Overview Snapshot A 58-year-old male presents with difficulties in concentration and worsening insomnia. These symptoms have been progressively worsening over the past month. Startle myoclonus is appreciated on physical examination. Electroencephalography shows biphasic sharp wave patterns. Introduction Prions misfolded intracellular proteins that lead to neurodegeneration PrPc (normal; α-helix isoform) undergoes conformational change into PrPsc (abnormal; β-pleated sheet isoform) PrPsc is resistant to intracellular proteases can further induce PrPc into PrPsc → cytoplasmic vacuoles and neuronal death Spongiform encephalopathy Creutzfeld-Jakob disease (CJD) most common can be sporadic, familial or acquired acquired via iatrogenic or dietary methods Presentation Symptoms rapidly progressive dementia occurs in weeks to months myoclonus startling the patient can induce myoclonus ataxia distrubances in vision e.g., visual field defects, abnormalities in perception Evaluation Histology spongiform cortex large intracellular vacuoles Electroencephalography spike (sharp) wave pattern Cerebral spinal fluid (CSF) 14-3-3 protein Magnetic resonance imaging hyperintensity in the head of the caudate and putamen on T2-weighted and FLAIR images Differential Alzheimer disease Frontotemporal dementia Vascular dementia HIV-associated dementia Treatment Supportive No effective treatment Prognosis, Prevention, and Complications Prognosis death typically within 1 year of symptom onset Prevention iatrogenic screen dura mater and cornea donors incinerate medical tools used in patients with/suspective of CJD recombinant human growth hormone use instead of human derived Complications seizures aspiration pneumonia