Determining the effects of elevated partial pressure of oxygen on hypercapnia-induced cerebrovascular reactivity

Journal of Cerebral Blood Flow & Metabolism, Год журнала: 2023, Номер 43(12), С. 2085 - 2095

Опубликована: Авг. 26, 2023

Evaluation of cerebrovascular reactivity (CVR) to hypo- and hypercapnia is a valuable test for the assessment vasodilatory reserve. While hypercapnia-induced CVR testing usually performed at normoxia, mild hyperoxia may increase tolerability by reducing ventilatory distress. However, effects on was unknown. We therefore recruited 21 patients with range steno-occlusive diseases 12 healthy participants who underwent standardized 13-minute step plus ramp carbon dioxide gas challenge subject’s resting end-tidal partial pressure oxygen or (PetO 2 = 150 mmHg) depending which group they were assigned. In 11 patients, second normoxia examine test-retest differences. defined as % Δ Signal/ΔPetCO . found that there no significant difference between results conducted in Groups 1 portion. also retest pathology (Group 3) concluded normoxic repeatable, does not affect CVR.

Язык: Английский

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Assessing Cerebrovascular Resistance in Patients With Sickle Cell Disease

Frontiers in Physiology, Год журнала: 2022, Номер 13

Опубликована: Март 29, 2022

In patients with sickle cell disease (SCD) the delivery of oxygen to brain is compromised by anemia, abnormal rheology, and steno-occlusive vascular disease. Meeting demands for requires compensatory features perfusion. The cerebral vasculature's regulatory function reserves can be assessed observing flow response a vasoactive stimulus. traditional approach we measured voxel-wise change in Blood Oxygen-Level Dependent (BOLD) MRI signal as surrogate blood (CBF) linear progressive ramping end-tidal partial pressure carbon dioxide (PETCO2). Cerebrovascular reactivity (CVR) was defined ΔBOLD/ΔPETCO2. We used computer model fit virtual sigmoid resistance curve CBF stimulus, enabling calculation parameters: amplitude, midpoint, range response, sensitivity vasodilatory reserve. quality expressed r2 fit. tested 35 SCD, well 24 healthy subjects provide an indication normal ranges parameters. found that gray matter CVR range, reserve, are reduced SCD compared controls, while midpoint increased. This study first document measures adult SCD. It also score these comparison range. anticipate data will complement current understanding pathophysiology identify paths therapeutic interventions, biomarkers monitoring progress

Язык: Английский

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Cerebral circulation

Elsevier eBooks, Год журнала: 2023, Номер unknown, С. 203 - 207

Опубликована: Янв. 1, 2023

Язык: Английский

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Efeitos da estimulação elétrica transcraniana de alta definição sobre a hemodinâmica cerebral em humanos saudáveis: ensaio clínico randomizado e controlado

Опубликована: Апрель 16, 2024

Doctoral thesis in Neurology

Язык: Английский

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Comparing single- and multi-post labeling delays for the measurements of resting cerebral and hippocampal blood flow for cerebrovascular testing in midlife adults

Frontiers in Physiology, Год журнала: 2024, Номер 15

Опубликована: Окт. 2, 2024

Objectives To assess the reliability and validity of measuring resting cerebral blood flow (CBF) hippocampal CBF using a single-post-labeling delay (PLD) multi-PLD pseudo-continuous arterial spin labeling (pCASL) protocol for cerebrovascular reactivity (CVR) testing. Methods 25 healthy, midlife adults (57 ± 4 years old) were imaged in Siemens Prisma 3T magnetic resonance imaging (MRI) scanner. Resting assessed two pCASL protocols, our modified single-PLD (pCASL-MOD) to accommodate needs CVR testing Human Connectome Project (HCP) Lifespan serve as reference control (pCASL-HCP). During pCASL-MOD, was calculated change from rest hypercapnia (+9 mmHg increase end-tidal partial pressure carbon dioxide [P ET CO 2 ]) then normalized P . The gray matter (GM) CBF, white (WM) between pCASL-MOD pCASL-HCP protocols examined correlation analyses, paired t-tests, Bland Altman plots. Results significantly correlated GM [r = 0.72; F (1, 23) 25.24, p < 0.0001], WM 0.57; 10.83, 0.003], 0.77; 32.65, 0.0001]. However, underestimated (pCASL-MOD: 53.7 11.1 v. pCASL-HCP: 69.1 13.1 mL/100 g/min; 0.0001), 32.4 4.8 35.5 6.9 0.01), 50.5 9.0 68.1 12.5 g / min; 0.0001). increased by 8.0 0.7 induce (GM CBF: 4.8% 2.6%; 2.9% 2.5%; 3.4% 3.8%). Conclusion Our reliably measured at given significant with protocol. Despite lower magnitude relative pCASL-HCP, we recommend which an exact estimate is not required such assessment hypercapnia.

Язык: Английский

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