Abstract

The polyomavirus are a family of opportunistic virus, which belongs to the JC virus whose primary manifestation is the Progressive Multifocal Leukoencephalopathy and neuronopathy of granulosa cells. Recently given the use of PCR for BK virus in transplant patients have also been described CNS pathologies in relation to this, and most frequent encephalitis and leukoencephalopathy. Each entity has a compatible clinical and genetic testing have allowed a diagnosis of high specificity, however the RNM is the great diagnostic pillar in these pathologies, allowing differentiate the different entities, the progression of lesions and response to treatment, especially in cases where it is indicated antiretroviral therapy, as gadolinium enhancement and mass effect may suggest Syndrome Immune and worse prognosis.