What is Primary Progressive Aphasia?

Primary Progressive Aphasia (PPA) is a degenerative disorder that primarily affects language, especially early in the course of the disease. PPA can be the result of various neuropathological conditions, including frontotemporal lobar degeneration and Alzheimer's disease. Because of the variety of pathologies and the inability to determine histopathology before death and autopsy, diagnosis of PPA is based on the clinical features. Language problems must predominate over other cognitive and behavioral deficits during the initial phases of the disorder.

PPA has been divided into three subtypes (Gorno-Tempini et al., 2011):

Nonfluent/Agrammatic variant (nfvPPA)

Individuals with nfvPPA have agrammatic sentence production and/or effortful, halting speech with inconsistent speech errors. Comprehension of syntactically complex sentences may also be impaired, while single-word comprehension and object knowledge may be spared. nfvPPA is associated with left posterior fronto-insular atrophy.

Semantic variant (svPPA)

svPPA is characterized by single-word comprehension deficits and impaired object naming. Impaired object knowledge and surface dyslexia or dysgraphia may also be present, whereas grammar, motor speech, and repetition of sentences and phrases may be unimpaired. svPPA is associated with anterior temporal lobe atrophy.

Logopenic variant (lvPPA)

Individuals with lvPPA have impaired single-word retrieval in speech and naming, as well as impaired repetition of sentences and phrases. They may also make phonological errors during spontaneous speech and naming. Single-word comprehension, object knowledge, motor speech, and grammar may be unimpaired. lvPPA is associated with left posterior perisylvian or parietal atrophy.