Deep brain stimulation and ethics: perspectives from a multisite qualitative study of Canadian neurosurgical centers

Best practices for clinical trials of deep brain stimulation for neuropsychiatric indications

Deep brain stimulation (DBS) is well suited to target disorders with network dysregulation, as is the case in many neuropsychiatric diseases. While DBS is a well-established therapy for Parkinson's disease, essential tremor, dystonia, and medically refractory epilepsy, it is actively being studied in clinical trials for neuropsychiatric disorders including treatment-refractory major depressive disorder (MDD). Due to the nature of symptomology and participant characteristics, special care must be taken in the design and implementation of clinical trials testing DBS for neuropsychiatric disorders. In particular, these studies typically include multi-year relationships between participants and study staff with frequent interactions, high burden of study activities on participants, and disclosure by participants of sensitive information related to symptoms and disease state. Through our experience with six participants across more than 5 years of the Presidio clinical trial assessing personalized closed-loop DBS for treatment-refractory MDD, we have gathered experience and evidence to inform best practices for conducting these interaction-intensive clinical studies in a vulnerable population. Here, we present these Key Practices along with discussion, informed by multiple fundamental principles: The Belmont Report; emotional and physical safety for study participants and staff; and integrity and validity of scientific outcomes.

Public Perceptions of Neurotechnologies Used to Target Mood, Memory, and Motor Symptoms

Background

Advances in the development of neurotechnologies have the potential to revolutionize treatment of brain-based conditions. However, a critical concern revolves around the willingness of the public to embrace these technologies, especially considering the tumultuous histories of certain neurosurgical interventions. Therefore, examining public attitudes is paramount to uncovering potential barriers to adoption ensuring ethically sound innovation.

Methods

In the present study, we investigate public attitudes towards the use of four neurotechnologies (within-subjects conditions): deep brain stimulation (DBS), transcranial magnetic stimulation (TMS), pills, and MRI-guided focused ultrasound (MRgFUS) as potential treatments to a person experiencing either mood, memory, or motor symptoms (between-subjects conditions). US-based participants (N=1052; stratified to be nationally representative based on sex, race, age) were asked about their perceptions of risk, benefit, invasiveness, acceptability, perceived change to the person, and personal interest in using these neurotechnologies for symptom alleviation.

Results

Descriptive results indicate variability between technologies that the U.S. public is willing to consider if experiencing severe mood, memory, or motor symptoms. The main effect of neurotechnology revealed DBS was viewed as the most invasive and risky treatment and was perceived to lead to the greatest change to who someone is as a person. DBS was also viewed as least likely to be personally used and least acceptable for use by others. When examining the main effects of symptomatology, we found that all forms of neuromodulation were perceived as significantly more beneficial, acceptable, and likely to be used by participants for motor symptoms, followed by memory symptoms, and lastly mood symptoms. Neuromodulation (averaging across neurotechnologies) was perceived as significantly riskier, more invasive, and leading to a greater change to person for mood versus motor symptoms; however, memory and motor symptoms were perceived similarly with respect to risk, invasiveness, and change to person.

Conclusion

These results suggest that the public views neuromodulatory approaches that require surgery (i.e., DBS and MRgFUS) as riskier, more invasive, and less acceptable than those that do not. Further, findings suggest individuals may be more reluctant to alter or treat psychological symptoms with neuromodulation compared to physical symptoms.

Researcher Views on Changes in Personality, Mood, and Behavior in Next-Generation Deep Brain Stimulation

The literature on deep brain stimulation (DBS) and adaptive DBS (aDBS) raises concerns that these technologies may affect personality, mood, and behavior. We conducted semi-structured interviews with researchers (n = 23) involved in developing next-generation DBS systems, exploring their perspectives on ethics and policy topics including whether DBS/aDBS can cause such changes. The majority of researchers reported being aware of personality, mood, or behavioral (PMB) changes in recipients of DBS/aDBS. Researchers offered varying estimates of the frequency of PMB changes. A smaller majority reported changes in personality specifically. Some expressed reservations about the scientific status of the term 'personality,' while others used it freely. Most researchers discussed negative PMB changes, but a majority said that DBS/aDBS can also result in positive changes. Several researchers viewed positive PMB changes as part of the therapeutic goal in psychiatric applications of DBS/aDBS. Finally, several discussed potential causes of PMB changes other than the device itself.

