Yes, a concussion is an MTBI (I believe).

It can be frustrating dealing with family - I had some of the same issues (in my case, my parents kept encouraging me to "go outside for a walk" and "get some fresh air," even though at first I couldn't do this without feeling worse). It's exhausting enough riding the PCS rollercoaster; the last thing you feel like doing is expending energy educating others, especially when they could take the initiative to educate themselves.

But it's worth a try. One thing that can be helpful is providing links to short, clear articles and videos on the subject. I provided my family with links to the Sidney Crosby press conference, which seemed to help them understand a bit more.

I would also listen to Mark - he provides good advice on many aspects of coping and recovering from concussions.