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Phillips WT, Schwartz JG. Nasal turbinate lymphatic obstruction: a proposed new paradigm in the etiology of essential hypertension. Front Med (Lausanne) 2024; 11:1380632. [PMID: 39219790 PMCID: PMC11362006 DOI: 10.3389/fmed.2024.1380632] [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: 02/01/2024] [Accepted: 08/07/2024] [Indexed: 09/04/2024] Open
Abstract
Hypertension affects an estimated 1.3 billion people worldwide and is considered the number one contributor to mortality via stroke, heart failure, renal failure, and dementia. Although the physiologic mechanisms leading to the development of essential hypertension are poorly understood, the regulation of cerebral perfusion has been proposed as a primary cause. This article proposes a novel etiology for essential hypertension. Our hypothesis developed from a review of nuclear medicine scans, where the authors observed a significantly abnormal increase in nasal turbinate vasodilation in hypertensive patients using quantitative region of interest analysis. The authors propose that nasal turbinate vasodilation and resultant blood pooling obstruct the flow of cerebrospinal fluid passing through nasal turbinate lymphatics, thereby increasing intracranial pressure. The authors discuss the glymphatic/lymphatic clearance system which is impaired with age, and at which time hypertension also develops. The increased intracranial pressure leads to compensatory hypertension via Cushing's mechanism, i.e., the selfish brain hypothesis. The nasal turbinate vasodilation, due to increased parasympathetic activity, occurs simultaneously along with the well-established increased sympathetic activity of the cardiovascular system. The increased parasympathetic activity is likely due to an autonomic imbalance secondary to the increase in worldwide consumption of processed food. This hypothesis explains the rapid worldwide rise in essential hypertension in the last 50 years and offers a novel mechanism and a new paradigm for the etiology of essential hypertension. This new paradigm offers compelling evidence for the modulation of parasympathetic nervous system activity as a novel treatment strategy, specifically targeting nasal turbinate regulation, to treat diseases such as hypertension, idiopathic intracranial hypertension, and degenerative brain diseases. The proposed mechanism of essential hypertension presented in this paper is a working hypothesis and confirmatory studies will be needed.
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Xu H, Zhao X, Luo J. Combination of tumor antigen drainage and immune activation to promote a cancer-immunity cycle against glioblastoma. Cell Mol Life Sci 2024; 81:275. [PMID: 38907858 PMCID: PMC11335198 DOI: 10.1007/s00018-024-05300-5] [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: 01/02/2024] [Revised: 04/26/2024] [Accepted: 05/28/2024] [Indexed: 06/24/2024]
Abstract
While conventional cancer modalities, such as chemotherapy and radiotherapy, act through direct killing of tumor cells, cancer immunotherapy elicits potent anti-tumor immune responses thereby eliminating tumors. Nevertheless, promising outcomes have not been reported in patients with glioblastoma (GBM) likely due to the immune privileged status of the central nervous system and immunosuppressive micro-environment within GBM. In the past years, several exciting findings, such as the re-discovery of meningeal lymphatic vessels (MLVs), three-dimensional anatomical reconstruction of MLV networks, and the demonstration of the promotion of GBM immunosurveillance by lymphatic drainage enhancement, have revealed an intricate communication between the nervous and immune systems, and brought hope for the development of new GBM treatment. Based on conceptual framework of the updated cancer-immunity (CI) cycle, here we focus on GBM antigen drainage and immune activation, the early events in driving the CI cycle. We also discuss the implications of these findings for developing new therapeutic approaches in tackling fatal GBM in the future.
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Affiliation(s)
- Han Xu
- Laboratory of Vascular Biology, Institute of Molecular Medicine, College of Future Technology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, 100871, China
| | - Xiaomei Zhao
- Laboratory of Vascular Biology, Institute of Molecular Medicine, College of Future Technology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, 100871, China
| | - Jincai Luo
- Laboratory of Vascular Biology, Institute of Molecular Medicine, College of Future Technology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, 100871, China.
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Haley MJ, Barroso R, Jasim DA, Haigh M, Green J, Dickie B, Craig AG, Brough D, Couper KN. Lymphatic network drainage resolves cerebral edema and facilitates recovery from experimental cerebral malaria. Cell Rep 2024; 43:114217. [PMID: 38728141 DOI: 10.1016/j.celrep.2024.114217] [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: 11/22/2022] [Revised: 11/29/2023] [Accepted: 04/25/2024] [Indexed: 05/12/2024] Open
Abstract
While brain swelling, associated with fluid accumulation, is a known feature of pediatric cerebral malaria (CM), how fluid and macromolecules are drained from the brain during recovery from CM is unknown. Using the experimental CM (ECM) model, we show that fluid accumulation in the brain during CM is driven by vasogenic edema and not by perivascular cerebrospinal fluid (CSF) influx. We identify that fluid and molecules are removed from the brain extremely quickly in mice with ECM to the deep cervical lymph nodes (dcLNs), predominantly through basal routes and across the cribriform plate and the nasal lymphatics. In agreement, we demonstrate that ligation of the afferent lymphatic vessels draining to the dcLNs significantly impairs fluid drainage from the brain and lowers anti-malarial drug recovery from the ECM syndrome. Collectively, our results provide insight into the pathways that coordinate recovery from CM.
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Affiliation(s)
- Michael J Haley
- Division of Immunology, Immunity to Infection & Respiratory Medicine, Faculty of Biology, Medicine & Health, The University of Manchester, Manchester M13 9PT, UK; Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance NHS Group, University of Manchester, Manchester, UK; The Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester, UK
| | - Ruben Barroso
- Division of Immunology, Immunity to Infection & Respiratory Medicine, Faculty of Biology, Medicine & Health, The University of Manchester, Manchester M13 9PT, UK; Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance NHS Group, University of Manchester, Manchester, UK; The Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester, UK
| | - Dhifaf A Jasim
- Nanomedicine Lab, National Graphene Institute and Faculty of Biology, Medicine & Health, The University of Manchester, AV Hill Building, Manchester M13 9PT, UK; Medicines Discovery Catapult (MDC), Alderley Park, Macclesfield SK10 4TG, UK
| | - Megan Haigh
- Division of Immunology, Immunity to Infection & Respiratory Medicine, Faculty of Biology, Medicine & Health, The University of Manchester, Manchester M13 9PT, UK
| | - Jack Green
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance NHS Group, University of Manchester, Manchester, UK; The Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester, UK; Division of Neuroscience, Faculty of Biology, Medicine & Health, The University of Manchester, Manchester M13 9PT, UK
| | - Ben Dickie
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance NHS Group, University of Manchester, Manchester, UK; Division of Informatics, Imaging & Data Sciences, Faculty of Biology, Medicine & Health, The University of Manchester, Manchester M13 9PT, UK
| | - Alister G Craig
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - David Brough
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance NHS Group, University of Manchester, Manchester, UK; The Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester, UK; Division of Neuroscience, Faculty of Biology, Medicine & Health, The University of Manchester, Manchester M13 9PT, UK
| | - Kevin N Couper
- Division of Immunology, Immunity to Infection & Respiratory Medicine, Faculty of Biology, Medicine & Health, The University of Manchester, Manchester M13 9PT, UK; Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance NHS Group, University of Manchester, Manchester, UK; The Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester, UK.
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Jukkola J, Kaakinen M, Singh A, Moradi S, Ferdinando H, Myllylä T, Kiviniemi V, Eklund L. Blood pressure lowering enhances cerebrospinal fluid efflux to the systemic circulation primarily via the lymphatic vasculature. Fluids Barriers CNS 2024; 21:12. [PMID: 38279178 PMCID: PMC10821255 DOI: 10.1186/s12987-024-00509-9] [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: 11/16/2023] [Accepted: 01/03/2024] [Indexed: 01/28/2024] Open
Abstract
BACKGROUND Inside the incompressible cranium, the volume of cerebrospinal fluid is directly linked to blood volume: a change in either will induce a compensatory change in the other. Vasodilatory lowering of blood pressure has been shown to result in an increase of intracranial pressure, which, in normal circumstances should return to equilibrium by increased fluid efflux. In this study, we investigated the effect of blood pressure lowering on fluorescent cerebrospinal fluid tracer absorption into the systemic blood circulation. METHODS Blood pressure lowering was performed by an i.v. administration of nitric oxide donor (sodium nitroprusside, 5 µg kg-1 min-1) or the Ca2+-channel blocker (nicardipine hydrochloride, 0.5 µg kg-1 min-1) for 10, and 15 to 40 min, respectively. The effect of blood pressure lowering on cerebrospinal fluid clearance was investigated by measuring the efflux of fluorescent tracers (40 kDa FITC-dextran, 45 kDa Texas Red-conjugated ovalbumin) into blood and deep cervical lymph nodes. The effect of nicardipine on cerebral hemodynamics was investigated by near-infrared spectroscopy. The distribution of cerebrospinal fluid tracers (40 kDa horse radish peroxidase,160 kDa nanogold-conjugated IgG) in exit pathways was also analyzed at an ultrastructural level using electron microscopy. RESULTS Nicardipine and sodium nitroprusside reduced blood pressure by 32.0 ± 19.6% and 24.0 ± 13.3%, while temporarily elevating intracranial pressure by 14.0 ± 7.0% and 18.2 ± 15.0%, respectively. Blood pressure lowering significantly increased tracer accumulation into dorsal dura, deep cervical lymph nodes and systemic circulation, but reduced perivascular inflow along penetrating arteries in the brain. The enhanced tracer efflux by blood pressure lowering into the systemic circulation was markedly reduced (- 66.7%) by ligation of lymphatic vessels draining into deep cervical lymph nodes. CONCLUSIONS This is the first study showing that cerebrospinal fluid clearance can be improved with acute hypotensive treatment and that the effect of the treatment is reduced by ligation of a lymphatic drainage pathway. Enhanced cerebrospinal fluid clearance by blood pressure lowering may have therapeutic potential in diseases with dysregulated cerebrospinal fluid flow.
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Affiliation(s)
- Jari Jukkola
- Oulu Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Mika Kaakinen
- Oulu Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Abhishek Singh
- Oulu Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Sadegh Moradi
- Opto-Electronics and Measurement Technique Research Unit, Infotech Oulu, University of Oulu, Oulu, Finland
| | - Hany Ferdinando
- Research Unit of Health Science and Technology, University of Oulu, Oulu, Finland
| | - Teemu Myllylä
- Opto-Electronics and Measurement Technique Research Unit, Infotech Oulu, University of Oulu, Oulu, Finland
- Research Unit of Health Science and Technology, University of Oulu, Oulu, Finland
| | - Vesa Kiviniemi
- Oulu Functional NeuroImaging (OFNI), Diagnostic Imaging, Medical Research Center (MRC), Oulu University Hospital, Oulu, Finland
- Research Unit of Health Sciences and Technology (HST), Faculty of Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Lauri Eklund
- Oulu Center for Cell-Matrix Research, Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland.
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Semyachkina-Glushkovskaya O, Sokolovski S, Fedosov I, Shirokov A, Navolokin N, Bucharskaya A, Blokhina I, Terskov A, Dubrovski A, Telnova V, Tzven A, Tzoy M, Evsukova A, Zhlatogosrkaya D, Adushkina V, Dmitrenko A, Manzhaeva M, Krupnova V, Noghero A, Bragin D, Bragina O, Borisova E, Kurths J, Rafailov E. Transcranial Photosensitizer-Free Laser Treatment of Glioblastoma in Rat Brain. Int J Mol Sci 2023; 24:13696. [PMID: 37762000 PMCID: PMC10530910 DOI: 10.3390/ijms241813696] [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: 07/29/2023] [Revised: 08/29/2023] [Accepted: 09/02/2023] [Indexed: 09/29/2023] Open
Abstract
Over sixty years, laser technologies have undergone a technological revolution and become one of the main tools in biomedicine, particularly in neuroscience, neurodegenerative diseases and brain tumors. Glioblastoma is the most lethal form of brain cancer, with very limited treatment options and a poor prognosis. In this study on rats, we demonstrate that glioblastoma (GBM) growth can be suppressed by photosensitizer-free laser treatment (PS-free-LT) using a quantum-dot-based 1267 nm laser diode. This wavelength, highly absorbed by oxygen, is capable of turning triplet oxygen to singlet form. Applying 1267 nm laser irradiation for a 4 week course with a total dose of 12.7 kJ/cm2 firmly suppresses GBM growth and increases survival rate from 34% to 64%, presumably via LT-activated apoptosis, inhibition of the proliferation of tumor cells, a reduction in intracranial pressure and stimulation of the lymphatic drainage and clearing functions. PS-free-LT is a promising breakthrough technology in non- or minimally invasive therapy for superficial GBMs in infants as well as in adult patients with high photosensitivity or an allergic reaction to PSs.
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Affiliation(s)
- Oxana Semyachkina-Glushkovskaya
- Physics Department, Humboldt University, Newtonstrasse 15, 12489 Berlin, Germany;
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (A.S.); (N.N.); (I.B.); (A.T.); (V.T.); (A.T.); (A.E.); (D.Z.); (V.A.); (A.D.); (M.M.); (V.K.)
| | - Sergey Sokolovski
- Optoelectronics and Biomedical Photonics Group, AIPT, Aston University, Birmingham B4 7ET, UK;
| | - Ivan Fedosov
- Physics Department, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (I.F.); (A.D.); (M.T.)
| | - Alexander Shirokov
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (A.S.); (N.N.); (I.B.); (A.T.); (V.T.); (A.T.); (A.E.); (D.Z.); (V.A.); (A.D.); (M.M.); (V.K.)
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Prospekt Entuziastov 13, 410049 Saratov, Russia
| | - Nikita Navolokin
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (A.S.); (N.N.); (I.B.); (A.T.); (V.T.); (A.T.); (A.E.); (D.Z.); (V.A.); (A.D.); (M.M.); (V.K.)
