Deep Brain Stimulation Procedures Research Articles

Functional assessment and quality of life in essential tremor with bilateral or unilateral DBS and focused ultrasound thalamotomy.

Thalamic deep brain stimulation (DBS) has largely replaced radiofrequency thalamotomy as the treatment of choice for disabling, medication-refractory essential tremor. Recently, the development of transcranial, high-intensity focused ultrasound has renewed interest in thalamic lesioning. The purpose of this study is to compare functional outcomes and quality of life in essential tremor patients treated with either bilateral Vim DBS or unilateral procedures (focused ultrasound or DBS). We hypothesized that all three would effectively treat the dominant hand and positively impact functional outcomes and quality of life as measured with the Clinical Rating Scale for Tremor and the Quality of Life in Essential Tremor Questionnaire. This is a retrospective study of medication-refractory essential tremor patients treated at the University of Virginia with bilateral Vim DBS (n = 57), unilateral Vim DBS (n = 13), or unilateral focused ultrasound Vim thalamotomy (n = 15). Tremor was rated for all patients before and after treatment, using the Clinical Rating Scale for Tremor and Quality of Life in Essential Tremor Questionnaire. Patients undergoing bilateral DBS treatment had more baseline tremor and worse quality of life scores. Patients had significant improvements in tremor symptoms and quality of life with all three treatments. Both DBS procedures improved axial tremor. No difference was seen in the degree of improvement in upper extremity tremor score, disability, or overall quality of life between bilateral and either unilateral procedure. Bilateral thalamic DBS improves overall tremor more than unilateral DBS or focused ultrasound treatment; however, unilateral treatments are equally effective in treating contralateral hand tremor. Despite the greater overall tremor reduction with bilateral DBS, there is no difference in disability or quality of life comparing bilateral versus unilateral treatments.

An Ethical Evaluation of Stereotactic Neurosurgery for Anorexia Nervosa

Anorexia nervosa (AN) is one of several neuropsychiatric disorders that are increasingly tackled experimentally using stereotactic neurosurgery (deep brain stimulation and ablative procedures). We analyze all 27 such cases published between 1990 and 2014. The majority of the patients benefitted significantly from neurosurgical treatments, in terms of both weight restoration and psychiatric morbidity. A remission of AN was reported in 61% of patients treated with DBS and 100% of patients treated with ablative surgery. Unfortunately, information on side effects is insufficient, and after DBS, severe side effects occurred in some cases. Altogether, the risk–benefit evaluation is positive, particularly for ablative stereotactic procedures. However, fundamental ethical issues are raised. We discuss whether neurosurgery can be justified for treating psychiatric disorders of the will that are seemingly self-inflicted, such as addiction or AN, and where cultural factors contribute significantly to their development. We suggest that although psychosocial factors determine the onset of AN, this is not a legitimate argument for banning neurosurgical treatments, since in AN, a vicious circle develops that deeply affects the brain, undermines the will, and prevents ceasing the self-destructive behavior. Three confounding issues provide ethical challenges for research in neurosurgery for AN: first, a scarce information base regarding risks and benefits of the intervention; second, doubtful capabilities for autonomous decision making; and third, the minor age of many patients. We recommend protective measures to ensure that stereotactic neurosurgery research can proceed with respect for the patients' autonomy and orientation to the beneficence principle.

Anaesthesia for deep brain stimulation: a review.

Deep brain stimulation (DBS) is a well tolerated and efficacious surgical treatment for movement disorders, chronic pain, psychiatric disorder, and a growing number of neurological disorders. Given that the brain targets are deep and small, accurate electrode placement is commonly accomplished by utilizing frame-based systems. DBS electrode placement is confirmed by microlectrode recordings and macrostimulation to optimize and verify target placement. With a reliance on electrophysiology, proper anaesthetic management is paramount to balance patient comfort without interfering with neurophysiology. To achieve optimal pain control, generous amounts of local anaesthesia are instilled into the planned incision. During the opening and closing states, conscious sedation is the prevailing method of anaesthesia. The preferred agents are dexmedetomidine, propofol, and remifentanil, as they affect neurocognitive testing the least, and shorter acting. All the agents are turned off 15-30 min prior to microelectrode recording. Dexmedetomidine has gained popularity in DBS procedures, but has some considerations at higher doses. The addition of ketamine is helpful for pediatric cases. DBS is a robust surgical treatment for a variety of neurological disorders. Appropriate anaesthetic agents that achieve patient comfort without interfering with electrophysiology are paramount.

