Ultrasound Blood-Brain Barrier Opening and Aducanumab in Alzheimer's Disease.

Antiamyloid antibodies have been used to reduce cerebral amyloid-beta (Aß) load in patients with Alzheimer's disease. We applied focused ultrasound with each of six monthly aducanumab infusions to temporarily open the blood-brain barrier with the goal of enhancing amyloid removal in selected brain regions in three participants over a period of 6 months. The reduction in the level of Aß was numerically greater in regions treated with focused ultrasound than in the homologous regions in the contralateral hemisphere that were not treated with focused ultrasound, as measured by fluorine-18 florbetaben positron-emission tomography. Cognitive tests and safety evaluations were conducted over a period of 30 to 180 days after treatment. (Funded by the Harry T. Mangurian, Jr. Foundation and the West Virginia University Rockefeller Neuroscience Institute.).

Single neurons in the thalamus and subthalamic nucleus process cardiac and respiratory signals in humans.

Visceral signals are constantly processed by our central nervous system, enable homeostatic regulation, and influence perception, emotion, and cognition. While visceral processes at the cortical level have been extensively studied using non-invasive imaging techniques, very few studies have investigated how this information is processed at the single neuron level, both in humans and animals. Subcortical regions, relaying signals from peripheral interoceptors to cortical structures, are particularly understudied and how visceral information is processed in thalamic and subthalamic structures remains largely unknown. Here, we took advantage of intraoperative microelectrode recordings in patients undergoing surgery for deep brain stimulation (DBS) to investigate the activity of single neurons related to cardiac and respiratory functions in three subcortical regions: ventral intermedius nucleus (Vim) and ventral caudalis nucleus (Vc) of the thalamus, and subthalamic nucleus (STN). We report that the activity of a large portion of the recorded neurons (about 70%) was modulated by either the heartbeat, the cardiac inter-beat interval, or the respiration. These cardiac and respiratory response patterns varied largely across neurons both in terms of timing and their kind of modulation. A substantial proportion of these visceral neurons (30%) was responsive to more than one of the tested signals, underlining specialization and integration of cardiac and respiratory signals in STN and thalamic neurons. By extensively describing single unit activity related to cardiorespiratory function in thalamic and subthalamic neurons, our results highlight the major role of these subcortical regions in the processing of visceral signals.

Noninvasive hippocampal blood-brain barrier opening in Alzheimer's disease with focused ultrasound.

The blood-brain barrier (BBB) presents a significant challenge for treating brain disorders. The hippocampus is a key target for novel therapeutics, playing an important role in Alzheimer's disease (AD), epilepsy, and depression. Preclinical studies have shown that magnetic resonance (MR)-guided low-intensity focused ultrasound (FUS) can reversibly open the BBB and facilitate delivery of targeted brain therapeutics. We report initial clinical trial results evaluating the safety, feasibility, and reversibility of BBB opening with FUS treatment of the hippocampus and entorhinal cortex (EC) in patients with early AD. Six subjects tolerated a total of 17 FUS treatments with no adverse events and neither cognitive nor neurological worsening. Post-FUS contrast MRI revealed immediate and sizable hippocampal parenchymal enhancement indicating BBB opening, followed by BBB closure within 24 h. The average opening was 95% of the targeted FUS volume, which corresponds to 29% of the overall hippocampus volume. We demonstrate that FUS can safely, noninvasively, transiently, reproducibly, and focally mediate BBB opening in the hippocampus/EC in humans. This provides a unique translational opportunity to investigate therapeutic delivery in AD and other conditions.

Restoring cortical control of functional movement in a human with quadriplegia.

Millions of people worldwide suffer from diseases that lead to paralysis through disruption of signal pathways between the brain and the muscles. Neuroprosthetic devices are designed to restore lost function and could be used to form an electronic 'neural bypass' to circumvent disconnected pathways in the nervous system. It has previously been shown that intracortically recorded signals can be decoded to extract information related to motion, allowing non-human primates and paralysed humans to control computers and robotic arms through imagined movements. In non-human primates, these types of signal have also been used to drive activation of chemically paralysed arm muscles. Here we show that intracortically recorded signals can be linked in real-time to muscle activation to restore movement in a paralysed human. We used a chronically implanted intracortical microelectrode array to record multiunit activity from the motor cortex in a study participant with quadriplegia from cervical spinal cord injury. We applied machine-learning algorithms to decode the neuronal activity and control activation of the participant's forearm muscles through a custom-built high-resolution neuromuscular electrical stimulation system. The system provided isolated finger movements and the participant achieved continuous cortical control of six different wrist and hand motions. Furthermore, he was able to use the system to complete functional tasks relevant to daily living. Clinical assessment showed that, when using the system, his motor impairment improved from the fifth to the sixth cervical (C5-C6) to the seventh cervical to first thoracic (C7-T1) level unilaterally, conferring on him the critical abilities to grasp, manipulate, and release objects. This is the first demonstration to our knowledge of successful control of muscle activation using intracortically recorded signals in a paralysed human. These results have significant implications in advancing neuroprosthetic technology for people worldwide living with the effects of paralysis.

