Rozenberg F
Université Paris Descartes & Department of Virology, Hôpital Cochin, France.
Handb Clin Neurol. 2013;112:1171-81. doi: 10.1016/B978-0-444-52910-7.00038-6.
Acute viral encephalitis is a rare but devastating complication of common virus infections. Primary viral encephalitis is due to brain invasion by the virus and subsequent replication in the central nervous system, whereas postinfectious encephalitis is thought to be immune-mediated. The most frequent causes of primary encephalitis worldwide are rabies and the arboviruses, which comprise different families of viruses distributed according to geography and seasonality. Herpes simplex virus (HSV) is the commonest cause of encephalitis in Western countries. Herpes simplex encephalitis (HSE) occurs at all ages during infancy and childhood with a peak incidence during the first year of life. Its pathogenesis remains unsolved, although defects in the innate immune response have been observed in a few cases. Direct and sensitive virological diagnosis is available, but may be difficult at early stages of the disease. Specific antiviral therapy has proven to improve the prognosis of HSE dramatically, if administered early. Despite use of antiviral drugs, sequelae remain high and relapses may occur, presumably secondary to HSV latency in the brain. In addition, deleterious host inflammatory responses might account for failure of therapy. Immunomodulatory treatments have been proposed but require a better understanding of the respective roles of the multiple pathways of the immune response.
急性病毒性脑炎是常见病毒感染中一种罕见但极具破坏性的并发症。原发性病毒性脑炎是由于病毒侵入大脑并随后在中枢神经系统中复制，而感染后脑炎被认为是免疫介导的。全球范围内原发性脑炎最常见的病因是狂犬病和虫媒病毒，虫媒病毒包括根据地理和季节性分布的不同病毒科。单纯疱疹病毒（HSV）是西方国家脑炎最常见的病因。单纯疱疹病毒性脑炎（HSE）在婴儿期和儿童期的各个年龄段均可发生，在出生后第一年发病率最高。尽管在少数病例中观察到先天免疫反应存在缺陷，但其发病机制仍未解决。虽然可以进行直接且灵敏的病毒学诊断，但在疾病早期可能会有困难。如果早期给予特异性抗病毒治疗，已证明可显著改善HSE的预后。尽管使用了抗病毒药物，但后遗症发生率仍然很高，且可能会复发，推测这继发于HSV在大脑中的潜伏。此外，有害的宿主炎症反应可能是治疗失败的原因。已经提出了免疫调节治疗方法，但需要更好地了解免疫反应多种途径各自的作用。
