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Burla GKR, Shrestha D, Bowen M, Horvath JD, Martin BA. Evaluating the effect of injection protocols on intrathecal solute dispersion in non-human primates: an in vitro study using a cynomolgus cerebrospinal fluid system. Fluids Barriers CNS 2024; 21:61. [PMID: 39061067 PMCID: PMC11282645 DOI: 10.1186/s12987-024-00556-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 06/16/2024] [Indexed: 07/28/2024] Open
Abstract
BACKGROUND Achieving effective drug delivery to the central nervous system (CNS) remains a challenge for treating neurological disorders. Intrathecal (IT) delivery, which involves direct injection into the cerebrospinal fluid (CSF), presents a promising strategy. Large animal studies are important to assess the safety and efficacy of most drugs and treatments and translate the data to humans. An understanding of the influence of IT injection parameters on solute distribution within the CNS is essential to optimize preclinical research, which would potentially help design human clinical studies. METHODS A three-dimensional (3D) in vitro model of a cynomolgus monkey, based on MRI data, was developed to evaluate the impact of lumbar injection parameters on intrathecal solute dispersion. The parameters evaluated were (a) injection location, (b) bolus volume, (c) flush volume, (d) bolus rate, and (e) flush rate. To simulate the CSF flow within the subarachnoid space (SAS), an idealized CSF flow waveform with both cardiac and respiratory-induced components was input into the model. A solution of fluorescein drug surrogate tracer was administered in the lumbar region of the 3D in vitro model filled with deionized water. After injection of the tracer, the CSF system wide-solute dispersion was imaged using high-resolution cameras every thirty seconds for a duration of three hours. To ensure repeatability each injection protocol was repeated three times. For each protocol, the average spatial-temporal distribution over three hours post-injection, the area under the curve (AUC), and the percent injected dose (%ID) to extra-axial CSF (eaCSF) at three hours were determined. RESULTS The changes to the lumbar injection parameters led to variations in solute distribution along the neuro-axis. Specifically, injection location showed the most impact, enhancing the delivery to the eaCSF up to + 10.5%ID (p = 0.0282) at three hours post-injection. Adding a post-injection flush of 1.5 ml at 1 ml/min increased the solute delivery to the eaCSF by + 6.5%ID (p = 0.0218), while the larger bolus volume resulted in a + 2.3%ID (p = 0.1910) increase. The bolus and flush rates analyzed had minimal, statistically non-significant effects. CONCLUSION These results predict the effects of lumbar injection parameters on solute distribution in the intrathecal space in NHPs. Specifically, the choice of injection location, flush, and bolus volume significantly improved solute delivery to eaCSF. The in vitro NHP CSF model and results offer a system to help predict and optimize IT delivery protocols for pre-clinical NHP studies.
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Affiliation(s)
- Goutham Kumar Reddy Burla
- Department of Chemical and Biological Engineering, University of Idaho, 875 Perimeter Dr. MC1122, Moscow, ID, 83844, USA
| | - Dev Shrestha
- Department of Chemical and Biological Engineering, University of Idaho, 875 Perimeter Dr. MC1122, Moscow, ID, 83844, USA
| | - Mayumi Bowen
- Genentech, Inc., a member of the Roche Group, South San Francisco, CA, USA
| | - Joshua D Horvath
- Genentech, Inc., a member of the Roche Group, South San Francisco, CA, USA
| | - Bryn A Martin
- Department of Chemical and Biological Engineering, University of Idaho, 875 Perimeter Dr. MC1122, Moscow, ID, 83844, USA.
- Alcyone Therapeutics Inc., Lowell, MA, USA.
- Flux Neuroscience, LLC., Troy, ID, USA.
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2
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Hladky SB, Barrand MA. Regulation of brain fluid volumes and pressures: basic principles, intracranial hypertension, ventriculomegaly and hydrocephalus. Fluids Barriers CNS 2024; 21:57. [PMID: 39020364 PMCID: PMC11253534 DOI: 10.1186/s12987-024-00532-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 03/21/2024] [Indexed: 07/19/2024] Open
Abstract
The principles of cerebrospinal fluid (CSF) production, circulation and outflow and regulation of fluid volumes and pressures in the normal brain are summarised. Abnormalities in these aspects in intracranial hypertension, ventriculomegaly and hydrocephalus are discussed. The brain parenchyma has a cellular framework with interstitial fluid (ISF) in the intervening spaces. Framework stress and interstitial fluid pressure (ISFP) combined provide the total stress which, after allowing for gravity, normally equals intracerebral pressure (ICP) with gradients of total stress too small to measure. Fluid pressure may differ from ICP in the parenchyma and collapsed subarachnoid spaces when the parenchyma presses against the meninges. Fluid pressure gradients determine fluid movements. In adults, restricting CSF outflow from subarachnoid spaces produces intracranial hypertension which, when CSF volumes change very little, is called idiopathic intracranial hypertension (iIH). Raised ICP in iIH is accompanied by increased venous sinus pressure, though which is cause and which effect is unclear. In infants with growing skulls, restriction in outflow leads to increased head and CSF volumes. In adults, ventriculomegaly can arise due to cerebral atrophy or, in hydrocephalus, to obstructions to intracranial CSF flow. In non-communicating hydrocephalus, flow through or out of the ventricles is somehow obstructed, whereas in communicating hydrocephalus, the obstruction is somewhere between the cisterna magna and cranial sites of outflow. When normal outflow routes are obstructed, continued CSF production in the ventricles may be partially balanced by outflow through the parenchyma via an oedematous periventricular layer and perivascular spaces. In adults, secondary hydrocephalus with raised ICP results from obvious obstructions to flow. By contrast, with the more subtly obstructed flow seen in normal pressure hydrocephalus (NPH), fluid pressure must be reduced elsewhere, e.g. in some subarachnoid spaces. In idiopathic NPH, where ventriculomegaly is accompanied by gait disturbance, dementia and/or urinary incontinence, the functional deficits can sometimes be reversed by shunting or third ventriculostomy. Parenchymal shrinkage is irreversible in late stage hydrocephalus with cellular framework loss but may not occur in early stages, whether by exclusion of fluid or otherwise. Further studies that are needed to explain the development of hydrocephalus are outlined.
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Affiliation(s)
- Stephen B Hladky
- Department of Pharmacology, Tennis Court Rd, Cambridge, CB2 1PD, UK.
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3
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Malek AM, Beneduce BM, Heilman CB. Endovascular Shunting for Communicating Hydrocephalus Using a Biologically Inspired Transdural Cerebrospinal Fluid Valved eShunt® Implant. Neurosurg Clin N Am 2024; 35:379-387. [PMID: 38782531 DOI: 10.1016/j.nec.2024.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Cerebrospinal fluid (CSF) bathing the central nervous system is produced by brain and choroid plexus within the ventricles for re-absorption into the venous circulation through arachnoid granulations (AG). Communicating hydrocephalus results from disruption of the absorptive process, necessitating surgical catheter-based shunt placement to relieve excess pressure from CSF buildup. Adjustable valve designs and antibiotic impregnation have minimally impacted persistent failure rates and postoperative complications. To confront this challenge, we have developed an innovative endovascular shunt implant biologically inspired from AG function to restore the natural dynamics of CSF drainage while concurrently addressing the predominant factors contributing to conventional shunt malfunction.
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Affiliation(s)
- Adel M Malek
- Department of Neurosurgery, Tufts Medical Center, 800 Washington Street, Proger 7, Boston, MA 02111, USA; CereVasc Inc., 100 1st Avenue, Bldg. 39, Suite 403, Charlestown Navy Yard, Charlestown, MA 02129, USA.
| | - Brandon M Beneduce
- CereVasc Inc., 100 1st Avenue, Bldg. 39, Suite 403, Charlestown Navy Yard, Charlestown, MA 02129, USA
| | - Carl B Heilman
- Department of Neurosurgery, Tufts Medical Center, 800 Washington Street, Proger 7, Boston, MA 02111, USA
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Sriram S, Carstens K, Dewing W, Fiacco TA. Astrocyte regulation of extracellular space parameters across the sleep-wake cycle. Front Cell Neurosci 2024; 18:1401698. [PMID: 38988660 PMCID: PMC11233815 DOI: 10.3389/fncel.2024.1401698] [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: 03/15/2024] [Accepted: 06/07/2024] [Indexed: 07/12/2024] Open
Abstract
Multiple subfields of neuroscience research are beginning to incorporate astrocytes into current frameworks of understanding overall brain physiology, neuronal circuitry, and disease etiology that underlie sleep and sleep-related disorders. Astrocytes have emerged as a dynamic regulator of neuronal activity through control of extracellular space (ECS) volume and composition, both of which can vary dramatically during different levels of sleep and arousal. Astrocytes are also an attractive target of sleep research due to their prominent role in the glymphatic system, a method by which toxic metabolites generated during wakefulness are cleared away. In this review we assess the literature surrounding glial influences on fluctuations in ECS volume and composition across the sleep-wake cycle. We also examine mechanisms of astrocyte volume regulation in glymphatic solute clearance and their role in sleep and wake states. Overall, findings highlight the importance of astrocytes in sleep and sleep research.
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Affiliation(s)
- Sandhya Sriram
- Interdepartmental Graduate Program in Neuroscience, University of California, Riverside, Riverside, CA, United States
- Department of Biochemistry and Molecular Biology, University of California, Riverside, Riverside, CA, United States
| | - Kaira Carstens
- Department of Biochemistry and Molecular Biology, University of California, Riverside, Riverside, CA, United States
| | - Wayne Dewing
- Undergraduate Major in Neuroscience, University of California, Riverside, Riverside, CA, United States
| | - Todd A Fiacco
- Interdepartmental Graduate Program in Neuroscience, University of California, Riverside, Riverside, CA, United States
- Department of Biochemistry and Molecular Biology, University of California, Riverside, Riverside, CA, United States
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5
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Cao X, Lu J, Chen C, Gui J. Exploring the correlation and difference between cerebrospinal fluid in the lateral ventricle and lumbar subarachnoid based on infants with intraventricular hemorrhage treated by the ommaya reservoir. Heliyon 2024; 10:e32252. [PMID: 38912498 PMCID: PMC11190596 DOI: 10.1016/j.heliyon.2024.e32252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 05/29/2024] [Accepted: 05/30/2024] [Indexed: 06/25/2024] Open
Abstract
Objective To explore the relationship and difference between ventricular and lumbar cerebrospinal fluid(CSF), this study presents equations transforming their measures. By assessing the viability of substituting lumbar puncture, we aim to minimize the associated medical risks and trauma faced by infants with intraventricular hemorrhage(IVH) from anesthesia and lumbar puncture. Methods We retrospectively analyzed CSF data from 27 infants diagnosed with IVH treated by Ommaya reservoir and lumbar puncture at our center, comprising 35 paired samples. Paired-sample and regression analyses were employed to determine test correlations, differences, and to derive transformation equations for the measurements. Results Comparative analyses between the CSF from the lateral ventricle and the lumbar vertebrae revealed significant differences in the levels of chloride, glucose, protein, erythrocytes, total cells, and Pandy's test. Specifically:1. Levels of chloride, glucose, protein, and Pandy's test were higher in the lumbar vertebrae.2. Conversely, erythrocyte and total cell counts were higher in the lateral ventricle.There were no significant differences observed for lumbar lactate dehydrogenase(LDH), leukocytes, occult blood, clot, clarity, and color. Nevertheless, significant correlations were identified between various measures, including LDH, glucose, chloride, protein, erythrocyte, leukocyte, total cell count, Pandy's test, occult blood, clot, transparency, and color. Interestingly, the correlation strength and equation fit for each component are inversely proportional to its molecular weight.Notably, well-fitting regression equations were found for LDH, glucose, chloride, protein, leukocytes, erythrocytes, and total cells. Conclusion In infants with IVH and unobstructed CSF channels, a robust correlation was noted between ventricular CSF sourced via the Ommaya reservoir and lumbar CSF. This correlation tended to be inversely related to molecular weight, with smaller molecular weights showing lesser disparities. Ventricular CSF data could anticipate lumbar CSF trends, and using regression equations with Ommaya-obtained CSF, one can derive approximate values for lumbar CSF.
