Default mode network and medial temporal lobe functional connectivity changes with Alzheimer’s disease severity and cognitive impairment in individuals with Down syndrome

By age 40, virtually all people with Down syndrome (DS) have sufficient beta‐amyloid and tau pathologies present to meet the criteria for pathological Alzheimer's disease (AD). Determining the timing and location of neurobiological changes caused by AD is critically important for effective intervention within this high‐risk population and more broadly in the general population, but little is known about the brain changes associated with clinical onset of AD in DS. Previous studies in sporadic AD suggest that functional connectivity of the default mode network (DMN) and medial temporal lobe (MTL) is vulnerable to AD pathology‐related impairment.