I've just made the connection that Riley does this head nodding also. I noticed it this morning and remembered there was this thread and reread it. Interesting that there seems to be no connection to SM. Riley's nodding seems to be like Oliver's and Gus's except that when Riley nods, she almost always does lose her footing and falls over. I think this is because she has a badly damaged vestibular system. I'm wondering if she started this when we decreased her prednisone dosage 5 months ago. She sees her neurologist next month for blood work so I will ask about it. It never seems to bother her though and she gets right up. I'll let you know what he says.