Having a brain and pituitary MRI can reveal if you have a tumor in your pituitary which causes your TSH to be so high.
Are you on 400 mcg per day or per week? if it is per day, then that is a very high a dose, it is possible that your TSH does not reflect your true thyroid status and thus you are hypER thyroid.
As I said above ask for brain/pituitary MRI/CT !
Do you have heart palpitations ?what is your resting heart rate ?
Good luck,
Post Edited (hypoHashimoto) : 1/22/2014 12:01:10 PM (GMT-7)