Comparative effectiveness of neuroablation and deep brain stimulation for treatment-resistant obsessive-compulsive disorder: a meta-analytic study

White matter changes after Gamma Knife Capsulotomy in patients with intractable obsessive-compulsive disorder

Background

Anterior capsulotomy is one of the therapeutic options for refractory obsessive-compulsive disorder (OCD). Safety and efficacy of Gamma Knife Capsulotomy (GKC) have been demonstrated in the past.

Objective

To characterize changes induced by GKC using a fixel-based analysis (FBA) and possible predictors of efficacy.

Methods

Patients with OCD refractory to other therapies underwent bilateral GKC with 120 Gy as a maximum dose on the anterior limb of the internal capsule (ALIC). The clinical outcome was percent reduction in Yale- Brown Obsessive-Compulsive Scale (Y-BOCS). White Matter changes were analyzed using fixel-based analysis (FBA) for fibre density (FD), fibre-bundle cross-section (FC) and the combination of the two (FDC).

Results

Seven patients underwent GKC. Median follow-up was 13 months (range 12-58 months). Mean (±SD) decrease in Y-BOCS score at last follow-up was 61 % ± 35 % with five patients considered as responders. FBA showed a symmetric FD reduction in the ALIC with extension to the anterior fronto-thalamic radiation; a reduction of FC along the superior longitudinal fasciculus (SLF) in both hemispheres with a predominance in the left one. Reductions in FDC were detected predominantly in the right hemisphere, with a similar pattern to FD reductions and associated with a positive correlation (p < 0.05) between Y-BOCS reduction and fibres passing in the ventral part.

Conclusions

GKC is safe and efficient in reducing OCD severity in selected patients. Changes induced in white matter by GKC extend over the ALIC. Reduction of fibres passing the ventral part of the right sided ALIC correlates with better results.

Cost-effectiveness and threshold analysis of deep brain stimulation vs. treatment-as-usual for treatment-resistant depression

Treatment-resistant depression (TRD) affects approximately 2.8 million people in the U.S. with estimated annual healthcare costs of $43.8 billion. Deep brain stimulation (DBS) is currently an investigational intervention for TRD. We used a decision-analytic model to compare cost-effectiveness of DBS to treatment-as-usual (TAU) for TRD. Because this therapy is not FDA approved or in common use, our goal was to establish an effectiveness threshold that trials would need to demonstrate for this therapy to be cost-effective. Remission and complication rates were determined from review of relevant studies. We used published utility scores to reflect quality of life after treatment. Medicare reimbursement rates and health economics data were used to approximate costs. We performed Monte Carlo (MC) simulations and probabilistic sensitivity analyses to estimate incremental cost-effectiveness ratios (ICER; USD/quality-adjusted life year [QALY]) at a 5-year time horizon. Cost-effectiveness was defined using willingness-to-pay (WTP) thresholds of $100,000/QALY and $50,000/QALY for moderate and definitive cost-effectiveness, respectively. We included 274 patients across 16 studies from 2009-2021 who underwent DBS for TRD and had ≥12 months follow-up in our model inputs. From a healthcare sector perspective, DBS using non-rechargeable devices (DBS-pc) would require 55% and 85% remission, while DBS using rechargeable devices (DBS-rc) would require 11% and 19% remission for moderate and definitive cost-effectiveness, respectively. From a societal perspective, DBS-pc would require 35% and 46% remission, while DBS-rc would require 8% and 10% remission for moderate and definitive cost-effectiveness, respectively. DBS-pc will unlikely be cost-effective at any time horizon without transformative improvements in battery longevity. If remission rates ≥8-19% are achieved, DBS-rc will likely be more cost-effective than TAU for TRD, with further increasing cost-effectiveness beyond 5 years.

Management and Treatment of Obsessive-Compulsive Disorder (OCD): A Literature Review

Obsessive-compulsive disorder (OCD) is a prevalent and debilitating mental health condition. This literature review examines the latest strategies in managing and treating OCD, with an emphasis on psychotherapy, pharmacological interventions, and neurosurgical options. A comprehensive literature search utilizing PubMed, Google Scholar, ClinicalKey, and Embase databases was conducted. Utilizing chosen keywords, the resulting articles were filtered based on inclusion and exclusion criteria. Included articles were used to discuss current research regarding OCD treatment and management. Findings reveal the efficacy and obstacles of treatments such as cognitive-behavioral therapy, selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and evidence-based neurosurgical methods, offering a broad perspective on OCD management. We discuss the limitations of these established treatments and examine the innovative response of neurosurgery in treating patients with OCD. This review highlights the importance of individualized treatment plans and areas for future research.

Severe Refractory Obsessive Compulsive Disorder and Depression: Should We Consider Stereotactic Neurosurgery?

Functional neurosurgery involves modulation of activity within neural circuits that drive pathological activity. Neurologists and neurosurgeons have worked closely together, advancing the field for over a century, such that neurosurgical procedures for movement disorders are now accepted as "standard of care", benefiting hundreds of thousands of patients. As with movement disorders, some neuropsychiatric illnesses, including obsessive compulsive disorder and depression, can be framed as disorders of neural networks. Over the past two decades, evidence has accumulated that stereotactic neurosurgery can help some patients with mental disorders. Nevertheless, despite the availability of class I evidence for some interventions, there is a huge mismatch between the prevalence of severe refractory mental disorders and the number of referrals made to specialised functional neurosurgery services. This paper examines the historical trajectory of neurosurgery for movement and mental disorders. A review of neurosurgical techniques, including stereotactic radiofrequency ablation, gamma knife, deep brain stimulation, and magnetic resonance imaging guided focused ultrasound, explains the high degree of safety afforded by technological advances in the field. Evidence from clinical trials supporting functional neurosurgery for mental disorders, including obsessive compulsive disorder and depression, is presented. An improved understanding of modern functional neurosurgery should foster collaboration between psychiatry and neurosurgery, providing hope to patients whose symptoms are refractory to all other treatments.

Responsive deep brain stimulation guided by ventral striatal electrophysiology of obsession durably ameliorates compulsion

Treatment-resistant obsessive-compulsive disorder (OCD) occurs in approximately one-third of OCD patients. Obsessions may fluctuate over time but often occur or worsen in the presence of internal (emotional state and thoughts) and external (visual and tactile) triggering stimuli. Obsessive thoughts and related compulsive urges fluctuate (are episodic) and so may respond well to a time-locked brain stimulation strategy sensitive and responsive to these symptom fluctuations. Early evidence suggests that neural activity can be captured from ventral striatal regions implicated in OCD to guide such a closed-loop approach. Here, we report on a first-in-human application of responsive deep brain stimulation (rDBS) of the ventral striatum for a treatment-refractory OCD individual who also had comorbid epilepsy. Self-reported obsessive symptoms and provoked OCD-related distress correlated with ventral striatal electrophysiology. rDBS detected the time-domain area-based feature from invasive electroencephalography low-frequency oscillatory power fluctuations that triggered bursts of stimulation to ameliorate OCD symptoms in a closed-loop fashion. rDBS provided rapid, robust, and durable improvement in obsessions and compulsions. These results provide proof of concept for a personalized, physiologically guided DBS strategy for OCD.

