 Traumatic Brain Injury is the most frequent cause of death and disability world wide. It can be the result of a motor vehicle accident, fall, assault or external blows to the head.
- What is traumatic brain injury?
- How is the brain damaged is in a closed or open brain injury?
- How do we know how severe the injury is?
- How is Traumatic Brain Injury Diagnosed & Treated?
- What are the possible short and long- term effects of TBI?
What is traumatic Brain Injury?
A Traumatic Brain Injury or TBI is an injury to the brain caused by a blow to the head or other external force, which may cause rapid movement of the brain inside the skull. This may occur through an event such as a car accident, assault, fall or sporting accident. A traumatic brain injury can be described in different ways, depending on how the injury occurred. A traumatic brain injury can be described as being a closed or open brain injury:
A closed brain injury - Closed injuries mean that injury to the brain has occurred without the skull being broken or penetrated and the brain has not been exposed. An example of a closed head injury is when the rapid movement of the head backward and forward (acceleration-deceleration movement) causes the brain to move inside the skull and slam against its hard inner bone.
An open brain injury - A traumatic brain injury may also result from the head hitting an object or an object piercing the skull and brain tissue (open or penetrating head injury).
A traumatic brain injury can be focal or diffuse, meaning damage may be isolated to one specific area of the brain in focal injuries or wide spread in the case of diffuse injuries.
How is the brain damaged?
With a Traumatic Brain Injury the brain may be damaged as a result of a blow or rapid movement of the head back in cases of whiplash. As a result the brain may be torn, stretched, penetrated, bruised or become swollen.
A traumatic brain injury can be diffuse or focal; however the two often occur together. Diffuse damage involves damage to axons, the brain’s microscopic communication pathways, which extend from brain cells. Damage occurs when the axons are stretched or severed.
Focal damage involves damage to specific areas of brain tissue. Types of focal injuries include contusions (bruised brain tissue), which often occurs under the sight of impact, lacerations (torn brain tissue), and or Haematoma (a collection of blood inside or around the brain), which can be the result of haemorrhaging and can lead to increased pressure on the brain.
A traumatic brain injury often results in secondary injuries, which arise due to the brain’s reaction to the first injury. These further injuries include brain swelling and haemorrhaging. Complications such as brain swelling, puts pressure on brain tissue, which can restrict oxygen supply to other parts of the brain leading to cell death. Often treatment of a traumatic brain injury is focused on controlling the secondary effects to prevent further damage.
How do we know how severe the injury is?
A traumatic brain injury can range from a mild brain injury, or sometimes thought of as Concussion, to severe or profound brain damage. Two reliable indicators of severity of damage include how long the person is in Coma and the length of time in post-traumatic Amnesia.
Another widely used indicator of severity is the Glasgow Coma Scale (GCS). This scale measures a person’s level of consciousness on a scale of 3-15, with 3 being the lowest level of consciousness. Scoring is based on Verbal, motor and eye-opening reactions to stimuli. Generally, a score of 13 or above on the GCS is considered a mild brain injury or concussion, 9-12 as moderate and 8 or below severe.
How is Traumatic Brain Injury Diagnosed & Treated?
When a person suffers a TBI generally they are brought to the hospital emergency room for initial diagnosis and treatment. This stage generally focuses on assessing and stabilising the person’s condition. Once the person is assessed as not being in immediate medical danger a complete neurological evaluation is performed to rule out conditions requiring neurosurgery, such as hematomas, certain skull fractures, and high intra-crantial pressure (ICP) and to asses the severity of the injury.
Different imaging tests may be used in diagnosis including-
- Computed Tomography (CT) Scans – can provide a three dimensional view of the structure of the brain and can be used to detect abnormalities for example, fractures, tumors or clots. When someone has a CT Scan they are required to lie flat and have their head placed within a large cylinder for a series of x ray images to be taken.
- Magnetic Resonance Imaging (MRI) – The MRI uses electromagnetic radio waves to produce either 3-D or 2-D images of the brain. MRI produces more detailed images of soft tissue and organs compared to a CT scan and can differentiate between similar tissues effectively.
- X-Radiation (composed of X-rays) is a form of radiation used as a diagnostic tool that reveals damage to structures of the brain or other body parts.
- Inter Cranial Pressure (ICP) Monitor – part of the monitor is implanted inside the skull, just above the brain, or into one of the brain's Ventricles to monitor changes in intracranial pressure.
What are the possible short and long- term effects of TBI?
Effects of traumatic brain injury will depend on the location and extent of the resulting damage and success of rehabilitation. Each person is different and Recovery and effects will also vary according to pre- injury personality and life factors, however some of the common effects include:
- Increased Irritability
- Cognitive difficulties, such as memory difficulties, short attention, and difficulties with executive functions
- Impulsivity
- Anger
- Fatigue
- Headaches
- Depression
A Diffuse Brain Injury may result in a wider range of effects whereas focal injuries may have specific effects depending on which area of the brain is damaged. For example, localised damage to the temporal lobe may lead to specific problems with short-term memory. However it should be kept in mind that the brain is a complex organ and that many of its functions are not located in one specific area, but is the result of interactions between many different parts of the brain.
Picture of Traumatic brain injury in Australia
Statistics on brain injury in Australia can be found in reports by the Australian Institute of Health and Welfare (AIHW). These reports are based on hospital data collected over specified time periods. According to recent report of hospital separations (hospital discharge data) due to traumatic brain injury in Australia for the period 2004-05 (AIHW 2008):
- 22,710 people were hospitalised with either TBI as a primary (the main reason for a person’s hospitalisation) or additional diagnosis (it was not the primary reason for hospitalisation) to other medical complications in Australia.
- Rates of traumatic brain injury were found to be generally higher for younger people and seniors.
- Younger males were hospitalised at higher rates than females across all age groups.
- The most common causes of traumatic brain injury for those presenting to a hospital with TBI as the primary diagnosis were falls, transportation and assault.
- Concussion and brief loss of consciousness occurred in many patients (60%) who presented to hospital in this time with a primary diagnosis of TBI.
Links and References
Australian Institute of Health and Welfare (2008). Hospital separations due to traumatic brain injury, Australia 2004-05. Retrieved on 11 October, 2009, from http://www.aihw.gov.au/publications/index.cfm/title/10505
Neurology Channel: http://www.neurologychannel.com/diagnostictests/CTscan.shtml
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Introduction to brain injury