Clinical and radiological spectrum of Japanese encephalitis

Tinospora cordifolia Miers enhances the immune response in mice immunized with JEV-vaccine: A network pharmacology and experimental approach

BACKGROUND

Tinospora cordifolia Miers. (TC) (Giloya/Guduchi) is a native Indian herb, reported for its wide array of medicinal activities including immunomodulatory activity. However, the exact pharmacological mechanism of TC as an immunomodulatory agent remains unclear. Central to this, to the best of our knowledge, no study has explored the immunoadjuvant potential of TC in response to the Japanese encephalitis (JE) vaccines.

PURPOSE

The study aims to explore the immunoadjuvant potential of TC ethanolic extract in response to the JE vaccine and illustrates its potential mechanism of immunomodulation using an integrated approach of network pharmacology and in-vivo experimental study.

STUDY DESIGN AND METHODS

Initially, the extract was prepared and the components of TC were identified through high-resolution liquid chromatography mass spectrometry (HR-LC/MS). The compounds were then screened for network pharmacology analysis. Next, the drug and disease targets were identified and the network was constructed using Cytoscape 3.7.2 to obtain different signalling pathways of TC in JEV. We then evaluated the immunoadjuvant potential of TC ethanolic extract in mice immunized with inactivated JE vaccine (SA-14-14-2 strain). BALB/c mice were supplemented with TC extract (30 and 100 mg/kg, i.g.), daily for 56 days, marked with immunization on 28th day of the study, by JE vaccine. Blood was collected for flow cytometry and haematological analysis (total and differential cell counts). The surface expression of immune-cell markers (CD3+, CD4+, CD19+, CD11c+, CD40+) were evaluated on day 0 (pre-immunization), day 14 and 28 post-immunization. Additionally, inflammatory cytokines (IFN-γ+/IL-17A+) were evaluated post-14 and 28 days of immunization.

RESULTS

The HR-LC/MS analysis identified the presence of glycosides, terpenoids, steroids and alkaloids in the TC extract. Through network analysis, 09 components and 166 targets were obtained, including pathways that involve toll-like receptor signalling, pattern-recognition receptor signalling, cytokine receptor and cytokine mediated signalling, etc. The in-vivo results showed that preconditioning with TC ethanolic extract significantly elevated the haematological variables (leucocyte count) as well as the surface expression of CD markers (B and T cell subsets) on day 0 (pre-immunization), day 14 and 28 post-immunization. Furthermore, preconditioning of TC demonstrated a dose-dependant augmentation of immune cells (CD3+, CD4+, CD19+, CD11c+) and inflammatory cytokines (IFN-γ+/IL-17A+) on day 14 and 28 post-immunization when compared to vaccine alone group.

CONCLUSION

Results showed that preconditioning with TC extract before immunization might play a potential role in enhancing the cell-mediated as well as humoral immunity. Altogether, the combinatorial approach of network pharmacology and in-vivo animal experimentation demonstrated the immunoadjuvant potential of TC in response to JEV vaccine.

Profile of Acute Encephalitis Syndrome Patients from South India

Introduction

Encephalitis is a major public health problem worldwide that causes huge emotional and economic loss to humanity. Encephalitis, being a serious illness, affects people of all ages. The aim is to describe the sociodemographic, clinical, etiological, and neuroimaging profile among 101 acute encephalitis syndrome (AES) patients visiting a tertiary neuro-specialty care hospital in India.

Methods

Record review of medical records of all patients attending neurology emergency and outpatient services at NIMHANS Hospital, diagnosed with AES in 2019, was conducted. Data were collected using standardized data collection forms for all cases in the study. Descriptive analyses (mean and standard deviation for continuous variables and proportions for categorical variables) were conducted. The Chi-square test/Fisher's exact test was used for the comparison of independent groups for categorical variables, and t-test for comparing means for continuous variables.

Results

About 42.6% of AES patients had viral etiology, while in 57.4%, etiology was not ascertained. Common presenting symptoms were fever (96%), altered sensorium (64.4%), seizures (70.3%), headache (42.6%), and vomiting (27.7%). Herpes simplex was the most common (21.8%) identified viral encephalitis, followed by chikungunya (5%), arboviruses (chikungunya and dengue) (4%), Japanese encephalitis (4%), rabies (3%), dengue (1%), and varicella virus (1%). About 40% of AES patients showed cerebrospinal fluid pleocytosis (44%), increased protein (39.6%), abnormal computed tomography brain (44.6%), and magnetic resonance imaging abnormalities (41.6%).

Conclusion

The study highlights the need to ascertain etiology and importance of evidence-based management of AES patients. A better understanding of opportunities and limitations in the management and implementation of standard laboratory and diagnostic algorithms can favor better diagnosis and management of AES.

Japanese encephalitis transmission trends in Gansu, China: A time series predictive model based on spatial dispersion

Objective

This study serves to ascertain trends of space and time for Japanese encephalitis (JE) transmission at the township-level and develop an innovative time series predictive model to predict the geographical spread of JE in Gansu Province, China.

Methods

We collected weekly data on JE from 2005 to 2019 at the township-level. Kriging interpolation maps were used to visualize the trend of the epidemic spread of JE, and linear regression models were used to calculate the monthly changes in minimum longitude and maximum latitude of emerging towns with JE to assess the speed of the epidemic's spread to the northwest. Additionally, we utilized a time series Seasonal Autoregressive Integrated Moving Average (SARIMA) model to dynamically predict the ongoing weekly number of JE emerging townships.

Results

The Kriging difference map revealed a significant trend of JE spread towards the northwest. Our regression model indicated that the rate of decrease in minimum longitude was approximately 0.64 km per month, while the rate of increase in maximum latitude was approximately 1.00 km per month. Furthermore, the SARIMA pattern (2,0,0)(2,0,1)₅₂ exhibited a better goodness-of-fit for predicting JE transmission, with an overall agreement of 93.27% to 94.23%.

