Creutzfeldt–Jakob disease ( ) or
CJD is a
degenerative neurological disease that is incurable and invariably fatal. CJD is at times called a human form of mad cow disease (
bovine spongiform encephalopathy or BSE). However, given that BSE is believed to be the cause of variant Creutzfeldt–Jakob (vCJD) disease in humans, the two are often confused.