Association of Japanese encephalitis virus infection with Guillain-Barré syndrome in endemic areas of South India*

This study is a report of 34 cases of Guillain-Barré syndrome (GBS) observed in Bangalore (South India), an endemic area for Japanese encephalitis virus (JEV) infection. Virological and immunological findings suggested an antecedent and recent JEV infection in 21/34 patients. Nineteen patients among them showed high levels of JEV-specific IgM antibodies in serum and/or CSF, while the viral antigen could be demonstrated in one case and virus isolation from the CSF was successful in one patient. EMG studies revealed features of predominantly demyelinating neuropathy in 18/25 cases. Comparison of clinical findings, duration of illness and outcome in GBS patients with evidence of JEV infection and those without did not reveal any differences. Pathological findings in one patient corroborated the association of JEV with GBS. We conclude that, JEV infection may predispose to Guillain-Barré syndrome in endemic areas.     

Clinical,radiological and neurophysiological spectrum of JEV encephalitis and other non-specific encephalitis during post-monsoon period in India

AIMS: To study the spectrum of encephalitis during the post-monsoon period in a tertiary care centre of India. METHODS: Clinical, neurophysiological and radiological features of patients with encephalitis are reported in this communication. The patients were subjected to clinical examination, CT or MRI scan, EEG, motor and somatosensory evoked potentials in both upper and lower limbs bilaterally and concentric needle electromyography. The laboratory studies for Japanese encephalitis (JE) comprised virus isolated, IgM capture ELISA, mercaptoethanol test and hemagglutination inhibition titre in paired sera against JE virus. Patients were classified into JEV encephalitis and non-specific encephalitis. On the basis of radiological features, they were classified into group I (thalamic or basal ganglia involvement), group II (brainstem involvement only) and group III (normal MRI). The outcome was defined into poor (bedridden), partial (dependent for daily activities) and complete (independent) recovery at the end of 3 months. RESULTS: Out of 26 patients (Age 7-70 years, mean 24.8 years), laboratory evidences of JEV infection was present in 14 patients and one patient had herpes simplex encephalitis. The patients with JEV encephalitis had more severe illness as evidenced by lower GCS score, higher frequency of anterior horn cell involvement, movement disorders and more extensive MRI changes. The EEG and MEP changes were also more frequently abnormal in the JEV group. On radiology, 15 patients had thalamic or basal ganglia involvement (group I), 3 isolated midbrain involvement (group II) and 8 had normal MRI (group III). Laboratory evidence consistent with JE were present in 11 out of 12 patients in group I and 3 out of 8 in group III, however, there was no laboratory evidence of JE virus infection in patients with isolated brainstem involvement. There was overlap in the neurologic and systemic manifestations in all the 3 radiological groups as well as in the groups with and without laboratory evidences of JEV infection. CONCLUSION: The observed overlap in neurological and systemic involvement in different subgroups of encephalitis may be due to JE or JE-like viral infection. The possibility of strain variation, change in virulence of organism or immunity of host needs further studies.     

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

ObjectivesA 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.MethodsWe 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.ResultsWe 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.ConclusionsJE 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%.     

Development of a recombinant vaccine against Japanese encephalitis

Japanese encephalitis (JE) is the major form of viral encephalitis in much of the South-East Asia, India, and China. The disease is caused by a mosquito-borne virus known as Japanese encephalitis virus (JEV). The virus spreads in the form of epidemics, although several endemic areas for JEV activity are known. In recent years, JEV has spread to newer geographic locations such as Australia and Pakistan, and thus has become an important emerging virus infection in these areas. A mouse brain-derived, formalin-inactivated vaccine is available for immunization against JE. Because the formalin-inactivated JEV vaccine has limitations in terms of safety, availability, and cost, attempts are being made to develop improved vaccine using the recombinant DNA technology. This article reviews various attempts in this direction and summarizes the latest developments such as the recombinant yellow fever virus- or the plasmid DNA-based JEV vaccine.     

