A Retrospective Study of the Clinical Characteristics of Japanese Encephalitis in Adults.

OBJECTIVE: This study aimed to explore the diagnostic points and treatment modes of the clinical characteristics of Japanese encephalitis (JE) in the middle-aged and elderly population. METHODS: Six patients aged 47-72 who were diagnosed with JE at the Beijing Chaoyang Hospital Affiliated with the Capital Medical University between August 2018 and September 2019 were enrolled in the study. Their clinical manifestations, biochemical indicators, imaging data, diagnostic methods, and the evolution and outcomes of the treatments they underwent were retrospectively analyzed. RESULTS: (1) All six patients had severe clinical symptoms and poor prognoses that were more likely to be associated with other systemic diseases. (2) Lesions were most commonly distributed in the thalamus, basal ganglia, and midbrain. The appearance of hyperintensity in the corpus callosum, hippocampus, and subcortical white matter was more specific. The hyperperfusion metabolism in the lesion area in head computed tomography perfusion imaging indicated the state of inflammatory activity in the lesion. In cranial magnetic resonance imaging (MRI), T2 and fluid-attenuated inversion recovery (FLAIR) were more sensitive. (3) After a patient has been systematically treated in the intensive care unit (ICU), the patient gradually recovered and the level of consciousness improved (p < 0.05). CONCLUSIONS: In brain MRI-especially T2 and FLAIR-intracranial infection is often accompanied by abnormal signals in the thalamus, midbrain, hippocampus, and white matter hyperintensity (WMH), which is highly suggestive of JE. The positive detection of anti-JE virus immunoglobulin M antibodies in a patient's serum and/or cerebrospinal fluid can confirm the diagnosis of JE, and comprehensive ICU treatment (hormones combined with anti-inflammatory, antiviral, and mild hypothermic cerebral protection therapies) can improve the survival rate.

Japanese encephalitis (JE) mimicking acute ischemic stroke: A case report.

INTRODUCTION: Japanese encephalitis (JE) is one of the most serious viral infectious diseases of the central nervous system in Asia. The clinical manifestations of it might be non-specific. We herein report a case of JE mimicking acute ischemic stroke. PATIENT CONCERNS: A 52-year-old man presented with acute onset of left-sided limb weakness for 2 hours and a 5-year history of hypertension but with no fever or cold before the onset. Immediate cranial computed tomography scan showed small ischemic foci. DIAGNOSIS: Initial diagnosis revealed acute cerebral infarction as the symptoms mimicked stroke at onset. Furthermore, his symptoms progressed and magnetic resonance scan after 6 days of onset appeared negative on diffusion weighted imaging. Other etiologies were also then considered. Japanese encephalitis virus immunoglobulin M in the serum supported positive diagnosis of JE. INTERVENTIONS: The patient was given Ribavirin, and then his symptoms slowly improved. OUTCOMES: Brain MRI on day 29 after the onset revealed high-intensity lesions in bilateral thalamus on diffusion weighted imaging. During the follow-up (at about 2 months after the onset), the patient's consciousness was clear but could not walk. At about 6 months after the onset, he could walk with parkinsonian features. CONCLUSION: Diagnosis of JE that mimicked acute stroke at onset and with no fever can be challenging. Recognition of disease development, MRI and Japanese encephalitis virus immunoglobulinM findings are helpful in early definitive diagnosis.

Case Report: Japanese Encephalitis Associated with Chorioretinitis after Short-Term Travel to Bali, Indonesia.

Japanese encephalitis (JE) virus is a mosquito-borne flavivirus endemic throughout Asia. Incidence in non-endemic countries is rare, with an estimate of less than one case per one million travelers. Most human JE infections are asymptomatic or cause a mild, nonspecific febrile illness. Neurological involvement, if present, is usually severe and associated with high mortality or ongoing neurological sequelae in survivors. Ocular manifestations are rare with JE, but uveitis has been described to be associated with other flavivirus infections, including West Nile virus. We report the first probable case of JE chorioretinitis acquired by a 45-year-old Australian traveler to Bali. This case highlights the importance of a detailed ocular examination when there is clinical suspicion of JE.

Chronic post-encephalitic epilepsy following Japanese encephalitis: Clinical features, neuroimaging data, and outcomes.