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.

Intraoperative valence testing to adjudicate between ventral capsule/ventral striatum and bed nucleus of the stria terminalis target selection in deep brain stimulation for obsessive-compulsive disorder

OBJECTIVE

Deep brain stimulation (DBS) is an accepted therapy for severe, treatment-refractory obsessive-compulsive disorder (trOCD). The optimal DBS target location within the anterior limb of the internal capsule, particularly along the anterior-posterior axis, remains elusive. Empirical evidence from several studies in the past decade has suggested that the ideal target lies in the vicinity of the anterior commissure (AC), either just anterior to the AC, above the ventral striatum (VS), or just posterior to the AC, above the bed nucleus of the stria terminalis (BNST). Various methods have been utilized to optimize target selection for trOCD DBS. The authors describe their practice of planning trajectories to both the VS and BNST and adjudicating between them with awake intraoperative valence testing to individualize permanent target selection.

METHODS

Eight patients with trOCD underwent awake DBS with trajectories planned for both VS and BNST targets bilaterally. The authors intraoperatively assessed the acute effects of stimulation on mood, energy, and anxiety and implanted the trajectory with the most reliable positive valence responses and least stimulation-induced side effects. The method of intraoperative target adjudication is described, and the OCD outcome at last follow-up is reported.

RESULTS

The mean patient age at surgery was 41.25 ± 15.1 years, and the mean disease duration was 22.75 ± 10.2 years. The median preoperative Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score was 39 (range 34-40). Two patients had previously undergone capsulotomy, with insufficient response. Seven (44%) of 16 leads were moved to the second target based on intraoperative stimulation findings, 4 of them to avoid strong negative valence effects. Three patients had an asymmetric implant (1 lead in each target). All 8 patients (100%) met full response criteria, and the mean Y-BOCS score reduction across the full cohort was 51.2% ± 12.8%.

CONCLUSIONS

Planning and intraoperatively testing trajectories flanking the AC-superjacent to the VS anteriorly and to the BNST posteriorly-allowed identification of positive valence responses and acute adverse effects. Awake testing helped to select between possible trajectories and identify individually optimized targets in DBS for trOCD.

Mechanisms underlying capsulotomy for refractory obsessive-compulsive disorder: neural correlates of negative affect processing overlap with deep brain stimulation targets

Ablative procedures such as anterior capsulotomy are potentially effective in refractory obsessive-compulsive disorder (OCD). Converging evidence suggests the ventral internal capsule white matter tracts traversing the rostral cingulate and ventrolateral prefrontal cortex and thalamus is the optimal target for clinical efficacy across multiple deep brain stimulation targets for OCD. Here we ask which prefrontal regions and underlying cognitive processes might be implicated in the effects of capsulotomy by using both task fMRI and neuropsychological tests assessing OCD-relevant cognitive mechanisms known to map across prefrontal regions connected to the tracts targeted in capsulotomy. We tested OCD patients at least 6 months post-capsulotomy (n = 27), OCD controls (n = 33) and healthy controls (n = 34). We used a modified aversive monetary incentive delay paradigm with negative imagery and a within session extinction trial. Post-capsulotomy OCD subjects showed improved OCD symptoms, disability and quality of life with no differences in mood or anxiety or cognitive task performance on executive, inhibition, memory and learning tasks. Task fMRI revealed post-capsulotomy decreases in the nucleus accumbens during negative anticipation, and in the left rostral cingulate and left inferior frontal cortex during negative feedback. Post-capsulotomy patients showed attenuated accumbens-rostral cingulate functional connectivity. Rostral cingulate activity mediated capsulotomy improvement on obsessions. These regions overlap with optimal white matter tracts observed across multiple stimulation targets for OCD and might provide insights into further optimizing neuromodulation approaches. Our findings also suggest that aversive processing theoretical mechanisms may link ablative, stimulation and psychological interventions.

Neuroethical implications of focused ultrasound for neuropsychiatric illness

BACKGROUND

MR-guided focused ultrasound is a promising intervention for treatment-resistant mental illness, and merits contextualized ethical exploration in relation to more extensive ethical literature regarding other psychosurgical and neuromodulation treatment options for this patient population. To our knowledge, this topic has not yet been explored in the published literature.

OBJECTIVE

The purpose of this paper is to review and discuss in detail the neuroethical implications of MR-guided focused ultrasound for neuropsychiatric illness as an emerging treatment modality.

METHODS

Due to the lack of published literature on the topic, the approach involved a detailed survey and review of technical and medical literature relevant to focused ultrasound and established ethical issues related to alternative treatment options for patients with treatment-resistant, severe and persistent mental illness. The manuscript is structured according to thematic and topical findings.

RESULTS

This technology has potential benefits for patients suffering with severe mental illness, compared with established alternatives. The balance of technical, neuroscientific and clinical considerations should inform ethical deliberations. The nascent literature base, nuances in legal classification and permissibility depending upon jurisdiction, influences of past ethical issues associated with alternative treatments, tone and framing in media articles, and complexity of clinical trials all influence ethical assessment and evaluations of multiple stakeholders. Recommendations for future research are provided based on these factors.

CONCLUSION

Salient ethical inquiry should be further explored by researchers, clinicians, and ethicists in a nuanced manner methodologically, one which is informed by past and present ethical issues related to alternative treatment options, broader psychiatric treatment frameworks, pragmatic implementation challenges, intercultural considerations, and patients' ethical concerns.

Neurosurgical interventions for psychiatric illness – an underutilised option in treatment?

Neurosurgery for mental disorder is performed in the UK for treatment-refractory obsessive–compulsive disorder and depression. In this commentary, the procedures used are considered alongside other surgical interventions for psychiatric conditions. Given the evidence for efficacy, this commentary agrees with Whitehead & Barrera's assessment that such procedures be considered more widely in treatment-refractory illness and concurs that the advent of minimally invasive radiosurgery is an exciting prospect for patients who have not responded to other treatments.

Cost-effectiveness analysis of radiosurgical capsulotomy versus treatment as usual for treatment-resistant obsessive-compulsive disorder

OBJECTIVE

Stereotactic radiosurgical capsulotomy (SRS-C) is an effective neurosurgical option for patients with treatment-resistant obsessive-compulsive disorder (TROCD). Unlike other procedures such as deep brain stimulation and radiofrequency ablation, the cost-effectiveness of SRS-C for TROCD has not been investigated. The authors herein report the first cost-effectiveness analysis of SRS-C for TROCD.