An evaluation of the usefulness of neuroimaging for the diagnosis of Japanese encephalitis

Japanese encephalitis virus (JEV) is estimated to cause 30–50,000 cases of encephalitis every year. The disease occurs mainly in rural Asia and is transmitted to humans from birds and pigs by mosquitoes of the genus Culex. JE is diagnosed with antibody testing of the serum and CSF, but this is not available in many hospitals. Neuroimaging abnormalities, particularly thalamic hypodensity on computed tomography (CT) and hyperintensity on T2 weighted magnetic resonance imaging (MRI) have been described in case studies, but their usefulness for diagnosing JE is not known. We have therefore evaluated the usefulness of neuroimaging (CT and MRI) for the diagnosis of JE. The findings of thalamic lesions were compared with the final serological diagnosis in a cohort of 75 patients (children and adults) with suspected CNS infections in Southern Vietnam, a JEV endemic area. Thalamic lesions on CT and/or MRI combined had sensitivity 23% (95% confidence interval 12.9–33.1%), specificity 100%, positive predictive value 100% and negative predictive value 42.1% (95% confidence interval 30.2–53.8%) for a diagnosis of JE in this cohort. Over time, the thalamic lesions resolved in some patients. One patient showed disappearance of lesions on CT followed by reappearance of the lesions some time later, known as the fogging effect. In this setting, the presence of thalamic abnormalities suggested the diagnosis of JE, but their absence did not exclude it.     

Inflammatory markers in the patients of Japanese encephalitis

OBJECTIVES: Japanese encephalitis (JE) is one of the commonest viral encephalitis especially prevalent in Southeast Asia. Estimated mortality rate of JE is approximately 30%, with survivors undergoing severe and irreversible neurological sequelae. Although central nervous system (CNS) inflammation is imminent upon JE infection, the pathways underlying the same have not yet been clearly elucidated. However, cytokines-tumor necrosis factor-alpha (TNF-alpha) and interlukin-2 (IL-2), are small secreted proteins, which mediate and regulate immunity. Therefore, we wanted to evaluate the role, if any, of these cytokines in the pathogenesis of JE.METHODS: We measured the levels of TNF-alpha and IL-2 in the serum and cerebrospinal fluid (CSF) of patients suffering JE, using enzyme-linked immunosorbent assay (ELISA).RESULTS: JE infection caused a remarkable increase (p<0.0001) in the levels of TNF-alpha in the serum and CSF, while IL-2 levels were unaffected.DISCUSSION: These results show that TNF-alpha pathway is involved in JE infection-triggered neuroinflammation.     

Persistent movement disorders following Japanese encephalitis.

The authors report on movement disorders that persist for a long duration following Japanese encephalitis (JE). Fifteen patients with diagnosed JE were followed up after an interval of 3 to 5 years. Of the four patients with a movement disorder, two were children with severe generalized dystonia in whom MRI revealed bilateral thalamic lesions. The two adult patients had parkinsonism. MRI in both adult patients showed lesions confined to the substantia nigra. Viral antibody and antigen were absent in the CSF of all patients.     

Enterovirus 71 encephalomyelitis and Japanese encephalitis can be distinguished by topographic distribution of inflammation and specific intraneuronal detection of viral antigen and RNA

K. T. Wong, K. Y. Ng, K. C. Ong, W. F. Ng, S. K. Shankar, A. Mahadevan, B. Radotra, I. J. Su, G. Lau, A. E. Ling, K. P. Chan, P. Macorelles, S. Vallet, M. J. Cardosa, A. Desai, V. Ravi, N. Nagata, H. Shimizu and T. Takasaki (2012) Neuropathology and Applied Neurobiology 38, 443–453 Enterovirus 71 encephalomyelitis and Japanese encephalitis can be distinguished by topographic distribution of inflammation and specific intraneuronal detection of viral antigen and RNA Aims: To investigate if two important epidemic viral encephalitis in children, Enterovirus 71 (EV71) encephalomyelitis and Japanese encephalitis (JE) whose clinical and pathological features may be nonspecific and overlapping, could be distinguished. Methods: Tissue sections from the central nervous system of infected cases were examined by light microscopy, immunohistochemistry and in situ hybridization. Results: All 13 cases of EV71 encephalomyelitis collected from Asia and France invariably showed stereotyped distribution of inflammation in the spinal cord, brainstem, hypothalamus, cerebellar dentate nucleus and, to a lesser extent, cerebral cortex and meninges. Anterior pons, corpus striatum, thalamus, temporal lobe, hippocampus and cerebellar cortex were always uninflamed. In contrast, the eight JE cases studied showed inflammation involving most neuronal areas of the central nervous system, including the areas that were uninflamed in EV71 encephalomyelitis. Lesions in both infections were nonspecific, consisting of perivascular and parenchymal infiltration by inflammatory cells, oedematous/necrolytic areas, microglial nodules and neuronophagia. Viral inclusions were absent. Conclusions: Immunohistochemistry and in situ hybridization assays were useful to identify the causative virus, localizing viral antigens and RNA, respectively, almost exclusively to neurones. The stereotyped distribution of inflammatory lesions in EV71 encephalomyelitis appears to be very useful to help distinguish it from JE.     

