Deep Brain Stimulation System Research Articles

Lesion-like effect of gliosis secondary to deep brain stimulation electrode infection: illustrative case.

Deep brain stimulation (DBS) is commonly used to treat Parkinson's disease (PD) and other movement disorders when other treatments fail. Although DBS can significantly improve motor symptoms, it carries risks such as infections, which can require multiple surgeries and prolonged antibiotic therapy. Research on the long-term neurological effects of DBS-related infections is limited. A 58-year-old man with a 13-year history of PD, refractory to optimized clinical management, underwent subthalamic nucleus (STN) DBS after previous contralateral lesioning of the posterior subthalamic area. Postoperatively, the DBS lead migrated upward and was repositioned, but he developed perielectrode cerebritis 5 days later. The DBS system was completely removed, and he underwent a 28-day course of intravenous antibiotics. Initially, his motor symptoms remained unchanged, but 4 months later, he experienced a significant and sustained motor symptom improvement that continued until the last follow-up assessment (40 months). Magnetic resonance imaging performed 2 years after the explantation showed gliosis and hemosiderin deposition in the STN, suggesting that the infection-induced gliosis had a lesion-like effect, leading to the observed clinical improvement. This case suggests that infection-induced gliosis from DBS complications can unexpectedly result in long-term motor symptom improvements, potentially influencing future management strategies for similar cases. https://thejns.org/doi/10.3171/CASE24502.

Deep Brain Stimulation and Neuropsychiatric Anthropology – The “Prosthetisability” of the Lifeworld

Deep Brain Stimulation (DBS) represents a key area of neuromodulation that has gained wide adoption for the treatment of neurological and experimental testing for psychiatric disorders. It is associated with specific therapeutic effects based on the precision of an evolving mechanistic neuroscientific understanding. At the same time, there are obstacles to achieving symptom relief because of the incompleteness of such an understanding. These obstacles are at least in part based on the complexity of neuropsychiatric disorders and the incompleteness of DBS devices to represent prosthetics that modulate the breadth of pathological processes implicated in these disorders. Neuroprostheses, such as an implanted DBS system, can have vast effects on subjects in addition to the specific neuropsychiatric changes they are intended to produce. These effects largely represent blind spots in the current debate on neuromodulation. Anthropological accounts can illustrate the broad existential dimensions of patients’ illness and responses to neural implants. In combination with current neuroscientific understanding, neuropsychiatric anthropology may illuminate the possibilities and limits of neurodevices as technical “world enablers”.

Focused Ultrasound as Rescue Treatment of Essential Tremor After Deep Brain Stimulation: 2 Case Reports

BACKGROUND AND IMPORTANCE: Approximately 25% to 55% of patients with essential tremor will eventually develop medication-refractory tremor. Currently, the standard surgical treatment for this condition is deep brain stimulation (DBS) of the ventralis intermedius nucleus of the thalamus and, more recently, the posterior subthalamic area. However, MRI-guided focused ultrasound (FUS) thalamotomy has shown promising results in improving tremor in patients with refractory essential tremor. CLINICAL PRESENTATION: We present 2 cases of patients with a disabling action tremor, recurring after DBS. A 55-year-old right-handed male and a 52-year-old woman presented with bilateral medically refractory action tremor, which began in their second decade of life. Both underwent bilateral DBS-ventralis intermedius, with the first patient showing a good initial response but the second patient showing a suboptimal response within the first year after DBS. In both cases, the DBS system was removed and the patients subsequently underwent left-sided FUS thalamotomy with a dramatic improvement of their tremor. CONCLUSION: These cases demonstrate the feasibility of performing FUS thalamotomy as a rescue treatment for disabling tremor after DBS.

Standardized wireless deep brain stimulation system for mice

Deep brain stimulation (DBS) has emerged as a revolutionary technique for accessing and modulating brain circuits. DBS is used to treat dysfunctional neuronal circuits in neurological and psychiatric disorders. Despite over two decades of clinical application, the fundamental mechanisms underlying DBS are still not well understood. One reason is the complexity of in vivo electrical manipulation of the central nervous system, particularly in rodent models. DBS-devices for freely moving rodents are typically custom-designed and not commercially available, thus making it difficult to perform experimental DBS according to common standards. Addressing these challenges, we have developed a novel wireless microstimulation system for deep brain stimulation (wDBS) tailored for rodents. We demonstrate the efficacy of this device for the restoration of behavioral impairments in hemiparkinsonian mice through unilateral wDBS of the subthalamic nucleus. Moreover, we introduce a standardized and innovative pipeline, integrating machine learning techniques to analyze Parkinson’s disease-like and DBS-induced gait changes.

