ArticleFluids and barriers of the CNS2019
Hydraulic resistance of periarterial spaces in the brain.
Article in Fluids and barriers of the CNS, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 59 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
59 citing papers in PubMed.
- Vascular drivers of cerebrospinal fluid movement and enlarged perivascular spaces.Alzheimer's & dementia : the journal of the Alzheimer's Association · 2026Review
- High frame ratebioRxiv : the preprint server for biology · 2026Article
- Enhanced Taylor-Aris dispersion in slender pulsatile annular channels: Implications for perivascular solute transport.Journal of fluid mechanics · 2026Article
- Stretch and flow at the gliovascular interface: High-fidelity modeling of astrocyte endfeet.Proceedings of the National Academy of Sciences of the United States of America · 2026Article
- Quantifying cerebrospinal fluid flow in pial perivascular spaces of rats.Fluids and barriers of the CNS · 2026Article
- The glymphatic system in neurodegenerative diseases and brain tumors: mechanistic insights, biomarker advances, and therapeutic opportunities.Acta neuropathologica communications · 2025Review
- Computational Fluid Dynamic Model Prediction of Enhanced Glymphatic Clearance in Response to Focused Ultrasound-Mediated Blood-Brain Barrier Opening.Advanced science (Weinheim, Baden-Wurttemberg, Germany) · 2025Article
- Cerebral small vessel disease: The impact of glymphopathy and sleep disorders.Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism · 2025Review
- Advection and diffusion in perivascular and extracellular spaces in the brain.Journal of the Royal Society, Interface · 2025Article
- A review of cerebrospinal fluid circulation with respect to Chiari-like malformation and syringomyelia in brachycephalic dogs.Fluids and barriers of the CNS · 2025Review
- Covert cerebrospinal fluid dynamics dysfunction: evolution from conventional to innovative therapies.Frontiers in neurology · 2025Review
- Directional flow in perivascular networks: mixed finite elements for reduced-dimensional models on graphs.Journal of mathematical biology · 2024Article
- A brain-wide solute transport model of the glymphatic system.Journal of the Royal Society, Interface · 2024Article
- Regulation of brain fluid volumes and pressures: basic principles, intracranial hypertension, ventriculomegaly and hydrocephalus.Fluids and barriers of the CNS · 2024Review
- Circadian Mechanisms in Brain Fluid Biology.Circulation research · 2024Review
- Investigation of Antibody Pharmacokinetics in the Brain Following Intra-CNS Administration and Development of PBPK Model to Characterize the Data.The AAPS journal · 2024Article
- Hydraulic resistance of three-dimensional pial perivascular spaces in the brain.Fluids and barriers of the CNS · 2024Article
- The directional flow generated by peristalsis in perivascular networks-Theoretical and numerical reduced-order descriptions.Journal of applied physics · 2023Article
- Real-time Quantification of in vivo cerebrospinal fluid velocity using fMRI inflow effect.bioRxiv : the preprint server for biology · 2023Article
- Image analysis techniques for in vivo quantification of cerebrospinal fluid flow.Experiments in fluids · 2023Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors.
Funding
Abstract
backgroundPeriarterial spaces (PASs) are annular channels that surround arteries in the brain and contain cerebrospinal fluid (CSF): a flow of CSF in these channels is thought to be an important part of the brain's system for clearing metabolic wastes. In vivo observations reveal that they are not concentric, circular annuli, however: the outer boundaries are often oblate, and the arteries that form the inner boundaries are often offset from the central axis.
methodsWe model PAS cross-sections as circles surrounded by ellipses and vary the radii of the circles, major and minor axes of the ellipses, and two-dimensional eccentricities of the circles with respect to the ellipses. For each shape, we solve the governing Navier-Stokes equation to determine the velocity profile for steady laminar flow and then compute the corresponding hydraulic resistance.
resultsWe find that the observed shapes of PASs have lower hydraulic resistance than concentric, circular annuli of the same size, and therefore allow faster, more efficient flow of cerebrospinal fluid. We find that the minimum hydraulic resistance (and therefore maximum flow rate) for a given PAS cross-sectional area occurs when the ellipse is elongated and intersects the circle, dividing the PAS into two lobes, as is common around pial arteries. We also find that if both the inner and outer boundaries are nearly circular, the minimum hydraulic resistance occurs when the eccentricity is large, as is common around penetrating arteries.
conclusionsThe concentric circular annulus assumed in recent studies is not a good model of the shape of actual PASs observed in vivo, and it greatly overestimates the hydraulic resistance of the PAS. Our parameterization can be used to incorporate more realistic resistances into hydraulic network models of flow of cerebrospinal fluid in the brain. Our results demonstrate that actual shapes observed in vivo are nearly optimal, in the sense of offering the least hydraulic resistance. This optimization may well represent an evolutionary adaptation that maximizes clearance of metabolic waste from the brain.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.