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Transcranial doppler ultrasound

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https://www.readbyqxmd.com/read/28204998/discrimination-between-emboli-and-artifacts-for-outpatient-transcranial-doppler-ultrasound-data
#1
Blaise Kévin Guépié, Bruno Sciolla, Fabien Millioz, Marilys Almar, Philippe Delachartre
This paper addresses the detection of emboli in transcranial Doppler ultrasound data acquired from an original portable device. The challenge is the removal of several artifacts (motion and voice) intrinsically related to long-duration (up to 1 h 40 mn per patient) outpatient signals monitoring from this device, as well as high intensities due to the stochastic nature of blood flow. This paper proposes an adapted removal procedure. This firstly consists of reducing the background noise and detecting the blood flow in the time-frequency domain using a likelihood method for contour detection...
February 15, 2017: Medical & Biological Engineering & Computing
https://www.readbyqxmd.com/read/28199523/detection-and-differentiation-of-cerebral-microemboli-in-patients-undergoing-major-orthopaedic-surgery-using-transcranial-doppler-ultrasound
#2
C Kietaibl, A Engel, I Horvat Menih, M Huepfl, G Erdoes, B Kubista, R Ullrich, R Windhager, K Markstaller, K U Klein
No abstract text is available yet for this article.
February 10, 2017: British Journal of Anaesthesia
https://www.readbyqxmd.com/read/28188214/transcranial-doppler-determined-change-in-posterior-cerebral-artery-blood-flow-velocity-does-not-reflect-vertebral-artery-blood-flow-during-exercise
#3
Takuro Washio, Hiroyuki Sasaki, Shigehiko Ogoh
We examined whether a change in posterior cerebral artery flow velocity (PCAv) reflected the posterior cerebral blood flow, in healthy subjects, during both static and dynamic exercise. PCAv and vertebral artery (VA) blood flow, as an index of posterior blood flow, were continuously measured during an exercise trial, using transcranial Doppler (TCD) ultrasonography and Doppler ultrasound, respectively. Static handgrip exercise significantly increased both PCAv and VA blood flow. Increasing intensity of dynamic exercise further increased VA blood flow from moderate exercise, while PCAv decreased to almost resting level...
February 10, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28114163/doppler-ultrasonography-of-the-central-retinal-vessels-in-children-with-brain-death
#4
Becky J Riggs, Joanna S Cohen, Bhavana Shivakumar, Carmelina Trimboli-Heidler, Jason T Patregnani, Marijean M Miller, Michael C Spaeder, Nathan P Dean
OBJECTIVE: The purpose of this observational study is to explore if bedside Doppler ultrasonography of the central retinal vessels has the potential to become an ancillary study to support the timely diagnosis of brain death in children. DESIGN: Seventeen-month prospective observational cohort. SETTING: Forty-four bed pediatric medical and surgical ICU in an academic teaching hospital. PATIENTS: All children 0-18 years old who were clinically evaluated for brain death at Children's National Health Systems were enrolled and followed until discharge or death...
January 20, 2017: Pediatric Critical Care Medicine
https://www.readbyqxmd.com/read/28113579/functional-transcranial-doppler-ultrasound-for-measurement-of-hemispheric-lateralization-during-visual-memory-and-visual-search-cognitive-tasks
#5
Benjamin Hage, Mohammed Alwatban, Erin Barney, Mark Mills, Michael Dodd, Edward Truemper, Gregory Bashford
Functional transcranial Doppler ultrasound (fTCD) is a non-invasive sensing modality that measures blood flow velocities in cerebral arteries (CBFV) with high temporal resolution. CBFV change is correlated to changes in cerebral oxygen uptake, enabling fTCD to measure brain activity and lateralization with high accuracy. However, few studies have examined the relationship of CBFV change during visual search and visual memory tasks. Here a protocol to compare lateralization between these two similar cognitive tasks using fTCD is demonstrated...