Blood-Brain Barrier Opening with MRI-guided Focused Ultrasound Elicits Meningeal Venous Permeability in Humans with Early Alzheimer Disease.

Background Opening of the blood-brain barrier (BBB) induced with MRI-guided focused ultrasound has been shown in experimental animal models to reduce amyloid-ß plaque burden, improve memory performance, and facilitate delivery of therapeutic agents to the brain. However, physiologic effects of this procedure in humans with Alzheimer disease (AD) require further investigation. Purpose To assess imaging effects of focused ultrasound-induced BBB opening in the hippocampus of human participants with early AD and to evaluate fluid flow patterns after BBB opening by using serial contrast-enhanced MRI. Materials and Methods Study participants with early AD recruited to a Health Insurance Portability and Accountability Act-compliant, prospective, ongoing phase II clinical trial (ClinicalTrials.gov identifier, NCT03671889) underwent three separate focused ultrasound-induced BBB opening procedures that used a 220-kHz transducer with a concomitant intravenous microbubble contrast agent administered at 2-week intervals targeting the hippocampus and entorhinal cortex between October 2018 and May 2019. Posttreatment effects and gadolinium-based contrast agent enhancement patterns were evaluated by using 3.0-T MRI. Results Three women (aged 61, 72, and 73 years) consecutively enrolled in the trial successfully completed repeated focused ultrasound-induced BBB opening of the hippocampus and entorhinal cortex. Postprocedure contrast enhancement was clearly identified within the targeted brain volumes, indicating immediate spatially precise BBB opening. Parenchymal enhancement resolved within 24 hours after all treatments, confirming BBB closure. Transient perivenous enhancement was consistently observed during the acute phase after BBB opening. Notably, contrast enhancement reappeared in the perivenular regions after BBB closure. This imaging marker is consistent with blood-meningeal barrier permeability and persisted for 24-48 hours before spontaneous resolution. No evidence of intracranial hemorrhage or other adverse effect was identified. Conclusion MRI-guided focused ultrasound-induced blood-brain barrier opening was safely performed in the hippocampi of three participants with Alzheimer disease without any adverse effects. Posttreatment MRI reveals a unique spatiotemporal contrast enhancement pattern that suggests a perivenular immunologic healing response downstream from targeted sites. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Klibanov in this issue.

Improving Safety of MRI in Patients with Deep Brain Stimulation Devices.

MRI is a valuable clinical and research tool for patients undergoing deep brain stimulation (DBS). However, risks associated with imaging DBS devices have led to stringent regulations, limiting the clinical and research utility of MRI in these patients. The main risks in patients with DBS devices undergoing MRI are heating at the electrode tips, induced currents, implantable pulse generator dysfunction, and mechanical forces. Phantom model studies indicate that electrode tip heating remains the most serious risk for modern DBS devices. The absence of adverse events in patients imaged under DBS vendor guidelines for MRI demonstrates the general safety of MRI for patients with DBS devices. Moreover, recent work indicates that-given adequate safety data-patients may be imaged outside these guidelines. At present, investigators are primarily focused on improving DBS device and MRI safety through the development of tools, including safety simulation models. Existing guidelines provide a standardized framework for performing safe MRI in patients with DBS devices. It also highlights the possibility of expanding MRI as a tool for research and clinical care in these patients going forward.

Deep Brain Stimulation for Multiple Sclerosis Tremor: A Meta-Analysis.

