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Sincomb S, Moral-Pulido F, Campos O, Martínez-Bazán C, Haughton V, Sánchez A. An in vitro experimental investigation of oscillatory flow in the cerebral aqueduct. EUROPEAN JOURNAL OF MECHANICS. B, FLUIDS 2024; 105:180-191. [PMID: 38770034 PMCID: PMC11105671 DOI: 10.1016/j.euromechflu.2024.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
This in vitro study aims at clarifying the relation between the oscillatory flow of cerebrospinal fluid (CSF) in the cerebral aqueduct, a narrow conduit connecting the third and fourth ventricles, and the corresponding interventricular pressure difference. Dimensional analysis is used in designing an anatomically correct scaled model of the aqueduct flow, with physical similarity maintained by adjusting the flow frequency and the properties of the working fluid. The time-varying pressure difference across the aqueduct corresponding to a given oscillatory flow rate is measured in parametric ranges covering the range of flow conditions commonly encountered in healthy subjects. Parametric dependences are delineated for the time-averaged pressure fluctuations and for the phase lag between the transaqueductal pressure difference and the flow rate, both having clinical relevance. The results are validated through comparisons with predictions obtained with a previously derived computational model. The parametric quantification in this study enables the derivation of a simple formula for the relation between the transaqueductal pressure and the stroke volume. This relationship can be useful in the quantification of transmantle pressure differences based on non-invasive magnetic-resonance-velocimetry measurements of aqueduct flow for investigation of CSF-related disorders.
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Affiliation(s)
- S. Sincomb
- Department of Aerospace and Mechanical Engineering, University of California, San Diego, La Jolla, 92093-0411, CA, USA
| | - F. Moral-Pulido
- Department of Mechanical and Mining Engineering, University of Jaen, Jaen, 23071, Spain
- Andalusian Institute for Earth System Research, University of Jaen, Jaen, 23071, Spain
| | - O. Campos
- Department of Aerospace and Mechanical Engineering, University of California, San Diego, La Jolla, 92093-0411, CA, USA
| | - C. Martínez-Bazán
- Department of Mechanics of Structures and Hydraulic Engineering, University of Granada, Granada, 18001, Spain
- Andalusian Institute for Earth System Research, University of Granada, Granada, 18006, Spain
| | - V. Haughton
- School of Medicine and Public Health, University of Wisconsin-Madison, Madison, 53706, WI, USA
| | - A.L. Sánchez
- Department of Aerospace and Mechanical Engineering, University of California, San Diego, La Jolla, 92093-0411, CA, USA
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Br G, Sharma PK, Polaka Y, S P, Natarajan P. The Role of Phase-Contrast MRI in Diagnosing Cerebrospinal Fluid Flow Abnormalities. Cureus 2024; 16:e57114. [PMID: 38681281 PMCID: PMC11055472 DOI: 10.7759/cureus.57114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 03/28/2024] [Indexed: 05/01/2024] Open
Abstract
Background Cerebrospinal fluid (CSF) dynamics play a crucial role in maintaining the homeostasis of the central nervous system (CNS). Any disruption in CSF flow can lead to various congenital and acquired conditions, impacting neurological function and overall health. This study aims to analyze the significance of phase-contrast MRI in evaluating abnormalities in CSF flow and its diagnostic utility in various CSF-related disorders. Phase contrast MRI has emerged as a valuable tool for evaluating CSF dynamics non-invasively by examining CSF flow characteristics such as pulsatile flow patterns, hyperdynamic or hypodynamic flow, and disruptions in CSF circulation. Alterations in CSF pulsatility and stroke volume can indicate changes in intracranial compliance, vascular resistance, or CSF production and absorption rates. The findings of this study will advance our understanding of CSF physiology and its relevance in neurological pathologies, potentially leading to improved patient outcomes and management approaches. Materials and methods The study involved 36 patients and was conducted as an observational, prospective study over 18 months (October 2020 to March 2022) at the Department of Radiology, Saveetha Medical College and Hospital, Chennai. We utilized a 1.5 T Philips Multiva MRI scanner by Philips Healthcare in Amsterdam, Netherlands. The study included patients with suspected CSF flow abnormalities and abnormal MRI findings (normal pressure hydrocephalus (NPH), age-related brain atrophy, aqueduct stenosis (AS), Chiari malformation type 1, syringomyelia, or arachnoid cyst), alongside control exhibiting normal neurological symptoms and MRI results. Exclusions involved individuals with febrile seizures, neurological diseases, cerebrovascular accidents, anti-convulsive medication use, cardiac arrhythmia, or MRI contraindications. Post-processing involved analyzing stroke volume (SV), peak systolic velocity (PSV), end diastolic velocity (EDV), and mean flux. Statistical analysis was conducted using the Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Version 24.0, Armonk, NY), employing the χ2-test for categorical variables and nonparametric tests like Mann-Whitney U and Kruskal-Wallis H-tests for quantitative variables. A p-value < 0.05 was considered significant. Results The 36 patients, aged 1 to 80 years, were referred by the neurology department and categorized into four subgroups based on clinical history and conventional MRI findings: NPH, AS, age-related brain atrophy, and a normal control group. MRI CSF flowmetry evaluation focused on PSV, PDV, and SV. We found peak diastolic velocity (PDV), PSV, and average blood velocity (ABV) to be significantly higher in NPH compared to the control group (PSV, EDV, and SV: 9.96 +/- 1.73, 4.72 +/- 0.62, and 63 +/- 12.88 for NPH versus 4.8 +/- 0.39, 3.21 +/- 0.55, and 20.72 +/- 5.7 for control, respectively; p = 0.000). Conversely, patients with age-related brain atrophy and AS exhibited lower values (1.6 +/- 0.44, 1.13 +/- 0.09, and 6.33 +/- 2.08 for AS, and 2.07 +/- 0.09, 1.62 +/- 0.33, and 6.8 +/- 2.16 for age-related brain atrophy versus control; p = 0.002). Conclusion MRI CSF flowmetry emerges as a rapid, accurate, and non-invasive diagnostic tool for various neurological disorders associated with abnormal CSF flow. Additionally, this technique may aid in selecting appropriate treatment strategies.
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Affiliation(s)
- Govindarajan Br
- Department of Radio-Diagnosis, Saveetha Medical College and Hospital, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, IND
| | - Praveen K Sharma
- Department of Radio-Diagnosis, Saveetha Medical College and Hospital, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, IND
| | - Yashaswinii Polaka
- Department of Radio-Diagnosis, Saveetha Medical College and Hospital, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, IND
| | - Pujitha S
- Department of Radio-Diagnosis, Saveetha Medical College and Hospital, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, IND
| | - Paarthipan Natarajan
- Department of Radio-Diagnosis, Saveetha Medical College and Hospital, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, IND
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Capel C, Owashi K, Metanbou S, Peltier J, Balédent O. Impact of Shunt Placement on CSF Dynamics. Biomedicines 2023; 12:20. [PMID: 38275381 PMCID: PMC10813594 DOI: 10.3390/biomedicines12010020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/11/2023] [Accepted: 12/17/2023] [Indexed: 01/27/2024] Open
Abstract
BACKGROUND CSF dynamics are disturbed in chronic hydrocephalus (NPH). We hypothesise that these alterations reflect a disturbance of intracranial compliance. The aim of our study is to investigate the variations in intracranial hydrodynamics in NPH after ventricular shunt surgery. PATIENTS AND METHOD We included 14 patients with definite NPH. All patients improved after ventriculoperitoneal shunting. The patients underwent an analysis of intracranial haemodynamics by phase-contrast MRI (pcMRI) preoperatively, at 6 months postoperatively, and at 1 year postoperatively. We analysed the dynamics of intraventricular CSF at the level of the aqueduct of Sylvius (SVAQU) and CSF at the level of the high cervical subarachnoid spaces (SVCERV). We calculated the ratio between SVAQU and SVCERV, called CSFRATIO, which reflects the participation of intraventricular pulsatility in overall intracranial CSF pulsatility. RESULTS SVAQU significantly (p = 0.003) decreased from 240 ± 114 μL/cc to 214 ± 157 μL/cc 6 months after shunt placement. Six months after shunt placement, SVCERV significantly (p = 0.007) decreased from 627 ± 229 μL/cc to 557 ± 234 μL/cc. Twelve months after shunt placement, SVCERV continued to significantly (p = 0.001) decrease to 496 ± 234 μL/cc. CSFRATIO was not changed by surgery. CONCLUSIONS CSF dynamics are altered by shunt placement and might be a useful marker of the shunt's effectiveness-especially if pressure values start to rise again. The detection of changes in CSF dynamics would require a reference postoperative pcMRI measurement for each patient.
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Affiliation(s)
- Cyrille Capel
- Department of Neurosurgery, Hospital University Center of Amiens-Picardie, 80054 Amiens, France;
- CHIMERE UR UPJV 7516, Jules Verne University, 80000 Amiens, France; (K.O.); (O.B.)
| | - Kimi Owashi
- CHIMERE UR UPJV 7516, Jules Verne University, 80000 Amiens, France; (K.O.); (O.B.)
- Image Processing Department, Hospital University Center of Amiens-Picardie, 80054 Amiens, France
| | - Serge Metanbou
- Radiology Department, Hospital University Center of Amiens-Picardie, 80054 Amiens, France;
| | - Johann Peltier
- Department of Neurosurgery, Hospital University Center of Amiens-Picardie, 80054 Amiens, France;
- CHIMERE UR UPJV 7516, Jules Verne University, 80000 Amiens, France; (K.O.); (O.B.)
| | - Olivier Balédent
- CHIMERE UR UPJV 7516, Jules Verne University, 80000 Amiens, France; (K.O.); (O.B.)
- Image Processing Department, Hospital University Center of Amiens-Picardie, 80054 Amiens, France
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Xiang J, Hua Y, Xi G, Keep RF. Mechanisms of cerebrospinal fluid and brain interstitial fluid production. Neurobiol Dis 2023; 183:106159. [PMID: 37209923 PMCID: PMC11071066 DOI: 10.1016/j.nbd.2023.106159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/16/2023] [Accepted: 05/17/2023] [Indexed: 05/22/2023] Open
Abstract
Fluid homeostasis is fundamental for brain function with cerebral edema and hydrocephalus both being major neurological conditions. Fluid movement from blood into brain is one crucial element in cerebral fluid homeostasis. Traditionally it has been thought to occur primarily at the choroid plexus (CP) as cerebrospinal fluid (CSF) secretion due to polarized distribution of ion transporters at the CP epithelium. However, there are currently controversies as to the importance of the CP in fluid secretion, just how fluid transport occurs at that epithelium versus other sites, as well as the direction of fluid flow in the cerebral ventricles. The purpose of this review is to evaluate evidence on the movement of fluid from blood to CSF at the CP and the cerebral vasculature and how this differs from other tissues, e.g., how ion transport at the blood-brain barrier as well as the CP may drive fluid flow. It also addresses recent promising data on two potential targets for modulating CP fluid secretion, the Na+/K+/Cl- cotransporter, NKCC1, and the non-selective cation channel, transient receptor potential vanilloid 4 (TRPV4). Finally, it raises the issue that fluid secretion from blood is not constant, changing with disease and during the day. The apparent importance of NKCC1 phosphorylation and TRPV4 activity at the CP in determining fluid movement suggests that such secretion may also vary over short time frames. Such dynamic changes in CP (and potentially blood-brain barrier) function may contribute to some of the controversies over its role in brain fluid secretion.
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Affiliation(s)
- Jianming Xiang
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ya Hua
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI 48109, USA
| | - Guohua Xi
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI 48109, USA
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI 48109, USA.
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Eslamian M, Habibi Z, Berchi Kankam S, Khoshnevisan A. Role of CSF flow parameters in diagnosis and management of persistent postoperative hydrocephalus. INTERDISCIPLINARY NEUROSURGERY 2022. [DOI: 10.1016/j.inat.2022.101634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022] Open
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6
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Zhang H, Yang H, Duan W, Li X, Wang Y, Cogswell PM, Elder BD. Influence of the area of the aqueduct and region of interest on quantification of stroke volume in healthy volunteers using phase-contrast cine magnetic resonance imaging. Acta Radiol 2022; 64:1615-1622. [PMID: 37023028 DOI: 10.1177/02841851221125916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Phase-contrast cine magnetic resonance imaging (PC-MRI) has been used to measure cerebrospinal fluid (CSF) flow dynamics, but the influence of the area of the aqueduct and region of interest (ROI) on quantification of stroke volume (SV) has not been assessed. Purpose To assess the influence of the area of the ROI in quantifying the aqueductal SV measured with PC-MRI within the cerebral aqueduct. Material and Methods Nine healthy volunteers (mean age = 29.6 years) were enrolled in the study, and brain MRI examinations were performed on a 3.0-T system. Quantitative analysis of the aqueductal CSF flow was performed using manual ROI placement. ROIs were separately drawn for each of the 12 phases of the cardiac cycle, and changes in aqueduct size during the cardiac cycle were determined. The SV was calculated using 12 different aqueductal ROIs and compared with the SV calculated using a fixed ROI size. Results There was variation in the size of the aqueduct during the cardiac cycle. In addition, the measured SV increased with a greater area of the ROI. A significant difference in the calculated SVs with the 12 variable ROIs was observed compared with that using a fixed ROI throughout the cardiac cycle. Conclusion To establish reliable reference values for the SV in future studies, a variable ROI should be considered.
