Deep Brain Stimulation Procedures Research Articles

Stress response of autonomic nervous system during conditioned inhalation general anesthesia for deep brain stimulation

Purpose: It is proved in our previous reports that neuronal activities of subthalamic nucleus (STN) could be well recorded via single neuron microelectrode recording (MER) under conditioned general anesthesia (cGA) by volatile anesthetics, yet, without jeopardize patient’s safety during deep brain stimulation (DBS) procedures. In this study, we aimed to investigate the autonomic response under cGA, by which, MER could be properly obtained during DBS.

Deep brain stimulation for movement disorders: Surgical nuances.

Parkinson's disease (PD) and dystonia are common indications for the deep brain stimulation (DBS) procedure. It is very important to be diligent about target localization and execution of the procedure. The single most important predictor of a good postoperative outcome is proper patient selection. The various steps of performing DBS include taking a preoperative non - stereotactic MRI, stereotactic frame fixation, fusion of MRI with stereotactic CT scan images, planning of the target and trajectory, lead placement at target through the planned trajectory, implantation of pulse generator/ battery and programming of the implanted device. Utmost care and precision are required to execute the procedure, which decide the final outcome of the surgical procedure.

Deep brain stimulation for severe treatment-resistant obsessive-compulsive disorder: An open-label case series.

Deep brain stimulation can be of benefit in carefully selected patients with severe intractable obsessive-compulsive disorder. The aim of this paper is to describe the outcomes of the first seven deep brain stimulation procedures for obsessive-compulsive disorder undertaken at the Neuropsychiatry Unit, Royal Melbourne Hospital. The primary objective was to assess the response to deep brain stimulation treatment utilising the Yale-Brown Obsessive Compulsive Scale as a measure of symptom severity. Secondary objectives include assessment of depression and anxiety, as well as socio-occupational functioning. Patients with severe obsessive-compulsive disorder were referred by their treating psychiatrist for assessment of their suitability for deep brain stimulation. Following successful application to the Psychosurgery Review Board, patients proceeded to have deep brain stimulation electrodes implanted in either bilateral nucleus accumbens or bed nucleus of stria terminalis. Clinical assessment and symptom rating scales were undertaken pre- and post-operatively at 6- to 8-week intervals. Rating scales used included the Yale-Brown Obsessive Compulsive Scale, Obsessive Compulsive Inventory, Depression Anxiety Stress Scale and Social and Occupational Functioning Assessment Scale. Seven patients referred from four states across Australia underwent deep brain stimulation surgery and were followed for a mean of 31 months (range, 8-54 months). The sample included four females and three males, with a mean age of 46 years (range, 37-59 years) and mean duration of obsessive-compulsive disorder of 25 years (range, 15-38 years) at the time of surgery. The time from first assessment to surgery was on average 18 months. All patients showed improvement on symptom severity rating scales. Three patients showed a full response, defined as greater than 35% improvement in Yale-Brown Obsessive Compulsive Scale score, with the remaining showing responses between 7% and 20%. Deep brain stimulation was an effective treatment for obsessive-compulsive disorder in these highly selected patients. The extent of the response to deep brain stimulation varied between patients, as well as during the course of treatment for each patient. The results of this series are comparable with the literature, as well as having similar efficacy to ablative psychosurgery techniques such as capsulotomy and cingulotomy. Deep brain stimulation provides advantages over lesional psychosurgery but is more expensive and requires significant multidisciplinary input at all stages, pre- and post-operatively, ideally within a specialised tertiary clinical and/or academic centre. Ongoing research is required to better understand the neurobiological basis for obsessive-compulsive disorder and how this can be manipulated with deep brain stimulation to further improve the efficacy of this emerging treatment.

Postoperative lead migration in deep brain stimulation surgery: Incidence, risk factors, and clinical impact.

