The build-up of urea, also known as carbamide, in the brain to toxic levels can cause brain damage — and eventually dementia, according to new research. An old man diagnosed as suffering from senile dementia. Color lithograph, 1896, J. Williamson, Byrom Bramwell. Image credit: Wellcome Images / CC BY 4.0. Published in the Proceedings of the National Academy of Sciences, the study shows that the neurodegenerative disorder Huntington’s Disease...