Consciousness is one of the main properties of the brain, which is a complex psychological mechanism. Consciousness allows people to exercise control over their behavior, explain the motives of their actions, interpret current events, and weigh and evaluate their consequences. Consciousness is called upon to reflect the essence of the personality and its inherent characteristic individual features, reflecting the reality surrounding the personality, both emotionally and rationally. Consciousness is characterized by constant activity since people learn about external reality throughout life and form their opinions and ideas about it. From the point of view of physiology, consciousness includes two components: wakefulness, that is, the ability to open the eyes spontaneously, and the content of consciousness, that is, the ability to perceive information coming from the outside world consciously. The work of the cerebral cortex determines the content of consciousness. Wakefulness is provided by the work of the ascending reticular activating system of the brainstem.
A disorder of consciousness involves a complete or partial loss of the ability to concentrate attention, orientation in place, time, one’s personality, and the implementation of other processes that make up the content of consciousness. Disorders of consciousness arise from brain activity disorders caused by injuries and diseases of the central nervous system, intoxication, mental disorders, and somatic diseases. People with a disorder of consciousness may be in a coma, in a vegetative state, or a state of minimal consciousness (Wilson et al., 2016). From both an ethical and a medical point of view, it is necessary to ensure proper care and the availability of rehabilitation for such patients.
Diagnosis
Diagnosis of disorders of consciousness is sophisticated since it can be complicated by the complete lack of reactions in the patient. Diagnosis includes analysis of complaints and anamnesis of the disease, neurological examination, blood test, toxicological analysis, and MRI. Neuroimaging studies have demonstrated functional interactions between autonomic and brain structures involved in higher brain functions, including attention and conscious processes. The interactions between these structures are based on the two-way interaction between the brain and the heart. Heart rate indicators can be reliable for describing the functioning of the autonomic and central nervous systems and a marker of higher brain functions. Autonomic function mediated by the autonomic nervous system, reactivity, and interaction of the autonomic and central nervous systems is considered possible independent indicators of clinical and functional assessment and prognosis in disorders of consciousness (Riganello et al., 2019). Such an analysis is a simple, inexpensive, non-invasive approach; it can provide useful information for the clinical evaluation of patients with disorders of consciousness.
Treatment
Several treatments have been proposed for patients with impaired consciousness, including pharmacological and invasive. However, no single treatment has shown a sustained positive effect on consciousness or functional recovery in a significant group of patients. The basis of modern treatment of disorders of consciousness is medications, but they do not always have proven effectiveness. Classical psychedelics are currently undergoing significant research for various psychiatric disorders (Scott & Carhart-Harris, 2019). Due to their ability to increase the complexity of the brain, they could be a breakthrough in the treatment of disorders of consciousness. However, further research in this area will be hampered by ethical and moral norms. With a deep disorder of consciousness, connection with reality is lost, so psychotherapeutic treatment in such a situation seems unlikely. The relief of acute symptoms is carried out in a hospital under round-the-clock medical supervision. The list of drugs used, doses, and treatment duration depends on individual characteristics and diagnosis.
Most often, disorders of consciousness arise due to traumatic brain injury, especially in the elderly. Some of the most devastating consequences of traumatic brain injury include reduced levels of consciousness or impaired executive function. Pharmacological and rehabilitative therapies are limited; so, deep brain stimulation has been used to treat several conditions, including Parkinson’s disease, essential tremor, and epilepsy (Kundu et al., 2018). Deep brain stimulation offers a means to quickly trigger dormant networks or modulate activity in the right areas of the brain to make it work easier. Large prospective studies in patients with traumatic brain injury targeting specific areas of the brain that have demonstrated the ability to modulate cognition are critically important safely. Although many ethical issues must be considered when treating patients with disorders of consciousness, deep brain stimulation combined with intensive behavioral therapy may offer devastating traumatic brain injury patients a means to restore cognitive function and a meaningful quality of life.
Recovery
Monitoring the recovery of behavior in patients who developed impaired consciousness after severe traumatic brain injury is important for diagnostic and prognostic assessment. The degree of behavioral recovery in patients with traumatic consciousness disorders after discharge from the emergency department is not well understood and increases the risk of overly pessimistic outcome predictions. About 20 percent of patients recovered all six target behaviors within six weeks (Giacino et al., 2020). Patients with preserved language function recover most behaviors and have the least disability. Restoration of the high-level behavior underlying functional independence is common in patients with long-term traumatic consciousness disorder.