Conclusion

Our study highlights the expansion of JE cases towards the northwest of Gansu, indicating the need for ongoing surveillance and control efforts. The use of the SARIMA model provides a valuable tool for predicting the trend of JE spatial dispersion, thereby improving early warning systems. Our findings suggest that the number of emerging townships can be used to predict the trend of JE spatial dispersion, providing crucial insights for future research on JE incidence.

Mice as an Animal Model for Japanese Encephalitis Virus Research: Mouse Susceptibility, Infection Route, and Viral Pathogenesis

Japanese encephalitis virus (JEV), a zoonotic flavivirus, is principally transmitted by hematophagous mosquitoes, continually between susceptible animals and incidentally from those animals to humans. For almost a century since its discovery, JEV was geographically confined to the Asia-Pacific region with recurrent sizable outbreaks involving wildlife, livestock, and people. However, over the past decade, it has been detected for the first time in Europe (Italy) and Africa (Angola) but has yet to cause any recognizable outbreaks in humans. JEV infection leads to a broad spectrum of clinical outcomes, ranging from asymptomatic conditions to self-limiting febrile illnesses to life-threatening neurological complications, particularly Japanese encephalitis (JE). No clinically proven antiviral drugs are available to treat the development and progression of JE. There are, however, several live and killed vaccines that have been commercialized to prevent the infection and transmission of JEV, yet this virus remains the main cause of acute encephalitis syndrome with high morbidity and mortality among children in the endemic regions. Therefore, significant research efforts have been directed toward understanding the neuropathogenesis of JE to facilitate the development of effective treatments for the disease. Thus far, multiple laboratory animal models have been established for the study of JEV infection. In this review, we focus on mice, the most extensively used animal model for JEV research, and summarize the major findings on mouse susceptibility, infection route, and viral pathogenesis reported in the past and present, and discuss some unanswered key questions for future studies.

A Profile Study of Japanese Encephalitis in an Industrial Hospital in Eastern India

Introduction Japanese encephalitis (JE), caused by a Flavivirus, is one of the common causes of mosquito-borne encephalitis the world over including India. The disease is endemic in many states of India, including Jharkhand. Mortality ranges from 30 to 40% in different studies and a large number of patients survive with permanent neuropsychiatric sequelae. Aim The study aimed to evaluate the clinical spectrum, laboratory (including radiological) features and outcomes of cases of JE admitted in our hospital. Methods and materials This is a retrospective observational study consisting of confirmed cases of JE admitted to the medical wards and critical care unit of Tata Main Hospital (TMH) from January to December 2022. The case records of patients were retrieved from Hospital Management System (HMS) and analysed for demographic characteristics, clinical presentations and treatment details along with outcome measures, which included length of stay (LOS), complications, and mortality. Observation Of the 14 confirmed cases, six (43.9%) were males and eight (57.1%) were females. The average age of male and female patients was 41.8 ± 23.1 and 35.1 ± 20.5 years respectively. A total of 35.7% of the patients were in the age group of 21 to 30 years. The clinical manifestations in the decreasing frequency were altered sensorium in 11 (78.6%) patients, headache in six (42.8%) patients, generalised convulsions in four (28.6%) cases, vomiting in three (21.4%) cases and weakness in all limbs and of the right half of the body in one (7.1%) case each. Objective neurological findings noted were neck stiffness (3, 21.4%), cog-wheel rigidity (3, 21.4%), tremors (2, 14.3%), delirium (2,14.3%), quadriparesis, facio-brachial dystonia and hemiparesis (1, 7.14%) patient each. Neutrophilic leucocytosis was observed in five (35.7%) patients and mild thrombocytopenia in two (14.3%) patients. The average C-reactive protein (CRP) level was 7.3 ± 6.6 mg/dL. Three (21.4%) patients had mild transaminitis. Cerebrospinal fluid analysis was abnormal in all patients with varying degrees of elevated protein and cell count, while adenosine deaminase (ADA) levels and sugar were normal in all patients. Magnetic resonance imaging (MRI) brain revealed bilateral thalamic T2 FLAIR (fluid-attenuated inversion recovery) hyperintensities in 11 patients (78.6%). The average length of hospital stay was 9.6 ± 4.7 days. Ten patients (71.4%) needed treatment in the critical care unit. Complications seen were acute respiratory distress syndrome (2, 14.3%), sepsis with multiorgan failure (2, 14.3%) and ventilator-associated pneumonia (1, 7.1%). The case fatality rate was one (7.1%). Six patients (42.9%) had residual neuropsychiatric sequelae. Conclusion JE continues to be a major health-related problem. Most cases are concentrated during the post-monsoon period, coinciding with a higher vector density. Patients from rural backgrounds were seen to be more susceptible. JE may present with varying severities of acute encephalitic syndrome. As there is no specific treatment, timely diagnosis is important to reduce the morbidity and mortality associated with this disease. Clinicians must be aware of the wide spectrum of presentation of this disease. A high degree of suspicion along with thorough clinical examination and appropriate investigations are needed to diagnose this condition early and prevent complications.

A comparison of clinical manifestations of Japanese encephalitis between children and adults in Gansu Province, Northwest China (2005-2020)

Japanese encephalitis (JE), a mosquito-borne zoonotic disease, has emerged as a major public health concern around the world. Previous research has shown that JE has serious sequelae, and the recent shift in the population from children to adults presents a significant challenge for JE treatment and prevention. Therefore, we examined the differences in clinical manifestations (clinical symptoms, clinical signs, complications, and clinical typing) of JE between children and adults over the 15 years in Gansu Province to provide a theoretical basis for better response to JE treatment. Clinical typing was found to be statistically significant in the child versus adult groups and the groups with or without vaccination. Only the dysfunction of consciousness differed statistically between children with and without vaccination, whereas neurological symptoms such as vomiting (jet vomiting), irritability, drowsiness, convulsions, and hyperspasmia differed statistically between children and adults, and the rest of the symptoms did not differ statistically. Only pupil size changes were statistically different in clinical signs between the children with and without vaccination, while blood pressure changes, change in pupil size, positive meningeal stimulation signs, and positive pathological reflexes (increased muscle tone and Babinski's sign) were statistically different between adults and children. Bronchopneumonia was the most common complication, especially in adults. Therefore, the authors believe that children and adults differ in some clinical manifestations and propose that efforts should be directed toward developing individualized treatment plans for different age groups and employing more effective supportive treatment for various populations. In addition, we suggest expanding the coverage of the JE vaccine and increasing overall vaccination rates and adopting multiple measures in conjunction with JE prevention and control.

