Examining cognitive change in magnetic resonance-guided focused ultrasound capsulotomy for psychiatric illness

Focused ultrasound as an emerging therapy for neuropsychiatric disease: Historical perspectives and a review of current clinical data

Psychiatric disorders are a common source of disease morbidity with high rates of refractoriness to first-line treatments. As such, many have investigated the utility of neurosurgical interventions for treatment-resistant forms of these conditions. More recently among these, functional neurosurgical techniques using high- and low-intensity focused ultrasound (FUS) have emerged as promising options in this arena, largely due to their minimally-invasive nature and encouraging early safety and efficacy data. Existing clinical data have thus far demonstrated FUS to be a potentially useful intervention for treatment-refractory forms of obsessive-compulsive disorder, major depressive disorder, various anxiety disorders, substance-use disorder, and schizophrenia. This report presents a comprehensive review of existing clinical trial data, summarizing key findings, study specifications, and providing critical analysis. In addition to giving the most complete summary of modern clinical research on this topic to date, this report characterizes the current state of this body of literature using bibliometric analysis, succinctly highlighting the most investigated topics and the most promising areas of modern investigation. Based on our review of the literature, current work on this topic is highly heterogeneous with regard to specific treatment protocols and anatomic targets for FUS - targeting multiple nuclei at a wide variety of intensities. We recommend that future studies aim to clarify more precise therapeutic targets and specific treatment protocols which optimize the efficacy of these techniques.

Long-term clinical outcome of a novel bilateral capsulotomy with focused ultrasound in refractory obsessive-compulsive disorder treatment

Magnetic resonance-guided focused ultrasound (MRgFUS) capsulotomy is a promising treatment for refractory obsessive-compulsive disorder (OCD); however, long-term clinical outcome studies are lacking. We aimed to investigate the long-term efficacy and safety of MRgFUS capsulotomy in patients with refractory OCD. Ten of the eleven patients who underwent MRgFUS capsulotomy for treatment-resistant OCD between 2013 and 2014 were included in this study. Clinical outcomes were assessed after 10 years of follow-up post-MRgFUS capsulotomy using tools such as neuropsychological test, the Frontal Systems Behavior Scale (FrSBe), and a locally developed MRgFUS-patient-centered outcomes questionnaire. After 10 years of follow-up, there was a mean improvement of 52.3% in the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) score. Seven out of the ten participants responded fully (Y-BOCS reduction ≥35% + CGI-I 1 or 2) to the procedure, two of whom achieved remission (Y-BOCS score ≤12 and CGI-S 1 or 2). Obsessive-compulsive symptoms and overall functioning significantly reduced and improved, respectively (Y-BOCS = 20.7 after 2 years vs. 16.4 after 10 years, p = 0.012; Global Assessment of Functioning = 57.4 after 2 years vs. 69.0 after 10 years, p = 0.011). The patients experienced significantly improved frontal lobe-related functions (FrSBe Sum before 91.0 ± 17.6 vs. after 78.6 ± 17.7, p < 0.05). No adverse effects, including cases of suicide and neurological deficits, were reported. The majority of the respondents were generally satisfied with MRgFUS capsulotomy. MRgFUS capsulotomy is an effective and safe treatment option for the treatment of severe refractory OCD with sustained efficacy even after 10 years.

Long-Term Safety and Efficacy of Focused Ultrasound Capsulotomy for Obsessive-Compulsive Disorder and Major Depressive Disorder

BACKGROUND

Magnetic resonance-guided focused ultrasound (MRgFUS) trials targeting the anterior limb of the internal capsule have shown promising results. We evaluated the long-term safety and efficacy of MRgFUS capsulotomy in patients with obsessive-compulsive disorder (OCD) and major depressive disorder (MDD).

METHODS

This phase 1, single-center, open-label study recruited patients with treatment-resistant OCD and MDD. Outcomes were measured 6 months, 12 months, and 18 to 24 months (long term) after MRgFUS capsulotomy. Neuropsychological testing and neuroimaging were conducted at baseline and 12 months postoperatively. The primary outcome was safety. The secondary outcome was clinical response, defined for OCD as a ≥35% improvement in Yale-Brown Obsessive Compulsive Scale scores and for MDD as a ≥50% reduction in Hamilton Depression Rating Scale scores compared with baseline.

