Scientific and ethical issues related to deep brain stimulation for disorders of mood, behavior, and thought

Effectiveness of deep brain stimulation on refractory aggression in pediatric patients with autism and severe intellectual disability: meta-analytic review

Some patients with autism and severe intellectual disability may experience uncontrolled aggression, causing serious injury or harm to others, and the therapeutic ineffectiveness of traditional pharmacological and behavioral treatment may aggravate symptoms. Deep brain stimulation (DBS) has been tested in patients with little evidence in children and adolescents. Therefore, we analyzed the efficacy and safety of DBS in refractory aggression in pediatric subjects with autism (ASD) and severe intelligence deficit (ID).Methods A meta-analytic review of Web of Science (WOS) and Scopus articles, following Prisma criteria. A total of 555 articles were identified, but after applying the inclusion criteria, only 18 were analyzed. The review of the registries and the extraction of information was performed by 2 independent groups, to reduce the evaluator's bias. For the description of the results, pediatric patients with ASD or ID present in each registry, with an application of specialized scales (Overt aggression scale, OAS, and THE modified version of the OAS, MOAS) pre and post-DBS, with a clinical follow-up of at least 12 months, were considered valid. Clinical improvement was calculated using tests of aggressiveness. In each registry with available data and then pooling the means of all patients in the OAS and MOAS, the effect size of DBS (overall and per study) was estimated. Finally, the adapted NOS scale was applied to rate the studies' quality and level of bias.Results In the studies analyzed, 65/100 were pediatric patients, with a mean age of 16.8 years. Most of the studies were conducted in South America and Europe. In all teams, aggressive behavior was intractable, but only 9 groups (53/65) applied specialized scales to measure aggressiveness, and of these, only 51 subjects had a follow-up of at least 12 months. Thus, in 48/51 a clinical improvement of patients was estimated (94.2%), with a considerable overall effect size (OAS: d = 4.32; MOAS: d = 1.46). However, adverse effects and complications were found in 13/65 subjects undergoing DBS. The brain target with the most evidence and the fewest side effects was the posteromedial hypothalamic nuclei (pHypN). Finally, applying the adapted NOS scale, quality, and bias, only 9 studies show the best indicators.Conclusion An optimal level of efficacy was found in only half of the publications. This is mainly due to design errors and irrelevant information in the reports. We believe that DBS in intractable aggressiveness in children and adolescents with ASD and severe ID can be safe and effective if working groups apply rigorous criteria for patient selection, interdisciplinary assessments, objective scales for aggressiveness, and known surgical targets.

[Pacemaker, organ or walking stick? Pre-op association with and post-op subjective perception of a deep brain stimulation device]

AIM OF THE STUDY

This study was conducted in a pre-post design with a survey of patients who had undergone deep brain stimulation (DBS) as treatment for a neurological movement disorder. The aim of the study was to compare patients' expectations and beliefs before a DBS intervention with patients' subjective experience of this intervention.

METHODOLOGY

The longitudinal study of patients (n=132) with an indication for DBS therapy was based on a written survey at the time points of preoperative screening (pre-op) and one-year follow-up (post-op).

RESULTS

Preoperatively, a clear majority of respondents believed DSB to be similar to a pacemaker intervention, but one year after the intervention less than one third did so, as they compared DBS to using a walking stick or glasses.

CONCLUSION

The experience of DBS in the patient's own body seems to be comparable by means of individually different associations, whereby the comparison with non-invasive aids predominates postoperatively. The discussion of these descriptions in the educational interview can contribute to a realistic horizon of patients' expectations before DBS.

Neuroablative Intervention for Refractory Obsessive-Compulsive Disorder

OBJECTIVE

This review aims to investigate the progression of neuroablation, along with documented clinical efficacy and safety, in the management of treatment-resistant obsessive-compulsive disorder (OCD).

METHODS

We searched and compiled clinical research results of neuroablation therapy reported to date. We extracted outcomes related to clinical efficacy, side effects, and surgical complications. Additionally, we summarized key claims and findings.

RESULTS

Neuroablative intervention is a potential treatment approach for refractory OCD. Recent advancements, such as real-time magnetic resonance monitoring and minimally invasive techniques employing ultrasound and laser, offer distinct advantages in terms of safety and comparative efficacy when compared to conventional methods. However, the absence of randomized controlled trials and long-term outcome data underscores the need for cautious consideration when selecting neuroablation.

CONCLUSION

Neuroablative intervention shows promise for refractory OCD, but vigilant consideration is essential in both patient selection and surgical method choices due to the potential for rare yet serious complications.

How I became myself after merging with a computer: Does human-machine symbiosis raise human rights issues?

