Limbic system surgery for treatment-refractory obsessive-compulsive disorder: a prospective long-term follow-up of 64 patients

What can neuroimaging of neuromodulation reveal about the basis of circuit therapies for psychiatry?

Neuromodulation is increasingly becoming a therapeutic option for treatment resistant psychiatric disorders. These non-invasive and invasive therapies are still being refined but are clinically effective and, in some cases, provide sustained symptom reduction. Neuromodulation relies on changing activity within a specific brain region or circuit, but the precise mechanisms of action of these therapies, is unclear. Here we review work in both humans and animals that has provided insight into how therapies such as deep brain and transcranial magnetic stimulation alter neural activity across the brain. We focus on studies that have combined neuromodulation with neuroimaging such as PET and MRI as these measures provide detailed information about the distributed networks that are modulated and thus insight into both the mechanisms of action of neuromodulation but also potentially the basis of psychiatric disorders. Further we highlight work in nonhuman primates that has revealed how neuromodulation changes neural activity at different scales from single neuron activity to functional connectivity, providing key insight into how neuromodulation influences the brain. Ultimately, these studies highlight the value of combining neuromodulation with neuroimaging to reveal the mechanisms through which these treatments influence the brain, knowledge vital for refining targeted neuromodulation therapies for psychiatric disorders.

Bilateral Anterior Capsulotomy for Treatment-Resistant Obsessive-Compulsive Disorder

INTRODUCTION

Ablative surgery is an intervention of last resort for treatment-resistant obsessive-compulsive disorder (TROCD). Our center has been using bilateral anterior capsulotomy (BAC) for the past 20 years for patients eligible for limbic surgery. This report details our experience with BAC for TROCD.

METHOD

Five patients with OCD met eligibility criteria for BAC. Entry protocols were complex and took around 6 months to complete. Stereotactic radiofrequency was used to produce the capsulotomies. Lesion length varied between 5.7 and 16.9 mm in the coronal plane. Patients were followed between 4 and 20 years.

RESULTS

All 5 patients (100%) were responders as defined by the widely accepted criteria of a reduction of ≥35% in Yale-Brown Obsessive Compulsive Scale (YBOCS) score at 18-month follow-up. Four patients remained responders at the 48 months. One patient was lost to follow-up. Responder status when viewed from the perspective of the YBOCS was sustained over the 4- to 20-year follow-up with one relapse 19 years postsurgery when medications were discontinued. Real-world psychiatric outcomes were different as other vulnerabilities surfaced illustrating the multifactorial determinants of mental health. No patient had any significant long-term neurocognitive or physical side effects.

CONCLUSION

BAC should remain an option of last resort for patients with severe OCD who remain unresponsive to all other interventions.

Beta activity in human anterior cingulate cortex mediates reward biases

The rewards that we get from our choices and actions can have a major influence on our future behavior. Understanding how reward biasing of behavior is implemented in the brain is important for many reasons, including the fact that diminution in reward biasing is a hallmark of clinical depression. We hypothesized that reward biasing is mediated by the anterior cingulate cortex (ACC), a cortical hub region associated with the integration of reward and executive control and with the etiology of depression. To test this hypothesis, we recorded neural activity during a biased judgment task in patients undergoing intracranial monitoring for either epilepsy or major depressive disorder. We found that beta (12-30 Hz) oscillations in the ACC predicted both associated reward and the size of the choice bias, and also tracked reward receipt, thereby predicting bias on future trials. We found reduced magnitude of bias in depressed patients, in whom the beta-specific effects were correspondingly reduced. Our findings suggest that ACC beta oscillations may orchestrate the learning of reward information to guide adaptive choice, and, more broadly, suggest a potential biomarker for anhedonia and point to future development of interventions to enhance reward impact for therapeutic benefit.

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.

Reduced olfactory bulb volume and olfactory sulcus depth in obsessive compulsive disorder

Many studies have shown that limbic system abnormalities are seen in obsessive-compulsive disorder (OCD), but the neurobiological changes in OCD are still unclear. Moreover, olfactory bulb volume (OBV) and its association with symptom severity have not been yet investigated in patients with OCD. This is the first study on OBV and olfactory sulcus depth (OSD) values in OCD patients, to the best of our knowledge. Between January 2018 and March 2022, 25 patients with OCD and 26 healthy controls with brain magnetic resonance imaging (MRI) were included. Detailed disease history of OCD patients was taken, and Yale-Brown obsessive-compulsive scale (YBOCS) was applied. The mean age of the patient group was 33.40±9.58, the mean age of the control group was 32.84±8.01. LOBV, ROBV, TOBV, and LOSD in the patient group were significantly lower than in the control group (p=.013, p=.005, p=.001, p=.015, respectively). ROBV and TOBV were negatively correlated with YBOCS total and subscale scores. A negative correlation was found between ROBV and TOBV and disease duration (r=-0.749 and r=-0.640, respectively). The negative correlation of ROBV and TOBV values with disease duration and disease severity can be used to monitor the neurodegenerative process of OCD disease.

Phase-adaptive brain stimulation of striatal D1 medium spiny neurons in dopamine-depleted mice

Brain rhythms are strongly linked with behavior, and abnormal rhythms can signify pathophysiology. For instance, the basal ganglia exhibit a wide range of low-frequency oscillations during movement, but pathological "beta" rhythms at ~ 20 Hz have been observed in Parkinson's disease (PD) and in PD animal models. All brain rhythms have a frequency, which describes how often they oscillate, and a phase, which describes the precise time that peaks and troughs of brain rhythms occur. Although frequency has been extensively studied, the relevance of phase is unknown, in part because it is difficult to causally manipulate the instantaneous phase of ongoing brain rhythms. Here, we developed a phase-adaptive, real-time, closed-loop algorithm to deliver optogenetic stimulation at a specific phase with millisecond latency. We combined this Phase-Adaptive Brain STimulation (PABST) approach with cell-type-specific optogenetic methods to stimulate basal ganglia networks in dopamine-depleted mice that model motor aspects of human PD. We focused on striatal medium spiny neurons expressing D1-type dopamine receptors because these neurons can facilitate movement. We report three main results. First, we found that our approach delivered PABST within system latencies of 13 ms. Second, we report that closed-loop stimulation powerfully influenced the spike-field coherence of local brain rhythms within the dorsal striatum. Finally, we found that both 4 Hz PABST and 20 Hz PABST improved movement speed, but we found differences between phase only with 4 Hz PABST. These data provide causal evidence that phase is relevant for brain stimulation, which will allow for more precise, targeted, and individualized brain stimulation. Our findings are applicable to a broad range of preclinical brain stimulation approaches and could also inform circuit-specific neuromodulation treatments for human brain disease.

