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.

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.

Sequential brain perfusion abnormalities in various stages of Japanese encephalitis.

There is a paucity of regional cerebral blood flow studies on Japanese encephalitis (JE) with none of these studies describing brain perfusion abnormalities in all three stages of the disease. In this communication we report the changes noted in brain perfusion as detected by single photon emission tomography (SPET), in the acute, subacute and chronic stages of JE. Between December 2000 and March 2006, 31 patients, 19 men and 12 women, mean age 49 y, range 6-64 y of various stages of JE underwent brain perfusion SPET. Tauhese patients were at the following stages of the disease: acute stage, five patients, subacute stage 17 and chronic stage nine . The acute stage was considered as up to seven days from the onset of symptoms, the subacute, from seven to 56 days and any duration beyond 56 days was considered as the chronic stage. In the acute stage all five patients demonstrated focal areas of hyperperfusion involving mainly the thalamus. Additionally, bilateral thalami involvement was noted in three, frontal lobe involvement in four and parietotemporal hyperperfusion in three of these patients. In the subacute stage group, hypoperfusion of the thalamus was noted in all patients while frontoparietal hypoperfusion in seven patients. In the chronic stage group, hypoperfusion of thalamus was noted in four, one patient demonstrated additional occipital lobe hypoperfuion whereas normal perfusion was noted in the remaining five patients. In conclusion, the brain perfusion abnormalities observed depended on the stage of the disease. In the acute stage there was focal hyperperfusion to sites of the brain where JE virus is considered to replicate. In the subacute stage focal hypoperfusion was found to be possibly due to virus induced damage of cellular protein synthesis and in the chronic stage perfusion returns to normal due to regeneration of cellular organelles. Our results also confirm the high frequency of thalamic involvement in JE.