Bilingualism And Language Networks In The Semantic Variant Of Primary Progressive Aphasia

CALANDRI I, AMENGUAL A, CHAVES H, FAREZ M, SABE L, MEDINA C, RUSSO G, VAZQUEZ S, ALLEGRI RF

Congreso; Annual Meeting of the American Academy of Neurology; 2014

American Academy of Neurology

OBJECTIVE:To compare using DTI-based tractography, language-related white matter tracts in bilingual and monolingual patients with Semantic variant of Primary Progressive Aphasia (Sv-APP).BACKGROUND:Accumulating research shows that bilingualism influences the development, efficiency, and decline of crucial cognitive abilities, and it has been associated with neuroplasticity, cognitive training and cognitive reserve.Disorders in a second language compared to the mother language in bilingualism can be considered a semantic system impairment. In this regard, assessing patients with Sv-PPA, offers the opportunity to evaluate the influence of bilingualism in a model of selective damage of the semantic system.To our knowledge, few studies have used diffusion tensor imaging (DTI) to analyze changes occurring in the white matter (WM) of the patients with PPA or bilingualism.DESIGN/METHODS:We used DTI-based tractography in 6 patients with Sv-PPA to evaluate inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus (SLF), and uncinate fasciculus (UF) bilaterally, and compared fractional anisotropy (FA) and mean difussivity (MD) between bilinguals and monolinguals. Bilingualism was assessed through number of spoken languages and proficiency.RESULTS:The sample included 6 patients divided in two groups: bilinguals (n=3) and monolinguals (n=3)Statistical analysis showed significant differences between groups only when comparing FA values in the right UF (p <0.037). Diffusivity values did not differ.CONCLUSIONS:Results indicated significantly higher microstructural integrity in the bilingual group in the right UF, compared to their monolingual peers, showing higher FA.The UF has been proposed to play a role in lexical retrieval, semantic association and aspects of naming that require connections from temporal to frontal areas. Previous research consistently showed its selective damage in Sv-PPA.The management of multilingual semantic knowledge could determine an improvement in the conditions of the tract and strengthen it against degeneration, but further research is needed to address this item.