- Department of Pathological Anatomy, Saratov Medical State University, Bolshaya Kazachaya Str. 112, 410012 Saratov, Russia;
| | - Alla Bucharskaya
- Department of Pathological Anatomy, Saratov Medical State University, Bolshaya Kazachaya Str. 112, 410012 Saratov, Russia;
| | - Inna Blokhina
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (A.S.); (N.N.); (I.B.); (A.T.); (V.T.); (A.T.); (A.E.); (D.Z.); (V.A.); (A.D.); (M.M.); (V.K.)
| | - Andrey Terskov
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (A.S.); (N.N.); (I.B.); (A.T.); (V.T.); (A.T.); (A.E.); (D.Z.); (V.A.); (A.D.); (M.M.); (V.K.)
| | - Alexander Dubrovski
- Physics Department, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (I.F.); (A.D.); (M.T.)
| | - Valeria Telnova
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (A.S.); (N.N.); (I.B.); (A.T.); (V.T.); (A.T.); (A.E.); (D.Z.); (V.A.); (A.D.); (M.M.); (V.K.)
| | - Anna Tzven
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (A.S.); (N.N.); (I.B.); (A.T.); (V.T.); (A.T.); (A.E.); (D.Z.); (V.A.); (A.D.); (M.M.); (V.K.)
| | - Maria Tzoy
- Physics Department, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (I.F.); (A.D.); (M.T.)
| | - Arina Evsukova
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (A.S.); (N.N.); (I.B.); (A.T.); (V.T.); (A.T.); (A.E.); (D.Z.); (V.A.); (A.D.); (M.M.); (V.K.)
| | - Daria Zhlatogosrkaya
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (A.S.); (N.N.); (I.B.); (A.T.); (V.T.); (A.T.); (A.E.); (D.Z.); (V.A.); (A.D.); (M.M.); (V.K.)
| | - Viktoria Adushkina
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (A.S.); (N.N.); (I.B.); (A.T.); (V.T.); (A.T.); (A.E.); (D.Z.); (V.A.); (A.D.); (M.M.); (V.K.)
| | - Alexander Dmitrenko
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (A.S.); (N.N.); (I.B.); (A.T.); (V.T.); (A.T.); (A.E.); (D.Z.); (V.A.); (A.D.); (M.M.); (V.K.)
| | - Maria Manzhaeva
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (A.S.); (N.N.); (I.B.); (A.T.); (V.T.); (A.T.); (A.E.); (D.Z.); (V.A.); (A.D.); (M.M.); (V.K.)
| | - Valeria Krupnova
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (A.S.); (N.N.); (I.B.); (A.T.); (V.T.); (A.T.); (A.E.); (D.Z.); (V.A.); (A.D.); (M.M.); (V.K.)
| | - Alessio Noghero
- Lovelace Biomedical Research Institute, Albuquerque, NM 87108, USA; (A.N.); (D.B.); (O.B.)
| | - Denis Bragin
- Lovelace Biomedical Research Institute, Albuquerque, NM 87108, USA; (A.N.); (D.B.); (O.B.)
- Department of Neurology, School of Medicine, University of New Mexico, Albuquerque, NM 87131, USA
| | - Olga Bragina
- Lovelace Biomedical Research Institute, Albuquerque, NM 87108, USA; (A.N.); (D.B.); (O.B.)
- Department of Neurology, School of Medicine, University of New Mexico, Albuquerque, NM 87131, USA
| | - Ekaterina Borisova
- Institute of Electronics, Bulgarian Academy of Sciences, Tsarigradsko Chaussee Blvd. 72, 1784 Sofia, Bulgaria;
| | - Jürgen Kurths
- Physics Department, Humboldt University, Newtonstrasse 15, 12489 Berlin, Germany;
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (A.S.); (N.N.); (I.B.); (A.T.); (V.T.); (A.T.); (A.E.); (D.Z.); (V.A.); (A.D.); (M.M.); (V.K.)
- Potsdam Institute for Climate Impact Research, Telegrafenberg A31, 14473 Potsdam, Germany
- Centre for Analysis of Complex Systems, Sechenov First Moscow State Medical University Moscow, 119991 Moscow, Russia
| | - Edik Rafailov
- Optoelectronics and Biomedical Photonics Group, AIPT, Aston University, Birmingham B4 7ET, UK;
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Laaker C, Baenen C, Kovács KG, Sandor M, Fabry Z. Immune cells as messengers from the CNS to the periphery: the role of the meningeal lymphatic system in immune cell migration from the CNS. Front Immunol 2023; 14:1233908. [PMID: 37662908 PMCID: PMC10471710 DOI: 10.3389/fimmu.2023.1233908] [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: 06/05/2023] [Accepted: 07/31/2023] [Indexed: 09/05/2023] Open
Abstract
In recent decades there has been a large focus on understanding the mechanisms of peripheral immune cell infiltration into the central nervous system (CNS) in neuroinflammatory diseases. This intense research led to several immunomodulatory therapies to attempt to regulate immune cell infiltration at the blood brain barrier (BBB), the choroid plexus (ChP) epithelium, and the glial barrier. The fate of these infiltrating immune cells depends on both the neuroinflammatory environment and their type-specific interactions with innate cells of the CNS. Although the fate of the majority of tissue infiltrating immune cells is death, a percentage of these cells could become tissue resident immune cells. Additionally, key populations of immune cells can possess the ability to "drain" out of the CNS and act as messengers reporting signals from the CNS toward peripheral lymphatics. Recent data supports that the meningeal lymphatic system is involved not just in fluid homeostatic functions in the CNS but also in facilitating immune cell migration, most notably dendritic cell migration from the CNS to the meningeal borders and to the draining cervical lymph nodes. Similar to the peripheral sites, draining immune cells from the CNS during neuroinflammation have the potential to coordinate immunity in the lymph nodes and thus influence disease. Here in this review, we will evaluate evidence of immune cell drainage from the brain via the meningeal lymphatics and establish the importance of this in animal models and humans. We will discuss how targeting immune cells at sites like the meningeal lymphatics could provide a new mechanism to better provide treatment for a variety of neurological conditions.
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Affiliation(s)
- Collin Laaker
- Neuroscience Training Program, University of Wisconsin Madison, Madison, WI, United States
| | - Cameron Baenen
- Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin Madison, Madison, WI, United States
| | - Kristóf G. Kovács
- Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin Madison, Madison, WI, United States
| | - Matyas Sandor
- Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin Madison, Madison, WI, United States
| | - Zsuzsanna Fabry
- Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin Madison, Madison, WI, United States
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Asal N, Bayar Muluk N, Özdemir A, Say B. Evaluation of peripheral and central olfactory regions by MRI in patients with idiopathic intracranial hypertension. Neurol Res 2023; 45:346-353. [PMID: 36373831 DOI: 10.1080/01616412.2022.2146261] [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: 11/16/2022]
Abstract
OBJECTIVES We investigated the peripheral and central smell regions in patients with idiopathic intracranial hypertension (IIH) by cranial MRI. METHODS In this retrospective study, cranial MRI images of 43 adult patients with IIH (Group 1) and 43 healthy adults without IIH (Group 2) were included. In both groups, peripheral [Olfactory bulb (OB) volume and Olfactory sulcus (OS) depth] and central smell regions (insular gyrus and corpus amygdala area, and thalamus volume) were measured in cranial MRI. RESULTS Bilateral OB volume and insular gyrus area, and right corpus amygdala and thalamus volumes of the IIH group were significantly lower than those of the control group (p < 0.05). In the IIH group, OB volume of the right side was significantly lower, and insular gyrus area of the right side was significantly higher than those of the left side (p < 0.05). In the IIH group, there were positive correlations between OB volumes; OS depths; insular gyrus areas; corpus amygdala areas; and thalamus volumes bilaterally (p < 0.05). In older patients, right OS depth and right corpus amygdala area decreased (p < 0.05). CONCLUSION In conclusion, IIH may be related to olfactory impairment. Cranial MRI images showed a decrease in peripheral (OB volume) and central (insular gyrus and corpus amygdala area and thalamus volume) smell regions. To prevent olfactory impairment in IIH patients, treatment should be done in IIH patients to decrease intracranial pressure. It is very important to prevent the circulation of CSF with increased pressure between the sheets of the olfactory nerve in IIH patients.
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Affiliation(s)
- Neşe Asal
- Faculty of Medicine, Radiology Department, Kırıkkale University, Kırıkkale, Turkey
| | - Nuray Bayar Muluk
- Faculty of Medicine, ENT Department, Kırıkkale University, Kırıkkale, Turkey
| | - Adnan Özdemir
- Faculty of Medicine, Radiology Department, Kırıkkale University, Kırıkkale, Turkey
| | - Bahar Say
- Faculty of Medicine, Neurology Department, Kırıkkale University, Kırıkkale, Turkey
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8
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Fan Z, Li Z, Zhao S, Chen Y, Su Y, Peng G, Luo B. Salivary Aβ 1-42 may be a quick-tested biomarker for clinical use in Alzheimer's disease: a meta-analysis. J Neurol 2023; 270:1945-1954. [PMID: 36562850 DOI: 10.1007/s00415-022-11509-w] [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: 08/20/2022] [Revised: 11/26/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Alzheimer's disease (AD) is the most prevalent form of dementia among the aging population. Cumulative studies aim to find non-invasive biomarkers in the early stages of AD. Saliva can be obtained easily, and salivary biomarkers have been proven effective in detecting neurodegenerative diseases. To find effective biomarkers in saliva and to help the diagnosis of AD, we performed a meta-analysis focusing on the salivary biomarkers (β-amyloid 1-42 (Aβ1-42), total tau (t-tau), phosphorylated tau (p-tau) and acetylcholinesterase (AChE)) in AD. METHODS We conducted a systematic online search for eligible studies reporting data on salivary biomarkers reflecting Aβ1-42, t-tau, p-tau, and AChE in AD cohorts versus controls. Biomarkers' performance was assessed in a random-effects meta-analysis with the ratio of mean (RoM). RESULTS A total of thirteen studies were included in the meta-analysis, of them seven involved salivary Aβ1-42 (271 AD and 489 controls), five involved salivary t-tau (324 AD and 252 controls), four involved salivary p-tau (130 AD and 161 controls), and three involved salivary AChE (81 AD and 54 controls). AD showed significantly higher salivary Aβ1-42 levels than control (ROM = 1.90 (95% CI 1.28-2.81, P = 0.001), while AD and control did not differ significantly on salivary t-tau, p-tau and AChE (ROM = 0.94, 95% CI 0.67-1.31, P = 0.72; ROM = 0.91, 95% CI 0.56-1.45, P = 0.68; ROM = 0.83, 95% CI 0.24-2.88, P = 0.77; respectively). CONCLUSION The pooled results provide evidence that salivary Aβ1-42 may serve as a sensitive biomarker for AD; nevertheless, larger AD cohorts are required to further confirm the sensitivity and specificity of salivary Aβ1-42 for AD diagnosis.
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Affiliation(s)
- Ziqi Fan
- Department of Neurology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310003, China
| | - Zheyu Li
- Department of Neurology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Shuai Zhao
- Department of Neurology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Yanxing Chen
- Department of Neurology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Yujie Su
- Department of Neurology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310003, China
| | - Guoping Peng
- Department of Neurology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310003, China
| | - Benyan Luo
- Department of Neurology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310003, China.
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9
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Lan YL, Wang H, Chen A, Zhang J. Update on the current knowledge of lymphatic drainage system and its emerging roles in glioma management. Immunology 2023; 168:233-247. [PMID: 35719015 DOI: 10.1111/imm.13517] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/22/2022] [Indexed: 01/17/2023] Open
Abstract
The draining of brain interstitial fluid (ISF) to cerebrospinal fluid (CSF) and the subsequent draining of CSF to meningeal lymphatics is well-known. Nonetheless, its role in the development of glioma is a remarkable finding that has to be extensively understood. The glymphatic system (GS) collects CSF from the subarachnoid space and brain ISF through aquaporin-4 (AQP4) water channels. The glial limiting membrane and the perivascular astrocyte-end-feet membrane both have elevated levels of AQP4. CSF is thought to drain through the nerve sheaths of the olfactory and other cranial nerves as well as spinal meningeal lymphatics via dorsal or basal lymphatic vessels. Meningeal lymphatic vessels (MLVs) exist below the skull in the dorsal and basal regions. In this view, MLVs offer a pathway to drain macromolecules and traffic immunological cells from the CNS into cervical lymph nodes (CLNs), and thus can be used as a candidate curing strategy against glioma and other associated complications, such as neuro-inflammation. Taken together, the lymphatic drainage system could provide a route or approach for drug targeting of glioma and other neurological conditions. Nevertheless, its pathophysiological role in glioma remains elusive, which needs extensive research. The current review aims to explore the lymphatic drainage system, its role in glioma progression, and possible therapeutic techniques that target MLVs in the CNS.
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Affiliation(s)
- Yu-Long Lan
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Hongjin Wang
- Department of Neurology, Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Aiqin Chen
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jianmin Zhang
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
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10
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Proulx ST, Engelhardt B. Central nervous system zoning: How brain barriers establish subdivisions for CNS immune privilege and immune surveillance. J Intern Med 2022; 292:47-67. [PMID: 35184353 PMCID: PMC9314672 DOI: 10.1111/joim.13469] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The central nervous system (CNS) coordinates all our body functions. Neurons in the CNS parenchyma achieve this computational task by high speed communication via electrical and chemical signals and thus rely on a strictly regulated homeostatic environment, which does not tolerate uncontrolled entry of blood components including immune cells. The CNS thus has a unique relationship with the immune system known as CNS immune privilege. Previously ascribed to the presence of blood-brain barriers and the lack of lymphatic vessels in the CNS parenchyma prohibiting, respectively, efferent and afferent connections with the peripheral immune system, it is now appreciated that CNS immune surveillance is ensured by cellular and acellular brain barriers that limit immune cell and mediator accessibility to specific compartments at the borders of the CNS. CNS immune privilege is established by a brain barriers anatomy resembling the architecture of a medieval castle surrounded by two walls bordering a castle moat. Built for protection and defense this two-walled rampart at the outer perimeter of the CNS parenchyma allows for accommodation of different immune cell subsets and efficient monitoring of potential danger signals derived from inside or outside of the CNS parenchyma. It enables effective mounting of immune responses within the subarachnoid or perivascular spaces, while leaving the CNS parenchyma relatively undisturbed. In this study, we propose that CNS immune privilege rests on the proper function of the brain barriers, which allow for CNS immune surveillance but prohibit activation of immune responses from the CNS parenchyma unless it is directly injured.
