The management of encephalitis: clinical practice guidelines by the Infectious Diseases Society of America

Integrating One Health research in Sarawak, Malaysia: Addressing emerging and re-emerging infectious disease through international collaboration

Comprising much of the northern side of the Island of Borneo, the Malaysian region of Sarawak is unique for its dense rainforests, diverse wildlife, and a human population that interacts closely with nature. One Health research in Sarawak, particularly that conducted by the Duke-SEGi-CRC Laboratory in the town of Sibu, has led to discoveries that are improving the health of Sarawakians. One Health research has resulted in the discovery of a novel canine-feline recombinant alphacoronavirus (genotype II), highlighting the potential for zoonotic transmission of respiratory viruses. Other One Health research has helped to determine the etiologies of human encephalitis and diarrheal illnesses, and specially improved the understanding of Japanese encephalitis (JE), Plasmodium knowlesi malaria, and melioidosis in Sarawak. This paper highlights the recent impact of international One Health collaborations in emerging and re-emerging infectious disease surveillance in this region. The collaborations have markedly improved local diagnostic capacity, identified previously unrecognized pathogens, and provided public health officials with a better understanding regarding the epidemiology of a number of infectious diseases.

Aseptic meningitis: a foundation review

PURPOSE OF REVIEW

This review addresses the multifaceted nature of aseptic meningitis, a condition with diverse infectious and noninfectious etiologies. Despite its common presentation in clinical settings, over half of the cases remain without an identified cause, necessitating a comprehensive examination of diagnostic and management strategies. The increasing availability of advanced molecular diagnostics and the challenge of distinguishing bacterial from nonbacterial cases make this an opportune time to explore its implications for clinical practice.

RECENT FINDINGS

The literature highlights the pivotal role of advanced molecular diagnostics, such as multiplex PCR and metagenomic sequencing, in improving the identification of pathogens in aseptic meningitis. Enteroviruses remain the leading cause, but pathogens like Herpesviridae, arboviruses, and nonviral agents such as fungi and spirochetes also contribute significantly. New diagnostic algorithms and clinical models are emerging to distinguish bacterial from viral meningitis, reducing unnecessary treatments.

SUMMARY

Aseptic meningitis management is evolving with advancements in diagnostic technologies that allow for earlier pathogen identification, improving patient outcomes and minimizing healthcare costs. These findings underscore the importance of timely and accurate diagnostics and tailored therapeutic strategies in both clinical and research settings. Enhanced awareness of noninfectious causes is also crucial for comprehensive care.

Infectious Encephalitis: A Persistent Clinical Challenge

Encephalitis is a serious neurologic condition that frequently results in long-term neurologic complications. Effective management in adults with suspected infectious encephalitis involves testing the cerebrospinal fluid for common pathogens, including herpes simplex virus-1, varicella-zoster virus, enteroviruses, and West Nile virus. Early initiation of high-dose intravenous acyclovir is recommended. Epidemiologic clues and immune status of the host should be considered when attempting to identify the cause of encephalitis. When no cause is identified, next-generation sequencing or a brain biopsy may be warranted. Further research should focus on developing new therapeutic options for this challenging clinical syndrome.

Clinical characteristics and treatment of varicella zoster virus central nervous system infection in an Australian tertiary hospital

BACKGROUND AND AIM

Varicella zoster virus (VZV) is a neurotropic herpesvirus. With improved access to molecular diagnostics, there is increasing recognition of VZV with central nervous system involvement. This study aimed to describe the demographic, clinical and treatment characteristics of patients admitted to an Australian tertiary hospital with VZV central nervous system infection.

METHODS

Retrospective study of all adult patients (aged ≥18 years) presenting to an Australian tertiary hospital between November 2010 and May 2023 with a clinical syndrome of or imaging consistent with meningitis or encephalitis and detectable VZV DNA in cerebrospinal fluid using polymerase chain reaction.

RESULTS

There were 48 cases of VZV meningitis and 13 cases of VZV encephalitis identified during the study period. The median age of patients with VZV meningitis and encephalitis was 34 years (range 21-86 years) and 73 years (range 22-94 years) respectively. All patients with VZV encephalitis and 37 of 48 (77.1%) with meningitis received intravenous (IV) acyclovir. Eight patients with VZV meningitis were treated with oral antivirals alone and seven were managed without antivirals or with ≤48 h of empiric antiviral therapy only; none of these patients experienced an adverse clinical outcome. Two patients with VZV encephalitis died. Seven patients experienced neurological complications, three with VZV meningitis and four with VZV encephalitis. Age and length of stay were associated with adverse clinical outcomes.

CONCLUSION

VZV encephalitis predominates in older patients while VZV meningitis predominates in younger patients. IV acyclovir remains the standard of care for treatment of VZV encephalitis; however, its role in VZV meningitis is less clear. Controlled trials should be conducted to inform its use, particularly in low-risk patients with VZV meningitis.

Tiny needles, major benefits: acupuncture in child health

OBJECTIVE

To retrospectively investigate the utilization patterns and clinical indications of acupuncture within the pediatric population in general hospitals from 2015 to 2020, including disease spectrum characteristics and relevance to pediatric subspecialties.

METHODS

The clinical data of pediatric inpatients consulted by Acupuncture-Moxibustion and Tuina Department of Qilu Hospital of Shandong University was collected from January 1, 2015, to December 31, 2020. The data collected include the number of wards in which consultation was requested, the diseases that require consultation, the distribution of pediatric tertiary disciplines and the system of disease affiliation.

RESULTS

This study summarizes 55 types of pediatric diseases treated with acupuncture. The most common health issues addressed include peripheral facial paralysis, diarrhea, reduced limb mobility or decreased muscle strength, postoperative bloating, and Guillain-Barré syndrome. Acupuncture is utilized across all pediatric subdisciplines, with notable applications in neurology, critical care medicine, general surgery, respiratory medicine, and orthopedics. The classification of diseases for acupuncture consultations primarily focuses on disorders of the nervous system, respiratory system, neoplasms, and digestive system (according to ICD-11).

CONCLUSIONS

In summary, acupuncture has a broad range of applications in the treatment of pediatric diseases and can serve as a valuable complementary and alternative therapy. The advancement of Traditional Chinese Medicine (TCM) acupuncture in general hospitals is closely linked to the involvement of pediatric practices. The findings of this study provide valuable insights for clinical practice, acupuncture education, pediatric healthcare systems, and social research.

Encephalitis: intersections between infections and autoimmunity

BACKGROUND

Encephalitis is a serious condition accompanied by substantial morbidity. Although infections have long been recognized as causes, there has been growing appreciation of autoimmune aetiologies of encephalitis, most notably those associated with anti-neuronal antibodies.

OBJECTIVES

This narrative review focuses on points of commonality among clinical features, pathophysiology, and management of infectious and autoimmune encephalitis, while also noting important distinctions.

SOURCES

I identified studies, comprising research articles and reviews, that provide data on the epidemiology of infectious versus autoimmune encephalitis, and on clinical features that either co-occur or distinguish between them. In addition, I reviewed management practices, preclinical data, and clinical trials on the treatment of infectious and autoimmune encephalitis.

CONTENT

I first discuss the clinical overlap between infectious and autoimmune causes of encephalitis, highlighting features and syndromes that can confound the diagnosis. I next turn to the pathogenic overlap between the two, exemplified by the development of autoimmune encephalitis with antibodies against the N-methyl-D-aspartate receptor following a bout of herpes simplex encephalitis. Finally, I discuss management of infectious and autoimmune encephalitis, focusing on current and future avenues of treatment.

IMPLICATIONS

Although our understanding of causes of infectious and autoimmune encephalitis has improved considerably over the past decade, diagnosis remains challenging given the clinical and pathophysiological overlap between the two. Large multicentre clinical trials are needed to evaluate treatments that target inflammation and potentially benefit both.

