I have very little cog fog, since I've been on LDN, I know you are on it,too, so, I guess it's not helping you as much..
It could be, that you are out in the heat too much....that will cause cog fog, in a hurry! I can't think at all, if I'm overheated.
Some alhiemer(sp) disease meds have been used for PwMS...ask your Doc.
Stay Cool and stay well..