scholarly journals Study of cerebrovascular reactivity to hypercapnia by imaging photoplethysmography to develop a method for intraoperative assessment of the brain functional reserve

2021 ◽  
Author(s):  
Maxim Volynsky ◽  
Oleg Mamontov ◽  
Anastasiia Osipchuk ◽  
Valeriy Zaytsev ◽  
Alexey Sokolov ◽  
...  
Keyword(s):  
Cerebrovascular Reactivity ◽  
Functional Reserve ◽  
Intraoperative Assessment ◽  
The Brain

Medicinal correction of cerebrovascular reactivity — a necessary component of the treatment of cerebral blood circulation disorders

1999 ◽  
Vol 80 (2) ◽  
pp. 94-96
Author(s):  
V. I. Danilov
Keyword(s):  
Blood Circulation ◽  
Organic Phosphorus ◽  
Experimental Studies ◽  
Cerebrovascular Reactivity ◽  
Cerebral Vessels ◽  
Regulatory Mechanisms ◽  
Phosphorus Compounds ◽  
Low Toxic ◽  
The Brain ◽  
Cerebral Blood Circulation

The results of experimental studies made it possible to draw a conclusion on the reality of cerebral vessels reactivity recovery using drugs with primary neurometabolic activity, in particular, dimephosphone, sermion and pyracetam. The advantages of low-toxic nonauticholinesterasic organic phosphorus compounds among the correctors of regulatory mechanisms of circular provision of the brain are shown.

Effects of experimental fluid-percussion injury of the brain on cerebrovascular reactivity to hypoxia and to hypercapnia

1982 ◽  
Vol 56 (3) ◽  
pp. 332-338 ◽  
Author(s):  
Wlodimierz Lewelt ◽  
Larry W. Jenkins ◽  
J. Douglas Miller
Keyword(s):  
Blood Gases ◽  
Cerebrovascular Reactivity ◽  
Arterial Blood Gases ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Fluid Percussion ◽  
Arterial Blood ◽  
Fluid Percussion Injury ◽  
The Brain ◽  
Experimental Fluid

✓ To test the hypothesis that concussive brain injury interferes with the normal vasodilator response of the cerebral circulation to hypoxemia, 30 cats were subjected to mild (PaO2 50 mm Hg) and severe (PaO2 30 mm Hg) hypoxemia while measurements were made of arterial and intracranial pressure, regional cerebral blood flow (CBF), and arterial blood gases. Ten cats served as controls, 10 were subjected to mild fluid-percussion injury of the brain (0.8 to 1.7 atmospheres (atm)), and 10 to severe injury (2.4 to 4.1 atm). The CBF response to hypercapnia (PaCO2 50 mm Hg) was also tested in most animals, and the response of CBF autoregulation to hemorrhagic hypotension was tested in four animals of each group. Trauma was found to severely attenuate the capacity of CBF to increase during hypoxemia. Responsiveness to hypoxemia appeared to be better preserved in traumatized animals than was autoregulation, but was less robust than the response to hypercapnia.

Real-Time Intraoperative Assessment of Residual Liver Functional Reserve Using Pulse Dye Densitometry

2008 ◽  
Vol 32 (12) ◽  
pp. 2668-2674 ◽  
Author(s):  
Hirofumi Akita ◽  
Yo Sasaki ◽  
Terumasa Yamada ◽  
Kunihito Gotoh ◽  
Hiroaki Ohigashi ◽  
...  
Keyword(s):  
Real Time ◽  
Functional Reserve ◽  
Intraoperative Assessment ◽  
Liver Functional Reserve

scholarly journals The Relationship Between Cognition and Cerebrovascular Reactivity: Implications for Task-Based fMRI

2021 ◽  
Vol 9 ◽  
Author(s):  
Rebecca J. Williams ◽  
M. Ethan MacDonald ◽  
Erin L. Mazerolle ◽  
G. Bruce Pike
Keyword(s):  
Cognitive Processes ◽  
Brain Function ◽  
Vascular Function ◽  
Brain Regions ◽  
Cerebrovascular Reactivity ◽  
Vascular Health ◽  
Vascular Changes ◽  
Future Directions ◽  
The Relationship ◽  
The Brain

Elucidating the brain regions and networks associated with cognitive processes has been the mainstay of task-based fMRI, under the assumption that BOLD signals are uncompromised by vascular function. This is despite the plethora of research highlighting BOLD modulations due to vascular changes induced by disease, drugs, and aging. On the other hand, BOLD fMRI-based assessment of cerebrovascular reactivity (CVR) is often used as an indicator of the brain's vascular health and has been shown to be strongly associated with cognitive function. This review paper considers the relationship between BOLD-based assessments of CVR, cognition and task-based fMRI. How the BOLD response reflects both CVR and neural activity, and how findings of altered CVR in disease and in normal physiology are associated with cognition and BOLD signal changes are discussed. These are pertinent considerations for fMRI applications aiming to understand the biological basis of cognition. Therefore, a discussion of how the acquisition of BOLD-based CVR can enhance our ability to map human brain function, with limitations and potential future directions, is presented.