The timing of deep brain stimulation for Parkinson disease in the UK from 1997 to 2012.

Deep brain stimulation (DBS) for Parkinson disease (PD) has traditionally been reserved for the late stages of the disease. There is evidence that DBS is also effective if applied earlier in the disease course. Changes in the frequency of DBS procedures in the UK over a 15-year period were investigated. A retrospective review was performed of patient age and disease duration for DBS surgery for PD in UK neurosurgical units from 1997 to 2012 using departmental databases. The number of DBS procedures in the UK increased from three in 1997 to over 80 per year during this period. The mean age at the time of surgery (60 years) and the mean duration of PD at the time of DBS (11 years) remained unchanged over 15 years. The age and disease duration at which DBS is performed for PD in the UK has been static over a 15-year period and DBS appears to remain a therapy for PD applied late in its course. This may change in the light of clinical evidence suggesting a benefit for earlier DBS.

Deep brain stimulation for movement disorders: 2015 and beyond.

The purpose of this review was to review the recent and future developments of deep brain stimulation (DBS) for movement disorders. In the last 2 years, we have gained a better understanding of established indications, particularly with respect to the debate on whether subthalamus or globus pallidus pars interna should be the target of choice for Parkinson's disease. In addition, the role of DBS for dystonia has been further defined in terms of patients' selection and outcome of surgery. Other established (e.g. essential tremor) and novel indications (e.g. Tourette syndrome) have been addressed. Along with the evolving knowledge of the clinical aspects of DBS, technological advances are also shaping the present and the future of DBS. New implantable pulse generators (e.g. allowing storage of electrophysiological data and eventual adaptive stimulation) as well as new electrode configurations are now available. Furthermore, high-resolution structural imaging, including high-field MRI and diffusion tensor tractography, will facilitate both the planning of DBS procedures, and the optimization of postoperative outcomes by aiding stimulation programming. The recent successes of DBS along the clinical and technological directions are changing the current practice of neuromodulation and, more importantly, will also drive future developments of this fascinating treatment.

Analysis of Stereotactic Accuracy in Patients Undergoing Deep Brain Stimulation Using Nexframe and the Leksell Frame

Objective: To determine and compare the accuracy of Nexframe and the Leksell stereotactic frame in deep brain stimulation (DBS) procedures. Background: The ‘frameless' Nexframe uses bone fiducials rather than a head-mounted frame, which offers potential benefits for both the patient and the surgical team. Accuracy of lead implantation and factors affecting this accuracy are of crucial importance but have not been extensively studied for the frameless system. Design/Methods: The location of 194 (Leksell frame, n = 116; Nexframe, n = 78) DBS leads was determined on postoperative MRI. Obtained stereotactic coordinates were compared with expected intraoperative target coordinates. Resulting absolute errors in the X (medial-lateral), Y (anterior-posterior), and Z (dorsal-ventral) coordinates (ΔX, ΔY, and ΔZ) were then used to calculate the vector error (VE). The vector error describes the total error in 3-D space and represents our main outcome measure. Results: The vector error (mean ± SD) was 2.8 ± 1.3 for Nexframe and 2.5 ± 1.2 for the Leksell frame (p = 0.43). For Nexframe, absolute X, Y, and Z errors were 1.4 ± 1.3, 1.7 ± 1.2, and 1.0 ± 0.9 mm. For the Leksell frame, the absolute X, Y, and Z errors were 1.4 ± 1.0, 1.2 ± 1.0, and 1.3 ± 0.9 mm. On the anterior-posterior plane (Y coordinate), the Leksell frame was more accurate than Nexframe (p = 0.04). In contrast, Nexframe was more accurate on the dorsal-ventral plane (Z coordinate) (p = 0.04). There was no difference in accuracy between the two methods on the medial-lateral plane (X coordinate). Conclusion: This comparison of Nexframe and the Leksell frame shows that both techniques have equivalent overall 3-D accuracy.