METHODS

Using a decision analytic model, the authors compared the cost-effectiveness of SRS-C to treatment as usual (TAU) for TROCD. Treatment response and complication rates were derived from a review of relevant clinical trials. Published algorithms were used to convert Yale-Brown Obsessive Compulsive Scale scores into utility scores reflecting improvements in quality of life. Costs were approached from the healthcare sector perspective and were drawn from Medicare reimbursement rates and available healthcare economics data. A Monte Carlo simulation and probabilistic sensitivity analysis were performed to estimate the incremental cost-effectiveness ratio.

RESULTS

One hundred fifty-eight TROCD patients across 9 studies who had undergone SRS-C and had at least 36 months of follow-up were included in the model. Compared to TAU, SRS-C was more cost-effective, with an estimated incremental cost-effectiveness ratio of $28,960 per quality-adjusted life year (QALY) gained. Within the 3-year time horizon, net QALYs gained were greater in the SRS-C group than the TAU group by 0.27 (95% CI 0.2698-0.2702, p < 0.0001). At willingness-to-pay thresholds of $50,000 and $100,000 per QALY, the Monte Carlo simulation revealed that SRS-C was more cost-effective than TAU in 83% and 100% of iterations, respectively.

CONCLUSIONS

Compared to TAU, SRS-C for TROCD is more cost-effective under a range of possible cost and effectiveness values.

Potential therapeutic mechanism of deep brain stimulation of the nucleus accumbens in obsessive-compulsive disorder

Deep brain stimulation (DBS) of the nucleus accumbens (NAc) (NAc-DBS) is an effective solution to refractory obsessive-compulsive disorder (OCD). However, evidence for the neurobiological mechanisms of OCD and the effect of NAc-DBS is still lacking. One hypothesis is that the electrophysiological activities in the NAc are modulated by DBS, and another hypothesis is that the activities of neurotransmitters in the NAc are influenced by DBS. To investigate these potential alterations, rats with quinpirole (QNP)- induced OCD were treated with DBS of the core part of NAc. Then, extracellular spikes (SPK) and local field potentials (LFP) in the NAc were recorded, and the levels of relevant neurotransmitters and related proteins were measured. Analysis of SPK revealed that the firing rate was decreased and the firing pattern was changed after NAc-DBS, and analysis of LFP showed that overall power spectral density (PSD) levels were reduced after NAc-DBS. Additionally, we found that the relative powers of the theta band, alpha band and beta band were increased in OCD status, while the relative powers of the delta band and gamma band were decreased. This pathological pattern of power distribution was reformed by NAc-DBS. Furthermore, we found that the local levels of monoamines [dopamine (DA) and serotonin (5-HT)] and amino acids [glutamate (Glu) and gamma-aminobutyric acid (GABA)] in the NAc were increased in OCD status, and that the expression of the two types of DA receptors in the NAc exhibited an opposite change. These abnormalities could be reversed by NAc-DBS. These findings provide a more comprehensive understanding about the function of the NAc in the pathophysiology of OCD and provide more detailed evidence for the potential effect of NAc-DBS.

Neuromodulation of OCD: A review of invasive and non-invasive methods

Early research into neural correlates of obsessive compulsive disorder (OCD) has focused on individual components, several network-based models have emerged from more recent data on dysfunction within brain networks, including the the lateral orbitofrontal cortex (lOFC)-ventromedial caudate, limbic, salience, and default mode networks. Moreover, the interplay between multiple brain networks has been increasingly recognized. As the understanding of the neural circuitry underlying the pathophysiology of OCD continues to evolve, so will too our ability to specifically target these networks using invasive and noninvasive methods. This review discusses the rationale for and theory behind neuromodulation in the treatment of OCD.

Stereotactic cingulotomy and capsulotomy for obsessive-compulsive disorders: Indications and comparative results

Stereotactic cingulotomy and capsulotomy have been used to treat obsessive-compulsive disorders (OCD) and treatment-resistant depression since the 1950s-60s. To date, these surgical procedures have gained a number of advancements due to progress of neuroimaging and upgrading of stereotactic technique. The effectiveness of operations is related to the restoration of the normal level of limbic regulation in treated patients. In cases of OCD, capsulotomy is somewhat more effective, while cingulotomy has a more favorable safety profile. Moreover, clinical experience shows that these procedures may be efficient for management not only OCD itself, but for obsessive-compulsive symptoms in cases of other mental diseases, such as Tourette syndrome and schizophrenia, thus may be considered in carefully selected patients. An individualized treatment strategy, including staged stereotactic interventions, seems most promising for attainment of the best possible outcomes, and may allow to achieve socialization of 75% of the operated patients with minimal pharmacological support. Other potential stereotactic targets for management of OCD, which selection may depend on detail of clinical manifestation of disease, include thalamic nuclei, nucleus accumbens, globus pallidus, the amygdala, etc., and are currently under active evaluation, and their use is tremendously facilitated by the development of deep brain stimulation techniques. Nevertheless, cingulotomy and capsulotomy still remain highly relevant for treatment of patients with therapy-resistant mental disorders.

Modern neurosurgical techniques for psychiatric disorders

Psychosurgery refers to an ensemble of more or less invasive techniques designed to reduce the burden caused by psychiatric diseases in patients who have failed to respond to conventional therapy. While most surgeries are designed to correct apparent anatomical abnormalities, no discrete cerebral anatomical lesion is evident in most psychiatric diseases amenable to invasive interventions. Finding the optimal surgical targets in mental illness is troublesome. In general, contemporary psychosurgical procedures can be classified into one of two primary modalities: lesioning and stimulation procedures. The first group is divided into (a) thermocoagulation and (b) stereotactic radiosurgery or recently introduced transcranial magnetic resonance-guided focused ultrasound, whereas stimulation techniques mainly include deep brain stimulation (DBS), cortical stimulation, and the vagus nerve stimulation. The most studied psychiatric diseases amenable to psychosurgical interventions are severe treatment-resistant major depressive disorder, obsessive-compulsive disorder, Tourette syndrome, anorexia nervosa, schizophrenia, and substance use disorder. Furthermore, modern neuroimaging techniques spurred the interest of clinicians to identify cerebral regions amenable to be manipulated to control psychiatric symptoms. On this way, the concept of a multi-nodal network need to be embraced, enticing the collaboration of psychiatrists, psychologists, neurologists and neurosurgeons participating in multidisciplinary groups, conducting well-designed clinical trials.

