scholarly journals Effects of Signal Salience and Cueing on Cerebral Blood Flow Velocity during Sustained Attention

2000 ◽  
Vol 44 (21) ◽  
pp. 3-382-3-385
Author(s):  
Edward M. Hitchcock ◽  
Joel S. Warm ◽  
William N. Dember ◽  
Gerald M. Matthews ◽  
Paula K. Shear ◽  
...  
Keyword(s):  
Blood Flow ◽  
Right Hemisphere ◽  
Cerebral Blood Flow Velocity ◽  
Low Cost ◽  
Cerebral Arteries ◽  
Transcranial Doppler Sonography ◽  
Flow Measurements ◽  
Blood Flow Measurements ◽  
Signal Salience ◽  
Over Time

Transcranial Doppler sonography*** a low-cost noninvasive procedure which allows continuous monitoring of blood flow in the left and right middle cerebral arteries, was employed while participants performed a 40-min vigil. Two levels of signal salience (high and low) were combined factorially with four conditions in which monitors were forewarned about the imminent arrival of critical signals (100%, 80%, and 40% reliable cueing and a no-cue control). For both levels of signal salience, the frequency of signal detections remained stable over time in the 100% cue-reliability condition but declined over time in the remaining cue conditions, so that by the end of the vigil performance efficiency was best in the 100% condition followed in order by the 80%, 40%, and no-cue conditions. These performance effects for cueing were mirrored by blood flow measurements taken from the right hemisphere in conjunction with low salience signals. No effects for cueing were observable in blood flow recordings taken from the left hemisphere in conjunction with either high or low salience signals. The results indicate that blood flow and signal detection in vigilance are at least partially related to common mechanisms, such as the expenditure of information-processing resources. They are also consistent with past findings indicating that vigilance performance is right-lateralized.

scholarly journals Transcranial Doppler Evaluation of the Cerebral Vasculature in Women Patients who Have Migraine with Aura

Pain Medicine ◽  
2020 ◽  
Vol 21 (11) ◽  
pp. 3012-3017
Author(s):  
Igor Petrušić ◽  
Ana Podgorac ◽  
Aleksandra Radojičić ◽  
Jasna Zidverc-Trajković
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Migraine With Aura ◽  
Transcranial Doppler ◽  
Cerebral Blood Flow Velocity ◽  
Cerebral Arteries ◽  
Transcranial Doppler Sonography ◽  
Cerebrovascular Reactivity ◽  
Breath Holding ◽  
Left And Right

Abstract Background Previous studies suggest that increased cerebrovascular reactivity might be a feature of patients who have migraine with aura (MwA). The correlation between the clinical presentation of migraine with aura and transcranial Doppler parameters remains unclear. Objective The main aim of this study was to explore cerebral blood flow, vascular resistance, and cerebrovascular reactivity in women MwA. Also, the relationships between hemodynamic conditions and aura characteristics are examined. Design Cross-sectional study. Setting Headache Center, Neurology Clinic, Clinical Center of Serbia. Subjects Fifty-four women MwA and 49 healthy controls (HCs). Methods Transcranial Doppler sonography examination was used to determine blood flow mean velocity (MV) and pulsatility index (PI), as well as breath-holding index (BHI), in 15 arterial segments comprising the circle of Willis. Results A total of 54 women MwA and 49 HCs were studied. The PIs of all segments of the left and right middle cerebral arteries and the left and right anterior cerebral arteries were significantly higher in MwA with regards to HCs. Also, both the left and right BHIs were significantly higher in MwA than HCs. In addition, MVs of the right vertebral artery and the first segment of the basilar artery were significantly lower in MwA than HCs. Longer duration of migraine aura showed a weak negative correlation with the PI of the left posterior cerebral artery. Conclusions Our findings suggest increased vessel pulsatility, abnormal cerebrovascular reactivity, and decreased cerebral blood flow velocity in several arterial segments of the Willis circle in women MwA.

