My 7 yo. niece has recently developed a tic - it's a very violent tic where she throws her head backwards with force. It's so severe that she had to be taken immediately to do an MRI and various other tests, but it's been concluded that it is a tic and nothing else. We are supposed to get together at Christmas, but i'm really worried that my 8yo and 6 yo DDs might mimic this tic. My DD already has a very slight tic with her mouth and i fear she may be influenced by seeing her niece. Does anyone have any experience with this?