Surgical Target Research Articles

First experience with augmented reality neuronavigation in endoscopic assisted midline skull base pathologies in children

IntroductionEndoscopic skull base approaches are broadly used in modern neurosurgery. The support of neuronavigation can help to effectively target the lesion avoiding complications. In children, endoscopic-assisted skull base surgery in combination with navigation systems becomes even more important because of the morphological variability and rare diseases affecting the sellar and parasellar regions. This paper aims to analyze our first experience on augmented reality navigation in endoscopic skull base surgery in a pediatric case series.Patients and methodsA retrospective review identified seventeen endoscopic-assisted endonasal or transoral procedures performed in an interdisciplinary setting in a period between October 2011 and May 2020. In all the cases, the surgical target was a lesion in the sellar or parasellar region. Clinical conditions, MRI appearance, intraoperative conditions, postoperative MRI, possible complications, and outcomes were analyzed.ResultsThe mean age of our patients was 14.5 ± 2.4 years. The diagnosis varied, but craniopharyngiomas (31.2%) were mostly represented. AR navigation was experienced to be very helpful for effectively targeting the lesion and defining the intraoperative extension of the pathology. In 65% of the oncologic cases, a radical removal was proven in postoperative MRI. The mean follow-up was 89 ± 79 months. There were no deaths in our series. No long-term complications were registered; two cerebrospinal fluid (CSF) fistulas and a secondary abscess required further surgery.ConclusionThe implementation of augmented reality to endoscopic-assisted neuronavigated procedures within the skull base was feasible and did provide relevant information directly in the endoscopic field of view and was experienced to be useful in the pediatric cases, where anatomical variability and rarity of the pathologies make surgery more challenging.

Grinding trajectory generator in robot-assisted laminectomy surgery.

Grinding trajectory planning for robot-assisted laminectomy is a complicated and cumbersome task. The purpose of this research is to automatically obtain the surgical target area from the CT image, and based on this, formulate a reasonable robotic grinding trajectory. We propose a deep neural network for laminae positioning, a trajectory generation strategy, and a grinding speed adjusting strategy. These algorithms can obtain surgical information from CT images and automatically complete grinding trajectory planning. The proposed laminae positioning network can reach a recognition accuracy of 95.7%, and the positioning error is only 1.12mm in the desired direction. The simulated surgical planning on the public dataset has achieved the expected results. In a set of comparative robotic grinding experiments, those using the speed adjustment algorithm obtained a smoother grinding force. Our work can automatically extract laminar centers from the CT image precisely to formulate a reasonable surgical trajectory plan. It simplifies the surgical planning process and reduces the time needed for surgeons to perform such a cumbersome operation manually.

Hand Motion-Aware Surgical Tool Localization and Classification from an Egocentric Camera.

Detecting surgical tools is an essential task for the analysis and evaluation of surgical videos. However, in open surgery such as plastic surgery, it is difficult to detect them because there are surgical tools with similar shapes, such as scissors and needle holders. Unlike endoscopic surgery, the tips of the tools are often hidden in the operating field and are not captured clearly due to low camera resolution, whereas the movements of the tools and hands can be captured. As a result that the different uses of each tool require different hand movements, it is possible to use hand movement data to classify the two types of tools. We combined three modules for localization, selection, and classification, for the detection of the two tools. In the localization module, we employed the Faster R-CNN to detect surgical tools and target hands, and in the classification module, we extracted hand movement information by combining ResNet-18 and LSTM to classify two tools. We created a dataset in which seven different types of open surgery were recorded, and we provided the annotation of surgical tool detection. Our experiments show that our approach successfully detected the two different tools and outperformed the two baseline methods.

Anterior limb of the internal capsule tractography: relationship with capsulotomy outcomes in obsessive-compulsive disorder

ObjectivesSurgical procedures targeting the anterior limb of the internal capsule (aLIC) can be effective in patients with selected treatment-refractory obsessive-compulsive disorder (OCD). The aLIC consists of white-matter tracts connecting cortical...

