What are the symptoms of Bovine Spongiform Encephalopathy (BSE) and variant Creutzfeldt-Jakob disease (vCJD)?

Symptoms of Bovine Spongiform Encephalopathy (BSE) and Variant Creutzfeldt-Jakob Disease (vCJD)

Bovine Spongiform Encephalopathy (BSE) and its human form, variant Creutzfeldt-Jakob disease (vCJD), are fatal neurodegenerative disorders characterized by progressive neurological deterioration that inevitably leads to death.

Bovine Spongiform Encephalopathy (Mad Cow Disease) Symptoms

BSE affects cattle and presents with the following clinical manifestations:

• Neurological symptoms:

  • Irregular body posture
  • Incoordination and difficulty standing
  • Abnormal gait and movement patterns 1

• Behavioral changes:

  • Agitation and hostility
  • Temperamental changes
  • Nervousness and hyperreactivity 1

• Physical deterioration:

  • Progressive weight loss despite normal appetite
  • Decreased milk production in dairy cows 1

Variant Creutzfeldt-Jakob Disease (vCJD) Symptoms

vCJD is the human form of BSE, caused by consumption of BSE-contaminated beef products. It differs from sporadic CJD in several important ways:

Early Symptoms (Initial Phase)

• Psychiatric manifestations (often predominate early):

  • Personality changes
  • Depression and anxiety
  • Withdrawal and social isolation 2

• Sensory disturbances:

  • Persistent painful sensory symptoms
  • Dysesthesias and paresthesias 2

Progressive Phase

• Cognitive decline:

  • Rapidly progressive dementia
  • Memory impairment
  • Confusion and disorientation 2

• Movement disorders:

  • Ataxia (unsteady gait)
  • Myoclonus (involuntary muscle jerking)
  • Dystonia and chorea 2

• Advanced neurological signs:

  • Akinetic mutism (awake but unresponsive)
  • Pyramidal and extrapyramidal signs
  • Cerebellar dysfunction 2

Terminal Phase

• Complete loss of voluntary movement
• Inability to communicate
• Coma preceding death 2

Key Diagnostic Features

Clinical Presentation

• Age of onset: vCJD typically affects younger individuals (median age 28 years) compared to sporadic CJD (median age 65 years) 2
• Disease duration: vCJD has a longer clinical course (median 14 months) compared to sporadic CJD (median 5 months) 2

Diagnostic Testing

• MRI findings: Bilateral hyperintensities in the pulvinar nuclei of the thalamus ("pulvinar sign") are characteristic of vCJD 2, 3
• EEG patterns: Periodic sharp wave complexes (PSWCs) are common in sporadic CJD but less frequent in vCJD 2, 3
• CSF biomarkers:
  • RT-QuIC (Real-time Quaking-Induced Conversion) has the highest sensitivity and specificity for CJD diagnosis
  • 14-3-3 protein and total Tau protein may be elevated 2, 3

Disease Course and Prognosis

• vCJD is universally fatal with no effective treatment
• Median survival from symptom onset is approximately 14 months for vCJD
• Most patients die within 1-2 years of diagnosis 2, 3

Distinguishing Features from Other Rapidly Progressive Dementias

It's important to distinguish vCJD from other causes of rapidly progressive dementia, including:

• Other neurodegenerative diseases (15% of rapidly progressive dementias)
• Autoimmune encephalitis (8%)
• Infectious encephalitis (4%)
• Toxic-metabolic conditions (2%)
• Vascular disorders (2%) 2

The combination of young age of onset, psychiatric symptoms preceding neurological manifestations, painful sensory symptoms, and characteristic MRI findings helps differentiate vCJD from other rapidly progressive dementias.