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cerebral blood flow velocity

Laurence Ducharme-Crevier, Michele G Mills, Priya M Mehta, Craig M Smith, Mark S Wainwright
BACKGROUND: The primary objective of this study was to characterize changes in cerebral blood flow measured using transcranial Doppler in children with central nervous system infections. We hypothesized that children with central nervous system infections have abnormal cerebral blood flow, associated with a greater frequency of complications and poor neurological outcome. METHODS: We conducted a single-center, retrospective study of children admitted to the neonatal or pediatric intensive care unit with central nervous system infection and undergoing transcranial Doppler as part of routine care between March 2011 and July 2015...
September 4, 2016: Pediatric Neurology
Maria Skytioti, Signe Søvik, Maja Elstad
Intact cerebral blood flow (CBF) is essential for cerebral metabolism and function, whereas hypoperfusion in relation to hypovolemia and hypocapnia can lead to severe cerebral damage. This study was designed to assess internal carotid artery blood flow (ICA-BF) during simulated hypovolemia and noninvasive positive pressure ventilation (PPV) in young healthy humans. Beat-by-beat blood velocity (ICA and aorta) were measured by Doppler ultrasound during normovolemia and simulated hypovolemia (lower body negative pressure), with or without PPV in 15 awake subjects...
October 2016: Physiological Reports
P E Frid, S J Schreiber, O Pade, F Doepp, J Valdueza
PURPOSE: To differentiate PCA segments and cortical branches by means of transcranial color-coded duplex sonography (TCCD) and to measure flow parameters at rest and during visual stimulation. MATERIALS AND METHODS: 60 healthy subjects with a good acoustic temporal bone window were examined. The main stem of the PCA (P1, P2 and P3) and 4 main cortical branches - the anterior temporal artery (ATA), the occipital temporal artery (OTA), the parietooccipital artery (POA) and the calcarine artery (CA) - were assessed using an axial transtemporal approach...
November 2015: Ultrasound Int Open
Misaki Kohama, Shinichiro Sugiyama, Kenichi Sato, Hidenori Endo, Kuniyasu Niizuma, Toshiki Endo, Makoto Ohta, Yasushi Matsumoto, Miki Fujimura, Teiji Tominaga
BACKGROUND: Transcranial Doppler (TCD) is used to monitor cerebral vasospasm after subarachnoid hemorrhage (SAH), but its diagnostic ability is reported to be limited. Therefore, the purpose of this study was to investigate the relationship between the diagnosability of TCD and the localization of the vasospasm. METHODS: This retrospective study included 20 patients who presented with symptomatic vasospasm after SAH. All 20 patients underwent daily TCD examinations and cerebral angiography after the onset of delayed cerebral ischemia...
2016: Cerebrovascular Diseases Extra
Daniel Schuepbach, Stephan T Egger, Heinz Boeker, Stefan Duschek, Stefan Vetter, Erich Seifritz, Sabine C Herpertz
Patients with schizophrenia show deficits in cognitive functioning, and studies on cerebral hemodynamics have revealed aberrant patterns of mean cerebral blood flow velocity (MFV), an equivalent of cerebral blood flow (CBF). Therefore, we carried out a controlled study that assessed MFV in schizophrenia during a well-known neuropsychological task, the Trail Making Test (TMT). We measured MFV in the middle cerebral arteries using functional transcranial Doppler sonography in 15 schizophrenia patients and 15 healthy subjects...
September 17, 2016: Brain and Cognition
Xavier Waltz, Andrew E Beaudin, Patrick J Hanly, Georgios D Mitsis, Marc J Poulin
Cerebral autoregulation (CA) impairment may contribute to the increased risk of stroke associated with obstructive sleep apnea (OSA). It is unknown if impaired CA is further exacerbated by isocapnic-hypoxia and whether it is improved by treatment of OSA with continuous positive airway pressure (CPAP). CA was assessed during wakefulness in 53 OSA patients (50.3 ± 9.3 years) and 21 controls (49.8 ± 8.6 years) at baseline and following a minimum of 1 month of effective CPAP therapy (OSA patients, n = 40)...
September 20, 2016: Journal of Physiology
Junichiro Hashimoto
Arterial structure and function change progressively with advancing age. Owing to long-lasting repetitive stretch with intermittent cardiac contraction, elastic fibers in the tunica media of large arteries gradually degenerate and are replaced by collagenous fibers. Such medial degeneration causes elastic arteries to stiffen and dilate. However, the speed of the vascular aging varies considerably among individuals; a discrepancy often exists between the chronological age of an individual and the biological age of his or her arteries...
