Hi there - I was just checking on Luna. My cat, Shaddy, has a head twitch/bob thing as well and it is only when he is my lap resting or relaxing - just like yours. But he just suffered a bout of pancreatitis and they had him on metrodazinole. This seemed to make his twitches and bobbing even worse. He only has three more doses of the pill but I'm thinking of taking him off because it has made his twitching so much worse. But on the other hand - I want to get rid of all his pancreatitis. I hate this! I've asked my vet numerous times what would cause the twitching and they never have a good answer for me. Have you had a "breakthrough" about what is wrong with her? And what is the s/d diet you talked about? Thanks!