Subacute sclerosing panencephalitis (SSPE) is a long-lasting (chronic) infection of the central nervous system that causes inflammation of the brain. The infection is caused by an altered form of the measles virus.

As SSPE is almost always fatal, emphasis is placed upon maintaining comfort, rather than rehabilitation.

The disease progresses so that the individual becomes increasingly dependent, ultimately becoming bedridden and unaware of his or her surroundings.

Initial symptoms include a change in behavior, irritability, memory loss, and difficulty in forming thoughts and solving problems.

It is most common among people who had measles infection prior to the age of two years.