Asleep Deep Brain Stimulation Research Articles

Clinical evaluation of a stereotactic system for single-stage deep brain stimulation surgery under general anesthesia: technical note.

Conventional frame-based stereotactic systems have circumferential base frames, often necessitating deep brain stimulation (DBS) surgery in two stages: intracranial electrode insertion followed by surgical re-preparation and pulse generator implantation. Some patients do not tolerate awake surgery, underscoring the need for a safe alternative for asleep DBS surgery. A frame-based stereotactic system with a skull-mounted "key" in lieu of a circumferential base frame received US FDA clearance. The authors describe the system's application for single-stage, asleep DBS surgery in 8 patients at their institution and review its workflow and technical considerations. Eight patients underwent DBS lead insertion and IPG implantation in a single surgical preparation under general anesthesia using the system. Postoperative CT imaging confirmed lead placement. Eight patients underwent implantation of 15 total leads targeting the ventral intermediate nucleus (4 patients), globus pallidus internus (GPi; 3 patients), and subthalamic nucleus (STN; 1 patient). Intraoperative microelectrode recording was conducted for GPi and STN targets. Postoperative CT imaging revealed a mean ± SD radial error of 1.24 ± 0.45 mm (n = 15 leads), without surgical complications. The stereotactic system facilitated safe and effective asleep, single-stage DBS surgery, maintaining traditional lead accuracy standards.

Deep brain stimulation from past to future: research trends and global outcomes with bibliometric analysis during 1980-2022

Aims: We aimed to summarize the intellectual structure of the deep brain stimulation (DBS), to reveal the global productivity, to identify and map the latest trends by analysing the social and structural relationships between the different research components of scientific articles published on DBS.
 Methods: 5939 articles on DBS published during 1980 and 2022 were analysed utilized various statistical approaches. Network visualization maps were created to reveal trend topics, citation analysis, and international collaborations. Spearman's correlation analysis was used for correlation investigations. The exponential smoothing predictor was used to determine the article productivity trend.
 Results: The most prolific author on DBS was Okun, Michael S. (209 articles) and the most productive institution was the University of Toronto (n=283). The top 3 productive countries were United States of America (n=2371, 39.9%), Germany (910, 15.3%), and United Kingdom (550, 9.2%). From past to present, the most studied topics were Parkinson's disease, subthalamic nucleus DBS, dystonia, globus pallidus, essential tremor, movement disorders, thalamus, functional neurosurgery, neuromodulation, depression, obsessive compulsive disorder, basal ganglia.
 Conclusion: The primary trend topics that have been studied more in recent years are tractography, freezing of gait, Parkinson’s disease, Parkinson&#8217, Parkinson#apos, autonomy, self, machine learning, non-motor symptoms, functional connectivity, globus pallidus interna, volume of tissue activated, adaptive deep brain stimulation, beta oscillations, medial forebrain bundle, and local field potential. The secondery trend topics were optogenetics, pediatric, frameless, closed-loop DBS, refractory epilepsy, satellite broadcasting, asleep DBS, optimization, biomarker, directional Leeds, nucleus bassals of meynert, personality, authenticity, and anterior nucleus of thalamus.

Cognitive and psychiatric outcomes in the GALAXY trial: effect of anaesthesia in deep brain stimulation

BackgroundThis study aims: (1) To compare cognitive and psychiatric outcomes after bilateral awake versus asleep subthalamic nucleus (STN) deep brain stimulation (DBS) surgery for Parkinson’s disease (PD). (2) To explore...

