A case of new onset refractory status epilepticus in a U.S. traveler with Japanese encephalitis.

New onset refractory status epilepticus (NORSE) is a rare but critical condition characterized by refractory status epilepticus (RSE) in an individual without prior history of epilepsy or known structural, toxic, or metabolic cause. Postinfectious immune activation is an important cause of NORSE. Early testing for autoimmune antibodies is strongly recommended (Wickstrom et al., 2022). We report a case of NORSE triggered by Japanese encephalitis (JE) in an unvaccinated US adult traveler. Her CSF later revealed positive anti-N-methyl-d-aspartate (NMDA)-receptor antibody. The patient responded well to first line immunotherapy with favorable functional outcome. This case highlights the diagnostic and treatment challenges in this rare presentation.

The underlying mechanism of Guillain-Barré syndrome in a young patient suffered from Japanese encephalitis virus infection: a case report.

BACKGROUND: The presentation of Guillain-Barré syndrome (GBS) caused by Japanese encephalitis virus (JEV) is uncommon, although clusters of GBS cases were observed in China in 2018. The underlying mechanism is unclear, particularly in individuals vaccinated against Japanese encephalitis in childhood. CASE PRESENTATION: We report a patient with acute flaccid paralysis involving four extremities and respiratory muscles, while magnetic resonance imaging of the brain and spine were standard. Electrophysiological examination displayed slowed motor nerve conduction speed and reduced evoked velocity amplitude. GBS was finally considered which was related to JEV infection verified by positive anti-JEV immunoglobulin M antibody and positive immunoglobulin G antibody in the serum. Unfortunately, the patient refused intravenous immunoglobulin and declined the use of mechanical ventilation again. He voluntarily withdrew from the hospital and died on the 36th day after the onset of illness. We also performed a review of previously reported related cases and discussed the underlying mechanism. CONCLUSION: JEV infection-associated GBS is unusual. We should pay attention to the atypical manifestations of JEV infection and explore possible pathogenesis in particular individuals.

Label-free proteomics-based analysis of peripheral nerve injury induced by Japanese encephalitis virus.

Japanese encephalitis (JE) is just an acute encephalitis syndrome contributed to Japanese encephalitis virus (JEV) infection. It the chief causes of viral encephalitis in Asia. In recent years, association of JEV infection with neurological problems such as Guillain-Barré syndrome(GBS) had reported. Nevertheless, its potential pathogenic mechanism has not previously been reported. Therefore, it is urgent to study the relationship between peripheral nerve injury (PNI) and JEV infection. Here, we use the liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique to make out the protein expression levels of mice sciatic nerve between JEV infection group and the sham group. In general, 4303 proteins were designated by MS, and 187 differentially expressed proteins(DEPs) were found. There were 105 proteins up-regulated in the injured sciatic nerve, and 82 proteins were down-regulated. Functional enrichment analysis of DEPs showed that the up-regulated proteins were mainly related to immune regulatory response, and down-regulated proteins were related to ribosomal structural components and translation. SIGNIFICANCE: The Japanese encephalitis virus, a member of the flavivirus, is a Mosquito borne virus. It leads to central nervous system injury by the immune response and inflammation in the brain. In addition, the virus also gave rise to PNI. It is a major public health problem in Asia. The diversity of clinical symptoms has brought serious challenges to the diagnosis and treatment of the disease. Label-Free Proteomics was undertaken to explore the potential mechanisms between JEV and peripheral nervous system in this study. It provided strong evidence that tissue damage is caused by the immune-mediated mechanisms rather than the virus, which offers a basis for the prevention of the disease and further looking for treatment targets.

Risk factors and a predictive model for the development of epilepsy after Japanese encephalitis.