Fluorescent microspheres are superior to radioactive microspheres in chronic blood flow measurements

1998 ◽  
Vol 275 (1) ◽  
pp. H110-H115 ◽  
Author(s):  
Matthijs F. M. Van Oosterhout ◽  
Frits W. Prinzen ◽  
S. Sakurada ◽  
Robb W. Glenny ◽  
J. Robert S. Hales
Keyword(s):  
Blood Flow ◽  
Liver Blood Flow ◽  
Mean Difference ◽  
Radioactive Microspheres ◽  
Fluorescent Microspheres ◽  
Flow Measurements ◽  
Change Over Time ◽  
Radioactive Microsphere ◽  
Blood Flow Measurements ◽  
Over Time

The accuracy of the fluorescent (FM) and radioactive microsphere (RM) techniques is similar in acute experiments but has not been established in chronic experiments. In the present study various combinations (at least pairs) of FM and/or RM labels were injected simultaneously between 2 mo and 5 min before each animal was killed. Blood flow was determined in many organs. Intramethod mean difference and variation did not change over time for FM but increased significantly for RM (from 1.8 ± 1.4 to 25.6 ± 21.8% and from 4.4 ± 3.2 to 32.4 ± 23.0% at 5 min and 2 mo, respectively). Also the FM-RM intermethod mean difference and variation increased (from −0.5 ± 8.5 to 40.8 ± 23.8% and from 23.6 ± 4.6 to 71.8 ± 34.3%, respectively). After 2 mo, blood flow estimations were 20–50% lower with the various RM, whereas brain and liver blood flow values varied even more between isotopes. Underestimation started within 1 day for51Cr and within 2 wk for141Ce,95Nb, and85Sr. We conclude that FM are superior to RM for blood flow determination in experiments lasting longer than 1 day, presumably because of leaching of isotopes from RM.

Usefulness of Intravascular Doppler Flow Measurements in Cerebral Endovascular Treatment

1996 ◽  
Vol 2 (2) ◽  
pp. 103-110 ◽  
Author(s):  
K. Fukui ◽  
M. Negoro ◽  
I. Takahashi ◽  
K. Fukasaku ◽  
K. Nakabayashi ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Endovascular Treatment ◽  
Transcranial Doppler Sonography ◽  
Resistance Index ◽  
Flow Measurements ◽  
Doppler Flow ◽  
Carotid Stenoses ◽  
Blood Flow Measurements ◽  
Carotid Cavernous Fistulas

Measurement of cerebral blood flow in cerebral endovascular procedures is useful for the assessment of treatment effects. We used transcranial Doppler sonography (TCD) and Doppler guide wires (SmartWire®, Cardiometrics Co.) in intravascular treatment. The cases were 6 brain arteriovenous malformations (AVM), 2 carotid cavernous fistulas (CCF), 2 facial angiomas, and 2 carotid stenoses. Intravascular cerebral blood flow measurements with the SmartWire were performed during the endovascular procedure. TCD was used pre- and post-endovascular treatment, and velocity, pulsatility index (PI) and resistance index (RI) were compared with the SmartWire. For both TCD and SmartWire, blood velocity of the main artery decreased, and PI and RI were improved after embolisation of AVM. In angioplasty cases, post stenotic flow velocity, as measured by SmartWire, was improved, and the flow of MCA measured with TCD was also improved after treatment. The SmartWire is useful to assess cerebral blood flow changes during the neuroendovascular procedure. Combined with repeated follow up with TCD, Doppler flow measurements are useful to assess the effect of endovascular treatment.

scholarly journals Measurement of cerebral blood flow using phase contrast magnetic resonance imaging and duplex ultrasonography

2016 ◽  
Vol 37 (2) ◽  
pp. 541-549 ◽  
Author(s):  
Muhammad Ayaz Khan ◽  
Jie Liu ◽  
Takashi Tarumi ◽  
Justin Stevan Lawley ◽  
Peiying Liu ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Vertebral Artery ◽  
Phase Contrast ◽  
Cerebral Blood Flow Velocity ◽  
Vessel Diameter ◽  
Resonance Imaging ◽  
Flow Measurements ◽  
Contrast Magnetic Resonance ◽  
Blood Flow Measurements

