Original scientific paper
https://doi.org/10.3325/cmj.2017.58.384
Starling forces drive intracranial water exchange during normal and pathological states
Andreas A. Linninger
; Laboratory for Product and Process Design, Department ofBioengineering, University of Illinoisat Chicago, Chicago, Illinois, USA
Colin Xu
; Laboratory for Product and Process Design, Department ofBioengineering, University of Illinoisat Chicago, Chicago, Illinois, USA
Kevin Tangen
; Laboratory for Product and Process Design, Department ofBioengineering, University of Illinoisat Chicago, Chicago, Illinois, USA
Grant Hartung
; Laboratory for Product and Process Design, Department ofBioengineering, University of Illinoisat Chicago, Chicago, Illinois, USA
Abstract
Aim To quantify the exchange of water between cerebral
compartments, specifically blood, tissue, perivascular
pathways, and cerebrospinal fluid-filled spaces, on the basis
of experimental data and to propose a dynamic global
model of water flux through the entire brain to elucidate
functionally relevant fluid exchange phenomena.
Methods The mechanistic computer model to predict
brain water shifts is discretized by cerebral compartments
into nodes. Water and species flux is calculated between
these nodes across a network of arcs driven by Hagen-Poiseuille
flow (blood), Darcy flow (interstitial fluid transport),
and Starling’s Law (transmembrane fluid exchange). Compartment
compliance is accounted for using a pressurevolume
relationship to enforce the Monro-Kellie doctrine.
This nonlinear system of differential equations is solved implicitly
using MATLAB software.
Results The model predictions of intraventricular osmotic
injection caused a pressure rise from 10 to 22 mmHg, followed
by a taper to 14 mmHg over 100 minutes. The computational
results are compared to experimental data with
R2 = 0.929. Moreover, simulated osmotic therapy of systemic
(blood) injection reduced intracranial pressure from 25
to 10 mmHg. The modeled volume and intracranial pressure
changes following cerebral edema agree with experimental
trends observed in animal models with R2 = 0.997.
Conclusion The model successfully predicted time course
and the efficacy of osmotic therapy for clearing cerebral
edema. Furthermore, the mathematical model implicated
the perivascular pathways as a possible conduit for water
and solute exchange. This was a first step to quantify fluid
exchange throughout the brain.
Keywords
Hrčak ID:
200217
URI
Publication date:
28.12.2017.
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