Dementia Caused By Infection?

"An intriguing new study suggests dementia is caused by the brain's immune system going awry." Johns Hopkins School of Medicine

If true, this will lead to new treatment methods.  A group of scientists now believe that the plaque which forms in the brains of those with dementia, rather than being harmful, is the brain's attempt to protect itself. If this turns out to be true, scientists will try to pinpoint the virus or bacteria doing the harm.