There have been many studies that show that impact force has nothing to do with brain damage. The inside of the cranium also does not always come into play to cause damage. The damage to the corpus colosum is never caused by an impact against the cranium since the corpus colosum is in the middle of the brain. Diffuse axonal injury is tearing from the movement of the axons, not impact of the axons.

The idea that a concussion is caused by the brain hitting the bony protuberances of the inside of the cranium has validity, but only regarding those types of injuries. There are many other ways the brain matter can be damaged.

If a mild bump causes symptoms, then the brain has been injured. The brain does not have symptoms without an outside force effecting it.

There are plenty who claim that since they cannot image the damage, then there is no damage. That is like saying that if a tree falls in the forest and no body is there to hear it, that it does not make a sound.

When MRI technology allows us to see individual brain cells, especially axons, and neurons, then we will have evidence one way or the other. Diffusion Tensored MRI will possibly do this some day as it can image the interaction between cells.

There are many unexplained phenomenon in the human body. The brain holds many of them. Alzheimer's, ALS, MS and many other neurological ailments still baffle the scientists. But we know that AD, ALS, and MS do exist.

Some doctors have an attitude that if they can't image it, it does not exist. Only a dozen humans have seen the back side of the moon, but we all agree that it exists.

Maybe when doctors decide that they are not God, they will believe our symptoms.