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A computational model of cerebrospinal fluid production and reabsorption driven by Starling forces.

Buishas J, Gould IG, Linninger AA - Croat. Med. J. (2014)

Bottom Line: This model investigates the effect of osmotic pressure on water transport between the cerebral vasculature, the extracellular space (ECS), the perivascular space (PVS), and the CSF.Water flux from the ECS to the CSF is identified as a key feature of intracranial dynamics.A complete mathematical model with all equations and scenarios is fully described, as well as a guide to constructing a computational model of intracranial water balance dynamics.

View Article: PubMed Central - PubMed

Affiliation: Andreas A. Linninger, Professor of Chemical Engineering and Bioengineering, University of Illinois at Chicago, Laboratory for Product and Process Design, M/C 063, 851 S. Morgan St. - 218 SEO, Chicago, Illinois 60607-7000, linninge@uic.edu.

ABSTRACT
Experimental evidence has cast doubt on the classical model of river-like cerebrospinal fluid (CSF) flow from the choroid plexus to the arachnoid granulations. We propose a novel model of water transport through the parenchyma from the microcirculation as driven by Starling forces. This model investigates the effect of osmotic pressure on water transport between the cerebral vasculature, the extracellular space (ECS), the perivascular space (PVS), and the CSF. A rigorous literature search was conducted focusing on experiments which alter the osmolarity of blood or ventricles and measure the rate of CSF production. Investigations into the effect of osmotic pressure on the volume of ventricles and the flux of ions in the blood, choroid plexus epithelium, and CSF are reviewed. Increasing the osmolarity of the serum via a bolus injection completely inhibits nascent fluid flow production in the ventricles. A continuous injection of a hyperosmolar solution into the ventricles can increase the volume of the ventricle by up to 125%. CSF production is altered by 0.231 μL per mOsm in the ventricle and by 0.835 μL per mOsm in the serum. Water flux from the ECS to the CSF is identified as a key feature of intracranial dynamics. A complete mathematical model with all equations and scenarios is fully described, as well as a guide to constructing a computational model of intracranial water balance dynamics. The model proposed in this article predicts the effects the osmolarity of ECS, blood, and CSF on water flux in the brain, establishing a link between osmotic imbalances and pathological conditions such as hydrocephalus and edema.

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The effect of bolus injection of sucrose solution into the femoral artery during ventriculo-cisternal perfusion (VCP) in a feline model (26). Injection of hypo-osmolar solution was found to increase the bulk flow of nascent fluid up to 220%, while injection of hyperosmolar solution completely inhibited nascent fluid flow. The osmolarity of the serum was determined to alter bulk flow by 0.835 µL per Osm as reported in the original experiment.
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Figure 5: The effect of bolus injection of sucrose solution into the femoral artery during ventriculo-cisternal perfusion (VCP) in a feline model (26). Injection of hypo-osmolar solution was found to increase the bulk flow of nascent fluid up to 220%, while injection of hyperosmolar solution completely inhibited nascent fluid flow. The osmolarity of the serum was determined to alter bulk flow by 0.835 µL per Osm as reported in the original experiment.

Mentions: E3. Serum osmolarity and bulk flow of nascent fluid. Experiment 3 examined the effect of serum osmolarity on the bulk flow of nascent fluid (26). The results obtained are shown in Figure 5 and Table 2. Bolus IV injection with the control solution of 322 mOsm yielded a bulk flow rate of 22.7 µL/min. The osmolarity of the serum was shown to completely inhibit the nascent fluid flow using a 360 mOsm injection, while flow was increased by 220% of the control when the osmolarity of the serum was decreased to 290 mOsm.


A computational model of cerebrospinal fluid production and reabsorption driven by Starling forces.

Buishas J, Gould IG, Linninger AA - Croat. Med. J. (2014)

The effect of bolus injection of sucrose solution into the femoral artery during ventriculo-cisternal perfusion (VCP) in a feline model (26). Injection of hypo-osmolar solution was found to increase the bulk flow of nascent fluid up to 220%, while injection of hyperosmolar solution completely inhibited nascent fluid flow. The osmolarity of the serum was determined to alter bulk flow by 0.835 µL per Osm as reported in the original experiment.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4228294&req=5

Figure 5: The effect of bolus injection of sucrose solution into the femoral artery during ventriculo-cisternal perfusion (VCP) in a feline model (26). Injection of hypo-osmolar solution was found to increase the bulk flow of nascent fluid up to 220%, while injection of hyperosmolar solution completely inhibited nascent fluid flow. The osmolarity of the serum was determined to alter bulk flow by 0.835 µL per Osm as reported in the original experiment.
Mentions: E3. Serum osmolarity and bulk flow of nascent fluid. Experiment 3 examined the effect of serum osmolarity on the bulk flow of nascent fluid (26). The results obtained are shown in Figure 5 and Table 2. Bolus IV injection with the control solution of 322 mOsm yielded a bulk flow rate of 22.7 µL/min. The osmolarity of the serum was shown to completely inhibit the nascent fluid flow using a 360 mOsm injection, while flow was increased by 220% of the control when the osmolarity of the serum was decreased to 290 mOsm.

Bottom Line: This model investigates the effect of osmotic pressure on water transport between the cerebral vasculature, the extracellular space (ECS), the perivascular space (PVS), and the CSF.Water flux from the ECS to the CSF is identified as a key feature of intracranial dynamics.A complete mathematical model with all equations and scenarios is fully described, as well as a guide to constructing a computational model of intracranial water balance dynamics.

View Article: PubMed Central - PubMed

Affiliation: Andreas A. Linninger, Professor of Chemical Engineering and Bioengineering, University of Illinois at Chicago, Laboratory for Product and Process Design, M/C 063, 851 S. Morgan St. - 218 SEO, Chicago, Illinois 60607-7000, linninge@uic.edu.

ABSTRACT
Experimental evidence has cast doubt on the classical model of river-like cerebrospinal fluid (CSF) flow from the choroid plexus to the arachnoid granulations. We propose a novel model of water transport through the parenchyma from the microcirculation as driven by Starling forces. This model investigates the effect of osmotic pressure on water transport between the cerebral vasculature, the extracellular space (ECS), the perivascular space (PVS), and the CSF. A rigorous literature search was conducted focusing on experiments which alter the osmolarity of blood or ventricles and measure the rate of CSF production. Investigations into the effect of osmotic pressure on the volume of ventricles and the flux of ions in the blood, choroid plexus epithelium, and CSF are reviewed. Increasing the osmolarity of the serum via a bolus injection completely inhibits nascent fluid flow production in the ventricles. A continuous injection of a hyperosmolar solution into the ventricles can increase the volume of the ventricle by up to 125%. CSF production is altered by 0.231 μL per mOsm in the ventricle and by 0.835 μL per mOsm in the serum. Water flux from the ECS to the CSF is identified as a key feature of intracranial dynamics. A complete mathematical model with all equations and scenarios is fully described, as well as a guide to constructing a computational model of intracranial water balance dynamics. The model proposed in this article predicts the effects the osmolarity of ECS, blood, and CSF on water flux in the brain, establishing a link between osmotic imbalances and pathological conditions such as hydrocephalus and edema.

Show MeSH
Related in: MedlinePlus