A narrative review of ablative neurosurgery in refractory mental disorders

Neurosurgery for mental disorder (NMD) is currently performed in the UK for cases of severe depressive disorder and obsessive–compulsive disorder refractory to treatment, under stringent regulations as set out under the Mental Health Act 1983. These surgical procedures appear to be effective for a proportion of individuals in this particularly treatment-resistant cohort. The two ablative procedures currently in use in the UK are anterior cingulotomy (ACING) and anterior capsulotomy (ACAPS). After briefly outlining these procedures, their evidence base and how they compare with other neurosurgical procedures, we suggest two ways in which they could be enhanced in terms of precision, namely the use of stereotactic (Gamma Knife®) radiosurgery guided by magnetic resonance imaging as well as a detailed and expanded standardised psychopathological and neuropsychological assessment both before and after surgery. The latter should involve extended long-term follow-up. We then reflect on how such psychopathological and neuropsychological assessments could help to understand why and how these procedures relieve patients’ suffering and distress.

Stereotactic surgeries for abuse syndromes: Patient selection and results

It is known that in present time heroin addiction is the most widespread and difficult to treat. It includes two factors: physical and psychological addiction. The vast majority of patients remained mentally addicted to drugs after physical drug addiction has been eliminated and the organism has been completely detoxed. It is an indomitable desire to take drugs. Neurophysiological mechanisms are in base of psychological dependence. It is similar to those that implement obsessive states (obsessive-compulsive disorders). The central role in these neurophysiological mechanisms is played by limbic system of the brain that provides emotional and motivational behavior of humans (and animals). It was shown that the treatment of medical-resistant forms of obsessive-compulsive disorders requires stereotactic impacts on various structures of the limbic system, including cingulate gyrus. According to literature data, there was several hundred stereotactic effects on the cingulate gyrus in the world. About 1000 stereotactic operations have been performed in our country as a mental addiction of heroin dependent patients' treatment. The efficiency was of about 70%.

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.

Elimination of anxiety after laser interstitial thermal ablation of the dominant cingulate gyrus for epilepsy

Background:

Anxiety is a common symptom of mental health disorders. Surgical treatment of anxiety-related disorders is limited by our understanding of the neural circuitry responsible for emotional regulation. Limbic regions communicate with other cortical and subcortical regions to generate emotional responses and behaviors toward anxiogenic stimuli. Epilepsy involving corticolimbic regions may disrupt normal neural circuitry and present with mood disorders. Anxiety presenting in patients with mesial temporal lobe epilepsy is common; however, anxiety in patients with cingulate epilepsy is not well described. Neurosurgical cases with rare clinical presentations may provide insight into the basic functionality of the human mind and ultimately lead to improvements in surgical treatments.

Case Description:

We present the case of a 24-year-old male with a 20-year history of nonlesional and cingulate epilepsy with an aura of anxiety and baseline anxiety. Noninvasive work-up was discordant. Intracranial evaluation using stereoelectroencephalography established the epileptogenic zone in the left anterior and mid-cingulate gyrus. Stimulation of the cingulate reproduced a sense of anxiety typical of the habitual auras. We performed laser interstitial thermal therapy of the left anterior and mid-cingulate gyrus. At 8 months following ablation, the patient reported a substantial reduction in seizure frequency and complete elimination of his baseline anxiety and anxious auras.

Conclusion:

This case highlights the role of the cingulate cortex (CC) in regulating anxiety. Ablation of the epileptic focus resolved both epilepsy-related anxiety and baseline features.a Future studies assessing the role of the CC in anxiety disorders may enable improvements in surgical treatments for anxiety disorders.

The Evolution of Modern Ablative Surgery for the Treatment of Obsessive-Compulsive and Major Depression Disorders

In this review, we describe the evolution of modern ablative surgery for intractable psychiatric disease, from the original image-guided cingulotomy procedure described by Ballantine, to the current bilateral anterior cingulotomy using MRI-guided stereotactic techniques. Extension of the single lesion bilateral cingulotomy to the extended bilateral cingulotomy and subsequent staged limbic leucotomy (LL) is also discussed. Other ablative surgeries for psychiatric disease including subcaudate tractotomy (SCT) and anterior capsulotomy (AC) using modern MRI-guided ablative techniques, as well as radiosurgical capsulotomy, are described. Finally, the potential emerging role of MR-guided focused ultrasound (MRgFUS) for treating conditions such as major depressive disorder (MDD) and obsessive-compulsive disorder (OCD) is discussed.

Toward personalized medicine in connectomic deep brain stimulation

At the group-level, deep brain stimulation leads to significant therapeutic benefit in a multitude of neurological and neuropsychiatric disorders. At the single-patient level, however, symptoms may sometimes persist despite "optimal" electrode placement at established treatment coordinates. This may be partly explained by limitations of disease-centric strategies that are unable to account for heterogeneous phenotypes and comorbidities observed in clinical practice. Instead, tailoring electrode placement and programming to individual patients' symptom profiles may increase the fraction of top-responding patients. Here, we propose a three-step, circuit-based framework with the aim of developing patient-specific treatment targets that address the unique symptom constellation prevalent in each patient. First, we describe how a symptom network target library could be established by mapping beneficial or undesirable DBS effects to distinct circuits based on (retrospective) group-level data. Second, we suggest ways of matching the resulting symptom networks to circuits defined in the individual patient (template matching). Third, we introduce network blending as a strategy to calculate optimal stimulation targets and parameters by selecting and weighting a set of symptom-specific networks based on the symptom profile and subjective priorities of the individual patient. We integrate the approach with published literature and conclude by discussing limitations and future challenges.

Influencing Human Behavior with Noninvasive Brain Stimulation: Direct Human Brain Manipulation Revisited

The use of tools to perturb brain activity can generate important insights into brain physiology and offer valuable therapeutic approaches for brain disorders. Furthermore, the potential of such tools to enhance normal behavior has become increasingly recognized, and this has led to the development of various noninvasive technologies that provides a broader access to the human brain. While providing a brief survey of brain manipulation procedures used in the past decades, this review aims at stimulating an informed discussion on the use of these new technologies to investigate the human. It highlights the importance to revisit the past use of this unique armamentarium and proceed to a detailed analysis of its present state, especially in regard to human behavioral regulation.

