Elsevier

Journal of Biomechanics

Volume 43, Issue 3, 10 February 2010, Pages 579-582
Journal of Biomechanics

Short communication
The effects of the interthalamic adhesion position on cerebrospinal fluid dynamics in the cerebral ventricles

https://doi.org/10.1016/j.jbiomech.2009.10.002Get rights and content

Abstract

The interthalamic adhesion is a unique feature of the third ventricle in the brain. It differs in shape and size and its location varies between individuals. In this study, computational fluid dynamics was performed on 4 three-dimensional models of the cerebral ventricular system with the interthalamic adhesion modeled in different locations in the third ventricle. Cerebrospinal fluid (CSF) was modeled as incompressible Newtonian fluid and flow was assumed laminar. The periodic motion of CSF flow as a function of the cardiac cycle starting from diastole was prescribed as the inlet boundary condition at the foramen of Monroe. Results from this study show how the location of the interthalamic adhesion influences the pattern of pressure distribution in the cerebral ventricles. In addition, the highest CSF pressure in the third ventricle can vary by ∼50% depending on the location of the interthalamic adhesion. We suggest that the interthalamic adhesion may have functional implications on the development of hydrocephalus and it is important to model this anatomical feature in future studies.

Introduction

The cerebral ventricle is the main route for cerebrospinal fluid (CSF) to flow from within the brain to the subarachnoid space. According to phase-contrast cine magnetic resonance (MR) imaging studies, CSF flows in a pulsatile manner in the cerebral ventricles and its source of pulsation is related to the increase in cerebral blood flow during cardiac systole. The increase in blood flow in the cranium during systole results in expansion of the brain parenchyma and causes slight compression of the lateral ventricles. During systole, CSF flows from the lateral ventricle to the third ventricle through the foramen of Monroe (Feinberg and Mark, 1987; Enzmann and Pelc, 1991). It then flows from the third ventricle to the cerebral aqueduct and exits after the fourth ventricle. During diastole, CSF flow reverses and flows back towards the lateral ventricle.

The third ventricle has a complex geometry, as part of its cavity is fused by the medial border of the left and right thalamus. This anatomical feature is known as interthalamic adhesion (massa intermedia) and is found in approximately 80% of humans. Interestingly, the location of the interthalamic adhesion is highly variable, and its size may be related to the formation of congenital anomalies such as Arnold-Chiari malformation and meningomyelocele (Cooding et al., 1967; Naidich et al., 1980).

The functional implications of the interthalamic adhesion and how it influences CSF dynamics in the cerebral ventricular system remain unclear. In this study, we present 4 three-dimensional computational models of the cerebral ventricles with the interthalamic adhesion modeled at different locations in the third ventricle. We hypothesize that the interthalamic adhesion influences the pattern of CSF recirculation and the level of pressure in the third ventricle. The aim of this study was to emphasize the importance of modeling this anatomical feature and investigate whether its location may increase the susceptibility of developing hydrocephalus.

Section snippets

Reconstruction and meshing of the cerebral ventricles

A three-dimensional model of the third ventricle and the cerebral aqueduct were reconstructed based on a series of coronal and axial images of a human from a magnetic resonance imaging scan. This was achieved by first manually outlining the cross section of the ventricle and aqueduct in each image to obtain the volumetric spline representation (Surfdriver, version 3.5). These splines were then exported to modeling software (Rhinoceros, version 3, McNeel, USA, Seattle) where the surfaces of the

Results

At the beginning of the cardiac cycle, CSF flows from the foramen of Monroe to the cerebral aqueduct and exits after the fourth ventricle. At 25% of the cardiac cycle, the direction of the CSF flow reverses and recirculation is observed in the third ventricle in all the models except for the second model. Fig. 2 shows that the region of recirculation (indicated by *) is different in all of the models. At 25% of the cardiac cycle, two CSF recirculation zones can be observed in model I. One of

Discussion

The location of the interthalamic adhesion was found to play an important role in the distribution of CSF pressure in the third ventricle. In addition, its location influences CSF flow dynamics and the location of fluid recirculation in different regions of the third ventricle at different times of the cardiac cycle. Recirculation occurs when there is a change in CSF flow direction and is dependent on the individual CSF flow characteristics (in the third ventricle) that precede it. Results from

Conflict of interest

No conflicts of interest to declare.

References (17)

  • E.L. Foltz et al.

    Diagnosis of hydrocephalus by CSF pulse-wave analysis: a clinical study

    Surgical Neurology

    (1981)
  • V. Kurtcuoglu et al.

    Computational investigation of subject-specific cerebrospinal fluid flow in the third ventricle and aqueduct of Sylvius

    Journal of Biomechanics

    (2007)
  • I.G. Bloomfield et al.

    Effects of proteins, blood cells and glucose on the viscosity of cerebrospinal fluid

    Pediatric Neurosurgery

    (1998)
  • S. Cheng et al.

    Models of the pulsatile hydrodynamics of cerebrospinal fluid flow in the normal and abnormal intracranial system

    Computer Methods in Biomechanics and Biomedical Engineering

    (2007)
  • C.A. Cooding et al.

    New ventriculographic aspects of the Arnold-Chiari malformation

    Radiology

    (1967)
  • M. Egnor et al.

    A model of pulsations in communicating hydrocephalus

    Pediatric Neurosurgery

    (2002)
  • D.R. Enzmann et al.

    Normal flow patterns of intracranial and spinal cerebrospinal fluid defined with phase-contrast cine MR imaging

    Radiology

    (1991)
  • D.A. Feinberg et al.

    Human brain motion and cerebrospinal fluid circulation demonstrated with MR velocity imaging

    Radiology

    (1987)
There are more references available in the full text version of this article.

Cited by (21)

  • The presence of arachnoiditis affects the characteristics of CSF flow in the spinal subarachnoid space: A modelling study

    2012, Journal of Biomechanics
    Citation Excerpt :

    These difficulties can be overcomed by the computational modelling of CSF flow in the SAS. Indeed, there is increasing interest in the use of biomechanical analyses to improve our understanding of conditions involving abnormalities in CSF hydrodynamics (e.g. hydrocephalus; Gupta et al., 2010; Cheng et al., 2009), including syringomyelia. Both analytical (Carpenter et al., 2003; Martin and Loth, 2009; Martin et al., 2009) and numerical (computational fluid dynamics) models of the spinal subarachnoid space have been reported (Loth et al., 2001; Bilston et al., 2006; Bertram et al., 2008; Sweetman and Linninger, 2011).

  • Three-dimensional computational prediction of cerebrospinal fluid flow in the human brain

    2011, Computers in Biology and Medicine
    Citation Excerpt :

    More advanced aqueductal models accounted for the aqueduct's deformability [8]. Three-dimensional CSF flow studies inside the third ventricle have also been reported [9,10]. Gupta et al. [11] investigated the CSF flow in the lower region of the subarachnoid space, caudal to the lateral and third ventricles.

  • Massa intermedia: an innocent bystander?

    2023, Acta Neurologica Belgica
View all citing articles on Scopus
View full text