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Affiliation(s)
- Hongri Zhang
- Department of Neurosurgery, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, Henan, PR China
| | - Haixin Yang
- Department of Neurosurgery, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, Henan, PR China
| | - Weike Duan
- Department of Neurosurgery, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, Henan, PR China
| | - Xiaopan Li
- Department of Radiology, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, Henan, PR China
| | - Yixin Wang
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | | | - Benjamin D Elder
- Department of Neurosurgery, Mayo Clinic, Rochester, MN, USA
- Department of Bioengineering, Mayo Clinic, Rochester, MN, USA
- Department of Orthopedics, Mayo Clinic, Rochester, MN, USA
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Bonney PA, Briggs RG, Wu K, Choi W, Khahera A, Ojogho B, Shao X, Zhao Z, Borzage M, Wang DJJ, Liu C, Lee DJ. Pathophysiological Mechanisms Underlying Idiopathic Normal Pressure Hydrocephalus: A Review of Recent Insights. Front Aging Neurosci 2022; 14:866313. [PMID: 35572128 PMCID: PMC9096647 DOI: 10.3389/fnagi.2022.866313] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 03/28/2022] [Indexed: 01/18/2023] Open
Abstract
The pathophysiologic mechanisms underpinning idiopathic normal pressure hydrocephalus (iNPH), a clinically diagnosed dementia-causing disorder, continue to be explored. An increasing body of evidence implicates multiple systems in the pathogenesis of this condition, though a unifying causative etiology remains elusive. Increased knowledge of the aberrations involved has shed light on the iNPH phenotype and has helped to guide prognostication for treatment with cerebrospinal fluid diversion. In this review, we highlight the central role of the cerebrovasculature in pathogenesis, from hydrocephalus formation to cerebral blood flow derangements, blood-brain barrier breakdown, and glymphatic pathway dysfunction. We offer potential avenues for increasing our understanding of how this disease occurs.
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Affiliation(s)
- Phillip A. Bonney
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- *Correspondence: Phillip A. Bonney
| | - Robert G. Briggs
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Kevin Wu
- Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Wooseong Choi
- Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Anadjeet Khahera
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Brandon Ojogho
- Laboratory of Functional MRI Technology, Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- USC Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Xingfeng Shao
- Laboratory of Functional MRI Technology, Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Zhen Zhao
- Department of Physiology & Neuroscience and the Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Matthew Borzage
- Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- Division of Neonatology, Department of Pediatrics, Fetal and Neonatal Institute, Children’s Hospital Los Angeles, Los Angeles, CA, United States
| | - Danny J. J. Wang
- Laboratory of Functional MRI Technology, Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Charles Liu
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- USC Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Darrin J. Lee
- Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
- USC Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
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Eide PK, Lashkarivand A, Hagen-Kersten ÅA, Gjertsen Ø, Nedregaard B, Sletteberg R, Løvland G, Vatnehol SAS, Pripp AH, Valnes LM, Ringstad G. Intrathecal Contrast-Enhanced Magnetic Resonance Imaging of Cerebrospinal Fluid Dynamics and Glymphatic Enhancement in Idiopathic Normal Pressure Hydrocephalus. Front Neurol 2022; 13:857328. [PMID: 35463139 PMCID: PMC9019061 DOI: 10.3389/fneur.2022.857328] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 03/10/2022] [Indexed: 01/09/2023] Open
Abstract
Idiopathic normal pressure hydrocephalus (iNPH) is a neurodegenerative disease, characterized by cerebrospinal fluid (CSF) flow disturbance. Today, the only available treatment is CSF diversion surgery (shunt surgery). While traditional imaging biomarkers typically assess CSF space anatomy, recently introduced imaging biomarkers of CSF dynamics and glymphatic enhancement, provide imaging of CSF dynamics and thereby more specifically reveal elements of the underlying pathophysiology. The biomarkers address CSF ventricular reflux grade as well as glymphatic enhancement and derive from intrathecal contrast-enhanced MRI. However, the contrast agent serving as CSF tracer is administered off-label. In medicine, the introduction of new diagnostic or therapeutic methods must consider the balance between risk and benefit. To this end, we performed a prospective observational study of 95 patients with iNPH, comparing different intrathecal doses of the MRI contrast agent gadobutrol (0.10, 0.25, and 0.50 mmol, respectively), aiming at the lowest reasonable dose needed to retrieve diagnostic information about the novel MRI biomarkers. The present observations disclosed a dose-dependent enrichment of subarachnoid CSF spaces (cisterna magna, vertex, and velum interpositum) with dose-dependent ventricular reflux of tracer in iNPH, as well as dose-dependent glymphatic tracer enrichment. The association between tracer enrichment in CSF and parenchymal compartments were as well dose-related. Intrathecal gadobutrol in a dose of 0.25 mmol, but not 0.10 mmol, was at 1.5T MRI considered sufficient for imaging altered CSF dynamics and glymphatic enhancement in iNPH, even though 3T MRI provided better sensitivity. Tracer enrichment in CSF at the vertex and within the cerebral cortex and subcortical white matter was deemed too low for maintaining diagnostic information from a dose of 0.10 mmol. We conclude that reducing the intrathecal dose of gadobutrol from 0.50 to 0.25 mmol gadobutrol improves the safety margin while maintaining the necessary diagnostic information about disturbed CSF homeostasis and glymphatic failure in iNPH.
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Affiliation(s)
- Per Kristian Eide
- Department of Neurosurgery, Oslo University Hospital-Rikshospitalet, Oslo, Norway.,Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Aslan Lashkarivand
- Department of Neurosurgery, Oslo University Hospital-Rikshospitalet, Oslo, Norway.,Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | | | - Øivind Gjertsen
- Department of Radiology, Oslo University Hospital-Rikshospitalet, Oslo, Norway
| | - Bård Nedregaard
- Department of Radiology, Oslo University Hospital-Rikshospitalet, Oslo, Norway
| | - Ruth Sletteberg
- Department of Radiology, Oslo University Hospital-Rikshospitalet, Oslo, Norway
| | - Grethe Løvland
- The Intervention Centre, Oslo University Hospital-Rikshospitalet, Oslo, Norway
| | - Svein Are Sirirud Vatnehol
- The Intervention Centre, Oslo University Hospital-Rikshospitalet, Oslo, Norway.,Institute of Optometry Radiography and Lighting Design, Faculty of Health and Social Sciences, University of South Eastern Norway, Drammen, Norway
| | - Are Hugo Pripp
- Oslo Centre of Biostatistics and Epidemiology, Research Support Services, Oslo University Hospital, Oslo, Norway.,Faculty of Health Sciences, Oslo Metropolitan University, Oslo, Norway
| | - Lars Magnus Valnes
- Department of Neurosurgery, Oslo University Hospital-Rikshospitalet, Oslo, Norway
| | - Geir Ringstad
- Department of Radiology, Oslo University Hospital-Rikshospitalet, Oslo, Norway.,Department of Geriatrics and Internal Medicine, Sorlandet Hospital, Arendal, Norway
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9
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Theologou M, Natsis K, Kouskouras K, Chatzinikolaou F, Varoutis P, Skoulios N, Tsitouras V, Tsonidis C. Cerebrospinal Fluid Homeostasis and Hydrodynamics: A Review of Facts and Theories. Eur Neurol 2022; 85:313-325. [PMID: 35405679 DOI: 10.1159/000523709] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 02/04/2022] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND PURPOSE According to the classical hypothesis, the cerebrospinal fluid (CSF) is actively secreted inside the brain's ventricular system, predominantly by the choroid plexuses, before flowing unidirectionally in a cranio-caudal orientation toward the arachnoid granulations (AGs), where it is reabsorbed into the dural venous sinuses. This concept has been accepted as a doctrine for more than 100 years and was subjected only to minor modifications. Its inability to provide an adequate explanation to questions arising from the everyday clinical practice, in addition to the ever growing pool of experimental data contradicting it, has led to the identification of its limitations. Literature includes an increasing number of studies suggesting a more complex mechanism than that previously described. This review article summarizes the proposed mechanisms of CSF regulation, referring to the key clinical and experimental developments supporting or defying them. METHODS A non-systematical literature search of the major databases was performed for studies on the mechanisms of CSF homeostasis. Gray literature was additionally assessed employing a hand-search technique. No restrictions were imposed regarding the time, language, or type of publication. CONCLUSION CSF secretion and absorption are expected to take place throughout the entire brain's capillaries network under the regulation of hydrostatic and osmotic gradients. The unidirectional flow is defied, highlighting the possibility of its complete absence. The importance of AGs is brought into question, potentiating the significance of the lymphatic system as the primary site of reabsorption. However, the definition of hydrocephalus and its treatment strategies remain strongly associated with the classical hypothesis.
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Affiliation(s)
- Marios Theologou
- Second Department of Neurosurgery, Aristotle University of Thessaloniki, General Hospital of Thessaloniki Hippokratio, Thessaloniki, Greece
| | - Konstantinos Natsis
- Department of Anatomy and Surgical Anatomy, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Konstantinos Kouskouras
- Department of Radiology, AHEPA University Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Fotios Chatzinikolaou
- Department of Forensic Medicine and Toxicology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Panagiotis Varoutis
- Second Department of Neurosurgery, Aristotle University of Thessaloniki, General Hospital of Thessaloniki Hippokratio, Thessaloniki, Greece
| | - Nikolaos Skoulios
- Second Department of Neurosurgery, Aristotle University of Thessaloniki, General Hospital of Thessaloniki Hippokratio, Thessaloniki, Greece
| | - Vassilios Tsitouras
- Second Department of Neurosurgery, Aristotle University of Thessaloniki, General Hospital of Thessaloniki Hippokratio, Thessaloniki, Greece
| | - Christos Tsonidis
- Second Department of Neurosurgery, Aristotle University of Thessaloniki, General Hospital of Thessaloniki Hippokratio, Thessaloniki, Greece
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10
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Using deep learning convolutional neural networks to automatically perform cerebral aqueduct CSF flow analysis. J Clin Neurosci 2021; 90:60-67. [PMID: 34275582 DOI: 10.1016/j.jocn.2021.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 04/11/2021] [Accepted: 05/01/2021] [Indexed: 11/22/2022]
Abstract
Since the development of phase-contrast magnetic resonance imaging (PC-MRI), quantification of cerebrospinal fluid (CSF) flow across the cerebral aqueduct has been utilized for diagnosis of conditions such as normal pressure hydrocephalus (NPH). This study aims to develop an automated method of aqueduct CSF flow analysis using convolution neural networks (CNNs), which can replace the current standard involving manual segmentation of aqueduct region of interest (ROI). Retrospective analysis was performed on 333 patients who underwent PC-MRI, totaling 353 imaging studies. Aqueduct flow measurements using manual ROI placement was performed independently by two radiologists. Two types of CNNs, MultiResUNet and UNet, were trained using ROI data from the senior radiologist, with PC-MRI studies being randomly divided into training (80%) and validation (20%) datasets. Segmentation performance was assessed using Dice similarity coefficient (DSC), and CSF flow parameters were calculated from both manual and CNN-derived ROIs. MultiResUNet, UNet and second radiologist (Rater 2) had DSCs of 0.933, 0.928, and 0.867, respectively, with p < 0.001 between CNNs and Rater 2. Comparison of CSF flow parameters showed excellent intraclass correlation coefficients (ICCs) for MultiResUNet, with lowest correlation being 0.67. For UNet, lower ICCs of -0.01 to 0.56 were observed. Only 3/353 (0.8%) studies failed to have appropriate ROIs placed by MultiResUNet, compared to 12/353 (3.4%) failed cases for UNet. In conclusion, CNNs were able to measure aqueductal CSF flow with similar performance to a senior neuroradiologist. MultiResUNet demonstrated fewer cases of segmentation failure and more consistent flow measurements compared to the widely adopted UNet.
