Dear Mohamad,

No doubt you mean "inversely proportional" since you mention that bilingual people are more resilient to dementia.

Since already mastering 2 languages densifies more completely the verbal areas of the neocortex and that this seems to correlate with more resiliency to dementia, then mastering more languages yet will densify the verbal areas yet more and this should logically increase resiliency to dementia, as you suspect:

Mastering many languages seems to establish more complex pathways that favour easier problem resolution.

These 3 papers refer to research on the establishment of conceptual thinking by means of structuring the verbal areas depending on the level reached by individuals in mastering articulated languages:

https://doi.org/10.4236/ce.2019.102028

https://www.omicsonline.org/open-access/on-the-relation-between-the-comprehension-ability-and-the-neocortexverbal-areas-2155-6180-1000331.pdf

https://www.omicsonline.org/open-access/intelligence-and-early-mastery-of-the-reading-skill-2155-6180-1000327.pdf

Best Regards, André

Thanks @André Michaud for your enlightening reply!

I agree with your hypothesis Mohamad .. this goes well with what is termed cognitive reserve which is for sure delay the manifestations of neurocognitive decline .. it resembles the well known fact that illiterates suffer dementia in a severe form than literate and that subjects who goes on pension and stop training their brains began to suffer decline in their cognitive abilities ..

I once encountered a case multilingual who overcame her post stroke aphasia through such language tricks shifting from one language to another and this is again cognitive reserve.

Here is a study that discuss brain gray matter volume in multilingual compared to monolingual and its role in dementia

Neuropsychologia. 2018 Jan 31;109:270-282. doi: 10.1016/j.neuropsychologia.2017.12.036. Epub 2017 Dec 26.

Here is the active link: https://www.ncbi.nlm.nih.gov/pubmed/29287966

Anton H. Ailabouni

Am in the GI research but the discussion is very interesting. I have questions to your expertise in regards to multilingual persons. A case history for a close person of mine. This patient is multilingual (3) fluent; yet she had a mild concussion but was not followed closely. In a matter of 2-3 month she exhibited a deterioration in mental cognitive issues as measure by the standard techniques. Upon preforming 2 MRI and showed normal shrinkage commensurate to he age of 70, and these were done at 2 different Neurologists there was no indication of brain trauma that would explain her severe cognitive decline ( down to 20%).

In your expert opinions do you feel that a multilingual as this patient should still be deteriorating fast or is there an underlaying that normal cognitive testing is missing?

Any suggestions and comments would be greatly very helpful.@ to mention the above scientists

Dear @Anton

Sorry to hear about your patient ,

I'm not a neurology expert, but in my opiniin: as the research gives overall insight about the increased brain resilience with multilingual ability , this may have protected your patient from more severe course . It may also offer further hope if the treating neurologist find it useful to incorporate some linguistic exercise into the patient's rehabilitation program ?

Best Wishes

Dear Anton

Exclude other metabolic issues like hypothyroidism or encephalopathy due to metabolic errors also mild concussion may cause some psychiatric manifestations including depression which may then mask her cognitive abilities and reserve and appear as if declining cognitively while the fact that she is depressed so is not communicating or refusing to.

I do recommend what @Tamer Roushdy advised : to explore any treatable causes as well!

Nice Dear Anton Hanna Ailabouni