P116. DBS electrode imaging using 3D transcranial ultrasound – A feasibility study with first quantitative results

Purpose Deep Brain Stimulation (DBS) is an established surgical treatment for neurodegenerative diseases such as Parkinson’s Disease (PD) or Dystonia. In terms of imaging, pre-operative MRI scans are used for surgical planning and post-operative CT scans for control of electrode placement. Intra-operatively, however, imaging guidance is often avoided, due to contra-indications of DBS electrode contacts with MRI and difficulty of acquiring CT scans. Ultrasound imaging could be an attractive alternative, but has not been investigated yet due to difficult positioning of the transducer in the narrow burr-holes. Recently, there has been interest in the community towards the usage of non-invasive transcranial ultrasound (TCUS) through the pre-aureal bone window. In a seminal work ( Walter, 2012 ), Walter described the intra-operative usage of TCUS for lead electrode imaging and post-operative placement assessment of DBS electrode, showing its potential and limitations. In this work, we investigate, for the first time, the feasibility of using 3D-TCUS for imaging of already implanted Deep Brain Stimulation (DBS) electrodes. As a first step towards this goal, we report electrode localization errors outside of the operating room on six previously operated DBS patients. Methods Post-operative CT scans are registered to already acquired pre-operative T1 and T2 MRI sequences to localize the actual electrode tip locations in MRI. We then acquire 3D-TCUS sweeps and co-register them to the pre-operative MRI as well, using a head-surface point-cloud registration first (using Iterative Closest Points, ICP) and a manual refinement using several pairs of corresponding points on anatomical structures (midbrain, ventricles) in TCUS and MRI. The comparison between electrode tips identified in 3D-TCUS and actual tip positions in CT are a first step towards assessing whether 3D-TCUS could provide a benefit intra-operatively in future. Results Quantitative evaluation is performed by reporting the accuracy of electrode tip localization after ICP-based registration (mean 5.62 mm, stdev 2.26 mm) and after manual registration refinement (mean 4.09 mm, stdev 1.75 mm). Additionally, we provide multiple image examples showing the dependence of 3D-TCUS quality depending on the bone window, and multiple examples of image artifacts in TCUS images and 3D reconstructions. Conclusions Intra-operative 3D ultrasound imaging has potential for electrode tip localization during DBS procedures. 3D transcranial US could be an attractive alternative to intra-cranial imaging through the narrow burr-hole. We report the first results of volumetric 3D-TCUS imaging on already operated patients in a post-operative scenario. Initial results still show a relatively high inaccuracy of electrode tip localization, e.g. due to TCUS artifacts and imperfect registration to the pre-operative MRI. Nevertheless, the potential of TCUS for DBS electrode imaging as described by Walter (2012) can be extended to 3D, allowing for electrode tip and shaft localization. This motivates further work, e.g. on improved MRI-US registration and computer-aided tip detection ( Fig. 1 , Fig. 2 ).

Internal Pulse Generators in Deep Brain Stimulation: Rechargeable or Not?

