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Hydrodynamic and longitudinal impedance analysis of cerebrospinal fluid dynamics at the craniovertebral junction in type I Chiari malformation.

Martin BA, Kalata W, Shaffer N, Fischer P, Luciano M, Loth F - PLoS ONE (2013)

Bottom Line: All hydrodynamic parameters, except pressure drop, decreased post-surgically for the CMI patients, but remained greater than in the healthy case.Peak pressure drop alterations were mixed.Further study in a larger patient and control group is needed to determine if the presented geometric and/or hydrodynamic parameters are helpful for surgical planning.

View Article: PubMed Central - PubMed

Affiliation: Conquer Chiari Research Center, University of Akron, Ohio, United States of America ; Department of Mechanical Engineering, University of Akron, Ohio, United States of America.

ABSTRACT
Elevated or reduced velocity of cerebrospinal fluid (CSF) at the craniovertebral junction (CVJ) has been associated with type I Chiari malformation (CMI). Thus, quantification of hydrodynamic parameters that describe the CSF dynamics could help assess disease severity and surgical outcome. In this study, we describe the methodology to quantify CSF hydrodynamic parameters near the CVJ and upper cervical spine utilizing subject-specific computational fluid dynamics (CFD) simulations based on in vivo MRI measurements of flow and geometry. Hydrodynamic parameters were computed for a healthy subject and two CMI patients both pre- and post-decompression surgery to determine the differences between cases. For the first time, we present the methods to quantify longitudinal impedance (LI) to CSF motion, a subject-specific hydrodynamic parameter that may have value to help quantify the CSF flow blockage severity in CMI. In addition, the following hydrodynamic parameters were quantified for each case: maximum velocity in systole and diastole, Reynolds and Womersley number, and peak pressure drop during the CSF cardiac flow cycle. The following geometric parameters were quantified: cross-sectional area and hydraulic diameter of the spinal subarachnoid space (SAS). The mean values of the geometric parameters increased post-surgically for the CMI models, but remained smaller than the healthy volunteer. All hydrodynamic parameters, except pressure drop, decreased post-surgically for the CMI patients, but remained greater than in the healthy case. Peak pressure drop alterations were mixed. To our knowledge this study represents the first subject-specific CFD simulation of CMI decompression surgery and quantification of LI in the CSF space. Further study in a larger patient and control group is needed to determine if the presented geometric and/or hydrodynamic parameters are helpful for surgical planning.

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Distributions of hydrodynamic parameters computed for each case.Position is relative to the location of the foramen magnum moving caudally down the SAS. Highlighted segment of waveforms indicate values in the first 2.5
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pone-0075335-g004: Distributions of hydrodynamic parameters computed for each case.Position is relative to the location of the foramen magnum moving caudally down the SAS. Highlighted segment of waveforms indicate values in the first 2.5

Mentions: As expected, mean and increased pre- to post-surgery for both CMI cases. Trends in the distributions of both and were similar for the CP1-pre, CP1-post, and CP2-pre cases; both parameters had a relatively sharp increase from a minimum value near the cranial end and then tapered gradually (Figure 4). In contrast, distributions of and in the CP2-post and Healthy geometries both showed only a taper from a maximum value at the cranial end. Mean values of were 6.0, 1.2, 2.0, 2.4, and 2.9 cm2 for the healthy, CP1-pre, CP1-post, CP2-pre, and CP2-post cases, respectively. Mean values of were 1.84, 0.52, 0.77, 0.82, and 0.92 cm for the healthy, CP1-pre, CP1-post, CP2-pre, and CP2-post cases, respectively.


Hydrodynamic and longitudinal impedance analysis of cerebrospinal fluid dynamics at the craniovertebral junction in type I Chiari malformation.

Martin BA, Kalata W, Shaffer N, Fischer P, Luciano M, Loth F - PLoS ONE (2013)

Distributions of hydrodynamic parameters computed for each case.Position is relative to the location of the foramen magnum moving caudally down the SAS. Highlighted segment of waveforms indicate values in the first 2.5
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3794956&req=5

pone-0075335-g004: Distributions of hydrodynamic parameters computed for each case.Position is relative to the location of the foramen magnum moving caudally down the SAS. Highlighted segment of waveforms indicate values in the first 2.5
Mentions: As expected, mean and increased pre- to post-surgery for both CMI cases. Trends in the distributions of both and were similar for the CP1-pre, CP1-post, and CP2-pre cases; both parameters had a relatively sharp increase from a minimum value near the cranial end and then tapered gradually (Figure 4). In contrast, distributions of and in the CP2-post and Healthy geometries both showed only a taper from a maximum value at the cranial end. Mean values of were 6.0, 1.2, 2.0, 2.4, and 2.9 cm2 for the healthy, CP1-pre, CP1-post, CP2-pre, and CP2-post cases, respectively. Mean values of were 1.84, 0.52, 0.77, 0.82, and 0.92 cm for the healthy, CP1-pre, CP1-post, CP2-pre, and CP2-post cases, respectively.

Bottom Line: All hydrodynamic parameters, except pressure drop, decreased post-surgically for the CMI patients, but remained greater than in the healthy case.Peak pressure drop alterations were mixed.Further study in a larger patient and control group is needed to determine if the presented geometric and/or hydrodynamic parameters are helpful for surgical planning.

View Article: PubMed Central - PubMed

Affiliation: Conquer Chiari Research Center, University of Akron, Ohio, United States of America ; Department of Mechanical Engineering, University of Akron, Ohio, United States of America.

ABSTRACT
Elevated or reduced velocity of cerebrospinal fluid (CSF) at the craniovertebral junction (CVJ) has been associated with type I Chiari malformation (CMI). Thus, quantification of hydrodynamic parameters that describe the CSF dynamics could help assess disease severity and surgical outcome. In this study, we describe the methodology to quantify CSF hydrodynamic parameters near the CVJ and upper cervical spine utilizing subject-specific computational fluid dynamics (CFD) simulations based on in vivo MRI measurements of flow and geometry. Hydrodynamic parameters were computed for a healthy subject and two CMI patients both pre- and post-decompression surgery to determine the differences between cases. For the first time, we present the methods to quantify longitudinal impedance (LI) to CSF motion, a subject-specific hydrodynamic parameter that may have value to help quantify the CSF flow blockage severity in CMI. In addition, the following hydrodynamic parameters were quantified for each case: maximum velocity in systole and diastole, Reynolds and Womersley number, and peak pressure drop during the CSF cardiac flow cycle. The following geometric parameters were quantified: cross-sectional area and hydraulic diameter of the spinal subarachnoid space (SAS). The mean values of the geometric parameters increased post-surgically for the CMI models, but remained smaller than the healthy volunteer. All hydrodynamic parameters, except pressure drop, decreased post-surgically for the CMI patients, but remained greater than in the healthy case. Peak pressure drop alterations were mixed. To our knowledge this study represents the first subject-specific CFD simulation of CMI decompression surgery and quantification of LI in the CSF space. Further study in a larger patient and control group is needed to determine if the presented geometric and/or hydrodynamic parameters are helpful for surgical planning.

Show MeSH
Related in: MedlinePlus