There are a variety of conditions that can occur as a result of injury to the human brain. One of the effects that these disorders can have is decreased level of consciousness.
Below we will see the different degrees to which a person may lose consciousness due to a pathology and why it is thought to be happening. Before speaking, however, of this kind of decrement and therefore of the appearance of disorders, it should be established that by consciousness is meant.
What do we mean by conscience?
The ability that allows us to gain knowledge of ourselves and the environment around us is called consciousness. And the degree to which a person can have will be determined by what they do or do not do with a neural system known as reticular formation, which spreads to the brainstem, diencephalon and cerebral hemispheres.
Use of the ascending reticular activation system (SARA), reticular formation controls the activity of cortical and thalamic neurons, 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 unconsciousness
There are different phases in terms of loss of consciousness, Some more deadly than others. Let’s review the:
At this stage the damage is relatively lightDespite this, the person cannot reason quickly and clearly, and thinking is slow.
In this state the person is drowsy and even falls asleep, Even if it is neither the time nor the place indicated. When awake, she is unable to stay alert and her movements are very limited. If he can wake up to stimuli and is able to give reactions to verbal or painful stimulation.
3. Stupid semi-coma
Here the individual affected by the accident or pathology he only manages to wake up if he receives repetitive and intense stimuli, But the answers it produces will be inconsistent and will be slowed down. Faced with painful stimuli, he confronts them by avoiding them. There is no sphincter control and motor activity is zero.
4. The coma
Etymologically, coma means deep sleep. It is a pathological condition that presents a great loss of the level of consciousness, is identified as a stage in which the individual cannot feel or wake up, it produces no verbal or motor response to external stimuli, however penetrating and painful they may be.
It should be noted that in a coma, which causes loss of consciousness it is a product of not supplying blood to the brain for 20 seconds or more, Or when the blood perfusion is less than 35 ml / minute per 100 grams of brain mass. It enters a state of physiological savings, so the brain seeks to reduce its energy consumption (using less glucose, for example) to avoid further damage to brain cells.
5. Brain death
This is the last phase in terms of loss of consciousness, in this case he has no record of brain activity nor in the brainstem, because there is a global infarction and a total paralysis of the cerebral blood flow. Breathing is suspended (apnea) and can only be maintained by artificial means.
The pathologies that cause them
These types of disorders can have many different causes. For example, product of cranioencephalic trauma, vascular disorder, brain tumor, epilepsy, excessive alcohol consumption and very long time and so on.
Essentially, any illness or accident that can damage the diencephalon or brainstem has a high chance of producing coma or brain death, while less severe degrees of unconsciousness can be caused by more superficial injuries.
Some patients remain in a coma for weeks, months, and even years and go into in a state called vegetative state, Which is characterized by the fact that autonomic functions such as heart rate, respiration, temperature regulation and blood pressure are retained, not reasoning, behavior or voluntary outward interaction.
- Antoni, PP (2010). Introduction to neuropsychology. Madrid: McGraw-Hill.