Pedro Castro, Mariana Gutierres, Gilberto Pereira, Susana Ferreira, João Paulo Oliveira, Elsa Azevedo
BACKGROUND: Fabry disease (FD) causes cerebrovascular disease (CVD) even if asymptomatic, and this is why it is important to identify non-invasive methods to monitor the disease. We evaluated the usefulness of the cerebral autoregulation, vasoreactivity, and neurovascular coupling assessed by transcranial Doppler (TCD) in FD. METHODS: Ten adult patients with classic phenotype FD, without clinical expression of CVD, and ten healthy controls, were included. We monitored cerebral blood flow velocity with TCD in the middle and posterior cerebral arteries, blood pressure, heart rate, and non-invasive expired carbon dioxide (CO2 )...
August 7, 2020: Brain Sciences
Jia Liu, Zhen-Ni Guo, David Martin Simpson, Pandeng Zhang, Chang Liu, Jia-Ning Song, Xinyi Leng, Yi Yang
Transfer function analysis (TFA) is extensively used to assess human physiological functions. However, extracting parameters from TFA is not usually optimized for detecting impaired function. In this study, we proposed to use data-driven approaches to improve the performance of TFA in assessing blood flow control in the brain (dynamic cerebral autoregulation - dCA). Data were collected from two distinct groups of subjects deemed to have normal and impaired dCA. Continuous arterial blood pressure (ABP) and cerebral blood flow velocity (CBFV) were simultaneously recorded for approximately 10 mins in 82 subjects (including 41 healthy controls) to give 328 labeled samples of the TFA variables...
August 11, 2020: IEEE Journal of Biomedical and Health Informatics
Jasmine M Khan, Michael D Wood, Kevin F H Lee, David Maslove, John Muscedere, Shane W English, Ian Ball, Marat Slessarev, J Gordon Boyd
RATIONALE: Studies suggest that reduced cerebral perfusion may contribute to delirium development in the intensive care unit (ICU). However, evidence is limited due to factors including small sample size and limited inclusion of covariates. OBJECTIVES: To assess the feasibility of a multicentre prospective observational study using a multi-modal data collection platform. Feasibility was assessed by enrollment, data capture, and follow-up rates. The full study will aim to assess the association between non-invasively derived surrogate markers of cerebral perfusion, delirium development and long-term cognitive outcomes in critically ill patients...
August 11, 2020: Annals of the American Thoracic Society
Mohammad Moeini, Christophe Cloutier-Tremblay, Xuecong Lu, Ashok Kakkar, Frédéric Lesage
We exploited two-photon microscopy and Doppler optical coherence tomography to examine the cerebral blood flow and tissue pO2 response to forced treadmill exercise in awake mice. To our knowledge, this is the first study performing both direct measure of brain tissue pO2 during acute forced exercise and underlying microvascular response at capillary and non-capillary levels. We observed that cerebral perfusion and oxygenation are enhanced during running at 5 m/min compared to rest. At faster running speeds (10 and 15 m/min), decreasing trends in arteriolar and capillary flow speed were observed, which could be due to cerebral autoregulation and constriction of arterioles in response to blood pressure increase...
August 7, 2020: Scientific Reports
Qiong Yu, Jiangtao Qi, Yingwei Wang
PURPOSE OF REVIEW: Intraoperative hypotension (IOH) may render patients at a risk of cerebral hypoperfusion with decreasing cerebral blood flow (CBF), and lead to postoperative neurological injury. On the basis of the literature in recent years, this review attempts to refine the definition of IOH and evaluate its impact on neurological outcomes. RECENT FINDINGS: Although both absolute and relative blood pressure (BP) thresholds, with or without a cumulative period, have been used in collective clinical studies, no definitive threshold of IOH has been established for neurological complications, including perioperative stroke, postoperative cognitive disorder and delirium...
August 6, 2020: Current Opinion in Anaesthesiology
Armin Quispe Cornejo, Carla Sofía Fernandes Vilarinho, Ilaria Alice Crippa, Lorenzo Peluso, Lorenzo Calabrò, Jean-Louis Vincent, Jacques Creteur, Fabio Silvio Taccone
Background: Critically ill patients are at high risk of developing neurological complications. Among all the potential aetiologies, brain hypoperfusion has been advocated as one of the potential mechanisms. Impairment of cerebral autoregulation (CAR) can result in brain hypoperfusion. However, assessment of CAR is difficult at bedside. We aimed to evaluate whether the automated pupillometer might be able to detect impaired CAR in critically ill patients. Methods: We included 92 patients in this retrospective observational study; 52 were septic...
2020: Journal of Intensive Care
Andrew Silverman, Sreeja Kodali, Kevin N Sheth, Nils H Petersen
Hemorrhagic transformation remains a potentially catastrophic complication of reperfusion therapies for the treatment of large-vessel occlusion ischemic stroke. Observational studies have found an increased risk of hemorrhagic transformation in patients with elevated blood pressure as well as a high degree of blood pressure variability, suggesting a link between hemodynamics and hemorrhagic transformation. Current society-endorsed guidelines recommend maintaining blood pressure below a fixed threshold of 180/105 mmHg regardless of thrombolytic or endovascular intervention...
