Mind-Brain-Law Reading Group – 28 Nov 2014
Deep Brain Stimulation
Paper for Discussion
Deep brain stimulation (DBS) has been used for over a decade to treat movement disorders. It is now being used experimentally for other conditions, such as Tourette syndrome and depression. Like any biological intervention, it can have unintended effects. However, given the nature of DBS, its unintended effects can be more unpredictable and more pervasive than simple side effects like headache, nausea, and drowsiness. Sometimes they can go as far as changing aspects of personality. The group discussed what purposes may be appropriate for DBS and considered two case studies. One involved a young patient with Tourette syndrome suffering psychosocially from the condition to the extent that he had been withdrawn from school. The other, commented on in Schermer (2011), involved a patient who was treated unsuccessfully for OCD with DBS but who wanted treatment to continue because it made her feel happier.
Consider a child with severe Tourette Syndrome whose psychosocial development is affected to the extent that he has been taken out of school. Should DBS be used if other treatments have failed? Consider that Tourette Syndrome tends to resolve to a great extent by adulthood.
Schermer (2011) discusses the case of a patient who had DBS implanted to treat OCD. The treatment was unsuccessful. However, the patient reported that it made her feel happier and so wanted to keep the DBS implant active. Yet the physician deactivated it because it did not treat the illness for which it was intended. Was this ethical?
1. Ethically relevant differences between surgery and pharmacology
- Surgery is more expensive and carries some unique greater risks (e.g. bleeding, infection, swelling, surgical mistakes, electrode misplacement). That said, pharmacology does carry unique risks that can be severe depending on the drug, including rare risks such as allergic reactions, serotonin syndrome (antidepressants), tardive dyskinesia (antipsychotics), etc. It is not generally true that an intervention that is pharmacological must be safer than an intervention that is surgical. However, as a practical matter it is true that the majority of approved drugs are safer than the majority of surgeries.
- In terms of their impact on behaviour and subjective experience, surgery and pharmacology are simply alternate means to alter the biophysical functioning of the brain. For many ethical considerations It is the end (the alteration) and not the means that matters.
The thought/sight/feel of a physically invasive procedure like surgery may elicit more unease at an intuitive level than pharmacology which is invisible. Such unease may not be factually justifiable.
2. Consider a child with severe Tourette Syndrome whose psychosocial development is being affected to the extent that he has been taken out of school. Should DBS be used if other treatments have failed? Consider that Tourette Syndrome tends to resolve to a great extent by adulthood.
- Other biological treatments failing is usually unambiguous but we are much worse at judging whether sufficient psychosocial and environmental adjustments have also been tried. We should at least make doubly sure that all that can be done has been done in these regards before escalating biological intervention.
- While Tourette Syndrome may go away, the impact on the child's psychosocial development may be permanent. There may even be suicide risk. Thus, the transience of the condition is not a necessary reason to discount invasive treatments.
- Perhaps we should not treat Tourette Syndrome if the cost is such high risk because, generally speaking, negative experiences can bring unique positive effects in the long-term. For example, a child who is bullied may grow to be more compassionate as an adult. More generally, negative and unfair experiences are an inevitable aspect of life and learning to deal and exist with them is a positive thing. A person who lives without experience of adversity may be said to lead a rather impoverished life in the long run, both from the perspective of her interaction with society, her ability to handle later adversity, and even her own mental life.
- Then again, there is no easy way to answer how much and what kind of adversity is the “best” amount or kind for building a well-rounded person, nor even what an optimally well-rounded person is. Also, just because there are some positive aspects to a negative experience does not mean that having it is on balance as good or better than not having it. The person who says that she is happy to have had a certain adverse experience and wouldn't want to un-have it runs the risk of rationalizing misfortune since she cannot know how she would have felt otherwise.
- What if the “problem” is not with the child with Tourette's but with society's reaction to the child? Why should the child have to bear the risks of a procedure like DBS if the only problem is society's immaturity?
- But could it be that even in an ideal mature and reasonable society there would still be deleterious social effects to Tourette Syndrome given the basic immutable characteristics of human social interaction? How socially constructed versus objective is Tourette Syndrome as an “illness”?
- Even if Tourette Syndrome is a problem only because society is immature and we can work to change society, we cannot change it quickly enough to avoid most or all of the negative effects on this child. Should the child go untreated and shoulder these consequences purely on principle? To serve as a necessary example to propel society forward? If others make such a decision for him or even exert influence on this decision, is this using him as a means rather than an end?
- In all of these questions, what balance should we strike between the child's opinions, the parents' opinions, and the opinions of the social and medical system? Consider that effects relating to psychosocial development and effects relating to long-term gains coming from short-term adversity are not easily understood by children.
