Types of traumatic brain injury
Traumatic brain injury (TBI) is an insult to the brain as a result of trauma that could lead to permanent or temporary injury. This injury may cause impairment in function that can be cognitive or fisical.
Usually following a TBI (Traumatic brain injury) consciousness is altered either temporarily or permanently. In the United States the are an estimated 600,000 TBI's per year, responsible for 40% of deaths occurring as a result of acute injuries.
The brain is located within the skull, a rigid bone structure with no elastic properties and thus, unable to expand. Swelling of the brain as a result of injury will produce increased intracranial pressure preventing adequate blood flow. Decreased blood flow will result in the brain being unable to obtain oxygen and nutrients necessary for function.
In general TBI are classified as closed or penetrating injuries.
Examples of closed injuries include motor vehicle accidents, the most common cause of traumatic brain injury. Falls are the second cause of closed injuries, specially in people over 70 years old. Closed injuries also occur as the result of assaults and contact sports.
Penetrating injuries are usually the result of gunshot wounds by the use of firearms. These injuries are most commonly seen in young males.
Quick management is essential to prevent irreversible damage to the brain. Evaluation of a patient with TBI is initiated as soon as the patient is stabilized. For example; bleeding controlled, seizures treated. The evaluation basically consists of determining the state of consciousness. One of the methods used to evaluate a patient with TBI is the Glasgow Coma Scale. This scale describes the level of consciousness in patients with TBI and defines categories of head injury. Three categories are considered and evaluated by physical examination; eye opening, motor response, and verbal response. Based on these clinical findings a score is given following a table. It helps determining response to treatment and prognosis. Basic laboratory studies and head imaging are done to evaluate the extent of the damage.
In general the goal of treating closed injuries is to reduce the intracranial pressure. This can be achieved using medications that reduce brain swelling, such as mannitol and steroids. Surgical methods include decompression craniotomy, removal of a portion of the cranial bone to provide space for the brain.
The treatment of penetrating brain injuries will involve treatment of the TBI caused by the penetrating object similar to the treatment of closed head injuries. Additionally penetrating head injury treatment requires cleansing of the affected area of the brain by debridement and removal of the penetrating objects as these may lead to infection. After a TBI, most patients will need physical and, occupational therapy. Some may need cognitive rehabilitation.