Electrical and Magnetic Neuromodulation Technologies and Brain-Computer Interfaces: Ethical Considerations for Enhancement of Brain Function in Healthy People - A Systematic Scoping Review

INTRODUCTION

This scoping review aimed to synthesize the fragmented evidence on ethical concerns related to the use of electrical and magnetic neuromodulation technologies, as well as brain-computer interfaces for enhancing brain function in healthy individuals, addressing the gaps in understanding spurred by rapid technological advancements and ongoing ethical debates.

METHODS

The following databases and interfaces were queried: MEDLINE (via PubMed), Web of Science, PhilPapers, and Google Scholar. Additional references were identified via bibliographies of included citations. References included experimental studies, reviews, opinion papers, and letters to editors published in peer-reviewed journals that explored the ethical implications of electrical and magnetic neuromodulation technologies and brain-computer interfaces for enhancement of brain function in healthy adult or pediatric populations.

RESULTS

A total of 23 articles were included in the review, of which the majority explored expert opinions in the form of qualitative studies or surveys as well as reviews. Two studies explored the view of laypersons on the topic. The majority of evidence pointed to ethical concerns relating to a lack of sufficient efficacy and safety data for these new technologies, with the risks of invasive procedures potentially outweighing the benefits. Additionally, concerns about potential socioeconomic consequences were raised that could further exacerbate existing socioeconomic inequalities, as well as the risk of changes to person and environment.

CONCLUSION

This scoping review highlights a critical shortage of ethical research on electrical and magnetic neuromodulation technologies and brain-computer interfaces for enhancement of brain function in healthy individuals, with key concerns regarding the safety, efficacy, and socioeconomic impacts of neuromodulation technologies. It underscores the urgent need for integrating ethical considerations into neuroscientific research to address significant gaps and ensure equitable access and outcomes.

Thirty Years of Global Deep Brain Stimulation: "Plus ça change, plus c'est la même chose"?

BACKGROUND

The advent of deep brain stimulation (DBS) of the subthalamic nucleus (STN) for Parkinson's disease 30 years ago has ushered a global breakthrough of DBS as a universal method for therapy and research in wide areas of neurology and psychiatry. The literature of the last three decades has described numerous concepts and practices of DBS, often branded as novelties or discoveries. However, reading the contemporary publications often elicits a sense of déjà vu in relation to several methods, attributes, and practices of DBS. Here, we review various applications and techniques of the modern-era DBS and compare them with practices of the past.

SUMMARY

Compared with modern literature, publications of the old-era functional stereotactic neurosurgery, including old-era DBS, show that from the very beginning multidisciplinarity and teamwork were often prevalent and insisted upon, ethical concerns were recognized, brain circuitries and rational for brain targets were discussed, surgical indications were similar, closed-loop stimulation was attempted, evaluations of surgical results were debated, and controversies were common. Thus, it appears that virtually everything done today in the field of DBS bears resemblance to old-time practices, or has been done before, albeit with partly other tools and techniques. Movement disorders remain the main indications for modern DBS as was the case for lesional surgery and old-era DBS. The novelties today consist of the STN as the dominant target for DBS, the tremendous advances in computerized brain imaging, the sophistication and versatility of implantable DBS hardware, and the large potential for research.

KEY MESSAGES

Many aspects of contemporary DBS bear strong resemblance to practices of the past. The dominant clinical indications remain movement disorders with virtually the same brain targets as in the past, with one exception: the STN. Other novel brain targets - that are so far subject to DBS trials - are the pedunculopontine nucleus for gait freezing, the anteromedial internal pallidum for Gilles de la Tourette and the fornix for Alzheimer's disease. The major innovations and novelties compared to the past concern mainly the unmatched level of research activity, its high degree of sponsorship, and the outstanding advances in technology that have enabled multimodal brain imaging and the miniaturization, versatility, and sophistication of implantable hardware. The greatest benefit for patients today, compared to the past, is the higher level of precision and safety of DBS, and of all functional stereotactic neurosurgery.

