What is TBI?
Traumatic brain injury (TBI) occurs when an external mechanical force causes brain dysfunction.
TBI usually results from a violent blow or jolt to the head or body. An object penetrating the skull, like a bullet or shattered piece of skull, can also cause TBI.
Mild TBI can cause temporary dysfunction of brain cells. More serious traumatic injury can result in bruising, torn tissues, bleeding and other physical damage to the brain that can result in long-term complications or death.
TBI can have wide-ranging physical and psychological effects. Some signs and symptoms appear immediately after the event, while others may appear days or weeks later.
Mild traumatic brain injury
The signs and symptoms of mild TBI may include:
- Loss of consciousness for a few seconds to a few minutes
- No loss of consciousness, but a state of being dazed, confused or disoriented
- Memory or concentration problems
- Dizziness or loss of balance
- Nausea or vomiting
- Sensory problems, such as blurred vision, ringing in the ears or a bad taste in the mouth
- Sensitivity to light or sound
- Mood changes or mood swings
- Feeling depressed or anxious
- Fatigue or drowsiness
- Difficulty sleeping
- Sleeping more than usual
Moderate to severe traumatic brain injuries
Moderate or severe TBI can include any of the signs and symptoms of mild injury, as well as the following symptoms that may appear within the first hours to days after a head injury:
- Loss of consciousness from several minutes to hours
- Profound confusion
- Agitation, combativeness or other unusual behavior
- Slurred speech
- Inability to awaken from sleep
- Weakness or numbness in fingers and toes
- Loss of coordination
- Persistent headache or headache that worsens
- Repeated vomiting or nausea
- Convulsions or seizures
- Dilation of one or both pupils of the eyes
- Clear fluids draining from the nose or ears
Causes of Traumatic Brain Injury
TBI is caused by a blow or other traumatic injury to the head or body. The degree of damage can depend on several factors, including the nature of the event and the force of the impact. Injury may include one or more of the following factors:
- Damage to brain cells may be limited to the area directly below the point of impact on the skull.
- A severe blow or jolt can cause multiple points of damage because the brain may move back and forth in the skull.
- A severe rotational or spinning jolt can cause the tearing of cellular structures.
- A blast, as from an explosive device, can cause widespread damage.
- An object penetrating the skull can cause severe, irreparable damage to brain cells, blood vessels and protective tissues around the brain.
- Bleeding in or around the brain, swelling, and blood clots can disrupt the oxygen supply to the brain and cause wider damage.
Complications of Traumatic Brain Injury
Moderate to severe traumatic brain injury can result in prolonged or permanent changes in a person’s state of consciousness, awareness or responsiveness. Different states of consciousness include:
- Coma. A person in a coma is unconscious, unaware of anything and unable to respond to any stimulus. This results from widespread damage to all parts of the brain.
- Vegetative state. Widespread damage to the brain can result in a vegetative state. Although the person is unaware of his or her surroundings, he or she may open his or her eyes, make sounds, respond to reflexes, or move.
- Minimally conscious state. A minimally conscious state is a condition of severely altered consciousness but with some evidence of self-awareness or awareness of one’s environment.
- Locked-in syndrome. A person in a locked-in state is aware of his or her surroundings and awake, but he or she isn’t able to speak or move.
Some people with traumatic brain injury will have seizures within the first week. Some serious injuries may result in recurring seizures, called post-traumatic epilepsy.
Cerebrospinal fluid may build up in the spaces in the brain (cerebral ventricles) of some people who have had traumatic brain injuries, causing swelling and increased pressure in the brain.
Skull fractures or penetrating wounds can tear the layers of protective tissues (meninges) that surround the brain.
Blood vessel damage
Several small or large blood vessels in the brain may be damaged in a traumatic brain injury. This damage could lead to a stroke, blood clots or other problems.
Injuries to the base of the skull can damage nerves that emerge directly from the brain (cranial nerves). Cranial nerve damage may result in:
- Paralysis of facial muscles
- Damage to the nerves responsible for eye movements, which can cause double vision
- Damage to the nerves that provide sense of smell
- Loss of vision
- Loss of facial sensation
- Swallowing problems
Most people who have had a significant brain injury will experience changes in their thinking (cognitive) skills. Traumatic brain injury can result in problems with many skills, including:
- Problem solving
- Speed of mental processing
- Attention or concentration
- Decision making
- Beginning or completing tasks
Language and communications problems are common following traumatic brain injuries. These problems can cause frustration, conflict and misunderstanding for people with a traumatic brain injury, as well as family members, friends and care providers. Communication problems may include:
- Difficulty understanding speech or writing
- Difficulty speaking or writing
- Difficulty deciphering nonverbal signals
- Inability to organize thoughts and ideas
- Inability to use the muscles needed to form words (dysarthria)
- Problems with changes in tone, pitch or emphasis to express emotions, attitudes or subtle differences in meaning
- Trouble starting or stopping conversations
- Trouble with turn taking or topic selection
- Trouble reading cues from listeners
- Trouble following conversations
People who’ve experienced brain injury often experience changes in behaviors. These may include:
- Difficulty with self-control
- Lack of awareness of abilities
- Risky behavior
- Inaccurate self-image
- Difficulty in social situations
- Verbal or physical outbursts
Emotional changes may include:
- Mood swings
- Lack of empathy for others
- Changes in self-esteem
Problems involving senses may include:
- Persistent ringing in the ears
- Difficulty recognizing objects
- Impaired hand-eye coordination
- Blind spots or double vision
- A bitter taste or a bad smell
- Skin tingling, pain or itching
- Trouble with balance or dizziness
Degenerative brain diseases
A traumatic brain injury may increase the risk of diseases that result in the gradual degeneration of brain cells and gradual loss of brain functions. These include:
- Alzheimer’s disease, which primarily causes the progressive loss of memory and other thinking skills
- Parkinson’s disease, a progressive condition that causes movement problems, such as tremors, rigidity and slow movements
- Dementia pugilistica — most often associated with repetitive blows to the head in career boxing — which causes symptoms of dementia and movement problems
Many combat veterans are affected by TBI. Let’s stand together with these men and women and show them our gratitude for their honorable service by fighting TBI. By raising awareness about this injury and expanding treatment options, we can help our veterans combat an injury that could otherwise go without the attention it needs and deserves. We should give our all to help those who gave their all.
Source: Mayo Clinic http://www.mayoclinic.com/health/traumatic-brain-injury/DS00552