Deep brain stimulation (DBS) is a cost-effective strategy for the treatment of different neurologic disorders. However, DBS procedures are associated with high costs of implantation and replacement of the internal pulse generator (IPG). Different manufacturers propose the use of rechargeable IPGs. The objective of this study is to compare the implantation costs of nonrechargeable IPGs versus the estimated costs of rechargeable IPGs in different categories of patients to evaluate if an economic advantage for the health care system could be derived. The study looked at 149 patients who underwent a surgical procedure for IPG replacement. In a hypothetical scenario, rechargeable IPGs were implanted instead of nonrechargeable IPGs at the time of DBS system implantation. Another scenario was outlined in a perspective period of time, corresponding to the patients' life expectancy. Costs were calculated, and inferential analysis was performed. A savings of €234,194, including the cost of management of complications, was calculated during a follow-up period of 7.9 years. In a comprehensive life expectancy period of 47 years, a savings of €5,918,188 would be obtained (P < 0.05). Long-term group data point out that a relevant savings would be expected from implantation of rechargeable IPGs in dystonic patients (P < 0.05) and patients with Parkinson disease (P < 0.05), and a savings isprojected to occur in other categories of patients (P < 0.05). Implantation of rechargeable IPGs presents clinical advantages compared with nonrechargeable devices. A huge economic savings can be realized with the implantation of rechargeable IPGs in categories of patients implanted with IPGs for DBS.

Robotic system for MRI-guided stereotactic neurosurgery.

Stereotaxy is a neurosurgical technique that can take several hours to reach a specific target, typically utilizing a mechanical frame and guided by preoperative imaging. An error in any one of the numerous steps or deviations of the target anatomy from the preoperative plan such as brain shift (up to mm), may affect the targeting accuracy and thus the treatment effectiveness. Moreover, because the procedure is typically performed through a small burr hole opening in the skull that prevents tissue visualization, the intervention is basically “blind” for the operator with limited means of intraoperative confirmation that may result in reduced accuracy and safety. The presented system is intended to address the clinical needs for enhanced efficiency, accuracy, and safety of image-guided stereotactic neurosurgery for deep brain stimulation lead placement. The study describes a magnetic resonance imaging (MRI)-guided, robotically actuated stereotactic neural intervention system for deep brain stimulation procedure, which offers the potential of reducing procedure duration while improving targeting accuracy and enhancing safety. This is achieved through simultaneous robotic manipulation of the instrument and interactively updated in situ MRI guidance that enables visualization of the anatomy and interventional instrument. During simultaneous actuation and imaging, the system has demonstrated less than 15% signal-to-noise ratio variation and less than 0.20 geometric distortion artifact without affecting the imaging usability to visualize and guide the procedure. Optical tracking and MRI phantom experiments streamline the clinical workflow of the prototype system, corroborating targeting accuracy with three-ax- s root mean square error 1.38 ± 0.45 mm in tip position and 2.03 ± 0.58° in insertion angle.

Evidence of improved immediate verbal memory and diminished category fluency following STN-DBS in Chinese-Cantonese patients with idiopathic Parkinson's disease.

The present study investigated the neuropsychological effects of bilateral deep brain stimulation (DBS) on subthalamic nucleus (STN) in Chinese-Cantonese patients with idiopathic Parkinson's disease (PD). Twenty-seven patients were prospectively recruited from the Movement Disorder Clinic at the Hong Kong Prince of Wales Hospital. Neuropsychological evaluations were performed at baseline, 6 and 12 months following the DBS procedure. Assessment battery included standardized tests on global cognitive function, verbal memory, non-verbal memory, confrontation naming, visuospatial organization, attention and executive functions. Anxiety and depressive symptoms were measured by two self-reported questionnaires. Results demonstrated diminished performance on a category fluency task that occurred at 6 months post-operatively and persisted at 12-month re-evaluation; 29.6-33.3 % of patients showed reduction of more than 1 SD (standard deviation) at post-operative measure. Conversely, performance on an immediate recall task in a verbal memory test was found to improve significantly at the same time point and persisted through 12 months after surgery; 22.2-25.9 % showed an improvement (≥1 SD). Psychologically, anxiety symptoms were statistically decreased and the significant reduction occurred at 12 months after surgery. Patients who reported a moderate to severe level of anxiety reduced from 51.9 to 18.5 %. Our findings concurred with most evidences on the effects of STN-DBS on verbal fluency; on the other hand, we demonstrated improvement of immediate verbal memory that warranted further investigation.

