I just saw your post and while I know you posted a long time ago I still wanted to try to reply. I am older then your son (i'm 21) but my symptoms match almost perfectly. The only difference is that mine are much more frequent. I have them about every 2.5-3 hours. It is a horrible pain that feels like a stabbing and before I can take any medication it is gone. I have been to the doctors twice and have an appt tomorrow to get a cat scan done. The doctors have no clue what it is so they just try to say that it is a headache or a migrane. However I know that it is not... Mostly because the symptoms don't match. My only symptom is the head pains, no nausia, no vomiting, etc... Just head pains.
Anyway I wanted to post and find out if you found anything out. If so please enlighten me and if not then I will repost if I find anything out.
Thanks