Cool head-out water immersion does not alter cerebrovascular reactivity to hypercapnia despite elevated middle cerebral artery blood velocity: A pilot study

PLoS ONE, Год журнала: 2024, Номер 19(3), С. e0298587 - e0298587

Опубликована: Март 13, 2024

Episodic increases in cerebral blood flow (CBF) are thought to contribute improved cerebrovascular function and health. Head-out water immersion (HOWI) may be a useful modality increase CBF secondary the hydrostatic pressure placed on body. However, it is unclear whether temperatures common general public elicit similar responses. We tested hypothesis that mean middle artery velocity (MCAvmean) reactivity CO2 (CVRCO2) would higher during an acute bout of thermoneutral (TN; 35°C) vs. cool (COOL; 25°C) HOWI. Ten healthy participants (age: 23±3 y; 4 women) completed two randomized HOWI visits. Right MCAvmean, end-tidal (PETCO2) arterial (MAP), MCA conductance (MCAvmean/MAP) were continuously recorded. CVRCO2 was assessed using stepped hypercapnia protocol before (PRE), at 30 minutes (HOWI), immediately after (POST-1), 45 (POST-2). Absolute values reported as ± SD. PETCO2, MAP, not different between conditions any timepoint (all P≥0.17). In COOL, MCAvmean increased from PRE (61±9 cm/s) (68±11 cm/s), POST-1 (69±11 POST-2 (72±8 P<0.01), TN (66±13 71±14 cm/s; P = 0.05). PETCO2 did change over time either condition. MAP (85±5 mmHg) (101±4 mmHg), (97±7 (96±9 (88±5 (98±7 (99±8 P<0.01). (1.66±0.55 1.92±0.52 cm/s/mmHg; 0.04). or within conditions. These data indicate augments persists beyond does alter young adults.

Язык: Английский

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Non-invasive perfusion MR imaging of the human brain via breath-holding

Scientific Reports, Год журнала: 2024, Номер 14(1)

Опубликована: Март 27, 2024

Abstract Dynamic susceptibility contrast (DSC) MRI plays a pivotal role in the accurate diagnosis and prognosis of several neurovascular diseases, but is limited by its reliance on gadolinium, an intravascularly injected chelated metal. Here, we determined feasibility measuring perfusion using DSC analysis breath-hold-induced gradient-echo-MRI signal changes. We acquired data at both 3 T 7 from ten healthy participants who engaged eight consecutive breath-holds. By pairing novel arterial input function strategy with standard analysis, measured cerebral blood volume, flow, transit delay, found values to agree those documented literature gadolinium. also observed voxel-wise agreement between breath-hold spin labeling measures flow. Breath-holding resulted significantly higher contrast-to-noise (6.2 vs. 8.5 T) gray matter-to-white matter field strength. Finally, simulation framework assess effect dynamic vasodilation estimation, global underestimation 20–40%. For first time, have assessed limitations associated breath-holds for estimation DSC. hope that methods results presented this study will help pave way toward contrast-free imaging, basic clinical research.

Язык: Английский

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Cerebrovascular Reactivity Following Spinal Cord Injury

Topics in Spinal Cord Injury Rehabilitation, Год журнала: 2024, Номер 30(2), С. 78 - 95

Опубликована: Май 1, 2024

Spinal cord injuries (SCI) often result in cardiovascular issues, increasing the risk of stroke and cognitive deficits.

Язык: Английский

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Hemodynamic Imaging in Cerebral Diffuse Glioma—Part B: Molecular Correlates, Treatment Effect Monitoring, Prognosis, and Future Directions

Cancers, Год журнала: 2022, Номер 14(5), С. 1342 - 1342

Опубликована: Март 5, 2022

Gliomas, and glioblastoma in particular, exhibit an extensive intra- inter-tumoral molecular heterogeneity which represents complex biological features correlating to the efficacy of treatment response survival. From a neuroimaging point view, these specific histopathological may be used yield imaging biomarkers as surrogates for distinct tumor genotypes phenotypes. The development comprehensive glioma markers has potential improved characterization that would assist clinical work-up preoperative planning effect monitoring. In differentiation recurrence or true progression from pseudoprogression, pseudoresponse, radiation-induced necrosis can still not reliably made through standard only. Given abundant vascular hemodynamic alterations present diffuse glioma, advanced approaches constitute attractive area development. this context, inclusion objective measurable have enhance individualized care patients, better informing standard-of-care novel therapies, such immunotherapies are currently increasingly investigated. Part B two-review series, we assess available evidence pertaining feature prediction, particular focusing on isocitrate dehydrogenase (IDH) mutation status, MGMT promoter methylation, 1p19q codeletion, EGFR alterations. results progression/recurrence effects also been focus active research presented together with prognostic correlations identified by studies. Finally, state-of-the-art concepts advancements modalities reviewed advantages derived implementation radiomics machine learning analyses pipelines.

