This page discusses prion diseases, or transmissible spongiform encephalopathies (TSEs), caused by misfolded proteins, which can damage brain tissue and transmit between species. Examples include CJD ...This page discusses prion diseases, or transmissible spongiform encephalopathies (TSEs), caused by misfolded proteins, which can damage brain tissue and transmit between species. Examples include CJD and BSE. It highlights that prions are protein-only phenomena and contrasts them with other diseases like Alzheimer's and Parkinson's, which involve non-transmissible amyloid deposits.