There is a neurosurgeon who used to be a NFL team doctor who calls these sub-concussion impacts. He is the only one who has ever acknowledged this as far as I have seen. Dr. Julian Bailes is at University of Virginia.

I have these same problems. I believe they are concussions to those of us with very susceptible brains. I can get them from riding in a car down a rough road. I have received them from shaky roller coasters. My first was from riding a "Tilt-a-Whirl" at an amusement park.

I have learned how to reduce their likelihood. If I am riding in the car on a rough road or even on a roller coaster, I must not have my back and shoulders, much less my head against the framework or back of the seat. It is amazing how much vibration can be absorbed by the spine, especially if it is hunched or relaxed.

I can get the same concussion symptoms if I shake my head NO or turn my head back and forth to much.

When I go out to pick up after my two dogs, I have learned to turn my shoulders to look for the 'targets'. It slows the speed of rotation of my head.

Be cautious mentioning this to a doctor. They will try to tell you it is impossible and is just 'in your head.' Been there, done that, got a 'somatoform disorder' label in my medical records. "Somatoform disorder' can be the kiss of death in your pursuit for medical help.

I wish they would just say, idiopathic, which means 'of unknown origin.' But doctors do not like to say "I don't know or understand."

They prefer to say somatoform because it puts the burden on the patient, not the doctor.