My Brother Had Several Concussions After Hitting His Head (falling)

My brother had several concussions after hitting his head (falling) on the sidewalk while walking his dog. His last one was a year ago. He has severe migraines, is dizzy, and his hands shake. I mentioned that maybe he should have his blood supply checked at the base of the back of his head.
Also, does botox help to calm the nerves in your head (face)? Thanks