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Affiliation(s)
- Xingyu Cao
- Department of Pediatric Neurosurgery, Guangdong Women and Children Hospital, No.521 Xingnan Avenue, Panyu District, Guangzhou City, Guangdong Province, China
| | - Jiazhang Lu
- Department of Pediatric Neurosurgery, Guangdong Women and Children Hospital, No.521 Xingnan Avenue, Panyu District, Guangzhou City, Guangdong Province, China
| | - Chengxian Chen
- Department of Pediatric Neurosurgery, Guangdong Women and Children Hospital, No.521 Xingnan Avenue, Panyu District, Guangzhou City, Guangdong Province, China
| | - Jian Gui
- Department of Pediatric Neurosurgery, Guangdong Women and Children Hospital, No.521 Xingnan Avenue, Panyu District, Guangzhou City, Guangdong Province, China
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Jurjević I, Orešković D, Radoš M, Brgić K, Klarica M. Changes of cerebrospinal fluid pressure gradient in different body positions under experimental impairment of cerebrospinal fluid pathway: new insight into hydrocephalus development. Front Mol Neurosci 2024; 17:1397808. [PMID: 38947218 PMCID: PMC11212498 DOI: 10.3389/fnmol.2024.1397808] [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: 03/08/2024] [Accepted: 05/24/2024] [Indexed: 07/02/2024] Open
Abstract
It is generally accepted that hydrocephalus is a consequence of the disbalance between cerebrospinal fluid (CSF) secretion and absorption which should in turn lead to CSF pressure gradient development and ventricular enlargement. To test CSF pressure gradient role in hydrocephalus development, we experimentally caused CSF system impairment at two sites in cats. In the first group of animals, we caused Sylvian aqueduct obstruction and recorded CSF pressure changes pre and post obstruction at three measuring sites (lateral ventricle -LV, cortical-CSS and lumbar subarachnoid space -LSS) during 15 min periods and in different body positions over 360 degrees. In the second group of experiments, we caused cervical stenosis by epidural plastic semiring implantation and monitored CSF pressure changes pre and post stenosis implantation at two measuring sites (lateral ventricle and lumbar subarachnoid space) during 15 min periods in different body positions over 360 degrees. Both groups of experimental animals had similar CSF pressures before stenosis or obstruction at all measuring points in the horizontal position. During head-up verticalization, CSF pressures inside the cranium gradually became more subatmospheric with no significant difference between LV and CSS, as they are measured at the same hydrostatic level, while CSF pressure inside LSS became more positive, causing the development of a large hydrostatic gradient between the cranial and the spinal space. With cervical stenosis, CSF pressure inside the cranium is positive during head-up verticalization, while in cats with aqueductal obstruction CSF pressure inside the CSS remains negative, as it was during control period. Concomitantly, CSF pressure inside LV becomes less negative, thus creating a small hydrostatic gradient between LV and CSS. Since CSF pressure and gradient changes occur only by shifting body position from the horizontal plane, our results indicate that cervical stenosis in a head-up vertical position reduces blood perfusion of the whole brain, while aqueductal obstruction impairs only the perfusion of the local periventricular brain tissue. It seems that, for evolutionary important bipedal activity, free craniospinal communication and good spinal space compliance represent crucial biophysical parameters for adequate cerebral blood perfusion and prevention of pathophysiological changes leading to the development of hydrocephalus.
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Affiliation(s)
- Ivana Jurjević
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
- Department of Neurology, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Darko Orešković
- Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Milan Radoš
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Klara Brgić
- Department of Neurosurgery, Univesity Hospital Centre Zagreb, Zagreb, Croatia
| | - Marijan Klarica
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
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7
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Kumaria A. Neural stem cells and pediatric hydrocephalus: further observations. Cereb Cortex 2024; 34:bhae086. [PMID: 38489787 DOI: 10.1093/cercor/bhae086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 02/17/2024] [Accepted: 02/19/2024] [Indexed: 03/17/2024] Open
Affiliation(s)
- Ashwin Kumaria
- Senior Fellow in Neurosurgery, Department of Neurosurgery, Queen's Medical Centre, Derby Road, Nottingham NG7 2UH, United Kingdom
- Clinical Trustee, Harry's Hydrocephalus Awareness Trust (Harry's HAT), Yateley, Hampshire GU46 6EB, United Kingdom
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Agarwal N, Lewis LD, Hirschler L, Rivera LR, Naganawa S, Levendovszky SR, Ringstad G, Klarica M, Wardlaw J, Iadecola C, Hawkes C, Octavia Carare R, Wells J, Bakker EN, Kurtcuoglu V, Bilston L, Nedergaard M, Mori Y, Stoodley M, Alperin N, de Leon M, van Osch MJ. Current Understanding of the Anatomy, Physiology, and Magnetic Resonance Imaging of Neurofluids: Update From the 2022 "ISMRM Imaging Neurofluids Study group" Workshop in Rome. J Magn Reson Imaging 2024; 59:431-449. [PMID: 37141288 PMCID: PMC10624651 DOI: 10.1002/jmri.28759] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/18/2023] [Accepted: 04/18/2023] [Indexed: 05/05/2023] Open
Abstract
Neurofluids is a term introduced to define all fluids in the brain and spine such as blood, cerebrospinal fluid, and interstitial fluid. Neuroscientists in the past millennium have steadily identified the several different fluid environments in the brain and spine that interact in a synchronized harmonious manner to assure a healthy microenvironment required for optimal neuroglial function. Neuroanatomists and biochemists have provided an incredible wealth of evidence revealing the anatomy of perivascular spaces, meninges and glia and their role in drainage of neuronal waste products. Human studies have been limited due to the restricted availability of noninvasive imaging modalities that can provide a high spatiotemporal depiction of the brain neurofluids. Therefore, animal studies have been key in advancing our knowledge of the temporal and spatial dynamics of fluids, for example, by injecting tracers with different molecular weights. Such studies have sparked interest to identify possible disruptions to neurofluids dynamics in human diseases such as small vessel disease, cerebral amyloid angiopathy, and dementia. However, key differences between rodent and human physiology should be considered when extrapolating these findings to understand the human brain. An increasing armamentarium of noninvasive MRI techniques is being built to identify markers of altered drainage pathways. During the three-day workshop organized by the International Society of Magnetic Resonance in Medicine that was held in Rome in September 2022, several of these concepts were discussed by a distinguished international faculty to lay the basis of what is known and where we still lack evidence. We envision that in the next decade, MRI will allow imaging of the physiology of neurofluid dynamics and drainage pathways in the human brain to identify true pathological processes underlying disease and to discover new avenues for early diagnoses and treatments including drug delivery. Evidence level: 1 Technical Efficacy: Stage 3.
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Affiliation(s)
- Nivedita Agarwal
- Neuroradiology Unit, Scientific Institute IRCCS E. Medea, Bosisio Parini, Italy
| | - Laura D. Lewis
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Lydiane Hirschler
- C.J. Gorter MRI Center, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Leonardo Rivera Rivera
- Wisconsin Alzheimer’s Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Shinji Naganawa
- Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | | | - Geir Ringstad
- Department of Radiology, Oslo University Hospital Rikshospitalet, Oslo, Norway
- Department of Geriatrics and Internal Medicine, Sorlandet Hospital, Arendal, Norway
| | - Marijan Klarica
- Department of Pharmacology and Croatian Institute of Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Joanna Wardlaw
- Centre for Clinical Brain Sciences and UK Dementia Research Institute Centre, University of Edinburgh, Edinburgh, UK
| | - Costantino Iadecola
- Department of Pharmacology and Croatian Institute of Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Cheryl Hawkes
- Biomedical and Life Sciences, Lancaster University, Lancaster, UK
| | | | - Jack Wells
- UCL Centre for Advanced Biomedical Imaging, University College of London, London, UK
| | - Erik N.T.P. Bakker
- Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | | | - Lynne Bilston
- Neuroscience Research Australia and UNSW Medicine, Sydney, Australia
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York, USA
- Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
| | - Yuki Mori
- Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
| | - Marcus Stoodley
- Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, Australia
- Department of Neurosurgery, Macquarie University Hospital, Sydney, Australia
| | - Noam Alperin
- Department of Radiology and Biomedical Engineering, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Mony de Leon
- Weil Cornell Medicine, Department of Radiology, Brain Health Imaging Institute, New York City, New York, USA
| | - Matthias J.P. van Osch
- C.J. Gorter MRI Center, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
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Zhao H, Sun M, Zhang Y, Kong W, Fan L, Wang K, Xu Q, Chen B, Dong J, Shi Y, Wang Z, Wang S, Zhuang X, Li Q, Lin F, Yao X, Zhang W, Kong C, Zhang R, Feng D, Zhao X. Connecting the Dots: The Cerebral Lymphatic System as a Bridge Between the Central Nervous System and Peripheral System in Health and Disease. Aging Dis 2024; 15:115-152. [PMID: 37307828 PMCID: PMC10796102 DOI: 10.14336/ad.2023.0516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Accepted: 05/16/2023] [Indexed: 06/14/2023] Open
Abstract
As a recently discovered waste removal system in the brain, cerebral lymphatic system is thought to play an important role in regulating the homeostasis of the central nervous system. Currently, more and more attention is being focused on the cerebral lymphatic system. Further understanding of the structural and functional characteristics of cerebral lymphatic system is essential to better understand the pathogenesis of diseases and to explore therapeutic approaches. In this review, we summarize the structural components and functional characteristics of cerebral lymphatic system. More importantly, it is closely associated with peripheral system diseases in the gastrointestinal tract, liver, and kidney. However, there is still a gap in the study of the cerebral lymphatic system. However, we believe that it is a critical mediator of the interactions between the central nervous system and the peripheral system.
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Affiliation(s)
- Hongxiang Zhao
- Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China.
- Shandong Provincial Medicine and Health Key Laboratory of Clinical Anesthesia, School of Anesthesiology, Weifang Medical University, Weifang, China.
| | - Meiyan Sun
- Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China.
- Shandong Provincial Medicine and Health Key Laboratory of Clinical Anesthesia, School of Anesthesiology, Weifang Medical University, Weifang, China.
| | - Yue Zhang
- Shandong Provincial Medicine and Health Key Laboratory of Clinical Anesthesia, School of Anesthesiology, Weifang Medical University, Weifang, China.
| | - Wenwen Kong
- Shandong Provincial Medicine and Health Key Laboratory of Clinical Anesthesia, School of Anesthesiology, Weifang Medical University, Weifang, China.
| | - Lulu Fan
- Shandong Provincial Medicine and Health Key Laboratory of Clinical Anesthesia, School of Anesthesiology, Weifang Medical University, Weifang, China.
| | - Kaifang Wang
- Shandong Provincial Medicine and Health Key Laboratory of Clinical Anesthesia, School of Anesthesiology, Weifang Medical University, Weifang, China.
| | - Qing Xu
- Department of Anesthesiology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, China.
| | - Baiyan Chen
- Shandong Provincial Medicine and Health Key Laboratory of Clinical Anesthesia, School of Anesthesiology, Weifang Medical University, Weifang, China.
| | - Jianxin Dong
- Shandong Provincial Medicine and Health Key Laboratory of Clinical Anesthesia, School of Anesthesiology, Weifang Medical University, Weifang, China.
| | - Yanan Shi
- Shandong Provincial Medicine and Health Key Laboratory of Clinical Anesthesia, School of Anesthesiology, Weifang Medical University, Weifang, China.
| | - Zhengyan Wang
- Shandong Provincial Medicine and Health Key Laboratory of Clinical Anesthesia, School of Anesthesiology, Weifang Medical University, Weifang, China.
| | - ShiQi Wang
- Shandong Provincial Medicine and Health Key Laboratory of Clinical Anesthesia, School of Anesthesiology, Weifang Medical University, Weifang, China.
| | - Xiaoli Zhuang
- Department of Anesthesiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
| | - Qi Li
- Department of Anesthesiology, Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
| | - Feihong Lin
- Department of Anesthesiology, Shanghai Pulmonary Hospital, School of Medicine, Tongji University, Shanghai, China.
| | - Xinyu Yao
- Department of Anesthesiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
| | - WenBo Zhang
- Department of Neurosurgery, The Children’s Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China.
| | - Chang Kong
- Department of Anesthesiology and Critical Care Medicine, Tianjin Nankai Hospital, Tianjin Medical University, Tianjin, China.
| | - Rui Zhang
- Department of Anesthesiology, Affiliated Hospital of Weifang Medical University, Weifang, China.
- Shandong Provincial Medicine and Health Key Laboratory of Clinical Anesthesia, School of Anesthesiology, Weifang Medical University, Weifang, China.
| | - Dayun Feng
- Department of neurosurgery, Tangdu hospital, Fourth Military Medical University, Xi'an, China.
| | - Xiaoyong Zhao
- Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China.
- Department of Anesthesiology, Affiliated Hospital of Weifang Medical University, Weifang, China.
- Shandong Provincial Medicine and Health Key Laboratory of Clinical Anesthesia, School of Anesthesiology, Weifang Medical University, Weifang, China.