Novel usages of brain stimulation combined with artificially intelligent (AI) systems promise to address a large range of diseases. These new conjoined technologies, such as brain-computer interfaces (BCI), are increasingly used in experimental and clinical settings to predict and alleviate symptoms of various neurological and psychiatric disorders. Due to their reliance on AI algorithms for feature extraction and classification, these BCI systems enable a novel, unprecedented, and direct connection between human cognition and artificial information processing. In this paper, we present the results of a study that investigates the phenomenology of human-machine symbiosis during a first-in-human experimental BCI trial designed to predict epileptic seizures. We employed qualitative semi-structured interviews to collect user experience data from a participant over a six-years period. We report on a clinical case where a specific embodied phenomenology emerged: namely, after BCI implantation, the patient reported experiences of increased agential capacity and continuity; and after device explantation, the patient reported persistent traumatic harms linked to agential discontinuity. To our knowledge, this is the first reported clinical case of a patient experiencing persistent agential discontinuity due to BCI explantation and potential evidence of an infringement on patient right, where the implanted person was robbed of her de novo agential capacities when the device was removed.

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.

International Regulatory Standards for the Qualitative Measurement of Deep Brain Stimulation in Clinical Research

Deep brain stimulation (DBS) has progressed to become a promising treatment modality for neurologic and psychiatric disorders like epilepsy and major depressive disorder due to its growing personalization. Despite evidence pointing to the benefits of DBS if tested on these personalized qualitative metrics, rather than randomized-control trial quantitative standards, the evaluation of these novel devices appears to be based on the latter. This study surveyed the presence of this trend in the national regulatory guidelines of the prominent DBS researching countries. It was found that two governing bodies, in the European Union and Australia, acknowledged the option for qualitative measures. These findings support further development of national regulatory guidelines, so the neuroscientific community developing these neurotechnologies can better understand the impact their treatments have on patients.

Concerns About Psychiatric Neurosurgery and How They Can Be Overcome: Recommendations for Responsible Research

Background

Psychiatric neurosurgery is experiencing a revival. Beside deep brain stimulation (DBS), several ablative neurosurgical procedures are currently in use. Each approach has a different profile of advantages and disadvantages. However, many psychiatrists, ethicists, and laypeople are sceptical about psychiatric neurosurgery.

Methods

We identify the main concerns against psychiatric neurosurgery, and discuss the extent to which they are justified and how they might be overcome. We review the evidence for the effectiveness, efficacy and safety of each approach, and discuss how this could be improved. We analyse whether and, if so, how randomised controlled trials (RCTs) can be used in the different approaches, and what alternatives are available if conducting RCTs is impossible for practical or ethical reasons. Specifically, we analyse the problem of failed RCTs after promising open-label studies.

Results

The main concerns are: (i) reservations based on historical psychosurgery, (ii) concerns about personality changes, (iii) concerns regarding localised interventions, and (iv) scepticism due to the lack of scientific evidence. Given the need for effective therapies for treatment-refractory psychiatric disorders and preliminary evidence for the effectiveness of psychiatric neurosurgery, further research is warranted and necessary. Since psychiatric neurosurgery has the potential to modify personality traits, it should be held to the highest ethical and scientific standards.

Conclusions

Psychiatric neurosurgery procedures with preliminary evidence for efficacy and an acceptable risk–benefit profile include DBS and micro- or radiosurgical anterior capsulotomy for intractable obsessive–compulsive disorder. These methods may be considered for individual treatment attempts, but multi-centre RCTs are necessary to provide reliable evidence.

Stakeholders' Perspectives regarding Participation in Neuromodulation-Based Dementia Intervention Research

This study evaluated stakeholders' perspectives regarding participation in two hypothetical neuromodulation trials focused on individuals with Alzheimer's disease and related disorders (ADRDs). Stakeholders (i.e., individuals at risk for ADRDs [n = 56], individuals with experience as a caregiver for someone with a cognitive disorder [n = 60], and comparison respondents [n = 124]) were recruited via MTurk. Primary outcomes were willingness to enroll (or enroll one's loved one), feeling lucky to have the opportunity to enroll, and feeling obligated to enroll in two protocols (transcranial magnetic stimulation, TMS; deep brain stimulation, DBS). Relative to the Comparison group, the At Risk group endorsed higher levels of "feeling lucky" regarding both research protocols, and higher willingness to participate in the TMS protocol. These findings provide tentative reassurance regarding the nature of decision making regarding neurotechnology-based research on ADRDs. Further work is needed to evaluate the full range of potential influences on research participation.

Methodological Considerations for Setting Up Deep Brain Stimulation Studies for New Indications

Deep brain stimulation (DBS) is a neurosurgical treatment with a growing range of indications. The number of clinical studies is expanding because of DBS for new indications and efforts to improve DBS for existing indications. To date, various methods have been used to perform DBS studies. Designing a clinical intervention study with active implantable medical devices has specific challenges while expanding patient treatment. This paper provides an overview of the key aspects that are essential for setting up a DBS study.

