CJD

Creutzfeldt-Jakob Disease (CJD)

Creutzfeldt-Jakob Disease (CJD) is a rare, degenerative, invariably fatal brain disorder. It is one of the human prion diseases, which are caused by abnormally folded proteins that lead to brain damage. CJD is characterized by rapid mental deterioration, usually within a few months.

Epidemiology

CJD affects about one person in every one million people per year worldwide. It usually appears later in life, with the average age of onset being around 60 years. There are three major categories of CJD:

• Sporadic CJD: Accounts for about 85% of cases. It occurs with no known risk factors or genetic mutations.
• Hereditary CJD: Accounts for 10-15% of cases. It is associated with mutations in the PRNP gene.
• Acquired CJD: Accounts for less than 1% of cases. It results from exposure to infectious prions, such as through contaminated medical equipment or consumption of infected beef (as in variant CJD).

Pathophysiology

CJD is caused by prions, which are misfolded proteins that can induce other normal proteins to also misfold. This leads to a chain reaction that results in the accumulation of abnormal proteins in the brain, causing neuronal damage and the characteristic spongiform changes seen in brain tissue.

Clinical Features

The symptoms of CJD can vary but typically include:

• Rapidly progressive dementia
• Myoclonus (involuntary muscle jerks)
• Visual disturbances
• Ataxia (loss of coordination)
• Akinetic mutism in the later stages

Diagnosis

Diagnosis of CJD is challenging and involves a combination of clinical evaluation, imaging studies, and laboratory tests. Key diagnostic tools include:

• Electroencephalogram (EEG): May show characteristic periodic sharp wave complexes.
• Magnetic Resonance Imaging (MRI): Can reveal hyperintensities in the basal ganglia or cortical ribboning.
• Cerebrospinal fluid (CSF) analysis: Detection of 14-3-3 protein or real-time quaking-induced conversion (RT-QuIC) assay.

Treatment

There is currently no cure for CJD, and treatment is primarily supportive. This may include:

• Pain management
• Anticonvulsants for myoclonus
• Psychological support for patients and families

Prognosis

CJD is invariably fatal, with most patients succumbing to the disease within one year of onset. The rapid progression and lack of effective treatment options make it a particularly devastating condition.

Prevention

Preventive measures focus on reducing the risk of transmission, particularly in healthcare settings. This includes:

• Strict sterilization protocols for surgical instruments
• Avoiding the use of contaminated human-derived products
• Monitoring and controlling the spread of prion diseases in livestock

See Also

• Prion disease
• Variant Creutzfeldt-Jakob Disease
• Kuru

References

• Prusiner, S. B. (1998). Prions. Proceedings of the National Academy of Sciences, 95(23), 13363-13383.
• Brown, P., & Gajdusek, D. C. (1991). The human spongiform encephalopathies: Kuru, Creutzfeldt-Jakob disease, and the Gerstmann-Sträussler-Scheinker syndrome. Current Topics in Microbiology and Immunology, 172, 1-20.