Wow, it looks like an insane amount of polies on the head. I don't think it's a good idea to use all that poly to get the wrinkle effects. You should probably play around with bump maps for that the really detailed effects. I'm not good at that yet, so I wouldn't be able to tell you how to do it, but a good idea might be to have a simple shape, map it and then play around with the bumps on that until you're comfortable with it. Just my opinon, but it looks cool though.