Shared Decision Making for Deep Brain Stimulation


Associate Professor, Penn State University

Dr Laura Cabrera is an associate professor of Neuroethics at the Engineering Science and Mechanics department at Penn State University. She began her career as an engineer and holds a bachelor’s degree in Electrical and Communication Engineering. While pursuing her studies, she began to consider the impacts of neurotechnologies, which inspired her to pursue a master’s and later a PhD in applied ethics. She has since written about a variety of issues relating to neurotechnology, from implantables like DBS to other non-implantables like transcranial magnetic stimulation and other similar fields with a primary focus on social and ethical implications.

How old is Neuroethics, why did it come into existence and why do we need it?

Laura: In relative terms, it is new, but there has been work in this field since 1992, when some papers started to coin the term neuroethics. In 2002, a big conference brought together the first cohort of people interested in this area, and that was the catalyzer of the area. The field also had a crucial moment when the international neuroethics society was created in 2006. It’s been many years in the making, during which many papers have been published and a society that focuses on the field has been created. Now we have journals focusing on neuroethics; before that, we had bioethics.

The field of neuroethics started because we now have more technologies and ways in which we understand and change the brain, and we needed a field that allows us to focus more intensely on those areas. A lot of people would say that neuroethics is not a unique field, it’s just a subfield of bioethics, others would disagree. However, I think we can at least agree that the way we intervene in the brain and the nervous system, creates issues that are pressing in ways that when we intervene in other organs are not. The field of neuroethics and in my view is a very fascinating field.

Jonathan: You’re more interested in applied ethics. Does that mean you are focusing more on the day-to-day implications and decisions that we need to take around actual devices being deployed to people?

Laura: Philosophy is a vast area of study, and then within Philosophy, you have ethics. So applied ethics is ethics that is applied to a field. You could do ethics where you discuss moral theory, but for example, bioethics applies moral theory to ethical issues in life sciences. In this case, neuroethics is applied ethics because it applies moral theory to the area of the brain sciences.

When we talk about neuroethics, there are different flavours of it -that is what I love in the field-. You have neuroethicists that will be very much philosophers and will be debating and discussing issues about how these technologies affect agency or identity from a very philosophical point of view, very theoretical. However, there are others that are more practical. When I started I was using a normative discussion before moving towards a more empirical and practical approach. So in a lot of my current research, I do empirical work, meaning I do interviews, focus groups, and surveys, where I try to understand different public perceptions or concerns and beliefs around neurotechnologies. Not all neuroethicists, do that, but I think the field enables a variety of people and neuroethicists to do and use different tools to address the various issues in the field.

What role does shared decision-making play in having DBS for PD?

Jonathan: What would you say to someone that said patients should listen to their doctor because they are the expert, and when they say it’s the right time, that’s when this should undergo DBS?

Laura: I think that is a very paternalistic way of thinking about how medical decisions should be made, and I believe in the field of neuro bioethics and neuroethics, there’s the idea that this hard decision should be a shared decision, where the physician engages with the patient or caregiver in trying to explore what they value in their life, what preferences they have and whether this treatment really allows them to achieve these values and preferences or not. A classical example is an academic from Germany who had PD and undergone DBS, and as a side effect, he had a speech slur. So his speech would be slowed by the device, and being an academic, he really enjoyed being able to talk to people; thus, he couldn’t teach the way he used to. He later wrote a book saying, “if I had known about this, I probably would not have wanted to have DBS”. So it makes us realize that for some patients, this might not be the solution, and I think we need to explore what might be the potential side effects. 

Sometimes we can modulate the side effects by reducing stimulation or changing the lead. We have ways in which we can try to overcome some of these side effects. Still, that is just to say that patients sometimes are not fully informed of what can be the side effects that could result from having DBS for too long in their life. That is also something that we’re starting to grasp better. So these decisions of whether to get DBS and when I should get it in the course of my disease should be decisions that should involve the patient and the clinician.

