What is the definition or description of: encephalitis?

Brain inflammation: Usually describes an infection within brain tissue itself (meningitis involves coverings). Viral infections such as herpes, mosquito borne problems such as equine enceph., acquired amoeba, variety of parasites in hiv, malaria, parasites in food (pork tapeworm), west nile virus.

Inflamed brain: The encephalon is considered to be the gray matter of the brain. This is where all the neuron cells are located. If an infection sets in to this region it is called an encephalitis. The -itis ending just means inflammation. It is usually virus infections that like to go specifically to the neurons of the brain.