Brain injury

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at September 22, 2016
StartDiseasesBrain injury

Brain injuries encompass a broad range of conditions involving brain dysfunction or brain damage. Brain injuries can cause problems with thinking, speech, memory, movement, and behavior. They can also cause a range of debilitating physical symptoms and death, depending on the type and severity of the injury. The most common type of brain injury is a concussion.

Contents

Definition & Facts

Brain injury can result from a blow to the head or other traumatic injury to either the head or body. Children from birth to four years old and adults aged 75 or older are particularly vulnerable to brain injury. Also at increased risk are young adults between the ages of 15 and 24.

Studies over the last 30 years show a link between moderate to severe traumatic brain injury (TBI) and an increased risk of developing a degenerative brain disease. Studies show older adults with a history of moderate TBIs have a greater risk for developing a degenerative brain disease. For those with a history of severe TBIs, the risk increases further.

Evidence continues to emerge suggesting that people who have had repeated concussions without losing consciousness, such as military veterans or professional athletes, are at an increased risk of developing chronic traumatic encephalopathy (CTE). Ongoing studies are researching the link between TBI and a change in brain chemistry linked to Alzheimer’s disease.

Symptoms & Complaints

In severe cases, brain injury can result in coma, persistent vegetative state, locked-in syndrome or brain death.

Injuries occurring at the base of the skull can cause damage to the cranial nerves directly responsible for sending messages to the brain that control facial expressions, eye movement, vision, touch, sense of smell, and swallowing. People may complain of having:

Symptoms could extend to executive functions such as problem-solving, organization, tasking, multitasking and decision-making. Communication may suffer from difficulty in speaking or writing (speech disorders and language disorders). Patients with brain injuries may experience dysarthria which is the inability to properly form words. Other symptoms include difficulty organizing thoughts or ideas, following conversations, or understanding what others are saying or have written.

Behavioral changes such as difficulty with self-control could result in social problems. A person with a brain injury may experience difficulty in deciphering nonverbal cues, and he or she may develop an array of emotional symptoms and mental disorders. These may include:

It is now speculated that the gradual loss of brain function from damage to brain cells related to TBI may have a direct link to such degenerative brain diseases as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis (ALS), Pick’s disease, and dementia pugilistica (also known as chronic traumatic encephalopathy) which is most often associated with those whose careers involve sustaining repetitive trauma to the head such as football players and boxers.

Causes

The most common cause of TBI is from falling down, and falls in older adults are especially serious. The direct effects of a head injury for seniors may result in long-term cognitive impairment and a loss of the ability to function. This most often leads to changes in the individual's emotional health. Other typical causes of brain injury are:

  • Vehicle crashes
  • Sports injuries
  • Indirect forces, such as the concussive impact from an explosion
  • Penetrating injuries, such as a gunshot wound to the head

Damage to brain cells as a result of injury may be the result of a severe blow or jolt producing multiple points of damage depending on how the brain may move within the skull. The skull and protective tissue are there to protect the brain, but they can only do so much in preventing cell damage. Other causes of TBI can be from severe rotation of the body or a spinning jolt, producing tears in the cellular structures.

About 30 percent of TBIs are the result of violence. Shaken baby syndrome involves the injury of an infant's brain as a result of being shaken. The effects of this movement cause the brain to move back and forth within the skull causing damage to the cells and connective tissue.

Diagnosis & Tests

Brain injuries are typically medical emergencies calling for a rapid assessment to determine the physical and neurological effects. Doctors check the person’s capabilities in eye and limb movement as well as the ability to follow directions. It is also helpful for the doctor to know how the injury occurred, if the person has lost consciousness and for how long. Observing changes in speech, coordination and alertness give strong clues.

It is also helpful to understand where the impact on the body occurred and the force of the injury, such as from a height or being thrown from a vehicle. Whipping and jarring movements in an accident affect the brain in different ways and can indicate the severity of damage.

There are imaging tests that create a detailed view of what has happened to the brain in the event of injury. The computed tomography (CT) scan reveals bone fractures and evidence of cerebral hemorrhage, blood clots, bruised tissue or swelling. Magnetic resonance imaging (MRI) uses magnets and powerful radio waves to produce a detailed view of the brain. This test is only used after a person’s status is determined to be stable.

Treatment & Therapy

Mild brain injuries such as mild concussions typically require no treatment other than rest and the aid of over-the-counter pain relievers. However, close monitoring of the individual with mild TBI is recommended to assess whether the symptoms are persistent or worsening or if new symptoms arise that may indicate the injury is more severe than originally diagnosed.

Returning to work, school or recreation may be indicated under doctor’s orders. Until symptoms have resolved, it is recommended to avoid physical or cognitive activities (cognitive rest). Engaging in challenging thinking rather than resting during this time may exacerbate conditions and slow recovery.

For moderate to severe TBI, there are vital processes within the body that must continue to function following moderate to severe brain injury. Emergency care focuses on ensuring adequate oxygen and blood are supplied to the brain and that blood pressure is maintained sufficiently to achieve this. Doctors also want to prevent any further head trauma or neck trauma.

Medications may assist in limiting further secondary damage to the brain in the immediate aftermath of injury such as diuretics to reduce fluid retention and anti-seizure drugs. Sometimes doctor prescribe coma-inducing drugs. This is helpful as the brain requires less oxygen when it is at rest.

Emergency surgery may be performed to remove blood clots, or hematomas, to repair skull fractures or to open the skull in order to ease the pressure from swelling. Depending upon which part of the brain was injured and the severity of the injury, the individual may require rehabilitation such as physical therapy and occupational therapy to improve functioning.

Prevention & Prophylaxis

Prevention of brain injuries involves taking proper precautions. While driving, one should ensure that all riders and passengers are secured in place with seat belts or child safety seats where applicable. One should also ensure that he or she has airbags in the car.

One should avoid operating motor vehicles while under the influence of alcohol or drugs, including prescription medications. It is also important to wear protective helmets while engaging in contact sports, riding horses, or any other activities that call for head gear when vulnerably exposed such as riding a motorcycle, a bicycle or skateboarding.

Following TBI, people may experience post-traumatic seizures (PTS). Anti-seizure or anticonvulsant therapy for early PTS prophylaxis is recommended during the first week after a TBI. Phenytoin and levetiracetam are medications that have proved effective for early PTS prophylaxis.