Why I Discourage "ED Course" in Oral Patient Presentations

Trainees frequently present data, including vital signs, laboratory test results, and imaging results, just after the history or presenting illness in a section labeled "ED Course." This practice distracts from the history and physical and decenters the patient as the most valuable source of diagnostic data. Reformatting presentations to appropriately present objective data after the complete history may improve diagnosis and refocuses attention on the patient.

Diagnosing infectious encephalitis: a narrative review

BACKGROUND

Diagnosing infectious encephalitis can be challenging as it can be caused by a wide range of pathogens, with viruses being the most common cause. In a substantial number of patients, no pathogen is identified despite a clinical diagnosis of infectious encephalitis. Recent advancements in diagnostic testing have introduced new methods to address this diagnostic challenge and improve pathogen detection.

OBJECTIVES

The objective of this study is to provide a comprehensive clinical approach for diagnosing infectious encephalitis and explore novel diagnostic methods.

SOURCES

We searched PubMed to identify relevant literature on diagnosing encephalitis in English up to 1 September 2024, as well as included articles known by the authors.

CONTENT

Clinical characteristics may suggest a specific cause of infectious encephalitis, but are insufficient to guide treatment decisions. Therefore, cerebrospinal fluid (CSF) examination remains the cornerstone of the diagnostic process, with CSF leucocyte count being the most reliable predictor for central nervous system infections. CSF features can be normal, however, in a proportion of patients presenting with infectious encephalitis. A definite diagnosis of infectious encephalitis is established by microbiological or histopathological tests in ∼50% of patients. Additional investigations, including neuroimaging or electroencephalography, can provide evidence for encephalitis or help to identify alternate conditions, although their role is primarily supportive. Emerging diagnostic techniques, including next-generation sequencing metagenomics and unbiased serology (Phage ImmunoPrecipitation Sequencing), have the potential to increase the proportion of patients with a confirmed diagnosis. However, these techniques are not yet practical because of their complex analysis, long turnaround times and high costs.

IMPLICATIONS

Microbiological confirmation is paramount in the diagnosis of infectious encephalitis, but it is currently established in about half of cases. Although novel techniques show promise to increase the proportion of cause-specific diagnoses, they are not yet suitable for routine use. This highlights the ongoing need for advancements in diagnostic methods.

Clinical and cost implications of Biofire FilmArray® meningitis / encephalitis panel testing: a systematic review

BACKGROUND

Meningitis and encephalitis are diseases with high case fatality rates and serious long-term sequalae. A significant percentage do not receive an aetiological diagnosis, in part due to limitations of conventional testing methods. The Biofire FilmArray® Meningitis / Encephalitis Panel (MEP) is the first commercially approved multiplex PCR panel for diagnosis of infectious meningoencephalitis. It provides rapid results and has the potential to reduce empiric antimicrobial use and length of hospitalisation when compared to conventional testing.

METHODS

We conducted a systematic review to evaluate the impact of MEP implementation by searching the Medline and Embase databases. The outcomes of interest were duration of acyclovir treatment, duration of antimicrobials, length of stay and healthcare cost.

RESULTS

A total of 23 studies satisfied the inclusion criteria, the majority of which were retrospective studies comparing cohorts before and after MEP implementation. The included studies were very heterogenous, with variation in MEP implementation strategies, standard of care diagnostics and study populations. MEP testing resulted in reduction in acyclovir use in 75 % of studies with an average reduction of 39 h (range 11-144 h). Antimicrobial use and length of stay was reduced in 44 % and 40 % of studies respectively. Five studies looked at healthcare costs, variably described between studies as hospitalisation, antimicrobial and microbiology costs. Total hospitalisation cost was reduced in 1 study and unchanged in 2 studies.

CONCLUSION

Whilst MEP implementation reduces acyclovir usage in patients evaluated for ME, the benefits in terms of antibiotic use, and length of stay are variable and likely depend on the study population, implementation strategy and standard of care testing available in each institution.

Unveiling the clinical spectrum of herpes simplex virus CNS infections in adults: a systematic review

BACKGROUND

Herpes simplex virus (HSV) infections of the central nervous system (CNS) are associated with high morbidity and mortality. Prompt recognition and antiviral treatment are critical to improve patient outcomes. This systematic review of the literature aimed to aggregate the symptoms described with HSV infections of the CNS which may provide a framework to aid in early diagnosis.

METHODS

This review was registered (PROSPERO; CRD42022366036) and adheres to PRISMA guidelines. MEDLINE, Embase, and Cochrane databases were systematically screened for studies including adult patients with HSV infections confirmed by histopathology or polymerase chain reaction. Demographics, clinical characteristics, diagnostics, and outcomes were assessed.

RESULTS

Of 21 studies from 18 countries describing 1605 patients, the most frequently reported symptoms were fever (75%), headache (65%), neck stiffness (55%), and language/speech abnormalities (41%). Other common symptoms included seizures (36%) and gastrointestinal issues (35%). Information regarding a combination of symptoms was not provided. Diagnostics often included lumbar puncture and magnetic resonance imaging, revealing temporal lobe abnormalities in 88%. While mortality was 13%, 72% of survivors had good neurological outcomes. The risk of bias was high in most studies.

CONCLUSIONS

Fever, headache, neck stiffness, and language/speech abnormalities were frequently reported clinical findings in patients with proven HSV infection of the CNS. Despite limited evidence, these symptoms warrant a high index of suspicion, prompting early empiric antiviral therapy, especially when alternative diagnoses lack strong support. The predictive value of these symptoms and their combination for diagnosing HSV infection of the CNS should be further investigated, as they could accelerate diagnostics and treatment.

Are Glucocorticoids Truly Effective in Improving the Clinical Prognosis of HSV-1 Encephalitis?

Background

Survivors of herpes simplex encephalitis (HSE) commonly experience significant neurological sequelae, imposing a substantial burden on both society and families. The efficacy of glucocorticoids in treating patients with HSE remains controversial. This study aims to evaluate the effectiveness of glucocorticoids in patients with HSE and analyze the clinical characteristics of this patient population.

Methods

This retrospective study evaluated the clinical characteristics, auxiliary examinations, and patient prognosis of HSE patients diagnosed with mNGS, and analyzed the prognosis of patients in both Glucocorticoid and Non-glucocorticoid groups. Assess the prognosis based on the improvement of GOS score and MMSE score at 1 and 3 months after discharge.

Results

A retrospective analysis was conducted in 29 hSE patients who met the criteria for GOS score improvement 3 months after discharge. The hormone group was better than the non-hormone group (2 (0-2) scores VS 1 (1-2) scores). There was no significant difference between the two groups in GOS score 1 month after discharge. However, no statistical difference was found in improving patient outcomes between the two groups.

Conclusion

Despite the hormone group not obtaining the anticipated positive outcomes, potentially due to the relatively limited sample size in this study, previous case series reports have indicated that glucocorticoids, when used as an adjunct to acyclovir therapy, may enhance patient outcomes. Consequently, further extensive clinical studies involving multiple centers and larger sample sizes are warranted to investigate this matter further.

Central Nervous System Infections in Recipients of Solid Organ Transplant

BACKGROUND

Central nervous system (CNS) infections are severe and life-threatening complications that can occur in solid organ transplant (SOT) recipients. We describe the epidemiology, clinical presentation, diagnosis, disease course, and outcome of CNS infections in SOT.

METHODS

We analyzed data of patients who underwent transplantation from September 2012 to February 2023, diagnosed and treated for CNS infections at our institution in Houston, TX. Data were retrospectively collected from medical charts.

