DISORDERS OF CONSCIOUSNESS: CAUSES AND TREATMENTS - NEUROPSYCHOLOGY - 2025

The term disorder of consciousness refers both to an alteration in the level of consciousness (drowsiness, stupor, coma, etc.) and to an alteration in the content of consciousness (temporal or spatial disorientation, or difficulty in maintaining attention).

In figures, between 30% and 40% of individuals who suffer severe brain damage have disorders of consciousness. The causes of these alterations can be diverse, and originate from lesions at the focal or diffuse level, specifically in the brain stem or in related structures, such as the thalamus and the association cortex (Más-Sesé et al., 2015).

The most recent studies show that there is a significant increase in the number of patients with this type of condition after vascular injuries. This is due to the drastic reduction in the number of road accidents that occurred with severe head injuries.

In general, the figures tend to vary between studies, with 44% of cases of vascular origin and 72% of cases of traumatic origin (Más-Sesé et al., 2015).

The suffering of this type of alterations represents a serious medical emergency. A correct diagnosis and treatment is essential to prevent them from triggering irreversible injuries or even the death of the person (Puerto-Gala et al., 2012)

Awareness

The term consciousness is defined as the state in which an individual has knowledge of himself and his environment (Puerto-Gala et al., 2012). However, in consciousness, the terms arousal and awarness are essential in its definition.

• Arousal: refers to the level of alertness as “being aware” and is responsible for maintaining the ability to be awake and regulate the sleep-wake rhythm (Más-Sesé et al., 2015).
• Awareness: refers to the level of alertness as “being aware” and refers to the ability we have to detect stimuli from the environment and be aware of them and ourselves (Más-Sesé et al., 2015).

When we refer to the alteration of consciousness, we can refer both to the level of activation or vigilance and to the capacity that it presents to interact with the internal.

Therefore, an individual can present a level alteration and present a state of drowsiness, stupor or coma or present an alteration of content presenting a disorientation, with or without delusional ideas (De Castro, 2008).

It was not until approximately the middle of the 20th century that precise descriptions of alterations in consciousness were found beyond Ronsenblath's first descriptions in 1899. It is in the 1940s that multiple references to these states begin to appear with the discovery of the structures of the formation. reticular brainstem (Más-Sesé et al., 2015).

Thus, the role of the RAAS (ascending activating reticular system) in the regulation of alert levels was highlighted. The ability to stay awake will depend on the correct functioning of the structures that make up this system (De Castro, 2008).

The ability of human beings to think, perceive, respond to stimuli, is due to the functioning of the cerebral cortex, however, it will not show an efficient execution if the participation of other structures and without the maintenance of a state of proper alert. When we are sleeping, it is necessary for the RAAS to activate the cortex to wake us up (Hodelín-Tablada, 2002).

Any injury to the structures that make it up will lead to a decrease or loss of the level of consciousness (Castro, 2008). Consciousness is impossible if the SRRA is seriously injured or damaged (Hodelín-Tablada, 2002).

States of decreased consciousness

The absence of response is not always comparable to a total loss of consciousness. For example, babies with botulism do not present any type of response to stimulation, but are nevertheless on alert (Puerto-Gala et al., 2012).

Therefore, the consciousness or the level of activation can be represented in a continuum, from a mild state to a severe state of total absence of response. Thus, we can distinguish intermediate states between the waking state (alert) and the state of total absence of response (coma) (Puerto-Gala et al., 2012).

• Confusion: the individual is not able to think clearly and quickly. Responds to simple verbal commands, but shows difficulty with complex ones.
• Drowsiness: the patient is asleep, but can be awakened without difficulty to sensory or sensitive stimuli and presents an adequate response to verbal commands, both simple and complex.
• Clouding: responds to simple verbal commands and painful stimuli, but there is no adequate response to complex verbal commands.
• Stupor: wakes up only with very intense and persistent stimuli and verbal responses are slow or nil; the patient makes some effort to avoid painful stimuli.
• Coma: represents the maximum degree of alteration of the level of consciousness, and can vary in severity from superficial (there is only a response to deep painful stimuli with movement of the limbs) to deep (there is no response to painful stimuli or presence of any kind of reflection).
• Brain death: irreversible loss of all brain functions and inability to maintain autonomous breathing.

Coma

The term coma is used to define a state of decreased level of consciousness characterized by the absence of responses to external stimuli.

Normally, the individual presents in a state with their eyes closed, without signs of voluntary behavior or responses to orders or any type of stimulation (León-Carrión, Domínguez-roldan, & Domínguez-morales, 2001).

Causes

Coma, based on its definition, is caused by a structural or functional (metabolic) dysfunction of the ascending activating reticular system, but it can also be the consequence of diffuse cortico-subcortical damage (De Castro, 2008).

Therefore, in the etiology of coma, numerous alterations can be distinguished that will give rise to the suffering of this:

Among the structural injuries we can find cerebral hemorrhages, cerebral infarction, subdural and epidural hematomas, brain tumors, infectious and demilinizing processes (Puerto-Gala et al., 2012).

On the other hand, metabolic toxic alterations can also occur: Endogenous intoxication (liver, kidney, adrenal failure, hypercapnia, pancreatitis, hyperglycemia or hyperrosmolar).

• Exogenous intoxication (sedatives, barbiturates, amphetamines, alcohol, MAO inhibitors, antiepileptics, opioids, cocaine, methanol, ethylene glycol, neuroleptics, etc.).
• Metabolic deficit (bronchopneumopathies, CO poisoning, shock, cardiovascular diseases, Wernicke, vitamin B6 and B12 deficiency and folic acid).
• Hydroelectrolyte changes and acid-base balance).
• Temperature disorders.
• Epilepsy (Puerto-Gala et al., 2012).

