Creutzfeldt-Jakob Disease (CJD): A Neurodegenerative Conundrum

Creutzfeldt-Jakob disease (CJD) is a rare and fatal neurodegenerative disease caused by prions, infectious proteins that affect the brain. CJD causes progressive dementia, loss of motor coordination, and eventually death. The variant form of CJD (vCJD), linked to the consumption of beef contaminated with bovine spongiform encephalopathy (BSE), known as "mad cow disease", raised great concern in the 1990s.

What are Prions?

Prions are infectious proteins that cause neurodegenerative diseases by causing normal brain proteins to fold abnormally. This abnormal folding leads to the formation of protein aggregates that damage brain cells, causing degeneration of brain tissue.

Forms of CJD

CJD can manifest itself in different ways:

• Sporadic CJD (aJCJD): The most common form, accounting for about 85% of cases. AJCJD occurs when the normal prion protein spontaneously folds abnormally, with no known cause.
• Familial CJD (fCJD): An inherited form of the disease, accounting for about 10-15% of cases. fCJD is caused by genetic mutations that increase the likelihood of the prion protein folding abnormally.
• Iatrogenic CJD (iCJD): A rare form of the disease, transmitted through medical procedures such as corneal transplantation, dura mater implantation or the use of contaminated surgical instruments.
• Variant CJD (vCJD): The form of the disease related to the consumption of BSE-contaminated beef. vCJD mainly affects younger people and has a different clinical course from aJCJD.

Symptoms and Disease Progression

Symptoms of CJD vary depending on the form of the disease, but generally include:

• Progressive dementia
• Loss of motor coordination (ataxia)
• Muscle spasms (myoclonus)
• Visual disturbances
• Behavioral changes
• Insomnia
• Depression

The disease progresses rapidly, leading to death within months or years.

Diagnosis and Treatment

Diagnosis of CJD is based on symptoms, neurological examinations, electroencephalogram (EEG), magnetic resonance imaging (MRI), and analysis of cerebrospinal fluid (CSF). A definitive diagnosis can only be made by brain biopsy or autopsy.

There is currently no cure for CJD. Treatment is supportive, aimed at relieving symptoms and improving the patient's quality of life.

Prevention

Prevention of vCJD involves measures to control BSE in animals, such as prohibiting the use of meat and bone meal in cattle feed and health surveillance in slaughterhouses. Prevention of CJD involves safety measures in medical procedures, such as adequate sterilization of surgical instruments and the use of safe transplant materials.

The Importance of Surveillance

CJD epidemiological surveillance is essential to monitor the occurrence of the disease and identify possible outbreaks. Reporting of suspected cases is mandatory in many countries, allowing investigation and control of the disease.