Biopsy of the brain tissue is the definitive diagnostic test for Creutzfeldt-Jakob disease(CJD), but is not usually performed. EEG findings are not diagnostic of CJD, but may help in the diagnosis of CJD. Typical EEG findings in Creutzfeldt-Jakob disease include periodic biphasic or triphasic sharp wave complexes (PSWCs). Periodic synchronous discharges (PSDs) occur either before or in synchronicity with myoclonus.

• Deposits of prion protein (scrapie), PrP^Sc, can be found in the skeletal muscle and/or the spleen (approximately 30% of cases).
• Diagnosis of vCJD can be supported by biopsy of the tonsils, which harbor significant amounts of PrpSc.
• Biopsy of the brain tissue is the definitive diagnostic test, but is not usually performed.

• 
  Micrograph of brain tissue reveals the cytoarchitectural histopathologic changes found in bovine spongiform encephalopathy. From Public Health Image Library (PHIL). ^[1]
• 
  Photomicrograph of brain tissue stained with H&E reveals the presence of prominent spongiotic changes in the cortex, and loss of neurons in a case of variant Creutzfeldt-Jakob disease (100x mag). From Public Health Image Library (PHIL). ^[1]
• 
  Photomicrograph of brain tissue stained with H&E reveals the presence of prominent spongiotic changes in the cortex, and loss of neurons in a case of variant Creutzfeldt-Jakob disease (100x mag). From Public Health Image Library (PHIL). ^[1]
• 
  Neural tissue specimen harvested from a scrapie-affected mouse, revealed the presence of prion protein stained in red. From Public Health Image Library (PHIL). ^[1]

Template:WikiDoc Sources