Brain injury

A CT of the head years after a traumatic brain injury showing an empty space where the damage occurred marked by the arrow.

A brain injury is an injury to the brain of a living organism, and can be categorized by many properties. Primary and secondary brain injuries identify the processes involved, while focal and diffuse brain injury describe the severity and localization.

Types of brain injury

Traumatic brain injury

A traumatic brain injury is an alteration of a structural, physiological, or chemical transmitter pathway as well as other brain pathology, and is caused by an external force. A post-traumatic brain injury is the alteration of the neurological function by the traumatic event. Multiple traumatic injuries can lead to chronic traumatic encephalopathy.

Concussion

A concussion is the most common type of brain trauma, and can be caused by direct damage to the head, gunshot wounds, violent shaking of the head (very common in children), or force from a whiplash type injury. A concussion occurs when the brain receives trauma from an impact or a sudden momentum or movement change. The blood vessels in the brain may stretch, and cranial nerves may be damaged.

Contusion

A contusion can be caused by direct damage to the head, when a bruise results in bleeding in the brain.

Coup-contrecoup injury

A coup-contrecoup injury occurs when the force impacting the head is not only strong enough to cause a contusion at the site of impact but also able to move the brain and cause it to slam into the opposite side of the skull, which causes an additional contusion.

Diffuse axonal injury

A diffuse axonal injury can be caused by a strong shake on the head, as in "shaken baby syndrome", or by rotational forces, such as a car accident. Injury occurs when the brain lags behind the movement of the skull and causes the brain structures to tear. The tearing of nerve tissue disrupts the brain's communication and chemical processes. This disturbance in the brain could cause brain damage or death. There are specific areas were connections can be broken within the brain substance that are indicative of a diffuse axonal injury.

Locked in syndrome

Locked-in syndrome is a rare neurological condition wherein the patient is unable to physically move any part of the body except the eyes. The patient is still conscious and able to think.

Penetrating injury

A penetrating injury occurs when a sharp object enters the brain, causing a large damage area. Penetrating injuries caused by bullets have a 91 percent mortality rate.

Acquired brain injury

An acquired brain injury is an injury to the brain that has occurred after birth and therefore isn't hereditary, congenital, degenerative, or induced by birth trauma.

Anoxic brain injury

An anoxic brain injury occurs when the human brain doesn’t receive oxygen. Cells in the brain begin to die due to lack of oxygen.

Hypoxic brain injury

Hypoxic brain injury happens when the brain receives insufficient oxygen. A hypoxic brain injury, also called stagnant hypoxia, is caused by a reduction in blood flow or low blood pressure leading to a lack of blood flow to the brain.

Treatments and drugs

Traumatic brain injury

The treatment for emergency traumatic brain injuries focuses on making sure the patient has enough oxygen, blood supply and on trying to maintain normal blood pressure to avoid further injuries of the head or neck. The patient may need surgery to remove clotted blood or repair skull fractures, for which cutting a hole in the skull is sometimes necessary. The medicines that are usually used for traumatic injuries are Diuretics, Anti-seizure or Coma-inducing drugs. Diuretics reduce the fluid in tissues lowering the pressure on the brain. In the first week after a traumatic brain injury, patients can have a risk of seizures, which anti-seizure drugs help prevent. Coma-inducing drugs may be used during the surgery to reduce the oxygen flow required.

Common problems after brain injury

Brain injuries have far-reaching and varied consequences due to the nature of the brain as the main source of bodily control.

Patients commonly experience issues with memory. This can be issues with either long or short term memories depending on the location and severity of the injury. Sometimes memory can be improved through rehabilitation although it can be permanent.

Brain injury can also affect muscle control and coordination ranging from difficulty writing to being unable to perform basic bodily functions such as swallowing or coughing.

Behavioral and personality changes are also commonly observed due to changes of the brain structure in areas controlling hormones or major emotions.

Headaches and pain can also occur as a result of a brain injury either directly from the damage. or due to neurological conditions stemming from the injury.

Due to the changes in the brain as well as the issues associated with the change in physical and mental capacity, depression and low self-esteem are common side effects that can be treated with psychological help. Antidepressants must be used with caution in brain injury patients due to the potential for undesired effects because of the already altered brain chemistry.

Brain Injuries affect on Age and Gender

Are children and adults affected differently?

The human brain continues developing until age 20 to 25. If the brain is damaged during this time, then while the patient physically might fully recover, they may not be able to pick up some new skills. The child's brain is easier to damage and the recovery time for brain injuries in children is six to ten times more than a similar injury in an adult. Jeffrey Barth, PhD at the University of Virginia School of Medicine did an experiment which gave baby and adult mice a mild brain injury. It was then recorded how many days it took for the mice to fully recover. Barth stated that “the younger mice are more vulnerable to injury and will take 6 to 10 times more time to recover than the adult”.

Brain injuries as affecting gender

A study by the Stanford University Medical Center ^[1] has found evidence that brain injuries may affect girls more than boys. To come to this conclusion, researchers surveyed over 9,000 Canadian students in grades seven through 12. In this particular study, the girls who reported that they had incurred a TBI at some point in their life were more likely to respond that they had experienced psychological distress, contemplated committing suicide, smoked cigarettes or become the target of bullying. ^[2]

References

"About Brain Injury." Brain Injury Association of America. National Brain Injury information center, 12 Oct. 2012. Web. 2 Mar 2016.

“Traumatic Brain Injury.” MAYO CLINIC. 15 May 2014. Web. 4 March 2016.

Johnson, Glen. "TRAUMATIC BRAIN INJURY SURVIVAL GUIDE."TRAUMATIC BRAIN INJURY SURVIVAL GUIDE (2010): 1-86.TRAUMATIC BRAIN INJURY SURVIVAL GUIDE. Glen Johnson, 2010. Web. 4 Mar. 2016.

"What Is Acquired Brain Injury?" Brain Injury Hub. The Children's Trust, 4 Jan. 2016. Web. 5 Mar. 2016.

Barth, Jeffrey. "Child Brain Versus Adult Brain with TBI." BrainLine Kids. BrainLine, 28 Apr. 2011. Web. 5 Mar. 2016.

External links

• Brain injury at DMOZ