The prefrontal cortex and neurosurgical treatment for intractable OCD

Over the past two decades, circuit-based neurosurgical procedures have gained increasing acceptance as a safe and efficacious approach to the treatment of the intractable obsessive-compulsive disorder (OCD). Lesions and deep brain stimulation (DBS) of the longitudinal corticofugal white matter tracts connecting the prefrontal cortex with the striatum, thalamus, subthalamic nucleus (STN), and brainstem implicate orbitofrontal, medial prefrontal, frontopolar, and ventrolateral cortical networks in the symptoms underlying OCD. The highly parallel distributed nature of these networks may explain the relative lack of adverse effects observed following surgery. Additional pre-post studies of cognitive tasks in more surgical patients are needed to confirm the role of these networks in OCD and to define therapeutic responses to surgical intervention.

Clinical applications of magnetic resonance imaging based functional and structural connectivity

Advances in computational neuroimaging techniques have expanded the armamentarium of imaging tools available for clinical applications in clinical neuroscience. Non-invasive, in vivo brain MRI structural and functional network mapping has been used to identify therapeutic targets, define eloquent brain regions to preserve, and gain insight into pathological processes and treatments as well as prognostic biomarkers. These tools have the real potential to inform patient-specific treatment strategies. Nevertheless, a realistic appraisal of clinical utility is needed that balances the growing excitement and interest in the field with important limitations associated with these techniques. Quality of the raw data, minutiae of the processing methodology, and the statistical models applied can all impact on the results and their interpretation. A lack of standardization in data acquisition and processing has also resulted in issues with reproducibility. This limitation has had a direct impact on the reliability of these tools and ultimately, confidence in their clinical use. Advances in MRI technology and computational power as well as automation and standardization of processing methods, including machine learning approaches, may help address some of these issues and make these tools more reliable in clinical use. In this review, we will highlight the current clinical uses of MRI connectomics in the diagnosis and treatment of neurological disorders; balancing emerging applications and technologies with limitations of connectivity analytic approaches to present an encompassing and appropriate perspective.

Magnetic Resonance-Guided Focused Ultrasound Capsulotomy for Treatment-Resistant Psychiatric Disorders

BACKGROUND

Psychiatric surgery is an important domain of functional neurosurgery and involves deep brain stimulation (DBS) or lesional procedures performed for treatment-resistant psychiatric illness. It has recently become possible to use magnetic-guided focused ultrasound (MRgFUS) to perform bilateral capsulotomy, a lesional technique commonly carried out with surgical radiofrequency ablation or stereotactic radiosurgery. MRgFUS offers several advantages, including improved safety and real-time imaging of the lesions.

OBJECTIVE

To describe the clinical and technical aspects of performing bilateral MRgFUS capsulotomy in patients with severe refractory depression and obsessive-compulsive disorder.

METHODS

We describe the clinical and technical considerations of performing MRgFUS capsulotomy. Topics discussed include patient selection, headframe application, targeting, sonication strategies, and follow-up procedures.

RESULTS

MRgFUS capsulotomy was performed in 16 patients without serious clinical or radiographic adverse events.

CONCLUSION

MRgFUS allows for a safe, less invasive technique for performing a well-studied psychiatric surgery procedure-the anterior capsulotomy.

[Contemporary methods of non-drug therapy for depression]

The review presents information on the most effective current non-drug methods of treatment of depression used in practice. A review of publications in PubMed and PsycINFO and Cochrane Library over the past 10 years was conducted. Non-drug biological therapies demonstrate high efficacy in the reduction of depressive symptoms in patients with recurrent depressive disorder. The use of non-drug therapy does not preclude the continuation of pharmacological therapy. In order to choose an optimal method of treatment, the psychophysical state of a patient, severity of depressive symptoms, response to drug therapy, and possibility of prescribing pharmacological therapy should be taken into account, and the principles of evidence-based medicine should be taken into consideration when making a decision.

Lesion location and outcome following cingulotomy for obsessive-compulsive disorder

OBJECTIVE

Obsessive-compulsive disorder (OCD) is among the most debilitating and medically refractory psychiatric disorders. While cingulotomy is an anatomically targeted neurosurgical treatment that has shown significant promise in treating OCD-related symptoms, the precise underlying neuroanatomical basis for its beneficial effects has remained poorly understood. Therefore, the authors sought to determine whether lesion location is related to responder status following cingulotomy.

METHODS

The authors reviewed the records of 18 patients who had undergone cingulotomy. Responders were defined as patients who had at least a 35% improvement in the Yale-Brown Obsessive Compulsive Scale (YBOCS) score. The authors traced the lesion sites on T1-weighted MRI scans and used an anatomical registration matrix generated by the imaging software FreeSurfer to superimpose these lesions onto a template brain. Lesion placement was compared between responders and nonresponders. The placement of lesions relative to various anatomical regions was also compared.

RESULTS

A decrease in postoperative YBOCS score was significantly correlated with more superiorly placed lesions (decrease -0.52, p = 0.0012). While all lesions were centered within 6 mm of the cingulate sulcus, responder lesions were placed more superiorly and posteriorly along the cingulate sulcus (1-way ANOVA, p = 0.003). The proportions of the cingulum bundle, cingulate gyrus, and paracingulate cortex affected by the lesions were the same between responders and nonresponders. However, all responders had lesions covering a larger subregion of Brodmann area (BA) 32. In particular, responder lesions covered a significantly greater proportion of the posterior BA32 (1-way ANOVA, p = 0.0064).

CONCLUSIONS

Lesions in patients responsive to cingulotomy tended to be located more superiorly and posteriorly and share greater coverage of a posterior subregion of BA32 than lesions in patients not responsive to this treatment.

Technical and radiographic considerations for magnetic resonance imaging-guided focused ultrasound capsulotomy

OBJECTIVE

Magnetic resonance imaging-guided focused ultrasound (MRgFUS) is an emerging treatment modality that enables incisionless ablative neurosurgical procedures. Bilateral MRgFUS capsulotomy has recently been demonstrated to be safe and effective in treating obsessive-compulsive disorder (OCD) and major depressive disorder (MDD). Preliminary evidence has suggested that bilateral MRgFUS capsulotomy can present increased difficulties in reaching lesional temperatures as compared to unilateral thalamotomy. The authors of this article aimed to study the parameters associated with successful MRgFUS capsulotomy lesioning and to present longitudinal radiographic findings following MRgFUS capsulotomy.