OBJECTIVES: To examine the effect of deep brain stimulation (DBS) on multiple sclerosis (MS)-tremor, as measured by a normalized scale of tremor severity, with a meta-analysis of the published literature. METHODS: Medline and EBSCO Host (January, 1998 to June, 2018) were systematically reviewed with librarian guidance, using the keywords "Deep brain stimulation" and "multiple sclerosis." Bibliographies and experts in the field were also consulted to identify missed articles. All therapeutic studies on DBS for MS-tremor, reported in the English language, within the study period were included. Papers that reported outcomes without a measure of central tendency and/or distribution were excluded. The papers were read in their entirety and graded for risk of bias according to the American Academy of Neurology (AAN) standards. To maximize statistical power, papers using different stimulation targets were grouped together. Outcomes were reported with the Fahn-Tolosa-Marin scale (FTM), the Bain-Finchley scale (CRS) and 3- and 4-point tremor severity scales and normalized with a Hedges g. RESULTS: The search produced 13 studies suitable for meta-analysis. The random-effects meta-analysis showed that DBS improved the Hedges standardized mean tremor score by 2.86 (95%CI 2.03-3.70, p < .00001). Heterogeneity was high, with an I2 of 84%, suggesting that random effects model is more appropriate. Adverse event rates varied from 8% to 50%. CONCLUSIONS: This meta-analysis provides level III evidence that DBS may improve MS-related tremor as measured by standardized tremor severity scales.

Clinically Significant Gains in Skillful Grasp Coordination by an Individual With Tetraplegia Using an Implanted Brain-Computer Interface With Forearm Transcutaneous Muscle Stimulation.

OBJECTIVE: To demonstrate naturalistic motor control speed, coordinated grasp, and carryover from trained to novel objects by an individual with tetraplegia using a brain-computer interface (BCI)-controlled neuroprosthetic. DESIGN: Phase I trial for an intracortical BCI integrated with forearm functional electrical stimulation (FES). Data reported span postimplant days 137 to 1478. SETTING: Tertiary care outpatient rehabilitation center. PARTICIPANT: A 27-year-old man with C5 class A (on the American Spinal Injury Association Impairment Scale) traumatic spinal cord injury INTERVENTIONS: After array implantation in his left (dominant) motor cortex, the participant trained with BCI-FES to control dynamic, coordinated forearm, wrist, and hand movements. MAIN OUTCOME MEASURES: Performance on standardized tests of arm motor ability (Graded Redefined Assessment of Strength, Sensibility, and Prehension [GRASSP], Action Research Arm Test [ARAT], Grasp and Release Test [GRT], Box and Block Test), grip myometry, and functional activity measures (Capabilities of Upper Extremity Test [CUE-T], Quadriplegia Index of Function-Short Form [QIF-SF], Spinal Cord Independence Measure-Self-Report [SCIM-SR]) with and without the BCI-FES. RESULTS: With BCI-FES, scores improved from baseline on the following: Grip force (2.9 kg); ARAT cup, cylinders, ball, bar, and blocks; GRT can, fork, peg, weight, and tape; GRASSP strength and prehension (unscrewing lids, pouring from a bottle, transferring pegs); and CUE-T wrist and hand skills. QIF-SF and SCIM-SR eating, grooming, and toileting activities were expected to improve with home use of BCI-FES. Pincer grips and mobility were unaffected. BCI-FES grip skills enabled the participant to play an adapted "Battleship" game and manipulate household objects. CONCLUSIONS: Using BCI-FES, the participant performed skillful and coordinated grasps and made clinically significant gains in tests of upper limb function. Practice generalized from training objects to household items and leisure activities. Motor ability improved for palmar, lateral, and tip-to-tip grips. The expects eventual home use to confer greater independence for activities of daily living, consistent with observed neurologic level gains from C5-6 to C7-T1. This marks a critical translational step toward clinical viability for BCI neuroprosthetics.

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.

Neurological adverse event profile of magnetic resonance imaging-guided focused ultrasound thalamotomy for essential tremor.

BACKGROUND: Magnetic resonance imaging-guided focused ultrasound thalamotomy is approved by the U.S. Food and Drug Administration for treatment of essential tremor. Although this incisionless technology creates an ablative lesion, it potentially avoids serious complications of open stereotactic surgery. OBJECTIVE: To determine the safety profile of magnetic resonance imaging-guided focused ultrasound unilateral thalamotomy for essential tremor, including frequency, and severity of adverse events, including serious adverse events. METHODS: Analysis of safety data for magnetic resonance imaging-guided focused ultrasound thalamotomy (186 patients, five studies). RESULTS: Procedure-related serious adverse events were very infrequent (1.6%), without intracerebral hemorrhages or infections. Adverse events were usually transient and were commonly rated as mild (79%) and rarely severe (1%). As previously reported, abnormalities in sensation and balance were the commonest thalamotomy-related adverse events. CONCLUSION: The overall safety profile of magnetic resonance imaging-guided focused ultrasound thalamotomy supports its role as a new option for patients with medically refractory essential tremor. © 2018 International Parkinson and Movement Disorder Society.

