Neurological aspects of rubella virus infection

Rubella virus is a single-stranded, plus-sense RNA virus belonging to the Togaviridae family. Rubella virus infection causes a benign disease known as rubella or German measles, however infection during early pregnancy can lead to severe birth defects known as congenital rubella syndrome (CRS). Sequelae of rubella virus infection include three distinct neurological syndromes: a postinfectious encephalitis following acute infection, a spectrum of neurological manifestations following congenital infection, and an extremely rare neurodegenerative disorder, progressive rubella panencephalitis (PRP), that can follow either congenital or postnatal infection. The pathogenesis of all three of these syndromes is incompletely understood. Virus invasion and replication in the brain has only been definitively demonstrated in CRS and appears to account for the majority of neurological lesions observed in this disease. Immune-mediated pathology is particularly evident in PRP and may be autoimmune in nature, possibly triggered by molecular mimicry between viral and host epitopes, considering the apparent lack of virus in the brain. The pathogenesis of rubella encephalitis following acute infection has not been determined.