This inflammation of the brain is usually due to infection with a virus, but occasionally it occurs as a result of an immune system problem.
It may be due to infection by bacteria or other organisms, or it can be a complication of meningitis or a brain abscess.
Encephalitis causes flulike symptoms, fever, and headache; more severe cases may progress rapidly to cause confusion, seizures, and coma.
A person with any of these symptoms needs urgent medical attention. Treatment is with medication. Some people recover fully but others are left with long-term problems due to brain damage