RESULTS

No serious adverse effects were registered. In patients with OCD (n= 15), baseline Yale-Brown Obsessive Compulsive Scale scores (31.9 ± 1.2) were significantly reduced by 23% (p = .01) at 6 months and 35% (p < .0001) at 12 months. In patients with MDD (n = 12), a 26% and 25% nonsignificant reduction in Hamilton Depression Rating Scale scores (baseline 24.3 ± 1.2) was observed at 6 months and 12 months, respectively. Neuropsychological testing revealed no negative effects of capsulotomy. In the OCD and MDD cohorts, we found a correlation between clinical outcome and lesion laterality, with more medial left-placed lesions (OCD, p = .08) and more lateral right-placed lesions (MDD, p < .05) being respectively associated with a stronger response. In the MDD cohort, more ventral tracts appeared to be associated with a poorer response.

CONCLUSIONS

MRgFUS capsulotomy is safe in patients with OCD and MDD and particularly effective in the former population.

Past and Present Role of Neurosurgical Interventions in the Management of Psychiatric Disorders: A Literature Review on the Evolution of Psychosurgery

Despite advancements in psychiatric treatments, many patients with treatment-resistant disorders are turning to neurosurgical interventions. These include neuromodulation-based surgeries such as deep brain stimulation (DBS) and ablative surgeries such as cingulotomy, offering relief for severe conditions such as post-traumatic stress disorder (PTSD), depression, schizophrenia, obsessive-compulsive disorder (OCD), anxiety, and substance use disorder. While "psychosurgery" has sparked debate due to concerns about patient well-being, recent studies indicate promising symptom improvement rates across various psychiatric conditions while also demonstrating overall safety. Neuromodulation techniques, such as DBS, transcranial magnetic stimulation (TMS), and electroconvulsive therapy (ECT), have evolved in regard to their sensitivity and their ability to target specific brain regions to alleviate psychiatric symptoms. Despite their benefits, these therapies have been shown to elicit side effects such as memory loss and seizures in patients, which has sparked controversy in the use of this technology across clinicians and patients. Ablative therapies, on the other hand, are concerning for being overly invasive in their approach toward psychiatric care. Despite the stigma associated with these neurosurgical interventions for psychiatric care, these procedures often remain a last resort for many patients, highlighting the need for continued research to improve these treatments and expand options for those in need. In this narrative review, we examine the current literature to elicit an understanding of neurosurgical history in regard to psychiatric disorder treatment and its implications for clinical practice.

Ultrasound Applications in the Treatment of Major Depressive Disorder (MDD): A Systematic Review of Techniques and Efficacy

Objective

Major depressive disorder (MDD) is a debilitating mental health condition characterized by persistent feelings of sadness, loss of interest, and impaired daily functioning. It affects approximately 8% of the U.S. population, posing a significant personal and economic burden. Around 30% of patients with MDD do not respond to conventional antidepressant and psychotherapeutic treatments. Current treatment options for refractory MDD include transcranial magnetic stimulation (TMS) and invasive surgical procedures such as surgical ablation, vagus nerve stimulation, and deep brain stimulation. TMS has modest efficacy, and surgical procedures are associated with surgical risk and low patient acceptance. With the unique advantage of combining non-invasiveness with selective targeting, therapeutic ultrasound emerges as a promising alternative for treating refractory MDD. Over the past 10 years, there has been a growth in focused ultrasound research, leading to an exponential increase in academic and public interest in the technology. To support the continued development of ultrasound for treating MDD, we conducted a systematic review following Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines.

Methods

We included peer-reviewed prospective cohort studies, case-control studies, and randomized control trials that evaluate the efficacy of ultrasonic treatment for depression (PROSPERO registration number: CRD42024626093). We summarized ultrasonic techniques for treating depression and their efficacy. Furthermore, we identified key challenges and future directions for applying ultrasound in treating MDD.

