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Gastroenterology Mar 2021Hepatic encephalopathy (HE) is a serious neurologic complication in patients with liver cirrhosis. Very little is known about the role of the meningeal lymphatic system...
BACKGROUND & AIMS
Hepatic encephalopathy (HE) is a serious neurologic complication in patients with liver cirrhosis. Very little is known about the role of the meningeal lymphatic system in HE. We tested our hypothesis that enhancement of meningeal lymphatic drainage could decrease neuroinflammation and ameliorate HE.
METHODS
A 4-week bile duct ligation model was used to develop cirrhosis with HE in rats. Brain inflammation in patients with HE was evaluated by using archived GSE41919. The motor function of rats was assessed by the rotarod test. Adeno-associated virus 8-vascular endothelial growth factor C (AAV8-VEGF-C) was injected into the cisterna magna of HE rats 1 day after surgery to induce meningeal lymphangiogenesis.
RESULTS
Cirrhotic rats with HE showed significantly increased microglia activation in the middle region of the cortex (P < .001) as well as increased neuroinflammation, as indicated by significant increases in interleukin 1β, interferon γ, tumor necrosis factor α, and ionized calcium binding adaptor molecule 1 (Iba1) expression levels in at least 1 of the 3 regions of the cortex. Motor function was also impaired in rats with HE (P < .05). Human brains of patients with cirrhosis with HE also exhibited up-regulation of proinflammatory genes (NFKB1, IbA1, TNF-α, and IL1β) (n = 6). AAV8-VEGF-C injection significantly increased meningeal lymphangiogenesis (P = .035) and tracer dye uptake in the anterior and middle regions of the cortex (P = .006 and .003, respectively), their corresponding meninges (P = .086 and .006, respectively), and the draining lymph nodes (P = .02). Furthermore, AAV8-VEGF-C decreased microglia activation (P < .001) and neuroinflammation and ameliorated motor dysfunction (P = .024).
CONCLUSIONS
Promoting meningeal lymphatic drainage and enhancing waste clearance improves HE. Manipulation of meningeal lymphangiogenesis could be a new therapeutic strategy for the treatment of HE.
Topics: Animals; Cell Line; Cerebral Cortex; Cisterna Magna; Dependovirus; Disease Models, Animal; Genetic Vectors; Glymphatic System; Hepatic Encephalopathy; Humans; Liver Cirrhosis; Lymphangiogenesis; Male; Microglia; Motor Disorders; Rats; Vascular Endothelial Growth Factor C
PubMed: 33227282
DOI: 10.1053/j.gastro.2020.11.036 -
AJNR. American Journal of Neuroradiology Feb 2022The arachnoid membranes are projections of connective tissue in the subarachnoid space that connect the arachnoid mater to the pia mater. These are underappreciated and... (Review)
Review
The arachnoid membranes are projections of connective tissue in the subarachnoid space that connect the arachnoid mater to the pia mater. These are underappreciated and largely unrecognized by most neuroradiologists despite being found to be increasingly important in the pathogenesis, imaging, and treatment of communicating hydrocephalus. This review aims to provide neuroradiologists with an overview of the history, embryology, histology, anatomy, and normal imaging appearance of these membranes, as well as some examples of their clinical importance.
Topics: Arachnoid; Consciousness; Humans; Pia Mater; Radiology; Subarachnoid Space
PubMed: 34711549
DOI: 10.3174/ajnr.A7309 -
Journal of Clinical Medicine Apr 2023Chiari I malformation has been defined as cerebellar tonsillar descent greater than 5 mm below the foramen magnum. Suboccipital decompression remains the mainstay of...
Chiari I malformation has been defined as cerebellar tonsillar descent greater than 5 mm below the foramen magnum. Suboccipital decompression remains the mainstay of treatment for symptomatic patients. Other conditions sometimes have imaging features that mimic Chiari I malformation. These patients are at risk of misdiagnosis and mismanagement, including surgery that may be unnecessary or may even worsen the underlying condition. The aim of this study was to analyse a series of Chiari I malformation mimics and identify differentiating imaging features. The mimics are categorised as post-traumatic cranio-cervical junction arachnoiditis, dural band, spontaneous intracranial hypotension, idiopathic intracranial hypertension, and cysts. Better understanding of these conditions will assist with diagnosis and optimal management, including avoiding unnecessary surgery.