Cognitive outcome after ventral capsule/ventral striatum stimulation for treatment-resistant major depression.

BACKGROUND: We report the neuropsychological outcome of 25 patients with treatment-resistant major depressive disorder (TRD) who participated in an Institutional Review Board (IRB)-approved randomised double-blind trial comparing active to sham deep brain stimulation (DBS) in the anterior limb of the ventral capsule/ventral striatum (VC/VS). METHODS: Participants were randomised to active (n=12) versus sham (n=13) DBS for 16 weeks. Data were analysed at the individual and group levels. Group differences were analysed using repeated measures ANOVAs. Relationships between depression severity and cognition were examined using partial correlations. The false discovery rate method controlled for multiple analyses. RESULTS: No significant interactions comparing active versus sham stimulation over time were evident. Change in depression was unrelated to change in neuropsychological measures. Twenty patients declined by ≥1 SD on at least one measure (41.3% of declines occurred in active group participants; 63.0% in older participants regardless of stimulation status). Twenty-two patients exhibited improvements >1 SD on neuropsychological measures (47.7% in the active group; 63.1% in younger participants). CONCLUSIONS: These data suggest that VC/VS DBS in patients with TRD does not significantly affect neuropsychological function. Age at surgery, regardless of stimulation status, may be related to cognitive outcome at the individual patient level. TRIAL REGISTRATION NUMBER: NCT00837486; Results.

Spinal Cord Stimulation (SCS) and Functional Magnetic Resonance Imaging (fMRI): Modulation of Cortical Connectivity With Therapeutic SCS.

INTRODUCTION: The neurophysiological basis of pain relief due to spinal cord stimulation (SCS) and the related cortical processing of sensory information are not completely understood. The aim of this study was to use resting state functional magnetic resonance imaging (rs-fMRI) to detect changes in cortical networks and cortical processing related to the stimulator-induced pain relief. METHODS: Ten patients with complex regional pain syndrome (CRPS) or neuropathic leg pain underwent thoracic epidural spinal cord stimulator implantation. Stimulation parameters associated with "optimal" pain reduction were evaluated prior to imaging studies. Rs-fMRI was obtained on a 3 Tesla, Philips Achieva MRI. Rs-fMRI was performed with stimulator off (300TRs) and stimulator at optimum (Opt, 300 TRs) pain relief settings. Seed-based analysis of the resting state functional connectivity was conducted using seeds in regions established as participating in pain networks or in the default mode network (DMN) in addition to the network analysis. NCUT (normalized cut) parcellation was used to generate 98 cortical and subcortical regions of interest in order to expand our analysis of changes in functional connections to the entire brain. We corrected for multiple comparisons by limiting the false discovery rate to 5%. RESULTS: Significant differences in resting state connectivity between SCS off and optimal state were seen between several regions related to pain perception, including the left frontal insula, right primary and secondary somatosensory cortices, as well as in regions involved in the DMN, such as the precuneus. In examining changes in connectivity across the entire brain, we found decreased connection strength between somatosensory and limbic areas and increased connection strength between somatosensory and DMN with optimal SCS resulting in pain relief. This suggests that pain relief from SCS may be reducing negative emotional processing associated with pain, allowing somatosensory areas to become more integrated into default mode activity. CONCLUSION: SCS reduces the affective component of pain resulting in optimal pain relief. Study shows a decreased connectivity between somatosensory and limbic areas associated with optimal pain relief due to SCS.

Consensus on guidelines for stereotactic neurosurgery for psychiatric disorders.