Estimates of Japanese Encephalitis mortality and morbidity: A systematic review and modeling analysis

Background

Japanese Encephalitis (JE) is known for its high case fatality ratio (CFR) and long-term neurological sequelae. Over the years, efforts in JE treatment and control might change the JE fatality risk. However, previous estimates were from 10 years ago, using data from cases in the 10 years before this. Estimating JE disease severity is challenging because data come from countries with different JE surveillance systems, diagnostic methods, and study designs. Without precise and timely JE disease severity estimates, there is continued uncertainty about the JE disease burden and the effect of JE vaccination.

Methodology

We performed a systematic review to collate age-stratified JE fatality and morbidity data. We used a stepwise model selection with BIC as the selection criteria to identify JE CFR drivers. We used stacked regression, to predict country-specific JE CFR from 1961 to 2030. JE morbidity estimates were grouped from similar study designs to estimate the proportion of JE survivors with long-term neurological sequelae.

Principal findings

We included 82 and 50 peer-reviewed journal articles published as of March 06 2021 for JE fatality and morbidity with 22 articles in both analyses. Results suggested overall JE CFR estimates of 26% (95% CI 22, 30) in 1961–1979, 20% (95% CI 17, 24) in 1980–1999, 14% (95% CI 11, 17) in 2000–2018, and 14% (95% CI 11, 17) in 2019–2030. Holding other variables constant, we found that JE fatality risk decreased over time (OR: 0.965; 95% CI: 0.947–0.983). Younger JE cases had a slightly higher JE fatality risk (OR: 1.012; 95% CI: 1.003–1.021). The odds of JE fatality in countries with JE vaccination is 0.802 (90% CI: 0.653–0.994; 95% CI: 0.62–1.033) times lower than the odds in countries without JE vaccination. Ten percentage increase in the percentage of rural population to the total population was associated with 15.35% (95% CI: 7.71, 22.57) decrease in JE fatality odds. Ten percentage increase in population growth rate is associated with 3.71% (90% CI: 0.23, 7.18; 95% CI: -0.4, 8.15) increase in JE fatality odds. Adjusting for the effect of year, rural population percent, age of JE cases, and population growth rate, we estimated that there was a higher odds of JE fatality in India compared to China. (OR: 5.46, 95% CI: 3.61–8.31). Using the prediction model we found that, in 2000–2018, Brunei, Pakistan, and Timor-Leste were predicted to have the highest JE CFR of 20%. Bangladesh, Guam, Pakistan, Philippines, and Vietnam had projected JE CFR over 20% for after 2018, whereas the projected JE CFRs were below 10% in China, Indonesia, Cambodia, Myanmar, Malaysia, and Thailand. For disability, we estimated that 36% (min-max 0–85) JE patients recovered fully at hospital discharge. One year after hospital discharge, 46% (min-max 0%-97%) JE survivors were estimated to live normally but 49% (min-max 3% - 86%)till had neurological sequelae.

Conclusion

JE CFR estimates were lower than 20% after 2000. Our study provides an updated estimation of CFR and proportion of JE cases with long-term neurological sequelae that could help to refine cost-benefit assessment for JE control and elimination programs.

Japanese Encephalitis (JE) is known for its high case fatality ratio (CFR) and long-term neurological sequelae. Although JE fatality and morbidity risk might change as the characteristics of the population change with the strengthened surveillance scales, expanded immunization coverage, and healthcare improvements, there have not been any updates in the estimates for JE mortality and morbidity estimates for 10 years. In this paper, we made updated estimates of the JE CFR and the proportion of JE survivors with long-term neurological sequelae by performing a systematic review and developing statistical and machine learning models. We estimated JE CFR decreased over time, with estimates of 26% (95% CI 22, 30) in 1961–1979, 20% (95% CI 17, 24) in 1980–1999, 14% (95% CI 11, 17) in 2000–2018, and 14% (95% CI 11, 17) in 2019–2030. countries without JE vaccination, younger JE cases, higher population growth rate, and lower rural population percentage were associated with higher JE CFR. We estimated that 36% (min-max 0–85) JE patients recovered fully at hospital discharge. One year after hospital discharge, 46% (min-max 0%-97%) JE survivors were estimated to live normally but 49% (min-max 3% - 86%) JE patients still had neurological sequelae. The insights gained will be important in evaluating and updating current JE disease burden among all endemic areas and effectively channeling resources to most needed areas.

Detection of Japanese Encephalitis by Metagenomic Next-Generation Sequencing of Cerebrospinal Fluid: A Case Report and Literature Review

Japanese encephalitis (JE) is an acute viral central nervous system disease, although less than 1% of patients infected with Japanese encephalitis virus (JEV) result in JE, which has an extremely poor prognosis. The Routine detection methods for JEV are time-consuming or limited by hospital conditions, therefore, need the quicker and sensitive techniques to detect JEV. Here, we reported a 14-year-old female who was admitted to our hospital with a severe fever, progressively headache and unconsciousness. Based on the clinical presentation, Preliminary diagnosis on admission indicated central nervous system infection of suspected viral meningoencephalitis or autoimmune encephalitis. The patient's symptoms were unrelieved after being treated with empiric antiviral therapy. Magnetic resonance imaging (MRI) showed that the lesions were located in the bilateral thalamus, head of caudate nucleus, and right lenticular nucleus, so we had to consider the possibility of Flaviviruses infection. We sent the cerebrospinal fluid (CSF) for metagenomic next-generation sequencing (mNGS) immediately, subsequent result suggested the infection caused by JEV. Two days later the results of the serum agglutination test confirmed that virus immunoglobulin M antibody positive. After a week treatment with intravenous immunoglobulin (IVIG), meanwhile, the lumbar puncture was used to check the pressure and various indicators of the CSF again to evaluate the treatment effect, An decrease in the number of WBC indicates, protein and unique RNA reads that the previous experimental treatment was effective, accompany by temperature and consciousness of the patient was normalized. Two weeks after admission, the patient was transferred to the rehabilitation hospital, MR showed the lesions had disappeared completely after 2 months of follow-up. We believed that mNGS may be an effective method for rapid identification of JE.