BACKGROUND: We aimed to study seizure characteristics during the acute phase of Japanese encephalitis (JE) in children, determine the risk factors of postencephalitic epilepsy (PEE), establish a risk prediction model for the disease, and construct a nomogram to visualize the model. METHODS: We retrospectively analyzed the clinical data and follow-up results of 328 children with JE who were hospitalized between January 2011 and December 2020. Risk factors were screened using univariable analysis, a predictive model was built using binary logistic analysis, lasso regression was used for variable screening, and a nomogram was developed. RESULTS: Of the 328 children with JE enrolled in the study, 216 (65.9%, 216/328) had seizures in the acute phase. The incidence of PEE was 14.7% (39/264), The cumulative percentages of PEE after discharge was 10.6% (28/264)at 6 months, which increased to 13.6%(36/264)at 3 years. 38.5% of patients with PEE had generalized onset seizures, and 17.9% had focal motor seizures. Univariable analysis revealed that 22 clinical indicators were related to the PPE; Multivariable analysis identified seizure number >5 (OR (95%CI) = 3.013 (1.046-8.676), P = 0.041), status epilepticus (OR (95%CI) = 3.918 (1.212-12.669), P = 0.023), and Coma (OR (95%CI) = 22.495 (8.686-58.285), P<0.001) as independent risk factors for PEE. The risk prediction model: ln(p/1p)= -3.533 + 1.103 × (seizures number > 5) +1.366 × (status epilepticus) + 3.113 × (Coma) was developed, and a nomogram was constructed. The area under the ROC curve (AUC), calibration plot, and Hosmer-Lemeshow test showed that the model had good discrimination and calibration. Ordinary bootstrapping was used for internal validation, and the predictive results of the original and test sets were consistent. CONCLUSIONS: Seizure is a common manifestation during acute encephalitis and sequelae in children with JE. The nomogram constructed in this study could be used for early prediction, and could facilitate early intervention.

Proteomic landscape subtype and clinical prognosis of patients with the cognitive impairment by Japanese encephalitis infection.

BACKGROUND: Cognitive impairment is one of the primary sequelae affecting the quality of life of patients with Japanese encephalitis (JE). The clinical treatment is mainly focused on life support, lacking of targeted treatment strategy. METHODS: A cerebrospinal fluid (CSF) proteomic profiling study was performed including 26 patients with JE in Gansu province of China from June 2017 to October 2018 and 33 other concurrent hospitalized patients who were excluded central nervous system (CNS) organic or CNS infection diseases. The clinical and proteomics data of patients with JE were undergoing combined analysis for the first time. RESULTS: Two subtypes of JE associated with significantly different prognoses were identified. Compared to JE1, the JE2 subtype is associated with lower overall survival rate and a higher risk of cognitive impairment. The percentages of neutrophils (N%), lymphocyte (L%), and monocytes (M%) decreased in JE2 significantly. CONCLUSIONS: The differences in proteomic landscape between JE subgroups have specificity for the prognosis of cognitive impairment. The data also provided some potential target proteins for treatment of cognitive impairments caused by JE. Trial registration ChiCTR, ChiCTR2000030499. Registered 1st June 2017, http://www.medresman.org.cn/pub/cn/proj/projectshow.aspx?proj=6333.

Myelitis with flaccid paralysis due to Japanese encephalitis: case report and review of the literature.

BACKGROUND: Japanese encephalitis is an arthropod-borne zoonotic flavivirus infection endemic to tropical and subtropical Asia. A minority of infections leads to a symptomatic course, but affected patients often develop life-threatening encephalitis with severe sequelae. LITERATURE REVIEW: Myelitis with flaccid paralysis is a rare complication of Japanese Encephalitis, which-according to our literature search-was reported in 27 cases, some of which were published as case reports and others as case series. Overall, there is a broad clinical spectrum with typically asymmetric manifestation and partly severe motor sequelae and partly mild courses. Lower limb paralysis appears to be more frequent than upper limb paralysis. An encephalitic component is not apparent in all cases CASE PRESENTATION: We herein add the case of a 29 year-old female who developed encephalitis and myelitis with flaccid paralysis during a long-time stay in Indonesia. Diagnostic workup in Indonesia did not clearly reveal an underlying cause. Upon clinical stabilization, the patient was evacuated to her home country Germany, where further diagnostics confirmed Japanese encephalitis virus as the causative agent. The patient has partly recovered, but still suffers from residual paralysis of the upper limb. CONCLUSION: Flaccid paralysis is a rare, and likely underdiagnosed complication of Japanese encephalitis, which, to the best of our knowledge, has never been diagnosed outside endemic areas before.