A Novel Framework for Network-Targeted Neuropsychiatric Deep Brain Stimulation

Deep brain stimulation (DBS) has emerged as a promising therapy for neuropsychiatric illnesses, including depression and obsessive-compulsive disorder, but has shown inconsistent results in prior clinical trials. We propose a shift away from the empirical paradigm for developing new DBS applications, traditionally based on testing brain targets with conventional stimulation paradigms. Instead, we propose a multimodal approach centered on an individualized intracranial investigation adapted from the epilepsy monitoring experience, which integrates comprehensive behavioral assessment, such as the Research Domain Criteria proposed by the National Institutes of Mental Health. In this paradigm-shifting approach, we combine readouts obtained from neurophysiology, behavioral assessments, and self-report during broad exploration of stimulation parameters and behavioral tasks to inform the selection of ideal DBS parameters. Such an approach not only provides a foundational understanding of dysfunctional circuits underlying symptom domains in neuropsychiatric conditions but also aims to identify generalizable principles that can ultimately enable individualization and optimization of therapy without intracranial monitoring.

The Nucleus Basalis of Meynert and Its Role in Deep Brain Stimulation for Cognitive Disorders: A Historical Perspective

The nucleus basalis of Meynert (nbM) was first described at the end of the 19th century and named after its discoverer, Theodor Meynert. The nbM contains a large population of cholinergic neurons that project their axons to the entire cortical mantle, the olfactory tubercle, and the amygdala. It has been functionally associated with the control of attention and maintenance of arousal, both key functions for appropriate learning and memory formation. This structure is well-conserved across vertebrates, although its degree of organization varies between species. Since early in the investigation of its functional and pathological significance, its degeneration has been linked to various major neuropsychiatric disorders. For instance, Lewy bodies, a hallmark in the diagnosis of Parkinson's disease, were originally described in the nbM. Since then, its involvement in other Lewy body and dementia-related disorders has been recognized. In the context of recent positive outcomes following nbM deep brain stimulation in subjects with dementia-associated disorders, we review the literature from an historical perspective focusing on how the nbM came into focus as a promising therapeutic option for patients with Alzheimer's disease. Moreover, we will discuss what is needed to further develop and widely implement this approach as well as examine novel medical indications for which nbM deep brain stimulation may prove beneficial.

Efficacy and Safety of Gamma Ventral Capsulotomy for Treatment-Resistant Obsessive-Compulsive Disorder: A Single-Center Experience

BACKGROUND

Obsessive-compulsive disorder (OCD) is a chronic disease with a lifetime prevalence of 3% and is associated with severe impairment in familial and socio-occupational functioning. Gamma ventral capsulotomy (GVC) is a treatment choice in carefully chosen patients, with few published reports. In this study, we aimed to report the efficacy and safety of GVC in 21 patients with treatment-resistant OCD.

METHODS

This is a retrospective single-center study. Twenty-one patients meeting the selection criteria were included. Patients were considered responders if there were ≥35% reduction in post-GVC Yale-Brown Obsessive Compulsive Scale scores and considered in remission if scores were ≤8. The mean and median clinical follow-up durations were 60.7 and 56 months, respectively (range, 38-149 months).

RESULTS

The mean baseline Yale-Brown Obsessive Compulsive Scale score of 35.7 (n = 21) decreased to 15.3 (n = 20) at 36 months follow-up evaluation (P < 0.0001). Fifteen patients (75%) achieved a full response. Of those patients, 7 (35%) were considered to be in remission. There were no partial responders, and 5 patients (25%) were classified as nonresponders. The pre-GVC mean Beck Depression Inventory-II score of 35.1 (n = 21) decreased to 13.8 (n = 20) at 36 months follow-up evaluation (P < 0.0001). Three patients (14.3%) had a transient post-GVC headache that resolved within a week, and 2 patients (9.5%) had persistent headaches that responded to 2-week oral corticosteroid treatment. A brain cyst developed after GVC in 2 patients (10%). No clinically notable abnormalities were seen on neurologic examination at any follow-up.

CONCLUSIONS

Gamma ventral capsulotomy is a reasonable treatment method in select patients with treatment-resistant OCD.

