I have a little Dementia like problem, from nerve damage from decades ago, in the military, but it only affects my ability to process and remember some things, and don't retain things like I should. But I have fought it and do still fight it with diet,, herbs and supplements, with the Word of Wisdom, guided by the Holy Ghost.
This may not be where you wanted this to go, but I feel sorry for LDS members who have health problems, because they don't understand the Spiritual side and the potential of the Word of Wisdom; and lack of use of the Holy Spirt to seek direction; instead they turn to man for help. Most degenerative diseases are totally preventable with diet.