scholarly journals Cerebrovascular Reactivity Mapping Without Gas Challenges: A Methodological Guide

2021 ◽  
Vol 11 ◽  
Author(s):  
Joana Pinto ◽  
Molly G. Bright ◽  
Daniel P. Bulte ◽  
Patrícia Figueiredo
Keyword(s):  
Transcranial Doppler Ultrasound ◽  
Cerebrovascular Reactivity ◽  
Breath Holding ◽  
Vasoactive Factors ◽  
Practical Guidelines ◽  
Mapping Techniques ◽  
Respiratory Gases ◽  
New Generation ◽  
Methodological Aspects ◽  
Coupling Mechanisms

Cerebrovascular reactivity (CVR) is defined as the ability of vessels to alter their caliber in response to vasoactive factors, by means of dilating or constricting, in order to increase or decrease regional cerebral blood flow (CBF). Importantly, CVR may provide a sensitive biomarker for pathologies where vasculature is compromised. Furthermore, the spatiotemporal dynamics of CVR observed in healthy subjects, reflecting regional differences in cerebral vascular tone and response, may also be important in functional MRI studies based on neurovascular coupling mechanisms. Assessment of CVR is usually based on the use of a vasoactive stimulus combined with a CBF measurement technique. Although transcranial Doppler ultrasound has been frequently used to obtain global flow velocity measurements, MRI techniques are being increasingly employed for obtaining CBF maps. For the vasoactive stimulus, vasodilatory hypercapnia is usually induced through the manipulation of respiratory gases, including the inhalation of increased concentrations of carbon dioxide. However, most of these methods require an additional apparatus and complex setups, which not only may not be well-tolerated by some populations but are also not widely available. For these reasons, strategies based on voluntary breathing fluctuations without the need for external gas challenges have been proposed. These include the task-based methodologies of breath holding and paced deep breathing, as well as a new generation of methods based on spontaneous breathing fluctuations during resting-state. Despite the multitude of alternatives to gas challenges, existing literature lacks definitive conclusions regarding the best practices for the vasoactive modulation and associated analysis protocols. In this work, we perform an extensive review of CVR mapping techniques based on MRI and CO2 variations without gas challenges, focusing on the methodological aspects of the breathing protocols and corresponding data analysis. Finally, we outline a set of practical guidelines based on generally accepted practices and available data, extending previous reports and encouraging the wider application of CVR mapping methodologies in both clinical and academic MRI settings.

scholarly journals Effect of Smoking on Cerebrovascular Reactivity

1996 ◽  
Vol 16 (4) ◽  
pp. 746-749 ◽  
Author(s):  
Mauro Silvestrini ◽  
Elio Troisi ◽  
Maria Matteis ◽  
Letizia Maria Cupini ◽  
Giorgio Bernardi
Keyword(s):  
Flow Velocity ◽  
Cerebral Arteries ◽  
Transcranial Doppler Ultrasound ◽  
Cerebrovascular Reactivity ◽  
Breath Holding ◽  
Mean Flow ◽  
Increased Risk ◽  
Middle Cerebral Arteries ◽  
Cerebrovascular Regulation ◽  
Breath Holding Index

Current smoking is a risk factor for stroke. The aim of this study was to evaluate the effect of smoking one cigarette on cerebral hemodynamics. Using transcranial Doppler ultrasound, we studied the changes of flow velocity after hypercapnia in the middle cerebral arteries (MCAs) of 24 healthy young smokers and 24 healthy controls matched for age and sex. We obtained hypercapnia with breath-holding and evaluated cerebrovascular reactivity with the breath-holding index. In smokers, the evaluation was performed during basal condition, immediately after smoking one cigarette, and at 10-, 20-, and 30-min intervals thereafter. In controls, the evaluation was performed at corresponding time intervals. Breath-holding index (BHI) values at rest were similar for both controls and smokers. In the former, breath-holding index values remained constant for each of the different evaluations. On the contrary, in smokers, breath-holding index values were significantly lower immediately ( p < 0.0001), at 10 min ( p < 0.001), and at 20 min ( p < 0.0001) after smoking with respect to baseline values. Smoking also caused more short-lasting changes, in this case increases in mean flow velocity (MFV), heart rate (HR), and mean blood pressure (MBP). These results suggest that a failure of cerebrovascular regulation occurs after smoking. This phenomenon might contribute to the increased risk of cerebrovascular disease in current smokers.