Super-Men and Wonder-Women: the Relationship Between the Acceptance of Self-enhancement, Personality, and Values

Due to ongoing technological innovations, self-enhancement methods are publicly discussed, researched from different perspectives, and part of ethical debates. However, only few studies investigated the acceptance of these methods and its relationship with personality traits and values. The present study investigated to what extent people accept different enhancement methods and whether acceptance can be predicted by Big Five and Dark Triad traits, vulnerable narcissism, and values. In an online survey (N = 450), we measured personality traits and values. Additionally, participants read scenarios about enhancement methods and answered questions about their acceptance of these scenarios. Factor analysis indicated a general factor of acceptance across scenarios. Correlation analyses showed that high agreeableness, agreeableness-compassion, conscientiousness, conscientiousness-industriousness, and conservation- and self-transcendence values are related to less acceptance of self-enhancement. Moreover, individuals high on Dark Triad traits, vulnerable narcissism, and self-enhancement values exhibit more acceptance. Hierarchical regression analysis revealed that said values and Big Five traits explained unique variance in the acceptance of self-enhancement. These findings highlight the importance of considering personality and values when investigating self-enhancement—a topic that is receiving increasing attention by the public, politicians, and scientists.

Deep Brain Stimulation for Post-Traumatic Stress Disorder: A Review of the Experimental and Clinical Literature

INTRODUCTION

Up to 30% of patients with post-traumatic stress disorder (PTSD), especially combat veterans, remain refractory to conventional treatment. For them, deep brain stimulation (DBS) has been suggested. Here, we review the literature on animal models of PTSD in which DBS has been used to treat PTSD-type behavior, and we review and discuss patient reports of DBS for PTSD.

METHODS

A broad search was performed to find experimental animal articles and clinical reports on PubMed, Ovid MEDLINE, Cochrane Library, and PsycINFO, using combinations and variations of search words pertinent to DBS and PTSD.

RESULTS

The search yielded 30 articles, 24 on DBS in rat models of PTSD, and 6 publications between 2016 and 2020 reporting on a total of 3 patients. DBS in rat models targeted 4 brain areas: medial prefrontal cortex (mPFC), ventral striatum, amygdala, and hippocampus. Clinical publications reported on 2 male combat veterans who received DBS in basolateral amygdala, and 1 female with PTSD due to domestic abuse, who received DBS of mPFC. All 3 patients benefitted to various extents from DBS, at follow-ups of 4 years, 6 months, and 7 months, respectively.

CONCLUSIONS

PTSD is the only potential clinical indication for DBS that shows extensive animal research prior to human applications. Nevertheless, DBS for PTSD remains highly investigational. Despite several years of government funding of DBS research in view of treating severe PTSD in combat veterans, ethical dilemmas, recruitment difficulties, and issues related to use of DBS in such a complex and heterogenous disorder remain prevalent.

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.

Clinical Perspectives on Psychiatric Neurosurgery

INTRODUCTION

Surgical interventions such as stereotactic radiosurgery and magnetic resonance-guided focused ultrasound, and neuromodulatory interventions such as deep brain stimulation (DBS) and vagal nerve stimulation, are under investigation to remediate psychiatric conditions resistant to conventional therapies involving drugs and psychological supports.

OBJECTIVE

Given the complicated history of psychiatric neurosurgery and its renaissance today, we sought to examine current perceptions and predictions about the field among practicing functional neurosurgeons.

METHODS

We designed a 51-question online survey comprising Likert-type, multiple-choice, and rank-order questions and distributed it to members of the American Society for Stereotactic and Functional Neurosurgery (ASSFN). Descriptive and inferential statistical analyses were performed on the data.

RESULTS

We received 38 completed surveys. Half (n = 19) of responders reported devoting at least a portion of their clinical practice to psychiatric neurosurgery, utilizing DBS and treating obsessive compulsive disorder (OCD) most frequently overall. Respondents indicated that psychiatric neurosurgery is more medically effective (OR 0, p = 0.03242, two-sided Fisher's exact test) and has clearer clinical indications for the treatment of OCD than for the treatment of depression (OR 0.09775, p = 0.005137, two-sided Fisher's exact test). Seventy-one percent of all respondents (n = 27) supported the clinical utility of ablative surgery in modern neuropsychiatric practice, 87% (n = 33) agreed that ablative procedures constitute a valid treatment alternative to DBS for some patients, and 61% (n = 23) agreed that ablative surgery may be an acceptable treatment option for patients who are unlikely to comply with postoperative care.