Increased tibiofemoral rotation on MRI with increasing clinical severity of patellar instability.

Tibiofemoral rotation through the knee joint, specifically relative external tibial rotation, has been identified as a potential contributing factor to patellar instability. The purpose of this study is to investigate the relationship between severity of instability with degree of tibiofemoral rotation in three clinical cohorts: fixed or obligatory dislocators (in which the patella either is constantly laterally dislocated or laterally dislocates with every instance of knee flexion, respectively), standard traumatic instability patients, and normal controls. A retrospective study was performed with three cohorts from April 2009 to February 2019: fixed or obligatory dislocators, standard traumatic instability patients, and controls with normal magnetic resonance imaging (MRI) of the knee. All fixed or obligatory dislocation patients from the study time frame were analyzed; controls and standard traumatic instability patients were randomly selected. Inclusion criteria were age under 18years and qualifying diagnosis; exclusion criteria were outside institution MRI and previous MPFL reconstruction or tibial tubercle osteotomy. Tibiofemoral rotation was measured blindly on initial axial MRI using the posterior femoral and tibial condylar lines. Tibial tubercle to trochlear groove distance (TT-TG) was measured. Intraclass correlation coefficient (ICC) was calculated among four measurers. A total of 100 patients were included, 20 fixed or obligatory dislocators, 40 standard traumatic instability patients, and 40 controls. Median age was 13.2years (range 10-17years), with 55 females. Age was significantly higher in the standard traumatic instability group than both the control (p < 0.001) and fixed or obligatory dislocator groups (p = 0.003). ICC for TT-TG and tibiofemoral rotation were 0.92 and 0.96, respectively. Fixed or obligatory dislocator patients averaged 8.5° external tibiofemoral rotation, standard traumatic instability patients 1.6° external tibiofemoral rotation, and controls 3.8° internal tibiofemoral rotation. Both tibiofemoral rotation and TT-TG were highest in the fixed or obligatory dislocator cohort, followed by the standard traumatic instability cohort, and lowest in the controls (p < 0.0001 for tibiofemoral rotation and TT-TG). Multivariate analysis showed no correlation between age and tibiofemoral rotation. Measurement of tibiofemoral rotation was reproducible with excellent interrater reliability. The degree of tibiofemoral rotation is correlated with severity of patellar instability, with the greatest external tibiofemoral rotation in fixed or obligatory dislocator patients, followed by standard traumatic instability patients, and slight internal tibiofemoral rotation in controls. High external tibiofemoral rotation may be an important pathoanatomic factor in fixed or obligatory dislocators, and with further understanding may become a prognostic factor or surgical target. III.

Redefining cervical spine deformity classification through novel cutoffs: An assessment of the relationship between radiographic parameters and functional neurological outcomes.

Purpose:The aim is to investigate the relationship between cervical parameters and the modified Japanese Orthopedic Association scale (mJOA).Materials and Methods:Surgical adult cervical deformity (CD) patients were included in this retrospective analysis. After determining data followed a parametric distribution through the Shapiro–Wilk Normality (P = 0.15, P > 0.05), Pearson correlations were run for radiographic parameters and mJOA. For significant correlations, logistic regressions were performed to determine a threshold of radiographic measures for which the correlation with mJOA scores was most significant. mJOA score of 14 and <12 reported cut-off values for moderate (M) and severe (S) disability. New modifiers were compared to an existing classification using Spearman's rho and logistic regression analyses to predict outcomes up to 2 years.Results:A total of 123 CD patients were included (60.5 years, 65%F, 29.1 kg/m2). For significant baseline factors from Pearson correlations, the following thresholds were predicted: MGS (M:-12 to-9° and 0°–19°, P = 0.020; S: >19° and <−12°, χ2= 4.291, P = 0.036), TS-CL (M: 26°to 45°, P = 0.201; S: >45°, χ2= 7.8, P = 0.005), CL (M:-21° to 3°, χ2= 8.947, P = 0.004; S: <−21°, χ2= 9.3, P = 0.009), C2-T3 (M: −35° to −25°, χ2= 5.485, P = 0.046; S: <−35°, χ2= 4.1, P = 0.041), C2 Slope (M: 33° to 49°, P = 0.122; S: >49°, χ2= 5.7, P = 0.008), and Frailty (Mild: 0.18–0.27, P = 0.129; Severe: >0.27, P = 0.002). Compared to existing Ames- International Spine Study Group classification, the novel thresholds demonstrated significant predictive value for reoperation and mortality up to 2 years.Conclusions:Collectively, these radiographic values can be utilized in refining existing classifications and developing collective understanding of severity and surgical targets in corrective surgery for adult CD.

