When tau pathology has extended through the entire network, cognitive deficits generally involve multiple domains and patients will have developed overt AD. Therefore the breakdown of this network due to neurodegeneration may track progression to dementia. In subjects with mild cognitive impairment, preliminary evidence indicates that reduced DMN connectivity is a significant predictor of conversion to AD independently of global atrophy.74 Interestingly, the predictive value of DMN connectivity was no longer significant when memory performance was taken into account,74 suggesting that functional connectivity changes are related to memory deficits.
