1
|
Villacis G, Schmidt A, Rudolf JC, Schwenke H, Küchler J, Schramm P, Ulloa P. Evaluating the glymphatic system via magnetic resonance diffusion tensor imaging along the perivascular spaces in brain tumor patients. Jpn J Radiol 2024; 42:1146-1156. [PMID: 38819694 PMCID: PMC11442616 DOI: 10.1007/s11604-024-01602-7] [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: 12/22/2023] [Accepted: 05/23/2024] [Indexed: 06/01/2024]
Abstract
PURPOSE To investigate glymphatic system function in patients with brain tumors, including both primary and secondary tumors, using diffusion tensor imaging along perivascular spaces (DTI-ALPS). METHODS We retrospectively analyzed the MR DTI of 24 patients with unilateral brain tumors and compared them with age and sex-matched controls. We compared the DTI-ALPS index of the ipsi- and contralateral brain hemispheres. The region of interest was placed in the periventricular vessels adjacent to the lateral ventricles. Differences between sex, age, and kind of tumor (primary or brain metastasis) were evaluated. Correlations between DTI-ALPS index and age and the tumor's apparent diffusion coefficient (ADC) were also investigated. RESULTS The DTI-ALPS index was significantly lower (p < 0.05) in the tumor-affected hemisphere (mean = 1.26 ± 0.24) than contralateral (mean = 1.43 ± 0.28). A comparison with healthy controls revealed no significant difference on the matched ipsilateral side. However, the DTI-ALPS index of the contralateral side of the patients was larger than the HC. Additionally, no statistically significant differences were found when analyzing the DTI-ALPS index vs. age, sex, and tumor entity. Additionally, we did not find a correlation between the DTI-ALPS index and patient age or tumor ADC. CONCLUSION The decreased DTI-ALPS index in the tumor-affected hemisphere may be related to impaired glymphatic system function. However, cancer is often a systemic disease; thus, the DTI-ALPS index from the contralateral brain hemisphere may not generally be considered as a normal control. Nonetheless, the DTI-ALPS index does not only reflect diffusion in the perivascular spaces but it can also be influenced by factors such as axonal degeneration. Therefore, it does not directly reflect brain waste clearance and changes in the index should be interpreted carefully.
Collapse
Affiliation(s)
- Gabriela Villacis
- Department of Neuroradiology, University Hospital Schleswig-Holstein (UKSH), Luebeck, Germany
| | - Aileen Schmidt
- Department of Neuroradiology, University Hospital Schleswig-Holstein (UKSH), Luebeck, Germany
| | - Justus C Rudolf
- Department of Neuroradiology, University Hospital Schleswig-Holstein (UKSH), Luebeck, Germany
| | - Hannes Schwenke
- Department of Neuroradiology, University Hospital Schleswig-Holstein (UKSH), Luebeck, Germany
| | - Jan Küchler
- Department of Neurosurgery, University Hospital Schleswig-Holstein (UKSH), Luebeck, Germany
| | - Peter Schramm
- Department of Neuroradiology, University Hospital Schleswig-Holstein (UKSH), Luebeck, Germany
| | - Patricia Ulloa
- Department of Neuroradiology, University Hospital Schleswig-Holstein (UKSH), Luebeck, Germany.
| |
Collapse
|
2
|
Wright AM, Wu YC, Feng L, Wen Q. Diffusion magnetic resonance imaging of cerebrospinal fluid dynamics: Current techniques and future advancements. NMR IN BIOMEDICINE 2024; 37:e5162. [PMID: 38715420 PMCID: PMC11303114 DOI: 10.1002/nbm.5162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 02/20/2024] [Accepted: 03/30/2024] [Indexed: 05/22/2024]
Abstract
Cerebrospinal fluid (CSF) plays a critical role in metabolic waste clearance from the brain, requiring its circulation throughout various brain pathways, including the ventricular system, subarachnoid spaces, para-arterial spaces, interstitial spaces, and para-venous spaces. The complexity of CSF circulation has posed a challenge in obtaining noninvasive measurements of CSF dynamics. The assessment of CSF dynamics throughout its various circulatory pathways is possible using diffusion magnetic resonance imaging (MRI) with optimized sensitivity to incoherent water movement across the brain. This review presents an overview of both established and emerging diffusion MRI techniques designed to measure CSF dynamics and their potential clinical applications. The discussion offers insights into the optimization of diffusion MRI acquisition parameters to enhance the sensitivity and specificity of diffusion metrics on underlying CSF dynamics. Lastly, we emphasize the importance of cautious interpretations of diffusion-based imaging, especially when differentiating between tissue- and fluid-related changes or elucidating structural versus functional alterations.
