Estimation of CSF Flow Resistance in the Upper Cervical Spine

Chiari I patients have increased CSF velocities in the foramen magnum due hypothetically to increased pressure gradients or reduced flow resistance. We calculated flow resistance in the cervical spinal canal in a group of subjects with and without the Chiari malformation. Eight subjects including healthy volunteers and Chiari I patients were studied. From 3D high resolution MR images of the cervical spine mathematical models of the subarachnoid spaces were created by means of standard programs for segmentation and discretization. Oscillatory flow through the subarachnoid space was simulated. Cross-sectional area of the subarachnoid space was computed at each level from C1 through C4 and the length of this spinal canal segment was measured. Peak caudad CSF flow velocity at each level was plotted against cross-section area. CSF volumetric flux and resistance were calculated for each subject. The correlation between velocity and resistance was calculated. In all subjects, peak velocities increased progressively from C1 to C4 by 0.6 to 0.7 cm/s per level. Spinal canal areas diminished from C1 to C5 in each subject at a rate of 0.25 to 0.29 cm2per level. Resistance averaged 4.3 pascal/ml/s in the eight subjects; 3.8 pascal/ml/s in patients with tonsilar herniation and 6.0 pascal/ml/s in volunteers. Velocity correlated inversely with resistance (R2= 0.6). CSF velocities correlated inversely with the flow resistance in the upper cervical spinal canal. Resistance tends to be lower in Chiari I patients than in healthy volunteers.

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CSF Flow through the Upper Cervical Spinal Canal in Chiari I Malformation

American Journal of Neuroradiology ◽

10.3174/ajnr.a2460 ◽

2011 ◽

Vol 32 (6) ◽

pp. 1149-1153 ◽

Cited By ~ 30

Author(s):

S. Shah ◽

V. Haughton ◽

A. Muñoz del Río

Keyword(s):

Spinal Canal ◽

Chiari I Malformation ◽

Csf Flow ◽

Cervical Spinal Canal ◽

Upper Cervical ◽

Chiari I ◽

Flow Through

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Anatomical features of the cervical spinal canal in Chiari I deformity with presyrinx: A case-control study

The Neuroradiology Journal ◽

10.1177/1971400917718842 ◽

2017 ◽

Vol 30 (5) ◽

pp. 405-409 ◽

Cited By ~ 2

Author(s):

Judith A Gadde ◽

Vinil Shah ◽

Greta B Liebo ◽

Geir A Ringstad ◽

I Jonathan Pomeraniec ◽

...

Keyword(s):

Spinal Cord ◽

Cervical Spine ◽

Spinal Canal ◽

Statistical Significance ◽

Upper Cervical Spine ◽

Tonsillar Herniation ◽

Cerebrospinal Fluid Flow ◽

Chiari I ◽

The Difference ◽

Normal Controls

Purpose The relationship between syringomyelia and presyrinx, characterized by edema in the spinal cord, has not been firmly established. Patients with syringomyelia have abnormal spinal canal tapering that alters cerebrospinal fluid flow dynamics, but taper ratios in presyrinx have never been reported. We tested the hypothesis that presyrinx patients have abnormal spinal canal tapering. Materials and methods At six medical institutions, investigators searched the PACS system for patients with Chiari I and spinal cord edema unassociated with tumor, trauma, or other evident cause. In each case taper ratios were calculated for C1 to C4 and C4 to C7. In two age- and gender-matched control groups, Chiari I patients with no syringomyelia and patients with normal MR scans, the same measurements were made. Differences between groups were tested for statistical significance with t tests. Results The study enrolled 21 presyrinx patients and equal numbers of matched Chiari I and normal controls. C4 to C7 taper ratios were positive and steeper in presyrinx patients than in the normal controls ( p = 0.04). The upper cervical spine, C1 to C4, tapered negatively in cases and controls without significant differences between the groups. The difference in degree of tonsillar herniation was statistically significant between presyrinx patients and Chiari I controls ( p = 0.01). Conclusions Presyrinx patients have greater than normal positive tapering in the lower cervical spine and greater degree of tonsillar herniation than the controls.

