Being a Prolonged Disorder of Consciousness (PDOC) expert
Date published:
Date Last updated:
February 9, 2025
I often appear as an expert witness in the UK Court of Protection, giving evidence and my opinion on the best interests of someone with a prolonged disorder of consciousness (PDOC). Generally, this is when continuing active medical treatment is considered, and their best interests are in doubt or dispute. I will discuss my role at a meeting in Manchester on 6 February 2025. I will explore and discuss my thoughts in this post, as this makes me reflect on my role.
An expert must provide the Court with relevant, accurate information. Areas of uncertainty should be identified, and all opinions and conclusions should be justified using the evidence. I shall discuss five aspects of interest:
- clinical variability, which leads to the invalidity of categorical distinctions, and how these impact the expert questioned by non-experts
- issues around the experience of pain, pleasure, and feelings of familiarity
- philosophical issues around what are consciousness and awareness and who is the person we are discussing
- strongly expressed matters of belief when seeing the person before the court appearance
- uncertainty, especially when facing a barrister (lawyer) who wants absolute certainty
Table of Contents
Introduction
I started being an expert in 1995. Then, one referred to the vegetative state and, later, the minimally conscious state. The term, state, implies something fixed and separate from other states. As cases were disputed, decisions were made concentrating on whether the person was completely unaware or had some minimal awareness, and two matters became apparent. Patients vary for many reasons, including diurnal variation, intercurrent illness, varying levels of drug intake, etc. Consequently, it also became evident that there are no categorical states and no criterion or a limited number of valid indicators of awareness. My experience in one case made me write a paper on this topic.
At the same time, national guidelines were developed in the UK and many other countries. These were inevitably based on consensus and heavily influenced by local healthcare practices and culture and the broader societal culture. Moreover, research, experience, legal and healthcare frameworks rapidly changed, and guidelines were inevitably dated and inappropriate in some areas. Expert practice inevitably deviated from guidelines, distressing some families and lawyers who considered them immutable rules, not guidance.
Matters are further complicated by separate guidance developed by the Royal College of Physicians and British Medical Association to cover Clinically-assisted nutrition and hydration (CANH) and adults who lack the capacity to consent. Guidance for decision-making in England and Wales. This guidance applies to people with a prolonged disorder of consciousness, but it also applies to people who are not unconscious. In contrast, the National Guidelines on PDOC cover all treatment decisions, such as continuing renal dialysis or ventilation, issues not considered in the BMA guidance.
Clinical variability in PDOC.
Variability is present in all living organisms. It allows adaptation and underlies evolution. I have discussed homeostasis as a crucial part of the General Theory of Rehabilitation. Homeostatic mechanisms never achieve perfect unvarying control over any physiological or other parameter. If something does not vary, it is not alive. Variability is present in all aspects, such as biochemical, physiological, psychological, and structural measures.
It is, therefore, no surprise that people with a prolonged disorder of consciousness show variability that is present at all time scales and levels, from blood biochemistry to complexity of reaction to pain.
Consequently, one cannot categorise a person into a state based on a few specific criteria. A person will naturally move from one state to another. They might be assessed on one day and fall within one category. Natural variation will cause some variables to change, so, on the following assessment, the person might fall into another category. This phenomenon leads to the widely repeated but mistaken idea that 40% of diagnoses are incorrect; I have published a detailed analysis of this error.
A second reason for variability in diagnosing a categorical state relates to test sensitivity and specificity. Any indicator used to determine a state will be subject to false positive and negative results; someone in the state may not be identified, and someone identified as being in a state might not be. This phenomenon cannot be avoided.
Relatives always recognised variability, even though clinicians paid little attention to it. For example, families often report how the patient seems different, usually more relaxed when they are present, or they notice a slight change that they interpret as presaging further recovery. Moreover, spontaneous movements are frequently interpreted as attempts at communication, responses to requests, etc. Rather than accepting the validity of the observation and correcting the interpretation, clinicians usually dismissed the reports as wishful thinking.
Some observed variation is associated with external changes and can be quite marked. A patient I saw once was almost entirely unreactive whenever seen, yet when taken to a music therapy session, they would wake up and show pleasure and movement in time with the music. In her room without music, she scarcely altered even when her family visited her.
There is always a diurnal variation, usually sleeping at night and awake with open eyes for some of the day. This has been well-known from the beginning but has been overlooked. Another identifiable cause is intercurrent illness. Most people with a prolonged disorder of consciousness are less reactive when ill, for example, with influenza or a urinary tract infection. Other causes include changes in the level of sedative drugs, for instance, after a dose of codeine for pain or disturbed sleep when someone else is noisy at night.
