Noninvasive transcranial Doppler ultrasound recording of flow velocity in basal cerebral arteries

Aaslid, Rune; Markwalder, Thomas-Marc; Nornes, Helge

doi:10.3171/jns.1982.57.6.0769

Cited by 2,761 publications

(1,403 citation statements)

References 7 publications

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“…The insonation depth and angle were adjusted to optimize the signal quality and strength according to a standard procedure. 16 End-tidal CO 2 and breathing frequency were monitored by a nasal cannula. During data collection, subjects were instructed to breathe normally and avoid body movement and swallow maneuvers.…”

Section: Methodsmentioning

confidence: 99%

Cerebral Hemodynamics in Normal Aging: Central Artery Stiffness, Wave Reflection, and Pressure Pulsatility

Tarumi

Khan

Liu

et al. 2014

J Cereb Blood Flow Metab

177

143

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Blood ejected from the left ventricle perfuses the brain via central elastic arteries, which stiffen with advancing age and may elevate the risk of end-organ damage. The purpose of this study was to determine the impact of central arterial aging on cerebral hemodynamics. Eighty-three healthy participants aged 22 to 80 years underwent the measurements of cerebral blood flow (CBF) and CBF velocity (CBFV) using magnetic resonance imaging (MRI) and transcranial Doppler, respectively. The CBF pulsatility was determined by the relative amplitude of CBFV to the mean value (CBFV%). Central arterial stiffness (carotid-femoral pulse wave velocity), wave reflection (carotid augmentation index), and pressure were measured using applanation tonometry. Total volume of white-matter hyperintensity (WMH) was quantified from MR images. Total CBF decreased with age while systolic and pulsatile CBFV% increased and diastolic CBFV% decreased. Women showed greater total CBF and lower cerebrovascular resistance than men. Diastolic CBFV% was lower in women than in men. Age-and sex-related differences in CBF pulsatility were independently associated with carotid pulse pressure and arterial wave reflection. In older participants, higher pulsatility of CBF was associated with the greater total volume of WMH. These findings indicate that central arterial aging has an important role in age-related differences in cerebral hemodynamics.

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Section: Methodsmentioning

confidence: 99%

Cerebral Hemodynamics in Normal Aging: Central Artery Stiffness, Wave Reflection, and Pressure Pulsatility

Tarumi

Khan

Liu

et al. 2014

J Cereb Blood Flow Metab

177

143

View full text Add to dashboard Cite

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“…At least 1 min of beat-by-beat data were averaged for each steady-state posture. The MCA was identified using previously described criteria (1). Technical difficulties in acquiring a valid ultrasound signal through the temporal window varied the sample size (valid sample sizes: n ϭ 7 for young women, n ϭ 11 for young men, n ϭ 8 for older women, and n ϭ 9 for older men).…”

Section: Methodsmentioning

confidence: 99%

Hemodynamics and brain blood flow during posture change in younger women and postmenopausal women compared with age-matched men