A study of CSF catecholamine and its metabolites in acute and convalescent period of encephalitis

AIMS: To evaluate cerebrospinal fluid (CSF) catecholamine (CA) and its metabolites in encephalitis patients in acute and convalescent period and correlate these with clinical and magnetic resonance imaging (MRI) features. SUBJECTS AND METHODS: Patients with acute encephalitis diagnosed on the basis of clinical, CSF, MRI and virological parameters underwent detailed neurological evaluation including Glasgow Coma Scale (GCS), Unified Parkinson's Disease Rating Scale (UPDRS) and Dystonia Rating Scale. Cranial MRI was carried out and CSF dopamine (DA), norepinephrine (NE), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxytryptamine (5HT) levels were estimated by High Performance Liquid Chromatography (HPLC). The CSF catecholamine levels were compared with convalescent phase as well as with controls. These levels were also correlated with parkinsonian features, dystonia and radiological abnormalities. RESULTS: There were 29 encephalitis patients; whose age ranged between 2 and 65 years, 4 were females and 11 children. 25 patients had Japanese encephalitis (JE) and 4 nonspecific encephalitis. The mean GCS score was 8 and 13 had seizures. Movement disorders were present in 13 patients and included parkinsonian features in 5, dystonia in 1 and combination of both in 7 patients. MRI revealed abnormalities in 15 out of 21 patients and included thalamic lesion in 10, globus pallidus in 4, putamen in 5, caudate in 4 and midbrain in 9 patients. In acute stage NE, DOPAC, 5HT and HVA levels were significantly lower compared to controls. NE levels significantly correlated with dystonia and thalamic lesions. Convalescent CSF study revealed significantly lower levels of DOPAC compared to acute phase. CSF catecholamine levels in encephalitis patients with and without movement disorders were not significantly different. CONCLUSION: In encephalitis, catecholamine and its metabolites are lower in acute and convalescent phase. Norepinephrine level correlates with dystonia and thalamic lesions.     

Immunofluorescence detection of herpes simplex virus type 1 antigen in cerebrospinal fluid cells of experimentally infected mice

Experimentally infected mice were used to assess the value of immunofluorescence (IF) procedures in cerebrospinal fluid (CSF) cells in comparison with routine viral culture of CSF for diagnosis of herpes simplex type-1 (HSV-1) encephalitis. Virus specific antigen was detected by immunofluorescence in the majority of CSF cells in 75% of infected animals. In contrast, only 20% of infected mice had positive viral cultures, which sometimes took as long as a week to show a cytopathological effect (CPE). It is concluded that antigen detection by immunofluorescence is a rapid, specific and sensitive technique for demonstrating HSV-1 antigen in CSF cells of experimentally infected mice. Our results put forward a plea for further studies using these techniques on CSF samples from patients with suspected HSV-1 encephalitis. The prerequisites for reliable interpretation of results have been defined in this study.     

Epstein-Barr Virus Antibodies in Neurological Diseases

Abstract: Antibody titers to the Epstein-Barr virus (EBV) in the serum and cerebrospinal fluid (CSF) were determined in 57 cases of acute or subacute neurological diseases. As a result, sera from 11 cases (7 Bell's palsy, 2 encephalitis and 2 acute cerebellar ataxia) were found to be positive for antibodies to early antigen. Seven of these 11 cases either seroconverted for IgG antibodies to viral capsid antigen (VCA) or were proven positive for anti-VCA-IgM antibodies in the serum. While 4 were found positive for IgG antibodies to VCA in CSF, 3 tested by the anti-complement immunofluorescence method were all negative for EBV-associated nuclear antigen (EBNA) in CSF. Three of the 11 cases were considered to be of a primary infection with EBV because of a negative serologic test for antibodies to EBNA initially; a reinfection with the virus or a reactivation of the latent infection was suspected in some of the remaining cases.     

