Stroke and Traumatic Brain Injury
The body depends on the brain for instructions for all of its functions - breathing, eating, talking, moving and thinking. Each part of the brain has specific functions it controls. In fact, the more the brain is studied the more that is learned about the very detailed areas and their functions. Thus, brain cells must have a steady supply of oxygen and nutrients, such as glucose, in order to function properly.
Brain cells are very delicate. When a blood vessel ruptures, or is blocked, and disrupts the blood supply for more than a few minutes the cells may be killed or permanently damaged. The result is a stroke. Other names for stroke include cerebral vascular accident (CVA); ruptured aneurysm; cerebral or brain hemorrhage; cerebral infarction, and ischemic attack.
Traumatic Brain Injury
Head injury causes more deaths and disabilities than any other neurologic cause in individuals under age 34. Over 80% of all head injuries are due to road accidents. Other causes include falls, gunshot wounds and other interpersonal violence.
Due to improved emergency medicine and improved diagnostic and neurosurgical techniques, the survival rate of the head-injured person has increased dramatically. The very young tend to have the best chance of surviving and recovering from a brain injury.
There are two types of injuries as the result of TBI, with a range of effects.
The first type is primary. Of those, there are three different effects:
- Direct and blunt - (acceleration, deceleration injuries, skull fractures, scalp lacerations, coup and countercoup injuries). These injuries are often widespread and diffuse.
- Direct and Penetrating - (bullet wounds, sharp objects, crushed skull). These usually produce an area of localized damage.
- Indirect - (flexion and extension injuries of the cervical spine, whiplash, fall on buttocks). These injuries tend to be comparatively mild.
The other type of injury is secondary.
These secondary insults happen to the brain after the initial injury. Bleeding inside the brain may occur and accumulation of blood may put pressure on the brain tissue and cause further damage. Blood flow to other parts of the brain may be cut off due to swelling of the brain tissue, and damage occurs when it tries to expand in the limited area of the skull.
Post-traumatic epilepsy is another factor to deal with. Early onset epilepsy occurs in the first week after injury; late onset occurs after the first week. Approximately 75% of brain injured patients will have their first seizure within the first year, the remaining 25% within four years.