Creutzfeldt-Jakob disease (CJD) is a rare, degenerative,
invariably fatal brain disorder.1 Although the agent of sporadic
CJD (sCJD), the most common type of CJD, differs from the agent
of bovine spongiform encephalopathy (BSE) or “mad cow disease”,
sCJD is often confused with the human form of BSE. This
confusion usually stems from similarities in terminology for the
different illnesses, as variant CJD (vCJD) is acquired from
exposure to the BSE agent. Variant CJD will be discussed in
further detail in the vCJD section of the resource. Because of
this confusion, throughout the resource, the term “classic CJD”
or “CJD” with no qualifying adjective will be used to refer to
any of the several categories of CJD that are not vCJD. The term
“classic CJD” was originally used to describe the most common
subtype of sCJD (M/M 1; M/V 1), but for the purpose of this
resource, it is defined to include all types of CJD other than
vCJD. The three major categories of CJD include: - Sporadic CJD
(sCJD): the disease appears e