Coma - Reduced Consciousness

On this page we explain the different levels of consciousness. There are a number of successive levels of consciousness that most people go through and that we discuss on this page.
Unfortunately, not everyone emerges from a coma or reduced state of consciousness.

• Acute phase of coma
  
• Unresponsive wakefulness syndrome
  
• Minimal consciousness- Minimal conscious state-
  
• Minimal consciousness+ Minimal conscious state+ Minimal conscious state+
  
• Conscious confusional state
  
• Locked-in syndrome / Pseudo coma

Furthermore, we explain the different scales or classifications in which a coma or reduced consciousness is expressed:

• GCS/ Glasgow Coma Scale
• PGCS / Pediatric Glasgow coma scale
• PALOC-sr
• CRS-R/Coma Revcovery scale revised

We also discuss practical care, forms of interaction (especially humane interaction!) and the consequences of a coma.
Another form of reduced consciousness is delirium. This is an acute confusion, see information on this page.

After a serious brain injury, many people end up in a state of coma. A doctor may also decide to keep someone in an artificial sleep, artificial coma, until the situation is more stable.

Most people who are in a coma can regain consciousness after a few days to a few weeks. For others, unfortunately, it takes much longer: months or years.

Acute phase of a coma

Coma is the Greek word for 'deep sleep'. The definition is 'unarousable unresponsiveness'. A person in coma cannot be awakened. For loved ones of a person in coma, the period of coma is often a horrible period of uncertainty and hovering between hope and fear.

Coma is a state of deep unconsciousness due to brain injury. The brain cortex does not respond to stimuli. It may be a result of a cerebral hemorrhage or cerebral infarction, of oxygen deficiency, for example after heart failure, an accident with traumatic brain injury, poisoning or overdose, by alcohol intoxication, infection in the brains or due to fluid accumulation in the brains (brain edema), for example after an operation.

In the acute phase of a coma, the patient does not move at all or very little, does not respond to painful stimuli or on appeal. The movements that do occur in a later coma stage are reflexively, spasmodic, spastic and not consciously.

The eyes are closed and the patient must be artificially fed and sometimes artificially ventilated. Fluid and nutrient can be administered through a tube or by infusion. The comatose state can go in three directions. The patient may gradually awaken from the coma (65%). The comatose situation can turn into a vegetative state, this is the chronic state of a coma. The patient may die (18%).

Reduce intracranial pressure

The patient is administered medications per infusion in order to reduce the intracranial pressure, that is to say, to attain the pressure of the brains and to reduce swelling of the brains. Also, the breathing can be controlled with the aid of a respiration machine.

Read more about brain pressure on our special page.
For neurological recovery, the following vital functions should be as stable as possible: breathing, circulation and body temperature.

Artificial coma

Sometimes a patient is deliberately kept in a coma (artificial coma) in order to limit (further) damage to the brains. In this way the damaged tissue will have the chance to restore as far as possible. This is often done by lowering the body temperature.

Difference between a coma and braindead

A coma is caused by the fact that part of the brain functions has been interrupted or is working less well (functional disorder of the brains). Coma is not the same as braindead. When someone is brain dead, there is no more brain activity, not even from the brain stem or the medulla oblongata.
Read more on our special page about brain death and the protocols to determine that there is no more brain activity.

When a person is in a coma, his or her brain cells are still alive, but they receive no more signals from other brain cells. They do not send signals. Yet there is still a very minimal electrical activity and metabolism. With the most modern techniques sometimes very small isolated spots can be seen that show minimal activity, but do not pass signals.

In a coma primitive reflexes like cough and swallowing may occur, as well as vegetative functions such as heart rate, blood pressure, respiration, temperature, and the wake-sleep rhythm is controlled by the brainstem. It also occurs that the functions of respiratory regulation, blood pressure regulation and temperature regulation are affected.

The brain stem: the On/Off button of the brain

For people who are not in a coma, the brain stem has the function to control the activation and the alarm (arousal) of the whole brain. In other words, the brain stem contains the "on and off button" of consciousness.

This is called the reticular activating system (RAS). The brain stem, midbrain, medulla oblongata, thalamus, red and black nuclei together constitute the reticular formation (RAS); the so called control room of consciousness. Nerve impulses enter here and are sorted and filtered and, if they are important, passed on to the cerebral cortex in the large brains.

The cortex contains the function of consciousness. In a comatose situation consciousness disappears.

Formatio reticularis

The reticulo-thalamo-cortical system controls the arousal state of the cortex (in the big brains).

Unresponsive wakefulness syndrome or vegetative state

Minimally conscious state (MCS)

If the person responds a little but cannot communicate yet, this is called minimally conscious (MCS) or lowly conscious (LCS) state.

The cerebral cortex slowly begins to function somewhat. The person shows small but clear behavioral reactions, especially emotions. The eyes can follow movements or people and there are more focused actions on stimuli. However, no commands are carried out. Sometimes automatic and non-complex movements are visible.

Emotional reactions such as crying and laughing may occur, but it is not always in accordance with a trigger, which also makes it difficult for those involved in the environment to see it. The person in minimally / lowly conscious state can 'cry compulsively' which gives the impression that the patient is sad.

The face may contort into a grimace at a painful stimulus. Someone with minimal consciousness can sometimes temporarily regress into the vegetative state but can also recover to a wakeful state.

Minimally Conscious State + (MSC+)

If a simple task is sometimes carried out, the condition is called MCS+.
There may be purposeful movements.
There is no mutual communication.
Alertness has increased somewhat.