Collapse
Affiliation(s)
- Adam M. Wright
- Department of Radiology and Imaging Sciences, Indiana
University School of Medicine, Indianapolis, Indiana, USA
- Weldon School of Biomedical Engineering Department, Purdue
University, West Lafayette, Indiana, USA
| | - Yu-Chien Wu
- Department of Radiology and Imaging Sciences, Indiana
University School of Medicine, Indianapolis, Indiana, USA
- Weldon School of Biomedical Engineering Department, Purdue
University, West Lafayette, Indiana, USA
- Stark Neurosciences Research Institute, Indiana University
School of Medicine, Indianapolis, Indiana, USA
| | - Li Feng
- Center for Advanced Imaging Innovation and Research
(CAI2R), New York University Grossman School of Medicine, New York, New York,
USA
| | - Qiuting Wen
- Department of Radiology and Imaging Sciences, Indiana
University School of Medicine, Indianapolis, Indiana, USA
- Weldon School of Biomedical Engineering Department, Purdue
University, West Lafayette, Indiana, USA
| |
Collapse
|
3
|
Liu X, Barisano G, Shao X, Jann K, Ringman JM, Lu H, Arfanakis K, Caprihan A, DeCarli C, Gold BT, Maillard P, Satizabal CL, Fadaee E, Habes M, Stables L, Singh H, Fischl B, van der Kouwe A, Schwab K, Helmer KG, Greenberg SM, Wang DJ. Cross-Vendor Test-Retest Validation of Diffusion Tensor Image Analysis along the Perivascular Space (DTI-ALPS) for Evaluating Glymphatic System Function. Aging Dis 2024; 15:1885-1898. [PMID: 37307817 PMCID: PMC11272201 DOI: 10.14336/ad.2023.0321-2] [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: 01/03/2023] [Accepted: 03/21/2023] [Indexed: 06/14/2023] Open
Abstract
The diffusion tensor image analysis along the perivascular space (DTI-ALPS) method was proposed to evaluate glymphatic system (GS) function. However, few studies have validated its reliability and reproducibility. Fifty participants' DTI data from the MarkVCID consortium were included in this study. Two pipelines by using DSI studio and FSL software were developed for data processing and ALPS index calculation. The ALPS index was obtained by the average of bilateral ALPS index and was used for testing the cross-vendor, inter-rater and test-retest reliability by using R studio software. The ALPS index demonstrated favorable inter-scanner reproducibility (ICC=0.77 to 0.95, P< 0.001), inter-rater reliability (ICC=0.96 to 1, P< 0.001) and test-retest repeatability (ICC=0.89 to 0.95, P< 0.001), offering a potential biomarker for in vivo evaluation of GS function.
Collapse
Affiliation(s)
- Xiaodan Liu
- Laboratory of FMRI Technology (LOFT), Mark & Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA.
- Zilkha Neurogenetic Institute, University of Southern California, Los Angeles, CA, USA.
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA.
| | | | - Xingfeng Shao
- Laboratory of FMRI Technology (LOFT), Mark & Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA.
| | - Kay Jann
- Laboratory of FMRI Technology (LOFT), Mark & Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA.
| | - John M Ringman
- Department of Neurology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
| | - Hanzhang Lu
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Konstantinos Arfanakis
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA.
- Department of Diagnostic Radiology and Nuclear Medicine, Rush University, Chicago, IL, USA.
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA.
| | | | - Charles DeCarli
- Department of Neurology, University of California, Davis, Davis, CA, USA.
| | - Brian T Gold
- Department of Neuroscience, University of Kentucky, Lexington, KY, USA.
| | - Pauline Maillard
- Department of Neurology, University of California, Davis, Davis, CA, USA.
| | - Claudia L Satizabal
- Population Health Sciences and Glenn Biggs Institute for Neurodegenerative Diseases, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
| | - Elyas Fadaee
- Neuroimage Analytics Laboratory and Biggs Institute Neuroimaging Core, Glenn Biggs Institute for Neurodegenerative Diseases, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
| | - Mohamad Habes
- Neuroimage Analytics Laboratory and Biggs Institute Neuroimaging Core, Glenn Biggs Institute for Neurodegenerative Diseases, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
| | - Lara Stables
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
| | - Herpreet Singh
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.
| | - Bruce Fischl
- Department of Radiology, Harvard Medical School, Boston, MA, USA.