A longitudinal multiethnic study of biomarkers in systemic lupus erythematosus: Launching the GLADEL 2.0 Study Group

Lupus ◽  
2021 ◽  
pp. 096120332098858
Author(s):  
José A Gómez-Puerta ◽  
Guillermo J Pons-Estel ◽  
Rosana Quintana ◽  
Romina Nieto ◽  
Rosa M Serrano Morales ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Renal Disease ◽  
Latin American ◽  
Lupus Erythematosus ◽  
Renal Involvement ◽  
Systemic Lupus ◽  
Original Cohort ◽  
Beneficial Effects ◽  
New Generation ◽  
Methodological Aspects

Introduction: After more than 20 years of sustained work, the Latin American Group for the Study of Lupus (GLADEL) has made a significant number of contributions to the field of lupus, not only in the differential role that race/ethnicity plays in its course and outcome but also in several other studies including the beneficial effects of using antimalarials in lupus patients and the development of consensus guidelines for the treatment of lupus in our region. Methods: A new generation of “Lupus Investigators” in more than 40 centers throughout Latin America has been constituted in order to continue the legacy of the investigators of the original cohort and to launch a novel study of serum and urinary biomarkers in patients with systemic lupus erythematosus. Results: So far, we have recruited 807 patients and 631 controls from 42 Latin-American centers including 339 patients with SLE without renal involvement, 202 patients with SLE with prevalent but inactive renal disease, 176 patients with prevalent and active renal disease and 90 patients with incident lupus nephritis. Conclusions: The different methodological aspects of the GLADEL 2.0 cohort are discussed in this manuscript, including the challenges and difficulties of conducting such an ambitious project.

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.

scholarly journals Low-Dose Endotoxin Reduces Human Cerebrovascular Reactivity and Produces Procoagulant State

Stroke ◽  
2001 ◽  
Vol 32 (suppl_1) ◽  
pp. 360-360
Author(s):  
Maria Perez Barreto ◽  
Glenn M Fischberg ◽  
Annlia Paganini-Hill ◽  
Yodchai Lapakulchai ◽  
Sebastian F Ameriso ◽  
...  
Keyword(s):  
Low Dose ◽  
Stroke Risk ◽  
Endothelial Activation ◽  
Cerebrovascular Reactivity ◽  
Breath Holding ◽  
Inflammatory Stimulus ◽  
Post Infusion ◽  
Marked Decline ◽  
Change In Mean ◽  
Soluble E Selectin

P118 Stroke risk is increased in the presence of some infections. We studied potential mechanisms linking infections and stroke risk. We used endotoxin, a component of gram negative bacteria, as a standardized inflammatory stimulus. We infused low-dose endotoxin (1ng/kg) as a bolus in four healthy men, and analyzed cerebrovascular and hemostatic effects over 24 hours. We measured cerebral vasomotor reactivity, using transcranial Doppler ultrasonography to calculate breath-holding index (BHI); the latter consists of the percent change of middle cerebral artery blood flow velocity over time during breath holding. We also measured thrombin-antithrombin complexes (TAT, an index of thrombin generation), and soluble e-selectin (a marker of endothelial activation). Following infusion of endotoxin, there were substantial physiological changes primarily at three to six hours post-infusion. Temperature peaked at 100 °F (p<.05), with no significant change in mean arterial pressure. BHI showed maximum decline from 1.55 ± 0.88 to 0.33 ± 0.35 %/sec (p<.05). TAT levels increased from 3.0 ± 0.9 to 41.0 ± 21.1 ug/ml (p<.05). Soluble e-selectin levels increased from 66.6 ± 35.2 to 207.4 ± 78.9 ug/ml (p<.05). These findings indicate that a standardized low-dose inflammatory stimulus produces a marked decline in human cerebrovascular reactivity while simultaneously inducing a procoagulant state with endothelial activation . The reduction in cerebrovascular reactivity combined with a procoagulant state may contribute to increased stroke risk in this setting.

