Best surgical practices: a stepwise approach to the University of Pennsylvania deep brain stimulation protocol

Subthalamic nucleus synchronization between beta band local field potential and single-unit activity in Parkinson's disease

Local field potential (LFP) oscillations in the beta band (13-30 Hz) in the subthalamic nucleus (STN) of Parkinson's disease patients have been implicated in disease severity and treatment response. The relationship between single-neuron activity in the STN and regional beta power changes remains unclear. We used spike-triggered average (STA) to assess beta synchronization in STN. Beta power and STA magnitude at the beta frequency range were compared in three conditions: STN versus other subcortical structures, dorsal versus ventral STN, and high versus low beta power STN recordings. Magnitude of STA-LFP was greater within the STN compared to extra-STN structures along the trajectory path, despite no difference in percentage of the total power. Within the STN, there was a higher percent beta power in dorsal compared to ventral STN but no difference in STA-LFP magnitude. Further refining the comparison to high versus low beta peak power recordings inside the STN to evaluate if single-unit activity synchronized more strongly with beta band activity in areas of high beta power resulted in a significantly higher STA magnitude for areas of high beta power. Overall, these results suggest that STN single units strongly synchronize to beta activity, particularly units in areas of high beta power.

Minimizing pneumocephalus during deep brain stimulation surgery

BACKGROUND

Deep brain stimulation (DBS) surgery is an effective treatment for movement disorders. Introduction of intracranial air following dura opening in DBS surgery can result in targeting inaccuracy and suboptimal outcomes. We develop and evaluate a simple method to minimize pneumocephalus during DBS surgery.

METHODS

A retrospective analysis of prospectively collected data was performed on patients undergoing DBS surgery at our institution from 2014 to 2022. A total of 172 leads placed in 89 patients undergoing awake or asleep DBS surgery were analyzed. Pneumocephalus volume was compared between leads placed with PMT and leads placed with standard dural opening. (112 PMT vs. 60 OPEN). Immediate post-operative high-resolution CT scans were obtained for all leads placed, from which pneumocephalus volume was determined through a semi-automated protocol with ITK-SNAP software. Awake surgery was conducted with the head positioned at 15-30°, asleep surgery was conducted at 0°.

RESULTS

PMT reduced pneumocephalus from 11.2 cm3±9.2 to 0.8 cm3±1.8 (P<0.0001) in the first hemisphere and from 7.6 cm3 ± 8.4 to 0.43 cm3 ± 0.9 (P<0.0001) in the second hemisphere. No differences in adverse events were noted between PMT and control cases. Lower rates of post-operative headache were observed in PMT group.

CONCLUSION

We present and validate a simple yet efficacious technique to reduce pneumocephalus during DBS surgery.

Automatic extraction of upper-limb kinematic activity using deep learning-based markerless tracking during deep brain stimulation implantation for Parkinson's disease: A proof of concept study

Optimal placement of deep brain stimulation (DBS) therapy for treating movement disorders routinely relies on intraoperative motor testing for target determination. However, in current practice, motor testing relies on subjective interpretation and correlation of motor and neural information. Recent advances in computer vision could improve assessment accuracy. We describe our application of deep learning-based computer vision to conduct markerless tracking for measuring motor behaviors of patients undergoing DBS surgery for the treatment of Parkinson's disease. Video recordings were acquired during intraoperative kinematic testing (N = 5 patients), as part of standard of care for accurate implantation of the DBS electrode. Kinematic data were extracted from videos post-hoc using the Python-based computer vision suite DeepLabCut. Both manual and automated (80.00% accuracy) approaches were used to extract kinematic episodes from threshold derived kinematic fluctuations. Active motor epochs were compressed by modeling upper limb deflections with a parabolic fit. A semi-supervised classification model, support vector machine (SVM), trained on the parameters defined by the parabolic fit reliably predicted movement type. Across all cases, tracking was well calibrated (i.e., reprojection pixel errors 0.016-0.041; accuracies >95%). SVM predicted classification demonstrated high accuracy (85.70%) including for two common upper limb movements, arm chain pulls (92.30%) and hand clenches (76.20%), with accuracy validated using a leave-one-out process for each patient. These results demonstrate successful capture and categorization of motor behaviors critical for assessing the optimal brain target for DBS surgery. Conventional motor testing procedures have proven informative and contributory to targeting but have largely remained subjective and inaccessible to non-Western and rural DBS centers with limited resources. This approach could automate the process and improve accuracy for neuro-motor mapping, to improve surgical targeting, optimize DBS therapy, provide accessible avenues for neuro-motor mapping and DBS implantation, and advance our understanding of the function of different brain areas.

