Influence of Traumatic Brain Injuries on Neuroplasticity

Introduction

There are approximately 57 million people around the world who have been admitted to the hospital due to traumatic brain injury. Some people either die or become disabled due to this injury, for example, 30,000 people died in India. People who have the highest risk of experiencing a traumatic brain injury are children, teenagers, and young adult men between the ages of 15 to 25 years. Traumatic Brain Injury (TBI) is a brain injury when the brain experiences sudden damage of a blow or jolt to the head. For example, these causes include car crashes, falls, sports injuries, and many more. These injuries include from mild concussions to severe permanent brain damage. The primary injury is when people experience the injury at that moment when it happened and can affect a specific area of the brain or the entire of the brain. Another injury is known as a secondary injury which is usually more damaging than the primary injury. There are different treatments for different brain injuries such as for mild concussions, people rest and take medication while those who have severe permanent brain damage, may require intensive care and surgeries. There are some people who have died and can die from this brain injury. However, there are some people who have survived and can survive from this brain injury. When people do survive from this brain injury, they will experience some long-lasting effects that could physically and mentally affect them. When people survive from a severe brain injury, they will go through rehabilitation to recover and relearn skills because when their brains change, it would affect their daily normal activities and their personality and behavior.

These traumatic brain injuries will affect neuroplasticity because the injuries will cause the brain to move and forth causing bruising, bleeding, and destroying nerve fibers. Immediately after the impact, people would become confused, cannot remember what just happened, dizzy and blurry vision or lose consciousness. Then their brain will swell up, pushing itself against the skull and decreasing the flow of oxygen-rich blood. Neuroplasticity is the brain’s ability to develop new neural synapses and neural pathways from new experiences such as new interactions with the environment and these changes occur in behavior, environmental and neural processes. Neuroplasticity allows us to understand the changes in the brain, especially after brain injuries. When the brain is recovering, it is developing more new neurons and cells.

The symptoms of traumatic brain injuries are the lack of consciousness, memory, change of moods, cannot pay attention, and many other neurological or neuropsychological abnormalities. It’s important to rehabilitate and treat those who have suffered from traumatic brain injuries because it’s one of the world’s most leading causes of disability. Traumatic brain injuries have the ability to change people’s behavior, mood, thinking and understanding, memory, attention, communication, and many other functions. Every year, the price to assist those who have survived from traumatic brain injuries and become disabled will continue to increase. Not only the price is increasing, however, the number of victims experiencing this injury is also increasing. Therefore, it’s important to treat these people who have disabilities from this injury and prevent any further injuries in the future. The objective of this essay is to research how these traumatic brain injuries affect neuroplasticity because it focuses on the processes of learning and memory and this can change by the development of new neurons.

Cognitive

When people experience a traumatic brain injury, there would be cognitive effects because it would affect the way people think and learn. People would struggle when concentrating, speaking, learning, remembering, reasoning, and problem-solving. They would be unable to concentrate on one thing at a time. They are easily distracted when trying to finish a task. They cannot work on many tasks at once because it’s difficult for them to finish one project at once. Furthermore, they cannot participate in a conversation for so long and stay still for long periods of time. Attention skills help people’s memory and reasoning, however, if they cannot concentrate then they will also have more cognitive problems.

Not only people can’t concentrate or pay attention to an important matter, they would also have a hard time remembering information, especially short-term memory and “working memory”. For example, they would have trouble trying to figure out people’s names or what other people have said to them. It’s a possibility that their knowledge before the injury would be still intact, however, people would have trouble trying to learn new information. Although people could remember information by rehearsing it over and over again, however, this cannot help people remember information after they have gone through a traumatic brain injury. Even though they have a hard time remembering information that happened recently, they can remember their childhood clearly. It’s a possibility that they cannot remember certain information such as events and conversations. The brain is trying to “fill in the gaps” of missing information and recall things that didn’t actually happen. This leads to the development of false memories.

People would also have trouble processing and understanding information, especially what is being said and read to them. Also, they would have trouble trying to find the right words to say and write. Therefore it’s difficult for them to express themselves and it would be difficult for them to try to communicate with others. It would take longer for them to understand what others are trying to say and slower for them to react. People would struggle to make sense of visualizing and drawing images and finding their way to their destination. Another example is when people have agnosia because they cannot recognize certain objects. Another issue is when people have difficulty when recognizing there is a problem because they have a hard time trying to analyze information. When they are trying to solve the problem, they either only have one solution they could think of and ignore the rest of the possibilities, or they have a hard time trying to decide what’s the best decision to fix the problem.