Diffusion tensor imaging findings of patients with parkinson's disease refractory to medical treatment

Aim: Diffusion Tensor Imaging (DTI) findings can be useful to detect and measure neurodegeneration that is seen in Parkinson’sdisease (PD). Microstructural changes in regions of the brain related with motor function are evaluated by using DTI measurementsof fractional anisotropy (FA) to find out the possible role of the technique in diagnosis in patients with PD.Materials and Methods: The study includes 18 PD patients who were candidates for deep brain stimulation surgery, and 19 controlgroup patients. DTI was performed in all cases. DTI characteristics of FA were measured in primary motor cortex (M1), supplementarymotor area (SMA), inferior parietal lobule, putamen (P), globus pallidus externus (GPe) and internus (GPi), ventrolateral nucleus ofthalamus (Th), substantia nigra (SN), cuneus, precuneus and cerebellar dentate nucleus (D) bilaterally. Additionally, we processed“raw” FA images and colored them according to fiber orientation to visualize STN and GPi nuclei.Results: Mean age of the control group was 59.2±13.2 (range: 31-79) years, while it was 56.7±16 (range: 42-77) years for the patientgroup. Mean duration of PD was 12.4±7.1 (range: 5-30) years. Study group FA values were significantly lower than the control groupin all areas bilaterally (p<0.05). Additionally, FA-M1, FA-GPi and FA-GPe values were significantly lower on left side compared to rightside (p<0.05).Conclusion: Decrease in FA values in all regions in the study group is thought to result from loss of nerve cells. Additionally, raw FAimages that are processed, and colored in relation to fiber orientation can be useful for a better identification of STN and GPi nuclei.This type of imaging will provide a more precise anatomy necessary for surgical targeting.

Connectivity correlates to predict essential tremor deep brain stimulation outcome: Evidence for a common treatment pathway

Background and purposeDeep brain stimulation (DBS) is the most common surgical treatment for essential tremor (ET), yet there is variation in outcome and stimulation targets. This study seeks to consolidate proposed stimulation “sweet spots,” as well as assess the value of structural connectivity in predicting treatment outcomes. Materials and methodsNinety-seven ET individuals with unilateral thalamic DBS were retrospectively included. Using normative brain connectomes, structural connectivity measures were correlated with the percentage improvement in contralateral tremor, based on the Fahn-Tolosa-Marin tremor rating scale (TRS), after parameter optimization (range 3.1–12.9 months) using a leave-one-out cross-validation in 83 individuals. The predictive feature map was used for cross-validation in a separate cohort of 14 ET individuals treated at another center. Lastly, estimated volumes of tissue activated (VTA) were used to assess a treatment “sweet spot,” which was compared to seven previously reported stimulation sweet spots and their relationship to the tract identified by the predictive feature map. ResultsIn the training cohort, structural connectivity between the VTA and dentato-rubro-thalamic tract (DRTT) correlated with contralateral tremor improvement (R = 0.41; p < 0.0001). The same connectivity profile predicted outcomes in a separate validation cohort (R = 0.59; p = 0.028). The predictive feature map represented the anatomical course of the DRTT, and all seven analyzed sweet spots overlapped the predictive tract (DRTT). ConclusionsOur results strongly support the possibility that structural connectivity is a predictor of contralateral tremor improvement in ET DBS. The results suggest the future potential for a patient-specific functionally based surgical target. Finally, the results showed convergence in “sweet spots” suggesting the importance of the DRTT to the outcome.