The Patient Lived-Experience of Ventral Capsulotomy for Obsessive-Compulsive Disorder: An Interpretive Phenomenological Analysis of Neuroablative Psychiatric Neurosurgery

Ventral Capsulotomy (VC) is a surgical intervention for treatment-resistant Obsessive-Compulsive Disorder (OCD). Despite clinical studies, little is known about patient perception and lived experience after neurosurgery for severe OCD. To examine the lived experiences of patients who have undergone VC for severe, treatment-resistant OCD through qualitative analysis. We conducted semi-structured interviews with six participants treated with VC for OCD. Interviews were analyzed using Interpretive Phenomenological Analysis. The following themes emerged: (1) After years of conventional treatments, patients felt neurosurgery was their “last hope” and described themselves as “desperate,” (2) While some described the surgery as a “supernatural experience,” patients also demonstrated understanding of the scientific procedure, its risks and potential benefits, (3) The surgical experience itself was positive or neutral, which was linked to trust in the clinical team, (4) Post-surgery, participants described months of heightened fear as they awaited lesion formation and functional improvement. (5) Patients consistently contextualized outcome in the context of their own life goals. Patients undergoing VC have positive views of this neurosurgical intervention, but psychiatric neurosurgical teams should anticipate patient discomfort with the time needed to achieve behavioral improvement following surgery and emphasize the importance of post-operative psychiatric care.

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.

Can responsive deep brain stimulation be a cost-effective treatment for severe obesity?

OBJECTIVE

A first-in-human responsive deep brain stimulation (rDBS) trial (NCT03868670) for obesity is under way, which is based on promising preclinical evidence. Given the upfront costs of rDBS, it is prudent to examine the success threshold for cost-effectiveness compared with laparoscopic Roux-en-Y gastric bypass (LRYGB).

METHODS

Efficacy and safety data on LRYGB and safety data on rDBS were collected for established indications through a literature search. The success threshold was defined as minimum BMI reduction. Treatment costs were calculated via Medicare national reimbursement data.

RESULTS

LRYGB had a mean BMI reduction of 13.75 kg/m² . Based on adverse events, LRYGB was a less-preferred health state (overall adverse event utility of 0.96 [0.02]) than rDBS (0.98 [0.01]), but LRYGB ($14,366 [$6,410]) had a significantly lower treatment cost than rDBS ($29,951 [$4,490]; p < 0.0001). Therefore, for rDBS to be cost-effective compared with LRYGB, the multiple models yielded a success threshold range of 13.7 to 15.2 kg/m² .

CONCLUSIONS

This study established a preliminary efficacy success threshold for rDBS to be cost-effective for severe obesity, and results from randomized controlled trials are needed. This analysis allows for interpretation of the economic impact of advancing rDBS for obesity in light of ongoing trial results and suggests an attainable threshold is needed for cost-effectiveness.

Efficacy of Gamma Knife Radiosurgery in Refractory Obsessive-Compulsive Disorder: An Indian Experience

Background Obsessive-compulsive disorder (OCD) is a chronic debilitating psychiatric condition with adverse impact on patient's sociooccupational health. Refractoriness to pharmacotherapy and psychotherapy is not uncommon. Gamma Knife radiosurgery (GKRS) is the comprehensively used and reviewed treatment modality in refractory OCD worldwide. In India, the past two decades of increasing GKRS availability has failed to create the necessary local awareness of its usefulness in refractory OCD. Limited native literature deepens the problem.

Objective To analyze our experience with GKRS in refractory OCD, and report the safety and efficacy/long-term outcome in patients using the Yale–Brown Obsessive-Compulsive Scale (Y-BOCS).

Materials and Methods A retrospective review of patients receiving GKRS for refractory OCD between 2000 and 2020 was carried out. Case files of the eligible (n = 9) patients were reviewed for clinical, radiotherapeutic, and outcome data. Additionally, patients were contacted via telephone to enquire about their experiences, and to obtain retroactive consent for GKRS in June 2021. Information obtained was collated, computed, and analyzed.

Results Male-to-female sex ratio was 8:1. Mean age at the time of GKRS and mean duration of OCD prior to GKRS was 30.1 ± 9.4 and 10.2 ± 5.8 years, respectively. Mean baseline Y-BOCS score was 29.6 ± 4.7. Our first patient received cingulotomy, while the rest underwent anterior capsulotomy. Median margin dose (50% isodose) was 70 Gy. Also, 23.8 ± 7.7 was the mean Y-BOCS score at the last follow-up (median = 30 months). Overall, 44.4% patients showed full/partial response (≥25% reduction in Y-BOCS score) at the last follow-up. In anterior capsulotomy (eight patients), patients with moderate/severe OCD showed better response (4/5 responders) than those with extreme OCD (0/3 responders). Single case of cingulotomy resulted in no response (<25% reduction in Y-BOCS score). No adverse radiation effects were noted. Also, 55.6% patients gave retroactive consent telephonically.

Conclusion GKRS is a safe and effective noninvasive treatment modality for refractory OCD. Ventral anterior capsule is the preferred target. Maximum radiation doses of 120 to 160 Gy are well tolerated. Extremely severe OCD cases fared poorer. Proper awareness about the availability and efficacy of GKRS in refractory OCD is required in India.

Distribution of electric field in patients with obsessive compulsive disorder treated with deep brain stimulation of the bed nucleus of stria terminalis

Background

Deep brain stimulation (DBS) is being investigated as a treatment for therapy-refractory obsessive compulsive disorder (OCD). Many different brain targets are being trialled. Several of these targets such as the ventral striatum (including the nucleus accumbens (NAc)), the ventral capsule, the inferior thalamic peduncle, and the bed nucleus of stria terminalis (BNST)) belong to the same network, are anatomically very close to one another, or even overlap. Data is still missing on how various stimulation parameters in a given target will affect surrounding anatomical areas and impact the clinical outcome of DBS.

Methods

In a pilot study of eleven participants with DBS of the BNST, we investigate through patient-specific simulation of electric field, which anatomical areas are affected by the electric field, and if this can be related to the clinical results. Our study combined individual patient’s stimulation parameters at 12- and 24-month follow-up with image data from the preoperative MRI and postoperative CT. These data were used to calculate the distribution of electric field and create individual anatomical models of the field of stimulation.

Results

The individual electric stimulation fields by stimulation in the BNST were similar at both the 12- and 24-month follow-up, involving mainly anterior limb of the internal capsule (ALIC), genu of the internal capsule (IC), BNST, fornix, anteromedial globus pallidus externa (GPe), and the anterior commissure. A statistical significant correlation (p < 0.05) between clinical effect measured by the Yale-Brown Obsessive Compulsive Scale and stimulation was found at the 12-month follow-up in the ventral ALIC and anteromedial GPe.

Conclusions

Many of the targets under investigation for OCD are in anatomical proximity. As seen in our study, off-target effects are overlapping. Therefore, DBS in the region of ALIC, NAc, and BNST may perhaps be considered to be stimulation of the same target.