August 26, 2016: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28088127/cerebral-laterality-for-language-is-related-to-adult-salivary-testosterone-levels-but-not-digit-ratio-2d-4d-in-men-a-functional-transcranial-doppler-ultrasound-study
#6
Marietta Papadatou-Pastou, Maryanne Martin
The adequacy of three competing theories of hormonal effects on cerebral laterality are compared using functional transcranial Doppler sonography (fTCD). Thirty-three adult males participated in the study (21 left-handers). Cerebral lateralization was measured by fTCD using an extensively validated word generation task. Adult salivary testosterone (T) and cortisol (C) concentrations were measured by luminescence immunoassay and prenatal T exposure was indirectly estimated by the somatic marker of 2nd to 4th digit length ratio (2D:4D)...
January 11, 2017: Brain and Language
https://www.readbyqxmd.com/read/28063107/the-relationship-between-right-to-left-shunt-and-brain-white-matter-lesions-in-japanese-patients-with-migraine-a-single-center-study
#7
Akio Iwasaki, Keisuke Suzuki, Hidehiro Takekawa, Ryotaro Takashima, Ayano Suzuki, Shiho Suzuki, Koichi Hirata
BACKGROUND: There may be a link between right-to-left shunt (RLs) and brain white matter lesions (WMLs) in patients with migraine. In this study, we assessed the relationship between WMLs and RLs in Japanese migraine patients. METHODS: A total of 107 consecutive patients with migraine with (MA) and without aura (MWOA) were included in this study. Contrast transcranial Doppler ultrasound was used to detect RLs. WMLs were graded using brain magnetic resonance imaging based on well-established criteria...
December 2017: Journal of Headache and Pain
https://www.readbyqxmd.com/read/28054939/effects-of-resveratrol-on-cognitive-performance-mood-and-cerebrovascular-function-in-post-menopausal-women-a-14-week-randomised-placebo-controlled-intervention-trial
#8
Hamish M Evans, Peter R C Howe, Rachel H X Wong
We tested whether chronic supplementation with resveratrol (a phytoestrogen) could improve cerebrovascular function, cognition and mood in post-menopausal women. Eighty post-menopausal women aged 45-85 years were randomised to take trans-resveratrol or placebo for 14 weeks and the effects on cognitive performance, cerebral blood flow velocity and pulsatility index (a measure of arterial stiffness) in the middle cerebral artery (using transcranial Doppler ultrasound), and cerebrovascular responsiveness (CVR) to both cognitive testing and hypercapnia were assessed...
January 3, 2017: Nutrients
https://www.readbyqxmd.com/read/28005566/anesthesia-for-functional-endoscopic-sinus-surgery
#9
Daniel A Carlton, Satish Govindaraj
PURPOSE OF REVIEW: The present article summarizes anesthetic techniques used during functional endoscopic sinus surgery to decrease bleeding and aid in creating a clear surgical field. The applicable physiology behind these anesthetic techniques is reviewed with emphasis on the effect on bleeding and the surgical field. Deliberate hypotension, reverse Trendelenburg positioning, regional anesthesia, and cerebral monitoring are discussed. RECENT FINDINGS: There are mixed data as to whether traditional inhalation anesthesia or total intravenous anesthesia is superior with respect to better surgical fields and decreased blood loss...
February 2017: Current Opinion in Otolaryngology & Head and Neck Surgery
https://www.readbyqxmd.com/read/27935138/characteristics-of-accredited-transcranial-doppler-ultrasound-laboratories-in-the-united-states
#10
Mary Beth Farrell, John Y Choi, Endrit Ziu, Kevin M Cockroft
PURPOSE: The aim of this study was to describe in detail the characteristics and accreditation compliance of laboratories in the United States applying for Intersocietal Accreditation Commission (IAC) transcranial Doppler (TCD) accreditation. METHODS: This was a retrospective study of all applicant laboratories from 2012 to 2015. We used the IAC database to extract laboratory characteristics and guideline compliance metrics. RESULTS: Evaluation of 97 laboratories demonstrated that 67% were hospital-based and located in the South (43...