IntroductionDeep brain stimulation (DBS) is an effective treatment for multiple movement disorders and shows substantial promise for the treatment of some neuropsychiatric and other disorders of brain neurocircuitry. Optimal neuroanatomical lead position is a critical determinant of clinical outcomes in DBS surgery. Lead migration, defined as an unintended post-operative displacement of the DBS lead, has been previously reported. Despite several reports, however, there have been no systematic investigations of this issue. This study aimed to: 1) quantify the incidence of lead migration in a large series of DBS patients, 2) identify potential risk factors contributing to DBS lead migration, and 3) investigate the practical importance of this complication by correlating its occurrence with clinical outcomes.MethodsA database of all DBS procedures performed at UF was queried for patients who had undergone multiple post-operative DBS lead localization imaging studies separated by at least two months. Bilateral DBS implantation has commonly been performed as a staged procedure at UF, with an interval of six or more months between sides. To localize the position of each DBS lead, a head CT is acquired ~4 weeks after lead implantation and fused to the pre-operative targeting MRI. The fused targeting images (MR + stereotactic CT) acquired in preparation for the delayed second side lead implantation provide an opportunity to repeat the localization of the first implanted lead. This paradigm offers an ideal patient population for the study of delayed DBS lead migration because it provides a large cohort of patients with localization of the same implanted DBS lead at two time points. The position of the tip of each implanted DBS lead was measured on both the initial post-operative lead localization CT and the delayed CT. Lead tip displacement, intracranial lead length, and ventricular indices were collected and analyzed. Clinical outcomes were characterized with validated rating scales for all cases, and a comparison was made between outcomes of cases with lead migration versus those where migration of the lead did not occur.ResultsData from 138 leads in 132 patients with initial and delayed lead localization CT scans were analyzed. The mean distance between initial and delayed DBS lead tip position was 2.2 mm and the mean change in intracranial lead length was 0.45 mm. Significant delayed migration (>3 mm) was observed in 17 leads in 16 patients (12.3% of leads, 12.1% of patients). Factors associated with lead migration were: technical error, repetitive dystonic head movement, and twiddler’s syndrome. Outcomes were worse in dystonia patients with lead migration (p = 0.035). In the PD group, worse clinical outcomes trended in cases with lead migration.ConclusionsOver 10% of DBS leads in this large single center cohort were displaced by greater than 3 mm on delayed measurement, adversely affecting outcomes. Multiple risk factors emerged, including technical error during implantation of the DBS pulse generator and failure of lead fixation at the burr hole site. We hypothesize that a change in surgical technique and a more effective lead fixation device might mitigate this problem.

A novel assistive method for rigidity evaluation during deep brain stimulation surgery using acceleration sensors.

OBJECTIVE Despite the widespread use of deep brain stimulation (DBS) for movement disorders such as Parkinson's disease (PD), the exact anatomical target responsible for the therapeutic effect is still a subject of research. Intraoperative stimulation tests by experts consist of performing passive movements of the patient's arm or wrist while the amplitude of the stimulation current is increased. At each position, the amplitude that best alleviates rigidity is identified. Intrarater and interrater variations due to the subjective and semiquantitative nature of such evaluations have been reported. The aim of the present study was to evaluate the use of an acceleration sensor attached to the evaluator's wrist to assess the change in rigidity, hypothesizing that such a change will alter the speed of the passive movements. Furthermore, the combined analysis of such quantitative results with anatomy would generate a more reproducible description of the most effective stimulation sites. METHODS To test the reliability of the method, it was applied during postoperative follow-up examinations of 3 patients. To study the feasibility of intraoperative use, it was used during 9 bilateral DBS operations in patients suffering from PD. Changes in rigidity were calculated by extracting relevant outcome measures from the accelerometer data. These values were used to identify rigidity-suppressing stimulation current amplitudes, which were statistically compared with the amplitudes identified by the neurologist. Positions for the chronic DBS lead implantation that would have been chosen based on the acceleration data were compared with clinical choices. The data were also analyzed with respect to the anatomical location of the stimulating electrode. RESULTS Outcome measures extracted from the accelerometer data were reproducible for the same evaluator, thus providing a reliable assessment of rigidity changes during intraoperative stimulation tests. Of the 188 stimulation sites analyzed, the number of sites where rigidity-suppressing amplitudes were found increased from 144 to 170 when the accelerometer evaluations were considered. In general, rigidity release could be observed at significantly lower amplitudes with accelerometer evaluation (mean 0.9 ± 0.6 mA) than with subjective evaluation (mean 1.4 ± 0.6 mA) (p < 0.001). Of 14 choices for the implant location of the DBS lead, only 2 were the same for acceleration-based and subjective evaluations. The comparison across anatomical locations showed that stimulation in the fields of Forel ameliorates rigidity at similar amplitudes as stimulation in the subthalamic nucleus, but with fewer side effects. CONCLUSIONS This article describes and validates a new assistive method for assessing rigidity with acceleration sensors during intraoperative stimulation tests in DBS procedures. The initial results indicate that the proposed method may be a clinically useful aid for optimal DBS lead placement as well as a new tool in the ongoing scientific search for the optimal DBS target for PD.