Robot-Assisted Deep Brain Stimulation: High Accuracy and Streamlined Workflow

BACKGROUND

A number of stereotactic platforms are available for performing deep brain stimulation (DBS) lead implantation. Robot-assisted stereotaxy has emerged more recently demonstrating comparable accuracy and shorter operating room times compared with conventional frame-based systems.

OBJECTIVE

To compare the accuracy of our streamlined robotic DBS workflow with data in the literature from frame-based and frameless systems.

METHODS

We retrospectively reviewed 126 consecutive DBS lead placement procedures using a robotic stereotactic platform. Indications included Parkinson disease (n = 94), essential tremor (n = 21), obsessive compulsive disorder (n = 7), and dystonia (n = 4). Procedures were performed using a stereotactic frame for fixation and the frame pins as skull fiducials for robot registration. We used intraoperative fluoroscopic computed tomography for registration and postplacement verification.

RESULTS

The mean radial error for the target point was 1.06 mm (SD: 0.55 mm, range 0.04-2.80 mm) on intraoperative fluoroscopic computed tomography. The mean operative time for an asleep, bilateral implant without implantable pulse generator placement was 238 minutes (SD: 52 minutes), and skin-to-skin procedure time was 116 minutes (SD: 42 minutes).

CONCLUSION

We describe a streamlined workflow for DBS lead placement using robot-assisted stereotaxy with a comparable accuracy profile. Obviating the need for checking and switching coordinates, as is standard for frame-based DBS, also reduces the chance for human error and facilitates training.

Tractography-Based Surgical Targeting for Thalamic Deep Brain Stimulation: A Comparison of Probabilistic vs Deterministic Fiber Tracking of the Dentato-Rubro-Thalamic Tract

BACKGROUND

The ventral intermediate (VIM) thalamic nucleus is the main target for the surgical treatment of refractory tremor. Initial targeting traditionally relies on atlas-based stereotactic targeting formulas, which only minimally account for individual anatomy. Alternative approaches have been proposed, including direct targeting of the dentato-rubro-thalamic tract (DRTT), which, in clinical settings, is generally reconstructed with deterministic tracking. Whether more advanced probabilistic techniques are feasible on clinical-grade magnetic resonance acquisitions and lead to enhanced reconstructions is poorly understood.

OBJECTIVE

To compare DRTT reconstructed with deterministic vs probabilistic tracking.

METHODS

This is a retrospective study of 19 patients with essential tremor who underwent deep brain stimulation (DBS) with intraoperative neurophysiology and stimulation testing. We assessed the proximity of the DRTT to the DBS lead and to the active contact chosen based on clinical response.

RESULTS

In the commissural plane, the deterministic DRTT was anterior (P < 10-4) and lateral (P < 10-4) to the DBS lead. By contrast, although the probabilistic DRTT was also anterior to the lead (P < 10-4), there was no difference in the mediolateral dimension (P = .5). Moreover, the 3-dimensional Euclidean distance from the active contact to the probabilistic DRTT was smaller vs the distance to the deterministic DRTT (3.32 ± 1.70 mm vs 5.01 ± 2.12 mm; P < 10-4).

CONCLUSION

DRTT reconstructed with probabilistic fiber tracking was superior in spatial proximity to the physiology-guided DBS lead and to the empirically chosen active contact. These data inform strategies for surgical targeting of the VIM.

Frameless Robot-Assisted vs Frame-Based Awake Deep Brain Stimulation Surgery: An Evaluation of Technique and New Challenges

BACKGROUND

Methodological approaches to deep brain stimulation (DBS) continue to evolve from awake frame-based to asleep frameless procedures with robotic assistance, primarily directed to optimize operative efficiency, lead accuracy, and patient comfort. Comparison between the 2 is scarce.

OBJECTIVE

To analyze the impacts of methodological differences on operative efficiency and stereotactic accuracy using a frame compared with a frameless robotic platform while maintaining the awake state and use of multiple microelectrode recording (MER) trajectories.