Chapter 7 - Posterior hypothalamus as a target in the treatment of aggression: From lesioning to deep brain stimulation

Intermittent explosive disorder can be described as a severe "affective aggression" condition, for which drugs and other supportive therapies are not fully effective. In the first half of the 19th century, experimental studies progressively increased knowledge of aggressive disorders. A neurobiologic approach revealed the posterior hypothalamic region as a key structure for the modulation of aggression. In the 1960s, patients with severe aggressive disorder, frequently associated with intellectual disability, were treated by bilateral stereotactic lesioning of the posterior hypothalamic area, with efficacy. This therapy was later abandoned because of issues related to the misuse of psychosurgery. In the last 2 decades, however, the same diencephalic target has been selected for the reversible treatment by deep brain stimulation, with success. This chapter presents a comprehensive approach to posterior hypothalamic surgery for the treatment of severely aggressive patients and discusses the experimental steps that allowed this surgical target to be selected. Surgical experiences are reported, together with considerations on target features and related encephalic circuits.

Selective modulation of human wakefulness -surgical targeting of brainstem arousal pathways

Selective modulation of human wakefulness -surgical targeting of brainstem arousal pathways

Progressive Orbitotomy and Graduated Expansion of the Supraorbital Keyhole: A Comparison with Alternative Minimally Invasive Approaches to the Paraclinoid Region

Various minimally invasive approaches, such as supraorbital (SO), minipterional (MPT), and translateral orbital (TLO), can access the paraclinoid region. Studies have described these approaches individually but have not directly compared all of them in the same anatomic specimen. Using virtual reality models generated from computed tomography studies of living subjects, we simulated TLO, MPT, and variations of SO approaches, without and with removal of the orbital rim and sphenoid wing. We measured the area of freedom (AOF), distance, and angle of attack to 4 paraclinoid targets: anterior clinoid process, optic foramen, lateral superior orbital fissure, and maxillary strut. For superiorly positioned targets, such as anterior clinoid process and optic foramen, MPT provided a larger AOF compared with the supraorbital approach. However, with progressive drilling of the orbital roof and lesser wing of the sphenoid, the SO corridor AOF was equivalent to MPT at the anterior clinoid process and larger at the optic foramen (P= 0.003). To the lateral superior orbital fissure, TLO had the most limited AOF, and MPT had the greatest (P < 0.01 for all comparisons). For the maxillary strut, MPT, TLO, and SO with orbitotomy and sphenoidectomy all provided a similar AOF. For surgical targets in the paraclinoid region, MPT provided a greater AOF and shorter distance compared with TLO and limited SO approaches. With progressive enlargement of the SO corridor, SO with orbitotomy and sphenoidectomy matched and occasionally superseded the AOF of MPT. However, the AOF to inferomedial targets such as the maxillary strut was similar among all approaches.