Negative association of perceived risk and willingness to participate in innovative psychiatric research protocols

Psychiatric researchers grapple with concerns that individuals with mental illness may be less likely to appreciate risks of research participation, particularly compared to people not suffering from mental illness. Therefore, empirical studies that directly compare the perspectives of such individuals are needed. In addition, it is important to evaluate perspectives regarding varied types of research protocols, particularly as innovative psychiatric research protocols emerge. In this pilot study, respondents with a mood disorder (n = 25) as well as respondents without a mood disorder (n = 55) were recruited using Amazon's Mechanical Turk (MTurk) platform. These respondents were surveyed regarding four psychiatric research projects (i.e., experimental medication [pill form]; non-invasive magnetic brain stimulation; experimental medication [intravenous infusion]; and implantation of a device in the brain). Regardless of health status, respondents rated the four research protocols as somewhat to highly risky. The brain-device implant protocol was seen as the most risky, while the magnetic brain stimulation project was viewed as "somewhat risky". Respondents, on average and regardless of health status, rated their willingness at or below "somewhat willing." Respondents were least willing to participate in the brain-device implant protocol, whereas they were "somewhat willing" to participate in the magnetic brain stimulation protocol. Trust in medical research was negatively associated with perceived risk of research protocols. Perceived risk was negatively associated with willingness to participate, even when adjusting for potential confounders, suggesting that attunement to risk crosses diagnostic, gender, and ethnic categories, and is more salient to research decision-making than trust in medical research and dispositional optimism. The findings of this study may offer reassurance about the underlying decision-making processes of individuals considering participation in innovative neuroscience studies.

Deep brain stimulation: current challenges and future directions

The clinical use of deep brain stimulation (DBS) is among the most important advances in the clinical neurosciences in the past two decades. As a surgical tool, DBS can directly measure pathological brain activity and can deliver adjustable stimulation for therapeutic effect in neurological and psychiatric disorders correlated with dysfunctional circuitry. The development of DBS has opened new opportunities to access and interrogate malfunctioning brain circuits and to test the therapeutic potential of regulating the output of these circuits in a broad range of disorders. Despite the success and rapid adoption of DBS, crucial questions remain, including which brain areas should be targeted and in which patients. This Review considers how DBS has facilitated advances in our understanding of how circuit malfunction can lead to brain disorders and outlines the key unmet challenges and future directions in the DBS field. Determining the next steps in DBS science will help to define the future role of this technology in the development of novel therapeutics for the most challenging disorders affecting the human brain.

Ethical Challenges of Risk, Informed Consent, and Posttrial Responsibilities in Human Research With Neural Devices: A Review

Importance

Developing more and better diagnostic and therapeutic tools for central nervous system disorders is an ethical imperative. Human research with neural devices is important to this effort and a critical focus of the National Institutes of Health Brain Research Through Advancing Innovative Neurotechnologies (BRAIN) Initiative. Despite regulations and standard practices for conducting ethical research, researchers and others seek more guidance on how to ethically conduct neural device studies. This article draws on, reviews, specifies, and interprets existing ethical frameworks, literature, and subject matter expertise to address 3 specific ethical challenges in neural devices research: analysis of risk, informed consent, and posttrial responsibilities to research participants.

Observations

Research with humans proceeds after careful assessment of the risks and benefits. In assessing whether risks are justified by potential benefits in both invasive and noninvasive neural device research, the following categories of potential risks should be considered: those related to surgery, hardware, stimulation, research itself, privacy and security, and financial burdens. All 3 of the standard pillars of informed consent-disclosure, capacity, and voluntariness-raise challenges in neural device research. Among these challenges are the need to plan for appropriate disclosure of information about atypical and emerging risks of neural devices, a structured evaluation of capacity when that is in doubt, and preventing patients from feeling unduly pressured to participate. Researchers and funders should anticipate participants' posttrial needs linked to study participation and take reasonable steps to facilitate continued access to neural devices that benefit participants. Possible mechanisms for doing so are explored here. Depending on the study, researchers and funders may have further posttrial responsibilities.

Conclusions and Relevance

This ethical analysis and points to consider may assist researchers, institutional review boards, funders, and others engaged in human neural device research.

Deep Brain Stimulation in Psychiatry: Mechanisms, Models, and Next-Generation Therapies

Deep brain stimulation has preliminary evidence of clinical efficacy, but has been difficult to develop into a robust therapy, in part because its mechanisms are incompletely understood. We review evidence from movement and psychiatric disorder studies, with an emphasis on how deep brain stimulation changes brain networks. From this, we argue for a network-oriented approach to future deep brain stimulation studies. That network approach requires methods for identifying patients with specific circuit/network deficits. We describe how dimensional approaches to diagnoses may aid that identification. We discuss the use of network/circuit biomarkers to develop self-adjusting "closed loop" systems.

Gamma Ventral Capsulotomy in Intractable Obsessive-Compulsive Disorder

BACKGROUND

Despite the development of effective pharmacologic and cognitive behavioral treatments for obsessive-compulsive disorder (OCD), some patients continue to be treatment-refractory and severely impaired. Fiber tracts connecting orbitofrontal and dorsal anterior cingulate cortex with subcortical nuclei have been the target of neurosurgical lesions as well as deep brain stimulation in these patients. We report on the safety and efficacy of ventral gamma capsulotomy for patients with intractable OCD.