Our paper argues that an excellent way to do this is by engaging prospective patients with patients who already have DBS because that could help leverage the expectations. A clinician knows from the scientific literature the side effects and the benefits, but those that already have gone through DBS are the experts in living with DBS, and some clinics already do this with their patients. We argue that this is a vital way in which they can benefit in leveraging their expectations and maybe better understanding what can go wrong that is not always there in the literature or clinicians might not think is relevant.

Jonathan: Or the clinician passes over by saying, “it can cause changes in your speech, but it doesn’t happen in the majority of cases”, without saying, “well; the speech could make you sound like you’re a bit drunk the whole time and stop you from speaking properly at academic forums”.

Is it fair to conclude that the study's goal is patient-based decision-making considering the patient's values and preferences?

Jonathan: So it almost sounds like the idea that you’re aiming for is not shared decision making but actually whereby the clinician is merely acting as a source of information, and other patients are acting as a source of information, and really what you’re driving at is patient-based decision making. The patient is the primary and perhaps even the only agent in the decision-making process. Is that a fair characterization?

Laura: It could be that the patient says, “I want to have DBS, but the clinician knows based on the genetic makeup of the patient, maybe this is not the right thing to do; the clinician could then say, “I’m not going to let you go with this. You’re free to go with someone else if you are willing to do it, but based on what I believe, this could harm you for these reasons”. The physician still holds some level of decisions, and that’s why it’s still shared.

Jonathan: You mentioned that this perspective could have practical implications whereby you don’t just have a conversation with your clinician, but you are introduced to other people that have had this intervention, and then you can talk to them about how it went. I presume there are online resources that serve that as well, like Facebook groups and other platforms that meet some of these requirements or is it something that needs a formal realization in clinical workflows?

Laura: I think people have different preferences. For some patients, Facebook or social media groups are the proper forum because they might feel more comfortable with those groups than with old-fashioned groups. I cherish more in-person conversations, and I know some clinics have this monthly get-together with patients that want to share their experiences. I think those could be very powerful venues to engage with. I’m not arguing that we should only do this and not the social ones. I think we should allow as many different venues for people to share and learn from each other.

What was the methodology and conclusion of the study?

Jonathan: Perhaps we can get into the methodology and conclusions of your paper; you mentioned that it was largely questionnaire-based. I believe you did it online and used a few things like the Michael J Fox Foundation and the American PD’s Association to recruit, so what happened to these patients, how were they found, what happened to them and what were your conclusions?

Laura: As you mentioned, we used the Michael J Fox and Parkinson’s Disease Association to reach out, they have newsletters that help to distribute the survey, and Michael J Fox Foundation has a clinical trial section. Although this wasn’t a clinical trial, in the sense that it was an intervention, the patients could still find, read about it, and click if they were interested. We recruited both patients who have and haven’t had DBS. They took the survey online, all the data was anonymized and analyzed. 

We were very fortunate to have two students from Cornell that were interested in the project and helped with the data analysis. This data set led to at least two papers. In this paper on shared decision-making, we were trying to compare the two types of patients, those that already have and those that haven’t had DBS. The hypothesis was that perhaps those that already have had DBS might have different views on how early would be too early to have it versus those that haven’t. We found that for both groups, there’s this idea that there’s a “half-half”. Half of one group would say, “I would go early if I had the chance”, and the other half would say, “I think I got it when it was the right time for me. I wouldn’t have done it earlier”. Also, the concerns of those two groups are very similar. For this particular paper, we were interested to see whether having had DBS makes any difference regarding patients’ concerns or desires to have DBS earlier.

Jonathan: So I was wondering about that. Weren’t you concerned about the possible confounder that maybe people have DBS because they’re already different, not the DBS has made them different?

Laura: It’s interesting because that could be a potential outcome. However, when you look at the data, almost half of the patients who have had DBS said I got it when it was the right time, I would not have had it earlier, and then the other half said, if the doctor had told me, I would have done it earlier for sure, and the type of concerns are very similar.

