Nonfluent / agrammatic variant primary progressive aphasia

Diagnosis

Diagnostic criteria (Gorno-Tempini 2011)

1) Must have at least one of the following:

a. Agrammatism in language production (frequently loses small, closed class words such as a, or, and, the)

b. Effortful, halting speech with inconsistent speech sound errors (apraxia of speech – impaired motor speech planning resulting in articulation problems)

2) And must have at least two of the following:

a. Impaired comprehension of syntactically complex sentences (confused by question “The lion was killed by the tiger. Which one is still alive?” (Finger 2016)

b. Spared single-word comprehension

c. Sparing object knowledge

3) Imaging-supported nonfluent/agrammatic variant diagnosis requires clinical diagnosis above plus imaging with at least one of:

a. Predominant left posterior fronto-insular atrophy on MRI or

b. Predominant left posterior fronto-insular hypoperfusion or hypometabolism on SPECT or PET

4) Nonfluent/agrammatic variant PPA with definite pathology diagnosis requires clinical diagnosis above plus either of the following:

a. Histopathologic evidence of a specific neurodegenerative pathology (e.g., FTLD-tau, FTLD-TDP, AD, other)

b. Presence of known pathogenic mutation

Patients may also develop symptoms of bvFTD, CBS, or PSP (Finger 2016)

Imaging

- Axial view shows asymmetric L>R atrophy of the frontal operculum (arrow)

- Coronal view shows L>R atrophy of anterior perisylvian region (arrow)

- Sagittal view shows L lateral cerebral hemisphere with L anterior perisylvian atrophy, including frontal operculum (arrow)

Pathology

- pathology is typically 4R tau (CBD and PSP) > 3R tau and TDP-43 type A (Ljubenkov and Miller 2016)

References

Finger, E. C. Frontotemporal Dementias. Contin. Minneap. Minn 22, 464–489 (2016). https://pubmed.ncbi.nlm.nih.gov/27042904/

Gorno-Tempini, M. L. et al. Classification of primary progressive aphasia and its variants. Neurology 76, 1006–1014 (2011). https://pubmed.ncbi.nlm.nih.gov/21325651/

Ljubenkov, P. A. & Miller, B. L. A Clinical Guide to Frontotemporal Dementias. FOCUS 14, 448–464 (2016). https://pubmed.ncbi.nlm.nih.gov/31975825/