RESULTS

Of 1,345 patients who received a SOT, 30 (2.23%) were diagnosed with CNS infection, with a median age of 63 years, 60% were male. Time to CNS infection onset after transplant in 53.3% of the cases was after the first year. There were 15/30 (50%) cases of fungal infection, 8/30(26.7%) of viral infection, 7/30 (23.3%) of bacterial infection. There were no unknown causes. The most common etiologies were Cryptococcus neoformans 14/30(46.6%), and nocardiosis 3/30 (10%). On presentation, 22 (73.4%) patients had normal mental status, but 21 (70%) reported headaches, and 18 (60%) were febrile. Abnormal neuroimaging was found in 5 cases (16.6%) on computed tomography (CT)-scans and 10 cases (33.3%) on magnetic resonance imaging (MRI) scans. An adverse clinical outcome on discharge was noticed in 33%, and 6.7% died. Fever was associated with an increased risk of adverse clinical outcomes (OR 11; P = .018).

CONCLUSION

The incidence of CNS infections in SOT recipients is low but associated with substantial adverse clinical outcomes. The most common causes are fungal, with no unknown etiologies seen in this study.

Plasma-Derived Neuronal Exosomal CircRNAs as Potential Biomarkers for Central Nervous System Infections

Infections of central nervous system (ICNSs) are inflammatory diseases caused by infectious agents that can infiltrate the brain and spinal cord through various routes, including the bloodstream, peripheral nerves, or cranial nerves. Exosomes are found in plasma and have the capacity to cross the blood-brain barrier (BBB). Exosome constituents, including lipids, proteins, DNA, and RNA, change significantly over time and are correlated with the course of disease. Circular RNA (circRNA) has become a potential biomarker for various diseases, such as ICNSs. This study explores the diagnostic potential of circRNAs derived from brain-derived exosomes in ICNSs. Our research shows that the brain-derived exosomes from patients with CNS illnesses have different patterns of circRNA expression than those from healthy controls. Plasma samples from patients with bacterial ICNSs show significantly elevated levels of hsa_circ__0020840 and hsa_circ_0116108. In contrast, higher expression levels of hsa_circ_0056947 and hsa_circ_0021531 are observed in plasma samples from individuals with viral ICNSs compared to healthy subjects. These observations suggest their potential utility as sensitive and specific biomarkers for these diseases. Moreover, the capacity of circRNAs to be encapsulated within exosomes and released into circulation offers a noninvasive approach for diagnosing ICNSs. These findings highlight the promise of utilizing brain-derived exosomal circRNAs as novel diagnostic markers for ICNSs, which may have implications for improving patient outcomes and disease management.

Abnormal CSF-Specific OCBs in Neuronal Surface Antibody-Associated Autoimmune Encephalitis Differentiating from Viral Encephalitis

Purpose

The present study aimed to examine the clinical distinctions among patients with neuronal surface antibody-associated autoimmune encephalitis (NSAE) diagnosed with anti-N-methyl-D-aspartate receptor encephalitis (NMDAR-E), anti-leucine-rich glioma-inactivated 1 encephalitis (LGI1-E), and anti-gamma aminobutyric acid-B receptor encephalitis (GABABR-E), compared with those with viral encephalitis (VE). Additionally, the study aimed to assess the impact of cerebrospinal fluid (CSF) oligoclonal bands (OCBs) on the severity and prognosis of NSAE.

Patients and Methods

This retrospective analysis included patients with NSAE, encompassing NMDAR-E, LGI1-E, and GABABR-E, alongside individuals with VE. Participants with NSAE were categorized into two groups based on the presence or absence of CSF-specific OCBs. Data regarding demographics, clinical manifestations, magnetic resonance imaging (MRI) findings, CSF analyses and prognosis were collected and analyzed.

Results

The findings indicated that younger female with NSAE exhibited a higher incidence of seizure onset, disruption of the blood-CSF barrier (BCSFB), and elevated QAlb/QLim ratios compared to VE patients, with NSAE patients demonstrating more severe clinical outcomes at discharge. Among the 185 NSAE patients, 43 (23.24%) were positive for OCBs, while 142 (76.76%) negative. The OCB-positive cohort displayed a greater prevalence of younger females and NMDAR-E (both P<0.05). No significant differences were observed in CSF white blood cell counts, protein concentrations, or immunoglobulin G levels between the two groups (all P>0.05). The modified Rankin Scale (mRS) scores at discharge and the final follow-up were higher in the OCB-positive group than the OCB-negative group (both P<0.05). Both univariate and multivariate analyses identified OCBs and NSAE subtypes as independent risk factors influencing the clinical prognosis of NSAE.

Conclusion

In comparison to VE patients, NSAE patients with positive OCBs were more frequently female and exhibited CSF pleocytosis, particularly among those with NMDAR-E. Importantly, the presence of positive OCBs emerged as an independent predictor of unfavorable outcomes in patients with NMDAR-E, LGI1-E, and GABABR-E.

Ictal vomiting as an unusual presentation of herpes simplex encephalitis - Pathophysiological and therapeutic perspectives

Introduction

Herpes Simplex Encephalitis (HSE) is a formidable neurological infection that is often challenging to diagnose owing to its diverse clinical manifestations. This case report details the clinical odyssey of a sixty-year-old female with diabetes, hypothyroidism, and hypertension, who presented with fever, vomiting, and evolving neurological symptoms.

Case Presentation

The patient's initial admission failed to yield a diagnosis, and her condition worsened, marked by behavioral changes, cognitive decline, and focal seizures. Neuroimaging revealed characteristic findings, confirming non-hemorrhagic herpetic encephalitis. Despite antiviral and antiepileptic therapy, persistent vomiting prompted further investigations, uncovering infrequent right temporal sharp waves on EEG, leading to a diagnosis of "ictus emiticus."

Conclusion

This case of Herpes Simplex Encephalitis (HSE) underscores the diverse clinical spectrum and challenges in management. The patient's atypical presentation underscores the importance of considering HSE in patients with fever and unexplained persistent vomiting for early diagnosis and better prognosis.Diagnostic tools (neuroimaging, cerebrospinal fluid analysis, and electroencephalography) confirmed HSE involvement in the right temporal lobe, emphasizing the strong association between HSV encephalitis and seizures, which can be explained by various mechanisms.Timely antiviral therapy and tailored antiepileptic strategies led to gradual clinical improvement, showcasing the potential of valproate beyond antiepileptic use.This case prompts further exploration into HSE's pathophysiology and treatment. It emphasizes individualized patient care and vigilance for potential post-resolution sequelae, contributing to our evolving understanding of HSE.

Neuroborreliosis with encephalitis: a broad spectrum of clinical manifestations

BACKGROUND

Lyme neuroborreliosis is the disseminated stage of an infectious disease caused by Borrelia burgdorferi (BB). The most prevalent clinical manifestations include meningoradiculitis and involvement of the cranial nerves with lymphocytic meningitis. Facial nerve is the most frequently affected cranial nerve. Neuroborreliosis presenting as encephalitis is only scarcely described in the literature.

METHODS

Medical records of patients between 2014 and 2024 were screened and reviewed for neuroborreliosis. Patients were only included if they met the diagnostic criteria for definite neuroborreliosis.

RESULTS

A total of seven patients with neuroborreliosis induced encephalitis were identified. The median age was 72 years, and except for one man, all patients were women. Clinical manifestations ranged from cognitive impairments resembling primary dementia to movement disorders mimicking Parkinson's disease, tremor, and epileptic seizures. In 5/7 patients (71%) they occurred between August to September. In addition to central nervous system involvement, all patients exhibited characteristic features of neuroborreliosis like painful meningoradiculitis or peripheral facial palsy. An elevated cell count in cerebrospinal fluid (CSF), positive oligoclonal bands, and blood-CSF barrier dysfunction indicated by an elevated albumin quotient (QAlb) was found in all patients. Advanced age, in which immunosenescence can occur, might contribute in developing encephalitis caused by neuroborreliosis in the patients of this cohort.

