Deep Brain Stimulation System Research Articles

Suppression of seizure in childhood absence epilepsy using robust control of deep brain stimulation: a simulation study

Deep brain stimulation (DBS) is a promising technique to relieve the symptoms in patients with intractable seizures. Although the DBS therapy for seizure suppression dates back more than 40 years, determining stimulation parameters is a significant challenge to the success of this technique. One solution to this challenge with application in a real DBS system is to design a closed-loop control system to regulate the stimulation intensity using computational models of epilepsy automatically. The main goal of the current study is to develop a robust control technique based on adaptive fuzzy terminal sliding mode control (AFTSMC) for eliminating the oscillatory spiking behavior in childhood absence epilepsy (CAE) dynamical model consisting of cortical, thalamic relay, and reticular nuclei neurons. To this end, the membrane voltage dynamics of the three coupled neurons are considered as a three-input three-output nonlinear state delay system. A fuzzy logic system is developed to estimate the unknown nonlinear dynamics of the current and delayed states of the model embedded in the control input. Chattering-free control input (continuous DBS pulses) without any singularity problem is the superiority of the proposed control method. To guarantee the bounded stability of the closed-loop system in a finite time, the upper bounds of the external disturbance and minimum estimation errors are updated online with adaptive laws without any offline tuning phase. Simulation results are provided to show the robustness of AFTSMC in the presence of uncertainty and external disturbances.

The efficacy of kicking and knee strike exercises in the rehabilitation of patients with walking disorders

The article is devoted to evaluating the effectiveness of exercises that were used in neurorehabilitation for patients with walking disorders. Disorders of walking, coordination of movement, balance are among the main symptoms of diseases such as Parkinson's disease (PD), Parkinsonism and dystonia. For such patients with motor disorders, exercise is a very important part of rehabilitation. At this time, the insufficiently studied problem remains therapeutic physical culture, exercises to improve patients' coordination of movement, gait, balance. The purpose of the study: to study the effectiveness of a set of kicking exercises for patients with walking disorders by evaluating rehabilitation scales (Test “Up and Go” (TUG) и mini BESTest). Methods. Prospective cohort study. The results of rehabilitation of patients treated at the clinic of neurology and neurorehabilitation "Shashkin clinic" are presented. The main criteria for inclusion in the study: patients with Parkinson's disease – at least 3 stages on the Hoehn-Yahr scale, patients with Parkinsonism and dystonia syndrome, patients who underwent surgery to install a deep brain stimulation system with walking disorders. The age of patients is from 50 to 78 years, men - 21, women - 29. The patients were divided into 2 groups of 25 people. The patients were randomly divided into two groups. The 1st group underwent neurorehabilitation without a set of exercises, the 2nd group - with a daily additional load – kicking and knee exercises. Before rehabilitation and 2 weeks after rehabilitation, a test was conducted. All patients prior to enrollment in the study signed informed consent voluntarily. Results. There was an improvement in the indicators of two scales used in the work (mini-test of balance assessment systems, or Mini-BESTest, "Up and Go” test) in the research group, compared with the control group. Conclusions. The inclusion of a set of kicks and knee exercises in rehabilitation has a positive effect on improving the patient's walking.

Artifacts Can Be Deceiving: The Actual Location of Deep Brain Stimulation Electrodes Differs from the Artifact Seen on Magnetic Resonance Images

Introduction: Deep brain stimulation (DBS) is a common treatment for a variety of neurological and psychiatric disorders. Recent studies have highlighted the role of neuroimaging in localizing the position of electrode contacts relative to target brain areas in order to optimize DBS programming. Among different imaging methods, postoperative magnetic resonance imaging (MRI) has been widely used for DBS electrode localization; however, the geometrical distortion induced by the lead limits its accuracy. In this work, we investigated to what degree the difference between the actual location of the lead’s tip and the location of the tip estimated from the MRI artifact varies depending on the MRI sequence parameters such as acquisition plane and phase encoding direction, as well as the lead’s extracranial configuration. Accordingly, an imaging technique to increase the accuracy of lead localization was devised and discussed. Methods: We designed and constructed an anthropomorphic phantom with an implanted DBS system following 18 clinically relevant configurations. The phantom was scanned at a Siemens 1.5 Tesla Aera scanner using a T₁MPRAGE sequence optimized for clinical use and a T₁TSE sequence optimized for research purposes. We varied slice acquisition plane and phase encoding direction and calculated the distance between the caudal tip of the DBS lead MRI artifact and the actual tip of the lead, as estimated from MRI reference markers. Results: Imaging parameters and lead configuration substantially altered the difference in the depth of the lead within its MRI artifact on the scale of several millimeters − with a difference as large as 4.99 mm. The actual tip of the DBS lead was found to be consistently more rostral than the tip estimated from the MR image artifact. The smallest difference between the tip of the DBS lead and the tip of the MRI artifact using the clinically relevant sequence (i.e., T₁MPRAGE) was found with the sagittal acquisition plane and anterior-posterior phase encoding direction. Discussion/Conclusion: The actual tip of an implanted DBS lead is located up to several millimeters rostral to the tip of the lead’s artifact on postoperative MR images. This distance depends on the MRI sequence parameters and the DBS system’s extracranial trajectory. MRI parameters may be altered to improve this localization.

