Subacute sclerosing panencephalitis is a progressive neurological disorder of children and young adults caused by a measles virus that became defective by persisting in the host. According to the results of clinical trials, antiviral and/or immunomodulatory therapy can slow the progression of the disease and improve life expectancy in patients. However, its long-term effects and eventual outcome remain debatable due to conflicting results and its lack of effect on the rapidly progressive form of the disease. Possible future therapies for subacute sclerosing panencephalitis are RNAi and antiapoptotic agents, which are currently in the hypothetical and experimental stages of research.