A compact stereotactic system for image-guided surgical intervention

Objective. Stereotactic technology enables fine navigation to small structures in the human body. While current stereotactic systems facilitate accurate targeting, they are mechanically cumbersome and limited in scope. Here, we hypothesized that a stereotactic system could be developed with a reduced footprint while maintaining broad targeting capabilities in order to improve versatility in frame placement location and surgical workflow. Approach. We designed a stereotactic system around the center-of-arc principle, with mechanical properties that would enable a compact design and ample targeting and trajectory maneuverability. To examine the opportunity for a low-cost rapidly-deployable system we developed two fabrication variants, one using three dimensional (3D)-printing and the other using conventional machining. Mechanical and image-guided accuracies were tested in phantom studies using magnetic resonance imaging (MRI) and computed tomography. Using human cadaver head specimens, we assessed the system’s surgical workflow and its ability to reliably and accurately implant electrodes in deep brain stimulation (DBS) surgery. Main results. We developed a small 7.7 × 5.4 cm2 device platform that rigidly mounts to curvilinear bone and supports the attachment of surgical instrumentation. Attachment of two surgical instruments, an imaging localizer and a compact targeting device, demonstrated successful MRI-guided intervention in phantom studies with a vector error of 1.79 ± 0.41 mm. Evaluation of the 3D-printed system for DBS surgery confirmed ease of device platform attachment and instrument functionality, as well as demonstrated a surgical targeting accuracy of 1.83 ± 0.15 mm. In addition, we found the surgical time to be 78.3 ± 5.4 min for bilateral electrode implantation. Significance. We developed a light and compact stereotactic system whose accuracy is on par with those used clinically. This technology is suitable for clinical translation and its flexibility in positioning will seamlessly expand the capabilities for stereotaxy to treat a wide range of conditions, both within neurosurgery and beyond.

Connectome biomarkers of drug-resistant epilepsy.

Drug-resistant epilepsy (DRE) considerably affects patient health, cognition, and well-being, and disproportionally contributes to the overall burden of epilepsy. The most common DRE syndromes are temporal lobe epilepsy related to mesiotemporal sclerosis and extratemporal epilepsy related to cortical malformations. Both syndromes have been traditionally considered as "focal," and most patients benefit from brain surgery for long-term seizure control. However, increasing evidence indicates that many DRE patients also present with widespread structural and functional network disruptions. These anomalies have been suggested to relate to cognitive impairment and prognosis, highlighting their importance for patient management. The advent of multimodal neuroimaging and formal methods to quantify complex systems has offered unprecedented ability to profile structural and functional brain networks in DRE patients. Here, we performed a systematic review on existing DRE network biomarker candidates and their contribution to three key application areas: (1) modeling of cognitive impairments, (2) localization of the surgical target, and (3) prediction of clinical and cognitive outcomes after surgery. Although network biomarkers hold promise for a range of clinical applications, translation of neuroimaging biomarkers to the patient's bedside has been challenged by a lack of clinical and prospective studies. We therefore close by highlighting conceptual and methodological strategies to improve the evaluation and accessibility of network biomarkers, and ultimately guide clinically actionable decisions.

Model-Based Image Updating for Brain Shift in Deep Brain Stimulation Electrode Placement Surgery.

The efficacy of deep brain stimulation (DBS) depends on accurate placement of electrodes. Although stereotactic frames enable co-registration of image-based surgical planning and the operative field, the accuracy of electrode placement can be degraded by intra-operative brain shift. In this study, we adapted a biomechanical model to estimate whole brain displacements from which we deformed preoperative CT (preCT) to generate an updated CT (uCT) that compensates for brain shift. We drove the deformation model using displacement data derived from deformation in the frontal cortical surface that occurred during the DBS intervention. We evaluated 15 patients, retrospectively, who underwent bilateral DBS surgery, and assessed the accuracy of uCT in terms of target registration error (TRE) relative to a CT acquired post-placement (postCT). We further divided subjects into large (Group L) and small (Group S) deformation groups based on a TRE threshold of 1.6mm. Anterior commissure (AC), posterior commissure (PC) and pineal gland (PG) were identified on preCT and postCT and used to quantify TREs in preCT and uCT. In the group of large brain deformation, average TREs for uCT were 1.11 ± 0.13 and 1.07 ± 0.38 mm at AC and PC, respectively, compared to 1.85 ± 0.17 and 0.92 ± 0.52 mm for preCT. The model updating approach improved AC localization but did not alter TREs at PC. This preliminary study suggests that our image updating method may compensate for brain shift around surgical targets of importance during DBS surgery, although further investigation is warranted before conclusive evidence will be available. With further development and evaluation, our model-based image updating method using intraoperative sparse data may compensate for brain shift in DBS surgery efficiently, and have utility in updating targeting coordinates.

