Minimal consciousness: symptoms and causes

We explain the characteristics of this condition and its differences with coma.

Perceiving our environment and ourselves, understanding it and interacting with it are essential abilities that we possess thanks to our state of consciousness. When this state is intact, we are perfectly able to function in our environment and respond to external stimuli and demands.

However, this state can be altered by a series of damages to the nervous system. Among many other conditions, this damage can lead to the so-called state of minimal consciousnessof which we will speak throughout this article.

What is the state of minimal consciousness?

Formerly known as "minimally responsive state", the minimally conscious state consists of a neurologically based disturbance whereby the person is immersed in a severe state of consciousness. This disposition of the person is categorized within the diagnostic category of the diagnostic category of disorders of consciousness, which include coma, coma, coma, coma, coma, coma, coma, coma, coma, coma, coma, coma, coma.Among these are coma, obnubilation or stupor.

By consciousness we mean the state by which the person retains knowledge of himself and his environment, together with the ability to interact with it.

Taking this into account, we can understand that the state of minimal consciousness is a disposition or condition of the person in which consciousness is maintained at such low levels that it does not allow him to communicate or maintain interaction with his environment in an optimal and functional manner.

Nevertheless, In this type of neurological disorder, people show minimal but noticeable signs of behavior and response to external stimuli. and response to external stimuli. These reactions to the environment are given by eye tracking, basic gestural responses or a kind of intelligible language.

As for the duration of this state of minimal consciousness, it can become permanent or permanent. Furthermore, in cases in which it is a temporary state, recovery from a minimally conscious state is an arduous process in which the possibilities of improvement are reduced.

Although the exact incidence of this disorder is not known in Spain, it is estimated that between 30% and 40% of patients with severe brain injuries present alterations in the level of consciousness.

The etiopathogenesis of this minimal state of consciousness, as well as of many other disorders related to it, is to be found at a series of damages or lesions in different areas of the brainstem, as well as in various structures such as the thalamus or the association cortex. or the association cortex.

What are the symptoms?

In terms of neurological functioning, patients in a state of minimal consciousness have reduced cerebral metabolic activity, down to around 20 to 40%. Despite such reduced levels of brain activity, the body manages to maintain automatic functions to sustain the person's life.

This means that, despite the brain damage cardiac functions as well as respiratory capacity manage to remain active, functioning as in a fully functioning person.functioning just as in a completely healthy person.

This state of minimal consciousness is characterized by the fact that the person can manage to make small, barely comprehensible verbalizations, basic gestural reactions and execute small elementary instructions. and execute small elementary instructions.

However, in order for a diagnosis of minimally conscious state to be established, the person must exhibit at least one of the following signs or behaviors:

• Response to simple commands.
• Verbal or nonverbal yes and no responses.
• Incomprehensible verbalizationswith or without the presence of an eliciting stimulus.
• Basic gesturing in response to oral questions.
• Visual fixation and visual tracking of a stimulus..
• Stereotyped movements in response to an external stimulus.
• Emotional responsessuch as laughing or crying, congruent with the stimulus.
• Perception of Pain and localization of painful stimuli.
• Touching and holding small objects.

Differences with coma and vegetative state.

As mentioned above, the minimally conscious state is categorized within the disorders of altered consciousness. Among these disorders are coma and vegetative states, and although in all of them there are anomalies in the level of consciousness, there are also significant differences.

While in the former, the person has the capacity to respond and react by means of basic expressions, in the latter, there is no reaction possible, in the comatose state there is no reaction possible.. The person maintains basic functions but does not even keep his eyes open, nor does he express any type of response to stimuli, so it is considered that there is not the slightest level of consciousness.

If this state of coma lasts for more than four weeks, it is considered a vegetative state.In this state, basic motor reactions caused by brain stem reflexes may appear.

What are the causes?

As with the rest of the disorders that affect consciousness, the main cause is found in a lesion in the central nervous system, specifically in a structure known as the ascending reticular system. a structure known as the ascending reticular system, which controls levels of alertness and consciousness.which controls levels of alertness and consciousness.

There are a multitude of conditions, both organic and external, that can generate a minimal state of consciousness. Some of them are:

1. organic causes

• Autoimmune diseases that cause inflammation of the nervous system.
• Ischemic accidents or hemorrhagic strokes.
• Primary and secondary neoplasms.
• Anoxic encephalopathies.

2. External causes

• Meningitis or infectious diseases.
• Cranioencephalic traumas.
• Encephalopathies due to toxic agents.
• Encephalopathies due to radiation, electrocution, hyper- or hypothermia.
• Treatment and prognosis.

Due to the characteristics of this condition, an effective intervention protocol has not yet been established to reduce the minimal state. However, a series of actions can be carried out depending on the severity of the patient's condition.

At the beginning of the disease, it is vitally important to stabilize the person's vital signs, and then to to try to recover the cognitive functions that remain in the person.. This is done through multisensory stimulation programs and neurological activation exercises.

As for the prognosis of patients in a state of minimal activation, they may remain in this state for years, which may involve serious brain damage. may involve serious and irreversible brain lesions.. However, there are cases in which the person achieves a certain degree of progressive or gradual recovery.