There’s literature that said some DBS patients tend to be more risk-prone, so they are fine with taking risks, and those might be the ones that are more likely to try to have it earlier than not. But then you have the type of patients that said, “this is brain surgery, I don’t take this lightly. I’m only going to go through it when it’s the last thing I can do. I’m going to try everything else before I go through brain surgery”, and these type of concerns again were very similar both in groups that have had DBS and have not had DBS. So I think that people still have a lot of concerns about intervening in the brain in an invasive way. We still need to work with that, and I think we can educate the patients, but we also need to be respectful of their values and preferences. Perhaps people feel that the medications are still handling their symptoms and don’t feel the need to have surgery.

Others might say, “I don’t even want to deal with the potential side effects of medication. Thus I’m going to have the surgery now.” As we continue to explore science, we might find out that our current medications are harming in the long term; therefore, we may start offering DBS earlier. There are a lot of scientific studies trying to understand what are the long-term effects of levodopa in patients.

What importance does patient values and preferences play in having DBS, and should they be included as a form of a standardized test?

Jonathan: A fashionable topic nowadays is precision medicine, and in the field of neuromodulation, we have significant opportunities because there is enormous heterogeneity of patients, but also, the devices are often highly configurable and can be programmed with multiple different settings, as you’re no doubt aware. These systems can have hundreds of millions of different possible parameter settings, so there’s an enormous opportunity for personalizing these therapies to individuals, but one interesting aspect that seems to emerge from your work and perhaps related work is that another thing that needs to be personalized is the therapeutic preferences of the individual. You could have two individuals who were being offered exactly the same therapy and have exactly the same disease and be in exactly the same disease state but yet need to be personalized in quite a different way because things like their risk appetite or risk aversion are quite different.

Laura: That is the idea of this shared decision-making, and in many places, this is how things are done; they try to involve the patient in understanding what’s going to happen. In my interviews, I also had neurosurgeons or neurologists tell me, “Well, we have this DBS group, we make the decision and then we just present it to the patients.”, with very little input from the patient in terms of what are their values and preferences.

Hopefully, as we continue in the field, there will be more awareness of the importance of including the patient’s values and preferences and even the caregiver, especially in the late stage of Parkinson’s, the caregiver plays a crucial role in people’s lives, understanding the dynamics and the values as a couple is important in making this type of decision.

Jonathan: Do you think there are ways to educate clinicians and train them to take these things into account? Are there many tools that facilitate this thing? Could there be tools that would enable this thing? I imagine that in PD, for example, there are some standard assessments which are done before DBS, like the Part III Motor Assessment or a mock cognitive assessment, speech assessment and so forth. Should we be including a profile of the patient’s values and concerns as a standard assessment that is being done that could then be included in the MDT meeting when those neurosurgeons and neurologists are making a decision about a patient, are there tools to do this and have they been invented yet?

Laura: This is interesting, that is why neuroethics is an interdisciplinary field, and we should certainly do a little bit more in exploring different stakeholders. My interviews and surveys touch on neurologists and neurosurgeons, but social workers probably play a significant role. They have important conversations with patients regarding their resources and where they live; they might already have some questions that might elicit some of these crucial areas for us to explore. I don’t have an answer to the question of how much of that input funnels into the larger decision-making of DBS, as I haven’t really interviewed social workers 

Although I think the idea of having more tools to help clinicians, neurologists, neurosurgeons, and others involved in the decision to elicit these values in a more standardized way would be relevant. To my knowledge, there aren’t, but I haven’t explored too deeply in this area. One thing that my group is doing next is trying to develop a decision aid for patients in making decisions not only about DBS but also a wider spectrum of potential therapies that a PD patient can undertake. So really trying to help patients navigate these vast opportunities will be important, and as we teach them about the available options, for example, to do a Levodopa pump or take a different medication, or have DBS or an ultrasound, we need to walk them through the risks and benefits and by integrating their values and preferences help them make a decision that might align with them.

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