METHODS

Using data from 22 attempted MRgFUS capsulotomy treatments, the authors investigated the relationship between various sonication parameters and the maximal temperature achieved at the intracranial target. Lesion volume and morphology were analyzed longitudinally using structural and diffusion tensor imaging. A retreatment procedure was attempted in one patient, and their postoperative imaging is presented.

RESULTS

Skull density ratio (SDR), skull thickness, and angle of incidence were significantly correlated with the maximal temperature achieved. MRgFUS capsulotomy lesions appeared similar to those following MRgFUS thalamotomy, with three concentric zones observed on MRI. Lesion volumes regressed substantially over time following MRgFUS. Fractional anisotropy analysis revealed a disruption in white matter integrity, followed by a gradual return to near-baseline levels concurrent with lesion regression. In the patient who underwent retreatment, successful bilateral lesioning was achieved, and there were no adverse clinical or radiographic events.

CONCLUSIONS

With the current iteration of MRgFUS technology, skull-related parameters such as SDR, skull thickness, and angle of incidence should be considered when selecting patients suitable for MRgFUS capsulotomy. Lesions appear to follow morphological patterns similar to what is seen following MRgFUS thalamotomy. Retreatment appears to be safe, although additional cases will be necessary to further evaluate the associated safety profile.

Double blind randomized controlled trial of deep brain stimulation for obsessive-compulsive disorder: Clinical trial design

Obsessive-compulsive disorder (OCD), a leading cause of disability, affects ~1–2% of the population, and can be distressing and disabling. About 1/3 of individuals demonstrate poor responsiveness to conventional treatments. A small proportion of these individuals may be deep brain stimulation (DBS) candidates. Candidacy is assessed through a multidisciplinary process including assessment of illness severity, chronicity, and functional impact. Optimization failure, despite multiple treatments, is critical during screening. Few patients nationwide are eligible for OCD DBS and thus a multi-center approach was necessary to obtain adequate sample size. The study was conducted over a six-year period and was a NIH-funded, eight-center sham-controlled trial of DBS targeting the ventral capsule/ventral striatum (VC/VS) region. There were 269 individuals who initially contacted the sites, in order to achieve 27 participants enrolled. Study enrollment required extensive review for eligibility, which was overseen by an independent advisory board. Disabling OCD had to be persistent for ≥5 years despite exhaustive medication and behavioral treatment. The final cohort was derived from a detailed consent process that included consent monitoring. Mean illness duration was 27.2 years. OCD symptom subtypes and psychiatric comorbidities varied, but all had severe disability with impaired quality of life and functioning. Participants were randomized to receive sham or active DBS for three months. Following this period, all participants received active DBS. Treatment assignment was masked to participants and raters and assessments were blinded. The final sample was consistent in demographic characteristics and clinical features when compared to other contemporary published prospective studies of OCD DBS. We report the clinical trial design, methods, and general demographics of this OCD DBS sample.

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 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.

Stimulation in the Rat Anterior Insula and Anterior Cingulate During an Effortful Weightlifting Task

When performing tasks, animals must continually assess how much effort is being expended, and gage this against ever-changing physiological states. As effort costs mount, persisting in the task may be unwise. The anterior cingulate cortex (ACC) and the anterior insular cortex are implicated in this process of cost-benefit decision-making, yet their precise contributions toward driving effortful persistence are not well understood. Here we investigated whether electrical stimulation of the ACC or insular cortex would alter effortful persistence in a novel weightlifting task (WLT). In the WLT an animal is challenged to pull a rope 30 cm to trigger food reward dispensing. To make the action increasingly effortful, 45 g of weight is progressively added to the rope after every 10 successful pulls. The animal can quit the task at any point - with the rope weight at the time of quitting taken as the "break weight." Ten male Sprague-Dawley rats were implanted with stimulating electrodes in either the ACC [cingulate cortex area 1 (Cg1) in rodent] or anterior insula and then assessed in the WLT during stimulation. Low-frequency (10 Hz), high-frequency (130 Hz), and sham stimulations were performed. We predicted that low-frequency stimulation (LFS) of Cg1 in particular would increase persistence in the WLT. Contrary to our predictions, LFS of Cg1 resulted in shorter session duration, lower break weights, and fewer attempts on the break weight. High-frequency stimulation of Cg1 led to an increase in time spent off-task. LFS of the anterior insula was associated with a marginal increase in attempts on the break weight. Taken together our data suggest that stimulation of the rodent Cg1 during an effortful task alters certain aspects of effortful behavior, while insula stimulation has little effect.

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).

Harmonizing the Neurobiology and Treatment of Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) is a common, chronic, and oftentimes disabling disorder. The only established first-line treatments for OCD are exposure and response prevention, and serotonin reuptake inhibitor medications (SRIs). However, a subset of patients fails to respond to either modality, and few experience complete remission. Beyond SRI monotherapy, antipsychotic augmentation is the only medication approach for OCD with substantial empirical support. Our incomplete understanding of the neurobiology of OCD has hampered efforts to develop new treatments or enhance extant interventions. This review focuses on several promising areas of research that may help elucidate the pathophysiology of OCD and advance treatment. Multiple studies support a significant genetic contribution to OCD, but pinpointing the specific genetic determinants requires additional investigation. The preferential efficacy of SRIs in OCD has neither led to discovery of serotonergic abnormalities in OCD nor to development of new serotonergic medications for OCD. Several lines of preclinical and clinical evidence suggest dysfunction of the glutamatergic system in OCD, prompting testing of several promising glutamate modulating agents. Functional imaging studies in OCD show consistent evidence for increased activity in brain regions that form a cortico-striato-thalamo-cortical (CSTC) loop. Neuromodulation treatments with either noninvasive devices (e.g., transcranial magnetic stimulation) or invasive procedures (e.g., deep brain stimulation) provide further support for the CSTC model of OCD. A common substrate for various interventions (whether drug, behavioral, or device) may be modulation (at different nodes or connections) of the CSTC circuit that mediates the symptoms of OCD.