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10
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Taoka T, Ito R, Nakamichi R, Nakane T, Kawai H, Naganawa S. Interstitial Fluidopathy of the Central Nervous System: An Umbrella Term for Disorders with Impaired Neurofluid Dynamics. Magn Reson Med Sci 2024; 23:1-13. [PMID: 36436975 PMCID: PMC10838724 DOI: 10.2463/mrms.rev.2022-0012] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 08/29/2022] [Indexed: 01/05/2024] Open
Abstract
Interest in interstitial fluid dynamics has increased since the proposal of the glymphatic system hypothesis. Abnormal dynamics of the interstitial fluid have been pointed out to be an important factor in various pathological statuses. In this article, we propose the concept of central nervous system interstitial fluidopathy as a disease or condition in which abnormal interstitial fluid dynamics is one of the important factors for the development of a pathological condition. We discuss the aspects of interstitial fluidopathy in various diseases, including Alzheimer's disease, Parkinson's disease, normal pressure hydrocephalus, and cerebral small vessel disease. We also discuss a method called "diffusion tensor image analysis along the perivascular space" using MR diffusion images, which is used to evaluate the degree of interstitial fluidopathy or the activity of the glymphatic system.
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Affiliation(s)
- Toshiaki Taoka
- Department of Innovative Biomedical Visualization (iBMV), Nagoya University, Nagoya, Aichi, Japan
- Department of Radiology, Nagoya University, Nagoya, Aichi, Japan
| | - Rintaro Ito
- Department of Innovative Biomedical Visualization (iBMV), Nagoya University, Nagoya, Aichi, Japan
- Department of Radiology, Nagoya University, Nagoya, Aichi, Japan
| | - Rei Nakamichi
- Department of Radiology, Nagoya University, Nagoya, Aichi, Japan
| | - Toshiki Nakane
- Department of Radiology, Nagoya University, Nagoya, Aichi, Japan
| | - Hisashi Kawai
- Department of Radiology, Aichi Medical University, Nagakute, Aichi, Japan
| | - Shinji Naganawa
- Department of Radiology, Nagoya University, Nagoya, Aichi, Japan
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11
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Vandenbulcke A, Messerer M, Daniel RT, Cossu G. The Role of Cisternostomy and Cisternal Drainage in the Treatment of Aneurysmal Subarachnoid Hemorrhage: A Comprehensive Review. Brain Sci 2023; 13:1580. [PMID: 38002540 PMCID: PMC10670052 DOI: 10.3390/brainsci13111580] [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: 10/07/2023] [Revised: 11/06/2023] [Accepted: 11/09/2023] [Indexed: 11/26/2023] Open
Abstract
Aneurysmal subarachnoid hemorrhage (aSAH) provokes a cascade reaction that is responsible for early and delayed brain injuries mediated by intracranial hypertension, hydrocephalus, cerebral vasospasm (CV), and delayed cerebral ischemia (DCI), which result in increased morbidity and mortality. During open microsurgical repair, cisternal access is achieved essentially to gain proximal vascular control and aneurysm exposition. Cisternostomy also allows brain relaxation, removal of cisternal clots, and restoration of the CSF dynamics through the communication between the anterior and posterior circulation cisterns and the ventricular system, with the opening of the Membrane of Liliequist and lamina terminalis, respectively. Continuous postoperative CSF drainage through a cisternal drain (CD) is a valuable option for treating acute hydrocephalus and intracranial hypertension. Moreover, it efficiently removes the blood and toxic degradation products, with a potential benefit on CV, DCI, and shunt-dependent hydrocephalus. Finally, the CD is an effective pathway to administer vasoactive, fibrinolytic, and anti-oxidant agents and shows promising results in decreasing CV and DCI rates while minimizing systemic effects. We performed a comprehensive review to establish the adjuvant role of cisternostomy and CD performed in cases of direct surgical repair for ruptured intracranial aneurysms and their role in the prevention and treatment of aSAH complications.
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Affiliation(s)
- Alberto Vandenbulcke
- Department of Neurosurgery, University Hospital of Lausanne (CHUV), University of Lausanne, 1015 Lausanne, Switzerland
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12
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Hussain R, Graham U, Elder A, Nedergaard M. Air pollution, glymphatic impairment, and Alzheimer's disease. Trends Neurosci 2023; 46:901-911. [PMID: 37777345 DOI: 10.1016/j.tins.2023.08.010] [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: 04/21/2023] [Revised: 07/12/2023] [Accepted: 08/29/2023] [Indexed: 10/02/2023]
Abstract
Epidemiological evidence demonstrates a link between air pollution exposure and the onset and progression of cognitive impairment and Alzheimer's disease (AD). However, current understanding of the underlying pathophysiological mechanisms is limited. This opinion article examines the hypothesis that air pollution-induced impairment of glymphatic clearance represents a crucial etiological event in the development of AD. Exposure to airborne particulate matter (PM) leads to systemic inflammation and neuroinflammation, increased metal load, respiratory and cardiovascular dysfunction, and sleep abnormalities. All these factors are known to reduce the efficiency of glymphatic clearance. Rescuing glymphatic function by restricting the impact of causative agents, and improving sleep and cardiovascular system health, may increase the efficiency of waste metabolite clearance and subsequently slow the progression of AD. In sum, we introduce air pollution-mediated glymphatic impairment as an important mechanistic factor to be considered when interpreting the etiology and progression of AD as well as its responsiveness to therapeutic interventions.
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Affiliation(s)
- Rashad Hussain
- Center for Translational Neuromedicine, University of Rochester, Rochester, NY 14642, USA.
| | | | - Alison Elder
- Department of Environmental Medicine, University of Rochester, Rochester, NY 14642, USA
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Rochester, Rochester, NY 14642, USA; Center for Translational Neuroscience, University of Copenhagen, 2200 Copenhagen, Denmark.
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13
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Kudelić N, Koprek I, Radoš M, Orešković D, Jurjević I, Klarica M. Predictive value of spinal CSF volume in the preoperative assessment of patients with idiopathic normal-pressure hydrocephalus. Front Neurol 2023; 14:1234396. [PMID: 37869132 PMCID: PMC10585139 DOI: 10.3389/fneur.2023.1234396] [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: 06/04/2023] [Accepted: 09/19/2023] [Indexed: 10/24/2023] Open
Abstract
Introduction The pathophysiology, diagnosis, and management of idiopathic normal pressure hydrocephalus (iNPH) remain unclear. Although some prognostic tests recommended in iNPH guidelines should have high sensitivity and high predictive value, there is often no positive clinical response to surgical treatment. Materials and methods In our study, 19 patients with clinical and neuroradiological signs of iNPH were selected for preoperative evaluation and possible further surgical treatment according to the guidelines. MR volumetry of the intracranial and spinal space was performed. Patients were exposed to prolonged external lumbar drainage in excess of 10 ml per hour during 3 days. Clinical response to lumbar drainage was assessed by a walk test and a mini-mental test. Results Twelve of 19 patients showed a positive clinical response and underwent a shunting procedure. Volumetric values of intracranial space content in responders and non-responders showed no statistically significant difference. Total CSF volume (sum of cranial and spinal CSF volumes) was higher than previously published. No correlation was found between spinal canal length, CSF pressure, and CSF spinal volume. The results show that there is a significantly higher CSF volume in the spinal space in the responder group (n = 12) (120.5 ± 14.9 ml) compared with the non-responder group (103.1 ± 27.4 ml; n = 7). Discussion This study demonstrates for the first time that CSF volume in the spinal space may have predictive value in the preoperative assessment of iNPH patients. The results suggest that patients with increased spinal CSF volume have decreased compliance. Additional prospective randomized clinical trials are needed to confirm our results.
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Affiliation(s)
- Nenad Kudelić
- Department of Neurosurgery, General Hospital Varaždin, Varaždin, Croatia
| | - Ivan Koprek
- Department of Neurosurgery, General Hospital Varaždin, Varaždin, Croatia
| | - Milan Radoš
- Department of Pharmacology, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Darko Orešković
- Department of Molecular Biology, Ruđer Bošković Institute, Zagreb, Croatia
| | - Ivana Jurjević
- Department of Pharmacology, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
- Department of Neurology, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Marijan Klarica
- Department of Pharmacology, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
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14
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Spierer R. The debated neuroanatomy of the fourth ventricle. J Anat 2023; 243:555-563. [PMID: 37170923 PMCID: PMC10485575 DOI: 10.1111/joa.13885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/21/2023] [Accepted: 05/01/2023] [Indexed: 05/13/2023] Open
Abstract
The fourth ventricle is a small, fluid-filled cavity located within the brain that plays a vital role in the body's physiological functions. Therefore, the anatomical elements forming it bear significant clinical relevance. However, the exact relations between the elements that form its roof are still debated in the neuroanatomical literature; the inferior medullary velum, and the ventricle's median aperture in particular. In some atlases, the inferior medullary velum is placed in the midline, while in others, it is placed in the transverse plane. The median aperture is also displayed in different ways in midsagittal drawings: as a round perforation of a midline velum, as a foramen in an uncharacterized part of the ventricle, and as a gap between the nodule and the brainstem. This work aims to provide a comprehensive review of the different descriptions of the fourth ventricle, in order to gain a clearer understanding of the ventricular system's structure.
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Affiliation(s)
- Ronen Spierer
- Rappaport Faculty of MedicineTechnion‐Israel Institute of TechnologyHaifaIsrael
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15
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Bajda J, Pitla N, Gorantla VR. Bulat-Klarica-Oreskovic Hypothesis: A Comprehensive Review. Cureus 2023; 15:e45821. [PMID: 37876400 PMCID: PMC10593140 DOI: 10.7759/cureus.45821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2023] [Indexed: 10/26/2023] Open
Abstract
Classical theories of cerebrospinal fluid (CSF) production and flow are taught throughout medical education. The idea that CSF is produced and/or filtered by the choroid plexus and flows in one direction throughout the ventricular system has been a largely accepted thesis. However, modern studies have called into question the validity of this hypothesis, suggesting that CSF does not move unidirectionally but rather is driven by microvessel contractions in a to-and-fro manner throughout the cerebrospinal system. Moreover, new insights suggest that in addition to CSF production, the exchange of fluids and proteins between the cortical vasculature and the interstitium may function as the brain's version of a lymphatic system. This comprehensive review provides evidence for a different framework of CSF flow. One that includes perivascular pulsations that push CSF back and forth, allowing exchange between the CSF and interstitium, and with CSF production occurring throughout the cerebrospinal system. These findings could be revolutionary in understanding the pathophysiology of CSF flow and in the treatment of pathologies such as intracranial hypertension, hydrocephalus, Alzheimer's disease, and many others.
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Affiliation(s)
- Joe Bajda
- Neurology, St. George's University, St. George's, GRD
| | - Neharaj Pitla
- Neurology, St. George's University, St. George's, GRD
| | - Vasavi Rakesh Gorantla
- Biomedical Sciences, West Virginia University School of Osteopathic Medicine, Lewisburg , USA
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16
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Ueki S, Suzuki Y, Nakamura Y, Igarashi H. Age-Dependent Changes in Regulation of Water Inflow Into the Vitreous Body. Invest Ophthalmol Vis Sci 2023; 64:22. [PMID: 37698528 PMCID: PMC10501487 DOI: 10.1167/iovs.64.12.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 08/22/2023] [Indexed: 09/13/2023] Open
Abstract
Purpose Water inflow into the vitreous body regulated by retinal aquaporin-4 distributed within Müller cells has been observed in mice; however, the changes in this phenomenon with age remain unknown. This study aimed to evaluate whether intravenously injected H2O also flows into the vitreous body of human subjects and to investigate whether water dynamics in the human posterior eye change with age using [15O]H2O positron emission tomography (PET). Methods Forty-six normal adult volunteers underwent [15O]H2O PET, and the standard uptake value (SUV) in the center of the vitreous body after 1000-MBq [15O]H2O administration was assessed. The SUV was fitted to an exponential curve, and y0, the steady state of the SUV, and b, the speed of increase in the SUV, were calculated. The results for patients ranging from in age from 20 to 39, 40 to 59, and 60 to 79 years were compared using analyses of variance followed by Games to Howell tests. Results For the parameter y0, statistical analysis revealed no statistically significant differences among the three groups. For parameter b, statistical analysis revealed statistically significant differences between the 20 to 39 and 60 to 79 age groups (P = 0.000), the 40 to 59 and 60 to 79 age groups (P = 0.025), and the 20 to 39 and 40 to 59 age groups (P = 0.037). Conclusions The present study revealed that H2O injected into the vein flows into the human vitreous body and that the speed of increase in water flow into the vitreous body decreases with aging. This study suggests that water dynamics in the posterior eye, or the retinal glymphatic pathway, change significantly with aging.