Clinical spectrum and management of dystonia in patients with Japanese encephalitis: A systematic review

BACKGROUND

Japanese encephalitis (JE) is a potentially fatal viral infection with a wide range of manifestations and can also present with a variety of movement disorders (MD) including dystonia. Dystonic features in JE are uncommon. Here, we have tried to summarize the clinical features and management of dystonia among JE patients with a comprehensive literature search.

METHODS

Various databases, including PubMed, Embase, and Google Scholar, were searched against the predefined criteria using suitable keywords combination and boolean operations. Relevant information from observational and case studies was extracted according to the author, dystonic features, radiological changes in the brain scans, treatment options, and outcome wherever provided.

RESULT

We identified 19 studies with a total of 1547 JE patients, the diagnosis of which was confirmed by IgM detection in serum and/or cerebrospinal fluid in the majority of the patients (88.62%). 234 (15.13%) of JE patients had dystonia with several types of focal dystonia being present in 131 (55.98%) either alone or in combination. Neuroimaging showed predominant involvement of thalami, basal ganglia, and brainstem. Oral medications including anticholinergics, GABA agonists, and benzodiazepines followed by botulinum toxin were the most common treatment modalities.

CONCLUSION

Dystonia can be a disabling consequence of JE, and various available medical therapies can significantly improve the quality of life. Owing to insufficient studies on the assessment of dystonia associated with JE, longitudinal studies with a larger number of patients are warranted to further clarify the clinical course, treatment, and outcome of dystonia.

Acute neurologic emerging flaviviruses

The COVID-19 pandemic has shed light on the challenges we face as a global society in preventing and containing emerging and re-emerging pathogens. Multiple intersecting factors, including environmental changes, host immunological factors, and pathogen dynamics, are intimately connected to the emergence and re-emergence of communicable diseases. There is a large and expanding list of communicable diseases that can cause neurological damage, either through direct or indirect routes. Novel pathogens of neurotropic potential have been identified through advanced diagnostic techniques, including metagenomic next-generation sequencing, but there are also known pathogens which have expanded their geographic distribution to infect non-immune individuals. Factors including population growth, climate change, the increase in animal and human interface, and an increase in international travel and trade are contributing to the expansion of emerging and re-emerging pathogens. Challenges exist around antimicrobial misuse giving rise to antimicrobial-resistant infectious neurotropic organisms and increased susceptibility to infection related to the expanded use of immunomodulatory treatments. In this article, we will review key concepts around emerging and re-emerging pathogens and discuss factors associated with neurotropism and neuroinvasion. We highlight several neurotropic pathogens of interest, including West Nile virus (WNV), Zika Virus, Japanese Encephalitis Virus (JEV), and Tick-Borne Encephalitis Virus (TBEV). We emphasize neuroinfectious diseases which impact the central nervous system (CNS) and focus on flaviviruses, a group of vector-borne pathogens that have expanded globally in recent years and have proven capable of widespread outbreak.

Long-Term Neurological Sequelae and Disease Burden of Japanese Encephalitis in Gansu Province, China

Background and objects:

The study aimed to evaluate the long-term neurological sequelae and the disease burden of JE in Gansu, China.

Methods:

JE patients were included as study population from 2005–2011 in Gansu, and a follow-up survey was conducted in 2007–2014. Pair-matched healthy individuals were selected as controls. All subjects underwent a neurological examination and intelligence quotient (IQ) and memory quotient (MQ) assessments. Then, the disability-adjusted life years (DALYs), and direct and indirect medical expenses were systematic assessed.

Results:

Forty-four point seven percent of the JE patients had objective neurological deficits, compared with 2.4% of controls. Subnormal intelligence was found in 21.2% of JE subjects, compared with 1.2% control who exhibited a mildly reduced IQ. Abnormal MQ scores were noted in 56.3% JE subjects, compared with only 12.7% controls. Prevalence of each sequelae caused by JE were significantly higher in adults than in younger subjects. Furthermore, median DALY lost due to JE was 9.2 per subject. Median economic cost of JE was approximately $2776.6 per subject and significantly higher in adults than in younger subjects.

Findings and Conclusions:

JE patients suffered from severe neurological sequelae and high disease burden, resulting in a significant downstream burden for both the patients (especially adults) and the healthcare system.

Video Anthology of Movement Disorders Due to Infections in South Asia

South Asia, encompassing many populous countries including India, Pakistan, and Bangladesh, is home to a wide variety of infectious diseases several of which are disproportionately prevalent, endemic or distinctive to the region. These result in considerable morbidity and mortality, which can be greatly reduced through public-health measures, timely diagnosis and treatment. Some of these infectious diseases have neurological manifestations including movement disorders either due to the pathogen being neuroinvasive or via an immune-mediated response. For diseases such as Japanese encephalitis, movement disorders are the primary manifestation while for others, they can be a presenting feature. Thus, recognizing these movement disorders is often crucial to the diagnosis of the particular infection, and/or to exclude infection as a cause and arrive at the correct alternate diagnosis. Once diagnosed, the infection-related movement disorders are treated by targeting the infectious agent, or symptomatically. In this article, we describe and illustrate a variety of movement disorders that are seen in patients infected by viruses, bacteria and parasites in South Asia. This would be of value to neurologists practicing in the region and, with the increasing ease in movement of people and pathogens, those practicing elsewhere.

