Most recovery from viral encephalitis does not affect IQ.
The prognosis depends on the severity of the disease and the timeliness of treatment. The prognosis of the disease is poor without antiviral therapy, with untimely or inadequate treatment, and with severe disease.
However, most patients who are treated with adequate antiviral medication within a few days of onset or who have a milder form of the disease can be cured. However, about 10% of patients can be left with varying degrees of cognitive impairment, epilepsy, paralysis, and other sequelae.