Association of Preoperative Visual Hallucinations With Cognitive Decline After Deep Brain Stimulation for Parkinson's Disease.

Deep brain stimulation (DBS) is effective for the motor symptoms of Parkinson's disease (PD). Although most patients benefit with minimal cognitive side effects, cognitive decline is a risk, and there is little available evidence to guide preoperative risk assessment. Visual illusions or visual hallucinations (VHs) and impulse-control behaviors (ICBs) are relatively common complications of PD and its treatment and may be a marker of more advanced disease, but their relationship with postoperative cognition has not been established. The authors aimed to determine whether any preoperative history of VHs or ICBs is associated with cognitive change after DBS. Retrospective chart review identified 54 patients with PD who received DBS of the subthalamic nucleus or globus pallidus internus and who completed both pre- and postoperative neuropsychological testing. Linear regression models were used to assess whether any preoperative history of VHs or ICBs was associated with changes in attention, executive function, language, memory, or visuospatial cognitive domains while controlling for surgical target and duration between evaluations. The investigators found that a history of VHs was associated with declines in attention (b=-4.04, p=0.041) and executive function (b=-4.24, p=0.021). A history of ICBs was not associated with any significant changes. These results suggest that a history of VHs may increase risk of cognitive decline after DBS; thus, specific preoperative counseling and targeted remediation strategies for these patients may be indicated. In contrast, a history of ICBs does not appear to be associated with increased cognitive risk.

Globus Pallidus Internus (GPi) Deep Brain Stimulation for Parkinson's Disease: Expert Review and Commentary.

IntroductionThe globus pallidus internus (GPi) region has evolved as a potential target for deep brain stimulation (DBS) in Parkinson’s disease (PD). DBS of the GPi (GPi DBS) is an established, safe and effective method for addressing many of the motor symptoms associated with advanced PD. It is important that clinicians fully understand this target when considering GPi DBS for individual patients.MethodsThe literature on GPi DBS in PD has been comprehensively reviewed, including the anatomy, physiology and potential pitfalls that may be encountered during surgical targeting and post-operative management. Here, we review and address the implications of lead location on GPi DBS outcomes. Additionally, we provide a summary of randomized controlled clinical trials conducted on DBS in PD, together with expert commentary on potential applications of the GPi as target. Finally, we highlight future technologies that will likely impact GPi DBS, including closed-loop adaptive approaches (e.g. sensing-stimulating capabilities), advanced methods for image-based targeting and advances in DBS programming, including directional leads and pulse shaping.ResultsThere are important disease characteristics and factors to consider prior to selecting the GPi as the DBS target of PD surgery. Prior to and during implantation of the leads it is critical to consider the neuroanatomy, which can be defined through the combination of image-based targeting and intraoperative microelectrode recording strategies. There is an increasing body of literature on GPi DBS in patients with PD suggesting both short- and long-term benefits. Understanding the GPi target can be useful in choosing between the subthalamic (STN), GPi and ventralis intermedius nucleus as lead locations to address the motor symptoms and complications of PD.ConclusionGPi DBS can be effectively used in select cases of PD. As the ongoing DBS target debate continues (GPi vs. STN as DBS target), clinicians should keep in mind that GPi DBS has been shown to be an effective treatment strategy for a variety of symptoms, including bradykinesia, rigidity and tremor control. GPi DBS also has an important, direct anti-dyskinetic effect. GPi DBS is easier to program in the outpatient setting and will allow for more flexibility in medication adjustments (e.g. levodopa). Emerging technologies, including GPi closed-loop systems, advanced tractography-based targeting and enhanced programming strategies, will likely be future areas of GPi DBS expansion. We conclude that although the GPi as DBS target may not be appropriate for all PD patients, it has specific clinical advantages.Electronic supplementary materialThe online version of this article (10.1007/s40120-020-00220-5) contains supplementary material, which is available to authorized users.

Machine Learning's Application in Deep Brain Stimulation for Parkinson's Disease: A Review.

