Primary progressive aphasia(PPA) is a rare neurodegenerative condition and variant presentation of Alzheimer's disease or Frontotemporal Dementia. It is characterized by progressive decline isolated to language functions. PPA provides a model for understanding the anatomy of language, where each cortical language center corresponds to distinct PPA subtypes. Understanding this anatomy and its corresponding PPA subtypes helps clinicians choose testing, interpret imaging, and tailor treatment. These subtypes are termed agrammatic/nonfluent, semantic, and logopenic PPA. Each subtype is probabilistically associated with three proteinopathies: the amyloid and tau of Alzheimer's disease and frontotemporal lobar degeneration due to Tau or TDP-43. We will discuss when biomarker testing is indicated and the nuances of choosing among the increasing array of biomarker tests to improve diagnostic certainty. While medical treatment is limited, there are increasing pharmacologic options for treating Alzheimer's disease. Non-pharmacologic strategies can also be tailored to the patient's specific subtype and caregivers' needs.
Cahan et al. (Sat,) studied this question.