I have no info for you Edwin but want to wish you luck in sorting it all out. I do know these things can be temporary. I recall my eldest son having a slight tic (I think it was head turning) when he was about 1.5yr old. Do you think your DS is about to make a cognitive leap in some area? My supposition has been that just before a big leap (either physical or mental), the brain undergoes extensive re-wiring which can in the short-term, screw things up lol.