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Characterization of Cyclic CSF Flow in the Foramen Magnum and Upper Cervical Spinal Canal with MR Flow Imaging and Computational Fluid Dynamics

American Journal of Neuroradiology ◽

10.3174/ajnr.a1995 ◽

2010 ◽

Vol 31 (6) ◽

pp. 997-1002 ◽

Cited By ~ 32

Author(s):

S. Hentschel ◽

K.-A. Mardal ◽

A.E. Løvgren ◽

S. Linge ◽

V. Haughton

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Spinal Canal ◽

Foramen Magnum ◽

Flow Imaging ◽

Csf Flow ◽

Cervical Spinal Canal ◽

Upper Cervical

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Fracture of a sublaminar stainless steel cable in the upper cervical spine with neurological injury

Journal of Neurosurgery ◽

10.3171/jns.1994.81.6.0932 ◽

1994 ◽

Vol 81 (6) ◽

pp. 932-933 ◽

Cited By ~ 22

Author(s):

J. Bob Blacklock

Keyword(s):

Stainless Steel ◽

Cervical Spine ◽

Spinal Canal ◽

Neurological Injury ◽

Upper Cervical Spine ◽

Steel Cable ◽

Content Type ◽

Atlantoaxial Fusion ◽

Upper Cervical ◽

Fine Print

✓ Sublaminar cables have been used to stabilize bone grafts for arthrodesis in the cervical spine in recent years. Previous accounts of their use have indicated no instances of breakage or neurological injury. This report is of a delayed cable fracture that resulted in penetration of the dura with neurological injury in a patient who had undergone atlantoaxial fusion for rheumatoid subluxation. The cable fracture occurred in the epidural space beneath the attempted arthrodesis and resulted in uncoiling of the cable, which penetrated the spinal canal and caused a one-sided sensory deficit.

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Fiberoptic bronchoscopy versus video laryngoscopy guided intubation in patients with craniovertebral junction instability: A cinefluroscopic comparison

Surgical Neurology International ◽

10.25259/sni_522_2020 ◽

2021 ◽

Vol 12 ◽

pp. 92

Author(s):

Sanket Agrawal ◽

Pravin Salunke ◽

Shailesh Gupta ◽

Amlan Swain ◽

Kiran Jangra ◽

...

Keyword(s):

Cervical Spine ◽

General Anesthesia ◽

Spinal Canal ◽

Fiberoptic Bronchoscopy ◽

Craniovertebral Junction ◽

Cervical Spinal Canal ◽

Bony Landmarks ◽

Canal Diameter ◽

Number Of Patients ◽

Upper Cervical

Background: Manipulation during endotracheal intubation in patients with craniovertebral junction (CVJ) anomalies may cause neurological deterioration due to underlying instability. Fiberoptic-bronchoscopy (FOB) is better than video laryngoscope (VL) for minimizing cervical spine movement during intubation. However, evidence suggesting superiority of FOB in patients with CVJ instability is lacking. We prospectively compared dynamic movements of the upper cervical spine during intubation using FOB with VL in patients with CVJ anomalies. Methods: A prospective, randomized, and clinical trial was conducted in 62 patients of American Society of Anaesthesiologist Grade I-II aged between 12 and 65 years with CVJ anomalies. Patients were randomized for intubation under general anesthesia with either VL or FOB. The intubation process was done with application of skeletal traction and recorded cinefluroscopically. The dynamic interrelationship of bony landmarks (horizontal, vertical, and diagonal distances between fixed points on posterior C1 and C2) was analyzed to indirectly calculate alteration of the upper cervical spinal canal diameter (at CVJ). Atlanto-dental interval (ADI) was calculated wherever possible. Results: The alteration in canal diameter (using bony landmarks) at CVJ during intubation was not significant with the use of either VL or FOB (P > 0.05). In 41 patients, where ADI could be measured, ADI was reduced (increased spinal canal diameter) in a greater number of patients in VL group when compared to FOB group (P < 0.05). Conclusion: Using rigid skull traction, intubation under general anesthesia with VL offers similar advantage as FOB in terms of the spinal kinematics in patients with CVJ anomalies/instability. Nevertheless, greater number of patients intubated with VL may have an advantage of increased cervical spinal canal diameter when compared to FOB.