Necessity of MRI-compatible deep brain stimulation systems – Hits and hints for decision making

ObjectivesDeep brain stimulation (DBS) is a safe and effective treatment option for patients with movement disorders as Parkinson’s disease, essential tremor and dystonia[1]. For many of these patients the need for imaging may arise in the following years after implantation. The study’s aim was to get an overview of the amount of patients with a DBS system who needed an MRI after successful implantation, and if they did, whether the imaging led to a surgical consequence. Materials and methodsIn this retrospective descriptive work patients were included if they had their DBS implantation for at least 12 months at the time of analysis. Data were collected by retrospective analysis of the electronic patient files as well as a telephone interview. The reason of each imaging performed was assessed, if patients got MRI after the implantation, it was additionally recorded whether imaging led to a consequence (conservative treatment or surgery). An independent neurologist assessed if an MRI would have been better than a CT for the particular indication. ResultsFrom 54 included patients, 28 patients received imaging after implantation, either CT or MRI. 7 patients underwent MRIs, of whom 3 patients received cranial MRIs and 4 patients received lumbar spine MRIs. All cranial MRIs led to conservative therapy, in 2 lumbar MRIs the diagnosis led to surgery. Nearly 13 % of the imaging performed in our study population occurred because of fall events, 9 of the included patients developed or have had a tumor diagnosis. ConclusionsSafety of MRI for patients with implanted DBS-systems is and remains an important consideration. Since it can be assumed that patients at a younger age are more likely to get an MRI in the course of their disease, we suggest paying particular attention to the MRI's suitability of the DBS device by patients age. In the end it remains always an individual decision for the surgeon or the consulting physician, which system to use.

Combined Short-Pulse and Directional Deep Brain Stimulation of the Thalamic Ventral Intermediate Area for Essential Tremor

ObjectiveNovel deep brain stimulation (DBS) systems allow directional and short-pulse stimulation to potentially improve symptoms and reduce side effects. The aim of this study was to investigate the effect of short-pulse and directional stimulation, in addition to a combination of both, in the ventral intermediate thalamus (VIM)/posterior subthalamic area (PSA) on tremor and stimulation-induced side effects in patients with essential tremor. Materials and MethodsWe recruited 11 patients with essential tremor and VIM/PSA-DBS. Tremor severity (Fahn-Tolosa-Marin), ataxia (International Cooperative Ataxia Rating Scale), and paresthesia (visual analog scale) were assessed with conventional omnidirectional and directional stimulation with pulse width of 60 μs and 30 μs. ResultsAll stimulation conditions reduced tremor. The best directional stimulation with 60 μs reduced more tremor than did most other stimulation settings. The best directional stimulation, regardless of pulse width, effectively reduced stimulation-induced ataxia compared with the conventional stimulation (ring 60 μs) or worst directional stimulation with 60 μs. All new stimulation modes reduced occurrence of paresthesia, but only the best directional stimulation with 30 μs attenuated paresthesia compared with the conventional stimulation (ring 60 μs) or worst directional stimulation with 60 μs. The best directional stimulation with 30 μs reduced tremor, ataxia, and paresthesia compared with conventional stimulation in most patients. Correlation analyses indicated that more anterior stimulation sites are associated with stronger ataxia reduction with directional 30 μs than with conventional 60 μs stimulation. ConclusionDirectional and short-pulse stimulation, and a combination of both, revealed beneficial effects on stimulation-induced adverse effects.

