Alzheimer's-related brain changes occur 2 decades before symptom onset [As shown by PET scanning]

To reach their findings, which are published in the journal Brain, the team scanned the brains of more than 50 participants using positron emission tomography (PET).  Some of the study participants were at higher risk for Alzheimer's due to having relatives with gene mutations related to the disease, while some patients had non-inherited, "sporadic" Alzheimer's. {read more here}