Magnetic Resonance-Guided Focused Ultrasound Surgery for Obsessive-Compulsive Disorders: Potential for use as a Novel Ablative Surgical Technique

Surgical treatment for psychiatric disorders, such as obsessive-compulsive disorder (OCD) and depression, using ablative techniques, such as cingulotomy and capsulotomy, have historically been controversial for a number of scientific, social, and ethical reasons. Recently, with the elucidation of anatomical and neurochemical substrates of brain function in healthy controls and patients with such disorders using various functional neuroimaging techniques, these criticisms are becoming less valid. Furthermore, by using new techniques, such as deep brain stimulation (DBS), and identifying more precise targets, beneficial effects and the lack of serious complications have been demonstrated in patients with psychiatric disorders. However, DBS also has many disadvantages. Currently, magnetic resonance-guided focused ultrasound surgery (MRgFUS) is used as a minimal-invasive surgical method for generating precisely placed focal thermal lesions in the brain. Here, we review surgical techniques and their potential complications, along with anterior limb of the internal capsule (ALIC) capsulotomy by radiofrequency lesioning and gamma knife radiosurgery, for the treatment of OCD and depression. We also discuss the limitations and technical issues related to ALIC capsulotomy with MRgFUS for medically refractory OCD and depression. Through this review we hope MRgFUS could be considered as a new treatment choice for refractory OCD.

Neuromodulation for major depressive disorder: innovative measures to capture efficacy and outcomes

Major depressive disorder is a common and debilitating disorder. Although most patients with this disorder benefit from established treatments, a subset of patients have symptoms that remain treatment resistant. Novel treatment approaches, such as deep brain stimulation, are urgently needed for patients with treatment-resistant major depressive disorder. These novel treatments are currently being tested in clinical trials in which success hinges on how accurately and comprehensively the primary outcome measure captures the treatment effect. In this Personal View, we argue that current measures used to assess outcomes in neurosurgical trials of major depressive disorder might be missing clinically important treatment effects. A crucial problem of continuing to use suboptimal outcome measures is that true signals of efficacy might be missed, thereby disqualifying potentially effective treatments. We argue that a re-evaluation of how outcomes are measured in these trials is much overdue and describe several novel approaches that attempt to better capture meaningful change.

Predicting response to psychiatric surgery: a systematic review of neuroimaging findings

BACKGROUND

Psychiatric surgery, including deep brain stimulation and stereotactic ablation, is an important treatment option in severe refractory psychiatric illness. Several large trials have demonstrated response rates of approximately 50%, underscoring the need to identify and select responders preoperatively. Recent advances in neuroimaging have brought this possibility into focus. We systematically reviewed the psychiatric surgery neuroimaging literature to assess the current state of evidence for preoperative imaging predictors of response.

METHODS

We performed this study in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) frameworks, and preregistered it using PROSPERO. We systematically searched the Medline, Embase and Cochrane databases for studies reporting preoperative neuroimaging analyses correlated with clinical outcomes in patients who underwent psychiatric surgery. We recorded and synthesized the methodological details, imaging results and clinical correlations from these studies.

RESULTS

After removing duplicates, the search yielded 8388 unique articles, of which 7 met the inclusion criteria. The included articles were published between 2001 and 2018 and reported on the outcomes of 101 unique patients. Of the 6 studies that reported significant findings, all identified clusters of hypermetabolism, hyperconnectivity or increased size in the frontostriatal limbic circuitry.

LIMITATIONS

The included studies were few and highly varied, spanning 2 decades.

CONCLUSION

Although few studies have analyzed preoperative imaging for predictors of response to psychiatric surgery, we found consistency among the reported results: most studies implicated overactivity in the frontostriatal limbic network as being correlated with clinical response. Larger prospective studies are needed.

REGISTRATION

www.crd.york.ac.uk/prospero/display_record.php?RecordID=131151.

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.

Efficacy of Deep Brain Stimulation of the Ventral Anterior Limb of the Internal Capsule for Refractory Obsessive-Compulsive Disorder: A Clinical Cohort of 70 Patients

OBJECTIVE

Deep brain stimulation (DBS) is an effective treatment option for patients with refractory obsessive-compulsive disorder (OCD). However, clinical experience with DBS for OCD remains limited. The authors examined the tolerability and effectiveness of DBS in an open study of patients with refractory OCD.

METHODS

Seventy consecutive patients, including 16 patients from a previous trial, received bilateral DBS of the ventral anterior limb of the internal capsule (vALIC) between April 2005 and October 2017 and were followed for 12 months. Primary effectiveness was assessed by the change in scores on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) from baseline until the 12-month follow-up. Response was defined by a ≥35% decrease in Y-BOCS score, partial response was defined by a 25%-34% decrease, and nonresponse was defined by a <25% decrease. Secondary effectiveness measures were the Hamilton Anxiety Rating Scale (HAM-A) and the Hamilton Depression Rating Scale (HAM-D).

RESULTS

Y-BOCS, HAM-A, and HAM-D scores all decreased significantly during the first 12 months of DBS. Twelve months of DBS resulted in a mean Y-BOCS score decrease of 13.5 points (SD=9.4) (40% reduction; effect size=1.5). HAM-A scores decreased by 13.4 points (SD=9.7) (55%; effect size=1.4), and HAM-D scores decreased by 11.2 points (SD=8.8) (54%; effect size=1.3). At the 12-month follow-up, 36 of the 70 patients were categorized as responders (52%), 12 patients as partial responders (17%), and 22 patients as nonresponders (31%). Adverse events included transient symptoms of hypomania, agitation, impulsivity, and sleeping disorders.

CONCLUSIONS

These results confirm the effectiveness and safety of DBS of the vALIC for patients with treatment-refractory OCD in a regular clinical setting.

