-
BMC Neurology Sep 2022Meningitis is known as a meningeal inflammation accompanied by pleocytosis in the cerebrospinal fluid (CSF), and can be classified into acute, subacute, and chronic...
BACKGROUND
Meningitis is known as a meningeal inflammation accompanied by pleocytosis in the cerebrospinal fluid (CSF), and can be classified into acute, subacute, and chronic meningitis based on symptoms duration of ≤ 5 days, ≥ 5 days and ≥ 4 weeks, respectively. Subacute and chronic meningitis are caused mainly by indolent infectious agents and noninfectious causes such as autoimmune, and neoplastic. In this study, we investigated the characteristics, diagnosis, and treatment of subacute and chronic meningitis.
METHODS
We extracted the medical records of patients with chronic and subacute meningitis who were referred to three tertiary centers from Jun 2011 to Jun 2021. Initially, 2050 cases of meningitis were screened, and then 79 patients were included in the study.
RESULTS
Headache (87.3%), nausea and vomiting (74.7%), fever (56.4%), and visual impairments (55.7%) were the most prevalent symptoms. The most common signs were nuchal rigidity (45.3%), altered mental status (26.9%), and papillary edema (37.5%). Brain computed tomography (CT) was normal in 68.6% of the patients while 22.9% of the cases had hydrocephalus. Brain magnetic resonance imaging (MRI) was normal in 60.0% of the patients. The most common abnormal MRI findings were leptomeningeal enhancement (16.0%) and hydrocephalus (16.0%). We had a 44.3% definite diagnosis with bacterial (n:25, 31.6%) and neoplastic (n:8, 10.1%) being the most prevalent etiologies. Mycobacterium tuberculosis (60%) and Brucella spp. (12%) were the most prevalent bacterial pathogens.
CONCLUSIONS
The most common etiologies include infectious, neoplastic, and immunologic. Due to insidious presentation and uncommon etiologies, establishing a proper diagnosis, and providing timely targeted treatment for patients with subacute and chronic meningitis remains a challenge for clinicians.
Topics: Diagnosis, Differential; Humans; Hydrocephalus; Magnetic Resonance Imaging; Meningitis; Neuroimaging
PubMed: 36088290
DOI: 10.1186/s12883-022-02873-1 -
Neurosurgical Review Dec 2022Several complications have been reported after the use of grafts for duraplasty following posterior fossa decompression for the treatment of Chiari malformation type I.... (Meta-Analysis)
Meta-Analysis Review
Risk of meningitis after posterior fossa decompression with duraplasty using different graft types in patients with Chiari malformation type I and syringomyelia: a systematic review and meta-analysis.
Several complications have been reported after the use of grafts for duraplasty following posterior fossa decompression for the treatment of Chiari malformation type I. This study aims to investigate the rate of meningitis after posterior fossa decompression using different types of grafts in patients with Chiari malformation type I and associated syringomyelia. The search was conducted using multiple databases, including PubMed, Scopus, Web of Science, and Embase. Data on the rate of meningitis, syrinx change, and rate of reoperation were extracted and investigated. Quality of evidence was assessed using the Newcastle-Ottawa scale. Nineteen studies were included in the final meta-analysis, encompassing 1404 patients and investigating autografts, synthetic grafts, allografts, and xenografts (bovine collagen, bovine pericardium, and pig pericardium). Autografts were associated with the lowest rate of meningitis (1%) compared to allografts, synthetic grafts, and xenografts (2%, 5%, and 8% respectively). Autografts were also associated with the lowest rate of reoperation followed by xenografts, allografts, and synthetic grafts (4%, 5%, 9%, and 10% respectively). On the other hand, allografts were associated with the highest rate of syrinx improvement (83%) in comparison to autografts and synthetic grafts (77%, and 79% respectively). Autografts were associated with the lowest meningitis, reoperation, and syrinx improvement rates. Furthermore, synthetic grafts were associated with the highest reoperation and xenografts with the highest rate of meningitis, whereas allografts were associated with the best syrinx improvement rate and second-best meningitis rate. Future studies comparing autografts and allografts are warranted to determine which carries the best clinical outcome.
