What types of TBI are there?
Any injury to the head may cause traumatic brain injury (TBI). There are two major types of TBI:
Penetrating Injuries: In these injuries, a foreign object (e.g., a bullet) enters the brain and causes damage to specific brain parts. This focal, or localized, damage occurs along the route the object has traveled in the brain. Symptoms vary depending on the part of the brain that is damaged.
Closed Head Injuries: Closed head injuries result from a blow to the head as occurs, for example, in a car accident when the head strikes the windshield or dashboard. These injuries cause two types of brain damage:
Primary brain damage, which is damage that is complete at the time of impact, may include:
- skull fracture: breaking of the bony skull
- contusions/bruises: often occur right under the location of impact or at points where the force of the blow has driven the brain against the bony ridges inside the skull
- hematomas/blood clots: occur between the skull and the brain or inside the brain itself
- lacerations: tearing of the frontal (front) and temporal (on the side) lobes or blood vessels of the brain (the force of the blow causes the brain to rotate across the hard ridges of the skull, causing the tears)
- nerve damage (diffuse axonal injury): arises from a cutting, or shearing, force from the blow that damages nerve cells in the brain's connecting nerve fibers
Secondary brain damage, which is damage that evolves over time after the trauma, may include:
- brain swelling (edema)
- increased pressure inside of the skull (intracranial pressure)
- intracranial infection
- low or high blood pressure
- low sodium
- too much or too little carbon dioxide
- abnormal blood coagulation
- cardiac changes
- lung changes
- nutritional changes
Physical problems may include hearing loss, tinnitus (ringing or buzzing in the ears), headaches, seizures, dizziness, nausea, vomiting, blurred vision, decreased smell or taste, and reduced strength and coordination in the body, arms, and legs.
People with a brain injury often have cognitive (thinking) and communication problems that significantly impair their ability to live independently. These problems vary depending on how widespread brain damage is and the location of the injury.
Brain injury survivors may have trouble finding the words they need to express an idea or explain themselves through speaking and/or writing. It may be an effort for them to understand both written and spoken messages, as if they were trying to comprehend a foreign language. They may have difficulty with spelling, writing, and reading, as well.
The person may have trouble with social communication, including:
- taking turns in conversation
- maintaining a topic of conversation
- using an appropriate tone of voice
- interpreting the subtleties of conversation (e.g., the difference between sarcasm and a serious statement)
- responding to facial expressions and body language
- keeping up with others in a fast-paced conversation
Individuals may seem overemotional (overreacting) or "flat" (without emotional affect). Most frustrating to families and friends, a person may have little to no awareness of just how inappropriate he or she is acting. In general, communication can be very frustrating and unsuccessful.
In addition to all of the above, muscles of the lips and tongue may be weaker or less coordinated after TBI. The person may have trouble speaking clearly. The person may not be able to speak loudly enough to be heard in conversation. Muscles may be so weak that the person is unable to speak at all. Weak muscles may also limit the ability to chew and swallow effectively.
Cognitive difficulties are very common in people with TBI. Cognition (thinking skills) includes an awareness of one's surroundings, attention to tasks, memory, reasoning, problem solving, and executive functioning (e.g., goal setting, planning, initiating, self-awareness, self-monitoring and evaluation). Problems vary depending on the location and severity of the injury to the brain and may include the following:
- Trouble concentrating when there are distractions (e.g., carrying on a conversation in a noisy restaurant or working on a few tasks at once).
- Slower processing or "taking in" of new information. Longer messages may have to be "chunked," or broken down into smaller pieces. The person may have to repeat/rehearse messages to make sure he or she has processed the crucial information. Communication partners may have to slow down their rate of speech.
- Problems with recent memory. New learning can be difficult. Long-term memory for events and things that occurred before the injury, however, is generally unaffected (e.g., the person will remember names of friends and family).
- Executive functioning problems. The person may have trouble starting tasks and setting goals to complete them. Planning and organizing a task is an effort, and it is difficult to self-evaluate work. Individuals often seem disorganized and need the assistance of families and friends. They also may have difficulty solving problems, and they may react impulsively (without thinking first) to situations.
The speech-language pathologist (SLP) works with the person and his or her family/caregivers as part of a team that may also include:
- occupational therapists
- physical therapists
- social workers
The team works together to evaluate the person and develop an appropriate treatment plan.
The SLP completes a formal evaluation of speech and language skills. An oral motor evaluation checks the strength and coordination of the muscles that control speech. Understanding and use of grammar (syntax) and vocabulary (semantics), as well as reading and writing, are evaluated.
Social communication skills (pragmatic language) are evaluated with formal tests and the role-playing of various communication scenarios. The person may be asked to discuss stories and the points of view of various characters. Does he or she understand how the characters are feeling, and why they are reacting a certain way? Can he or she explain how different characters' actions affect what happens in the story? The person may be asked to interpret/explain jokes, sarcastic comments, or absurdities in stories/pictures (e.g., what is strange about a person using an umbrella on a sunny day?).
The SLP will assess cognitive-communication skills. Is the person aware of his or her surroundings? Does the person know his or her name, the date, where he or she is, what happened to him or her (orientation)? Recent memory skills are assessed, such as whether the main details in a short story are retained. Executive functioning is evaluated. The SLP assesses the patient's ability to plan, organize, and attend to details (e.g., completing all of the steps for brushing teeth). The SLP may read an incomplete story and ask for a logical beginning, middle, or conclusion. The person may be asked to provide solutions to problems (reasoning and problem solving; e.g., "What would you do if you locked your keys in your car? How can this problem be avoided in the future?").