CONCLUSIONS

This up-to-date account of practices, perceptions, and predictions about psychiatric neurosurgery contributes to the knowledge about evolving attitudes over time and informs priorities for education and further surgical innovation on the psychiatric neurosurgery landscape.

The re-emergence of psychiatric neurosurgery: insights from a cross-national study of newspaper and magazine coverage

BACKGROUND

Surgical approaches to treat psychiatric disorders have made a comeback. News media plays an essential role in exposing the public to trends in health care such as the re-emergence of therapeutic interventions in psychiatric neurosurgery that were set aside for decades, and in shaping attitudes and acceptance to them.

METHOD

We conducted an analysis of media articles covering all types of psychiatric neurosurgery published in Canada, USA, Germany, and Spain between the years 1960 and 2015. We applied both quantitative and qualitative methods to elucidate patterns of reporting for conditions, themes and tone, across geographic regions, time, and for type of intervention.

RESULTS

Coverage of psychiatric neurosurgery has surged since 2001 and is largely consistent across the countries examined. It focuses on depression and deep brain stimulation, and is explicit about historical context. The tone of coverage becomes more positive for Canada, USA and Spain over time; the tone of coverage from Germany remains cautious. Identity and privacy are among the few ethical and philosophical issues raised, notably in the German press.

CONCLUSIONS

The focused and optimistic attention to contemporary psychiatric neurosurgery in the media, but inattention to ethical issues, places an extra burden on functional neurosurgeons, psychiatrists, and other frontline health professionals to attend to queries from patients and policy makers about the full range of relevant emergent and emerging interventions and the mental health issues to which they may beneficially apply.

Public opinions about human enhancement can enhance the expert-only debate: A review study

Human enhancement, the non-medical use of biomedical technologies to improve the human body or performance beyond their 'natural' limitations, is a growing trend. At the same time, the use of these technologies has societal consequences. In societal debates about human enhancement, however, it is mainly the voices of experts that are being heard, and little is known about the public's understanding of human enhancement. The views of the public can give valuable insights, and can, in turn, supplement experts' voices in political decision-making as has been argued before for other emerging technologies. This study presents a systematic literature review of current public perceptions and attitudes towards technologies for human enhancement. Results show that the public's view has not been assessed often. Studies originate mainly from western-oriented countries and cover a broad range of enhancement technologies. In the studies, the majority of respondents hold moderate to strong negative attitudes towards enhancement technologies for non-medical applications, although the type of technology influences these opinions. The study provides an overview of what is known about citizens' attitudes towards technologies for human enhancement.

Brainjacking: Implant Security Issues in Invasive Neuromodulation

The security of medical devices is critical to good patient care, especially when the devices are implanted. In light of recent developments in information security, there is reason to be concerned that medical implants are vulnerable to attack. The ability of attackers to exert malicious control over brain implants ("brainjacking") has unique challenges that we address in this review, with particular focus on deep brain stimulation implants. To illustrate the potential severity of this risk, we identify several mechanisms through which attackers could manipulate patients if unauthorized access to an implant can be achieved. These include blind attacks in which the attacker requires no patient-specific knowledge and targeted attacks that require patient-specific information. Blind attacks include cessation of stimulation, draining implant batteries, inducing tissue damage, and information theft. Targeted attacks include impairment of motor function, alteration of impulse control, modification of emotions or affect, induction of pain, and modulation of the reward system. We also discuss the limitations inherent in designing implants and the trade-offs that must be made to balance device security with battery life and practicality. We conclude that researchers, clinicians, manufacturers, and regulatory bodies should cooperate to minimize the risk posed by brainjacking.