A method for the synchronization of inertial sensor signals and local field potentials from deep brain stimulation systems

Objective. Recent innovative neurostimulators allow recording local field potentials (LFPs) while performing motor tasks monitored by wearable sensors. Inertial sensors can provide quantitative measures of motor impairment in people with subthalamic nucleus deep brain stimulation. To the best of our knowledge, there is no validated method to synchronize inertial sensors and neurostimulators without an additional device. This study aims to define a new synchronization method to analyze disease-related brain activity patterns during specific motor tasks and evaluate how LFPs are affected by stimulation and medication. Approach. Fourteen male subjects treated with subthalamic nucleus deep brain stimulation were recruited to perform motor tasks in four different medication and stimulation conditions. In each condition, a synchronization protocol was performed consisting of taps on the implanted neurostimulator, which produces artifacts in the LFPs that a nearby inertial sensor can simultaneously record. Main results. In 64% of the recruited subjects, induced artifacts were detected at least in one condition. Among those subjects, 83% of the recordings could be synchronized offline analyzing LFPs and wearables data. The remaining recordings were synchronized by video analysis. Significance. The proposed synchronization method does not require an external system (e.g., TENS electrodes) and can be easily integrated into clinical practice. The procedure is simple and can be carried out in a short time. A proper and simple synchronization will also be useful to analyze subthalamic neural activity in the presence of specific events (e.g., freezing of gait events) to identify predictive biomarkers.

Robot-assisted deep brain stimulation

Deep brain stimulation (DBS) is recognised as a safe and effective treatment for several movement disorders, namely essential tremor, Parkinson's disease, and dystonia, as well as for obsessive–compulsive disorder and refractory epilepsy. The main anatomical target of DBS is the basal ganglia. The DBS system comprises a pulse generator and surgically implanted electrodes. Lead placements must be accurate because the effects of DBS rely on the spatial restriction of the stimulation. Neurosurgical centres have started adopting robot-assisted DBS surgery. The results so far have been promising, with lead placement accuracy comparable to that of frame-based procedures. Additionally, robot-assisted procedures are shorter and less demanding on patients. Robot-assisted DBS can be used on patients who are fully awake or under general anaesthesia, as well as on children.

Beta Burst-Driven Adaptive Deep Brain Stimulation Improves Gait Impairment and Freezing of Gait in Parkinson's Disease.

Freezing of gait (FOG) is a debilitating symptom of Parkinson's disease (PD) that is often refractory to medication. Pathological prolonged beta bursts within the subthalamic nucleus (STN) are associated with both worse impairment and freezing behavior in PD, which are improved with deep brain stimulation (DBS). The goal of the current study was to investigate the feasibility, safety, and tolerability of beta burst-driven adaptive DBS (aDBS) for FOG in PD. Seven individuals with PD were implanted with the investigational Summit™ RC+S DBS system (Medtronic, PLC) with leads placed bilaterally in the STN. A PC-in-the-loop architecture was used to adjust stimulation amplitude in real-time based on the observed beta burst durations in the STN. Participants performed either a harnessed stepping-in-place task or a free walking turning and barrier course, as well as clinical motor assessments and instrumented measures of bradykinesia, OFF stimulation, on aDBS, continuous DBS (cDBS), or random intermittent DBS (iDBS). Beta burst driven aDBS was successfully implemented and deemed safe and tolerable in all seven participants. Gait metrics such as overall percent time freezing and mean peak shank angular velocity improved from OFF to aDBS and showed similar efficacy as cDBS. Similar improvements were also seen for overall clinical motor impairment, including tremor, as well as quantitative metrics of bradykinesia. Beta burst driven adaptive DBS was feasible, safe, and tolerable in individuals with PD with gait impairment and FOG.

