PCR on CSF from lumbar puncture was positive for Enterovirus 71.

Human enteroviruses can cause a variety of disease states including respiratory infections, hand-foot-and-mouth disease, and aseptic meningitis. Enteroviruses have also been associated with neurological syndromes, particularly acute flaccid paralysis and brainstem enterovirus rhombencephalitis.

Infections with enteroviruses are common during summer and fall, especially in children, whose immunity is still being developed.

MR typically demonstrates a rhombencephalitis, the most common site of involvement is the brain stem, being the pontine tegmentum the most common site of brainstem involvement. It shows increased T2 signal. Ventral pontine lesions, substantia nigra and dentate nuclei affection can be found. Usually, no supratentorial lesions are identified. Spinal cord lesions are seen as T2 hyperintensity throughout the entire central spinal cord grey matter.

Clinical and laboratory correlation with radiological findings is mandatory to achieve a proper diagnosis.

Treatment is based on support therapy: steroids, intravenous immunoglobulin and/or plasma exchange. The antiviral drug pleconaril may be useful. Most patients recover completely within a year, although some deaths have been reported (mainly immunocompromised children or affected by other severe concurrent illnesses).

Differential diagnosis of the dorsal pontine hyperintensity includes:

• enterovirus rhomboencephalitis
• rabies encephalitis
• rhombencephalitis (H1N1, Listeria, Herpes)
• metronidazole toxicity, usually combined with dentate nuclei involvement