Dear Ask The Doctor: Hello. I have some questions. When i am doing exercise i often feel vibrations throuought my whole body. I wonder if this tiny vibrations can cause brain damage? Also, i sometimes have a tick to move my head really fast, can that cause brain damage? When i move it i feel pressure inside. How intense your head movement has to be to cause damage to your brain. I am really paranoic about this thing so please answer.
Dear Ivan: Brain injuries fall under two categories: traumatic brain injuries and acquired brain injuries. While traumatic and acquired brain injuries occur differently, both may impact the way a person thinks, feels, acts, and moves, and can also affect body functions and sensory perception. Traumatic brain injury usually is a result of a direct blow to the head. The force is large enough to break through the skull and damage the soft brain, or to cause the brain to move within the skull, as for example: car crashes, falls, sports, firearms, physical violence. The degree of damage can depend on several factors including the nature of the event and the force of impact. Types of injuries that cause the brain to be moved back and forth within the skull include those that cause a rapid acceleration or deceleration of the head, including motor vehicle accidents and Shaken Baby Syndrome. In these cases, the movement within the skull causes nerve fibers in the brain to separate and damage to brain tissue. The movement has to be strong and violent enough to produce such effect. A severe blow or jolt can cause multiple points of damage because the brain may bounce back and forth in the skull. A severe rotational or spinning jolt can cause the tearing of cellular structures. Mild traumatic brain injury may cause temporary dysfunction of brain cells. More serious traumatic brain injury can result in bruising, torn tissues, bleeding and other physical damage to the brain that can result in long-term complications or death. Keep in mind that even a minor head bump can cause a large swelling. And the mechanism of injury, speed, momentum and size of the people (full-grown adolescents versus children), and the forces involved (such as a concrete floor, other hard surface or acceleration-deceleration) may increase the possibility of serious injury. For example, some studies showed that frequent "heading" of soccer balls by amateur players may cause brain damage leading to subtle but serious declines in thinking and coordination skills. Even today with the development in the resolution of the MRI there are threshold levels where we don't see brain abnormalities, but it does not mean that there is none, because may be they are so subtle that may pass undetected.