title: Flow induced by ependymal cilia dominates near-wall cerebrospinal fluid dynamics in the lateral ventricles.
abstract: While there is growing experimental evidence that cerebrospinal fluid (CSF) flow induced by the beating of ependymal cilia is an important factor for neuronal guidance, the respective contribution of vascular pulsation-driven macroscale oscillatory CSF flow remains unclear. This work uses computational fluid dynamics to elucidate the interplay between macroscale and cilia-induced CSF flows and their relative impact on near-wall dynamics. Physiological macroscale CSF dynamics are simulated in the ventricular space using subject-specific anatomy, wall motion and choroid plexus pulsations derived from magnetic resonance imaging. Near-wall flow is quantified in two subdomains selected from the right lateral ventricle, for which dynamic boundary conditions are extracted from the macroscale simulations. When cilia are neglected, CSF pulsation leads to periodic flow reversals along the ventricular surface, resulting in close to zero time-averaged force on the ventricle wall. The cilia promote more aligned wall shear stresses that are on average two orders of magnitude larger compared with those produced by macroscopic pulsatile flow. These findings indicate that CSF flow-mediated neuronal guidance is likely to be dominated by the action of the ependymal cilia in the lateral ventricles, whereas CSF dynamics in the centre regions of the ventricles is driven predominantly by wall motion and choroid plexus pulsation.
authors.affiliation: Laboratory of Thermodynamics in Emerging Technologies, Department of Mechanical and Process Engineering, ETH Zurich, , Zurich, Switzerland.
authors.forename: Bercan
authors.initials: B
authors.lastname: Siyahhan
authors.forename: Verena
authors.initials: V
authors.lastname: Knobloch
authors.forename: Diane
authors.initials: D
authors.lastname: de Zélicourt
authors.forename: Mahdi
authors.initials: M
authors.lastname: Asgari
authors.forename: Marianne
authors.initials: M
authors.lastname: Schmid Daners
authors.forename: Dimos
authors.initials: D
authors.lastname: Poulikakos
authors.forename: Vartan
authors.initials: V
authors.lastname: Kurtcuoglu
mesh_terms: D000328:Adult; D002555:Cerebrospinal Fluid / Q000378:metabolism*; D002831:Choroid Plexus / Q000502:physiology*; D002923:Cilia / Q000502:physiology; D004805:Ependyma / Q000502:physiology*; D005260:Female; D006801:Humans; D011673:Pulsatile Flow / Q000502:physiology*
keywords: cerebrospinal fluid dynamics; computational fluid dynamics; ependymal cilia; magnetic resonance imaging; neuronal migration