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Affiliation(s)
- Steven T Proulx
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
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11
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Phillips WT, Issa NJ, Elhalwagi SB, Draeger HT, Schwartz JG, Gelfond JA. Nasal and Parotid Blood Pool Activity Is Significantly Correlated with Metabolic Syndrome Components and Sleep Apnea. Metab Syndr Relat Disord 2022; 20:395-404. [PMID: 35731008 DOI: 10.1089/met.2022.0015] [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: 11/12/2022] Open
Abstract
Background: Patients with metabolic syndrome components were frequently noted to have increased nasal and parotid activity on clinically referred scintigraphic whole-body blood pool scans. This increase in activity was not observed in patients without metabolic syndrome. Increased nasal blood pool activity in patients with elevated body mass indices (BMIs) has implications for (1) sleep apnea, (2) risk of nasal infection, and (3) possible impaired nasal lymphatic drainage of brain waste proteins. Methods: To follow-up this clinical observation, a retrospective study was performed on 200 patients having whole-body blood pool scans referred over a 3-year period. The whole-body blood pool scans were evaluated for an association between nose and parotid region of interest (ROI) to heart ROI maximum (max) pixel ratios as correlated with clinical conditions, including obesity, diabetes, hypertension, and sleep apnea. Continuous variables of BMI, hemoglobin A1c (HbA1c), blood glucose, and blood lipids were also correlated with these ratios. Results: A direct association of nose to heart max ratio (NHMR) with diabetes, sleep apnea, and hypertension was found with an increase in the ratio of +0.10 (P = 0.002), +0.13 (P = 0.0002), +0.08 (P = 0.0123), respectively. Correlation of NHMR with continuous variables had moderate correlation with BMI (r = 0.36, P < 0.0001), glucose (r = 0.27, P = 0.0001), HbA1c (r = 0.25, P = 0.0008) and less association with the number of diabetes medications (r = 0.22, P = 0.0021). Similar associations were found for parotid to heart max ratios but were weaker than the NHMR. Conclusions: Patients with metabolic syndrome components have significantly increased nasal and parotid activity on blood pool scans. These associations have implications for the treatment of sleep apnea, for nasal infections involving such agents as Covid-19, and for the risk of dementias related to decreased clearance of brain waste proteins through nasal turbinate lymphatics in patients with metabolic syndrome. If further studies support these findings, the nasal turbinates and the increased parasympathetic activity controlling their dilation could become a new therapeutic target.
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Affiliation(s)
- William T Phillips
- Department of Radiology, University of Texas Health-San Antonio, San Antonio, Texas, USA
| | - Nasser J Issa
- Department of Radiology, University of Texas Health-San Antonio, San Antonio, Texas, USA
| | - Shereef B Elhalwagi
- Department of Radiology, University of Texas Health-San Antonio, San Antonio, Texas, USA
| | | | - Joyce G Schwartz
- Department of Pathology, Methodist Hospital, San Antonio, Texas, USA
| | - Jonathan A Gelfond
- Population Health Sciences, University of Texas Health-San Antonio, San Antonio, Texas, USA
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12
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Bramall AN, Anton ES, Kahle KT, Fecci PE. Navigating the ventricles: Novel insights into the pathogenesis of hydrocephalus. EBioMedicine 2022; 78:103931. [PMID: 35306341 PMCID: PMC8933686 DOI: 10.1016/j.ebiom.2022.103931] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 02/16/2022] [Accepted: 02/24/2022] [Indexed: 12/14/2022] Open
Abstract
Congenital hydrocephalus occurs in one in 500-1000 babies born in the United States and acquired hydrocephalus may occur as the consequence of stroke, intraventricular and subarachnoid hemorrhage, traumatic brain injuries, brain tumors, craniectomy or may be idiopathic, as in the case of normal pressure hydrocephalus. Irrespective of its prevalence and significant impact on quality of life, neurosurgeons still rely on invasive cerebrospinal fluid shunt systems for the treatment of hydrocephalus that are exceptionally prone to failure and/or infection. Further understanding of this process at a molecular level, therefore, may have profound implications for improving treatment and quality of life for millions of individuals worldwide. The purpose of this article is to review the current research landscape on hydrocephalus with a focus on recent advances in our understanding of cerebrospinal fluid pathways from an evolutionary, genetics and molecular perspective.
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Affiliation(s)
- Alexa N Bramall
- Department of Neurosurgery, Duke University Hospital, 2301 Erwin Rd., Durham, NC 27710, United States.
| | - E S Anton
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Kristopher T Kahle
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, United States
| | - Peter E Fecci
- Department of Neurosurgery, Duke University Hospital, 2301 Erwin Rd., Durham, NC 27710, United States
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13
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Mureșan AN, Rusu MC, Rădoi PM, Toader C. Patterns of Pneumatization of the Posterior Nasal Roof. Tomography 2022; 8:316-328. [PMID: 35202191 PMCID: PMC8880248 DOI: 10.3390/tomography8010026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/15/2022] [Accepted: 01/28/2022] [Indexed: 11/16/2022] Open
Abstract
(1) Background: For good surgical performance, sound knowledge of anatomy is required. Although the ethmoid air cells and sphenoid sinuses are subject to a high degree of variation, their possible extensions above the nasal fossa at the posterior end of the cribriform plate of the ethmoid bone (CPEB) were seemingly overlooked. (2) Methods: We retrospectively studied 162 case files from 55 male and 107 female cases, with ages varying from 42 to 80, which were scanned using Cone Beam Computed Tomography. (3) Results: In 56.17% of cases, an unpneumatized CPEB (type I) was found. Nasal roof recesses of ethmoidal origin (type II) were found at the posterior end of the CPEB in 20.37% of cases. Different types of sphenoidal pneumatizations of the posterior end of the CPEB (type III) were found in 22.83% of the cases. Onodi cells projected nasal roof recesses (type IV) in only 10 cases. In all types, nasal roof recesses were found either above the CPEB or within/underneath it. Moreover, such nasal roof recesses were found to be either unilateral, extended contralaterally, or bilateral. (4) Conclusions: As such recesses of the posterior CPEB, previously overlooked, belong to the posterior rhinobase, they should be carefully documented preoperatively to avoid unwanted surgical damage to the olfactory bulb or CSF fistula.
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Affiliation(s)
- Alexandru Nicolae Mureșan
- Division of Anatomy, Department 1, Faculty of Dental Medicine, “Carol Davila” University of Medicine and Pharmacy, RO-020021 Bucharest, Romania;
- Research Department, “Dr. Carol Davila” Central Military Emergency Hospital, RO-010825 Bucharest, Romania
| | - Mugurel Constantin Rusu
- Division of Anatomy, Department 1, Faculty of Dental Medicine, “Carol Davila” University of Medicine and Pharmacy, RO-020021 Bucharest, Romania;
- Correspondence: (M.C.R.); (P.M.R.)
| | - Petrinel Mugurel Rădoi
- Division of Neurosurgery, Department 6—Clinical Neurosciences, Faculty of Medicine, “Carol Davila” University of Medicine and Pharmacy, RO-020021 Bucharest, Romania;
- Clinic of Neurosurgery, “Dr. Bagdasar-Arseni” Emergency Clinical Hospital, RO-041915 Bucharest, Romania
- Correspondence: (M.C.R.); (P.M.R.)
| | - Corneliu Toader
- Division of Neurosurgery, Department 6—Clinical Neurosciences, Faculty of Medicine, “Carol Davila” University of Medicine and Pharmacy, RO-020021 Bucharest, Romania;
- Clinic of Neurosurgery, “Dr. Bagdasar-Arseni” Emergency Clinical Hospital, RO-041915 Bucharest, Romania
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14
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Mehta NH, Sherbansky J, Kamer AR, Carare RO, Butler T, Rusinek H, Chiang GC, Li Y, Strauss S, Saint-Louis LA, Theise ND, Suss RA, Blennow K, Kaplitt M, de Leon MJ. The Brain-Nose Interface: A Potential Cerebrospinal Fluid Clearance Site in Humans. Front Physiol 2022; 12:769948. [PMID: 35058794 PMCID: PMC8764168 DOI: 10.3389/fphys.2021.769948] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 11/26/2021] [Indexed: 12/17/2022] Open
Abstract
The human brain functions at the center of a network of systems aimed at providing a structural and immunological layer of protection. The cerebrospinal fluid (CSF) maintains a physiological homeostasis that is of paramount importance to proper neurological activity. CSF is largely produced in the choroid plexus where it is continuous with the brain extracellular fluid and circulates through the ventricles. CSF movement through the central nervous system has been extensively explored. Across numerous animal species, the involvement of various drainage pathways in CSF, including arachnoid granulations, cranial nerves, perivascular pathways, and meningeal lymphatics, has been studied. Among these, there is a proposed CSF clearance route spanning the olfactory nerve and exiting the brain at the cribriform plate and entering lymphatics. While this pathway has been demonstrated in multiple animal species, evidence of a similar CSF egress mechanism involving the nasal cavity in humans remains poorly consolidated. This review will synthesize contemporary evidence surrounding CSF clearance at the nose-brain interface, examining across species this anatomical pathway, and its possible significance to human neurodegenerative disease. Our discussion of a bidirectional nasal pathway includes examination of the immune surveillance in the olfactory region protecting the brain. Overall, we expect that an expanded discussion of the brain-nose pathway and interactions with the environment will contribute to an improved understanding of neurodegenerative and infectious diseases, and potentially to novel prevention and treatment considerations.
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Affiliation(s)
- Neel H. Mehta
- Undergraduate Department of Biology, Cornell University, Ithaca, NY, United States
| | | | - Angela R. Kamer
- Department of Periodontology and Implant Dentistry, NYU College of Dentistry, New York, NY, United States
| | - Roxana O. Carare
- Department of Medicine, University of Southampton, Southampton, United Kingdom
| | - Tracy Butler
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Henry Rusinek
- Department of Radiology, NYU Langone Health, New York, NY, United States
| | - Gloria C. Chiang
- Department of Radiology, Weill Cornell Medicine, New York, NY, United States
| | - Yi Li
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Sara Strauss
- Department of Radiology, Weill Cornell Medicine, New York, NY, United States
| | - L. A. Saint-Louis
- Department of Radiology, NYU Langone Health, New York, NY, United States
| | - Neil D. Theise
- Department of Pathology, NYU Grossman School of Medicine, New York, NY, United States
| | - Richard A. Suss
- Division of Neuroradiology, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Kaj Blennow
- Clinical Neurochemistry Lab, Inst. of Neuroscience and Physiology, University of Gothenburg, Sahlgrenska University Hospital, Göteborg, Sweden
| | - Michael Kaplitt
- Laboratory of Molecular Neurosurgery, Department of Neurological Surgery, Weill Cornell Medical College, New York, NY, United States
| | - Mony J. de Leon
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
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15
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Inal M, Bayar Muluk N, Asal N, Çelik EN. Peripheric smell regions in patients with semicircular canal dehiscence: An MRI evaluation. J Clin Neurosci 2021; 94:173-178. [PMID: 34863433 DOI: 10.1016/j.jocn.2021.10.019] [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: 05/05/2021] [Revised: 09/10/2021] [Accepted: 10/15/2021] [Indexed: 11/25/2022]
Abstract
OBJECTIVES We investigated the peripheric smell regions in patients with semicircular canal dehiscence (SCD) by cranial MRI. METHODS In this retrospective study, cranial MRI images of 186 adult patients were included. Group 1 consisted of 83 adult patients with SCD. The control group (Group 2) consisted of 83 healthy subjects without central vertigo. Olfactory bulb (OB) volume and olfactory sulcus (OS) depth were measured in all groups. RESULTS In group 1, SCD was detected on the right (33.7%), left (26.5%) sides and bilateral (39.8%). Localization of dehiscence was at superior SC (75.9%), posterior SC (21.7%), lateral SC (1.2%), and posterior + superior SCs (1.2%). OB volumes of the SCD group were significantly lower than the control group bilaterally (p < 0.05). There were no significant differences between OS depths of groups 1 and 2 (p > 0.05). In SCD group, there were positive correlations between OB volumes; OS depths; and OB volumes and OS depths (p < 0.05). In older patients, bilateral OS depth values got lower (p < 0.05). In females, left OB volume values were lower than males (p < 0.05). In right SCD (+) patients, left OS depth values got lower (p < 0.05). CONCLUSION We concluded that possible changes in CSF dynamics may cause the development of SCD at thin bone segments; and a decrease in the OB volume. CSF leaks into the perineural sheet of the olfactory bulb (OB) maybe responsible for the decrease in the OB volume. In addition, minor trauma, infection, and inflammation may also be responsible for both coexistences of SCD development and OB volume decrease.