2020: Frontiers in Neurology
Yun-Kai Lee, Peter M Rothwell, Stephen John Payne, Alastair J S Webb
OBJECTIVE: Cerebral autoregulation (CA) is critical to maintenance of cerebral perfusion but its relevance to the risk of stroke and dementia has been under-studied due to small study sizes and a lack of consensus as to the optimal method of measurement. We determined the reliability and reproducibility of multiple CA indices and the effect of intensive data-processing in a large population with transient ischaemic attack or minor stroke. APPROACH: Consecutive, consenting patients in the population-based OXVASC (Oxford Vascular Study) Phenotyped cohort underwent up to 10-min supine continuous blood pressure monitoring (Finometer) with bilateral middle cerebral artery (MCA) transcranial ultrasound (DWL-Dopplerbox)...
August 7, 2020: Physiological Measurement
Anna Giulia Cimatti, Silvia Martini, Silvia Galletti, Francesca Vitali, Arianna Aceti, Giulia Frabboni, Giacomo Faldella, Luigi Corvaglia
Background: The transitional period, defined as the first 72 h after preterm birth, is often characterized by a significant hemodynamic instability, which represents an important risk factor for such neurological complications of prematurity as intraventricular hemorrhage (IVH). The impairment of cerebral autoregulation plays a key role in the pathogenesis of IVH, whose incidence is highest during the transitional period. This pilot study aimed to evaluate whether patterns of cerebral autoregulation and oxygenation differ in relation to IVH development in very preterm infants during the transitional period...
2020: Frontiers in Pediatrics
Jui-Lin Fan, Terrence O'Donnell, Jeremy Lanford, Kevin Croft, Eloise Watson, Duncan Smyth, Henrietta Koch, Lai-Kin Wong, Yu-Chieh Tzeng
Accentuated blood pressure (BP) fluctuation and low cerebral blood flow (CBF) response to CO2 increases the risk of transient ischemic attack (TIA) recurrence and stroke in TIA patients. Improving cardio- and cerebrovascular function may reduce stroke risk. We found dietary nitrate lowered dynamic blood pressure variability (BPV) in rats, and improved cerebrovascular CO2 reactivity in healthy individuals. In thirty TIA patients, we examined the effects of a 7-day supplementation of dietary nitrate (0.1mmol/kg/day) on cerebrovascular function using a randomized, single-blinded, placebo-controlled study design...
August 6, 2020: Journal of Applied Physiology
Elisabeth M W Kooi, Michelle E van der Laan, Ryan E Accord, Marcus T R Roofthooft, Marcel J Aries, Jan Willem J Elting
Objective: During ligation of the ductus arteriosus, cerebrovascular autoregulation (CAR) may deteriorate. It is unknown whether different surgical approaches affect changes in CAR differently. The objective of this study was to compare the potential change in CAR in preterm infants during and after ligation comparing two surgical approaches: sternotomy and posterolateral thoracotomy. Design: This was an observational cohort pilot study. Setting: Level III NICU. Patients: Preterm infants (GA < 32 weeks) requiring ductal ligation were eligible for inclusion...
2020: Frontiers in Pediatrics
Vianney Gilard, Abdellah Tebani, Soumeya Bekri, Stéphane Marret
Germinal matrix-intraventricular-intraparenchymal hemorrhage (GMH-IVH-IPH) is a major complication of very preterm births before 32 weeks of gestation (WG). Despite progress in clinical management, its incidence remains high before 27 WG. In addition, severe complications may occur such as post-hemorrhagic hydrocephalus and/or periventricular intraparenchymal hemorrhage. IVH is strongly associated with subsequent neurodevelopmental disabilities. For this review, an automated literature search and a clustering approach were applied to allow efficient filtering as well as topic clusters identification...
July 31, 2020: Journal of Clinical Medicine
Brian Appavu, Stephen Foldes, Brian T Burrows, Austin Jacobson, Todd Abruzzo, Varina Boerwinkle, Anthony Willyerd, Tara Mangum, Vishal Gunnala, Iris Marku, P D Adelson
BACKGROUND: Management after cerebral arteriovenous malformation (AVM) rupture aims toward preventing hemorrhagic expansion while maintaining cerebral perfusion to avoid secondary injury. We investigated associations of model-based indices of cerebral autoregulation (CA) and autonomic function (AF) with outcomes after pediatric cerebral AVM rupture. METHODS: Multimodal neurologic monitoring data from the initial 3 days after cerebral AVM rupture were retrospectively analyzed in children (< 18 years)...
