Definition of Creutzfeldt-Jakob Disease (CJD)

What is Creutzfeldt-Jakob Disease?

Creutzfeldt-Jakob disease (CJD) is a rare form of spongiform encephalopathy or brain disorder.^[1] Spongiform describes how the brain looks. In CJD, the brain has holes and looks like a sponge under a microscope. Encephalopathy is a brain disease that affects brain structure or function.^[2] Thus, CJD is a disease of the brain that causes the brain to look like a sponge under a microscope.

CJD is a rare disease with about one case per million people per year.^[3] In the United States, this is about 300 cases a year. Most commonly, it strikes late in life, usually after 60.^[1] CJD is always fatal, usually within one year of developing it.