The Role of Family Members in Psychiatric Deep Brain Stimulation Trials: More Than Psychosocial Support

Family members can provide crucial support to individuals participating in clinical trials. In research on the "newest frontier" of Deep Brain Stimulation (DBS)-the use of DBS for psychiatric conditions-family member support is frequently listed as a criterion for trial enrollment. Despite the significance of family members, qualitative ethics research on DBS for psychiatric conditions has focused almost exclusively on the perspectives and experiences of DBS recipients. This qualitative study is one of the first to include both DBS recipients and their family members as interview participants. Using dyadic thematic analysis-an approach that takes both the individuals and the relationship as units of analyses-this study analyzes the complex ways in which family relationships can affect DBS trial participation, and how DBS trial participation in turn influences family relationships. Based on these findings, we propose ways to improve study designs to better take family relationships into account, and better support family members in taking on the complex, essential roles that they play in DBS trials for psychiatric conditions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12152-023-09520-7.

Deep Brain Stimulation beyond the Clinic: Navigating the Future of Parkinson's and Alzheimer's Disease Therapy

Deep brain stimulation (DBS) is a surgical procedure that uses electrical neuromodulation to target specific regions of the brain, showing potential in the treatment of neurodegenerative disorders such as Parkinson's disease (PD) and Alzheimer's disease (AD). Despite similarities in disease pathology, DBS is currently only approved for use in PD patients, with limited literature on its effectiveness in AD. While DBS has shown promise in ameliorating brain circuits in PD, further research is needed to determine the optimal parameters for DBS and address any potential side effects. This review emphasizes the need for foundational and clinical research on DBS in different brain regions to treat AD and recommends the development of a classification system for adverse effects. Furthermore, this review suggests the use of either a low-frequency system (LFS) or high-frequency system (HFS) depending on the specific symptoms of the patient for both PD and AD.

Treating addiction with deep brain stimulation: Ethical and legal considerations

BACKGROUND

The use of neuromodulation in the treatment of psychiatric conditions is controversial despite its lengthy history. This particularly applies to the use of invasive neuromodulation, such as deep brain stimulation (DBS), to treat substance use disorder (SUD) due to the considerable risks of the procedures. However, given the advances in DBS research and the shortcomings of current treatment modalities for addiction, off-label use and clinical trials are being implemented for the management of treatment-refractory patients.

METHODS

Here we conduct an ethical and legal analysis of DBS for SUD, referencing the four foundational principles of medical ethics and key legal concepts.

RESULTS

There are major concerns related to the capacity of a SUD patient to provide informed consent, as well as the risks and benefits of DBS compared to traditional treatment methods. In addition to ethical concerns, we explore potential legal issues that may arise from DBS in the treatment of addiction. These include the potential mandate of these procedures in the context of the criminalization of substance use, and the issue of familial consent in the decision-making process. Given the paucity of relevant clinical guidelines or legal cases, general medico-legal principles serve as the reference in making decisions about the responsible use of DBS as a treatment for addiction.

CONCLUSIONS

Given the rapidly increasing evidence for DBS as a treatment for SUD, it is an urgent imperative to consider the relevant key ethical and legal issues. Incorporating IDEAL (Idea, Development, Exploration, Assessment, Long-term follow-up) framework into future research in DBS is recommended to evaluate patient safety and ethical perspectives. With the broad criminalization of SUD across the globe, legal coercion of DBS is not impossible, especially if proven to be effective to treat SUD. It is advised for stakeholders to urgently consider incorporating DBS-related drug policies so that the potential benefits of DBS within the rights of people with SUD are not hindered by the lack of clinical guidance and legislations.