Factors influencing the reliability of intraoperative testing in deep brain stimulation for Parkinson’s disease

BackgroundSeveral meta-analyses comparing the outcome of awake versus asleep deep brain stimulation procedures could not reveal significant differences concerning the postoperative improvement of motor symptoms. Only rarely information on the procedural details is provided for awake operations and how often somnolence and disorientation occurred, which might hamper the reliability of intraoperative clinical testing. The aim of our study was to investigate possible influencing factors on the occurrence of somnolence and disorientation in awake DBS procedures.MethodsWe retrospectively analyzed 122 patients with Parkinson's disease having received implantation of a DBS system at our centre. Correlation analyses were performed for the duration of disease prior to surgery, number of microelectrode trajectories, AC-PC-coordinates of the planned target, UPDRS-scores, intraoperative application of sedative drugs, duration of the surgical procedure, perioperative application of apomorphine, and the preoperative L-DOPA equivalence dosage with the occurrence of intraoperative somnolence and disorientation.ResultsPatients with intraoperative somnolence were significantly older (p=0.039). Increased duration of the DBS procedure (p=0.020), delayed start of the surgery (p=0.049), higher number of MER trajectories (p=0.041), and the patients’ % UPDRS improvement (p=0.046) also correlated with the incidence of intraoperative somnolence. We identified the main contributing factor to intraoperative somnolence as the use of sedative drugs applied during skin incision and burr hole trepanation (p=0.019). Perioperatively applied apomorphine could reduce the occurrence of somnolent phases during the operation (p=0.026).ConclusionSeveral influencing factors were found to seemingly increase the risk of intraoperative somnolence and disorientation, while the use of sedative drugs seems to be the main contributing factor. We argue that awake DBS procedures should omit the use of sedatives for best clinical outcome. When reporting on awake DBS surgery these factors should be considered and adjusted for, to permit reliable interpretation and comparison of DBS study results.

Motor Function and Quality of Life Improvement following Asleep versus Awake Deep Brain Stimulation (DBS) Procedures (P4-11.009)

<h3>Objective:</h3> To compare real-world outcomes in patients with Parkinson’s disease (PD) whose Deep Brain Stimulation (DBS) leads were implanted using asleep procedures versus those patients that underwent the procedure using awake conditions. <h3>Background:</h3> DBS procedures are typically conducted with patients being awake to allow for intraoperative clinical testing and/or micro-electrode recording to confirm lead location. However, asleep DBS procedures (i.e., under general anesthesia) are becoming increasingly popular due, at least in part, to technological improvements in imaging allowing alternative lead placement confirmation and shorter procedure duration (Brodsky 2017, Chen 2018, Vinke 2022). <h3>Design/Methods:</h3> A sub-analysis of patients receiving their DBS lead implant under asleep versus awake conditions was conducted in an ongoing, large, multicenter, prospective real-world outcomes study (Vercise, Boston Scientific). Motor function (MDS-UDPRS III), quality of life (PDQ-39) and related outcomes (GIC) were collected at baseline and up to 3-years. Safety events were also collected. <h3>Results:</h3> To date, 157 patients (mean age 61.2±8.3 years; 69% male) were asleep and 433 (mean age 60.1±8.5 years; 66% male) were awake during lead placement. Patients in both groups presented with similar baseline age, duration of disease and disease state. Improvement in quality-of-life was noted in both groups with a 5.3-point improvement (n = 104) in asleep group and a 4.5-point improvement (n = 319) in awake group at 1-year. Similarly, an 18.8- and 20.9-point improvement in motor function was noted in the asleep and awake groups, respectively. <h3>Conclusions:</h3> Outcomes from this large dataset of real-world outcomes examining the outcomes following asleep versus awake DBS demonstrate an alignment with results from previous studies (Holewijn 2021; LaHue 2017). Patient outcomes show little to no difference between awake versus asleep groups. Sleep DBS procedures may offer potential for shortening the total time taken for DBS procedures and offer a viable alternative for patients. <b>Disclosure:</b> Jan Vesper has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Boston Scientific . Jan Vesper has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Medtronic . Jan Vesper has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Abbott . Jan Vesper has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Abbott . Jan Vesper has received research support from German Research Council. Dr. Deuschl has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Boston Scientific Cavion Functional Neuromodulation. The institution of Dr. Deuschl has received research support from Medtronic. Dr. Deuschl has received publishing royalties from a publication relating to health care. Lilly Chen has received personal compensation for serving as an employee of Boston Scientific . Roshini Jain has received personal compensation for serving as an employee of Boston Scientific. Roshini Jain has received stock or an ownership interest from Boston Scientific.