Results

We identified 67 potentially relevant articles, of which 18 studies met all inclusion criteria. The techniques of applying ultrasound to treat depression include magnetic resonance-guided focused ultrasound (MRgFUS) for capsulotomy and low-intensity focused ultrasound (LIFUS) neuromodulation. In human trials, the response rate (⩾50% improvement from baseline on depression score) is 53.85% for MRgFUS and 80.49% for LIFUS neuromodulation. In all preclinical studies using rodent models (8 studies), LIFUS neuromodulation had a medium to large effect (|Cohen's d| > 0.6) on resolving depressive-like behavior in rodents without causing adverse effects such as tissue damage. MRgFUS faces inconsistent lesioning success and a limited response rate, while LIFUS neuromodulation lacks systematic exploration of parameter space and a clear understanding of its mechanistic effects. Future work should refine patient selection for MRgFUS and focus on individualized functional targeting.

Conclusion

LIFUS neuromodulation showed a medium to large effect in reducing depressive behaviors in both rodent models and human trials, representing a promising, noninvasive option for treating refractory MDD.

Transcranial Focused Ultrasound: A History of Our Future

The history of focused ultrasound is a parallel history of neuroradiology, functional neurosurgery, and physics and engineering. Multiple pioneers collaborated as ultrasound transitioned from a wartime technology to a therapeutic one, particularly in using it to ablate the brain to treat movement disorders. Several competing technologies ensured that this "ultrasonic neurosurgery" remained in a lull. An algorithm and other advancements that obviated a craniectomy for ultrasonic neurosurgery allowed magnetic resonance-guided focused ultrasound to flourish to its modern phase.

Assessment of memory deficits in psychiatric disorders: A systematic literature review

Memory deficits are observed across psychiatric disorders ranging from the prodrome of psychosis to common mental disorders such as anxiety, depression, and dissociative disorders. Memory deficits among patients recovering from psychiatric disorders could be directly related to the primary illness or secondary to the adverse effect of a treatment such as Electroconvulsive Therapy (ECT). The trouble in the meaningful integration of working-memory and episodic memory is the most commonly affected domain that requires routine assessments. An update on the recent trends of methods of assessment of memory deficits is the first step towards understanding and correcting these deficits to target optimum recovery. A systematic literature search was conducted from October 2018 to October 2022 to review the recent methods of assessment of memory deficits in psychiatric disorders. The definition of 'Memory deficit' was operationalized as 'selective processes of memory, commonly required for activities of daily living, and affected among psychiatric disorders resulting in subjective distress and dysfunction'. We included 110 studies, most of them being conducted in western countries on patients with schizophrenia. Other disorders included dementia and mild cognitive impairment. Brief Assessment of Cognition in Schizophrenia, Cambridge Automated Neuropsychological Test Battery, California Verbal Learning Test, Trail Making Test Part A and B, Rey Auditory Verbal Learning Test, Wechsler Memory Scale, Wechsler Adults Intelligence Scale-IV were the most common neuropsychological assessments used. Mini-Mental State Examination and Montreal Cognitive Assessment were the most common bedside assessment tools used while Squire Subjective Memory Questionnaire was commonly used to measure ECT-related memory deficits. The review highlights the recent developments in the field of assessment of memory deficits in psychiatric disorders. Findings recommend and emphasize routine assessment of memory deficits among psychiatric disorders in developing countries especially severe mental illnesses. It remains interesting to see the role of standardized assessments in diagnostic systems given more than a decade of research on memory deficits in psychiatric disorders.

Anterior Capsulotomy for Refractory Obsessive-Compulsive Disorder: A Tractography and Lesion Geometry study

INTRODUCTION

A bilateral anterior capsulotomy effectively treats refractory obsessive-compulsive disorder (OCD). We investigated the geometry of lesions and disruption of white matter pathways within the anterior limb of the internal capsule (ALIC) in patients with different outcomes.

