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https://www.readbyqxmd.com/read/28925802/higher-prevalence-of-spontaneous-cerebral-vasculopathy-and-cerebral-infarcts-in-a-mouse-model-of-sickle-cell-disease
#1
Hyacinth I Hyacinth, Courtney L Sugihara, Thomas L Spencer, David R Archer, Andy Y Shih
Stroke is a dramatic complication of sickle cell disease (SCD), which is associated with cerebral vasculopathies including moya moya, intravascular thrombi, cerebral hyperemia, and increased vessel tortuosity. The spontaneous occurrence of these pathologies in the sickle cell mouse model has not been described. Here, we studied Townes humanized sickle cell and age-matched control mice that were 13 months old. We used in vivo two-photon microscopy to assess blood flow dynamics, vascular topology, and evidence of cerebral vasculopathy...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28925529/cerebrovascular-response-to-the-cold-pressor-test-the-critical-role-of-carbon-dioxide
#2
Michael M Tymko, Thijs P Kerstens, Kevin W Wildfong, Philip N Ainslie
In addition to increasing sympathetic nervous activity, blood pressure, and cerebral blood flow (CBF), the cold pressor test (CPT) stimulates pain receptors, which may increase ventilation above metabolic demand; this response likely reduces the partial pressure of end-tidal carbon dioxide (PET CO2 ), and will attenuate elevations in CBF. We hypothesized: (1) CPT would elicit hyperventilation, effectively lowering PET CO2 ; (2) the CBF response will be elevated during an isocapnic (controlled PET CO2 ), compared to a poikilocapnic CPT (uncontrolled PET CO2 ); (3) In response to CPT, the common carotid artery (CCA) will vasodilatate, while the internal carotid artery (ICA) will remain unchanged to help regulate CBF...
September 19, 2017: Experimental Physiology
https://www.readbyqxmd.com/read/28919267/post-carotid-endarterectomy-hypertension-part-2-association-with-peri-operative-clinical-anaesthetic-and-transcranial-doppler-derived-parameters
#3
Jeremy E Newman, Mathew J Bown, Robert D Sayers, Jonathan P Thompson, Thompson G Robinson, Bryan Williams, Ronney Panerai, Peter Lacy, A Ross Naylor
OBJECTIVE/BACKGROUND: The first paper in this series observed that pre-operative baroreceptor dysfunction and poorly controlled hypertension were independently predictive for identifying patients who went on to require treatment for post-endarterectomy hypertension (PEH). The second paper examines the influence of intra-operative patient, transcranial Doppler (TCD) ultrasound, and anaesthetic variables on the incidence of PEH. METHODS: In total, 106 patients underwent carotid endarterectomy (CEA) under general anaesthesia...
September 14, 2017: European Journal of Vascular and Endovascular Surgery
https://www.readbyqxmd.com/read/28914134/blunted-cerebrovascular-response-is-associated-with-elevated-beta-amyloid
#4
Jason-Flor V Sisante, Eric D Vidoni, Kiersten Kirkendoll, Jaimie Ward, Yumei Liu, Sarah Kwapiszeski, Rebecca Maletsky, Jeffrey M Burns, Sandra A Billinger
The goal of this study was to explore the association of beta-amyloid accumulation and cerebrovascular response (CVR) in cognitively normal older adults. Beta-amyloid accumulation was characterized with [18F] Florbetapir positron emission tomography scans. CVR was calculated as middle cerebral artery blood flow velocity change from rest to moderate intensity exercise. We found that individuals with elevated beta-amyloid aggregation had a blunted CVR ( n = 25, age 70.1 ± 4.8; 3.3 ± 3.7 cm/s) compared to non-elevated individuals ( n = 45, age 72...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28913763/a-patient-specific-three-dimensional-hemodynamic-model-of-the-circle-of-willis
#5
Hamed Rezaie, Ali Ashrafizadeh, Afsaneh Mojra
Circle of Willis (CoW) is one of the most important cerebral arteries in the human body and various attempts have been made to study the hemodynamic of blood flow in this vital part of the brain. In the present study, blood flow in a patient specific CoW is numerically modeled to predict disease-prone regions of the CoW. Medical images and computer aided design software are used to construct a realistic three-dimensional model of the CoW for this particular case. The arteries are considered as elastic conduits and the interactions between arterial walls and the blood flow are taken into account...