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Affiliation(s)
- Satoshi Ueki
- Center for Integrated Human Brain Science, Brain Research Institute, Niigata University, Niigata, Japan
- Division of Ophthalmology and Visual Science, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Yuji Suzuki
- Center for Integrated Human Brain Science, Brain Research Institute, Niigata University, Niigata, Japan
| | - Yukimi Nakamura
- Center for Integrated Human Brain Science, Brain Research Institute, Niigata University, Niigata, Japan
| | - Hironaka Igarashi
- Center for Integrated Human Brain Science, Brain Research Institute, Niigata University, Niigata, Japan
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17
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Ajeeb R, Clegg JR. Intrathecal delivery of Macromolecules: Clinical status and emerging technologies. Adv Drug Deliv Rev 2023; 199:114949. [PMID: 37286086 DOI: 10.1016/j.addr.2023.114949] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 05/31/2023] [Accepted: 06/03/2023] [Indexed: 06/09/2023]
Abstract
The proximity and association of cerebrospinal fluid (CSF) and the intrathecal (IT) space with deep targets in the central nervous system (CNS) parenchyma makes IT injection an attractive route of administration for brain drug delivery. However, the extent to which intrathecally administered macromolecules are effective in treating neurological diseases is a question of both clinical debate and technological interest. We present the biological, chemical, and physical properties of the intrathecal space that are relevant to drug absorption, distribution, metabolism, and elimination from CSF. We then analyze the evolution of IT drug delivery in clinical trials over the last 20 years. Our analysis revealed that the percentage of clinical trials assessing IT delivery for the delivery of biologics (i.e., macromolecules, cells) for treatment of chronic conditions (e.g., neurodegeneration, cancer, and metabolic diseases) has steadily increased. Clinical trials exploring cell or macromolecular delivery within the IT space have not evaluated engineering technologies, such as depots, particles, or other delivery systems. Recent pre-clinical studies have evaluated IT macromolecule delivery in small animals, postulating that delivery efficacy can be assisted by external medical devices, micro- or nanoparticles, bulk biomaterials, and viral vectors. Further studies are necessary to evaluate the extent to which engineering technologies and IT administration improve CNS targeting and therapeutic outcome.
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Affiliation(s)
- Rana Ajeeb
- Stephenson School of Biomedical Engineering, The University of Oklahoma, Norman, OK, United States
| | - John R Clegg
- Stephenson School of Biomedical Engineering, The University of Oklahoma, Norman, OK, United States; Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States; Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States; Institute for Biomedical Engineering, Science, and Technology, University of Oklahoma, Norman, OK, United States.
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18
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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: 5] [Impact Index Per Article: 5.0] [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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19
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Kyyriäinen J, Andrade P, Hämäläinen E, Pitkänen A. Sleep Disturbance and Severe Hydrocephalus in a Normally Behaving Wistar Rat With Traumatic Brain Injury. Neurotrauma Rep 2023; 4:384-395. [PMID: 37350791 PMCID: PMC10282974 DOI: 10.1089/neur.2022.0090] [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] [Indexed: 06/24/2023] Open
Abstract
We report on a case study of a Wistar rat that was investigated in detail because it exhibited no N3 sleep in electroencephalography (EEG) after lateral fluid-percussion injury (FPI)-induced traumatic brain injury (TBI). The rat (#112) belonged to a cohort of 28 adult Wistar rats exposed to lateral FPI. Rats were monitored by continuous video EEG for 30 days to follow-up on the evolution of sleep disturbances. The beam walking test was used to measure post-TBI functional recovery. Severity of the cortical lesion area, total brain volume, and cortical volume were measured from histological brain sections. Rat #112 had a normal body and skull appearance. Its baseline body weight did not differ from that of the rest of the cohort. At baseline, rat #112 crossed the beam in 6.3 sec (score range for the rest of the cohort, 4.7-44.3) and showed no evident slipping of the paws, scoring a 5.3 (score range for the rest of cohort, 4.3-6.0). On day 30 post-TBI, however, rat #112 was the only rat with a score of 0 on the beam. Histological analysis at 30 days post-TBI revealed a small 0.6-mm2 post-TBI lesion in the somatosensory cortex (lesion size range for the rest of the cohort, 1.2-10.9). The brain volume of rat #112 was 2-fold larger than the mean volume of the rest of the cohort (1592 vs. 758 mm3), the ventricles were remarkably enlarged, and the layered cerebral cortex was very thin. Analysis of the sleep EEG revealed that rat #112 had rapid eye movement sleep and wakefulness, but no N3 sleep, during the 72-h EEG epoch analyzed. This case report demonstrates that brain abnormalities presumably unrelated to the impact-induced cortical lesion, such as presumed pre-existing hydrocephalus, may worsen TBI-induced behavioral and electrographical outcome measures and complicate the assessment of the cause of the abnormalities.
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Affiliation(s)
- Jenni Kyyriäinen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Pedro Andrade
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Elina Hämäläinen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Asla Pitkänen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
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20
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Ding Z, Fan X, Zhang Y, Yao M, Wang G, Dong Y, Liu J, Song W. The glymphatic system: a new perspective on brain diseases. Front Aging Neurosci 2023; 15:1179988. [PMID: 37396658 PMCID: PMC10308198 DOI: 10.3389/fnagi.2023.1179988] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Accepted: 05/29/2023] [Indexed: 07/04/2023] Open
Abstract
The glymphatic system is a brain-wide perivascular pathway driven by aquaporin-4 on the endfeet of astrocytes, which can deliver nutrients and active substances to the brain parenchyma through periarterial cerebrospinal fluid (CSF) influx pathway and remove metabolic wastes through perivenous clearance routes. This paper summarizes the composition, overall fluid flow, solute transport, related diseases, affecting factors, and preclinical research methods of the glymphatic system. In doing so, we aim to provide direction and reference for more relevant researchers in the future.
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21
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Grasso G, Sallì M, Kim HS, Torregrossa F. Possible Role of the New Identified "Subarachnoid Lymphatic-Like Membrane" in Traumatic Brain Injury. World Neurosurg 2023; 174:1-2. [PMID: 36868406 DOI: 10.1016/j.wneu.2023.02.105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 03/05/2023]
Affiliation(s)
- Giovanni Grasso
- Neurosurgical Unit, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy.
| | - Marcello Sallì
- Rehabilitation Medicine Outpatient Department, A.S.P. Palermo, Palermo, Italy
| | - Hyeun-Sung Kim
- Department of Spine Surgery, Nanoori Gangnam Hospital, Seoul, South Korea
| | - Fabio Torregrossa
- Neurosurgical Unit, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
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22
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Shi Y, Keep RF. Fluid movement in the healthy and diseased brain. Neurobiol Dis 2023:106168. [PMID: 37230181 DOI: 10.1016/j.nbd.2023.106168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Affiliation(s)
- Yejie Shi
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, United States of America
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, MI 48109, United States of America.
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23
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Eraky AM, Treffy R, Hedayat HS. Cisternostomy as a Surgical Treatment for Traumatic Brain Injury-Related Prolonged and Delayed Intracranial Pressure Elevation: A Case Report. Cureus 2023; 15:e37508. [PMID: 37193467 PMCID: PMC10181949 DOI: 10.7759/cureus.37508] [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] [Accepted: 04/12/2023] [Indexed: 05/18/2023] Open
Abstract
Traumatic brain injury (TBI) can be classified into primary, due to the effect of the initial trauma, or secondary, due to increased intracranial pressure (ICP). Increased ICP may cause brain herniation and also decreases cerebral blood perfusion leading to ischemia. Recently, a few studies showed that cisternostomy with decompressive craniectomy (DC) has better outcomes than DC alone in patients with TBI. This can be explained by the recent advances indicating that cisternal cerebrospinal fluid (CSF) communicates with cerebral interstitial fluid (IF) through Virchow-Robin spaces. Theoretically, opening cisterns to atmospheric pressure may induce IF drainage and subsequently decrease ICP. A 55-year-old man presented to the emergency department with subdural hematomas, hemorrhagic contusions, and subarachnoid hemorrhage after falling off a moving truck. ICP elevation was refractory despite increased sedation, initiation of paralysis with Cisatracurium, esophageal cooling, multiple doses of 23.4 % saline and mannitol, and DC. Lumbar drain (LD) placement was performed with beneficial results. Unfortunately, the LD stopped functioning multiple times and each time this occurred, he developed increased ventricular size with elevated ICP. The patient underwent cisternostomy and lamina terminalis fenestration. No further increased ICPs were observed after cisternostomy at a one-month follow-up. Cisternostomy is a potential surgical treatment for patients with TBI-related prolonged ICP elevation.
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Affiliation(s)
- Akram M Eraky
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, USA
| | - Randall Treffy
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, USA
| | - Hirad S Hedayat
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, USA
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24
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Korzh V. Development of the brain ventricular system from a comparative perspective. Clin Anat 2023; 36:320-334. [PMID: 36529666 DOI: 10.1002/ca.23994] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
The brain ventricular system (BVS) consists of brain ventricles and channels filled with cerebrospinal fluid (CSF). Disturbance of CSF flow has been linked to scoliosis and neurodegenerative diseases, including hydrocephalus. This could be due to defects of CSF production by the choroid plexus or impaired CSF movement over the ependyma dependent on motile cilia. Most vertebrates have horizontal body posture. They retain additional evolutionary innovations assisting CSF flow, such as the Reissner fiber. The causes of hydrocephalus have been studied using animal models including rodents (mice, rats, hamsters) and zebrafish. However, the horizontal body posture reduces the effect of gravity on CSF flow, which limits the use of mammalian models for scoliosis. In contrast, fish swim against the current and experience a forward-to-backward mechanical force akin to that caused by gravity in humans. This explains the increased popularity of the zebrafish model for studies of scoliosis. "Slit-ventricle" syndrome is another side of the spectrum of BVS anomalies. It develops because of insufficient inflation of the BVS. Recent advances in zebrafish functional genetics have revealed genes that could regulate the development of the BVS and CSF circulation. This review will describe the BVS of zebrafish, a typical teleost, and vertebrates in general, in comparative perspective. It will illustrate the usefulness of the zebrafish model for developmental studies of the choroid plexus (CP), CSF flow and the BVS.
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Affiliation(s)
- Vladimir Korzh
- International Institute of Molecular and Cell Biology, Warsaw, Poland
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25
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Uchida Y, Kan H, Sakurai K, Oishi K, Matsukawa N. Contributions of blood-brain barrier imaging to neurovascular unit pathophysiology of Alzheimer's disease and related dementias. Front Aging Neurosci 2023; 15:1111448. [PMID: 36861122 PMCID: PMC9969807 DOI: 10.3389/fnagi.2023.1111448] [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: 11/29/2022] [Accepted: 01/26/2023] [Indexed: 02/11/2023] Open
Abstract
The blood-brain barrier (BBB) plays important roles in the maintenance of brain homeostasis. Its main role includes three kinds of functions: (1) to protect the central nervous system from blood-borne toxins and pathogens; (2) to regulate the exchange of substances between the brain parenchyma and capillaries; and (3) to clear metabolic waste and other neurotoxic compounds from the central nervous system into meningeal lymphatics and systemic circulation. Physiologically, the BBB belongs to the glymphatic system and the intramural periarterial drainage pathway, both of which are involved in clearing interstitial solutes such as β-amyloid proteins. Thus, the BBB is believed to contribute to preventing the onset and progression for Alzheimer's disease. Measurements of BBB function are essential toward a better understanding of Alzheimer's pathophysiology to establish novel imaging biomarkers and open new avenues of interventions for Alzheimer's disease and related dementias. The visualization techniques for capillary, cerebrospinal, and interstitial fluid dynamics around the neurovascular unit in living human brains have been enthusiastically developed. The purpose of this review is to summarize recent BBB imaging developments using advanced magnetic resonance imaging technologies in relation to Alzheimer's disease and related dementias. First, we give an overview of the relationship between Alzheimer's pathophysiology and BBB dysfunction. Second, we provide a brief description about the principles of non-contrast agent-based and contrast agent-based BBB imaging methodologies. Third, we summarize previous studies that have reported the findings of each BBB imaging method in individuals with the Alzheimer's disease continuum. Fourth, we introduce a wide range of Alzheimer's pathophysiology in relation to BBB imaging technologies to advance our understanding of the fluid dynamics around the BBB in both clinical and preclinical settings. Finally, we discuss the challenges of BBB imaging techniques and suggest future directions toward clinically useful imaging biomarkers for Alzheimer's disease and related dementias.
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Affiliation(s)
- Yuto Uchida
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States,*Correspondence: Yuto Uchida, ; Noriyuki Matsukawa,
| | - Hirohito Kan
- Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Keita Sakurai
- Department of Radiology, National Center for Geriatrics and Gerontology, Ōbu, Aichi, Japan
| | - Kenichi Oishi
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Noriyuki Matsukawa
- Department of Neurology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan,*Correspondence: Yuto Uchida, ; Noriyuki Matsukawa,
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Saunders NR, Dziegielewska KM, Fame RM, Lehtinen MK, Liddelow SA. The choroid plexus: a missing link in our understanding of brain development and function. Physiol Rev 2023; 103:919-956. [PMID: 36173801 PMCID: PMC9678431 DOI: 10.1152/physrev.00060.2021] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 09/01/2022] [Accepted: 09/17/2022] [Indexed: 11/22/2022] Open
Abstract
Studies of the choroid plexus lag behind those of the more widely known blood-brain barrier, despite a much longer history. This review has two overall aims. The first is to outline long-standing areas of research where there are unanswered questions, such as control of cerebrospinal fluid (CSF) secretion and blood flow. The second aim is to review research over the past 10 years where the focus has shifted to the idea that there are choroid plexuses located in each of the brain's ventricles that make specific contributions to brain development and function through molecules they generate for delivery via the CSF. These factors appear to be particularly important for aspects of normal brain growth. Most research carried out during the twentieth century dealt with the choroid plexus, a brain barrier interface making critical contributions to the composition and stability of the brain's internal environment throughout life. More recent research in the twenty-first century has shown the importance of choroid plexus-generated CSF in neurogenesis, influence of sex and other hormones on choroid plexus function, and choroid plexus involvement in circadian rhythms and sleep. The advancement of technologies to facilitate delivery of brain-specific therapies via the CSF to treat neurological disorders is a rapidly growing area of research. Conversely, understanding the basic mechanisms and implications of how maternal drug exposure during pregnancy impacts the developing brain represents another key area of research.
