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chiari malformation flow

Radek Frič, Erika Kristina Lindstrøm, Geir Andre Ringstad, Kent-André Mardal, Per Kristian Eide
BACKGROUND: In symptomatic Chiari malformation type 1 (CMI), impaired intracranial compliance (ICC) is associated with an increased cranio-spinal pulsatile pressure gradient. Phase-contrast magnetic resonance imaging (MRI) represents a non-invasive modality for the assessment of the pulse pressure gradient at the cranio-cervical junction (CCJ). We wished to explore how the MRI-derived pulse pressure gradient (MRI-dP) compares with invasively measured pulsatile intracranial pressure (ICP) in CMI, and with healthy controls...
October 14, 2016: Acta Neurochirurgica
Karen-Helene Støverud, Hans Petter Langtangen, Geir Andre Ringstad, Per Kristian Eide, Kent-Andre Mardal
PURPOSE: Previous computational fluid dynamics (CFD) studies have demonstrated that the Chiari malformation is associated with abnormal cerebrospinal fluid (CSF) flow in the cervical part of the subarachnoid space (SAS), but the flow in the SAS of the posterior cranial fossa has received little attention. This study extends previous modelling efforts by including the cerebellomedullary cistern, pontine cistern, and 4th ventricle in addition to the cervical subarachnoid space. METHODS: The study included one healthy control, Con1, and two patients with Chiari I malformation, P1 and P2...
2016: PloS One
Woon Tak Yuh, Chi Heon Kim, Chun Kee Chung, Hyun-Jib Kim, Tae-Ahn Jahng, Sung Bae Park
OBJECTIVE: The pathophysiology of idiopathic Chiari malformation (CM) type 1 is disturbance of free cerebrospinal fluid (CSF) flow and restoration of normal CSF flow is the mainstay of treatment. Additional migration of the medulla oblongata in pediatric patients is referred to as CM type 1.5, but its significance in adult patients is unknown. This study is to compare surgical outcomes of adult idiopathic CM type 1.5 with that of type 1. METHODS: Thirty-eight consecutive adult patients (M : F=11 : 27; median, 33...
September 2016: Journal of Korean Neurosurgical Society
Helen Williams
It is proposed that negative central nervous system (CNS) pressure is one of the filling mechanisms of the fluid spaces of the CNS. Negative CNS pressure is caused by the combination of gravitational force and body movement. The venous system imposes pressure fluctuations on the CNS due to changes in posture and body cavity pressure. It is proposed here that filling of veins, arteries and cerebrospinal (CSF) spaces are all assisted by negative CNS pressure. Hyperemia in the CNS in response to pressure changes with movement was described in the first part of this hypothesis...
September 2016: Medical Hypotheses
Noam Alperin, James Ryan Loftus, Ahmet M Bagci, Sang H Lee, Carlos J Oliu, Ashish H Shah, Barth A Green
OBJECTIVE This study identifies quantitative imaging-based measures in patients with Chiari malformation Type I (CM-I) that are associated with positive outcomes after suboccipital decompression with duraplasty. METHODS Fifteen patients in whom CM-I was newly diagnosed underwent MRI preoperatively and 3 months postoperatively. More than 20 previously described morphological and physiological parameters were derived to assess quantitatively the impact of surgery. Postsurgical clinical outcomes were assessed in 2 ways, based on resolution of the patient's chief complaint and using a modified Chicago Chiari Outcome Scale (CCOS)...
August 5, 2016: Journal of Neurosurgery. Spine
Parag P Sayal, Arif Zafar, Thomas A Carroll
In a certain group of patients with syringomyelia, even with the advent of sophisticated magnetic resonance imaging (MRI), no associated abnormality or cerebrospinal fluid (CSF) block is easily identified. This type of syringomyelia is often termed idiopathic. Current literature has less than 10 reports of arachnoid webs to be the causative factor. We present our experience in the management of two cases of syringomyelia secondary to arachnoid webs. Both our patients presented with progressive neurological deterioration with MRI scans demonstrating cervical/thoracic syrinx without Chiari malformation or low-lying cord...
April 2016: Journal of Craniovertebral Junction and Spine
Sébastien Richard, Lisa Humbertjean, Gioia Mione, Marc Braun, Emmanuelle Schmitt, Sophie Colnat-Coulbois
BACKGROUND: Syringomyelia due to intracranial hypotension is rarely described. As a consequence, intracranial hypotension is less recognized as a potential cause of syringomyelia or mistaken with Chiari type 1 malformation. The pathogeny is poorly understood, and we lack diagnostic and therapeutic strategies for this particular setting. CASE DESCRIPTION: We describe a 45-year-old patient who developed syringomyelia after about 10 years of undiagnosed intracranial hypotension caused by traumatic C6 cerebrospinal fluid (CSF) leak...