METHODS

Thirty-four consecutive patients who underwent bilateral awake frameless robot-assisted DBS were compared with a previous cohort of 30 patients who underwent frame-based surgery. Patient demographics, operative times, and MER data were collected for both cohorts. Two-dimensional radial errors of lead placements were calculated.

RESULTS

Preoperative setup, surgical, and total operating room times were all significantly greater for the robot-assisted cohort (P < .001). The need for computed tomography imaging when referencing the robotic fiducials led to increased setup duration because of patient transport, unnecessary for the frame-based cohort. Multiple simultaneous MER trajectories increased surgical time (mean 26 min) for the robot-assisted cohort only. The mean radial errors in the robot-assisted and frame cohorts were 0.98 ± 0.66 and 0.74 ± 0.49 mm (P = .03), respectively.

CONCLUSION

The use of a truly frameless robotic platform such as the Mazor Renaissance (Mazor Robotics Ltd) presented challenges when implementing techniques used during awake frame-based surgery. Maintaining good accuracy, intraoperative reference imaging, and limited MER trajectories will help integrate frameless robot assistance into the awake DBS surgical workflow.

Frameless Robot-Assisted Deep Brain Stimulation Surgery: An Initial Experience

BACKGROUND

Modern robotic-assist surgical systems have revolutionized stereotaxy for a variety of procedures by increasing operative efficiency while preserving and even improving accuracy and safety. However, experience with robotic systems in deep brain stimulation (DBS) surgery is scarce.

OBJECTIVE

To present an initial series of DBS surgery performed utilizing a frameless robotic solution for image-guided stereotaxy, and report on operative efficiency, stereotactic accuracy, and complications.

METHODS

This study included the initial 20 consecutive patients undergoing bilateral robot-assisted DBS. The prior 20 nonrobotic, frameless cohort of DBS cases was sampled as a baseline historic control. For both cohorts, patient demographic and clinical data were collected including postoperative complications. Intraoperative duration and number of Microelectrode recording (MER) and final lead passes were recorded. For the robot-assisted cohort, 2D radial errors were calculated.

RESULTS

Mean case times (total operating room, anesthesia, and operative times) were all significantly decreased in the robot-assisted cohort (all P-values < .02) compared to frameless DBS. When looking at trends in case times, operative efficiency improved over time in the robot-assisted cohort across all time assessment points. Mean radial error in the robot-assisted cohort was 1.40 ± 0.11 mm, and mean depth error was 1.05 ± 0.18 mm. There was a significant decrease in the average number of MER passes in the robot-assisted cohort (1.05) compared to the nonrobotic cohort (1.45, P < .001).

CONCLUSION

This is the first report of application of frameless robotic-assistance with the Mazor Renaissance platform (Mazor Robotics Ltd, Caesarea, Israel) for DBS surgery, and our findings reveal that an initial experience is safe and can have a positive impact on operative efficiency, accuracy, and safety.

Thalamic Deep Brain Stimulation for Essential Tremor: Relation of the Dentatorubrothalamic Tract with Stimulation Parameters

BACKGROUND

In deep brain stimulation (DBS) for essential tremor, the primary target ventrointermedius (VIM) nucleus cannot be clearly visualized with structural imaging. As such, there has been much interest in the dentatorubrothalamic tract (DRTT) for target localization, but evidence for the DRTT as a putative stimulation target in tremor suppression is lacking. We evaluated proximity of the DRTT in relation to DBS stimulation parameters.

METHODS

This is a retrospective analysis of 26 consecutive patients who underwent DBS with microelectrode recordings (46 leads). Fiber tracking was performed with a published deterministic technique. Clinically optimized stimulation parameters were obtained in all patients at the time of most recent follow-up (6.2 months). Volume of tissue activated (VTA) around contacts was calculated from a published model.

RESULTS

Tremor severity was reduced in all treated hemispheres, with 70% improvement in the treated hand score of the Clinical Rating Scale for Tremor. At the level of the active contact (2.9 ± 2.0 mm superior to the commissural plane), the center of the DRTT was lateral to the contacts (5.1 ± 2.1 mm). The nearest fibers of the DRTT were 2.4 ± 1.7 mm from the contacts, whereas the radius of the VTA was 2.9 ± 0.7 mm. The VTA overlapped with the DRTT in 77% of active contacts. The distance from active contact to the DRTT was positively correlated with stimulation voltage requirements (Kendall τ = 0.33, P = 0.006), whereas distance to the atlas-based VIM coordinates was not.

