Bilingualism delays the onset of behavioral but not aphasic forms of frontotemporal dementia

Publication date: May 2017 Source:Neuropsychologia, Volume 99 Author(s): Suvarna Alladi, Thomas H. Bak, Mekala Shailaja, Divyaraj Gollahalli, Amuya Rajan, Bapiraju Surampudi, Michael Hornberger, Vasanta Duggirala, Jaydip Ray Chaudhuri, Subhash Kaul Bilingualism has been found to delay onset of dementia and this has been attributed to an advantage in executive control in bilinguals. However, the relationship between bilingualism and cognition is complex, with costs as well as benefits to language functions. To further explore the cognitive consequences of bilingualism, the study used Frontotemporal dementia (FTD) syndromes, to examine whether bilingualism modifies the age at onset of behavioral and language variants of Frontotemporal dementia (FTD) differently. Case records of 193 patients presenting with FTD (121 of them bilingual) were examined and the age at onset of the first symptoms were compared between monolinguals and bilinguals. A significant effect of bilingualism delaying the age at onset of dementia was found in behavioral variant FTD (5.7 years) but not in progressive nonfluent aphasia (0.7 years), semantic dementia (0.5 years), corticobasal syndrome (0.4 years), progressive supranuclear palsy (4.3 years) and FTD-motor neuron disease (3 years). On dividing all patients predominantly behavioral and predominantly aphasic groups, age at onset in the bilingual behavioral group (62.6) was over 6 years higher than in the monolingual patients (56.5, p=0.006)...

Source: Neuropsychologia - March 20, 2017 Category: Neurology Source Type: research