A novel stereotaxic system for implanting a curved lead to two intracranial targets with high accuracy

BackgroundThe multi-target deep brain stimulation (DBS) aimed at improving symptoms related to different nuclei is a promising research direction. However, to implant a single lead into multiple targets simultaneously is difficult with the current lead implantation method. New methodWe proposed a novel stereotaxic system used for implanting a curved lead to any two targets of the brain, and used the theoretical “curved lead method”. First, a customized novel stereotaxic system was fabricated, and a solid cranial model with six fixed internal targets was made; second, CT scan was performed to locate the fixed internal targets; third, five curved leads were implanted to five selected pairs of targets, each following the calculated parameters of “curved lead pathway” with the novel stereotaxic system, respectively. Finally, CT scans were performed again to determine the exact locations of the curved leads. ResultsThe five curved leads accurately passed through the five pairs of combined targets, respectively, and the average vector error of curved lead implantation was 0.70±0.24mm. Comparison with Existing Method(s)In most situations, performing a multiple-target DBS procedure with the current stereotaxic systems means increased number of implanted leads, increased incidence of operative complications, and increased medical costs. However, the novel stereotaxic system could guide a single lead to reach two selected targets of the brain with high accuracy. ConclusionsThe novel stereotaxic system enables curved lead implantation with high accuracy, and can be considered as a useful complement to the current stereotaxic system.

S62 Can we improve Deep Brain Stimulation targeting with neurophysiological recording?

Deep Brain Stimulation (DBS) is a well established therapy mainly for some movement disorders, like Parkinson’s disease (PD). However there is not agreement about which approach for targeting the different nuclei is more appropriate. The main objective was to compare the targeting of the subthalamic nucleus (STN) in PD patients with unitary activity recording (MER) alone versus MER combined with the simultaneous recording of the local field potential (LFP) through the same microelectrode. The methods included thirty consecutive PD patients undergone surgical DBS procedure in the STN that were divided in two groups of fifteen patients. For the first group the electrophysiological procedure consisted in MER only and for the second group LFP recording was also performed. The main results obtained were that in the Z-axis the length, defined as the presence of beta-activity, of the sensoriomotor region is shorter that the global length of the STN. The electrophysiological procedure was around 20 min shorter in each brain side combining together MER and LFP. There is an open debate about the functional-based methods to target deep brain structures for DBS versus image-based methods with a bias to the latter. An image-based procedure does not gives functional information and the objective of the DBS is a functional modulation of neuronal circuits. In conclusion MER together LFP give functional information that allows a more accurate placement of the DBS leads improving the outcomes of the therapy and does not increase the risk of bleeding in microelectrode trajectories.

Dual Anchor Internal Pulse Generator Technique May Lower Risk of Twiddler’s Syndrome: A Case Series and Literature Review