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Affiliation(s)
- Mikail Inal
- Kırıkkale University, Faculty of Medicine, Radiology Department, Kırıkkale, Turkey
| | - Nuray Bayar Muluk
- Kırıkkale University, Faculty of Medicine, ENT Department, Kırıkkale, Turkey.
| | - Neşe Asal
- Kırıkkale University, Faculty of Medicine, Radiology Department, Kırıkkale, Turkey
| | - Enes Nusret Çelik
- Kırıkkale University, Faculty of Medicine, Radiology Department, Kırıkkale, Turkey
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16
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Xie JS, Donaldson L, Margolin E. Papilledema: A review of etiology, pathophysiology, diagnosis, and management. Surv Ophthalmol 2021; 67:1135-1159. [PMID: 34813854 DOI: 10.1016/j.survophthal.2021.11.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 11/05/2021] [Accepted: 11/15/2021] [Indexed: 02/06/2023]
Abstract
Papilledema is optic nerve head edema secondary to raised intracranial pressure (ICP). It is distinct from other causes of optic disk edema in that visual function is usually normal in the acute phase. Papilledema is caused by transmission of elevated ICP to the subarachnoid space surrounding the optic nerve that hinders axoplasmic transport within ganglion cell axons. There is ongoing controversy as to whether axoplasmic flow stasis is produced by physical compression of axons or microvascular ischemia. The most common cause of papilledema, especially in patients under the age of 50, is idiopathic intracranial hypertension (IIH); however, conditions that decrease cerebrospinal fluid (CSF) outflow by either causing CSF derangements or mechanically blocking CSF outflow channels, and rarely conditions that increase CSF production, can be the culprit. When papilledema is suspected clinically, blood pressure should be measured, and pseudopapilledema should be ruled out. Magnetic resonance imaging of the brain and orbits with venography sequences is the preferred neuroimaging modality that should be performed next to look for indirect imaging signs of increased ICP and to rule out nonidiopathic causes. Lumbar puncture with measurement of opening pressure and evaluation of CSF composition should then be performed. In patients not in a typical demographic group for IIH, further investigations should be conducted to assess for underlying causes of increased ICP. Magnetic resonance imaging of the neck and spine, magnetic resonance angiography of the brain, computed tomography of the chest, complete blood count, and creatinine testing should be able to identify most secondary causes of intracranial hypertension. Treatment for patients with papilledema should be targeted toward the underlying etiology. Most patients with IIH respond to weight loss and oral acetazolamide. For patients with decreased central acuity and constricted visual fields at presentation, as well as patients who do not respond to treatment with acetazolamide, surgical treatments should be considered, with ventriculoperitoneal shunting being the typical procedure of choice.
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Affiliation(s)
- Jim Shenchu Xie
- Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Laura Donaldson
- Faculty of Medicine, Department of Ophthalmology and Visual Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Edward Margolin
- Faculty of Medicine, Department of Ophthalmology and Visual Sciences, University of Toronto, Toronto, Ontario, Canada; Faculty of Medicine, Department of Medicine, Division of Neurology, University of Toronto, Toronto, Ontario, Canada.
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17
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Molecular Mechanisms of Neuroimmune Crosstalk in the Pathogenesis of Stroke. Int J Mol Sci 2021; 22:ijms22179486. [PMID: 34502395 PMCID: PMC8431165 DOI: 10.3390/ijms22179486] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/26/2021] [Accepted: 08/28/2021] [Indexed: 12/21/2022] Open
Abstract
Stroke disrupts the homeostatic balance within the brain and is associated with a significant accumulation of necrotic cellular debris, fluid, and peripheral immune cells in the central nervous system (CNS). Additionally, cells, antigens, and other factors exit the brain into the periphery via damaged blood–brain barrier cells, glymphatic transport mechanisms, and lymphatic vessels, which dramatically influence the systemic immune response and lead to complex neuroimmune communication. As a result, the immunological response after stroke is a highly dynamic event that involves communication between multiple organ systems and cell types, with significant consequences on not only the initial stroke tissue injury but long-term recovery in the CNS. In this review, we discuss the complex immunological and physiological interactions that occur after stroke with a focus on how the peripheral immune system and CNS communicate to regulate post-stroke brain homeostasis. First, we discuss the post-stroke immune cascade across different contexts as well as homeostatic regulation within the brain. Then, we focus on the lymphatic vessels surrounding the brain and their ability to coordinate both immune response and fluid homeostasis within the brain after stroke. Finally, we discuss how therapeutic manipulation of peripheral systems may provide new mechanisms to treat stroke injury.
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18
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Lv T, Zhao B, Hu Q, Zhang X. The Glymphatic System: A Novel Therapeutic Target for Stroke Treatment. Front Aging Neurosci 2021; 13:689098. [PMID: 34305569 PMCID: PMC8297504 DOI: 10.3389/fnagi.2021.689098] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 06/07/2021] [Indexed: 12/25/2022] Open
Abstract
The glymphatic system (GS) is a novel defined brain-wide perivascular transit network between cerebrospinal fluid (CSF) and interstitial solutes that facilitates the clearance of brain metabolic wastes. The complicated network of the GS consists of the periarterial CSF influx pathway, astrocytes-mediated convective transport of fluid and solutes supported by AQP4 water channels, and perivenous efflux pathway. Recent researches indicate that the GS dysfunction is associated with various neurological disorders, including traumatic brain injury, hydrocephalus, epilepsy, migraine, and Alzheimer’s disease (AD). Meanwhile, the GS also plays a pivotal role in the pathophysiological process of stroke, including brain edema, blood–brain barrier (BBB) disruption, immune cell infiltration, neuroinflammation, and neuronal apoptosis. In this review, we illustrated the key anatomical structures of the GS, the relationship between the GS and the meningeal lymphatic system, the interaction between the GS and the BBB, and the crosstalk between astrocytes and other GS cellular components. In addition, we contributed to the current knowledge about the role of the GS in the pathology of stroke and the role of AQP4 in stroke. We further discussed the potential use of the GS in early risk assessment, diagnostics, prognostics, and therapeutics of stroke.
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Affiliation(s)
- Tao Lv
- Department of Neurosurgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Bing Zhao
- Department of Neurosurgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Qin Hu
- Central Laboratory, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaohua Zhang
- Department of Neurosurgery, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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19
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Kaur J, Fahmy LM, Davoodi-Bojd E, Zhang L, Ding G, Hu J, Zhang Z, Chopp M, Jiang Q. Waste Clearance in the Brain. Front Neuroanat 2021; 15:665803. [PMID: 34305538 PMCID: PMC8292771 DOI: 10.3389/fnana.2021.665803] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 06/15/2021] [Indexed: 12/15/2022] Open
Abstract
Waste clearance (WC) is an essential process for brain homeostasis, which is required for the proper and healthy functioning of all cerebrovascular and parenchymal brain cells. This review features our current understanding of brain WC, both within and external to the brain parenchyma. We describe the interplay of the blood-brain barrier (BBB), interstitial fluid (ISF), and perivascular spaces within the brain parenchyma for brain WC directly into the blood and/or cerebrospinal fluid (CSF). We also discuss the relevant role of the CSF and its exit routes in mediating WC. Recent discoveries of the glymphatic system and meningeal lymphatic vessels, and their relevance to brain WC are highlighted. Controversies related to brain WC research and potential future directions are presented.
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Affiliation(s)
- Jasleen Kaur
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
- Department of Physics, Oakland University, Rochester, MI, United States
| | - Lara M. Fahmy
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University, Detroit, MI, United States
| | - Esmaeil Davoodi-Bojd
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
- Department of Radiology, Henry Ford Health System, Detroit, MI, United States
| | - Li Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
| | - Guangliang Ding
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
| | - Jiani Hu
- Department of Radiology, Wayne State University, Detroit, MI, United States
| | - Zhenggang Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
- Department of Neurology, Wayne State University, Detroit, MI, United States
| | - Michael Chopp
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
- Department of Physics, Oakland University, Rochester, MI, United States
| | - Quan Jiang
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
- Department of Physics, Oakland University, Rochester, MI, United States
- Department of Neurology, Wayne State University, Detroit, MI, United States
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20
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Fahmy LM, Chen Y, Xuan S, Haacke EM, Hu J, Jiang Q. All Central Nervous System Neuro- and Vascular-Communication Channels Are Surrounded With Cerebrospinal Fluid. Front Neurol 2021; 12:614636. [PMID: 34220663 PMCID: PMC8247447 DOI: 10.3389/fneur.2021.614636] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 04/29/2021] [Indexed: 12/15/2022] Open
Abstract
Background: Recent emerging evidence has highlighted the potential critical role of cerebrospinal fluid (CSF) in cerebral waste clearance and immunomodulation. It is already very well-established that the central nervous system (CNS) is completely submerged in CSF on a macro-level; but to what extent is this true on a micro-level? Specifically, within the peri-neural and peri-vascular spaces within the CNS parenchyma. Therefore, the objective of this study was to use magnetic resonance imaging (MRI) to simultaneously map the presence of CSF within all peri-neural (cranial and spinal nerves) and peri-vascular spaces in vivo in humans. Four MRI protocols each with five participants were used to image the CSF in the brain and spinal cord. Our findings indicated that all CNS neuro- and vascular-communication channels are surrounded with CSF. In other words, all peri-neural spaces surrounding the cranial and spinal nerves as well as all peri-vascular spaces surrounding MRI-visible vasculature were filled with CSF. These findings suggest that anatomically, substance exchange between the brain parenchyma and outside tissues including lymphatic ones can only occur through CSF pathways and/or vascular pathways, warranting further investigation into its implications in cerebral waste clearance and immunity.
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Affiliation(s)
- Lara M Fahmy
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University, Detroit, MI, United States
| | - Yongsheng Chen
- Department of Neurology, Wayne State University, Detroit, MI, United States
| | - Stephanie Xuan
- Department of Radiology, Wayne State University, Detroit, MI, United States
| | - E Mark Haacke
- Department of Radiology, Wayne State University, Detroit, MI, United States
| | - Jiani Hu
- Department of Radiology, Wayne State University, Detroit, MI, United States
| | - Quan Jiang
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
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21
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The Need for Head Space: Brachycephaly and Cerebrospinal Fluid Disorders. Life (Basel) 2021; 11:life11020139. [PMID: 33673129 PMCID: PMC7918167 DOI: 10.3390/life11020139] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/06/2021] [Accepted: 02/08/2021] [Indexed: 12/12/2022] Open
Abstract
Brachycephalic dogs remain popular, despite the knowledge that this head conformation is associated with health problems, including airway compromise, ocular disorders, neurological disease, and other co-morbidities. There is increasing evidence that brachycephaly disrupts cerebrospinal fluid movement and absorption, predisposing ventriculomegaly, hydrocephalus, quadrigeminal cistern expansion, Chiari-like malformation, and syringomyelia. In this review, we focus on cerebrospinal fluid physiology and how this is impacted by brachycephaly, airorhynchy, and associated craniosynostosis.
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22
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Kratz SV. Case report: Manual therapies promote resolution of persistent post-concussion symptoms in a 24-year-old athlete. SAGE Open Med Case Rep 2021; 9:2050313X20952224. [PMID: 33628444 PMCID: PMC7829464 DOI: 10.1177/2050313x20952224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 07/30/2020] [Indexed: 12/24/2022] Open
Abstract
This case report illustrates the treatment outcomes of a collegiate athlete presenting with an 18-month history of post-concussion syndrome who received a series of mixed manual therapies in isolation of other therapy. Persistent symptoms were self-reported as debilitating, contributing to self-removal from participation in school, work, and leisure activities. Patient and parent interviews captured the history of multiple concussions and other sports-related injuries. Neurological screening and activities of daily living were baseline measured. Post-Concussion Symptom Checklist and Headache Impact Test-6™ were utilized to track symptom severity. Treatments applied included craniosacral therapy, manual lymphatic drainage, and glymphatic techniques. Eleven treatment sessions were administered over 3 months. Results indicated restoration of oxygen saturation, normalized pupil reactivity, and satisfactory sleep. Post-concussion syndrome symptom severity was reduced by 87% as reflected by accumulative Post-Concussion Symptom Checklist scores. Relief from chronic headaches was achieved, reflected by Headache Impact Test-6 scores. Restoration of mood and quality of life were reported. A 6-month follow-up revealed symptoms remained abated with full re-engagement of daily activities. The author hypothesized that post-concussion syndrome symptoms were related to compression of craniosacral system structures and lymphatic fluid stagnation that contributed to head pressure pain, severe sleep deprivation, and multiple neurological and psychological symptoms. Positive outcomes over a relatively short period of time without adverse effects suggest these therapies may offer viable options for the treatment of post-concussion syndrome.
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Affiliation(s)
- Susan Vaughan Kratz
- Registered Occupational Therapist,
CranioSacral Therapy—Diplomat, Special Therapies, Inc., Waukesha, WI,
USA
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23
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Proulx ST. Cerebrospinal fluid outflow: a review of the historical and contemporary evidence for arachnoid villi, perineural routes, and dural lymphatics. Cell Mol Life Sci 2021; 78:2429-2457. [PMID: 33427948 PMCID: PMC8004496 DOI: 10.1007/s00018-020-03706-5] [Citation(s) in RCA: 158] [Impact Index Per Article: 52.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/23/2020] [Accepted: 11/06/2020] [Indexed: 12/19/2022]
Abstract
Cerebrospinal fluid (CSF) is produced by the choroid plexuses within the ventricles of the brain and circulates through the subarachnoid space of the skull and spinal column to provide buoyancy to and maintain fluid homeostasis of the brain and spinal cord. The question of how CSF drains from the subarachnoid space has long puzzled scientists and clinicians. For many decades, it was believed that arachnoid villi or granulations, outcroppings of arachnoid tissue that project into the dural venous sinuses, served as the major outflow route. However, this concept has been increasingly challenged in recent years, as physiological and imaging evidence from several species has accumulated showing that tracers injected into the CSF can instead be found within lymphatic vessels draining from the cranium and spine. With the recent high-profile rediscovery of meningeal lymphatic vessels located in the dura mater, another debate has emerged regarding the exact anatomical pathway(s) for CSF to reach the lymphatic system, with one side favoring direct efflux to the dural lymphatic vessels within the skull and spinal column and another side advocating for pathways along exiting cranial and spinal nerves. In this review, a summary of the historical and contemporary evidence for the different outflow pathways will be presented, allowing the reader to gain further perspective on the recent advances in the field. An improved understanding of this fundamental physiological process may lead to novel therapeutic approaches for a wide range of neurological conditions, including hydrocephalus, neurodegeneration and multiple sclerosis.