There are case studies that propose that traumatic brain injuries lead to a possibility of precipitating two contradictory processes: excessive glutamate accumulation that has a possibility of leading up to NMDA-mediated excitotoxicity, and excess in GABA-mediated inhibition that could lead to lasting cognitive deficits. A case study of this 44-year-old male had a concussion when playing soccer. He came head-to-head with another soccer player. After making contact, he lost consciousness for approximately 90 seconds. Then, he was confused, and about 2 minutes of retrograde and 4 minutes of anterograde amnesia. Retrograde amnesia is when a person lost their memories prior to the head injury. Anterograde amnesia is when a person lost their memories after a head injury. Approximately 20 minutes after the event was over, his physical and neurological exams were normal. For 10 days, he was normal. 2 weeks after the accident, he was extremely tired and couldn’t concentrate. Furthermore, he couldn’t remember anything and had mild headaches and difficulty sleeping. Due to these symptoms, his total symptom score was 13 according to the Immediate Post Concussion and Assessment and Cognitive Test (ImPACT). 6 weeks after the accident, he began to slowly improve. He still experienced mild headaches, some tiredness, and had trouble remembering information. Since he began to improve, his total symptom was 8. 10 weeks after the accident, he was completely asymptomatic and continued his normal daily activities. He didn’t take any medications that we're able to change the plasticity of the brain. The only exception was acetaminophen for headaches. This shows that a brain injury can have a serious impact on people’s cognitive behavior as this man lost this memory prior from the head injury and after the head injury, couldn’t concentrate, and other symptoms. This only happened after the brain injury so this shows the long-lasting effects from the brain injury.

 Perceptual

One of the effects after people experienced a traumatic injury is the way people perceive, act, and feel differently in a matter of seconds. Even though they were recovering from treatments and rehabilitations, they still would feel side effects from the brain injury. Due to these side effects, this may also play a role of affecting their daily normal activities as they cannot function correctly. People who have experienced traumatic brain injury, they are not only physically suffering but also emotionally. They are perceiving things differently from others. Perception plays a significant role on behavior and attitude.

There are different areas of the brain that process information from senses such as touch, sight, sound, smell, and taste. For example, when consuming an apple, the brain will report information such as feeling how the apple is round and smooth, the color of the red could be red or green, the crunchy sound when taking a bite, and smelling how the apple is fresh, and how sweet and ripe it is. If there was damage to the right side of the brain or the parietal and occipital lobes of the brain from brain disorders such as traumatic brain injuries, then it could change the senses and people would perceive things differently such as auditory, visual, tactile, olfactory, and gustatory.

While there are difficulties occurring in the sensory system, the visuospatial problems are often more noticeable. For example, people who have experienced a traumatic brain injury could struggle when drawing objects, recognizing objects (agnosia), analyzing and remembering visual information, manipulating or constructing objects, following directions, and many more.

A very noticeable problem is neglect when the brain neglects one side of all it perceives which is usually the left-hand side. For example, people fail to analyze the whole picture because it doesn’t notice the left side of an image. There is a case study of Elsie, a 52-year-old woman, who had a case of a stroke 3 years ago. Ever since from that incident, Elsie would have had trouble driving next to parked vehicles because she would scrape against the cars. Also, she would hit against signs on the left side of her car. Since this caused many troubles, Elsie visited a doctor to check her eyesight. Her doctor referred Elsie to a neuropsychologist who identified the problem as left-sided neglect. The neuropsychologist asked how Elsie was able to drive this whole time while neglecting her left side. She answered how she knew when to steer to the right because she would hear her tires going off the road.

One of the least common examples of neglect is prosopagnosia which is the inability to recognize faces. There are rare cases when people cannot distinguish the differences between one face from another or read facial expressions. They must rely on other factors to help recognize other people such as their voice and their personality. There is a case study of when Lincoln couldn’t recognize himself by observing a picture of himself after the car accident. Lincoln would have a hard time trying to look for his family in large crowds when they are separated from each other. Even though Lincoln had the difficulty of recognizing people’s faces, others couldn’t understand his ability to see and recognize objects.

Another case study was done on a woman who fell down several flights of stairs in March 2012. She was diagnosed with traumatic brain injury. Ever since that incident, she couldn’t smell or taste anything and it’s reported that it’s high as 25% after traumatic brain injury. It’s not hard to for them to notice how they’ve lost their sense of smell and taste. Loss of smell is also known as anosmia and the loss of taste is known as ageusia. The loss of smell influences the loss of taste. There are many reasons that cause the loss of smell such as damage to the nose, nasal passages, sinuses, olfactory nerve, and the brain. The olfactory nerve helps transfer the smell from the nose to the brain to process input. It’s difficult to pinpoint the exact reason why people lose their sense of smell, but the reason could be how there’s damage to the nasal passageways, olfactory nerve, and the frontotemporal regions of the brain. It’s important how not only the nasal passageways or the nerves play a significant role but the brain as well because they help process the sensation from the nasal passageways. If that area of the brain is damaged, then it’s difficult for the individual to have the ability to smell. If the individual cannot smell anything, then it would be difficult for them to have an appetite and it will slow down the production of saliva because the smell of food causes the individual to be hungry.