Topics: Humans; Animals; Cattle; Swine; Arnold-Chiari Malformation; Syringomyelia; Decompression, Surgical; Dura Mater; Treatment Outcome; Meningitis; Retrospective Studies
PubMed: 36180807
DOI: 10.1007/s10143-022-01873-6 -
Cells Apr 2021The lymphatic system serves key functions in maintaining fluid homeostasis, the uptake of dietary fats in the small intestine, and the trafficking of immune cells.... (Review)
Review
The lymphatic system serves key functions in maintaining fluid homeostasis, the uptake of dietary fats in the small intestine, and the trafficking of immune cells. Almost all vascularized peripheral tissues and organs contain lymphatic vessels. The brain parenchyma, however, is considered immune privileged and devoid of lymphatic structures. This contrasts with the notion that the brain is metabolically extremely active, produces large amounts of waste and metabolites that need to be cleared, and is especially sensitive to edema formation. Recently, meningeal lymphatic vessels in mammals and zebrafish have been (re-)discovered, but how they contribute to fluid drainage is still not fully understood. Here, we discuss these meningeal vessel systems as well as a newly described cell population in the zebrafish and mouse meninges. These cells, termed brain lymphatic endothelial cells/Fluorescent Granular Perithelial cells/meningeal mural lymphatic endothelial cells in fish, and Leptomeningeal Lymphatic Endothelial Cells in mice, exhibit remarkable features. They have a typical lymphatic endothelial gene expression signature but do not form vessels and rather constitute a meshwork of single cells, covering the brain surface.
Topics: Animals; Brain; Endothelial Cells; Humans; Lymphangiogenesis; Lymphatic System; Macromolecular Substances; Meninges
PubMed: 33918497
DOI: 10.3390/cells10040799 -
Frontiers in Cellular and Infection... 2019The discrimination of tuberculous meningitis and bacterial meningitis remains difficult at present, even with the introduction of advanced diagnostic tools. This study...
The discrimination of tuberculous meningitis and bacterial meningitis remains difficult at present, even with the introduction of advanced diagnostic tools. This study aims to differentiate these two kinds of meningitis by using the rule of clinical and laboratory features. A prospective observational study was conducted to collect the clinical and laboratory parameters of patients with tuberculous meningitis or bacterial meningitis. Logistic regression was used to define the diagnostic formula for the discrimination of tuberculous meningitis and bacterial meningitis. A receiver operator characteristic curve was established to determine the best cutoff point for the diagnostic formula. Five parameters (duration of illness, coughing for two or more weeks, meningeal signs, blood sodium, and percentage of neutrophils in cerebrospinal fluid) were predictive of tuberculous meningitis. The diagnostic formula developed from these parameters was 98% sensitive and 82% specific, while these were 95% sensitive and 91% specific when prospectively applied to another 70 patients. The diagnostic formula developed in the present study can help physicians to differentiate tuberculous meningitis from bacterial meningitis in high-tuberculosis-incidence-areas, particularly in settings with limited microbiological and radiological resources.
Topics: Adolescent; Adult; Aged; Diagnostic Tests, Routine; Female; Humans; Logistic Models; Male; Meningitis, Bacterial; Middle Aged; Neutrophils; Prospective Studies; ROC Curve; Regression Analysis; Sensitivity and Specificity; Tuberculosis, Meningeal; Vietnam; Young Adult
PubMed: 32010636
DOI: 10.3389/fcimb.2019.00448 -
Immunology Nov 2021Ectopic lymphoid follicles (ELFs), resembling germinal centre-like structures, emerge in a variety of infectious and autoimmune and neoplastic diseases. ELFs can be... (Review)
Review
Ectopic lymphoid follicles (ELFs), resembling germinal centre-like structures, emerge in a variety of infectious and autoimmune and neoplastic diseases. ELFs can be found in the meninges of around 40% of the investigated progressive multiple sclerosis (MS) post-mortem brain tissues and are associated with the severity of cortical degeneration and clinical disease progression. Of predominant importance for progressive neuronal damage during the progressive MS phase appears to be meningeal inflammation, comprising diffuse meningeal infiltrates, B-cell aggregates and compartmentalized ELFs. However, the absence of a uniform definition of ELFs impedes reproducible and comparable neuropathological research in this field. In this review article, we will first highlight historical aspects and milestones around the discovery of ELFs in the meninges of progressive MS patients. In the next step, we discuss how animal models may contribute to an understanding of the mechanisms underlying ELF formation. Finally, we summarize challenges in investigating ELFs and propose potential directions for future research.