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Affiliation(s)
- Steven T Proulx
- Theodor Kocher Institute, University of Bern, Bern, Switzerland.
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24
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Wostyn P. COVID-19 and chronic fatigue syndrome: Is the worst yet to come? Med Hypotheses 2021; 146:110469. [PMID: 33401106 PMCID: PMC7836544 DOI: 10.1016/j.mehy.2020.110469] [Citation(s) in RCA: 110] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 12/17/2020] [Indexed: 01/05/2023]
Abstract
There has been concern about possible long-term sequelae resembling myalgic encephalomyelitis/chronic fatigue syndrome in COVID-19 patients. Clarifying the mechanisms underlying such a "post-COVID-19 fatigue syndrome" is essential for the development of preventive and early treatment methods for this syndrome. In the present paper, by integrating insights pertaining to the glymphatic system and the nasal cerebrospinal fluid outflow pathway with findings in patients with chronic fatigue syndrome, idiopathic intracranial hypertension, and COVID-19, I provide a coherent conceptual framework for understanding the pathophysiology of post-COVID-19 fatigue syndrome. According to this hypothesis, this syndrome may result from damage to olfactory sensory neurons, causing reduced outflow of cerebrospinal fluid through the cribriform plate, and further leading to congestion of the glymphatic system with subsequent toxic build-up within the central nervous system. I further postulate that patients with post-COVID-19 fatigue syndrome may benefit from cerebrospinal fluid drainage by restoring glymphatic transport and waste removal from the brain. Obviously, further research is required to provide further evidence for the presence of this post-viral syndrome, and to provide additional insight regarding the relative contribution of the glymphatic-lymphatic system to it. Other mechanisms may also be involved. If confirmed, the glymphatic-lymphatic system could represent a target in combating post-COVID-19 fatigue syndrome. Moreover, further research in this area could also provide new insights into the understanding of chronic fatigue syndrome.
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Affiliation(s)
- Peter Wostyn
- Department of Psychiatry, PC Sint-Amandus, Reigerlostraat 10, 8730 Beernem, Belgium.
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25
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Brady M, Rahman A, Combs A, Venkatraman C, Kasper RT, McQuaid C, Kwok WCE, Wood RW, Deane R. Cerebrospinal fluid drainage kinetics across the cribriform plate are reduced with aging. Fluids Barriers CNS 2020; 17:71. [PMID: 33256800 PMCID: PMC7706057 DOI: 10.1186/s12987-020-00233-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/20/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Continuous circulation and drainage of cerebrospinal fluid (CSF) are essential for the elimination of CSF-borne metabolic products and neuronal function. While multiple CSF drainage pathways have been identified, the significance of each to normal drainage and whether there are differential changes at CSF outflow regions in the aging brain are unclear. METHODS Dynamic in vivo imaging of near infrared fluorescently-labeled albumin was used to simultaneously visualize the flow of CSF at outflow regions on the dorsal side (transcranial and -spinal) of the central nervous system. This was followed by kinetic analysis, which included the elimination rate constants for these regions. In addition, tracer distribution in ex vivo tissues were assessed, including the nasal/cribriform region, dorsal and ventral surfaces of the brain, spinal cord, cranial dura, skull base, optic and trigeminal nerves and cervical lymph nodes. RESULTS Based on the in vivo data, there was evidence of CSF elimination, as determined by the rate of clearance, from the nasal route across the cribriform plate and spinal subarachnoid space, but not from the dorsal dural regions. Using ex vivo tissue samples, the presence of tracer was confirmed in the cribriform area and olfactory regions, around pial blood vessels, spinal subarachnoid space, spinal cord and cervical lymph nodes but not for the dorsal dura, skull base or the other cranial nerves. Also, ex vivo tissues showed retention of tracer along brain fissures and regions associated with cisterns on the brain surfaces, but not in the brain parenchyma. Aging reduced CSF elimination across the cribriform plate but not that from the spinal SAS nor retention on the brain surfaces. CONCLUSIONS Collectively, these data show that the main CSF outflow sites were the nasal region across the cribriform plate and from the spinal regions in mice. In young adult mice, the contribution of the nasal and cribriform route to outflow was much higher than from the spinal regions. In older mice, the contribution of the nasal route to CSF outflow was reduced significantly but not for the spinal routes. This kinetic approach may have significance in determining early changes in CSF drainage in neurological disorder, age-related cognitive decline and brain diseases.
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Affiliation(s)
- Molly Brady
- Departments of Neuroscience, University of Rochester, URMC, 601 Elmwood Avenue, Rochester, NY, 14642, USA
| | - Akib Rahman
- Departments of Neuroscience, University of Rochester, URMC, 601 Elmwood Avenue, Rochester, NY, 14642, USA
| | - Abigail Combs
- Departments of Neuroscience, University of Rochester, URMC, 601 Elmwood Avenue, Rochester, NY, 14642, USA
| | - Chethana Venkatraman
- Departments of Neuroscience, University of Rochester, URMC, 601 Elmwood Avenue, Rochester, NY, 14642, USA
| | - R Tristan Kasper
- Departments of Neurosurgery, University of Rochester, URMC, 601 Elmwood Avenue, Rochester, NY, 14642, USA
| | - Conor McQuaid
- Departments of Neuroscience, University of Rochester, URMC, 601 Elmwood Avenue, Rochester, NY, 14642, USA
| | - Wing-Chi Edmund Kwok
- Departments of Imaging Sciences, University of Rochester, URMC, 601 Elmwood Avenue, Rochester, NY, 14642, USA
| | - Ronald W Wood
- Departments of Neuroscience, University of Rochester, URMC, 601 Elmwood Avenue, Rochester, NY, 14642, USA
- Departments of Obstetrics and Gynecology, Urology, University of Rochester, URMC, 601 Elmwood Avenue, Rochester, NY, 14642, USA
| | - Rashid Deane
- Departments of Neuroscience, University of Rochester, URMC, 601 Elmwood Avenue, Rochester, NY, 14642, USA.
- Departments of Neurosurgery, University of Rochester, URMC, 601 Elmwood Avenue, Rochester, NY, 14642, USA.
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26
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Fame RM, Lehtinen MK. Emergence and Developmental Roles of the Cerebrospinal Fluid System. Dev Cell 2020; 52:261-275. [PMID: 32049038 DOI: 10.1016/j.devcel.2020.01.027] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 01/14/2020] [Accepted: 01/24/2020] [Indexed: 12/21/2022]
Abstract
We summarize recent work illuminating how cerebrospinal fluid (CSF) regulates brain function. More than a protective fluid cushion and sink for waste, the CSF is an integral CNS component with dynamic and diverse roles emerging in parallel with the developing CNS. This review examines the current understanding about early CSF and its maturation and roles during CNS development and discusses open questions in the field. We focus on developmental changes in the ventricular system and CSF sources (including neural progenitors and choroid plexus). We also discuss concepts related to the development of fluid dynamics including flow, perivascular transport, drainage, and barriers.
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Affiliation(s)
- Ryann M Fame
- Department of Pathology, Boston Children's Hospital, Boston, MA 02115, USA
| | - Maria K Lehtinen
- Department of Pathology, Boston Children's Hospital, Boston, MA 02115, USA.
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27
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Hu X, Deng Q, Ma L, Li Q, Chen Y, Liao Y, Zhou F, Zhang C, Shao L, Feng J, He T, Ning W, Kong Y, Huo Y, He A, Liu B, Zhang J, Adams R, He Y, Tang F, Bian X, Luo J. Meningeal lymphatic vessels regulate brain tumor drainage and immunity. Cell Res 2020; 30:229-243. [PMID: 32094452 PMCID: PMC7054407 DOI: 10.1038/s41422-020-0287-8] [Citation(s) in RCA: 199] [Impact Index Per Article: 49.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 01/21/2020] [Indexed: 11/14/2022] Open
Abstract
Recent studies have shown that meningeal lymphatic vessels (MLVs), which are located both dorsally and basally beneath the skull, provide a route for draining macromolecules and trafficking immune cells from the central nervous system (CNS) into cervical lymph nodes (CLNs), and thus represent a potential therapeutic target for treating neurodegenerative and neuroinflammatory diseases. However, the roles of MLVs in brain tumor drainage and immunity remain unexplored. Here we show that dorsal MLVs undergo extensive remodeling in mice with intracranial gliomas or metastatic melanomas. RNA-seq analysis of MLV endothelial cells revealed changes in the gene sets involved in lymphatic remodeling, fluid drainage, as well as inflammatory and immunological responses. Disruption of dorsal MLVs alone impaired intratumor fluid drainage and the dissemination of brain tumor cells to deep CLNs (dCLNs). Notably, the dendritic cell (DC) trafficking from intracranial tumor tissues to dCLNs decreased in mice with defective dorsal MLVs, and increased in mice with enhanced dorsal meningeal lymphangiogenesis. Strikingly, disruption of dorsal MLVs alone, without affecting basal MLVs or nasal LVs, significantly reduced the efficacy of combined anti-PD-1/CTLA-4 checkpoint therapy in striatal tumor models. Furthermore, mice bearing tumors overexpressing VEGF-C displayed a better response to anti-PD-1/CTLA-4 combination therapy, and this was abolished by CCL21/CCR7 blockade, suggesting that VEGF-C potentiates checkpoint therapy via the CCL21/CCR7 pathway. Together, the results of our study not only demonstrate the functional aspects of MLVs as classic lymphatic vasculature, but also highlight that they are essential in generating an efficient immune response against brain tumors.
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Affiliation(s)
- Xueting Hu
- Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, 100871, Beijing, China
| | - Qiuping Deng
- Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, 100871, Beijing, China
| | - Lu Ma
- Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, 100871, Beijing, China
| | - Qingqing Li
- Biodynamic Optical Imaging Center, College of Life Sciences, Peking University, 100871, Beijing, China
| | - Yidong Chen
- Biodynamic Optical Imaging Center, College of Life Sciences, Peking University, 100871, Beijing, China
| | - Yuhan Liao
- Biodynamic Optical Imaging Center, College of Life Sciences, Peking University, 100871, Beijing, China
| | - Fan Zhou
- State Key Laboratory of Proteomics, Translational Medicine Center of Stem Cells, 307-Ivy Translational Medicine Center, Laboratory of Oncology, Affiliated Hospital, Academy of Military Medical Sciences, 100071, Beijing, China
| | - Chen Zhang
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, 100069, Beijing, China
| | - Linlin Shao
- Eye Hospital of China Academy of Chinese Medical Sciences, 100040, Beijing, China
| | - Jun Feng
- Eye Hospital of China Academy of Chinese Medical Sciences, 100040, Beijing, China
| | - Tubao He
- Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, 100871, Beijing, China
| | - Weihai Ning
- Sanbo Brain Hospital, Capital Medical University, 100093, Beijing, China
| | - Yan Kong
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Cell Biology, Peking University Cancer Hospital and Institute, 100142, Beijing, China
| | - Yingqing Huo
- Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, 100871, Beijing, China
| | - Aibin He
- Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, 100871, Beijing, China
- Peking-Tsinghua Center for Life Sciences, 100871, Beijing, China
| | - Bing Liu
- State Key Laboratory of Proteomics, Translational Medicine Center of Stem Cells, 307-Ivy Translational Medicine Center, Laboratory of Oncology, Affiliated Hospital, Academy of Military Medical Sciences, 100071, Beijing, China
| | - Jingjing Zhang
- Affiliated Hospital of Guangdong Medical University, Zhanjiang, 524001, Guangdong, China
| | - Ralf Adams
- Max-Planck-Institute for Molecular Biomedicine, Department of Tissue Morphogenesis, and University of Münster, Faculty of Medicine, Münster, D-48149, Germany
| | - Yulong He
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, 215123, Jiangsu, China
| | - Fuchou Tang
- Biodynamic Optical Imaging Center, College of Life Sciences, Peking University, 100871, Beijing, China
- Peking-Tsinghua Center for Life Sciences, 100871, Beijing, China
| | - Xiuwu Bian
- Institute of Pathology and Southwest Cancer Center, Key Laboratory of the Ministry of Education, Southwest Hospital, Army Medical University (Third Military Medical University), 400038, Chongqing, China
| | - Jincai Luo
- Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, 100871, Beijing, China.
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28
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Abstract
PURPOSE OF REVIEW This article describes the physiology of cerebrospinal fluid (CSF). We review current evidence and new concepts relating to CSF physiology with respect to CSF secretion, circulation and resorption and we highlight key pathophysiological associations including the relationship between CSF and intracranial pressure. RECENT FINDINGS CSF secretion occurs primarily via the choroid plexus. Various transport mechanisms facilitate CSF secretion but the role Aquaporins play in this process is a recent discovery and an area of ongoing research. CSF circulation is a dynamic process but the importance of the perivascular 'Glymphatic system' and extraarachnoidal pathways of resorption are relatively new concepts. SUMMARY CSF physiology is dependent on various interacting factors and is critical for normal brain development and function.