September 2016: Journal of Hypertension
Jian Wang, Weici Wang, Bi Jin, Yanrong Zhang, Ping Xu, Feixiang Xiang, Yi Zheng, Juan Chen, Shi Sheng, Chenxi Ouyang, Yiqing Li
Purpose. To investigate the alternation in cerebral and ocular blood flow velocity (BFV) in patients of carotid stenosis (CS) with or without contralateral carotid occlusion (CO) early after carotid endarterectomy (CEA). Patients and Methods. Nineteen patients underwent CEA for ≥50% CS. Fourteen patients had the unilateral CS, and five patients had the ipsilateral CS and the contralateral CO. Transcranial Doppler (TCD) and Color Doppler Imaging (CDI) were performed before and early after CEA. Results. In patients with unilateral CS, significant improvements in BFV were observed in anterior cerebral artery (ACA) and middle cerebral artery (MCA) on the ipsilateral side after CEA...
2016: BioMed Research International
T Pincez, L Calamy, Z Germont, A Lemoine, A-A Lopes, A Massiot, J Tencer, C Thivent, A Hadchouel
Acute and chronic pulmonary complications are frequent in sickle cell disease (SCD), with different spectrum and characteristics in children and adults. Chronic hypoxia is frequent and plays a role in several respiratory complications in SCD. Furthermore, hypoxia has been associated with a higher risk of cerebral ischemia. Despite differing oxygen affinity between hemoglobin A and S, standard pulse oximetry was shown to be accurate in diagnosing hypoxia in SCD patients. Whereas acute hypoxia management is similar to non-SCD patients, chronic hypoxia treatment is mainly based on a transfusion program rather than long-term oxygen therapy...
October 2016: Archives de Pédiatrie: Organe Officiel de la Sociéte Française de Pédiatrie
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
Michael M Tymko, Caroline A Rickards, Rachel J Skow, Nathan C Ingram-Cotton, Michael K Howatt, Trevor A Day
Steady-state tilt has no effect on cerebrovascular reactivity to increases in the partial pressure of end-tidal carbon dioxide (PETCO2). However, the anterior and posterior cerebral circulations may respond differently to a variety of stimuli that alter central blood volume, including lower body negative pressure (LBNP). Little is known about the superimposed effects of head-up tilt (HUT; decreased central blood volume and intracranial pressure) and head-down tilt (HDT; increased central blood volume and intracranial pressure), and LBNP on cerebral blood flow (CBF) responses...
September 2016: Physiological Reports
Bryan Heath Curry, Vernon Bond, Sudhakar Pemminati, Vasavi Rakesh Gorantla, Yulia Andreevna Volkova, Kishan Kadur, Richard Mark Millis
INTRODUCTION: Beetroot Juice (BJ) contains dietary nitrates that increase the blood Nitric Oxide (NO) level, decrease Blood Pressure (BP), increase athletic performance and improve cognitive functions but the mechanism remains unclear. Ultrasonographic measurement of middle cerebral artery blood flow velocity with computation of Cerebral Augmentation Index (CAIx) is a measure of the reflected flow signal, modulated by changes in cerebrovascular resistance and compliance. AIM: This pilot study tests the hypothesis that ingestion of an amount of BJ sufficient to raise the blood NO level two-to three-fold, decreases Transcranial Doppler (TCD) measured CAIx...
July 2016: Journal of Clinical and Diagnostic Research: JCDR
Hüsnü Alptekin, Hatice Işık, Nazife Alptekin, Fatih Kayhan, Duran Efe, Türkan Cengiz, Emine Gök
Maternal smoking is known to have adverse effects on the foetus. This study aimed to evaluate the effects of maternal smoking during pregnancy on arterial blood flow velocities in the foetal-placental-maternal circulation, and the pathophysiological relationship with placental and foetal birth weight. A total of 148 singleton pregnancies in 59 smokers and 89 non-smoking controls were examined during the 37th week of gestation. Blood flow in the maternal uterine, foetal umbilical and middle cerebral arteries was analysed with Doppler ultrasonography...
