Acute encephalopathy and encephalitis caused by influenza virus infection.
OBJECTIVE
Influenza-associated acute encephalopathy/encephalitis (IAE) is an uncommon but serious complication with high mortality and neurological sequelae. This review discusses recent progress in IAE research for a better understanding of the disease features, populations, outcomes, diagnosis, and pathogenesis.


RESULTS
In recent years, many IAE cases were reported from many countries, including Japan, Canada, Australia, Austria, The Netherlands, United States, Sweden, and other countries and regions. During the novel influenza A/H1N1 pandemic, many IAE cases with A/H1N1 infection in children were reported, particularly in those hospitalized with influenza infection. Pathogenesis of IAE is not fully understood but may involve viral invasion of the CNS, proinflammatory cytokines, metabolic disorders, or genetic susceptibility. An autosomal dominant viral acute necrotizing encephalopathy (ANE) was recently found to have missense mutations in the gene Ran-binding 2 (RANBP2). Another recurrent ANE case following influenza A infection was also reported in a genetically predisposed family with an RANBP2 mutation.


CONCLUSIONS
Although IAE is uncommon, compared with the high incidence of influenza infection, it is severe. However, this complication is not duly recognized by health practitioners. Recent advances highlight the threat of this complication, which will help us to have a better understanding of IAE.
Wang
Gefei F
GF
Department of Microbiology and Immunology, Key Immunopathology Laboratory of Guangdong Province, Shantou University Medical College, Shantou, Guangdong, PR China.
Li
Weizhong
W
Li
Kangsheng
K
D001921:Brain / Q000276:immunology / Q000503:physiopathology / Q000821:virology; D004196:Disease Outbreaks; D004660:Encephalitis / Q000235:genetics / Q000503:physiopathology* / Q000821:virology*; D004673:Encephalomyelitis, Acute Disseminated / Q000235:genetics / Q000503:physiopathology* / Q000821:virology*; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D007251:Influenza, Human / Q000150:complications*; D004684:Leukoencephalitis, Acute Hemorrhagic / Q000235:genetics / Q000503:physiopathology* / Q000821:virology*; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D028861:Nuclear Pore Complex Proteins / Q000235:genetics / Q000378:metabolism; D009975:Orthomyxoviridae / Q000502:physiology
D018832:Molecular Chaperones; D028861:Nuclear Pore Complex Proteins; C094493:ran-binding protein 2