Combined ventilatory and breath-holding evaluation of sensitivity to respiratory gases

1959 ◽  
Vol 14 (3) ◽  
pp. 353-356 ◽  
Author(s):  
Robert C. Stroud
Keyword(s):  
Carbon Dioxide ◽  
Ventilatory Response ◽  
Direct Determination ◽  
Breath Holding ◽  
Respiratory Response ◽  
Data Comparison ◽  
Direct Measurements ◽  
Respiratory Gases ◽  
Definite Role

Direct measurements of the ventilatory response to variations in CO2 tension independent of changes in O2 tension are easily obtained by breathing mixtures of carbon dioxide in 100% oxygen. Direct determination of the respiratory response to O2, however, is not possible due to alternations in CO2 tension resulting from changes in ventilation. Therefore, an attempt has been made to determine this response empirically by a combined analysis of breath-holding and ventilatory data. Comparison of experimentally determined responses to various combinations of O2 and CO2 tensions agree quite well with those predicted by this approach and indicate that oxygen plays a small but definite role in the regulation of eupnic breathing at sea level. Submitted on October 22, 1958

Impaired cerebral haemodynamic function associated with chronic traumatic brain injury in professional boxers

2012 ◽  
Vol 124 (3) ◽  
pp. 177-189 ◽  
Author(s):  
Damian M. Bailey ◽  
Daniel W. Jones ◽  
Andrew Sinnott ◽  
Julien V. Brugniaux ◽  
Karl J. New ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Function Analysis ◽  
Transcranial Doppler Ultrasound ◽  
Cerebrovascular Reactivity ◽  
Cerebral Hypoperfusion ◽  
Mechanical Trauma ◽  
Neurocognitive Dysfunction ◽  
Arterial Blood ◽  
Transfer Function Analysis

The present study examined to what extent professional boxing compromises cerebral haemodynamic function and its association with CTBI (chronic traumatic brain injury). A total of 12 male professional boxers were compared with 12 age-, gender- and physical fitness-matched non-boxing controls. We assessed dCA (dynamic cerebral autoregulation; thigh-cuff technique and transfer function analysis), CVRCO2 (cerebrovascular reactivity to changes in CO2: 5% CO2 and controlled hyperventilation), orthostatic tolerance (supine to standing) and neurocognitive function (psychometric tests). Blood flow velocity in the middle cerebral artery (transcranial Doppler ultrasound), mean arterial blood pressure (finger photoplethysmography), end-tidal CO2 (capnography) and cortical oxyhaemoglobin concentration (near-IR spectroscopy) were continuously measured. Boxers were characterized by fronto-temporal neurocognitive dysfunction and impaired dCA as indicated by a lower rate of regulation and autoregulatory index (P<0.05 compared with controls). Likewise, CVRCO2 was also reduced resulting in a lower CVRCO2 range (P<0.05 compared with controls). The latter was most marked in boxers with the highest CTBI scores and correlated against the volume and intensity of sparring during training (r=−0.84, P<0.05). These impairments coincided with more marked orthostatic hypotension, cerebral hypoperfusion and corresponding cortical de-oxygenation during orthostatic stress (P<0.05 compared with controls). In conclusion, these findings provide the first comprehensive evidence for chronically impaired cerebral haemodynamic function in active boxers due to the mechanical trauma incurred by repetitive, sub-concussive head impact incurred during sparring training. This may help explain why CTBI is a progressive disease that manifests beyond the active boxing career.

Impaired transcranial Doppler ultrasound cerebrovascular reactivity before carotid intervention is not predictive of a subsequent ischaemic event

2008 ◽  
Vol 12 (1) ◽  
pp. 11-15
Author(s):  
George Kwok-Chu Wong ◽  
Stephanie Chi-Ping Ng ◽  
Matthew Tak-Vai Chan ◽  
David Tin-Fung Sun ◽  
Wynnie Wai-Man Lam ◽  
...  
Keyword(s):  
Doppler Ultrasound ◽  
Transcranial Doppler ◽  
Transcranial Doppler Ultrasound ◽  
Cerebrovascular Reactivity ◽  
Ischaemic Event

scholarly journals Transcranial Doppler ultrasound to assess cerebrovascular reactivity: reliability, reproducibility and effect of posture

PeerJ ◽  
2013 ◽  
Vol 1 ◽  
pp. e65 ◽  
Author(s):  
Michelle N. McDonnell ◽  
Narelle M. Berry ◽  
Mark A. Cutting ◽  
Hannah A. Keage ◽  
Jonathan D. Buckley ◽  
...  
Keyword(s):  
Doppler Ultrasound ◽  
Transcranial Doppler ◽  
Transcranial Doppler Ultrasound ◽  
Cerebrovascular Reactivity
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