Twiddler's syndrome (TS) is described as a spontaneous rotation or intentional external manipulation of implanted internal pulse generator (IPG) for neurological or cardiac disorders. There have been identified some predisposing factors of the development of TS such as: loose subcutaneous tissue, older age of individuals undergoing deep brain stimulation (DBS) procedures, creation of too large pockets for IPG. Apart from these factors, the construction of IPG itself may predispose to the development of TS. To report the clinical course of three patients with TS. Moreover, the purpose of this study is to present the change in fixation technique of IPG that can prevent the occurrence of TS in patients after DBS procedure. A prospectively collected database of all hardware related complications for patients operated on for various movement disorders was analyzed. In a total number of 347 DBS systems implanted since 1999 we have identified three patients diagnosed with TS. All three patients with TS in our series were implanted with the IPG harboring a single anchoring hole. This complication has never occurred in patients with the IPG harboring two anchoring holes in our center. All three patients underwent revision surgery. During reoperations all connection cables were replaced and IPG sutured with one additional silk stich through the plastic housing to immobilize it properly in subcutaneous pocket. There were no recurrences of TS in our patients. Our case series suggests that a predisposing factor of TS may also be the construction of IPG itself (a single anchoring hole intended for fixation), which naturally represents less fixation of the IPG to the fascia or muscle in the subcutaneous pocket. In this preliminary report we present suggestions to lower the risk of TS, including using dual anchor capable IPGs, reducing pocket volume and using nonabsorbable suture.

High-frequency measurement of depressive severity in a patient treated for severe treatment-resistant depression with deep-brain stimulation

Although there have been previous studies of deep-brain stimulation (DBS), we present, to our knowledge, the first example of high-frequency depressive severity measurement-based DBS treatment in particular and psychiatric treatment in general. Daily post-surgical e-mail prompts for a period of 6 months resulted in 93 administrations of a computerized adaptive test (CAT) of depression severity (CAT-Depression Inventory or CAT-DI) via the internet. There was an average of 3.37 weekly measurements with an average separation of 2.12 days. No additional incentive was provided to the patient for completing the adaptive tests. The patient is a 55-year-old female with six psychiatric hospitalizations for depression, two suicide attempts, marginal response to eight electroconvulsive therapy (ECT) treatments and 35 psychotropic medications. We report results after high-frequency stimulation of the superolateral branch of the medial forebrain bundle. The CAT-DI was used for daily assessments before, during and after (remotely in response to an e-mail prompt) the DBS procedure. Two follow-up Hamilton Depression Scales (HAM-Ds) were also collected. Response to treatment varied markedly, with a decrease from severe (>75) to mild (60), which is three times the size of the uncertainty level. Although the HAM-D scores decreased, they missed the more complete temporal pattern identified by CAT-DI daily monitoring. We demonstrated feasibility of daily depressive severity measurement at high levels of precision and compliance. Clinician ratings confirm the general pattern of treatment benefit, but mask the marked variability in mood and more marked periods of benefit and decline.

Thirty-Day Readmission Rates Following Deep Brain Stimulation Surgery.

Deep brain stimulation (DBS) has emerged as a safe and efficacious surgical intervention for several movement disorders; however, the 30-day all-cause readmission rate associated with this procedure has not previously been documented. To perform a retrospective cohort study to estimate the 30-day all-cause readmission rate associated with DBS. We reviewed medical records of patients over the age of 18 who underwent DBS surgery at Pennsylvania Hospital of the University of Pennsylvania between 2009 and 2014. We identified patients who were readmitted to an inpatient medical facility within 30 days from their initial discharge. Over the study period, 23 (6.6%) of 347 DBS procedures resulted in a readmission to the hospital within 30 days. Causes of readmission were broadly categorized into surgery-related (3.7%): intracranial lead infection (0.6%), battery-site infection (0.6%), intracranial hematoma along the electrode tract (0.6%), battery-site hematoma (0.9%), and seizures (1.2%); and nonsurgery-related (2.9%): altered mental status (1.8%), nonsurgical-site infections (0.6%), malnutrition and poor wound healing (0.3%), and a pulse generator malfunction requiring reprogramming (0.3%). Readmissions could be predicted by the presence of medical comorbidities ( P < .001), but not by age, gender, or length of stay ( P s > .15). All-cause 30-day readmission for DBS is 6.6%. This compares favorably to previously studied neurosurgical procedures. Readmissions frequently resulted from surgery-related complications, particularly infection, seizures, and hematomas, and were significantly associated with the presence of medical comorbidities ( P < .001).