Deep brain stimulation for obsessive-compulsive disorder: A systematic review of worldwide experience after 20 years

BACKGROUND

Twenty years after its first use in a patient with obsessive-compulsive disorder (OCD), the results confirm that deep brain stimulation (DBS) is a promising therapy for patients with severe and resistant forms of the disorder. Nevertheless, many unknowns remain, including the optimal anatomical targets, the best stimulation parameters, the long-term (LT) effects of the therapy, and the clinical or biological factors associated with response. This systematic review of the articles published to date on DBS for OCD assesses the short and LT efficacy of the therapy and seeks to identify predictors of response.

AIM

To summarize the existing knowledge on the efficacy and tolerability of DBS in treatment-resistant OCD.

METHODS

A comprehensive search was conducted in the PubMed, Cochrane, Scopus, and ClinicalTrials.gov databases from inception to December 31, 2020, using the following strategy: “(Obsessive-compulsive disorder OR OCD) AND (deep brain stimulation OR DBS).” Clinical trials and observational studies published in English and evaluating the effectiveness of DBS for OCD in humans were included and screened for relevant information using a standardized collection tool. The inclusion criteria were as follows: a main diagnosis of OCD, DBS conducted for therapeutic purposes and variation in symptoms of OCD measured by the Yale-Brown Obsessive-Compulsive scale (Y-BOCS) as primary outcome. Data were analyzed with descriptive statistics.

RESULTS

Forty articles identified by the search strategy met the eligibility criteria. Applying a follow-up threshold of 36 mo, 29 studies (with 230 patients) provided information on short-term (ST) response to DBS in, while 11 (with 155 patients) reported results on LT response. Mean follow-up period was 18.5 ± 8.0 mo for the ST studies and 63.7 ± 20.7 mo for the LT studies. Overall, the percentage of reduction in Y-BOCS scores was similar in ST (47.4%) and LT responses (47.2%) to DBS, but more patients in the LT reports met the criteria for response (defined as a reduction in Y-BOCS scores > 35%: ST, 60.6% vs LT, 70.7%). According to the results, the response in the first year predicts the extent to which an OCD patient will benefit from DBS, since the maximum symptom reduction was achieved in most responders in the first 12-14 mo after implantation. Reports indicate a consistent tendency for this early improvement to be maintained to the mid-term for most patients; but it is still controversial whether this improvement persists, increases or decreases in the long term. Three different patterns of LT response emerged from the analysis: 49.5% of patients had good and sustained response to DBS, 26.6% were non responders, and 22.5% were partial responders, who might improve at some point but experience relapses during follow-up. A significant improvement in depressive symptoms and global functionality was observed in most studies, usually (although not always) in parallel with an improvement in obsessive symptoms. Most adverse effects of DBS were mild and transient and improved after adjusting stimulation parameters; however, some severe adverse events including intracranial hemorrhages and infections were also described. Hypomania was the most frequently reported psychiatric side effect. The relationship between DBS and suicide risk is still controversial and requires further study. Finally, to date, no clear clinical or biological predictors of response can be established, probably because of the differences between studies in terms of the neuroanatomical targets and stimulation protocols assessed.

CONCLUSION

The present review confirms that DBS is a promising therapy for patients with severe resistant OCD, providing both ST and LT evidence of efficacy.

Identification of biomarkers that predict response to subthalamic nucleus deep brain stimulation in resistant obsessive-compulsive disorder: protocol for an open-label follow-up study

INTRODUCTION

Deep brain stimulation (DBS) of bilateral anteromedial subthalamic nucleus (amSTN) has been found to be helpful in a subset of patients with severe, chronic and treatment-refractory obsessive-compulsive disorder (OCD). Biomarkers may aid in patient selection and optimisation of this invasive treatment. In this trial, we intend to evaluate neurocognitive function related to STN and related biosignatures as potential biomarkers for STN DBS in OCD.

METHODS AND ANALYSIS

Twenty-four subjects with treatment-refractory OCD will undergo open-label STN DBS. Structural/functional imaging, electrophysiological recording and neurocognitive assessment would be performed at baseline. The subjects would undergo a structured clinical assessment for 12 months postsurgery. A group of 24 healthy volunteers and 24 subjects with treatment-refractory OCD who receive treatment as usual would be recruited for comparison of biomarkers and treatment response, respectively. Baseline biomarkers would be evaluated as predictors of clinical response. Neuroadaptive changes would be studied through a reassessment of neurocognitive functioning, imaging and electrophysiological activity post DBS.

ETHICS AND DISSEMINATION

The protocol has been approved by the National Institute of Mental Health and Neurosciences Ethics Committee. The study findings will be disseminated through peer-reviewed scientific journals and scientific meetings.

Potential optimization of focused ultrasound capsulotomy for obsessive compulsive disorder

Obsessive-compulsive disorder is a debilitating and often refractory psychiatric disorder. Magnetic resonance-guided focused ultrasound is a novel, minimally invasive neuromodulatory technique that has shown promise in treating this condition. We investigated the relationship between lesion location and long-term outcome in obsessive-compulsive disorder patients treated with focused ultrasound to discern the optimal lesion location and elucidate the efficacious network underlying symptom alleviation. Postoperative images of eleven patients who underwent focused ultrasound capsulotomy were used to correlate lesion characteristics with symptom improvement at one year follow-up. Normative resting-state functional MRI and normative diffusion MRI-based tractography analyses were used to determine the networks associated with successful lesions. Obsessive-compulsive disorder patients treated with inferior thalamic peduncle deep brain stimulation (n = 5) and lesions from the literature implicated in obsessive-compulsive disorder (n = 18) were used for external validation. Successful long-term relief of obsessive-compulsive disorder was associated with lesions that included a specific area in the dorsal anterior limb of the internal capsule. Normative resting-state functional MRI analysis showed that lesion engagement of areas 24 and 46 was significantly associated with clinical outcomes (R = 0.79, p = 0.004). The key role of areas 24 and 46 was confirmed by (1) normative diffusion MRI-based tractography analysis showing that streamlines associated with better outcome projected to these areas, (2) association of these areas with inferior thalamic peduncle deep brain stimulation patients' outcome (R = 0.83, p = 0.003); (3) the connectedness of these areas to obsessive-compulsive disorder-causing lesions, as identified using literature-based lesion network mapping. These results provide considerations for target improvement, outlining the specific area of the internal capsule critical for successful magnetic resonance-guided focused ultrasound outcome and demonstrating that discrete frontal areas are involved in symptom relief. This could help refine focused ultrasound treatment for obsessive-compulsive disorder and provide a network-based rationale for potential alternative targets.