However, most variation has no evident explanation. Events occur randomly; as with all random events, they cluster, and it is easy to think a pattern underlies variability.
When giving evidence in court, saying, “That’s just natural variability”, often sounds weak and unconvincing unless one provides examples such as the changes associated with sleep and everyone’s typical experience of “having an off day”.
In the early stages after acute onset, routine weekly assessment using the Wessex Head Injury Matrix may help. For example, natural variability may hide slow improvement, but plotting scores against time may reveal trends underlying variability; the minimum total number of behaviours seen or the highest scoring item may slowly but consistently increase.
Does a person with PDOC experience pain?
Clinicians, families, and lawyers are naturally and correctly concerned about pain in an unconscious person. On the one hand, we follow the mantra, “If it looks like pain, treat it as pain,” yet experts are also likely to say that “they cannot feel pain because they are unconscious.”
In a blog post published on 30 July 2021, I concluded that people who were unaware were unlikely to experience pain because cortical pain networks overlapped with networks establishing awareness. Over the last year, I have changed my mind so that when I see a person who shows pain behaviours when undergoing an activity likely to cause pain, I conclude they are probably experiencing pain at some level. Two things changed my opinion.
In May 2023, I saw a person with a Prolonged Disorder of Consciousness. and I reviewed her in 2024 when she was showing many more pain behaviours, requiring more opiates to control them. They included noises, and the care staff were distressed by them. The family disputed the decision that continuing gastrostomy feeding and hydration was no longer in her best interests. The case went to the Court of Protection, where I argued that pain was an additional consideration.
The initial judgement supported the clinical decision. The family appealed, and my change of opinion over the interval was one ground for the appeal. The Appeal Court judges dismissed the appeal on all the grounds proposed; they considered my change of mind acceptable.
After seeing the patient the second time, I researched the literature and came across a paper by a neurosurgeon written in 1991, Michael McQuillen asked, “Can people who are unconscious or in the “vegetative state” perceive pain?”. His answer was, “Although by definition the unconscious patient cannot tell you that he perceives pain, available data suggest that he may; therefore, you cannot know that he doesn’t.”
Further research I undertook supported this, and, on balance, I consider the unconscious patient who exhibits pain behaviours when associated with a stimulus that may cause pain does experience pain.
In this context, pain refers to an aversive, unpleasant feeling. It is not necessarily the more complex and nuanced experience that a fully conscious person has because their experience of pain includes an understanding of many associated aspects, such as an appreciation of the significance of the sensation and what might happen.
The pain in an unconscious person is likely only to be experienced ‘in the moment’. It is probably forgotten immediately after because hippocampi are usually damaged by whatever process leads to the person being unconscious. They also will not anticipate pain. Third, they do not show behaviours that might stop or reduce the pain, illustrating a distinction between the basic aversive feeling and the complex, cortically-mediated experience most people have. However, the aversive feeling is still unpleasant.
This analysis suggests pleasure could be experienced. While this may be true, it seems less likely. Pain is evolutionarily basic, with nociceptors being present in all animals. In contrast, pleasure has no dedicated specific receptors and is an experience dependent on more complex processing of stimuli. As cortical processing is severely disrupted in people with a prolonged disorder of consciousness, pleasure is probably minimal or absent.
However, families and carers may also notice that the person seems more relaxed when they are present. Moreover, patients are often more tense when in a noisy, cold, or otherwise stressful environment. This subtle variation is difficult to substantiate, but the person likely feels less stressed by familiar sounds, smells, and touch. I do not know if they experienced anything else at the same time.
In conclusion, a person with a prolonged disorder of consciousness may experience pain, especially from the many care procedures they need. But who is it that experiences the pain
Who is the person experiencing pain?
Who experiences the pain, and what is the experience like? This is the obvious question; answering it is essentially a philosophical matter.
The nature of the aversive feeling cannot be specified; the person cannot describe it, and even if they could, we could only relate to our experience and what we feel. There is no way to know the sensations and feelings of another person.
The experience will be unpleasant because the fundamental goal of all nociception is to ensure the animal notices and reacts to harm, and an unpleasant feeling achieves that. The lack of any meaningful planned actions to stop or reduce the pain shows that minimal or no cognitive analytic processing occurs. Therefore, the experience is unlikely to include fear or anticipation of future pain as both depend on cognitive processing.
The lack of cognitive processing and impaired memory also means there is no ongoing narrative personality to experience the pain; I have discussed the concept of the person and narrative identity. Nonetheless, the person is experiencing the pain. This person is not the once conscious person. The person is embodied; the word encompasses the body and all processes, including cognitive processes. The unconscious person is an extreme example of how the person alters with time, especially after significant ‘life-changing’ events. Lily Johnson has undertaken further exploration of the person in rehabilitation.
