain and body need more oxygen.
Cerebral metabolism (typically given by the cerebral metabolic requirement for oxgygen, CMRO2) has a linear association with cerebral blood flow - this is known as flow-metabolism coupling. This is controlled locally through the release of vasoactive mediators, such as H+, adenosine, and NO. Determinants of cerebral metabolism include:. ...
TY - JOUR. T1 - Age-related cerebrovascular reactivity to CO2 after cerebral ischemia in swine. AU - Helfaer, M. A.. AU - Kirsch, J. R.. AU - Haun, S. E.. AU - Koehler, Raymond C. AU - Traystman, R. J.. PY - 1991. Y1 - 1991. N2 - We tested the hypothesis that cerebral blood flow (CBF) reactivity to CO2 after global ischemia takes longer to recover in 1- to 2-wk-old piglets than in 6- to 10-mo-old pigs. All animals were sedated with ketamine and anesthetized with pentobarbital sodium. Cerebral ischemia was produced by sequentially tightening ligatures around the inferior vena cava and ascending aorta for 10 min. The microsphere-determined CBF response to hypercapnia (arterial PCO2 ~65 mmHg) was depressed at 60 min of reperfusion (9 ± 6% of preischemia; means ± SE) and remained depressed at 120 min (33 ± 23% of preischemia, means ± SE) in young pigs. In older pigs, the response was also depressed at 60 min of reperfusion (21 ± 9% of preischemia) but was not depressed at 120 min. The pattern ...
Functional magnetic resonance imaging, or fMRI for short, is a non-invasive method with which changes in local cerebral blood flow can be viewed superimposed on anatomical reconstructions of the brain in humans. The spin axes of the nuclei of hydrogen atoms are aligned upright in a strong magnetic field. Short radio pulses deflect the spin axes. Small discrepancies in the time that the nuclei take to newly upright their axes are dependent on the blood oxygenation. fMRI uses blood oxygen level-dependent (BOLD) signals. Brain tissue cannot store the oxygen and sugar brain cells need to function. Therefore, local blood flow increases when nerve cells start processing information and the blood oxygen level rises. Conversely, blood flow diminishes when nerve cell activity is inhibited. With fMRI, scientists exploit the relationship between nerve cell activity and blood flow to reconstruct functional cerebral activation maps. It is important to note that, while nerve cells respond to sensory ...