BACKGROUND: For patients with psychiatric illnesses remaining refractory to 'standard' therapies, neurosurgical procedures may be considered. Guidelines for safe and ethical conduct of such procedures have previously and independently been proposed by various local and regional expert groups. METHODS: To expand on these earlier documents, representative members of continental and international psychiatric and neurosurgical societies, joined efforts to further elaborate and adopt a pragmatic worldwide set of guidelines. These are intended to address a broad range of neuropsychiatric disorders, brain targets and neurosurgical techniques, taking into account cultural and social heterogeneities of healthcare environments. FINDINGS: The proposed consensus document highlights that, while stereotactic ablative procedures such as cingulotomy and capsulotomy for depression and obsessive-compulsive disorder are considered 'established' in some countries, they still lack level I evidence. Further, it is noted that deep brain stimulation in any brain target hitherto tried, and for any psychiatric or behavioural disorder, still remains at an investigational stage. Researchers are encouraged to design randomised controlled trials, based on scientific and data-driven rationales for disease and brain target selection. Experienced multidisciplinary teams are a mandatory requirement for the safe and ethical conduct of any psychiatric neurosurgery, ensuring documented refractoriness of patients, proper consent procedures that respect patient's capacity and autonomy, multifaceted preoperative as well as postoperative long-term follow-up evaluation, and reporting of effects and side effects for all patients. INTERPRETATION: This consensus document on ethical and scientific conduct of psychiatric surgery worldwide is designed to enhance patient safety.

Accuracy and precision of targeting using frameless stereotactic system in deep brain stimulator implantation surgery.

OBJECTIVES: To assess the accuracy of targeting using NexFrame frameless targeting system during deep brain stimulation (DBS) surgery. MATERIALS AND METHODS: Fifty DBS leads were implanted in 33 patients using the NexFrame (Medtronic, Minneapolis, MN) targeting system. Postoperative thin cut CT scans were used for lead localization. X, Y, Z coordinates of the tip of the lead were calculated and compared with the intended target coordinates to assess the targeting error. Comparative frame-based data set was obtained from randomly selected 33 patients during the same period that underwent 65 lead placements using Leksell stereotactic frame. Euclidean vector was calculated for directional error. Multivariate analysis of variance was used to compare the accuracy between two systems. RESULTS: The mean error of targeting using frameless system in medio-lateral plane was 1.4 mm (SD ± 1.3), in antero-posterior plane was 0.9 mm (SD ± 1.0) and in supero-inferior plane Z was 1.0 mm (SD ± 0.9). The mean error of targeting using frame-based system in medio-lateral plane was 1.0 mm (SD ± 0.7), in antero-posterior plane was 0.9 mm (SD ± 0.5) and in supero-inferior plane Z was 0.7 mm (SD ± 0.6). The error in targeting was significantly more (P = 0.03) in the medio-lateral plane using the frameless system as compared to the frame-based system. Mean targeting error in the Euclidean directional vector using frameless system was 2.2 (SD ± 1.6) and using frame-based system was 1.7 (SD ± 0.6) (P = 0.07). There was significantly more error in the first 25 leads placed using the frameless system than the second 25 leads (P = 0.0015). CONCLUSION: The targeting accuracy of the frameless system was lower as compared to frame-based system in the medio-lateral direction. Standard deviations (SDs) were higher using frameless system as compared to the frame-based system indicating lower accuracy of this system. Error in targeting should be considered while using frameless stereotactic system for DBS implantation surgery.

Neurosurgical neuromodulation therapy for psychiatric disorders.

Psychiatric disorders are among the leading contributors to global disease burden and disability. A significant portion of patients with psychiatric disorders remain treatment-refractory to best available therapy. With insights from the neurocircuitry of psychiatric disorders and extensive experience of neuromodulation with deep brain stimulation (DBS) in movement disorders, DBS is increasingly being considered to modulate the neural network in psychiatric disorders. Currently, obsessive-compulsive disorder (OCD) is the only U.S. FDA (United States Food and Drug Administration) approved DBS indication for psychiatric disorders. Medically refractory depression, addiction, and other psychiatric disorders are being explored for DBS neuromodulation. Studies evaluating DBS for psychiatric disorders are promising but lack larger, controlled studies. This paper presents a brief review and the current state of DBS and other neurosurgical neuromodulation therapies for OCD and other psychiatric disorders. We also present a brief review of MR-guided Focused Ultrasound (MRgFUS), a novel form of neurosurgical neuromodulation, which can target deep subcortical structures similar to DBS, but in a noninvasive fashion. Early experiences of neurosurgical neuromodulation therapies, including MRgFUS neuromodulation are encouraging in psychiatric disorders; however, they remain investigational. Currently, DBS and VNS are the only FDA approved neurosurgical neuromodulation options in properly selected cases of OCD and depression, respectively.

