Search Results (17)

The mitigation measures adopted to reduce the spread of COVID-19 have not only impacted the transmission of respiratory infections but also other infectious diseases. In this study, we explored the effect of the pandemic on the epidemiology of Central Nervous System (CNS) infections by conducting a retrospective analysis of diagnostic data obtained from cerebrospinal fluids (CSFs) collected before, during, and after the pandemic from patients with acute-suspected neuro-infectious syndrome. The samples were analyzed using a meningitis/encephalitis molecular syndromic panel. A total of 4203 CSFs were split into three groups: pre-pandemic (August 2018–February 2020), pandemic (March 2020–March 2022) and post-pandemic (April 2022–March 2024). Each pathogen was statistically assessed individually, comparing one group vs. another. Results showed that viral pathogens were the most frequently detected across all groups; however, Streptococcus pneumoniae was the single most identified pathogen. Comparison of the pre-pandemic and pandemic groups by statistical analysis showed a significant reduction in neuro-infections caused by enterovirus, S. pneumoniae and N. meningitidis, while the other pathogens were not affected. In conclusion, a reduction in CNS infections caused by respiratory and close-contact-transmitted pathogens, including both viral and bacterial agents, was observed during the period when COVID-19 containment measures were in effect. Full article

Background: Influenza-associated encephalopathy, encephalitis, and acute necrotizing encephalopathy (ANE) are rare but potentially life-threatening neurological complications of influenza. Adult cases remain poorly characterized because the available literature is largely limited to isolated case reports and small case series. Methods: A PRISMA-guided scoping review of the MEDLINE database was conducted through 31 May 2026. Published adult cases of influenza-associated encephalopathy, encephalitis, and ANE were identified and analyzed for demographic characteristics, clinical presentation, neuroimaging findings, treatment, and outcomes. Results: Eighty-three adult cases reported between 1958 and 2026 were included. The mean age was 45.6 ± 17.8 years, and 57.8% were male. Two-thirds did not have any underlying comorbidities. Neurological symptoms developed a mean of 4.6 days after influenza onset, with influenza A accounting for 80.7% of infections. Fever (91.6%), altered mental status (86.7%), and seizures (36.1%) were the most common manifestations. Encephalitis was the predominant presentation (44.5%), followed by encephalopathy (31.3%) and ANE (24.1%). MRI most frequently demonstrated cerebral hemispheric lesions (53.0%) and bilateral thalamic involvement (36.4%), while EEG abnormalities were reported in 69.6% of patients. Overall mortality was 22.9%, highest among patients with ANE (45.0%). Among survivors, 28.9% experienced persistent neurological sequelae. Conclusions: Influenza-associated encephalopathy, encephalitis, and ANE are rare in adults but are associated with substantial morbidity and mortality. This review represents the largest adult cohort reported to date and provides important insights into the clinical spectrum, neurodiagnostic findings, and outcomes of these uncommon complications. This review highlights significant gaps in knowledge and the need for collaborative multicenter studies to improve the diagnosis, treatment, and outcome of these severe complications of influenza infection. Full article

Background and Clinical Significance: When diverse clinical presentations coincide with complex laboratory findings, particularly in older adults, the diagnostic process can be especially challenging. Case Presentation: We report the case of a geriatric patient who was hospitalized with initial gastrointestinal and respiratory symptoms, followed by progressive chest pain and profound weakness, accompanied by elevated transaminases, troponin elevation, and hyponatremia, initially suggesting multiple competing diagnostic entities. During the clinical course, the patient developed neurological symptoms. Ultimately, careful history-taking, including detailed exposure assessment, raised suspicion for tick-borne encephalitis, which was subsequently confirmed by serological testing. Conclusions: This case highlights the diagnostic complexity of tick-borne encephalitis in older adults, where atypical and multisystem presentations may obscure the underlying etiology and delay recognition of a neuroinfectious disease. Full article