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Affiliation(s)
- Norman R Saunders
- Department of Neuroscience, The Alfred Centre, Monash University, Melbourne, Victoria, Australia
| | | | - Ryann M Fame
- Department of Pathology, Boston Children's Hospital, Boston, Massachusetts
| | - Maria K Lehtinen
- Department of Pathology, Boston Children's Hospital, Boston, Massachusetts
| | - Shane A Liddelow
- Neuroscience Institute, NYU Grossman School of Medicine, New York, New York
- Department of Neuroscience and Physiology, NYU Grossman School of Medicine, New York, New York
- Department of Ophthalmology, NYU Grossman School of Medicine, New York, New York
- Parekh Center for Interdisciplinary Neurology, NYU Grossman School of Medicine, New York, New York
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27
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Poulain A, Riseth J, Vinje V. Multi-compartmental model of glymphatic clearance of solutes in brain tissue. PLoS One 2023; 18:e0280501. [PMID: 36881576 PMCID: PMC9990927 DOI: 10.1371/journal.pone.0280501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 01/02/2023] [Indexed: 03/08/2023] Open
Abstract
The glymphatic system is the subject of numerous pieces of research in biology. Mathematical modelling plays a considerable role in this field since it can indicate the possible physical effects of this system and validate the biologists' hypotheses. The available mathematical models that describe the system at the scale of the brain (i.e. the macroscopic scale) are often solely based on the diffusion equation and do not consider the fine structures formed by the perivascular spaces. We therefore propose a mathematical model representing the time and space evolution of a mixture flowing through multiple compartments of the brain. We adopt a macroscopic point of view in which the compartments are all present at any point in space. The equations system is composed of two coupled equations for each compartment: One equation for the pressure of a fluid and one for the mass concentration of a solute. The fluid and solute can move from one compartment to another according to certain membrane conditions modelled by transfer functions. We propose to apply this new modelling framework to the clearance of 14C-inulin from the rat brain.
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Affiliation(s)
- Alexandre Poulain
- Laboratoire Paul Painlevé, UMR 8524 CNRS, Université de Lille, Lille, France
- Department for Numerical Analysis and Scientific Computing, Simula Research Laboratory, Oslo, Norway
- * E-mail:
| | - Jørgen Riseth
- Department of Mathematics, University of Oslo, Oslo, Norway
- Department for Numerical Analysis and Scientific Computing, Simula Research Laboratory, Oslo, Norway
| | - Vegard Vinje
- Department for Numerical Analysis and Scientific Computing, Simula Research Laboratory, Oslo, Norway
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28
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Fedin AI. [The glymphatic system in the brain - neurobiology and clinical pathology]. Zh Nevrol Psikhiatr Im S S Korsakova 2023; 123:13-19. [PMID: 37315237 DOI: 10.17116/jnevro202312305113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Given new information about the neurobiology of the processes of removal of waste products of the brain, consisting of the lymphatic vessels into the dura and the glial-lymphatic (glymphatic) system. The role of astrocytes and water-conducting channels located on them in cell membranes formed by the protein aquaporin-4 is emphasized. The connection between the functioning of the glymphatic system and the slow phase of sleep is discussed. Possible mechanisms for the development of cognitive impairments in violation of the function of the glymphatic system and a delay in the elimination of β-amyloid are shown. Directions of pathogenetic therapy are given.
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Affiliation(s)
- A I Fedin
- Pirogov Russian National Research Medical University, Moscow, Russia
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29
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Liu G, Ladrón-de-Guevara A, Izhiman Y, Nedergaard M, Du T. Measurements of cerebrospinal fluid production: a review of the limitations and advantages of current methodologies. Fluids Barriers CNS 2022; 19:101. [PMID: 36522656 PMCID: PMC9753305 DOI: 10.1186/s12987-022-00382-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 10/13/2022] [Indexed: 12/23/2022] Open
Abstract
Cerebrospinal fluid (CSF) is an essential and critical component of the central nervous system (CNS). According to the concept of the "third circulation" originally proposed by Cushing, CSF is mainly produced by the choroid plexus and subsequently leaves the cerebral ventricles via the foramen of Magendie and Luschka. CSF then fills the subarachnoid space from whence it disperses to all parts of the CNS, including the forebrain and spinal cord. CSF provides buoyancy to the submerged brain, thus protecting it against mechanical injury. CSF is also transported via the glymphatic pathway to reach deep interstitial brain regions along perivascular channels; this CSF clearance pathway promotes transport of energy metabolites and signaling molecules, and the clearance of metabolic waste. In particular, CSF is now intensively studied as a carrier for the removal of proteins implicated in neurodegeneration, such as amyloid-β and tau. Despite this key function of CSF, there is little information about its production rate, the factors controlling CSF production, and the impact of diseases on CSF flux. Therefore, we consider it to be a matter of paramount importance to quantify better the rate of CSF production, thereby obtaining a better understanding of CSF dynamics. To this end, we now review the existing methods developed to measure CSF production, including invasive, noninvasive, direct, and indirect methods, and MRI-based techniques. Depending on the methodology, estimates of CSF production rates in a given species can extend over a ten-fold range. Throughout this review, we interrogate the technical details of CSF measurement methods and discuss the consequences of minor experimental modifications on estimates of production rate. Our aim is to highlight the gaps in our knowledge and inspire the development of more accurate, reproducible, and less invasive techniques for quantitation of CSF production.
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Affiliation(s)
- Guojun Liu
- Department of Neurosurgery, The Fourth Affiliated Hospital of China Medical University, Shenyang, 110032, China
- School of Pharmacy, China Medical University, Shenyang, 110122, China
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark
- Center for Translational Neuromedicine, Department of Neurosurgery, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Antonio Ladrón-de-Guevara
- Center for Translational Neuromedicine, Department of Neurosurgery, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Yara Izhiman
- Center for Translational Neuromedicine, Department of Neurosurgery, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark.
- Center for Translational Neuromedicine, Department of Neurosurgery, University of Rochester Medical Center, Rochester, NY, 14642, USA.
| | - Ting Du
- School of Pharmacy, China Medical University, Shenyang, 110122, China.
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen, Denmark.
- Center for Translational Neuromedicine, Department of Neurosurgery, University of Rochester Medical Center, Rochester, NY, 14642, USA.
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Asnafi S, Chen BS, Biousse V, Newman NJ, Saindane AM. Intracranial computed tomography histogram analysis detects changes in the setting of elevated intracranial pressure and normal imaging. Neuroradiol J 2022; 35:718-723. [PMID: 35506947 PMCID: PMC9626849 DOI: 10.1177/19714009221096832] [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] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Patients with idiopathic intracranial hypertension (IIH) have elevated intracranial pressure (ICP) of unclear etiology. This study evaluated the ability of quantitative intracranial Hounsfield unit (HU) histogram analysis to detect pathophysiological changes from elevated ICP in the setting of a normal head CT. METHODS Retrospective analysis of non-contrast-enhanced head CT images of IIH patients and matched controls. Following skull stripping, total intracranial CT voxels within the range of 0-70 HU were divided into seven 10 HU bins. A measurement of total intracranial HU was also calculated for each patient. Imaging studies for IIH patients were reviewed for features of IIH including transverse sinus stenosis (TSS). Histogram measures were compared between IIH and control groups and correlated with imaging and clinical data. RESULTS Fourteen IIH patients with CSF opening pressure ≥25 cm water, and 31 age-, sex-, and ethnicity-matched controls were included. Compared to controls, IIH patients had a significantly greater proportion of voxels in the 40-50, 50-60, and 60-70 HU bins (p = 0.003, 0.001, and 0.003, respectively) but similar proportion in the 0-10 HU range. Severity of TSS significantly correlated with total intracranial HU measures. 50-60 HU and 60-70 HU bins demonstrated high AUCs of 0.81 and 0.80, respectively, in differentiating IIH from normal status. CONCLUSION Idiopathic intracranial hypertension patients have a greater proportion of high intracranial HU voxels representing blood volume, which may be explained by TSS causing venous congestion. The pattern provides further insights into the pathophysiology of IIH and may be useful for detecting elevated ICP in the setting of normal head CT imaging.
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Affiliation(s)
- Solmaz Asnafi
- Department of Radiology and Imaging
Sciences, Emory University School of
Medicine, Atlanta, GA, USA
| | - Benson S Chen
- Department of Ophthalmology, Emory University School of
Medicine, Atlanta, GA, USA
| | - Valérie Biousse
- Department of Ophthalmology, Emory University School of
Medicine, Atlanta, GA, USA
- Department of Neurology, Emory University School of
Medicine, Atlanta, GA, USA
| | - Nancy J Newman
- Department of Ophthalmology, Emory University School of
Medicine, Atlanta, GA, USA
- Department of Neurology, Emory University School of
Medicine, Atlanta, GA, USA
- Department of Neurological Surgery, Emory University School of
Medicine, Atlanta, GA, USA
| | - Amit M Saindane
- Department of Radiology and Imaging
Sciences, Emory University School of
Medicine, Atlanta, GA, USA
- Department of Neurological Surgery, Emory University School of
Medicine, Atlanta, GA, USA
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31
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Muacevic A, Adler JR, Hedayat HS. Cisternotomy and Liliequist's Membrane Fenestration as a Surgical Treatment for Idiopathic Intracranial Hypertension (Pseudotumor Cerebri): A Case Report. Cureus 2022; 14:e31363. [PMID: 36514638 PMCID: PMC9741810 DOI: 10.7759/cureus.31363] [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] [Accepted: 11/10/2022] [Indexed: 11/13/2022] Open
Abstract
Subarachnoid basal cistern opening (cisternotomy) is used during many microsurgical operations to relax the brain by removing or diverting cerebrospinal fluid (CSF). Recently, cisternotomy has been used in patients with traumatic brain injury to improve outcomes due to its ability to decrease intracranial pressure (ICP) and brain edema by diverting CSF. Theoretically, another condition that can benefit from cisternotomy is idiopathic intracranial hypertension (IIH) as it presents with manifestations of increased ICP, such as headache, vomiting, and papilledema. Here, we discuss the case of a 39-year-old woman with IIH who presented with headache, nausea, and papilledema in the setting of maximally tolerated medical management after five months of shunt removal due to infection. The patient did not want to proceed with the replacement of her shunt and therefore underwent a right eyebrow craniotomy for cisternotomy, lamina terminals fenestration, and Liliequist's membrane opening. Postoperatively, her symptoms improved completely. She was off acetazolamide altogether at the three-month follow-up and no longer had pseudotumor cerebri headaches. This case report demonstrates the use of cisternotomy to relieve the manifestations of increased ICP and its potential as a surgical option for patients with IIH.
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Choi S, Jang DC, Chung G, Kim SK. Transcutaneous Auricular Vagus Nerve Stimulation Enhances Cerebrospinal Fluid Circulation and Restores Cognitive Function in the Rodent Model of Vascular Cognitive Impairment. Cells 2022; 11:cells11193019. [PMID: 36230988 PMCID: PMC9564197 DOI: 10.3390/cells11193019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 09/21/2022] [Accepted: 09/23/2022] [Indexed: 11/16/2022] Open
Abstract
Vascular cognitive impairment (VCI) is a common sequela of cerebrovascular disorders. Although transcutaneous auricular vagus nerve stimulation (taVNS) has been considered a complementary treatment for various cognitive disorders, preclinical data on the effect of taVNS on VCI and its mechanism remain ambiguous. To measure cerebrospinal fluid (CSF) circulation during taVNS, we used in vivo two-photon microscopy with CSF and vasculature tracers. VCI was induced by transient bilateral common carotid artery occlusion (tBCCAO) surgery in mice. The animals underwent anesthesia, off-site stimulation, or taVNS for 20 min. Cognitive tests, including the novel object recognition and the Y-maze tests, were performed 24 h after the last treatment. The long-term treatment group received 6 days of treatment and was tested on day 7; the short-term treatment group received 2 days of treatment and was tested 3 days after tBCCAO surgery. CSF circulation increased remarkably in the taVNS group, but not in the anesthesia-control or off-site-stimulation-control groups. The cognitive impairment induced by tBCCAO was significantly restored after both long- and short-term taVNS. In terms of effects, both long- and short-term stimulations showed similar recovery effects. Our findings provide evidence that taVNS can facilitate CSF circulation and that repetitive taVNS can ameliorate VCI symptoms.
