Radiological and pathological characteristics of PPA
| Nonfluent/agrammatic variant of PPA | Semantic variant of PPA | Logopenic variant of PPA | |
|---|---|---|---|
| Radiology | Left posterior fronto-insular (Broca's area) | Anterior temporal lobe (asymmetric bilateral atrophy left > right) | Left temporo-parietal |
| Pathology | Tau inclusions (tauopathy) | TDP-43 inclusions | Alzheimer (amyloid) See Bergeron et al., 2018 |
Based on Mesulam, 2014
Note that PPA primarily affects left hemispheric networks. Moreover, tauopathies are well-known to be associated with parkinsonism. Therefore, nonfluent/agrammatic PPA is often associated with progressive supranuclear palsy or corticobasal syndrome.