Long-Term Outcomes in Children Surviving Tropical Arboviral Encephalitis: A Systematic Review

BACKGROUND

Survivors of childhood encephalitis often suffer from physical and neurocognitive sequelae, particularly in tropical, resource-limited areas with a large burden of arboviral, neurotropic pathogens and limited resources with which to address chronic morbidities. Research into overall and pathogen-specific outcomes following childhood encephalitis may help identify risk factors for poor outcomes, quantify the burden of sequelae, assist with resource allocation and help focus rehabilitative efforts. However, such research is limited. To this end, we systematically reviewed the literature on this topic to identify gaps in knowledge worthy of future investigation.

METHODS

A search of PubMed, Web of Knowledge and the Cochrane databases was performed 10 January through 20 February 2020, using 17 search terms for sequelae and 14 for tropical, arboviral pathogens. Eligible reports demonstrated post-discharge follow-up of ≥3 months and assessment of clinical outcome in a child with an arboviral encephalitis ≤18 years of age at diagnosis.

RESULTS

Of 1513 articles, 35 were eligible, comprising 693 children. Japanese encephalitis accounted for 18 articles and 93.2% of all subjects (646 total). Sequelae were documented in ∼60% of subjects overall and in those with Japanese encephalitis. For non-Japanese encephalitis virus encephalitides (47 children), sequelae were found in 78.1%. No studies utilized comprehensive neurocognitive testing or assessed the efficacy of rehabilitative efforts. Only nine studies reported data from ≥1 follow-up visit.

CONCLUSION

Investigation into long-term outcomes following tropical childhood encephalitis is limited, particularly for neurocognitive sequelae, serial assessments over time and the effect of rehabilitative measures.

LAY SUMMARY

Encephalitis, an infection of the brain, is frequently caused by arboviruses (viruses spread via the bite of infected arthropods, such as mosquitoes) in tropical locales. Following infection, surviving children may be plagued with severe physical and cognitive deficits. Unfortunately, research into the type of deficits, their frequency and their responsiveness to rehabilitative efforts is lacking. We identified and reviewed 35 studies describing outcomes in children recovering from tropical, arboviral encephalitis at least 3 months following hospital discharge. Poor outcomes were common and found in up to 60% of children. Long-term and serial follow-up visits were rare, as was the use of comprehensive neurocognitive testing. No studies assessed the efficacy of rehabilitative measures. Further study into these areas is recommended.

MRI Spectrum of Japanese Encephalitis in Northeast India: A Cross-Sectional Study

Objective  Japanese encephalitis (JE) is an arthropod-borne flavivirus infection having high mortality and morbidity. This study was performed to evaluate the conventional magnetic resonance imaging (MRI) findings in JE and to find out any difference between pediatric and adult JE.

Materials and Methods  This retrospective study was performed on serologically positive 54 JE patients presented to a tertiary care hospital with acute encephalitic symptoms between April 2016 and October 2019. Relevant neurological examination, cerebrospinal fluid analysis, and MRI scan of the brain were performed.

Results  Fifty-four JE patients ( n = 31 males and n = 23 females) having 32 pediatric and 22 adult JE were included in the study sample. Group 1 JE ( n = 16) patients had encephalitic symptoms with duration less than 15 days up to the day of MRI scan and group 2 JE ( n = 38) had symptoms more than 15 days. Group 1 JE had mean apparent diffusion coefficient (ADC) value of 0.563 ± 0.109 (standard deviation [SD]) × 10 ^–3 mm ² /sec and group 2 JE had 1.095 ± 0.206 (SD) × 10 ^–3 mm ² /sec. The mean ADC value of pediatric JE was 0.907 ± 0.336 (SD) × 10 ^–3 mm ² /sec and adult JE was 0.982 ± 0.253 (SD) × 10 ^–3 mm ² /sec.

Conclusion  The majority of the JE patient shows abnormal signal alterations in bilateral thalami and substantia nigra. Diffusion-weighted imaging with ADC mapping helps in evaluating the stage of the JE. No statistical significance of the various conventional MRI findings was found between the pediatric JE and adult JE.

Japanese encephalitis virus manipulates lysosomes membrane for RNA replication and utilizes autophagy components for intracellular growth

Japanese encephalitis virus is absolutely dependent on their host cells and has evolved various strategies to manipulate the cellular secretory pathways for viral replication. However, how cellular secretory pathways are hijacked, and the origin of the viral vesicles remains elusive during JEV replication. Here we show how JEV manipulates multiple components of the cellular secretory pathway, including autophagic machinery, to generate a superior environment for genome replication. We utilized double-strand RNA antibodies to label JEV RNA complex seeking the viral replication compartments and found that JEV genome replication takes place in lysosomes (LAMP1), not in autophagosomes (LC3). Subsequently, in situ hybridization results showed that viral RNAs (vRNAs) of JEV strongly colocalized with LAMP1. What surprised us was that JEV vRNAs markedly colocalized with LC3, indicating that autophagy plays an active role in JEV replication. Interestingly, we found that JEV utilized autophagic components for intracellular growth in an autophagy-dependent manner and the fusion of autophagosome-lysosome plays a positive role in JEV post-RNA replication processes. Collectively, our findings demonstrate that JEV can manipulate cellular secretory pathway to form genome replication organelles and exploit autophagy components for intracellular growth, providing new insights into the life cycle of JEV and uncovering an attractive target for antiviral drugs.

Adults with severe Japanese encephalitis: a retrospective analysis of 9 cases in Linyi, China

Objective

Japanese encephalitis (JE) is a critical problem of public health worldwide; however, there is limited data about the clinical features and indicators of outcome in adults with severe Japanese encephalitis.

Methods

The clinical manifestations and laboratory study on brain neuroimaging of patients with severe JE were statistically analyzed retrospectively. All patients were followed up for 6 months after discharge. The patients were grouped into good outcome and poor outcome according to the results of the follow-up.