CONCLUSIONS

Active contacts in proximity to the DRTT had lower voltage requirements. Data from a large cohort provide support for the DRTT as an effective stimulation target for tremor control.

Dual responsive neurostimulation implants for epilepsy

Closed-loop brain-responsive neurostimulation via the RNS System is a treatment option for adults with medically refractory focal epilepsy. Using a novel technique, 2 RNS Systems (2 neurostimulators and 4 leads) were successfully implanted in a single patient with bilateral parietal epileptogenic zones. In patients with multiple epileptogenic zones, this technique allows for additional treatment options. Implantation can be done successfully, without telemetry interference, using proper surgical planning and neurostimulator positioning.Trajectories for the depth leads were planned using neuronavigation with CT and MR imaging. Stereotactic frames were used for coordinate targeting. Each neurostimulator was positioned with maximal spacing to avoid telemetry interference while minimizing patient discomfort. A separate J-shaped incision was used for each neurostimulator to allow for compartmentalization in case of infection. In order to minimize surgical time and risk of infection, the neurostimulators were implanted in 2 separate surgeries, approximately 3 weeks apart.The neurostimulators and leads were successfully implanted without adverse surgical outcomes. The patient recovered uneventfully, and the early therapy settings over several months resulted in preliminary decreases in aura and seizure frequency. Stimulation by one of the neurostimulators did not result in stimulation artifacts detected by the contralateral neurostimulator.

Improved operative efficiency using a real-time MRI-guided stereotactic platform for laser amygdalohippocampotomy

OBJECTIVE

MR-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive method for thermal destruction of benign or malignant tissue that has been used for selective amygdalohippocampal ablation for the treatment of temporal lobe epilepsy. The authors report their initial experience adopting a real-time MRI-guided stereotactic platform that allows for completion of the entire procedure in the MRI suite.

METHODS

Between October 2014 and May 2016, 17 patients with mesial temporal sclerosis were selected by a multidisciplinary epilepsy board to undergo a selective amygdalohippocampal ablation for temporal lobe epilepsy using MRgLITT. The first 9 patients underwent standard laser ablation in 2 phases (operating room [OR] and MRI suite), whereas the next 8 patients underwent laser ablation entirely in the MRI suite with the ClearPoint platform. A checklist specific to the real-time MRI-guided laser amydalohippocampal ablation was developed and used for each case. For both cohorts, clinical and operative information, including average case times and accuracy data, was collected and analyzed.

RESULTS

There was a learning curve associated with using this real-time MRI-guided system. However, operative times decreased in a linear fashion, as did total anesthesia time. In fact, the total mean patient procedure time was less in the MRI cohort (362.8 ± 86.6 minutes) than in the OR cohort (456.9 ± 80.7 minutes). The mean anesthesia time was significantly shorter in the MRI cohort (327.2 ± 79.9 minutes) than in the OR cohort (435.8 ± 78.4 minutes, p = 0.02).

CONCLUSIONS

The real-time MRI platform for MRgLITT can be adopted in an expedient manner. Completion of MRgLITT entirely in the MRI suite may lead to significant advantages in procedural times.

Impact of Trajectory Planning With Susceptibility-Weighted Imaging for Intracranial Electrode Implantation

BACKGROUND

While T1-weighted gadolinium-enhanced (T1-Gd) magnetic resonance imaging (MRI) is the standard imaging sequence for trajectory planning of stereotactic procedures, including deep brain stimulation, stereoelectroencephalography, and laser interstitial thermal therapy, susceptibility-weighted imaging (SWI) has been reported to demonstrate increased sensitivity for the visualization of microvasculature.

OBJECTIVE

To determine the impact of SWI visualization on trajectory planning for electrode implantation and evaluate the relationship between the rate of vessel-electrode intersections and intracerebral hemorrhage (ICH).

METHODS

We conducted a retrospective study of 13 patients who underwent stereoelectroencephalography and laser interstitial thermal therapy placement between 2014 and 2015, using their preoperative T1-Gd and SWI scans, and postoperative MRI scans to determine the rate of vessel-electrode intersections seen on the 2 imaging modalities, the mean diameter and depth of the vessels identified, and the rate of ICH after implantation.