Topics: Animals; B-Lymphocytes; Disease Models, Animal; Humans; Meninges; Multiple Sclerosis, Chronic Progressive; Tertiary Lymphoid Structures
PubMed: 34293193
DOI: 10.1111/imm.13395 -
Neuromolecular Medicine Sep 2021Traditionally, the primary role of the meninges is thought to be structural, i.e., to act as a surrounding membrane that contains and cushions the brain with... (Review)
Review
Traditionally, the primary role of the meninges is thought to be structural, i.e., to act as a surrounding membrane that contains and cushions the brain with cerebrospinal fluid. During development, the meninges is formed by both mesenchymal and neural crest cells. There is now emerging evidence that subsets of undifferentiated stem cells might persist in the adult meninges. In this mini-review, we survey representative studies of brain-meningeal interactions and discuss the hypothesis that the meninges are not just protective membranes, but instead contain multiplex stem cell subsets that may contribute to central nervous system (CNS) homeostasis. Further investigations into meningeal multipotent cells may reveal a "hidden" target for promoting neurovascular remodeling and repair after CNS injury and disease.
Topics: Adapalene; Adult Stem Cells; Animals; Brain Ischemia; Central Nervous System; Central Nervous System Diseases; Glymphatic System; Homeostasis; Humans; Male; Meninges; Multipotent Stem Cells; Neural Crest; Neural Stem Cells; Rats; Rats, Sprague-Dawley; Regeneration
PubMed: 33893971
DOI: 10.1007/s12017-021-08663-1 -
Cephalalgia : An International Journal... Nov 2019The exact mechanisms underlying the onset of a migraine attack are not completely understood. It is, however, now well accepted that the onset of the excruciating... (Review)
Review
BACKGROUND
The exact mechanisms underlying the onset of a migraine attack are not completely understood. It is, however, now well accepted that the onset of the excruciating throbbing headache of migraine is mediated by the activation and increased mechanosensitivity (i.e. sensitization) of trigeminal nociceptive afferents that innervate the cranial meninges and their related large blood vessels.
OBJECTIVES
To provide a critical summary of current understanding of the role that the cranial meninges, their associated vasculature, and immune cells play in meningeal nociception and the ensuing migraine headache.
METHODS
We discuss the anatomy of the cranial meninges, their associated vasculature, innervation and immune cell population. We then debate the meningeal neurogenic inflammation hypothesis of migraine and its putative contribution to migraine pain. Finally, we provide insights into potential sources of meningeal inflammation and nociception beyond neurogenic inflammation, and their potential contribution to migraine headache.
Topics: Afferent Pathways; Animals; Autonomic Fibers, Postganglionic; Capillary Permeability; Humans; Inflammation; Macrophages; Mast Cells; Meninges; Mice; Migraine Disorders; Models, Biological; Nociception; Nociceptors; Ophthalmic Nerve; Pituitary Adenylate Cyclase-Activating Polypeptide; Rats; T-Lymphocytes; Trigeminal Nerve; Vasodilation
PubMed: 29929378
DOI: 10.1177/0333102418771350 -
Progress in Molecular Biology and... 2015Migraine is the most common neurological disorder. Attacks are complex and consist of multiple phases but are most commonly characterized by intense, unilateral,... (Review)
Review
Migraine is the most common neurological disorder. Attacks are complex and consist of multiple phases but are most commonly characterized by intense, unilateral, throbbing headache. The pathophysiology contributing to migraine is poorly understood and the disorder is not well managed with currently available therapeutics, often rendering patients disabled during attacks. The mechanisms most likely to contribute to the pain phase of migraine require activation of trigeminal afferent signaling from the cranial meninges and subsequent relay of nociceptive information into the central nervous system in a region of the dorsal brainstem known as the trigeminal nucleus caudalis. Events leading to activation of meningeal afferents are unclear, but nerve endings within this tissue are mechanosensitive and also express a variety of ion channels including acid-sensing ion channels and transient receptor-potential channels. These properties may provide clues into the pathophysiology of migraine by suggesting that decreased extracellular pH and environmental irritant exposure in the meninges contributes to headache. Neuroplasticity is also likely to play a role in migraine given that attacks are triggered by routine events that are typically nonnoxious in healthy patients and clear evidence of sensitization occurs during an attack. Where and how plasticity develops is also not clear but may include events directly on the afferents and/or within the TNC. Among the mediators potentially contributing to plasticity, calcitonin gene-related peptide has received the most attention within the migraine field but other mechanisms may also contribute. Ultimately, greater understanding of the molecules and mechanisms contributing to migraine will undoubtedly lead to better therapeutics and relief for the large number of patients across the globe who suffer from this highly disabling neurological disorder.
