P4‐074: ITALIAN NETWORK FOR AUTOSOMAL DOMINANT ALZHEIMER'S DISEASE AND FRONTOTEMPORAL LOBAR DEGENERATION (ITALIANDIAFN)

Diffusion datasets were corrected for motion and eddy current distortions (Smith et al., 2004) and then processed with a Spherical Deconvolution algorithm based on a damped version of the Richardson-Lucy algorithm (Dell’acqua et al., 2010, Dell’Acqua et al., 2013). Tractography was performed following the method described in (Catani et al., 2012). We dissected fiftyfive frontal tracts including U-shaped fibers. For each dissection FA (Basser and Pierpaoli, 1996) and hindrance modulated oriented anisotropy (HMOA) (Dell’Acqua et al., 2013) were extracted as an indirect measure of the tract integrity and correlated with the age of the participants regressing out the level of education. P values are presented after false discovery rate (FDR) correction for multiple comparisons (* p < 0.05 ; ** p < 0.01 ; *** p < 0.001). Results: Aging was significantly associated with a decrease of FA (r1⁄4 0.501*) and OA (r1⁄4 0.508**) in the frontal projections of the corpus callosum. Aging was also associated with a decrease of OA in the right frontal lobe including the SLF I (r 1⁄4 0.401**) and SLF III (r 1⁄4 0.576***) branches of the superior longitudinal fasciculus, inferior fronto-occipital fasciculus (r 1⁄4 0.331*), fronto-thalamic projections (r 1⁄4 0.515***). In the left hemisphere, OA measure also decreased with aging for the frontal inferior longitudinal fasciculus (r1⁄4 0.542***) and the frontal orbito-polar tract (r 1⁄4 0.542***). Results are summarized in Figure 1. Conclusions: We confirmed preliminary evidences reporting reduced integrity in the frontal portion of the corpus callosum associated with aging (Lebel et al., 2010). This commissural decline may explain the increased reaction times associated with aging reported in tasks requiring interhemispheric transfer (Reuter-Lorenz and Stanczak, 2000). Our results also suggest for the first time that aging alters significantly other tracts in the right hemisphere which brings up interesting pathophysiological hypotheses for ageing decline in visuospatial and verbal working memory, memory encoding and retrieval, reward-based associative learning that can be tested in the elderly (Cabeza and Dennis, 2012). IC-P-069 ITALIAN NETWORK FOR AUTOSOMAL DOMINANTALZHEIMER’S DISEASE AND FRONTOTEMPORAL LOBAR DEGENERATION (ITALIANDIAFN) Martina Bocchetta, Michela Pievani, Claudio Babiloni, Amalia C. Bruni, Elio Scarpini, Sandro Sorbi, Fabrizio Tagliavini, Alessandro Padovani, Luisa Benussi, Livia Bernardi, Giuliano Binetti, Barbara Borroni, Giuseppe Di Fede, Emilio Di Maria, Silvia Fostinelli, Daniela Galimberti, Massimo Gennarelli, Roberta Ghidoni, Nicola Marzano, Anna Mega, Benedetta Nacmias, Irene Piaceri, Corinna Porteri, Giacomina Rossi, Silvia Suardi, Fabrizio Vecchio, Giovanni B. Frisoni, IRCCS Centro S. Giovanni di Dio, Fatebenefratelli, Brescia, Italy; IRCCS Fatebenefratelli, Brescia, Italy; 3 University of Rome "La Sapienza", Rome, Italy; 4 Centro Regionale di Neurogenetica, Lamezia Terme (CZ), Italy; 5 Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy; University of Florence, Florence, Italy; IRCCS Foundation "Carlo Besta" Neurological Institute, Milano, Italy; 8 University of Brescia, Brescia, Italy; 9 IRCCS Instituto Centro S. Giovanni di Dio Fatebenefratelli, Brescia, Italy; 10 Centro Regionale di Neurogenetica, Lamezia Terme, Italy; IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy; University of Genova, Genova, Italy; 13 IRCCS Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy; University of Milan, Ospedale Policlinico, Milan, Italy; IRCCS Centro San Giovanni di Dio, Fatebenefratelli, Brescia, Italy; 16 University of Florence, Florence, Italy; 17 IRCCS Fondazione Instituto Neurologico Carlo Besta, Milano, Italy; 18 IRCCS Fondazione Instituto Neurologico Carlo Besta, Milan, Italy; IRCCS Instituto San Giovanni di Dio Fatebenefratelli, Brecia, Italy. Contact e-mail: mbocchetta@ fatebenefratelli.it