View source for 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==
*Progressive [[dementia]], behavioral changes, loss of cortical function over several months on average
*Myoclonus
*[[Extrapyramidal symptoms]] (hypokinesia)
*Cerebellar dysfunction- [[ataxia]], [[dysarthria]]
*[[Coma]]

==Differential Diagnosis==
{{Dementia DDX}}

==Evaluation==
*'''Not''' an ED diagnosis, however MRI (if done) can raise significant suspicion and provide a presumptive diagnosis in the right clinical context
*LP with CSF studies can be diagnostic but should never be performed in the ED and must be done under special precautions
*Evaluate for reversible/treatable causes of dementia
**CBC, B12, folate, thiamine
**[[LFTs]], BMP, TSH, [[Urinalysis]] 
**[[ECG]], [[CXR]] 
**ETOH, [[Utox]], urine heavy metals
**RPR, ESR, ANA, HIV
*[[brain MRI|MRI]]: 
**Areas of increased signal intensity bilaterally, mostly in caudate and putamen
**Posterior thalamic hyperintensity
*EEG
**Usually nonspecific but abnormal

==Management==
*No specific treatment, doxycycline has been used but evidence is weak
*Ongoing research
*Consider [[palliative care]] consult for symptom alleviation and support

==Disposition==

==See Also==
*[[Dementia]]
*[[Altered mental status]]
*[[Microbiology (Main)]]

==External Links==

==References==
<references/>

[[Category:Neurology]]