Braak Neurofibrillary Tangle Staging Prediction Using In Vivo MRI Metrics (2728)

Objective: We aimed to examine the validity of cross-sectional regional metrics to predict postmortem neurofibrillary degeneration staging from in vivo brain magnetic resonance imaging (MRI). Background: A definitive diagnosis of Alzheimer’s disease (AD) can only be established following postmortem examination. A current accepted assessment method is the “ABC staging scheme”, which requires the neuropathological gradation of (a) diffuse amyloid plaques, (b) neurofibrillary tangles (NFT), and (c) neuritic plaques. Among all pathological features of AD, the strongest correlate of brain atrophy on MRI appears to be NFT pathology. There is an evident need for the development of new biomarkers that could be used to detect the presence of AD pathology in preclinical stages of the disease. Design/Methods: We selected participants from three databases (ADNI, NACC and Rush Memory and Aging Project) providing both antemortem MRI scans and postmortem neuropathological data. After initial quality control, 186 participants were included. Bilateral surfaces, thicknesses and volumes from cortical and subcortical brain structures were extracted using FreeSurfer 5.3. Spearman’s rank correlation tests and multivariable support vector machine classification were performed to create a predictive model of the severity and distribution of AD-associated neurofibrillary degeneration. Results: We demonstrated that 59 of our 232 MRI variables were significantly associated with Braak stages (p Conclusions: Regional atrophy detected by in vivo brain imaging reflects underlying severity and distribution of AD-associated neurofibrillary degeneration. In vivo MRI metrics may therefore be considered as a potential biomarker for the prediction of AD neuropathological staging in the living brain. Disclosure: Dr. Dallaire-Theroux has nothing to disclose. Dr. Beheshti has nothing to disclose. Dr. Potvin has nothing to disclose. Dr. Dieumegarde has nothing to disclose. Dr. Saikali has nothing to disclose. Dr. Duchesne has nothing to disclose.