CONCLUSION

Neuroborreliosis can present with symptoms that mimic various neurological disorders, such as dementia, movement disorders, and epilepsy. Radiculitis, peripheral facial palsy or meningitis are an additional hint for this infectious disease. Analysis of CSF, which includes testing for intrathecally produced BB antibodies, is crucial for the diagnosis.

Varicella-zoster virus meningitis with hypoglycorrhachia, presenting with painless occipital herpes zoster mimicking atopic dermatitis

Varicella-zoster virus (VZV) is a known cause of meningoencephalitis, typically in immunocompromised inpatients. We report a case of meningitis caused by VZV in an immunocompetent man in his 20s. Diagnosis was delayed due to the atypical presentation of painless occipital zoster mimicking atopic dermatitis, and the presence of hypoglycorrhachia in his cerebrospinal fluid. The clinical diagnosis of VZV meningitis poses significant diagnostic challenges, and nucleic acid tests for VZV detection are recommended for patients with severe cases who require empiric acyclovir treatment.

Presentation, Management, and Outcome of Tick-Borne Encephalitis in Patients Referred to Infectious Diseases or Neurology

Background: In Slovenia, patients with suspected tick-borne encephalitis (TBE) were historically referred to infectious diseases (ID), but during the COVID-19 pandemic, there were increased referrals to neurology. This study compared the clinical management of TBE patients between ID specialists and neurologists and assessed patients' outcomes. Methods: We retrospectively reviewed the clinical, laboratory, and imaging data of 318 adult patients with TBE managed by ID (n = 256; 80.5%) and neurology (n = 62; 19.5%) at a tertiary centre in Slovenia between March 2020 and September 2022 to explore variations in diagnostic and therapeutic approaches by specialty and to assess the severity and outcome of acute illness. Results: Patients referred to ID or neurology did not differ regarding their basic demographic and epidemiologic characteristics or basic laboratory parameters. However, patients referred to neurology more often presented with severe illness, including impaired consciousness and/or focal neurological signs (72.6% vs. 55.5%; p < 0.001). ID specialists used head imaging before lumbar puncture (6.6% vs. 64.5%; p < 0.001), performed microbiological tests other than for TBE (16.0% vs. 51.6%; p < 0.001), and empirically prescribed antimicrobials less often than neurology (5.1% vs. 22.6%; p < 0.001). When adjusting for age, sex, comorbidities, vaccination status, and the severity of acute illness, clinical outcomes were similar between the two groups of patients, but those with more severe acute illness had higher odds for incomplete recovery. Conclusions: Differences in clinical presentation between ID and neurology referrals could only partially explain the narrower diagnostic and therapeutic approach used by ID, which, given the study design, was not associated with adverse outcomes. Additionally, in patients with clinical characteristics suggestive of TBE in endemic areas, tremor in the absence of other focal neurological signs or impaired consciousness may not necessitate head imaging before lumbar puncture. Future prospective studies could help to optimise the management of this clinical syndrome.

The Role of Corticosteroids in Non-Bacterial and Secondary Encephalitis

Encephalitis affects 1.9 to 14.3 people per 100,000 each year, and the mortality rate varies but can be up to 40%. After the identification of a particular microorganism in a patient with encephalitis, appropriate antimicrobial therapy should be initiated. Corticosteroid therapy represents a therapeutic option in the treatment of primary central nervous system diseases due to its ability to reduce the inflammatory commitment of CNS and consequently reduce mortality rates regardless of the causative agent of injury. Corticosteroid therapy represents a therapeutic option in the treatment of primary central nervous system diseases. Their use is also recommended in meningitis with autoimmune etiology. While corticosteroids have repeatedly been used as adjunctive treatment in encephalitis of viral etiology, the scientific evidence supporting their effectiveness remains scarce. The use of standard doses recommended by the guidelines seems reasonable as an initial setting, especially when a definitive diagnosis of the causal agent is still awaited. The subsequent adjustment should be personalized based on the individual clinical response.

The diagnostic and prognostic value of heparin-binding protein in cerebrospinal fluid for patients with intracranial infections

BACKGROUND

This study aims to evaluate the diagnostic and prognostic value of heparin-binding protein (HBP) in cerebrospinal fluid (CSF) for patients with intracranial infections.

METHODS

This study included 211 subjects, of whom 138 were diagnosed with intracranial infections, 20 were patients with non-infectious inflammatory encephalopathies, and 53 controls who were eventually excluded from intracranial infections and inflammatory encephalopathies. The levels of HBP and procalcitonin (PCT) in CSF were detected in the subjects, and the diagnostic value of CSF HBP and PCT for intracranial infections was assessed using the receiver operating characteristic (ROC) curves. In addition, CSF HBP levels in patients with intracranial infections were dynamically monitored on days 1, 5, and 9 post-treatment.

RESULTS

The levels of HBP in CSF were significantly higher in the infection group compared to both the non-infectious inflammatory encephalopathy group and the control group. The area under the ROC curve (AUC) for CSF HBP in diagnosing intracranial infection was 0.916 (95% CI 0.870-0.950), which was significantly higher than that of CSF PCT (AUC: 0.543, 95% CI 0.474-0.612). Furthermore, the combination of CSF HBP and white blood cell (WBC) counts exhibited a significantly higher AUC of 0.957 (95% CI 0.920-0.980) compared to HBP alone (P<0.05). The AUC for the combination of CSF HBP and PCT was 0.920 (95% CI 0.875-0.953). In addition, elevated concentrations of CSF HBP were observed in patients with bacterial infections and positive microbiological results (P<0.05). Following treatment, CSF HBP levels in patients with intracranial infections showed a significant decrease from day 1 to day 9.

CONCLUSIONS

The level of HBP in CSF serves as a reliable diagnostic marker for identifying intracranial infections, particularly aiding in the identification of bacterial infections. In addition, they can be used as a valuable tool for monitoring the severity and prognosis of intracranial infection.

In Children, N-Methyl-D-Aspartate Receptor Antibody Encephalitis Incidence Exceeds That of Japanese Encephalitis in Vietnam

Background

The recognition of autoimmune causes of encephalitis has led to epidemiological shifts in the worldwide characteristics of encephalitis. N-methyl-D-aspartate receptor (NMDAR) antibody encephalitis leads to well-established complex neuropsychiatric manifestations. In low- and middle-income countries, including Vietnam, its relative incidence, especially in children, is unknown and most neurologists currently consider infectious encephalitis prior to autoimmune etiologies.

Methods

The study was prospectively conducted at Children's Hospital 1 in Ho Chi Minh City between March 2020 and December 2022. Any child admitted to the Department of Infectious Diseases and Neurology fulfilling the case definition of encephalitis was eligible to participate. Cerebrospinal fluid samples were collected alongside meta-clinical data for analysis.

Results

We recruited 164 children with a clinical diagnosis of encephalitis. Etiologies were determined as NMDAR antibody encephalitis in 23 of 164 cases (14.0%), Japanese encephalitis virus in 14 of 164 (8.5%), and herpes simplex virus in 4 of 164 (2.4%). Clinical categorizations suggested idiopathic viral encephalitis in another 71 (43.3%), and autoimmune encephalitis of unknown origin in the remaining 52. Factors including demographics, specific clinical features, cerebrospinal fluid and electroencephalogram findings, and length of hospital stay were significantly different between NMDAR antibody encephalitis and Japanese encephalitis.

Conclusions

At a tertiary children's hospital in Vietnam, the prevalence of NMDAR antibody encephalitis exceeds that of Japanese encephalitis, the most common infectious encephalitis cause in Southeast Asia. NMDAR antibody encephalitis is associated with long hospital stay and poor outcomes. These findings should change pediatric diagnostics, to earlier consider autoimmune treatments in this clinical setting.