September 14, 2017: Cardiovascular Engineering and Technology
https://www.readbyqxmd.com/read/28912713/meta-analysis-for-clinical-evaluation-of-xingnaojing-injection-for-the-treatment-of-cerebral-infarction
#6
REVIEW
Xiao Ma, Yu X Yang, Nian Chen, Qian Xie, Tao Wang, Xuan He, Jian Wang
Objective: Xingnaojing injection (XNJ) is derived from An-Gong-Niu-Huang pill, a well-known traditional Chinese patent medicine, which is widely used for stroke. To evaluate the therapeutic effect of XNJ on cerebral infarction, an extensive meta-analysis was used. Methods: Six major electronic databases including the Chinese Biomedical Database (CBM), Wanfang, the VIP medicine information system (VMIS) and the China National Knowledge Infrastructure (CNKI), PubMed, Embase, and the Cochrane Library were examined to retrieve randomized controlled trials designed to evaluate the clinical efficacy of XNJ in treating CI before November 26, 2016...
2017: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/28912128/aging-modifies-the-effect-of-cardiac-output-on-middle-cerebral-artery-blood-flow-velocity
#7
Anne-Sophie G T Bronzwaer, Jasper Verbree, Wim J Stok, Mat J A P Daemen, Mark A van Buchem, Matthias J P van Osch, Johannes J van Lieshout
An association between cerebral blood flow (CBF) and cardiac output (CO) has been established in young healthy subjects. As of yet it is unclear how this association evolves over the life span. To that purpose, we continuously recorded mean arterial pressure (MAP; finger plethysmography), CO (pulse contour; CO-trek), mean blood flow velocity in the middle cerebral artery (MCAV; transcranial Doppler ultrasonography), and end-tidal CO2 partial pressure (PetCO2) in healthy young (19-27 years), middle-aged (51-61 years), and elderly subjects (70-79 years)...
September 2017: Physiological Reports
https://www.readbyqxmd.com/read/28900720/respiration-related-cerebral-blood-flow-variability-increases-during-control-mode-non-invasive-ventilation-in-normovolemia-and-hypovolemia
#8
Maria Skytioti, Signe Søvik, Maja Elstad
PURPOSE: Increased variability in cerebral blood flow (CBF) predisposes to adverse cerebrovascular events. Oscillations in arterial blood pressure and PaCO2 induce CBF variability. Less is known about how heart rate (HR) variability affects CBF. We experimentally reduced respiration-induced HR variability in healthy subjects, hypothesizing that CBF variability would increase. METHODS: Internal carotid artery (ICA) blood velocity was recorded by Doppler ultrasound in ten healthy subjects during baseline, control-mode, non-invasive mechanical ventilation (NIV), i...
September 12, 2017: European Journal of Applied Physiology
https://www.readbyqxmd.com/read/28894559/pattern-of-cerebral-blood-flow-velocity-using-transcranial-doppler-ultrasonography-in-children-with-sickle-cell-disorder-in-lagos-state-nigeria
#9
Motunrayo Oluwabukola Adekunle, Adeola Barakat Animasahun, Ijeoma Nnenna Diaku-Akinwumi, Olisamedua Fidelis Njokanma
Cerebrovascular accident (CVA) is a common, devastating neurological complication of sickle cell disorder (SCD) with a high recurrent and mortality rate. The Stroke Prevention Trial in Sickle Cell Anaemia study (STOP) recommends routine screening with transcranial Doppler ultrasonography in children aged two to sixteen years with SCD. The present study assessed cerebral blood flow velocities of children with SCD in accordance with the recommendation of routine screening by the STOP study. METHODS: Transcranial Doppler ultrasonography was done for children with SCD that attended Sickle Cell Foundation, Nigeria between July and November 2015...
2017: Mediterranean Journal of Hematology and Infectious Diseases
https://www.readbyqxmd.com/read/28892981/effect-of-transdermal-nitroglycerine-on-doppler-velocity-waveforms-of-the-uterine-umbilical-and-fetal-middle-cerebral-arteries-in-patients-with-chronic-placental-insufficiency-a-prospective-rct
#10
Suruchi Gupta, Meenakshi Chauhan, Jyotsna Sen, Smiti Nanda
INTRODUCTION: Increase in Nitric Oxide (NO) may be important in vascular adaptation needed to accommodate increased uteroplacental blood flow as pregnancy advances. Hence, in certain conditions like Pregnancy Induced Hypertension (PIH) and Fetal Growth Restriction (FGR), NO donors may play an effective role in increasing uteroplacental perfusion. Transdermal route appears to be a safe and effective route. AIM: To evaluate the effect of nitroglycerine patch on Doppler velocity waveforms of the uterine, umbilical and fetal middle cerebral arteries in patients with chronic placental insufficiency...