- How does the question of treatment change with age of the child? A younger child has less capacity to understand the treatment, and the future course and severity of his Tourette syndrome are more uncertain, but at the same time he has more to gain since much of his psychosocial development is ahead of him. An older child has more capacity, more certainty, but less to gain.
- Compare: What if there had been a similarly risky “cure” for homosexuality decades ago when it had relatively extreme social and even legal consequences? What if a person wanted that cure? What if at the time the person thought that the “disease” aspect of homosexuality was mostly/entirely socially constructed and that hopefully society would grow out of them in the future, but the immediate and unavoidable consequences in his life were extreme enough that he wanted the cure regardless?
- Compare: What if DBS worked to change characteristics that society currently views not as illness but merely as personality traits, but that a given patient may view as negatively affecting her quality of life or even as debilitating? e.g. cynicism, perfectionism.
3. Schermer (2011) discusses the case of a patient who had DBS implanted to treat OCD. The treatment was unsuccessful. However, the patient reported that it made her feel happier and so wanted to keep the DBS implant active. Yet the physician deactivated it because it did not treat the illness for which it was intended. Was this ethical?
- Was the physician's decision based solely on viewing increasing the patient's happiness as enhancement and not as mitigation of illness?
- If the physician made his decision based on a view that medicine should treat but not enhance, where is the threshold between treatment/enhancement and how much of a grey area is there at that threshold? One view is that there is no meaningful difference between treatment and enhancement—there is simply “improvement”, like an engineering endeavour.
- However, the Canada Health Act states that government must fund “medically necessary” treatment for citizens, so we must distinguish treatment and enhancement at least for practical purposes. Also, physicians are obligated to treat but cannot be obligated to enhance, so the law must contemplate a distinction between therapy and enhancement in this respect too. Also, while grey points like mild sleeping aids and growth treatments exist, it does seem like other examples that have reasonable consensus also exist—e.g. that reconstructive plastic surgery following trauma is treatment but purely cosmetic surgery on an average person is enhancement. So, there seems to be something more than subjective or arbitrary about the distinction.
- Still, is the treatment/enhancement distinction just pragmatic, i.e. purely relative to the resources of physicians and society, so that as those resources increase or certain interventions become less costly or risky, interventions that were considered enhancement can become treatment?
- How much of the distinction is socially constructed versus biologically objective? If a part is biologically objective, does that still apply to intervention working on the brain where the range of biologically normal functioning (e.g. the range of normal personalities) is much greater than for “purely physical” organs?
- The monopoly or near-monopoly that the medical establishment seems to have over deciding what is treatment and what is enhancement only applies to interventions that are technically complex or risky such that a physician's expertise is required. In other domains people can choose to “enhance” as they please, e.g. buying cosmetics, exercise, eating well, reading. A grey zone exists for over-the-counter treatments that carry minimal risks. So, as technology advances, treatments that are currently complex and risky may one day be less so and enter the hands of laypeople to categorize as treatment/enhancement as they please.
- If we decide how to determine the treatment/enhancement threshold in general, where does increasing a patient's happiness, as in the case discussed by Schermer, fall? Can we simply say that any increase in happiness beyond a neutral point of neither-happy-nor-sad is enhancement, not treatment?
- If the patient had reported being depressed prior to DBS, would the physician's decision have been different given that he may then have viewed DBS as treatment of a disorder rather than enhancement from a neutral point? Given that many patients are not scored on a psychometric test for depression but rather freely report depressive symptoms in short interviews, could the patient in fact have been depressed before the treatment and simply not have regarded it as such or not properly communicated it? Could it even be that the patient was dysthymic but could not realize it until she had the opportunity to experience what not being dysthymic is like? Thus, with regard to reporting depression, is the before/after DBS time distinction unfair?
- Does it matter that the system was already implanted and would remain so unless the patient opted for another surgery to remove it, both from her brain and the leads and electrical impulse generator elsewhere in her body? The patient had already undertaken the risks of implantation. The health care system or patient had already paid the costs of implantation. That said, there are further risks to active use of the system that are not present in leaving it implanted but dormant.
- Consider the fundamental issue of evidence-based medicine—that is, basing medical practice on established evidence synthesized using sound methodology across prior practice. The established evidence for this procedure may have gone only as far as the benefits in OCD versus the overall risks. If the only benefit that materialized (increased happiness) was not well understood in the established evidence, could the physician have ethically justified the risks of continuing to use DBS? What if that benefit turned out to be short-lived or more placebo effect, or even to herald a novel and severe adverse event? If the physician continued to use DBS and the patient were to experience a severe adverse event, what would be the legal consequences for the physician given that he knew that the extent of benefit supported by evidence had not materialized? This especially when the treatment is novel, risky, and thus its use tightly circumscribed? Perhaps the physician opted to turn off DBS because he could not justify its use working within the framework of evidence-based medicine.