Background: Tick-borne encephalitis (TBE) is an endemic neuroinfectious disease prevalent in parts of Europe and is often associated with persistent neurological and cognitive sequelae. The aim of this study was to evaluate the long-term outcomes and predictors of post-encephalitic sequelae in adult patients with TBE in Latvia. Methods: A retrospective cohort with prospective follow-up was used that included 105 adult patients hospitalized with laboratory-confirmed TBE between 2018 and 2024. The patients’ clinical and demographic data were extracted from medical records, and reassessments were performed ≥6 months after discharge using structured clinical and neurological evaluations for neurocognitive, subjective, and neurological sequelae. Disease severity was classified using the Mickienė and Bogovič criteria, and sequelae severity was defined according to the Bohr criteria for post-encephalitic syndrome (PES). Results: Sequelae were observed in 52/105 (49.5%) patients and were more frequent in meningoencephalitis than in meningitis cases (18/25 [72.0%] vs. 33/77 [42.9%]). The most common persistent symptoms were impaired concentration (33/52 [63.5%]), fatigue (29/52 [55.8%]), and sleep disturbances (21/52 [40.4%]). Neurological sequelae included tremor (23/52 [44.2%]), vertigo (11/52 [21.2%]), and hearing impairment (5/52 [9.8%]). According to the Bohr criteria, most of the patients had mild sequelae (42/52 [80.8%]), while 10/52 [19.2%] had moderate sequelae; no severe cases were observed. In the multivariable analysis, increasing age was independently associated with greater sequelae severity (OR = 1.045 per year; 95% CI, 1.015–1.073; p = 0.003). Sex, comorbidities, biphasic disease, and length of hospital stay were not significant predictors. Acute neurological manifestations, particularly paresis (p = 0.002) and tremor (p = 0.019), were associated with worse outcomes. Although the disease severity scores correlated with sequelae in unadjusted analyses, neither the Mickienė nor the Bogovič classification independently predicted outcomes after adjustment. Conclusions: Nearly half of the hospitalized patients with TBE included in this study developed long-term sequelae, which were predominantly neurocognitive and mild in severity. Age was the primary independent predictor of worse outcomes, while acute neurological deficits such as paresis and tremor also indicated increased risk. These findings highlight the substantial burden of post-encephalitic syndrome and the need for structured long-term follow-up in TBE survivors. Full article

Background: Bilateral facial nerve palsy (BFNP) is a rare clinical entity in children and is more often associated with systemic or infectious diseases than unilateral facial palsy. Epstein–Barr virus (EBV) infection is an uncommon but recognized cause of facial nerve palsy and may present with bilateral involvement. Case presentation: We report the case of a 3-year-old boy who presented with progressive bilateral facial weakness following a febrile illness with pharyngitis and cervical lymphadenopathy. Neurological examination revealed complete bilateral facial paralysis (House–Brackmann grade VI). Laboratory investigations showed lymphocytosis and confirmed acute EBV infection through positive viral capsid antigen IgM and detectable EBV DNA in peripheral blood. Cerebrospinal fluid analysis demonstrated mild pleocytosis with negative EBV DNA. Brain magnetic resonance imaging revealed unilateral enhancement of the left facial nerve. Audiologic evaluation supported peripheral facial nerve dysfunction. The patient was treated with systemic corticosteroids, vitamin B complex supplementation, artificial tears, and speech therapy, resulting in gradual and substantial clinical improvement over five months. Discussion: A review of the pediatric literature identified only six previously reported cases of EBV-associated BFNP. The pathogenesis may involve either direct viral neurotropism or a post-infectious immune-mediated mechanism. Diagnostic evaluation is essential to exclude other serious causes of BFNP, particularly Lyme disease and Guillain–Barré syndrome. Conclusions: EBV infection should be considered in the differential diagnosis of BFNP in children. Prognosis is generally favorable, although recovery may be prolonged. Further studies are needed to clarify optimal diagnostic and therapeutic approaches. Full article

Subacute sclerosing panencephalitis (SSPE) is a rare, progressive, and fatal neurological disorder caused by persistent measles virus infection. Reliable prognostic biomarkers remain limited. Systemic inflammation has been implicated in the pathogenesis of neuroinfectious diseases, and hematology-derived indices are increasingly recognized as accessible markers of inflammatory burden. This retrospective case–control study was conducted at İnönü University Faculty of Medicine, Malatya, Türkiye, between 2010 and 2025, including 40 pediatric patients with SSPE and 40 age- and sex-matched healthy controls. Demographic and laboratory data were retrieved from institutional records, and disease severity was classified according to Jabbour stages. Compared with controls, patients with SSPE had significantly higher pan-immune inflammation value (PIV: 710.5 [320–1050] vs. 280.0 [150–460], p < 0.001), systemic immune-inflammation index (SII: 640.0 [310–1240] vs. 410.0 [210–720], p = 0.02), and neutrophil-to-lymphocyte ratio (NLR: 2.1 [1.2–3.8] vs. 1.6 [1.0–2.5], p = 0.03), along with lower lymphocyte counts (p = 0.04). Elevated PIVs were strongly associated with advanced Jabbour stages, impaired ambulation, and a higher case-fatality ratio (35%). Multivariate regression identified PIV as an independent predictor of death (OR: 3.25, 95% CI: 1.45–7.28, p = 0.004), and receiver operating characteristic analysis demonstrated superior discriminative accuracy of PIV (AUC = 0.87) compared with other indices. These findings suggest that PIV, a simple and inexpensive biomarker derived from routine blood tests, may provide useful prognostic information in SSPE and aid early risk stratification. Further multicenter, prospective studies are warranted to validate its clinical utility. Full article