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11
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Development, calibration, and testing of 3D amplified MRI (aMRI) for the quantification of intrinsic brain motion. BRAIN MULTIPHYSICS 2021. [DOI: 10.1016/j.brain.2021.100022] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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12
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Eide PK, Valnes LM, Lindstrøm EK, Mardal KA, Ringstad G. Direction and magnitude of cerebrospinal fluid flow vary substantially across central nervous system diseases. Fluids Barriers CNS 2021; 18:16. [PMID: 33794929 PMCID: PMC8017867 DOI: 10.1186/s12987-021-00251-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 03/20/2021] [Indexed: 11/10/2022] Open
Abstract
Background Several central nervous system diseases are associated with disturbed cerebrospinal fluid (CSF) flow patterns and have typically been characterized in vivo by phase-contrast magnetic resonance imaging (MRI). This technique is, however, limited by its applicability in space and time. Phase-contrast MRI has yet to be compared directly with CSF tracer enhanced imaging, which can be considered gold standard for assessing long-term CSF flow dynamics within the intracranial compartment. Methods Here, we studied patients with various CSF disorders and compared MRI biomarkers of CSF space anatomy and phase-contrast MRI at level of the aqueduct and cranio-cervical junction with dynamic intrathecal contrast-enhanced MRI using the contrast agent gadobutrol as CSF tracer. Tracer enrichment of cerebral ventricles was graded 0–4 by visual assessment. An intracranial pressure (ICP) score was used as surrogate marker of intracranial compliance. Results The study included 94 patients and disclosed marked variation of CSF flow measures across disease categories. The grade of supra-aqueductal reflux of tracer varied, with strong reflux (grades 3–4) in half of patients. Ventricular tracer reflux correlated with stroke volume and aqueductal CSF pressure gradient. CSF flow in the cerebral aqueduct was retrograde (from 4th to 3rd ventricle) in one third of patients, with estimated CSF net flow volume about 1.0 L/24 h. In the cranio-cervical junction, net flow was cranially directed in 78% patients, with estimated CSF net flow volume about 4.7 L/24 h. Conclusions The present observations provide in vivo quantitative evidence for substantial variation in direction and magnitude of CSF flow, with re-direction of aqueductal flow in communicating hydrocephalus, and significant extra-cranial CSF production. The grading of ventricular reflux of tracer shows promise as a clinical useful method to assess CSF flow pattern disturbances in patients. Graphic abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12987-021-00251-6.
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Affiliation(s)
- Per Kristian Eide
- Deptartment of Neurosurgery, Oslo University Hospital-Rikshospitalet, Nydalen, PB 4950, 0424, Oslo, Norway. .,Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
| | - Lars Magnus Valnes
- Deptartment of Neurosurgery, Oslo University Hospital-Rikshospitalet, Nydalen, PB 4950, 0424, Oslo, Norway
| | - Erika Kristina Lindstrøm
- Department of Mathematics, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway.,Institute for Cancer Genetics and Informatics, Oslo University Hospital, Oslo, Norway
| | - Kent-Andre Mardal
- Department of Mathematics, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway.,Department of Numerical Analysis and Scientific Computing, Simula Research Laboratory, Oslo, Norway
| | - Geir Ringstad
- Department. of Radiology, Oslo University Hospital-Rikshospitalet, Oslo, Norway
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13
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Ahmad N, Salama D, Al-Haggar M. MRI CSF flowmetry in evaluation of different neurological diseases. THE EGYPTIAN JOURNAL OF RADIOLOGY AND NUCLEAR MEDICINE 2021. [DOI: 10.1186/s43055-021-00429-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Phase contrast MR imaging is a rapid and non-invasive technique which is sensitive in diagnosis and follow-up of different neurological diseases that cause CSF flow abnormality. MRI CSF flowmetry will be currently assessed in different neurological diseases that may cause CSF flow abnormalities.
Results
This study includes 39 patients with their ages ranging from 1 to 65 years; they were referred from the neurology department, with nine individuals of matched age and sex as a control group. Based on clinical history and conventional MRI, patients were subdivided into five subgroups; normal pressure hydrocephalus (NPH), hydrocephalus, idiopathic intracranial hypertension (IIH), brain atrophy (BA), and Chiari malformation type I (CM-I). All patients and control were subjected to MRI CSF flowmetry evaluation with stress on peak diastolic velocity (PDV), peak systolic velocity (PSV), stroke volume (SV), and maximum velocity (Vmax). PDV, PSV, and SV were found significantly higher in NPH, CM-I, and hydrocephalus compared to control (4.2, 4.96, and 83.23 for NPH; 3.95, 4.93, and 37.38 for CM-I; and 4.2, 5.6, and 125 in hydrocephalus versus 2.11, 2.73, and 75.33 in control, respectively; P = 0.0004, 0.0008, and 0.0009 for NPH; 0.03, 0.003, and 0.06 for CM-I; and 0.0005, 0.0002, and 0.0003, respectively). On the other hand, patients with BA showed significantly lower values (1.37, 1.66, and 1.53, respectively) compared to control (P = 0.001, 0.001, and 0.004, respectively).
Conclusion
MRI CSF flowmetry provides an easy, accurate, and non-invasive method for diagnosis of different neurological diseases that cause CSF flow abnormality. Moreover, this diagnostic modality could be helpful in selecting the therapeutic option.
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14
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Wymer DT, Patel KP, Burke WF, Bhatia VK. Phase-Contrast MRI: Physics, Techniques, and Clinical Applications. Radiographics 2021; 40:122-140. [PMID: 31917664 DOI: 10.1148/rg.2020190039] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
With phase-contrast imaging, the MRI signal is used to visualize and quantify velocity. This imaging modality relies on phase data, which are intrinsic to all MRI signals. With use of bipolar gradients, degrees of phase shift are encoded and in turn correlated directly with the velocity of protons. The acquisition of diagnostic-quality images requires selection of the correct imaging plane to ensure accurate measurement and selection of the encoding velocity and thus prevent aliasing and achieve the highest signal-to-noise ratio. Multiple applications of phase-contrast imaging are actively used in clinical practice. One of the most common clinical uses is in cardiac valvular flow imaging, at which the data are used to assess the severity of valvular disease and quantify the shunt fraction. In neurologic imaging, phase-contrast imaging can be used to measure the flow of cerebrospinal fluid. This measurement can aid in the diagnosis and direct management of normal pressure hydrocephalus or be used to evaluate the severity of stenosis, such as that in Chiari I malformations. At vascular analysis, phase-contrast imaging can be used to visualize arterial and venous flow, and this application is used most commonly in the brain. Three-dimensional imaging can yield highly detailed flow data in a technique referred to as four-dimensional flow. A more recently identified application is in MR elastography. Shear waves created by using an impulse device can be velocity encoded, and this velocity is directly proportional to the stiffness of the organ, or the shear modulus. This imaging modality is most commonly used in the liver for evaluation of cirrhosis and steatosis, although research on the assessment of other organs is being performed. Phase-contrast imaging is an important tool in the arsenal of MRI examinations and has many applications. Proper use of phase-contrast imaging requires an understanding of the many practical and technical factors and unique physics principles underlying the technique.©RSNA, 2020.
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Affiliation(s)
- David T Wymer
- From the Department of Diagnostic Radiology, Mount Sinai Medical Center, 4300 Alton Rd, Miami Beach, FL 33140
| | - Kunal P Patel
- From the Department of Diagnostic Radiology, Mount Sinai Medical Center, 4300 Alton Rd, Miami Beach, FL 33140
| | - William F Burke
- From the Department of Diagnostic Radiology, Mount Sinai Medical Center, 4300 Alton Rd, Miami Beach, FL 33140
| | - Vinay K Bhatia
- From the Department of Diagnostic Radiology, Mount Sinai Medical Center, 4300 Alton Rd, Miami Beach, FL 33140
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15
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Fame RM, Cortés-Campos C, Sive HL. Brain Ventricular System and Cerebrospinal Fluid Development and Function: Light at the End of the Tube: A Primer with Latest Insights. Bioessays 2020; 42:e1900186. [PMID: 32078177 DOI: 10.1002/bies.201900186] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 01/02/2020] [Indexed: 12/12/2022]
Abstract
The brain ventricular system is a series of connected cavities, filled with cerebrospinal fluid (CSF), that forms within the vertebrate central nervous system (CNS). The hollow neural tube is a hallmark of the chordate CNS, and a closed neural tube is essential for normal development. Development and function of the ventricular system is examined, emphasizing three interdigitating components that form a functional system: ventricle walls, CSF fluid properties, and activity of CSF constituent factors. The cellular lining of the ventricle both can produce and is responsive to CSF. Fluid properties and conserved CSF components contribute to normal CNS development. Anomalies of the CSF/ventricular system serve as diagnostics and may cause CNS disorders, further highlighting their importance. This review focuses on the evolution and development of the brain ventricular system, associated function, and connected pathologies. It is geared as an introduction for scholars with little background in the field.
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Affiliation(s)
- Ryann M Fame
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
| | | | - Hazel L Sive
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
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16
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Diagnostica per immagini dell’idrocefalo del bambino. Neurologia 2020. [DOI: 10.1016/s1634-7072(20)43300-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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17
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Impaired Glymphatic Transport in Spontaneously Hypertensive Rats. J Neurosci 2019; 39:6365-6377. [PMID: 31209176 DOI: 10.1523/jneurosci.1974-18.2019] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 03/31/2019] [Accepted: 05/30/2019] [Indexed: 12/21/2022] Open
Abstract
The glymphatic system is a brainwide CSF transport system that uses the perivascular space for fast inflow of CSF. Arterial pulsations are a major driver of glymphatic CSF inflow, and hypertension that causes vascular pathologies, such as arterial stiffening and perivascular alterations, may impede the inflow. We used dynamic contrast-enhanced MRI to assess the effect of hypertension on glymphatic transport kinetics in male young and adult spontaneously hypertensive (SHR) rats compared with age-matched normotensive Wistar-Kyoto rats (WKY). We anesthetized the rats with dexmedetomidine/isoflurane and infused paramagnetic contrast (Gd-DOTA) into the cisterna magna during dynamic contrast-enhanced MRI to quantify glymphatic transport kinetics. Structural MRI analysis showed that cerebroventricular volumes are larger and brain volumes significantly smaller in SHR compared with WKY rats, regardless of age. We observed ventricular reflux of Gd-DOTA in SHR rats only, indicating abnormal CSF flow dynamics secondary to innate hydrocephalus. One-tissue compartment analysis revealed impeded glymphatic transport of Gd-DOTA in SHR compared with WKY rats in both age groups, implying that glymphatic transport, including solute clearance from brain parenchyma, is impaired during evolving hypertension in young SHR, an effect that worsens in states of chronic hypertension. The study demonstrates the suppression of glymphatic clearance in SHR rats and thus offers new insight into the coexistence of hypertension and concomitant vascular pathologies in Alzheimer's disease. The study further highlights the importance of considering the distribution of tracers in the CSF compartment in the analysis of the glymphatic system.SIGNIFICANCE STATEMENT The glymphatic system contributes to the removal of amyloid β from the brain and is disrupted in Alzheimer's disease and aging. Using a rat model of hypertension, we measured gross CSF flow and tracked glymphatic influx and efflux rates with dynamic contrast-enhanced MRI, showing that glymphatic transport is compromised in both early and advanced stages of hypertension. The study provides a new perspective on the importance for brain metabolite and fluid homeostasis of maintaining healthy blood vessels, an increasingly pertinent issue in an aging population that in part may explain the link between vascular pathology and Alzheimer's disease.
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18
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Vivas-Buitrago T, Lokossou A, Jusué-Torres I, Pinilla-Monsalve G, Blitz AM, Herzka DA, Robison J, Xu J, Guerrero-Cazares H, Mori S, Quiñones-Hinojosa A, Baledént O, Rigamonti D. Aqueductal Cerebrospinal Fluid Stroke Volume Flow in a Rodent Model of Chronic Communicating Hydrocephalus: Establishing a Homogeneous Study Population for Cerebrospinal Fluid Dynamics Exploration. World Neurosurg 2019; 128:e1118-e1125. [PMID: 31121363 DOI: 10.1016/j.wneu.2019.05.093] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 05/09/2019] [Accepted: 05/10/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND Idiopathic normal pressure hydrocephalus (iNPH) is a cause of dementia that can be reversed when treated timely with cerebrospinal fluid (CSF) diversion. Understanding CSF dynamics throughout the development of hydrocephalus is crucial to identify prognostic markers to estimate benefit/risk to shunts. OBJECTIVE To explore the cerebral aqueduct CSF flow dynamics with phase-contrast magnetic resonance imaging (MRI) in a novel rodent model of adult chronic communicating hydrocephalus. METHODS Kaolin was injected into the subarachnoid space at the convexities in Sprague-Dawley adult rats. 11.7-T Bruker MRI was used to acquire T2-weighted images for anatomic identification and phase-contrast MRI at the cerebral aqueduct. Aqueductal stroke volume (ASV) results were compared with the ventricular volume (VV) at 15, 60, 90, and 120 days. RESULTS Significant ventricular enlargement was found in kaolin-injected animals at all times (P < 0.001). ASV differed between cases and controls/shams at every time point (P = 0.004, 0.001, 0.001, and <0.001 at 15, 60, 90, and 120 days, respectively). After correlation between the ASV and the VV, there was a significant correlation at 15 (P = 0.015), 60 (P = 0.001), 90 (P < 0.001), and 120 days. Moreover, there was a significant positive correlation between the VV expansion and the aqueductal CSF stroke between 15 and 60 days. CONCLUSIONS An initial active phase of rapid ventricular enlargement shows a strong correlation between the expansion of the VV and the increment in the ASV during the first 60 days, followed by a second phase with less ventricular enlargement and heterogeneous behavior in the ASV. Further correlation with complementary data from intracranial pressure and histologic/microstructural brain parenchyma assessments are needed to better understand the ASV variations after 60 days.