July 2017: Journal of Clinical and Diagnostic Research: JCDR
https://www.readbyqxmd.com/read/28891839/the-relative-effects-of-dexmedetomidine-and-propofol-on-cerebral-blood-flow-velocity-and-regional-brain-oxygenation-a-randomised-noninferiority-trial
#11
Ehab Farag, Michael Kot, Attila Podolyak, Maged Argalious, Milind Deogaonkar, Edward J Mascha, Zekun Xu, Irene Katzan, Zeyd Ebrahim
BACKGROUND: Dexmedetomidine constricts cerebral blood vessels without a concomitant reduction in cerebral metabolic oxygen consumption. Its safety as a sedative in patients with neurological diseases thus remains uncertain. OBJECTIVE: Our primary objective was to test the hypothesis that dexmedetomidine is noninferior to propofol as regards cerebral blood flow (CBF) velocity and brain oxygenation. DESIGN: Unblinded randomised trial. SETTING: Cleveland Clinic Hospital, Cleveland, from November 2010 to July 2013...
June 19, 2017: European Journal of Anaesthesiology
https://www.readbyqxmd.com/read/28887332/the-cerebro-cardiovascular-response-to-periodic-squat-stand-maneuvers-in-healthy-subjects-a-time-domain-analysis
#12
Sam C Barnes, Naomi Ball, Victoria Joanna Haunton, Thompson G Robinson, Ronney B Panerai
BACKGROUND: Squat-stand maneuvers (SSMs) have been used to improve the coherence of transfer function analysis (TFA) estimates during the assessment of dynamic cerebral autoregulation (dCA). There is a need to understand the influence of peripheral changes resulting from SSMs on cerebral blood flow, which might confound estimates of dCA. METHODS: 29 healthy subjects underwent recordings at rest (5 min standing) and 15 SSMs (0.05Hz). Heart rate (3-lead ECG), end-tidal CO2 (capnography), blood pressure (Finometer), cerebral blood velocity (CBV, transcranial Doppler, MCA) and the angle of the thigh (tilt sensor) were measured continuously...
September 8, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28884722/-severe-carotid-stenosis-cerebral-autoregulation-in-the-ipsilateral-region
#13
V B Semenyutin, G А Asaturyan, А А Nikiforova, G К Panuntsev, V A Aliev, V B Iblyaminov, A V Savello, А Patzak, K V Laptev, I P Dudanov, О А Pavlov
AIM: To study cerebral autoregulation (CA) in region of the stenotic carotid artery. MATERIAL AND METHODS: The study involved 35 patients with critical stenosis of the carotid arteries, including 24 patients were asymptomatic and 11 patients with symptomatic course. Blood flow velocity in middle cerebral arteries was monitored using Multi Dop X (DWL, Germany) with simultaneous noninvasive systemic blood pressure registration (CNAP, Austria). CA was assessed by calculating the phase shift (PS) between spontaneous oscillations of blood flow velocity and blood pressure within the range of systemic Mayer waves (80-120 mHz)...
2017: Zhurnal Nevrologii i Psikhiatrii Imeni S.S. Korsakova
https://www.readbyqxmd.com/read/28880397/transcranial-doppler-a-stethoscope-for-the-brain-neurocritical-care-use
#14
REVIEW
Chiara Robba, Danilo Cardim, Mypinder Sekhon, Karol Budohoski, Marek Czosnyka
Transcranial Doppler (TCD) ultrasonography is a noninvasive bedside monitoring technique that can evaluate cerebral blood flow hemodynamics in the intracranial arterial vasculature. TCD allows assessment of linear cerebral blood flow velocity, with a high temporal resolution and is inexpensive, reproducible, and portable. The aim of this review is to provide an overview of the most commonly used TCD derived signals and measurements used commonly in neurocritical care. We describe both basic (flow velocity, pulsatility index) and advanced concepts, including critical closing pressure, wall tension, autoregulation, noninvasive intracranial pressure, brain compliance, and cerebrovascular time constant; we also describe the clinical applications of TCD to highlight their utility in the diagnosis and monitoring of cerebrovascular diseases as the "stethoscope for the brain...
September 7, 2017: Journal of Neuroscience Research
https://www.readbyqxmd.com/read/28877097/application-of-transcranial-color-doppler-ultrasonography-for-assessing-middle-cerebral-arteries-in-rheumatoid-arthritis
#15
Qiuyue Chen, Shilin Li, Guorong Lv, Yanchun Zhao
To assess the role of ultrasonography for assessing middle cerebral arteries (MCAs) in rheumatoid arthritis (RA). Middle cerebral arteries of 32 RA patients and 32 healthy volunteers were examined by ultrasonography. Peak systolic blood flow velocity (PSV), end-diastolic velocity, and resistance index (RI) of MCA were measured using Doppler ultrasound. Results were expressed as mean ± SD. No significant difference in peak systolic velocity was obtained between RA patients (52.44 ± 19.56 cm/s) and healthy volunteers (51...