RESULTS

Among 13 patients, 106 electrodes were implanted. Sixty-three unique vessel-electrode intersections were identified on SWI with a mean of 4.85 intersections per patient. There were 13 intersections seen on T1-Gd with a mean of 1 intersection per patient. The intersected vessels visualized on SWI had a diameter of 1.49 ± 0.46 mm and those on T1-Gd were 2.01 ± 0.52 mm. There was no clear ICH observed in this series.

CONCLUSION

SWI allows for improved visualization of the smaller, deep vessels, whereas T1-Gd adequately detects superficial, larger vessels. Despite the larger number of vessel-electrode intersections seen on SWI, no clear evidence of ICH was identified. Increased detection of deep vasculature does not appear to significantly benefit trajectory planning for stereotactic intracranial procedures and may limit the number of trajectories perceived to be safe.

Deep Brain Stimulation in Anorexia Nervosa: Hope for the Hopeless or Exploitation of the Vulnerable? The Oxford Neuroethics Gold Standard Framework

Neurosurgical interventions for psychiatric disorders have a long and troubled history (1, 2) but have become much more refined in the last few decades due to the rapid development of neuroimaging and robotic technologies (2). These advances have enabled the design of less invasive techniques, which are more focused, such as deep brain stimulation (DBS) (3). DBS involves electrode insertion into specific neural targets implicated in pathological behavior, which are then repeatedly stimulated at adjustable frequencies. DBS has been used for Parkinson's disease and movement disorders since the 1960s (4-6) and over the last decade has been applied to treatment-refractory psychiatric disorders, with some evidence of benefit in obsessive-compulsive disorder (OCD), major depressive disorder, and addictions (7). Recent consensus guidelines on best practice in psychiatric neurosurgery (8) stress, however, that DBS for psychiatric disorders remains at an experimental and exploratory stage. The ethics of DBS-in particular for psychiatric conditions-is debated (1, 8-10). Much of this discourse surrounds the philosophical implications of competence, authenticity, personality, or identity change following neurosurgical interventions, but there is a paucity of applied guidance on neuroethical best practice in psychiatric DBS, and health-care professionals have expressed that they require more (11). This paper aims to redress this balance by providing a practical, applied neuroethical gold standard framework to guide research ethics committees, researchers, and institutional sponsors. We will describe this as applied to our protocol for a particular research trial of DBS in severe and enduring anorexia nervosa (SE-AN) (https://clinicaltrials.gov/ct2/show/NCT01924598, unique identifier NCT01924598), but believe it may have wider application to DBS in other psychiatric disorders.

Thirty-Day Readmission Rates Following Deep Brain Stimulation Surgery

BACKGROUND: 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.

OBJECT: To perform a retrospective cohort study to estimate the 30-day all-cause readmission rate associated with DBS.

METHODS: 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.

RESULTS: 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 &lt; .001), but not by age, gender, or length of stay (Ps &gt; .15).

CONCLUSION: 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 &lt; .001).

Deep Brain Stimulation: Expanding Applications

For over two decades, deep brain stimulation (DBS) has shown significant efficacy in treatment for refractory cases of dyskinesia, specifically in cases of Parkinson's disease and dystonia. DBS offers potential alleviation from symptoms through a well-tolerated procedure that allows personalized modulation of targeted neuroanatomical regions and related circuitries. For clinicians contending with how to provide patients with meaningful alleviation from often debilitating intractable disorders, DBSs titratability and reversibility make it an attractive treatment option for indications ranging from traumatic brain injury to progressive epileptic supra-synchrony. The expansion of our collective knowledge of pathologic brain circuitries, as well as advances in imaging capabilities, electrophysiology techniques, and material sciences have contributed to the expanding application of DBS. This review will examine the potential efficacy of DBS for neurologic and psychiatric disorders currently under clinical investigation and will summarize findings from recent animal models.