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Affiliation(s)
- Tito Vivas-Buitrago
- Department of Neurosurgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA; Department of Neurosurgery, Mayo Clinic Florida, Jacksonville, Florida, USA; School of Medicine, Faculty of Health Sciences, Universidad de Santander UDES, Bucaramanga, Colombia
| | - Armelle Lokossou
- Chimère EA, Research Team for Head & Neck, University of Picardie Jules Verne, Amiens, France
| | - Ignacio Jusué-Torres
- Department of Neurosurgery, Loyola University School of Medicine, Maywood, Illinois, USA
| | | | - Ari M Blitz
- Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Daniel A Herzka
- Department of Biomedical Engineering, Johns Hopkins School of Engineering, Baltimore, Maryland, USA
| | - Jamie Robison
- Department of Neurosurgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Jiadi Xu
- Department of Neurosurgery, Kennedy Krieger Institute, Kirby Research Center for Functional Brain Imaging, Baltimore, Maryland, USA
| | | | - Susumu Mori
- Department of Radiology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA; Department of Neurosurgery, Kennedy Krieger Institute, Kirby Research Center for Functional Brain Imaging, Baltimore, Maryland, USA
| | | | - Olivier Baledént
- Chimère EA, Research Team for Head & Neck, University of Picardie Jules Verne, Amiens, France; Department of Image Processing, Jules Verne University Hospital, Amiens, France
| | - Daniele Rigamonti
- Department of Neurosurgery, Johns Hopkins School of Medicine, Baltimore, Maryland, USA; Department of Neurosurgery, Johns Hopkins Aramco Healthcare, Dhahran, Saudi Arabia.
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19
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Predicting the Aqueductal Cerebrospinal Fluid Pulse: A Statistical Approach. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9102131] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The cerebrospinal fluid (CSF) pulse in the Aqueduct of Sylvius (aCSF pulse) is often used to evaluate structural changes in the brain. Here we present a novel application of the general linear model (GLM) to predict the motion of the aCSF pulse. MR venography was performed on 13 healthy adults (9 female and 4 males—mean age = 33.2 years). Flow data was acquired from the arterial, venous and CSF vessels in the neck (C2/C3 level) and from the AoS. Regression analysis was undertaken to predict the motion of the aCSF pulse using the cervical flow rates as predictor variables. The relative contribution of these variables to predicting aCSF flow rate was assessed using a relative weights method, coupled with an ANOVA. Analysis revealed that the aCSF pulse could be accurately predicted (mean (SD) adjusted r2 = 0.794 (0.184)) using the GLM (p < 0.01). Venous flow rate in the neck was the strongest predictor of aCSF pulse (p = 0.001). In healthy individuals, the motion of the aCSF pulse can be predicted using the GLM. This indicates that the intracranial fluidic system has broadly linear characteristics. Venous flow in the neck is the strongest predictor of the aCSF pulse.
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20
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Shanks J, Markenroth Bloch K, Laurell K, Cesarini KG, Fahlström M, Larsson EM, Virhammar J. Aqueductal CSF Stroke Volume Is Increased in Patients with Idiopathic Normal Pressure Hydrocephalus and Decreases after Shunt Surgery. AJNR Am J Neuroradiol 2019. [PMID: 30792248 DOI: 10.3174/ajnr.a5972 [epub 2019 feb 21]] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Increased CSF stroke volume through the cerebral aqueduct has been proposed as a possible indicator of positive surgical outcome in patients with idiopathic normal pressure hydrocephalus; however, consensus is lacking. In this prospective study, we aimed to compare CSF flow parameters in patients with idiopathic normal pressure hydrocephalus with those in healthy controls and change after shunt surgery and to investigate whether any parameter could predict surgical outcome. MATERIALS AND METHODS Twenty-one patients with idiopathic normal pressure hydrocephalus and 21 age- and sex-matched healthy controls were prospectively included and examined clinically and with MR imaging of the brain. Eighteen patients were treated with shunt implantation and were re-examined clinically and with MR imaging the day before the operation and 3 months postoperatively. All MR imaging scans included a phase-contrast sequence. RESULTS The median aqueductal CSF stroke volume was significantly larger in patients compared with healthy controls (103.5 μL; interquartile range, 69.8-142.8 μL) compared with 62.5 μL (interquartile range, 58.3-73.8 μL; P < .01) and was significantly reduced 3 months after shunt surgery from 94.8 μL (interquartile range, 81-241 μL) to 88 μL (interquartile range, 51.8-173.3 μL; P < .05). Net flow in the caudocranial direction (retrograde) was present in 11/21 patients and in 10/21 controls. Peak flow and net flow did not differ between patients and controls. There were no correlations between any CSF flow parameters and surgical outcomes. CONCLUSIONS Aqueductal CSF stroke volume was increased in patients with idiopathic normal pressure hydrocephalus and decreased after shunt surgery, whereas retrograde aqueductal net flow did not seem to be specific for patients with idiopathic normal pressure hydrocephalus. On the basis of the results, the usefulness of CSF flow parameters to predict outcome after shunt surgery seem to be limited.
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Affiliation(s)
- J Shanks
- From the Departments of Surgical Sciences and Radiology (J.S., M.F., E.-M.L.)
| | - K Markenroth Bloch
- Lund University Bioimaging Center (K.M.B.), Lund University, Lund, Sweden
| | - K Laurell
- Department of Pharmacology and Clinical Neuroscience (K.L.), Umeå University, Umeå, Sweden
| | | | - M Fahlström
- From the Departments of Surgical Sciences and Radiology (J.S., M.F., E.-M.L.)
| | - E-M Larsson
- From the Departments of Surgical Sciences and Radiology (J.S., M.F., E.-M.L.)
| | - J Virhammar
- Neuroscience and Neurology (J.V.), Uppsala University, Uppsala, Sweden
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21
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Shanks J, Markenroth Bloch K, Laurell K, Cesarini KG, Fahlström M, Larsson EM, Virhammar J. Aqueductal CSF Stroke Volume Is Increased in Patients with Idiopathic Normal Pressure Hydrocephalus and Decreases after Shunt Surgery. AJNR Am J Neuroradiol 2019; 40:453-459. [PMID: 30792248 DOI: 10.3174/ajnr.a5972] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 12/31/2018] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Increased CSF stroke volume through the cerebral aqueduct has been proposed as a possible indicator of positive surgical outcome in patients with idiopathic normal pressure hydrocephalus; however, consensus is lacking. In this prospective study, we aimed to compare CSF flow parameters in patients with idiopathic normal pressure hydrocephalus with those in healthy controls and change after shunt surgery and to investigate whether any parameter could predict surgical outcome. MATERIALS AND METHODS Twenty-one patients with idiopathic normal pressure hydrocephalus and 21 age- and sex-matched healthy controls were prospectively included and examined clinically and with MR imaging of the brain. Eighteen patients were treated with shunt implantation and were re-examined clinically and with MR imaging the day before the operation and 3 months postoperatively. All MR imaging scans included a phase-contrast sequence. RESULTS The median aqueductal CSF stroke volume was significantly larger in patients compared with healthy controls (103.5 μL; interquartile range, 69.8-142.8 μL) compared with 62.5 μL (interquartile range, 58.3-73.8 μL; P < .01) and was significantly reduced 3 months after shunt surgery from 94.8 μL (interquartile range, 81-241 μL) to 88 μL (interquartile range, 51.8-173.3 μL; P < .05). Net flow in the caudocranial direction (retrograde) was present in 11/21 patients and in 10/21 controls. Peak flow and net flow did not differ between patients and controls. There were no correlations between any CSF flow parameters and surgical outcomes. CONCLUSIONS Aqueductal CSF stroke volume was increased in patients with idiopathic normal pressure hydrocephalus and decreased after shunt surgery, whereas retrograde aqueductal net flow did not seem to be specific for patients with idiopathic normal pressure hydrocephalus. On the basis of the results, the usefulness of CSF flow parameters to predict outcome after shunt surgery seem to be limited.
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Affiliation(s)
- J Shanks
- From the Departments of Surgical Sciences and Radiology (J.S., M.F., E.-M.L.)
| | - K Markenroth Bloch
- Lund University Bioimaging Center (K.M.B.), Lund University, Lund, Sweden
| | - K Laurell
- Department of Pharmacology and Clinical Neuroscience (K.L.), Umeå University, Umeå, Sweden
| | | | - M Fahlström
- From the Departments of Surgical Sciences and Radiology (J.S., M.F., E.-M.L.)
| | - E-M Larsson
- From the Departments of Surgical Sciences and Radiology (J.S., M.F., E.-M.L.)
| | - J Virhammar
- Neuroscience and Neurology (J.V.), Uppsala University, Uppsala, Sweden
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22
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Hamilton RB, Scalzo F, Baldwin K, Dorn A, Vespa P, Hu X, Bergsneider M. Opposing CSF hydrodynamic trends found in the cerebral aqueduct and prepontine cistern following shunt treatment in patients with normal pressure hydrocephalus. Fluids Barriers CNS 2019; 16:2. [PMID: 30665428 PMCID: PMC6341759 DOI: 10.1186/s12987-019-0122-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Accepted: 01/11/2019] [Indexed: 01/22/2023] Open
Abstract
Background This study investigated cerebrospinal fluid (CSF) hydrodynamics using cine phase-contrast MRI in the cerebral aqueduct and the prepontine cistern between three distinct groups: pre-shunt normal pressure hydrocephalus (NPH) patients, post-shunt NPH patients, and controls. We hypothesized that the hyperdynamic flow of CSF through the cerebral aqueduct seen in NPH patients was due to a reduction in cisternal CSF volume buffering. Both hydrodynamic (velocity, flow, stroke volume) and peak flow latency (PFL) parameters were investigated. Methods Scans were conducted on 30 pre-treatment patients ranging in age from 58 to 88 years along with an additional 12 controls. Twelve patients also received scans following either ventriculoatrial (VA) or ventriculoperitoneal (VP) shunt treatment (9 VP, 3 VA), ranging in age from 74 to 89 years with a mean follow up time of 6 months. Results Significant differences in area, velocity, flow, and stroke volume for the cerebral aqueduct were found between the pre-treatment NPH group and the healthy controls. Shunting caused a significant decrease in both caudal and cranial mean flow and stroke volume in the cerebral aqueduct. No significant changes were found in the prepontine cistern between the pre-treatment group and healthy controls. For the PFL, no significant differences were seen in the cerebral aqueduct between any of the three groups; however, the prepontine cistern PFL was significantly decreased in the pre-treatment NPH group when compared to the control group. Conclusions Although several studies have quantified the changes in aqueductal flow between hydrocephalic groups and controls, few studies have investigated prepontine cistern flow. Our study was the first to investigate both regions in the same patients for NPH pre- and post- treatment. Following shunt treatment, the aqueductal CSF metrics decreased toward control values, while the prepontine cistern metrics trended up (not significantly) from the normal values established in this study. The opposing trend of the two locations suggests a redistribution of CSF pulsatility in NPH patients. Furthermore, the significantly decreased latency of the prepontine cisternal CSF flow suggests additional evidence for CSF pulsatility dysfunction.
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Affiliation(s)
- Robert B Hamilton
- Neural Systems and Dynamics Laboratory, Department of Neurosurgery, The David Geffen School of Medicine, University of California-Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA.,Biomedical Engineering Graduate Program, Henry Samueli School of Engineering and Applied Science, University of California-Los Angeles, 7400 Boelter Hall, Los Angeles, CA, 90095, USA.,Neural Analytics, Inc., 2440 S Sepulveda Blvd, Suite 115, Los Angeles, CA, 90064, USA
| | - Fabien Scalzo
- Neural Systems and Dynamics Laboratory, Department of Neurosurgery, The David Geffen School of Medicine, University of California-Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA.,Neural Analytics, Inc., 2440 S Sepulveda Blvd, Suite 115, Los Angeles, CA, 90064, USA
| | - Kevin Baldwin
- Neural Systems and Dynamics Laboratory, Department of Neurosurgery, The David Geffen School of Medicine, University of California-Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA
| | - Amber Dorn
- Neural Analytics, Inc., 2440 S Sepulveda Blvd, Suite 115, Los Angeles, CA, 90064, USA.
| | - Paul Vespa
- The David Geffen School of Medicine, University of California-Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA
| | - Xiao Hu
- Neural Systems and Dynamics Laboratory, Department of Neurosurgery, The David Geffen School of Medicine, University of California-Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA.,Biomedical Engineering Graduate Program, Henry Samueli School of Engineering and Applied Science, University of California-Los Angeles, 7400 Boelter Hall, Los Angeles, CA, 90095, USA
| | - Marvin Bergsneider
- Neural Systems and Dynamics Laboratory, Department of Neurosurgery, The David Geffen School of Medicine, University of California-Los Angeles, 10833 Le Conte Ave, Los Angeles, CA, 90095, USA.,Biomedical Engineering Graduate Program, Henry Samueli School of Engineering and Applied Science, University of California-Los Angeles, 7400 Boelter Hall, Los Angeles, CA, 90095, USA
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23
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Lindstrøm EK, Ringstad G, Mardal KA, Eide PK. Cerebrospinal fluid volumetric net flow rate and direction in idiopathic normal pressure hydrocephalus. NEUROIMAGE-CLINICAL 2018; 20:731-741. [PMID: 30238917 PMCID: PMC6154456 DOI: 10.1016/j.nicl.2018.09.006] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 09/06/2018] [Accepted: 09/11/2018] [Indexed: 12/11/2022]
Abstract
The aim of the present study was to examine cerebrospinal fluid (CSF) volumetric net flow rate and direction at the cranio-cervical junction (CCJ) and cerebral aqueduct in individuals with idiopathic normal pressure hydrocephalus (iNPH) using cardiac-gated phase-contrast magnetic resonance imaging (PC-MRI). An in-depth, pixel-by-pixel analysis of regions of interest from the CCJ and cerebral aqueduct, respectively, was done in 26 iNPH individuals, and in 4 healthy subjects for validation purposes. Results from patients were compared with over-night measurements of static and pulsatile intracranial pressure (ICP). In iNPH, CSF net flow at CCJ was cranially directed in 17/22 as well as in 4/4 healthy subjects. Estimated daily CSF volumetric net flow rate at CCJ was 6.9 ± 9.9 L/24 h in iNPH patients and 4.5 ± 5.0 L/24 h in healthy individuals. Within the cerebral aqueduct, the CSF net flow was antegrade in 7/21 iNPH patients and in 4/4 healthy subjects, while it was retrograde (i.e. towards ventricles) in 14/21 iNPH patients. Estimated daily CSF volumetric net flow rate in cerebral aqueduct was 1.1 ± 2.2 L/24 h in iNPH while 295 ± 53 mL/24 h in healthy individuals. Magnitude of cranially directed CSF net flow in cerebral aqueduct was highest in iNPH individuals with signs of impaired intracranial compliance. The study results indicate CSF flow volumes and direction that are profoundly different from previously assumed. We hypothesize that spinal CSF formation may serve to buffer increased demand for CSF flow through the glymphatic system during sleep and during deep inspiration to compensate for venous outflow.
