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Acta Neurochirurgica Jun 2024The discovery of the glymphatic system has fundamentally altered our comprehension of cerebrospinal fluid transport and the removal of waste from brain metabolism. In... (Review)
Review
The discovery of the glymphatic system has fundamentally altered our comprehension of cerebrospinal fluid transport and the removal of waste from brain metabolism. In the past decade, since its initial characterization, research on the glymphatic system has surged exponentially. Its potential implications for central nervous system disorders have sparked significant interest in the field of neurosurgery. Nonetheless, ongoing discussions and debates persist regarding the concept of the glymphatic system, and our current understanding largely relies on findings from experimental animal studies. This review aims to address several key inquiries: What methodologies exist for evaluating glymphatic function in humans today? What is the current evidence supporting the existence of a human glymphatic system? Can the glymphatic system be considered distinct from the meningeal-lymphatic system? What is the human evidence for glymphatic-meningeal lymphatic system failure in neurosurgical diseases? Existing literature indicates a paucity of techniques available for assessing glymphatic function in humans. Thus far, intrathecal contrast-enhanced magnetic resonance imaging (MRI) has shown the most promising results and have provided evidence for the presence of a glymphatic system in humans, albeit with limitations. It is, however, essential to recognize the interconnection between the glymphatic and meningeal lymphatic systems, as they operate in tandem. There are some human studies demonstrating deteriorations in glymphatic function associated with neurosurgical disorders, enriching our understanding of their pathophysiology. However, the translation of this knowledge into clinical practice is hindered by the constraints of current glymphatic imaging modalities.
Topics: Humans; Glymphatic System; Neurosurgical Procedures; Meninges; Animals; Magnetic Resonance Imaging
PubMed: 38904802
DOI: 10.1007/s00701-024-06161-4 -
Neurological Sciences : Official... Jun 2023We summarized the clinical and radiological characteristics of meningitis-retention syndrome (MRS), its therapeutic options, and urological outcome, to better understand... (Review)
Review
OBJECTIVES
We summarized the clinical and radiological characteristics of meningitis-retention syndrome (MRS), its therapeutic options, and urological outcome, to better understand the pathogenesis of this syndrome and to evaluate the effectiveness of corticosteroids in reducing the period of urinary retention.
METHODS
We reported a new case of MRS in a male adolescent. We also reviewed the previously 28 reported cases of MRS, collected from inception up to September 2022.
RESULTS
MRS is characterized by aseptic meningitis and urinary retention. The mean length of the interval between the onset of the neurological signs and the urinary retention was 6.4 days. In most cases, no pathogens were isolated in cerebrospinal fluid, except for 6 cases in which Herpesviruses were detected. The urodynamic study resulted in a detrusor underactivity, with a mean period for urination recovery of 4.5 weeks, regardless of therapies.
DISCUSSION
Neurophysiological studies and electromyographic examination are not pathological, distinguishing MRS from polyneuropathies. Although there are no encephalitic symptoms or signs, and the magnetic resonance is often normal, MRS may represent a mild form of acute disseminated encephalomyelitis, without radiological detectable medullary involvement, due to the prompt use of steroids. It is believed that MRS is a self-limited disease, and no evidence suggests the effectiveness of steroids, antibiotics, and antiviral treatment in its clinical course.
Topics: Adolescent; Humans; Male; Urinary Retention; Meningitis; Meningitis, Aseptic; Encephalomyelitis, Acute Disseminated; Magnetic Resonance Imaging; Syndrome
PubMed: 36867276
DOI: 10.1007/s10072-023-06704-0 -
Current Opinion in Neurobiology Apr 2023The spatial and temporal development of the brain, overlying meninges (fibroblasts, vasculature and immune cells) and calvarium are highly coordinated. In particular,... (Review)
Review
The spatial and temporal development of the brain, overlying meninges (fibroblasts, vasculature and immune cells) and calvarium are highly coordinated. In particular, the timing of meningeal fibroblasts into molecularly distinct pia, arachnoid and dura subtypes coincides with key developmental events in the brain and calvarium. Further, the meninges are positioned to influence development of adjacent structures and do so via depositing basement membrane and producing molecular cues to regulate brain and calvarial development. Here, we review the current knowledge of how meninges development aligns with events in the brain and calvarium and meningeal fibroblast "crosstalk" with these structures. We summarize outstanding questions and how the use of non-mammalian models to study the meninges will substantially advance the field of meninges biology.
