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Background Meige syndrome is a segmental dystonia affecting the head and neck, with bilateral blepharospasm as the primary symptom. First-line treatment typically involves Botox injections. For cases resistant to this treatment, bilateral deep brain stimulation of the globus pallidus internus (GPi) is considered. This study explores the efficacy of unilateral radiofrequency (RF) lesioning as an alternative surgical treatment for Meige syndrome. Methods We investigated six cases of medically refractory Meige syndrome treated with unilateral RF lesioning between October 2022 and August 2023. The procedures utilized the Leksell Stereotactic System (Elekta, Stockholm, Sweden) and the StealthStation S8 system (Medtronic, Dublin, Ireland). Target coordinates were initially set at 8-9 mm lateral and 1-2 mm inferior to the mid-commissure point (MCP) for the pallidothalamic tract (PTT), and 20 mm lateral, 2 mm anterior, and 3.0-4.5 mm inferior to the MCP for GPi, with fine adjustments based on MRI findings. Results The mean age of patients was 53. 3 ±16.5 years. Five patients underwent PTT RF lesioning, while one received GPi RF lesioning (pallidotomy). No surgical complications were reported. The Burke-Fahn-Marsden Dystonia Rating Scale scores were 32.9 ± 19.4 preoperatively and 17.7 ± 13.9 three months postoperatively, reflecting an average improvement of 42.7%. The Jankovic Rating Scale scores were 7.17 ± 0.76 preoperatively, 2.33 ± 2.34 the day after surgery (average improvement of 67%), and 3.50 ± 1.64 three months postoperatively (average improvement of 51%). Bilateral facial symptoms improved in four patients (67%). Conclusion Unilateral RF lesioning for Meige syndrome demonstrated the potential to improve bilateral symptoms and may be considered a viable treatment option for patients with refractory cases.

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Frame-based stereotactic localization is an important step for targeting during a surgical procedure. The motion may cause artifacts in this step reducing the accuracy of surgical targeting. While modeling of motion in real-life scenarios may be difficult, herein we analyzed the case where motion was suspected to impact the localization step. In this case, a scan with and without motion was performed with a 3N localizer, allowing for a thorough analysis. Pseudo-bending of straight rods was seen when analyzing the data. This pseudo-bending appears to occur because head-frame motion during imaging acquisition decreases the accuracy of the subsequent reconstruction, which depends on Digital Imaging and Communications in Medicine (DICOM) metadata to specify the slice-to-slice location that assumes embedded object stability. Comparison of single-slice and multi-slice stereotactic localization allowed for comparative errors for each slice in a volume. This comparative error demonstrated low error when the patient was under general anesthesia and presumed not to have moved, whereas a higher error was present during the scan with motion. Pseudo-bending can be corrected by using only localizer fiducial-based information to reorient the pixels in the volume, thus creating a reoriented localizer scan. Finally, targeting demonstrated a low error of 0.1 mm (+/- 0.1 mm) using this reoriented localizer scan, signifying that this method could be used to improve or recover from motion problems. Finally, it is concluded that stability and elimination of motion for all images utilized for stereotactic surgery are critical to ensure the best possible accuracy for the procedure.

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Frame-based stereotactic localization generally assumes that all required fiducials are present in a single-slice image which can then be used to form targeting coordinates. Previously, we have published the use of novel localizers and mathematics that can improve stereotactic localization. As stereotactic procedures include numerous imaging slices, we sought to investigate, develop, and test techniques that utilize multiple slices for stereotactic localization and provide a solution for a parallel bipanel N-localizer.  Several multi-slice equations were tested. Specifically, multi-slice stereotactic matrices (ms-SM) and multi-slice normal to parallel planes (ms-nPP) were of particular interest. Bipanel (2N) and tripanel (3N) localizer images were explored to test approaches for stereotactic localization. In addition, combination approaches using single-slice stereotactic matrices (ss-SM) and multi-slice methods were tested. Modification of ss-SM to form ms-SM was feasible. Likewise, a method to determine ms-nPP was developed. For the special case of the parallel bipanel N-localizer, single-slice and multi-slice methods fail, but a novel non-linear solution is a robust solution for ms-nPP. Several methods for single-slice and multi-slice stereotactic localization are described and can be adapted for nearly any stereotactic system. It is feasible to determine ms-SM and ms-nPP. In particular, these methods provide an overdetermined means to calculate the vertical z, which is determined for a tripanel system using single-slice methods. In addition, the multi-slice methods can be used for extrapolation outside of the localizer space. Importantly, a novel non-linear solution can be used for parallel bipanel N-localizer systems, where other methods fail. Finally, multi-slice stereotactic localization assumes strict patient and imaging system stability, which should be carefully assessed for each case.

