13/05/2026
About 20 years ago, neuropathologists began to report an inconvenient finding in the autopsied brains of people with dementia: Most have evidence of more than one disease. Studies since have shown the brains of up to half of people diagnosed with Alzheimerās disease also have a key feature of Parkinsonās diseaseādeposits of the protein alpha synuclein. At the same time, up to half of Parkinsonās patients who develop dementia have elevated levels of beta amyloid and tau proteins, hallmarks of Alzheimerās.
Researchers studying neurodegenerative diseases are catching on to the importance of this phenomenon, often called copathology.
Tests now being developed to pick up multiple biomarkers should give a clearer picture of these mixed pathologies in living patients. And an upcoming clinical trial will be the first to take aim at a common dementia copathology, testing the amyloid-clearing Alzheimerās drug donanemab in people who have both amyloid in their brains and dementia with Lewy bodiesāabnormal clumps of alpha synuclein.
Learn more: https://scim.ag/4ujMAkn