Topics: Meninges; Dura Mater; Arachnoid; Brain
PubMed: 36773497
DOI: 10.1016/j.conb.2023.102676 -
Internal Medicine (Tokyo, Japan) Feb 2022Behçet disease and its related disorder, Sweet disease, are multifactorial disorders whose susceptibility loci have been identified in the genes of various...
Behçet disease and its related disorder, Sweet disease, are multifactorial disorders whose susceptibility loci have been identified in the genes of various immunological factors aside from human leukocyte antigens. The neurological involvement of these diseases, including encephalitis, myelitis, and meningitis, referred to as neuro-Behçet disease (NBD) and neuro-Sweet disease (NSD) respectively, is sometimes difficult to diagnose, especially when the characteristic mucocutaneous symptoms do not precede neurological symptoms or when characteristics of both diseases are present in a single patient. NBD and NSD constitute a spectrum of diseases that are differentiated according to the combination of risk factors, including the genetic background. Encephalitis, myelitis, and meningitis similar to NBD or NSD can be diagnosed as spectrum disorders, even if the characteristic mucocutaneous symptoms fail to be detected. Understanding these conditions as a disease spectrum may help elucidate the disease pathogenesis and assist in the development of therapeutic agents.
Topics: Behcet Syndrome; Diagnosis, Differential; Encephalitis; Humans; Meningitis; Sweet Syndrome
PubMed: 34615825
DOI: 10.2169/internalmedicine.8227-21 -
Trends in Immunology Apr 2023The emphasis on mechanisms driving multiple sclerosis (MS) symptomatic worsening suggests that we move beyond categorical clinical classifiers such as... (Review)
Review
The emphasis on mechanisms driving multiple sclerosis (MS) symptomatic worsening suggests that we move beyond categorical clinical classifiers such as relapsing-remitting MS (RR-MS) and progressive MS (P-MS). Here, we focus on the clinical phenomenon progression independent of relapse activity (PIRA), which begins early in the disease course. PIRA occurs throughout MS, becoming more phenotypically evident as patients age. The underlying mechanisms for PIRA include chronic-active demyelinating lesions (CALs), subpial cortical demyelination, and nerve fiber injury following demyelination. We propose that much of the tissue injury associated with PIRA is driven by autonomous meningeal lymphoid aggregates, present before disease onset and unresponsive to current therapeutics. Recently, specialized magnetic resonance imaging (MRI) has identified and characterized CALs as paramagnetic rim lesions in humans, enabling novel radiographic-biomarker-clinical correlations to further understand and treat PIRA.
Topics: Humans; Multiple Sclerosis; Meninges; Disease Progression; Multiple Sclerosis, Relapsing-Remitting
PubMed: 36868982
DOI: 10.1016/j.it.2023.02.002 -
Fluids and Barriers of the CNS Dec 2023Traditionally, the meninges are described as 3 distinct layers, dura, arachnoid and pia. Yet, the classification of the connective meningeal membranes surrounding the...
Traditionally, the meninges are described as 3 distinct layers, dura, arachnoid and pia. Yet, the classification of the connective meningeal membranes surrounding the brain is based on postmortem macroscopic examination. Ultrastructural and single cell transcriptome analyses have documented that the 3 meningeal layers can be subdivided into several distinct layers based on cellular characteristics. We here re-examined the existence of a 4 meningeal membrane, Subarachnoid Lymphatic-like Membrane or SLYM in Prox1-eGFP reporter mice. Imaging of freshly resected whole brains showed that SLYM covers the entire brain and brain stem and forms a roof shielding the subarachnoid cerebrospinal fluid (CSF)-filled cisterns and the pia-adjacent vasculature. Thus, SLYM is strategically positioned to facilitate periarterial influx of freshly produced CSF and thereby support unidirectional glymphatic CSF transport. Histological analysis showed that, in spinal cord and parts of dorsal cortex, SLYM fused with the arachnoid barrier layer, while in the basal brain stem typically formed a 1-3 cell layered membrane subdividing the subarachnoid space into two compartments. However, great care should be taken when interpreting the organization of the delicate leptomeningeal membranes in tissue sections. We show that hyperosmotic fixatives dehydrate the tissue with the risk of shrinkage and dislocation of these fragile membranes in postmortem preparations.
