Disorders of consciousness and coma

Find out how a child’s consciousness can be affected by acquired brain injury.

This section talks about how a child’s consciousness can be affected by acquired brain injury.

Many children are unconscious after a brain injury, sometimes for a matter of seconds and sometimes a great deal longer. In some cases a child may not be fully conscious for weeks or even longer after their injury. 

Most of us think of this kind of state as ‘a coma’, but it’s actually a little more complicated than this. There are different levels of how aware and awake someone can be, and a coma is just one of them.1

These different states are best thought of as a spectrum, or a range of different states. These states are assessed with something called the Glasgow Coma Scale. This is used to work out the severity of the acquired brain injury. The Paediatric Glasgow Coma Scale is used for children up to the age of five years old. See below for how these scales work. 

Professionals group all of these states together under the phrase ‘disorders of consciousness’.2 You may also hear terms such as ‘vegetative state’3 or ‘low awareness state’, which can be terrifying for family and friends/any parent. 

Here, we hope to set out what these terms actually mean for your child. 

But before we look at how a child’s consciousness can be affected by an acquired brain injury, it may be helpful to talk about what our ‘consciousness’ actually is. 

Our consciousness can be broken down into two key parts4, 5:

  • Wakefulness: at its simplest, how awake we are. Clinicians will look to see whether a child is opening their eyes (among other tests).
  • Awareness: how aware we are of our surroundings, the people around us, and of ourselves. Clinicians might look to see if a child turns their head towards a sound (again, among other tests).4

Together these two elements make up our consciousness. 

And there is a relationship between the two. Think of those moments before you drop off to sleep. Your ‘wakefulness’ is dropping away, just as you become less ‘aware’ of your surroundings and yourself. 

Any kind of ‘disorder of consciousness’ is where there are difficulties with wakefulness, awareness, or both.

Disorders of consciousness

The way a child’s consciousness is affected is divided up into different levels by healthcare professionals. But these levels aren’t fixed. Children may move through these levels as their condition gets better or worse.6 

And to make things even more complicated the different levels aren’t always easy to identify.  Not least because doctors have no way of asking their patient how aware they are of what’s going on around them.7 

Let’s look at the different levels and what they mean.

Coma

Children may spend some time in a coma, which can last for a couple of days or weeks.

It’s different from concussion in that a coma lasts one hour or more.8 

A coma means a child has their eyes closed and they can’t be woken. This means they are not aware of their surroundings or themselves. Some children will move from this level to a ‘vegetative state’.9

Vegetative state

Let’s go back to the two things that make up our consciousness – wakefulness and awareness.

In a vegetative state, ‘wakefulness’ is there – children will sleep and wake in cycles (though not necessarily at night and day).10  They may appear to be awake but children in this state won’t show any signs of awareness of what’s going on around them. 

The things children do in a vegetative state, such as moving their eyes, will be more out of reflex – a kind of autopilot.11 

A ‘vegetative state’ may sound deeply distressing to parents and family. But although in some circumstances it can be permanent, this can also be a transition stage that leads to further recovery.10, 11 

You may hear this state and the ‘minimally conscious state’ grouped together as a ‘low awareness state’.

Permanent vegetative state/persistent vegetative state

Some are uncomfortable with these phrases because it may not be certain whether or not the vegetative state is actually permanent.

It’s been suggested that healthcare professionals avoid these phrases altogether and instead concentrate on the child’s individual circumstances.12 

In the UK, ‘permanent’ is used if the vegetative state we describe above has lasted more than six months after a non-traumatic injury and a year after a traumatic injury.

‘Persistent’ is used if it has lasted more than a month. 

But there are differences of opinion both in the UK and around the globe about these terms.13

Minimally conscious state

Children in a minimally conscious state will have periods of being awake. They also show some signs of ‘purposeful’ behaviour – things they have meant to do, rather than ‘autopilot’ reflexes. 

They might follow a person or an object with their eyes or fix upon a person on request. Some children in this state might be able to make some sounds or say words.14 

But all of these responses are limited, often subtle, and not consistent. Much like a vegetative state this state may be permanent or it may be a stage that leads to further recovery15.

Locked-in syndrome

Sometimes called a ‘pseudocoma’, locked-in syndrome is very much as it sounds. People with this syndrome are both awake and aware. But they are unable to move or speak. 

Generally they have limited up and down eye movement, which can be used to communicate. 

Locked-in syndrome isn’t really a ‘disorder of consciousness’, because the person is actually awake and aware. But there is a danger that it can be misdiagnosed.16

Parents dealing with any of the above can face an horrific time, filled with uncertainty. It’s hard for family members to know what to do. But there is some evidence that people in a coma may be able to hear what’s going on around them, even if they can’t respond.17 

Talking to your child and holding hands while they’re in this state might be of benefit to everyone. You may have heard of arousal programmes. 

