dogs head is atrophing

Question
My friend has a dog that the vets still do not know what is wrong.  Her head is atrophing, not as active and loosing her appetite but these are her only symptoms.

Answer
You don't really have a question here, and I am not a veterinarian, but I was curious enough to do some searching, and this is what I came up with:

http://www.vetinfo4dogs.com/dhead.html#Masticatory%20myopathy%20possible

You need to find a veterinary neurologist.