What are the causes of Acquired Brain Injury (ABI)?

Posted on 18 August 2015 by Yooralla

This week is Brain Injury Awareness Week, which aims to raise awareness of acquired brain injury (ABI) in the community.

Over the past couple of years, ‘one punch’ or ‘coward-punch’ assaults have had significant media coverage nationwide, as a cause of brain injury and death among young men.

In Victoria, specific laws have been introduced, with mandatory sentencing of 10 years if someone is found guilty of a fatal ‘one punch’ attack. 

But while such assaults can result in an acquired brain injury, victims of ‘one punch’ assaults represent only a small percentage of the 330,000 Australians who have an acquired brain injury (ABI). While awareness around the harm of ‘one punch’ assaults is important, it has resulted in some confusion around the leading causes of brain injury. 

But first, let’s explore what an acquired brain injury actually is. 

The definition for an ABI is broad, referring to any type of brain damage caused by events that have occurred after birth. An ABI can be the result of a traumatic brain injury, such as an accident or assault, or a non-traumatic brain injury, such as a stroke, tumour, lack of oxygen or substance abuse.  

The complexity of the brain and its responsibility for all aspects of human development and activity means that the effects of an ABI are widespread, and no two people with an acquired brain injury will be affected in the same way. 

An ABI can result in physical, intellectual, emotional and behavioural changes. Such changes can mean individuals need to access specific disability services. At Yooralla, our Therapy Services are often necessary for individuals dealing with the effects of an ABI, helping to increase communication, improve physical mobility and develop independence through modified living solutions.

Making things more difficult is the fact that an ABI is often an ‘invisible’ disability, and the effects of an injury are often not recognised by others. 

What causes an ABI?

The leading cause of an ABI is stroke, where the supply of blood to the brain is stopped by a clot or bleeding. Strokes often result in physical disability, and can also cause emotional and behavioural changes. As the Australian population ages, the incidences of stroke are expected to increase - resulting in a higher rate of ABIs in the community. 

But while strokes normally affect older people, one in every five happens to a person under 55. For these young people, it can be difficult finding suitable accommodation, and many young people with an ABI end up in nursing homes. Over the past five years, this has been addressed with specialised accommodation services for young people, which emphasise independence and community engagement. 

The second largest cause is accident or trauma, where an injury is sustained following a blow or use of force applied to the head. Almost 50 percent of traumatic brain injuries are the result of road accidents.

This is where ‘one punch’ injuries come in, with violent assault rated among the top three most common causes of traumatic brain injury. But while ABIs are more common in young men, who are normally overrepresented in road accident and assault statistics, ABI as the result of assault also affects women and children. This year, Brain Injury Awareness Week has focused on domestic violence as an often ignored, but significant, contributor to ABIs in Australia on two contrasting fronts - ABIs can result from sustained blows to the head, and additionally, those with an ABI can develop behaviours that contribute to domestic violence. 

So after looking at ABIs, it’s clear that the most known causes of brain injury aren’t necessarily the most common. But why is awareness around ‘one punch’ assaults so important? Because when it comes to causes of ABIs, violent assaults are the only major cause that can be prevented through behavioural and societal change. Addressing and publicising the potential impact of assault has the potential to dramatically reduce ABIs resulting from violent assault. Given the significant impact of ABIs on individuals, their families and their community, reducing violent assaults is an important and achievable path to prevention.  

Related links


Synapse have a number of helpful resources about ABIs.

ABI – The Facts booklet

Violence and assault fact sheet

Stroke fact sheet

Visit the Australian Brain Injury Australia website for general information and resources.


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