Topics: Mice; Animals; Meninges; Dura Mater; Arachnoid; Subarachnoid Space; Cerebral Cortex
PubMed: 38098084
DOI: 10.1186/s12987-023-00500-w -
International Journal of Infectious... Apr 2020To describe and analyse the epidemiological and clinical characteristics of imported human angiostrongyliasis in Europe. (Review)
Review
OBJECTIVES
To describe and analyse the epidemiological and clinical characteristics of imported human angiostrongyliasis in Europe.
METHODS
A systematic literature review of cases of human angiostrongyliasis in Europe was performed. Seven databases were searched. The epidemiological and clinical characteristics were extracted from included records and simple summary statistics were performed on extracted data.
RESULTS
Twenty-two cases reported between 1988 and 2019 were identified. They were mainly from French Polynesia, Southeast Asia, and the Caribbean Islands. The dominant suspected mode of transmission was ingestion of prawns, shrimp, or salad. For patients with data, 90% had a history of headache, often lasting, and half had paresthesia. Eighty-nine percent had eosinophilia, 93% had cerebrospinal fluid (CSF) eosinophilia, and 92% had elevated CSF protein. Central nervous system (CNS) imaging was normal in most cases. Two-thirds received albendazole or mebendazole treatment, although this is not currently recommended.
CONCLUSIONS
We have increased previous numbers to 22 reported cases in total since 1988. Angiostrongyliasis should generally be suspected in patients with a lasting headache who have returned from Southeast Asia, China, the Caribbean Islands, Australia, or French Polynesia, as well as parts of North America and Tenerife, Spain, although one autochthonous case from mainland Europe has also been reported. A dietary history should focus on prawns, shrimp, and salad, whilst also including slugs and snails and other paratenic hosts where relevant. The clinical diagnosis is supported by the presence of blood eosinophilia, CSF eosinophilia, and elevated CSF protein. A definitive laboratory diagnosis should be sought, and CNS imaging should be used to support, not to rule out the diagnosis. The most up-to-date evidence should always be consulted before initiating treatment. Current recommendations include analgesics, corticosteroids, and periodic removal of CSF for symptom relief, while antihelminthic treatment is debated.
Topics: Adolescent; Adult; Angiostrongylus cantonensis; Animals; Asia, Southeastern; Australia; Eosinophilia; Europe; Female; Humans; Infant; Male; Meningitis; Middle Aged; Polynesia; Seafood; Snails; Strongylida Infections; West Indies
PubMed: 31972289
DOI: 10.1016/j.ijid.2020.01.012 -
Microbiology Spectrum Jun 2023Central nervous system (CNS) infections such as meningitis and encephalitis are life-threatening conditions that demand hospital care and prompt identification of the...
Central nervous system (CNS) infections such as meningitis and encephalitis are life-threatening conditions that demand hospital care and prompt identification of the causative agent. Since 2015, there has been only one CE-IVD-marked rapid multiplexed diagnostic assay in cassette format for bacterial and viral detection from cerebrospinal fluid (CSF): the BioFire FilmArray meningitis/encephalitis (ME) panel. In the beginning of 2022, Qiagen introduced the QIAstat-Dx meningitis/encephalitis panel. It is a CE-IVD-marked multiplex PCR cassette test intended for the identification of suspected infectious meningitis, encephalitis, or meningoencephalitis caused by bacterial, viral, or fungal pathogens. In this study, we evaluated patient and quality control samples using the QIAstat-Dx meningitis/encephalitis panel and compared the results to those of the BioFire FilmArray meningitis/encephalitis panel and reference methods (current routine analysis methods in our laboratory, PCR, or cultivation). The combined positive percent agreement between the two panel assays was 100%, and the negative percent agreement was 94%. We further compared specifically herpes simplex virus 1 (HSV-1), HSV-2, and varicella-zoster virus (VZV) dilution series using six commercial herpesvirus assays, including the two cassette tests. The results suggested that real-time PCR methods (with separate extraction) were the most sensitive methods. When comparing the cassette tests, the BioFire FilmArray meningitis/encephalitis panel produced more positive results than the QIAstat-Dx meningitis/encephalitis panel in the herpesvirus analyses. The diagnosis of infectious meningitis and encephalitis relies mostly on specific PCR and culturing methods, but commercial syndromic panel assays are bringing a change in diagnostics. With multiplexed analysis, the identification of the pathogen is potentially faster, and less sample material is needed. The novel QIAstat-Dx meningitis/encephalitis panel assay is intended for the rapid identification of pathogens from cerebrospinal fluid for suspected central nervous system (CNS) infection, which is a life-threatening condition and difficult to diagnose. We studied the performance of this panel assay using patient samples and dilution series of selected viruses. The evaluation data for this novel meningitis/encephalitis panel assay are useful for other clinical laboratories and organizations using or considering using this test.