Awake Versus Asleep Deep Brain Stimulation in Parkinson’s Disease: Comparison of Accuracy Using Three-Dimensional Target Analysis and Clinical Outcomes

Awake Versus Asleep Deep Brain Stimulation in Parkinson’s Disease: Comparison of Accuracy Using Three-Dimensional Target Analysis and Clinical Outcomes

Frameless Robot-Assisted Asleep Centromedian Thalamic Nucleus Deep Brain Stimulation Surgery in Patients with Drug-Resistant Epilepsy: Technical Description and Short-Term Clinical Results.

This purpose of this work is to give a detailed description of a surgical technique for frameless robot-assisted asleep deep brain stimulation (DBS) of the centromedian thalamic nucleus (CMT) in drug-resistant epilepsy (DRE). Ten consecutively enrolled patients who underwent CMT-DBS were included in the study. The FreeSurfer "Thalamic Kernel Segmentation" module and experience target coordinates were used for locating the CMT, and quantitative susceptibility mapping (QSM) images were used to check the target. The patient's head was secured with a head clip, and electrode implantation was performed with the assistance of the neurosurgical robot Sinovation®. After opening the dura, the burr hole was continuously flushed with physiological saline to stop air from entering the skull. All procedures were performed under general anesthesia without intraoperative microelectrode recording (MER). The mean age of the patients at surgery and onset of seizures was 22years (range 11-41years) and 11years (range 1-21years), respectively. The median duration of seizures before CMT-DBS surgery was 10years (2-26years). CMT was successfully segmented, and its position was verified by experience target coordinates and QSM images in all ten patients. The mean surgical time for bilateral CMT-DBS in this cohort was 165 ± 18min. The mean pneumocephalus volume was 2 cm3. The median absolute errors in the x-, y-, and z-axes were 0.7mm, 0.5mm, and 0.9mm, respectively. The median Euclidean distance (ED) and radial error (RE) was 1.3 ± 0.5mm and 1.0 ± 0.3mm, respectively. No significant difference was found between right- and left-sided electrodes regarding the RE nor the ED. After a mean 12-month follow-up, the average reduction in seizures was 61%, and six patients experienced a ≥ 50% reduction in seizures, including one patient who had no seizures after the operation. All patients tolerated the anesthesia operation, and no permanent or serious complications were reported. Frameless robot-assisted asleep surgery is a precise and safe approach for placing CMT electrodes in patients with DRE, shortening the surgery time. The segmentation of the thalamic nuclei enables the precise location of the CMT, and the flow of physiological saline to seal the burr holes is a good way to reduce the influx of air. CMT-DBS is an effective method to reduce seizures.

Awake Versus Asleep Subthalamic Nucleus Deep Brain Stimulation in Parkinson’s Disease: Comparison of Normalised Target Accuracy and Clinical Outcomes

Traditionally, studies comparing awake and asleep Deep Brain Stimulation (DBS) for estimation of accuracy have measured the deviation of final lead position from the intended position, as opposed to the distance from actual target location. This allows introduction of bias in accuracy assessment.

TU-202. Microelectrode recordings of the nucleus basalis of Meynert during asleep deep brain stimulation surgery

TU-202. Microelectrode recordings of the nucleus basalis of Meynert during asleep deep brain stimulation surgery

Association of clinical outcomes and connectivity in awake versus asleep deep brain stimulation for Parkinson disease.