METHODS

Fifty-five patients with severely disabling, treatment-refractory OCD received bilateral lesions in the ventral portion of the anterior limb of the internal capsule over a 20-year period using the Leksell Gamma Knife. The patients were prospectively followed over 3 years with psychiatric, neurologic, and neuropsychological assessments of safety and efficacy, as well as structural neuroimaging.

RESULTS

Thirty-one of 55 patients (56%) had an improvement in the primary efficacy measure, the Yale-Brown Obsessive Compulsive Scale, of ≥35% over the 3-year follow-up period. Patients had significant improvements in depression, anxiety, quality of life, and global functioning. Patients tolerated the procedure well without significant acute adverse events. Five patients (9%) developed transient edema that required short courses of dexamethasone. Three patients (5%) developed cysts at long-term follow-up, 1 of whom developed radionecrosis resulting in an ongoing minimally conscious state.

CONCLUSIONS

Gamma Knife ventral capsulotomy is an effective radiosurgical procedure for many treatment-refractory OCD patients. A minority of patients developed cysts at long-term follow-up, 1 of whom had permanent neurological sequelae.

Opening the debate on deep brain stimulation for Alzheimer disease - a critical evaluation of rationale, shortcomings, and ethical justification

BACKGROUND

Deep brain stimulation (DBS) as investigational intervention for symptomatic relief from Alzheimer disease (AD) has generated big expectations. Our aim is to discuss the ethical justification of this research agenda by examining the underlying research rationale as well as potential methodological pitfalls. The shortcomings we address are of high ethical importance because only scientifically valid research has the potential to be ethical.

METHOD

We performed a systematic search on MEDLINE and EMBASE. We included 166 publications about DBS for AD into the analysis of research rationale, risks and ethical aspects. Fifty-eight patients were reported in peer-reviewed journals with very mixed results. A grey literature search revealed hints for 75 yet to be published, potentially enrolled patients.

RESULTS

The results of our systematic review indicate methodological shortcomings in the literature that are both scientific and ethical in nature. According to our analysis, research with human subjects was performed before decisive preclinical research was published examining the specific research question at stake. We also raise the concern that conclusions on the potential safety and efficacy have been reported in the literature that seem premature given the design of the feasibility studies from which they were drawn. In addition, some publications report that DBS for AD was performed without written informed consent from some patients, but from surrogates only. Furthermore, registered ongoing trials plan to enroll severely demented patients. We provide reasons that this would violate Art. 28 of the Declaration of Helsinki, because DBS for AD involves more than minimal risks and burdens, and because its efficacy and safety are not yet empirically established to be likely.

CONCLUSION

Based on our empirical analysis, we argue that clinical research on interventions of risk class III (Food and Drug Administration and European Medicines Agency) should not be exploratory but grounded on sound, preclinically tested, and disease-specific a posteriori hypotheses. This also applies to DBS for dementia as long as therapeutic benefits are uncertain, and especially when research subjects with cognitive deficits are involved, who may foreseeably progress to full incapacity to provide informed consent during the required follow-up period.

Deep brain stimulation for obsessive-compulsive disorder: Knowledge and concerns among psychiatrists, psychotherapists and patients

Background:

Deep brain stimulation (DBS) is under investigation for severe obsessive-compulsive disorder (OCD) resistant to other therapies. The number of implants worldwide is slowly increasing. Therefore, it is of importance to explore knowledge and concerns of this novel treatment among patients and their psychiatric healthcare contacts. This information is relevant for scientific professionals working with clinical studies for DBS for this indication. Especially, for future study designs and the creation of information targeting healthcare professionals and patients. The aim of this study was to explore the knowledge and concerns toward DBS among patients with OCD, psychiatrists, and cognitive behavioral therapists.

Methods:

The study was conducted through web-based surveys for the aimed target groups –psychiatrist, patients, and cognitive behavioral therapists. The surveys contained questions regarding previous knowledge of DBS, source of knowledge, attitudes, and concerns towards the therapy.

Results:

The main source of information was from scientific sources among psychiatrists and psychotherapists. The patient's main source of information was the media. Common concerns among the groups included complications from surgery, anesthesia, stimulation side effects, and the novelty of the treatment. Specific concerns for the groups included; personality changes mentioned by patients and psychotherapists, and ethical concerns among psychiatrists.

Conclusion:

There are challenges for DBS in OCD as identified by the participants of this study; source and quality of information, efficacy, potential adverse effects, and eligibility. In all of which the current evidence base still is limited. A broad research agenda is needed for studies going forward.