Thus, the person experiencing the pain is a continuation of the person from before the injury, just as you are a continuation of the person who went to sleep last night. You may have altered slightly after a dream or other event, but you are the same in almost every way. If you have a traumatic brain injury or a leg amputation, you will change more. The person with a prolonged disorder of consciousness has altered so dramatically they may no longer recall their earlier narrative identity, so they are genuinely naïve. They remain human but have minimal self-awareness of their past or future.
The person's personal beliefs
A small proportion of families disagree with any suggested limits on medical actions to prolong life or any proposed withdrawal of an existing treatment. This usually arises from the deeply held beliefs of one or more family members. This is the main reason behind most disagreements coming to Court and must be considered.
What I wrote above reflects my belief and how I interpret everything I have read and seen clinically and in my day-to-day life (experienced). I base my conclusions on the evidence I have considered, starting as an agnostic.
A belief is “an acceptance that something exists or is true, especially one without proof”, and “something one accepts as true or real; a firmly held opinion”. [Oxford English Dictionary] Belief refers to “the attitude we have, roughly, whenever we take something to be the case or regard it as true.” and “Forming beliefs is thus one of the most basic and important features of the mind, and the concept of belief plays a crucial role in both philosophy of mind and epistemology.” [Stanford Encyclopedia of Philosophy.]
Beliefs emerge, develop, and evolve in response to many factors, including experience, the expressed beliefs of other people, books (often religious), and others. Belief is personal and frequently guides actions and decisions. It may be based on sound, externally verifiable evidence, based on no evidence when evidence is lacking or impossible, or held despite proof that it is incorrect.
Some beliefs will be associated with success in predicting the future or deciding on action, and others will not.
Most religions include a belief in an afterlife, usually better than an earthly life. Most Holy Books, such as the Bible, can be interpreted in many ways. None give specific advice on medical treatment for people with a prolonged disorder of consciousness. Religious organisations such as the Catholic Church include people with opposing points of view.
Their beliefs will lead a few families to disagree with any suggested limits on medical actions to prolong life or any proposed withdrawal of an existing treatment. This disagreement may be expressed as, for example, “The patient should be allowed a natural death” or “Only God can decide when someone may die.” Usually, the family put this forward as a general matter of religious faith – it is what we believe – rather than providing evidence that the patient had this view. A few people feel withdrawing treatment is wrong, not calling on any religion.
In such circumstances, independent mediation is unlikely to help because there is no intermediate position. Sometimes, disagreements arise from misunderstandings or a lack of understanding of medical information, but only an expert clinician can remedy that; a trained mediator who is not an expert clinician will not alter the disagreement. In most instances, the Court of Protection must decide. The legal process is undoubtedly stressful for and distressing to the judges, barristers, other legal personnel involved, the families and clinical teams involved, and the experts. However, they are the least involved and typically least stressed.
One particular issue interests me: what is a natural death when someone is being kept alive by artificial means? In addition to clinically assisted nutrition and hydration, the person may have a tracheostomy, drugs to control blood pressure and pulse rate, anticoagulants, and much specialist care. All these are unnatural.
Sometimes, families say that “God will decide when the person will die”. However, I wonder how God will be able to cause a natural death if doctors and nurses interfere to maintain ventilation and blood pressure. God presumably must act through other humans, who may decide it is no longer correct to start or continue treatment.
When families disagree with a clinical decision, lawyers, judges, or medical experts may discuss many other issues during the case:
- Caring for someone who appears to be suffering without benefit causes moral injury to care staff.
- Seeing a close friend or relative in pain or just existing without any social interaction may distress other people, not least by preventing natural grieving.
- Some patients will be at risk of a sudden, unpleasant, unplanned death, with the patient or family experiencing avoidable pain or distress.
- Not infrequently, the patient has been someone devoted to helping and considering the well-being of others and intrinsically valuing others above themselves. Rarely is evidence provided that the patient personally held the views ascribed to them.
No one doubts the family holds the beliefs, and usually, though not always, the patient also based their life on similar religious beliefs. However, there is rarely evidence that the person would interpret their religious beliefs as the family does and decide to continue active treatment when there is no prospect of significant change. Indeed, the available evidence often suggests the person prioritised the well-being of others over their own.
The judge and all other people in court always acknowledge and respect the family’s beliefs and distress, and it must be exceptionally challenging for the judge to reach and justify a conclusion in the face of the family’s commitment.
Uncertainty is the unifying feature.