Deep brain stimulation in movement disorders: evidence and therapy standards

The deep brain stimulation (DBS) in movement disorders is well established and in many aspects evidence-based procedure. The treatment indications are very heterogeneous and very specific in their course and therapy. The deep brain stimulation plays very important, but usually not the central role in this conditions. The success in the application of DBS is essentially associated with the correct, appropriate and timely indication of the therapy in the course of these diseases. Thanks to the good standardization of the DBS procedure and sufficient published data, the recommendations for indication, diagnosis and operative procedures can be generated. The following article attempts to summarize the most important decision-making criteria and current therapy standards in this fairly comprehensive subject and to present them in close proximity to practice.

Robot-assisted procedures in pediatric neurosurgery.

OBJECTIVE During the last 3 decades, robotic technology has rapidly spread across several surgical fields due to the continuous evolution of its versatility, stability, dexterity, and haptic properties. Neurosurgery pioneered the development of robotics, with the aim of improving the quality of several procedures requiring a high degree of accuracy and safety. Moreover, robot-guided approaches are of special interest in pediatric patients, who often have altered anatomy and challenging relationships between the diseased and eloquent structures. Nevertheless, the use of robots has been rarely reported in children. In this work, the authors describe their experience using the ROSA device (Robotized Stereotactic Assistant) in the neurosurgical management of a pediatric population. METHODS Between 2011 and 2016, 116 children underwent ROSA-assisted procedures for a variety of diseases (epilepsy, brain tumors, intra- or extraventricular and tumor cysts, obstructive hydrocephalus, and movement and behavioral disorders). Each patient received accurate preoperative planning of optimal trajectories, intraoperative frameless registration, surgical treatment using specific instruments held by the robotic arm, and postoperative CT or MR imaging. RESULTS The authors performed 128 consecutive surgeries, including implantation of 386 electrodes for stereo-electroencephalography (36 procedures), neuroendoscopy (42 procedures), stereotactic biopsy (26 procedures), pallidotomy (12 procedures), shunt placement (6 procedures), deep brain stimulation procedures (3 procedures), and stereotactic cyst aspiration (3 procedures). For each procedure, the authors analyzed and discussed accuracy, timing, and complications. CONCLUSIONS To the best their knowledge, the authors present the largest reported series of pediatric neurosurgical cases assisted by robotic support. The ROSA system provided improved safety and feasibility of minimally invasive approaches, thus optimizing the surgical result, while minimizing postoperative morbidity.

Tiefe Hirnstimulation bei Bewegungsstörungen: Evidenz und Therapiestandards

The deep brain stimulation (DBS) in movement disorders is well established and in many aspects evidence-based procedure. The treatment indications are very heterogeneous and very specific in their course and therapy. The deep brain stimulation plays very important, but usually not the central role in this conditions. The success in the application of DBS is essentially associated with the correct, appropriate and timely indication of the therapy in the course of these diseases. Thanks to the good standardization of the DBS procedure and sufficient published data, the recommendations for indication, diagnosis and operative procedures can be generated. The following article attempts to summarize the most important decision-making criteria and current therapy standards in this fairly comprehensive subject and to present them in close proximity to practice.

Deep Brain Stimulation in Parkinson’s Disease: Overview and Complications

Deep brain stimulation (DBS) of basal ganglia has become a frequently performed surgery in patients with advanced Parkinson’s disease. Throughout the years, this technique has reached advances in imaging techniques, neurophysiological recording possibilities, and in hardware and software technology. Nevertheless, to reach optimal results of DBS therapy, a number of aspects must be carefully considered. In current paper, overview of DBS procedure is provided with special focus on complications of this, an even so ever more promising therapeutic approach.

Considerations in deep brain stimulation (DBS) for pediatric secondary dystonia.