PubMed: 37109124
DOI: 10.3390/jcm12082786 -
Revue Medicale de Liege Sep 2020We report the case of a 28-year-old male admitted to the emergency department for generalized seizure. A brain computed tomography (CT) revealed a ruptured dermoid cyst...
We report the case of a 28-year-old male admitted to the emergency department for generalized seizure. A brain computed tomography (CT) revealed a ruptured dermoid cyst of the supra-tentorial stage (multiple drop-shaped fat structures were found in the subarachnoid space, basal cisterns and in ventricular system). An additional magnetic resonance imaging (MRI) was conducted to confirm the CT findings.
Topics: Adult; Dermoid Cyst; Humans; Magnetic Resonance Imaging; Male; Rupture, Spontaneous; Subarachnoid Space; Tomography, X-Ray Computed
PubMed: 32909404
DOI: No ID Found -
Clinical Radiology Oct 2021To evaluate the reliability of synthetic magnetic resonance imaging (SyMRI) for detecting complications associated with subarachnoid haemorrhage (SAH), such as ischaemic...
AIM
To evaluate the reliability of synthetic magnetic resonance imaging (SyMRI) for detecting complications associated with subarachnoid haemorrhage (SAH), such as ischaemic lesions, hydrocephalus, or bleeding complications.
MATERIALS AND METHODS
Twenty patients with SAH, who underwent a conventional brain MRI and a SyMRI on a 3 T MRI machine. Comparable conventional and synthetic T2-weighted fluid attenuated inversion recovery (FLAIR) images were acquired. The presence of ischaemic lesions, hydrocephalus, extra-axial blood collections as well as the volumes of grey matter (GMv), white matter (WMv), and cerebrospinal (CSFv) were compared. The acquisition times of both sequences was also analysed.
RESULTS
The concordance between the two techniques was excellent for the detection of ischaemic lesions and extra-axial collections (kappa = 0.80 and 0.88 respectively) and good for the detection of hydrocephalus (kappa = 0.69). No significant differences were detected in the number of ischaemic lesions (p=0.31) or in the Evans index (p=0.11). The WMv and CSFv measures were also similar (p=0.18 and p=0.94, respectively), as well as the volume of ischaemic lesions (p=0.79). Compared to conventional MRI, the SyMRI acquisition time was shorter regardless of the number of sections (32% and 6% time reduction for 4 or 3 mm section thickness, respectively).
CONCLUSIONS
SyMRI allows the detection of potential complications of SAH in a similar way to conventional MRI with a shorter acquisition time.
Topics: Female; Humans; Image Interpretation, Computer-Assisted; Magnetic Resonance Imaging; Male; Middle Aged; Prospective Studies; Reproducibility of Results; Subarachnoid Hemorrhage; Subarachnoid Space
PubMed: 34193343
DOI: 10.1016/j.crad.2021.05.021 -
Brain & Spine 2022Spinal arachnoid cysts (SACs) are rare lesions with challenging and controversial management. (Review)
Review
INTRODUCTION
Spinal arachnoid cysts (SACs) are rare lesions with challenging and controversial management.
RESEARCH QUESTION
We analyzed our experiences from a case series and provide a systematic review to determine 1) Demographic and clinical features of SACs, 2) Optimal imaging for diagnosis and operative planning, 3) Optimal management of SACs, and 4) Clinical outcomes following surgery.
MATERIALS AND METHODS
A single-institution, ambispective analysis of patients with symptomatic SACs surgically managed between May 2005 and May 2019 was performed. Data were collected as per local ethics committee stipulations. A systematic review of SACs in adults was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and a preapproved protocol.
RESULTS
Our series consisted of 11 patients, M:F 8:3, mean age 47.8 years (range 18-73 years). Mean follow-up was 19 months (range 5-36 months). SACs were excised or marsupialised (7), fenestrated (3) or partially excised (1). Eight patients had expansile duroplasty, 3 primary dural closure. One patient had a cystoperitoneal shunt. All patients were AIS D preoperatively; 4 remained unchanged and 7 improved to AIS E at follow-up. Our systematic search retrieved 725 citations. Fourteen case series met the inclusion criteria. There was no evidence to support superiority of one surgical strategy over another. Surgery for symptomatic patients resulted in positive clinical outcomes.