Sub-graph entropy based network approaches for classifying adolescent obsessive-compulsive disorder from resting-state functional MRI

This paper presents a novel approach for classifying obsessive-compulsive disorder (OCD) in adolescents from resting-state fMRI data. Currently, the state-of-the-art for diagnosing OCD in youth involves interviews with adolescent patients and their parents by an experienced clinician, symptom rating scales based on Diagnostic and Statistical Manual of Mental Disorders (DSM), and behavioral observation. Discovering signal processing and network-based biomarkers from functional magnetic resonance imaging (fMRI) scans of patients has the potential to assist clinicians in their diagnostic assessments of adolescents suffering from OCD. This paper investigates the clinical diagnostic utility of a set of univariate, bivariate and multivariate features extracted from resting-state fMRI using an information-theoretic approach in 15 adolescents with OCD and 13 matched healthy controls. Results indicate that an information-theoretic approach based on sub-graph entropy is capable of classifying OCD vs. healthy subjects with high accuracy. Mean time-series were extracted from 85 brain regions and were used to calculate Shannon wavelet entropy, Pearson correlation matrix, network features and sub-graph entropy. In addition, two special cases of sub-graph entropy, namely node and edge entropy, were investigated to identify important brain regions and edges from OCD patients. A leave-one-out cross-validation method was used for the final predictor performance. The proposed methodology using differential sub-graph (edge) entropy achieved an accuracy of 0.89 with specificity 1 and sensitivity 0.80 using leave-one-out cross-validation with in-fold feature ranking and selection. The high classification accuracy indicates the predictive power of the sub-network as well as edge entropy metric.

Deep brain stimulation for obsessive-compulsive disorder

Neurosurgical interventions have been used for decades to treat severe, refractory obsessive-compulsive disorder (OCD). Deep brain stimulation (DBS) is a neurosurgical procedure that is used routinely to treat movement disorders such as Parkinson's disease and essential tremor. Over the past two decades, DBS has been applied to OCD, building on earlier experience with lesional procedures. Promising results led to Humanitarian Device Exemption (HDE) approval of the therapy from the United States Food and Drug Administration in 2009. In this review, the authors describe the development of DBS for OCD, the most recent outcome data, and areas for future research.

Case Studies in Neuroscience: The electrophysiology of a human obsession in nucleus accumbens

Microelectrode recordings were performed during awake deep brain stimulation surgery for obsessive-compulsive disorder, revealing robust brain oscillations that were plainly visible throughout the ventral striatum. There was an elegant topological correspondence between each oscillation and the underlying brain anatomy, most prominently a ~35-Hz gamma-oscillation specific to the nucleus accumbens. Direct provocation of the patient's contamination obsession modulated both firing rate and gamma-oscillation amplitude within the nucleus accumbens. NEW & NOTEWORTHY Surgical implantation of deep brain stimulating electrodes (DBS) to treat obsessive-compulsive disorder (OCD) is an option for patients who have not fully responded to medical intervention or cognitive behavioral therapy. We measured the electrophysiology of a collection of deep brain structures during awake DBS surgery for an OCD patient with an obsession about cleanliness and contamination. The anatomic delineation of these deep brain structures was revealed by distinct brain rhythms, most notably a ~35 Hz oscillation specific to the nucleus accumbens. In the first ever measurement of a human obsessive thought, we found that this ~35-Hz biomarker, as well as the local neuronal action potential rate, were modulated by handing the patient a toothbrush to bring to his face and instructing him to "imagine brushing your teeth with this dirty toothbrush."

Aberrant functional connectivity density in patients with treatment-refractory obsessive-compulsive disorder: a pilot study

Objective

Functional connectivity (FC) is altered in patients with obsessive-compulsive disorder (OCD). Most previous studies have focused on the strength of FC in patients with OCD; few have examined the number of functional connections in these patients. The number of functional connections is an important index for assessing aberrant FC. In the present study, we used FC density (FCD) mapping to explore alterations in the number of functional connections in patients with treatment-refractory OCD (TROCD) using the FCD index.

Methods

Twenty patients with TROCD and 20 patients with OCD in clinical remission were enrolled in the study. Global FCD (gFCD) was adopted to compare the differences between the two groups of patients.

Results

The gFCD in the left middle temporal gyrus was lower in the patients with TROCD than in those with remitted OCD, suggesting that decreased information processing ability may play a significant role in TROCD.

Conclusion

The left middle temporal gyrus is a key component of the emotional processing circuit and attentional processing circuit. Decreased information processing ability in this brain region may play a significant role in TROCD; however, further well-designed follow-up studies are needed to support this hypothesis.

Compulsivity in Alcohol Use Disorder and Obsessive Compulsive Disorder: Implications for Neuromodulation

Alcohol use Disorder (AUD) is one of the leading causes of morbidity and mortality worldwide. The progression of the disorder is associated with the development of compulsive alcohol use, which in turn contributes to the high relapse rate and poor longer term functioning reported in most patients, even with treatment. While the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) defines AUD by a cluster of symptoms, parsing its heterogeneous phenotype by domains of behavior such as compulsivity may be a critical step to improve outcomes of this condition. Still, neurobiological underpinnings of compulsivity need to be fully elucidated in AUD in order to better design targeted treatment strategies. In this manuscript, we review and discuss findings supporting common mechanisms between AUD and OCD, dissecting the construct of compulsivity and focusing specifically on characteristic disruptions in habit learning and cognitive control in the two disorders. Finally, neuromodulatory interventions are proposed as a probe to test compulsivity as key pathophysiologic feature of AUD, and as a potential therapy for the subgroup of individuals with compulsive alcohol use, i.e., the more resistant stage of the disorder. This transdiagnostic approach may help to destigmatize the disorder, and suggest potential treatment targets across different conditions.

Evolution of gamma knife capsulotomy for intractable obsessive-compulsive disorder

For more than half a century, stereotactic neurosurgical procedures have been available to treat patients with severe, debilitating symptoms of obsessive-compulsive disorder (OCD) that have proven refractory to extensive, appropriate pharmacological, and psychological treatment. Although reliable predictors of outcome remain elusive, the establishment of narrower selection criteria for neurosurgical candidacy, together with a better understanding of the functional neuroanatomy implicated in OCD, has resulted in improved clinical efficacy for an array of ablative and non-ablative intervention techniques targeting the cingulum, internal capsule, and other limbic regions. It was against this backdrop that gamma knife capsulotomy (GKC) for OCD was developed. In this paper, we review the history of this stereotactic radiosurgical procedure, from its inception to recent advances. We perform a systematic review of the existing literature and also provide a narrative account of the evolution of the procedure, detailing how the procedure has changed over time, and has been shaped by forces of evidence and innovation. As the procedure has evolved and adverse events have decreased considerably, favorable response rates have remained attainable for approximately one-half to two-thirds of individuals treated at experienced centers. A reduction in obsessive-compulsive symptom severity may result not only from direct modulation of OCD neural pathways but also from enhanced efficacy of pharmacological and psychological therapies working in a synergistic fashion with GKC. Possible complications include frontal lobe edema and even the rare formation of delayed radionecrotic cysts. These adverse events have become much less common with new radiation dose and targeting strategies. Detailed neuropsychological assessments from recent studies suggest that cognitive function is not impaired, and in some domains may even improve following treatment. We conclude this review with discussions covering topics essential for further progress of this therapy, including suggestions for future trial design given the unique features of GKC therapy, considerations for optimizing stereotactic targeting and dose planning using biophysical models, and the use of advanced imaging techniques to understand circuitry and predict response. GKC, and in particular its modern variant, gamma ventral capsulotomy, continues to be a reliable treatment option for selected cases of otherwise highly refractory OCD.

