Sorry to hear of your son's injury. My first concussion was in 1965 at 10 years old. I suffered slurred speech for 3 or 4 days and academic struggles on and off ever since. I was a A student. I struggled after that but did recover to get top grades. My academic life was a roller coaster ever since.
My first recommendation is simple. Get him evaluated at a Rehabilitation Hospital. The specific doctor to look for is called a Rehabilitation and Physical Medicine specialist, or vice versa.
He needs to be evaluated by an occupational therapist, a speech therapist, etc. The R&PM doctor will have referrals.
Get the TBI Survival Guide. It can be downloaded at
http://www.drakecenter.com/file.axd?...vivalGuide.pdf
You can read it online at the author's web site:
www.tbiguide.com
You are likely in for a long haul. Most important is to become informed with good information, then relax and let time and therapy do its best.
If you haven't already seen them, be prepared for personality and behavioral changes that may be a struggle. Don't blame him for the personality and behavior issues. In time, you and his therapist may be able to teach him how to work-around the behavioral issues.
Let us know how he is doing. My heart goes out to you and your family.
My best to you.