Clinical Characteristics of Children With Anti-N-Methyl-d-Aspartate Receptor Encephalitis After Japanese Encephalitis.

BACKGROUND: Viral encephalitis is an important trigger for anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis. We analyzed the clinical characteristics of anti-NMDAR encephalitis after Japanese encephalitis (JE) in children. METHODS: Clinical data of 185 children with anti-NMDAR encephalitis were retrospectively reviewed. Patients with a history of viral encephalitis other than JE or who were identified with other autoantibodies were excluded. RESULTS: Twenty children with anti-NMDAR encephalitis after JE were enrolled with a median age of 6 years and 10 months (interquartile range [IQR]: 3 years to 11 years and 5 months). The median time from JE to anti-NMDAR encephalitis was 29 (IQR: 25 to 32) days. At 12 months, most patients (17 of 18) recovered to at least their baseline modified Rankin scale (mRS) scores caused by JE. One hundred forty two children with classical anti-NMDAR encephalitis were enrolled. Compared with classical anti-NMDAR encephalitis, patients after JE had significantly more decreased level of consciousness (50% vs 18.3%, P = 0.003), more autonomic dysfunction (30.0% vs 9.9%, P = 0.021), fewer psychiatric or behavioral symptoms (70.0% vs 90.8%, P = 0.016), fewer seizures (25.0% vs 68.3%, P < 0.001), lesser improvement 4 weeks after immunotherapy (35.0% vs 73.2%, P = 0.001), and worse outcomes at 12 months (median mRS: 1 vs 0, P < 0.001). CONCLUSIONS: Anti-NMDAR encephalitis after JE in children mainly occurred within two months. Their clinical manifestation may differ from classical anti-NMDAR encephalitis. The prognosis of children with anti-NMDAR encephalitis after JE probably depends on the neurological sequelae after 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.

Development and characterization of an animal model of Japanese encephalitis virus infection in adolescent C57BL/6 mouse.

A mouse-adapted isolate of Japanese encephalitis virus (JEV), designated as JEV-S3, was generated by serially passaging the P20778 strain of the virus in 3- to 4-week-old C57BL/6 mice. Blood-brain barrier leakage was evident in JEV-S3-infected mice, in which viral antigens and RNA were consistently demonstrated in the brain, along with infiltration of activated immune cells, as evidenced by an increased CD45+CD11b+ cell population. Histopathology studies showed the presence of perivascular cuffing, haemorrhage and necrotic foci in the virus-infected brain, conforming to the pathological changes seen in the brain of JEV-infected patients. Mass spectrometry studies characterized the molecular events leading to brain inflammation in the infected mice. Notably, a significant induction of inflammatory cytokines, such as IFNγ, IL6, TNFα and TGFß, was observed. Further, genome sequencing of the JEV-S3 isolate identified the mutations selected during the mouse passage of the virus. Overall, we present an in-depth characterization of a robust and reproducible mouse model of JEV infection. The JEV-S3 isolate will be a useful tool to screen antivirals and study virus pathogenesis in the adolescent mouse model.

Pathogenicity and virulence of Japanese encephalitis virus: Neuroinflammation and neuronal cell damage.

