Acquired brain injuries affect more than three million people every year. These injuries can be caused by multiple factors, but falls, strikes to the head, and vehicle crashes are among the most common. People of every age are affected, with children and elderly adults the most vulnerable. The consequences of suffering an acquired brain injury (ABI) may be temporary or permanent and mild, moderate, or severe. Brain damage cannot be reversed, but depending on the individual and the severity of the injury, various types of therapies can help improve symptoms or help a person live with disabilities.

What is an Acquired Brain Injury?

An acquired brain injury is defined as any injury to the brain that occurs after birth. Injury that occurs during fetal development, in the womb, or during childbirth is congenital rather than acquired. When a brain injury occurs after birth, but before the brain is fully developed, up to about five years old, a child is likely to be diagnosed with acquired cerebral palsy. Damage to the brain caused by degenerative conditions like Alzheimer’s disease, is not considered an acquired brain injury.

An ABI May Be Traumatic or Non-Traumatic

There are two main types of acquired brain injuries, depending on the cause: traumatic brain injuries, or TBIs, and non-traumatic brain injuries, non-TBIs. A TBI is brain damage caused by an external force, like a blow to the head or being struck and knocked down during a football game. A non-traumatic brain injury is caused by internal factors, like an infection or bleeding on the brain. Both types can be mild or severe and either may cause temporary or permanent disabilities.

Among TBIs, an injury may further be classified as closed or penetrating. A closed brain injury occurs when the skull does not break. The head may be struck or not, but the force of impact in either case damages the brain by causing it to be shaken within the closed skull. A penetrating, open injury is when an object that strikes the head breaks and penetrates the skull, damaging the brain. A bullet to the brain would be an example of a penetrating injury.

Primary and Secondary Brain Injuries

The initial injury to the brain is primary. This is the immediate impact that occurs during the event. It is short-lived and is concluded once the force is removed. The secondary brain injuries are those that occur over a period of time as a result of the primary injury. These can be more complicated and result from things like tissue damage, blood vessel damage, and changes to cells and brain chemicals.

Causes of TBI

Any violent force to the head or body can cause a TBI, including a concussion. A concussion occurs as the brain strikes the inside of the skull. A single concussion does not typically cost lasting damage, but several can lead to serious and permanent TBI symptoms and disabilities. Possible causes of TBI include falls, assaults, car accidents, or abuse. In children, abuse and accidents are common causes of TBI. In babies, shaken baby syndrome, can lead to TBI.

Two sub-populations vulnerable to TBI because of their activities are certain types of athletes and people serving active duty in the military. Veterans have higher than average rates of TBI because of brain damage caused by explosives and strikes from guns and other devices. Football players are particularly vulnerable to concussion and TBIs from repeated strikes from other players.

Causes of Non-TBI

Non-traumatic brain injuries can have all of the same symptoms, impact, and severity of TBIs, but they are caused by internal factors, not external physical forces. In children, infections are especially common causes of non-TBIs, but adults may suffer as a result of infections as well. Meningitis, an infection of the meninges covering the brain and spinal cord, and encephalitis, an infection of the brain, are both potential causes of brain injury.

Bleeding or blockages in the brain may also cause injury. A stroke, for instance, which is a more common cause in adults, can either block blood from part of the brain, or cause hemorrhaging in part of the brain. The result is brain damage, which can range from mild to severe. An aneurysm, a bulging blood vessel that may burst, is also a potential cause of non-TBI.

Lack of oxygen to part of the brain may also cause brain injury. There are many ways that this can happen, from ingesting a poison to drowning and being revived, to smoke inhalation, or having a severe asthma attack. Finally, a brain tumor may cause non-traumatic injury by growing and pressing on part of the brain. That pressure can cause damage.

Symptoms of Acquired Brain Injuries

Regardless of the cause of the brain injury, traumatic or not, there is a wide range of potential symptoms caused by the damage. How a person is affected by brain injury is highly individualized. It depends on a number of factors, including the health and age of the person and the severity of the injury. Symptoms can range from physical to cognitive to behavioral or even psychological.
Physical symptoms of brain injury may include paralyzed or weak muscles, muscle spasms, tremors, difficulty swallowing, poor balance, delayed movements, fatigue, headaches, dizziness, changes in sleep patterns, and impaired endurance. Sensory symptoms include loss of sensations or decreased sensations, loss of sense of limbs, vision problems, or hearing problems. Communication symptoms may include trouble speaking, difficulty finding words or forming sentences, difficulty identifying objects, and trouble reading or writing.

Cognitive deficits may also result from ABIs. These can include confusion, memory loss, impaired problem solving ability, decreased judgement, short attention span, lowered self-awareness, and being in a coma. Social and psychological symptoms of ABI include impaired ability to socialize, difficulty understanding social interactions, anxiety, depression, apathy, irritability, loss of inhibition. Symptoms may also result in impaired function, meaning a decreased ability to perform daily activities, to drive, or to function at a job.

A potential complication of TBIs, although rare, is chronic traumatic encephalopathy, or CTE. This is sometimes seen in athletes and others who have suffered multiple concussions. CTE is not yet well understood, but signs may include aggression and irritability, vision problems, speech problems, cognitive impairment, memory loss, impulsive behaviors, suicidal thought, and dementia. Unlike most other brain injuries, CTE is progressive and gets worse with time. It should be addressed as soon as possible after signs appear.

Treatment for ABIs

Treatment for a brain injury varies widely depending on the individual patient, the symptoms, and the severity of disabilities. Brain damage can’t be reversed, but treatments and therapies can improve symptoms and make living with disabilities easier. There are also treatments that can be administered immediately after an injury to try to limit brain damage. Diuretics, for instance, can reduce pressure on the brain. Anti-seizure drugs prevent damage by preventing seizures, which may occur right after a brain injury. Surgery to drain fluids and relieve pressure on the brain can also be done.

The bulk of treatment that is done for ABIs is post-injury rehabilitation. For instance, a physical therapist may work with a patient to restore movement to affected muscles. An occupation therapist my help a patient learn how to perform daily activities again. Someone with an ABI may also work with neurologists, psychiatrists, massage therapists, speech and language pathologists, nutritionists, nurses, and others.

Among symptoms that can be helped by medications, pain is most common. Headaches and other types of pain can be managed with pain medications, including prescription narcotics for severe to moderate pain. There are serious risks of using these medications, though, most importantly the risk of addiction. Narcotics like hydrocodone, oxycodone, and similar pain medications are highly addictive.

ABI Statistics

Nearly four million people each year will suffer an ABI. According to the Centers for Disease Control and Prevention, 2.8 million people suffered a TBI in 2016, making up the majority of cases of ABIs. Less than one million non-TBIs occur each year in the U.S. More than 50,000 people who suffer TBIs each year die as a result, while the majority recover to some degree. Seventy-five percent of TBIs are classified as mild, and many of these are the result of concussions.

The most common cause of a TBI is falling. The second most common cause is being struck on the head, followed by being in a vehicle accident. Children between infancy and age four, teens between the ages of 15 and 19, and adults over the age of 65 are the most likely age groups to suffer a traumatic brain injury, while adults over 75 are most likely to die from a TBI. Non-TBIs are much less common, but children are especially vulnerable to them. The leading causes of non-traumatic brain injury in children are ingestion of something toxic, brain tumors, and viral or bacterial meningitis.

Acquired brain injuries affect millions of people every year and the impact they have on these individuals reach to the friends and loved ones of these patients. Although some may be mild, other injuries lead to permanent disabilities that require lifelong care, therapy, and medications.