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Affiliation(s)
- Seunghwan Choi
- Department of East-West Medicine, Graduate School, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
| | - Dong Cheol Jang
- Department of Physiology, College of Korean Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
| | - Geehoon Chung
- Department of Physiology, College of Korean Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
| | - Sun Kwang Kim
- Department of East-West Medicine, Graduate School, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
- Department of Physiology, College of Korean Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Korea
- Correspondence:
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Klarica M, Radoš M, Erceg G, Jurjević I, Petošić A, Virag Z, Orešković D. Cerebrospinal fluid micro-volume changes inside the spinal space affect intracranial pressure in different body positions of animals and phantom. Front Mol Neurosci 2022; 15:931091. [PMID: 36187355 PMCID: PMC9518230 DOI: 10.3389/fnmol.2022.931091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 08/09/2022] [Indexed: 11/13/2022] Open
Abstract
Interpersonal differences can be observed in the human cerebrospinal fluid pressure (CSFP) in the cranium in an upright body position, varying from positive to subatmospheric values. So far, these changes have been explained by the Monroe–Kellie doctrine according to which CSFP should increase or decrease if a change in at least one of the three intracranial volumes (brain, blood, and CSF) occurs. According to our hypothesis, changes in intracranial CSFP can occur without a change in the volume of intracranial fluids. To test this hypothesis, we alternately added and removed 100 or 200 μl of fluid from the spinal CSF space of four anesthetized cats and from a phantom which, by its dimensions and biophysical characteristics, imitates the cat cerebrospinal system, subsequently comparing CSFP changes in the cranium and spinal space in both horizontal and vertical positions. The phantom was made from a rigid “cranial” part with unchangeable volume, while the “spinal” part was made of elastic material whose modulus of elasticity was in the same order of magnitude as those of spinal dura. When a fluid volume (CSF or artificial CSF) was removed from the spinal space, both lumbar and cranial CSFP pressures decreased by 2.0–2.5 cm H2O for every extracted 100 μL. On the other hand, adding fluid volume to spinal space causes an increase in both lumbar and cranial CSFP pressures of 2.6–3.0 cm H2O for every added 100 μL. Results observed in cats and phantoms did not differ significantly. The presented results on cats and a phantom suggest that changes in the spinal CSF volume significantly affect the intracranial CSFP, but regardless of whether we added or removed the CSF volume, the hydrostatic pressure difference between the measuring sites (lateral ventricle and lumbar subarachnoid space) was always constant. These results suggest that intracranial CSFP can be increased or decreased without significant changes in the volume of intracranial fluids and that intracranial CSFP changes in accordance with the law of fluid mechanics.
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Affiliation(s)
- Marijan Klarica
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
- *Correspondence: Marijan Klarica
| | - Milan Radoš
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Gorislav Erceg
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Ivana Jurjević
- Department of Pharmacology and Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Antonio Petošić
- Department of Electroacoustics, Faculty of Electrical Engineering and Computing University of Zagreb, Zagreb, Croatia
| | - Zdravko Virag
- Department of Fluid Mechanics, Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Zagreb, Croatia
| | - Darko Orešković
- Department of Molecular Biology, Ruder Bošković Institute, Zagreb, Croatia
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Thompson D, Brissette CA, Watt JA. The choroid plexus and its role in the pathogenesis of neurological infections. Fluids Barriers CNS 2022; 19:75. [PMID: 36088417 PMCID: PMC9463972 DOI: 10.1186/s12987-022-00372-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 08/27/2022] [Indexed: 11/10/2022] Open
Abstract
AbstractThe choroid plexus is situated at an anatomically and functionally important interface within the ventricles of the brain, forming the blood-cerebrospinal fluid barrier that separates the periphery from the central nervous system. In contrast to the blood–brain barrier, the choroid plexus and its epithelial barrier have received considerably less attention. As the main producer of cerebrospinal fluid, the secretory functions of the epithelial cells aid in the maintenance of CNS homeostasis and are capable of relaying inflammatory signals to the brain. The choroid plexus acts as an immunological niche where several types of peripheral immune cells can be found within the stroma including dendritic cells, macrophages, and T cells. Including the epithelia cells, these cells perform immunosurveillance, detecting pathogens and changes in the cytokine milieu. As such, their activation leads to the release of homing molecules to induce chemotaxis of circulating immune cells, driving an immune response at the choroid plexus. Research into the barrier properties have shown how inflammation can alter the structural junctions and promote increased bidirectional transmigration of cells and pathogens. The goal of this review is to highlight our foundational knowledge of the choroid plexus and discuss how recent research has shifted our understanding towards viewing the choroid plexus as a highly dynamic and important contributor to the pathogenesis of neurological infections. With the emergence of several high-profile diseases, including ZIKA and SARS-CoV-2, this review provides a pertinent update on the cellular response of the choroid plexus to these diseases. Historically, pharmacological interventions of CNS disorders have proven difficult to develop, however, a greater focus on the role of the choroid plexus in driving these disorders would provide for novel targets and routes for therapeutics.
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35
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Bitanihirwe BKY, Lizano P, Woo TUW. Deconstructing the functional neuroanatomy of the choroid plexus: an ontogenetic perspective for studying neurodevelopmental and neuropsychiatric disorders. Mol Psychiatry 2022; 27:3573-3582. [PMID: 35618887 PMCID: PMC9133821 DOI: 10.1038/s41380-022-01623-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 04/15/2022] [Accepted: 05/11/2022] [Indexed: 02/08/2023]
Abstract
The choroid plexus (CP) is a delicate and highly vascularized structure in the brain comprised of a dense network of fenestrated capillary loops that help in the synthesis, secretion and circulation of cerebrospinal fluid (CSF). This unique neuroanatomical structure is comprised of arachnoid villi stemming from frond-like surface projections-that protrude into the lumen of the four cerebral ventricles-providing a key source of nutrients to the brain parenchyma in addition to serving as a 'sink' for central nervous system metabolic waste. In fact, the functions of the CP are often described as being analogous to those of the liver and kidney. Beyond forming a barrier/interface between the blood and CSF compartments, the CP has been identified as a modulator of leukocyte trafficking, inflammation, cognition, circadian rhythm and the gut brain-axis. In recent years, advances in molecular biology techniques and neuroimaging along with the use of sophisticated animal models have played an integral role in shaping our understanding of how the CP-CSF system changes in relation to the maturation of neural circuits during critical periods of brain development. In this article we provide an ontogenetic perspective of the CP and review the experimental evidence implicating this structure in the pathophysiology of neurodevelopmental and neuropsychiatric disorders.
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Affiliation(s)
- Byron K Y Bitanihirwe
- Humanitarian and Conflict Response Institute, University of Manchester, Manchester, UK.
| | - Paulo Lizano
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA, USA
- Translational Neuroscience Division, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Tsung-Ung W Woo
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA
- Program in Molecular Neuropathology, McLean Hospital, Belmont, MA, USA
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36
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Harrer C, Otto F, Radlberger RF, Moser T, Pilz G, Wipfler P, Harrer A. The CXCL13/CXCR5 Immune Axis in Health and Disease—Implications for Intrathecal B Cell Activities in Neuroinflammation. Cells 2022; 11:cells11172649. [PMID: 36078057 PMCID: PMC9454489 DOI: 10.3390/cells11172649] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 08/21/2022] [Accepted: 08/22/2022] [Indexed: 11/16/2022] Open
Abstract
The chemokine C-X-C- ligand 13 (CXCL13) is a major B cell chemoattractant to B cell follicles in secondary lymphoid organs (SLO) that proposedly recruits B cells to the cerebrospinal fluid (CSF) during neuroinflammation. CXCR5, the cognate receptor of CXCL13, is expressed on B cells and certain T cell subsets, in particular T follicular helper cells (Tfh cells), enabling them to follow CXCL13 gradients towards B cell follicles for spatial proximity, a prerequisite for productive T cell–B cell interaction. Tfh cells are essential contributors to B cell proliferation, differentiation, and high-affinity antibody synthesis and are required for germinal center formation and maintenance. Circulating Tfh cells (cTfh) have been observed in the peripheral blood and CSF. Furthermore, CXCL13/CXCR5-associated immune activities organize and shape adaptive B cell-related immune responses outside of SLO via the formation of ectopic lymphoid structures in inflamed tissues, including the central nervous system (CNS). This review summarizes the recent advances in our understanding of the CXCL13/CXCR5 immune axis and its role in vaccination, autoimmunity, and infection with a special focus on its relevance for intrathecal B cell activities in inflammatory CNS diseases.
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Affiliation(s)
- Christine Harrer
- Department of Neurology, Christian Doppler University Hospital, Paracelsus Medical University and Center for Cognitive Neuroscience, 5020 Salzburg, Austria
- Clinical Division of Social Psychiatry, Department of Psychiatry and Psychotherapy, Medical University of Vienna, 1090 Vienna, Austria
| | - Ferdinand Otto
- Department of Neurology, Christian Doppler University Hospital, Paracelsus Medical University and Center for Cognitive Neuroscience, 5020 Salzburg, Austria
| | - Richard Friedrich Radlberger
- Department of Neurology, Christian Doppler University Hospital, Paracelsus Medical University and Center for Cognitive Neuroscience, 5020 Salzburg, Austria
| | - Tobias Moser
- Department of Neurology, Christian Doppler University Hospital, Paracelsus Medical University and Center for Cognitive Neuroscience, 5020 Salzburg, Austria
| | - Georg Pilz
- Department of Neurology, Christian Doppler University Hospital, Paracelsus Medical University and Center for Cognitive Neuroscience, 5020 Salzburg, Austria
| | - Peter Wipfler
- Department of Neurology, Christian Doppler University Hospital, Paracelsus Medical University and Center for Cognitive Neuroscience, 5020 Salzburg, Austria
| | - Andrea Harrer
- Department of Neurology, Christian Doppler University Hospital, Paracelsus Medical University and Center for Cognitive Neuroscience, 5020 Salzburg, Austria
- Department of Dermatology and Allergology, Paracelsus Medical University Salzburg, 5020 Salzburg, Austria
- Correspondence:
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37
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Revisiting Cerebrospinal Fluid Flow Direction and Rate in Physiologically Based Pharmacokinetic Model. Pharmaceutics 2022; 14:pharmaceutics14091764. [PMID: 36145511 PMCID: PMC9504371 DOI: 10.3390/pharmaceutics14091764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/17/2022] [Accepted: 08/21/2022] [Indexed: 11/28/2022] Open
Abstract
The bidirectional pulsatile movement of cerebrospinal fluid (CSF), instead of the traditionally believed unidirectional and constant CSF circulation, has been demonstrated. In the present study, the structure and parameters of the CSF compartments were revisited in our comprehensive and validated central nervous system (CNS)-specific, physiologically based pharmacokinetic (PBPK) model of healthy rats (LeiCNS-PK3.0). The bidirectional and site-dependent CSF movement was incorporated into LeiCNS-PK3.0 to create the new LeiCNS-PK“3.1” model. The physiological CSF movement rates in healthy rats that are unavailable from the literature were estimated by fitting the PK data of sucrose, a CSF flow marker, after intra-CSF administration. The capability of LeiCNS-PK3.1 to describe the PK profiles of other molecules was compared with that of the original LeiCNS-PK3.0 model. LeiCNS-PK3.1 demonstrated superior description of the CSF PK profiles of a range of small molecules after intra-CSF administration over LeiCNS-PK3.0. LeiCNS-PK3.1 also retained the same level of predictability of CSF PK profiles in cisterna magna after intravenous administration. These results support the theory of bidirectional and site-dependent CSF movement across the entire CSF space over unidirectional and constant CSF circulation in healthy rats, pointing out the need to revisit the structures and parameters of CSF compartments in CNS-PBPK models.
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Sato Y, Minami K, Hirato T, Tanizawa K, Sonoda H, Schmidt M. Drug delivery for neuronopathic lysosomal storage diseases: evolving roles of the blood brain barrier and cerebrospinal fluid. Metab Brain Dis 2022; 37:1745-1756. [PMID: 35088290 PMCID: PMC9283362 DOI: 10.1007/s11011-021-00893-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 12/06/2021] [Indexed: 12/14/2022]
Abstract
Whereas significant strides have been made in the treatment of lysosomal storage diseases (LSDs), the neuronopathy associated with these diseases remains impervious mainly because of the blood-brain barrier (BBB), which prevents delivery of large molecules to the brain. However, 100 years of research on the BBB since its conceptualization have clarified many of its functional and structural characteristics, spurring recent endeavors to deliver therapeutics across it to treat central nervous system (CNS) disorders, including neuronopathic LSDs. Along with the BBB, the cerebrospinal fluid (CSF) also functions to protect the microenvironment of the CNS, and it is therefore deeply involved in CNS disorders at large. Recent research aimed at developing therapeutics for neuronopathic LSDs has uncovered a number of critical roles played by the CSF that require further clarification. This review summarizes the most up-to-date understanding of the BBB and the CSF acquired during the development of therapeutics for neuronopathic LSDs, and highlights some of the associated challenges that require further research.
