[4][1] Early symptoms include memory problems, behavioral changes, poor coordination, and visual disturbances.

[4] The name "Creutzfeldt–Jakob disease" was introduced by Walther Spielmeyer in 1922, after the German neurologists Hans Gerhard Creutzfeldt and Alfons Maria Jakob.

[4] There is no evidence that sporadic CJD can spread among people via normal contact or blood transfusions,[4] although this is possible in variant Creutzfeldt–Jakob disease.

[13] The first symptom of CJD is usually rapidly progressive dementia, leading to memory loss, personality changes, and hallucinations.

[15] This is accompanied by physical problems such as speech impairment, balance and coordination dysfunction (ataxia), changes in gait, and rigid posture.

[16] Most affected people die six months after initial symptoms appear, often of pneumonia due to impaired coughing reflexes.

When brain tissue from a person with CJD is examined under a microscope, many tiny holes can be seen where the nerve cells have died.

Mutations in the gene for the prion protein can cause a misfolding of the dominantly alpha helical regions into beta pleated sheets.

[30] Prions, the infectious agent of CJD, may not be inactivated by means of routine surgical instrument sterilization procedures.

Thermal depolymerization also destroys prions in infected organic and inorganic matter, since the process chemically attacks protein at the molecular level, although more effective and practical methods involve destruction by combinations of detergents and enzymes similar to biological washing powders.

[31] People can also develop CJD because they carry a mutation of the gene that codes for the prion protein (PRNP), located on chromosome 202p12-pter.

[32] In sporadic cases, the misfolding of the prion protein is a process that is hypothesized to occur as a result of the effects of aging on cellular machinery, explaining why the disease often appears later in life.

"[34] Testing for CJD has historically been problematic, due to nonspecific nature of early symptoms and difficulty in safely obtaining brain tissue for confirmation.

The diagnosis may initially be suspected in a person with rapidly progressing dementia, particularly when they are also found with the characteristic medical signs and symptoms such as involuntary muscle jerking,[35] difficulty with coordination/balance and walking, and visual disturbances.

[44] As of 2010[update], screening tests to identify infected asymptomatic individuals, such as blood donors, are not yet available, though methods have been proposed and evaluated.

[46] While imaging plays a lesser role in diagnosis of CJD,[47] characteristic findings on brain MRI in some cases may precede onset of clinical manifestations.

[53] In one-third of people with sporadic CJD, deposits of "prion protein (scrapie)", PrPSc, can be found in the skeletal muscle and/or the spleen.

[66] One of the world's longest survivors of vCJD was Jonathan Simms, a Northern Irish man who lived for 10 years after his diagnosis and received experimental treatment with pentosan polysulphate.

Some of the clinical findings described in their first papers do not match current criteria for Creutzfeldt–Jakob disease, and it has been speculated that at least two of the people in initial studies had a different ailment.

[76] Stanley B. Prusiner of the University of California, San Francisco (UCSF) was awarded the Nobel Prize in Physiology or Medicine in 1997 "for his discovery of Prions—a new biological principle of infection".

[78] Yale University neuropathologist Laura Manuelidis has challenged the prion protein (PrP) explanation for the disease.

Five of the deaths resulted after the patients, who were in treatment either for infertility or short stature, were treated using contaminated pituitary extract hormone but no new cases have been noted since 1991.

Massachusetts General Hospital believed the person acquired the disease from a surgical instrument at a podiatrist's office.

The person had undergone brain surgery at Catholic Medical Center three months before his death, and a surgical probe used in the procedure was subsequently reused in other operations.

Public health officials identified thirteen people at three hospitals who may have been exposed to the disease through the contaminated probe but said the risk of anyone contracting CJD is "extremely low".

[86] John Carroll, former editor of The Baltimore Sun and Los Angeles Times, died of CJD in Kentucky in June 2015, after having been diagnosed in January.

[88] José Baselga, clinical oncologist having headed the AstraZeneca oncology division, died in Cerdanya, March 21, 2021, from CJD.