In vivo measurement of the frame-based application accuracy of the Neuromate neurosurgical robot.

The application accuracy of the Neuromate neurosurgical robot has been validated in vitro but has not been evaluated in vivo for deep brain stimulation (DBS) electrode implantations. The authors conducted a study to evaluate this application accuracy in routine frame-based DBS procedures, with an independent system of measurement. The Euclidian distance was measured between the point theoretically targeted by the robot and the point actually reached, based on their respective stereotactic coordinates. The coordinates of the theoretical target were given by the robot's dedicated targeting software. The coordinates of the point actually reached were recalculated using the Stereoplan localizer system. This experiment was performed in vitro, with the frame fixed in the robot space without a patient, for 21 points spatially distributed. The in vivo accuracy was then measured in 30 basal ganglia targets in 17 consecutive patients undergoing DBS for movement disorders. The mean in vitro application accuracy was 0.44 ± 0.23 mm. The maximal localization error was 1.0 mm. The mean (± SD) in vivo application accuracy was 0.86 ± 0.32 mm (Δx = 0.37 ± 0.34 mm, Δy = 0.32 ± 0.24 mm, Δz = 0.58 ± 0.31 mm). The maximal error was 1.55 mm. The in vivo application accuracy of the Neuromate neurosurgical robot, measured with a system independent from the robot, in frame-based DBS procedures was better than 1 mm. This accuracy is at least similar to the accuracy of stereotactic frame arms and is compatible with the accuracy required in DBS procedures.

Chronological Changes of C-Reactive Protein Levels Following Uncomplicated, Two-Staged, Bilateral Deep Brain Stimulation.

ObjectiveThe occurrence of acute cerebral infection following deep brain stimulation (DBS) is currently being reported with elevation of C-reactive protein (CRP) level. The aim of the present study was to establish normal range of the magnitude and time-course of CRP increases following routine DBS procedures in the absence of clinical and laboratory signs of infection.MethodsA retrospective evaluation of serial changes of plasma CRP levels in 46 patients undergoing bilateral, two-staged DBS was performed. Because DBS was performed as a two-staged procedure involving; implantation of lead and internal pulse generator (IPG), CRP was measured preoperatively and postoperatively every 2 days until normalization of CRP (post-lead implantation day 2 and 4, post-IPG implantation day 2, 4, and 6).ResultsCompared with preoperative CRP levels (0.12±0.17 mg/dL, n=46), mean CRP levels were significantly elevated after lead insertion day 2 and 4 (1.68±1.83 mg/dL, n=46 and 0.76±0.38 mg/dL, n=16, respectively, p<0.001). The mean CRP levels at post-lead implantation day 2 were further elevated at post-IPG implantation day 2 (3.41±2.56 mg/dL, n=46, respectively, p<0.01). This elevation in post-IPG day 2 rapidly declined in day 4 (1.24±1.29 mg/dL, n=46, p<0.05) and normalized to preoperative value at day 6 (0.42±0.33 mg/dL, n=46, p>0.05). Mean CRP levels after IPG implantation were significantly higher in patients whose IPGs were implanted at post-lead day 3 than those at post-lead day 5-6 (3.99±2.80 mg/dL, n=30, and 2.31±1.56 mg/dL, n=16, respectively, p<0.05). However, there was no difference in post-IPG day 2 and 4 between them (p>0.05).ConclusionThe mean postoperative CRP levels were highest on post-IPG insertion day 2 and decreased rapidly, returning to the normal range on post-IPG implantation day 6. The duration of post-lead implantation period influenced the magnitude of CRP elevation at post-IPG insertion day 2. Information about the normal response of CRP following DBS could help to avoid unnecessary diagnostic and therapeutic efforts.

