The experts do not know the answer to this question except that some researchers believe genetics may play a part. Some people are more prone to trigger improper functions of neurofibrillary Tau tangles. They are the cause of many dementia related diseases.

Plus, there is agreement that you cannot compare any two concussions. The brain is complex and the angle of the concussion along with the force and duration plus the metabolic condition of the brain all combine to create an immeasurable number of possible combinations.

Impacts with a rotational component often result in more damage.