July 2016: World Neurosurgery
Erin J Kelly, Shinya Yamada
This article provides an overview of magnetic resonance imaging (MRI) techniques used to assess cerebrospinal fluid (CSF) movement in the central nervous system (CNS), including Phase-Contrast (PC), Time-Spatial Labeling Inversion Pulse, and simultaneous multi slice echo planar phase contrast imaging. These techniques have been used to assess CSF movement in the CNS under normal and pathophysiological situations. PC can quantitatively measure stroke volume in selected regions, particularly the aqueduct of Sylvius, as synchronized to the heartbeat...
April 2016: Seminars in Ultrasound, CT, and MR
Soroush Heidari Pahlavian, Alexander C Bunck, Suraj Thyagaraj, Daniel Giese, Francis Loth, Dennis M Hedderich, Jan Robert Kröger, Bryn A Martin
Abnormal alterations in cerebrospinal fluid (CSF) flow are thought to play an important role in pathophysiology of various craniospinal disorders such as hydrocephalus and Chiari malformation. Three directional phase contrast MRI (4D Flow) has been proposed as one method for quantification of the CSF dynamics in healthy and disease states, but prior to further implementation of this technique, its accuracy in measuring CSF velocity magnitude and distribution must be evaluated. In this study, an MR-compatible experimental platform was developed based on an anatomically detailed 3D printed model of the cervical subarachnoid space and subject specific flow boundary conditions...
April 4, 2016: Annals of Biomedical Engineering
J Rajiv Bapuraj, Frank J Londy, Nader Delavari, Cormac O Maher, Hugh J L Garton, Bryn A Martin, Karin M Muraszko, El-Sayed H Ibrahim, Douglas J Quint
PURPOSE: To assess the effects of cerebrospinal fluid (CSF) bidirectional motion in Chiari malformation type I (CMI), we monitored CSF velocity amplitudes on phase contrast MRI (PC-MRI) in patients before and after surgery; and in healthy volunteers. MATERIALS AND METHODS: 10 pediatric volunteers and 10 CMI patients participated in this study. CMI patients underwent PC-MRI scans before and approximately 14 months following surgery. Two parameters-amplitude of mean velocity (AMV) and amplitude of peak velocity (APV) of CSF-were derived from the data...
August 2016: Journal of Magnetic Resonance Imaging: JMRI
R Shane Tubbs, Christina M Kirkpatrick, Elias Rizk, Joshua J Chern, Rod J Oskouian, W Jerry Oakes
BACKGROUND: In the past, diagnosis of the Chiari I malformation has primarily been made on midsagittal MRI. We hypothesized that based on the frequent presentation of opisthotonos in patients with hindbrain hernia (primarily Chiari II malformation but sometimes Chiari I malformation) that the hyperextension might be a compensatory technique used by such patients to bring the cerebellar tonsils up out of the cervical spine. PATIENTS AND METHODS: This prospective study reviewed imaging of patients with Chiari I malformation who underwent flexion/extension MRI for evaluation of their hindbrain herniation...
March 2016: Child's Nervous System: ChNS: Official Journal of the International Society for Pediatric Neurosurgery
Vannessa Leung, John S Magnussen, Marcus A Stoodley, Lynne E Bilston
OBJECTIVE: The pathogenesis of syringomyelia associated with Chiari malformation type I (CM-I) is unclear. Theories of pathogenesis suggest the cerebellar tonsils may obstruct CSF flow or alter pressure gradients, or their motion might act as a piston to increase CSF pressure in the spinal subarachnoid space. This study was performed to measure cerebellar tonsillar and hindbrain motion in CM-I and assess the potential contributions to syrinx formation. METHODS: Sixty-four CM-I patients and 25 controls were retrospectively selected from a clinical database, and all subjects had undergone cardiac-gated cine balanced fast-field echo MRI...