These are where carefully-planned periods of stimulation (usually vision, sounds, touch, smell and taste) are combined with periods of rest. But these are controversial in the healthcare community and their effectiveness is disputed.18

Looking after yourselves

It should go without saying that the circumstances described here are incredibly difficult for any family. Children who emerge from these states are confused and agitated. 

Sometimes they may display behaviour such as swearing or aggression. This may be difficult for parents and family but they must be reassured that it is not uncommon.19

The Glasgow Coma Scale

The Glasgow Coma Scale (GCS) allows healthcare professionals to assess how severely someone's brain has been injured following a head injury.

There is a special version for children up to five years of age, called the Paediatric Glasgow Coma Scale. It scores people on:

  • verbal responses (whether they can make any noise)
  • physical reflexes (whether they can move)
  • how easily they can open their eyes

The highest possible score is 15. This means that the person knows where they are and can speak and move as instructed. The lowest possible score is 3. 

This means that the body is in a deep coma (a sleep-like state when the body is unconscious for a long period of time).20

References

  1. Boly M, Demertzi A, Laureys S (2009). Coma, Persistent Vegetative States, and Diminished Consciousness. Encyclopedia of Consciousness. (1), pp147-156.
  2. Gosseries O, Bruno MA, Chatelle C, Vanhaudenhuyse A, Schnakers C, Soddu A, Laureys S (2011). Disorders of consciousness: what's in a name? NeuroRehabilitation, 28(1),pp3-14.
  3. Laureys S, Monti MM, Owen AM (2010). The vegetative state. British Medical Journal (341), August 2010. Pp292-296. p292. Defines vegetative state.
  4. Boly M, Demertzi A, Laureys S (2009). Coma, Persistent Vegetative States, and Diminished Consciousness. Encyclopedia of Consciousness. (1), pp147-156.
  5. Laureys S, Monti MM, Owen AM (2010). The vegetative state. British Medical Journal (341), August 2010, pp292-296.
  6. Laureys S, Monti MM, Owen AM (2010). The vegetative state. British Medical Journal (341), August 2010, pp292-296.
  7. Laureys S, Monti MM, Owen AM (2010). The vegetative state. British Medical Journal (341), August 2010, pp292-296. Boly M, Demertzi A, Laureys S (2009). Coma, Persistent Vegetative States, and Diminished Consciousness. Encyclopedia of Consciousness (1), pp147-156.
  8. Boly M, Demertzi A, Laureys S (2009). Coma, Persistent Vegetative States, and Diminished Consciousness. Encyclopedia of Consciousness (1), pp147-156.
  9. Laureys S, Monti MM, Owen AM (2010). The vegetative state. British Medical Journal (341), August 2010, pp292-296.
  10. Boly M, Demertzi A, Laureys S (2009). Coma, Persistent Vegetative States, and Diminished Consciousness. Encyclopedia of Consciousness (1), pp147-156.
  11. Laureys S, Monti MM, Owen AM (2010). The vegetative state. British Medical Journal (341), August 2010. Pp292-296.
  12. Boly M, Demertzi A, Laureys S (2009). Coma, Persistent Vegetative States, and Diminished Consciousness. Encyclopedia of Consciousness (1), pp147-156.
  13. Boly M, Demertzi A, Laureys S (2009). Coma, Persistent Vegetative States, and Diminished Consciousness. Encyclopedia of Consciousness (1), pp147-156. Laureys S, Monti MM, Owen AM (2010). The vegetative state. British Medical Journal (341), August 2010, pp292-296.
  14. Boly M, Demertzi A, Laureys S (2009). Coma, Persistent Vegetative States, and Diminished Consciousness. Encyclopedia of Consciousness (1), pp147-156.
  15. Laureys S, Monti MM, Owen AM (2010). The vegetative state. British Medical Journal (341), August 2010, pp292-296.
  16. Laureys S, Monti MM, Owen AM (2010). The vegetative state. British Medical Journal (341), August 2010, pp292-296.
  17. NHS evidence, and Sheridan J (2002). Coma after brain injury: how you can help. Nottingham: Headway.
  18. Walker S (2009). Educational Implications of Acquired Brain Injury: a resource for educational psychologists. Brain and Spine Foundation, p36.
  19. Demellweek C, Appleton R (2006). The impact of brain injury on the family. In Appleton R, Baldwin T (Eds.), Management of Brain-injured Children (pp261-294). Oxford: Oxford University Press.
  20. NICE guidelines. Head Injury: Triage, assessment, investigation and early management of head injury in infants, children and adults, p90. GCS is widely used in assessment and monitoring of patients.