Multiple input algorithm-guided Deep Brain stimulation-programming for Parkinson’s disease patients

Technological advances of Deep Brain Stimulation (DBS) within the subthalamic nucleus (STN) for Parkinson’s disease (PD) provide increased programming options with higher programming burden. Reducing the effort of DBS optimization requires novel programming strategies. The objective of this study was to evaluate the feasibility of a semi-automatic algorithm-guided-programming (AgP) approach to obtain beneficial stimulation settings for PD patients with directional DBS systems. The AgP evaluates iteratively the weighted combination of sensor and clinician assessed responses of multiple PD symptoms to suggested DBS settings until it converges to a final solution. Acute clinical effectiveness of AgP DBS settings and DBS settings that were found following a standard of care (SoC) procedure were compared in a randomized, crossover and double-blind fashion in 10 PD subjects from a single center. Compared to therapy absence, AgP and SoC DBS settings significantly improved (p = 0.002) total Unified Parkinson’s Disease Rating Scale III scores (median 69.8 interquartile range (IQR) 64.6|71.9% and 66.2 IQR 58.1|68.2%, respectively). Despite their similar clinical results, AgP and SoC DBS settings differed substantially. Per subject, AgP tested 37.0 IQR 34.0|37 settings before convergence, resulting in 1.7 IQR 1.6|2.0 h, which is comparable to previous reports. Although AgP long-term clinical results still need to be investigated, this approach constitutes an alternative for DBS programming and represents an important step for future closed-loop DBS optimization systems.

Recrudescent infection after deep brain stimulator reimplantation.

The efficacy of deep brain stimulation (DBS) in treating the symptoms of movement disorders can be life changing for patients. Thus, the 5%-15% incidence of stimulator-related infection requiring removal of the device can be particularly disheartening. Although DBS system reimplantation is generally successful, this is not always the case. The literature is replete with publications describing the incidence of infection and the associated features. However, the literature is sparse in terms of information on the incidence of recurrent or recrudescent infection after system reimplantation. The goal of this paper was to evaluate factors leading to unsuccessful reimplantation of a DBS system following initial infection. Data were reviewed for all DBS procedures performed by one surgeon (K.L.H.) over 19 years including the infectious agent, location of infection, treatment regimen, and subsequent reimplantation of a DBS system and long-term outcome. In this series of 558 patients who had undergone DBS surgery, 37 (6.6%) subsequently developed an infection. Infections with methicillin-sensitive Staphylococcus aureus, Enterobacter species, or coagulase-negative staphylococci were predominant. Four patients had cerebritis, one had meningitis, and the rest had soft tissue infections of the pocket or scalp. All had their entire DBS system explanted, followed by 4-6 weeks of intravenous antibiotics and surveillance for recrudescence for an additional period of at least 30 days. Twenty-five patients subsequently underwent DBS system reimplantation, and the procedure was successful in 22. Three of the 4 patients with cerebritis developed a subsequent wound infection after system reimplantation. None of the other 22 patients developed a recurrence. The odds ratio for developing a recurrent infection after cerebritis was 28.5 (95% CI 1.931-420.5, p = 0.007). This study, the largest series of DBS system reimplantations following infection, demonstrated that most patients can have successful reimplantations without recurrent infection. However, patients who have had DBS-related cerebritis have a nearly 30-fold increased risk of developing reinfection after reimplantation. Alternative strategies for these patients are discussed.

O031 / #240 LONG-TERM MOTOR FUNCTION AND QUALITY OF LIFE OUTCOMES FROM A PROSPECTIVE, INTERNATIONAL DBS REGISTRY: TRACK 2: DEEP BRAIN STIMULATION FOR MOVEMENT DISORDERS

Several studies have demonstrated the use of high-frequency Deep Brain Stimulation (DBS) to be effective in reducing the motor complications of Parkinson’s Disease (PD) that are not adequately controlled with medication and improved quality of life.1-7 In addition, motor improvement following DBS has been shown to be sustained for up to 10 years.8 Here, we report the outcomes of an ongoing prospective, international, large-scale registry of Deep Brain Stimulation (DBS) systems for Parkinson’s Disease.

