I've had various twitches on occasion my whole life (under my eyes, on my arm, leg). I recall when lying down seeing a little twitch below my rib cage near my tummy. I thought it was just a twitch or some pulsing artery. It would stop. That was maybe even pre-medications. Are you 100% sure Seroquel is the culprit? Would you like to go off it even if it isn't?