I am also a new member and happened to come upon your post first thing. I have a son who suffered a severe traumatic open head brain injury when he was 12. All the things you tell about your son is true for my son also. He has grown progressively worse over the years, he is now 38, and although he was once a very successful game animator, he can no longer work and is very disabled emotionally. He c/o severe HA's for years, and finally we found out that he was having migraines. Every day, all day. For 25 years. For treatment he was given Botox injections, and after two treatments his migraines have cleared up. The Botox made him sick for about 2 weeks after the injections--they do them all around his head--but after time his HA's have virtually gone away. I hope your appointment at the HA clinic is the answer for him.