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BACKGROUND: Magnetic resonance imaging (MRI)-guided laser interstitial thermal therapy (MRgLITT) has been used successfully to treat epileptogenic cortical cerebral cavernous malformations (CCM). It is unclear whether MRgLITT would be as feasible or safe for deep CCMs. OBJECTIVE: To describe our experience with MRgLITT for symptomatic deep CCMs. METHODS: Patients' records were reviewed retrospectively. MRgLITT was carried out using a commercially available system in an interventional MRI suite with efforts to protect adjacent brain structures. Immediate postoperative imaging was used to judge ablation adequacy. Delayed postoperative MRI was used to measure lesion volume changes during follow-up. RESULTS: Four patients with CCM in the thalamus, putamen, midbrain, or subthalamus presented with persistent and disabling neurological symptoms. A total of 2 patients presented with disabling headaches and sensory disturbances and 2 with recurrent symptomatic hemorrhages, of which 1 had familial CCM. Patients were considered by vascular neurosurgeons to be poor candidates for open surgery or had refused it. Multiple trajectories were used in most cases. Adverse events included device malfunction with leakage of saline causing transient mass effect in one patient, and asymptomatic tract hemorrhage in another. One patient suffered an expected mild but persistent exacerbation of baseline deficits. All patients showed improvement from a previously aggressive clinical course with lesion volume decreased by 20% to 73% in follow-up. CONCLUSION: MRgLITT is feasible in the treatment of symptomatic deep CCM but may carry a high risk of complications without the benefit of definitive resection. We recommend cautious patient selection, low laser power settings, and conservative temperature monitoring in surrounding brain parenchyma.

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Introduction Stereotactic radiosurgery for trigeminal neuralgia (TN) has gained interest among patients who are not suitable for surgical procedures. Although two target zones are more recognized - dorsal root entry zone (DREZ) and retrogasserian zone (RGZ) - the optimal targeting technique remains controversial in terms of clinical outcomes and rates of complications. Therefore, various modifications to the radiosurgical technique for TN have been made. Objective This study aimed to determine the differences in shoot location (i.e., RGZ vs. DREZ) regarding effectiveness and adverse effects in patients with medically refractory TN. Additionally, we evaluated the effect of the integral dose (ID) on treatment outcomes and complications. Methods We present a retrospective cohort study of 49 patients with primary, drug-resistant TN treated with gamma knife radiosurgery targeting the distal and proximal parts of the nerve regarding the DREZ with a prescription dose of 90 Gy (80 to 96 Gy). A subset of these patients (n=38) where the ID could be measured to the nerve was correlated to treatment outcomes and complications. Results The median follow-up time was 36 months for RGZ and 51 months for DREZ targets. Neurovascular conflict was identified in 87.5% of the RGZ group and 88.2% of the DREZ group. Using the Barrow Neurological Institute (BNI) pain score, 26 (81.3%) RGZ and 12 (70.6%) DREZ patients were successfully treated (BNI I-IIIb; p=0.02). Seven (21.9%) RGZ and eight (47.1%) DREZ patients reported complete pain relief without medication (BNI I). Time response was 22.3 days for RGZ and 34.1 days for DREZ (p=0.277). There were 10 (31.3%) patients in the RGZ group with associated complications versus six (35.3%) patients in the DREZ group (χ2=0.0826, degree of freedom=1, p=0.773). Treatment outcomes using higher ID were better in the RGZ than DREZ (81.8% vs. 57.1, respectively), and a significant association was found between a higher ID delivered to the nerve and the development of complications (p=0.02). Conclusion Based on the obtained results, the RGZ was a more effective targeting area with better treatment outcomes without significant differences in complication rates than DREZ. A higher ID at the RGZ than DREZ had a greater therapeutical effect. Further investigation regarding the optimal target area along the ID delivered and clinical outcomes are required.