Deep Brain Stimulation as Clinical Innovation: An Ethical and Organizational Framework to Sustain Deliberations About Psychiatric Deep Brain Stimulation

Deep brain stimulation (DBS) for psychiatric disorders needs to be investigated in proper research trials. However, there are rare circumstances in which DBS could be offered to psychiatric patients as a form of surgical innovation, therefore potentially blurring the lines between these research trials and health care. In this article, we discuss the conditions under which surgical innovation may be accepted as a practice falling at the frontiers of standard clinical care and research per se. However, recognizing this distinction does not settle all ethical issues. Our article offers ethical guideposts to allow clinicians, surgical teams, institutions, and institutional review boards to deliberate about some of the fundamental issues that should be considered before surgical innovation with psychiatric DBS is undertaken. We provide key guiding questions to sustain this deliberation. Then we review the normative and empirical literature that exists to guide reflection about the ethics of surgical innovation and psychiatric DBS with respect to general ethical questions pertinent to psychiatric DBS, multidisciplinary team perspectives in psychiatric DBS, mechanisms for oversight in psychiatric DBS, and capacity and consent in psychiatric DBS. The considerations presented here are to recognize the very specific nature of surgical innovation and to ensure that surgical innovation in the context of psychiatric DBS remains a limited, special category of activity that does not replace appropriate surgical research or become the standard of care based on limited evidence.

ABBREVIATIONS

DBS, deep brain stimulationIRB, institutional review boardOCD, obsessive-compulsive disorder.

Teens and Research

On seeing promising results in a small number of patients, some researchers are conducting trials to determine whether deep brain stimulation (DBS) is an effective treatment for anorexia nervosa (AN). This article asks whether we should open enrollment in trials of DBS for AN to adolescents. Despite concerns about informed consent, parental consent, and unforeseeable psychological sequelae, the article concludes that the risks to anorexic adolescents associated with participation in trials of DBS are reasonable considering the substantial risks of not enrolling teens with AN in research on DBS. The seriousness of AN, its high incidence in teens, and serious shortfalls in the AN treatment literature point to the need for improved, evidence-based treatments for teens with AN. This unmet need generates an obligation on the part of researchers and physicians to promote and conduct research on AN in adolescents.

Removing and reimplanting deep brain stimulation therapy devices in resistant OCD (when the patient does not respond): case report

BACKGROUND

Deep brain stimulation (DBS) is emerging as a promising tool in the treatment of refractory obsessive-compulsive disorder (OCD) but the search for the best target still continues. This issue is especially relevant when particularly resistant profiles are observed in some patients, which have been ascribed to individual responses to DBS according to differential patterns of connectivity. As patients have been implanted, new dilemmas have emerged, such as what to do when the patient does not respond to surgery.

CASE PRESENTATION

Here we describe a 22-year-old male with extremely severe OCD who did not respond to treatment with DBS in the nucleus accumbens, but who did respond after explanting and reimplanting leads targeting the ventral capsule-ventral striatum region. Information regarding the position of the electrodes for both surgeries is provided and possible brain structures affected during stimulation are reviewed. To our knowledge this case is the first in the literature reporting the removal and reimplantation of DBS leads for therapeutical benefits in a patient affected by a mental disorder.

CONCLUSION

The capability for explantation and reimplantation of leads should be considered as part of the DBS therapy reversibility profile in resistant mental disorders, as it allows application in cases of non-response to the first surgery.

A Young Scientists' Perspective on DBS: A Plea for an International DBS Organization

Our think tank tasked by the Dutch Health Council, consisting of Radboud University Nijmegen Honours Academy students with various backgrounds, investigated the implications of Deep Brain Stimulation (DBS) for psychiatric patients. During this investigation, a number of methodological, ethical and societal difficulties were identified. We consider these difficulties to be a reflection of a still fragmented field of research that can be overcome with improved organization and communication. To this effect, we suggest that it would be useful to found a centralized DBS organization. Such an organization makes it possible to 1) set up and maintain a repository, 2) facilitate DBS studies with a larger sample size, 3) improve communication amongst researchers, clinicians and ethical committees, and 4) improve communication between DBS experts and the public at large.

Deep brain stimulation in the treatment of depression

Major depressive disorder is a worldwide disease with debilitating effects on a patient's life. Common treatments include pharmacotherapy, psychotherapy, and electroconvulsive therapy. Many patients do not respond to these treatments; this has led to the investigation of alternative therapeutic modalities. Deep brain stimulation (DBS) is one of these modalities. It was first used with success for treating movement disorders and has since been extended to the treatment of psychiatric disorders. Although DBS is still an emerging treatment, promising efficacy and safety have been demonstrated in preliminary trials in patients with treatment-resistant depression (TRD). Further, neuroimaging has played a pivotal role in identifying some DBS targets and remains an important tool for evaluating the mechanism of action of this novel intervention. Preclinical animal studies have broadened knowledge about the possible mechanisms of action of DBS for TRD, Given that DBS involves neurosurgery in patients with severe psychiatric impairment, ethical questions concerning capacity to consent arise; these issues must continue to be carefully considered.