Deep brain stimulation (DBS) for Parkinson disease (PD) is traditionally performed with awake intraoperative testing and/or microelectrode recording. Recently, however, the procedure has been increasingly performed under general anesthesia with image-based verification. The authors sought to compare structural and functional networks engaged by awake and asleep PD-DBS of the subthalamic nucleus (STN) and correlate them with clinical outcomes. Levodopa equivalent daily dose (LEDD), pre- and postoperative motor scores on the Movement Disorders Society-Unified Parkinson's Disease Rating Scale part III (MDS-UPDRS III), and total electrical energy delivered (TEED) at 6 months were retroactively assessed in patients with PD who received implants of bilateral DBS leads. In subset analysis, implanted electrodes were reconstructed using the Lead-DBS toolbox. Volumes of tissue activated (VTAs) were used as seed points in group volumetric and connectivity analysis. The clinical courses of 122 patients (52 asleep, 70 awake) were reviewed. Operating room and procedure times were significantly shorter in asleep cases. LEDD reduction, MDS-UPDRS III score improvement, and TEED at the 6-month follow-up did not differ between groups. In subset analysis (n = 40), proximity of active contact, VTA overlap, and desired network fiber counts with motor STN correlated with lower DBS energy requirement and improved motor scores. Discriminative structural fiber tracts involving supplementary motor area, thalamus, and brainstem were associated with optimal clinical improvement. Areas of highest structural and functional connectivity with VTAs did not significantly differ between the two groups. Compared to awake STN DBS, asleep procedures can achieve similarly optimal targeting-based on clinical outcomes, electrode placement, and connectivity estimates-in more efficient procedures and shorter operating room times.

Use of probabilistic tractography to provide reliable distinction of the motor and sensory thalamus for prospective targeting during asleep deep brain stimulation.

Accurate electrode placement is key to effective deep brain stimulation (DBS). The ventral intermediate nucleus (VIM) of the thalamus is an established surgical target for the treatment of essential tremor (ET). Retrospective tractography-based analysis of electrode placement has associated successful outcomes with modulation of motor input to VIM, but no study has yet evaluated the feasibility and efficacy of prospective presurgical tractography-based targeting alone. Therefore, the authors sought to demonstrate the safety and efficacy of probabilistic tractography-based VIM targeting in ET patients and to perform a systematic comparison of probabilistic and deterministic tractography. Fourteen patients with ET underwent preoperative diffusion imaging. Probabilistic tractography was applied for preoperative targeting, and deterministic tractography was performed as a comparison between methods. Tractography was performed using the motor and sensory areas as initiation seeds, the ipsilateral thalamus as an inclusion mask, and the contralateral dentate nucleus as a termination mask. Tract-density maps consisted of voxels with 10% or less of the maximum intensity and were superimposed onto anatomical images for presurgical planning. Target planning was based on probabilistic tract-density images and indirect target coordinates. Patients underwent robotic image-guided, image-verified implantation of directional DBS systems. Postoperative tremor scores with and without DBS were recorded. The center of gravity and Dice similarity coefficients were calculated and compared between tracking methods. Prospective probabilistic targeting of VIM was successful in all 14 patients. All patients experienced significant tremor reduction. Formal postoperative tremor scores were available for 9 patients, who demonstrated a mean 68.0% tremor reduction. Large differences between tracking methods were observed across patients. Probabilistic tractography-identified VIM fibers were more anterior, lateral, and superior than deterministic tractography-identified fibers, whereas probabilistic tractography-identified ventralis caudalis fibers were more posterior, lateral, and superior than deterministic tractography-identified fibers. Deterministic methods were unable to clearly distinguish between motor and sensory fibers in the majority of patients, but probabilistic methods produced distinct separation. Probabilistic tractography-based VIM targeting is safe and effective for the treatment of ET. Probabilistic tractography is more precise than deterministic tractography for the delineation of VIM and the ventralis caudalis nucleus of the thalamus. Deterministic algorithms tended to underestimate separation between motor and sensory fibers, which may have been due to its limitations with crossing fibers. Larger studies across multiple centers are necessary to further validate this method.

