A Multimodal Approach for Clinical Diagnosis and Treatment of Primary Progressive Aphasia, MAINSTREAM ID:3430931

60 patients with PPA will be recruited from IRCCS Istituto Centro San Giovanni di Dio, Fatebenefratelli, Brescia; IRCCS Fondazione Istituto Neurologico Nazionale C. Mondino, Pavia; Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan and Fondazione Don Carlo Gnocchi - ONLUS, Milan. The diagnostic evaluation will include cognitive and language testing, neurologic examination and neuroimaging (Magnetic Resonance Imaging (MRI) or Positron Emission Tomography PET)). All the patients will undergo five consecutive days a week for two weeks of treatment sessions of 25 minutes: * 30 patients will receive Active tDCS over dorsolateral prefrontal cortex-DLPFC (anode over the left DLPFC with the cathode over the right supraorbital region) while performing an individualized language training; * 30 patients will receive Placebo tDCS during an individualized language training. The two groups will be matched for sex, age, education, language severity (as defined in the Frontotemporal Dementia Clinical Dementia Rating subscale), and overall severity according to the FTD Clinical Dementia Rating. Two trained neuropsychologists will administer the neuropsychological testing at baseline (T0), post-treatment (T1) and 3-months (T2) follow-up. All of assessments will be conducted by the same assessor. To elucidate the mechanisms underlying tDCS effects, Magnetic Resonance Imaging (MRI) and bimolecular data will be collected at T0 and T1 (after the treatment).