I love this site http://ww.daimonismo.altervista.org/forum/viewtopic.php?f=39&t=1004&p=84678 redtubes One possible answer is known as the “two hit” theory of amyloid and vascular disease. Some research suggests that “amyloid collects in the brain over years and decades until the brain can no longer compensate for it and cognitive impairment begins to set in,” Hughes says. The combination of amyloid deposition and damage to small arteries that nourish brain tissue could, hypothetically, tip the scales. “Amyloid deposition and vascular disease may be the double hit that may really cause a person to convert to dementia.”