Elevated medial temporal lobe and pervasive brain tau-PET signal in normal participants

MTL tau-PET signal is often associated with abnormal extra-MTL tau-PET signal in CU participants and may represent neurofibrillary tangle development that could identify participants most likely to develop AD dementia. Tau-PET signal exclusively outside of the MTL is seen in 17% of CU participants and could be the initial findings in participants in different AD dementia pathways. Significant (P < .001) differences in tau-standardized uptake value ratio between sides were noted in 26 of 41 examined brain regions implicating further study of side-specific deficits.