Specialty knowledge and competency standards for pharmacotherapy for adult obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) affects approximately one person in 40 and causes substantial suffering. Evidence-based treatments can benefit many; however, optimal treatment can be difficult to access. Diagnosis is frequently delayed, and pharmacological and psychotherapeutic interventions often fail to follow evidence-based guidelines. To ameliorate this distressing situation, the International OCD Accreditation Task Force of the Canadian Institute for Obsessive-Compulsive Disorders has developed knowledge and competency standards for specialized treatments for OCD through the lifespan. These are foundational to evidence-based practice and will form the basis for upcoming ATF development of certification/accreditation programs. Here, we present specialty standards for the pharmacological treatment of adult OCD. We emphasize the importance of integrating pharmacotherapy with clear diagnosis, appreciation of complicating factors, and evidence-based cognitive behavioral therapy. Clear evidence exists to inform first- and second-line pharmacological treatments. In disease refractory to these initial efforts, multiple strategies have been investigated, but the evidence is more equivocal. These standards summarize this limited evidence to give the specialist practitioner a solid basis on which to make difficult decisions in complex cases. It is hoped that further research will lead to development of a clear, multi-step treatment algorithm to support each step in clinical decision-making.

Deep brain stimulation of the nucleus accumbens/ventral capsule for severe and intractable opioid and benzodiazepine use disorder

Given high relapse rates and the prevalence of overdose deaths, novel treatments for substance use disorder (SUD) are desperately needed for those who are treatment refractory. The objective of this study was to evaluate the safety of deep brain stimulation (DBS) for SUD and the effects of DBS on substance use, substance craving, emotional symptoms, and frontal/executive functions. DBS electrodes were implanted bilaterally within the Nucleus Accumbens/Ventral anterior internal capsule (NAc/VC) of a man in his early 30s with >10-year history of severe treatment refractory opioid and benzodiazepine use disorders. DBS of the NAc/VC was found to be safe with no serious adverse events noted and the participant remained abstinent and engaged in comprehensive treatment at the 12-week endpoint (and 12-month extended follow-up). Using a 0-100 visual analog scale, substance cravings decreased post-DBS implantation; most substantially in benzodiazepine craving following the final DBS titration (1.0 ± 2.2) compared to baseline (53.4 ± 29.5; p < .001). A trend toward improvement in frontal/executive function was observed on the balloon analog risk task performance following the final titration (217.7 ± 76.2) compared to baseline (131.3 ± 28.1, p = .066). FDG PET demonstrated an increase in glucose metabolism in the dorsolateral prefrontal and medial premotor cortices at the 12-week endpoint compared to post-surgery/pre-DBS titration. Heart Rate Variability (HRV) improved following the final titration (rMSSD = 56.0 ± 11.7) compared to baseline (19.2 ± 8.2; p < .001). In a participant with severe, treatment refractory opioid and benzodiazepine use disorder, DBS of the NAc/VC was safe, reduced substance use and craving, and improved frontal and executive functions. Confirmation of these findings with future studies is needed. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Deep brain stimulation versus ablative surgery for treatment-refractory obsessive-compulsive disorder: A meta-analysis

OBJECTIVE

Ablative surgery (ABL) and deep brain stimulation (DBS) are last-resort treatment options for patients suffering from treatment-refractory obsessive-compulsive disorder (OCD). The aim of this study was to conduct an updated meta-analysis comparing the clinical outcomes of the ablative procedures capsulotomy and cingulotomy and deep brain stimulation.

METHODS

We conducted a PubMed search to identify all clinical trials on capsulotomy, cingulotomy, and DBS. Random effects meta-analyses were performed on 38 articles with a primary focus on efficacy in reducing OCD symptoms as measured by a reduction in the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) score and the responder rate (≥35% reduction in Y-BOCS score).

RESULTS

With responder rates of 48% and 53% after 12-16 months and 56% and 57% at last follow-up for ABL and DBS, respectively, and large effect sizes in the reduction in Y-BOCS scores, both surgical modalities show effectiveness in treating refractory OCD. Meta-regression did not show a statistically significant difference between ABL and DBS regarding these outcomes. Regarding adverse events, a statistically significant higher rate of impulsivity is reported in studies on DBS.

CONCLUSION

This meta-analysis shows equal efficacy of ABL and DBS in the treatment of refractory OCD. For now, the choice of intervention should, therefore, rely on factors such as risk of developing impulsivity, patient preferences, and experiences of psychiatrist and neurosurgeon. Future research should provide more insight regarding differences between ABL and DBS and response prediction following direct comparisons between the surgical modalities, to enable personalized and legitimate choices between ABL and DBS.

The Decline of Deep Brain Stimulation for Obsessive-Compulsive Disorder Following FDA Humanitarian Device Exemption Approval

Background: In February 2009, the US Food and Drug Administration (FDA) granted Humanitarian Device Exemption (HDE) for deep brain stimulation (DBS) in the anterior limb of the internal capsule (ALIC) for the treatment of severely debilitating, treatment refractory obsessive–compulsive disorder (OCD). Despite its promise as a life altering treatment for patients with otherwise refractory, severely debilitating OCD, the use of DBS for the treatment of OCD has diminished since the FDA HDE endorsement and is now rarely performed even at busy referral centers. We sought to identify factors hindering OCD patients from receiving DBS therapy.

Materials and Methods: University of Florida (UF) clinical research databases were queried to identify patients evaluated as potential candidates for OCD DBS from January 1, 2002 to July 30, 2020. A retrospective review of these patients' medical records was performed to obtain demographic information, data related to their OCD, and details relevant to payment such as third-party payer, study participation, evaluation prior to or after HDE approval, and any stated factors prohibiting surgical intervention.

Results: Out of 25 patients with severe OCD identified as candidates for DBS surgery during the past 18 years, 15 underwent surgery. Prior to FDA HDE approval, 6 out of 7 identified candidates were treated. After the HDE, only 9 out of 18 identified candidates were treated. Seven of the 9 were funded by Medicare, 1 paid out of pocket, and 1 had “pre-authorization” from her private insurer who ultimately refused to pay after the procedure. Among the 10 identified OCD DBS candidates who were ultimately not treated, 7 patients—all with private health insurance—were approved for surgery by the interdisciplinary team but were unable to proceed with surgery due to lack of insurance coverage, 1 decided against surgical intervention, 1 was excluded due to medical comorbidities and excessive perceived surgical risk, and no clear reason was identified for 1 patient evaluated in 2004 during our initial NIH OCD DBS trial.

