Table 1

Language characteristics in primary progressive aphasia variants52 55 61–64

	Spontaneous speech	Motor speech	Single word comprehension	Grammar/sentence comprehension	Sentence repetition	Naming/word retrieval	Fluency	Reading
Semantic dementia	Fluent Grammatically correct Empty and circumlocutory Semantic errors	Spared	Impaired	Initially spared, becomes impaired as single word comprehension deteriorates	Spared	Anomia (nouns>verbs)	Impaired (categorical>letter)	Surface dyslexia
Progressive non-fluent aphasia	Decreased fluency Articulatory errors Apraxia of speech and/or Agrammatism	Impaired	Initially spared, becomes affected in late disease	Impaired for complex sentences	Can be impaired	Spared initially but anomic as disease progresses (verbs>nouns)	Impaired (letter>categorical)	Phonological dyslexia
Logopenic or phonological variant	Slow output with word-finding pauses Phonemic paraphasias	Spared	Relatively spared	Impaired for simple and complex sentences	Impaired	Impaired	Impaired (letter≈categorical)	Phonological dyslexia