December 9, 2016: Journal of Neuroimaging: Official Journal of the American Society of Neuroimaging
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
#11
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/27875362/relationship-between-hiv-infection-antiretroviral-therapy-inflammatory-markers-and-cerebrovascular-endothelial-function-among-adults-in-urban-china
#12
Felicia C Chow, Yanling Li, Yinghuan Hu, Joy Chan, Huanling Wang, Weihai Xu, Richard W Price, Farzaneh A Sorond, Taisheng Li
BACKGROUND: Cerebrovascular risk is increased in people living with HIV infection compared with age-matched uninfected individuals. Cerebrovascular endothelial dysfunction related to antiretroviral therapy (ART) and inflammation may contribute to higher stroke risk in HIV infection. METHODS: We compared cerebral vasoreactivity-a measure of cerebrovascular endothelial function assessed by the breath-holding index (BHI) using transcranial Doppler ultrasound-between virologically suppressed Chinese HIV-infected individuals followed in an HIV clinic in Beijing, China, and uninfected controls...
March 1, 2017: Journal of Acquired Immune Deficiency Syndromes: JAIDS
https://www.readbyqxmd.com/read/27843693/treatment-and-imaging-of-intracranial-atherosclerotic-stenosis-current-perspectives-and-future-directions
#13
REVIEW
Ido R van den Wijngaard, Ghislaine Holswilder, Marianne A A van Walderveen, Ale Algra, Marieke J H Wermer, Osama O Zaidat, Jelis Boiten
BACKGROUND AND PURPOSE: Intracranial atherosclerosis is a common cause of stroke worldwide. It results in ischemic stroke due to different mechanisms including artery-to-artery embolism, in situ thrombo-occlusion, occlusion of perforating arteries, and hemodynamic failure. In this review, we present an overview of current treatment and imaging modalities in intracranial atherosclerotic stenosis. METHODS: PubMed was searched for relevant articles in English that evaluated the treatment and imaging of intracranial atherosclerotic stenosis (ICAS)...
November 2016: Brain and Behavior
https://www.readbyqxmd.com/read/27837190/hyperoxia-results-in-increased-aerobic-metabolism-following-acute-brain-injury
#14
Arnab Ghosh, David Highton, Christina Kolyva, Ilias Tachtsidis, Clare E Elwell, Martin Smith
Acute brain injury is associated with depressed aerobic metabolism. Below a critical mitochondrial pO2 cytochrome c oxidase, the terminal electron acceptor in the mitochondrial respiratory chain, fails to sustain oxidative phosphorylation. After acute brain injury, this ischaemic threshold might be shifted into apparently normal levels of tissue oxygenation. We investigated the oxygen dependency of aerobic metabolism in 16 acutely brain-injured patients using a 120-min normobaric hyperoxia challenge in the acute phase (24-72 h) post-injury and multimodal neuromonitoring, including transcranial Doppler ultrasound-measured cerebral blood flow velocity, cerebral microdialysis-derived lactate-pyruvate ratio (LPR), brain tissue pO2 (pbrO2), and tissue oxygenation index and cytochrome c oxidase oxidation state (oxCCO) measured using broadband spectroscopy...
November 11, 2016: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/27796172/risk-factors-between-intracranial-extracranial-atherosclerosis-and-anterior-posterior-circulation-stroke-in-ischaemic-stroke
#15
Yan Li, Yefeng Cai, Min Zhao, Jingbo Sun
OBJECTIVES: Atherosclerosis is an important cause of stroke and remains a challenge for stroke prevention. Risk factors involved in atherosclerotic stroke and anterior and posterior circulation strokes (ACS and PCS, respectively) are different. The purpose of this study is to investigate differences in risk factors between intracranial and extracranial atherosclerosis (ICAS and ECAS), ACS and PCS, and ICAS/ECAS with ACS/PCS in a Chinese acute ischaemic stroke population. METHODS: We analysed 551 ischaemic stroke patients who had been enrolled between August 2005 and July 2008...
January 2017: Neurological Research
https://www.readbyqxmd.com/read/27757739/cerebral-hemodynamics-in-sepsis-assessed-by-transcranial-doppler-a-systematic-review-and-meta-analysis
#16
REVIEW
Daniel Silva de Azevedo, Angela Salomao Macedo Salinet, Marcelo de Lima Oliveira, Manoel Jacobsen Teixeira, Edson Bor-Seng-Shu, Ricardo de Carvalho Nogueira
Cerebral microcirculation is gradually compromised during sepsis, with significant reductions in the function of capillaries and blood perfusion in small vessels. Transcranial Doppler ultrasound (TCD) has been used to assess cerebral circulation in a typical clinical setting. This study was to systematically review TCD studies, assess their methodological quality, and identify trends that can be associated with the temporal evolution of sepsis and its clinical outcome. A meta-analysis of systematic reviews was conducted according to the PRISMA statement...