Reproducibility of cerebrovascular reactivity measurements: A systematic review of neuroimaging techniques*

2021 ◽  
pp. 0271678X2110567
Author(s):  
Moss Y Zhao ◽  
Amanda Woodward ◽  
Audrey P Fan ◽  
Kevin T Chen ◽  
Yannan Yu ◽  
...  
Keyword(s):  
Imaging Modality ◽  
Stress Test ◽  
Cerebrovascular Reactivity ◽  
Brain Health ◽  
Wide Range ◽  
Clinical Biomarker ◽  
Blood Characteristics ◽  
Meta Analyses ◽  
The Brain ◽  
Neuroimaging Techniques

Cerebrovascular reactivity (CVR), the capacity of the brain to increase cerebral blood flow (CBF) to meet changes in physiological demand, is an important biomarker to evaluate brain health. Typically, this brain “stress test” is performed by using a medical imaging modality to measure the CBF change between two states: at baseline and after vasodilation. However, since there are many imaging modalities and many ways to augment CBF, a wide range of CVR values have been reported. An understanding of CVR reproducibility is critical to determine the most reliable methods to measure CVR as a clinical biomarker. This review focuses on CVR reproducibility studies using neuroimaging techniques in 32 articles comprising 427 total subjects. The literature search was performed in PubMed, Embase, and Scopus. The review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We identified 5 factors of the experimental subjects (such as sex, blood characteristics, and smoking) and 9 factors of the measuring technique (such as the imaging modality, the type of the vasodilator, and the quantification method) that have strong effects on CVR reproducibility. Based on this review, we recommend several best practices to improve the reproducibility of CVR quantification in neuroimaging studies.

Cerebroprotective effects of the CO-releasing molecule CORM-A1 against seizure-induced neonatal vascular injury

2007 ◽  
Vol 293 (4) ◽  
pp. H2501-H2507 ◽  
Author(s):  
Aliz Zimmermann ◽  
Charles W. Leffler ◽  
Dilyara Tcheranova ◽  
Alexander L. Fedinec ◽  
Helena Parfenova
Keyword(s):  
Cerebral Circulation ◽  
Blood Gases ◽  
Epileptic Seizures ◽  
Cerebrovascular Reactivity ◽  
Water Soluble ◽  
Vascular Effects ◽  
Delayed Effects ◽  
Cerebrovascular Injury ◽  
Newborn Pigs ◽  
The Brain

Endogenous CO, a product of heme oxygenase activity, has vasodilator and cytoprotective effects in the cerebral circulation of newborn pigs. CO-releasing molecule (CORM)-A1 (sodium boranocarbonate) is a novel, water-soluble, CO-releasing compound. We addressed the hypotheses that CORM-A1 1) can deliver CO to the brain and exert effects of CO on the cerebral microvasculature and 2) is cerebroprotective. Acute and delayed effects of topically and systemically administered CORM-A1 on cerebrovascular and systemic circulatory parameters were determined in anesthetized newborn pigs with implanted closed cranial windows. Topical application of CORM-A1 (10−7–10−5 M) to the brain produced concentration-dependent CO release and pial arteriolar dilation. Systemically administered CORM-A1 (2 mg/kg ip or iv) caused pial arteriolar dilation and increased cortical cerebrospinal fluid CO concentration. Systemic CORM-A1 did not have acute or delayed effects on blood pressure, heart rate, or blood gases. Potential cerebroprotective vascular effects of CORM-A1 (2 mg/kg ip, 30 min before seizures) were tested 2 days after bicuculline-induced epileptic seizures (late postictal period). In control piglets, seizures reduced postictal cerebrovascular responsiveness to selective physiologically relevant vasodilators (bradykinin, hemin, and isoproterenol) indicative of cerebrovascular injury. In contrast, in CORM-A1-pretreated animals, no loss of postictal cerebrovascular reactivity was observed. We conclude that systemically administered CORM-A1 delivers CO to the brain, elicits the vasodilator and cytoprotective effects of CO in the cerebral circulation, and protects the neonatal brain from cerebrovascular injury caused by epileptic seizures.

scholarly journals Intraoperative BOLD-fMRI Cerebrovascular Reactivity Assessment

2021 ◽  
pp. 139-143
Author(s):  
Giovanni Muscas ◽  
Christiaan Hendrik Bas van Niftrik ◽  
Martina Sebök ◽  
Giuseppe Esposito ◽  
Luca Regli ◽  
...  
Keyword(s):  
Cerebrovascular Diseases ◽  
Blood Oxygenation ◽  
Cerebrovascular Reactivity ◽  
Hemodynamic State ◽  
Neurosurgical Patients ◽  
Blood Oxygenation Level ◽  
Oxygenation Level ◽  
Ischemic Cerebrovascular Diseases ◽  
Brain Gliomas ◽  
The Brain

AbstractBlood oxygenation-level dependent cerebrovascular reactivity (BOLD-CVR) has gained attention in recent years as an effective way to investigate CVR, a measure of the hemodynamic state of the brain, with high spatial and temporal resolution. An association between impaired CVR and diverse pathologies has been observed, especially in ischemic cerebrovascular diseases and brain gliomas. The ability to obtain this information intraoperatively is novel and has not been widely tested. We report our first experience with this intraoperative technique in vascular and oncologic neurosurgical patients, discuss the results of its feasibility, and the possible developments of the intraoperative employment of BOLD-CVR.