Epstein-Barr virus antibodies in neurological diseases

Antibody titers to the Epstein-Barr virus (EBV) in the serum and cerebrospinal fluid (CSF) were determined in 57 cases of acute or subacute neurological diseases. As a result, sera from 11 cases (7 Bell's palsy, 2 encephalitis and 2 acute cerebellar ataxia) were found to be positive for antibodies to early antigen. Seven of these 11 cases either seroconverted for IgG antibodies to viral capsid antigen (VCA) or were proven positive for anti-VCA-IgM antibodies in the serum. While 4 were found positive for IgG antibodies to VCA in CSF, 3 tested by the anti-complement immunofluorescence method were all negative for EBV-associated nuclear antigen (EBNA) in CSF. Three of the 11 cases were considered to be of a primary infection with EBV because of a negative serologic test for antibodies to EBNA initially; a reinfection with the virus or a reactivation of the latent infection was suspected in some of the remaining cases.     

Japanese encephalitis in the Kurume region of Japan: CT and MRI findings

Summary Neurological, computed tomography (CT) and magnetic resonance imaging (MRI) findings were recorded from 13 patients with Japanese encephalitis (JE) in the Kurume region diagnosed by serological criteria. The patients averaged 63 years of age, and 5 were older than 70 years. The serological data mostly indicated a primary response. Hemiplegia and tetraplegia were common, together with extrapyramidal signs. A few cases had a stroke-like onset and cerebral haemorrhage during the course of JE. CT and MRI in 7 cases revealed abnormalities in the thalamus and basal ganglia including the putamen. The CT and MRI findings from the acute stage to the convalescent stage were considered to be characteristic of JE.     

Status epilepticus in encephalitis: a study of clinical findings,magnetic resonance imaging,and response to antiepileptic drugs

This study evaluates clinical findings, magnetic resonance imaging (MRI), and response to antiepileptic drugs (AEDs) in encephalitis patients with status epilepticus (SE). Encephalitis patients with SE were included and they were grouped into herpes (HSE), Japanese (JE), dengue, and nonspecific encephalitis on the basis of virological studies. The demographic and clinical details, including SE type and duration, were noted. Cranial MRI and cerebrospinal fluid (CSF) were carried out. Response to first, second, and third AEDs were noted and the patients not responding to the second AED were considered refractory SE. The relationships of the mortality and the refractoriness of SE with various clinical findings, MRI, CSF, and the type of encephalitis were evaluated. Thirty SE patients with encephalitis aged 1 to 64 years were included. Nine patients had JE, 4 HSE, 1 dengue, and 16 nonspecific encephalitis. Generalized convulsive SE was present in 26 and nonconvulsive SE in 4 patients. The mean duration of SE was 21 (0.83 to 72) h. MRI was abnormal in 20 patients. A 46.7% of patients responded to the first AED and 36.7% remained refractory to the second AED. In 26.7% patients, the seizure continued even after the third AED. The response to AED was not related to the clinical, MRI, and laboratory variables. Nine patients died and the mortality was related to gender and Glasgow Coma Scale (GCS) score. In encephalitis with SE, 46.7% patients responded to the fist AED and 36.7% remained refractory to the second AED. One third of patients died, which was related to the depth of coma.     

Japanese encephalitis: identification of inflammatory cells in cerebrospinal fluid

Fifteen patients with acute encephalitis were studied during the epidemic season of Japanese encephalitis (JE) in Northern Thailand; 13 of 15 proved to have the encephalitis. In serial cerebrospinal fluids and blood samples, mononuclear cells were identified using monoclonal antibodies. In cerebrospinal fluid from the patients with Japanese encephalitis, T cells predominated with a 4.2:1 ratio of T helper/inducer cells to T suppressor/cytotoxic cells; B cells and macrophages were often present but in small numbers compared to their presence in blood. Distribution of cell types did not vary between the first and fifth day of hospitalization, were similar in fatal and nonfatal cases, and were unaffected by administration of steroids.     

