Pro,

Not every concussion sufferer has the same stress intolerance. For some, they are just intolerant of cognitive load. Others, visual stimulation or audio stimulation. Even others, tactile stimulation.

My neuro explained it this way. Sensory information is received into the brain. It needs to be filtered and directed to the proper processing areas. The term he used was 'gating,' as in gates open and close to control the flow of information. He could see how this flow was happening by observing the wave forms in a qEEG. In my case, he could see the amount of sensory information that was being received by the brain and then compare it to the amount of information that was being sent to the various parts of the brain for processing. He responded with "You hear everything. How do you handle that ?" He had not been informed that I had horrible struggles with audio over-stimulation.

If I remember it correctly, this gating happens in the area of the the pons and corpus callosum. If you look at the anatomy of the brain. This area has a different mechanical structure. The pons is connected to the brain stem that is anchored in the spinal column. The corpus callosum is between the two hemispheres. This creates shear points where axons have greater risk to physical stresses from all directions. Forces on the right hemisphere are different than the forces on the left hemisphere with the strain concentrated at the connection between the two. Just as the neck is traumatized when the head moves with more force than the body can follow. So, as these communication pathways between the right and left and front and back are strained, the information that needs to travel along these pathways become disrupted.

Add to this the chemical strains on the brain as it tries to rebalance itself, and you have a problem. Since sensory stimuli processing is such a huge percentage of the total brain processing load, this becomes a big problem.

Some of this chemical strain is due to the strain to the vascular and glymph system that needs to drain away the waste products. The brain's 'sewer' system gets backed up.

The injured brain gets stuck in a Catch-22. It is overloaded with processing demand and the resulting chemical waste reducing its capability thus increasing the waste output in a clogged system.