What the law is in any particular state is a difficult question to address. I would say the question is "who" told you that this kind of injury isn't covered in your state.
It's probably a good idea to get an attorney to deal with the appeal of your claim. You may also want to talk to your doctor about the denial, as it could be just a technical problem on his/her fault. And you might also want to discuss how actively fighting the denial might be helpful or detrimental to your thearapy.
Example: If your doctor thinks fighting back will empower you, simply consulting an attorney, and then fighting it yourself might be the way to go. Or not. It may be better for your recovery if you find an attorney you can trust, and let them work for you.
But no matter how active you can or will be in the appeal process, I think it's important to appeal it. My unprofessional gut feeling is that letting them deny your claim without a fight isn't good for you financially, or healthwise, either.
Best of luck.