Topics: Humans; Multiplex Polymerase Chain Reaction; Meningitis; Encephalitis; Viruses; Bacteria
PubMed: 37042772
DOI: 10.1128/spectrum.05144-22 -
Clinical Infectious Diseases : An... Mar 2023Cognitive impairment is reported as a common complication in adult tuberculous meningitis (TBM), yet few studies have systematically assessed the frequency and nature of...
BACKGROUND
Cognitive impairment is reported as a common complication in adult tuberculous meningitis (TBM), yet few studies have systematically assessed the frequency and nature of impairment. Moreover, the impact of impairment on functioning and medication adherence has not been described.
METHODS
A cognitive test battery (10 measures assessing 7 cognitive domains) was administered to 34 participants with human immunodeficiency virus (HIV)-associated TBM 6 months after diagnosis. Cognitive performance was compared with that a comparator group of 66 people with HIV without a history of tuberculosis. A secondary comparison was made between participants with TBM and 26 participants with HIV 6 months after diagnosis of tuberculosis outside the central nervous system (CNS). Impact on functioning was evaluated, including through assessment of medication adherence.
RESULTS
Of 34 participants with TBM, 16 (47%) had low performance on cognitive testing. Cognition was impaired across all domains. Global cognitive performance was significantly lower in participants with TBM than in people with HIV (mean T score, 41 vs 48, respectively; P < .001). These participants also had lower global cognition scores than those with non-CNS tuberculosis (mean global T score, 41 vs 46; P = .02). Functional outcomes were not significantly correlated with cognitive performance in the subgroup of participants in whom this was assessed (n = 19).
CONCLUSIONS
Low cognitive performance following HIV-associated TBM is common. This effect is independent of, and additional to, effects of HIV and non-CNS tuberculosis disease. Further studies are needed to understand longer-term outcomes, clarify the association with treatment adherence, a key predictor of outcome in TBM, and develop context-specific tools to identify individuals with cognitive difficulties in order to improve outcomes in TBM.
Topics: Adult; Humans; Tuberculosis, Meningeal; HIV Infections; Cognitive Dysfunction
PubMed: 36262054
DOI: 10.1093/cid/ciac831 -
Global Health, Epidemiology and Genomics 2022The Global Burden of Disease Study in 2016 estimated that the global incident cases of meningitis have increased by 320,000 between 1990 and 2016. Current evidence... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The Global Burden of Disease Study in 2016 estimated that the global incident cases of meningitis have increased by 320,000 between 1990 and 2016. Current evidence suggests that diabetes may be a prime risk factor for meningitis among individuals, including older adults. However, findings of prior studies on this topic remain inconsistent, making a general conclusion relatively difficult. This study aimed to quantitatively synthesize the literature on the risk of meningitis associated with diabetes and compare the risk across different global regions.
METHOD
Literature search and study design protocol followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search was conducted in PubMed, Web of Science, African Journal Online, and Google Scholar using relevant MESH terms. A random effect model was used to pull effect sizes.
RESULTS
Initial search yielded 772 papers but 756 studies were excluded due to duplicity and not meeting inclusion criteria. In all, 16 papers involving 16847 cases were used. The pulled effect size (ES) of the association between diabetes and meningitis was 2.240 (OR = 2.240, 95% CI = 1.716-2.924). Regional-base analysis showed that diabetes increased the risk of developing meningitis in Europe (OR = 1.737, 95% CI = 1.299-2.323), Asia (OR = 2.192, 95% CI = 1.233-3.898), and North America (OR = 2.819, 95% CI = 1.159-6.855). These associations remained significant in the study design and etiological classe-based subgroup analyses. However, we surprisingly found no studies in Africa or South America.
CONCLUSION
Diabetes is a risk factor for developing meningitis. Given that no research on this topic came from Africa and South America, our findings should be contextually interpreted. We, however, encourage studies on diabetes-meningitis linkages from all parts of the world, particularly in Africa and South America, to confirm the findings of the present study.
Topics: Humans; Aged; Diabetes Mellitus; Risk Factors; Africa; Meningitis; Asia
PubMed: 36570413
DOI: 10.1155/2022/3996711