How did you get your TBI? Is there a possibility that your neck was also damaged?

I was severely whiplashed in an MVA and left with an unstable neck. Road bumps bother me, too. I find it helps to stabilize my neck with a cervical collar anytime I have to do something that involves my being shaken or jostled.

Just be mindful that wearing a collar, while driving, can implications with some car insurance policies. I only wear mine as a passenger.