The impact of spinal cord nerve roots and denticulate ligaments on cerebrospinal fluid dynamics in the cervical spine.
Cerebrospinal fluid (CSF) dynamics in the spinal subarachnoid space (SSS) have been thought to play an important pathophysiological role in syringomyelia, Chiari I malformation (CM), and a role in intrathecal drug delivery. Yet, the impact that fine anatomical structures, including nerve roots and denticulate ligaments (NRDL), have on SSS CSF dynamics is not clear. In the present study we assessed the impact of NRDL on CSF dynamics in the cervical SSS. The 3D geometry of the cervical SSS was reconstructed based on manual segmentation of MRI images of a healthy volunteer and a patient with CM. Idealized NRDL were designed and added to each of the geometries based on in vivo measurments in the literature and confirmation by a neuroanatomist. CFD simulations were performed for the healthy and patient case with and without NRDL included. Our results showed that the NRDL had an important impact on CSF dynamics in terms of velocity field and flow patterns. However, pressure distribution was not altered greatly although the NRDL cases required a larger pressure gradient to maintain the same flow. Also, the NRDL did not alter CSF dynamics to a great degree in the SSS from the foramen magnum to the C1 level for the healthy subject and CM patient with mild tonsillar herniation (∼ 6 mm). Overall, the NRDL increased fluid mixing phenomena and resulted in a more complex flow field. Comparison of the streamlines of CSF flow revealed that the presence of NRDL lead to the formation of vortical structures and remarkably increased the local mixing of the CSF throughout the SSS.
Center of Excellence in Design and Optimization of Energy Systems (CEDOES), School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran.
Soroush
S
Heidari Pahlavian
Laboratory of Hemodynamics and Cardiovascular Technology, EPFL, Lausanne, Switzerland.
Theresia
T
Yiallourou
Children's of Alabama, Birmingham, Alabama, United States of America.
R Shane
RS
Tubbs
Department of Radiology, University Hospital of Cologne, Cologne, Germany.
Alexander C
AC
Bunck
Conquer Chiari Research Center, Dept. of Mech. Engineering, University of Akron, Akron, Ohio, United States of America.
Francis
F
Loth
SimuTech Group, Hudson, Ohio, United States of America.
Mark
M
Goodin
Center of Excellence in Design and Optimization of Energy Systems (CEDOES), School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran; Hydraulic Machinery Research Institute, School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran.
Mehrdad
M
Raisee
Conquer Chiari Research Center, Dept. of Mech. Engineering, University of Akron, Akron, Ohio, United States of America.
Bryn A
BA
Martin
D001139:Arnold-Chiari Malformation / Q000134:cerebrospinal fluid / Q000000981:diagnostic imaging / Q000503:physiopathology; D002555:Cerebrospinal Fluid / Q000000981:diagnostic imaging*; D066193:Cervical Cord / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008022:Ligaments / Q000000981:diagnostic imaging / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D011859:Radiography; D013126:Spinal Nerve Roots / Q000000981:diagnostic imaging / Q000503:physiopathology; D013346:Subarachnoid Space / Q000000981:diagnostic imaging / Q000503:physiopathology; D013595:Syringomyelia / Q000134:cerebrospinal fluid / Q000000981:diagnostic imaging / Q000503:physiopathology