Chemical exchange saturation transfer (CEST) MRI is a novel technique that allows for the specific imaging of certain molecules that contain exchangeable protons. Neuroimaging is a major contributor to diagnosing and monitoring infections of the central nervous system (CNS). This review focuses on summarizing the current literature surrounding the use of CEST MRI imaging in diagnosing, monitoring, and treating CNS infections. BacCEST is a new technique to detect bacterial infection in organs at profound levels. This technique allows for the specific pathogen causing the infection to be understood, allowing for tailored antibiotic therapies. The bacCEST signal is also directly proportional to the number of bacterial cells; this means it can be used over periods to track response to treatment via cell numbers. The results show that most of the research in this area has focused on infections of the brain parenchyma (e.g., encephalitis) and that most studies investigate the use of CEST in animal models, with a minority exploring the application of CEST to human participants. The common neuroinfectious disease presentations relevant to clinical medicine are also briefly described, as well as the traditional and modern imaging techniques used to visualize them. Full article

Meningitis is the acute or chronic inflammation of the protective membranes, surrounding the brain and spinal cord, and this inflammatory process spreads throughout the subarachnoid space. The traditional drug delivery methods pose a disadvantage in limiting the capacity of crossing the blood–brain barrier (BBB) to reach the central nervous system (CNS). Hence, it is imperative to develop novel approaches that can overcome these constraints and offer efficient therapy for meningitis. Nanoparticle (NP)-based therapeutic approaches have the potential to address the limitations such as penetrating the BBB and achieving targeted drug release in specific cells and tissues. This review highlights recent advancements in nanotechnology-based approaches, such as functionalized polymeric nanoparticles, solid lipid nanoparticles (SLNs), nanostructured lipid carriers, nanoemulsions, liposomes, transferosomes, and metallic NPs for the treatment of meningitis. Recently, bionics has emerged as a next-generation technology in the development of novel ideas from biological principles, structures, and interactions for neurological and neuroinfectious diseases. Despite their potential, more studies are needed to ensure the safety and efficacy of NP-based drug delivery systems focusing on critical aspects such as toxicity, immunogenicity, and pharmacokinetics. Therefore, this review addresses current treatment strategies and innovative nanoparticle approaches, and it discusses future directions for efficient and targeted meningitis therapies. Full article

Abstract: People living with HIV (PLWH) may present atypical neurological complications. Recently, autoimmune manifestations of the central nervous system (CNS) have been described. We retrospectively described the features of PLWH presenting with acute neurological symptoms with positive anti-CNS antibodies. We analyzed relevant CSF characteristics. Twelve patients were identified, with demyelinating, inflammatory, or no MRI lesions. We observed CSF inflammatory features. Aspecific CSF anti-CNS antibodies were found in all subjects and a specific antibody (second-level blotting panel) was found in one. The cases presented a slow resolution of symptoms with sequelae. More studies are needed to better describe the spectrum and prognosis of autoimmune CNS diseases in PLWH. Full article

Microglia, the resident macrophages of the central nervous system, exhibit altered gene expression in response to various neurological conditions. This study investigates the relationship between West Nile Virus infection and microglial senescence, focusing on the role of LGALS3BP, a protein implicated in both antiviral responses and aging. Using spatial transcriptomics, RNA sequencing and flow cytometry, we characterized changes in microglial gene signatures in adult and aged mice following recovery from WNV encephalitis. Additionally, we analyzed Lgals3bp expression and generated Lgals3bp-deficient mice to assess the impact on neuroinflammation and microglial phenotypes. Our results show that WNV-activated microglia share transcriptional signatures with aged microglia, including upregulation of genes involved in interferon response and inflammation. Lgals3bp was broadly expressed in the CNS and robustly upregulated during WNV infection and aging. Lgals3bp-deficient mice exhibited reduced neuroinflammation, increased homeostatic microglial numbers, and altered T cell populations without differences in virologic control or survival. These data indicate that LGALS3BP has a role in regulating neuroinflammation and microglial activation and suggest that targeting LGALS3BP might provide a potential route for mitigating neuroinflammation-related cognitive decline in aging and post-viral infections. Full article

On behalf of the SNS, we are pleased to present the Abstracts of the Annual Meeting which is held at the Congress Center in Basel, Switzerland, from 6–7 June 2024. In total, 83 abstracts were selected, whereof we include 8 abstracts for the Plenary Sessions, 6 abstracts for the SAYN GemSession, 30 abstracts for Poster flash presentations, and 39 abstracts as ePosters. We congratulate all the presenters on their research work and contributions. Full article