Navigating herpes simplex encephalitis: Family medicine perspectives from Jharkhand, India

Background

Herpes simplex encephalitis (HSE), caused by herpes simplex virus (HSV) is the most common cause of sporadic encephalitis that often presents as an emergency case of acute or sub-acute nature associated with poor prognosis. Early suspicion and prompt diagnostic testing with adequate antiviral therapy can only reduce morbidity and mortality associated with the disease. This study aims to evaluate the role of serological and molecular diagnosis of encephalitis caused by HSV 1 and 2 for timely detection of the disease.

Methods

This cross-sectional study was conducted at the Department of Microbiology, Rajendra Institute of Medical Science, Ranchi, from April 2021 to September 2022. Cerebrospinal fluid (CSF) samples were collected and processed for the detection of HSV DNA by polymerase chain reaction (PCR) as well as serum samples were collected from those patients and were processed for the detection of IgM by ELISA.

Results

A total of 188 CSF samples were collected, out of which 4 HSV-1 and 1 HSV-2 samples were found to be positive by conventional PCR. 36 samples were positive for HSV-1 and 2 IgM ELISA. 26.06% of cases belonged to patients between 0 and 10 years of age followed by 17.06% in 51-60 years age groups.

Conclusion

PCR is the optimal diagnostic test, but the sample must be collected in the early stages of the disease. Diagnosis by PCR assay of CSF samples targeting HSV DNA is the best confirmatory test at hand for early detection and also helps in estimating the incidence of herpes simplex virus encephalitis.

Ramsay Hunt Syndrome With Multiple Cranial Neuropathies, Meningitis, and Subsequent Brainstem Encephalitis: A Case Report

We present a case of Ramsay Hunt syndrome in a previously healthy 49-year-old male, complicated by ipsilateral glossopharyngeal, vagus, accessory, and hypoglossal nerve palsies, along with meningitis. Despite a course of antiviral therapy and steroids for meningitis, the patient experienced a relapse, developing varicella-zoster virus (VZV) brainstem encephalitis after an initial period of stability. Hunt syndrome can be encountered in otolaryngology and internal medicine, dermatology, and other specialties. We report a case of Ramsay Hunt syndrome complicated by multiple cranial neuropathies and Hunt syndrome-associated meningitis and encephalitis, accompanied by a literature review.

A Case of Varicella Zoster Virus Encephalitis with Advanced Human Immunodeficiency Virus Disease Diagnosed by Brain Biopsy

A 40-year-old Japanese man with human immunodeficiency virus presented with disturbance of consciousness 2 years after dropping out. He was emaciated without any zoster skin lesions, and his CD4+ lymphocyte count was 4 cells/μL. Disseminated Mycobacterium avium infection and pneumocystis pneumonia were diagnosed, and a brain biopsy revealed varicella zoster virus (VZV) encephalitis with multiple real-time polymerase chain reaction tests and immunochemistry. Antiretroviral therapy and intravenous acyclovir were administered, and the patient survived with neurological sequelae. VZV encephalitis is rare, particularly among people with AIDS, but it is a significant disease with a poor prognosis.

Neurological Manifestation Associated with Chikungunya Infection in a Pediatric Patient from Itacoatiara, Brazilian Amazon: A Case Report

A 9-year-old male with autism and a history of well-controlled epilepsy presented with acute headache, fever, and generalized tonic-clonic seizures. Initial diagnostics, including imaging and cerebrospinal fluid analysis, were inconclusive. However, further serological testing suggested the presence of the chikungunya virus, establishing a diagnosis of chikungunya-associated neurological manifestation. The patient was treated with anticonvulsants, antibiotics for secondary bacterial pneumonia, and supportive care, leading to a gradual recovery. This case highlights the importance of considering systemic viral infections in pediatric patients with neurological symptoms and underscores the potential for arboviruses like chikungunya to cause neurological manifestation.

SIV-specific antibodies protect against inflammasome-driven encephalitis in untreated macaques

Viral encephalitis is a growing public health threat with limited diagnostic and treatment options. Simian immunodeficiency virus (SIV)-infected macaques are an established model for human immunodeficiency virus (HIV), and approximately 60% of untreated pigtail macaques rapidly progress to characteristic SIV encephalitis (SIVE). The immune responses of SIV-infected macaques are investigated in plasma, cerebrospinal fluid (CSF), and brain tissue to determine correlates with SIVE pathology. Macaques with SIVE show myeloid-dominant brain lesions with inflammasome activation in infected and bystander cells, as assessed by interleukin (IL)-1β, IL-18, and apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC), and elevations in monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, and tumor necrosis factor alpha (TNF-α). SIV-specific immunoglobulin (Ig)G in plasma and CSF is predictive of SIVE as early as 21 days post-inoculation; animals with SIVE continue to show negligible seroconversion 3 months after infection. This dichotomy in immune responses, wherein some macaques fail to initiate robust IgG responses and subsequently develop SIVE, provides insight into the pathogenesis and heterogeneous outcomes in viral encephalitis.

Etiology, Clinical Profiles, and Outcomes of Acute Encephalitis Syndrome Cases Admitted to a Tertiary Care Center in Myanmar in 2023

BACKGROUND/OBJECTIVES

The diagnosis of encephalitis is a challenging problem due to the heterogeneity of clinical presentations. The objective was to determine the etiology, clinical features, laboratory parameters, radiological findings, and in-hospital outcome of acute encephalitis syndrome (AES) cases in Myanmar.

METHODS

A prospective descriptive study was conducted at the Neuromedical Ward of Yangon General Hospital from March to August 2023. Eighty-one AES cases were enrolled, and cerebrospinal fluid (CSF) samples were collected. A Qiastat ME Panel was used to detect viral, bacterial, and fungal pathogens.

RESULTS

Seventeen out of eighty-one (21%) cases were non-encephalitis with alternative definite diagnosis. Among the remaining 64 encephalitis cases, the exact infectious and immune etiologies were identified in 31 of 64 cases (48.4%); 26 of these (83.9%) were due to infectious causes and 5 (16.1%) were immune encephalitis. Among the infectious causes, six Herpes Simplex Virus-1-, one bacteriologically confirmed and seven probable Mycobacterium tuberculosis-, three Haemophilus influenzae-, two Streptococcus pneumoniae-, one Streptococcus pyogenes-, one Varicella-Zoster Virus (Ramsay Hunt Syndrome with meningoencephalitis)-, and two Cryptococcus neoformans-infected patients and rare causes such as Listeria monocytogenes, Burkholdelria cepacia, Sphingomonas paucimobilis, and Aspergillus were identified. One case was a dual infection with Haemophilus influenzae and Cryptococcus neformans. Abnormal protein levels and CSF pleocytosis were significantly higher among bacterial causes (p < 0.05). In total, 6.45% (2/31) of encephalitis patients with identified causes and 12.12% (4/33) of those without an identified organism had poor outcome.

CONCLUSIONS

Herpes encephalitis and tuberculous meningoencepalitis were the commonest. This study highlighted that molecular testing with a multidisciplinary approach is required to ensure the right treatment on time.

A systematic review of case reports on mortality, modes of infection, diagnostic tests, and treatments for Nipah virus infection

BACKGROUND

First identified in Malaysia in 1998, the Nipah virus is a paramyxovirus related to the Hendra virus. The clinical manifestation can vary from a silent infection to a life-threatening encephalitis. The World Health Organization (WHO) has documented 25 outbreaks in South Asia, resulting in 429 cases and 307 deaths to date. Currently, there are no approved treatments for the deadly Nipah virus infection, which is a serious threat to public health worldwide. Consequently, a review was conducted to examine the geographic distribution of the Nipah virus, mortality, transmission pathways, and available methods for diagnosis and treatment.