Beta Oscillations in the Sensory Thalamus During Severe Facial Neuropathic Pain Using Novel Sensing Deep Brain Stimulation

ObjectiveAdvancements in deep brain stimulation (DBS) devices provide a unique opportunity to record local field potentials longitudinally to improve the efficacy of treatment for intractable facial pain. We aimed to identify potential electrophysiological biomarkers of pain in the ventral posteromedial nucleus (VPM) of the thalamus and periaqueductal gray (PAG) using a long-term sensing DBS system. Materials and MethodsWe analyzed power spectra of ambulatory pain-related events from one patient implanted with a long-term sensing generator, representing different pain intensities (pain >7, pain >9) and pain qualities (no pain, burning, stabbing, and shocking pain). Power spectra were parametrized to separate oscillatory and aperiodic features and compared across the different pain states. ResultsOverall, 96 events were marked during a 16-month follow-up. Parameterization of spectra revealed a total of 62 oscillatory peaks with most in the VPM (77.4%). The pain-free condition did not show any oscillations. In contrast, β peaks were observed in the VPM during all episodes (100%) associated with pain >9, 56% of episodes with pain >7, and 50% of burning pain events (center frequencies: 28.4 Hz, 17.8 Hz, and 20.7 Hz, respectively). Episodes of pain >9 indicated the highest relative β band power in the VPM and decreased aperiodic exponents (denoting the slope of the power spectra) in both the VPM and PAG. ConclusionsFor this patient, an increase in β band activity in the sensory thalamus was associated with severe facial pain, opening the possibility for closed-loop DBS in facial pain.

Neurofeedback-enabled beta power control with a fully implanted DBS system in patients with Parkinson’s disease

ObjectiveParkinsonian motor symptoms are linked to pathologically increased beta oscillations in the basal ganglia. Studies with externalised deep brain stimulation electrodes showed that Parkinson patients were able to rapidly gain control over these pathological basal ganglia signals through neurofeedback. Studies with fully implanted deep brain stimulation systems duplicating these promising results are required to grant transferability to daily application. MethodsIn this study, seven patients with idiopathic Parkinson’s disease and one with familial Parkinson’s disease were included. In a postoperative setting, beta oscillations from the subthalamic nucleus were recorded with a fully implanted deep brain stimulation system and converted to a real-time visual feedback signal. Participants were instructed to perform bidirectional neurofeedback tasks with the aim to modulate these oscillations. ResultsWhile receiving regular medication and deep brain stimulation, participants were able to significantly improve their neurofeedback ability and achieved a significant decrease of subthalamic beta power (median reduction of 31% in the final neurofeedback block). ConclusionWe could demonstrate that a fully implanted deep brain stimulation system can provide visual neurofeedback enabling patients with Parkinson’s disease to rapidly control pathological subthalamic beta oscillations. SignificanceFully-implanted DBS electrode-guided neurofeedback is feasible and can now be explored over extended timespans.

Robust adaptive deep brain stimulation control of in-silico non-stationary Parkinsonian neural oscillatory dynamics

Objective. Closed-loop deep brain stimulation (DBS) is a promising therapy for Parkinson’s disease (PD) that works by adjusting DBS patterns in real time from the guidance of feedback neural activity. Current closed-loop DBS mainly uses threshold-crossing on-off controllers or linear time-invariant (LTI) controllers to regulate the basal ganglia (BG) Parkinsonian beta band oscillation power. However, the critical cortex-BG-thalamus network dynamics underlying PD are nonlinear, non-stationary, and noisy, hindering accurate and robust control of Parkinsonian neural oscillatory dynamics. Approach. Here, we develop a new robust adaptive closed-loop DBS method for regulating the Parkinsonian beta oscillatory dynamics of the cortex-BG-thalamus network. We first build an adaptive state-space model to quantify the dynamic, nonlinear, and non-stationary neural activity. We then construct an adaptive estimator to track the nonlinearity and non-stationarity in real time. We next design a robust controller to automatically determine the DBS frequency based on the estimated Parkinsonian neural state while reducing the system’s sensitivity to high-frequency noise. We adopt and tune a biophysical cortex-BG-thalamus network model as an in-silico simulation testbed to generate nonlinear and non-stationary Parkinsonian neural dynamics for evaluating DBS methods. Main results. We find that under different nonlinear and non-stationary neural dynamics, our robust adaptive DBS method achieved accurate regulation of the BG Parkinsonian beta band oscillation power with small control error, bias, and deviation. Moreover, the accurate regulation generalizes across different therapeutic targets and consistently outperforms current on-off and LTI DBS methods. Significance. These results have implications for future designs of closed-loop DBS systems to treat PD.

