Cerebrovascular reactivity before and after carotid endarterectomy

1999 ◽  
Vol 51 (3) ◽  
pp. 321-326 ◽  
Author(s):  
V. D’Angelo ◽  
G. Catapano ◽  
V. Bozzini ◽  
D. Catapano ◽  
P. De Vivo ◽  
...  
Keyword(s):  
Carotid Endarterectomy ◽  
Cerebrovascular Reactivity ◽  
Before And After

scholarly journals Incomplete circle of Willis and cerebrovascular reactivity in asymptomatic patients before and after carotid endarterectomy

2020 ◽  
pp. 68-68
Author(s):  
Vladimir Manojlovic ◽  
Djordje Milosevic ◽  
Nebojsa Budakov ◽  
Dragan Nikolic
Keyword(s):  
Carotid Artery ◽  
Carotid Endarterectomy ◽  
Carotid Artery Disease ◽  
Circle Of Willis ◽  
Cerebrovascular Reactivity ◽  
Collateral Flow ◽  
Apnea Test ◽  
Asymptomatic Patients ◽  
Before And After ◽  
Artery Disease

Introduction/Objective. Circle of Willis (CoW) provides the most significant collateral flow in the presence of significant stenosis or occlusion of internal carotid artery. In terms of collateral flow ?incomplete? type and ?complete? type of CoW can be recognized. Patients with carotid artery disease with incomplete CoW have lower cerebrovascular reactivity and higher risk for stroke. Cerebrovascular reactivity refers to the residual capacity of dilatation of cerebral blood vessels in the condition of insufficient blood flow. In this study we analyzed changes in cerebrovascular reactivity after carotid endarterectomy in asymptomatic patients with respect to complete and incomplete CoW morphology. Methods. In this study in 97 patients with asymptomatic carotid artery disease we measured cerebrovascular reactivity before and after carotid endarterectomy by using method of ?apnea test? and ? Breath Hold Index? (BHI). Patients were divided into two following groups: patients with ?complete? CoW and ?incomplete? CoW based on non-contrast magnetic resonance angio performed previously to the operation. Descriptive statistics, univariate analysis, and ANOVA for comparison of BHI values between groups were used. Results. Results showed significant increase in cerebrovascular reactivity at the side of stenosis in both groups of patients with complete CoW (BHI value increased from 0,897 to 1.090; F(1.65) = 30.788, p < 0.0005, parc. ?2 = 0.321) and incomplete CoW (BHI value increased from 0.690 to 1.010; F ( 1.27 ) = 62.318 , p < 0.0005, parc. ?2 = 0.698) and the more significant increase in the group of incomplete CoW compared to the group with complete CoW (F (1.92 ) = 4.557 , p =0.035 , parc. ?2 =0.047) Conclusion. In most asymptomatic patients, cerebrovascular reactivity restores to normal following carotid endarterectomy. Parameters of cerebrovascular reactivity are lower in patients with incomplete CoW and the increase after carotid endarterectomy is more significant in such patients.

Artifact removal from neurophysiological signals: impact on intracranial and arterial pressure monitoring in traumatic brain injury

2020 ◽  
Vol 132 (6) ◽  
pp. 1952-1960 ◽  
Author(s):  
Seung-Bo Lee ◽  
Hakseung Kim ◽  
Young-Tak Kim ◽  
Frederick A. Zeiler ◽  
Peter Smielewski ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Neurological Status ◽  
Cerebrovascular Reactivity ◽  
Cerebral Hypoperfusion ◽  
Clinical Parameters ◽  
Artifact Removal ◽  
Clinical Events ◽  
Arterial Blood ◽  
Before And After

OBJECTIVEMonitoring intracranial and arterial blood pressure (ICP and ABP, respectively) provides crucial information regarding the neurological status of patients with traumatic brain injury (TBI). However, these signals are often heavily affected by artifacts, which may significantly reduce the reliability of the clinical determinations derived from the signals. The goal of this work was to eliminate signal artifacts from continuous ICP and ABP monitoring via deep learning techniques and to assess the changes in the prognostic capacities of clinical parameters after artifact elimination.METHODSThe first 24 hours of monitoring ICP and ABP in a total of 309 patients with TBI was retrospectively analyzed. An artifact elimination model for ICP and ABP was constructed via a stacked convolutional autoencoder (SCAE) and convolutional neural network (CNN) with 10-fold cross-validation tests. The prevalence and prognostic capacity of ICP- and ABP-related clinical events were compared before and after artifact elimination.RESULTSThe proposed SCAE-CNN model exhibited reliable accuracy in eliminating ABP and ICP artifacts (net prediction rates of 97% and 94%, respectively). The prevalence of ICP- and ABP-related clinical events (i.e., systemic hypotension, intracranial hypertension, cerebral hypoperfusion, and poor cerebrovascular reactivity) all decreased significantly after artifact removal.CONCLUSIONSThe SCAE-CNN model can be reliably used to eliminate artifacts, which significantly improves the reliability and efficacy of ICP- and ABP-derived clinical parameters for prognostic determinations after TBI.

