Still trying to figure this all out. Had complete thyroidectomy Nov. 15, 2007. Taking tiny bits of thyroid hormones or IsoCort causes horrible brain problems, hot brain, hurting brain in front, horrible anxiety, obsessive thoughts, sometimes racing, fleeting thoughts, feel like eyes jump around, but I dont think they really do. SEVERE insomnia. I've been on a low dose of Synthroid which is not a good thyroid drug, only because the GOOD STUFF activates those horrible brain problems. I still have worsened brain function from the Synthroid just not ACUTE like with the DESSICATED thyroid hormones. I had a possible dx. of Lyme back in June '07 based on a very low CD57 test result. Have not followed up with Igenix testing, yet. Soon. So, does anyone have similiar symptoms when taking either hormones, or any stimulant type meds or even caffeine? Wish I could figure this out.