METHODS

PubMed, Scopus, Web of Science, and Google Scholar servers were used to conduct a systematic search in compliance with the PRISMA guidelines. The results were tabulated and analyzed.

RESULTS

A total of 12 studies (7 case series and 5 case reports) were included in the final analysis, and 92 cases were analyzed. The most frequent symptoms were fever (80%), myalgia (47%), headache (47%), shortness of breath/acute respiratory distress syndrome (n = 44.1%), altered sensorium (44.1%), and vomiting (42.6%). The most commonly used diagnostic test was RT-PCR (45.5%). The most common route of transmission reported is direct human contact with the infected patients. Treatment modalities include interventional procedures, antiviral drugs, and symptomatic treatment. The most common complications were seizures (39.2%) and altered sensorium (35.7%). The mortality rate was 73.9%.

CONCLUSION

It is crucial to emphasize the importance of early Nipah virus infection diagnosis and treatment to prevent life-threatening consequences.

Acyclovir treatment of varicella-zoster virus meningeal infections and acute kidney injury: a multicentre case series study

BACKGROUND

Systematic treatment with intravenous acyclovir is usually given when varicella zoster virus (VZV) DNA is isolated in cerebrospinal fluid (CSF), indicating central nervous system (CNS) involvement. Our study aimed to describe therapeutic management and acute kidney injury (AKI) occurrence during acyclovir treatment of VZV infection with CNS involvement.

METHODS

Multicentre, retrospective study including all patients from 2010 to 2022 with VZV DNA in CSF. Patient management and outcomes were compared according to clinical presentation and indications for intravenous acyclovir: i) definite (encephalitis, myelitis or stroke, peripheral nervous system (PNS) with ≥ 2 roots, herpes zoster ≥ 3 dermatomes, immunosuppression), ii) questionable (1 or 2 dermatomes) or iii) no indication (other situations).

RESULTS

154 patients were included (median age 66 (interquartile range 43-77), 87 (56%) males); 60 (39%) had encephalitis, myelitis or stroke, 35 (23%) had PNS involvement, 37 (24%) had isolated meningitis, 14 (9%) had isolated cutaneous presentation, and 8 (5%) had other presentations. Overall, 128 (83%) received intravenous acyclovir for more than 72 h. AKI occurred in 57 (37%) patients. Finally, 42 (27%) and 25 (16%) patients had respectively no or a questionable indication for intravenous acyclovir, while 29 (69%) and 23 (92%) of them received it for more than 72 h, with AKI in 13 (35%) and 13 (52%) patients, respectively. In-hospital mortality was 12% (n = 18), and no deaths were reported in isolated meningitis.

CONCLUSIONS

Intravenous acyclovir is widely prescribed when VZV DNA is isolated in CSF, regardless of the clinical presentation, with a high rate of AKI. Further studies are needed to better define the value of intravenous acyclovir in isolated VZV meningitis.

Early Recognition and Treatment of Acute Disseminated Encephalomyelitis in Pediatrics: A Case Series

OBJECTIVE

Our aim is to emphasize the varied presentation of acute disseminated encephalomyelitis (ADEM) to help health care professionals improve recognition of the disease in a timely manner, thereby allowing for the selection of an appropriate treatment regimen. Therefore, this may avoid neurocognitive consequences and the ultimate fatality of the patient.

PATIENTS AND METHODS

This is a retrospective case series involving 7 cases of children presenting to the Pediatric Emergency Department of Hackensack University Medical Center who were ultimately diagnosed with ADEM.

RESULTS

In many of the cases, a preceding viral-like illness with nonspecific symptomatology made it difficult to accurately establish an initial diagnosis. Ultimately, the neurologic symptoms spontaneously resolved or improved with administration of high-dose steroids.

CONCLUSIONS

Children presenting to the emergency department with nonspecific symptoms associated with any neurological deficits should undergo further investigation using magnetic resonance imaging and lumbar puncture to rule out rare yet possibly fatal diseases such as ADEM.

Varicella‑zoster virus‑associated meningitis followed peripheral facial palsy: A case report

Although central nervous system infection following varicella zoster virus infection is relatively common, subsequent peripheral nervous system infection is comparatively rare. The present case documents a case of meningitis after varicella-zoster virus (VZV) infection, which was then followed by peripheral facial palsy. Specifically, a 54-year-old female patient was first admitted to Shengli Oilfield Central Hospital (Dongying, China) with headache and fever. Physical examination revealed herpes that formed along the intercostal nerve in the left forebreast, armpit and back. Subsequently, neurological examination found cervical resistance in more than three fingers (neck resistance of less than two transverse fingers is not evidence of meningeal irritation; the neck resistance of this patient was approximately three transverse fingers, so the patient was presumed to be positive for meningeal irritation, highly suggestive of meningitis) and Kernig sign was positive. There were no significant abnormalities according to brain MRI and lumbar puncture pressure was 330 mmH2O. In addition, the leukocyte count was 734x106/l, 50% monocyte count, 50% multinucleated cells, chloride levels of 109.1 mmol/l, protein levels of 235 mg/dl and glucose levels of 4.18 mmol/l in the cerebrospinal fluid. DNA and RNA metagenomic detection of pathogenic microorganisms in the cerebrospinal fluid revealed the presence of VZV. The patient was therefore treated with acyclovir, ceftriaxone, mannitol and methylprednisolone, but then developed right peripheral facial palsy at 10 days after treatment. This complication was not found in the literature, and the occurrence of facial neuritis was unexpected. The active period of VZV virus was 21 days, and the patient had herpes 5 days before admission. The active period of the virus was considered to have subsided and the patient was in the recovery period. Moreover, the results of lumbar puncture showed that the white blood cells, the proportion of neutrophils and the protein in cerebrospinal fluid were all decreasing, which also indicated that the patient had entered the recovery period. The patient was discharged 18 days after admission. In conclusion, observations from the present case suggested that the clinical manifestations of VZV infection can be complex and varied, requiring the clinician to have an accurate understanding of its disease progression and treatment.

Varicella zoster virus meningoencephalitis presenting as orbital myositis - a case report

The authors present a case of meningoencephalitis caused by Varicella zoster virus (VZV) infection, which initially manifested as orbital myositis followed by rapid progression to orbital apex syndrome, meningoencephalitis and death. There was no development of a cutaneous rash. An orbital biopsy demonstrated VZV infection, which was confirmed on a lumbar puncture. In this case, VZV meningoencephalitis was not responsive to steroid or antiviral therapy. This case highlights an atypical presentation of VZV with orbital myositis preceding intracranial involvement.

Unveiling the Masked Culprit: Central Nervous System Infection With Varicella-Zoster Virus Diagnosed by Multiplex PCR in an Elderly Patient With Atypical Neurological Symptoms

Varicella-zoster virus (VZV) infections of the central nervous system can be atypical, particularly in elderly patients. Herein, we describe the case of an 80-year-old male presenting with persistent hiccups and dysphagia without the characteristic rash typically associated with VZV infection. Cerebrospinal fluid multiplex polymerase chain reaction (PCR) allowed rapid identification of VZV, thereby enabling the prompt initiation of antiviral therapy. This case underscores the importance of considering VZV in atypical neurological presentations and highlights the utility of multiplex PCR in diagnosing zoster sine herpes, potentially altering the diagnostic approach for similar cases.

Varicella-Zoster Disease of the Central Nervous System in Immunocompetent Children: Case Series and a Scoping Review

BACKGROUND

Varicella-Zoster Virus (VZV) is characterized by its ability to enter a dormant state within the body. When the wild or vaccine virus reactivates, it can lead to herpes zoster (HZ), which infrequently manifests as a neuroinfection.

OBJECTIVES

The aim of the study was to analyze the clinical manifestations and outcomes associated with VZV reactivation in the CNS in immunocompetent children.