Deep Brain Stimulation for Obsessive Compulsive Disorder: Evolution of Surgical Stimulation Target Parallels Changing Model of Dysfunctional Brain Circuits

Obsessive compulsive disorder (OCD) is a common, disabling psychiatric disease characterized by persistent, intrusive thoughts and ritualistic, repetitive behaviors. Deep brain stimulation (DBS) is thought to alleviate OCD symptoms by modulating underlying disturbances in normal cortico-striato-thalamo-cortical (CSTC) circuitry. Stimulation of the ventral portion of the anterior limb of the internal capsule (ALIC) and underlying ventral striatum (“ventral capsule/ventral striatum” or “VC/VS” target) received U.S. FDA approval in 2009 for patients with severe, treatment-refractory OCD. Over the decades, DBS surgical outcome studies have led to an evolution in the electrical stimulation target. In parallel, advancements in neuroimaging techniques have allowed investigators to better visualize and define CSTC circuits underlying the pathophysiology of OCD. A critical analysis of these new data suggests that the therapeutic mechanism of DBS for OCD likely involves neuromodulation of a widespread cortical/subcortical network, accessible by targeting fiber bundles in the ventral ALIC that connect broad network regions. Future studies will include advances in structural and functional imaging, analysis of physiological recordings, and utilization of next-generation DBS devices. These tools will enable patient-specific optimization of DBS therapy, which will hopefully further improve outcomes.

Indian guidelines on neurosurgical interventions in psychiatric disorders

Neurosurgery for psychiatric disorders (NPD) has been practiced for >80 years. However, the interests have waxed and waned, from 1000s of surgeries in 1940-1950s to handful of surgery in 60-80s. This changed with the application of deep brain stimulation surgery, a surgery, considered to be "reversible" there has been a resurgence in interest. The Indian society for stereotactic and functional neurosurgery (ISSFN) and the world society for stereotactic and functional neurosurgery took the note of the past experiences and decided to form the guidelines for NPD. In 2011, an international task force was formed to develop the guidelines, which got published in 2013. In 2018, eminent psychiatrists from India, functional neurosurgeon representing The Neuromodulation Society and ISSFN came-together to deliberate on the current status, need, and legal aspects of NPD. In May 2018, Mental Health Act also came in to force in India, which had laid down the requirements to be fulfilled for NPD. In light of this after taking inputs from all stakeholders and review of the literature, the group has proposed the guidelines for NPD that can help to steer these surgery and its progress in India.

Ablative neurosurgery and deep brain stimulation for obsessive-compulsive disorder

Despite advancements in pharmacotherapeutic and behavioral interventions, a substantial proportion of patients with obsessive-compulsive disorder (OCD) continue to have disabling and treatment-refractory illness. Neurosurgical interventions, including ablative procedures and deep brain stimulation (DBS), have emerged as potential treatment options in this population. We review the recent literature on contemporary surgical options for OCD, focusing on clinical aspects such as patient selection, presurgical assessment, and safety and effectiveness of these procedures. Given the invasiveness and limited evidence, these procedures have been performed in carefully selected patients with severe, chronic, and treatment-refractory illness. Along with informed consent, an independent review by a multidisciplinary team is mandated in many centers. Both ablative procedures and DBS have been found to be helpful in around half the patients, with improvement observed months after the procedure. Various targets have been proposed for either procedure, based on the dominant corticostriatal model of OCD. There is no strong evidence to recommend one procedure over the other. Hence, the choice of procedure is often based on the factors such as affordability, expertise, and reversibility of adverse effects. Surgery is not recommended as a standalone treatment but should be provided as part of a comprehensive package including medications and psychotherapeutic interventions. Available evidence suggest that the benefits of the procedure outweigh the risks in a treatment-refractory population. Advances in neurosurgical techniques and increasing knowledge of neurobiology are likely to bring about further progress in the efficacy, safety, and acceptability of the procedures.

Neurotherapeutic Interventions for Psychiatric Illness

Many patients with mental illness do not respond to common evidence-based treatments such as psychopharmacology and psychotherapy. We increasingly understand these illnesses as disorders of brain circuits, suggesting that otherwise treatment-refractory patients might be helped by direct intervention in those circuits. Non-invasive techniques for circuit intervention include electro-convulsive therapy (ECT) and transcranial magnetic stimulation (TMS). Circuits can also be targeted more directly and focally through neurosurgical intervention, including through vagus nerve stimulation (VNS), ablative neurosurgery (cingulotomy and capsulotomy), cortical brain stimulation (EpCS), or deep brain stimulation (DBS). Each of these approaches has evidence supporting its use in a major psychiatric disorder, although many have yet to demonstrate a strong clinical signal in a randomized controlled trial. New technologies that may aid in that demonstration include non-invasive techniques that can focus energy more precisely in the deep brain and invasive devices that respond in real time to changes in brain activity (closed-loop stimulation). In this article, we review the modalities and evidence base for these neurotherapeutics, with an emphasis on their clinical readiness and relative advantages.

Charting the road forward in psychiatric neurosurgery: proceedings of the 2016 American Society for Stereotactic and Functional Neurosurgery workshop on neuromodulation for psychiatric disorders

OBJECTIVE

Refractory psychiatric disease is a major cause of morbidity and mortality worldwide, and there is a great need for new treatments. In the last decade, investigators piloted novel deep brain stimulation (DBS)-based therapies for depression and obsessive-compulsive disorder (OCD). Results from recent pivotal trials of these therapies, however, did not demonstrate the degree of efficacy expected from previous smaller trials. To discuss next steps, neurosurgeons, neurologists, psychiatrists and representatives from industry convened a workshop sponsored by the American Society for Stereotactic and Functional Neurosurgery in Chicago, Illinois, in June of 2016.

