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https://www.readbyqxmd.com/read/27923636/the-impact-of-early-aerobic-exercise-on-brain-microvascular-alterations-induced-by-cerebral-hypoperfusion
#1
Marina Leardini-Tristão, Juliana Pereira Borges, Felipe Freitas, Raquel Rangel, Anissa Daliry, Eduardo Tibiriçá, Vanessa Estato
The therapeutic potential of early exercise training following cerebral hypoperfusion was investigated on brain perfusion and inflammation in rats with permanent bilateral occlusion of the common carotid arteries (2VO). Wistar rats were subjected to 2VO or sham surgery and each group was then subdivided randomly into sedentary orexercisegroups. Early exercise training was initiated after three days of 2VO or sham surgery and consisted of seven days of treadmill training (30 min/day at ∼60% of maximal exercise test), composing four groups: 1) Sham sedentary (Sham-Sed), 2) Sham exercised (Sham-Ex), 3) 2VO sedentary (2VO-Sed) and 4) 2VO exercised (2VO-Ex)...
December 3, 2016: Brain Research
https://www.readbyqxmd.com/read/27910802/near-infrared-spectroscopy-evaluated-cerebral-oxygenation-during-anesthesia
#2
Henrik Sørensen
Likely, maintained organ and notably cerebral perfusion, secures rapid recovery following anesthesia. To secure cerebral blood flow (CBF) at least mean arterial pressure (MAP) and the arterial carbon dioxide tension (PaCO2) need to be considered. CBF is "autoregulated", i.e. stays more or less stable within a MAP of 50-150 mmHg, but the lower limit appears to depend on the central blood volume and/or cardiac output, illustrated by a decrease in CBF at a MAP of 80 mmHg with a compromised central blood volume, while CBF remains constant with a MAP < 40 mmHg, if the central blood volume is maintained...
December 2016: Danish Medical Journal
https://www.readbyqxmd.com/read/27907083/effects-of-acute-systemic-hypoxia-and-hypercapnia-on-brain-damage-in-a-rat-model-of-hypoxia-ischemia
#3
Wanchao Yang, Xuezhong Zhang, Nan Wang, Jing Tan, Xianhai Fang, Qi Wang, Tao Tao, Wenzhi Li
Therapeutic hypercapnia has the potential for neuroprotection after global cerebral ischemia. Here we further investigated the effects of different degrees of acute systemic hypoxia in combination with hypercapnia on brain damage in a rat model of hypoxia and ischemia. Adult wistar rats underwent unilateral common carotid artery (CCA) ligation for 60 min followed by ventilation with normoxic or systemic hypoxic gas containing 11%O2,13%O2,15%O2 and 18%O2 (targeted to PaO2 30-39 mmHg, 40-49 mmHg, 50-59 mmHg, and 60-69 mmHg, respectively) or systemic hypoxic gas containing 8% carbon dioxide (targeted to PaCO2 60-80 mmHg) for 180 min...
2016: PloS One
https://www.readbyqxmd.com/read/27902858/reliable-estimation-of-microvascular-flow-patterns-in-patients-with-disrupted-blood-brain-barrier-using-dynamic-susceptibility-contrast-mri
#4
Mikkel Bo Hansen, Anna Tietze, Jayashree Kalpathy-Cramer, Elizabeth R Gerstner, Tracy T Batchelor, Leif Østergaard, Kim Mouridsen
PURPOSE: To present and quantify the performance of a method to compute tissue hemodynamic parameters from dynamic susceptibility contrast (DSC) MRI data in brain tissue with possible nonintact blood-brain barrier. THEORY AND MATERIALS AND METHODS: We propose a Bayesian scheme to obtain perfusion metrics, including capillary transit-time heterogeneity (CTH), from DSC-MRI data in the presence of contrast agent extravasation. Initial performance assessment is performed through simulations...
November 30, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27900535/evaluation-of-cerebral-circulation-during-retrograde-perfusion-by-laser-speckle-flowgraphy
#5
Fumiaki Kimura, Hirotsugu Kanda, Yuki Toyama, Takayuki Kunisawa, Taiji Nagaoka, Akitoshi Yoshida, Hiroto Kitahara, Hiroyuki Kamiya
Laser speckle flowgraphy (LSFG) is an ophthalmologic equipment that qualitatively detects the blood flow of the optic nerve head, which is known to be related with cerebral microcirculation. LSFG can also measure the mean blur rate, which quantitatively calculates the blood flow. We aimed to assess the utility of LSFG in the evaluation of cerebral perfusion during aortic surgery under hypothermic circulatory arrest with retrograde and antegrade cerebral perfusion. Two patients underwent total arch replacement for aneurysm...