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All stereotactic neurosurgical procedures utilize coordinate systems to allow navigation through the brain to a target. During the surgical planning, indirect and direct targeting determines the planned target point and trajectory. This targeting allows a surgeon to precisely reach points along the trajectory while minimizing risks to critical structures. Oftentimes, once a target point and a trajectory are determined, a frame-based coordinate system is used for the actual procedure. Considerations include the use of various coordinate spaces such as the anatomical ([Formula: see text]), the frame ([Formula: see text]), the head-stage ([Formula: see text]), and an atlas. Therefore, the relationships between these coordinate systems are integral to the planning and implementation of the neurosurgical procedure. Although coordinate transformations are handled in planning via stereotactic software, critical understanding of the mathematics is required as it has implications during surgery. Further, intraoperative applications of these coordinate conversions, such as for surgical navigation from the head-stage, are not readily available in real-time. Herein, we discuss how to navigate these coordinate systems and provide implementations of the techniques with samples.

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OBJECTIVE: Deep brain stimulation (DBS) is a well-established therapy for treating neurological movement disorders. Some patients who have received DBS therapy have noticed significant weight gain. Further investigation into correlations between patient characteristics and weight gain following DBS device implantation, which the authors here have done, will provide physicians with useful clinical information. METHODS: The authors performed a retrospective study of patients with Parkinson's disease (PD) and essential tremor (ET) who had received DBS therapy in the period from 2012 to 2017. Patient weights had been recorded preoperatively and at 3, 6, and 12 months postoperatively. These data were used to compare patient characteristics, including diagnosis, body mass index (BMI), sex, levodopa equivalent dose (LED), and change in Unified Parkinson's Disease Rating Scale (UPDRS) score. For PD patients, a quantile multivariate regression analysis was used to examine whether significant correlations existed between several of these patient characteristics, as well as age and weight gain following implantation. RESULTS: PD patients had gained a significant amount of weight at 3 months (mean [SE] 2.66 [0.428] kg, p < 0.001), 6 months (3.64 [0.492] kg, p < 0.001), and 12 months (4.18 [0.540] kg, p < 0.001) after DBS placement. Patients who had undergone subthalamic nucleus (STN) DBS device placement gained, on average, more weight than the patients with globus pallidus internus (GPi) placement at both 6 months (mean 2.558 [1.020] kg, p = 0.01) and 12 months (2.358 [1.130] kg, p = 0.04). BMI in the STN cohort was greater than that in the GPi cohort at 6 months (mean difference [SE] 2.60 [1.127] kg/m2, p = 0.02) and at 12 months (2.36 [1.112] kg/m2, p = 0.04). A reduction in LED was negatively correlated with weight change at 6 months (r = -0.33, p < 0.001) and 12 months (r = -0.41, p < 0.001). There was no weight gain correlated with DBS therapy for ET. CONCLUSIONS: PD patients experienced a significant change in weight over time after DBS therapy, whereas ET patients did not. PD patients with an STN target site experienced greater weight gain, on average, than those with a GPi target site. Furthermore, there was a significant increase in BMI at 6 and 12 months in patients with an STN target compared to that in patients with a GPi target. PD patients whose LED was reduced after DBS gained more weight at 6 and 12 months after surgery than the patients whose LED was kept at the same level or increased.

