My mom has a brain tumor and is a fall risk because of right-side weakness and balance issues. I've discovered that it is pretty much impossible to completely prevent falls because they have sometimes happened even when I'm looking right at her. Once she starts falling, there's little I can do because of the risk of dislocating her arms if I grab them, so I just try to cushion her fall.
Unfortunately, the last time she fell she hit her head on the carpet. She says she is fine and she doesn't appear to have any external injuries. Because of her tumor symptoms which mirror concussion symptoms anyway, I don't think I would even know if something was wrong. Going to a PCP isn't helpful, and I am loathe to drag my mom to the ER every time she falls because she is already exhausted of the hospital, having been there 4 times this year already for tumor-related issues.
Maybe a member here who has gone through this can offer you more concrete advice.