November 29, 2016: General Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/27897064/diagnosis-of-dementia-with-lewy-bodies-can-123-i-imp-and-123-i-mibg-scintigraphy-yield-new-core-features
#6
Fumi Sakamoto, Shinya Shiraishi, Noriko Tsuda, Mamoru Hashimoto, Seiji Tomiguchi, Manabu Ikeda, Yasuyuki Yamashita
OBJECTIVE: Since the clinical symptoms of different types of dementia frequently overlap, especially in the earlier stages at onset, it is difficult to distinguish dementias with Lewy bodies (DLB) from other neurodegenerative dementias based on their clinical manifestations alone. Nuclear medicine imaging has been reported as a high-value index for the objective evaluation and diagnosis of DLB. The aim of this study was to evaluate whether nuclear medicine imaging findings may yield core features to be added to the diagnosis of DLB...
November 29, 2016: British Journal of Radiology
https://www.readbyqxmd.com/read/27896005/cerebral-blood-flow-is-decoupled-from-blood-pressure-and-linked-to-eeg-bursting-after-resuscitation-from-cardiac-arrest
#7
Christian Crouzet, Robert H Wilson, Afsheen Bazrafkan, Maryam H Farahabadi, Donald Lee, Juan Alcocer, Bruce J Tromberg, Bernard Choi, Yama Akbari
In the present study, we have developed a multi-modal instrument that combines laser speckle imaging, arterial blood pressure, and electroencephalography (EEG) to quantitatively assess cerebral blood flow (CBF), mean arterial pressure (MAP), and brain electrophysiology before, during, and after asphyxial cardiac arrest (CA) and resuscitation. Using the acquired data, we quantified the time and magnitude of the CBF hyperemic peak and stabilized hypoperfusion after resuscitation. Furthermore, we assessed the correlation between CBF and MAP before and after stabilized hypoperfusion...
November 1, 2016: Biomedical Optics Express
https://www.readbyqxmd.com/read/27894887/ultrasound-tissue-pulsatility-imaging-suggests-impairment-in-global-brain-pulsatility-and-small-vessels-in-elderly-patients-with-orthostatic-hypotension
#8
Julie Biogeau, Thomas Desmidt, Paul-Armand Dujardin, Redouane Ternifi, Charlotte Eudo, Emilie Vierron, Jean-Pierre Remenieras, Frédéric Patat, Vincent Camus, Thierry Constans
BACKGROUND: Orthostatic hypotension (OH) is highly prevalent in the elderly, and this population can be exposed to serious complications, including falls and cognitive disorders, as well as overall mortality. However, the pathophysiology of OH is still poorly understood, and innovative methods of cerebral blood flow (CBF) assessment have been required to accurately investigate cerebrovascular reactivity in OH. OBJECTIVES: We want to compare brain tissue pulsatility (BTP) changes during an orthostatic challenge in elderly patients over 80 with and without OH...
November 25, 2016: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
https://www.readbyqxmd.com/read/27881556/nitrite-and-s-nitrosohemoglobin-exchange-across-the-human-cerebral-and-femoral-circulation-relationship-to-basal-and-exercise-blood-flow-responses-to-hypoxia
#9
Damian M Bailey, Peter Rasmussen, Morten Overgaard, Kevin A Evans, Aske M Bohm, Thomas Seifert, Patrice Brassard, Morten Zaar, Henning B Nielsen, Peter Raven, Niels H Secher
BACKGROUND: -The mechanisms underlying red blood cell (RBC)-mediated hypoxic vasodilation remain controversial with separate roles for nitrite (NO2(-)) and S-nitrosohemoglobin (SNO-Hb) widely contested given their ability to transduce nitric oxide (NO) bioactivity within the microcirculation. To establish their relative contribution in vivo, we quantified arterial-venous (a-v) concentration gradients across the human cerebral and femoral circulation at rest and during exercise, an ideal model system characterized by physiological extremes of O2 tension and blood flow...
November 15, 2016: Circulation
https://www.readbyqxmd.com/read/27879446/quantification-of-serial-cerebral-blood-flow-in-acute-stroke-using-arterial-spin-labeling
#10
George W J Harston, Thomas W Okell, Fintan Sheerin, Ursula Schulz, Phil Mathieson, Ian Reckless, Kunal Shah, Gary A Ford, Michael A Chappell, Peter Jezzard, James Kennedy
BACKGROUND AND PURPOSE: Perfusion-weighted imaging is used to select patients with acute ischemic stroke for intervention, but knowledge of cerebral perfusion can also inform the understanding of ischemic injury. Arterial spin labeling allows repeated measurement of absolute cerebral blood flow (CBF) without the need for exogenous contrast. The aim of this study was to explore the relationship between dynamic CBF and tissue outcome in the month after stroke onset. METHODS: Patients with nonlacunar ischemic stroke underwent ≤5 repeated magnetic resonance imaging scans at presentation, 2 hours, 1 day, 1 week, and 1 month...