METHODS

We searched medical databases for case reports using the keywords "zoster", "meningitis", "encephalitis", and "immunocompetent". The inclusion criteria were age below 18 years, any gender, race, and ethnicity, no features or history of immunodeficiency, and confirmation of VZV reactivation through the detection of VZV DNA in the CSF. Patients were categorized into two groups: children experiencing the reactivation of the wild virus and children with the vaccine strain virus.

RESULTS

The cohort included six children hospitalized in our hospital and 49 children reported in the literature. In 37 (67%), a wild-type virus was detected, while in 18 (33%), an infection was caused by the vaccine strain. There were no differences in the clinical presentation between the two groups. A typical rash was observed in 32 (58%) children. Approximately 41 of the 55 children (75%) received antiviral treatment. Four patients experienced complications.

CONCLUSIONS

Neither a history of VZV immunization nor the absence of a skin rash can definitively exclude VZV meningitis. It is important to note that any seemingly healthy child, regardless of recognized risk factors, could develop HZ meningitis.

Unveiling the Impact of Human Herpesviruses-Associated on CNS Infections: An Observational Study

Human Herpesviruses (HHVs) play a significant role in neurological diseases such as encephalitis and meningitis, adding significant morbidity. This study aims to retrospectively analyze the effect of HHVs on patients with neurological symptoms, focusing on the Herpesviridae family's contributions to central nervous system (CNS) infections.

METHODS

This retrospective cohort study included 895 patients suspected of viral CNS infections, utilizing molecular diagnosis via qPCR to identify HHVs in cerebrospinal fluid (CSF) samples. This was conducted at a reference tertiary care hospital for infectious diseases in the western Brazilian Amazon from January 2015 to December 2022, focusing on the Herpesviridae family's clinical repercussions and of Cytomegalovirus in CNS infections.

RESULTS

The findings revealed that 7.5% of the analyzed samples tested positive for HHVs, with Human Cytomegalovirus (HCMV) and Epstein-Barr Virus (EBV) being the most prevalent. A significant association was found between HHVs and neurological diseases such as encephalitis and meningitis, especially among people living with HIV/AIDS (PLWHA), highlighting the opportunistic nature of these viruses. The study underscores the critical role of CSF analysis in diagnosing CNS infections and the complexity of managing these infections in HIV patients due to their immunocompromised status.

CONCLUSIONS

The results emphasize the need for comprehensive diagnostic approaches and tailored treatment strategies for CNS infections in immunocompromised individuals. The study calls for ongoing research and advancements in clinical practice to improve patient outcomes facing CNS infections, particularly those caused by HHVs.

Probable Causative Agents and Demographic Patterns of Encephalitis, Meningitis, and Meningoencephalitis in a Single Tertiary Care Center

Introduction Encephalitis, meningitis, and meningoencephalitis present significant challenges in clinical management owing to their diverse etiologies and potential complications. A high suspicion index is critical for guiding treatment strategies and improving patient outcomes. Understanding the demographic characteristics and frequency of causes of these conditions is essential to deliver optimized care. Objective This study aimed to investigate epidemiological causes and relative outcomes, including mortality, based on cultures, laboratory investigations, and demographic factors among patients with encephalitis, meningitis, and meningoencephalitis in a Saudi Arabian tertiary care center. Methods A retrospective cross-sectional study was conducted at King Abdulaziz Medical City (KAMC) in Jeddah, Saudi Arabia. Data were collected from patients admitted between April 2016 and December 2022 who met the specified inclusion criteria. Results Among 233 patients, meningitis was the most prevalent diagnosis (65.77%), with bacterial agents being the predominant causative agents (79.74%). Higher mortality was significant with pediatrics <5 years and adults >60 years. Conclusion This study provides valuable insights into the epidemiology and clinical outcomes of central neurological infections based on a Saudi Arabian cohort. These findings underscore the importance of an accurate diagnosis and tailored management strategies. Further studies are warranted to enhance our understanding and to inform more predictable characteristics targeted in optimizing healthcare delivery for patients with such conditions.

Aetiological profile of acute encephalitis syndrome in Assam, India, during a 4-year period from 2019 to 2022

Acute encephalitis syndrome (AES) is a major public health concern in India as the aetiology remains unknown in the majority of cases with the current testing algorithm. We aimed to study the incidence of Japanese encephalitis (JE) and determine the aetiology of non-JE AES cases to develop an evidence-based testing algorithm. Cerebrospinal fluid (CSF) samples were tested for Japanese encephalitis virus by ELISA and polymerase chain reaction (PCR). Multiplex real-time PCR was done for Dengue, Chikungunya, West Nile, Zika, Enterovirus, Epstein Barr Virus, Herpes Simplex Virus, Adenovirus, Cytomegalovirus, Herpesvirus 6, Parechovirus, Parvovirus B19, Varicella Zoster Virus, Scrub typhus, Rickettsia species, Leptospira, Salmonella species, Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Plasmodium species and by ELISA for Mumps and Measles virus. Of the 3173 CSF samples, 461 (14.5%) were positive for JE. Of the 334 non-JE AES cases, 66.2% viz. Scrub typhus (25.7%), Mumps (19.5%), Measles (4.2%), Parvovirus B19 (3.9%) Plasmodium (2.7%), HSV 1 and 2 (2.4%), EBV and Streptococcus pneumoniae (2.1% each), Salmonella and HHV 6 (1.2% each) were predominant. Hence, an improved surveillance system and our suggested expanded testing algorithm can improve the diagnosis of potentially treatable infectious agents of AES in India.

Differentiation between viral and autoimmune limbic encephalitis: a prospective cohort study with development and validation of a diagnostic model

BACKGROUND

Distinguishing between viral encephalitis (VE) and autoimmune limbic encephalitis (ALE) presents a clinical challenge due to the overlap in symptoms. We aimed to develop and validate a diagnostic prediction model to differentiate VE and ALE.

METHODS

A prospective observational multicentre cohort study, which continuously enrolled patients diagnosed with either ALE or VE from October 2011 to April 2023. The demographic data, clinical features, and laboratory test results were collected and subjected to logistic regression analyses. The model was displayed as a web-based nomogram and then modified into a scored prediction tool. Model performance was assessed in both derivation and external validation cohorts.

RESULTS

A total of 2423 individuals were recruited, and 1001 (496 VE, 505 ALE) patients were included. Based on the derivation cohort (389 VE, 388 ALE), the model was developed with eight variables including age at onset, acuity, fever, headache, nausea/vomiting, psychiatric or memory complaints, status epilepticus, and CSF white blood cell count. The model showed good discrimination and calibration in both derivation (AUC 0.890; 0.868-0.913) and external validation (107 VE, 117 ALE, AUC 0.872; 0.827-0.917) cohorts. The scored prediction tool had a total point that ranged from - 4 to 10 also showing good discrimination and calibration in both derivation (AUC 0.885, 0.863-0.908) and external validation (AUC 0.868, 0.823-0.913) cohorts.

CONCLUSIONS

The prediction model provides a reliable and user-friendly tool for differentiating between the VE and ALE, which would benefit early diagnosis and appropriate treatment and alleviate economic burdens on both patients and society.

