An acquired brain injury (ABI) is brain damage that may affect a person of any age, from infancy through old age. Cerebral palsy, in some cases, may be the result of an acquired brain injury, damage that is caused after birth. With acquired cerebral palsy, it is easier to determine the ultimate cause, such as a fall, but it makes no difference to the severity of symptoms or course of treatment. At any age, an ABI may lead to mild to severe impairment and disability that is temporary or permanent. There are treatments and therapies though, that can help a person recover and learn to live with permanent disabilities.
Acquired Brain Injuries Defined
A brain injury that is acquired occurs after birth. Some kind of external trauma like a blow to the head or an internal cause like an infection or stroke causes damage to the brain that result in an ABI. Any damage to or malformation in the brain that occurs before a baby is born is considered congenital rather than acquired. Damage to the brain caused by a degenerative disorder, like Alzheimer’s or Parkinson’s, is not considered an acquired brain injury. An ABI can occur at any point in a person’s life, from infancy through adulthood.
Traumatic Brain Injuries, Definition and Causes
Acquired brain injuries can be roughly divided into two main types: traumatic brain injuries (TBI), which are caused by some kind of external force or damage, and non-traumatic brain injuries, those caused by something inside the body, such as a stroke or an infection like meningitis. The causes of injury define these two types of ABI, but within each category there are many potential causes.
In both children and adults, the causes of TBI may be any force that strikes the head or causes the brain to impact against the inside of the skull. Car accidents are among the most common causes of TBI in adults and children. Other causes may include violence and abuse or falls. In young children, shaking is a common cause of TBI. It is sometimes referred to as shaken baby syndrome and is the result of abuse.
Older children and teens, as well as adults, may also be vulnerable to injuries caused by concussions from athletics. Football is a particularly risky sport in terms of TBI. A player does not need to be hit on the head, only struck forcefully to cause a concussion that may lead to TBI. A concussion occurs when the brain strikes the inside of the skull. One concussion may not cause TBI, but accumulated damage from multiple concussions can.
Veterans in the military are also particularly vulnerable to traumatic brain injuries. It is estimated that 22 percent of casualties in veterans of the conflicts in Afghanistan and Iraq are TBIs. The Veterans Administration has estimated that over 200,000 veterans enrolled in the VA health care system have some degree of TBI. The number is likely higher, as this includes only those that have sought treatment through the VA. Causes of TBI in the military can include falls, assaults, or vehicle accidents, as well as damage caused by explosive devices.
According to the Centers for Disease Control and Prevention (CDC), more than two million people develop a TBI every year in the U.S. Most of these, are treated and released, but 52,000 die from their injuries, while the remainder are hospitalized. Most TBIs, 75 percent approximately, are mild and are related to concussions. Falls are the most common of TBI causes, followed being struck on the head, and car accidents.
Children are especially vulnerable to TBIs, as are older adults. The age groups that are most likely to sustain a traumatic brain injury are birth to four years old, teenagers between 15 and 19, and adults over the age of 65. Adults over 75 are most likely to die from a TBI, but nearly 500,000 hospital visits each year for TBI are children.
Causes of non-Traumatic Brain Injuries
An acquired brain injury that is not caused by an external force or action is considered non-traumatic, but can be just as damaging. As with a TBI, this kind of injury can range from mild to severe. In children, the most common cause of a non-TBI is infection. The most common infections to cause brain injury in children are meningitis, an infection of the membrane around the brain and spinal cord, and encephalitis, an infection in the brain.
A non-TBI may also be caused by a brain tumor, either benign or malignant, as it grows and puts pressure on the brain. Anoxia and hypoxia, absence of oxygen or too little oxygen to part of the brain, can also cause an acquired brain injury—possible causes of anoxia and hypoxia are drowning, smoke inhalation, carbon monoxide poisoning, heart defects, or severe asthma. A poisoning by a toxic substance can also cause brain damage.
Strokes, aneurysms, and hemorrhages in the brain may also cause a non-TBI. A stroke is a more likely cause in an adult and occurs when blood is cut off to part of the brain because of a blocked or burst blood vessel. An aneurysm is a bulging blood vessel, which may burst and cause a stroke and hemorrhaging, or bleeding on the brain.
Non-traumatic injuries are less common. While millions of people suffer TBIs every year, there are approximately 800,000 non-traumatic acquired brain injuries. In a study of children with non-TBI, the rate in the general population was found to be 82.3 per 100,000 children. The leading cause was a toxic substance, followed by brain tumors, and meningitis.
Acquired Cerebral Palsy
About ten percent of diagnosed cases of cerebral palsy in children are considered acquired. This means that damage occurred in the brain after a baby was born, but before the brain finished developing. The period between birth and full brain development is not firmly known, but is somewhere between two and five years. Any acquired injury that occurs in a child after the brain is fully developed may result in symptoms and neurological conditions, but these are not diagnosed as cerebral palsy. Even if it is not diagnosed as cerebral palsy, symptoms may be similar and a child with ABI may be treated similarly to a child with cerebral palsy.
Symptoms of ABI
If a child suffers a brain injury before the brain is fully developed, he is likely to be diagnosed with cerebral palsy and will have symptoms characteristic of CP: stiff muscles, abnormal movements, speech difficulties, repetitive motions, poor posture, difficulty walking, unsteady balance, tremors, and many others.
For a child or adult that develops an ABI after full brain development has been reached, there are many possible symptoms, and they can range from mild to severe, depending on the injury. Symptoms may be related to movement, they may be cognitive, sensory, related to communications, function, personality, socializing, and many other factors. Some of the possible symptoms include:
- Short attention span.
- Difficulty problem solving.
- Judgement difficulties.
- Paralysis or muscle weakness.
- Memory deficits.
- Spastic muscles.
- Poor coordination.
- Loss of sensation.
- Slowed speech.
- Trouble choosing correct words or forming sentences.
- Vision problems.
- Hearing deficits.
- Inability to complete ordinary activities.
- Impaired social interactions.
- Loss of control of bowels or bladder.
- Anxiety or depression.
- Lowered inhibitions.
Treatment for ABIs, much like treatment for cerebral palsy, is highly dependent on the individual, on symptom types and severity. Like cerebral palsy from any cause, brain damage cannot be reversed. Depending on the severity of the damage, other parts of the brain may be able to compensate for the damage and full to near full recovery may be possible. For most people, the degree of recovery is not known.
Much of treatment for ABIs is based on rehabilitation, using therapeutic strategies to help a patient recover as much function as possible or to live with the damage and resulting symptoms. Types of treatment may include physical and occupational therapy, speech therapy, educational interventions, vocal training, management of pain, adaptive equipment, and psychological counseling and therapy.
Treatment and therapy may involve a range of specialists, including neurologists, psychiatrist and psychologists, physical and occupational therapists, massage therapists, educators, audiologists, pediatricians, nutritionists, speech therapists, nurses, and others. Family support is also crucial to help a patient recover as much as possible.