November 22, 2016: Stroke; a Journal of Cerebral Circulation
https://www.readbyqxmd.com/read/27877133/decomposition-of-near-infrared-spectroscopy-signals-using-oblique-subspace-projections-applications-in-brain-hemodynamic-monitoring
#11
Alexander Caicedo, Carolina Varon, Borbala Hunyadi, Maria Papademetriou, Ilias Tachtsidis, Sabine Van Huffel
Clinical data is comprised by a large number of synchronously collected biomedical signals that are measured at different locations. Deciphering the interrelationships of these signals can yield important information about their dependence providing some useful clinical diagnostic data. For instance, by computing the coupling between Near-Infrared Spectroscopy signals (NIRS) and systemic variables the status of the hemodynamic regulation mechanisms can be assessed. In this paper we introduce an algorithm for the decomposition of NIRS signals into additive components...
2016: Frontiers in Physiology
https://www.readbyqxmd.com/read/27873224/therapeutic-potential-of-transdermal-glyceryl-trinitrate-in-the-management-of-acute-stroke
#12
Jason P Appleton, Nikola Sprigg, Philip M Bath
The nitric oxide donor, glyceryl trinitrate (GTN), is a candidate treatment for the management of acute stroke with haemodynamic and potential reperfusion and neuroprotective effects. When administered as a transdermal patch during the acute and subacute phases after stroke, GTN was safe, lowered blood pressure, maintained cerebral blood flow, and did not induce cerebral steal or alter functional outcome. However, when given within 6 h of stroke onset, GTN reduced death and dependency (odds ratio 0.52; 95% confidence interval 0...
November 21, 2016: CNS Drugs
https://www.readbyqxmd.com/read/27871574/cerebral-oxygenation-in-the-beach-chair-position-for-shoulder-surgery-in-regional-anesthesia-impact-on-cerebral-blood-flow-and-neurobehavioral-outcome
#13
José A Aguirre, Olivia Märzendorfer, Muriel Brada, Andrea Saporito, Alain Borgeat, Philipp Bühler
STUDY OBJECTIVE: Beach chair position is considered a potential risk factor for central neurological events particularly if combined with low blood pressure. The aim of this study was to assess the impact of regional anesthesia on cerebral blood flow and neurobehavioral outcome. DESIGN: This is a prospective, assessor-blinded observational study evaluating patients in the beach chair position undergoing shoulder surgery under regional anesthesia. SETTING: University hospital operating room...
December 2016: Journal of Clinical Anesthesia
https://www.readbyqxmd.com/read/27861273/thermodilution-determined-internal-jugular-venous-flow
#14
Peter Rasmussen, Mario Widmer, Matthias P Hilty, Mike Hug, Henrik Sørensen, Shigehiko Ogoh, Kohei Sato, Niels H Secher, Marco Maggiorini, Carsten Lundby
PURPOSE: Cerebral blood flow (CBF) increases ~20% during whole body exercise although a Kety-Schmidt-determined CBF is reported to remain stable; a discrepancy that could reflect evaluation of arterial vs. internal jugular venous (IJV) flow and/or that CBF is influenced by posture. Here we test the hypothesis that IJV flow, as determined by retrograde thermodilution increases during exercise when body position is maintained. METHODS: Introducing retrograde thermodilution, IJV flow was measured in 8 healthy humans at supine and upright rest and during exercise in normoxia and hypoxia with results compared to changes in ultrasound-derived IJV flow and middle cerebral artery mean velocity (MCA Vmean)...
November 17, 2016: Medicine and Science in Sports and Exercise
https://www.readbyqxmd.com/read/27861231/wavelet-based-angiographic-reconstruction-of-computed-tomography-perfusion-data-diagnostic-value-in-cerebral-venous-sinus-thrombosis
#15
Wolfgang G Kunz, Felix Schuler, Wieland H Sommer, Matthias P Fabritius, Lukas Havla, Felix G Meinel, Maximilian F Reiser, Birgit Ertl-Wagner, Kolja M Thierfelder
OBJECTIVE: The aim of this study was to test the diagnostic value of wavelet-based angiographic reconstruction of CT perfusion data (waveletCTA) to detect cerebral venous sinus thrombosis (CVST) in patients who underwent whole-brain CT perfusion imaging (WB-CTP). MATERIALS AND METHODS: Datasets were retrospectively selected from an initial cohort of 2863 consecutive patients who had undergone multiparametric CT including WB-CTP. WaveletCTA was reconstructed from WB-CTP: the angiographic signal was generated by voxel-based wavelet transform of time attenuation curves (TACs) from WB-CTP raw data...
