Neuroethics

Stuck in Modern Limbo: How can we help the (un)conscious patients?

Milena Malcharek


Abstract

Numerous disputes surrounding the case of Vincent Lambert have shown us that the treatment of unresponsive patients is still a highly controversial topic. Disorders of consciousness are also yet to be properly understood, which can potentially contribute to a wrong diagnosis – and for the people concerned that may truly be a matter of life and death. However, recent advances in neuroimaging can provide us with a solution to the problem in question by not only allowing more accurate differentiation between related conditions, but also enabling us to communicate with some of the seemingly unconscious patients. Nonetheless, ethical concerns linked to the use of these techniques, including lack of a person’s informed consent, should also be taken into account if neuroimaging becomes a common diagnostic tool in the assessment of non–communicating patients.

 

The controversial case of Vincent Lambert: does ‘unresponsive’ mean ‘unconscious’? 

The recent verdict of the French Supreme Appeals Court seems to have been a final ruling on the case of Vincent Lambert. The fate of this mostly unconscious man, who also suffered from quadriplegia, not only caused a serious disagreement between his family members and made them engage in a year-long legal struggle, but also electrified people all over the world and prompted prominent figures – including Pope Francis and France’s former president François Hollande – to take a stance on it. Although Lambert’s life support was eventually withdrawn on July 2nd, 2019, the controversy surrounding this decision shows that the treatment of unresponsive patients is a debatable issue, and that we have yet to reach a consensus on this delicate matter [1].

 

Differential diagnosis of disorders of consciousness and other related conditions

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Vincent Lambert had initially been assessed as ‘minimally conscious’, but afterwards his diagnosis was changed to ‘permanent vegetative state’ [2]. One could ask, however, about the difference between these two disorders and about their relation to other similar conditions – such as coma, locked–in syndrome, or brain death. Brain death – a complete and irreversible loss of brain function – implies the greatest extent of damage, and its defining features include electrocerebral silence (i.e. “flat” EEG – meaning no electrical activity takes place in the brain) and cessation of breathing (apnea). Contrarily, in locked–in patients, despite their being (almost) entirely paralyzed, cognition remains intact. The remaining three disorders are, unfortunately, slightly more difficult to distinguish. In order to do so, today’s neurologists usually rely on a battery of tests, assessing the person’s arousal (presence of sleep–wake cycles) and awareness (ability to perceive and process information). Both of these components of consciousness are absent in comatose patients, arousal being nevertheless preserved in vegetative (unaware) and minimally conscious (aware occasionally or to a limited extent) ones [3].

Although the bedside assessment, based on the evaluation of an individual’s responses to external stimuli, is still the most widespread diagnostic tool, neuroimaging techniques (such as PET or fMRI) have recently been introduced to refine the quality of care and treatment given to patients with disorders of consciousness. Thanks to this innovation, pioneered by Adrian Owen and Steven Laureys, it has become possible to measure cerebral metabolism and identify the most active brain areas – which has allowed for more accurate differentiation between aforementioned disorders. Moreover, Dr. Owen’s team, relying on a newly established experimental paradigm, not only managed to detect clear signs of consciousness in approximately 20% of seemingly unaware patients, but also made contact with them [4]. Such a feat was possible thanks to the careful use of an fMRI scanner, detecting blood flow changes in the brains of patients who were asked various questions – and who had previously been instructed to imagine playing tennis for ‘yes’ and walking around their home for ‘no’. Consequently, the answers of those tested could be immediately seen on a computer screen, as the mental tasks described result in the activation of, respectively, supplementary motor area or parahippocampal gyrus, posterior parietal cortex, and lateral premotor cortex [5] [6].

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Ethical aspects of neuroimaging in patients with disorders of consciousness

The research described seems unequivocally beneficial, potentially improving the patients’ everyday life as well as providing them with a means to communicate with the outside world. However, there are several ethical concerns linked to it – such as the issue of participants’ informed consent. Today’s medical sciences usually require that the experimental subjects are fully aware of the purpose of the study and its associated risks and that they make an autonomous decision on whether to participate in a trial. This can be waived only in a few cases, one of them being a direct danger to the patient’s life [7]. Thus, scanning the brains of unresponsive people can be seen as a violation of the principle discussed, especially given that the very procedure might offer no straightforward benefits to the subjects themselves. What is more, although fMRI and PET appear to be relatively ‘safe’, some patients, recovered from vegetative state, recall their extreme distress following their having been put into the dark, claustrophobic inside of a scanner – distress they were unable to signal [8]. All that, coupled with the elevated cost of each neuroimaging study, prompts a reflection that such research should be conducted with caution, to avoid medically unjustified expenditure, and to assure the respect of patients’ rights.