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Affiliation(s)
- Yuji Sato
- Research and Development, JCR Pharmaceuticals, Ashiya, Hyogo, Japan.
| | - Kohtaro Minami
- Research and Development, JCR Pharmaceuticals, Ashiya, Hyogo, Japan
| | - Toru Hirato
- Research and Development, JCR Pharmaceuticals, Ashiya, Hyogo, Japan
| | | | - Hiroyuki Sonoda
- Research and Development, JCR Pharmaceuticals, Ashiya, Hyogo, Japan
| | - Mathias Schmidt
- Research and Development, JCR Pharmaceuticals, Ashiya, Hyogo, Japan
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Mehta NH, Suss RA, Dyke JP, Theise ND, Chiang GC, Strauss S, Saint-Louis L, Li Y, Pahlajani S, Babaria V, Glodzik L, Carare RO, de Leon MJ. Quantifying cerebrospinal fluid dynamics: A review of human neuroimaging contributions to CSF physiology and neurodegenerative disease. Neurobiol Dis 2022; 170:105776. [PMID: 35643187 PMCID: PMC9987579 DOI: 10.1016/j.nbd.2022.105776] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 05/21/2022] [Indexed: 01/13/2023] Open
Abstract
Cerebrospinal fluid (CSF), predominantly produced in the ventricles and circulating throughout the brain and spinal cord, is a key protective mechanism of the central nervous system (CNS). Physical cushioning, nutrient delivery, metabolic waste, including protein clearance, are key functions of the CSF in humans. CSF volume and flow dynamics regulate intracranial pressure and are fundamental to diagnosing disorders including normal pressure hydrocephalus, intracranial hypotension, CSF leaks, and possibly Alzheimer's disease (AD). The ability of CSF to clear normal and pathological proteins, such as amyloid-beta (Aβ), tau, alpha synuclein and others, implicates it production, circulation, and composition, in many neuropathologies. Several neuroimaging modalities have been developed to probe CSF fluid dynamics and better relate CSF volume and flow to anatomy and clinical conditions. Approaches include 2-photon microscopic techniques, MRI (tracer-based, gadolinium contrast, endogenous phase-contrast), and dynamic positron emission tomography (PET) using existing approved radiotracers. Here, we discuss CSF flow neuroimaging, from animal models to recent clinical-research advances, summarizing current endeavors to quantify and map CSF flow with implications towards pathophysiology, new biomarkers, and treatments of neurological diseases.
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Affiliation(s)
- Neel H Mehta
- Department of Biology, Cornell University, Ithaca, NY, USA
| | - Richard A Suss
- Division of Neuroradiology, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jonathan P Dyke
- Citigroup Biomedical Imaging Center, Weill Cornell Medicine, New York, NY, USA
| | - Neil D Theise
- Department of Pathology, NYU Grossman School of Medicine, New York, NY, USA
| | - Gloria C Chiang
- Division of Neuroradiology, Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Sara Strauss
- Division of Neuroradiology, Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | | | - Yi Li
- Brain Health Imaging Institute, Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Silky Pahlajani
- Brain Health Imaging Institute, Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Vivek Babaria
- Orange County Spine and Sports, Interventional Physiatry, Newport Beach, CA, USA
| | - Lidia Glodzik
- Brain Health Imaging Institute, Department of Radiology, Weill Cornell Medicine, New York, NY, USA
| | - Roxana O Carare
- Department of Medicine, University of Southampton, Southampton, UK
| | - Mony J de Leon
- Brain Health Imaging Institute, Department of Radiology, Weill Cornell Medicine, New York, NY, USA.
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Prediction of adult post-hemorrhagic hydrocephalus: a risk score based on clinical data. Sci Rep 2022; 12:12213. [PMID: 35842469 PMCID: PMC9288433 DOI: 10.1038/s41598-022-16577-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 07/12/2022] [Indexed: 11/08/2022] Open
Abstract
There is lacking research on risk factors and prediction models associated with Post-hemorrhagic hydrocephalus (PHH). Thus, this present study aimed to analyze the risk factors of PHH and establish a risk-scoring system through a large-scale study. A retrospective study of 382 patients with intracranial hemorrhage assessed age, history and diagnosis, Glasgow coma score (GCS), and fever time. After univariate and logistic regression analysis, a risk scoring system was established according to independent risk factors and evaluated using the area under the curve (AUC). Of the 382 patients, 133 (34.8%) had PHH, 43 (11.3%) received surgical treatment. Factor classification showed that age > 60 years old [odds ratio (OR): 0.347, II = 5 points], GCS < 5 (OR: 0.09, IV = 10 points), GCS 6‒8 (OR = 0.232, III = 6 points), fever time > 9 (OR: 0.202, III = 7 points), fever time 5-9 (OR: 0.341, II = 5 points), CSF-TP x time > 14,4000 group (OR: 0.267, IV = 6 points), and CSF-TP x time 9,601‒14,400 group (OR: 0.502, III = 3 points) were independent risk factors. The result of the receiver operating characteristic (ROC) prediction showed that AUC = 0.790 (0.744‒0.836). Low-risk (IV-VII), moderate (VIII-X), and high-risk group (XI-XIII) incidence of PHH were 11.76%, 50.55%, and 70.00% (p < 0.001), respectively. The coincidence rates in the validation cohort were 26.00%, 74.07%, and 100.0% (p < 0.001), respectively. AUC value was 0.860 (0.780‒0.941). The predictive model was conducive to determining the occurrence of PHH and facilitating early intervention.
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Christensen J, Li C, Mychasiuk R. Choroid plexus function in neurological homeostasis and disorders: The awakening of the circadian clocks and orexins. J Cereb Blood Flow Metab 2022; 42:1163-1175. [PMID: 35296175 PMCID: PMC9207490 DOI: 10.1177/0271678x221082786] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
As research regarding the role of circadian rhythms, sleep, and the orexinergic system in neurodegenerative diseases is growing, it is surprising that the choroid plexus (CP) remains underappreciated in this realm. Despite its extensive role in the regulation of circadian rhythms and orexinergic signalling, as well as acting as the primary conduit between cerebrospinal fluid (CSF) and the circulatory system, providing a mechanism by which toxic waste molecules can be removed from the brain, the CP has been largely unexplored in neurodegeneration. In this review, we explore the role of the CP in maintaining brain homeostasis and circadian rhythms, regulating CSF dynamics, and how these functions change across the lifespan, from development to senescence. In addition, we examine the relationship between the CP, orexinergic signalling, and the glymphatic system, highlighting gaps in the literature and areas that require immediate exploration. Finally, we assess current knowledge, including possible therapeutic strategies, regarding the role of the CP in neurological disorders, such as traumatic brain injury, migraine, Alzheimer's disease, and multiple sclerosis.
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Affiliation(s)
- Jennaya Christensen
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Crystal Li
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Richelle Mychasiuk
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
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Faryami A, Menkara A, Viar D, Harris CA. Testing and validation of reciprocating positive displacement pump for benchtop pulsating flow model of cerebrospinal fluid production and other physiologic systems. PLoS One 2022; 17:e0262372. [PMID: 35550626 PMCID: PMC9098063 DOI: 10.1371/journal.pone.0262372] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 04/15/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND The flow of physiologic fluids through organs and organs systems is an integral component of their function. The complex fluid dynamics in many organ systems are still not completely understood, and in-vivo measurements of flow rates and pressure provide a testament to the complexity of each flow system. Variability in in-vivo measurements and the lack of control over flow characteristics leave a lot to be desired for testing and evaluation of current modes of treatments as well as future innovations. In-vitro models are particularly ideal for studying neurological conditions such as hydrocephalus due to their complex pathophysiology and interactions with therapeutic measures. The following aims to present the reciprocating positive displacement pump, capable of inducing pulsating flow of a defined volume at a controlled beat rate and amplitude. While the other fluidic applications of the pump are currently under investigation, this study was focused on simulating the pulsating cerebrospinal fluid production across profiles with varying parameters. METHODS Pumps were manufactured using 3D printed and injection molded parts. The pumps were powered by an Arduino-based board and proprietary software that controls the linear motion of the pumps to achieve the specified output rate at the desired pulsation rate and amplitude. A range of 0.01 [Formula: see text] to 0.7 [Formula: see text] was tested to evaluate the versatility of the pumps. The accuracy and precision of the pumps' output were evaluated by obtaining a total of 150 one-minute weight measurements of degassed deionized water per output rate across 15 pump channels. In addition, nine experiments were performed to evaluate the pumps' control over pulsation rate and amplitude. RESULTS Volumetric analysis of a total of 1200 readings determined that the pumps achieved the target output volume rate with a mean absolute error of -0.001034283 [Formula: see text] across the specified domain. It was also determined that the pumps can maintain pulsatile flow at a user-specified beat rate and amplitude. CONCLUSION The validation of this reciprocating positive displacement pump system allows for the future validation of novel designs to components used to treat hydrocephalus and other physiologic models involving pulsatile flow. Based on the promising results of these experiments at simulating pulsatile CSF flow, a benchtop model of human CSF production and distribution could be achieved through the incorporation of a chamber system and a compliance component.
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Affiliation(s)
- Ahmad Faryami
- Department of Biomedical Engineering, Wayne State University, Detroit, MI, United States of America
| | - Adam Menkara
- Department of Biomedical Engineering, Wayne State University, Detroit, MI, United States of America
| | - Daniel Viar
- Department of Computer Science and Engineering, University of Toledo, Toledo, Ohio, United States of America
| | - Carolyn A. Harris
- Wayne State University Dept. of Chemical Engineering and Materials Science, Detroit, MI, United States of America
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Atchley TJ, Vukic B, Vukic M, Walters BC. Review of Cerebrospinal Fluid Physiology and Dynamics: A Call for Medical Education Reform. Neurosurgery 2022; 91:1-7. [PMID: 35522666 DOI: 10.1227/neu.0000000000002000] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 12/05/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The flow of cerebrospinal fluid (CSF) has been described as a unidirectional system with the choroid plexus serving as the primary secretor of CSF and the arachnoid granulations as primary reabsorption site. This theory of neurosurgical forefathers has been universally adopted and taught as dogma. Many neuroscientists have found difficulty reconciling this theory with common pathologies, and recent studies have found that this "classic" hypothesis may not represent the full picture. OBJECTIVE To review modern CSF dynamic theories and to call for medical education reform. METHODS We reviewed the literature from January 1990 to December 2020. We searched the PubMed database using key terms "cerebrospinal fluid circulation," "cerebrospinal fluid dynamics," "cerebrospinal fluid physiology," "glymphatic system," and "glymphatic pathway." We selected articles with a primary aim to discuss either CSF dynamics and/or the glymphatic system. RESULTS The Bulat-Klarica-Orešković hypothesis purports that CSF is secreted and reabsorbed throughout the craniospinal axis. CSF demonstrates similar physiology to that of water elsewhere in the body. CSF "circulates" throughout the subarachnoid space in a pulsatile to-and-fro fashion. Osmolarity plays a critical role in CSF dynamics. Aquaporin-4 and the glymphatic system contribute to CSF volume and flow by establishing osmolarity gradients and facilitating CSF movement. Multiple studies demonstrate that the choroid plexus does not play any significant role in CSF circulation. CONCLUSION We have highlighted major studies to illustrate modern principles of CSF dynamics. Despite these, the medical education system has been slow to reform curricula and update learning resources.
