Neural Tissue Motion Impacts Cerebrospinal Fluid Dynamics at the Cervical Medullary Junction: A Patient-Specific Moving-Boundary Computational Model
Central nervous system (CNS) tissue motion of the brain occurs over 30 million cardiac cycles per year due to intracranial pressure differences caused by the pulsatile blood flow and cerebrospinal fluid (CSF) motion within the intracranial space. This motion has been found to be elevated in type 1 Chiari malformation. The impact of CNS tissue motion on CSF dynamics was assessed using a moving-boundary computational fluid dynamics (CFD) model of the cervical-medullary junction (CMJ). The cerebellar tonsils and spinal cord were modeled as rigid surfaces moving in the caudocranial direction over the cardiac cycle. The CFD boundary conditions were based on in vivo MR imaging of a 35-year old female Chiari malformation patient with ~150–300 µm motion of the cerebellar tonsils and spinal cord, respectively. Results showed that tissue motion increased CSF pressure dissociation across the CMJ and peak velocities up to 120 and 60%, respectively. Alterations in CSF dynamics were most pronounced near the CMJ and during peak tonsillar velocity. These results show a small CNS tissue motion at the CMJ can alter CSF dynamics for a portion of the cardiac cycle and demonstrate the utility of CFD modeling coupled with MR imaging to help understand CSF dynamics.
KeywordsCerebrospinal fluid Computational fluid dynamics Moving boundary simulation Central nervous system
Central nervous system
Phase-contrast magnetic resonance imaging
Computational fluid dynamics
Region of interest
Field of view
Sampling perfection with application optimized contrasts using different flip angle evolutions
Integrated longitudinal impedance
Wall shear stress
Static baseline model
Static systolic model
Static diastolic model
Displacement encoded stimulated echo
Authors would like to appreciate Conquer Chiari and National Institutes of Health (NIH) (Grant No. 1R15NS071455-01) for the support of this work. The authors also thank Nicholas Shaffer for helping with the post-processing of MRI data.
Conflict of interest
Authors have no conflict of interests.
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