Overview
Traumatic brain injuries (TBI) are sudden traumatic injuries that damage and disrupt the normal function of the brain. TBIs can happen due to various factors such as a head bump, a blow to the head, a jolt, or a piercing of the skull by an object which enters the brain tissue. Primary TBIs refer to those where damage occurs immediately, whilst, in secondary injuries, brain damage occurs gradually over time.
There are two types of TBI, depending on their cause:
- Penetrating TBI (open TBI) - Occurs when an object pierces the skull and enters the brain tissue, only damaging part of the brain.
- Non-penetrating (also referred to as closed or blunt TBI) - Occurs when an external force causes the brain to move inside the skull. This can be due to rapid, forward or backward movements, as well as violent head shakes, which cause bruising and tearing, of brain tissue and blood vessels.
TBIs are a worldwide cause of mortality and morbidity, especially among children. TBIs are also the most common cause of death under the age of 40.1 In the UK, around 200,000 people receive hospital treatment for a head injury every year, with 40,000 of these cases showing evidence of a TBI.
TBIs can range from mild or moderate, to severe:
- Mild TBI - The most common form of TBI, accounting for 75% of cases. It can also be referred to as a concussion. People with mild TBI may have trouble returning to their daily routines, especially regarding their occupation. Despite this type of TBI being classed as mild, it can lead to significant long-term problems.
- Moderate to severe TBI - Usually these severe forms of TBI lead to life-long physical and cognitive problems, which affect a person's day-to-day function function.
There are several causes for TBI such as accidental falls, sports-related injuries, and violence, which can influence the severity of the injury. The signs and symptoms of TBI range from mild to severe. Recognising the symptoms of TBI is vital for a timely diagnosis and effective treatment.
The highest rates of TBI are found in children (ages 0-4), young people (ages 15-24), and in older adults over the age of 65.
Causes of traumatic brain injury
TBI is caused by external physical impacts to the head. The severity of the damage depends on factors such as the force of impact and the nature of the injury.
Falls
Falls are the leading cause of TBI especially in young children under 4 and the elderly.
Falls in the elderly, between 80-90 years, account for 1 in 5 cases of TBI.1,2 This is mainly because the ageing population typically face weakened muscles and balance issues, which increases their chances of falling over.
Common types of falls include:
- Falling from a bed or a ladder
- Falling in the bath
- Falling down the stairs
- From hazards such as slippery floors
Additional causes of falls in young children can be attributed to:3
- Children rolling, climbing, tripping, running, or jumping.
- Reaching developmental stages such as independent mobility and exploratory behaviour before having an awareness to avoid hazards
- Unstable surfaces such as floors, stairs and carpets
- Furniture including beds, doors, windows and bathtubs
- Toys sports and recreational equipment
Vehicle-related accidents
Globally, an estimated 34 million people sustain TBIs in road-traffic collisions each year. In Europe, the majority of those injured are people between the ages of 16-55.4
Vehicle-related collisions causing TBI include:
- Cars
- Motorcycles
- Bicycles
- Pedestrians
Studies show that motorcyclists, cyclists, and pedestrians have a higher risk of TBI because of a direct impact with a colliding vehicle followed by a fall. Additionally, cyclists are prone to developing severe TBI, with a loss of consciousness and fractures to the base of the skull.4 Wearing protective gear (e.g. helmets) is essential to minimise the risk of injury.
Sports-related injuries
TBIs can be caused by a number of sports, commonly referred to as a concussions, from collisions and blows to the head.
In sports, direct head impacts can arise from being struck in the head, helmet-to-helmet collisions, or striking an opponent's head with a blunt object (e.g. a stick or bat). Indirect impacts are usually caused by tackling, which abruptly stops an opponent from travelling in the direction they were originally moving.5
Sports-related TBIs are common among young people who partake in sports competitively or recreationally, such as:
- Football
- Boxing
- Hockey
- Skateboarding
- Skiing
- Skateboarding
Violence
Many violence-related actions can result in TBIs, examples include:
- Physical assaults, such as street fights, domestic abuse, or child abuse that cause blows to the head
- Gunshot wounds in the skull which cause penetrating TBI
- Penetrating wounds are blows to the head with shrapnel, or debris from explosive blasts
- Waves produced from an explosion may affect brain function without direct impact
Traumatic brain injury symptoms
Symptoms of TBI can be physical, sensory, and cognitive, ranging from mild to severe. The symptoms one experiences from a TBI depend on the type of injury, severity, and location of injury in the brain, which can differ between each person.
TBIs can be local, affecting the exact place on the brain where the injury occurred, but can also affect surrounding areas. Therefore, some symptoms can appear immediately, while others may evolve over several days or weeks after the injury.
Symptoms of mild traumatic brain injury
Symptoms of mild TBI can vary from person to person and may change during the recovery stage.
Injuries that cause concussion are often labelled as mild TBI. Concussions are usually the result of a direct or indirect blow to the head, that may present with a combination of physical, sensory, and cognitive symptoms for a few minutes.6 Most people who suffer from concussions experience a complete resolution of their symptoms.7
Physical symptoms
Physical symptoms of mild TBI include:
- Headaches
- Fatigue and drowsiness
- Nausea and vomiting
- Difficulties with speech
- Loss of balance and dizziness
Sensory symptoms
Those suffering from mild TBI may also encounter sensory symptoms including:
- Sensitivity to light and sound
- Blurred vision
- Ringing in the ears
- Changes in the sense of smell
- Bad taste in the mouth
Cognitive symptoms
Some people may also face cognitive symptoms such as:
- A state of unconsciousness ranging from a few seconds to a few minutes
- State of confusion, disorientation, or daze with no loss of consciousness
- Problems with memory or concentration
- Mood changes
- Feeling depressed or anxious
- Difficulty sleeping
Moderate to severe traumatic brain injury symptoms
Moderate to severe TBIs have similar signs to those of mild TBIs alongside other symptoms which may arise after a couple of hours or days following a head injury. Severe TBI is always associated with a period of unconsciousness, during which the person is not able to remain awake.