Effect of surgical modification of deep brain stimulation lead trajectories on radiofrequency heating during MRI at 3T: from phantom experiments to clinical implementation.

Radiofrequency (RF) tissue heating around deep brain stimulation (DBS) leads is a well-known safety risk during MRI, resulting in strict imaging guidelines and limited allowable protocols. The implanted lead's trajectory and orientation with respect to the MRI electric fields contribute to variations in the magnitude of RF heating across patients. Currently, there are no surgical requirements for implanting the extracranial portion of the DBS lead, resulting in substantial variations in clinical lead trajectories and consequently RF heating. Recent studies have shown that incorporating concentric loops in the extracranial lead trajectory can reduce RF heating. However, optimal positioning of the loops and the quantitative benefit of trajectory modification in terms of added safety margins during MRI remain unknown. In this study, the authors systematically evaluated the characteristics of DBS lead trajectories that minimize RF heating during 3T MRI to develop the best surgical practices for safe access to postoperative MRI, and they present the first surgical implementation of these modified trajectories. The authors performed experiments to assess the maximum temperature increase of 244 distinct lead trajectories. They investigated the effect of the position, number, and size of the concentric loops on the skull. Experiments were performed in an anthropomorphic phantom implanted with a commercial DBS system, and RF exposure was generated by applying a high specific absorption rate sequence (B1+rms = 2.7 µT). The authors conducted test-retest experiments to assess the reliability of measurements. Additionally, they evaluated the effect of imaging landmarks and perturbations to the DBS device configuration on the efficacy of low-heating trajectories. Finally, two neurosurgeons implanted the recommended modified trajectories in patients, and the authors characterized their RF heating in comparison with unmodified trajectories. The maximum temperature increase ranged from 0.09°C to 7.34°C. The authors found that increasing the number of loops and positioning them closer to the surgical burr hole, particularly for the contralateral lead, substantially reduced RF heating. These trajectory modifications were easily incorporated during the surgical procedure and resulted in a threefold reduction in RF heating. Surgically modifying the extracranial portion of the DBS lead trajectory can substantially reduce RF heating during 3T MRI. The authors' results indicate that simple adjustments to the lead's configuration, such as small, concentric loops near the burr hole, can be readily adopted during DBS lead implantation to improve patient safety during MRI.

How Accurate Is Frameless Fiducial-Free Deep Brain Stimulation?

Frameless deep brain stimulation (DBS) offers advantages in terms of patient comfort and reduced operative time. However, the need for bony fiducial markers for localization remains a drawback due to the time-consuming and uncomfortable procedure. An alternative localization method involves the direct tracking of an intraoperative 3-dimensional scanner. This study aims to assess the accuracy of the NexFrame frameless DBS system in conjunction with the O-Arm (Medtronic Inc.), both with and without fiducial markers. The locations of 100 DBS leads were determined, with 50 cases using fiducial-free localization and 50 involving fiducial markers. The coordinates were compared with the expected intraoperative targets. Absolute errors in the X, Y, and Z coordinates (ΔX, ΔY, and ΔZ) were calculated, along with the vector error (Euclidean) (vector error ). The vector error averaged 1.61 ± 0.49 mm (right) and 1.52 ± 0.60 mm (left) for the group without fiducial bone markers and 1.66 ± 0.69 (right) and 1.44 ± 0.65 mm (left) for the other cohort (P = .76 right; P = .67 left). Absolute errors in the X, Y, and Z coordinates for the fiducial-free group were 0.88 ± 0.55, 0.79 ± 0.45, and 0.79 ± 0.57 mm (right) and 0.72 ± 0.37, 0.78 ± 0.56, and 0.77 ± 0.71 mm (left). For the group with fiducial markers, these errors were 0.87 ± 0.72, 0.92 ± 0.39, and 0.86 ± 0.50 mm (right) and 0.75 ± 0.33, 0.80 ± 0.51, and 0.73 ± 0.64 mm (left) with no statistically significant difference. Our analysis of the accuracy of NexFrame DBS, both with and without fiducial markers, using an intraoperative navigable cone-beam computed tomography, demonstrates that both techniques provide sufficient and equivalent 3-dimensional accuracy.