FV 15 Influencing factors for the occurrence of intraoperative drowsiness, which hamper the reliability of intraoperative clinical testing in deep brain stimulation

Question: Several meta-analyses comparing the outcome of awake versus asleep deep brain stimulation procedures did not reveal significant differences concerning the improvement of motor symptoms. Only rarely informations are given how the awake operations were performed and how often somnolence and disorientation occurred, which might hamper the reliability of intraoperative clinical testing. The aim of our study was to investigate possible influencing factors on the occurrence of somnolence and disorientation in awake procedures. Methods: We retrospectively analyzed 122 patients with Parkinson's disease having received implantation of a DBS system at our centre. Patient age ranged from 42 -75 years (mean 61,8 years). The occurrence of intraoperative somnolence and postoperative disorientation was correlated with the duration of disease prior to surgery, number of microelectrode trajectories, AC-PC-coordinates of the planned target, UPDRS-scores, intraoperative application of sedative drugs, duration of the surgical procedure, perioperative application of Apomorphin and the preoperative L-DOPA, equivalence dosage. Results: Patients in whom intraoperative somnolence occurred were significantly older than patients without this effect (p=0,039). Patients with intraoperative somnolence had a longer duration of the disease prior to surgery (p=0,080) and their preoperative off-medication- UPDRS was higher (p=0,071). If the planned target was more medial (p=0,060) and more inferior (p=0,051) intraoperative somnolence occurred more often. Sedative drugs, applied to cover skin incision and burr hole trepanation, again, led to more pronounced somnolence (p=0,019). The same was true for longer durations of the surgical procedure (p=0,020). Higher numbers of microelectrode trajectories were more likely associated with postoperative disorientation. Perioperatively applied Apomorphin could reduce the occurrence of somnolent phases during the operation (p=0,026). Conclusion: Several influencing factors were found to seemingly increase the risk of intraoperative somnolence and postoperative disorientation. These factors should be taken into account and adjusted, if possible, to permit reliable interpretations of intraoperative clinical testing.

Asleep deep brain stimulation with intraoperative magnetic resonance guidance: a single-institution experience.

Deep brain stimulation (DBS) is traditionally performed on an awake patient with intraoperative recordings and test stimulation. DBS performed under general anesthesia with intraoperative MRI (iMRI) has demonstrated high target accuracy, reduced operative time, direct confirmation of target placement, and the ability to place electrodes without cessation of medications. The authors describe their initial experience with using iMRI to perform asleep DBS and discuss the procedural and radiological outcomes of this procedure. All DBS electrodes were implanted under general anesthesia by a single surgeon by using a neuronavigation system with 3-T iMRI guidance. Clinical outcomes, operative duration, complications, and accuracy were retrospectively analyzed. In total, 103 patients treated from 2015 to 2019 were included, and all but 1 patient underwent bilateral implantation. Indications included Parkinson's disease (PD) (65% of patients), essential tremor (ET) (29%), dystonia (5%), and refractory epilepsy (1%). Targets included the globus pallidus pars internus (12.62% of patients), subthalamic nucleus (56.31%), ventral intermedius nucleus of the thalamus (30%), and anterior nucleus of the thalamus (1%). Technically accurate lead placement (radial error ≤ 1 mm) was obtained for 98% of leads, with a mean (95% CI) radial error of 0.50 (0.46-0.54) mm; all leads were placed with a single pass. Predicted radial error was an excellent predictor of real radial error, underestimating real error by only a mean (95% CI) of 0.16 (0.12-0.20) mm. Accuracy remained high irrespective of surgeon experience, but procedure time decreased significantly with increasing institutional and surgeon experience (p = 0.007), with a mean procedure duration of 3.65 hours. Complications included 1 case of intracranial hemorrhage (asymptomatic) and 1 case of venous infarction (symptomatic), and 2 patients had infection at the internal pulse generator site. The mean ± SD voltage was 2.92 ± 0.83 V bilaterally at 1-year follow-up. Analysis of long-term clinical efficacy demonstrated consistent postoperative improvement in clinical symptoms, as well as decreased drug doses across all indications and follow-up time points, including mean decrease in levodopa-equivalent daily dose by 53.57% (p < 0.0001) in PD patients and mean decrease in primidone dose by 61.33% (p < 0.032) in ET patients at 1-year follow-up. A total of 205 leads were placed in 103 patients by a single surgeon under iMRI guidance with few operative complications. Operative time trended downward with increasing institutional experience, and technical accuracy of radiographic lead placement was consistently high. Asleep DBS implantation with iMRI appears to be a safe and effective alternative to standard awake procedures.

