Table 2:

Diagnostic criteria for PPA variants

	lvPPA	svPPA	nfvPPA
Clinical diagnosis	1. Impaired single-word retrieval in spontaneous speech and naming AND	1. Impaired confrontation naming	1. Agrammatism in language production AND/OR
	2. Impaired repetition of sentences and phrases	2. Impaired single-word comprehension AND	2. Effortful, halting speech with inconsistent speech sound errors and distortions (apraxia of speech)
	At least 3 of the following:	At least 3 of the following:	At least 2 of the following:
	1. Speech (phonologic) errors in spontaneous speech and naming	1. Impaired object knowledge, particularly for low-frequency or low-familiarity items	1. Impaired comprehension of syntactically complex sentences
	2. Spared single-word comprehension and object knowledge	2. Surface dyslexia or dysgraphia	2. Spared single-word comprehension
	3. Spared motor speech	3. Spared repetition	3. Spared object knowledge
	4. Absence of frank agrammatism	4. Spared speech production (grammar and motor speech)
Imaging-supported diagnosis	Predominant left-posterior periSylvian or temporoparietal atrophy and/or hypoperfusion or hypometabolism	Predominant anterior temporal lobe atrophy and/or hypoperfusion or hypometabolism	Predominant left posterior frontoinsular atrophy and/or hypoperfusion or hypometabolism
Pathology-supported diagnosis (or presence of known pathogenic mutation)	ADa	TDP-43a	4R-τa

^aHistopathologic evidence of a specific neurodegenerative pathology (eg, FTLD-τ, FTLD-TDP, AD, other), particularly if most characteristic pathology.