PALOC-sr
On a scale of states of consciousness used in the Netherlands (PALOC-sr) with eight levels of information processing in the patient, the minimally conscious+ phase (MCS+) is divided into two parts:
P6
The first part of MCS+, called P6, states:
Variably adequate responses to simple tasks. Completely dependent.
The person concerned still has very serious cognitive disorders that cannot be tested. There is a low level of alertness, within which fluctuations can occur.

P7
The second part of MCS+, called P7, states:
Consistently responds adequately to simple commands. The person concerned has a more stable and higher alertness level. Still clear impairments in cognitive functions and complete dependency.

Further on this page we will go into the PALOC-sr scale in more detail.

Conscious (confused) state
The person responds adequately and is more focused on the environment.
Functional and understandable mutual communication is possible (with or without aids), or the person is able to systematically perform two different tasks.
Cognitive and behavioral disorders may be present.

Practical care and interaction

A good distribution of all activities during the day is important. Not only to normalize the sleep-wake cycle but also to ensure
a good alternation between stimulation and rest during the day
and to prevent overstimulation of the patient.

Stimulus regulation is an important aspect of nursing policy.

From the post-acute phase, stimuli should be adapted to the needs of the patient. In contact with the patient, it is desirable to talk and act calmly and at a slow pace, and to take extra time if an activity is expected from the patient. In patients with consciousness disorder
It can take much longer before there is a response.

The care for people with MCS- and MSC+ is very intensive.

In some countries Early Intensive Neurorehabilitation is applied. See for example here. 

Always treat the person in a humane way

There are still stories of people who have memories of the coma and can tell what was said, what was done.
Always continue to see the person in a coma as a human being.

Remain alert to what you say, do and continue to involve that person in everything and tell them what you are going to do, for example for physical care, or if you are transporting the person in a wheelchair that you are going to go left or right, and touch appropriately.

Do not talk about the person in a coma when he or she is with them. If someone comes to visit who does not know yet, and if that visitor is going to ask a question about the situation, take that person to the hallway for the answer.
Do not talk negatively. If it has already been decided to play music or show TV, then alternate! Even if someone were awake, he or she would never be able to tolerate the same songs or CD or the same TV program. Do not turn the volume up too loud.

The consequences of a coma

The consequences of a coma are difficult to predict and the consequences differ per person. There are people with hardly any consequences and people for whom the brain injury gives lifelong physical, cognitive or emotional and behavioral consequences or invisible consequences.

Post-Acute Level Of Consciousness scale revised (PALOC-sr)

In the Netherlands, a scale has been developed by M v.d.Wiel and H. Eilander to make detailed subdivisions of the different levels of consciousness.
They distinguish eight levels of information processing in patients with a serious disorder of consciousness in people with non-congenital brain injury.

Below you can download a document (in Dutch) about this conscious scale.

More information can be found here.

Glasgow coma schale

The level of consciousness is determined by the internationally applied Glasgow Coma Scale to assess the severity of a possible head injury. Whether or not opening the eyes (E: Eyes), whether or not carrying out movements (M: Movement) and whether or not answers to questions are given (V: Verbal response) is measured with points. A person with normal consciousness has up to 15 points and a person deep in coma has a score of 3. This is recorded as E1M1V1 = 3. It is called the EMV score.

If the score is less than E1M5V2 the patient is comatose. However, it must always be taken into account that there may be factors that affect the test: puffy eyes, deafness or hearing impairment or those who are intubated and therefore cannot speak.

Summary:
The minimum score is 3, the maximum is 15 points.

• There is very serious brain injury if the GCS score is 3-8
  
• There is moderately serious brain injury with a GCS score of 8-14
  
• There is milder brain injury with a score above 14

Pediatric Glasgow Coma Scale (PGCS) for children under 6 years of age

Normal total score for children on the PGCS:

5 years and older: E4, M5, V5

2 – 5 years: E4, M5, V4

1 – 2 years: E4, M4, V4

6 months – 1 year: E4, M4, V3

0 – 6 months: E4, M3, V2

PGCS criteria and points of attention:

• observation + registration + reporting: according to GCS
• not being able to close eyelids is not the same as opening eyes
• pain stimulus: on nail bed (no pen/pencil) or skin fold of chest, do not administer supra-orbital pain stimulus
• M3: no distinction between abnormal bending and retraction
• localization: any movement in the direction of a pain stimulus
• oriented: child calls own name or knows where he/she is

Coma Recovery Scale-Revised (CRS-R)

A second coma scale that is used is the Coma Recovery Scale-Revised (CRS-R) to distinguish between lower states of consciousness. The patient is assessed on six components:

• Reaction to sound stimuli
• Visual function
• Motor function
• Oral reflexes and response to speech
• Communication
• Wakefulness

In 2018, researchers discovered that adding pupillary responses to the GCS more accurately predicts the prognosis after traumatic brain injury, including the likelihood of death, than either measurement alone.

The GCS-Pupil response enables doctors to predict better the prognosis of patients in the first six months after a brain injury.

Locked-in syndrome / Pseudo coma

We have a separate page about the Locked-in syndrome (LIS). The Locked-in syndrome (LIS) is like a coma. The person can hear and feel, but cannot communicate. It is almost always caused by a blood flake (stroke) in the 'pons' (an organ near the brainstem) or a stroke in the brainstem. The blood clot inhibits the blood flow from the portion of the brains that sends signals to the spinal cord.

The story about a man who suffered a locked-in syndrome and for twelve years was not able to tell his parents that he understood everything they said is the remarkable and extremely sad story of Martin Pistorius (not related to the paralympic athlete Oscar).

More information

Wikipedia on Glascow Coma Scale

Coma Recovery Scale (CRS)

International Brain Injury Association on coma

Healthtalk on VT and LAS