September 4, 2017: Ultrasound Quarterly
https://www.readbyqxmd.com/read/28864026/cardiac-cycle-induced-epi-time-series-fluctuations-in-the-brain-their-temporal-shifts-inflow-effects-and-t2-%C3%A2-fluctuations
#16
Olivia Viessmann, Harald E Möller, Peter Jezzard
The cardiac-induced arterial pressure wave causes changes in cerebral blood flow velocities and volumes that affect the signals in echo-planar imaging (EPI). Using single-echo EPI time series data, acquired fast enough to unalias the cardiac frequency, we found that the cardiac cycle-induced signal fluctuations are delayed differentially in different brain regions. When referenced to the time series in larger arterial structures, the cortical voxels are only minimally shifted but significant shifts are observed in subcortical areas...
August 31, 2017: NeuroImage
https://www.readbyqxmd.com/read/28862474/tympanic-membrane-temperature-decreases-during-head-up-tilt-relation-to-frontal-lobe-oxygenation-and-middle-cerebral-artery-mean-blood-flow-velocity
#17
David Lorr, Anton Lund, Mats Fredrikson, Niels H Secher
INTRODUCTION: Changes in blood flow influence temperature of surrounding tissues. Since the internal carotid artery (ICA) and internal jugular vein (IJV) neighbor the tympanic membrane, changes in their blood flow most likely determine changes in tympanic membrane temperature (TMT). We sought to evaluate the relationship between changes during a head-up tilt (HUT) induced reduction in cerebral blood flow (CBF) and TMT. METHODS: Ten male subjects (age 19-28 years) underwent 50° HUT until presyncope...
September 1, 2017: Scandinavian Journal of Clinical and Laboratory Investigation
https://www.readbyqxmd.com/read/28860964/inter-individual-relationships-between-sympathetic-arterial-baroreflex-function-and-cerebral-perfusion-control-in-healthy-males
#18
Trevor Witter, Yu-Chieh Tzeng, Terry O'Donnell, Jessica Kusel, Bridget Walker, Mary Berry, Chloe E Taylor
Maintenance of adequate cerebral perfusion during normal physiological challenges requires integration between cerebral blood flow (CBF) and systemic blood pressure control mechanisms. Previous studies have shown that cardiac baroreflex sensitivity (BRS) is inversely related to some measures of cerebral autoregulation. However, interactions between the sympathetic arterial baroreflex and cerebral perfusion control mechanisms have not been explored. To determine the nature and magnitude of these interactions we measured R-R interval, blood pressure, CBF velocity, and muscle sympathetic nerve activity (MSNA) in 11 healthy young males...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28855602/cognitive-function-during-exercise-under-severe-hypoxia
#19
Takaaki Komiyama, Keisho Katayama, Mizuki Sudo, Koji Ishida, Yasuki Higaki, Soichi Ando
Acute exercise has been demonstrated to improve cognitive function. In contrast, severe hypoxia can impair cognitive function. Hence, cognitive function during exercise under severe hypoxia may be determined by the balance between the beneficial effects of exercise and the detrimental effects of severe hypoxia. However, the physiological factors that determine cognitive function during exercise under hypoxia remain unclear. Here, we examined the combined effects of acute exercise and severe hypoxia on cognitive function and identified physiological factors that determine cognitive function during exercise under severe hypoxia...
August 30, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28854913/reduced-growth-velocity-across-the-third-trimester-is-associated-with-placental-insufficiency-in-fetuses-born-at-a-normal-birthweight-a-prospective-cohort-study
#20
Teresa M MacDonald, Lisa Hui, Stephen Tong, Alice J Robinson, Kirsten M Dane, Anna L Middleton, Susan P Walker
BACKGROUND: While being small-for-gestational-age due to placental insufficiency is a major risk factor for stillbirth, 50% of stillbirths occur in appropriate-for-gestational-age (AGA, > 10th centile) fetuses. AGA fetuses are plausibly also at risk of stillbirth if placental insufficiency is present. Such fetuses may be expected to demonstrate declining growth trajectory across pregnancy, although they do not fall below the 10th centile before birth. We investigated whether reduced growth velocity in AGA fetuses is associated with antenatal, intrapartum and neonatal indicators of placental insufficiency...
August 31, 2017: BMC Medicine
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