Deep brain stimulation (DBS) is a surgical treatment for advanced Parkinson’s disease (PD) that has undergone technological evolution that parallels an expansion in clinical phenotyping, neurophysiology, and neuroimaging of the disease state. Machine learning (ML) has been successfully used in a wide range of healthcare problems, including DBS. As computational power increases and more data become available, the application of ML in DBS is expected to grow. We review the literature of ML in DBS and discuss future opportunities for such applications. Specifically, we perform a comprehensive review of the literature from PubMed, the Institute for Scientific Information’s Web of Science, Cochrane Database of Systematic Reviews, and Institute of Electrical and Electronics Engineers’ (IEEE) Xplore Digital Library for ML applications in DBS. These studies are broadly placed in the following categories: (1) DBS candidate selection; (2) programming optimization; (3) surgical targeting; and (4) insights into DBS mechanisms. For each category, we provide and contextualize the current body of research and discuss potential future directions for the application of ML in DBS.

Generalized Dystonia Treated With Deep Brain Stimulator: An Institutional Single Surgeon Experience.

IntroductionDystonia can cause severe disability when left untreated. Once a patient has exhausted medical management, surgical intervention may be the only treatment option. Although not curative, deep brain stimulation has been shown to be beneficial for patients affected by this condition. Our study sought to review patients undergoing deep brain stimulation for medically refractory dystonia to assess outcomes.MethodsOur institution's operative database was reviewed retrospectively for all patients undergoing deep brain stimulator placement over the last six years. These medical records were reviewed for the severity of dystonia preoperatively and followed postoperatively for 24 months, focusing on the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). Patients with less than two-year postoperative follow-up were excluded from the study. The patients were further stratified by age into Group A, consisting of patients less than 40 years old, and Group B, patients greater than or equal to 40 years old. Other attributes such as age, sex, age of disease onset, disease duration at the time of surgery, genetic tests for dystonia-related genes, and any complication associated with surgery were also reviewed.ResultsFour hundred fifty-five operative cases for deep brain stimulator placement were reviewed, and 16 patients met inclusion criteria for the study. The mean age for our patient cohort was 43.75 years, with four males and 12 females. The average time from the age of disease onset to time of surgery was 9.7 years for Group A and 10.8 years for Group B; the overall average was 10.3 years. All patients had globus pallidus interna (GPi) as their surgical target. The first incidence of a statistically significant decrease in BFMDRS score was noted at three months postoperatively (p<0.001) when compared to preoperative values. Fourteen patients in our cohort underwent preoperative genetic testing for DYT gene mutations, out of which four were found to have a mutation.ConclusionOur review of outcomes for primary generalized dystonia at our institution found that deep brain stimulator targeting the GPi is safe and effective. We found an overall 88% response rate with younger patients (< 40-year-old) showing a better response at two years than older patients.

Percutaneous endoscopic transforaminal and interlaminar lumbar discectomy for cranially migrated disc hernia