Thousands of human deaths occur annually due to Japanese encephalitis (JE), caused by Japanese encephalitis virus. During the virus infection of the central nervous system, reactive gliosis, uncontrolled inflammatory response, and neuronal cell death are considered as the characteristic features of JE. To date, no specific treatment has been approved to overcome JE, indicating a need for the development of novel therapies. In this article, we focused on basic biological mechanisms in glial (microglia and astrocytes) and neuronal cells that contribute to the onset of neuroinflammation and neuronal cell damage during Japanese encephalitis virus infection. We also provided comprehensive knowledge about anti-JE therapies tested in clinical or pre-clinical settings, and discussed recent therapeutic strategies that could be employed for JE treatment. The improved understanding of JE pathogenesis might lay a foundation for the development of novel therapies to halt JE.Abbreviations AKT: a serine/threonine-specific protein kinase; AP1: activator protein 1; ASC: apoptosis-associated speck-like protein containing a CARD; ASK1: apoptosis signal-regulated kinase 1; ATF3/4/6: activating transcription factor 3/4/6; ATG5/7: autophagy-related 5/7; BBB: blood-brain barrier; Bcl-3/6: B-cell lymphoma 3/6 protein; CCL: C-C motif chemokine ligand; CCR2: C-C motif chemokine receptor 2; CHOP: C/EBP homologous protein; circRNA: circular RNA; CNS: central nervous system; CXCL: C-X-C motif chemokine ligand; dsRNA: double-stranded RNA; EDEM1: endoplasmic reticulum degradation enhancer mannosidase alpha-like 1; eIF2-ɑ: eukaryotic initiation factor 2 alpha; ER: endoplasmic reticulum; ERK: extracellular signal-regulated kinase; GRP78: 78-kDa glucose-regulated protein; ICAM: intercellular adhesion molecule; IFN: interferon; IL: interleukin; iNOS: inducible nitric oxide synthase; IRAK1/2: interleukin-1 receptor-associated kinase 1/2; IRE-1: inositol-requiring enzyme 1; IRF: interferon regulatory factor; ISG15: interferon-stimulated gene 15; JE: Japanese encephalitis; JEV: Japanese encephalitis virus; JNK: c-Jun N-terminal kinase; LAMP2: lysosome-associated membrane protein type 2; LC3-I/II: microtubule-associated protein 1 light chain 3-I/II; lncRNA: long non-coding RNA; MAPK: mitogen-activated protein kinase; miR/miRNA: microRNA; MK2: mitogen-activated protein kinase-activated protein kinase 2; MKK4: mitogen-activated protein kinase kinase 4; MLKL: mixed-linage kinase domain-like protein; MMP: matrix metalloproteinase; MyD88: myeloid differentiation factor 88; Nedd4: neural precursor cell-expressed developmentally downregulated 4; NF-κB: nuclear factor kappa B; NKRF: nuclear factor kappa B repressing factor; NLRP3: NLR family pyrin domain containing 3; NMDAR: N-methyl-D-aspartate receptor; NO: nitric oxide; NS2B/3/4: JEV non-structural protein 2B/3/4; P: phosphorylation. p38: mitogen-activated protein kinase p38; PKA: protein kinase A; PAK4: p21-activated kinase 4; PDFGR: platelet-derived growth factor receptor; PERK: protein kinase R-like endoplasmic reticulum kinase; PI3K: phosphoinositide 3-kinase; PTEN: phosphatase and tensin homolog; Rab7: Ras-related GTPase 7; Raf: proto-oncogene tyrosine-protein kinase Raf; Ras: a GTPase; RIDD: regulated IRE-1-dependent decay; RIG-I: retinoic acid-inducible gene I; RIPK1/3: receptor-interacting protein kinase 1/3; RNF11/125: RING finger protein 11/125; ROS: reactive oxygen species; SHIP1: SH2-containing inositol 5' phosphatase 1; SOCS5: suppressor of cytokine signaling 5; Src: proto-oncogene tyrosine-protein kinase Src; ssRNA = single-stranded RNA; STAT: signal transducer and activator of transcription; TLR: toll-like receptor; TNFAIP3: tumor necrosis factor alpha-induced protein 3; TNFAR: tumor necrosis factor alpha receptor; TNF-α: tumor necrosis factor-alpha; TRAF6: tumor necrosis factor receptor-associated factor 6; TRIF: TIR-domain-containing adapter-inducing interferon-ß; TRIM25: tripartite motif-containing 25; VCAM: vascular cell adhesion molecule; ZO-1: zonula occludens-1.

