Progression of language profiles in primary progressive aphasia: A bicentric longitudinal study

Primary progressive aphasias (PPA) are syndromes characterised by a progressive loss of language functions. To date, four main variants have been identified: semantic (svPPA), non-fluent/agrammatic (nfvPPA), logopenic (lvPPA) and Primary Progressive Apraxia of Speech (PPAoS). Currently, little is known about their clinical course, especially in French-speaking populations, though such data could aid prognosis and guide therapy.

To characterise longitudinal changes in the language profiles in PPA using the GRÉMOTS, a French language assessment tool specifically developed for neurodegenerative disorders.

We retrospectively included PPA patients, as well as patients with typical amnesic Alzheimer's disease (AD) and behavioural variant frontotemporal degeneration (bvFTD), from the Lille and Toulouse Memory Centres, who underwent longitudinal assessment ≥6 months with the GRÉMOTS. We performed between-groups comparisons and within-group paired analyses of GRÉMOTS subscores.

Eighty-two patients were included: 20 svPPA, 9 lvPPA, 12 nfvPPA, 9 PPAoS, 20 AD and 12 bvFTD. svPPA patients showed a predominant decline in lexico-semantic domains. nfvPPA patients deteriorated mainly in phonetics and syntactic production. Apraxia remained the prominent symptom in PPAoS patients, although mild agrammatical aphasia emerged at follow-up. lvPPA patients exhibited a significant decline in lexical oral comprehension alongside their core impairments. Language impairments remained modest in AD and bvFTD.

Our results highlighted a progression of core language impairments across PPA variants, with lvPPA additionally showing significant decline beyond its defining criteria. These results support the development of tailored speech-language interventions that anticipate the evolving needs of PPA patients in French-speaking settings.