Model-based closed-loop control of thalamic deep brain stimulation.

Introduction: Closed-loop control of deep brain stimulation (DBS) is beneficial for effective and automatic treatment of various neurological disorders like Parkinson's disease (PD) and essential tremor (ET). Manual (open-loop) DBS programming solely based on clinical observations relies on neurologists' expertise and patients' experience. Continuous stimulation in open-loop DBS may decrease battery life and cause side effects. On the contrary, a closed-loop DBS system uses a feedback biomarker/signal to track worsening (or improving) of patients' symptoms and offers several advantages compared to the open-loop DBS system. Existing closed-loop DBS control systems do not incorporate physiological mechanisms underlying DBS or symptoms, e.g., how DBS modulates dynamics of synaptic plasticity. Methods: In this work, we propose a computational framework for development of a model-based DBS controller where a neural model can describe the relationship between DBS and neural activity and a polynomial-based approximation can estimate the relationship between neural and behavioral activities. A controller is used in our model in a quasi-real-time manner to find DBS patterns that significantly reduce the worsening of symptoms. By using the proposed computational framework, these DBS patterns can be tested clinically by predicting the effect of DBS before delivering it to the patient. We applied this framework to the problem of finding optimal DBS frequencies for essential tremor given electromyography (EMG) recordings solely. Building on our recent network model of ventral intermediate nuclei (Vim), the main surgical target of the tremor, in response to DBS, we developed neural model simulation in which physiological mechanisms underlying Vim-DBS are linked to symptomatic changes in EMG signals. By using a proportional-integral-derivative (PID) controller, we showed that a closed-loop system can track EMG signals and adjust the stimulation frequency of Vim-DBS so that the power of EMG reaches a desired control target. Results and discussion: We demonstrated that the model-based DBS frequency aligns well with that used in clinical studies. Our model-based closed-loop system is adaptable to different control targets and can potentially be used for different diseases and personalized systems.

Role of electrophysiological activity and interactions of lateral habenula in the development of depression-like behavior in a chronic restraint stress model

Closed-loop deep brain stimulation (DBS) system offers a promising approach for treatment-resistant depression, but identifying universally accepted electrophysiological biomarkers for closed-loop DBS systems targeting depression is challenging. There is growing evidence suggesting a strong association between the lateral habenula (LHb) and depression. Here, we took LHb as a key target, utilizing multi-site local field potentials (LFPs) to study the acute and chronic changes in electrophysiology, functional connectivity, and brain network characteristics during the formation of a chronic restraint stress (CRS) model. Furthermore, our model combining the electrophysiological changes of LHb and interactions between LHb and other potential targets of depression can effectively distinguish depressive states, offering a new way for developing effective closed-loop DBS strategies.

1137 Prospective, Multicenter, International Registry of Deep Brain Stimulation for Dystonia: A Sub-analysis of Cervical Dystonia Patients