FEATURES OF AUTOREGULATION OF CEREBRAL BLOOD FLOW IN LYMPHOMAS

2017 ◽  
Vol 63 (6) ◽  
pp. 920-925
Author(s):  
Vladimir Koptev ◽  
Vadim Nimaev ◽  
Vladimir Gorchakov
Keyword(s):  
Blood Circulation ◽  
Transcranial Doppler Sonography ◽  
Vascular Wall ◽  
Cerebrovascular Reactivity ◽  
Combined Chemotherapy ◽  
Functional Tests ◽  
Functional Reserve ◽  
Before And After ◽  
The Difference ◽  
Toxicity Of Drugs

The group of surveyed persons was made by 95 patients with hemoblastoses, of them 40 - with Hodgkin's lymphoma (HL) and 55 - with non-Hodgkin's malignant lymphoma (NHML) before and after a polychemotherapy at different stages of a disease. We investigated blood velocity with autoregulation assessment in the region of a medial cerebral artery by method of transcranial doppler sonography. In addition we did functional tests with calculation of indexes of reactivity. We established decrease in indicators of reactivity at functional tests that reflects restriction of a functional reserve of brain blood circulation at lymphomas. The range of vessels reaction was progressively narrowed that was confirmed by reduction of an index of vasomotorial reactivity by 34,6% to III-IV stages of a HL and by 47,3% at I-II and 74,6% at III-IV stages of a NHML. Degree of decrease in reactivity and violation of autoregulation of brain blood circulation progressed in process of transition of a disease to heavier stage against the happening remodeling of vascular wall. The degree of a reactivity decrease was higher at a NHML than at HL. There was an expansion of homeostatic range of reactions against the background of rising of compensatory opportunities of vessels because of decrease of cellular infiltration after a combined chemotherapy. Indexes of a cerebrovascular reactivity after the combined chemotherapy had higher sizes in comparison with similar indicators before treatment but they did not reach control. The difference between sizes of an index of a vaso-motorial reactivity arising before and after a polychemotherapy was most indicative. It was 7%-18,1% in HL and 17%-56,2% in NHML depending on disease duration. Full normalization of an autoregulation of a cerebral circulation did not happen after treatment that assumed a need of additional measures of the rehabilitation referred on decrease of toxicity of drugs and endogenic intoxication at lymphoproliferation diseases.

scholarly journals Higher cardiovascular fitness level is associated with lower cerebrovascular reactivity and perfusion in healthy older adults

2019 ◽  
Vol 40 (7) ◽  
pp. 1468-1481 ◽  
Author(s):  
Brittany Intzandt ◽  
Dalia Sabra ◽  
Catherine Foster ◽  
Laurence Desjardins-Crépeau ◽  
Richard D Hoge ◽  
...  
Keyword(s):  
Structural Changes ◽  
Quantitative Imaging ◽  
Cardiovascular Fitness ◽  
Cerebrovascular Reactivity ◽  
Aging Brain ◽  
Grey Matter Volume ◽  
Healthy Older Adults ◽  
Fitness Level ◽  
Physiological Outcomes ◽  
The Brain

Aging is accompanied by vascular and structural changes in the brain, which include decreased grey matter volume (GMV), cerebral blood flow (CBF), and cerebrovascular reactivity (CVR). Enhanced fitness in aging has been related to preservation of GMV and CBF, and in some cases CVR, although there are contradictory relationships reported between CVR and fitness. To gain a better understanding of the complex interplay between fitness and GMV, CBF and CVR, the present study assessed these factors concurrently. Data from 50 participants, aged 55 to 72, were used to derive GMV, CBF, CVR and VO2peak. Results revealed that lower CVR was associated with higher VO2peak throughout large areas of the cerebral cortex. Within these regions lower fitness was associated with higher CBF and a faster hemodynamic response to hypercapnia. Overall, our results indicate that the relationships between age, fitness, cerebral health and cerebral hemodynamics are complex, likely involving changes in chemosensitivity and autoregulation in addition to changes in arterial stiffness. Future studies should collect other physiological outcomes in parallel with quantitative imaging, such as measures of chemosensitivity and autoregulation, to further understand the intricate effects of fitness on the aging brain, and how this may bias quantitative measures of cerebral health.

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