In recent years, significant progress has been made in identifying, predicting, and promoting recovery of consciousness in patients with mental disorders. New evidence suggests that latent consciousness is present in 15-20% of patients with impaired consciousness and may predict functional recovery one year after injury (Edlow et al., 2021). Some patients with impaired consciousness can regain consciousness, communication, and functional independence. Recovery of consciousness can occur anytime, from acute to subacute and chronic periods. Unfortunately, there are no reliable predictive tools at every stage of recovery. It is unlikely that any single therapy will be effective in all patients; instead, clinicians support a mechanistic approach to therapy selection that involves an individual assessment of each patient’s potential for a therapeutic response.
Ethical Issues
Patients with disorders of consciousness are at risk for misdiagnosis and inappropriate medical treatment, which can negatively impact their access to ongoing care, rehabilitation, and pain and symptom management. The dismissive attitude of society towards patients with a disorder of consciousness is a violation of the bioethical principle of rejection of patients. In the ethical analysis of a disorder of consciousness, awareness and ignorance should be taken into account. Ignorance is ethically significant because it has the critical characteristics of awareness. If consciousness is considered ethically relevant for assessing a patient with a disorder of consciousness, and the unconscious is the result of consciousness, then the unconscious is also ethically relevant.
Ever since disorders of consciousness appeared in the clinical setting, clinicians, scientists, theologians, and ethicists have begun to question what it means to be in a state of profoundly disturbed consciousness. In severe cases, it becomes very difficult to assess the patient’s quality of life, and it is also impossible to assess the level of pain. This kind of controversy is mainly related to how people feel about indefinite survival in such disorders.
The dissociation between personal preferences and general opinions underlies differences in views on disability and implies that healthy people who are not in direct contact with this patient population may have distorted ideas about what life is like in these severely limited situations. However, with the help of functional neuroimaging and electrophysiology, the gray areas of the unconscious are beginning to clear up (Fins & Bernat, 2018). These developments are promising for identifying and assessing the preserved consciousness in these conditions; they should be used in clinical practice. In terms of treatment planning, including pain management and end-of-life decision-making, patients with impaired consciousness are now being offered to express their preferences through brain-computer interfaces. A common ethical framework needs to be established to guide clinicians and caregivers regarding clinical outcomes, prognosis, and treatment.
Conclusion
Disorders of consciousness represent a complex area of ​​neurological and psychological research. Diagnosis is complicated by the possible lack of reactions in the patient, treatment – by the lack of a single proven effective agent. The percentage of recovery after severe cases of such disorders also remains low. In addition, the treatment of disorders of consciousness is complicated by ethical issues. In severe cases, the decision for the patient must be made by a third party unaware of the patient’s real condition. Further study of effective methods, means of communication with patients, and assessment methods are necessary to provide quality care.
References
Edlow, B. L., Claassen, J., Schiff, N. D., & Greer, D. M. (2021). Recovery from disorders of consciousness: mechanisms, prognosis and emerging therapies.Nature Reviews Neurology, 17(3), 135-156.
Fins, J. J., & Bernat, J. L. (2018). Ethical, palliative, and policy considerations in disorders of consciousness. Neurology, 91(10), 471-475.
Giacino, J. T., Sherer, M., Christoforou, A., Maurer-Karattup, P., Hammond, F. M., Long, D., & Bagiella, E. (2020). Behavioral recovery and early decision making in patients with prolonged disturbance in consciousness after traumatic brain injury. Journal of neurotrauma, 37(2), 357-365.
Kundu, B., Brock, A. A., Englot, D. J., Butson, C. R., & Rolston, J. D. (2018). Deep brain stimulation for the treatment of disorders of consciousness and cognition in traumatic brain injury patients: a review. Neurosurgical focus, 45(2), 1-8. Web.
Riganello, F., Larroque, S. K., Di Perri, C., Prada, V., Sannita, W. G., & Laureys, S. (2019). Measures of CNS-autonomic interaction and responsiveness in disorder of consciousness. Frontiers in neuroscience, 13(1), 530.
Scott, G., & Carhart-Harris, R. L. (2019). Psychedelics as a treatment for disorders of consciousness. Neuroscience of consciousness, 2019(1), 1-8.
Wilson, B. A., Dhamapurkar, S., & Rose, A. (2016). Assessment and treatment of people with a disorder of consciousness: An account of some recent studies. Psychology & Neuroscience, 9(2), 221.