November 17, 2016: Investigative Radiology
https://www.readbyqxmd.com/read/27857034/superficial-temporal-artery-to-middle-cerebral-artery-bypass-with-interposed-saphenous-vein-graft-in-patients-with-atherosclerotic-internal-carotid-artery-occlusive-disease-and-impaired-cerebral-hemodynamics
#16
Petr Galkin, Artem Gushcha, Andrey Chechetkin, Irina Krotenkova
BACKGROUND: The aim of this study was to evaluate the efficacy of interposed saphenous vein graft (SVG) usage during extracranial-intracranial (EC-IC) bypass surgery in patients with cerebral ischemia and appropriate donor artery absence. METHODS: Since October 2010 till January 2014, 62 EC-IC bypass surgeries were applied in 60 patients. In nineteen patients SVG was used to create low-flow bypasses between superficial temporal artery trunk and cortical segment of middle cerebral artery...
February 2017: Journal of Neurosurgical Sciences
https://www.readbyqxmd.com/read/27845320/-perfusion-computed-tomography-in-the-diagnosis-of-mild-brain-injury
#17
I A Balandina, K V Shevchenko, E A Zolotovskaya
AIM: To evaluate and compare the characteristics of the regional cerebral blood flow in patients with mild cerebral concussion or injury using the results of perfusion computed tomography (CT). MATERIAL AND METHODS: Thirty-eight men, aged 18-35 years, including 21 with concussion and 17 with mild cranial/brain injury (CBI), were examined at the early stage of disease. The control group consisted of 7 age-matched men with non-confirmed CBI. RESULTS AND CONCLUSION: The results of CT-perfusion revealed generalized changes in the hemodynamics...
2016: Zhurnal Nevrologii i Psikhiatrii Imeni S.S. Korsakova
https://www.readbyqxmd.com/read/27828873/elevated-markers-of-vascular-remodeling-and-arterial-stiffness-are-associated-with-neurocognitive-function-in-older-hiv-adults-on-suppressive-antiretroviral-therapy
#18
Jessica L Montoya, Jennifer Iudicello, Pariya L Fazeli, Suzi Hong, Michael Potter, Ronald J Ellis, Igor Grant, Scott L Letendre, David J Moore
BACKGROUND: HIV is associated with elevated markers of vascular remodeling that may contribute to arterial fibrosis and stiffening, and changes in pulse pressure (PP). These changes may, in turn, deleteriously affect autoregulation of cerebral blood flow and neurocognitive function. METHODS: To evaluate these mechanisms, we studied markers of vascular remodeling, PP, and neurocognitive function among older (≥50 years of age) HIV-infected (HIV+; n = 72) and HIV-seronegative (HIV-; n = 36) adults...
November 4, 2016: Journal of Acquired Immune Deficiency Syndromes: JAIDS
https://www.readbyqxmd.com/read/27817953/mechanically-assisted-bidirectional-cavopulmonary-shunt-in-neonates-and-infants-an-acute-human-pilot-study
#19
Osami Honjo, Sandra L Merklinger, John B Poe, Anne-Marie Guerguerian, Hargen Zhang, Katherine L Taylor, Glen S Van Arsdell
OBJECTIVE: Poor survival following surgical palliation for hypoplastic left heart syndrome (HLHS) raises the question of the need for a paradigm shift. This is the first human study to investigate the possibility of primary "in-series" palliation in neonates and infants with HLHS in an acute setting with the aid of 2 types of mechanical assist: superior vena cava (SVC)-to-pulmonary artery (PA) pump assist and SVC-to-right atrium (RA) oxygenation assist. METHODS: By rearranging the cannula sites and flow rates for modified ultrafiltration, 2 types of mechanically assisted bidirectional cavopulmonary shunt (BCPS) circulation were simulated for 20 minutes...
September 28, 2016: Journal of Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/27816279/efficacy-of-early-superficial-temporal-artery-middle-cerebral-artery-double-anastomoses-for-atherosclerotic-occlusion-in-patients-with-progressing-stroke
#20
Akihiro Inoue, Kanehisa Kohno, Shinji Iwata, Shiro Ohue, Saya Ozaki, Satoko Ninomiya, Hitomi Tomita, Kenji Kamogawa, Kensho Okamoto, Shinya Fukumoto, Haruhisa Ichikawa, Shinji Onoue, Yawara Nakamura, Bungo Okuda
BACKGROUND: We investigated the efficacy of early superficial temporal artery-middle cerebral artery (STA-MCA) double anastomoses for patients with progressing stroke due to atherosclerotic occlusion. MATERIALS AND METHODS: Nine consecutive patients who underwent early STA-MCA double anastomoses were enrolled. All patients presented with progressing stroke despite maximal medical treatment. Cerebral blood flow in 7 patients was analyzed by single-photon emission tomography...
November 2, 2016: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
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