Conclusion: Based on compelling evidence that DBS provides substantial improvement of OCD symptoms and markedly improved functional capacity in 2 out of 3 patients with severely debilitating, treatment refractory OCD, the FDA approved this procedure under a Humanitarian Device Exemption in 2009, offering new hope to this unfortunate patient population. A careful review of our experience with OCD DBS at the University of Florida shows that since the HDE approval, only 50% of the severe OCD patients (9 of 18) identified as candidates for this potentially life altering treatment have been able to access the therapy. We found the most common limiting factor to be failure of private insurance policies to cover DBS for OCD, despite readily covering DBS for Parkinson's disease, essential tremor, and even dystonia—another HDE approved indication for DBS. We have identified an inherent discrimination in the US healthcare system against patients with medication-refractory OCD who are economically challenged and do not qualify for Medicare. We urge policy makers, insurance companies, and hospital administrations to recognize this health care disparity and seek to rectify it.

Oscillatory activity in the BNST/ALIC and the frontal cortex in OCD: acute effects of DBS

Deep brain stimulation (DBS) of the bed nucleus of the stria terminalis/anterior limb of the internal capsule (BNST/ALIC) is successfully used for treatment of patients with obsessive-compulsive disorder (OCD). Clinical and experimental studies have suggested that enhanced network synchronization in the theta band is correlated with severity of symptoms. The mechanisms of action of DBS remain unclear in OCD. We here investigate the effect of acute stimulation of the BNCT/ALIC on oscillatory neuronal activity in patients with OCD implanted with DBS electrodes. We recorded the oscillatory activity of local field potentials (LFPs) from DBS electrodes (contact + 0/- 3; bipolar configuration; both hemispheres) from the BNST/ALIC parallel with frontal cortical electroencephalogram (EEG) one day after DBS surgery in four patients with OCD. BNST/ALIC and frontal EEG oscillatory activities were analysed before stimulation as baseline, and after three periods of stimulation with different voltage amplitudes (1 V, 2 V and 3.5 V) at 130 Hz. Overall, acute high frequency DBS reduced oscillatory theta band (4-8 Hz; p < 0.01) but increased other frequency bands in BNST/ALIC and the frontal cortex (p < 0.01). We show that stimulation of the BNST/ALIC in OCD modulates oscillatory activity in brain regions that are involved in the pathomechanisms of OCD. Our findings confirm and extend the findings that enhanced theta oscillatory activity in neuronal networks may be a biomarker for OCD.

Anterior limb of the internal capsule tractography: relationship with capsulotomy outcomes in obsessive-compulsive disorder

OBJECTIVES

Surgical procedures targeting the anterior limb of the internal capsule (aLIC) can be effective in patients with selected treatment-refractory obsessive-compulsive disorder (OCD). The aLIC consists of white-matter tracts connecting cortical and subcortical structures and show a topographical organisation. Here we assess how aLIC streamlines are affected in OCD compared with healthy controls (HCs) and which streamlines are related with post-capsulotomy improvement.

METHODS

Diffusion-weighted MRI was used to compare white-matter microstructure via the aLIC between patients with OCD (n=100, 40 women, mean of age 31.8 years) and HCs (n=88, 39 women, mean of age 29.6 years). For each individual, the fractional anisotropy (FA) and streamline counts were calculated for each white-matter fibre bundle connecting a functionally defined prefrontal and subcortical region. Correlations between tractography measures and pre-capsulotomy and post-capsulotomy clinical outcomes (in obsessive-compulsive, anxiety and depression scores 6 months after surgery) were assessed in 41 patients with OCD.

RESULTS

Hierarchical clustering dendrograms show an aLIC organisation clustering lateral and dissociating ventral and dorsal prefrontal-thalamic streamlines, findings highly relevant to surgical targeting. Compared with HCs, patients with OCD had lower aLIC FA across multiple prefrontal cortical-subcortical regions (p<0.0073, false discovery rate-adjusted). Greater streamline counts of the dorsolateral prefrontal-thalamic tracts in patients with OCD predicted greater post-capsulotomy obsessive-compulsive improvement (p=0.016). In contrast, greater counts of the dorsal cingulate-thalamic streamlines predicted surgical outcomes mediated by depressive and anxiety improvements.

CONCLUSIONS

These findings shed light on the critical role of the aLIC in OCD and may potentially contribute towards precision targeting to optimise outcomes in OCD.

New Directions for Surgical Ablation Treatment of Obsessive Compulsive Disorder

Although there are effective treatments available for many, probably most, patients with OCD, a significant number do not respond, or fail to experience a sustained beneficial response. For patients with such chronic, disabling and 'treatment-refractory' OCD, neurosurgical treatments may be considered. The best-established neurosurgical treatments are so-called ablative procedures, where targeted lesions are created with the intention of interrupting and modifying specific circuitry functions. There is a lengthy history of such procedures and a substantial literature although this is largely of an observational nature. However, both stereotactic radiosurgery (gamma knife) and MR-guided high intensity focused ultrasound are methods of lesion generation that lend themselves to the conduct of blinded randomised trial designs and these are beginning to be utilised. In this chapter, we present a narrative review of the key recent literature that describes the evidence for the safety and efficacy of lesion procedures for OCD. For context, we also consider the strength and quality of evidence relating to intensive residential treatment for OCD (sometimes proposed as an alternative to neurosurgery), furthermore, we also present some comparative data for lesion surgery and deep brain stimulation (DBS).

Effectiveness and safety of neuroablation for severe and treatment-resistant obsessive-compulsive disorder: a systematic review and meta-analysis

Background

Several neuroablative procedures are available for severe and treatment-resistant obsessive-compulsive disorder (OCD), but limited knowledge about their relative clinical advantages and disadvantages poses obstacles for treatment decision-making.

Methods

We searched PubMed, Embase, Scopus, Web of Knowledge and the Cochrane Library for reports up to February 2019. We reviewed the literature on the effectiveness (assessed using the Yale-Brown Obsessive Compulsive Scale [Y-BOCS]) and safety of various neuroablative interventions for severe and treatment-resistant OCD.

Results

We included 23 studies involving 487 patients in the systematic review; 21 studies with 459 patients entered meta-analysis. Overall, neuroablation achieved a response rate (proportion of patients with ≥ 35% reduction in Y-BOCS) of 55%. Most of the adverse events (88.4%) were mild and transient. The top 3 adverse events were headache (14.9%), cognitive deficits (9.1%) and behaviour problems (8.1%). Severe or permanent adverse events included personality changes (2.3%) and brain edema or brain cyst (1.5%). The response rates associated with capsulotomy, limbic leucotomy and cingulotomy were 59% (95% confidence interval [CI] 54-65), 47% (95% CI 23-72) and 36% (95% CI 23-50), respectively. Interventions with different coverages of the dorsal part of the internal capsule were associated with different adverse-event profiles but were unlikely to modify clinical effectiveness.

Limitations

The level of evidence of most included studies was relatively low.

Conclusion

Ablative surgeries are safe and effective for a large proportion of patients with severe and treatment-resistant OCD. Among the available procedures, capsulotomy seemed to be the most effective. Further research is needed to improve clinical effectiveness and minimize risks.