The role of bioethics in the neurosurgical treatment of psychiatric disorders

Psychiatric neurosurgery or psychosurgery remains as an alternative for treatment of psychiatric disorders. However, its historical antecedents, the vulnerable specific condition of psychiatric patients, the high cost of instrumentation and the ethic dilemma about the autonomy of subjects whose are candidates to this kind of procedures condition to get a interdisciplinary and specialized staff and at less supervision for ethic local committee. There are ablative or deep brain stimulation procedures accepted as compassionate or investigational use. Into systematic review four International Ethic Guides are accepted for the indication, the implantation and the follow up of these treatments. 24 bioethics essays were found them and 9 ethics specific dilemmas were published. Expectancy and development of this medical issue are inherent to financial or biotechnological aspects, consequently is important to promote a scientific and philosophical discussion.

Predicting quality of life outcomes after subthalamic nucleus deep brain stimulation.

To examine disease, treatment, cognitive, and psychological factors associated with quality of life (QoL) before and after surgery and assess the ability to predict QoL outcomes. We identified a retrospective, cross-sectional sample of 85 patients with Parkinson disease who underwent subthalamic deep brain stimulation (DBS). Patients' QoL was categorized as "improved" and "stable/worsened" using reliable change indices. Univariate correlational analyses identified relationships between Parkinson's Disease Questionnaire-39 ratings and disease (Unified Parkinson's Disease Rating Scale-III [UPDRS-III] motor scores on and off medications, disease duration), treatment (medication burden, unilateral vs bilateral DBS), cognitive (neuropsychological battery), and psychological (depression) variables. Step-wise multiple linear regression and logistic regression models included selected preoperative variables to predict change in QoL ratings and QoL outcome after surgery. Fifty-one percent of patients reported clinically significant improvements in QoL while 47% reported stable QoL and 2% worsened. Motor scores (UPDRS-III) were not relevant to QoL changes, potentially because of the rarity of poor motor outcomes, while single-trial learning and depression scores were the most important variables in predicting QoL changes. There was a subtle additional benefit to undergoing bilateral subthalamic nucleus DBS. The findings provide greater insight into the nonmotor features that contribute to the success of subthalamic nucleus DBS procedures from the patient's perspective and raise questions about the treatment focus and emphasis on symptom profiles in DBS candidacy evaluations.

Intraoperative 3D imaging control during subthalamic Deep Brain Stimulation procedures using O-arm® technology: Experience in 15 patients

ObjectiveO-arm® now gives us the opportunity not only to perform 2D but also 3D scans during deep brain stimulation (DBS) procedures. We present our experience with the intraoperative use of this device. Our objective was to measure the geometrical accuracy of electrode placement during surgical procedures driven under O-arm® control. MethodsFifteen patients underwent STN-DBS. For the first 4 patients, 3D scans were performed at the end of the procedure. We calculated the accuracy of electrode positioning, i.e. the distance between final electrode positioning and the planned trajectory. For the next 11 patients, who underwent both intraoperative and final 3D scan, we also calculated the accuracy of the microelectrode positioning. ResultsAverage stimulation-induced improvement of UPDRS-III score was 52.5±15%. For the first 4 patients, the mean electrode positioning accuracy was 1.46±0.56mm. For the 11 patients who underwent intraoperative 3D scan, the mean microelectrodes positioning accuracy was 1.59±1.1mm. Aberrant positioning was detected in two cases, and was analyzed by fusing 3D scan with preoperative MR images. The definite electrodes positioning accuracy was 1.05±0.54mm. ConclusionIntraoperative 3D scan is feasible, and can help us detect and correct early aberrant trajectories.