PURPOSE: Japanese encephalitis (JE), the main cause of viral encephalitis in Asia, usually presents with acute symptomatic seizures; however, there have been very few systematic reports regarding late unprovoked seizures and epilepsy. We aimed to describe the clinical features and outcomes of post-encephalitic epilepsy following JE. METHODS: Patients with epilepsy with a previous confirmed diagnosis of JE visiting West China Hospital from 2013 to 2019 were enrolled in the observational case-controlled study. Patients with epilepsy with a history of other non-specific viral encephalitis were enrolled as controls. For all enrolled subjects, disease related information was recorded. RESULTS: Forty-eight patients with JE (20 males; median age, 21.0 years; average epilepsy duration, 8.55 years) were identified. The median duration from JE to the first unprovoked seizure was 7.73 years, which significantly differed from that of the controls (7.73 vs. 2.69 years, respectively; p = 4.59 × 10-6). Most patients had focal epilepsy, and 29 (78.38%) were drug resistant. Among 45 patients with available neuroimaging data, three in fourth had no obvious abnormality, and the temporal lobe and hippocampus (22.22%) were the most affected brain regions. Six patients had surgery, and three achieved class-one seizure-free status. CONCLUSION: The latency to the first unprovoked seizure was longer in patients with JE than controls. Regarding chronic epilepsy, three in four had structural abnormalities, and the long-term outcomes of post-encephalitic epilepsy following JE were poor. Surgery remains an option for drug-resistant epilepsy.

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.

Japanese Encephalitis Virus Transmitted Via Blood Transfusion, Hong Kong, China.

Japanese encephalitis virus (JEV) is a mosquitoborne virus endemic to China and Southeast Asia that causes severe encephalitis in <1% of infected persons. Transmission of JEV via blood transfusion has not been reported. We report transmission of JEV via blood donation products from an asymptomatic viremic donor to 2 immunocompromised recipients. One recipient on high-dose immunosuppressive drugs received JEV-positive packed red blood cells after a double lung transplant; severe encephalitis and a poor clinical outcome resulted. JEV RNA was detected in serum, cerebrospinal fluid, and bronchoalveolar lavage fluid specimens. The second recipient had leukemia and received platelets after undergoing chemotherapy. This patient was asymptomatic; JEV infection was confirmed in this person by IgM seroconversion. This study illustrates that, consistent with other pathogenic flaviviruses, JEV can be transmitted via blood products. Targeted donor screening and pathogen reduction technologies could be used to prevent transfusion-transmitted JEV infection in highly JEV-endemic areas.

Japanese encephalitis can trigger anti-N-methyl-D-aspartate receptor encephalitis.

Japanese encephalitis (JE) is usually a monophasic disease; however, in rare cases, patients with JE may have an early relapse after a partial recovery, giving rise to a biphasic pattern for the disease. In this study, we report three pediatric cases in which post-JE relapse was characterized by movement disorder and/or behavioral problems, and was related to anti-N-methyl-D-aspartate receptor (NMDAR) immunoglobulin G (IgG). Serum and cerebrospinal fluid were examined for anti-NMDAR IgG in three patients who had confirmed JE and then developed relapsing symptoms which were similar to those of anti-NMDAR encephalitis. The main symptoms of the two young children were choreoathetosis, irritability, and sleep disorder; while for the teenager, agitation, mutism, rigidity, and sleep disorder were the main symptoms. Samples of cerebrospinal fluid from all patients were positive for anti-NMDAR IgG, and all patients gradually improved with immunotherapy. Testing for NMDAR antibodies is highly recommend in patients with JE, especially those with a relapsing syndrome involving movement disorder and/or behavioral problems, as these patients may benefit from immunotherapy.

Diagnostic dilemma-dengue or Japanese encephalitis?

Dengue and Japanese encephalitis (JE) are arboviral diseases that are common in the tropical countries. JE virus is a classical neurotropic virus. The dengue virus, however, is usually not considered to be neurotropic, even though in recent years, reports of direct central nervous system involvement in dengue has been described. Here, we report a case wherein the patient had magnetic resonance imaging evidence of bilateral thalamic and brainstem involvement with positive serologies for both dengue and JE. We also discuss the diagnostic challenge in these cases.

Clinical and radiological spectrum of Japanese encephalitis.

INTRODUCTION: Japanese encephalitis (JE) is mosquito-borne flaviviral encephalitis that remains to be a major health problem in India--it still continues to cause havoc in many parts of the country. We undertook the study to analyze the clinical and radiological spectrum of JE in adults and children. METHOD: This prospective study consists of 148 patients with JE. The diagnosis of JE was based on clinical, epidemiological, radiological features and demonstration of JE virus specific IgM in CSF and serum by JE virus immunoglobulin M capture enzyme-linked immunosorbent assay (MAC ELISA). All patients underwent a detailed neurological examination, CSF study & neuroimaging of brain (either CT or MRI or both). All patients were followed-up at regular interval. RESULT: Seizures were present in adults (52.88%) and in children (43.18%). Dystonia was more common in children 19 (43.18%) compared to adults 19 (18.2%), and Parkinsonian features were observed in both groups 47 (45.19%) of the adults and 20 (45.45%) of the children. JE-specific IgM antibody was detected in both CSF and serum in 81.7%. In neuroimaging, apart from classical involvement of thalami, basal ganglia & midbrain, prominent involvement of hippocampus and other areas of the cortex was also found in 27 (45.6%) patients. Presence of thalamic lesion in CT/MRI showed significant relationship to the development of dystonia. However, no correlation was found between the neuroimaging features and poor clinical outcome. Twenty three patients (15.5%) died during acute phase of illness. On multivariate logistic regression analysis age, prolonged fever, Glasgow coma scale, recurrent seizures and reflex changes were found to be the predictors of outcome at the time of discharge. CONCLUSION: A trend of severe and frequent involvement in younger patients with dystonia and other movement disorders was observed. It should be emphasized that presence of atypical cranial CT/MRI features in JE was not unknown and they need to be differentiated from herpes simplex encephalitis in appropriate clinical setting.