The common thread underlying the first four aspects of being an expert witness is acknowledging and accepting uncertainty:
- Variability inevitably generates doubt. Lack of certainty extends through all science (e.g. Heisenberg’s uncertainty principle.). This is well recognised: “Scientific knowledge is a particular kind of knowledge with its own sources, justifications, ways of dealing with uncertainties, and agreed-on levels of certainty.”
- Another person’s experience is always unknowable.
- Consciousness, awareness, and personhood are philosophical, scientific, and clinical phenomena arising within an incredibly complex system (the human body), and complexity inevitably engenders uncertainty.
- Beliefs, especially religious beliefs, are one method of responding to the discomfort engendered by acknowledged uncertainty.
The solution is for the experts to acknowledge they are uncertain. Tempting though it may be, I avoid saying anything is absolute. The person questioning may imply that experts ought to be sure; in fact, experts should realise more than most people the complexity of most issues and that absolute certainty is impossible.
However, an expert will also be able to qualify their uncertainty. It is unhelpful to say, for example, when asked about late recovery from a prolonged disorder of consciousness, “Well, sometimes people can recover years later.” All parties interpret vague statements differently: for example, what constitutes recovery or later?
An expert should use words carefully, explaining, for example, that it is best to consider change, not recovery, pointing out that change occurs in both directions. A better answer would be, “Most people slowly get worse, but rarely, perhaps once in 100 similar cases, a person may improve sufficiently in three years to be awake for several hours a day, recognise friends consistently, and react to one item commands appropriately once a week, but remain unable to do anything.” This gives an impression of what might happen.
In the same vein, one should avoid saying that family observations are untrue; instead, emphasise the difference in interpretation and that neither the family nor the expert can be 100% sure their interpretation is correct.
What is an (PDOC) expert?
An expert is “a person who is very knowledgeable about or skilful in a particular area.” [OED, Oxford English Dictionary]
Who determines if someone is an expert, and how. There are agencies and organisations in medico-legal practice that say they ensure expertise. Still, it is unclear how they achieve this, and I have encountered experts who, in my opinion, lacked expertise. Examinations to establish that the person’s knowledge and skill is in the top five centiles are not available.
Furthermore, one must question whether medical expertise is solely a matter of knowledge and skill. An expert at some surgical or medical procedure, such as operating or removing clots from arteries, may have limited expertise outside a particular skill.
Michael Caley and colleagues took a systems perspective on expertise in taxonomy in marine science. Their approach reveals many factors outside knowledge and skills related to expertise; Figure 1 in their article illustrates this. They encompass academic activities such as collaborating with others and mentoring, breadth of experience, and publications.
James Shanteau and colleagues review the empirical assessment of expertise, pointing out the strengths and weaknesses of different approaches before proposing their own Cochran-Weiss-Shanteau approach. They hypothesise that an expert can discriminate between similar cases when others cannot and that they are consistent in their performance.
Their initial investigations suggest their approach may be valid. They also point out that teams undertake many activities, and this approach could be used to evaluate team expertise.
Last, Michael Croce evaluates what it takes to be an expert from a philosophical perspective. He refers to “a cognitive expert” and argues they are defined by their contribution “to the epistemic progress of their discipline”. This approach restricts itself to knowledge and skills.
This brief review demonstrates that the question, what is an expert, does not have any agreed answer.
My PDOC expertise
Considering my expertise, I think an expert will have the following characteristics.
First, they should consider a person’s situation holistically. In particular, I place the person now in the context of their life, both the past and, often overlooked, future. Any decision on someone’s best interests must consider both the prognosis for the condition and the prognosis for the social and physical context.
A second aspect of holism is maintaining a focus on the main issue and not overvaluing an aspect of the situation that is irrelevant to the decision.
Second, an expert should know better than most non-experts what they do not know, what is unknown but might be discovered, and what is unknowable.
Last, an expert in prolonged disorders of consciousness must manage uncertainty by admitting and quantifying it and giving appropriate weight to its overall relevance when deciding. For example, uncertainty about prognosis may be irrelevant if the best possible outcome is still significantly below a person’s threshold for continuing treatment.
Conclusion
An expert is someone who knows and admits what they do not know. An expert giving evidence about someone with a prolonged disorder of consciousness and their condition and prognosis should always emphasise that they recognise their limitations when answering any specific question. Someone who gives categorical and definite answers to questions about any complex matter is unlikely to be an expert. When asked whether it is in a person’s best interests to start or continue an active medical treatment, it is best always to clarify any ambiguous terms that can be interpreted differently and be as specific as possible while also giving the upper and lower limits of your uncertainty, using practical examples and analogies to illustrate your points, and acknowledging other beliefs and interpretations. Remember, as an expert, your answers are not wholly correct; they give the most likely answer with an estimate of the extent of residual doubt.
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