The Franco-Canadian multicolumn spinal cord stimulation prospective study: A subgroup analysis focusing on the decisive role of lead positioning

IntroductionMulticolumn spinal cord stimulation (SCS) is now considered to be effective for the treatment of the radicular and back component in refractory Failed Back Surgery Syndrome (FBSS) patients. The relationship between the paresthesia coverage of the back and clinical outcomes has recently been confirmed by an international prospective study. However, significant disparities in outcomes were identified and could result from the heterogeneity of lead implantation parameters which are dependant on local practices and experience. We therefore sought to analyse the impact of lead implantation level and its lateralization on the ability to address back pain with multicolumn SCS leads. Study objectives, materials and methodsThe present study was a retrospective subgroup analysis from an observational, prospective non-randomized trial that included 76 patients with refractory FBSS, implanted with multicolumn SCS between 2008 to 2011 in three neurosurgical pain centres (Poitiers, France, Montreal, Canada and Regina, Canada). A subgroup of 21 patients with “optimized lead positioning” (OLP) was identified, distinguished from the rest of the main study population (NON OLP subgroup; n=51) and submitted to specific data analysis. Baseline characteristics of both groups were strictly comparable. Our primary objective was to analyse the impact of lead positioning (vertebral level and lateralization) on the back paresthesia coverage. The secondary objectives were to compare the analgesic and functional efficacy of multicolumn stimulation in these OLP and NON OLP subgroups and to determine if a paresthesia coverage improvement leads to better clinical outcomes in these difficult-to-treat patients. ResultsIn this subgroup analysis, unilateral coverage of the low back area was achieved in 85.0% of OLP patients vs. 76.5% in the NON OLP group. Bilateral and complete coverage of the low back area was achieved in 60% of OLP patients vs. 51% in the NON OLP group but these differences were not statistically significant. At 6months, 81.0% of OLP patients vs. 69.4% in the NON OLP group presented at least 30% improvement of the low back VAS, while 52.4% of them achieved at least 50% improvement of the low back VAS vs. 38.8% in the NON OLP group. Functional improvement at 6months, available and calculated only in the French group of OLP patients (n=14) by the Oswestry Disability Index, was significant, decreasing from 60.67% to 33.43%. ConclusionDespite limitations in this retrospective subgroup analysis, this study suggests that the vertebral level (T8-T9) and midline positioning of the lead during implantation could be decisive factors to optimize paresthesia coverage and finally, clinical and functional outcomes. While sophistication has been responsible for an increase of the size and the programming possibilities of surgical SCS leads during the past years, multicolumn SCS lead implantation should in fact be considered as a “functional neurosurgical” procedure and could benefit from intraoperative patient cooperation, as in the case for deep brain stimulation procedures, due to minimally invasive implantation techniques.

Parkinsonism-hyperpyrexia syndrome after bilateral deep brain stimulation surgery: case report in a Brazilian man

AbstractDeep brain stimulation is a surgical treatment that has provided remarkable therapeutic benefits for otherwise treatment-resistant movement and affective disorders, including advanced Parkinson disease. Levodopa medications are usually discontinued the night before surgery to localize the optimal response site to intraoperative macrostimulation. However, abrupt withdrawal of medication may result in severe side effects. On the present report, we describe the case of a 65 years-old man that evolved parkinsonism-hyperpyrexia syndrome following deep brain stimulation procedure for bilateral subthalamic nucleus after discontinuation of antiparkinsonian medications. Physicians should be aware of this life-threatening clinical conditions, once early diagnosis and reintroduction of medication improve patient's clinical condition significantly.

Multisurgeon, multisite validation of a trajectory planning algorithm for deep brain stimulation procedures.

Deep brain stimulation, which is used to treat various neurological disorders, involves implanting a permanent electrode into precise targets deep in the brain. Reaching these targets safely is difficult because surgeons have to plan trajectories that avoid critical structures and reach targets within specific angles. A number of systems have been proposed to assist surgeons in this task. These typically involve formulating constraints as cost terms, weighting them by surgical importance, and searching for optimal trajectories, in which constraints and their weights reflect local practice. Assessing the performance of such systems is challenging because of the lack of ground truth and clear consensus on an optimal approach among surgeons. Due to difficulties in coordinating inter-institution evaluation studies, these have been performed so far at the sites at which the systems are developed. Whether or not a scheme developed at one site can also be used at another is thus unknown. In this paper, we conduct a study that involves four surgeons at three institutions to determine whether or not constraints and their associated weights can be used across institutions. Through a series of experiments, we show that a single set of weights performs well for all surgeons in our group. Out of 60 trajectories, our trajectories were accepted by a majority of neurosurgeons in 95% of the cases and the average acceptance rate was 90%. This study suggests, albeit on a limited number of surgeons, that the same system can be used to provide assistance across multiple sites and surgeons.