Involvement of nigrostriatal pathway in Japanese encephalitis with movement disorders: evidence from 99mTc-TRODAT-1 and 123I-IBZM SPECT imagings.

PURPOSE: The purpose of this study was to evaluate molecular evidence of nigrostriatal pathway involvement in Japanese encephalitis (JE) survivors with movement complications. METHODS: Three JE patients were recruited. All had cranial magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) studies with (99m)Tc-TRODAT-1 and (123)I-IBZM. RESULTS: Cranial MRI revealed involvement of bilateral thalami, substantia nigra, and medial temporal lobes in all three patients, but only case 1 had additional bilateral basal ganglia involvement. The (99m)Tc-TRODAT-1 SPECT for presynaptic dopamine transporter imaging disclosed asymmetrical decreases in bilateral striatal uptake in all three patients. However, the (123)I-IBZM SPECT imaging for postsynaptic D2 dopamine receptors (D2Rs) revealed inconsistent abnormalities including asymmetrical bilateral decreases (case 1), unilateral decrease (case 2), and bilateral increases (case 3) in striatal uptakes. CONCLUSION: Data have suggested that presynaptic dopaminergic neurons in JE patients are more susceptible to JE virus than postsynaptic striatal neurons. The degree of movement impairment was more closely correlated to the degree of D2Rs disruption seen in (123)I-IBZM SPECT imaging.

Clinical manifestations of Japanese encephalitis in southern Taiwan.

BACKGROUND AND PURPOSE: Japanese encephalitis virus infection is a sporadic infectious disease in Taiwan. Despite progress in laboratory examinations and imaging studies, diagnosis of Japanese encephalitis remains underestimated. This study was conducted to identify clinical symptoms and laboratory findings that may assist in early identification of this disease. METHODS: This retrospective study included all patients diagnosed with Japanese encephalitis at Kaohsiung Veterans General Hospital from January 2000 through December 2007. Epidemiologic data, predisposing factors, neurological and non-neurological signs and symptoms, laboratory data, and treatment were analyzed. Outcomes and neurological complications were evaluated. RESULTS: Eleven patients had Japanese encephalitis, and 10 had sufficient information for enrolment into the study. Nine patients presented with non-significant constitutional symptoms of fever, nausea, or headache. Other signs and symptoms included rhinorrhea, sore throat, abdominal pain, cough, myalgia, or arthralgia. Eight patients had lymphocytic pleocytosis with elevated protein and borderline low glucose levels in the cerebrospinal fluid. Leptomeningeal enhancement and low density lesions were the most common computed tomography findings. T2 hyperintensity lesions and leptomeningeal enhancement were seen in 5 patients. Two patients presenting with acute flaccid paralysis had high intensity lesions on the thalamus and basal ganglion. There were no correlations between clinical, laboratory, and imaging findings. None of the patients had neurological sequelae. CONCLUSIONS: Presentations, laboratory examination, and clinical signs are not specific for Japanese encephalitis. Sporadic cases are usually seen from May to August, which are associated with monsoon rains. Hence increased awareness of this disease is recommended during these periods.

Japanese encephalitis - serial CT findings and neuropathology in an autopsy case.

The patient was a 17-year-old man, who developed Japanese encephalitis in the autumn of 1990 in Japan. He was admitted to our hospital 4 days after onset because of consciousness disturbance. On admission, neurological examination demonstrated left hemiparesis, neck stiffness, and Kernig's sign. He developed generalized tonico-clonic seizure, and required a respirator on the next day of admission. Brain CT 10 days after onset demonstrated hypodensities in the right hippocampus, and the CT obtained 39 days after onset showed whole brain atrophy and hypodensities in the anterior portion of the bilateral thalamus. He died 40 days after onset. Postmortem examination demonstrated perivascular and parenchymal infiltration of lymphocytes and macrophages, proliferation of microglia and astrocytes, and necrosis in the gray matter of the brain. Involvement of the hippocampus and thalamus on CT seemed to reflect the severe lesions characterized by cellular infiltration and necrosis. We discussed for the first time the correlation of CT and neuropathological findings in a patient with Japanese encephalitis.

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

Japanese encephalitis virus (JEV) is estimated to cause 30­50,000 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 12.9­33.1%), specificity 100%, positive predictive value 100% and negative predictive value 42.1% (95% confidence interval 30.2­53.8%) 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.