Acute infections of the central nervous system in children and adults: diagnosis and management

Central nervous system infections are due to different microorganisms such as viruses, bacteria, mycobacteria, fungi, amoebas, and other parasites. The etiology depends on multiple risk factors, and it defines the infection location because some microorganisms prefer meninges, brain tissue, cerebellum, brain stem or spinal cord. The microorganisms induce diseases in the nervous system through direct invasion, neurotoxin production, and the triggered immune response. To determine the infection etiology, there are several diagnostic tests which may be conducted with cerebrospinal fluid, blood, respiratory and stool samples. These tests include but are not limited to direct microscopic examination of the sample, stains, cultures, antigenic tests, nucleic acid amplification tests, metagenomic next-generation sequencing, immunologic biomarker and neuroimaging, especially contrast-enhanced magnetic resonance imaging. The treatment may consist of specific antimicrobial treatment and supportive standard care. Since viruses have no specific antiviral treatment, antimicrobial treatment is mainly targeted at non-viral infections. This article will focus on diagnosis and treatment of acute acquired infections of the central nervous system beyond the neonatal period. The discussion defines the disease, provides the clinical presentation, explains the etiology and risk factors, and briefly mentions potential complications. This updated review aims to provide the reader with all the elements needed to adequately approach a patient with a central nervous system infection. Mycobacterium tuberculosis infection, Cryptococcus spp. infection and vaccines are not within the scope of this article.

Neurocognitive outcome in children and adolescents following infectious encephalitis

Infectious encephalitis in children is fairly uncommon, but unfavorable outcomes are seen in many survivors. The aim of this study was to prospectively describe the long-term neurocognitive consequences following infectious encephalitis in childhood. Children admitted to a primary and tertiary hospital in Sweden between 2011 and 2016 were asked to participate. Fifty-nine children were assessed at a median time of 18 months (IQR 18-20) after hospitalization. Follow-up included measures of intellectual functioning, attention, working memory, and executive functions. Caregiver ratings of executive functioning and behavioral - emotional symptoms were assessed with standardized questionnaires. Neurocognitive outcome and measures of executive functions and behavioral-emotional symptoms varied greatly among participants. Basic auditory attention, working memory, and mental processing speed were affected and significantly lower compared to a standardized mean. Other domains identified as areas of vulnerability included executive functions, sustained attention, and the exert of self-control. Behavioral-emotional symptoms were less common; however, somatic complaints and behaviors related to conduct problems were seen in about one-third of individuals. This study highlights the importance of a comprehensive neurocognitive examination to identify children with unfavorable outcomes.

Herpes zoster in neuro-ophthalmology: a practical approach

Herpes Zoster (HZ) or shingles is the reactivation of the Varicella Zoster Virus (VZV), usually along a single sensory nerve, but can affect both sensory and motor cranial nerves. Major risk factors for HZ include immunosuppressed status and age older than 60 years. In the United States, the lifetime risk of HZ is approximately 30%. Worldwide, the median incidence of HZ is 4-4.5 per 1000 person-years across the Americas, Eurasia, and Australia. HZ ophthalmicus, occurring in 10-20% of patients, is an ophthalmic emergency characterized by VZV reactivation along the V1 branch of the trigeminal nerve. Approximately half of this patient subgroup will go on to develop ocular manifestations, requiring prompt diagnosis and management. While anterior segment complications are more common, neuro-ophthalmic manifestations are rarer and can also occur outside the context of overt HZ ophthalmicus. Neuro-ophthalmic manifestations include optic neuropathy, acute retinal necrosis or progressive outer retinal necrosis, cranial neuropathy (isolated or multiple), orbitopathy, and CNS manifestations. Although typically a clinical diagnosis, diagnosis may be aided by neuroimaging and laboratory (e.g., PCR and serology) studies. Early antiviral therapy is indicated as soon as a presumptive diagnosis of VZV is made and the role of corticosteroids remains debated. Generally, there is wide variation of prognosis with neuro-ophthalmic involvement. Vaccine-mediated prevention is recommended. In this review, we summarize neuro-ophthalmic manifestations of VZV.

Neonatal varicella

Primary infection with varicella zoster virus (VZV) in the final 3 weeks of pregnancy may cause transplacental infection and neonatal varicella. Infants are most at risk of severe disease if born from 5 days before to 2 days after onset of the maternal varicella rash. Administration of post-exposure prophylaxis with varicella zoster immunoglobulin and treatment of varicella with aciclovir for those at highest risk of progression to severe disease is advised. Universal vaccination against VZV significantly reduces the incidence of neonatal varicella.

Time to Confirmed Neuroinfectious Diagnoses: Diagnostic Testing and Resource Allocation

Background and Objectives

In a retrospective study evaluating the diagnostic approach of definitive neurological infections at a tertiary referral center, we assessed the time to diagnosis from presentation, number of diagnostic tests ordered, and modality of etiologic diagnosis.

Methods

A total of 111 confirmed clinical cases of neurological infections from 2010-2018 were reviewed. Definitive neuroinfectious diagnoses were defined by positive cerebrospinal (CSF) polymerase chain reaction (PCR)/antigen, CSF culture, CSF antibody, serology, or pathology tests.

Results

An etiologic diagnosis was determined at an average (SD) of 3.1 (5.9) days after presentation with an average (SD) of 27.7 (15.6) diagnostic tests ordered per workup.Viral neuro-infections were associated with lower intensive care unit (ICU) admission rates, shorter length of hospitalization, and fewer diagnostic tests ordered, as well as shorter time to definitive diagnosis (P < .05). Longer hospitalizations were associated with immunosuppression status regardless of infectious etiology (P < .001).

Discussion

Given the high morbidity and mortality of neuroinfectious disease, specifically meningitis and encephalitis, efficient diagnostic testing is imperative to facilitate the most appropriate clinical course of action with special attention to the specific patient population.

Elsberg Syndrome With Albuminocytologic Dissociation - A Guillain-Barré Syndrome Mimic or Guillain-Barré Syndrome Variant?

Introduction

Elsberg Syndrome is a presumed infectious lumbosacral radiculitis, with or without accompanying lumbar myelitis, that is often attributed to herpes simplex virus type 2 (HSV-2).

Case

A 58-year-old man presented with lower extremity anesthesia, ataxic gait, radiological evidence of radiculitis, and CSF albuminocytologic dissociation. Polymerase chain reaction testing of CSF confirmed HSV-2 infection.

Conclusion

A variety of presentations are reported within the scope of Elsberg Syndrome, potentially with distinct disease mechanisms. Delayed onset of neurological symptoms after resolution of rash and absence of pleocytosis raises the possibility that some patients meeting criteria for Elsberg Syndrome have a post-infectious immune-mediated neuropathy. We advise a lower threshold for PCR testing of herpes viruses in patients with acute neuropathy and albuminocytologic dissociation, particularly in cases with early sacral involvement.

New Insights Into the Therapeutic Management of Varicella Zoster Virus Meningitis: A Series of 123 Polymerase Chain Reaction-Confirmed Cases

Background

Varicella zoster virus (VZV) can reactivate and cause meningitis, but few studies have distinguished it from meningoencephalitis regarding treatment recommendations.The objective of this study was to assess the outcomes of a large series of patients with VZV meningitis according to their therapeutic management.

Methods

We conducted a bicentric retrospective cohort study, in Paris, France, including all adult patients with a cerebrospinal fluid sample positive for VZV by polymerase chain reaction between April 2014 and June 2022. We distinguished meningitis from encephalitis according to the International Encephalitis Consortium criteria. Unfavorable outcome was defined as mortality or functional sequelae defined by a loss of 2 points on the modified Rankin Scale.

Results

We included 123 patients with meningitis. Among them, 14% received no antivirals, while 20% were treated with oral valacyclovir alone, 41% with a short course of intravenous (IV) acyclovir before switch to valacyclovir, and 25% with a long course of IV acyclovir. Outcomes were favorable regardless of antiviral regimen. In multivariate analysis, only age, underlying immunosuppression, and cranial radiculitis appear to be predictive factors for longer IV therapy, based on the Akaike information criterion.

Conclusions

In this study, patients with VZV meningitis had a good outcome, with no evidence of any impact of the treatment strategy. However, further studies are needed to support the possibility of milder treatment in immunocompetent patients, avoiding cost and side effects of IV acyclovir.