Clinical Overview of Creutzfeldt-Jakob Disease (CJD)

Key points

  • Creutzfeldt-Jakob disease (CJD) is a rapidly progressive and always fatal neurodegenerative disorder.
  • It is believed to be caused by prions, disease-causing agents that can cause abnormal folding of normal proteins in the body.
  • Infection usually leads to death within one year of symptom onset.
  • CJD occurs worldwide and the estimated annual incidence in many countries, including the United States, has been reported to be about one to two cases per million population.
A microscope image of brain tissue infected with CJD

Overview

CJD is classified as a transmissible spongiform encephalopathy (TSE) along with other prion diseases that occur in humans and animals. CJD was first recognized in the 1920s. The risk of CJD increases with a person's age.

In about 85% of patients, CJD occurs as a sporadic disease with no recognizable pattern of transmission. A smaller proportion of patients (5 to 15%) develop CJD because of inherited mutations of the prion protein gene. These inherited forms include Gerstmann-Straussler-Scheinker syndrome and fatal familial insomnia.

Confirming CJD in a patient requires neuropathologic and/or immunodiagnostic testing of brain tissue obtained either at biopsy or autopsy.

Clinical features

CJD typically affects people 55 years old and older. The primary symptom is dementia with early neurologic signs.

Once symptoms begin, the patient's decline is fairly quick, with a median of 4-5 months until death.

Diagnosis

There are standard diagnostic criteria for definite, probable and possible sporadic CJD cases. There are separate diagnostic criteria for cases that may be iatrogenic and those that may be inherited. [link to diagnosis page].

Patient management

Treatment of prion diseases remains supportive. There is unfortunately no specific therapy that has been shown to stop the progression of these diseases.

Death rates

Creutzfeldt-Jakob disease deaths and age-adjusted death rate, United States, 1979–2022*

Bar graph showing death rates for CJD
Annual CJD deaths and age-adjusted death rate from 1979-2022.

*Deaths obtained from multiple cause-of-death data include all forms of human prion disease and are based on ICD-9 and ICD-10 codes and available computerized literal death certificate data. Some modifications have been made to these data based on relevant information obtained from other surveillance mechanisms. Rates are adjusted to the US standard 2000 projected population.

Not everyone who is thought to have died from prion disease has had their brain tissue analyzed, which is required to confirm prion disease. Because of this, these case counts include people with probable CJD based on clinical tests provided a prion disease diagnosis is listed on their death certificate. A recently developed clinical laboratory test, when positive, has been shown to strongly indicate prion disease. Annual numbers of people with this positive test but no brain tissue analyses can be found on the National Prion Disease Pathology Surveillance Center website (NPDPSC Tables). More information on the test is available here.

Similar diseases

It's important to note that classic CJD is different than variant CJD. vCJD is a prion disease caused by eating cow products from cattle infected with Bovine Spongiform Encephalopathy

CJD is not related to BSE. Instead, cases occur either sporadically, via healthcare associated infections or via genetic links.

Classic CJD characteristics, as compared to variant CJD, are presented in the table here.