Motor Evoked Potentials Improve Targeting in Deep Brain Stimulation Surgery

ObjectivesOne of the main challenges posed by the surgical deep brain stimulation (DBS) procedure is the successful targeting of the structures of interest and avoidance of side effects, especially in asleep surgery. Here, intraoperative motor evoked potentials (MEPs) might serve as tool to identify the pyramidal tract. We hypothesized that intraoperative MEPs are useful to define the distance to the pyramidal tract and reduce the occurrence of postoperative capsular side effects. Materials and MethodsMotor potentials were evoked through both microelectrode and DBS-electrode stimulation during stereotactic DBS surgery on 25 subthalamic nuclei and 3 ventral intermediate thalamic nuclei. Internal capsule proximity was calculated for contacts on microelectrode trajectories, as well as for DBS-electrodes, and correlated with the corresponding MEP thresholds. Moreover, the predictivity of intraoperative MEP thresholds on the probability of postoperative capsular side effects was calculated. ResultsIntraoperative MEPs thresholds correlated significantly with internal capsule proximity, regardless of the stimulation source. Furthermore, MEPs thresholds were highly accurate to exclude the occurrence of postoperative capsular side effects. ConclusionsIntraoperative MEPs provide additional targeting guidance, especially in asleep DBS surgery, where clinical value of microelectrode recordings and test stimulation may be limited. As this technique can exclude future capsular side effects, it can directly be translated into clinical practice.

General Anesthesia vs Local Anesthesia in Microelectrode Recording–Guided Deep-Brain Stimulation for Parkinson Disease

It is unknown if there is a difference in outcome in asleep vs awake deep brain stimulation (DBS) of the subthalamic nucleus for advanced Parkinson disease. To determine the difference in adverse effects concerning cognition, mood, and behavior between awake and asleep DBS favoring the asleep arm of the study. This study was a single-center prospective randomized open-label blinded end point clinical trial. A total of 187 persons with Parkinson disease were referred for DBS between May 2015 to March 2019. Analysis took place from January 2016 to January 2020. The primary outcome follow-up visit was conducted 6 months after DBS. Bilateral subthalamic nucleus DBS was performed while the patient was asleep (under general anesthesia) in 1 study arm and awake in the other study arm. Both arms of the study used a frame-based intraoperative microelectrode recording technique to refine final target placement of the DBS lead. The primary outcome variable was the between-group difference in cognitive, mood, and behavioral adverse effects as measured by a composite score. The secondary outcomes included the Movement Disorders Society Unified Parkinson's Disease Rating Scale, the patient assessment of surgical burden and operative time. A total of 110 patients were randomized to awake (local anesthesia; n = 56; mean [SD] age, 60.0 (7.4) years; 40 [71%] male) or to asleep (general anesthesia; n = 54; mean [SD] age, 61.3 [7.9] years; 38 [70%] male) DBS surgery. The 6-month follow-up visit was completed by 103 participants. The proportion of patients with adverse cognitive, mood, and behavioral effects on the composite score was 15 of 52 (29%) after awake and 11 of 51 (22%) after asleep DBS (odds ratio, 0.7 [95% CI, 0.3-1.7]). There was no difference in improvement in the off-medication Movement Disorders Society Unified Parkinson's Disease Rating Scale Motor Examination scores between groups (awake group: mean [SD], -27.3 [17.5] points; asleep group: mean [SD], -25.3 [14.3] points; mean difference, -2.0 [95% CI, -8.1 to 4.2]). Asleep surgery was experienced as less burdensome by patients and was 26 minutes shorter than awake surgery. There was no difference in the primary outcome of asleep vs awake DBS. Future large randomized clinical trials should examine some of the newer asleep based DBS technologies because this study was limited to frame-based microelectrode-guided procedures. trialregister.nl Identifier: NTR5809.

