Hi S.,
Running into a pole could qualify as a mild traumatic brain injury. It can also simply cause the sutures of the skull to push themselves into a misalignment that then affects the jaw--the temporal mandibular joint (TMJ). This is where all the nerves for the face go through, and a misalignment here can cause severe and ongoing headaches. My eldest daughter who is now almost 21 has had a chronic, very severe problem with this ever since having her tonsils and adenoids out when she was 12. (under general anesthesia, neck propped backwards, mouth propped open...took us over 2 years to find out that her jaw had become dislocated and severely misaligned.) She is now finally wearing braces, working with a TMJ specialist, and feeling better.
I had a head injury a year ago--fell over with my full weight (190 lbs) onto the back of my head while ice skating. Slammed the back of my head into the ice so hard I needed five staples to close the wound. Mild concussion.
Now, a year later, I started having dizzy spells after major exertion or pressure on that area.
What to do? First understand what may be going on. Basically, when we are in utero, our skull develops into several parts, and those parts slide over each other as we are born so they can fit through the narrow birth canal. The "soft spot" on top of a newborn's head is there because it takes awhile for the cartilage to turn into solid bone, but really, the "sutures" or seams between these parts never completely solidify but have an ever so slight ability to shift. There are small points all along the sutures, like gear teeth, to help hold them in place. A blow to the head can cause these to become misaligned.
I have personally been working with a chiropractor who does a very specific cranial technique that realigns these "teeth" in the sutures. And the dizziness stopped with the first treatment! My face looked different--a part that had slightly been sagging, apparently, became aligned again. Inside my head it feels like a "flatness" has been rounded back out again, giving room for my brain.
I think your son just might have had some level of cranial misalignment from his hit against a pole.
By the way, FIRST I saw a doctor, had an MRI, saw a neurologist, took various meds, etc. Not one of them was able to help.