April 2016: Journal of Neurosurgery. Spine
Bryn A Martin, Theresia I Yiallourou, Soroush Heidari Pahlavian, Suraj Thyagaraj, Alexander C Bunck, Francis Loth, Daniel B Sheffer, Jan Robert Kröger, Nikolaos Stergiopulos
For the first time, inter-operator dependence of MRI based computational fluid dynamics (CFD) modeling of cerebrospinal fluid (CSF) in the cervical spinal subarachnoid space (SSS) is evaluated. In vivo MRI flow measurements and anatomy MRI images were obtained at the cervico-medullary junction of a healthy subject and a Chiari I malformation patient. 3D anatomies of the SSS were reconstructed by manual segmentation by four independent operators for both cases. CFD results were compared at nine axial locations along the SSS in terms of hydrodynamic and geometric parameters...
May 2016: Annals of Biomedical Engineering
Akbar Fakhri, Manish N Shah, Manu S Goyal
Type I Chiari malformations are congenital deformities involving cerebellar tonsillar herniation downward through the foramen magnum. Structurally, greater than 5 mm of tonsillar descent in adults and more than 6 mm in children is consistent with type I Chiari malformations. However, the radiographic severity of the tonsillar descent does not always correlate well with the clinical symptomatology. Advanced imaging can help clinically correlate imaging to symptoms. Specifically, cerebrospinal fluid (CSF) flow abnormalities are seen in patients with type I Chiari malformation...
October 2015: Neurosurgery Clinics of North America
Arjun R Khanna, Jean-Valery Coumans
BACKGROUND AND IMPORTANCE: Syringomyelia is highly associated with Chiari I malformation, but the pathophysiologic mechanism of syrinx formation and its relation to downward cerebellar tonsillar displacement remains elusive. Cough, Valsalva maneuver, and other physiological strains transiently exacerbate the clinical symptoms of these conditions, exert profound effects on the flow dynamics across the craniospinal junction, and are thought to play an important role in the pathogenesis of syringomyelia...
February 2016: Neurosurgery
Karen H Støverud, Martin Alnæs, Hans Petter Langtangen, Victor Haughton, Kent-André Mardal
Syringomyelia, fluid-filled cavities within the spinal cord, occurs frequently in association with a Chiari I malformation and produces some of its most severe neurological symptoms. The exact mechanism causing syringomyelia remains unknown. Since syringomyelia occurs frequently in association with obstructed cerebrospinal fluid (CSF) flow, it has been hypothesized that syrinx formation is mechanically driven. In this study we model the spinal cord tissue either as a poro-elastic medium or as a solid linear elastic medium, and simulate the propagation of pressure waves through an anatomically plausible 3D geometry, with boundary conditions based on in vivo CSF pressure measurements...
2016: Computer Methods in Biomechanics and Biomedical Engineering
Soroush Heidari Pahlavian, Francis Loth, Mark Luciano, John Oshinski, Bryn A Martin
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...
December 2015: Annals of Biomedical Engineering
Radek Frič, Per Kristian Eide
BACKGROUND: In Chiari malformation type 1 (CMI), the obstruction of cerebrospinal fluid (CSF) flow through the foramen magnum is believed to cause alterations of intracranial pressure (ICP) pulsations. Foramen magnum decompression (FMD) is therefore considered a treatment of choice. However, the pathophysiology of CMI is poorly understood and it remains unknown how ICP alterations relate to symptoms and radiological findings. This study was undertaken to measure pulsatile pressure and its gradient between intracranial and lumbar compartments, and to determine its relationship to clinical and radiological findings...
September 2015: Acta Neurochirurgica
Jennifer Williams McVige, Jody Leonardo
Chiari malformation type I (CMI) involves the caudal displacement of the cerebellar tonsils through the foramen magnum with resultant brainstem compression in some individuals. Due to pathophysiologic changes, secondary conditions may arise, such as syringohydromyelia (SH) and scoliosis. This disorder is unique, as the diagnosis is confirmed through radiologic findings. At times CMI is discovered incidentally on neuroimaging, but more frequently a patient will present with specific symptoms, the most common being a prototypic occipital headache...
June 2015: Current Pain and Headache Reports
Claudia F E Kirsch
Introduction Over the past 20 years, magnetic resonance imaging (MRI) has advanced due to new techniques involving increased magnetic field strength and developments in coils and pulse sequences. These advances allow increased opportunity to delineate the complex skull base anatomy and may guide the diagnosis and treatment of the myriad of pathologies that can affect the skull base. Objectives The objective of this article is to provide a brief background of the development of MRI and illustrate advances in skull base imaging, including techniques that allow improved conspicuity, characterization, and correlative physiologic assessment of skull base pathologies...
October 2014: International Archives of Otorhinolaryngology
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