Exit from Brain Device Research: A Modified Grounded Theory Study of Researcher Obligations and Participant Experiences

As clinical trials end, little is understood about how participants exiting from clinical trials approach decisions related to the removal or post-trial use of investigational brain implants, such as deep brain stimulation (DBS) devices. This empirical bioethics study examines how research participants experience the process of exit from research at the end of clinical trials of implanted neural devices. Using a modified grounded theory study design, we conducted semi-structured, in-depth interviews with 16 former research participants from clinical trials of DBS and responsive neurostimulation (RNS). Open-ended questions elicited motivations for joining the trial, understanding of study procedures at the time of initial informed consent, the process of exiting from research, and decisions about device removal or post-trial device use. Thematic analysis identified categories related to: limited preparedness for the end of research participation, straightforwardness of decisions to explant or keep the device, reconciling with the end of research participation, reconciling post-trial expectations, and achieving a sense of closure after exit from research. A preliminary theoretical model describes contextual factors influencing the process and experience of exit from research. Experiences of clinical trial participants should guide research practices to enhance the ethical design and conduct of clinical trials in DBS and other brain devices.

Ethical Considerations in the Implantation of Neuromodulatory Devices

OBJECTIVES

Neuromodulatory devices are increasingly used by neurosurgeons to manage a variety of chronic conditions. Given their potential benefits, it is imperative to create clear ethical guidelines for the use of these devices. We present a tiered ethical framework for neurosurgeon recommendations for the use of neuromodulatory devices.

MATERIALS AND METHODS

We conducted a literature review to identify factors neurosurgeons should consider when choosing to offer a neuromodulatory device to a patient.

RESULTS

Neurosurgeons must weigh reductions in debilitating symptoms, improved functionality, and preserved quality of life against risks for intraoperative complications and adverse events due to stimulation or the device itself. Neurosurgeons must also evaluate whether patients and families will maintain responsibility for the management of neuromodulatory devices. Consideration of these factors should occur on an axis of resource allocation, ranging from provision of neuromodulatory devices to those with greatest potential benefit in resource-limited settings to provision of neuromodulatory devices to all patients with indications in contexts without resource limitations. Neurosurgeons must also take action to promote device effectiveness throughout the duration of care.

CONCLUSIONS

Weighing risks and benefits of providing neuromodulatory devices and assessing ability to remain responsible for the devices on the level of the individual patient indicate which patients are most likely to achieve benefit from these devices. Consideration of these factors on an axis of resource allocation will allow for optimal provision of neuromodulatory devices to patients in settings of varied resources. Neurosurgeons play a primary role in promoting the effectiveness of these devices.

Ethical considerations in the surgical and neuromodulatory treatment of epilepsy

Surgical resection and neuromodulation are well-established treatments for those with medically refractory epilepsy. These treatments entail important ethical considerations beyond those which extend to the treatment of epilepsy generally. In this paper, the authors explore these unique considerations through a framework that relates foundational principles of bioethics to features of resective epilepsy surgery and neuromodulation. The authors conducted a literature review to identify ethical considerations for a variety of epilepsy surgery procedures and to examine how foundational principles in bioethics may inform treatment decisions. Healthcare providers should be cognizant of how an increased prevalence of somatic and psychiatric comorbidities, the dynamic nature of symptom burden over time, the individual and systemic barriers to treatment, and variable sociocultural contexts constitute important ethical considerations regarding the use of surgery or neuromodulation for the treatment of epilepsy. Moreover, careful attention should be paid to how resective epilepsy surgery and neuromodulation relate to notions of patient autonomy, safety and privacy, and the shared responsibility for device management and maintenance. A three-tiered approach-(1) gathering information and assessing the risks and benefits of different treatment options, (2) clear communication with patient or proxy with awareness of patient values and barriers to treatment, and (3) long-term decision maintenance through continued identification of gaps in understanding and provision of information-allows for optimal treatment of the individual person with epilepsy while minimizing disparities in epilepsy care.