August 4, 2020: Neurocritical Care
Marcelo de-Lima-Oliveira, Almir Andrade Ferreira, Alessandro Rodrigo Belon, Angela Macedo Salinet, Ricardo Carvalho Nogueira, Brasil Chian Ping, Wellingson Silva Paiva, Manoel Jacobsen Teixeira, Edson Bor-Seng-Shu
OBJECTIVES: To analyze the influences of mild and severe intracranial hypertension on cerebral autoregulation (CA). PATIENTS AND METHODS: Duroc piglets were monitored with an intracranial pressure (ICP) catheter. Intracranial hypertension was induced via infusion of 4 or 7 ml of saline solution by a bladder catheter that was inserted into the parietal lobe. The static cerebral autoregulation (sCA) index was evaluated via cerebral blood flow velocities (CBFv). Piglets with ICPs ≤ 25 and > 25 mmHg were considered as group 1 and 2, respectively...
August 3, 2020: Brain Injury
Wei-Liang Chen, Julie Wagner, Nicholas Heugel, Jeffrey Sugar, Yu-Wen Lee, Lisa Conant, Marsha Malloy, Joseph Heffernan, Brendan Quirk, Anthony Zinos, Scott A Beardsley, Robert Prost, Harry T Whelan
Similar to functional magnetic resonance imaging (fMRI), functional near-infrared spectroscopy (fNIRS) detects the changes of hemoglobin species inside the brain, but via differences in optical absorption. Within the near-infrared spectrum, light can penetrate biological tissues and be absorbed by chromophores, such as oxyhemoglobin and deoxyhemoglobin. What makes fNIRS more advantageous is its portability and potential for long-term monitoring. This paper reviews the basic mechanisms of fNIRS and its current clinical applications, the limitations toward more widespread clinical usage of fNIRS, and current efforts to improve the temporal and spatial resolution of fNIRS toward robust clinical usage within subjects...
2020: Frontiers in Neuroscience
Abbie C Johnson
The adaptation of the cerebral circulation to pregnancy is unique compared with other organs and circulatory systems, because the brain requires relatively constant blood flow and water and solute composition to maintain homeostasis. Thus, a major adaptation of the maternal cerebrovasculature to pregnancy is to maintain normalcy in the face of expanded plasma volume, increased cardiac output, and high levels of permeability factors. In this chapter, the effect of pregnancy on critical functions of the cerebral circulation is discussed, including changes occurring at the endothelium and blood-brain barrier (BBB), which protect the maternal brain from changes in BBB permeability...
2020: Handbook of Clinical Neurology
Chun-Gu Cheng, Hsin Chu, Jiunn-Tay Lee, Wu-Chien Chien, Chun-An Cheng
(1) Background: Patients with benign prostatic hyperplasia (BPH) were questioned about quality of life and sleep. Most BPH patients were treated with alpha-1 adrenergic receptor antagonists, which could improve cerebral blood flow for 1-2 months. Patients with ischemic stroke (IS) could experience cerebral autoregulation impairment for six months. The relationship between BPH and recurrent IS remains unclear. The aim of this study was to determine the risk of one-year recurrent IS conferred by BPH. (2) Methods: We used data from the Taiwanese National Health Insurance Database to identify newly diagnosed IS cases entered from 1 January 2008 to 31 December 2008...
July 25, 2020: International Journal of Environmental Research and Public Health
Marc Kermorgant, Nathalie Nasr, Marek Czosnyka, Dina N Arvanitis, Ophélie Hélissen, Jean-Michel Senard, Anne Pavy-Le Traon
It is well known that exposure to microgravity in astronauts leads to a plethora physiological responses such as headward fluid shift, body unloading, and cardiovascular deconditioning. When astronauts return to Earth, some encounter problems related to orthostatic intolerance. An impaired cerebral autoregulation (CA), which could be compromised by the effects of microgravity, has been proposed as one of the mechanisms responsible for orthostatic intolerance. CA is a homeostatic mechanism that maintains cerebral blood flow for any variations in cerebral perfusion pressure by adapting the vascular tone and cerebral vessel diameter...
2020: Frontiers in Physiology
Teodor Svedung Wettervik, Henrik Engquist, Timothy Howells, Samuel Lenell, Elham Rostami, Lars Hillered, Per Enblad, Anders Lewén
BACKGROUND: Ischemic and hypoxic secondary brain insults are common and detrimental in traumatic brain injury (TBI). Treatment aims to maintain an adequate cerebral blood flow with sufficient arterial oxygen content. It has been suggested that arterial hyperoxia may be beneficial to the injured brain to compensate for cerebral ischemia, overcome diffusion barriers, and improve mitochondrial function. In this study, we investigated the relation between arterial oxygen levels and cerebral energy metabolism, pressure autoregulation, and clinical outcome...
July 27, 2020: Journal of Intensive Care Medicine
Elisabeth M W Kooi, Anne E Richter
Cerebrovascular autoregulation is the ability to maintain stable cerebral blood flow within a range of cerebral perfusion pressures. When cerebral perfusion pressure is outside the limits of effective autoregulation, the brain is subjected to hypoperfusion or hyperperfusion, which may cause vascular injury, hemorrhage, and/or hypoxic white matter injury. Infants born preterm, after fetal growth restriction, with congenital heart disease, or with hypoxic-ischemic encephalopathy are susceptible to a failure of cerebral autoregulation...
September 2020: Clinics in Perinatology
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