There is a paucity of effective long-term medication treatment for secondary dystonias. In situations where significantly impairing secondary dystonias fail to respond to typical enteral medications and intrathecal (or even intraventricular) baclofen, consideration should be given to the use of deep brain stimulation (DBS). While Level I evidence and long-term follow-up clearly demonstrate the efficacy of DBS for primary dystonia, the evidence for secondary dystonia remains mixed and unclear. In this study, we report our experience with pediatric subjects who have undergone DBS for secondary dystonia. We discuss the indications and outcomes of DBS procedures completed at our center. We also present a detailed discussion of the considerations in the management of these patients as well as a literature review. Of the four cases retrospectively examined here, all subjects experienced reductions in the severity of their dystonia (ranging from 0 to 100% on both the Barry-Albright Dystonia (BAD) and Burke-Fahn-Marsden Dystonia Rating Scale-Motor (BFMDRS-M) scales). Pallidal DBS should be considered among children with functionally debilitating, medication-resistant secondary dystonia. Patients without fixed skeletal deformities who have experienced a short duration of symptoms are most likely to benefit from this intervention.

Local vs. volume conductance activity of field potentials in the human subthalamic nucleus.

Subthalamic nucleus field potentials have attracted growing research and clinical interest over the last few decades. However, it is unclear whether subthalamic field potentials represent locally generated neuronal subthreshold activity or volume conductance of the organized neuronal activity generated in the cortex. This study aimed at understanding of the physiological origin of subthalamic field potentials and determining the most accurate method for recording them. We compared different methods of recordings in the human subthalamic nucleus: spikes (300-9,000 Hz) and field potentials (3-100 Hz) recorded by monopolar micro- and macroelectrodes, as well as by differential-bipolar macroelectrodes. The recordings were done outside and inside the subthalamic nucleus during electrophysiological navigation for deep brain stimulation procedures (150 electrode trajectories) in 41 Parkinson's disease patients. We modeled the signal and estimated the contribution of nearby/independent vs. remote/common activity in each recording configuration and area. Monopolar micro- and macroelectrode recordings detect field potentials that are considerably affected by common (probably cortical) activity. However, bipolar macroelectrode recordings inside the subthalamic nucleus can detect locally generated potentials. These results are confirmed by high correspondence between the model predictions and actual correlation of neuronal activity recorded by electrode pairs. Differential bipolar macroelectrode subthalamic field potentials can overcome volume conductance effects and reflect locally generated neuronal activity. Bipolar macroelectrode local field potential recordings might be used as a biological marker of normal and pathological brain functions for future electrophysiological studies and navigation systems as well as for closed-loop deep brain stimulation paradigms.NEW & NOTEWORTHY Our results integrate a new method for human subthalamic recordings with a development of an advanced mathematical model. We found that while monopolar microelectrode and macroelectrode recordings detect field potentials that are considerably affected by common (probably cortical) activity, bipolar macroelectrode recordings inside the subthalamic nucleus (STN) detect locally generated potentials that are significantly different than those recorded outside the STN. Differential bipolar subthalamic field potentials can be used in navigation and closed-loop deep brain stimulation paradigms.

Field evoked potentials in the globus pallidus of non-human primates

Stimulation-induced field evoked potentials (fEPs) have been described in the basal ganglia output nuclei of patients with Parkinson’s disease and dystonia. The aim of this study was to ascertain whether fEPs were inducible in the external (GPe) and internal (GPi) segments of the globus pallidus in normal non-human primates (NHPs). Microelectrode recording and stimulation was performed in the GPe and GPi of 2 healthy NHPs. Stimulus response curves of the fEP response to changing pulse width and amplitude examined strength-duration relationships and allowed for calculation of fEP chronaxie in the GPe and GPi. Traditional localization techniques were also used, including comparison of neuronal firing rates, optic tract activation, and internal capsule activation. Notable differences were seen in the fEPs found in GPe compared to the fEPs found in GPi. The GPe fEP had a smaller chronaxie time and larger positive deflection amplitude compared to GPi. In addition, an earlier negative deflection was identified in both nuclei and a late negative deflection was observed in the GPe in contrast to reported fEPs in patients with movement disorders. fEPs proved valuable as an ancillary method in localizing the GPe and GPi in NHPs and may be useful in the operating room during human GPi deep brain stimulation or pallidotomy procedures.

Meta-Analysis of the Relationship between Deep Brain Stimulation in Patients with Parkinson's Disease and Performance in Evaluation Tests for Executive Brain Functions.