METHODS

In this retrospective study, we analyzed data from 18 patients with refractory OCD who underwent capsulotomies. Patients were grouped into "responders" and "nonresponders" based on the percentage of decrease in the Yale-Brown Obsessive-Compulsive Scale (YBOCS) after surgery. We investigated neurobehavioral adverse effects and analyzed the overlap between lesions and the ventromedial prefrontal (vmPFC) and dorsolateral prefrontal (dlPFC) pathways. Probabilistic maps were constructed to investigate the relationship between lesion location and clinical outcomes.

RESULTS

Of the 18 patients who underwent capsulotomies, 12 were responders (>35% improvement in YBOCS), and six were nonresponders. The vmPFC pathway was more involved than the dlPFC pathway in responders (p = 0.01), but no significant difference was observed in nonresponders (p = 0.10). The probabilistic voxel-wise efficacy map showed a relationship between ventral voxels within the ALIC with symptom improvement. Weight gains occurred in 11/18 (61%) patients and could be associated with medial voxels within the ALIC.

CONCLUSION

The optimal outcome after capsulotomy in refractory OCD is linked to vmPFC disruption in the ALIC. Medial voxels within the ALIC could be associated with weight gains following capsulotomy.

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.

High-Frequency Ultrasound Ablation in Neurosurgery

Modern transcranial magnetic resonance-guided focused ultrasound is an incisionless, ablative treatment modality for a growing number of neurologic disorders. This procedure selectively destroys a targeted volume of cerebral tissue and relies on real-time MR thermography to monitor tissue temperatures. By focusing on a submillimeter target through a hemispheric phased array of transducers, ultrasound waves pass through the skull and avoid overheating and brain damage. High-intensity focused ultrasound techniques are increasingly used to create safe and effective stereotactic ablations for medication-refractory movement and other neurologic and psychiatric disorders.

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.

Lesional psychiatric neurosurgery: meta-analysis of clinical outcomes using a transdiagnostic approach

BACKGROUND

Four ablative neurosurgical procedures are used in the treatment of refractory psychiatric illness. The long-term effects of these procedures on psychiatric symptoms across disorders has never been synthesised and meta-analysed.

METHODS

A preregistered systematic review was performed on studies reporting clinical results following ablative psychiatric neurosurgery. Four possible outcome measures were extracted for each study: depression, obsessive-compulsive symptoms, anxiety and clinical global impression. Effect sizes were calculated using Hedge's g. Equipercentile linking was used to convert symptom scores to a common metric. The main outcome measures were the magnitude of improvement in depression, obsessive compulsive symptoms, anxiety and clinical global impression. The secondary outcome was a subgroup analysis comparing the magnitude of symptom changes between the four procedures.

RESULTS

Of 943 articles, 43 studies reporting data from 1414 unique patients, were included for pooled effects estimates with a random-effects meta-analysis. Results showed that there was a large effect size for improvements in depression (g=1.27; p<0.0001), obsessive-compulsive symptoms (g=2.25; p<0.0001) and anxiety (g=1.76; p<0.0001). The pooled clinical global impression improvement score was 2.36 (p<0.0001). On subgroup analysis, there was only a significant degree of heterogeneity in effect sizes between procedure types for anxiety symptoms, with capsulotomy resulting in a greater reduction in anxiety than cingulotomy.

CONCLUSIONS

Contemporary ablative neurosurgical procedures were significantly associated with improvements in depression, obsessive-compulsive symptoms, anxiety and clinical global impression.

PROSPERO REGISTRATION NUMBER

CRD42020164784.

Focused ultrasound: Innovation in use for neurologic conditions

Focused ultrasound has emerged as a key tool for neurologic disorders. In this focused review, we discuss the utility in disrupting the blood brain barrier to maximize treatment. This can facilitate creating direct coagulative lesions and aid in the administration of chemotherapy. Furthermore, it can facilitate neuromodulation when used in pulse sequencing. The current literature regarding brain tumors, essential tremor, and obsessive-compulsive disorder is reviewed. Additionally, concepts and experimental outcomes for neurodegenerative disease such as Alzheimer's is presented. Focused ultrasound as a tool is still in its infancy but the potential for adjuvant and direct therapy is promising. More clinical uses will become apparent in coming decades.

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.