Topics: Animals; Brain-Derived Neurotrophic Factor; Calcitonin Gene-Related Peptide; Humans; Ion Channels; Meninges; Migraine Disorders; Neuronal Plasticity; Signal Transduction
PubMed: 25744685
DOI: 10.1016/bs.pmbts.2015.01.001 -
Cellular and Molecular Life Sciences :... Nov 2023The lymphatic vasculature plays a crucial role in fluid clearance and immune responses in peripheral organs by connecting them to distal lymph nodes. Recently, attention... (Review)
Review
The lymphatic vasculature plays a crucial role in fluid clearance and immune responses in peripheral organs by connecting them to distal lymph nodes. Recently, attention has been drawn to the lymphatic vessel network surrounding the brain's border tissue (Aspelund et al. in J Exp Med 212:991-999, 2015. https://doi.org/10.1084/jem.20142290 ; Louveau et al. in Nat Neurosci 21:1380-1391, 2018. https://doi.org/10.1038/s41593-018-0227-9 ), which guides immune cells in mediating protection against tumors (Song et al. in Nature 577:689-694, 2020. https://doi.org/10.1038/s41586-019-1912-x ) and pathogens Li et al. (Nat Neurosci 25:577-587, 2022. https://doi.org/10.1038/s41593-022-01063-z ) while also contributing to autoimmunity (Louveau et al. 2018) and neurodegeneration (Da Mesquita et al. in Nature 560:185-191, 2018. https://doi.org/10.1038/s41586-018-0368-8 ). New studies have highlighted the integral involvement of meningeal lymphatic vessels in neuropathology. However, our limited understanding of spinal cord meningeal lymphatics and immunity hinders efforts to protect and heal the spinal cord from infections, injury, and other immune-mediated diseases. This review aims to provide a comprehensive overview of the state of spinal cord meningeal immunity, highlighting its unique immunologically relevant anatomy, discussing immune cells and lymphatic vasculature, and exploring the potential impact of injuries and inflammatory disorders on this intricate environment.
Topics: Central Nervous System; Meninges; Lymphatic System; Spinal Cord; Lymphatic Vessels
PubMed: 37985518
DOI: 10.1007/s00018-023-05013-1 -
Glymphatic-lymphatic coupling: assessment of the evidence from magnetic resonance imaging of humans.Cellular and Molecular Life Sciences :... Mar 2024The discoveries that cerebrospinal fluid participates in metabolic perivascular exchange with the brain and further drains solutes to meningeal lymphatic vessels have... (Review)
Review
The discoveries that cerebrospinal fluid participates in metabolic perivascular exchange with the brain and further drains solutes to meningeal lymphatic vessels have sparked a tremendous interest in translating these seminal findings from animals to humans. A potential two-way coupling between the brain extra-vascular compartment and the peripheral immune system has implications that exceed those concerning neurodegenerative diseases, but also imply that the central nervous system has pushed its immunological borders toward the periphery, where cross-talk mediated by cerebrospinal fluid may play a role in a range of neoplastic and immunological diseases. Due to its non-invasive approach, magnetic resonance imaging has typically been the preferred methodology in attempts to image the glymphatic system and meningeal lymphatics in humans. Even if flourishing, the research field is still in its cradle, and interpretations of imaging findings that topographically associate with reports from animals have yet seemed to downplay the presence of previously described anatomical constituents, particularly in the dura. In this brief review, we illuminate these challenges and assess the evidence for a glymphatic-lymphatic coupling. Finally, we provide a new perspective on how human brain and meningeal clearance function may possibly be measured in future.
Topics: Animals; Humans; Lymphatic Vessels; Central Nervous System; Brain; Meninges; Magnetic Resonance Imaging
PubMed: 38472405
DOI: 10.1007/s00018-024-05141-2