What kinds of brain injury are there?
There are two main types of brain injury:-
Traumatic Brain Injury (TBI)
A traumatic brain injury (TBI) is an injury to the brain caused by some form of external trauma to the head.
Road traffic accidents are a common cause of this type of injury, but there are many possible causes, including falls, acts of violence, and accidents at home or at work.
The effects of a TBI can have devastating effects on a person’s physical and mental abilities.
The exact nature of the symptoms can be wide ranging, and depends on the type and severity of injury. While the symptoms of brain injury can appear immediately, this is not always the case, and they might not be apparent for days, or even weeks, after an accident.
Acquired Brain Injury (ABI)
An Acquired Brain Injury (ABI) is a term used to describe any type of brain injury (including a Traumatic Brain Injury) that occurs after birth.
The most common cause of ABI is from a build-up of pressure on the brain, such as a brain tumour, or a neurological illness such as a stroke.
A TBI is initially caused by some form of outside force, however, complications can follow, such as damage caused by lack of oxygen, and rising pressure and swelling in the brain.
These effects can have an impact on the severity and outcome of a TBI.
Types of traumatic brain injury
Closed head injuries
This is the most common type on brain injury.
It is described as a closed head injury as there is no break of the skin or no visible open wound.
The most frequent cause of closed head injuries occur when the head has been forced to rock back and forth or even rotated.
Consequently, the brain becomes injured either due to the impact on the skull, and can become twisted, stretched and torn in the process. An example where this type of brain injury often occurs is in a car accident.
Open or penetrating wounds
This type of brain injury is not as common.
It occurs when there is an open wound and the skull is fractured and the brain is exposed and damaged.
An example where this may occur is when the head collides with a sharp object such as a motorcycle brake lever.
This is the least common type of brain injury. It usually occurs where the head might be caught between two hard objects.
This kind of injury might occur is in a car accident, where the head could be caught between the wheel of a car and the road. The base of the skull and nerves of the brain stem are often damaged, rather than the brain itself.
There are different levels of severity of brain injury:
Minor head injury and concussion
A minor head injury is usually classified as a minor head trauma or a brief period of concussion. This usually results from some kind of bang on the head.
The symptoms are often temporary and can involve both physical and mental problems.
These include, loss of consciousness, lack of balance, blurred vision, disorientation and dizziness, sleep disturbance, nausea or vomiting, headaches, intolerance to light and sound, fatigue, concentration problems, memory loss, and changes to social behaviour.
It is estimated that 75-80% of all head injuries fall into this category.
In most cases the symptoms of post-concussion syndrome will resolve themselves within a few weeks.
However, in some cases they may persist much longer. The majority of people who experience a minor head injury usually recover after 3 to 4 months following the accident, but there are occasions when the period of recovery can take longer.
Moderate brain injury
A moderate head injury is generally defined as loss of consciousness for between 15 minutes and 6 hours, or a period of post-traumatic amnesia of up to 24 hours.
A person with a moderate head injury is likely to suffer from a number of residual symptoms.
The symptoms can vary and can include similar problems to those of a minor head injury, although not exclusively, and the person may experience more behavioural difficulties and aggressive warning signs.
The symptoms will last for a longer period of time and will be more significant than from a minor head injury.
Common symptoms include fatigue, severe headaches and dizziness, difficulties with memory loss and concentration problems, organisational and planning problems, word-finding problems and irritability and emotional difficulties.
For the majority of people these residual symptoms gradually improve, although this can sometimes take between 6 to 9 months.
Severe brain injury
A severe head injury is usually defined as being a condition where the injured person has been in an unconscious state for 6 hours or more, or a post-traumatic amnesia of 24 hours or more.
In these situations, the person is likely to be hospitalised and receive rehabilitation.
In extreme cases, the head injury is classed as very severe where the injured person has been in unconsciousness for 48 hours or more, or a post-traumatic amnesia of 7 days or more.
The longer the length of coma and post-traumatic amnesia, the poorer will be the outcome.
In cases of severe and very severe head injuries, the symptoms can include, loss of consciousness, seizures and convulsions, persistent headaches, persistent nausea, poor or loss of coordination, profound confusion, paralysis, numbness, agitation and aggressive social behaviour, and coma.
Visible recovery usually occurs in the first six months or so and the injured person can usually continue to make improvement for two years, and sometime even longer.