Язык: Английский

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Correspondence between BOLD fMRI task response and cerebrovascular reactivity across the cerebral cortex

Frontiers in Physiology, Год журнала: 2023, Номер 14

Опубликована: Май 9, 2023

BOLD sensitivity to baseline perfusion and blood volume is a well-acknowledged fMRI confound. Vascular correction techniques based on cerebrovascular reactivity (CVR) might reduce variance due cerebral volume, however this predicated an invariant linear relationship between CVR signal magnitude. Cognitive paradigms have relatively low signal, high involve spatially heterogenous cortical regions; it therefore unclear whether the response magnitude complex can be predicted by CVR. The feasibility of predicting from was explored in present work across two experiments using different approaches. first utilized large database containing breath-hold responses 3 cognitive tasks. second experiment, independent sample, calculated delivery fixed concentration carbon dioxide task. An atlas-based regression approach implemented for both evaluate shared task-invoked cortex. Both found significant relationships task-based magnitude, with activation right cuneus (R2 = 0.64) paracentral gyrus 0.71), left pars opercularis 0.67), superior frontal 0.62) inferior parietal cortex 0.63) strongly regions bilaterally were highly consistent, regressions these all four Group analyses showed that increased sensitivity. Overall, suggests magnitudes tasks are cortex, providing support use vascular physiology.

Язык: Английский

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Feasibility of glioblastoma tissue response mapping with physiologic BOLD imaging using precise oxygen and carbon dioxide challenge

Magnetic Resonance Materials in Physics Biology and Medicine, Год журнала: 2021, Номер 35(1), С. 29 - 44

Опубликована: Дек. 7, 2021

Язык: Английский

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Comprehensive Assessment of Drug Kinetics, Neurotoxicity, and Safety of Sirolimus-Eluting Intracranial Stents in Canine Basilar Artery

Neurosurgery, Год журнала: 2024, Номер 95(5), С. 1199 - 1208

Опубликована: Июль 10, 2024

BACKGROUND AND OBJECTIVES: Sirolimus-eluting stents (SESs) have shown promise in treating intracranial atherosclerosis but concerns about potential neurotoxicity due to prolonged drug release exist. The aim of this study was comprehensively assess the safety SES, with a focus on neurotoxicity. METHODS: Stents (1.50 × 7 or 12 mm) were implanted into basilar arteries 154 Labrador Retrievers (weighing >25 kg and aged older than 1 year) divided 4 groups: bare-metal stent, polymer-coated standard-dose SES (sirolimus dose: 71 μg), high-dose group 284 μg). Pharmacokinetic analysis conducted using liquid chromatography-mass spectrometry blood tissue samples, brain performed 5 different special stains immunohistochemistry protocols axonal degeneration, vacuolization, astrocyte proliferation, microglial activation, widespread neurodegeneration. RESULTS: In group, stent released 10.56% day 95.41% 28 postimplantation. corresponding figures 40.20% 98.08% 28. Systemic concentration consistently remained below 1.5 ng/mL throughout study. Arterial reached its peak at days group. Importantly, related concentrations 0.4 µg/g both groups, peaking 21 detailed 180-day assessment revealed no adverse effects brain, even high sirolimus doses CONCLUSION: This provides robust evidence supporting long-term pharmacokinetic SESs context interventions for high-grade atherosclerosis. results adequately alleviate substantiate feasibility these as therapeutic choice neurosurgery.

Язык: Английский

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Understanding the potential mechanisms of disease modifying effects of physical activity and exercise in people with schizophrenia

Schizophrenia Research, Год журнала: 2024, Номер 274, С. 381 - 391

Опубликована: Окт. 28, 2024

Язык: Английский

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Detection and Mitigation of Neurovascular Uncoupling in Brain Gliomas

Cancers, Год журнала: 2023, Номер 15(18), С. 4473 - 4473

Опубликована: Сен. 8, 2023

Functional magnetic resonance imaging (fMRI) with blood oxygen level-dependent (BOLD) technique is useful for preoperative mapping of brain functional networks in tumor patients, providing reliable vivo detection eloquent cortex to help reduce the risk postsurgical morbidity. BOLD task-based fMRI (tb-fMRI) most often used noninvasive method that can reliably map cortical networks, including those associated sensorimotor, language, and visual functions. resting-state (rs-fMRI) emerging as a promising ancillary tool visualization diverse networks. Although powerful be an adjunct surgery planning, it has some constraints should taken into consideration proper clinical interpretation. interpretation may limited by neurovascular uncoupling (NVU) induced tumors. Cerebrovascular reactivity (CVR) obtained using breath-hold methods effective evaluating NVU potential.

Язык: Английский

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Understanding recovery of language after stroke: insights from neurovascular MRI studies

Frontiers in Language Sciences, Год журнала: 2023, Номер 2

Опубликована: Июнь 5, 2023

Stroke causes a disruption in blood flow to the brain that can lead profound language impairments. Understanding mechanisms of recovery after stroke is crucial for prognosis and effective rehabilitation people with aphasia. While role injured structures disruptions functional connectivity have been extensively explored, relationship between neurovascular measures both early later stages has not received sufficient attention field. Fully functioning healthy tissue requires oxygen nutrients be delivered promptly via its supply. Persistent decreases remaining non-lesioned shown contribute poor recovery. The goal current paper critically examine studies looking at different deficits changes metrics. Measures perfusion or cerebral (CBF) cerebrovascular reactivity (CVR) provide complementary approaches understanding post by capturing metabolic demands mechanical vascular properties. CBF indicate amount certain region serve as proxy area, CVR indices reflect ability vasculature recruit response shortage oxygen, such when one holding their breath. Increases during beyond site lesion promote gains. Similarly, changes, collateral vessels are recruited help reorganize hypoperfused regions, related stroke. In review, we highlight main findings literature investigating particular emphasis on how abilities affected CVR. We conclude summarizing existing methodological challenges knowledge gaps need addressed future work this outlining promising avenue research.

Язык: Английский

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