Rivaling paradigms in psychiatric neurosurgery: adjustability versus quick fix versus minimal-invasiveness

In the wake of deep brain stimulation (DBS) development, ablative neurosurgical procedures are seeing a comeback, although they had been discredited and nearly completely abandoned in the 1970s because of their unethical practice. Modern stereotactic ablative procedures as thermal or radiofrequency ablation, and particularly radiosurgery (e.g., Gamma Knife) are much safer than the historical procedures, so that a re-evaluation of this technique is required. The different approaches of modern psychiatric neurosurgery refer to different paradigms: microsurgical ablative procedures is based on the paradigm ‘quick fix,’ radiosurgery on the paradigm ‘minimal-invasiveness,’ and DBS on the paradigm ‘adjustability.’ From a mere medical perspective, none of the procedures is absolutely superior; rather, they have different profiles of advantages and disadvantages. Therefore, individual factors are crucial in decision-making, particularly the patients’ social situation, individual preferences, and individual attitudes. The different approaches are not only rivals, but also enriching mutually. DBS is preferable for exploring new targets, which may become candidates for ablative microsurgery or radiosurgery.

Future of brain stimulation: new targets, new indications, new technology

In the last quarter of a century, DBS has become an established neurosurgical treatment for Parkinson's disease (PD), dystonia, and tremors. Improved understanding of brain circuitries and their involvement in various neurological and psychiatric illnesses, coupled with the safety of DBS and its exquisite role as a tool for ethical study of the human brain, have unlocked new opportunities for this technology, both for future therapies and in research. Serendipitous discoveries and advances in structural and functional imaging are providing abundant "new" brain targets for an ever-increasing number of pathologies, leading to investigations of DBS in diverse neurological, psychiatric, behavioral, and cognitive conditions. Trials and "proof of concept" studies of DBS are underway in pain, epilepsy, tinnitus, OCD, depression, and Gilles de la Tourette syndrome, as well as in eating disorders, addiction, cognitive decline, consciousness, and autonomic states. In parallel, ongoing technological development will provide pulse generators with longer battery longevity, segmental electrode designs allowing a current steering, and the possibility to deliver "on-demand" stimulation based on closed-loop concepts. The future of brain stimulation is certainly promising, especially for movement disorders-that will remain the main indication for DBS for the foreseeable future-and probably for some psychiatric disorders. However, brain stimulation as a technique may be at risk of gliding down a slippery slope: Some reports indicate a disturbing trend with suggestions that future DBS may be proposed for enhancement of memory in healthy people, or as a tool for "treatment" of "antisocial behavior" and for improving "morality."

The contemporary practice of psychiatric surgery: results from a global survey of functional neurosurgeons

BACKGROUND

Interest in neurosurgery for psychiatric diseases (NPD) has grown globally. We previously reported the results of a survey of North American functional neurosurgeons that evaluated general attitudes towards NPD and the future directions of the field.

OBJECTIVES

The purpose of this study was to expand on our previous work and obtain a snapshot in time of global attitudes towards NPD among practicing functional neurosurgeons. We measure general and regional trends in functional neurosurgery and focus specifically on surgery for mind and mood, while exploring the future prospects of the field.

METHODS

We designed an online survey and distributed it electronically to 881 members of the following international organizations: World Society for Stereotactic and Functional Neurosurgery, European Society for Stereotactic and Functional Neurosurgery, Asian-Australasian Society for Stereotactic Functional Neurosurgery and the South and Latin American Society for Stereotactic and Functional Neurosurgery. Subsequent statistical and thematic analysis was performed on the data obtained.

RESULTS

Of 881 surveys distributed, 106 were returned (12.8%). Eighty-two percent of functional neurosurgeon respondents were fellowship trained, with movement disorders and pain making up the majority of their practice. Psychiatric indications are the most frequently treated conditions for 34% of survey respondents, and over half of participants (51%) perform epilepsy surgery. Of the psychiatric conditions, obsessive-compulsive disorder and depression are the most common disorders treated. The majority of respondents (90%) felt optimistic about the future of NPD. Two thirds cited the reluctance of psychiatrists to refer patients as the greatest obstacle facing the field, and a majority reported that a cultural stigma surrounding psychiatric diseases exists in their community. In response to hypothetical situations involving cognitive and personality enhancement, opinions varied, but the majority opposed enhancement interventions. Regional variations were examined as well and uncovered distinct attitudinal differences depending on geographic location.

