The present study aimed at investigating neural substrates of two distinct proxies of cognitive resilience: bilingualism and education in patients with Frontotemporal dementia (FTD), using cortical thickness as a measure of neurostructural plasticity.

Life-course experiences such as education and bilingualism are associated with enhanced neurostructural plasticity and can be protective against dementia.  However, it is not known whether mechanisms that underlie cognitive resilience are common or are distinct between different protective factors.

Forty five FTD patients were enrolled in the study. 27 bilinguals were matched with 18 monolinguals for age, education, gender, cognitive status (Addenbrooke’s Cognitive Examination III scores) and clinical severity (Clinical Dementia Rating scale). We examined cortical thickness using cortical based morphometry using two analytic approaches: 1) Whole brain vertex based cortical thickness analysis between bilingual and monolingual FTD patients and their associations of cortical ribbon metrics and, 2) Correlation between education and whole brain cortical thickness performed after controlling for age, gender, bilingualism CDR and Total intracranial volume.

Bilinguals with FTD had greater cortical thickness in bilateral dorsolateral and medial frontal cortices, and right temporo-parietal regions, areas associated with executive control, while they demonstrated smaller clusters of lesser cortical thickness predominantly in the language processing areas of left superior temporal, lateral occipital and right postcentral regions compared to a clinically matched monolingual FTD cohort. On the other hand, higher education was associated with decreased cortical thickness in bilateral frontal, medial temporal, parietal, occipital, and left temporal regions in the same cohort.

This study explores for the first time effects of two distinct proxies of cognitive resilience on cortical thickness in FTD. Our findings indicate that the neural substrate underlying the protective effect of bilingualism differs from effects of education in FTD, indicating specific effects of cognitive resilience for different life-course experiences.