Autoimmune encephalitis after Japanese encephalitis in children: A prospective study.

OBJECTIVE: To explore anti-neuronal surface antibodies and identify associated serum predictors of autoimmune encephalitis after Japanese encephalitis (JE). METHODS: This prospective study first detected anti-neuronal surface antibodies and cytokines in the serum and cerebrospinal fluid (CSF) of JE patients within one week of symptom onset. Anti-neuronal surface antibodies and cytokines in the serum were detected on day 21 post-JE. If the patients relapsed during the convalescent phase, we simultaneously detected JE virus RNA and cytokines in the CSF, as well as anti-neuronal surface antibodies in the serum and CSF. RESULTS: All 31 patients were negative for anti-neuronal surface antibodies at the onset of JE in the serum and CSF. During the convalescent phase, five patients developed autoimmune encephalitis (two had anti-N-methyl-d-aspartate receptor [NMDAR] antibodies, one had γ-aminobutyric acid-B receptor [GABABR] antibodies, and two had other antibodies against unknown neuronal surface antigens). Patients who developed autoimmune encephalitis experienced more severe outcomes than those who did not at the one-year follow-up (p = 0.044). The levels of serum CXCL13 and IL-6, as well as CXCL13, BAFF, CXCL10, and MMP-9 in the CSF were increased in the convalescent phase compared to the acute phase in patients who developed autoimmune encephalitis (p < 0.05). CONCLUSION: In addition to anti-NMDAR antibodies, anti-GABABR antibodies and antibodies against unknown neuronal surface antigens can trigger autoimmune encephalitis following JE. Patients who developed autoimmune encephalitis had a poorer prognosis at the one-year follow-up. Serum CXCL13 may represent a predictor of autoimmune encephalitis after JE.

Treatment of Severe Japanese Encephalitis Complicated With Hashimoto's Thyroiditis and Guillain-Barré Syndrome With Protein A Immunoadsorption: A Case Report.

A severely comatose female patient was diagnosed with Japanese encephalitis (JE). Her condition was complicated by Hashimoto's thyroiditis (HT) and Guillain-Barré syndrome (GBS). After antiviral, glucocorticoid, and immunoglobulin treatment, the patient's consciousness was restored, and she could breathe spontaneously. Following this, new-onset, primarily demyelinating GBS developed, which progressed to demyelination combined with axonal injury. The patient was switched to protein A immunoadsorption (PAIA) therapy, and her Hughes score decreased rapidly, from 4 to 1 after 6 months. This patient is the first to receive PAIA combined with an antiviral-glucocorticoid-immunoglobulin regimen to treat encephalitis, meningitis, HT, and GBS caused by JE infection, thereby reflecting the importance of clinical application of PAIA in the treatment of immunological complications of JE.

Co-infection of neurocysticercosis with Japanese encephalitis: coincidence or synchronism?

We report the case of an eight-year-old boy who presented with an acute encephalitis and was confirmed to have Japanese encephalitis (JE). In addition, we found the vesicular stage of neurocysticercosis (NCC). The co-occurrence of JE and NCC was thought to be synergistic as there is some evidence that in presence of NCC, the neuroinvasiveness and virulence of JE is greater and associated with poor outcome.

Acute Flaccid Paralysis as the Initial Manifestation of Japanese Encephalitis: a Case Report.