O033 / #241 REAL-WORLD OUTCOMES USING A NOVEL DIRECTIONAL LEAD FROM A MULTICENTER DBS REGISTRY FOR PARKINSON'S DISEASE: TRACK 2: DEEP BRAIN STIMULATION FOR MOVEMENT DISORDERS

Early Deep Brain Stimulation (DBS) systems used ring-shaped electrodes to achieve axial selectivity in stimulation of target tissue. However, directional current steering allows for rotational selectivity (in addition to axial) and has the potential to further improve patient outcomes by avoiding off-target stimulation due to the ability to create a well-defined field around the intended target. Several pilot studies have corroborated the use of directionality and its impact on therapeutic window and adverse effects.

O132 / #543 REAL-WORLD DEEP BRAIN STIMULATION OUTCOMES USING SYSTEMS WITH DIRECTIONALITY AND MULTIPLE INDEPENDENT CURRENT CONTROL: TRACK 2: DEEP BRAIN STIMULATION FOR MOVEMENT DISORDERS

Deep Brain Stimulation (DBS) is an established treatment for motor signs and fluctuations associated with Parkinson's disease (PD). Retrospective studies can provide a relatively quick and cost-effective means to obtain data regarding various types of patient outcomes when devices are being used per standard-of-care in the real-world clinical setting, thereby contributing to real-world evidence (RWE). Here, we report clinical outcomes associated with the use of DBS systems capable of directionality and Multiple Independent Current Control (MICC) used in the management of PD motor symptoms.

O030 / #531 DEEP BRAIN STIMULATION SCALP EROSION RISK REDUCTION WITH NOVEL SURGICAL TECHNIQUE: TRACK 2: BRAIN STIMULATION FOR TREATMENT RESISTANT DEPRESSION, PAIN, AND PARKINSON'S DISEASE

Deep Brain Stimulation (DBS) has a low risk profile with complication rates reported as less than ten percent. Most complications occur around the time of the surgery, but scalp erosion typically presents in a delayed fashion. An erosion can expose the underlying hardware significantly increasing the risk of infection. If present, infection often requires the complete removal of the DBS system and therefore loss of clinical effect. Scalp erosions occur most commonly at the surgical cap site followed by the extension connector site.

Self-sustainable intermittent deep brain stimulator

Brain-implanted stimulators are revolutionizing treatment of many neurological and psychiatric diseases, but still rely on temporary batteries for power, which require periodic replacements. Battery-free, self-sustainable deep brain stimulation (DBS) devices remain an unsolved challenge. Herein, we report a self-sustainable, battery-free, intermittent DBS system. This device is enabled by interfacing a high-performance bio-triboelectric nanogenerator (Bio-TENG) as an energy harvester with bio-supercapacitors as fast-charging energy storage units to intermittently drive a DBS pulse generator. The Bio-TENG acts as a smart breathing sensor and biomechanical energy harvester using the inhalation and exhalation motions of an inflated swine lung to charge bio-supercapacitors, which drive the pulse generator to stimulate neurons in mouse hippocampus tissues ex vivo . An intra-electrode triboelectrification strategy is used to boost the Bio-TENG power output. This sustainable intermittent power approach may provide a strategy for powering brain-machine bioelectronics. • Bio-supercap/Bio-TENG successfully harvests and stores energy from breathing lungs • The harvested energy intermittently stimulates the brain in a self-sustainable system • Intra-electrode triboelectrification is introduced to boost power Elsanadidy et al. report an implantable battery-free deep brain stimulator that relies on energy from breathing to stimulate the brain. This device harvests and stores the mechanical energy from breathing lungs and may be capable of stimulating the brain hippocampus in an intermittent fashion.

Subthalamic Beta Oscillations Are Transient and Encoded by Periodic Bursting of Individual Neurons

Increased beta (13-30Hz) in the subthalamic nucleus (STN) is a hallmark of Parkinson’s disease (PD) and a prime candidate for closed-loop deep brain stimulation (DBS) systems such as the Medtronic Percept PC. Investigating the dynamics of beta oscillations across spatiotemporal domains revealed insights into the nature of this activity, which can moreover be leveraged by closed-loop DBS systems.

On linear parameter varying control of time‐delayed positive systems

AbstractThe original purpose of this article is to tackle the stabilizing controller design for linear parameter varying positive systems with multiple delays, in which the considered delays are time‐invariant. The proposed control strategy consists of a parameter varying state‐feedback controller. A complete solution to the design problem is proposed by utilizing a Lyapunov approach. In order to decrease the conservativeness of the controller design, we define a slack variable to prevent the multiplication of the Lyapunov matrices with the system matrices. Moreover, the slack variable is considered as a parameter varying matrix. Finally, the criteria are transformed into linear matrix inequalities. Therefore, sufficient conditions stabilize the closed‐loop system and preserve the positive property. A special case for the mentioned system is the deep brain stimulation system used in the area of Parkinson's treatment. It enables neuroscientists to control abnormal brain activity by implanting electrodes that generate electrical impulses. This system is provided as a practical example to guarantee the effectiveness of the obtained outcomes.

