Despite receiving standard antiviral therapy, an appreciable number of patients with herpes simplex virus encephalitis (HSVE) experience poor acute outcome or delayed neurological progression. It is uncertain whether all poor outcomes are due to viral cytopathology or whether an immune mediated pathogenesis also occurs. In support of an immunopathological cause, Kamei et al (see pages XX–XX of this issue) report that corticosteroid administration was a significant predictor of favourable outcome at 3 months after HSVE infection.

Immune cells persist and elaborate cytokines in the nervous system long after the virus has entered latency.¹ It is …