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.
- Division of Health Sciences and Technology, Massachusetts Institute of Technology, Computer Science and AI Lab, Cambridge, Massachusetts, USA.
| | - Andre van der Kouwe
- Department of Radiology, Harvard Medical School, Boston, MA, USA.
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.
| | - Kristin Schwab
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.
| | - Karl G Helmer
- Department of Radiology, Harvard Medical School, Boston, MA, USA.
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.
| | - Steven M Greenberg
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA.
| | - Danny J.J Wang
- Laboratory of FMRI Technology (LOFT), Mark & Mary Stevens Neuroimaging and Informatics Institute, University of Southern California, Los Angeles, CA, USA.
| | | |
Collapse
|
4
|
Taoka T, Ito R, Nakamichi R, Nakane T, Kawai H, Naganawa S. Diffusion Tensor Image Analysis ALong the Perivascular Space (DTI-ALPS): Revisiting the Meaning and Significance of the Method. Magn Reson Med Sci 2024; 23:268-290. [PMID: 38569866 PMCID: PMC11234944 DOI: 10.2463/mrms.rev.2023-0175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2024] Open
Abstract
More than 5 years have passed since the Diffusion Tensor Image Analysis ALong the Perivascular Space (DTI-ALPS) method was proposed with the intention of evaluating the glymphatic system. This method is handy due to its noninvasiveness, provision of a simple index in a straightforward formula, and the possibility of retrospective analysis. Therefore, the ALPS method was adopted to evaluate the glymphatic system for many disorders in many studies. The purpose of this review is to look back and discuss the ALPS method at this moment.The ALPS-index was found to be an indicator of a number of conditions related to the glymphatic system. Thus, although this was expected in the original report, the results of the ALPS method are often interpreted as uniquely corresponding to the function of the glymphatic system. However, a number of subsequent studies have pointed out the problems on the data interpretation. As they rightly point out, a higher ALPS-index indicates predominant Brownian motion of water molecules in the radial direction at the lateral ventricular body level, no more and no less. Fortunately, the term "ALPS-index" has become common and is now known as a common term by many researchers. Therefore, the ALPS-index should simply be expressed as high or low, and whether it reflects a glymphatic system is better to be discussed carefully. In other words, when a decreased ALPS-index is observed, it should be expressed as "decreased ALPS-index" and not directly as "glymphatic dysfunction". Recently, various methods have been proposed to evaluate the glymphatic system. It has become clear that these methods also do not seem to reflect the entirety of the extremely complex glymphatic system. This means that it would be desirable to use various methods in combination to evaluate the glymphatic system in a comprehensive manner.
Collapse
Affiliation(s)
- Toshiaki Taoka
- Department of Innovative Biomedical Visualization (iBMV), Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
- Department of Radiology, Nagoya University, Nagoya, Aichi, Japan
| | - Rintaro Ito
- Department of Innovative Biomedical Visualization (iBMV), Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
- Department of Radiology, Nagoya University, Nagoya, Aichi, Japan
| | - Rei Nakamichi
- Department of Radiology, Nagoya University, Nagoya, Aichi, Japan
| | - Toshiki Nakane
- Department of Radiology, Nagoya University, Nagoya, Aichi, Japan
| | - Hisashi Kawai
- Department of Radiology, Aichi Medical University, Nagakute, Aichi, Japan
| | - Shinji Naganawa
- Department of Radiology, Nagoya University, Nagoya, Aichi, Japan
| |
Collapse
|
5
|
Al Masri M, Corell A, Michaëlsson I, Jakola AS, Skoglund T. The glymphatic system for neurosurgeons: a scoping review. Neurosurg Rev 2024; 47:61. [PMID: 38253938 PMCID: PMC10803566 DOI: 10.1007/s10143-024-02291-6] [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: 12/07/2023] [Revised: 01/05/2024] [Accepted: 01/14/2024] [Indexed: 01/24/2024]
Abstract
The discovery of the glymphatic system has revolutionized our understanding of cerebrospinal fluid (CSF) circulation and interstitial waste clearance in the brain. This scoping review aims to synthesize the current literature on the glymphatic system's role in neurosurgical conditions and its potential as a therapeutic target. We conducted a comprehensive search in PubMed and Scopus databases for studies published between January 1, 2012, and October 31, 2023. Studies were selected based on their relevance to neurosurgical conditions and glymphatic function, with both animal and human studies included. Data extraction focused on the methods for quantifying glymphatic function and the main results. A total of 67 articles were included, covering conditions such as idiopathic normal pressure hydrocephalus (iNPH), idiopathic intracranial hypertension (IIH), subarachnoid hemorrhage (SAH), stroke, intracranial tumors, and traumatic brain injury (TBI). Significant glymphatic dysregulation was noted in iNPH and IIH, with evidence of impaired CSF dynamics and delayed clearance. SAH studies indicated glymphatic dysfunction with the potential therapeutic effects of nimodipine and tissue plasminogen activator. In stroke, alterations in glymphatic activity correlated with the extent of edema and neurological recovery. TBI studies highlighted the role of the glymphatic system in post-injury cognitive outcomes. Results indicate that the regulation of aquaporin-4 (AQP4) channels is a critical target for therapeutic intervention. The glymphatic system plays a critical role in the pathophysiology of various neurosurgical conditions, influencing brain edema and CSF dynamics. Targeting the regulation of AQP4 channels presents as a significant therapeutic strategy. Although promising, the translation of these findings into clinical practice requires further human studies. Future research should focus on establishing non-invasive biomarkers for glymphatic function and exploring the long-term effects of glymphatic dysfunction.