DBS: a compelling example for ethical and legal reflection-a French perspective on ethical and legal concerns about DBS

Deep brain stimulation (DBS) is an approved treatment for neurological diseases and a promising one for psychiatric conditions, which may produce spectacular results very quickly. It is also a powerful tool for brain research and exploration. Beyond an overview of the ethical and legal literature on this topic, this paper aims at showing that DBS is a compelling example for ethical-legal reflection, as it combines a highly technical surgical procedure, a complex active medical device and neuromodulation of the human brain to restore lost abilities caused by a chronic and evolving disease. Some of the ethical and legal issues raised by DBS are not specific, but shed new light on medical ethics and law. Others are more DBS-specific, as they are linked to the intricacies of research and treatment, to the need to tune the device, to the patients' control over the device and its effects and to the involvement of family caregivers.

Patient's lived experience with DBS between medical research and care: some legal implications

In the past 50 years, an ethical-legal boundary has been drawn between treatment and research. It is based on the reasoning that the two activities pursue different purposes. Treatment is aimed at achieving optimal therapeutic benefits for the individual patient, whereas the goal of scientific research is to increase knowledge, in the public interest. From this viewpoint, the patient's experience should be clearly distinguished from that of a participant in a clinical trial. On this premise, two parallel and mutually exclusive regimes have been established. Yet in the case of deep brain stimulation (DBS), this presentation is a poor fit, for both the patient's lived experience and medical practice and research. The frictions may be explained by the specificities of the treatment (including surgery and medical devices) and of the pathologies concerned (chronic and evolutive), and by the characteristics of the medical team implementing the treatment. These particularities challenge the dominant frame of reference in medical bioethics and cause difficulties for the current legal framework in fulfilling its dual role: to protect patients while supporting the development of innovative treatments. The dominant model is still the clinical trial for medication safety and legal requirements of drug market regulation. However, DBS forces us to reflect on a medical device that is permanently implanted in the brain by highly specialized multi-disciplinary neurosurgical teams, for the treatment of chronic evolutive diseases. These devices demand fine-tuning on a case-by-case basis and there is still a lot to discover about why DBS is effective (or not). As a result, the wall between treatment and research is osmotic: many discoveries are made incidentally, in the course of treatment. The following study begins with these observations, and suggests that we review legal provisions (especially in French and United States law) so that they are better adapted to the first-person needs and experience of the patient undergoing brain stimulation.

Impact of deep brain stimulation on people with Parkinson's disease: A mixed methods feasibility study exploring lifespace and community outcomes

Background

Deep brain stimulation is a surgical treatment for Parkinson’s disease. Its impacts on motor symptoms are widely reported; however, little is known about the broader impact of deep brain stimulation on the community lives of people with Parkinson’s disease. Lifespace is a measure of lived community mobility, providing an indication of community access and participation.

Aims

This pilot study explored the feasibility of remotely monitoring the qualitative and quantitative community outcomes related to deep brain stimulation.

Methods

A longitudinal mixed methods study with a convergent design was undertaken exploring the lifespace, quality of life, life satisfaction and lived experiences of people with Parkinson’s disease before and after deep brain stimulation. Data were collected through questionnaires, semi-structured interviews and a smartphone-based application which collected geolocation data.

Results

Quantitative and qualitative data from eight participants living with Parkinson’s disease were analysed and integrated. At baseline, participants had a median age of 68 years and a median Hoehn and Yahr score of 2. Measuring a range of community-based outcomes indicated different change trajectories for individuals across outcomes. Key content areas were developed from the qualitative data: participation in occupations and travel and home. This study indicates the potential value of including geolocation data-based lifespace collection in metropolitan and regional areas.

Conclusions

Monitoring lifespace in conjunction with subjective measures provides insights into the complex and individually varied experiences. Further research could explore the impacts of deep brain stimulation on occupations and community participation to gain a deeper understanding of the related needs and support clinical approaches.

