Doberman with head-bobbing syndrome

My poor Dobie has this strange condition that happens about once every three weeks for about a half hour. No clue what causes it. Any answers out there? Thnx. ... Ok, Cooper’s ten years old now and still happy and healthy. Yes he gets the head bobbing every couple of months, but the spells don’t last long, in fact when I give him a tasty treat it stops instantly. This makes me think it’s not epilepsy. Anyway, thanks for all the advice and comments, he’s been to the doctor, he’s been checked out an