Encephalitis is an uncommon manifestation of enterovirus disease. Encephalitis is distinguished from meningitis by the severity of mental status changes and the presence of focal neurologic signs. Clinical presentation may range from lethargy, drowsiness, and personality change, to seizures, paresis, and coma. Lumbar puncture findings are similar to those in viral meningitis. Abnormalities on EEG can help determine the extent and severity of brain involvement.
Differential diagnosis includes encephalitis due to other viruses - especially arboviruses.
Herpes simplex virus, postinfectious encephalitis following measles, rubella, varicella, or pertussis. Reye syndrome and Lyme disease are also in the differential. Virologic culture of CSF, throat, and feces is imperative when the patient presents with encephalitis. In the meantime, clinicians should also be on the alert for the possibility of arbovirus infection. Fortunately, most arboviral infections are asymptomatic, but clinical syndromes overlap considerably with illness caused by enterovirus.