Variant Creutzfeldt–Jakob disease

Degenerative brain disease caused by prions

Not to be confused with Creutzfeldt–Jakob disease.

Variant Creutzfeldt–Jakob disease
Synonyms	New variant Creutzfeldt–Jakob disease (nvCJD)
Pronounce	N/A
Field	Neurology, Infectious disease
Symptoms	Psychiatric problems, behavioral changes, painful sensations, coordination problems
Complications	Severe neurological deterioration, immobility, respiratory failure
Onset	Usually under 30 years old
Duration	Approximately 13-month life expectancy after onset
Types
Causes	Prion infection
Risks	Eating beef from cattle with bovine spongiform encephalopathy
Diagnosis	Clinical suspicion, confirmed by brain biopsy or tonsil biopsy
Differential diagnosis	Multiple sclerosis, standard Creutzfeldt–Jakob disease, other neurodegenerative disorders
Prevention	Avoiding contaminated beef products
Treatment	Supportive care
Medication	None proven effective
Prognosis	Invariably fatal
Frequency	Extremely rare; fewer than 250 reported cases as of 2012
Deaths	Nearly 100% mortality rate

Variant Creutzfeldt–Jakob disease (vCJD), also known as new variant Creutzfeldt–Jakob disease (nvCJD), is a rare and fatal neurodegenerative disorder belonging to the group of diseases known as transmissible spongiform encephalopathies. These disorders are caused by abnormal proteins known as prions, which lead to progressive brain damage characterized by sponge-like degeneration of brain tissue.

Prion protein immunostaining in a tonsil biopsy from a patient with variant CJD.

Characteristic EEG pattern seen in Creutzfeldt–Jakob disease.

Global distribution of mad cow disease cases linked to vCJD.

UK data on variant Creutzfeldt-Jakob disease cases from the National Creutzfeldt-Jakob Disease Research & Surveillance Unit (2014).

Signs and symptoms

The clinical symptoms of vCJD typically begin with psychiatric and sensory disturbances and later progress to severe neurological impairment. Symptoms often include:

• Psychiatric problems such as depression, anxiety, irritability, and hallucinations.
• Behavioral changes, including withdrawal from social interactions and personality alterations.
• Painful or uncomfortable sensory symptoms such as dysesthesia (abnormal sensations) or unexplained pains.
• Coordination difficulties, unsteadiness, and involuntary movements (ataxia).
• Progressive dementia, confusion, and memory loss.
• Severe neurological deterioration leading eventually to immobility, inability to communicate, and coma.

Causes

Variant CJD is caused by prions, misfolded proteins capable of inducing other normal proteins in the brain to misfold and aggregate, resulting in irreversible neurological damage. Specifically, vCJD has been linked to consumption of contaminated beef products derived from cattle infected with bovine spongiform encephalopathy (BSE), commonly known as "mad cow disease."

Pathophysiology

Prions accumulate primarily in the brain, spinal cord, and lymphoid tissues, causing damage and cell death. The distinctive pathological hallmark is spongiform degeneration—tiny holes appearing throughout the brain tissue—leading to progressive neurological dysfunction.

Risk factors

Key risk factors for vCJD include:

• Consumption of beef contaminated with BSE prions.
• Exposure to contaminated medical instruments or blood products (though exceedingly rare).
• Genetic predisposition, particularly certain polymorphisms in the prion protein gene (PRNP), may influence susceptibility.

Diagnosis

Diagnosis of vCJD can be challenging due to symptom overlap with other neurological diseases. Methods include:

• Clinical evaluation based on symptoms and history of exposure.
• Magnetic resonance imaging (MRI), which can detect characteristic brain abnormalities.
• Electroencephalogram (EEG) to observe distinctive patterns.
• Confirmation typically requires biopsy of tonsillar tissue or, less commonly, brain tissue to identify prion proteins.

Differential diagnosis

Diseases to consider in differential diagnosis include:

• Classic Creutzfeldt–Jakob disease (sporadic or familial types)
• Multiple sclerosis
• Other neurodegenerative conditions (e.g., Alzheimer's disease)
• Psychiatric disorders with neurological manifestations

Treatment

Currently, there is no cure or specific effective treatment for vCJD. Management is limited to supportive and symptomatic care:

• Palliative care for comfort and quality of life.
• Management of psychiatric symptoms with medications.
• Physical and occupational therapies to maintain mobility and function as long as possible.

Prognosis

Variant CJD is always fatal, typically within 13 months from the onset of symptoms. Death usually results from complications related to immobility, malnutrition, aspiration pneumonia, or respiratory failure.

Epidemiology

Variant CJD remains exceedingly rare, with fewer than 250 confirmed cases globally as of 2012. The majority of cases have occurred in the United Kingdom, attributed to BSE outbreaks during the 1980s and 1990s. Incidence has dramatically declined following stringent food safety measures.

Prevention

Preventive measures primarily focus on reducing exposure to infected cattle products:

• Rigorous control and testing of cattle for BSE.
• Ban on using animal-derived proteins in livestock feed.
• Avoidance of high-risk beef products (e.g., neural tissues, bone marrow) especially in areas with known BSE cases.
• Enhanced sterilization and precautions in medical practices to prevent iatrogenic transmission.

History

Variant Creutzfeldt–Jakob disease was first identified in 1996 in the United Kingdom following the BSE epidemic. Its identification significantly impacted public health policy and regulations regarding food safety and medical practices worldwide.

Public Health Impact

The identification of vCJD led to major reforms in agriculture, food industry practices, and healthcare protocols globally, emphasizing prion disease awareness, animal health surveillance, and stringent infection control measures.

Research directions

Ongoing research aims to:

• Understand the prion replication process and disease mechanisms.
• Develop sensitive diagnostic tools for early detection.
• Explore potential therapies or interventions to halt or slow disease progression.

See also

• Creutzfeldt–Jakob disease
• Bovine spongiform encephalopathy
• Prion
• Transmissible spongiform encephalopathy

External links

• Variant Creutzfeldt-Jakob Disease Information (CDC)
• Variant Creutzfeldt-Jakob Disease (WHO)