Objective. To evaluate clinical outcomes, safety, and technical peculiarities of percutaneous endoscopic transforaminal and interlaminar removal of the lumber spine cranially migrated disc hernias. Material and Methods. In 2015–2018, percutaneous endoscopic transforaminal and interlaminar removal of cranially migrated hernias of the lumbar spine was performed in 53 patients (23 men and 30 women): 2 (3.8 %) at L2–L3 level, 13 (24.5 %) at L3–L4, 18 (34.0 %) at L4–L5, and 20 (37.7 %) at L5–S1. The age of patients ranged from 25 to 76 years and averaged 43.4 ± 11.6 years. Transforaminal approach was performed at the L4–L5 level and higher (62.3 % of cases), and interlaminar approach – at the L5–S1 level (37.7 %). Based on MRI, hernias with cranial migration were divided into zones: zone I – hernias with migration to the lower edge of the superjacent vertebra pedicle – 21 (39.6 %) patients; and zone II – hernias with migration above this border – 32 (60.4 %). Results were evaluated using ODI, VAS, and the McNab scale. Statistical analysis of VAS indicators (leg and back pain) and ODI scores before and after surgery was performed using the R and Microsoft Excel 2007 software. Results. Data collection was carried out using patient questionnaires at in-person examination, telephone interviews and electronic communications. Follow-up data of different terms were monitored in all patients. In one case (when mastering this technology), at the second stage, microdiscectomy was performed at the L4–L5 level for a residual hernia fragment in migration zone II, and in another case, a conversion into microdiscectomy was performed at L3–L4 level with a hernia in zone II due to lack of venous bleeding control in a patient receiving anticoagulants. In other patients, the mean VAS scores of preoperative radicular and axial pain decreased from 7.5 ± 1.4 and 3.8 ± 1.2 to 1.4 ± 1.2 and 3.5 ± 1.3, respectively, on the next day, to 1.7 ± 1.4 and 3.2 ± 1.1 in 1 month, to 1.5 ± 1.3 and 2.8 ± 1.4 in 6 months, to 1.6 ± 1.2 and 2.0 ± 1.3 in 12 months, and to 1.6 ± 1.2 and 2.0 ± 1.3 in 24 months after surgery. In the long-term follow-up period, no radicular leg pain was observed in any patient. According to the McNab scale, up to 6 months treatment results were assessed as excellent by 19 (35.8 %) patients, and as good – by 32 (60.3 %). In the case of lumbar pain in the long term period, blockade of facet joints and radiofrequency ablation of the medial nerve branch were performed. Relapse of hernias and instability of the operated spinal segment were not revealed. The average ODI score improved from 66.4 ± 7.2 to 20.5 ± 3.2 in 1 month, to 13.6 ± 2.1 in 6 months, to 12.4 ± 2.3 in 12 months, and to 12.4 ± 2.3 in 24 months after surgery. Conclusion. Percutaneous endoscopic transforaminal and interlaminar discectomy for cranially migrated lumbar disc hernia, while adhering the surgical technique target and exclusion criteria, is a safe and effective method, avoids excessive resection of the bone-ligamentous structures of the spine, can prevent iatrogenic instability of the spinal motion segment, and promotes early postoperative activation and recovery of the patient. Cranially migrated disc henias have a low probability of recurrence.

Clinical Effectiveness of Peripheral Nerve Blocks for Diagnosis of Migraine Trigger Points

BACKGROUND: With a 13% global prevalence, migraine headaches (MH) are the most commonly diagnosed neurologic disorder and are a top 5 cause of visits to the emergency room. Surgical techniques—such as decompression and/or ablation of neurovasculature—have shown to provide relief in patients suffering from MH. Popular diagnostic modalities to identify trigger loci include handheld doppler exams and botulinum toxin injection. This article aims to establish the positive predictive value (PPV) of peripheral nerve blocks for identifying therapeutic surgical targets for MH surgery. METHODS: Charts of 36 patients were retrospectively analyzed. These patients underwent peripheral nerve blocks using 1% lidocaine with epinephrine and subsequent surgery on identified MH trigger points. Patients were grouped into successful and unsuccessful blocks and further categorized into successful and unsuccessful surgery subgroups. Group analysis was done using paired t tests and PPV calculations were done on subgroups. RESULTS: Mean postsurgical follow-up was 11.5 months. Prior to surgery, Migraine headache index of patients was 168.16 versus 43.69 after surgery (P < 0.001). Each of the components of Migraine headache index also significantly decreased: frequency (24.54 MH/mo versus 8.53; P < 0.001), intensity (7.33 versus 4.75; P < 0.001), and duration (0.8 days versus 0.39; P < 0.001). The PPV of diagnostic peripheral nerve blocks in identifying a MH trigger point responsive to surgical intervention was calculated to be 0.89 (95% CI, 1, 0.74). CONCLUSION: Peripheral nerve blocks serve as a clinical tool in mapping migraine trigger points for surgical intervention while offering more flexibility in their administration and recording as compared to established diagnostic methods.