DISCUSSION AND CONCLUSIONS
Symptomatic SACs require surgical intervention. Limited evidence suggests that decompressing the cord, breakdown of arachnoid adhesions, and establishing CSF flow by consideration of expansile duroplasty are important for positive outcomes.
PubMed: 36248116
DOI: 10.1016/j.bas.2022.100904 -
Developmental Cell Apr 2023The arachnoid barrier, a component of the blood-cerebrospinal fluid barrier (B-CSFB) in the meninges, is composed of epithelial-like, tight-junction-expressing cells....
The arachnoid barrier, a component of the blood-cerebrospinal fluid barrier (B-CSFB) in the meninges, is composed of epithelial-like, tight-junction-expressing cells. Unlike other central nervous system (CNS) barriers, its' developmental mechanisms and timing are largely unknown. Here, we show that mouse arachnoid barrier cell specification requires the repression of Wnt-β-catenin signaling and that constitutively active β-catenin can prevent its formation. We also show that the arachnoid barrier is functional prenatally and, in its absence, a small molecular weight tracer and the bacterium group B Streptococcus can cross into the CNS following peripheral injection. Acquisition of barrier properties prenatally coincides with the junctional localization of Claudin 11, and increased E-cadherin and maturation continues after birth, where postnatal expansion is marked by proliferation and re-organization of junctional domains. This work identifies fundamental mechanisms that drive arachnoid barrier formation, highlights arachnoid barrier fetal functions, and provides novel tools for future studies on CNS barrier development.
Topics: Mice; Animals; beta Catenin; Meninges; Arachnoid; Blood-Brain Barrier; Central Nervous System; Tight Junctions
PubMed: 36996816
DOI: 10.1016/j.devcel.2023.03.005 -
Journal of Global Infectious Diseases 2023Tuberculous meningitis causes substantial morbidity and mortality in tropical countries. The various complications reported are hydrocephalus, vasculitic infarcts,...
Tuberculous meningitis causes substantial morbidity and mortality in tropical countries. The various complications reported are hydrocephalus, vasculitic infarcts, tuberculomas, abscesses, and optochiasmatic arachnoiditis. Vasculitis in tuberculosis is basically at the level of lenticulostriate arteries supplying the basal ganglia and terminal cortical branches. In this case report, we present a rare case of tuberculous meningitis with extensive vasculopathy. During hospitalization, she developed acute onset right-sided classical hemiplegia with the inability to speak due to left internal carotid artery occlusion on imaging. The cerebrospinal fluid depicted very high protein levels. The exact pathogenesis of such extensive involvement in tuberculous meningitis substantiates the need for further studies.
PubMed: 38292690
DOI: 10.4103/jgid.jgid_24_23 -
Nature Communications Sep 2023Meninges cover the surface of the brain and spinal cord and contribute to protection and immune surveillance of the central nervous system (CNS). How the meningeal...
Meninges cover the surface of the brain and spinal cord and contribute to protection and immune surveillance of the central nervous system (CNS). How the meningeal layers establish CNS compartments with different accessibility to immune cells and immune mediators is, however, not well understood. Here, using 2-photon imaging in female transgenic reporter mice, we describe VE-cadherin at intercellular junctions of arachnoid and pia mater cells that form the leptomeninges and border the subarachnoid space (SAS) filled with cerebrospinal fluid (CSF). VE-cadherin expression also marked a layer of Prox1 cells located within the arachnoid beneath and separate from E-cadherin arachnoid barrier cells. In vivo imaging of the spinal cord and brain in female VE-cadherin-GFP reporter mice allowed for direct observation of accessibility of CSF derived tracers and T cells into the SAS bordered by the arachnoid and pia mater during health and neuroinflammation, and detection of volume changes of the SAS during CNS pathology. Together, the findings identified VE-cadherin as an informative landmark for in vivo imaging of the leptomeninges that can be used to visualize the borders of the SAS and thus potential barrier properties of the leptomeninges in controlling access of immune mediators and immune cells into the CNS during health and neuroinflammation.
Topics: Female; Animals; Mice; Pia Mater; Neuroinflammatory Diseases; Central Nervous System; Arachnoid; Cadherins; Inflammation; Mice, Transgenic
PubMed: 37730744
DOI: 10.1038/s41467-023-41580-4