Focused Ultrasound for Neurodegenerative Diseases.

Neurodegenerative diseases are a leading cause of death and disability and pose a looming global public health crisis. Despite progress in understanding biological and molecular factors associated with these disorders and their progression, effective disease modifying treatments are presently limited. Focused ultrasound (FUS) is an emerging therapeutic strategy for Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. In these contexts, applications of FUS include neuroablation, neuromodulation, and/or blood-brain barrier opening with and without facilitated intracerebral drug delivery. Here, the authors review preclinical evidence and current and emerging applications of FUS for neurodegenerative diseases and summarize future directions in the field.

Safety and Efficacy of Staged, Bilateral Focused Ultrasound Thalamotomy in Essential Tremor: An Open-Label Clinical Trial.

Importance: Unilateral magnetic resonance-guided focused ultrasound ablation of ventralis intermedius nucleus of the thalamus for essential tremor reduces tremor on 1 side, but untreated contralateral or midline symptoms remain limiting for some patients. Historically, bilateral lesioning produced unacceptable risks and was supplanted by deep brain stimulation; increasing acceptance of unilateral focused ultrasound lesioning has led to interest in a bilateral option. Objective: To evaluate the safety and efficacy of staged, bilateral focused ultrasound thalamotomy. Design, Setting, and Participants: This prospective, open-label, multicenter trial treated patients with essential tremor from July 2020 to October 2021, with a 12-month follow-up, at 7 US academic medical centers. Of 62 enrolled patients who had undergone unilateral focused ultrasound thalamotomy at least 9 months prior to enrollment, 11 were excluded and 51 were treated. Eligibility criteria included patient age (22 years and older), medication refractory, tremor severity (Clinical Rating Scale for Tremor [CRST] part A score ≥2 for postural or kinetic tremor), and functional disability (CRST part C score ≥2 in any category). Intervention: A focused ultrasound system interfaced with magnetic resonance imaging allowed real-time alignment of thermography maps with anatomy. Subthreshold sonications allowed target interrogation for efficacy and off-target effects before creating an ablation. Main Outcomes and Measures: Tremor/motor score (CRST parts A and B) at 3 months for the treated side after treatment was the primary outcome measure, and secondary assessments for efficacy and safety continued to 12 months. Results: The mean (SD) population age was 73 (13.9) years, and 44 participants (86.3%) were male. The mean (SD) tremor/motor score improved from 17.4 (5.4; 95% CI, 15.9-18.9) to 6.4 (5.3; 95% CI, 4.9 to 7.9) at 3 months (66% improvement in CRST parts A and B scores; 95% CI, 59.8-72.2; P < .001). There was significant improvement in mean (SD) postural tremor (from 2.5 [0.8]; 95% CI, 2.3 to 2.7 to 0.6 [0.9]; 95% CI, 0.3 to 0.8; P < .001) and mean (SD) disability score (from 10.3 [4.7]; 95% CI, 9.0-11.6 to 2.2 [2.8]; 95% CI, 1.4-2.9; P < .001). Twelve participants developed mild (study-defined) ataxia, which persisted in 6 participants at 12 months. Adverse events (159 of 188 [85%] mild, 25 of 188 [13%] moderate, and 1 severe urinary tract infection) reported most commonly included numbness/tingling (n = 17 total; n = 8 at 12 months), dysarthria (n = 15 total; n = 7 at 12 months), ataxia (n = 12 total; n = 6 at 12 months), unsteadiness/imbalance (n = 10 total; n = 0 at 12 months), and taste disturbance (n = 7 total; n = 3 at 12 months). Speech difficulty, including phonation, articulation, and dysphagia, were generally mild (rated as not clinically significant, no participants with worsening in all 3 measures) and transient. Conclusions and Relevance: Staged, bilateral focused ultrasound thalamotomy significantly reduced tremor severity and functional disability scores. Adverse events for speech, swallowing, and ataxia were mostly mild and transient. Trial Registration: ClinicalTrials.gov Identifier NCT04112381.

Executive function and cortical thickness in biomarker aMCI.