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Endonasal Surgery of the Upper Cervical Spine: A Morphometric Analysis

Skull Base ◽

10.1055/s-2008-1093170 ◽

2008 ◽

Vol 18 (S 01) ◽

Author(s):

Harminder Singh ◽

Bartosz Grobelny ◽

Adam Flanders ◽

Marc Rosen ◽

Paul Schiffmacher ◽

...

Keyword(s):

Cervical Spine ◽

Morphometric Analysis ◽

Upper Cervical Spine ◽

Endonasal Surgery ◽

Upper Cervical

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Defining the Nasopalatine Line: Anatomic Limitations for Endoscopic Endonasal Surgery of the Odontoid Process and Upper Cervical Spine

Skull Base ◽

10.1055/s-2008-1093252 ◽

2008 ◽

Vol 18 (S 01) ◽

Author(s):

John de Almeida ◽

Adam Zanation ◽

Ricardo Carrau ◽

Amin Kassam ◽

Carl Snyderman

Keyword(s):

Cervical Spine ◽

Odontoid Process ◽

Upper Cervical Spine ◽

Endoscopic Endonasal Surgery ◽

Endonasal Surgery ◽

Endoscopic Endonasal ◽

Upper Cervical

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A 3D-Printed Model-Assisted Cervical Spine Instrumentation after Tumor Resection in a 4-Year-Old Child: A Case Report

Pediatric Neurosurgery ◽

10.1159/000514248 ◽

2021 ◽

pp. 1-7

Author(s):

Marko Jug

Keyword(s):

Cervical Spine ◽

3D Model ◽

Intraoperative Complications ◽

Tumor Resection ◽

Upper Cervical Spine ◽

Spine Instrumentation ◽

Cord Injury ◽

Spinal Navigation ◽

Upper Cervical ◽

3D Printed

Introduction: In the case of tumor resection in the upper cervical spine, a multilevel laminectomy with instrumented fixation is required to prevent kyphotic deformity and myelopathy. Nevertheless, instrumentation of the cervical spine in children under the age of 8 years is challenging due to anatomical considerations and unavailability of specific instrumentation. Case Presentation: We present a case of 3D-printed model-assisted cervical spine instrumentation in a 4-year-old child with post-laminectomy kyphotic decompensation of the cervical spine and spinal cord injury 1 year after medulloblastoma metastasis resection in the upper cervical spine. Due to unavailability of specific instrumentation, 3D virtual planning was used to assess and plan posterior cervical fixation. Fixation with 3.5 mm lateral mass and isthmic screws was suggested and the feasibility of fixation was confirmed “in vitro” in a 3D-printed model preoperatively to reduce the possibility of intraoperative implant-spine mismatch. Intraoperative conditions completely resembled the preoperative plan and 3.5 mm polyaxial screws were successfully used as planned. Postoperatively the child made a complete neurological recovery and 2 years after the instrumented fusion is still disease free with no signs of spinal decompensation. Discussion/Conclusion: Our case shows that posterior cervical fixation with the conventional screw-rod technique in a 4-year-old child is feasible, but we suggest that suitability and positioning of the chosen implants are preoperatively assessed in a printed 3D model. In addition, a printed 3D model offers the possibility to better visualize and sense spinal anatomy “in vivo,” thereby helping screw placement and reducing the chance for intraoperative complications, especially in the absence of intraoperative spinal navigation.

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