Thus, rstos factors will cause a comatose situation when they affect large areas of the diencephalon and brainstem, and / or the cerebral hemispheres. There is evidence that the most frequent causes of coma are: diffuse axonal damage, hypoxia and secondary lesions that will affect the brain stem (León-Carrión, Domínguez-roldan, & Domínguez-morales, 2001).

Evaluation of coma

When an individual presents to a hospital emergency service with a total absence of responses and without being fully conscious, before determining the degree of affectation and the type of alteration of consciousness that they suffer, it is essential to control the physical conditions that may pose a risk vital for the life of the person (De Castro, 2008).

Faced with a situation of lack of consciousness, the collection of information from people close to the affected individual will be essential: information about associated diseases, previous head injuries, time course of the alteration of consciousness, initial manifestations and place, drug consumption, exposures to toxins, etc (Puerto-Gala et al., 2012).

In addition, a general examination of the individual of physical variables will be performed: blood pressure (BP), rhythm and heart rate (HR) and respiratory, temperature, blood glucose, neck and skull palpitations and meningeal signs (Puerto-Gala et al., 2012).

Once the conditions that require immediate treatment have been ruled out and the pathologies that pose a vital risk to the patient have been controlled, the neurological assessment is performed (De Castro, 2008). The neurological assessment will explore: the level of consciousness, the respiratory pattern, the brainstem reflexes, the eye movements and the motor responses (Puerto-Gala et al., 2012).

Among the instruments used to assess the depth of coma states, the Glasgow Coma Scale (GCS) is the most accepted instrument for this type of assessment (León-Carrión, Domínguez-roldan, & Domínguez-morales, 2001).

This scale uses three categories of evaluation: ocular opening (spontaneous, verbal command, pain, no response), best motor response (obeys verbal commands, locates pain, withdrawal, abnormal flexion, prone-extension and no response) and better verbal response (oriented response, disoriented response, inappropriate words, incomprehensible sounds, no response). Therefore, the score that an individual can obtain on the scale ranges between 3 and 15 points (León-Carrión, Domínguez-roldan, & Domínguez-morales, 2001).

Getting a low score on the GCS will be indicative of the depth of the coma. A score lower than 9 is indicative of severe brain damage; a score between 3 and 5 is indicative of very deep brain damage and the existence of a deep coma (León-Carrión, Domínguez-roldan, & Domínguez-morales, 2001).

Prognosis and treatment

When the individual is in the ICU (intensive care unit) the priority is their survival. Medical treatment in the acute phase will include stabilization of the patient, control of pre-existing medical problems and those caused by the situation, prevention of complications. Generally, pharmacological and surgical treatments are used.

The prognosis for the evolution and recovery of patients in a coma is variable. In many cases their survival is threatened by different complications both in the acute phase (infectious processes, metabolic alterations, need for sondes and catheters, etc.) and in subacute phases (epileptic seizures, immobility, etc.) (More- Sesé et al., 2015).

Nursing intervention is essential for the prevention of infections and complications, the management of incontinence and nutrition (Más-Sesé et al., 2015).

In the subacute phase, when the individual cannot get out of the coma, an intensive neurological and neuropsychological intervention will be performed. The actions will be aimed at achieving an emergence from an altered state of consciousness to a higher one, through the use of multisensory stimulation that acts on three areas: somatic, vibratory and vestibular, trying to enhance the perceptual capacity of the patient (Más-Sesé et al., 2015).

Furthermore, the participation of a physiotherapist specialist will be essential for the control of muscle atrophy. Physiotherapy is mainly involved in postural control and maintenance of muscle tone and the osteoarticular system (Más-Sesé et al., 2015).

If the patient manages to emerge from the coma, it is likely that he or she may have significant neurocognitive, behavioral, affective, and social deficits. All of these will require a specialized intervention (León-Carrión, Domínguez-roldan, & Domínguez-morales, 2001).

Conclusions

When severe brain damage occurs involving a process of loss of consciousness, urgent and specialized medical care will be essential to control survival and future complications.

Suffering from a coma situation is a very limiting condition not only for the individual but also for their family members. In most cases, the family will have to receive support, guidance or even psychotherapy to face the situation (Más-Sesé et al., 2015).

Whether the patient evolves favorably or if the coma persists leading to a persistent state, it will be essential that the family works in a coordinated and organized manner with the medical and rehabilitation teams.

References

1. De Castro, P. (2008). Patient with altered consciousness in the emergency room. An. Syst. Sanit. Navar. 2008, 31 (1), 87-97.
2. del Puerto Gala, M., Ochoa Linares, S., Pueyo Val, J., & Cordero Torres, J. (2012). Alteration of the level of consciousness. In SemFYC, Urgencies and Emergencies Manual (pp. 29-44).
3. Hodelín-Tablada, R. (2002). Persistent vegetative state. Paradigm of current discussion on alterations of consciousness. Rev Neurol, 34 (11), 1066-109.
4. León-Carrión, J.; Domínguez-Rondán, JM; Domínguez-Morales, R.;. (2001). Coma and Vegetative State: Medical-legal aspects. Spanish Journal of Neuropsychology, 63-76.
5. Más-Sesé, G., Sanchis-Pellicer, M., Tormo-Micó, E., Vicente-Más, J., Vallalta-Morales, M., Rueda-Gordillo, D.,… Femenia-Pérez, M. (2015). Attention to patients with altered states of consciousness in a long-stay hospital for chronic patients. Rev Neurol, 60 (6), 249-256.