Contribution of Direct Cerebral Vascular Transport in Brain Substance Clearance

Aging and Disease, Год журнала: 2023, Номер unknown

Опубликована: Авг. 15, 2023

The accumulation of harmful substances has long been recognized as a likely cause many neurodegenerative diseases. two classic brain clearance pathways are cerebrospinal fluid (CSF) and vascular circulation systems. Since the discovery glymphatic system, research on CSF pathway gained momentum, impaired implicated in virtually all animal models. However, contribution direct participation transport across blood-brain barrier clearing is often ignored papers. Supportive evidence for involvement parenchymal vasculature substance accumulated. First, multiple mechanisms have proposed drainage exogenous endogenous barriers. Second, "traditional" role arachnoid villi granulations main site draining into system questioned. Third, MRI studies using different tracers indicate that directly participates tracer efflux, consistent with immunohistochemical findings. Here we will review literature supports clearance, addition to pathways.

Язык: Английский

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Paravascular fluid dynamics reveal arterial stiffness assessed using dynamic diffusion‐weighted imaging

NMR in Biomedicine, Год журнала: 2023, Номер 37(2)

Опубликована: Окт. 5, 2023

Abstract Paravascular cerebrospinal fluid (pCSF) surrounding the cerebral arteries within glymphatic system is pulsatile and moves in synchrony with pressure waves of vessel wall. Whether such pCSF can infer pulse wave propagation—a property tightly related to arterial stiffness—is unknown has never been explored. Our recently developed imaging technique, dynamic diffusion‐weighted (dynDWI), captures dynamics vivo explore this question. In work, we evaluated time shifts between finger waves, where were measured by dynDWI scanner's built‐in oximeter. We hypothesized that reflect brain‐finger travel are sensitive stiffness. applied framework 36 participants aged 18–82 years study age effect time, as well its associations cognitive function older ( N = 15, > 60 years). results revealed a strong consistent correlation (mean CorrCoeff 0.66), supporting pulsation major driver for dynamics. The delay pulses (TimeDelay) was significantly lower (i.e., faster propagation) advanced (Pearson's r −0.44, p 0.007). Shorter TimeDelay further associated worse participants. Overall, our demonstrated viable pathway measuring intracranial encouraged future studies investigate relevance cerebrovascular functions.

Язык: Английский

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Reduced cerebrospinal fluid motion in patients with Parkinson’s disease revealed by magnetic resonance imaging with low b-value diffusion weighted imaging

Fluids and Barriers of the CNS, Год журнала: 2024, Номер 21(1)

Опубликована: Май 9, 2024

Abstract Background Parkinson’s disease is characterized by dopamine-responsive symptoms as well aggregation of α-synuclein protofibrils. New diagnostic methods assess characteristics from cerebrospinal fluid (CSF) and recent pathophysiologic mechanisms suggest that CSF circulation disruptions may precipitate retention. Here, diffusion-weighted MRI with low-to-intermediate diffusion-weightings was applied to test the hypothesis motion reduced in relative healthy participants. Methods Multi-shell diffusion weighted (spatial resolution = 1.8 × 4.0 mm) weightings ( b -values 0, 50, 100, 200, 300, 700, 1000 s/mm 2 ) over approximate kinetic range suprasellar cistern at 3 Tesla n 27; age 66 ± 6.7 years) non-Parkinson’s control 32; 68 8.9 Wilcoxon rank-sum tests were primary noise floor-corrected decay rate signal a function -value, which reflects increasing motion, within persons versus without inversely relates choroid plexus activity assessed perfusion-weighted (significance-criteria: p < 0.05). Results Consistent hypothesis, rates higher D 0.00673 0.00213 mm /s) 0.00517 0.00110 This finding preserved after controlling for sex observed posterior region 0.001). An inverse correlation between perfusion voxels (Spearman’s- r =-0.312; 0.019) observed. Conclusions identify level adults disease; strengths limitations this methodology are discussed context growing literature on flow.