Results

This retrospective study consists of 9 adults with severe JE, including 5 cases with poor outcome, defined as the modified Rankin Scale (mRS) scores of greater than or equal to 4 points, and remained ventilator dependent. Typical clinical manifestations of JE include fever (100%), altered consciousness (100%), headache (66.7%), flaccid weakness (66.7%), and status epilepticus (44.4%). Serological examination revealed that a higher percentage of neutrophils and a lower percentage of lymphocytes at admission may be associated with a poor outcome. Abnormal neuroimaging of the thalamus (85.7%), hippocampal (71.4%), midbrain (28.6%), and basal ganglia (14.3%) was found. 42.9% of patients left severe irreversible disability, and the most prominent were mental symptoms (71.4%) and memory or understanding disorder (57.1%).

Conclusion

Our data suggest that respiratory failure is one of the important causes of early death. Serologic examination, coma, and status epilepticus may indicate a poor outcome for severe JE. Additionally, the hippocampus is the second most common lesion in the adults with severe JE. A large-scale clinical trial is required to further confirm these conclusions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-020-04867-8.

Review of Hereditary and Acquired Rare Choreas

Background:

Movement disorders are often a prominent part of the phenotype of many neurologic rare diseases. In order to promote awareness and diagnosis of these rare diseases, the International Parkinson’s and Movement Disorders Society Rare Movement Disorders Study Group provides updates on rare movement disorders.

Methods:

In this narrative review, we discuss the differential diagnosis of the rare disorders that can cause chorea.

Results:

Although the most common causes of chorea are hereditary, it is critical to identify acquired or symptomatic choreas since these are potentially treatable conditions. Disorders of metabolism and mitochondrial cytopathies can also be associated with chorea.

Discussion:

The present review discusses clues to the diagnosis of chorea of various etiologies. Authors propose algorithms to help the clinician in the diagnosis of these rare disorders.

Severe Japanese encephalitis with multiple intracranial hemorrhages: A case report

RATIONALE

Intracranial hemorrhage occurs infrequently in Japanese encephalitis (JE), and even less frequently with hemorrhage occurring twice. In this report, we describe the clinical features and outcomes of a patient with confirmed JE combined with hemorrhage twice.

PATIENT CONCERNS

The patient, a 71-year-old Asian woman, was admitted to the hospital with symptoms of hemiplegia following fever and diarrhea. Soon her condition worsened and a decreased level of consciousness, respiratory failure, and paralysis of extremities occurred.The brain diffusion-weighted imaging sequence showed suspicious abnormal signals in bilateral thalami. Japanese encephalitis virus immunoglobulin M antibody was detected in her serum and cerebrospinal fluid samples, so the patient was diagnosed with JE. During treatment, her condition became aggravated and the brain computed tomography (CT) scan showed multiple lobar hemorrhages. One month later, the multiple lobar hemorrhages occurred again, as observed by a brain CT scan.

DIAGNOSIS

JE with multiple intracranial hemorrhages.

INTERVENTIONS

The patient was treated comprehensively, including surgery, lowering her intracranial pressure and ventilator-assisted breathing.

OUTCOMES

One month later, the patient underwent another surgical procedure for intracranial hemorrhage and suffered a serious neurological disorder.

LESSONS

Severe intracranial hemorrhage may occur in elderly patients with JE, especially in those with poor vascular condition. Therefore, when treating such patients, great caution, as well as early detection and prevention, should be taken in case of the occurrence of severe intracranial hemorrhage.

Longitudinal magnetic resonance imaging changes in Japanese encephalitis

BACKGROUND

Japanese encephalitis is a flavivirus that can cause pandemic encephalitis, and is prevalent in Southeast Asia and Australia. Brain images of patients with Japanese encephalitis are characterized by thalamic lesions, distinct from those seen in viral encephalopathies caused by the herpes simplex virus and West Nile virus.

AIM

Herein, we describe for the first time a time-dependent magnetic resonance imaging pattern in Japanese encephalitis in a 10-month-old Japanese boy.

CASE

The patient was a previously healthy 10-month-old Japanese boy, who exhibited acute-onset flaccid tetraplegia and loss of tendon reflexes.

RESULTS

Brain MRI showed characteristic thalamic changes on diffusion weighted images from spotty to uniform and from the left to the right side, associated with low apparent diffusion coefficient maps. These images suggest that the Japanese encephalitis virus may first affect the unilateral thalamus, possibly expanding to the other side, with characteristic patterns changing from spotty to uniform in a manner consistent with the presentation of cytotoxic edema.

CONCLUSION

This report first showed longitudinal magnetic resonance changes in Japanese encephalitis, which may help in accurate diagnosis and in discrimination from other etiologies.

Clinical analysis of psychiatric symptoms of Japanese encephalitis during the convalescent Period: A single center study in Chongqing, China

BACKGROUND

This study aimed to analyze clinical and imaging features of children with severe Japanese encephalitis (JE), and to analyze causes and solutions for psychiatric symptoms of JE during the convalescent period.

METHODS

We analyzed clinical information for 78 children with severe JE at the Department of Neurology, Department of Infection, and Department of Rehabilitation in our hospital during 2014-2016. Seventy-eight cases of severe JE were divided into patients with psychiatric symptoms and no psychiatric symptoms groups. We focused on analysis of the patients with psychiatric symptoms group.

RESULTS

The incidence of psychiatric symptoms during the convalescent period was 46.15% (36/78). Antipsychotic drugs can effectively control psychiatric symptoms and shorten duration of symptoms. Seventy-one patients underwent reexamination with a head MRI. Of these, 8 cases (8/36 = 22.22%) in patients with psychiatric symptoms group showed new lesions in the basal ganglia, insula, and hippocampus. During the 12-month follow-up, two cases showed reappearance of psychiatric symptoms that had been relieved previously.

CONCLUSION

This study found that severe JE cases revealed a considerable proportion with psychiatric symptoms during the convalescent period.

