Loss of speech and functional impairment in Alzheimer's disease-related primary progressive aphasia: predictive factors of decline.

We aimed to identify features associated with different disease trajectories in Alzheimer's disease (AD)-related primary progressive aphasia (PPA). We considered 23 patients diagnosed with AD-related PPA. All patients underwent neuropsychological evaluation, F-Fluorodeoxyglucose-PET brain scan, CSF biomarkers measurement and APOE genotype analysis at baseline and underwent neurological follow-up for a mean time of 3 years. Patients who progressed to total loss of speech (TLoS) had greater impairment in writing and higher t-tau concentration as compared to TLoS patients. Patients who progressed to loss of functional autonomy (LoFA) had greater impairment in single-word comprehension as compared to patients who maintained autonomy in self-care. Furthermore, F-FDG-PET SPM analyses revealed different brain metabolic patterns between TLoS and TLoS and between LoFA and LoFA. In conclusion, linguistic profile, CSF t-tau and brain metabolic pattern might be useful tools to predict progression to total loss of speech and loss of functional autonomy in AD-related PPA patients.