Canadian Assessment of Deep Brain Stimulation Access: The Canada Study

BACKGROUND

The Canada Health Act requires reasonable access to all medically necessary therapies. No information is available to assess the current access to neuromodulation across Canada. This study quantifies the current rate of deep brain stimulation (DBS) for the entire country of Canada. Analyses were performed to determine whether there were differences in access based on provincial or territorial location, rural or non-rural region, or socioeconomic status.

METHODS

All implanted DBS devices in Canada over a 2-year epoch (January 2015 to December 2016) were supplied by either Boston Scientific or Medtronic. Investigators received anonymized data from these companies, including patient age and home residence region. The 2016 Statistics Canada census data were used to determine the rate of DBS surgery and whether access was related to provincial location, rural versus non-rural region or socioeconomic status.

RESULTS

A total of 722 patients were studied. The rate of DBS surgery for the entire country was ten per million population per year. Saskatchewan was significantly above (374%) the national average, whereas Quebec (40%) and Newfoundland & Labrador (32%) were significantly below the national average. No patients from the three territories received DBS. There were no significant differences in access from rural versus non-rural areas or in regions within provinces with different socioeconomic status.

CONCLUSIONS

This is the first study to quantify all patients receiving DBS within an entire country. The current rate of DBS surgery within Canada is ten cases per million per year. Statistically significant regional differences were discovered and discussed.

Ethics of Deep Brain Stimulation in Adolescent Patients with Refractory Tourette Syndrome: a Systematic Review and Two Case Discussions

Introduction

Tourette Syndrome (TS) is a childhood onset disorder characterized by vocal and motor tics and often remits spontaneously during adolescence. For treatment refractory patients, Deep Brain Stimulation (DBS) may be considered.

Methods and Results

We discuss ethical problems encountered in two adolescent TS patients treated with DBS and systematically review the literature on the topic. Following surgery one patient experienced side effects without sufficient therapeutic effects and the stimulator was turned off. After a second series of behavioural treatment, he experienced a tic reduction of more than 50%. The second patient went through a period of behavioural disturbances that interfered with optimal programming, but eventually experienced a 70% tic reduction. Sixteen DBS surgeries in adolescent TS patients have been reported, none of which pays attention to ethical aspects.

Discussion

Specific ethical issues arise in adolescent TS patients undergoing DBS relating both to clinical practice as well as to research. Attention should be paid to selecting patients fairly, thorough examination and weighing of risks and benefits, protecting the health of children and adolescents receiving DBS, special issues concerning patient's autonomy, and the normative impact of quality of life. In research, registration of all TS cases in a central database covering a range of standardized information will facilitate further development of DBS for this indication.

Conclusion

Clinical practice should be accompanied by ongoing ethical reflection, preferably covering not only theoretical thought but providing also insights in the views and perspectives of those concerned, that is patients, family members and professionals.

Role of clinical neuropsychology in deep brain stimulation: Review of the literature and considerations for clinicians

Deep Brain Stimulation (DBS) is an effective surgical therapy for several neurological movement disorders. The clinical neuropsychologist has a well-established role in the neuropsychological evaluation and selection of surgical candidates. In this article, we argue that the clinical neuropsychologist's role is much broader, when considered in relation to applied psychologists' core competencies. We consider the role of the clinical neuropsychologist in DBS in relation to: assessment, formulation, evaluation and research, intervention or implementation, and communication. For each competence the relevant evidence-base was reviewed. Clinical neuropsychology has a vital role in presurgical assessment of cognitive functioning and psychological, and emotional and behavioral difficulties. Formulation is central to the selection of surgical candidates and crucial to intervention planning. Clinical neuropsychology has a well-established role in postsurgical assessment of cognitive functioning and psychological, emotional, and behavioral outcomes, which is fundamental to evaluation on an individual and service level. The unique contribution clinical neuropsychology makes to pre- and postsurgical interventions is also highlighted. Finally, we discuss how clinical neuropsychology can promote clear and effective communication with patients and between professionals.

