Swimmom,
In answer to your question above about the high dose.... it really varies from person to person as to what helps versus what is tolerable.

I currently fluctuate for my normal dose between 200-250 mg without side-effects. At 300 mg I have word recall issues but they are mild, not noticeable to anyone else, I can recover quickly and some tingling. Beyond 300 it becomes more pronounced and I cannot function past 350. As an example, the neurologist mentioned he has someone taking 400 w/out any side effects but at 450 it starts for that person, yet another patient cannot not even tolerate beyond 50 mg, which is the right dose for them.

Go with what you notice for you that is right to control symptoms with the fewest side-effects. Best wishes.