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BACKGROUND: The quality of a scientific meeting can be quantified by the rate of full publications arising from the presented abstracts and the impact factor of the journals in which the studies were published. OBJECTIVES: The aim of this study was to investigate the publication rates of presentations from the 2013 World Society for Stereotactic and Functional Neurosurgery (WSSFN) quadrennial meeting. METHODS: Scopus and PubMed databases were searched for the authors of the presentations to identify full publications arising from the relevant abstracts. Author and content matching were used to match an abstract with a full publication. Mann-Whitney U and Kruskal-Wallis tests were used for statistical analysis. RESULTS: In total, 77% (57/74), 56% (44/79), and 50% (79/157) of the paper, flash, and poster presentations, respectively, have been published, with an overall publication rate of 58% (180/310). Articles received a total of 5,227 citations, with an average of 29 ± 64.1 citations per article. The first authors who published their studies had a significantly higher h-index than those who did not publish (p = 0.003). The most preferred journals for publication were Journal of Neurosurgery, Acta Neurochirurgica, and Stereotactic and Functional Neurosurgery. The majority of the articles (117/180 [65%]) were published in a quartile 1 or 2 journal. The average journal impact factor (JIF) was 4.5 for all presentations, and 7.8 for paper session presentations. Studies presented in paper sessions were published in significantly higher-impact factor journals than those presented in poster sessions (p < 0.001). CONCLUSIONS: The WSSFN Congress had a relatively high overall publication rate (58%) compared to both other neurosurgical congresses and congresses in other scientific fields. The average JIF of 7.8 is a reflection of the high quality and high impact of the paper session presentations.

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BACKGROUND: The anesthetic management of patients requiring surgery for movement disorders needs to balance microrecording quality and patient cooperation with safety and comfort. Anesthetics can alter microrecording, although the effect on outcome is debatable. They also provide a rested and cooperative patient and minimize complications such as intracranial hemorrhage by providing better hemodynamic control. Most teams use local anesthesia with monitored anesthesia care or conscious sedation with propofol. Recently, dexmedetomidine has emerged as an alternative that, at low doses, does not affect microrecording, and that does not impair respiratory drive. METHODS: In the past 15 years, we have used in our institution local anesthesia, remifentanil, or dexmedetomidine sedation. We compared functional outcome and rate of complications in a group of 145 patients with similar characteristics. RESULTS: We found 5 (3.4%) intracranial hemorrhages. Two (1.4%) were symptomatic. The remifentanil group had the highest risk of having systolic blood pressure >160 mm Hg during surgery (odds ratio [OR], 2.8; 95% confidence interval [CI], 0.9-9.9), whereas the dexmedetomidine group had the lowest (OR, 0.7; 95% CI, 0.2-1.8), compared with the local anesthesia group. Surgical time was shortest with dexmedetomidine (mean, 283 minutes) and longest with local anesthesia only (mean, 328 minutes). Functional outcome (Unified Parkinson's Disease Rating Scale, Part III motor component scale) was similar among groups. The dexmedetomidine group had a statistically significant lower risk of perioperative neurologic events compared with the local anesthesia group (OR, 0.09; 95% CI, 0.002-0.68). CONCLUSIONS: Sedation can be used safely without affecting outcome, and dexmedetomidine provides better hemodynamic management. Clinical significance remains unclear and larger studies need to be undertaken.

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OBJECTIVE: An usefulness and an accuracy of Neurosurgery Simulator(R)(NSS(R)) is evaluated for the clinical applications. The NSS(R) is a surgical planning tool for stereotactic and functional neurosurgery, recently developed in Korea. METHODS: Thirty-four surgical cases, performed with the NSS(R) from October 1999 to April 2002, were analyzed. The accuracy was examined by comparing the actual lesion with the planned target. The usefulness was discussed with time consuming factor and convenience for surgical steps. Results of surgical outcome were also reviewed. RESULTS: The precise coordinates of surgical target is directly acquired by designating an anatomical lesion on the magnetic resonance image with NSS(R) due to auto recognition algorithm of the fiducials on the MRI image. The correctness is confirmed again by examining the anatomical lesion with superimposing the Schaltenbrand-Wahren atlas on the image directly. Among eleven cases of the thalamotomy for tremors, five cases resulted in complete resolution, the remaining five patients showed significant reduction of tremors. Improvement of ADL and UPDRS was recorded in all 6 Parkinson's disease patients who had undergone pallidotomy. Seventy five percent of patient in pain and psychosurgery resulted in improvements. The NSS(R) achieved 100% accuracy in calculating stereotactic biopsy coordinates. There was no deviation in guiding surgical trajectory. There was no significant surgical complication. CONCLUSION: Stereotactic and functional neurosurgery performed with the assistance of the NSS(R) is relatively safe and accurate.

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