The Impact of Burr Hole Device and Lead Design on Deep Brain Stimulation Lead Stability in Benchtop and Ovine Models

Background and ObjectivesA market-released deep brain stimulation (DBS) lead and burr hole device (BHD) have been used for more than ten years to provide stable DBS therapy using leads with four equally distributed cylindrical electrodes along the distal lead length. Newer directional leads cluster segmented electrodes at the center of the electrode array. This work tests the hypothesis that improved chronic translational and rotational stability through enhanced BHD design may ensure that these newer directional electrodes remain in a stable orientation near the stimulation target to maintain therapy and maximize opportunities to adjust therapy, if needed. Materials and MethodsA new DBS lead system (commercially available in the United States and termed “new” throughout the manuscript) has been developed, and a combination of bench testing (45 product samples tested) and chronic sheep studies (17 animals followed for 13.5 weeks on average) was conducted to test the hypothesis that design changes incorporated into the new DBS system further stabilize the position and orientation of a DBS lead tip compared with a legacy DBS system. ResultsThe new DBS system demonstrated a 55% relative improvement in chronic lead tip stability compared with the legacy DBS system with over a decade of clinical use. In a bench test, the new system required 79% more applied torque and 203% more lead body revolutions to rotate the lead in the BHD than the legacy system that was not designed to offer rotational stability. ConclusionsThese measurements quantitatively demonstrate that DBS system design can positively improve lead translational and rotational stability and show that system design is an important consideration for future product development.

Analysis of the intended and actual orientations of directional deep brain stimulation leads across deep brain stimulation systems.

Deep brain stimulation (DBS) offers therapeutic benefits to patients suffering from a variety of treatment-resistant neurological and psychiatric disorders. The newest generation of DBS devices now offer directional leads, which utilize segmented electrodes to direct current asymmetrically to the neuronal tissue. Since segmented electrodes offer a larger degree of freedom for contact positioning, it is critical to assess how well the surgically intended and the actual orientation of the lead match to facilitate programming and allow appropriate interpretation of the therapeutic outcome. Postoperative image analysis algorithms, such as DiODe, are commonly used to determine DBS leads' actual orientation. In this work, we used DiODe to compare the deviation between intended and actual orientations of DBS leads across two most commonly implanted directional DBS systems, namely, Boston Scientific Cartesia™ and St. Jude Medical Infinity. This study is the first to investigate the rotation of leads from both DBS systems in a large group of 86 patients. Clinical Relevance- Our results quantify the variability between the surgically intended and actual orientations of Boston Scientific Vercise and St. Jude Medical Infinity DBS systems thus highlighting the need to develop more precise implantation procedures.

A workflow for predicting temperature increase at the electrical contacts of deep brain stimulation electrodes undergoing MRI.

PurposeThe purpose of this study is to present a workflow for predicting the radiofrequency (RF) heating around the contacts of a deep brain stimulation (DBS) lead during an MRI scan.MethodsThe induced RF current on the DBS lead accumulates electric charge on the metallic contacts, which may cause a high local specific absorption rate (SAR), and therefore, heating. The accumulated charge was modeled by imposing a voltage boundary condition on the contacts in a quasi‐static electromagnetic (EM) simulation allowing thermal simulations to be performed with the resulting SAR distributions. Estimating SAR and temperature increases from a lead in vivo through EM simulation is not practical given anatomic differences and variations in lead geometry. To overcome this limitation, a new parameter, transimpedance, was defined to characterize a given lead. By combining the transimpedance, which can be measured in a single calibration scan, along with MR‐based current measurements of the lead in a unique orientation and anatomy, local heating can be estimated. Heating determined with this approach was compared with results from heating studies of a commercial DBS electrode in a gel phantom with different lead configurations to validate the proposed method.ResultsUsing data from a single calibration experiment, the transimpedance of a commercial DBS electrode (directional lead, Infinity DBS system, Abbott Laboratories, Chicago, IL) was determined to be 88 Ω. Heating predictions using the DBS transimpedance and rapidly acquired MR‐based current measurements in 26 different lead configurations resulted in a <23% (on average 11.3%) normalized root‐mean‐square error compared to experimental heating measurements during RF scans.ConclusionIn this study, a workflow consisting of an MR‐based current measurement on the DBS lead and simple quasi‐static EM/thermal simulations to predict the temperature increase around a DBS electrode undergoing an MRI scan is proposed and validated using a commercial DBS electrode.