Neuroinfections rank among the top ten leading causes of child mortality globally, even in high-income countries. The crucial determinants for successful treatment lie in the timing and swiftness of diagnosis. Although viruses constitute the majority of infectious neuropathologies, diagnosing and treating viral neuroinfections remains challenging. Despite technological advancements, the etiology of the disease remains undetermined in over half of cases. The identification of the pathogen becomes more difficult when the infection is caused by atypical pathogens or multiple pathogens simultaneously. Furthermore, the modern surge in global passenger traffic has led to an increase in cases of infections caused by pathogens not endemic to local areas. This review aims to systematize and summarize information on neuroinvasive viral pathogens, encompassing their geographic distribution and transmission routes. Emphasis is placed on rare pathogens and cases involving atypical pathogens, aiming to offer a comprehensive and structured catalog of viral agents with neurovirulence potential. Full article

West Nile virus (WNV) neuroinvasive disease (WNND) occurs in approximately 1 percent of WNV-infected patients and typically presents as encephalitis, meningitis, or acute flaccid paralysis (AFP). WNND remains a difficult inpatient diagnosis, creating significant challenges for prognostication and therapy selection. We characterized the clinical and diagnostic features of WNND cases at two major academic medical centers in New York City in routine clinical practice. We retrospectively reviewed the charts of thirty-six patients with WNND, including twenty-six encephalitis, four meningitis, and six AFP cases. The most common presenting symptoms were fever (86.1%) and gastrointestinal symptoms (38.9%) in addition to altered mental status (72.2%), lethargy (63.9%), gait disturbances (46.2%), and headache (44.4%). Fourteen (48.3%) patients displayed acute magnetic resonance imaging (MRI) findings, particularly T2 hyperintensities in the bilateral thalami, brainstem, and deep white matter. New York State Department of Health WNV CSF IgM testing was utilized for diagnosis in 58.3% of patients; however, just 38.1% had the result by discharge, compared to 85.6% of those who underwent serum IgM testing. The median length of stay was 13.5 days, 38.9% were intubated, and three patients (8.9%) died during acute hospitalization. Our findings underscore the morbidity, mortality, and diagnostic challenges of WNND, suggesting the potential utility of serum IgM testing in combination with confirmatory CSF testing to expedite diagnosis in the acute setting. Full article

C-X-C-motif chemokine ligand 13 (CXCL13) in cerebrospinal fluid (CSF) is increasingly used in clinical routines, although its diagnostic specificity and divergent cut-off values have been defined so far mainly for neuroborreliosis. Our aim was to evaluate the value of CSF-CXCL13 as a diagnostic and treatment response marker and its role as an activity marker in a larger disease spectrum, including neuroborreliosis and other neuroinflammatory and malignant CNS-disorders. Patients who received a diagnostic lumbar puncture (LP) (n = 1234) between July 2009 and January 2023 were included in our retrospective cross-sectional study. The diagnostic performance of CSF-CXCL13 for acute neuroborreliosis was highest at a cut-off of 428.92 pg/mL (sensitivity: 92.1%; specificity: 96.5%). In addition, CXCL13 levels in CSF were significantly elevated in multiple sclerosis with clinical (p = 0.001) and radiographic disease activity (p < 0.001). The clinical utility of CSF-CXCL13 appears to be multifaceted. CSF-CXCL13 is significantly elevated in patients with neuroborreliosis and shows a rapid and sharp decline with antibiotic therapy, but it is not specific for this disease and is also highly elevated in less common subacute neuroinfectious diseases, such as neurosyphilis and cryptococcal meningitis or in primary/secondary B-cell lymphoma. Full article

The most recent and non-invasive approach for studying early-stage biomarkers is liquid biopsy. This implies the extraction and analysis of non-solid biological tissues (serum, plasma, saliva, urine, and cerebrospinal fluid) without undergoing invasive procedures to determine disease prognosis. Liquid biopsy can be used for the screening of several components, such as extracellular vesicles, microRNAs, cell-free DNA, cell-free mitochondrial and nuclear DNA, circulating tumour cells, circulating tumour DNA, transfer RNA, and circular DNA or RNA derived from body fluids. Its application includes early disease diagnosis, the surveillance of disease activity, and treatment response monitoring, with growing evidence for validating this methodology in cancer, liver disease, and central nervous system (CNS) disorders. This review will provide an overview of mentioned liquid biopsy components, which could serve as valuable biomarkers for the evaluation of complex neurological conditions, including Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, multiple sclerosis, epilepsy, stroke, traumatic brain injury, CNS tumours, and neuroinfectious diseases. Furthermore, this review highlights the future directions and potential limitations associated with liquid biopsy. Full article