Scientific discoveries may, however, help us tackle some controversial cases concerning unresponsive (but not necessarily unconscious) people. Nowadays, it is usually up to a close relative (or consort) to decide whether life support of such a person should be ended. Nevertheless, when family members cannot agree on the discontinuation of mechanical ventilation or the withdrawal of a feeding tube, as in the famous case of Terri Schiavo, the solution can require intervention from high–ranking state officials. And although it seems that such judicial fights could be prevented if ‘advance directives’ (or ‘living wills’) became more widespread and legally binding, they turn out not to be the best of options. Studies show that the majority of locked–in patients, appallingly often misdiagnosed as vegetative, are quite satisfied with their lives and do not wish to die [9] [10]. That is in sharp contrast to the public perception of their condition, likely to influence the content of the aforementioned documents. Therefore, too much trust put in an individual’s antecedent judgment may result in their being legally refused appropriate care and treatment – even against their actual will. The use of neuroimaging techniques could help the doctors to determine the person’s actual level of consciousness, and maybe even to ask them whether they want the administration of life–sustaining therapy to continue. Moreover, the patient might be consulted about the choice of care facility or the most efficient pain medication.

  In conclusion, it appears that despite the disorders of consciousness still being poorly understood, we begin to unravel their secrets. This gradually contributes to the change of attitude towards the people affected, as we discover that they may be far more aware than they seem. Thanks to advances in neuroimaging, they can also finally regain control over their lives. And although the present–day technologies are far from perfect, their potential benefits eventually outweigh the risks involved. Most importantly, they seem to be the best way to improve the lives of unconscious patients – and to pull them out of limbo.

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References

[1] Reilhac, Gilbert. (11/07/2019). French quadriplegic at center of life support battle dies. Reuters. https://www.reuters.com/article/us-france-life-lambert/french-quadriplegic-at-center-of-life-support-battle-dies-idUSKCN1U60WF. Retrieved: 12/07/2019.

[6] Monti, Martin et al. (18/02/2010). Willful modulation of brain activity in disorders of consciousness. The New England Journal of Medicine. 362:579-589. Retrieved: 12/07/2019.

[2] Béguin, François and Clavreul, Laetitia. (05/05/2014). Pas d'espoir d'amélioration pour Vincent Lambert d'après les experts. Le Monde. https://www.lemonde.fr/sante/article/2014/05/05/pas-d-espoir-d-amelioration-pour-vincent-lambert-d-apres-les-experts_4411913_1651302.html. Retrieved: 12/07/2019.

[7] Bauer, Philippe and Tate, Judith. (03/07/2018). Waiver of Informed Consent in Emergency Situations. Society of Critical Care Medicine. https://www.sccm.org/Communications/Critical-Connections/Archives/2018/Waiver-of-Informed-Consent-in-Emergency-Situations. Retrieved: 12/07/2019.

[3] Laureys, Steven et al. (09/2004). Brain function in coma, vegetative state, and related disorders. Lancet Neurology. 3:537-546. Retrieved: 12/07/2019.

[8] Owen, Adrian. (20/06/2017). Into the Gray Zone. Back from the Dead. 218-219. Retrieved: 12/07/2019.

[4] Costandi, Mo. (02/09/2011). Detecting covert consciousness in the vegetative state. The Guardian. https://www.theguardian.com/science/neurophilosophy/2011/sep/02/detecting-covert-consciousness-vegetative-state. Retrieved: 12/07/2019.

[9] Gallo, Ugo and Fontanarosa, Phil. (01/11/1989). Locked-in syndrome: report of a case. The American Journal of Emergency Medicine. 7:581–583. Retrieved: 12/07/2019.

[5] Owen, Adrian et al. (08/09/2006). Detecting awareness in the vegetative state. Science. 313:1402. Retrieved: 12/07/2019.

[10] Laureys, Steven et al. (02/2005). The locked-in syndrome: what is it like to be conscious but paralyzed and voiceless?. Progress in Brain Research. 150:495–511. Retrieved: 12/07/2019.



    Milena Malcharek

    Milena Malcharek


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