Abstract
INTRODUCTION: The impact of bilingualism on speech-language assessment and therapy in Primary Progressive Aphasia (PPA) remains underexplored, despite its suggested influence on disease presentation. METHODS: A bilingual Italian (L1)-English (L2) individual with logopenic-variant PPA completed a bilingual assessment and dual-language Lexical Retrieval Therapy. His bilingual experience was characterized, and therapy outcomes were evaluated within and across languages. RESULTS: Pre-morbidly, the patient was a relatively balanced bilingual with stronger L1 literacy. Following disease onset, L2 showed faster decline, while L1 remained stable. Age of acquisition, dominance, and language use were among the main factors contributing to language maintenance and decline. Therapy yielded equivalent item-specific gains in both languages (L1 d(2) =5.0; L2 d(2) =5.6), asymmetric cross-linguistic transfer to L2 > L1, and modest functional improvements. DISCUSSION: Findings support the relevance of in-depth bilingual assessment and therapy underpinning successful treatment in PPA, unveiling the significance of bilingual experience in shaping treatment outcomes.