Perioperative considerations for elective surgery in patients with deep brain stimulation implantation

In the more than 30 years that have passed since its introduction, deep brain stimulation (DBS) has been shown to be effective and safe for a growing number of diseases, such as depression and obsessive-compulsive disorder, as well as movement disorders such as Parkinson’s disease, dystonia, and essential tremor. As a result of population aging due to the increase in life expectancy, the number of patients requiring DBS implantation is increasing. These patients often require surgery or treatment for diseases other than the original disease that required DBS. Most diagnostic tests or procedures can damage the DBS system by various mechanisms, so clinicians unfamiliar with DBS have difficulty treating these patients. The purpose of this review is to summarize the knowledge necessary for patient management that will be useful for clinicians treating patients with DBS implantation.

Directional Stimulation in Parkinson's Disease and Essential Tremor: The Cleveland Clinic Experience

ObjectiveTo assess use of directional stimulation in Parkinson's disease and essential tremor patients programmed in routine clinical care. Materials and MethodsPatients with Parkinson's disease or essential tremor implanted at Cleveland Clinic with a directional deep brain stimulation (DBS) system from November 2017 to October 2019 were included in this retrospective case series. Omnidirectional was compared against directional stimulation using therapeutic current strength, therapeutic window percentage, and total electrical energy delivered as outcome variables. ResultsFifty-seven Parkinson's disease patients (36 males) were implanted in the subthalamic nucleus (105 leads) and 33 essential tremor patients (19 males) were implanted in the ventral intermediate nucleus of the thalamus (52 leads). Seventy-four percent of patients with subthalamic stimulation (65% of leads) and 79% of patients with thalamic stimulation (79% of leads) were programmed with directional stimulation for their stable settings. Forty-six percent of subthalamic leads and 69% of thalamic leads were programmed on single segment activation. There was no correlation between the length of microelectrode trajectory through the STN and use of directional stimulation. ConclusionsDirectional programming was more common than omnidirectional programming. Substantial gains in therapeutic current strength, therapeutic window, and total electrical energy were found in subthalamic and thalamic leads programmed on directional stimulation.

Thalamic Deep Brain Stimulation May Improve Restless Legs Syndrome in Patients With Essential Tremor

ObjectivesTo determine change in restless legs syndrome (RLS) symptoms in essential tremor (ET) patients undergoing bilateral thalamic ventral intermedius (VIM) deep brain stimulation (DBS) surgery. Materials and MethodsWe retrospectively reviewed our database of ET patients with RLS who had undergone VIM DBS for tremor from 2012 to 2020. We reviewed the patients with available International Restless Leg Syndrome Study Group RLS scale scores before and after DBS. Percentage of responders, defined as proportion of patients experiencing three or more point improvement of RLS scores post-DBS, was calculated. We performed two-tailed t-test of pre-DBS and post-DBS RLS scores. ResultsWe identified 13 patients with ET and RLS who had undergone bilateral VIM DBS, of whom nine (69%) were responders post-DBS. Five of 13 patients (38%) had complete resolution of RLS post-DBS. For all patients, mean pre-DBS RLS score was 15.8 ± 7.9 which improved by 46% post-DBS to a mean of 8.5 ± 8.8 (p = 0.007). Four patients rated their RLS scale one night with the stimulator OFF and another night with the stimulator ON. The mean RLS score with stimulator ON was 15.5 ± 7.6 which improved by 53% to a mean of 6.25 ± 7.8 (p = 0.008), with two having complete resolution of RLS with stimulator ON. Of the nine responders, six preferred to keep their stimulator ON at night due to relief of RLS and better subjective quality of sleep. ConclusionsWe report for the first time improvement of RLS in patients with ET after bilateral thalamic DBS. Although many ET patients with nonrechargeable DBS systems switch off their stimulator at night to conserve battery life, those with RLS may potentially benefit from keeping their stimulator ON at night to relieve their RLS.