Язык: Английский

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Coupled pulsatile vascular and paravascular fluid dynamics in the human brain

Fluids and Barriers of the CNS, Год журнала: 2024, Номер 21(1)

Опубликована: Сен. 11, 2024

Язык: Английский

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Glymphatic Imaging in Pediatrics

Journal of Magnetic Resonance Imaging, Год журнала: 2023, Номер 59(5), С. 1523 - 1541

Опубликована: Окт. 11, 2023

The glymphatic system, which facilitates cerebrospinal fluid (CSF) flow through the brain parenchyma, is important for development and waste clearance. Advances in imaging techniques, particularly magnetic resonance imaging, have make it possible to evaluate structures functions vivo. Recently, several studies focused on alterations of system pediatric disorders. This review discusses advances techniques their applications First, results reviewed indicate that a long‐lasting process continues into adulthood. Second, there need improved are non‐invasive fast improve suitability applications, as some existing methods use contrast injection susceptible motion artifacts from long scanning times. Several novel potentially feasible patients may be used future. Third, dysfunction associated with large number disorders, although only few recently been investigated. In conclusion, research remains an emerging field. preliminary provided unique insight pathological mechanism diseases, but mainly limited visualization enlarged perivascular spaces morphological measurements CSF volumes. More in‐depth required our understanding mechanisms underlying diseases. Level Evidence 5 Technical Efficacy Stage 3

Язык: Английский

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Transmantle pressure under the influence of free breathing: non-invasive quantification of the aqueduct pressure gradient in healthy adults

Fluids and Barriers of the CNS, Год журнала: 2025, Номер 22(1)

Опубликована: Янв. 3, 2025

Язык: Английский

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Characterizing the Spatial Patterns and Determinants of Cerebrospinal Fluid Pseudorandom Flow in the Human Brain with Low b-value Diffusion MRI

Imaging Neuroscience, Год журнала: 2025, Номер 3

Опубликована: Янв. 1, 2025

The circulation of cerebrospinal fluid (CSF) is essential for maintaining brain homeostasis and clearance, impairments in its flow can lead to various disorders. Recent studies have shown that CSF effective motility be interrogated using low b-value diffusion magnetic resonance imaging (low-b dMRI). Nevertheless, the spatial organization intracranial dynamics remains largely elusive. Here, we developed a whole-brain voxel-based analysis framework, termed pseudo-diffusion statistics ( CΨSS ), examine mean pseudo-diffusivity (MΨ) , measure magnitude derived from low-b dMRI. We showed MΨ demonstrates characteristic covariance patterns by employing seed-based correlation analysis. Next, applied non-negative matrix factorization further elucidate hypothesis-free, data-driven way. identified 10 distinct compartments with high reproducibility reliability, reflected adjusted Rand index standard deviation (0.82 [SD: 0.018]) split-half analyses discovery multimodal aging dataset (n = 187). displayed similar across three replication datasets. In cohorts (unique n 264), our study revealed age, sex, atrophy, ventricular anatomy, cerebral perfusion differentially influence these spaces. Notably, 35 individuals exhibiting anomalous patterns, five clinically consequential incidental findings on neuroradiological examinations, which were not observed other participants (p=3.04×10-5) . Our work sets forth new paradigm flow, potential applications clinical settings.

Язык: Английский

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Cerebrospinal Fluid Flow within Ventricles and Subarachnoid Space Evaluated by Velocity Selective Spin Labeling MRI

NeuroImage, Год журнала: 2025, Номер unknown, С. 121095 - 121095

Опубликована: Фев. 1, 2025

This study aims to evaluate cerebrospinal fluid (CSF) flow dynamics within ventricles, and the subarachnoid space (SAS) using velocity selective spin labeling (VSSL) MRI method with Fourier-transform-based inversion preparation. The included healthy volunteers who underwent scanning specific VSSL parameters optimized for CSF quantification. sequence was calibrated against phase-contrast (PC-MRI) ensure accurate measurements. patterns observed in ventricles were consistent those obtained 3D amplified other advanced techniques, verifying reliability of method. successfully measured SAS along major arteries, including middle cerebral artery (MCA), anterior (ACA), posterior (PCA), an average 0.339±0.117cm/s. diffusion component well suppressed by flow-compensated gradients, enabling comprehensive mapping rapid pattern system ventricles. closely resembles recently discovered perivascular (PVSAS) system. around MCA, PCA, ACA arteries exhibited a weak orientation dependency. also measured, of0.309±0.116cm/s, highest superior-inferior direction. underscores potential as non-invasive tool investigating both

Язык: Английский

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Altered Clearance in Alzheimer's Disease and Cerebral Amyloid Angiopathy

Neuroimaging Clinics of North America, Год журнала: 2025, Номер unknown

Опубликована: Фев. 1, 2025

Язык: Английский

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PET Imaging of Neurofluids

Neuroimaging Clinics of North America, Год журнала: 2025, Номер unknown

Опубликована: Фев. 1, 2025

Язык: Английский

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