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29
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Klebe D, McBride D, Krafft PR, Flores JJ, Tang J, Zhang JH. Posthemorrhagic hydrocephalus development after germinal matrix hemorrhage: Established mechanisms and proposed pathways. J Neurosci Res 2020; 98:105-120. [PMID: 30793349 PMCID: PMC6703985 DOI: 10.1002/jnr.24394] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 12/05/2018] [Accepted: 01/14/2019] [Indexed: 01/17/2023]
Abstract
In addition to being the leading cause of morbidity and mortality in premature infants, germinal matrix hemorrhage (GMH) is also the leading cause of acquired infantile hydrocephalus. The pathophysiology of posthemorrhagic hydrocephalus (PHH) development after GMH is complex and vaguely understood, although evidence suggests fibrosis and gliosis in the periventricular and subarachnoid spaces disrupts normal cerebrospinal fluid (CSF) dynamics. Theories explaining general hydrocephalus etiology have substantially evolved from the original bulk flow theory developed by Dr. Dandy over a century ago. Current clinical and experimental evidence supports a new hydrodynamic theory for hydrocephalus development involving redistribution of vascular pulsations and disruption of Starling forces in the brain microcirculation. In this review, we discuss CSF flow dynamics, history and development of theoretical hydrocephalus pathophysiology, and GMH epidemiology and etiology as it relates to PHH development. We highlight known mechanisms and propose new avenues that will further elucidate GMH pathophysiology, specifically related to hydrocephalus.
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Affiliation(s)
- Damon Klebe
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA 92350
| | - Devin McBride
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA 92350
| | - Paul R Krafft
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA 92350
- Department of Neurosurgery, Loma Linda University School of Medicine, Loma Linda, CA 92350
| | - Jerry J Flores
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA 92350
| | - Jiping Tang
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA 92350
| | - John H Zhang
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA 92350
- Department of Anesthesiology and Neurosurgery, Loma Linda University School of Medicine, Loma Linda, CA 92350
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30
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Frederick N, Louveau A. Meningeal lymphatics, immunity and neuroinflammation. Curr Opin Neurobiol 2019; 62:41-47. [PMID: 31816570 DOI: 10.1016/j.conb.2019.11.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 10/28/2019] [Accepted: 11/01/2019] [Indexed: 12/26/2022]
Abstract
In the past five years, the surrounding of the brain, that is the meninges (singular meninx) have evolved from being a physical barrier that protects the brain parenchyma to becoming a central player for both the maintenance of normal brain function and the modulation of neurological disorders. Indeed, the meninges are an immunologically active compartment that communicates with the periphery via the (re)discovered meningeal lymphatic system. From its ties to both the periphery and the central nervous system, the meninges are becoming a prevalent organ to understand and modulate brain homeostasis. Here we will focus on current advances in our understanding of the meningeal compartment with an emphasis on the meningeal lymphatic network as a key regulator.
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Affiliation(s)
- Natalie Frederick
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Antoine Louveau
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Department of Molecular Medicine, Cleveland Clinic College of Medicine, Case Western Reserve University, Cleveland, OH, USA.
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31
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Uncertainty quantification of parenchymal tracer distribution using random diffusion and convective velocity fields. Fluids Barriers CNS 2019; 16:32. [PMID: 31564250 PMCID: PMC6767654 DOI: 10.1186/s12987-019-0152-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 09/07/2019] [Indexed: 11/28/2022] Open
Abstract
Background Influx and clearance of substances in the brain parenchyma occur by a combination of diffusion and convection, but the relative importance of these mechanisms is unclear. Accurate modeling of tracer distributions in the brain relies on parameters that are partially unknown and with literature values varying by several orders of magnitude. In this work, we rigorously quantified the variability of tracer distribution in the brain resulting from uncertainty in diffusion and convection model parameters. Methods Using the convection–diffusion–reaction equation, we simulated tracer distribution in the brain parenchyma after intrathecal injection. Several models were tested to assess the uncertainty both in type of diffusion and velocity fields and also the importance of their magnitude. Our results were compared with experimental MRI results of tracer enhancement. Results In models of pure diffusion, the expected amount of tracer in the gray matter reached peak value after 15 h, while the white matter did not reach peak within 24 h with high likelihood. Models of the glymphatic system were similar qualitatively to the models of pure diffusion with respect to expected time to peak but displayed less variability. However, the expected time to peak was reduced to 11 h when an additional directionality was prescribed for the glymphatic circulation. In a model including drainage directly from the brain parenchyma, time to peak occured after 6–8 h for the gray matter. Conclusion Even when uncertainties are taken into account, we find that diffusion alone is not sufficient to explain transport of tracer deep into the white matter as seen in experimental data. A glymphatic velocity field may increase transport if a large-scale directional structure is included in the glymphatic circulation.
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32
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Norwood JN, Zhang Q, Card D, Craine A, Ryan TM, Drew PJ. Anatomical basis and physiological role of cerebrospinal fluid transport through the murine cribriform plate. eLife 2019; 8:44278. [PMID: 31063132 PMCID: PMC6524970 DOI: 10.7554/elife.44278] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 05/06/2019] [Indexed: 12/25/2022] Open
Abstract
Cerebrospinal fluid (CSF) flows through the brain, transporting chemical signals and removing waste. CSF production in the brain is balanced by a constant outflow of CSF, the anatomical basis of which is poorly understood. Here, we characterized the anatomy and physiological function of the CSF outflow pathway along the olfactory sensory nerves through the cribriform plate, and into the nasal epithelia. Chemical ablation of olfactory sensory nerves greatly reduced outflow of CSF through the cribriform plate. The reduction in CSF outflow did not cause an increase in intracranial pressure (ICP), consistent with an alteration in the pattern of CSF drainage or production. Our results suggest that damage to olfactory sensory neurons (such as from air pollution) could contribute to altered CSF turnover and flow, providing a potential mechanism for neurological diseases.
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Affiliation(s)
- Jordan N Norwood
- Cellular and Developmental Biology Graduate Program, Pennsylvania State University, University Park, United States
| | - Qingguang Zhang
- Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, United States
| | - David Card
- Department of Physics, Pennsylvania State University, University Park, United States
| | - Amanda Craine
- Department of Biomedical Engineering, Pennsylvania State University, University Park, United States
| | - Timothy M Ryan
- Department of Anthropology, Pennsylvania State University, University Park, United States
| | - Patrick J Drew
- Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, United States.,Department of Biomedical Engineering, Pennsylvania State University, University Park, United States.,Department of Neurosurgery, Pennsylvania State University, University Park, United States
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33
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Samancı B, Samancı Y, Şen C, Şahin E, Sezgin M, Kocasoy Orhan E, Orhan KS, Baykan B. Assessment of the Olfactory Function in Patients With Idiopathic Intracranial Hypertension Using the Sniffin' Sticks Test: A Case-Control Study. Headache 2019; 59:848-857. [PMID: 31001819 DOI: 10.1111/head.13538] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/26/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Despite the lack of recognition in clinical practice, there is increasing evidence that patients with idiopathic intracranial hypertension may suffer from hyposmia. The current case-control study aims to evaluate olfactory dysfunction in a large series of patients with idiopathic intracranial hypertension. METHODS All subjects, 44 idiopathic intracranial hypertension patients and 57 healthy controls, underwent olfactory function assessment using standardized "Sniffin' Sticks" test at a tertiary referral center of a university hospital. Threshold, discrimination, identification, and total threshold-discrimination-identification scores have been determined and analyzed statistically. RESULTS Idiopathic intracranial hypertension patients had significantly lower threshold (6.5 [3.69] vs 8 [1.88], P < .001, 95% CI [-2.250, -0.750]) and threshold-discrimination-identification scores (29.75 [5.56] vs 32.5 [5.25], P = .003, 95% CI [-4.250, -0.750]). Twenty-five patients (57%) were diagnosed with hyposmia. Test scores of patients with active idiopathic intracranial hypertension (n = 18) were not statistically different from patients with inactive disease (n = 26), except for discrimination score (14 [2.50] vs 11 [2.25], P = .005, 95% CI [-3.000, -1.000]). Although idiopathic intracranial hypertension patients with a cerebrospinal fluid opening pressure of ≥330 mmH2 O had lower test scores, the difference was significant only for total threshold-discrimination-identification scores (28.5 [5.50] vs 30.5 [4.38], P = .044, 95% CI [0.750, 5.500]). Multiple regression analysis revealed that test scores were related to disease activity, cerebrospinal fluid opening pressure, papilledema, headache, and medication. CONCLUSION Our clinical study revealed significant olfactory dysfunction in patients with idiopathic intracranial hypertension compared with healthy controls. Future research should employ larger samples to search for usability of olfactory testing in clinical management of patients with idiopathic intracranial hypertension.
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Affiliation(s)
- Bedia Samancı
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Yavuz Samancı
- Org. Abdurrahman Nafiz Gürman Cad. Etyemez, İstanbul, Turkey.,Department of Neuroscience, Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Cömert Şen
- Department of Otorhinolaryngology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Erdi Şahin
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Mine Sezgin
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Elif Kocasoy Orhan
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Kadir Serkan Orhan
- Department of Otorhinolaryngology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Betül Baykan
- Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
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Bothwell SW, Janigro D, Patabendige A. Cerebrospinal fluid dynamics and intracranial pressure elevation in neurological diseases. Fluids Barriers CNS 2019; 16:9. [PMID: 30967147 PMCID: PMC6456952 DOI: 10.1186/s12987-019-0129-6] [Citation(s) in RCA: 130] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 03/19/2019] [Indexed: 01/09/2023] Open
Abstract
The fine balance between the secretion, composition, volume and turnover of cerebrospinal fluid (CSF) is strictly regulated. However, during certain neurological diseases, this balance can be disrupted. A significant disruption to the normal CSF circulation can be life threatening, leading to increased intracranial pressure (ICP), and is implicated in hydrocephalus, idiopathic intracranial hypertension, brain trauma, brain tumours and stroke. Yet, the exact cellular, molecular and physiological mechanisms that contribute to altered hydrodynamic pathways in these diseases are poorly defined or hotly debated. The traditional views and concepts of CSF secretion, flow and drainage have been challenged, also due to recent findings suggesting more complex mechanisms of brain fluid dynamics than previously proposed. This review evaluates and summarises current hypotheses of CSF dynamics and presents evidence for the role of impaired CSF dynamics in elevated ICP, alongside discussion of the proteins that are potentially involved in altered CSF physiology during neurological disease. Undoubtedly CSF secretion, absorption and drainage are important aspects of brain fluid homeostasis in maintaining a stable ICP. Traditionally, pharmacological interventions or CSF drainage have been used to reduce ICP elevation due to over production of CSF. However, these drugs are used only as a temporary solution due to their undesirable side effects. Emerging evidence suggests that pharmacological targeting of aquaporins, transient receptor potential vanilloid type 4 (TRPV4), and the Na+-K+-2Cl- cotransporter (NKCC1) merit further investigation as potential targets in neurological diseases involving impaired brain fluid dynamics and elevated ICP.
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Affiliation(s)
- Steven William Bothwell
- Brain Barriers Group, School of Biomedical Sciences and Pharmacy, The University of Newcastle, Medical Sciences Building, University Drive, Callaghan, NSW 2308 Australia
| | - Damir Janigro
- FloTBI Inc., Cleveland, OH USA
- Department of Physiology, Case Western Reserve University, Cleveland, OH USA
| | - Adjanie Patabendige
- Brain Barriers Group, School of Biomedical Sciences and Pharmacy, The University of Newcastle, Medical Sciences Building, University Drive, Callaghan, NSW 2308 Australia
- Hunter Medical Research Institute, Newcastle, NSW Australia
- The Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
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35
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Munk AS, Wang W, Bèchet NB, Eltanahy AM, Cheng AX, Sigurdsson B, Benraiss A, Mäe MA, Kress BT, Kelley DH, Betsholtz C, Møllgård K, Meissner A, Nedergaard M, Lundgaard I. PDGF-B Is Required for Development of the Glymphatic System. Cell Rep 2019; 26:2955-2969.e3. [PMID: 30865886 PMCID: PMC6447074 DOI: 10.1016/j.celrep.2019.02.050] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 01/07/2019] [Accepted: 02/13/2019] [Indexed: 01/07/2023] Open
Abstract
The glymphatic system is a highly polarized cerebrospinal fluid (CSF) transport system that facilitates the clearance of neurotoxic molecules through a brain-wide network of perivascular pathways. Herein we have mapped the development of the glymphatic system in mice. Perivascular CSF transport first emerges in hippocampus in newborn mice, and a mature glymphatic system is established in the cortex at 2 weeks of age. Formation of astrocytic endfeet and polarized expression of aquaporin 4 (AQP4) consistently coincided with the appearance of perivascular CSF transport. Deficiency of platelet-derived growth factor B (PDGF-B) function in the PDGF retention motif knockout mouse line Pdgfbret/ret suppressed the development of the glymphatic system, whose functions remained suppressed in adulthood compared with wild-type mice. These experiments map the natural development of the glymphatic system in mice and define a critical role of PDGF-B in the development of perivascular CSF transport.