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Affiliation(s)
- Erika Kristina Lindstrøm
- Department of Mathematics, Faculty of Mathematics and Natural Sciences, University of Oslo, Norway
| | - Geir Ringstad
- Division of Radiology and Nuclear Medicine, Department of Radiology, Oslo University Hospital - Rikshospitalet, Oslo, Norway; Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Kent-Andre Mardal
- Department of Mathematics, Faculty of Mathematics and Natural Sciences, University of Oslo, Norway; Department of Numerical Analysis and Scientific Computing, Simula Research Laboratory, Oslo, Norway
| | - Per Kristian Eide
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway; Department of Neurosurgery, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
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Evaluation of the patency of endoscopic third ventriculostomy using phase contrast MRI-CSF flowmetry as diagnostic approach. THE EGYPTIAN JOURNAL OF RADIOLOGY AND NUCLEAR MEDICINE 2018. [DOI: 10.1016/j.ejrnm.2018.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Spijkerman JM, Geurts LJ, Siero JCW, Hendrikse J, Luijten PR, Zwanenburg JJM. Phase contrast MRI measurements of net cerebrospinal fluid flow through the cerebral aqueduct are confounded by respiration. J Magn Reson Imaging 2018; 49:433-444. [PMID: 29741818 PMCID: PMC6519345 DOI: 10.1002/jmri.26181] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 04/19/2018] [Indexed: 11/15/2022] Open
Abstract
Background Net cerebrospinal fluid (CSF) flow through the cerebral aqueduct may serve as a marker of CSF production in the lateral ventricles, and changes that occur with aging and in disease. Purpose To investigate the confounding influence of the respiratory cycle on net CSF flow and stroke volume measurements. Study Type Cross‐sectional study. Subjects Twelve young, healthy subjects (seven male, age range 19–39 years, average age 28.3 years). Field Strength/Sequence Phase contrast MRI (PC‐MRI) measurements were performed at 7T, with and without respiratory gating on expiration and on inspiration. All measurements were repeated. Assessment Net CSF flow and stroke volume in the aqueduct, over the cardiac cycle, was determined. Statistical Tests Repeatability was determined using the intraclass correlation coefficient (ICC) and linear regression analysis between the repeated measurements. Repeated measures analysis of variance (ANOVA) was performed to compare the measurements during inspiration/expiration/no gating. Linear regression analysis was performed between the net CSF flow difference (inspiration minus expiration) and stroke volume. Results Net CSF flow (average ± standard deviation) was 0.64 ± 0.32 mL/min (caudal) during expiration, 0.12 ± 0.49 mL/min (cranial) during inspiration, and 0.31 ± 0.18 mL/min (caudal) without respiratory gating. Respiratory gating did not affect stroke volume measurements (41 ± 18, 42 ± 19, 42 ± 19 μL/cycle for expiration, no respiratory gating and inspiration, respectively). Repeatability was best during inspiration (ICC = 0.88/0.56/–0.31 for gating on inspiration/expiration/no gating). A positive association was found between average stroke volume and net flow difference between inspiration and expiration (R = 0.678/0.605, P = 0.015/0.037 for the first/second repeated measurement). Data Conclusion Measured net CSF flow is confounded by respiration effects. Therefore, net CSF flow measurements with PC‐MRI cannot in isolation be directly linked to CSF production. Level of Evidence: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:433–444.
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Affiliation(s)
- Jolanda M Spijkerman
- Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Lennart J Geurts
- Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Jeroen C W Siero
- Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands.,Spinoza Center for Neuroimaging, Amsterdam, Netherlands
| | - Jeroen Hendrikse
- Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Peter R Luijten
- Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Jaco J M Zwanenburg
- Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands
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The Liebau phenomenon: a translational approach to new paradigms of CSF circulation and related flow disturbances. Childs Nerv Syst 2018; 34:227-233. [PMID: 29124390 DOI: 10.1007/s00381-017-3653-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 10/30/2017] [Indexed: 10/18/2022]
Abstract
PURPOSE The aim of the study is to provide a comparison between Liebau's effect, underlying the working principles of impedance pumps, and the cerebrospinal fluid (CSF) circulation. METHODS Gerhard Liebau was a cardiologist with a specific interest in severe aortic regurgitation. Such interest drew his scientific attention to the flow-driven efficiency of valveless pumps. During one of his experiments, he assembled two rubber tubes of different sizes and documented how water could be aspirated against gravity when the tube of larger diameter underwent rhythmic compression. He subsequently tested an elastic tube connected to glass pipes of the same size on both ends, immersed in a water bucket. When the elastic tube was periodically pumped with a finger, a net flow could be observed in both directions; depending on the pumping site on the elastic tube, the flow was directed towards the most closely connected glass tube. The principles of a hydraulic system of different elasticity and compliance were also recently applied to the physiology and fluid dynamics of embryonic hearts. RESULTS Impedance pumps and the CSF dynamics model are both valveless systems and can both be activated by the effects of the cardiac cycle. The novel hydraulic model of impedance pumps was the foundation for the development of modern valveless micropumps and contributes to explain how the embryonic valveless tubular heart is capable of generating blood flow. CONCLUSIONS Liebau's effect and the mechanism of impedance pumps can enlighten some of the aspects of CSF dynamics and related flow disturbances.
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Kang YS, Park EK, Kim JS, Kim DS, Thomale UW, Shim KW. Efficacy of endoscopic third ventriculostomy in old aged patients with normal pressure hydrocephalus. Neurol Neurochir Pol 2017; 52:29-34. [PMID: 29103634 DOI: 10.1016/j.pjnns.2017.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 09/16/2017] [Accepted: 10/13/2017] [Indexed: 10/18/2022]
Abstract
Normal pressure hydrocephalus (NPH) is a chronic disorder caused by interrupted CSF absorption or flow. Generally, shunt placement is first option for NPH treatment. Due to complications of ventriculo-peritoneal (VP) shunt placement, endoscopic third ventriculostomy (ETV) can be considered as an alternative treatment option. Here we report the efficacy of ETV especially in old aged patients with normal pressure hydrocephalus. Total 21 old aged patients with communicating hydrocephalus with opening pressure, measured via lumbar puncture, less than 20cm H2O underwent ETV. 15 patients had primary/idiopathic NPH and 6 patients had secondary NPH. All patients were studied with a MRI to observe the flow void at aqueduct and the fourth ventricle outflow. And all of them underwent ETV. In a group with peak velocity was higher than 5cm/s, nine patients (75%) were evaluated was 'favorable' and three of them (25%) was scored 'poor'. In another group with peak velocity less than 5cm/s, three of them were scored 'poor' and two of them were scored 'stable'. None of them was evaluated as 'favorable'. We also evaluated the outcomes according to etiology: 12 patients (80% of the patients with primary NPH) were evaluated with 'favorable' after ETV treatment. Two patients (13.3%) were as 'stable'. And one patient was as 'poor' evaluated. Five patients (83.3%) among patients with secondary NPH were as 'poor' evaluated and one of them was stable and no patient was as 'favorable' evaluated. 4 patients, which was as 'poor' evaluated in the group with the secondary NPH, underwent additional VP shunt implantation. Overall, the outcomes of the group with the idiopathic NPH after ETV treatment were more favorable than of the group with the secondary NPH. Our study suggest that ETV can be effective for selected elderly patients with primary/idiopathic NPH, when they satisfy criteria including positive aqueduct flow void on T2 Sagittal MRI and the aqueductal peak velocity, which is greater than 5cm/s on cine MRI.
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Affiliation(s)
- Young Sill Kang
- Department of Neurosurgery, Universitätsmedizin, Mainz, Germany; Division of Pediatric Neurosurgery, Charité Universitätsmedizin, Berlin, Germany
| | - Eun-Kyung Park
- Pediatric Neurosurgery, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Ju-Seong Kim
- Pediatric Neurosurgery, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Dong-Seok Kim
- Pediatric Neurosurgery, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | | | - Kyu-Won Shim
- Pediatric Neurosurgery, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
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Yin LK, Zheng JJ, Zhao L, Hao XZ, Zhang XX, Tian JQ, Zheng K, Yang YM. Reversed aqueductal cerebrospinal fluid net flow in idiopathic normal pressure hydrocephalus. Acta Neurol Scand 2017; 136:434-439. [PMID: 28247411 DOI: 10.1111/ane.12750] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2016] [Indexed: 12/01/2022]
Abstract
OBJECTIVES The changes of CSF flow dynamics in idiopathic normal pressure hydrocephalus (iNPH) are not fully elucidated. Most previous studies took the whole cardiac cycle as a unit. In this work, it is divided into systole and diastole phase and compared between iNPH patients and normal elderly and paid special attention to the change of netflow direction. MATERIALS AND METHODS Twenty iNPH patients according to international guideline and twenty healthy volunteers were included in this study and examined by MRI. Three categories of CSF flow parameters were measured: peak velocity (Vpeak ), stroke volume (SV), and minute flow volume (MinV) covering the whole cycle; peak velocity (Vpeak-s , Vpeak-d ) and flow volume (Vols , Vold ) of the systole and diastole, respectively; net flow. Evans index (EI) was also measured and compared statistically between the two groups. RESULTS EI, Vpeak , SV, MinV, Vols , Vold , and Vpeak-d significantly increased in iNPH group (P<0.05). Vpeak-s of the two groups were not significantly different (P>0.05). The net flow of 16 iNPH patients (16/20) was in the caudo-cranial direction, while 15 volunteers (15/20) were in the opposite direction, which showed statistically significant differences (P=.001). CONCLUSIONS INPH patients present hyperdynamic flow with increased velocity and volume both in systole and diastole phase. Degree of rising in diastole phase exceeds that of systole phase. The resulting reversal of netflow direction may play a key role in the occurrence of ventriculomegaly in iNPH patients.
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Affiliation(s)
- L. K. Yin
- Department of Radiology; Huashan Hospital; Fudan University; Shanghai China
| | - J. J. Zheng
- Department of Neurosurgery; Huashan Hospital; Fudan University; Shanghai China
| | - L. Zhao
- Department of Neurosurgery; The First Affiliated Hospital of Nanjing Medical University; Nanjing China
| | - X. Z. Hao
- Department of Radiology; Huashan Hospital; Fudan University; Shanghai China
| | - X. X. Zhang
- Department of Radiology; Huashan Hospital; Fudan University; Shanghai China
| | - J. Q. Tian
- Department of Radiology; Huashan Hospital; Fudan University; Shanghai China
| | - K. Zheng
- Department of Neurosurgery; Huashan Hospital; Fudan University; Shanghai China
| | - Y. M. Yang
- Department of Radiology; Huashan Hospital; Fudan University; Shanghai China
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Stecco A, Cassarà A, Zuccalà A, Anoaica MB, Genovese E, Car PG, Panzarasa GP, Guzzardi G, Carriero A. Quantitative analysis of cerebrospinal fluid dynamics at phase contrast cine-MRI: predictivity of neurosurgical "Shunt" responsiveness in patients with idiopathic normal pressure hydrocephalus. J Neurosurg Sci 2017; 64:420-426. [PMID: 28869371 DOI: 10.23736/s0390-5616.17.04092-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Aqueductal stroke volume (ACSV) measured by phase-contrast cine (PCC)-MRI has been proposed with controversy as a tool for the selection of patients with normal pressure hydrocephalus (NPH) as candidates for shunt-surgery. The aim of this study was to assess if PCC-MRI scan measurements of ACSV could select properly these patients. METHODS We retrospectively reviewed charts and MRI of 38 shunted patients (72.16±6.16 years). ACSV measurements were performed 7-30 days before shunt and at the first and sixth months after surgery. Normally distributed variables were compared in the two groups (improved/unimproved) by t-test for baseline values and with repeated measures analysis of variance. RESULTS Twenty-six patients (68,4%) improved after VPS (mean time of symptom onset was 8.15±7.19 months). Mean preoperative ACSV value was 271.85±143.03, which decreased by 21.6% (mean 213±125.14) at the first month and 40.3% sixth months after VPS (mean 162.15±91.5). Twelve patients (31.6%) did not improve (mean time of symptom onset was 29±5.62 months). Mean preoperative ACSV value was 79.83±31.24, decreased to 8.7% (mean 72.83±28.66) at first month after VPS. 21.2% (mean 62.83±31.12) after six months. We found statistical difference between preoperative ACSV of improved and unimproved patients (P<0.01), onset time of symptoms (P<0.01) and the changes in ACSV after one and six months in both groups (P<0.001). CONCLUSIONS ACSV is useful to stratify patients with NPH after surgery (improved /not improved) suggesting to proceed with serial ACSV measurements before deciding treatment.