Toward asleep DBS: cortico-basal ganglia spectral and coherence activity during interleaved propofol/ketamine sedation mimics NREM/REM sleep activity

Deep brain stimulation (DBS) is currently a standard procedure for advanced Parkinson’s disease. Many centers employ awake physiological navigation and stimulation assessment to optimize DBS localization and outcome. To enable DBS under sedation, asleep DBS, we characterized the cortico-basal ganglia neuronal network of two nonhuman primates under propofol, ketamine, and interleaved propofol-ketamine (IPK) sedation. Further, we compared these sedation states in the healthy and Parkinsonian condition to those of healthy sleep. Ketamine increases high-frequency power and synchronization while propofol increases low-frequency power and synchronization in polysomnography and neuronal activity recordings. Thus, ketamine does not mask the low-frequency oscillations used for physiological navigation toward the basal ganglia DBS targets. The brain spectral state under ketamine and propofol mimicked rapid eye movement (REM) and Non-REM (NREM) sleep activity, respectively, and the IPK protocol resembles the NREM-REM sleep cycle. These promising results are a meaningful step toward asleep DBS with nondistorted physiological navigation.

Functional Neuroimaging During Asleep DBS Surgery: A Proof of Concept Study.

Object: A real-time functional magnetic resonance imaging (fMRI) feedback during ventral intermediate nucleus (VIM) deep brain stimulation (DBS) under general anesthesia (or “asleep” DBS) does not exist. We hypothesized that it was feasible to acquire a reliable and responsive fMRI during asleep VIM DBS surgery.Methods: We prospectively enrolled 10 consecutive patients who underwent asleep DBS for the treatment of medication-refractory essential tremor. Under general anesthesia, we acquired resting-state functional MRI immediately before and after the cannula insertion. Reliability was determined by a temporal signal-to-noise-ratio >100. Responsiveness was determined based on the fMRI signal change upon insertion of the cannula to the VIM.Results: It was feasible to acquire reliable fMRI during asleep DBS surgery. The fMRI signal was responsive to the brain cannula insertion, revealing a reduction in the tremor network's functional connectivity, which did not reach statistical significance in the group analysis.Conclusions: It is feasible to acquire a reliable and responsive fMRI signal during asleep DBS. The acquisition steps and the preprocessing pipeline developed in these experiments will be useful for future investigations to develop fMRI-based feedback for asleep DBS surgery.

Optimized Propofol Anesthesia Increases Power of Subthalamic Neuronal Activity in Patients with Parkinson's Disease Undergoing Deep Brain Stimulation.

IntroductionPropofol is a general anesthetic option for deep brain stimulation (DBS) of the subthalamic nucleus (STN) of patients with Parkinson's disease (PD). However, its effects on STN activity and neuropsychological outcomes are controversial. The optimal propofol anesthesia for asleep DBS is unknown. This study investigated the safety and effectiveness of an optimized propofol anesthesia regimen in asleep DBS.MethodsThis retrospective study enrolled 68 PD patients undergoing bilateral STN-DBS surgery. All patients received local scalp anesthesia, with (asleep group, n = 35) or without (awake group, n = 33) propofol-remifentanil general anesthesia by target-controlled infusion under electroencephalogram monitoring. The primary outcome was subthalamic neuronal spiking characterization during microelectrode recording. The secondary outcomes were clinical outcomes including motor, cognition, mind, sleep, and quality of life at 6 months.ResultsSignificantly increased delta and theta power were obtained under propofol anesthesia (awake vs. asleep group, mean ± standard deviation; delta: 31.97 ± 9.87 vs. 39.77 ± 10.56, p < 0.01; theta: 21.09 ± 5.55 vs. 24.82 ± 6.63, p = 0.01). After excluding the influence of confounding factors of age and preoperative motor scores, there was a statistically significant influence on the delta, theta, and alpha power of STN neuronal activity under different anesthesia regimens (delta: β = 2.64, p < 0.01; theta: β = 2.11, p < 0.01; alpha: β = 1.42, p = 0.01). There were no differences in modified burst index, firing rate, tract numbers of microelectrode recording, and other clinical outcomes between the two groups.ConclusionOptimized propofol anesthesia enhanced the delta, theta, and alpha power in STN compared with the awake technique and likely contributed to target recognition under propofol anesthesia. These results demonstrate that propofol is suitable, but needs to be optimized, for asleep STN-DBS.Trial RegistrationChinese Clinical Trial Registry Identification number: ChiCTR2100045942. Registered 29 April 2021–Retrospectively registeredSupplementary InformationThe online version contains supplementary material available at 10.1007/s40120-021-00259-y.