September 13, 2016: Journal of Obstetrics and Gynaecology: the Journal of the Institute of Obstetrics and Gynaecology
Tingting Liu, Benxu Xiang, Deyu Guo, Fangling Sun, Renping Wei, Guoxing Zhang, Houxi Ai, Xin Tian, Zixin Zhu, Wenrong Zheng, Yufeng Wang, Wen Wang
Preservation of cerebral microvascular functional integrity is crucial for protecting and repairing the brain after stroke. Our previous study demonstrated that morroniside promoted angiogenesis 7days after stroke. The current study aimed to further evaluate the long-term effects of morroniside on angiogenesis and to examine whether angiogenesis induced by morroniside could improve blood flow velocity. Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO), and morroniside was then administered once per day at a dose of 270mg/kg...
September 8, 2016: Brain Research Bulletin
Cristina Fuente Mora, Jose-Alberto Palma, Horacio Kaufmann, Lucy Norcliffe-Kaufmann
Familial dysautonomia is an inherited autonomic disorder with afferent baroreflex failure. We questioned why despite low blood pressure standing, surprisingly few familial dysautonomia patients complain of symptomatic hypotension or have syncope. Using transcranial Doppler ultrasonography of the middle cerebral artery, we measured flow velocity (mean, peak systolic, and diastolic), area under the curve, pulsatility index, and height of the dictrotic notch in 25 patients with familial dysautonomia and 15 controls...
September 9, 2016: Journal of Cerebral Blood Flow and Metabolism
Frank Rasulo, Nicola Zugni, Simone Piva, Nazzareno Fagoni, Federico Pe, Arturo Toninelli, Stefano Calza, Nicola Latronico
BACKGROUND: Supraglottic airway devices (SGDs) are of current use in anesthesia practice and in emergency conditions. It has been suggested that cerebral blood flow (CBF) can decrease after SGD insertion or cuff inflation; however, it is uncertain if this reduction is caused by the SGD or the anesthetic drugs utilized for the anesthetic procedure. During minor surgery we separated CBF measurements by an adequate time interval in order to measure the distinctive changes in cerebral hemodynamics associated with anesthesia induction, SGD insertion and cuff inflation...
August 2016: Minerva Anestesiologica
Nicole D Osier, C Edward Dixon
Controlled cortical impact (CCI) is a mechanical model of traumatic brain injury (TBI) that was developed nearly 30 years ago with the goal of creating a testing platform to determine the biomechanical properties of brain tissue exposed to direct mechanical deformation. Initially used to model TBIs produced by automotive crashes, the CCI model rapidly transformed into a standardized technique to study TBI mechanisms and evaluate therapies. CCI is most commonly produced using a device that rapidly accelerates a rod to impact the surgically exposed cortical dural surface...
2016: Frontiers in Neurology
Jay H Levin, Jorge Benavides, Claudine Caddick, Kathleen Laurie, Janet Wilterdink, Shadi Yaghi, Brian Silver, Muhib Khan
BACKGROUND AND PURPOSE: Reversible cerebral vasoconstriction syndrome (RCVS) is a vascular headache disorder characterized by severe headaches with vasospasm of cerebral arteries. Transcranial Doppler ultrasonography (TCD) has been widely applied and validated in studying vasospasm of intracranial vessels, but the role of TCD in the diagnosis and monitoring of RCVS is less well established. We sought to determine the reliability of TCD for diagnosis and monitoring of RCVS. METHODS: Patients admitted to an inpatient neurology service between 2011 and 2014 with a discharge diagnosis of RCVS were retrospectively analyzed for demographics, neuroimaging, and functional outcomes...
2016: Rhode Island Medical Journal
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
Hiroshi Enaida, Shinji Nagata, Atsunobu Takeda, Shintaro Nakao, Yasuhiro Ikeda, Tatsuro Ishibashi
PURPOSE: To investigate the changes in chorioretinal blood flow velocity and cerebral blood after carotid endarterectomy (CEA). METHODS: Nine patients with moderate to severe internal carotid artery stenosis underwent CEA. Chorioretinal blood flow velocity was measured by laser speckle flowgraphy (LSFG), while cerebral blood flow (CBF) was measured by single-photon emission computed tomography (SPECT), on the affected side both before and after CEA. LSFG was evaluated in five areas to determine mean blur rate, while CBF was calculated from regional CBF and cerebrovascular reactivity (CVR), at the middle cerebral artery (MCA) region of each patient...
August 26, 2016: Japanese Journal of Ophthalmology
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