INTRODUCTION: Memory deficits are the primary symptom in amnestic Mild Cognitive Impairment (aMCI); however, executive function (EF) deficits are common. The current study examined EF in aMCI based upon amyloid status (A+/A-) and regional atrophy in signature areas of Alzheimer's disease (AD). METHOD: Participants included 110 individuals with aMCI (A+ = 66; A- = 44) and 33 cognitively healthy participants (HP). EF was assessed using four neuropsychological assessment measures. The cortical thickness of the AD signature areas was calculated using structural MRI data. RESULTS: A + had greater EF deficits and cortical atrophy relative to A - in the supramarginal gyrus and superior parietal lobule. A - had greater EF deficits relative to HP, but no difference in signature area cortical thickness. DISCUSSION: The current study found that the degree of EF deficits in aMCI are a function of amyloid status and cortical thinning in the parietal cortex.

Safety and feasibility clinical trial of nucleus accumbens deep brain stimulation for treatment-refractory opioid use disorder.

OBJECTIVE: There were more than 107,000 drug overdose deaths in the US in 2021, the most ever recorded. Despite advances in behavioral and pharmacological treatments, over 50% of those receiving treatment for opioid use disorder (OUD) experience drug use recurrence (relapse). Given the prevalence of OUD and other substance use disorders (SUDs), the high rate of drug use recurrence, and the number of drug overdose deaths, novel treatment strategies are desperately needed. The objective of this study was to evaluate the safety and feasibility of deep brain stimulation (DBS) targeting the nucleus accumbens (NAc)/ventral capsule (VC) and potential impact on outcomes in individuals with treatment-refractory OUD. METHODS: A prospective, open-label, single-arm study was conducted among participants with longstanding treatment-refractory OUD (along with other co-occurring SUDs) who underwent DBS in the NAc/VC. The primary study endpoint was safety; secondary/exploratory outcomes included opioid and other substance use, substance craving, and emotional symptoms throughout follow-up and 18FDG-PET neuroimaging. RESULTS: Four male participants were enrolled and all tolerated DBS surgery well with no serious adverse events (AEs) and no device- or stimulation-related AEs. Two participants sustained complete substance abstinence for > 1150 and > 520 days, respectively, with significant post-DBS reductions in substance craving, anxiety, and depression. One participant experienced post-DBS drug use recurrences with reduced frequency and severity. The DBS system was explanted in one participant due to noncompliance with treatment requirements and the study protocol. 18FDG-PET neuroimaging revealed increased glucose metabolism in the frontal regions for the participants with sustained abstinence only. CONCLUSIONS: DBS of the NAc/VC was safe, feasible, and can potentially reduce substance use, craving, and emotional symptoms in those with treatment-refractory OUD. A randomized, sham-controlled trial in a larger cohort of patients is being initiated.

Cognitive outcomes following unilateral magnetic resonance-guided focused ultrasound thalamotomy for essential tremor: findings from two cohorts.

Magnetic resonance-guided, focused ultrasound thalamotomy is a neurosurgical treatment for refractory essential tremor. This study examined cognitive outcomes following unilateral magnetic resonance-guided, focused ultrasound thalamotomy, targeting the ventral intermediate nucleus of the thalamus for essential tremor. The research was conducted at two sites: Sunnybrook Research Institute in Toronto, Canada, and West Virginia University School of Medicine Rockefeller Neuroscience Institute in West Virginia, USA. The study focused on cognitive changes at both the group and individual levels. Patients with refractory essential tremor completed cognitive testing before and after magnetic resonance-guided, focused ultrasound thalamotomy at both sites. The cognitive testing assessed domains of attention, processing speed, working memory, executive function, language and learning/memory. Postoperative changes in cognition were examined using paired t-tests and Wilcoxon signed-rank tests, as appropriate. Reliable change indices were calculated to assess clinically significant changes at the individual level. A total of 33 patients from Toronto and 22 patients from West Virginia were included. Following magnetic resonance-guided, focused ultrasound thalamotomy, there was a significant reduction in tremor severity in both cohorts. At the group level, there were no significant declines in postoperative cognitive performance in either cohort. The reliable change analyses revealed some variability at the individual level, with most patients maintaining stable performance or showing improvement. Taken together, the results from these two independent cohorts demonstrate that unilateral magnetic resonance-guided, focused ultrasound thalamotomy significantly reduces tremor severity without negatively impacting cognition at both the group and individual levels, highlighting the cognitive safety of magnetic resonance-guided focused ultrasound thalamotomy for essential tremor.