Edgell

Robertson

Hughson

2012

Journal of Applied Physiology

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Edgell H, Robertson AD, Hughson RL. Hemodynamics and brain blood flow during posture change in younger women and postmenopausal women compared with age-matched men. J Appl Physiol 112: 1482-1493, 2012. First published February 23, 2012 doi:10.1152/japplphysiol.01204.2011.-Increased incidence of orthostatic hypotension and presyncopal symptoms in young women could be related to hormonal factors that might be isolated by comparing cardiovascular and cerebrovascular responses to postural change in young and older men and women. Seven young women, 11 young men, 10 older women (Ͼ1 yr postmenopausal, no hormone therapy), and 9 older men participated in a supine-to-sit-to-stand test while measuring systemic hemodynamics, end-tidal PCO2, and blood flow velocity of the middle cerebral artery (MCA). Women had a greater reduction in stroke volume index compared with age-matched men (change from supine to standing: young women: Ϫ22.9 Ϯ 1.6 ml/m 2 ; young men: Ϫ14.4 Ϯ 2.4 ml/m 2 ; older women: Ϫ17.4 Ϯ 3.3 ml/m 2 ; older men: Ϫ13.8 Ϯ 2.2 ml/m 2 ). This was accompanied by offsetting changes in heart rate, particularly in young women, resulting in no age or sex differences in cardiac output index. Mean arterial pressure (MAP) was higher in older subjects and increased with movement to upright postures. Younger men and women had higher forearm vascular resistance that increased progressively in the upright posture compared with older men and women. There was no difference between sexes or ages in total peripheral resistance index. Women had higher MCA velocity, but both sexes had reduced MCA velocity while upright, which was a function of reduced blood pressure at the MCA and a significant reduction in end-tidal PCO2. The reductions in stroke volume index suggested impaired venous return in women, but augmented responses of heart rate and forearm vascular resistance protected MAP in younger women. Overall, these results showed significant sex and age-related differences, but compensatory mechanisms preserved MAP and MCA velocity in young women. cerebrovascular; sex; age; orthostatic ORTHOSTATIC HYPOTENSION (a condition that sometimes leads to fainting) is an important and sometimes dangerous condition that particularly affects young women during daily life, as reflected by admission to emergency rooms (51). It has been speculated that female sex hormones might modulate reflex neural or vascular properties, resulting in the greater incidence of orthostatic hypotension in young women (5,14,15,52,69). An additional indication of impaired orthostatic responses in women includes the observation that women have a greater propensity towards postural orthostatic tachycardia syndrome (18, 60).Contrary to observations for young women, clinical evidence supports the concept that orthostatic hypotension occurs less frequently in women ages 40 -60 yr (many of whom could be postmenopausal) (51). Investigations of men and women from 23-77 yr of age indicated that the heart rate response to tilt was reduced with aging, but vascular responses a...

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“…The introduction of transcranial Doppler sonography (TCD) provided a non-invasive means to monitor blood flow through the major cerebral vessels in real-time (Aaslid et al 1982). Functional TCD is the application of TCD for monitoring task-specific changes in cerebral blood flow.…”

Section: Introductionmentioning

confidence: 99%

Functional Tissue Pulsatility Imaging of the Brain During Visual Stimulation

Kucewicz

Dunmire

Leotta

et al. 2007

Ultrasound in Medicine & Biology

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Functional tissue pulsatility imaging (fTPI) is a new ultrasonic technique being developed to map brain function by measuring changes in tissue pulsatility due to changes in blood flow with neuronal activation. The technique is based in principle on plethysmography, an older, non-ultrasound technology for measuring expansion of a whole limb or body part due to perfusion. Perfused tissue expands by a fraction of a percent early in each cardiac cycle when arterial inflow exceeds venous outflow and relaxes later in the cardiac cycle when venous drainage dominates. Tissue pulsatility imaging (TPI) uses tissue Doppler signal processing methods to measure this pulsatile "plethysmographic" signal from hundreds or thousands of sample volumes in an ultrasound image plane. A feasibility study was conducted to determine if TPI could be used to detect regional brain activation during a visual contrast-reversing checkerboard block paradigm study. During a study, ultrasound data were collected transcranially from the occipital lobe as a subject viewed alternating blocks of a reversing checkerboard (stimulus condition) and a static, gray screen (control condition). Multivariate Analysis of Variance (MANOVA) was used to identify sample volumes with significantly different pulsatility waveforms during the control and stimulus blocks. In 7 out 14 studies, consistent regions of activation were detected from tissue around the major vessels perfusing the visual cortex.

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Noninvasive transcranial Doppler ultrasound recording of flow velocity in basal cerebral arteries

Cited by 2,761 publications

References 7 publications

Cerebral Hemodynamics in Normal Aging: Central Artery Stiffness, Wave Reflection, and Pressure Pulsatility

Cerebral Hemodynamics in Normal Aging: Central Artery Stiffness, Wave Reflection, and Pressure Pulsatility

Hemodynamics and brain blood flow during posture change in younger women and postmenopausal women compared with age-matched men

Functional Tissue Pulsatility Imaging of the Brain During Visual Stimulation

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