Cerebral Blood Flow before and After Carotid Endarterectomy

1972 ◽  
Vol 6 (1) ◽  
pp. 14-19 ◽  
Author(s):  
H.C. Engell ◽  
Gudrun Boysen ◽  
H.J. Ladegaard-Pedersen ◽  
H. Henriksen
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Endarterectomy ◽  
Before And After

The Effect of Arteriovenous Malformation Resection on Cerebrovascular Reactivity to Carbon Dioxide

Neurosurgery ◽  
1990 ◽  
Vol 27 (2) ◽  
pp. 257-267 ◽  
Author(s):  
William L. Young ◽  
Isak Prohovnik ◽  
Isak Prohovnik ◽  
Isak Prohovnik ◽  
Eugene Ornstein ◽  
...  
Keyword(s):  
Intracerebral Hemorrhage ◽  
Risk Score ◽  
Cerebrovascular Reactivity ◽  
Neurological Deficits ◽  
Control Group ◽  
Technical Problems ◽  
Before And After ◽  
Acute Increase ◽  
Patient’S History ◽  
Risk Score System

Abstract To investigate the cerebral hemodynamic changes associated with obliteration of arteriovenous malformations (AVMs), we studied 26 patients undergoing total microsurgical AVM resection during isoflurane and N2/O2anesthesia. Detectors were placed 5 to 6 cm from the margin of the lesion and in a homologous contralateral position. Cerebral blood flow (CBF) was measured using the intravenous xenon-133 technique before and after AVM resection, during both hypocapnia and normocapnia at each stage. Intraoperative changes in CBF were related to a risk score system based on the patient's history and preoperative angiograms. Seven otherwise healthy patients undergoing spinal surgery were studied to control for anesthetic effects. Patient demographic and clinical data for the AVM group conformed to the expected strata of a large AVM population. The CBF increased after excision (22 ± 1 ml/100 g/min before excision to 30 ± 2 ml/100 g/min after excision; mean ± SE. n = 25, P &lt; 0.002) without a hemispheric difference. CO2reactivity increased slightly after excision (4.2 ± 0.3% change/mm Hg before excision to 4.7 ± 0.3% change/mm Hg after excision; n = 14, P &lt; 0.02). The baseline CBF and CO2reactivity were not different from the control group. There was a weak correlation between the risk score and the percentage of change in the ipsilateral CBF, with a trend for the patients with the lowest risk to have the lowest CBF changes after resection. There was no relationship between CO2reactivity and risk grade. None of the patients awoke from anesthesia with unexpected neurological deficits. The highest CBF increases were associated with postoperative brain swelling in one patient and fatal intracerebral hemorrhage in another. Both patients had normal CO2reactivity before excision. One patient suffered postoperative intracerebral hemorrhage, attributable to technical problems, and had no increase in CBF. We conclude that, with an acute increase in the arteriovenous pressure gradient (and cerebral perfusion pressure) that results from shunt obliteration, there is an immediate global effect of AVM resection to increase CBF. Cerebrovascular reactivity to CO2remains intact both before and after excision.

Detection of Cerebral Microemboli by Means of Transcranial Doppler Monitoring Before and After Carotid Endarterectomy

Stroke ◽  
1995 ◽  
Vol 26 (2) ◽  
pp. 210-213 ◽  
Author(s):  
Erik V. van Zuilen ◽  
Frans L. Moll ◽  
Freddie E.E. Vermeulen ◽  
Henk W. Mauser ◽  
Jan van Gijn ◽  
...  
Keyword(s):  
Carotid Endarterectomy ◽  
Transcranial Doppler ◽  
Before And After

scholarly journals Hippocampal Blood Flow Is Increased After 20 min of Moderate-Intensity Exercise

2019 ◽  
Vol 30 (2) ◽  
pp. 525-533 ◽  
Author(s):  
J J Steventon ◽  
C Foster ◽  
H Furby ◽  
D Helme ◽  
R G Wise ◽  
...  
Keyword(s):  
Blood Flow ◽  
Temporal Dynamics ◽  
Therapeutic Potential ◽  
Cerebrovascular Reactivity ◽  
Moderate Intensity ◽  
Moderate Intensity Exercise ◽  
Exercise Interventions ◽  
Before And After ◽  
Exercise Induced

Abstract Long-term exercise interventions have been shown to be a potent trigger for both neurogenesis and vascular plasticity. However, little is known about the underlying temporal dynamics and specifically when exercise-induced vascular adaptations first occur, which is vital for therapeutic applications. In this study, we investigated whether a single session of moderate-intensity exercise was sufficient to induce changes in the cerebral vasculature. We employed arterial spin labeling magnetic resonance imaging to measure global and regional cerebral blood flow (CBF) before and after 20 min of cycling. The blood vessels’ ability to dilate, measured by cerebrovascular reactivity (CVR) to CO2 inhalation, was measured at baseline and 25-min postexercise. Our data showed that CBF was selectively increased by 10–12% in the hippocampus 15, 40, and 60 min after exercise cessation, whereas CVR to CO2 was unchanged in all regions. The absence of a corresponding change in hippocampal CVR suggests that the immediate and transient hippocampal adaptations observed after exercise are not driven by a mechanical vascular change and more likely represents an adaptive metabolic change, providing a framework for exploring the therapeutic potential of exercise-induced plasticity (neural, vascular, or both) in clinical and aged populations.

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