View clinical trials related to Cerebral Blood Flow.
Filter by:Oral supplements containing exogenous ketones have recently become available and represent a novel tool for increasing plasma ketone bodies without the need for dietary restriction. Early evidence suggests that oral ketone supplements may enhance cerebral blood flow (CBF). However, a higher dose of a ketone monoester has been shown to slightly lower blood pH and reduce end-tidal CO2 (PetCO2) due to compensatory hyperventilation, which is accompanied by parallel reductions in CBF. Whether reductions in PetCO2 causes reductions in CBF is currently unknown. The purpose of this study is to investigate the effect of manipulating PetCO2 at normocapnia (PetCO2 maintained at baseline) or poikilocapnia (no PetCO2 targeting; breathing room air), following the ingestion of a dose of a ketone monoester on CBF and cerebrovascular reactivity to CO2 in young adults.
This study aims to evaluate both Abdominal Normothermic Regional Perfusion (A-NRP) and Thoracoabdominal-NRP (TA-NRP) techniques, proving that brain blood flow is not resumed during NRP. This will be assessed through the use of two modalities: CT angiogram of the brain and continuous Hb02 readings. The study group hypothesise that such assessment methods will provide evidence to indicate that brain blood flow is not present during NRP and promote trust in the use of such novel techniques in routine practice.
Impaired brain vascular function precedes the development of reduced cognitive performance, while brain insulin-resistance is also associated with cognitive decline. Peanut consumption has already been shown to beneficially affect cognitive performance. However, underlying mechanisms have not yet been established, while well-controlled trials on longer-term effects of peanuts on cognitive performance are highly needed. The hypothesis is that longer-term peanut consumption has beneficial effects on (regional) cerebral blood flow responses (primary outcome), which may relate to an improved cognitive performance (secondary outcome) in older men and women. Important objectives are to investigate in older adults the effect of 16-week peanut consumption on (i) brain vascular function in cognitive-control brain areas, and (ii) brain insulin-sensitivity. We will also focus on changes in cognitive performance as assessed with a neuropsychological test battery (secondary objective). Cerebral blood flow responses before (brain vascular function) and after the administration of intranasal insulin (brain insulin sensitivity) will be non-invasively quantified by the non-invasive gold standard magnetic resonance imaging (MRI)-perfusion method Arterial Spin Labeling (ASL).
A randomized controlled clinical trial evaluates cerebral blood flow changes associated with HFOV-VG in comparison to HFOV alone in preterm neonates with respiratory insufficiency during the period of invasive respiratory support
The prevalence of cognitive impairment in maintenance hemodialysis (MHD) patients is 3 to 5 times higher than that in ordinary people, so it is essential to find the associated risk factors in this population. This project intends to evaluate whether changes in cerebral blood flow during dialysis have an impact on cognitive function in middle-aged and elderly MHD patients and clarify their influence on brain imaging characteristics. MHD patients who started hemodialysis at 3 to 6 months were selected to examine the difference in middle cerebral artery flow rate before and after dialysis by transcranial Doppler ultrasound to reflect the changes in cerebral blood flow. Changes in the cognitive function scale assessment (memory, executive function, and other five cognitive domains) and brain magnetic resonance imaging examinations are planned to collect both at baseline and after a one-year follow-up. Then the investigator used the multiple linear regression method to analyze the effects of the difference in middle cerebral artery flow on the changes in cognitive function and the characteristics in brain imaging. The investigators anticipate that the characteristics of the influence of changes in cerebral blood flow on cognitive impairment in Chinese MHD patients will be elucidated in this study, which may provide crucial clinical evidence for finding preventive and intervention measures for cognitive impairment in this group of population.
The cognitive trajectory varies among non-demented older adults. In a 12-year follow-up study, we found approximately 5% participants presented rapid cognitive decline. Cardiovascular diseases increased the risk of cognitive decline. However, the influence of cardiovascular risk factors on cognitive decline remained inconsistent. Besides, the potential mechanism of the cardiovascular risk factors and cognitive function has not been fully investigated. Therefore, the proposed program will include two sub-studies. The first sub-study will use the longitudinal data from the Chinese Longitudinal Healthy Longevity Survey to evaluate the influence of cardiovascular risk factors on the trajectories of cognitive function. The second sub-study will recruit cognitive intact older adults with different levels of cardiovascular risk factors. The association among cardiovascular risk factors, cerebral blood flow, brain functional connectivity and cognitive function will be investigated with structural equation modeling. The findings of the proposed program will provide novel insight on preventing cognitive decline from the angle of maintaining healthy vascular function, and will provide evidence in elucidating the potential neurovascular mechanism between cardiovascular risk factors and cognitive function.
A randomized controlled trial will be conducted. Patients with asymptomatic intracranial / carotid stenosis will be randomized into two arms (1:1): an intervention arm and a control arm. Patients in the intervention arm will be treated with standard medical treatment combined with Natto Products V, whereas Patient in the control arm will be treated with only standard medical treatment . And the impact of Natto Products V on improving cerebral blood flow and cognitive function in patients with asymptomatic intracranial / carotid stenosis will be assessed by neuropsychological scale and multimode magnetic resonance imaging.
Prone position (PP) is a key component to treat hypoxemia in patients with severe acute respiratory distress syndrome (ARDS). However, most studies evaluating PP effects in patients with ARDS exclude those with brain-injuries without providing any medical evidence. This prospectice observational study aimed to investigate if prone positioning leads to significant modification of cerebral perfusion in brain-injured patients with ARDS.
Although spontaneous hyperventilation patients with aneurysmal subarachnoid hemorrhage closely associated with poor outcomes, the standard therapy remains unavailable. Remifentanil has the pharmacological characterization of respiratory inhibition, mainly prolonging the expiratory time and decreasing the respiratory rate while preserving the respiratory drive. The investigators hypothesis that spontaneous hyperventilation could be corrected by titrating the dose of remifentanil and cerebral blood flow will augment during this process.
The purpose of this study is to explore the changes of fasting and postprandial cerebral blood flow in patients with type 2 diabetes mellitus. Some studies have proved that non-fasting blood glucose concentration is an independent predictor of ischemic stroke and lacunar infarction. At present, there are differences in cerebral blood flow velocity between diabetic patients and healthy controls. Therefore, it is of certain significance to explore the changes of fasting and postprandial cerebral blood flow in patients with type 2 diabetes mellitus.