Prion disease

Background

  • Prions are misfolded proteinaceous particles
    • Replicate exponentially by causing properly folded proteins to misfold
    • Rapidly leads to neurodegeneration
  • Universally fatal
  • Transmissible forms:
    • Variant CJD acquired by consuming diseased tissues of cows (e.g. human form of mad cow disease) or other humans (kuru)
    • Iatrogenic (handling diseased corneas/brain or improperly disinfected equipment)
  • Hereditary prion disease:
    • Familial CJD: mutation in PRNP, which encodes prion protein
    • Fatal familial insomnia
    • Gerstmann-Sträussler-Scheinker syndrome
  • Sporadic CJD: accounts for ~85% of cases, cause is unknown

Clinical Features

Differential Diagnosis

Dementia

Evaluation

  • Not an ED diagnosis, as definitive diagnosis only possible by autopsy
  • Evaluate for reversible/treatable causes of dementia
  • MRI:
    • Areas of increased signal intensity bilaterally, mostly in caudate and putamen
    • Posterior thalamic hyperintensity
  • EEG
    • Usually nonspecific but abnormal

Management

  • No specific treatment
  • Consider palliative care consult for symptom alleviation and support

Disposition

See Also

External Links

References