Disorders of consciousness: what are their causes and how are they classified? (Qualitative/quantitative)

What are disorders of consciousness and what causes them?

Psychological functions take place in consciousness. They help us to be aware of ourselves, our surroundings and our relationships with each other. Alertness is a state of the central nervous system in which we are able to respond to internal and external stimuli.

The main features of consciousness include:

• alertness (vigilance)
• clarity (lucidity)
• range (capacity)
• self-identification (idiognosy)
• self-awareness and evaluation of oneself in comparison with other people (heteroidentification)

For example, sleep is also a physiological disorder of consciousness.

If consciousness and its capacity is impaired in some way, we speak of a disorder of consciousness. These are further divided into qualitative or quantitative.

Qualitative is a disorder of lucidity and quantitative is a disorder of vigilance. Otherwise, they are divided into short-term or long-term.

Qualitative disorders of consciousness

It arises when lucidity is disturbed but vigilance is maintained. In simple terms, clarity of consciousness is disturbed with unchanged vigilance of the central nervous system.

Mental functions are disturbed and the ability to perceive the external world is lost. Disturbances of orientation, attention, memory, behaviour occur. It can be further divided into amenation, delirium and obtubilation.

Tip: More information on delirium in a separate article.

Amence is a confusion in which perception is disturbed. Hallucinations, illusions occur. Disorientation in person, place and even time.

The condition can be short or long term. After it subsides, amnesia sets in.

The main causes include, for example, hypoglycaemia in diabetes, or atherosclerotic brain disease and insufficient blood supply.

In the case of delirium, it is an organic mental disorder that occurs as a result of a disturbance in brain function. It develops over a short period of time, within days.

There are disturbances of memory, especially short-term, attention and perception. There are also hallucinations, delusions and disorientation, behavioural disorders.

Typical symptoms include body tremors, speech disorders such as dysarthria, tachycardia, hypertension, sweating, and urinary and fecal incontinence are common.

Obtundation is also known as the gloomy state. It occurs suddenly and subsides in the same short period of time.

The most common cause is epilepsy, a condition following an epileptic seizure. It also occurs after head injuries, heatstroke. It also occurs during fasting. A good example is pathological drunkenness or pathological affect.

Causes of qualitative disturbance of consciousness

A typical cause may be intoxication (poisoning) by drugs. This may be accidental or deliberate. Accidental often arises as a result of forgetting to take certain drugs.

In larger doses, it can cause a disturbance of consciousness. Examples include the use of psychiatric drugs or even heart and blood pressure medications. With low blood pressure, collapse can occur.

Deliberate intoxication with drugs is often accompanied by alcohol consumption. The important thing in this case is to know what drugs the person has taken, when and in what quantity, and also the combination with alcohol.

Problems with consciousness are also experienced by intoxicated people who have consumed excessive amounts of alcohol, drugs or have had a chemical or poisonous substance in their system.

Alcoholism causes damage to the brain, liver and heart.

So does the use of other addictive substances. Even the form of addiction to inhaled volatile substances causes damage to the liver and brain cells.

In addition to qualitative disturbances of consciousness, quantitative disturbances often occur, especially when the amount of the substance ingested (drug, alcohol, medicine) was higher, and especially in a short period of time.

It is important to monitor breathing. Some substances depress the respiratory centre. Vomiting is a frequent accompaniment of poisoning. In combination with unconsciousness, aspiration of vomit is the greatest complication.

Complicated pneumonitis is present after aspiration of vomit. But the most serious complication of aspiration of vomit is airway obstruction, resulting in suffocation and death.

Metabolic diseases and hypoxia also cause qualitative disturbances. Which is actually a reduced oxygen content in the body's tissues. The brain and then the heart muscle are most sensitive to it.

Another example of this type of disturbance of consciousness is focal brain damage, which can also be caused by trauma or ischemia.

Quantitative disorder of consciousness

This is caused by a disturbance in wakefulness. The body is unable to respond to external or internal stimuli.

It is further divided into:

• somnolence
• sopor
• coma

Somnolence is a state in which a person is asleep but awakens when addressed. Sophora is a disturbance of consciousness from which the person awakens only to a painful stimulus. Coma is unconsciousness. The person is unresponsive to external or internal stimuli.

A short-term disorder of consciousness occurs, for example, as a result of a seizure disorder such as the aforementioned epilepsy. Unconsciousness is present during epileptic seizures.

It can persist for a short time after an epileptic seizure, but also between multiple seizures. It is a serious condition if unconsciousness persists for a longer period of time, more than 5 minutes.

