IN ALZHEIMER’S DISEASE AND OTHER TAUOPATHIES

which was an average of the 32 maps of controls, was subdivided in 8 non-contiguous regions (PCC, medial frontal, right and left temporal, parietal and hippocampus). Connectivity of these regions were obtained. Results: A multivariate analysis of covariance were performed, using age as covariates. We found signiﬁcant dif-ferences (p < 0,05, corrected) in Right-hippocampus, Right-tempo-ral and PCC between controls and all AT(N) subcategories. Right parietal was different only in SNAP and A+. An inspection of the means scores shown lower connectivity in Right subparts of DMN in MCI and higher connectivity in PCC compared to controls. Conclusions: We found a lower connectivity in right subparts of DMN and a higher in PCC in MCI individuals compared to controls, independent of AT(N) status. These ﬁndings were not ex-pected and could imply that the different pathologic processes in MCI has similar outcomes on connectivity. Interestingly, we found patterns of hypo and hyperconnectivity in DMN of all MCI subgroups and, in addition, a right-left asymmetry in the studied DMN subparts. Background: In cognitively normal older adults, task-positive networks, such as the dorsal attention network (DAN), show greater neural recruitment in response to attention-demanding tasks than at rest, whereas the task-negative default mode network (DMN) shows the opposite pattern. The inverse relationship, or anticorrelation, between the two networks likely reﬂects efﬁcient competition for cognitive resources. We hypothesized that if functional connectivity between the DAN and DMN is dysregulated in early Alzheimer’s Disease (AD), then anticorrelations will be weaker and increased cognitive intraindividual variability (IIV), or increased inconsistencies in cognitive performance, will occur. Methods: Neuroimaging and cognitive measures from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) were used to assess within and between network functional connectivity and IIVin cognitively normal older adults and those with early AD. Analyses were then replicated using data from Washington University’s Knight Alzheimer’s Disease Research Center (ADRC) to ensure statistical val-idity. Results: In the ADNI sample, cognitive IIV was greater in individuals with early AD compared to cognitively normal older adults. Furthermore, the relationship between cognitive IIV and the DAN-DMN anticorrelation was weaker for individuals with early AD than cognitively normal individuals. Preliminary analyses on data from the ADRC showed similar results. Conclusions: Collectively, the results from ADNI and ADRC support conclu-sions that in early stages of AD, overall cognitive functioning be-comes less consistent, and that decreases in cognitive consistency are associated with a breakdown in functional network anticorrelations. This study provides insight into how alterations in the dy-namics of functional networks give rise to behavioral changes in early AD. Background: 18 F-PI2620 is a second-generation tau tracer, which has been developed to capture tau lesions of both Alzheimer’s disease (AD) and non-AD tauopathies. Past in vitro assessments and the initial clinical evaluation showed that 18 F-PI2620 captures all types of tau deposits (3R, 4R and 3R/4R) with high contrast and selectivity. Nevertheless, availability of this radiotracer for clinical evaluation of tau pathology in AD and non-AD tauopathies remains unclear. The purpose of the present study was to investigate spatial distribution of 18 F-PI2620 in patients with AD, progressive supur-anuclear palsy (PSP), frontotemporal dementia (FTD) and cortico-basal syndrome (CBS). Methods: Five Patients with AD (73.8 6 7.2 y/o), 3 patients with PSP (69.3 6 2.8 y/o), 2 patients with FTD (68 and 72 y/o), 1 patient with CBS (age: 70) and 4 healthy controls (HCs) (71.2 6 5.4 y/o) were scanned. Diagnosis of AD was made based on A b status determined by 18 F-ﬂorbetaben (FBB) PET. All subjects underwent 60-90 min scan with