A Japanese Encephalitis Patient Presenting with Parkinsonism with Corresponding Laterality of Magnetic Resonance and Dopamine Transporter Imaging Findings

Japanese encephalitis (JE) survivors often present with nigrostriatal aftereffects with parkinsonian features. A 67-year-old woman with JE showed right-dominant clinical parkinsonism and left-dominant substantia nigra lesions after magnetic resonance imaging (MRI). Dopamine transporter (DAT) imaging using ¹²³I-labeled 2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane (¹²³I-FP-CIT) revealed a corresponding left-dominant decrease. The present case is the first to reveal a clear match of laterality between clinical parkinsonism, MRI-based substantia nigra lesions, and impaired DAT in presynaptic dopaminergic neurons in JE.

Arterial spin-labeling perfusion imaging of childhood encephalitis: correlation with seizure and clinical outcome

PURPOSE

In childhood encephalitis, perfusion abnormalities have been infrequently reported to associate with clinical status. We investigated whether perfusion abnormalities correlated with seizure and clinical outcome in encephalitis.

METHODS

We retrospectively analyzed the MR studies of 77 pediatric patients with encephalitis. Pseudo-continuous arterial spin-labeling (ASL) imaging was performed on a 3-T scanner. The patients were divided into five groups according to ASL perfusion imaging pattern: normal perfusion (NP), focal hypoperfusion (Lf), extreme global hypoperfusion (LE), focal hyperperfusion (Hf), and extreme global hyperperfusion (HE). Clinical outcome at 3 weeks was dichotomized to unfavorable or favorable outcome according to the Glasgow outcome scale. Multivariate logistic regression was conducted to predict unfavorable outcome and presence of seizure separately, based on explanatory variables including age, sex, and ASL pattern.

RESULTS

Twenty-seven (35%) patients were designated as in group Hf, five (7%) in group Lf, 11 (14%) in group LE, none in group HE, and 34 (44%) in group NP. Multivariate logistic regression analysis showed that ASL pattern was significantly associated with unfavorable outcome (P = 0.005) and with presence of seizure (P = 0.005). For ASL pattern, group LE was 17.31 times as likely to have an unfavorable outcome as group NP (odds ratio confidence interval [CI] 3.084, 97.105; P = 0.001). Group Hf was 6.383 times as likely to have seizure as group NP (CI 1.765, 23.083; P = 0.005).

CONCLUSIONS

In childhood encephalitis, patients with extreme global hypoperfusion had poor neurological outcome and those with focal hypoperfusion were more likely to have seizure.

Brain Imaging in Cases with Positive Serology for Dengue with Neurologic Symptoms: A Clinicoradiologic Correlation

BACKGROUND AND PURPOSE

Dengue is a common arboviral disease, which uncommonly involves the brain. There has been a recent surge in dengue cases and dengue-related deaths in tropical countries. The aim of this study was to describe brain imaging findings in patients with dengue infection having neurologic symptoms.

MATERIALS AND METHODS

Thirty-five patients with positive serology for dengue with CNS symptoms undergoing imaging of the brain were included in the study. Clinical, laboratory, and imaging parameters were assessed and correlated to poor outcome.

RESULTS

A Glasgow Coma Scale score of ≤12 at presentation, clinical classification of severe-type dengue, and the presence of acute renal failure were associated with poor outcome. Imaging parameters associated with poor outcome were involvement of the thalami and cerebellar peduncles and the presence of diffusion restriction and hemorrhagic foci in the brain parenchyma.

CONCLUSIONS

Although not specific, dengue infection has imaging findings that can be used to narrow down the differential list and help in prognostication.

Cryptic etiopathological conditions of equine nervous system with special emphasis on viral diseases

The importance of horse (Equus caballus) to equine practitioners and researchers cannot be ignored. An unevenly distributed population of equids harbors numerous diseases, which can affect horses of any age and breed. Among these, the affections of nervous system are potent reason for death and euthanasia in equids. Many episodes associated with the emergence of equine encephalitic conditions have also pose a threat to human population as well, which signifies their pathogenic zoonotic potential. Intensification of most of the arboviruses is associated with sophisticated interaction between vectors and hosts, which supports their transmission. The alphaviruses, bunyaviruses, and flaviviruses are the major implicated groups of viruses involved with equines/humans epizootic/epidemic. In recent years, many outbreaks of deadly zoonotic diseases such as Nipah virus, Hendra virus, and Japanese encephalitis in many parts of the globe addresses their alarming significance. The equine encephalitic viruses differ in their global distribution, transmission and main vector species involved, as discussed in this article. The current review summarizes the status, pathogenesis, pathology, and impact of equine neuro-invasive conditions of viral origin. A greater understanding of these aspects might be able to provide development of advances in neuro-protective strategies in equine population.

Viral and Prion Infections of the Central Nervous System: Radiologic-Pathologic Correlation: From the Radiologic Pathology Archives

Viral infections of the central nervous system (CNS) range in clinical severity, with the most severe proving fatal within a matter of days. Some of the more than 100 different viruses known to affect the brain and spinal cord are neurotropic with a predilection for producing CNS infection. The host response to viral infection of the CNS is responsible for the pathophysiology and imaging findings seen in affected patients. Viral CNS infections can take the form of meningitis, encephalitis, encephalomyelitis, or, when involving the spinal cord and nerve roots, encephalomyeloradiculitis. In 1982, an infectious particle termed a prion that lacked nucleic acid and therefore was not a virus was reported to produce the fatal neurodegenerative disease Creutzfeldt-Jakob disease and related disorders. These prion diseases produce characteristic neuroimaging findings that are distinct from those seen in most viral infections. The clinical and imaging findings associated with viral CNS infection are often nonspecific, with microbiologic analysis of cerebrospinal fluid the most useful single test allowing for diagnosis of a specific viral infection. This review details the spectrum of viral CNS infections and uses case material from the archives of the American Institute for Radiologic Pathology, with a focus on the specific clinical characteristics and magnetic resonance imaging features seen in these infections. Where possible, the imaging features that allow distinction of these infections from other CNS inflammatory conditions are highlighted.