Understanding the lived experiences of Parkinson's disease and deep brain stimulation (DBS) through occupational changes

BACKGROUND

Deep brain stimulation (DBS), a surgically based treatment for people living with Parkinson's disease (PD), can result in a significant improvement of motor symptoms. However, the broader impact of DBS and the changes it creates are not well understood. Greater understanding of the experiences and needs related to DBS would enable development of relevant outcome measures and supports.

OBJECTIVES

To explore the lived experiences of people undergoing DBS for Parkinson's disease.

METHODS

A descriptive phenomenological study was undertaken exploring experiences, perspectives and outcomes with key stakeholders. Semi-structured, audiotaped interviews were undertaken with people with PD who have had DBS, their family members and health professionals across four states and territories in Australia.

RESULTS

Perspectives and experiences of 14 people with PD undergoing DBS, 10 family members and 11 health professionals were analysed. Occupations emerged as a key aspect throughout the DBS experience. Two major themes captured the role of occupation in relation to DBS: Occupations as a barometer, where occupational experiences and performances shaped people's understanding of their condition, the impact of treatments and their overall adjustment; and Shifting occupational identity where the life transition of DBS altered the occupational experiences of relationships, volition, roles and responsibilities of people with PD and their family members.

CONCLUSION

Occupational experiences and changes served as an important way for people with PD and their families to understand and communicate their experiences of PD and related treatments. There is an identified need for outcome measures and clinical education and interventions to reflect this.

Deep Brain Stimulation in Anorexia Nervosa: Hope for the Hopeless or Exploitation of the Vulnerable? The Oxford Neuroethics Gold Standard Framework

Neurosurgical interventions for psychiatric disorders have a long and troubled history (1, 2) but have become much more refined in the last few decades due to the rapid development of neuroimaging and robotic technologies (2). These advances have enabled the design of less invasive techniques, which are more focused, such as deep brain stimulation (DBS) (3). DBS involves electrode insertion into specific neural targets implicated in pathological behavior, which are then repeatedly stimulated at adjustable frequencies. DBS has been used for Parkinson's disease and movement disorders since the 1960s (4-6) and over the last decade has been applied to treatment-refractory psychiatric disorders, with some evidence of benefit in obsessive-compulsive disorder (OCD), major depressive disorder, and addictions (7). Recent consensus guidelines on best practice in psychiatric neurosurgery (8) stress, however, that DBS for psychiatric disorders remains at an experimental and exploratory stage. The ethics of DBS-in particular for psychiatric conditions-is debated (1, 8-10). Much of this discourse surrounds the philosophical implications of competence, authenticity, personality, or identity change following neurosurgical interventions, but there is a paucity of applied guidance on neuroethical best practice in psychiatric DBS, and health-care professionals have expressed that they require more (11). This paper aims to redress this balance by providing a practical, applied neuroethical gold standard framework to guide research ethics committees, researchers, and institutional sponsors. We will describe this as applied to our protocol for a particular research trial of DBS in severe and enduring anorexia nervosa (SE-AN) (https://clinicaltrials.gov/ct2/show/NCT01924598, unique identifier NCT01924598), but believe it may have wider application to DBS in other psychiatric disorders.

Establishing a Standard of Care for Deep Brain Stimulation Centers in Canada

During the “DBS Canada Day” symposium held in Toronto July 4-5, 2014, the scientific committee invited experts to share their knowledge regarding deep brain stimulation (DBS) management of movement disorders in three domains: (1) the programming algorithms, (2) the necessary team to run a neurosurgery program, and (3) the appropriate scales to better define in a more comprehensive fashion the effect of the brain surgery. Each presentation was followed by an open discussion, and this article reports on the conclusions of this meeting on these three questions. Concerning programming, the role of the pulse width and the switching off of the stimulation at night for thalamic stimulation for the control of tremor have been discussed. The algorithms proposed in the literature for programming in Parkinson’s disease (PD) need validation. In dystonia, the use of monopolar vs bipolar parameters, the use of low vs high frequencies and the use of smaller versus larger pulse widths all need to be examined properly. Concerning the necessary team to run a neurosurgical program, recommendations will follow the suggestions for standardized outcome measures. Regarding the outcome measures for DBS in PD, investigations need to focus on the non-motor aspects of PD. Identifying which nonmotor symptoms respond to DBS would allow a better screening before and satisfaction postoperatively. There is an important need for more data to determine the optimal programming protocol and the standard measures that should be performed routinely by all centers.