INTRODUCTION: Management of dystonia using Deep Brain Stimulation (DBS) is a well-established therapeutic approach. However, optimal DBS target sites in patients with cervical (focal) versus generalized dystonia are thought to diverge and be specific for particular connections (Horn 2022). DBS devices equipped with capabilities such as directionality and Multiple Independent Current Control (MICC) may offer potential for improved clinical outcomes. METHODS: This is a sub-analysis of patients with focal (cervical) dystonia only or cervical dystonia in the context of segmental or generalized dystonia assessed as part of a prospective, multicenter, international dystonia registry (NCT02686125). All patients receive an MICC-based, directional DBS system (Vercise, Boston Scientific). Patients are followed up to 3-years (post-implant). Several study assessments are being collected to evaluate their dystonia symptoms (e.g., TWSTRS), quality of life, and overall satisfaction. Adverse Events are also collected. RESULTS: A total of 43-patients (mean age 56.9-years, 58% females) with focal (cervical) dystonia only and 83 patients (mean 41.95-years, 61% females) with cervical dystonia in context of segmental or generalized dystonia have been evaluated. Both groups reported significant improvement in overall TWSTRS scores – however the extent varied. In the cervical-only cohort, a 19.9-point improvement was noted at 6-months (n = 25) and sustained up to 1-year (23.2-point improvement, n = 20). In those with cervical dystonia within frame of segmental or generalized dystonia, a 9.7-point and 7.3-point improvement in overall TWSTRS scores was noted at 6- (n = 50) and 12-months (n = 38), respectively. Updated data will be reported. CONCLUSIONS: This registry represents the first comprehensive, large-scale collection of real-world outcomes associated with dystonia patients implanted with a directional DBS system capable of MICC. Preliminary results demonstrate significant improvement in patients with cervical dystonia (alone or in context of segmental or generalized dystonia) following DBS.

Local field potentials: Therapeutic implications for DBS in dystonia including adaptive DBS for dystonia

Local field potentials (LFPs) are signals generated primarily by the result of the synchronous discharge of post-synaptic potentials. Detection of LFPs from intracranial electrodes sited within the basal ganglia has led to the recognition that there are specific features of the LFP that could serve as neurophysiological biomarkers of different disease states. For example, in Parkinson’s disease peaks in the beta frequency range of the power spectrum are known to correlate with the degree of bradykinesia and rigidity, whereas low frequency, alpha-theta peaks are increasingly considered a biomarker of dystonic activity. The introduction of newer deep brain stimulation (DBS) devices capable of simultaneous stimulation and LFP detection creates opportunities to investigate new strategies for treating patients with dystonia. This review aims to summarise the LFP findings seen in patients with dystonia undergoing DBS with a particular focus on the potential implications for future clinical practice and the development of adaptive DBS systems.

Coating of Neural Electrodes with Platinum Nanoparticles Reduces and Stabilizes Impedance In Vitro and In Vivo in a Rat Model

The efficacy of electrodes that are chronically implanted and used in the context of deep brain stimulation (DBS) for the treatment of neurological disorders critically depends on stable impedance. Platinum–iridium electrodes were coated with laser-generated platinum nanoparticle colloids (PtNPs) via electrophoretic deposition using pulsed direct currents (DC-EPD). Uncoated electrodes were used as controls. In vitro, electrodes were stimulated for four weeks in a 0.9% NaCl solution. For the in vivo (rats) study, coated electrodes were implanted in the left and uncoated control electrodes in the right subthalamic nucleus (STN). After two weeks of recovery, electrodes were stimulated for four weeks. Impedance measurements were conducted after each week of stimulation, both in vivo and in vitro. NP-coating resulted in a significant and long-lasting reduction in electrode impedance (p < 0.05) over four weeks of in vitro stimulation. Despite an initial increase in impedance after intracranial implantation, the impedance of the NP-coated electrodes was also reduced during in vivo stimulation over four weeks. NP-coated electrodes had a lower fluctuation of impedance during stimulation compared to uncoated electrodes both in vitro and in vivo (p < 0.05). Laser-generated PtNPs applied to electrodes by pulsed DC-EPD lead to lower and more stable electrode impedance during chronic stimulation, with the potential to enhance the performance of DBS systems during chronic use.

Do Antibiotic-Impregnated Envelopes Prevent Deep Brain Stimulation Implantable Pulse Generator Infections? A Prospective Cohort Study