Long-term outcome of globus pallidus internus deep brain stimulation in patients with Tourette syndrome

OBJECTIVE

To evaluate the effectiveness of deep brain stimulation (DBS) of the globus pallidus internus (GPi) on tic severity and common comorbidities in patients with severe Tourette syndrome that is refractory to pharmacological treatment and psychotherapy.

PATIENTS AND METHODS

We retrospectively assessed the long-term clinical outcomes of 13 patients with treatment-refractory Tourette syndrome who underwent DBS targeting the GPi at the Beijing Tiantan Hospital from January 1, 2006, through May 31, 2013. The primary outcome was a change in tic severity as measured by the Yale Global Tic Severity Scale, and the secondary outcome was a change in associated behavioral disorders and mood as measured by the Gilles de la Tourette Syndrome-Quality of Life Scale assessment.

RESULTS

Compared with baseline, the mean reduction in the total Yale Global Tic Severity Scale scores at last follow-up (mean, 41.9 months; range, 13-80 months) was 52.1% (range, 4.3%-83.6%), and the mean improvement rates at 1 month, 6 months, 12 months, 18 months, 24 months, 30 months, and 36 or more months were 11.8%, 20.0%, 26.8%, 36.7%, 44.7%, 49.0%, and 56.7%, respectively. A paired-sample t test revealed significant improvement of tic symptoms after 6 months of DBS programming (P<.05). The Gilles de la Tourette Syndrome-Quality of Life Scale score improved by a mean of 45.7% (range, 11.0%-77.2%).

CONCLUSION

This study is currently the largest reported GPi DBS case series of patients with treatment-refractory TS with the longest follow-up. Our results support the potential beneficial effect of GPi DBS on disabling tic reduction and improvement of quality of life.

Deep brain stimulation of the basolateral amygdala for treatment-refractory combat post-traumatic stress disorder (PTSD): study protocol for a pilot randomized controlled trial with blinded, staggered onset of stimulation

BACKGROUND

Combat post-traumatic stress disorder (PTSD) involves significant suffering, impairments in social and occupational functioning, substance use and medical comorbidity, and increased mortality from suicide and other causes. Many veterans continue to suffer despite current treatments. Deep brain stimulation (DBS) has shown promise in refractory movement disorders, depression and obsessive-compulsive disorder, with deep brain targets chosen by integration of clinical and neuroimaging literature. The basolateral amygdala (BLn) is an optimal target for high-frequency DBS in PTSD based on neurocircuitry findings from a variety of perspectives. DBS of the BLn was validated in a rat model of PTSD by our group, and limited data from humans support the potential safety and effectiveness of BLn DBS.

METHODS/DESIGN

We describe the protocol design for a first-ever Phase I pilot study of bilateral BLn high-frequency DBS for six severely ill, functionally impaired combat veterans with PTSD refractory to conventional treatments. After implantation, patients are monitored for a month with stimulators off. An electroencephalographic (EEG) telemetry session will test safety of stimulation before randomization to staggered-onset, double-blind sham versus active stimulation for two months. Thereafter, patients will undergo an open-label stimulation for a total of 24 months. Primary efficacy outcome is a 30% decrease in the Clinician Administered PTSD Scale (CAPS) total score. Safety outcomes include extensive assessments of psychiatric and neurologic symptoms, psychosocial function, amygdala-specific and general neuropsychological functions, and EEG changes. The protocol requires the veteran to have a cohabiting significant other who is willing to assist in monitoring safety and effect on social functioning. At baseline and after approximately one year of stimulation, trauma script-provoked 18FDG PET metabolic changes in limbic circuitry will also be evaluated.

DISCUSSION

While the rationale for studying DBS for PTSD is ethically and scientifically justified, the importance of the amygdaloid complex and its connections for a myriad of emotional, perceptual, behavioral, and vegetative functions requires a complex trial design in terms of outcome measures. Knowledge generated from this pilot trial can be used to design future studies to determine the potential of DBS to benefit both veterans and nonveterans suffering from treatment-refractory PTSD.

TRIAL REGISTRATION

PCC121657, 19 March 2014.

Consensus on guidelines for stereotactic neurosurgery for psychiatric disorders

BACKGROUND

For patients with psychiatric illnesses remaining refractory to 'standard' therapies, neurosurgical procedures may be considered. Guidelines for safe and ethical conduct of such procedures have previously and independently been proposed by various local and regional expert groups.

METHODS

To expand on these earlier documents, representative members of continental and international psychiatric and neurosurgical societies, joined efforts to further elaborate and adopt a pragmatic worldwide set of guidelines. These are intended to address a broad range of neuropsychiatric disorders, brain targets and neurosurgical techniques, taking into account cultural and social heterogeneities of healthcare environments.

