I agree with others it sounds like liver shunt. I had a friend with a yorkie with these symptons when she hit her head and her soft spot had not closed. This is a shot in the dark but I though I would mention. (probably not since the spot usually closes in a couple months and yet some never close and then it is a real concern) Hope your friends can get some answers that help.
8 week old yorkshire terrier pup, soft spot in his head? - Yahoo! Answers