Amelioration of binge eating by nucleus accumbens shell deep brain stimulation in mice involves D2 receptor modulation

Hedonic overconsumption contributing to obesity involves altered activation within the mesolimbic dopamine system. Dysregulation of dopamine signaling in the nucleus accumbens shell (NAS) has been implicated in reward-seeking behaviors, such as binge eating, which contributes to treatment resistance in obesity (Wise, 2012). Direct modulation of the NAS with deep brain stimulation (DBS), a surgical procedure currently under investigation in humans for the treatment of major depression, obsessive-compulsive disorder, and addiction, may also be effective in ameliorating binge eating. Therefore, we examined the ability of DBS of the NAS to block this behavior in mice. c-Fos immunoreactivity was assessed as a marker of DBS-mediated neuronal activation. NAS DBS was found to reduce binge eating and increased c-Fos levels in this region. DBS of the dorsal striatum had no influence on this behavior, demonstrating anatomical specificity for this effect. The dopamine D2 receptor antagonist, raclopride, attenuated the action of DBS, whereas the D1 receptor antagonist, SCH-23390, was ineffective, suggesting that dopamine signaling involving D2 receptors underlies the effect of NAS DBS. To determine the potential translational relevance to the obese state, chronic NAS DBS was also examined in diet-induced obese mice and was found to acutely reduce caloric intake and induce weight loss. Together, these findings support the involvement of the mesolimbic dopamine pathways in the hedonic mechanisms contributing to obesity, and the efficacy of NAS DBS to modulate this system.

Deep brain stimulation lead fixation after Stimloc failure

We report a method for deep brain stimulation (DBS) lead fixation in the event that the primary anchoring device fails to function effectively. The method involves the application of a titanium microplate to secure the lead to the skull, thereby providing a fast and reliable "rescue" mechanism for lead fixation. This method can supplement any burr hole cap and fixation method. Furthermore, this method has several advantages over removal and replacement of the primary anchor, such as a lower possibility of lead migration, faster procedural time, and cost-effectiveness.

Self-administered preoperative antiseptic wash to prevent postoperative infection after deep brain stimulation

BACKGROUND

Prevention of surgical site infections is critical in deep brain stimulation (DBS). In the present study, we tested the ability of a self-administered preoperative alcohol-based (70% ethyl alcohol) preparation to reduce the rate of postoperative infection after DBS surgery.

METHODS

This Institutional Review Board-approved retrospective review was conducted at our institution between January 2005 and October 2007 (mean follow-up, 23 months). The participants comprised a consecutive sample of 172 patients with movement disorders who underwent DBS surgery at our institution. Starting in January 2007, all patients were required to use the alcohol-based preparation. These patients (n = 48) were instructed to self-administer the wash on the night before surgery and the morning of surgery. Before this time, no self-administered wash was used (n = 122).

RESULTS

There was no difference in preoperative skin cleansing between the 2 groups, and all patients received intravenous antibiotics immediately before and after surgery for 24 hours. We compared the rate of postoperative infection in the 2 groups and reviewed other possible factors underlying infection. We found 11 cases of infection (6.47%), all in the group without the preoperative antiseptic wash. The infection rate was 9.02% in the group without the preoperative wash and 0 in the group with the preoperative wash (P < .029). There was no difference between the 2 groups in terms of mean age, duration of operative procedure, or number of microelectrode tracts attempted.

CONCLUSIONS

Our results support the incorporation of this self-administered antiseptic wash into our standard antiseptic protocol for patients undergoing DBS surgery.

Management of device-related wound complications in deep brain stimulation surgery

OBJECT

Wound complications are uncommon following deep brain stimulation (DBS) surgery. However, certain key technical steps can be performed in each procedure to minimize this still troublesome risk. The authors reviewed the incidence and management of all hardware-related wound dehiscences and infections in a large patient series.

METHODS

All patients undergoing new DBS hardware implantation surgery between 2002 and 2010 by a single surgeon (R.K.S.) were entered into a database after undergoing verification by cross-referencing manufacturer implantation records. All hardware-related complications such as wound dehiscence, erosions, and/or infections were identified, and wound location, time of incidence, and mechanism were categorized. Charts were reviewed to evaluate the success of conservative treatment versus partial or total hardware removal.

RESULTS

Seven hundred twenty-eight patients received 1333 new DBS leads and 1218 new implantable pulse generators (IPGs) in a total of 1356 stereotactic procedures for movement disorders. Seventy-eight percent of patients underwent staged lead and IPG implantations. Sixteen patients presented with atraumatic device-related infection and/or dehiscence within 12 months from original implantation; 9 of these patients (1.24%) required additional surgery after antibiotic failure. All 8 patients presenting with cranial wound complications were treated initially by debridement in an attempt to salvage the leads; debridement followed by intravenous antibiotics was only successful in 2 patients presenting with dehiscence alone. One of 2 lead-only removals was successful in infections originating in the cranium; the only IPG-originating infection was treated by partial hardware removal and intravenous antibiotics. Two of 637 IPG replacements resulted in infections within 12 months after revision, requiring either partial or total hardware removal, while 1 dehiscence in this group was treated by debridement alone.