Production of immunoglobulin G and increased antiviral antibody in cerebrospinal fluid of dogs with delayed-onset canine distemper viral encephalitis

Sera and cerebrospinal fluid (CSF) from four dogs with delayed-onset canine distemper viral (CDV) encephalitis (old dog encephalitis) were compared with samples from dogs with acute CDV and from recently vaccinated controls. Dogs with old dog encephalitis (ODE) had elevated CSF IgG concentrations (122 micrograms/ml) compared to controls (13 micrograms/ml) without elevated CSF albumin; their CSF IgG index was significantly greater. CSF proteins banding in the alkaline region of isoelectric focusing gels were immunochemically identified as IgG. Detectable viral neutralizing antibody was present in ODE CSF, and formed a larger proportion of IgG in CSF than in serum. Serum samples containing 2 mg IgG bound to all viral polypeptides of both R252 and Onderstepoort CDV isolates by immunoblot analysis. CSF samples of ODE patients bound viral antigens when diluted to contain as little as 5-40 micrograms IgG, while patient serum could be diluted to 40-200 micrograms IgG content compared to serum IgG of 100 micrograms/ml in vaccinated controls. Serial CSF dilutions consistently bound to H and NP polypeptides at the highest dilutions, similar to the binding of serums from recently vaccinated dogs. Thus, dogs with delayed-onset CDV encephalitis have elevated concentrations of CSF IgG, much of which is virus-specific, with an antigen binding pattern similar to that of sera of recently immunized dogs.     

脑脊液活性B细胞检测的研究

应用生物素－亲和素法检测７５例中枢神经系统（ＣＮＳ）疾病患者脑脊液（ＣＳＦ）中的活性Ｂ细胞（ＡＢＬ）。结果：感染、脱髓鞘疾病组与ＣＮＳ其他疾病组的阳性率分别为６１．５％和８．７％，其差别极为显著（Ｐ＜０．００５）；病毒性脑炎组与细菌性脑膜炎组的ＡＢＬ＞５％的阳性率也有显著性差异（Ｐ＜０．０５）；并发现ＣＳＦ中ＡＢＬ的出现较ＩｇＧ早。认为ＣＳＦ中ＡＢＬ的检测有助于神经系统感染性疾病的早期诊断和鉴别诊断。     

Viral antibodies in the CSF after acute CNS infections.

Viral antibodies were measured in the cerebrospinal fluid (CSF) and serum from 25 patients having acute viral central nervous system (CNS) infections, and from 39 control patients. The results, collected two weeks after the clinical onset, revealed the presence of antibodies in nine of 13 (69%) CSF specimens from patients suffering from encephalitis of myelitis, and in only one of nine (11%) of the CSF samples of those presenting a viral meningitis infection. This difference was statistically significant and suggests that the titration of viral antibodies in the CSF can be helpful in establishing the diagnosis of viral CNS infection. Our data also suggest that localized production of antibodies occurs during the course of acute CNS infections, and that the respiratory syncytial virus can be associated with CNS infections in man.     

Oromandibular dystonia in encephalitis

We report clinical and MRI findings of 17 patients with oromandibular dystonia (OMD) due to Japanese encephalitis (14) and nonspecific encephalitis (3). Their median age was 14(2-53) years and 9 were females. 8 patients had jaw open and 9 jaw close OMD. The severity ranged between 2 and 4 on a 0-4 scale, 11 patients were anarthric and needed tube feeding. Cranial MRI was abnormal in 13 patients; the abnormalities were in thalamus in 9, substantia nigra in 10, caudate in 3, globus pallidus and putamen in 2 each and pons in 1 patient. SPECT revealed hypoperfusion in thalamus in 4, basal ganglia in 1, frontal in 6, parietal in 3 and temporal in 1 patient. By 6 months, OMD regressed completely in 6, by 1 grade in 2 and remained unchanged in 7 patients. OMD in encephalitis is mainly due to JE and half of these patients improve.     

A case of Japanese encephalitis presenting with unilateral lesions in diffusion-weighted MRI]

We report the findings of diffusion-weighted MRI (DWI) taken serially in a patient with Japanese encephalitis (JE). The patient was a 43-year-old woman presenting with headache, high fever and consciousness disturbance. The diagnosis of JE was made based on more than fourfold elevation of serum complement fixation antibody titer for JE virus in the convalescent phase of illness. The DWI on the second day of illness (Day-2) disclosed high-signal intensity lesions in the left thalamus, substantia nigra and frontal lobe cortex. The signal intensity of these lesions on the DWI increased on Day-3 but gradually decreased thereafter and normalized on Day-28. The improvement of the DWI findings was paralleled with that of the consciousness level and the cell number and neuron specific enolase concentration in the CSF, suggesting that DWI is useful for evaluation of the disease activity in JE. The lesions in the brain suffering from Japanese encephalitis are usually bilateral and diffuse. To our knowledge, this is the first report of JE presenting with unilateral lesions on MRI, of which phathomechanism remains to be elucidated.