Introduction: Infection after deep brain stimulation (DBS) implanted pulse generator (IPG) replacement is uncommon but when it occurs can cause significant clinical morbidity, often resulting in partial or complete DBS system removal. An antibiotic absorbable envelope developed for cardiac implantable electronic devices (IEDs), which releases minocycline and rifampicin for a minimum of 7 days, was shown in the WRAP-IT study to reduce cardiac IED infections for high-risk cardiac patients. We aimed to assess whether placing an IPG in the same antibiotic envelope at the time of IPG replacement reduced the IPG infection rate. Methods: Following institutional ethics approval (UnitingCare HREC), patients scheduled for IPG change due to impending battery depletion were prospectively randomised to receive IPG replacement with or without an antibiotic envelope. Patients with a past history of DBS system infection were excluded. Patients underwent surgery with standard aseptic neurosurgical technique [J Neurol Sci. 2017;383:135–41]. Subsequent infection requiring antibiotic therapy and/or IPG removal or revision was recorded. Results: A total of 427 consecutive patients were randomised from 2018 to 2021 and followed for a minimum of 12 months. No patients were lost to follow-up. At the time of IPG replacement, 200 patients received antibiotic envelope (54 female, 146 male, mean age 72 years), and 227 did not (43 female, 184 male, mean age 71 years). The two groups were homogenous for risk factors of infection. The IPG replacement infection rate was 2.1% (9/427). There were six infections, which required antibiotic therapy and/or IPG removal, in the antibiotic envelope group (6/200) and three in the non-envelope group (3/227) (p = 0.66). Conclusion: This prospective randomised study did not find that an antibiotic envelope reduced the IPG infection rate in our 427 patients undergoing routine DBS IPG replacement. Further research to reduce IPG revisions and infections in a cost-effective manner is required.

Real-world outcomes of Deep Brain Stimulation for dystonia treatment: Protocol for a prospective, multicenter, international registry.

Deep Brain Stimulation (DBS) is an established therapeutic approach for the treatment of dystonia. However, to date, no large-scale or comprehensive DBS dystonia patient registry has been yet undertaken. Here, we describe the protocol for a world-wide registry of clinical outcomes in dystonia patients implanted with DBS. This protocol describes a multicenter, international clinical outcomes registry consisting of up to 200 prospectively enrolled participants at up to 40 different sites to be implanted with a constant-current, multiple independent current controlled (MICC) DBS device (Vercise DBS Systems, Boston Scientific) for treatment of dystonia. Key inclusion criteria for registry candidates include the following: understanding of study requirements and treatment procedures, a signed written informed consent form prior to participation, and meeting all criteria established in the locally applicable Instructions for Use (IFU) for the implanted DBS system. Key clinical endpoints include (but are not limited to) the evaluation of disease state (Burke-Fahn-Marsden Dystonia Rating Scale [BFMDRS], Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS), quality of life (Short Form Health Survey-36, Short Form Health Survey-10), and treatment satisfaction (Clinical Global Impression of Change [CGI-Clinician; CGI-Subject; CGI-Caregiver]) at 6-months, 12-months, 2-years, and 3-years post-lead placement. Adverse events are documented and reported using structured questionnaires. Treatment of patients with dystonia using DBS has progressed considering recent technological advances. This international dystonia outcomes registry aims to collect and evaluate real-world clinical data derived from patients who have been implanted with a constant-current, MICC-equipped DBS system (with available directional capabilities), per standard of care.

Closed-Loop Deep Brain Stimulation With Reinforcement Learning and Neural Simulation.

Deep Brain Stimulation (DBS) is effective for movement disorders, particularly Parkinson's disease (PD). However, a closed-loop DBS system using reinforcement learning (RL) for automatic parameter tuning, offering enhanced energy efficiency and the effect of thalamus restoration, is yet to be developed for clinical and commercial applications. In this research, we instantiate a basal ganglia-thalamic (BGT) model and design it as an interactive environment suitable for RL models. Four finely tuned RL agents based on different frameworks, namely Soft Actor-Critic (SAC), Twin Delayed Deep Deterministic Policy Gradient (TD3), Proximal Policy Optimization (PPO), and Advantage Actor-Critic (A2C), are established for further comparison. Within the implemented RL architectures, the optimized TD3 demonstrates a significant 67% reduction in average power dissipation when compared to the open-loop system while preserving the normal response of the simulated BGT circuitry. As a result, our method mitigates thalamic error responses under pathological conditions and prevents overstimulation. In summary, this study introduces a novel approach to implementing an adaptive parameter-tuning closed-loop DBS system. Leveraging the advantages of TD3, our proposed approach holds significant promise for advancing the integration of RL applications into DBS systems, ultimately optimizing therapeutic effects in future clinical trials.