Jinx, the same thing happened to me, when i had my first 2 done i wasnt protected much and ended up with all mental symptoms, ive always had a few muscle twitches but its mostly mental or headaches. I really thought i had alzeimers, i told my mum that i got it cos she knows all about it as my dad got it at 55yrs old.
If it wasnt for changing thyroid meds i know i wouldnt have been able to carry on.
Dawn.