Brain injury

Also known as Acquired Brain Injury (ABI)

A brain injury is damage to brain tissue. It can be the result of trauma or medical problems. The effects of brain injury are different for everyone. How you react depends on which parts of your brain were injured and how seriously.

Key points

  1. A brain injury is damage to brain tissue. It is different from congenital disorders, which are problems with the brain that you are born with.
  2. A brain injury can be the result of trauma such as a blow to the head or impact that causes your brain to shake within your skull.
  3. It can also be caused by a medical problem, such as a stroke, brain tumour, lack of oxygen or infection, or by substance abuse or poisoning.
  4. A brain injury can have a dramatic impact on your family, job, social and community life.
  5. There is support available for those living with brain injury. 
Need urgent medical help?

If someone is unconscious or unable to move all or some of their limbs or is complaining of neck pain call 111 immediately.

Don’t move the person (unless it’s dangerous to leave them where they are).

Get immediate medical help if you or someone you are caring for:

  • has received a hard bang on the head (say, from a major fall)
  • appears dazed or loses consciousness, even momentarily
  • seems unwell or vomits after the injury or shows any of the warning signs below:
• Complaints of neck pain 
• Increasing confusion or irritability 
• Repeated vomiting 
• Seizure or convulsion 
• Double vision
• Muscle weakness, tingling or burning in arms or legs 
• Deteriorating conscious state 
• Severe or increasing headache 
• Unusual behaviour change
See also: ACC SportSmart National Concussion Guidelines

Read more about concussion and head injury

What is a brain injury?

Brain injury is damage caused to brain tissue that occurs after birth and is not related to a congenital disorder (a problem you are born with). A brain injury can be the result of trauma (known as a traumatic brain injury) or a medical problem.

Traumatic brain injury (TBI)

A TBI is caused when an impact (bump or blow) to your head or body causes your brain to shake inside your skull.  

In New Zealand, the most common causes of TBI are: 

Medical brain injury

Brain injury can also be caused by medical problems, such as:

  • brain tumours
  • bleeding in your brain
  • stroke
  • infection
  • lack of oxygen.

Ongoing alcohol and drug abuse can also cause brain injury, as can poisoning with toxic substances such as pesticides, gases and solvents. 

How is brain injury diagnosed?

To assess the impact an injury has had on your brain, your doctor will use the Glasgow Coma Scale (GCS) to measure physical, verbal and eye-opening responses. Read more about the Glasgow Coma Scale

Brain injuries can range from mild to severe as determined by the GCS, with mild being GCS 14–15, moderate 9–13, and severe 8 or below.

Concussion is on the mild end of the traumatic brain injury spectrum.

What are the effects of brain injury?

The effects of brain injury are different for everyone. How you react depends on which parts of your brain were injured and how seriously.

About 5% of traumatic brain injuries in New Zealand are moderate to severe. If you have a moderate to severe brain injury, you are likely to have some level of physical, cognitive (thinking) or behavioural disability.

Some symptoms may appear right away, whereas others may not be present for days or weeks after the injury. Some symptoms may disappear after a few hours; some may continue for weeks or months.

Because the brain is so complicated, it is difficult to know exactly what the long-term outcome will be. Most people keep getting better slowly over time, but some people never recover to be exactly as they were before the injury.

Some ongoing problems include:

  • cognitive problems, eg, difficulties with thinking clearly, maintaining concentration, problem-solving and completing projects
  • memory problems particularly with learning and remembering new information
  • physical problems, eg, with sense of balance, fatigue causing reduced mental and physical stamina, slower reflexes and headaches
  • sensory problems, eg, lower tolerance to light and noise, or problems with taste, smell and touch
  • communication difficulties making it difficult to express yourself and understand others
  • personality changes, eg, irritability, intolerance, depression, anxiety, socially inappropriate behaviour and mood swings
  • loss of contact with friends and associates.

A brain injury can have a dramatic impact on family, job, social and community life. Brain Injury NZ has a range of resources for living with brain injury.

Brain injuries affect the whole family 

When someone in your family has a brain injury, the whole family/whānau is affected.

This could involve the following: 

  • The initial shock of the initial brain injury. This can include coping with intensive care treatment.
  • Dealing with ACC, hospitals, WINZ and other agencies.
  • Adjusting to the changes in the person with the brain injury and how these may affect other family members and friends.
  • Coping with financial and legal problems.
  • Stress related to caring for the person.

Read about Coping with brain injury for family and friends Brain Injury NZ

Learn more

Brain injury FAQs Brain Injury NZ
Brain injury in brief Headway NZ
What is brain injury? Headway NZ

Dr Stephen Kara

Stephen works with Axis Sports Medicine Specialists in their dedicated sports concussion clinic. His interest in concussion was generated from 15 years involvement in provincial and national rugby and has led to an education role with NZ rugby for community-based rugby and referees. 

Stephen is a subject matter expert in concussion and head injury.
Credits: Health Navigator Editorial Team . Reviewed By: Dr Stephen Kara, MBChB, FRNZCGP, Dip Sports Med, Dip Obs, MPhil (Hons) Last reviewed: 27 May 2019