Disparities in Access to Deep Brain Stimulation Surgery for Parkinson Disease

African American individuals experience barriers to accessing many types of health care in the United States, resulting in substantial health care disparities. To improve health care in this patient population, it is important to recognize and study the potential factors limiting access to care. To examine deep brain stimulation (DBS) use in Parkinson disease (PD) to determine which factors, among a variety of demographic, clinical, and socioeconomic variables, drive DBS use in the United States. We queried the Nationwide Inpatient Sample in combination with neurologist and neurological surgeon countywide density data from the Area Resource File. We used International Classification of Diseases, Ninth Revision codes to identify discharges of patients at multicenter, all-payer, nonfederal hospitals in the United States diagnosed with PD (code 332.0) who were admitted for implantation of intracranial neurostimulator lead(s) (code 02.39), DBS. We analyzed factors predicting DBS use in PD using a hierarchical logistic regression analysis including patient and hospital characteristics. Patient characteristics included age, sex, comorbidity score, race, income quartile of zip code, and insurance type. Hospital characteristics included teaching status, size, regional location, urban vs rural setting, experience with DBS discharges, year, and countywide density of neurologists and neurological surgeons. Query of the Nationwide Inpatient Sample yielded 2,408,302 PD discharges from 2002 to 2009; 18,312 of these discharges were for DBS. Notably, 4.7% of all PD discharges were African American, while only 0.1% of DBS for PD discharges were African American. A number of factors in the hierarchical multivariate analysis predicted DBS use including younger age, male sex, increasing income quartile of patient zip code, large hospitals, teaching hospitals, urban setting, hospitals with higher number of annual discharges for PD, and increased countywide density of neurologists (P < .05). Predictors of nonuse included African American race (P < .001), Medicaid use (P < .001), and increasing comorbidity score (P < .001). Countywide density of neurological surgeons and Hispanic ethnicity were not significant predictors. AND RELEVANCE: Despite the fact that African American patients are more often discharged from hospitals with characteristics predicting DBS use (ie, urban teaching hospitals in areas with a higher than average density of neurologists), these patients received disproportionately fewer DBS procedures compared with their non-African American counterparts. Increased reliance on Medicaid in the African American population may predispose to the DBS use disparity. Various other factors may be responsible, including disparities in access to care, cultural biases or beliefs, and/or socioeconomic status.

Aggressive behavior as a rare side effect of subthalamic stimulation in Parkinson’s disease

Although deep brain stimulation (DBS) has a well-established position in the treatment of Parkinson’s disease (PD), it may be accompanied by different side effects including behavioral changes. We present a patient with advanced PD after bilateral stimulation of the subthalamic nucleus (STN) who developed attacks of aggressive behavior. The patient with a 12 year history of PD underwent the procedure of DBS with one-stage bilateral stereotactic approach using the Leksel G stereotactic frame. For STN identification microrecording technique was applied (5 microelectrodes). Four weeks after surgery STN stimulation was switched on. With increasing the amplitude of stimulation on the right (active contacts 1 and 2) the patient experienced transient episodes of aggression. Change of stimulation mode led to withdrawal of all side effects. We hypothesize that aggression episodes in the patient were caused by stimulation of limbic circuit probable within STN although we cannot exclude simultaneous stimulation of neighboring structures. Aggression episodes are rare side effect of STN-DBS, nevertheless they may be expected in more posteromedial placement of the electrode within STN. The presented case extends the evidence for non-motor functions of STN and highlights its role as an integrating structure within the basal ganglia system.