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Affiliation(s)
- Anne Sofie Munk
- Center for Translational Neuromedicine, University of Rochester, Rochester, NY 14642, USA; Center for Basic and Translational Neuroscience, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Wei Wang
- Center for Translational Neuromedicine, University of Rochester, Rochester, NY 14642, USA
| | - Nicholas Burdon Bèchet
- Department of Experimental Medical Science, Lund University, 221 84 Lund, Sweden; Wallenberg Center for Molecular Medicine, Lund University, 221 84 Lund, Sweden
| | - Ahmed M Eltanahy
- Department of Experimental Medical Science, Lund University, 221 84 Lund, Sweden; Wallenberg Center for Molecular Medicine, Lund University, 221 84 Lund, Sweden; Mansoura University Hospital, Faculty of Medicine, Mansoura University, 35516 Mansoura, Egypt
| | - Anne Xiaoan Cheng
- Center for Translational Neuromedicine, University of Rochester, Rochester, NY 14642, USA
| | - Björn Sigurdsson
- Center for Basic and Translational Neuroscience, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Abdellatif Benraiss
- Center for Translational Neuromedicine, University of Rochester, Rochester, NY 14642, USA
| | - Maarja A Mäe
- Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden
| | - Benjamin Travis Kress
- Center for Translational Neuromedicine, University of Rochester, Rochester, NY 14642, USA; Center for Basic and Translational Neuroscience, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Douglas H Kelley
- Department of Mechanical Engineering, University of Rochester, Rochester, NY 14627, USA
| | - Christer Betsholtz
- Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden; Integrated Cardio Metabolic Center (ICMC), Karolinska Institutet, Novum, 141 57 Huddinge, Sweden
| | - Kjeld Møllgård
- Department of Cellular and Molecular Medicine, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Anja Meissner
- Department of Experimental Medical Science, Lund University, 221 84 Lund, Sweden; Wallenberg Center for Molecular Medicine, Lund University, 221 84 Lund, Sweden
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Rochester, Rochester, NY 14642, USA; Center for Basic and Translational Neuroscience, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Iben Lundgaard
- Center for Translational Neuromedicine, University of Rochester, Rochester, NY 14642, USA; Department of Experimental Medical Science, Lund University, 221 84 Lund, Sweden; Wallenberg Center for Molecular Medicine, Lund University, 221 84 Lund, Sweden.
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36
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Semyachkina-Glushkovskaya O, Postnov D, Kurths J. Blood⁻Brain Barrier, Lymphatic Clearance, and Recovery: Ariadne's Thread in Labyrinths of Hypotheses. Int J Mol Sci 2018; 19:ijms19123818. [PMID: 30513598 PMCID: PMC6320935 DOI: 10.3390/ijms19123818] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 11/21/2018] [Accepted: 11/23/2018] [Indexed: 12/25/2022] Open
Abstract
The peripheral lymphatic system plays a crucial role in the recovery mechanisms after many pathological changes, such as infection, trauma, vascular, or metabolic diseases. The lymphatic clearance of different tissues from waste products, viruses, bacteria, and toxic proteins significantly contributes to the correspondent recovery processes. However, understanding of the cerebral lymphatic functions is a challenging problem. The exploration of mechanisms of lymphatic communication with brain fluids as well as the role of the lymphatic system in brain drainage, clearance, and recovery is still in its infancy. Here we review novel concepts on the anatomy and physiology of the lymphatics in the brain, which warrant a substantial revision of our knowledge about the role of lymphatics in the rehabilitation of the brain functions after neural pathologies. We discuss a new vision on the connective bridge between the opening of a blood–brain barrier and activation of the meningeal lymphatic clearance. The ability to stimulate the lymph flow in the brain, is likely to play an important role in developing future innovative strategies in neurorehabilitation therapy.
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Affiliation(s)
| | - Dmitry Postnov
- Department of Optics and Biophotonics, Saratov State University, 83 Astrakhanskaya str., 410012 Saratov, Russia.
| | - Jürgen Kurths
- Department of Human and Animal Physiology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia.
- Physics Department, Humboldt University, Newtonstrasse 15, 12489 Berlin, Germany.
- Potsdam Institute for Climate Impact Research, Telegrafenberg A31, 14473 Potsdam, Germany.
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Louveau A, Herz J, Alme MN, Salvador AF, Dong MQ, Viar KE, Herod SG, Knopp J, Setliff JC, Lupi AL, Da Mesquita S, Frost EL, Gaultier A, Harris TH, Cao R, Hu S, Lukens JR, Smirnov I, Overall CC, Oliver G, Kipnis J. CNS lymphatic drainage and neuroinflammation are regulated by meningeal lymphatic vasculature. Nat Neurosci 2018; 21:1380-1391. [PMID: 30224810 PMCID: PMC6214619 DOI: 10.1038/s41593-018-0227-9] [Citation(s) in RCA: 542] [Impact Index Per Article: 90.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 08/02/2018] [Indexed: 12/25/2022]
Abstract
Neuroinflammatory diseases, such as multiple sclerosis, are characterized by invasion of the brain by autoreactive T cells. The mechanism for how T cells acquire their encephalitogenic phenotype and trigger disease remains, however, unclear. The existence of lymphatic vessels in the meninges indicates a relevant link between the CNS and peripheral immune system, perhaps affecting autoimmunity. Here we demonstrate that meningeal lymphatics fulfill two critical criteria: they assist in the drainage of cerebrospinal fluid components and enable immune cells to enter draining lymph nodes in a CCR7-dependent manner. Unlike other tissues, meningeal lymphatic endothelial cells do not undergo expansion during inflammation, and they express a unique transcriptional signature. Notably, the ablation of meningeal lymphatics diminishes pathology and reduces the inflammatory response of brain-reactive T cells during an animal model of multiple sclerosis. Our findings demonstrate that meningeal lymphatics govern inflammatory processes and immune surveillance of the CNS and pose a valuable target for therapeutic intervention.
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Affiliation(s)
- Antoine Louveau
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA.
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA.
| | - Jasmin Herz
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Maria Nordheim Alme
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Andrea Francesca Salvador
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA, USA
| | - Michael Q Dong
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Kenneth E Viar
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - S Grace Herod
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - James Knopp
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Joshua C Setliff
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Alexander L Lupi
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Sandro Da Mesquita
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Elizabeth L Frost
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Alban Gaultier
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Tajie H Harris
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Rui Cao
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - Song Hu
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA
| | - John R Lukens
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Igor Smirnov
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Christopher C Overall
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Guillermo Oliver
- Northwestern University, Feinberg School of Medicine, Chicago, IL, USA
| | - Jonathan Kipnis
- Center for Brain Immunology and Glia (BIG), University of Virginia, Charlottesville, VA, USA.
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA.
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA, USA.
- Gutenberg Research Fellowship Group of Neuroimmunology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn²), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.
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Abstract
For decades, the brain has been considered an immune-privileged organ, meaning that the brain was mainly ignored by the immune system and that the presence of immune cells, notably of the adaptive arm, was a hallmark of pathological conditions. Over the past few decades, the definition of the immune privilege continues to be refined. There has been evidence accumulating that shows that the immune system plays a role in proper brain function. This evidence may represent an effective source of therapeutic targets for neurological disorders. In this chapter, we discuss the recent advances in understanding the immunity of the brain and describe how tertiary lymphoid structures can be generated in the central nervous system, which might represent a new avenue to treat neurological disorders.
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Louveau A, Plog BA, Antila S, Alitalo K, Nedergaard M, Kipnis J. Understanding the functions and relationships of the glymphatic system and meningeal lymphatics. J Clin Invest 2017; 127:3210-3219. [PMID: 28862640 PMCID: PMC5669566 DOI: 10.1172/jci90603] [Citation(s) in RCA: 397] [Impact Index Per Article: 56.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Recent discoveries of the glymphatic system and of meningeal lymphatic vessels have generated a lot of excitement, along with some degree of skepticism. Here, we summarize the state of the field and point out the gaps of knowledge that should be filled through further research. We discuss the glymphatic system as a system that allows CNS perfusion by the cerebrospinal fluid (CSF) and interstitial fluid (ISF). We also describe the recently characterized meningeal lymphatic vessels and their role in drainage of the brain ISF, CSF, CNS-derived molecules, and immune cells from the CNS and meninges to the peripheral (CNS-draining) lymph nodes. We speculate on the relationship between the two systems and their malfunction that may underlie some neurological diseases. Although much remains to be investigated, these new discoveries have changed our understanding of mechanisms underlying CNS immune privilege and CNS drainage. Future studies should explore the communications between the glymphatic system and meningeal lymphatics in CNS disorders and develop new therapeutic modalities targeting these systems.
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Affiliation(s)
- Antoine Louveau
- Center for Brain Immunology and Glia, Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, Virginia, USA
| | - Benjamin A. Plog
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Salli Antila
- Wihuri Research Institute and Translational Cancer Biology Program, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland
| | - Kari Alitalo
- Wihuri Research Institute and Translational Cancer Biology Program, Biomedicum Helsinki, University of Helsinki, Helsinki, Finland
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York, USA
- Center of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jonathan Kipnis
- Center for Brain Immunology and Glia, Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, Virginia, USA
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40
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MRI-derived diffusion parameters in the human optic nerve and its surrounding sheath during head-down tilt. NPJ Microgravity 2017. [PMID: 28649640 PMCID: PMC5479856 DOI: 10.1038/s41526-017-0023-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
More than half of astronauts present with significant neuro-ophthalmic findings during 6-month missions onboard the International Space Station. Although the underlying cause of this Microgravity Ocular Syndrome is currently unknown, alterations in cerebrospinal fluid dynamics within the optic nerve sheath may play a role. In the presented study, diffusion tensor imaging was used to assess changes in diffusivity of the optic nerve and its surrounding sheath during head-down tilt, a ground-based model of microgravity. Nine healthy male subjects (mean age ± SD: 25 ± 2.4 years; mean body mass index ± SD: 24.1 ± 2.4 kg/m2) underwent 5 head-down tilt conditions: −6°,−12°, −18°,−12° and 1% CO2, and −12° and lower body negative pressure. Mean diffusivity, fractional anisotropy, axial diffusivity, radial diffusivity were quantified in the left and right optic nerves and surrounding sheaths at supine baseline and after 4.5 h head-down tilt for each condition. In the optic nerve sheath, mean diffusivity was increased with all head-down tilt conditions by (Best Linear Unbiased Predictors) 0.147 (SE: 0.04) × 10−3 mm2/s (P < 0.001), axial diffusivity by 0.188 (SE: 0.064) × 10−3 mm2/s (P < 0.001), and radial diffusivity by 0.126 (SE: 0.04) × 10−3 mm2/s (P = 0.0019). Within the optic nerve itself, fractional anisotropy was increased by 0.133 (SE: 0.047) (P = 0.0051) and axial diffusivity increased by 0.135 (SE: 0.08) × 10−3 mm2/s (P = 0.014) during head-down tilt, whilst mean diffusivity and radial diffusivity were unaffected (P > 0.3). These findings could be due to increased perioptic cerebral spinal fluid hydrodynamics during head-down tilt, as well as increased cerebral spinal fluid volume and movement within the optic nerve sheath. Changes to the optic nerve and surrounding sheath during microgravity could explain why space flight is harmful to an astronaut’s vision. Darius Gerlach from the German Aerospace Center in Cologne and colleagues studied the tissue architecture of the optic nerve and its surrounding sheath in nine healthy men who experienced head-down tilt, a commonly used ground-based model of weightlessness. Using a neuroimaging technique called diffusion tensor imaging, the researchers documented fluid dynamic changes wrought by the microgravity-like conditions that could be due to alterations in the volume and movement of cerebrospinal fluid within and around the optic nerve. The findings may help explain why many astronauts experience poorer vision after long-duration space flights, although more work is needed to explore the effects of true microgravity on the visual system.
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Louveau A, Da Mesquita S, Kipnis J. Lymphatics in Neurological Disorders: A Neuro-Lympho-Vascular Component of Multiple Sclerosis and Alzheimer's Disease? Neuron 2016; 91:957-973. [PMID: 27608759 PMCID: PMC5019121 DOI: 10.1016/j.neuron.2016.08.027] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Lymphatic vasculature drains interstitial fluids, which contain the tissue's waste products, and ensures immune surveillance of the tissues, allowing immune cell recirculation. Until recently, the CNS was considered to be devoid of a conventional lymphatic vasculature. The recent discovery in the meninges of a lymphatic network that drains the CNS calls into question classic models for the drainage of macromolecules and immune cells from the CNS. In the context of neurological disorders, the presence of a lymphatic system draining the CNS potentially offers a new player and a new avenue for therapy. In this review, we will attempt to integrate the known primary functions of the tissue lymphatic vasculature that exists in peripheral organs with the proposed function of meningeal lymphatic vessels in neurological disorders, specifically multiple sclerosis and Alzheimer's disease. We propose that these (and potentially other) neurological afflictions can be viewed as diseases with a neuro-lympho-vascular component and should be therapeutically targeted as such.
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Affiliation(s)
- Antoine Louveau
- Center for Brain Immunology and Glia, Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Sandro Da Mesquita
- Center for Brain Immunology and Glia, Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Jonathan Kipnis
- Center for Brain Immunology and Glia, Department of Neuroscience, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA.
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42
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Impaired Neurovisceral Integration of Cardiovascular Modulation Contributes to Multiple Sclerosis Morbidities. Mol Neurobiol 2016; 54:362-374. [DOI: 10.1007/s12035-015-9599-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 12/01/2015] [Indexed: 12/16/2022]
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43
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Development and functions of the choroid plexus-cerebrospinal fluid system. Nat Rev Neurosci 2015; 16:445-57. [PMID: 26174708 DOI: 10.1038/nrn3921] [Citation(s) in RCA: 355] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The choroid plexus (ChP) is the principal source of cerebrospinal fluid (CSF), which has accepted roles as a fluid cushion and a sink for nervous system waste in vertebrates. Various animal models have provided insights into how the ChP-CSF system develops and matures. In addition, recent studies have uncovered new, active roles for this dynamic system in the regulation of neural stem cells, critical periods and the overall health of the nervous system. Together, these findings have brought about a paradigm shift in our understanding of brain development and health, and have stimulated new initiatives for the treatment of neurological disease.
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44
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Abstract
A retrospective study was undertaken in order to choose the operative methods of adult huge frontal nasoethmoid meningoencephalocele. Ten patients were admitted to hospital for their craniofacial mass. Of these, 9 cases suffered meningocele and 1 case meningoencephalocele. Four cases undertook the mass resection and repairing operation with postoperative lumbar drainage; at final, they had to receive shunt operation. Six cases underwent mass resection and repairing operation with shunt surgery at one stage; they recovered smoothly. Our results suggest that the adult patients with huge meningoencephalocele have larger subarachnoid cavity. When they receive repairing operation, their subarachnoid cavity would be decreased in volume and cerebrospinal fluid (CSF) circulation could be disturbed. In order to maintain the balance of CSF production and absorption, the shunt operation should be given at the same stage.
