Unlike some of the other brain injuries that may be caused by a blow to the head this one is different. Diffuse axonal brain injury is caused by the movement of the brain within the skull. As a closed head injury, this can be much more dangerous than an open head injury because of the tearing of the brain tissue and the swelling that can occur. These movements, which are normally a back and forth type of movement, disrupt the nerve cells which allow the neurons to send messages between them. Once those cells are disrupted and the links between them broken, the signally process can not occur and functions like movement, speech, and even those that support life can cease.