Physical symptoms
The physical symptoms of moderate to severe TBI include:8
- A period of unconsciousness that can last from several minutes to a few hours
- An inability to awaken from sleep
- A persistent headache that progressively becomes worse and does not diminish
- Persistent nausea and vomiting
- Seizures
- Dilated pupils
- A numb or tingling feeling in the arms or legs
- Loss of coordination
Cognitive symptoms
A person's cognitive behaviour can also be affected by moderate to severe TBI, with symptoms such as:
- Agitation and unusual behaviour
- Slurred speech
- Profound confusion
- A state of complete unconsciousness, known as a coma
Signs of traumatic brain injury in children
TBI in young children can differ from that in adults. The scalp of newborns and young children is sensitive, therefore, head injuries can lead to lethal blood loss. In this age group, a small loss of blood can lead to a hemorrhagic shock without obvious external bleeding.9
Young children suffering from TBIs are usually not able to communicate common symptoms such as headaches, confusion, and sensory issues. Understanding the symptoms of this age group is critical to gaining appropriate and timely treatment. This is crucial, as TBI during early brain development has been shown to affect future behaviour and cognitive skills. Additionally, children under 4 are more likely to sustain head injuries, be hospitalised, or die from the leading cause of TBI, which is falls.3
Some indications of TBI you may observe in young children after a head injury include:
- A change in eating or nursing habits
- A change in sleeping habits
- Persistent and inconsolable crying
- Seizures
- Drowsiness
- Inability to pay attention
- Disinterest in their favourite activities or toys
When to seek medical attention
Always seek immediate medical attention if you or your child has suffered a bump, blow, or injury to the head that causes any physical, sensory or cognitive symptoms mentioned in this article. It is vital for those who have suffered moderate to severe TBI to seek immediate treatment to prevent further fatal complications.
Summary
- TBIs can disrupt the normal function of the brain, due to a bump, blow, jolt or penetration of an object into the head, causing damage to brain tissue and blood vessels.
- The most common causes of TBIs are falls, which mostly occur in young children and elders, and vehicle-related accidents mostly affecting the younger population.
- Other causes include sports-related injuries, where a concussion is commonly observed, and violent actions like gunshot wounds, domestic abuse, and child abuse.
- TBI can range from mild or moderate to severe, with physical, sensory, and cognitive symptoms.
- Common symptoms include headaches, periods of unconsciousness, nausea, confusion, and slurred speech.
- Young children often find it difficult to communicate their symptoms, it is important to keep in mind that the usual indications of TBI in children include a change in sleeping, eating and nursing habits, persistent crying, and the inability to pay attention.
References
- Lawrence T, Helmy A, Bouamra O, Woodford M, Lecky F, Hutchinson PJ. Traumatic brain injury in England and Wales: prospective audit of epidemiology, complications and standardised mortality. BMJ Open [Internet]. 2016 [cited 2024 May 31]; 6(11):e012197. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5168492/.
- Stocchetti N, Zanier ER. Chronic impact of traumatic brain injury on outcome and quality of life: a narrative review. Crit Care [Internet]. 2016 [cited 2024 Jun 3]; 20:148. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4915181/.
- Haarbauer-Krupa J, Haileyesus T, Gilchrist J, Mack KA, Law CS, Joseph A. Fall-related traumatic brain injury in children ages 0–4 years. J Safety Res [Internet]. 2019 [cited 2024 Jun 3]; 70:127–33. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6927527/.
- Baker CE, Martin P, Wilson MH, Ghajari M, Sharp DJ. The relationship between road traffic collision dynamics and traumatic brain injury pathology. Brain Commun [Internet]. 2022 [cited 2024 Jun 3]; 4(2):fcac033. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8914876/.
- Clark M, Guskiewicz K. Sport-Related Traumatic Brain Injury. In: Laskowitz D, Grant G, editors. Translational Research in Traumatic Brain Injury [Internet]. Boca Raton (FL): CRC Press/Taylor and Francis Group; 2016 [cited 2024 Jun 3]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK326721/.
- Galgano M, Toshkezi G, Qiu X, Russell T, Chin L, Zhao L-R. Traumatic Brain Injury. Cell Transplant [Internet]. 2017 [cited 2024 Jun 5]; 26(7):1118–30. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5657730/.
- Ferry B, DeCastro A. Concussion. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 [cited 2024 Jun 5]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK537017/.
- Traumatic Brain Injury (TBI) | National Institute of Neurological Disorders and Stroke [Internet]. [cited 2024 Jun 5]. Available from: https://www.ninds.nih.gov/health-information/disorders/traumatic-brain-injury-tbi.
- ARAKI T, YOKOTA H, MORITA A. Pediatric Traumatic Brain Injury: Characteristic Features, Diagnosis, and Management. Neurol Med Chir (Tokyo) [Internet]. 2017 [cited 2024 Jun 5]; 57(2):82–93. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5341344/.