Collapse
Affiliation(s)
- Mohammad Al Masri
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Alba Corell
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Neurosurgery, Sahlgrenska University Hospital, Blå Stråket 5, 3 tr, SE-41345, Gothenburg, Sweden
| | - Isak Michaëlsson
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Neurosurgery, Sahlgrenska University Hospital, Blå Stråket 5, 3 tr, SE-41345, Gothenburg, Sweden
| | - Asgeir S Jakola
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Neurosurgery, Sahlgrenska University Hospital, Blå Stråket 5, 3 tr, SE-41345, Gothenburg, Sweden
| | - Thomas Skoglund
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
- Department of Neurosurgery, Sahlgrenska University Hospital, Blå Stråket 5, 3 tr, SE-41345, Gothenburg, Sweden.
| |
Collapse
|
6
|
Taoka T, Ito R, Nakamichi R, Nakane T, Kawai H, Naganawa S. Interstitial Fluidopathy of the Central Nervous System: An Umbrella Term for Disorders with Impaired Neurofluid Dynamics. Magn Reson Med Sci 2024; 23:1-13. [PMID: 36436975 PMCID: PMC10838724 DOI: 10.2463/mrms.rev.2022-0012] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 08/29/2022] [Indexed: 01/05/2024] Open
Abstract
Interest in interstitial fluid dynamics has increased since the proposal of the glymphatic system hypothesis. Abnormal dynamics of the interstitial fluid have been pointed out to be an important factor in various pathological statuses. In this article, we propose the concept of central nervous system interstitial fluidopathy as a disease or condition in which abnormal interstitial fluid dynamics is one of the important factors for the development of a pathological condition. We discuss the aspects of interstitial fluidopathy in various diseases, including Alzheimer's disease, Parkinson's disease, normal pressure hydrocephalus, and cerebral small vessel disease. We also discuss a method called "diffusion tensor image analysis along the perivascular space" using MR diffusion images, which is used to evaluate the degree of interstitial fluidopathy or the activity of the glymphatic system.