Thinking Ahead on Deep Brain Stimulation: An Analysis of the Ethical Implications of a Developing Technology

Deep brain stimulation (DBS) is a developing technology. New generations of DBS technology are already in the pipeline, yet this particular fact has been largely ignored among ethicists interested in DBS. Focusing only on ethical concerns raised by the current DBS technology is, albeit necessary, not sufficient. Since current bioethical concerns raised by a specific technology could be quite different from the concerns it will raise a couple of years ahead, an ethical analysis should be sensitive to such alterations, or it could end up with results that soon become dated. The goal of this analysis is to address these changing bioethical concerns, to think ahead on upcoming and future DBS concerns both in terms of a changing technology and changing moral attitudes. By employing the distinction between inherent and noninherent bioethical concerns we identify and make explicit the particular limits and potentials for change within each category, respectively, including how present and upcoming bioethical concerns regarding DBS emerge and become obsolete. Many of the currently identified ethical problems with DBS, such as stimulation-induced mania, are a result of suboptimal technology. These challenges could be addressed by technical advances, while for instance perceptions of an altered body image caused by the mere awareness of having an implant may not. Other concerns will not emerge until the technology has become sophisticated enough for new uses to be realized, such as concerns on DBS for enhancement purposes. As a part of the present analysis, concerns regarding authenticity are used as an example.

Ethical Considerations in Deep Brain Stimulation for the Treatment of Addiction and Overeating Associated With Obesity

The success of deep brain stimulation (DBS) for movement disorders and the improved understanding of the neurobiologic and neuroanatomic bases of psychiatric diseases have led to proposals to expand current DBS applications. Recent preclinical and clinical work with Alzheimer's disease and obsessive-compulsive disorder, for example, supports the safety of stimulating regions in the hypothalamus and nucleus accumbens in humans. These regions are known to be involved in addiction and overeating associated with obesity. However, the use of DBS targeting these areas as a treatment modality raises common ethical considerations, which include informed consent, coercion, enhancement, threat to personhood, and manipulation of the reward center. Pilot studies for both of these conditions are currently investigational. If these studies show promise, then there is a need to address the ethical concerns related to the initiation of clinical trials including the reliability of preclinical evidence, patient selection, study design, compensation for participation and injury, cost-effectiveness, and the need for long-term follow-up. Multidisciplinary teams are necessary for the ethical execution of such studies. In addition to establishing safety and efficacy, the consideration of these ethical issues is vital to the adoption of DBS as a treatment for these conditions. We offer suggestions about the pursuit of future clinical trials of DBS for the treatment of addiction and overeating associated with obesity and provide a framework for addressing ethical concerns related to treatment.

Deep brain stimulation and cognitive decline in Parkinson's disease: a clinical review

Parkinson’s disease is a common and often debilitating disorder, with a growing prevalence accompanying global population aging. Current drug therapy is not satisfactory enough for many patients, especially after a few years of symptom progression. This is mainly due to the motor complications that frequently emerge as disease progresses. Deep brain stimulation (DBS) is a useful therapeutic option in carefully selected patients that significantly improves motor symptoms, functional status, and quality of life. However, cognitive impairment may limit patient selection for DBS, as patients need to have sufficient mental capabilities in order to understand the procedure, as well as its benefits and limitations, and cooperate with the medical team throughout the process of selection, surgery, and postsurgical follow-up. On the other hand it has been observed that certain aspects of cognitive performance may decline after DBS, namely when the therapeutic target is the widely used subthalamic nucleus. These are important pieces of information for patients, their families, and health care professionals. This manuscript reviews these aspects and their clinical implications.