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Affiliation(s)
- Travis J Atchley
- Department of Neurosurgery, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Barbara Vukic
- School of Medicine, University of Zagreb, Zagreb, Croatia
| | - Miroslav Vukic
- Department of Neurosurgery, Sisters of Mercy University Hospital, Zagreb, Croatia
| | - Beverly C Walters
- Department of Neurosurgery, University of Alabama at Birmingham, Birmingham, Alabama, USA
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Li AM, Chen L, Liu H, Li Y, Duan W, Xu J. Age-dependent cerebrospinal fluid-tissue water exchange detected by magnetization transfer indirect spin labeling MRI. Magn Reson Med 2022; 87:2287-2298. [PMID: 34958518 PMCID: PMC8847338 DOI: 10.1002/mrm.29137] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 12/06/2021] [Accepted: 12/10/2021] [Indexed: 01/29/2023]
Abstract
PURPOSE A non-invasive magnetization transfer indirect spin labeling (MISL) MRI method is developed to quantify the water exchange between cerebrospinal fluid (CSF) and other tissues in the brain and to examine the age-dependence of water exchange. METHOD In the pulsed MISL, we implemented a short selective pulse followed by a post-labeling delay before an MRI acquisition with a long echo time; in the continuous MISL, a train of saturation pulses was applied. MISL signal (∆Z) was obtained by the subtraction of the label MRI at -3.5 ppm from the control MRI at 200 ppm. CSF was extracted from the mouse ventricles for the MISL optimization and validation. Comparison between wild type (WT) and aquaporin-4 knockout (AQP4-/- ) mice was performed to examine the contributions of CSF water exchange, whereas its age-dependence was investigated by comparing the adult and young WT mice. RESULTS The pulsed MISL method observed that the MISL signal reached the maximum at 1.5 s. The continuous MISL method showed the highest MISL signal in the fourth ventricle (∆Z = 13.5% ± 1.4%), whereas the third ventricle and the lateral ventricles had similar MISL ∆Z values (∆Z = 12.0% ± 1.8%). Additionally, significantly lower ∆Z (9.3%-18.7% reduction) was found in all ventricles for the adult mice than those of the young mice (p < 0.02). For the AQP4-/- mice, the ∆Z values were 5.9%-8.3% smaller than those of the age-matched WT mice in the lateral and fourth ventricles, but were not significant. CONCLUSION The MISL method has a great potential to study CSF water exchange with the surrounding tissues in brain.
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Affiliation(s)
- Anna M. Li
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, MD 21205, USA
| | - Lin Chen
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, MD 21205, USA
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, School of Electronic Science and Engineering, National Model Microelectronics College, Xiamen University, Xiamen, China
| | - Hongshuai Liu
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Yuguo Li
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, MD 21205, USA
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Wenzhen Duan
- Division of Neurobiology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jiadi Xu
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, MD 21205, USA
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Maloveská M, Humeník F, Vikartovská Z, Hudáková N, Almášiová V, Krešáková L, Čížková D. Brain Fluid Channels for Metabolite Removal. Physiol Res 2022; 71:199-208. [DOI: 10.33549/physiolres.934802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The adult human brain represents only 2 % of the body's total weight, however it is one of the most metabolically active organs in the mammalian body. Its high metabolic activity necessitates an efficacious waste clearance system. Besides the blood, there are two fluids closely linked to the brain and spinal cord drainage system: interstitial fluid (ISF) and cerebrospinal fluid (CSF). The aim of this review is to summarize the latest research clarifying the channels of metabolite removal by fluids from brain tissue, subarachnoid space (SAS) and brain dura (BD). Special attention is focused on lymphatic vascular structures in the brain dura, their localizations within the meninges, morphological properties and topographic anatomy. The review ends with an account of the consequences of brain lymphatic drainage failure. Knowledge of the physiological state of the clearance system is crucial in order to understand the changes related to impaired brain drainage.
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Affiliation(s)
| | | | | | | | | | | | - D Čížková
- Centre of Experimental and Clinical Regenerative Medicine, University of Veterinary Medicine and Pharmacy in Kosice, Slovak Republic.
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46
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Zhang D, Li X, Li B. Glymphatic System Dysfunction in Central Nervous System Diseases and Mood Disorders. Front Aging Neurosci 2022; 14:873697. [PMID: 35547631 PMCID: PMC9082304 DOI: 10.3389/fnagi.2022.873697] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 03/31/2022] [Indexed: 12/13/2022] Open
Abstract
The glymphatic system, a recently discovered macroscopic waste removal system in the brain, has many unknown aspects, especially its driving forces and relationship with sleep, and thus further explorations of the relationship between the glymphatic system and a variety of possible related diseases are urgently needed. Here, we focus on the progress in current research on the role of the glymphatic system in several common central nervous system diseases and mood disorders, discuss the structural and functional abnormalities of the glymphatic system which may occur before or during the pathophysiological progress and the possible underlying mechanisms. We emphasize the relationship between sleep and the glymphatic system under pathological conditions and summarize the common imaging techniques for the glymphatic system currently available. The perfection of the glymphatic system hypothesis and the exploration of the effects of aging and endocrine factors on the central and peripheral regulatory pathways through the glymphatic system still require exploration in the future.
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Affiliation(s)
- Dianjun Zhang
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China
- Liaoning Province Key Laboratory of Forensic Bio-evidence Sciences, School of Forensic Medicine, China Medical University, Shenyang, China
- China Medical University Center of Forensic Investigation, School of Forensic Medicine, China Medical University, Shenyang, China
| | - Xinyu Li
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China
- Liaoning Province Key Laboratory of Forensic Bio-evidence Sciences, School of Forensic Medicine, China Medical University, Shenyang, China
- China Medical University Center of Forensic Investigation, School of Forensic Medicine, China Medical University, Shenyang, China
| | - Baoman Li
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China
- Liaoning Province Key Laboratory of Forensic Bio-evidence Sciences, School of Forensic Medicine, China Medical University, Shenyang, China
- China Medical University Center of Forensic Investigation, School of Forensic Medicine, China Medical University, Shenyang, China
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47
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Fang Y, Huang L, Wang X, Si X, Lenahan C, Shi H, Shao A, Tang J, Chen S, Zhang J, Zhang JH. A new perspective on cerebrospinal fluid dynamics after subarachnoid hemorrhage: From normal physiology to pathophysiological changes. J Cereb Blood Flow Metab 2022; 42:543-558. [PMID: 34806932 PMCID: PMC9051143 DOI: 10.1177/0271678x211045748] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Knowledge about the dynamic metabolism and function of cerebrospinal fluid (CSF) physiology has rapidly progressed in recent decades. It has traditionally been suggested that CSF is produced by the choroid plexus and drains to the arachnoid villi. However, recent findings have revealed that the brain parenchyma produces a large portion of CSF and drains through the perivascular glymphatic system and meningeal lymphatic vessels into the blood. The primary function of CSF is not limited to maintaining physiological CNS homeostasis but also participates in clearing waste products resulting from neurodegenerative diseases and acute brain injury. Aneurysmal subarachnoid hemorrhage (SAH), a disastrous subtype of acute brain injury, is associated with high mortality and morbidity. Post-SAH complications contribute to the poor outcomes associated with SAH. Recently, abnormal CSF flow was suggested to play an essential role in the post-SAH pathophysiological changes, such as increased intracerebral pressure, brain edema formation, hydrocephalus, and delayed blood clearance. An in-depth understanding of CSF dynamics in post-SAH events would shed light on potential development of SAH treatment options. This review summarizes and updates the latest physiological characteristics of CSF dynamics and discusses potential pathophysiological changes and therapeutic targets after SAH.
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Affiliation(s)
- Yuanjian Fang
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Lei Huang
- Department of Neurosurgery, Loma Linda University, Loma Linda, CA, USA.,Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, USA
| | - Xiaoyu Wang
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiaoli Si
- Department of Neurology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Cameron Lenahan
- Department of Neurosurgery, Loma Linda University, Loma Linda, CA, USA.,Burrell College of Osteopathic Medicine, Las Cruces, NM, USA
| | - Hui Shi
- Department of Neurosurgery, Loma Linda University, Loma Linda, CA, USA.,Department of Neurosurgery, Yongchuan Hospital, Chongqing Medical University, Chongqing, China
| | - Anwen Shao
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jiping Tang
- Department of Neurosurgery, Loma Linda University, Loma Linda, CA, USA.,Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, USA.,Department of Anesthesiology, Loma Linda University, Loma Linda, CA, USA
| | - Sheng Chen
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jianmin Zhang
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - John H Zhang
- Department of Neurosurgery, Loma Linda University, Loma Linda, CA, USA.,Department of Physiology and Pharmacology, Loma Linda University, Loma Linda, CA, USA.,Department of Anesthesiology, Loma Linda University, Loma Linda, CA, USA
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Morphometrics of the Spinal Cord and Surrounding Structures in Alligator mississippiensis. BIOLOGY 2022; 11:biology11040514. [PMID: 35453713 PMCID: PMC9024830 DOI: 10.3390/biology11040514] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/22/2022] [Accepted: 03/24/2022] [Indexed: 02/04/2023]
Abstract
Simple Summary Morphometric analysis of the spinal cord and surrounding tissue of the American alligator (Alligator mississippiensis) reveals that there are four significantly discrete regions; cervical, thoracic, lumbar, and caudal. Crocodylians, unlike mammals, have a caudal spinal cord that extends throughout the length of their tail (which accounts for roughly 50% of their total body length). Alligator mississippiensis has one of the largest ranges of body sizes among terrestrial vertebrates, this study documents how the different spinal structures change with increasing body size. Though most of the structures exhibit slightly positive allometry, a few exhibit slightly negative allometry; these differences mean that there are significant relational changes as hatchlings grow into large adults. This study provides the first documentation that A. mississippiensis has an expansive subdural space, a lumbar cistern, at the pelvis. Abstract Understanding the fluid dynamics of the cerebrospinal fluid requires a quantitative description of the spaces in which it flows, including the spinal cord and surrounding meninges. The morphometrics of the spinal cord and surrounding tissues were studied in specimens of the American alligator (Alligator mississippiensis) ranging from hatchlings through adults. Within any size class of alligators (i.e., hatchlings), along the axial length there are significant differences in the size of the spinal cord, meninges, and vertebral canal; these differences can be used to define discrete cervical, thoracic, lumbar and caudal regions. When compared across the range of body sizes in Alligator, every structure in each spinal region had a distinctive growth rate; thus, the physical arrangements between the structures changed as the alligator grew. The combination of regional differentiation and differential growth rates was particularly apparent in the lumbar meninges where a unique form of lumbar cistern could be identified and shown to decrease in relative size as the alligator ages. This analysis of the spinal cord and surrounding tissues was undertaken to develop a data set that could be used for computational flow dynamics of the crocodilian cerebrospinal fluid, and also to assist in the analysis of fossil archosaurs.
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Ramesh Chandra V, Bodapati Chandra mowliswara P, Banavath HN, Kalakoti CSR. “Cisternostomy Vs Decompressive Craniectomy for The Management of Traumatic Brain Injury: A Randomized Controlled Trial”. World Neurosurg 2022; 162:e58-e64. [DOI: 10.1016/j.wneu.2022.02.067] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/13/2022] [Accepted: 02/14/2022] [Indexed: 10/19/2022]
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50
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Elbert DL, Patterson BW, Lucey BP, Benzinger TLS, Bateman RJ. Importance of CSF-based Aβ clearance with age in humans increases with declining efficacy of blood-brain barrier/proteolytic pathways. Commun Biol 2022; 5:98. [PMID: 35087179 PMCID: PMC8795390 DOI: 10.1038/s42003-022-03037-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 12/27/2021] [Indexed: 12/21/2022] Open
Abstract
The kinetics of amyloid beta turnover within human brain is still poorly understood. We previously found a dramatic decline in the turnover of Aβ peptides in normal aging. It was not known if brain interstitial fluid/cerebrospinal fluid (ISF/CSF) fluid exchange, CSF turnover, blood-brain barrier function or proteolysis were affected by aging or the presence of β amyloid plaques. Here, we describe a non-steady state physiological model developed to decouple CSF fluid transport from other processes. Kinetic parameters were estimated using: (1) MRI-derived brain volumes, (2) stable isotope labeling kinetics (SILK) of amyloid-β peptide (Aβ), and (3) lumbar CSF Aβ concentration during SILK. Here we show that changes in blood-brain barrier transport and/or proteolysis were largely responsible for the age-related decline in Aβ turnover rates. CSF-based clearance declined modestly in normal aging but became increasingly important due to the slowing of other processes. The magnitude of CSF-based clearance was also lower than that due to blood-brain barrier function plus proteolysis. These results suggest important roles for blood-brain barrier transport and proteolytic degradation of Aβ in the development Alzheimer’s Disease in humans. To understand if brain interstitial fluid/cerebrospinal fluid (ISF/CSF) exchange, CSF turnover, blood-brain barrier function or proteolysis were affected by aging or the presence of β amyloid plaques, Elbert et al. develop a non-steady state physiological model using MRI-derived brain volumes, stable isotope labeling kinetics of Aβ, and lumbar CSF Aβ concentration. Their model suggests an important role for blood-brain barrier transport and proteolytic degradation of Aβ in the development Alzheimer’s Disease in humans.
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Affiliation(s)
- Donald L Elbert
- Department of Neurology, Dell Medical School, University of Texas at Austin, Austin, TX, USA.
| | - Bruce W Patterson
- Department of Medicine, Washington University in St. Louis, St. Louis, MO, USA
| | - Brendan P Lucey
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA.,Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, MO, USA
| | - Tammie L S Benzinger
- Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, MO, USA.,Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Randall J Bateman
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA.,Hope Center for Neurological Disorders, Washington University School of Medicine, St Louis, MO, USA
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