Encephalitis, or inflammation of the brain tissue, is rare, affecting about one in 200,000 people each year in the U.S.
When it strikes, it can be very serious, causing personality changes, seizures, weakness, and other symptoms depending on the part of the brain affected.
Children, the elderly, and those with a weak immune system are most vulnerable. The disease is usually caused by one of several viral infections, so it's sometimes referred to as viral encephalitis.
Many people who have encephalitis...