“…Despite the fact that all these studies report worse preserved brain in bilinguals compared to monolinguals, both in terms of grey and white matter structure (Duncan, Nikelski, Pilon, Steffener, Chertkow & Phillips, 2018;Gold, Kim, Johnson, Kryscio & Smith, 2013;Schweizer, Ware, Fischer, Craik & Bialystok, 2012), in all cases the bilingual groups matched or even outperformed the monolingual groups in cognitive tests, suggesting more efficient recruitment of the spared brain tissue in the former group. It is worth mentioning that a similar pattern (i.e., higher diffusivity but equal cognitive abilities) has also been reported in bilingual patients with temporal lobe epilepsy when compared to monolinguals matched on diagnosis (Reyes, Paul, Marshall, Chang, Bahrami, Kansal, Iragui, Tecoma, Gollan & McDonald, 2018). However, and despite some behavioural evidence, little is known about how bilingualism interacts with other neurodegenerative diseases, such as Parkinson's, Huntington's, Primary Progressive Aphasia and Multiple Sclerosis (for a review, see Voits, Robson, Rothman & Pliatsikas, in preparation); for example, a recent study with bilingual patients with Huntington's disease showed that the amount of usage of two languages predicted higher GM volume in the right IFG, although in the absence of a control group it is hard to tell whether this is a generic effect of bilingualism or an effect specific to this patient group (Martínez-Horta, Moreu, Perez-Perez, Sampedro, Horta-Barba, Pagonabarraga, Gomez-Anson, Lozano-Martinez, Lopez-Mora, Camacho, Fernández-León, Carrió & Kulisevsky, 2018).…”