Q&A: What is a Minimally Conscious State?

Doctor looking at MRI scans
Image caption Doctor looking at MRI scans

The Minimally Conscious State is a condition of severely altered consciousness, where there is minimal evidence of any form of awareness. Doctors are trying to draw up medical definitions of the condition - and that of similar states - such as vegetative state and locked-in syndrome, amid ethical and legal debates.

The condition may arise when someone has gone through a coma into what is known as a vegetative state, where they are "awake" but unaware.

How does Minimally Conscious State differ from a coma?

Someone can go into a coma when the nerve fibres deep inside the brain, which normally keep a person alert and conscious, are damaged. This can be through a severe brain injury caused by an accident or through something like an infection or stroke.

Unlike the Minimally Conscious State, the patient cannot be roused at all - they are unresponsive to the outside world, and their eyes do not open on their own. There is no response to internal cues, such as hunger or pain, or to external stimuli, like noise.

A person may be in a coma for a short while, or it may be a long-term state.

Doctors carry out tests to try to find out how severe the coma is, and what the chances of recovery are, although this is not an exact science.

How do doctors tell what state a person is in?

The Glasgow coma scale is used to assess a patient's neurological state, based on their ability to open their eyes, move and speak. It is also based on the responses from the central and peripheral nervous system.

A patient is given a score in each of these three categories, with a minimum number of three and a maximum number of 15.

The more severe the injury, the lower the responses from the injured person, and the lower the score.

The chances of recovery are determined by the extent and nature of the injury, and the age of the person injured, with younger people having more hope of improvement.

What is a vegetative state?

If a brain injury is very severe, someone may move from a coma into a vegetative state.

The patient cannot move or respond, but is able to breathe without mechanical assistance.

They have sleeping and "waking" cycles; but they do not speak or follow commands, although there have been instances where people have been known to shout out.

Doctors have to follow a rigorous checklist in diagnosing a vegetative state as there is a chance that a person could have awareness but is unable to express it.

Two other conditions have similar symptoms: "locked-in syndrome" where a person is fully aware but is unable to move any of their muscles, although they may be able to blink or move their eyes, and minimally conscious state.

If a person is in a vegetative state for more than one month, it is said they are in a persistent vegetative state although some people can make a recovery after this time.

If they are in the persistent vegetative state for more than a year, some doctors will say this is a permanent vegetative state, however not everyone likes using this terminology.

What are the criteria for the Minimally Conscious State?

Some patients with severely altered consciousness have neurological findings that don't meet the criteria for vegetative state. They show some signs of consciousness now and again, but find it very difficult to remain aware and communicate consistently.

In a minimally conscious state the person may have spontaneous eye opening and may visually track an object or another person around the room and have normal cycles of sleeping and "waking".

Communication can vary from nothing at all to inconsistent yes/no responses, verbalisation and gestures.

Unlike someone who is in a vegetative state, a person in a Minimally Conscious State is able to do at least one of the following:

  • Follow simple commands
  • Answer simple "yes" or "no" questions, either verbally or using gestures
  • Speak in a way that can be understood
  • Act in a purposeful way, for example by pressing a button on a remote control to change a TV channel or by crying or smiling at appropriate times.

The condition may be a stage towards recovery, or it may be the final stage of a patient's progress.

What future do patients face?

There is no treatment for a vegetative state. Care focuses on giving nutrition through a feeding tube, and keeping people clean. Withdrawing nutritional support may be considered if someone has been in a vegetative state for more than a year, and numerous criteria have been met, such as confirmation they are definitely in a persistent vegetative state and there is no evidence of awareness. There needs to be discussion with the family and agreement from the courts. This is a controversial area that receives much public and media scrutiny.

Sources: Headway, Patient UK, NHS Choices

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