The brain is responsible for processing all of the senses such as sight, hearing, taste, smell, and touch. Since the brain plays a significant role, if it’s injured then it could influence these senses to lose their sense. This depends on the location of the brain and severe the injury is.

Behavioral/Emotional

It’s been discovered that traumatic brain injuries cause a long-term disability, especially for those younger than 40-years old.

There are many areas in the brain that focuses on certain functions such as behavior and emotion. If there were any injuries that happened to the brain then there would be significant changes in behavior and emotion. For example, the frontal cortex’s function is personality expression and behavior. Therefore the individual will have a difficult time trying to control his anger. Or they cannot seem to express any emotion and this is known as “flat affect”. The most common behavior and mentioned problems include verbal and physical outbursts, poor judgment, negativity, intolerance, lack of empathy, lack of motivation, depression, or anxiety.

After they’ve been checked out by the doctor, they will experience some mood swings because they cannot control their moods. One day, they can be very excited and happy, and then in the next second, they become sad and depressed. The victim of traumatic brain injury may not even know that they cannot feel and express any emotions. They can just laugh for so long without feeling any emotions of joy and happiness.

In 1848, a famous case study was done on Phineas Gage who was a victim of a terrible accident of damaged this brain. His story was known as the “American Crowbar Case” and this story helped expand the knowledge of the brain and human behavior. Furthermore, the story contributed to the history of neuroscience. He was 25-years old when Gage experienced a terrible brain injury. When Gage survived the injury, the effects from the injury made the public curious and this case study became extremely important for scientists to research and understand more about the brain. In 1848, Gage was working as a foreman on the construction of the Rutland and Burlington Railroad in Vermont, USA. To build a clear pathway for the railway, construction workers must use dynamite to destroy and remove the rocks. On September 13, Gage was preparing to explode some rocks by using a tamping iron to condense the explosive powder onto the rock. When the tamping iron made contact with the rock, it made this spark that began the explosives. Then the tamping iron drove through Gage’s cheekbone and came out of the top of his head and was shot some 30 yards away from Gage and it was covered with his blood and parts of his brain. Several minutes after the accident, Gage was still conscious and was able to recall what happened. No one expected Gage to survive, even his family prepared a coffin for him. Although Gage physically recovered, the accident affected his mental condition.

After the accident, Gage wasn’t his old self, his personality and behavior changed. In 1868, Dr. John Harlow who took care of Gage’s wounds reported the changes of his personality and behavior. In his report, this description of Gage was written as “fitful, irreverent, indulging at times in the grossest profanity… capricious and vacillating” and being “radically changed, so decidedly that his friends and acquaintances said he was ‘no long Gage’.” Since the rod damaged the frontal cortex, Gage lost his sense of social inhibitions. This discovery found that the frontal cortex is responsible for cognitive and social behavior, expressing personality, and making decisions. However, these connections were made in the 19th century, many decades after the accident occurred. One of the researchers, David Ferrier, a Scottish neurologist, studied the cerebral cortex which is responsible for thinking, perceiving, producing, and understanding language. Ferrier did an experiment on damaging the animal’s frontal cortex. His conclusion was how there was no physical damage, however, there were changes in the animal’s character and behavior.

After Gage’s death in 1860, many scientists did their best to reconstruct Gage’s injury and establish which areas of his brain were damaged. A group of scientists and researchers led by Jack Van Horn of UCLA’s Laboratory of Neuroimaging. They designed a new digital model of the rod’s path and this helped conclude that the Gage’s injury was more severe than it was when first observed: it was 4% more of the cerebral cortex and 11% more of the frontal cortex were damaged. Furthermore, the model suggested that there was a connection between the frontal cortex to the limbic system was damaged. Since the limbic system was damaged, then Gage couldn’t feel any emotions such as fear, pleasure, and anger and didn’t have any desires such as hunger, sex, and dominance. This supports Gage’s report of his change in behavior and personality.

Conclusion

Over the past several decades, technology is continuously progressing and this helps save more lives. However, it still continues to be one of the most common and leading health problems to investigate and treat. Although, there has been a decrease in mortality due to the heavy focus on the prevention of secondary injuries since the recovery process requires time. Many potential therapeutic opportunities are being explored to target known changes with neuroplasticity, from differential gene expression and cellular proliferation to the upregulation of synaptic proteins and junctions for new network connections to the modulation of inflammatory reactions and the recruitment of immune cells to limit the size and volume of damage. Future therapies may find benefit in targeting multiple mechanisms of recovery and as such, stem cell therapies or a combination of different pharmacologic therapies are of utmost interest and currently under heavy investigation.