CONCLUSIONS

Surgery for psychiatric conditions is an expanding field within functional neurosurgery. The opinions of international functional neurosurgeons were largely in line with those of their North American colleagues. Optimism regarding the future of NPD predominates, and future editions of this survey can be used to track the evolution of neurosurgeons' attitudes towards NPD and neuroenhancement.

Therapeutic stimulation versus ablation

The renaissance of functional stereotactic neurosurgery was pioneered in the mid 1980s by Laitinen's introduction of Leksell's posteroventral pallidotomy for Parkinson´s disease (PD). This ablative procedure experienced a worldwide spread in the 1990s, owing to its excellent effect on dyskinesias and other symptoms of post-l-dopa PD. Modern deep brain stimulation (DBS), pioneered by Benabid and Pollak in 1987 for the treatment of tremor, first became popular when it was applied to the subthalamic nucleus (STN) in the mid 1990s, where it demonstrated a striking effect on all cardinal symptoms of advanced PD, and permitted reduced dosages of medication. DBS, as a nondestructive, adaptable, and reversible procedure that is proving safe in bilateral surgery on basal ganglia, has great appeal to clinicians and patients alike, despite the fact that it is expensive, laborious, and relies on very strict patient selection criteria, especially for STN DBS. Psychiatric surgery has experienced the same phenomenon, with DBS supplanting completely stereotactic ablative procedures. This chapter discusses the pros and cons of ablation versus stimulation and investigates the reasons why DBS has overshadowed proven efficient ablative procedures such as pallidotomy for PD, and capsulotomy and cingulotomy for obsessive-compulsive disorder and depression.

Strategies for the return of behavioral surgery

BACKGROUND

Behavioral surgery (BS) is resurging because of unmet clinical need, advances in basic sciences, neuroimaging, neurostimulation, and stereotaxy. However, there is a danger that BS will fall unless acceptable strategies are adopted by BS providers.

METHODS

A critical review of conditions leading to rise of psychosurgery (PS) and concerns resulting in its fall was conducted to learn lessons and safeguard BS of the future.

RESULTS

PS rose and spread in 1960 like wildfire without adequate preclinical and clinical studies. Hundreds of patients had PS without adequate preoperative diagnosis or assessment, proper consent, and non-objective reporting of outcome. Furthermore, there was public opposition against PS because of its potential abuse to control violent behavior and dissidents. Advances in neurostimulation, neuroimaging, and stereotaxy, and emergence of treatment-resistant mental disorders led to increased interest in BS. Several recent studies have shown BS to be safe and effective. However, concerns related to strength of evidence, safety, efficacy, consent, and objectivity of studies have been raised. Unless clinical and regulatory governance structures are adopted in each jurisdiction, BS will face the same fate as that of PS in the past.

CONCLUSION

THE FUTURE OF BS AS A SAFE AND EFFECTIVE THERAPY IS DEPENDENT UPON ADOPTING CLEAR MORAL ETHICAL AND GOVERNANCE STANDARDS ON THE FOLLOWING LINES: Patients must have failed adequate therapies; must be assessed by psychiatrist-led multidisciplinary teams; patients' abilities to give consent and diagnosis must be verified by independent authorities designated for this purpose by the state; and the independent authority must also decide whether the teams were adequately trained to perform BS.

Twenty-five years of deep brain stimulation: celebrations and apprehensions

The year 2012 marks the 25th anniversary of the birth of modern deep brain stimulation (DBS), which was introduced by Benabid et al in 1987, initially to treat tremor with DBS of the ventral intermediate nucleus of the thalamus. The subsequent extension of DBS to the subthalamic nucleus (STN), demonstrating its efficacy on virtually all symptoms of advanced Parkinson's disease (PD), sparked an era of intense clinical and research activities, eventually transcending PD and movement disorders to encompass mood and mind. Investigations of the role of DBS in a variety of neurological, psychiatric, cognitive, and behavioral conditions is ongoing. Serendipitous discoveries and advances in functional imaging are providing "new" brain targets for an increasing number of pathologies. Toward the end of this quarter of a century of DBS, there have been some indications that the field may be at risk of gliding down a slippery slope, reminiscent of the excesses of the old-era DBS. Although there are many reasons this year to celebrate the achievements of 25 years of modern DBS, there are also reasons to fear the opening of a new Pandora's box.