CONCLUSIONS

In a large series of new DBS hardware implantations, the incidence of postoperative wound dehiscence and/or infections requiring further surgery was 1.24%. Standard practice for all implantations was a short procedural duration, copious povidone-iodine irrigation, and postoperative antibiotic administration. Partial hardware removal should be initially attempted for infection. Debridement alone is successful in treating dehiscence without infection.

Deep brain stimulation compared with methadone maintenance for the treatment of heroin dependence: a threshold and cost-effectiveness analysis

AIMS

To determine the success threshold at which a theoretical course of deep brain stimulation (DBS) would provide the same quality of life (QoL) and cost-effectiveness for heroin dependence as methadone maintenance treatment (MMT).

DESIGN

We constructed a decision analysis model to calculate QoL after 6 months of MMT and compared it to a theoretical course of DBS. We also performed a cost-effectiveness analysis using societal costs of heroin dependence, MMT and DBS.

SETTING

Systematic literature review and meta-analysis.

PARTICIPANTS

Patients (n = 1191) from 15 trials administering 6 months of MMT and patients (n = 2937) from 45 trials of DBS for movement disorders.

MEASUREMENTS

Data on QoL before and after MMT, retention in MMT at 6 months, as well as complications of DBS and their impact on QoL in movement disorders.

FINDINGS

We found a QoL of 0.633 (perfect health = 1) in heroin addicts initiating MMT. Sixty-six per cent of patients completed MMT, but only 47% of them had opiate-free urine samples, resulting in an average QoL of 0.7148 (0.3574 quality-adjusted life years (QALYs) over 6 months). A trial of DBS is less expensive ($81,000) than untreated (or relapsed) heroin dependence ($100,000), but more expensive than MMT ($58,000). A theoretical course of DBS would need a success rate of 36.5% to match MMT, but a success rate of 49% to be cost-effective.

CONCLUSIONS

The success rate, defined as the percentage of patients remaining heroin-free after 6 months of treatment, at which deep brain stimulation would be similarly cost-effective in treating opiate addiction to methadone maintenance treatment, is estimated at 49%.

Surgical checklists: A detailed review of their emergence, development, and relevance to neurosurgical practice

In the fall of 1999, the Institute of Medicine released “To Err is Human: Building a Safer Health System,” a sobering report on the safety of the American healthcare industry. This work and others like it have ushered in an era where the science of quality assurance has quickly become an integral facet of the practice of medicine. One critical component of this new era is the development, application, and refinement of checklists. In a few short years, the checklist has evolved from being perceived as an assault on the practitioner’ integrity to being welcomed as an important tool in reducing complications and preventing medical errors. In an effort to further expand the neurosurgical community's acceptance of surgical checklists, we review the rationale behind checklists, discuss the history of medical and surgical checklists, and remark upon the future of checklists within our field.

The effect of intraventricular trajectory on brain shift in deep brain stimulation

BACKGROUND

Brain shift during deep brain stimulation (DBS) surgery may compromise target localization. Loss of cerebrospinal fluid is believed to be the underlying mechanism, thus an intraventricular trajectory during DBS surgery may be associated with increased shift, in addition to other complications, such as intraventricular hemorrhage.

OBJECTIVE

We set out to assess the effect of traversing the lateral ventricle on brain shift during DBS surgery.

METHODS

We performed a retrospective review of 65 pre- and postoperative MR images of patients who underwent bilateral subthalamic nucleus deep brain stimulator placement to treat advanced Parkinson's disease. Patients were separated into two groups: Group A (intraventricular trajectory, n = 46) and Group B (no intraventricular trajectory, n = 19). In these patients, we compared pre- and postoperative frame coordinates of the red nucleus (RN).

RESULTS

Group B demonstrated significantly more posterior shift of the center of the RN (1.40 ± 1.32 mm) than Group A (0.64 ± 1.76 mm; p < 0.02). We found no increase in incidence of intraventricular hemorrhage or the number of microelectrode trajectory attempts.

CONCLUSIONS

Intraventricular trajectories during DBS surgery do not appear to compromise safety or targeting accuracy.