You could ask them to do some Memory and Recall? type testing.   When I
was first diagnosed, a Psychologist did about 2? hours of tests on Picture
Detail recall, number recall, word series recall, etc.   Now THOSE might be
different for Kids than my Adult version,  but there are tests that they can
use to get a base case of how he's performing.   Those results should be
shared with the Family Dr. and any Neurologists etc. he might see.

  That really sucks!  I always get upset when I see kids having troubles
like this since when I first had it I was an Olde Guy (35) and it was
upsetting enough wrt self-image,  trying harder and doing poorer on tests
etc.    In a way it's unfortunate (?) they don't have some earlier tests
(*before the accident) so they could compare the Base Case of his
performance levels with the current levels.

  Maybe with some of the tests (like above) if they can identify that he
might, for example, be a little slower learning new stuff, or remembering
things *some schools in some areas might provide additional help by a
councillor or tutor after class that might allow him to catch up, assuming
they don't find any larger problems.
   Those Memory and 'Psych tests'  (what I called them) can help though in
identifying his basic levels now so that if he were to have the tests in
June or next November, they could measure the level of improvement and if
there was any.    Our Brains are amazingly flexible in programming around
some types of difficulties OR the Dr. could tell you if it might be
something that could be possible to grow out of.
   I wish you well and good fortune for his continued improvement.    Some
people around here might have other groups (stay HERE TOO!)   for *Parents
of Kids.   Howdy or Julie might have some links.
 I know someone from ~1998 who was here and had a Particular developmental
condition with her son, and she was able to find a support group specific to
his particular condition, for parents like her.  If along the way the Doctor
is able to put a particular 'name' on the type of condition, there might be
a parents group for that.    G.R.

Howdy!

I'm not a doctor but I don't think that a person has to be knocked
unconsious to get a concussion or get brain lesions.