FINDINGS

The proposed consensus document highlights that, while stereotactic ablative procedures such as cingulotomy and capsulotomy for depression and obsessive-compulsive disorder are considered 'established' in some countries, they still lack level I evidence. Further, it is noted that deep brain stimulation in any brain target hitherto tried, and for any psychiatric or behavioural disorder, still remains at an investigational stage. Researchers are encouraged to design randomised controlled trials, based on scientific and data-driven rationales for disease and brain target selection. Experienced multidisciplinary teams are a mandatory requirement for the safe and ethical conduct of any psychiatric neurosurgery, ensuring documented refractoriness of patients, proper consent procedures that respect patient's capacity and autonomy, multifaceted preoperative as well as postoperative long-term follow-up evaluation, and reporting of effects and side effects for all patients.

INTERPRETATION

This consensus document on ethical and scientific conduct of psychiatric surgery worldwide is designed to enhance patient safety.

Light and chemical control of neuronal circuits: possible applications in neurotherapy

Millions of people worldwide suffer from diseases that result from a failure of central pathways to regulate behavioral and physiological processes. Advances in genetics and pharmacology have already allowed us to appreciate that rather than this dysregulation being systemic throughout the brain, it is usually rooted in specific subsets of dysfunctional cells within discrete neurological circuits. This article discusses the advent of opto- and chemogenetic tools and how they are providing the means to dissect these circuits with a degree of temporal and spatial sensitivity not previously possible. We also highlight the potential applications for treating disease and the key developments likely to have the greatest impact over the next 5 years.

Beyond Consent in Research

Neuroethics Now welcomes papers addressing the ethical application of neuroscience in research and patient care, as well as its impact on society.

Intervening in the psychopath's brain

Psychopathy is a disorder involving personality and behavioral features associated with a high rate of violent aggression and recidivism. This paper explores potential psychopharmacological therapies to modulate dysfunctional neural pathways in psychopaths and reduce the incidence of their harmful behavior, as well as the ethical and legal implications of offering these therapies as an alternative to incarceration. It also considers whether forced psychopharmacological intervention in adults and children with psychopathic traits manifesting in violent behavior can be justified. More generally, the paper addresses the question of how to weigh the psychopath's presumptive right to non-interference in his brain and mind against the public interest in avoiding harm.

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.

Some recent trends and further promising directions in functional neurosurgery

The field of functional neurosurgery has developed a number of recent innovative neuromodulatory approaches to treat disease that remains resistant to the best medical therapy. These include novel surgical techniques to intervene in motor and cognitive sequelae of refractory epilepsy, neurodegenerative disease, and certain psychiatric conditions. To a large extent, much of the innovation in our field continues to be driven by a systems-level understanding of the impact of disease on the brain. For example, several groups have exploited findings from neuroimaging work to identify a number of new potential neuromodulatory targets for the treatment of refractory depression. Ongoing discoveries at the cellular and molecular level promise targeted gene or drug delivery aimed at curing disease. Neurosurgeons will certainly remain at the forefront of translating these strategies into practical clinical applications. Several randomized trials are now underway to assess the safety and efficacy of a number of new approaches, and we will continue to acquire better knowledge of optimal patient selection, identification of the most effective neuromodulatory targets, and recognition of adverse effects as these studies progress.

Deep brain stimulation (DBS) at the interface of neurology and psychiatry

Deep brain stimulation (DBS) is an emerging interventional therapy for well-screened patients with specific treatment-resistant neuropsychiatric diseases. Some neuropsychiatric conditions, such as Parkinson disease, have available and reasonable guideline and efficacy data, while other conditions, such as major depressive disorder and Tourette syndrome, have more limited, but promising results. This review summarizes both the efficacy and the neuroanatomical targets for DBS in four common neuropsychiatric conditions: Parkinson disease, Tourette syndrome, major depressive disorder, and obsessive-compulsive disorder. Based on emerging new research, we summarize novel approaches to optimization of stimulation for each neuropsychiatric disease and we review the potential positive and negative effects that may be observed following DBS. Finally, we summarize the likely future innovations in the field of electrical neural-network modulation.

Deep brain stimulation for Tourette syndrome

Gilles de la Tourette syndrome is a movement disorder characterized by repetitive stereotyped motor and phonic movements with varying degrees of psychiatric comorbidity. Deep brain stimulation (DBS) has emerged as a novel therapeutic intervention for patients with refractory Tourette syndrome. Since 1999, more than 100 patients have undergone DBS at various targets within the corticostriatothalamocortical network thought to be implicated in the underlying pathophysiology of Tourette syndrome. Future multicenter clinical trials and the use of a centralized online database to compare the results are necessary to determine the efficacy of DBS for Tourette syndrome.