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45
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Liu H, Ni Z, Chen Y, Wang D, Qi Y, Zhang Q, Wang S. Olfactory route for cerebrospinal fluid drainage into the cervical lymphatic system in a rabbit experimental model. Neural Regen Res 2015; 7:766-71. [PMID: 25737700 PMCID: PMC4345659 DOI: 10.3969/j.issn.1673-5374.2012.10.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2011] [Accepted: 11/22/2011] [Indexed: 12/24/2022] Open
Abstract
The present study analyzed the anatomical association between intracranial subarachnoid space and the cervical lymphatic system. X-ray contrast medium and Microfil(®) (Microfil compounds fill and opacify microvascular and other spaces of non-surviving animals and post-mortem tissue under physiological injection pressure) were injected into the cisterna magna of the rabbit, and perineural routes of cerebrospinal fluid outflow into the lymphatic system were visualized. Under a surgical operating microscope, Microfil was found within the subarachnoid space and along the olfactory nerves. At the nasal mucosa, a lymphatic network was identified near the olfactory nerves, which crossed the nasopharyngeal region and finally emptied into the superficial and deep cervical lymph nodes. Under a light microscope, Microfil was visible around the olfactory nerves and within lymphatic vessels. These results suggested that cerebrospinal fluid drained from the subarachnoid space along the olfactory nerves to nasal lymphatic vessels, which in turn, emptied into the cervical lymph nodes. This anatomical route, therefore, allowed connection between the central nervous system and the lymphatic system.
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Affiliation(s)
- Haisheng Liu
- Department of Neurosurgery, Yuquan Hospital, Tsinghua University, Beijing 100049, China
| | - Zhili Ni
- Department of Otorhinolaryngology and Head & Neck Surgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Yetao Chen
- Department of Neurosurgery, Yuquan Hospital, Tsinghua University, Beijing 100049, China
| | - Dong Wang
- Department of Neurosurgery, Yuquan Hospital, Tsinghua University, Beijing 100049, China
| | - Yan Qi
- Department of Otorhinolaryngology and Head & Neck Surgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Qiuhang Zhang
- Department of Otorhinolaryngology and Head & Neck Surgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
| | - Shijie Wang
- Department of Otorhinolaryngology and Head & Neck Surgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China
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Hladky SB, Barrand MA. Mechanisms of fluid movement into, through and out of the brain: evaluation of the evidence. Fluids Barriers CNS 2014; 11:26. [PMID: 25678956 PMCID: PMC4326185 DOI: 10.1186/2045-8118-11-26] [Citation(s) in RCA: 393] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 11/21/2014] [Indexed: 01/08/2023] Open
Abstract
Interstitial fluid (ISF) surrounds the parenchymal cells of the brain and spinal cord while cerebrospinal fluid (CSF) fills the larger spaces within and around the CNS. Regulation of the composition and volume of these fluids is important for effective functioning of brain cells and is achieved by barriers that prevent free exchange between CNS and blood and by mechanisms that secrete fluid of controlled composition into the brain and distribute and reabsorb it. Structures associated with this regular fluid turnover include the choroid plexuses, brain capillaries comprising the blood-brain barrier, arachnoid villi and perineural spaces penetrating the cribriform plate. ISF flow, estimated from rates of removal of markers from the brain, has been thought to reflect rates of fluid secretion across the blood-brain barrier, although this has been questioned because measurements were made under barbiturate anaesthesia possibly affecting secretion and flow and because CSF influx to the parenchyma via perivascular routes may deliver fluid independently of blood-brain barrier secretion. Fluid secretion at the blood-brain barrier is provided by specific transporters that generate solute fluxes so creating osmotic gradients that force water to follow. Any flow due to hydrostatic pressures driving water across the barrier soon ceases unless accompanied by solute transport because water movements modify solute concentrations. CSF is thought to be derived primarily from secretion by the choroid plexuses. Flow rates measured using phase contrast magnetic resonance imaging reveal CSF movements to be more rapid and variable than previously supposed, even implying that under some circumstances net flow through the cerebral aqueduct may be reversed with net flow into the third and lateral ventricles. Such reversed flow requires there to be alternative sites for both generation and removal of CSF. Fluorescent tracer analysis has shown that fluid flow can occur from CSF into parenchyma along periarterial spaces. Whether this represents net fluid flow and whether there is subsequent flow through the interstitium and net flow out of the cortex via perivenous routes, described as glymphatic circulation, remains to be established. Modern techniques have revealed complex fluid movements within the brain. This review provides a critical evaluation of the data.
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Affiliation(s)
- Stephen B Hladky
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD UK
| | - Margery A Barrand
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD UK
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Chen L, Elias G, Yostos MP, Stimec B, Fasel J, Murphy K. Pathways of cerebrospinal fluid outflow: a deeper understanding of resorption. Neuroradiology 2014; 57:139-47. [DOI: 10.1007/s00234-014-1461-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 10/30/2014] [Indexed: 11/30/2022]
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Bershad EM, Urfy MZ, Calvillo E, Tang R, Cajavilca C, Lee AG, Venkatasubba Rao CP, Suarez JI, Chen D. Marked olfactory impairment in idiopathic intracranial hypertension. J Neurol Neurosurg Psychiatry 2014; 85:959-64. [PMID: 24474821 DOI: 10.1136/jnnp-2013-307232] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE Many long-duration astronauts develop signs of elevated intracranial pressure and have neuro-ophthalmological findings similar to idiopathic intracranial hypertension (IIH) patients. Some also present with nasal congestion and subjective olfactory impairment. We prospectively evaluated olfactory function in IIH patients and the effect of 6° head-down tilt, which simulates the headward fluid shifting in microgravity, as spaceflight analogues. DESIGN Olfaction was tested for all subjects in upright and 6° head-down tilt positions using two different measures: University of Pennsylvania Smell Identification Test and Olfactory Threshold Sniffin' Sticks with phenylethyl alcohol. RESULTS IIH patients (n=19) had significant impairment on both olfactory measures compared with matched controls (n=19). The olfactory threshold dilution levels were 9.07 (95% CI 1.85 to 5.81) and 3.83 (95% CI 7.04 to 11.10), p=0.001, and smell identification scores were 35.61 (95% CI 34.03 to 37.18) and 32.47 (95% CI 30.85 to 34.09), p=0.008, for control and IIH subjects, respectively. The threshold detection was mildly impaired in head-down tilt compared with upright position in the combined subjects (6.05 (95% CI 4.58 to 7.51) vs 6.85 (95% CI 5.43 to 8.27), p=0.004). CONCLUSIONS We demonstrated that IIH patients have marked impairment in olfactory threshold levels, out of proportion to smell identification impairment. There was also impairment in olfactory threshold in head-down tilt compared with upright positioning, but not for smell identification. The underlying mechanisms for olfactory threshold dysfunction in IIH patients need further exploration.
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Affiliation(s)
- Eric M Bershad
- Department of Neurology, Baylor College of Medicine, Houston, Texas, USA
| | - Mian Z Urfy
- Department of Neurology, Baylor College of Medicine, Houston, Texas, USA
| | - Eusebia Calvillo
- Department of Neurology, Baylor College of Medicine, Houston, Texas, USA
| | - Rosa Tang
- Department of Optometry, University of Houston, Houston, Texas, USA
| | | | - Andrew G Lee
- Department of Neurology, Baylor College of Medicine, Houston, Texas, USA Departments of Ophthalmology, Neurology, and Neurosurgery, Houston Methodist and Weil Cornell, Houston, Texas, USA
| | | | - Jose I Suarez
- Department of Neurology, Baylor College of Medicine, Houston, Texas, USA
| | - Denise Chen
- Department of Neurology, Baylor College of Medicine, Houston, Texas, USA
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Murtha LA, Yang Q, Parsons MW, Levi CR, Beard DJ, Spratt NJ, McLeod DD. Cerebrospinal fluid is drained primarily via the spinal canal and olfactory route in young and aged spontaneously hypertensive rats. Fluids Barriers CNS 2014; 11:12. [PMID: 24932405 PMCID: PMC4057524 DOI: 10.1186/2045-8118-11-12] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 05/27/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Many aspects of CSF dynamics are poorly understood due to the difficulties involved in quantification and visualization. In particular, there is debate surrounding the route of CSF drainage. Our aim was to quantify CSF flow, volume, and drainage route dynamics in vivo in young and aged spontaneously hypertensive rats (SHR) using a novel contrast-enhanced computed tomography (CT) method. METHODS ICP was recorded in young (2-5 months) and aged (16 months) SHR. Contrast was administered into the lateral ventricles bilaterally and sequential CT imaging was used to visualize the entire intracranial CSF system and CSF drainage routes. A customized contrast decay software module was used to quantify CSF flow at multiple locations. RESULTS ICP was significantly higher in aged rats than in young rats (11.52 ± 2.36 mmHg, versus 7.04 ± 2.89 mmHg, p = 0.03). Contrast was observed throughout the entire intracranial CSF system and was seen to enter the spinal canal and cross the cribriform plate into the olfactory mucosa within 9.1 ± 6.1 and 22.2 ± 7.1 minutes, respectively. No contrast was observed adjacent to the sagittal sinus. There were no significant differences between young and aged rats in either contrast distribution times or CSF flow rates. Mean flow rates (combined young and aged) were 3.0 ± 1.5 μL/min at the cerebral aqueduct; 3.5 ± 1.4 μL/min at the 3rd ventricle; and 2.8 ± 0.9 μL/min at the 4th ventricle. Intracranial CSF volumes (and as percentage total brain volume) were 204 ± 97 μL (8.8 ± 4.3%) in the young and 275 ± 35 μL (10.8 ± 1.9%) in the aged animals (NS). CONCLUSIONS We have demonstrated a contrast-enhanced CT technique for measuring and visualising CSF dynamics in vivo. These results indicate substantial drainage of CSF via spinal and olfactory routes, but there was little evidence of drainage via sagittal sinus arachnoid granulations in either young or aged animals. The data suggests that spinal and olfactory routes are the primary routes of CSF drainage and that sagittal sinus arachnoid granulations play a minor role, even in aged rats with higher ICP.
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Affiliation(s)
- Lucy A Murtha
- University of Newcastle and Hunter Medical Research Institute, University of Newcastle: School of Biomedical Sciences & Pharmacy, Medical Sciences Building, Callaghan, NSW 2308, Australia
| | - Qing Yang
- Apollo Medical Imaging Technology Pty Ltd, Suite 611, 365 Little Collins Street, Melbourne, Vic 3000, Australia
| | - Mark W Parsons
- Hunter New England Local Health District: Department of Neurology, John Hunter Hospital, Locked Bag 1, Hunter Region M.C, NSW 2310, Australia
| | - Christopher R Levi
- Hunter New England Local Health District: Department of Neurology, John Hunter Hospital, Locked Bag 1, Hunter Region M.C, NSW 2310, Australia
| | - Daniel J Beard
- University of Newcastle and Hunter Medical Research Institute, University of Newcastle: School of Biomedical Sciences & Pharmacy, Medical Sciences Building, Callaghan, NSW 2308, Australia
| | - Neil J Spratt
- University of Newcastle and Hunter Medical Research Institute, University of Newcastle: School of Biomedical Sciences & Pharmacy, Medical Sciences Building, Callaghan, NSW 2308, Australia
- Hunter New England Local Health District: Department of Neurology, John Hunter Hospital, Locked Bag 1, Hunter Region M.C, NSW 2310, Australia
| | - Damian D McLeod
- University of Newcastle and Hunter Medical Research Institute, University of Newcastle: School of Biomedical Sciences & Pharmacy, Medical Sciences Building, Callaghan, NSW 2308, Australia
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Kim H, Moore SA, Johnston MG. Potential for intranasal drug delivery to alter cerebrospinal fluid outflow via the nasal turbinate lymphatics. Fluids Barriers CNS 2014; 11:4. [PMID: 24528926 PMCID: PMC3927830 DOI: 10.1186/2045-8118-11-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 02/10/2014] [Indexed: 12/02/2022] Open
Abstract
Background Cerebrospinal fluid absorption (CSF) at the cribriform plate is mediated by direct extracranial connections to the lymphatic system. Given the accessibility of these pharmacologically responsive vessels we hypothesized that the rate of CSF outflow can be modulated via the intranasal delivery of drugs known to affect lymphatic contractile activity. Findings Fluid was infused into the lateral ventricle of anesthetized sheep and inflow rate and CSF pressure measured during intranasal administration of pharmacological agents. CSF absorption was calculated at steady-state CSF pressures. The ability of a pharmacological agent to alter CSF absorption was related to the steady-state intracranial pressure (ICP), the concentration and the class of pharmacological agent delivered. An increase in drug concentration correlated with an increase in CSF absorption at high ICP (45 cm H2O, r = 0.42, p = 0.0058). Specifically, the delivery of NG-monomethyl L-arginine (L-NMMA) significantly increased CSF absorption by 2.29 fold over no treatment (2.29 ± 0.34 mL/min), while the thromboxane A2 analogue U46619 resulted in a 2.44 fold increase in CSF absorption over no treatment (2.44 ± 0.55 mL/min). Saline delivery did not significantly increase CSF absorption (0.88 ± 0.097 mL/min). A trend of increased CSF absorption upon noradrenaline delivery was observed: however, this did not reach statistical significance. Increasing drug concentrations inversely correlated with CSF outflow resistance across all drug classes (r = -0.26, p = 0.046). Conclusions The administration of nebulized pharmacological agents intranasally has the potential to provide an alternate method to non-invasively modulate CSF absorption and outflow resistance.
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Affiliation(s)
- Harold Kim
- Department of Laboratory Medicine and Pathobiology, University of Toronto and Sunnybrook Research Institute, Toronto, Canada.
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