Post-traumatic amnesia

What is post-traumatic amnesia (PTA)?

Post-traumatic amnesia (PTA) is the time after a period of unconsciousness when the injured person is conscious and awake, but is behaving or talking in a bizarre or uncharacteristic manner. The person has no continuous memory of day-to-day events, and recent events may be equally affected, so that they are unable to remember what happened a few hours or even a few minutes ago.

To complicate the issue, PTA can sometimes occur without the person having been unconscious beforehand.

The behaviour exhibited during PTA can be very distressing for family and friends to see. This page outlines some of the most common symptoms and hopefully this will reassure you that the condition is normal and will pass.

What are the symptoms of post-traumatic amnesia (PTA)?

The most obvious symptom is the loss of memory for the present time. The person may recognise family and friends but be unable to process the fact that they are in hospital or have had an injury of some kind. They may talk and behave as if they are at work, need to get to a meeting, or are on holiday. They may be very confused, agitated, distressed or anxious, and may even express themselves as if they are being held prisoner and have to escape.

Uncharacteristic behaviours may include violence or aggression, both physical and verbal, swearing, shouting and disinhibition (e.g. taking their clothes off, inappropriate sexual behaviour, making verbal remarks about other people, etc).

In some cases, people don’t recognise anyone but will ask for relatives or friends whom they haven’t seen for years. They may even believe themselves to be much younger than they actually are.

The person may also have a tendency to wander off, if they are physically able to, or may try to get out of bed even if they have broken limbs or other injuries. The risk of falls or of causing themselves further injury by pulling out catheters or intravenous drips may also be a problem at this time.

Alternatively, the injured person may be very quiet, docile, extra loving and friendly, clinging or childlike. While this behaviour is not threatening or seen as a management problem, it may still be strange and inappropriate.

What can be done about post-traumatic amnesia (PTA)?

PTA is a stage of recovery that the person goes through after the injury and, while it is very distressing for family and friends and may present a management problem for hospital staff, it is important to remember that this is a phase that will pass.

• Try to stay as calm as possible. Seeing other people distressed and not being able to understand the reason may add to the confusion and distress the injured person is feeling. The brain is struggling to cope with the injury, and too much stimulation should be avoided. It is therefore helpful to ensure a peaceful and quiet environment.

• Reduce the risk of harm. This may mean having someone sat with the person at all times, particularly if they are likely to wander off or try to get out of bed. During the day, a rota of familiar faces may be useful, perhaps with an assigned nurse at night. Discuss the situation with the hospital staff.

• The person may ask the same things over and over again, which can be very wearing. They may persist with a delusion, but it is best not to correct them or try to force them to remember. This will only make everyone more agitated. Gradually, the person will hold on to more information and begin to make sense of the world around them, such as where they are, why they are in hospital, and the month and year.

• Remember that the person is not in control of their actions and cannot be held responsible for what they do or say. It may be of some comfort to the family to realise that the person who is injured is likely to have little memory of this time, or that it may be experienced as a bad dream.

• Be sure to take time out for yourself or to share the visiting and supervision with others. Being tired adds to already stretched emotions and it is vital to look after yourself.

How long will post-traumatic amnesia (PTA) last?

PTA may last for a few minutes, hours, days, weeks or even, in rare cases, months. Certain types of medication have been used to try to improve the condition, with varying degrees of success. Sadly, there is usually no way of knowing exactly how long it will last.

What are the long-term effects of post-traumatic amnesia?

PTA itself does not have any adverse effects, unless the person’s behaviour causes them to injure themselves. However, the duration of PTA, along with length of time in coma, is often a good indicator of the severity of the brain injury and its likely long-term effects.

People who experience PTA for more than 24 hours are likely to have sustained a severe brain injury and to experience long-term complications, whereas PTA of less than 1 hour is likely to indicate a minor brain injury.

These are rough guidelines and the long-term effects will only become apparent when the PTA has passed.

This information was last reviewed in 2019.