Levels of loss of consciousness and associated disorders

There is a wide variety of pathologies that can arise as a result of an injury to the human brain. One of the effects that these disorders can have is decreased level of consciousness.

We'll see now the different degrees to which a person can lose consciousness because of a pathology, and why this is believed to occur. However, before speaking properly of this type of decrease and therefore the appearance of disorders, it is convenient to establish that we understand by consciousness.

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What do we understand by consciousness?

The ability that allows us to gain knowledge of ourselves and the environment that surrounds us is called consciousness. And the degree that a person can have of it will be determined by what a neural system known as reticular formation, which is distributed by the brainstem, the diencephalon and the brain hemispheres.

Through the Ascending Reticular Activator System (SARA), reticular formation controls the activity of cortical and thalamic neurons

This being the key for there to be wakefulness (being awake), all thanks to the bidirectional stimulation that exists between the cortical and reticular areas.

Levels of loss of consciousness

There are different phases regarding loss of consciousness, some more fatal than others. Let's review them:

1. Confusion

In this phase the damage is relatively slight, although despite this the person cannot reason quickly and clearly and thinking is slow.

2. Clouding

In this state the person is drowsy, and even falls asleep, even if it is not the right time or place. When she is awake, she is unable to stay alert, and her movements are severely restricted. If it can be awakened by coming into contact with stimuli, and is capable of emitting reactions to verbal or painful stimulation.

3. Stupor or semi coma

Here the individual affected by the accident or pathology can only wake up if they are presented with repetitive and intense stimuli, but the answers it produces will not be coherent and will be slowed down. When encountering painful stimuli, he copes with them by avoiding them. There is no toilet training and motor activity is nil.

4. The coma

Etymologically, coma means deep sleep. It is a pathological state that presents a great loss in the level of consciousness, it is identified as a stage in which the individual cannot feel or wake up, does not produce any verbal or motor response to external stimuli, however penetrating and painful they may be.

Notably, in coma, causing loss of consciousness It is a product of the lack of blood supply to the brain for 20 or more seconds, or when blood perfusion is below 35ml / minute per 100 grams of brain mass. A state of physiological savings is entered, so the brain seeks to reduce energy consumption (use less glucose, for example) in order to avoid further damage to brain cells

5. Brain death

It is the last phase regarding the loss of consciousness, in this case there is no record of brain activity nor in the brainstem, as there is a global infarction and total paralysis of cerebral blood flow. Breathing is suspended (apnea), and can only be maintained by artificial means.

Pathologies that cause them

These types of disorders can arise from many different causes. For example, product of head injury, vascular disorder, brain tumor, epilepsy, excessive alcohol consumption and a very long etcetera.

Fundamentally, any disease or accident with the potential to damage the diencephalon or the brainstem has a good chance of lead to coma or brain death, while less severe degrees of loss of consciousness can be caused by more severe injuries. superficial.

Some patients remain in a coma for weeks, months, and even years, and enter in a state known as a vegetative state, characterized by the fact that autonomic functions such as heart rate, respiration, regulation of temperature and blood pressure are preserved, but not voluntary reasoning, behavior or interaction with the outside.

Bibliographic references:

• Antonio, P. P. (2010). Introduction to neuropsychology. Madrid: McGraw-Hill.