B.M.
Dr Michael Kohrman at U of C is excellent. My son was a preemie and we saw him for the first 2 years of his life.
http://www.uchospitals.edu/physicians/michael-kohrman.html
He has an excellent bedside manner and he is very thorough. As much as it was a pain to get to U of C every few months, I was a little sad when he discharged us. He was GREAT!
Good luck and I hope that your son's headaches are normal!
B.