Primary Progressive Aphasia in Italian and English

Abstract

Background and ObjectivesCurrent formulations of primary progressive aphasia (PPA) derive largely from Englishspeaking patients. We hypothesized that language-specific characteristics influence PPA phenotypes in 2 contrasting languages: Italian and English. MethodsWe undertook a retrospective, cross-sectional, observational comparison of 2 patient cohorts representing all major PPA syndromes, in London and Florence. Neuropsychological scores in a range of linguistic and general cognitive domains were normalized to native speaker controls and dichotomized as impaired/unimpaired. Proportions were compared using χ 2 tests and adjusted for symptom duration and severity of cognitive impairment using logistic regression. ResultsThe cohorts comprised 106 (48.1% female) Italian speakers (14 nonfluent/agrammatic [nfvPPA], 20 semantic [svPPA], 41 logopenic variant [lvPPA], 31 mixed PPA [mPPA]) and 166 (45.2% female) English speakers (70 nfvPPA, 45 svPPA, 42 lvPPA, 9 mPPA). Comparing cohorts, the English cohort was younger (mean 62.7 [SD = 8.4] vs 65.9 [7.8] years; p = 0.003, Cohen d = 0.39), with longer symptom duration (4.6 [4.3] vs 3.1 [2.5] years; p = 0.048, d = 1.08), a higher proportion of nfvPPA cases (42% vs 13%, χ 2 = 25.4, p < 0.001), and lower proportions of lvPPA (25% vs 38%, χ 2 = 5.46, p = 0.019) and mPPA (5% vs 29%, χ 2 = 29.3, p < 0.001). English-speaking nfvPPA patients had less frequent expressive agrammatism (46% vs 93%, p = 0.015, odds ratio [OR] 16.05, 95% CI 1.70-151.13) but more frequently impaired single-word comprehension (60% vs 8%, p = 0.013, OR 0.06, 95% CI 0.00-0.56). English svPPA patients had more frequent surface dyslexia (68% vs 30%, p = 0.046, OR 0.24, 95% CI 0.06-0.97) and dysgraphia (38% vs 10%, p = 0.021, OR 0.09, 95% CI 0.01-0.70) while English lvPPA patients had more frequently impaired single-word comprehension (89% vs 29%, p < 0.