Collapse
Affiliation(s)
- Toshiaki Taoka
- Department of Innovative Biomedical Visualization (iBMV), Nagoya University, Nagoya, Aichi, Japan
- Department of Radiology, Nagoya University, Nagoya, Aichi, Japan
| | - Rintaro Ito
- Department of Innovative Biomedical Visualization (iBMV), Nagoya University, Nagoya, Aichi, Japan
- Department of Radiology, Nagoya University, Nagoya, Aichi, Japan
| | - Rei Nakamichi
- Department of Radiology, Nagoya University, Nagoya, Aichi, Japan
| | - Toshiki Nakane
- Department of Radiology, Nagoya University, Nagoya, Aichi, Japan
| | - Hisashi Kawai
- Department of Radiology, Aichi Medical University, Nagakute, Aichi, Japan
| | - Shinji Naganawa
- Department of Radiology, Nagoya University, Nagoya, Aichi, Japan
| |
Collapse
|
7
|
Qin Y, Li X, Qiao Y, Zou H, Qian Y, Li X, Zhu Y, Huo W, Wang L, Zhang M. DTI-ALPS: An MR biomarker for motor dysfunction in patients with subacute ischemic stroke. Front Neurosci 2023; 17:1132393. [PMID: 37065921 PMCID: PMC10102345 DOI: 10.3389/fnins.2023.1132393] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 03/03/2023] [Indexed: 04/03/2023] Open
Abstract
PurposeBrain glymphatic dysfunction is involved in the pathologic process of acute ischemic stroke (IS). The relationship between brain glymphatic activity and dysfunction in subacute IS has not been fully elucidated. Diffusion tensor image analysis along the perivascular space (DTI-ALPS) index was used in this study to explore whether glymphatic activity was related to motor dysfunction in subacute IS patients.MethodsTwenty-six subacute IS patients with a single lesion in the left subcortical region and 32 healthy controls (HCs) were recruited in this study. The DTI-ALPS index and DTI metrics (fractional anisotropy, FA, and mean diffusivity, MD) were compared within and between groups. Spearman's and Pearson's partial correlation analyses were performed to analyze the relationships of the DTI-ALPS index with Fugl-Meyer assessment (FMA) scores and with corticospinal tract (CST) integrity in the IS group, respectively.ResultsSix IS patients and two HCs were excluded. The left DTI-ALPS index of the IS group was significantly lower than that of the HC group (t = −3.02, p = 0.004). In the IS group, a positive correlation between the left DTI-ALPS index and the simple Fugl-Meyer motor function score (ρ = 0.52, p = 0.019) and a significant negative correlation between the left DTI-ALPS index and the FA (R = −0.55, p = 0.023) and MD (R = −0.48, p = 0.032) values of the right CST were found.ConclusionsGlymphatic dysfunction is involved in subacute IS. DTI-ALPS could be a potential magnetic resonance (MR) biomarker of motor dysfunction in subacute IS patients. These findings contribute to a better understanding of the pathophysiological mechanisms of IS and provide a new target for alternative treatments for IS.
Collapse
Affiliation(s)
- Yue Qin
- Department of Medical Imaging, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
- Department of Radiology, Xi'an Daxing Hospital, Xi'an, China
| | - Xin Li
- Department of Radiology, Xi'an Daxing Hospital, Xi'an, China
| | - Yanqiang Qiao
- Department of Medical Imaging, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
- Department of Radiology, Xi'an Daxing Hospital, Xi'an, China
| | - Huili Zou
- Department of Rehabilitation Medicine, Xi'an Daxing Hospital, Xi'an, China
| | - Yifan Qian
- Department of Radiology, Xi'an Daxing Hospital, Xi'an, China
| | - Xiaoshi Li
- Department of Radiology, Xi'an Daxing Hospital, Xi'an, China
| | - Yinhu Zhu
- Department of Radiology, Xi'an Daxing Hospital, Xi'an, China
| | - Wenli Huo
- Department of Medical Imaging, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Lei Wang
- Department of Medical Imaging, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
- Department of Radiology, Xi'an Daxing Hospital, Xi'an, China
- Lei Wang
| | - Ming Zhang
- Department of Medical Imaging, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
- *Correspondence: Ming Zhang
| |
Collapse
|
8
|
The Role of Glymphatic System in Alzheimer’s and Parkinson’s Disease Pathogenesis. Biomedicines 2022; 10:biomedicines10092261. [PMID: 36140362 PMCID: PMC9496080 DOI: 10.3390/biomedicines10092261] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 11/30/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common cause of neurodegenerative dementia, whilst Parkinson’s disease (PD) is a neurodegenerative movement disorder. These two neurodegenerative disorders share the accumulation of toxic proteins as a pathological hallmark. The lack of definitive disease-modifying treatments for these neurogenerative diseases has led to the hypothesis of new pathogenic mechanisms to target and design new potential therapeutic approaches. The recent observation that the glymphatic system is supposed to be responsible for the movement of cerebrospinal fluid into the brain and clearance of metabolic waste has led to study its involvement in the pathogenesis of these classic proteinopathies. Aquaporin-4 (AQP4), a water channel located in the endfeet of astrocyte membrane, is considered a primary driver of the glymphatic clearance system, and defective AQP4-mediated glymphatic drainage has been linked to proteinopathies. The objective of the present review is to present the recent body of knowledge that links the glymphatic system to the pathogenesis of AD and PD disease and other lifestyle factors such as sleep deprivation and exercise that may influence glymphatic system function. We will also focus on the potential neuroimaging approaches that could identify a neuroimaging marker to detect glymphatic system changes.
Collapse
|