Japanese encephalitis (JE) is a clinical disease caused by inflammation of the central nervous system. The symptoms of this disease range broadly in severity from mild febrile illness to acute meningomyeloencephalitis. JE has been associated with a variety of neurological abnormalities, such as altered sensorium, seizures, focal neurological deficit, and acute flaccid paralysis (AFP). However, to date, AFP has never been reported as an initial manifestation of JE. Here, we present a case of AFP manifesting as the initial symptom of JE in a Chinese patient. A 30-year-old Chinese man was admitted to the West China Hospital of Sichuan University after experiencing AFP in the right upper limb, followed by hyperpyrexia and unconsciousness. Assay of cerebrospinal fluid from a lumbar puncture revealed high levels of proteins and anti- JE virus IgM antibodies. Intravenous acyclovir was administered; however, the weakness persisted and more extensive muscle wasting from the proximal to distal right upper limb occurred over 7 months. This case report highlights that JE needs to be added to the differential diagnosis of AFP in adults, especially in JE endemic seasons and areas.

Japanese encephalitis-induced anti-N-methyl-d-aspartate receptor encephalitis: A hospital-based prospective study.

OBJECTIVES: A hospital-based prospective study was performed to determine: 1) whether Japanese encephalitis (JE) normally triggers anti-N-methyl-d-aspartate receptor (NMDAR) immunoglobulin G (IgG) synthesis, especially in monophasic JE patients; and 2) the incidence of JE-induced anti-NMDAR encephalitis in pediatric patients with JE. METHODS: We detected the level of anti-NMDAR IgG in the serum and cerebral spinal fluid (CSF) of JE patients within one week of onset. If patients relapsed during the convalescence phase, we detected JE virus RNA in the CSF and anti-NMDAR IgG in both the serum and CSF. For patients who did not relapse during the convalescence phase, serum was collected and anti-NMDAR IgG was detected during the 30-60-day course of the disease. RESULTS: We enrolled 65 JE patients, who were negative for anti-NMDAR IgG in the serum and CSF during the acute phase, of which 63 patients were successfully followed up. Five patients relapsed during the convalescence phase, for whom JE virus RNA in the CSF was negative and excluded latent JE reactivation. The distinctive symptoms of four younger patients were choreoathetosis, whereas the psychiatric and behavioral manifestations were the distinctive symptoms experienced by the teenager. Anti-NMDAR IgG in the CSF of three patients was positive and they were diagnosed with anti-NMDAR encephalitis. The other two patients were negative for anti-NMDAR IgG in both the serum and CSF. For the 58 patients who did not relapse during the convalescence phase, anti-NMDAR IgG was negative in the serum of all patients at 30-60 days during the course of the disease. CONCLUSIONS: JE does not typically trigger anti-NMDAR IgG synthesis. Besides anti-NMDAR IgG, other unknown autoantibodies can also cause autoimmune encephalitis in the convalescence phase of JE. The incidence of JE-induced autoimmune encephalitis in pediatric patients with JE was 7.9%, and the incidence of JE-induced anti-NMDAR encephalitis was 4.7%.

Japanese Encephalitis Virus infection induces inflammation of swine testis through RIG-I-NF-ĸB signaling pathway.

Japanese Encephalitis Virus (JEV) is an important zoonotic flavivirus transmitted by mosquitos. JEV infection in sows primarily manifests as a reproductive disease such as abortion and transient infertility while in infected boars, it can cause orchitis. Previous studies mainly focused on the pathogenesis of human encephalitis caused by JEV infection, while few concentrations have been made to unveil the potential mechanism of reproductive dysfunction in JEV-infected pigs. In this study, histopathological analysis and immunohistochemistry staining was performed on testis of JEV-infected boars, indicating that JEV could infect testicular cells and cause inflammatory changes in testis. In vitro assays reveal that primary swine testicular cells and swine testis (ST) cells are highly permissive to JEV and significant inflammatory response was shown during JEV infection. Mechanically, we found that JEV infection increases the expression of retinoic acid-inducible gene I (RIG-I) and activates transcription factor NF-κB. Production of pro-inflammatory cytokines was greatly reduced in JEV infected testicular cells after knockout of RIG-I or treatment with the NF-κB specific inhibitor. In addition, activation of NF-κB was also significantly suppressed upon RIG-I knockout. Taken together, our results reveal that JEV could infect boar testicles, and RIG-I-NF-κB signaling pathway is involved in JEV-induced inflammation in swine testicular cells.