October 18, 2016: Journal of Clinical Monitoring and Computing
https://www.readbyqxmd.com/read/27754235/os-34-02-concentration-dependent-effect-of-plasma-resveratrol-on-cerebral-vasodilator-responsiveness-cvr-in-adults-with-type-2-diabetes-mellitus-t2dm
#17
Rachel Wong, Rhenan Nealon, Daniel Raederstorff, Peter Howe
OBJECTIVE: Having shown that resveratrol consumption can improve flow mediated dilation of the brachial artery, we tested its effects on CVR to hypercapnia in adults with T2DM, a risk population for cerebrovascular disease and cognitive impairments. DESIGN AND METHOD: In a double-blind crossover trial, 34 adults with T2DM consumed 0, 75, 150 and 300 mg of synthetic trans-resveratrol (one dose per week in random order). Before and 1-2 hr after dosing, transcranial Doppler ultrasound was used to assess CVR to a hypercapnic stimulus (breathing Carbogen gas for 3 min) in the middle (MCA) and posterior (PCA) cerebral arteries...
September 2016: Journal of Hypertension
https://www.readbyqxmd.com/read/27721780/the-need-for-a-rational-approach-to-vasoconstrictive-syndromes-transcranial-doppler-and-calcium-channel-blockade-in-reversible-cerebral-vasoconstriction-syndrome
#18
Elisabeth B Marsh, Wendy C Ziai, Rafael H Llinas
INTRODUCTION: Reversible cerebral vasoconstriction syndrome (RCVS) typically affects young patients and left untreated can result in hemorrhage or ischemic stroke. Though the disorder has been well characterized in the literature, the most appropriate way to diagnose, treat, and evaluate therapeutic response remains unclear. In previous studies, transcranial Doppler ultrasound (TCD) has shown elevated velocities indicative of vasospasm. This imaging modality is noninvasive and inexpensive; an attractive option for diagnosis and therapeutic monitoring if it is sensitive enough to detect changes in the acute setting given that RCVS often affects the distal vessels early in the course of disease...
May 2016: Case Reports in Neurology
https://www.readbyqxmd.com/read/27643195/os-34-02-concentration-dependent-effect-of-plasma-resveratrol-on-cerebral-vasodilator-responsiveness-cvr-in-adults-with-type-2-diabetes-mellitus-t2dm
#19
Rachel Wong, Rhenan Nealon, Daniel Raederstorff, Peter Howe
OBJECTIVE: Having shown that resveratrol consumption can improve flow mediated dilation of the brachial artery, we tested its effects on CVR to hypercapnia in adults with T2DM, a risk population for cerebrovascular disease and cognitive impairments. DESIGN AND METHOD: In a double-blind crossover trial, 34 adults with T2DM consumed 0, 75, 150 and 300 mg of synthetic trans-resveratrol (one dose per week in random order). Before and 1-2 hr after dosing, transcranial Doppler ultrasound was used to assess CVR to a hypercapnic stimulus (breathing Carbogen gas for 3 min) in the middle (MCA) and posterior (PCA) cerebral arteries...
September 2016: Journal of Hypertension
https://www.readbyqxmd.com/read/27634602/brain-perfusion-and-arterial-blood-flow-velocity-during-prolonged-body-tilting
#20
David Montero, Sven Rauber
BACKGROUND: It remains unknown whether brain perfusion is preserved and mirrored by middle cerebral blood flow velocity (MCA BFV) during prolonged changes in body posture. Herein, we examined the impact of sustained (180 min) 30° head-up (HUT) and head-down (HDT) tilt on brain perfusion, as determined by MCA BFV and blood flow in the extracranial arteries. METHODS: In 10 healthy male subjects, arterial diameters, BFVs, and blood flows were determined in the left internal carotid (ICA) and vertebral (VA) arteries using duplex Doppler ultrasound in supine rest, and 5, 20, 60, 120, and 180 min following 30° HUT and HDT...
August 2016: Aerospace Medicine and Human Performance
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