DESIGN

Here we summarise the proceedings of the workshop. Participants discussed a number of issues of importance to the community. First, we discussed how to interpret results from the recent pivotal trials of DBS for OCD and depression. We then reviewed what can be learnt from lesions and closed-loop neurostimulation. Subsequently, representatives from the National Institutes of Health, the Food and Drug Administration and industry discussed their views on neuromodulation for psychiatric disorders. In particular, these third parties discussed their criteria for moving forward with new trials. Finally, we discussed the best way of confirming safety and efficacy of these therapies, including registries and clinical trial design. We close by discussing next steps in the journey to new neuromodulatory therapies for these devastating illnesses.

CONCLUSION

Interest and motivation remain strong for deep brain stimulation for psychiatric disease. Progress will require coordinated efforts by all stakeholders.

The Potential Usefulness of Magnetic Resonance Guided Focused Ultrasound for Obsessive Compulsive Disorders

Obsessive compulsive disorder is a debilitating condition characterized by recurrent obsessive thoughts and compulsive reactions. A great portion of the obsessive compulsive disorder (OCD) patients are managed successfully with psychiatric treatment such as selective serotonin-reuptake inhibitor and cognitive behavioral psychotherapy, but more than 10% of patients are remained as non-responder who needs neurosurgical treatments. These patients are potential candidates for the neurosurgical management. There had been various kind of operation, lesioning such as leucotomy or cingulotomy or capsulotomy or limbic leucotomy, and with advent of stereotaxic approach and technical advances, deep brain stimulation was more chosen by neurosurgeon due to its characteristic of reversibility and adjustability. Gamma knife radiosurgery are also applied to make lesion targeting based on magnetic resonance (MR) imaging, but the complication of adverse radiation effect is not predictable. In the neurosurgical field, MR guided focused ultrasound has advantage of less invasiveness, real-time monitored procedure which is now growing to attempt to apply for various brain disorder. In this review, the neurosurgical treatment modalities for the treatment of OCD will be briefly reviewed and the current state of MR guided focused ultrasound for OCD will be suggested.

Baby brain atlases

The baby brain is constantly changing due to its active neurodevelopment, and research into the baby brain is one of the frontiers in neuroscience. To help guide neuroscientists and clinicians in their investigation of this frontier, maps of the baby brain, which contain a priori knowledge about neurodevelopment and anatomy, are essential. "Brain atlas" in this review refers to a 3D-brain image with a set of reference labels, such as a parcellation map, as the anatomical reference that guides the mapping of the brain. Recent advancements in scanners, sequences, and motion control methodologies enable the creation of various types of high-resolution baby brain atlases. What is becoming clear is that one atlas is not sufficient to characterize the existing knowledge about the anatomical variations, disease-related anatomical alterations, and the variations in time-dependent changes. In this review, the types and roles of the human baby brain MRI atlases that are currently available are described and discussed, and future directions in the field of developmental neuroscience and its clinical applications are proposed. The potential use of disease-based atlases to characterize clinically relevant information, such as clinical labels, in addition to conventional anatomical labels, is also discussed.

Double Anterior Stereotactic Cingulotomy for Intractable Oncological Pain

BACKGROUND

Stereotactic anterior cingulotomy has been used in the treatment of patients suffering from refractory oncological pain due to its effects on pain perception. However, the optimal targets as well as suitable candidates and outcome measures have not been well defined. We report our initial experience in the ablation of 2 cingulotomy targets on each side and the use of the Brief Pain Inventory (BPI) as a perioperative assessment tool.

METHODS

A retrospective review of all patients who underwent stereotactic anterior cingulotomy in our Department between November 2015 and February 2017 was performed. All patients had advanced metastatic cancer with limited prognosis and suffered from intractable oncological pain.

RESULTS

Thirteen patients (10 women and 3 men) underwent 14 cingulotomy procedures. Their mean age was 54 ± 14 years. All patients reported substantial pain relief immediately after the operation. Out of the 6 preoperatively bedridden patients, 3 started ambulating shortly after. At the 1-month follow-up, the mean preoperative Visual Analogue Scale score decreased from 9 ± 0.9 to 4 ± 2.7 (p = 0.003). Mean BPI pain severity and interference scores decreased from levels of 29 ± 4 and 55 ± 12 to 16 ± 12 (p = 0.028) and 37 ± 15 (p = 0.043), respectively. During the 1- and 3-month follow-up visits, 9/11 patients (82%) and 5/7 patients (71%) available for follow-up reported substantial pain relief. No patient reported worsening of pain during the study period. Neuropsychological analyses of 6 patients showed stable cognitive functions with a mild nonsignificant decline in focused attention and executive functions. Adverse events included transient confusion or mild apathy in 5 patients (38%) lasting 1-4 weeks.

CONCLUSIONS

Our initial experience indicates that double stereotactic cingulotomy is safe and effective in alleviating refractory oncological pain.

State of the Art: Novel Applications for Cortical Stimulation

OBJECTIVE

Electrical stimulation via implanted electrodes that overlie the cortex of the brain is an upcoming neurosurgical technique that was hindered for a long time by insufficient knowledge of how the brain functions in a dynamic, physiological, and pathological way, as well as by technological limitations of the implantable stimulation devices.

METHODS

This paper provides an overview of cortex stimulation via implantable devices and introduces future possibilities to improve cortex stimulation.

RESULTS

Cortex stimulation was initially used preoperatively as a technique to localize functions in the brain and only later evolved into a treatment technique. It was first used for pain, but more recently a multitude of pathologies are being targeted by cortex stimulation. These disorders are being treated by stimulating different cortical areas of the brain. Risks and complications are essentially similar to those related to deep brain stimulation and predominantly include haemorrhage, seizures, infection, and hardware failures. For cortex stimulation to fully mature, further technological development is required to predict its outcomes and improve stimulation designs. This includes the development of network science-based functional connectivity approaches, genetic analyses, development of navigated high definition transcranial alternating current stimulation, and development of pseudorandom stimulation designs for preventing habituation.

CONCLUSION

In conclusion, cortex stimulation is a nascent but very promising approach to treating a variety of diseases, but requires further technological development for predicting outcomes, such as network science based functional connectivity approaches, genetic analyses, development of navigated transcranial electrical stimulation, and development of pseudorandom stimulation designs for preventing habituation.