Can you appeal an additional pain and suffering denial.?

I know that if your physical or mental injury gets denied or you’re not happy with the assigned % you can appeal through BPA, but l understand if you’re denied DEC status, BPA can’t intervene. But what about APSC, there are 3 grades, if you are assigned a grade and think VAC got it wrong, or you are denied it outright, can you appeal the decision?