Parkinson's disease (PD) is a neurodegenerative condition, which compromises the motor functions and causes the alteration of some executive brain functions. The presence of changes in cognitive symptoms in PD could be due to the procedure of deep brain stimulation (DBS). We searched in several databases for studies that compared performance in executive function tests before and after the DBS procedure in PE and then performed a meta-analysis. After the initial search, there were 15 articles that specifically evaluated the functions of verbal fluency, working memory, cognitive flexibility, abstract thinking, and inhibition. It was found that there were differences in the evaluation of the cognitive functions in terms of the protocols, which generated heterogeneity in the results of the meta-analysis. Likewise, a tendency to diminish functions like verbal fluency and inhibition was found, being this consistent with similar studies. In the other functions evaluated, no difference was found between pre- and postsurgery scores. Monitoring of this type of function is recommended after the procedure.

Using "Functional" Target Coordinates of the Subthalamic Nucleus to Assess the Indirect and Direct Methods of the Preoperative Planning: Do the Anatomical and Functional Targets Coincide?

Objective: To answer the question of whether the anatomical center of the subthalamic nucleus (STN), as calculated indirectly from stereotactic atlases or by direct visualization on magnetic resonance imaging (MRI), corresponds to the best functional target. Since the neighboring red nucleus (RN) is well visualized on MRI, we studied the relationships of the final target to its different borders. Methods: We analyzed the data of 23 PD patients (46 targets) who underwent bilateral frame-based STN deep brain stimulation (DBS) procedure with microelectrode recording guidance. We calculated coordinates of the active contact on DBS electrode on postoperative MRI, which we referred to as the final “functional/optimal” target. The coordinates calculated by the atlas-based “indirect” and “direct” methods, as well as the coordinates of the different RN borders were compared to these final coordinates. Results: The mean ± SD of the final target coordinates was 11.7 ± 1.5 mm lateral (X), 2.4 ± 1.5 mm posterior (Y), and 6.1 ± 1.7 mm inferior to the mid-commissural point (Z). No significant differences were found between the “indirect” X, Z coordinates and those of the final targets. The “indirect” Y coordinate was significantly posterior to Y of the final target, with mean difference of 0.6 mm (p = 0.014). No significant differences were found between the “direct” X, Y, and Z coordinates and those of the final targets. Conclusions: The functional STN target is located in direct proximity to its anatomical center. During preoperative targeting, we recommend using the “direct” method, and taking into consideration the relationships of the final target to the mid-commissural point (MCP) and the different RN borders.

Short-Term Adverse Outcomes After Deep Brain Stimulation Treatment in Patients with Parkinson Disease

Despite ongoing progress in our understanding of long-term outcomes after neuromodulation procedures, acute adverse outcomes shortly after deep brain stimulation (DBS) treatment have remained remarkably limited. To identify risk factors associated with acute 30-day outcomes after DBS treatment in patients with Parkinson disease (PD). We evaluated patients who underwent DBS treatment for PD from 2005 to 2014 through the American College of Surgeons National Surgical Quality Improvement Program database. We used bivariate analysis and multivariate logistic regression to identify short-term postoperative outcomes, including 30-day complication, discharge destination, and unplanned readmission. Overall, 650 patients with PD underwent DBS procedures and complications were identified in 32 patients (4.9%). Of 481 patients who had complete discharge data, 18 patients (3.7%) were discharged to a facility and 16 patients (3.3%) experienced an unplanned readmission. Patients with PD who were obese (P= 0.045), who had preoperative anemia (P= 0.008), and who experienced longer operative durations (P= 0.01) had increased odds of postoperative complications. Inpatient status (P=0.001), dependent functional status (P < 0.001), and anemia (P= 0.043) were all associated with discharge to a facility other than home. Longer operative duration (P=0.013), anemia (P= 0.036), and dependent functional status (P = 0.03) were significantly associated with unplanned readmission. As expected, complications increased the likelihood of unplanned readmission (P < 0.001). This study provides individualized estimates of the risks associated with short-term adverse outcomes based on patient demographics and comorbidities. These data can be used as an adjunct for short-term risk stratification of patients with PD being considered for DBS treatment.