Incisionless MR-guided focused ultrasound: technical considerations and current therapeutic approaches in psychiatric disorders

INTRODUCTION

MR-guided focused ultrasound operating at higher intensities have been reported to effectively and precisely ablate deeper brain structures like the basal ganglia or the thalamic nuclei for the treatment of refractory movement disorders, neuropathic pain and most recently neuropsychiatric disorders, while low-intensity focused ultrasound represents an approach promoting mechanical blood-brain-barrier opening and neuromodulation. This narrative review summarizes the technical development and the therapeutic potential of incisionless MRgFUS in order to treat neuropsychiatric disorders.

AREAS COVERED

A narrative review of clinical trials assessing the safety and efficacy of MRgFUS. A literature review was performed using the following search terms: MR-guided focused ultrasound, psychiatric disorders, noninvasive and invasive brain modulation/stimulation techniques.

EXPERT OPINION

MRgFUS ablation is under clinical investigation (unblinded study design) for obsessive-compulsive disorders (OCDs) [capsulotomy; ALIC] and depression/anxiety disorders [capsulotomy] and has demonstrated an improvement in OCD and depression, although of preliminary character. Low-intensity ultrasound applications have been explored in Alzheimer´s disease (phase 1 study) and healthy subjects. Currently, limited evidence hinders comparison and selection between MRgFUS and noninvasive/invasive brain modulation therapies. However, comparative, sham-controlled trials are needed to reexamine the preliminary findings for the treatment of psychiatric disorders.

Clinical remission of a treatment-refractory individual with severe repetitive rituals and rumination

BACKGROUND

Obsessive-compulsive disorder (OCD) is a severe chronic mental disorder and tends to be refractory to pharmacotherapy or psychotherapy. For treatment-refractory patients, neurosurgical interventions are options. 64 % of OCD patients who undergo neurosurgery still have greater than 16 in the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) after a long-term follow-up. Here, we reported a patient living with long-term OCD (20 years) who was refractory to pharmacotherapy, mindfulness-based psychotherapy, and neurosurgery that injured his bilateral anterior cingulates (AC) and caudate nucleus.

METHODS

The patient accepted a novel psychotherapy named cognitive-coping therapy (CCT) and completed Y-BOCS, Hamilton depression rating scale, the Hamilton anxiety rating scale, social and occupational function assessment, and resting-state function magnetic resonance imaging scans (rs-fMRI) before and after 4-week CCT.

RESULTS

His Y-BOCS score was reduced from 25 to 4. His depression score and anxiety score were reduced from 19 to 3 and from 12 to 3, respectively. The global assessment of functioning score increased from 32 to 88.

CONCLUSIONS

The remission of the patient suggested that CCT could be an alternative intervention for treatment-refractory OCD and those with severe OCD could be cured in short-term.

MR-Guided Focused Ultrasound Versus Radiofrequency Capsulotomy for Treatment-Refractory Obsessive-Compulsive Disorder: A Cost-Effectiveness Threshold Analysis

Meta-analytic techniques support neuroablation as a promising therapy for treatment-refractory obsessive-compulsive disorder (OCD). This technique appears to offer a more favorable complication rate and higher utility than deep brain stimulation. Moreover, these pooled findings suggest that bilateral radiofrequency (RF) capsulotomy has marginally greater efficacy than stereotactic radiosurgery or cingulotomy. MR-guided focused ultrasound (MRgFUS) capsulotomy is an emerging approach with a potentially more favorable profile than RF ablation and radiosurgery, with preliminary data suggesting safety and efficacy. As a clinical trial is being developed, our study examined the cost and clinical parameters necessary for MRgFUS capsulotomy to be a more cost-effective alternative to RF capsulotomy. A decision analytical model of MRgFUS with RF capsulotomy for OCD was performed using outcome parameters of percent surgical improvement in Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score, complications, and side effects. The analysis compared measured societal costs, derived from Medicare reimbursement rates, and effectiveness, based on published RF data. Effectiveness was defined as the degree to which MRgFUS lowered Y-BOCS score. Given that MRgFUS is a new therapy for OCD with scant published data, theoretical risks of MRgFUS capsulotomy were derived from published essential tremor outcomes. Sensitivity analysis yielded cost, effectiveness, and complication rates as critical MRgFUS parameters defining the cost-effectiveness threshold. Literature search identified eight publications (162 subjects). The average reduction of preoperative Y-BOCS score was 56.6% after RF capsulotomy with a 22.6% improvement in utility, a measure of quality of life. Complications occurred in 16.2% of RF cases. In 1.42% of cases, complications were considered acute-perioperative and incurred additional hospitalization cost. The adverse events, including neurological and neurobehavioral changes, in the other 14.8% of cases did not incur further costs, although they impacted utility. Rollback analysis of RF capsulotomy yielded an expected effectiveness of 0.212 quality-adjusted life years/year at an average cost of $24,099. Compared to RF capsulotomy, MRgFUS was more cost-effective under a range of possible cost and complication rates. While further study will be required, MRgFUS lacks many of the inherent risks associated with more invasive modalities and has potential as a safe and cost-effective treatment for OCD.

Deep brain stimulation in the treatment of obsessive-compulsive disorder: current perspectives

Deep brain stimulation (DBS) is a neuro-psychosurgical technique widely accepted in movement disorders, such as Parkinson's disease. Since 1999, DBS has been explored for severe, chronic and treatment-refractory psychiatric diseases. Our review focuses on DBS in obsessive-compulsive disorder (OCD), considered as a last treatment resort by most of learned societies in psychiatry. Two main stimulation areas have been studied: the striatal region and the subthalamic nucleus. But, most of the trials are open-labeled, and the rare controlled ones have failed to highlight the most efficient target. The recent perspectives are otherwise encouraging. Indeed, clinicians are currently considering other promising targets. A case series of 2 patients reported a decrease in OCD symptoms after DBS in the medial forebrain bundle and an open-label study is exploring bilateral habenula stimulation. New response criteria are also investigating such as quality of life, or subjective and lived-experience. Moreover, first papers about cost-effectiveness which is an important criterion in decision making, have been published. The effectiveness of tractography-assisted DBS or micro-assisted DBS is studying with the aim to improve targeting precision. In addition, a trial involving rechargeable pacemakers is undergoing because this mechanism could be efficient and have a positive impact on cost-effectiveness. A recent trial has discussed the possibility of using combined cognitive behavioral therapy (CBT) and DBS as an augmentation strategy. Finally, based on RDoc Research, the latest hypotheses about the understanding of cortico-striato-thalamo-cortical circuits could offer new directions including clinical predictors and biomarkers to perform adaptive closed-loop systems in the next future.