Another type is, for example, short-term unconsciousness due to syncope, collapse. There is a transient lack of blood flow or reduced blood supply to the brain.

A separate group is unconsciousness in metabolic diseases such as diabetes. As a result of low blood sugar (hypoglycaemia), brain cells fail to function and unconsciousness occurs.

The initial symptoms of hypoglycaemia include a qualitative disturbance, mainly confusion and disorientation. If it persists, it deepens into a quantitative disturbance.

When brain tissue is damaged, consciousness is also disturbed. The extent to which the disturbance occurs depends on the location, extent and associated brain swelling.

The damage may be the result of trauma. It may be, for example, a contusion (bruising) of the tissue. But the worst case is a penetrating injury (gunshot, stabbing).

A concussion is a head injury in which there is no direct tissue damage, but only impairment of the function of the central nervous system. Diffuse axonal damage is a separate group.

Brain tumours are serious, even in the case of a benign tumour. Due to the location of the brain in the skull, they have a destructive effect on the surrounding tissue by compressing it and thus increasing the intracranial pressure.

The increase in intracranial pressure also occurs in hydrocephalus. Cerebrospinal fluid accumulates in the skull and is not drained as it normally would be.

Inflammations of the brain and its membranes, such as encephalitis or meningitis, are also dangerous. As a result of inflammation, the functions of the brain are impaired.

Stroke is a distinctive group of causes of disturbances of consciousness. The ischaemic form occurs as a result of the brain tissue not clotting. In a haemorrhagic stroke, the risk is higher precisely because of the oppression of the brain tissue.

In cerebrovascular accidents, the location and extent are crucial. The amount of time from onset to recognition and initiation of appropriate treatment is very important.

Similarly, quantitative disturbances of consciousness are caused by toxic causes, which may be alcohol, drugs, chemicals or inhalation of combustion or fermentation products.

This is in the case of intoxication by gases such as carbon monoxide and carbon dioxide. The former is produced by combustion and combustion, as in the case of automobiles. Another example is the gas-fired instantaneous heater.

The second is as a product of fermentation. An example is the fermentation of grapes in wine cellars or other fruit for further processing.

Physical causes can be overheating of the organism, but also the result of electric shock. Dangerous is being struck by lightning.

Disturbances of consciousness in children are known to some mothers, especially in preschool age. Febrile convulsions due to fever are a cause of unconsciousness.

Hormonal and endocrine diseases are another group, diabetes insipidus being an example. In organ diseases, this is the case, for example, in liver failure.

But it is not always a disease state. Short-term loss of consciousness can occur when standing for a long time in an environment with expired air. It manifests itself in collapse.

Pre-eclampsia and eclampsia, also known as HELLP syndrome, occurs in pregnancy. It causes constriction of blood vessels and often unconsciousness.

Disturbances of consciousness also occur in acute infective endocarditis, which is characterised by a rapid rise in temperature, chills and shivering. In this disease, the lining of the heart becomes inflamed and is very dangerous.

Even in myocardial infarction, loss of consciousness can occur. Myocardial infarction is one of the ischemic diseases of the heart and occurs when a blood clot clogs a blood vessel.

In hypertrophic cardiomyopathy (disease of the heart muscle), syncope, which is a sudden short-term loss of consciousness, can occur. Sometimes fibrillation or other heart rhythm disorders are also the cause of unconsciousness.

In low blood pressure, there is also a short-term loss of consciousness, especially in very severe hypotension, which can also be caused by shock.

In the case of infectious diseases, disturbances of consciousness are most often related to complications of the infection in the body. For example, headaches and disturbances of consciousness also occur in toxoplasmosis if the infection affects the brain and central nervous system.

Disturbances of consciousness and even unconsciousness can also occur in tick-borne encephalitis, an infectious disease of viral origin affecting the brain and meninges.

It is most commonly transmitted by a tick.

Long-term disorders of consciousness

This includes coma. It is a condition in which a person does not regain consciousness. He or she does not communicate. There may be signs on stimulation such as grimacing, movement of the limbs, but no awakening.

A vegetative state or even an unresponsive waking state. There are occasional movements and reflex responses to stimuli. But there is no communication with the environment.

Locked-in syndrome is caused by a disorder of the central nervous system. It is not a state of consciousness, but the individual is unable to move. Only the ability to move the eyes vertically or blink is present. It may be confused with unconsciousness.

Mental states

This group includes catatonia and abulia. The manifestation of the former is stereotyped movements of the limbs, grimaces, stiffening of the body in an unusual position and for an indefinite period of time.

The latter is characterised by a lack of stimulus to action, indifference, inability to act. The person concerned may be aware of this condition.