Clinical Characteristics of Severe Japanese Encephalitis: A Case Series from South Korea

Japanese encephalitis (JE) virus is a major cause of devastating viral encephalitis, especially in Asia. Although a successful vaccination program led to its near-elimination over three decades in South Korea, the incidence of JE has increased since 2010. The present study investigated the clinical manifestations, laboratory findings, and factors affecting neurological outcomes of reemerging JE. We retrospectively reviewed medical records of laboratory-confirmed JE patients who presented with acute encephalitis syndrome at three tertiary hospitals between 2010 and 2015. A total of 17 patients with JE were identified. Their median age was 51 years, and 10 (58.5%) were men. The most common symptoms and signs were fever (94.1%), altered consciousness (94.1%), and headache (80.2%). Hyporeflexia (47.1%), seizures (35.2%), abnormal brainstem reflex (23.5%), and flaccid weakness (17.6%) were also noted. Brain imaging revealed thalamic lesions in all patients, with the hippocampus, midbrain, basal ganglia, and cerebral cortex affected to varying degrees. Sixteen patients (94.1%) required management in the intensive care unit with mechanical ventilation due to neurological deterioration. At the time of discharge, 11 (64.7%) had poor recovery, defined as Glasgow coma scale scores of less than 8, and remained ventilator dependent. Comparison between the two outcome groups indicated that midbrain involvement (P = 0.028) and rapid deterioration (P = 0.005) were associated with severe neurological sequelae. Given that JE is a vaccine-preventable disease, vaccination for adults should be considered in response to the reemergence of JE.

Infection-mediated autoimmune movement disorders

Infectious diseases remain the most common cause of neurological disability in the world. A number of movement disorders can develop in adults and children in response to infections. These can occur in isolation or as part of a broader neurological illness, with movement abnormalities consequent to an encephalopathy or a broader brain dysfunction. While most infection-related movement disorders are direct consequences of an active infectious process affecting cerebral structures implied in the motor network, at times a delayed immune-mediated process in response to a previous infectious is responsible for the neurological dysfunction. This immunological response can occur as a consequence of a number of pathogens, and develop at variable times after the initial infection. The most common infection-mediated autoimmune movement disorders are chorea, which is especially common in children, and other hyperkinetic disorders, but Parkinsonism and other hypokinetic movement disorders may also occur.

Movement disorders of probable infectious origin

Background:

Movement disorders (MDs) associated with infections remains an important debilitating disorder in the Asian countries.

Objectives:

The objective of the following study is to report the clinical and imaging profile of a large cohort of patients with MDs probably associated with infection.

Materials and Methods:

This was a chart review of 35 patients (F:M-15:20) presenting with MD in the Neurology services of National Institute of Mental Health and Neurosciences, India. The demographic profile, type of infection, time from infection to MD, phenomenology of MD and magnetic resonance imaging (MRI) findings were reviewed.

Results:

The mean age at presentation was 22.6 ± 13.3 years, (5-60), age of onset of MD was 15.7 ± 15 years, and duration of symptoms was 6.9 ± 8.1 years (42 days to 32 years). The mean latency of onset of MD after the infection was 5.9 ± 4.2 weeks. The phenomenology of MD were: (1) Pure dystonia-28.6%, (2) dystonia with choreoathetosis-22.9%, (3) Parkinsonism-14.6%, (4) pure tremor, hemiballismus, myoclonus and chorea-2.9% each, and (5) mixed MD-22.9%. Most often the MD was generalized (60%), followed by right upper limb (31.4%) and left upper limb (8.6%). A viral encephalitic type of neuroinfection was the most common infection (85.7%), which was associated with MD. Abnormalities of brain MRI, seen in 79.2%, included signal changes in (1) thalamus-52.0%, (2) putamen and subcortical white matter-16% each, (3) pons-12%, (4) striatopallidum, striatum and grey matter-8% each, and (5) caudate, cerebellum, lentiform nucleus, midbrain and subthalamic nucleus-4.0% each.

Conclusions:

MDs associated with infection were the most often post-encephalitic. Dystonia was the most common MD, and thalamus was the most common anatomical site involved.

Japanese encephalitis in a French traveler to Nepal

Japanese encephalitis is frequent in Asia, with a severe prognosis, but rare in travelers. Culex mosquitoes transmit Japanese encephalitis virus. Risk factors are destination, duration of stay, summer and fall seasons, outdoor activities, and type of accommodation. We report the case of a French traveler to Nepal with neutralization-based serological confirmed Japanese encephalitis. He presented classical clinical (viral syndrome before an encephalitis status with behavioral disorder, global hypotonia, mutism, movement disorders, seizure, and coma), radiological (lesions of thalami, cortico-spinal tracts, and brainstem) and biological features (lymphocytic meningitis). Nowadays, the presence of Japanese encephalitis virus in Nepal, including mountain areas, is established but Japanese encephalitis remains rare in travelers returning from this area and neurologist physicians need to become familiar with this. We recommend vaccination for travelers spending a long period of time in Nepal and having at-risk outdoor activities.

Recovery of a chemically synthesized Japanese encephalitis virus reveals two critical adaptive mutations in NS2B and NS4A

A full-length genome infectious clone is a powerful tool for functional assays in virology. In this study, using a chemical synthesized complete genome of Japanese encephalitis virus (JEV) strain SA14 (GenBank accession no. U14163), we constructed a full-length genomic cDNA clone of JEV. The recovered virus from the cDNA clone replicated poorly in baby hamster kidney (BHK-21) cells and in suckling mice brain. Following serial passage in BHK-21 cells, adaptive mutations within the NS2B and NS4A proteins were recovered in the passaged viruses leading to viruses with a large-plaque phenotype. Mutagenesis analysis, using a genome-length RNA and a replicon of JEV, demonstrated that the adaptive mutations restored replication to different degrees, and the restoration efficiencies were in the order: NS2B-T102M<NS4A-R79K<NS2B-T102M+NS4A-R79K. An in vivo virulence assay in mice showed that the recombinant virus containing double mutations showed similar virulence to the WT SA14 (GenBank accession no. M55506). This study reports the first chemically synthesized JEV. A reverse genetics assay demonstrated that substitutions of NS2B-T102M and NS4A-R79K altered JEV replication.