Characterization of mixed-primary progressive aphasia (mPPA)

Patients with primary progressive aphasia (PPA) who do not meet the criteria for any of the three prototypical variants are classified as having mixed-PPA. This group of patients represents a significant proportion (up to 40%) of PPA cases. However, the absence of a standardized definition for this condition leads to misclassification of cases in research papers on PPA and often results in the exclusion of these patients from clinical trials. In the present study, our objective was to provide a detailed analysis of language profiles, brain metabolic patterns, and the proportion of Alzheimer’s disease (AD) biomarkers in patients with mixed-PPA (mPPA).