Phase contrast magnetic resonance imaging (PC-MRI) and color-coded duplex ultrasonography (CDUS) are commonly used for measuring cerebral blood flow in the internal carotid (ICA) and vertebral arteries. However, agreement between the two methods has been controversial. Recent development of high spatial and temporal resolution blood vessel wall edge-detection and wall-tracking methods with CDUS increased the accuracy and reliability of blood vessel diameter, hence cerebral blood flow measurement. The aim of this study was to compare the improved CDUS method with 3 T PC-MRI for cerebral blood flow measurements. We found that cerebral blood flow velocity measured in the ICA was lower using PC-MRI than CDUS (left ICA: PC-MRI, 18.0 ± 4.2 vs. CDUS, 25.6 ± 8.6 cm/s; right ICA: PC-MRI, 18.5 ± 4.8 vs. CDUS, 26.6 ± 6.7 cm/s, both p < 0.01). However, ICA diameters measured using PC-MRI were larger (left ICA: PC-MRI, 4.7 ± 0.50 vs. CDUS, 4.1 ± 0.46 mm; right ICA: PC-MRI, 4.5 ± 0.49 vs. CDUS, 4.0 ± 0.45 mm, both p < 0.01). Cerebral blood flow velocity measured in the left vertebral artery with PC-MRI was also lower than CDUS, but no differences in vertebral artery diameter were observed between the methods. Dynamic changes and/or intrinsic physiological fluctuations may have caused these differences in vessel diameter and velocity measurements between the methods. However, estimation of volumetric cerebral blood flow was similar and correlated between the methods despite the presence of large individual differences. These findings support the use of CDUS for cerebral blood flow measurements in the ICA and vertebral artery.

scholarly journals Regional Differences in the Cerebral Blood Flow Velocity Response to Hypobaric Hypoxia at High Altitudes

2015 ◽  
Vol 35 (11) ◽  
pp. 1846-1851 ◽  
Author(s):  
Berend Feddersen ◽  
Pritam Neupane ◽  
Florian Thanbichler ◽  
Irmgard Hadolt ◽  
Vera Sattelmeyer ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Hypobaric Hypoxia ◽  
Cerebral Blood Flow Velocity ◽  
Cerebral Arteries ◽  
Acute Mountain Sickness ◽  
Transcranial Doppler Sonography ◽  
Beta Activity

Symptoms of acute mountain sickness (AMS) may appear above 2,500 m altitude, if the time allowed for acclimatization is insufficient. As the mechanisms underlying brain adaptation to the hypobaric hypoxic environment are not fully understood, a prospective study was performed investigating neurophysiological changes by means of near infrared spectroscopy, electroencephalograpy (EEG), and transcranial doppler sonography at 100, 3,440 and 5,050 m above sea level in the Khumbu Himal, Nepal. Fourteen of the 26 mountaineers reaching 5,050 m altitude developed symptoms of AMS between 3,440 and 5,050 m altitude (Lake-Louise Score ≥ 3). Their EEG frontal beta activity and occipital alpha activity increased between 100 and 3,440 m altitude, i.e., before symptoms appeared. Cerebral blood flow velocity (CBFV) in the anterior and middle cerebral arteries (MCAs) increased in all mountaineers between 100 and 3,440 m altitude. During further ascent to 5,050 m altitude, mountaineers with AMS developed a further increase in CBFV in the MCA, whereas in all mountaineers CBFV decreased continuously with increasing altitude in the posterior cerebral arteries. These results indicate that hypobaric hypoxia causes different regional changes in CBFV despite similar electrophysiological changes.

Brain Blood Flow

PEDIATRICS ◽  
1984 ◽  
Vol 74 (2) ◽  
pp. 317-317
Author(s):  
NANCY B. HANSEN ◽  
BARBARA S. STONESTREET ◽  
TED S. ROSENKRANTZ ◽  
WILLIAM OH
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Cerebral Blood Flow Velocity ◽  
Brain Blood Flow ◽  
Flow Measurements ◽  
Correlation Data ◽  
Microsphere Method ◽  
Blood Flow Measurements

In Reply.— We appreciate Rosenfeld's comments on our paper on the validity of Doppler measurements of anterior cerebral artery blood flow velocity. Rosenfeld raised two points regarding the validity of our correlation data between Doppler technique and cerebral blood flow measurements by the microsphere method. (1) Rosenfeld correctly pointed out that when we relate brain blood flow to any of the parameters obtained in the measurement of cerebral blood flow velocity, there is considerable variation in the values observed.

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