In addition, asymptomatic MAPT carriers showed altered metabolic connectivity without corresponding hypometabolism in the relays of the limbic CSTC circuit, which is consistent with recent studies that reported that intracortical transmission deficits preceded the emergence of white matter lesions, structural brain atrophy, degeneration of neuronal synapses, and cognitive impairment [18, 28, 29]. Here, MAPT is linked to Cognitive impairment.