Premium
Does bilingualism increase brain or cognitive reserve in patients with temporal lobe epilepsy?
Author(s) -
Reyes Anny,
Paul Brianna M.,
Marshall Anisa,
Chang YuHsuan A.,
Bahrami Naeim,
Kansal Leena,
Iragui Vicente J.,
Tecoma Evelyn S.,
Gollan Tamar H.,
McDonald Carrie R.
Publication year - 2018
Publication title -
epilepsia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.687
H-Index - 191
eISSN - 1528-1167
pISSN - 0013-9580
DOI - 10.1111/epi.14072
Subject(s) - fractional anisotropy , psychology , epilepsy , white matter , diffusion mri , audiology , boston naming test , cingulum (brain) , temporal lobe , neuroscience , uncinate fasciculus , cognition , executive functions , medicine , neuropsychology , magnetic resonance imaging , radiology
Summary Objective Bilingual healthy adults have been shown to exhibit an advantage in executive functioning ( EF ) that is associated with microstructural changes in white matter ( WM ) networks. Patients with temporal lobe epilepsy ( TLE ) often show EF deficits that are associated with WM compromise. In this study, we investigate whether bilingualism can increase cognitive reserve and/or brain reserve in bilingual patients with TLE , mitigating EF impairment and WM compromise. Methods Diffusion tensor imaging was obtained in 19 bilingual and 26 monolingual patients with TLE , 12 bilingual healthy controls ( HC ), and 21 monolingual HC . Fractional anisotropy ( FA ) and mean diffusivity ( MD ) were calculated for the uncinate fasciculus (Unc) and cingulum (Cing), superior frontostriatal tract ( SFS ), and inferior frontostriatal tract ( IFS ). Measures of EF included Trail Making Test‐B ( TMT ‐B) and Delis‐Kaplan Executive Function System Color‐Word Inhibition/Switching. Analyses of covariance were conducted to compare FA and MD of the Unc, Cing, SFS , and IFS and EF performance across groups. Results In bilingual patients, FA was lower in the ipsilateral Cing and Unc compared to all other groups. For both patient groups, MD of the ipsilateral Unc was higher relative to HC . Despite more pronounced reductions in WM integrity, bilingual patients performed similarly to monolingual TLE and both HC groups on EF measures. By contrast, monolingual patients performed worse than HC on TMT ‐B. In addition, differences in group means between bilingual and monolingual patients on TMT ‐B approached significance when controlling for the extent of WM damage ( P = .071; d = 0.62), suggesting a tendency toward higher performance for bilingual patients. Significance Despite poorer integrity of regional frontal lobe WM , bilingual patients performed similarly to monolingual patients and HC on EF measures. These findings align with studies suggesting that bilingualism may provide a protective factor for individuals with neurological disease, potentially through reorganization of EF networks that promote greater cognitive reserve.