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Affiliation(s)
- Alessandro Stecco
- Department of Radiology, Maggiore della Carità Hospital, University of Eastern Piedmont, Novara, Italy -
| | - Alessia Cassarà
- Department of Radiology, Maggiore della Carità Hospital, University of Eastern Piedmont, Novara, Italy
| | - Alberto Zuccalà
- Department of Radiology, Maggiore della Carità Hospital, University of Eastern Piedmont, Novara, Italy
| | - Mihaela B Anoaica
- Department of Radiology, Maggiore della Carità Hospital, University of Eastern Piedmont, Novara, Italy
| | - Egidio Genovese
- Department of Radiology, Maggiore della Carità Hospital, University of Eastern Piedmont, Novara, Italy
| | - Pier G Car
- Department of Neurosurgery, Maggiore della Carità Hospital, University of Eastern Piedmont, Novara, Italy
| | - Gabriele P Panzarasa
- Department of Neurosurgery, Maggiore della Carità Hospital, University of Eastern Piedmont, Novara, Italy
| | - Giuseppe Guzzardi
- Department of Radiology, Maggiore della Carità Hospital, University of Eastern Piedmont, Novara, Italy
| | - Alessandro Carriero
- Department of Radiology, Maggiore della Carità Hospital, University of Eastern Piedmont, Novara, Italy
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Intracranial volumetric changes govern cerebrospinal fluid flow in the Aqueduct of Sylvius in healthy adults. Biomed Signal Process Control 2017. [DOI: 10.1016/j.bspc.2017.03.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Coles JA, Myburgh E, Brewer JM, McMenamin PG. Where are we? The anatomy of the murine cortical meninges revisited for intravital imaging, immunology, and clearance of waste from the brain. Prog Neurobiol 2017; 156:107-148. [PMID: 28552391 DOI: 10.1016/j.pneurobio.2017.05.002] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 04/25/2017] [Accepted: 05/08/2017] [Indexed: 12/15/2022]
Abstract
Rapid progress is being made in understanding the roles of the cerebral meninges in the maintenance of normal brain function, in immune surveillance, and as a site of disease. Most basic research on the meninges and the neural brain is now done on mice, major attractions being the availability of reporter mice with fluorescent cells, and of a huge range of antibodies useful for immunocytochemistry and the characterization of isolated cells. In addition, two-photon microscopy through the unperforated calvaria allows intravital imaging of the undisturbed meninges with sub-micron resolution. The anatomy of the dorsal meninges of the mouse (and, indeed, of all mammals) differs considerably from that shown in many published diagrams: over cortical convexities, the outer layer, the dura, is usually thicker than the inner layer, the leptomeninx, and both layers are richly vascularized and innervated, and communicate with the lymphatic system. A membrane barrier separates them and, in disease, inflammation can be localized to one layer or the other, so experimentalists must be able to identify the compartment they are studying. Here, we present current knowledge of the functional anatomy of the meninges, particularly as it appears in intravital imaging, and review their role as a gateway between the brain, blood, and lymphatics, drawing on information that is scattered among works on different pathologies.
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Affiliation(s)
- Jonathan A Coles
- Centre for Immunobiology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, Sir Graeme Davis Building, University of Glasgow, Glasgow, G12 8TA, United Kingdom.
| | - Elmarie Myburgh
- Centre for Immunology and Infection Department of Biology, University of York, Wentworth Way, Heslington, York YO10 5DD, United Kingdom
| | - James M Brewer
- Centre for Immunobiology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, Sir Graeme Davis Building, University of Glasgow, Glasgow, G12 8TA, United Kingdom
| | - Paul G McMenamin
- Department of Anatomy & Developmental Biology, School of Biomedical and Psychological Sciences and Monash Biomedical Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, 10 Chancellor's Walk, Clayton, Victoria, 3800, Australia
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Qvarlander S, Ambarki K, Wåhlin A, Jacobsson J, Birgander R, Malm J, Eklund A. Cerebrospinal fluid and blood flow patterns in idiopathic normal pressure hydrocephalus. Acta Neurol Scand 2017; 135:576-584. [PMID: 27388230 DOI: 10.1111/ane.12636] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2016] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Increased aqueduct cerebrospinal fluid (CSF) flow pulsatility and, recently, a reversed CSF flow in the aqueduct have been suggested as hallmarks of idiopathic normal pressure hydrocephalus (INPH). However, these findings have not been adequately confirmed. Our objective was to investigate the flow of blood and CSF in INPH, as compared to healthy elderly, in order to clarify which flow parameters are related to the INPH pathophysiology. MATERIALS AND METHODS Sixteen INPH patients (73 years) and 35 healthy subjects (72 years) underwent phase-contrast magnetic resonance imaging (MRI). Measurements included aqueduct and cervical CSF flow, total arterial inflow (tCBF; i.e. carotid + vertebral arteries), and internal jugular vein flow. Flow pulsatility, net flow, and flow delays were compared (multiple linear regression, correcting for sex and age). RESULTS Aqueduct stroke volume was higher in INPH than healthy (148±95 vs 90±50 mL, P<.05). Net aqueduct CSF flow was similar in magnitude and direction. The cervical CSF stroke volume was lower (P<.05). The internal carotid artery net flow was lower in INPH (P<.05), although tCBF was not. No differences were found in internal jugular vein flow or flow delays. CONCLUSIONS The typical flow of blood and CSF in INPH was mainly characterized by increased CSF pulsatility in the aqueduct and reduced cervical CSF pulsatility. The direction of mean net aqueduct CSF flow was from the third to the fourth ventricle. Our findings may reflect the altered distribution of intracranial CSF volume in INPH, although the causality of these relationships is unclear.
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Affiliation(s)
- S. Qvarlander
- Department of Radiation Sciences; Umeå University; Umeå Sweden
- Centre for Biomedical Engineering and Physics; Umeå University; Umeå Sweden
| | - K. Ambarki
- Department of Radiation Sciences; Umeå University; Umeå Sweden
- Centre for Biomedical Engineering and Physics; Umeå University; Umeå Sweden
| | - A. Wåhlin
- Department of Radiation Sciences; Umeå University; Umeå Sweden
- Umeå Centre for Functional Brain Imaging; Umeå University; Umeå Sweden
| | - J. Jacobsson
- Department of Pharmacology and Clinical Neuroscience; Umeå University; Umeå Sweden
| | - R. Birgander
- Department of Radiation Sciences; Umeå University; Umeå Sweden
| | - J. Malm
- Department of Pharmacology and Clinical Neuroscience; Umeå University; Umeå Sweden
| | - A. Eklund
- Department of Radiation Sciences; Umeå University; Umeå Sweden
- Centre for Biomedical Engineering and Physics; Umeå University; Umeå Sweden
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Oner Z, Sagіr Kahraman A, Kose E, Oner S, Kavaklі A, Cay M, Ozbag D. Quantitative Evaluation of Normal Aqueductal Cerebrospinal Fluid Flow Using Phase-Contrast Cine MRI According to Age and Sex. Anat Rec (Hoboken) 2016; 300:549-555. [PMID: 27863121 DOI: 10.1002/ar.23514] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 09/27/2016] [Accepted: 09/30/2016] [Indexed: 11/06/2022]
Abstract
The aim of this study was cerebrospinal fluid (CSF) flow quantification in the cerebral aqueduct using phase-contrast cine magnetic resonance ımaging (PCC-MRI) according to both sexes and three different age groups to obtain normative data. Seventy two volunteers with no cerebral pathology were included in this study. Subjects were divided into three age groups: 20-34 years, 35-49 years, and 50-65 years including equal gender groups. CSF flow's quantitatively evaluation was performed with images that were obtained by 1.5 T Magnetic Resonance (MR) unit from cerebral aqueduct level on the semi-axial plan. Between groups, peak velocity (cm sec-1 ), average velocity (cm/s), forward volume (mL), reverse volume (mL), net forward volume (mL), and average flow over range (ml/min) values of current flowing through aqueduct and average aqueductal areas were compared. There were no statistically significant differences in CSF flow parameters among different age groups and between sexes (P > 0.05). There was a statistically significant difference in average cerebral aqueduct area between the age group of 50-65 years and the other age groups (P = 0.002). The average aqueductal area was higher in the age group of 50-65 years. Normal aqueductal CSF flow parameters evaluated with PCC-MRI don't show a significant difference by age and sex. We have achieved the lower and upper values of these parameters would be useful in future clinical studies. The size of aqueductal area may also be explained by atrophy-dependent ventricular system dilatation in the elderly. Anat Rec, 300:549-555, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Zulal Oner
- Department of Anatomy, Karabük University, Karabük, Turkey
| | | | - Evren Kose
- Department of Anatomy, İnönü University, Malatya, Turkey
| | - Serkan Oner
- Department of Radiology, Karabük University, Karabük, Turkey
| | - Ahmet Kavaklі
- Department of Anatomy, Fırat University, Elazığ, Turkey
| | - Mahmut Cay
- Department of Anatomy, İnönü University, Malatya, Turkey
| | - Davut Ozbag
- Department of Anatomy, İnönü University, Malatya, Turkey
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Hladky SB, Barrand MA. Fluid and ion transfer across the blood-brain and blood-cerebrospinal fluid barriers; a comparative account of mechanisms and roles. Fluids Barriers CNS 2016; 13:19. [PMID: 27799072 PMCID: PMC5508927 DOI: 10.1186/s12987-016-0040-3] [Citation(s) in RCA: 156] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 09/01/2016] [Indexed: 12/24/2022] Open
Abstract
The two major interfaces separating brain and blood have different primary roles. The choroid plexuses secrete cerebrospinal fluid into the ventricles, accounting for most net fluid entry to the brain. Aquaporin, AQP1, allows water transfer across the apical surface of the choroid epithelium; another protein, perhaps GLUT1, is important on the basolateral surface. Fluid secretion is driven by apical Na+-pumps. K+ secretion occurs via net paracellular influx through relatively leaky tight junctions partially offset by transcellular efflux. The blood-brain barrier lining brain microvasculature, allows passage of O2, CO2, and glucose as required for brain cell metabolism. Because of high resistance tight junctions between microvascular endothelial cells transport of most polar solutes is greatly restricted. Because solute permeability is low, hydrostatic pressure differences cannot account for net fluid movement; however, water permeability is sufficient for fluid secretion with water following net solute transport. The endothelial cells have ion transporters that, if appropriately arranged, could support fluid secretion. Evidence favours a rate smaller than, but not much smaller than, that of the choroid plexuses. At the blood-brain barrier Na+ tracer influx into the brain substantially exceeds any possible net flux. The tracer flux may occur primarily by a paracellular route. The blood-brain barrier is the most important interface for maintaining interstitial fluid (ISF) K+ concentration within tight limits. This is most likely because Na+-pumps vary the rate at which K+ is transported out of ISF in response to small changes in K+ concentration. There is also evidence for functional regulation of K+ transporters with chronic changes in plasma concentration. The blood-brain barrier is also important in regulating HCO3- and pH in ISF: the principles of this regulation are reviewed. Whether the rate of blood-brain barrier HCO3- transport is slow or fast is discussed critically: a slow transport rate comparable to those of other ions is favoured. In metabolic acidosis and alkalosis variations in HCO3- concentration and pH are much smaller in ISF than in plasma whereas in respiratory acidosis variations in pHISF and pHplasma are similar. The key similarities and differences of the two interfaces are summarized.