Efficacy and safety of general anesthesia deep brain stimulation for dystonia: an individual patient data meta-analysis of 341 cases.

The efficacy and safety of deep brain stimulation (DBS) under general anesthesia for the treatment of dystonia have not yet been confirmed with high level of evidence. This meta-analysis with pooled individual patient data aims to assess the clinical outcomes and identify the potential prognostic factors of dystonia patients who underwent general anesthesia DBS. We searched PubMed, Web of Science, and Embase for articles describing patients with dystonia who underwent asleep DBS and had individual Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) scores. The relative improvement in BFMDRS scores was considered the primary outcome. Pearson correlation analyses and multivariate linear regression analysis were conducted to explore the prognostic factors. A total of 34 studies involving 341 patients were included. The mean postoperative improvement in BFMDRS-M (BFMDRS movement subscale) and BFMDRS-D (BFMDRS disability subscale) scores were 58.6±36.2% and 48.5±38.7% at the last follow-up visit, respectively, with a mean follow-up time of 22.4±27.6 months. Age at surgery and disease duration showed a negative correlation with the percent improvement of BFMDRS-M (%) at the last visit (r=-0.134, P=0.013; r=-0.165, P=0.006). In the stepwise multivariate regression, only disease duration remained a relevant factor. Additionally, the adverse events were acceptable. General anesthesia DBS is a safe, effective, and feasible option for dystonia patients in the long term. Shorter disease duration predicts better clinical outcomes.

Hidden Error in Optical Stereotactic Navigation Systems and Strategy to Maximize Accuracy

Background: Optical neuronavigation has been established as a reliable and effective adjunct to many neurosurgical procedures. Operations such as asleep deep brain stimulation (aDBS) benefit from the potential increase in accuracy that these systems offer. Built into these technologies is a degree of tolerated error that may exceed the presumed accuracy resulting in suboptimal outcomes. Objective: The objective of this study was to identify an underlying source of error in neuronavigation and determine strategies to maximize accuracy. Methods: A Medtronic Stealth system (Stealth Station 7 hardware, S8 software, version 3.1.1) was used to simulate an aDBS procedure with the Medtronic Nexframe system. Multiple configurations and orientations of the Nexframe-Nexprobe system components were examined to determine potential sources of, and to quantify navigational error, in the optical navigation system. Virtual entry point and target variations were recorded and analyzed. Finally, off-plan error was recorded with the AxiEM system and visual observation on a phantom head. Results: The most significant source of error was found to be the orientation of the reference marker plate configurations to the camera system, with the presentation of the markers perpendicular to the camera line of site being the most accurate position. Entry point errors ranged between 0.134 ± 0.048 and 1.271 ± 0.0986 mm in a complex, reproducible pattern dependent on the orientation of the Nexprobe reference plate. Target errors ranged between 0.311 ± 0.094 and 2.159 ± 0.190 mm with a similarly complex, repeatable pattern. Representative configurations were tested for physical error at target with errors ranging from 1.2 mm to 1.4 mm. Throughout data acquisition, no orientation was indicated as outside the acceptable tolerance by the Stealth software. Conclusions: Use of optical neuronavigation is expected to increase in frequency and variety of indications. Successful implementation of this technology depends on understanding the tolerances built into the system. In situations that depend on extremely high precision, surgeons should familiarize themselves with potential sources of error so that systems may be optimized beyond the manufacturer’s built-in tolerances. We recommend that surgeons align the navigation reference plate and any optical instrument’s reference plate spheres in the plane perpendicular to the line of site of the camera to maximize accuracy.