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Affiliation(s)
- Stephen B. Hladky
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD UK
| | - Margery A. Barrand
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD UK
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Yousef MI, Abd El Mageed AE, Yassin AEN, Shaaban MH. Use of cerebrospinal fluid flow rates measured by phase-contrast MR to differentiate normal pressure hydrocephalus from involutional brain changes. THE EGYPTIAN JOURNAL OF RADIOLOGY AND NUCLEAR MEDICINE 2016. [DOI: 10.1016/j.ejrnm.2016.04.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Ringstad G, Emblem KE, Eide PK. Phase-contrast magnetic resonance imaging reveals net retrograde aqueductal flow in idiopathic normal pressure hydrocephalus. J Neurosurg 2015; 124:1850-7. [PMID: 26636385 DOI: 10.3171/2015.6.jns15496] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
OBJECT The objective of this study was to assess the net aqueductal stroke volume (ASV) and CSF aqueductal flow rate derived from phase-contrast MRI (PC-MRI) in patients with probable idiopathic normal pressure hydrocephalus (iNPH) before and after ventriculoperitoneal shunt surgery, and to compare observations with intracranial pressure (ICP) scores. METHODS PC-MRI at the level of the sylvian aqueduct was undertaken in patients undergoing assessment for probable iNPH. Aqueductal flow in the craniocaudal direction was defined as positive, or antegrade flow, and net ASV was calculated by subtracting retrograde from antegrade aqueductal flow. Aqueductal flow rate per minute was calculated by multiplying net ASV by heart rate. During the same hospital admission, clinical examination was performed using NPH score and overnight continuous ICP monitoring. Twelve patients were followed prospectively 12 months after shunt placement with clinical assessment and a second PC-MRI. The study also included 2 healthy controls. RESULTS Among 21 patients examined for iNPH, 17 (81%) received a shunt (shunt group), and 4 were treated conservatively (conservative group). Among the patients with shunts, a clinical improvement was observed in 16 (94%) of the 17. Net ASV was negative in 16 (76%) of 21 patients before shunt placement and in 5 (42%) of 12 patients after shunt placement, and increased from a median of -5 μl (range -175 to 27 μl) to a median of 1 μl (range -61 to 30 μl; p = 0.04). Among the 12 patients with PC-MRI after shunt placement, 11 were shunt responders, and in 9 of these 11 either a reduced magnitude of retrograde aqueductal flow, or a complete reversal from retrograde to antegrade flow, occurred. Net ASV was significantly lower in the shunt group than in the conservative group (p = 0.01). The aqueductal flow rate increased from -0.56 ml/min (range -12.78 to 0.58 ml/min) to 0.06 ml/min (range -4.51 to 1.93 ml/min; p = 0.04) after shunt placement. CONCLUSIONS In this cohort of patients with iNPH, retrograde net aqueductal flow was observed in 16 (76%) of 21 patients. It was reversed toward the antegrade direction after shunt placement either by magnitude or completely in 9 (75%) of 12 patients examined using PC-MRI both before and after shunt placement (p = 0.04); 11 of the 12 were shunt responders. The study results question previously established concepts with respect to both CSF circulation pathways and CSF formation rate.
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Affiliation(s)
| | | | - Per Kristian Eide
- Department of Neurosurgery, Oslo University Hospital-Rikshospitalet, and.,Faculty of Medicine, University of Oslo, Oslo, Norway
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Ringstad G, Emblem KE, Geier O, Alperin N, Eide PK. Aqueductal Stroke Volume: Comparisons with Intracranial Pressure Scores in Idiopathic Normal Pressure Hydrocephalus. AJNR Am J Neuroradiol 2015; 36:1623-30. [PMID: 25977480 DOI: 10.3174/ajnr.a4340] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 02/11/2015] [Indexed: 01/23/2023]
Abstract
BACKGROUND AND PURPOSE Aqueductal stroke volume from phase-contrast MR imaging has been proposed for predicting shunt response in normal pressure hydrocephalus. However, this biomarker has remained controversial in use and has a lack of validation with invasive intracranial monitoring. We studied how aqueductal stroke volume compares with intracranial pressure scores in the presurgical work-up and clinical score, ventricular volume, and aqueduct area and assessed the patient's response to shunting. MATERIALS AND METHODS Phase-contrast MR imaging was performed in 21 patients with probable idiopathic normal pressure hydrocephalus. Patients were selected for shunting on the basis of pathologically increased intracranial pressure pulsatility. Patients with shunts were offered a second MR imaging after 12 months. Ventricular volume and transverse aqueductal area were calculated, as well as clinical symptom score. RESULTS No correlations between aqueductal stroke volume and preoperative scores of mean intracranial pressure or mean wave amplitudes were observed. Preoperative aqueductal stroke volume was not different between patients with shunts and conservatively treated patients (P = .69) but was correlated with ventricular volume (R = 0.60, P = .004) and aqueductal area (R = 0.58, P = .006) but not with the severity or duration of clinical symptoms. After shunting, aqueductal stroke volume (P = .006) and ventricular volume (P = .002) were reduced. A clinical improvement was seen in 16 of 17 patients who had shunts (94%). CONCLUSIONS Aqueductal stroke volume does not reflect intracranial pressure pulsatility or symptom score, but rather aqueduct area and ventricular volume. The results do not support the use of aqueductal stroke volume for selecting patients for shunting.
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Affiliation(s)
- G Ringstad
- From the Department of Radiology and Nuclear Medicine (G.R.)
| | - K E Emblem
- Intervention Centre (K.E.E., O.G.), Oslo University Hospital-Rikshospitalet, Oslo, Norway
| | - O Geier
- Intervention Centre (K.E.E., O.G.), Oslo University Hospital-Rikshospitalet, Oslo, Norway
| | - N Alperin
- Department of Radiology (N.A.), University of Miami Miller School of Medicine, Miami, Florida
| | - P K Eide
- Department of Neurosurgery (P.K.E.), Oslo University Hospital, Oslo, Norway Faculty of Medicine (P.K.E.), University of Oslo, Oslo, Norway
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Hladky SB, Barrand MA. Mechanisms of fluid movement into, through and out of the brain: evaluation of the evidence. Fluids Barriers CNS 2014; 11:26. [PMID: 25678956 PMCID: PMC4326185 DOI: 10.1186/2045-8118-11-26] [Citation(s) in RCA: 388] [Impact Index Per Article: 38.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 11/21/2014] [Indexed: 01/08/2023] Open
Abstract
Interstitial fluid (ISF) surrounds the parenchymal cells of the brain and spinal cord while cerebrospinal fluid (CSF) fills the larger spaces within and around the CNS. Regulation of the composition and volume of these fluids is important for effective functioning of brain cells and is achieved by barriers that prevent free exchange between CNS and blood and by mechanisms that secrete fluid of controlled composition into the brain and distribute and reabsorb it. Structures associated with this regular fluid turnover include the choroid plexuses, brain capillaries comprising the blood-brain barrier, arachnoid villi and perineural spaces penetrating the cribriform plate. ISF flow, estimated from rates of removal of markers from the brain, has been thought to reflect rates of fluid secretion across the blood-brain barrier, although this has been questioned because measurements were made under barbiturate anaesthesia possibly affecting secretion and flow and because CSF influx to the parenchyma via perivascular routes may deliver fluid independently of blood-brain barrier secretion. Fluid secretion at the blood-brain barrier is provided by specific transporters that generate solute fluxes so creating osmotic gradients that force water to follow. Any flow due to hydrostatic pressures driving water across the barrier soon ceases unless accompanied by solute transport because water movements modify solute concentrations. CSF is thought to be derived primarily from secretion by the choroid plexuses. Flow rates measured using phase contrast magnetic resonance imaging reveal CSF movements to be more rapid and variable than previously supposed, even implying that under some circumstances net flow through the cerebral aqueduct may be reversed with net flow into the third and lateral ventricles. Such reversed flow requires there to be alternative sites for both generation and removal of CSF. Fluorescent tracer analysis has shown that fluid flow can occur from CSF into parenchyma along periarterial spaces. Whether this represents net fluid flow and whether there is subsequent flow through the interstitium and net flow out of the cortex via perivenous routes, described as glymphatic circulation, remains to be established. Modern techniques have revealed complex fluid movements within the brain. This review provides a critical evaluation of the data.
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Affiliation(s)
- Stephen B Hladky
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD UK
| | - Margery A Barrand
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD UK
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Locatelli M, Draghi R, DI Cristofori A, Carrabba G, Zavanone M, Pluderi M, Spagnoli D, Rampini P. Third Ventriculostomy in Late-onset Idiopathic Aqueductal Stenosis Treatment: A Focus on Clinical Presentation and Radiological Diagnosis. Neurol Med Chir (Tokyo) 2014; 54:1014-21. [PMID: 25446383 PMCID: PMC4533356 DOI: 10.2176/nmc.oa.2013-0367] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Endoscopic third ventriculostomy (ETV) is considered the gold standard treatment for obstructive hydrocephalus due to partial or complete obstruction of cerebrospinal fluid (CSF) ventricular pathways caused by mass lesions. However long-term efficacy of this procedure remains controversial as treatment of chronic adult hydrocephalus due to stenosis of Sylvian acqueduct [late-onset idiopathic aqueductal stenosis (LIAS)]. The authors describe clinical presentation, diagnostic investigations in patients affected by LIAS, and define their clinical and radiological outcome after ETV. From January 2003 to December 2008, 13 consecutive LIAS patients treated by ETV were retrospectively reviewed. Pre- and post-operative clinical and radiological findings, including conventional and phase-contrast (PC) cine magnetic resonance imaging (MRI) were investigated. ETV was successfully performed in all patients. Patient's neurological condition improved. No one required a second ETV procedure or shunt implantation. Clinical and radiological results reveal a satisfactory outcome of LIAS patients treated by ETV. At follow-up a clinical improvement could be demonstrated in all cases. Selection criteria of LIAS patients seem to be crucial to obtain satisfactory and long-lasting results. Even in elderly patients with chronic hydrocephalus, ETV can be considered the treatment of choice.
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Affiliation(s)
- Marco Locatelli
- Neurosurgery Unit, Fondazione I.R.C.C.S. "Ca' Granda" Ospedale Maggiore Policlinico
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Brinker T, Stopa E, Morrison J, Klinge P. A new look at cerebrospinal fluid circulation. Fluids Barriers CNS 2014; 11:10. [PMID: 24817998 PMCID: PMC4016637 DOI: 10.1186/2045-8118-11-10] [Citation(s) in RCA: 484] [Impact Index Per Article: 48.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 04/18/2014] [Indexed: 12/11/2022] Open
Abstract
According to the traditional understanding of cerebrospinal fluid (CSF) physiology, the majority of CSF is produced by the choroid plexus, circulates through the ventricles, the cisterns, and the subarachnoid space to be absorbed into the blood by the arachnoid villi. This review surveys key developments leading to the traditional concept. Challenging this concept are novel insights utilizing molecular and cellular biology as well as neuroimaging, which indicate that CSF physiology may be much more complex than previously believed. The CSF circulation comprises not only a directed flow of CSF, but in addition a pulsatile to and fro movement throughout the entire brain with local fluid exchange between blood, interstitial fluid, and CSF. Astrocytes, aquaporins, and other membrane transporters are key elements in brain water and CSF homeostasis. A continuous bidirectional fluid exchange at the blood brain barrier produces flow rates, which exceed the choroidal CSF production rate by far. The CSF circulation around blood vessels penetrating from the subarachnoid space into the Virchow Robin spaces provides both a drainage pathway for the clearance of waste molecules from the brain and a site for the interaction of the systemic immune system with that of the brain. Important physiological functions, for example the regeneration of the brain during sleep, may depend on CSF circulation.
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Affiliation(s)
- Thomas Brinker
- Department of Neurosurgery, The Warren Alpert Medical School of Brown University, Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903, USA
| | - Edward Stopa
- Department of Neurosurgery, The Warren Alpert Medical School of Brown University, Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903, USA
| | - John Morrison
- Department of Neurosurgery, The Warren Alpert Medical School of Brown University, Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903, USA
| | - Petra Klinge
- Department of Neurosurgery, The Warren Alpert Medical School of Brown University, Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903, USA
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Hladky SB, Barrand MA. Mechanisms of fluid movement into, through and out of the brain: evaluation of the evidence. Fluids Barriers CNS 2014. [PMID: 25678956 DOI: 10.1186/10.1186/2045-8118-11-26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023] Open
Abstract
Interstitial fluid (ISF) surrounds the parenchymal cells of the brain and spinal cord while cerebrospinal fluid (CSF) fills the larger spaces within and around the CNS. Regulation of the composition and volume of these fluids is important for effective functioning of brain cells and is achieved by barriers that prevent free exchange between CNS and blood and by mechanisms that secrete fluid of controlled composition into the brain and distribute and reabsorb it. Structures associated with this regular fluid turnover include the choroid plexuses, brain capillaries comprising the blood-brain barrier, arachnoid villi and perineural spaces penetrating the cribriform plate. ISF flow, estimated from rates of removal of markers from the brain, has been thought to reflect rates of fluid secretion across the blood-brain barrier, although this has been questioned because measurements were made under barbiturate anaesthesia possibly affecting secretion and flow and because CSF influx to the parenchyma via perivascular routes may deliver fluid independently of blood-brain barrier secretion. Fluid secretion at the blood-brain barrier is provided by specific transporters that generate solute fluxes so creating osmotic gradients that force water to follow. Any flow due to hydrostatic pressures driving water across the barrier soon ceases unless accompanied by solute transport because water movements modify solute concentrations. CSF is thought to be derived primarily from secretion by the choroid plexuses. Flow rates measured using phase contrast magnetic resonance imaging reveal CSF movements to be more rapid and variable than previously supposed, even implying that under some circumstances net flow through the cerebral aqueduct may be reversed with net flow into the third and lateral ventricles. Such reversed flow requires there to be alternative sites for both generation and removal of CSF. Fluorescent tracer analysis has shown that fluid flow can occur from CSF into parenchyma along periarterial spaces. Whether this represents net fluid flow and whether there is subsequent flow through the interstitium and net flow out of the cortex via perivenous routes, described as glymphatic circulation, remains to be established. Modern techniques have revealed complex fluid movements within the brain. This review provides a critical evaluation of the data.
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Affiliation(s)
- Stephen B Hladky
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD UK
| | - Margery A Barrand
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD UK
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Beggs CB, Magnano C, Shepherd SJ, Marr K, Valnarov V, Hojnacki D, Bergsland N, Belov P, Grisafi S, Dwyer MG, Carl E, Weinstock-Guttman B, Zivadinov R. Aqueductal cerebrospinal fluid pulsatility in healthy individuals is affected by impaired cerebral venous outflow. J Magn Reson Imaging 2013; 40:1215-22. [DOI: 10.1002/jmri.24468] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 09/15/2013] [Indexed: 11/11/2022] Open
Affiliation(s)
- Clive B. Beggs
- Medical Biophysics Laboratory; University of Bradford; Bradford UK
| | - Christopher Magnano
- Buffalo Neuroimaging Analysis Center; University at Buffalo; Buffalo New York USA
| | | | - Karen Marr
- Buffalo Neuroimaging Analysis Center; University at Buffalo; Buffalo New York USA
| | - Vesela Valnarov
- Buffalo Neuroimaging Analysis Center; University at Buffalo; Buffalo New York USA
| | - David Hojnacki
- Jacobs MS Comprehensive and Research Center; University at Buffalo; Buffalo New York USA
| | - Niels Bergsland
- Buffalo Neuroimaging Analysis Center; University at Buffalo; Buffalo New York USA
| | - Pavel Belov
- Buffalo Neuroimaging Analysis Center; University at Buffalo; Buffalo New York USA
| | - Steven Grisafi
- Buffalo Neuroimaging Analysis Center; University at Buffalo; Buffalo New York USA
| | - Michael G. Dwyer
- Medical Biophysics Laboratory; University of Bradford; Bradford UK
| | - Ellen Carl
- Medical Biophysics Laboratory; University of Bradford; Bradford UK
| | | | - Robert Zivadinov
- Buffalo Neuroimaging Analysis Center; University at Buffalo; Buffalo New York USA
- Jacobs MS Comprehensive and Research Center; University at Buffalo; Buffalo New York USA
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43
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Bateman GA. Letter to the Editor: Normal pressure hydrocephalus. J Neurosurg 2013; 119:1075-7. [DOI: 10.3171/2011.2.jns11216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Abstract
Flow compensation, a gradient pulse used for artifact reduction, often used to suppress cerebrospinal fluid (CSF) flow artifacts in spinal magnetic resonance imaging (MRI), can be switched off to make the CSF flow voids within syrinx (syringomyelia) and within aqueduct [normal pressure hydrocephalus (NPH)] more obvious (thus confirming CSF flow). It is a simple method which does not require much time or expertise.
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Affiliation(s)
- Anitha Sen
- Government Medical College, Kottayam, Kerala, India
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45
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Beggs CB. Venous hemodynamics in neurological disorders: an analytical review with hydrodynamic analysis. BMC Med 2013; 11:142. [PMID: 23724917 PMCID: PMC3668302 DOI: 10.1186/1741-7015-11-142] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 02/20/2013] [Indexed: 01/20/2023] Open
Abstract
Venous abnormalities contribute to the pathophysiology of several neurological conditions. This paper reviews the literature regarding venous abnormalities in multiple sclerosis (MS), leukoaraiosis, and normal-pressure hydrocephalus (NPH). The review is supplemented with hydrodynamic analysis to assess the effects on cerebrospinal fluid (CSF) dynamics and cerebral blood flow (CBF) of venous hypertension in general, and chronic cerebrospinal venous insufficiency (CCSVI) in particular.CCSVI-like venous anomalies seem unlikely to account for reduced CBF in patients with MS, thus other mechanisms must be at work, which increase the hydraulic resistance of the cerebral vascular bed in MS. Similarly, hydrodynamic changes appear to be responsible for reduced CBF in leukoaraiosis. The hydrodynamic properties of the periventricular veins make these vessels particularly vulnerable to ischemia and plaque formation.Venous hypertension in the dural sinuses can alter intracranial compliance. Consequently, venous hypertension may change the CSF dynamics, affecting the intracranial windkessel mechanism. MS and NPH appear to share some similar characteristics, with both conditions exhibiting increased CSF pulsatility in the aqueduct of Sylvius.CCSVI appears to be a real phenomenon associated with MS, which causes venous hypertension in the dural sinuses. However, the role of CCSVI in the pathophysiology of MS remains unclear.
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Affiliation(s)
- Clive B Beggs
- Medical Biophysics Laboratory, School of Engineering, Design and Technology, University of Bradford, Bradford, West Yorkshire BD7 1DP, UK.
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External hydrocephalus in infants: six cases with MR venogram and flow quantification correlation. Childs Nerv Syst 2011; 27:2087-96. [PMID: 21833725 DOI: 10.1007/s00381-011-1549-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Accepted: 07/29/2011] [Indexed: 10/17/2022]
Abstract
PURPOSE The cause of external hydrocephalus in infants is largely unknown. However, familial macrocephaly and delayed maturation of the arachnoid granulations are thought to play a part in the idiopathic cases. Secondary cases of external hydrocephalus are associated with hemorrhage, meningitis, and elevated venous pressure. Recently, elevated venous pressure has been shown to be a much more common cause of communicating hydrocephalus in children than previously thought. The purpose of this study is to investigate venous pressure as a cause of external hydrocephalus. METHODS Six children with external hydrocephalus underwent an MRI examination including MR venography and MR flow quantification techniques. A chart review was performed to correlate the clinical findings with the MR findings. Six children with normal head circumferences and growth profile served as controls. RESULTS The net aqueduct flow in both normal and hydrocephalic children was into the ventricles. There was a spectrum of blood flow findings in the infants with hydrocephalus. (1) Those with normal arterial inflow showed venous outflow stenoses or anomalies. (2) Those with normal MR venograms tended to have elevated cerebral blood inflow. CONCLUSIONS The absorption of CSF in infants is into the capillary bed of the deep white matter rather than the arachnoid granulations. Absorption into a capillary bed depends on hydrostatic pressure. Similar to older children with communicating hydrocephalus, the infants in this cohort with external hydrocephalus showed evidence of an elevation in venous pressure. Elevated venous pressure may be a much more common cause of external hydrocephalus than previously recognized.
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Park JH, Park YS, Suk JS, Park SW, Hwang SN, Nam TK, Kim YB, Lee WB. Cerebrospinal fluid pathways from cisterns to ventricles in N-butyl cyanoacrylate-induced hydrocephalic rats. J Neurosurg Pediatr 2011; 8:640-6. [PMID: 22132924 DOI: 10.3171/2011.8.peds1190] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Cerebrospinal fluid typically enters the subarachnoid space from the ventricles via the fourth ventricular foramina. However, there is clinical evidence that CSF also flows in the opposite direction. Ventricular reflux of CSF from a cistern is a well-known phenomenon in radioisotope studies in patients with normal-pressure hydrocephalus. Additionally, the presence of ventricular blood in acute subarachnoid hemorrhage is frequently observed. The goal of this investigation was to examine the potential CSF pathways from cisterns to ventricles. The authors examined pathways in rat models in which they occluded the fourth ventricular outlets and injected a tracer into the subarachnoid space. METHODS The model for acute obstructive hydrocephalus was induced using N-butyl cyanoacrylate (NBCA) in 10 Sprague-Dawley rats. After 3 days, cationized ferritin was infused into the lumbar subarachnoid space to highlight retrograde CSF flow pathways. The animals were sacrificed at 48 hours, and the brains were prepared. The CSF flow pathway was traced by staining the ferritin with ferrocyanide. RESULTS Ferritin was observed in the third ventricle in 7 of 8 rats with hydrocephalus and in the temporal horn of the lateral ventricles in 4 of 8 rats with hydrocephalus. There was no definite staining in the aqueduct, which suggests that the ventricular reflux originated from routes other than through the fourth ventricular outlets. CONCLUSIONS The interfaces between the quadrigeminal cistern and third ventricle and those between the ambient cistern and lateral ventricle appear to be potential sites of CSF reflux from cisterns to ventricles in obstructive hydrocephalus.
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Affiliation(s)
- Jong-Hyuk Park
- Department of Neurosurgery, Chung-Ang University College of Medicine, Seoul, Korea
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Dinçer A, Özek MM. Radiologic evaluation of pediatric hydrocephalus. Childs Nerv Syst 2011; 27:1543-62. [PMID: 21928020 DOI: 10.1007/s00381-011-1559-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 08/09/2011] [Indexed: 01/27/2023]
Abstract
INTRODUCTION The aim of this review is to present the contemporary role of radiology in evaluating pediatric hydrocephalus. Although conventional brain imaging with ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) reveal the degree of ventricular enlargement and often the etiology of the hydrocephalus, the diagnosis and management of hydrocephalus present common problems in pediatric populations. DISCUSSION US, usually sufficient to assess and monitor ventricular size, is used most commonly in preterm infants who have germinal matrix hemorrhages and not able to tolerate transport to the radiology department. Although CT can demonstrate gross dilatation of ventricles, in most cases, it will be necessary to more closely define the nature of the obstruction, either functionally or anatomically. MRI is the best imaging modality to provide such functional and anatomic information. However, since identification of obstructive pathologic processes at any level through the cerebrospinal fluid (CSF) pathway in patients with hydrocephalus is of significant importance because it can change the treatment options, avoiding shunt insertion, a more sophisticated MRI approach is needed instead of obtaining a routine cranial MRI. Furthermore, the outcome after neuroendoscopic procedures is clearly related to patient selection under guidance of neuroimaging. CONCLUSION Therefore, the article focuses mainly on the effective usage of various MRI sequences in both diagnosis and follow-up of pediatric hydrocephalus, such as 3D CISS, cine PC, TSE, and GRE T2* sequences, to be able to investigate all possible obstructive pathology through the CSF pathway and to assess the efficiency of treatment in a standardized way.
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Affiliation(s)
- Alp Dinçer
- Department of Radiology, School of Medicine, Acibadem University, Inonu Cad. Okur Sok. No:21, Kozyatagı, Istanbul 34742, Turkey.
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Magnetic resonance velocity mapping of 3D cerebrospinal fluid flow dynamics in hydrocephalus: preliminary results. Eur Radiol 2011; 22:232-42. [DOI: 10.1007/s00330-011-2247-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 06/21/2011] [Accepted: 07/08/2011] [Indexed: 10/17/2022]
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50
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Penn RD, Basati S, Sweetman B, Guo X, Linninger A. Ventricle wall movements and cerebrospinal fluid flow in hydrocephalus. J Neurosurg 2011; 115:159-64. [PMID: 21275563 DOI: 10.3171/2010.12.jns10926] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The dynamics of fluid flow in normal pressure hydrocephalus (NPH) are poorly understood. Normally, CSF flows out of the brain through the ventricles. However, ventricular enlargement during NPH may be caused by CSF backflow into the brain through the ventricles. A previous study showed this reversal of flow; in the present study, the authors provide additional clinical data obtained in patients with NPH and supplement these data with computer simulations to better understand the CSF flow and ventricular wall displacement and emphasize its clinical implications. METHODS Three NPH patients and 1 patient with aqueductal stenosis underwent cine phase-contrast MR imaging (cine MR imaging) for measurement of CSF flow and ventricle wall movement during the cardiac cycle. These data were compared to data previously obtained in 8 healthy volunteers. The CSF flow measurements were obtained at the outlet of the aqueduct of Sylvius. Calculation of the ventricular wall movement was determined from the complete set of cine MR images obtained axially at the middle of the lateral ventricle. The data were obtained before and after CSF removal with a ventriculoperitoneal shunt with an adjustable valve. To supplement the clinical data, a computational model was used to predict the transmural pressure and flow. RESULTS In healthy volunteers, net CSF aqueductal flow was 1.2 ml/minute in the craniocaudal direction. In patients with NPH, the net CSF flow was in the opposite direction--the caudocranial direction--before shunt placement. After shunting, the magnitude of the abnormal fluid flow decreased or reversed, with the flow resembling the normal flow patterns observed in healthy volunteers. CONCLUSIONS The authors' MR imaging-based measurements of the CSF flow direction and lateral ventricle volume size change and the results of computer modeling of fluid dynamics lead them to conclude that the directional pattern and magnitude of CSF flow in patients with NPH may be an indication of the disease state. This has practical implications for shunt design and understanding the mechanisms that produce hydrocephalus.
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Affiliation(s)
- Richard D Penn
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois 60607-7052, USA.
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