A Brief Insight on Magnetic Resonance Conditional Neurosurgery Robots.

The brain is a delicate organ in the human body that requires extreme care. Brain-related diseases are unavoidable. Perse, neurosurgery is a complicated procedure that demands high precision and accuracy. Developing a surgical robot is a complex task. To date, there are only a handful of neurosurgery robots in the market that distinctly undergo clinical procedures. These robots have exorbitant cost that hinders the utmost care progress in the area as they are unaffordable. This paper looked at the historical perspective and presented insight literature of the magnetic resonance conditional stereotactic neurosurgery robots that find their ways in clinics, abandoning research projects and promising research yet to undergo clinical use. In addition, the study also gives a thorough insight into the advantage of magnetic resonance imaging modalities and magnetic resonance conditional robots and the future challenges in automation use. Image compatibility test data and accuracy results are also examined because they guarantee that these systems work correctly in particular imaging settings. The primary differences between these systems include actuation and control technologies, construction materials, and the degree of freedom. Thus, one system has an advantage over the other.

Fusion of Preoperative and Postoperative Imaging May Predict the Diagnostic Yield of Stereotactic Needle Brain Biopsies.

BACKGROUND: Stereotactic needle brain biopsy is a commonly used neurosurgical procedure. However, up to 15% of biopsies result in undiagnostic pathology reports. Repeat biopsy or continued management without a diagnosis are often considered after undiagnostic biopsies. There have been no reports about the role of postoperative imaging in predicting the diagnostic yield of stereotactic biopsies. METHODS: We retrospectively assessed all stereotactic biopsies performed over an 11-year period. We performed fusion of immediate postoperative computed tomography (CT) with preoperative MRI, to document whether the air bubble in the postoperative CT was located within the targeted lesion. We then evaluated the association of this fusion-based accuracy assessment with the diagnostic yield of the biopsy. RESULTS: Fewer than 5% of biopsies did not have an air bubble on postoperative CT. A total of 226 biopsies were performed for 219 patients. In our sample, 213 of 226 biopsies were accurate (94.2% accuracy rate), and 203 of 226 biopsies gave a definitive diagnosis (89.8% diagnostic rate). In those cases where the fusion was accurate, the diagnostic rate was 93.9%. When the fusion was inaccurate, the diagnostic rate was only 23.1% (odds ratio 51.5, 95% confidence interval 12.6-210.44, P < 0.001). Of all patient, imaging, surgical, and admission parameters, the only parameter that correlated with diagnostic outcome of the biopsy was the fusion construct accuracy. CONCLUSIONS: Fusion of immediate postoperative CT with preoperative imaging is predictive of the diagnostic rate. In cases where the pathology report following a biopsy is not diagnostic, this fusion may be useful in making decisions regarding repeat biopsy or considering other diagnostic options.

Use of Stereoelectroencephalography Beyond Epilepsy: A Systematic Review.

BACKGROUND: Stereoelectroencephalography (sEEG) is an increasingly popular surgical technique used clinically to study neural circuits involved in medication-refractory epilepsy, and it is concomitantly used in the scientific investigation of neural circuitry underlying behavior. METHODS: Using PRISMA guidelines, the U.S. National Library of Medicine at the National Institutes of Health PubMed database was queried for investigational or therapeutic applications of sEEG in human subjects. Abstracts were analyzed independently by 2 authors for inclusion or exclusion. RESULTS: The study search identified 752 articles, and after exclusion criteria were applied, 8 studies were selected for in-depth review. Among those 8 studies, 122 patients were included, with indications ranging from schizophrenia to Parkinson disease. All the included studies were single-institution case series representing level IV scientific evidence. CONCLUSIONS: sEEG is an important method in epilepsy surgery that could be applied to other neurologic and psychiatric diseases. Information from these studies could provide additional pathophysiologic information and lead to further development and refinement of neuromodulation therapies for such conditions.

A novel surgical technique for spontaneous intracerebral hematoma evacuation.

Stereotactic removal of intracerebral hematoma is a routine procedure for treating hypertensive intracerebral hemorrhage, but the complex sequence of operations limits its adoption. We explored the application of a novel surgical technique for the removal of spontaneous intracerebral hematomas. The surgical technique based on computed tomography (CT) images was used in hematoma projection and surgical planning. Markers placed on the scalp based on an Android smartphone app allowed the installation of a stereotactic head frame to facilitate the selection of the best trajectory to the hematoma center for removing the hematoma. Forty-two patients with spontaneous intracerebral hemorrhage were included in the study, including 33 cases of supratentorial hemorrhage, 5 cases of cerebellum hemorrhage, and 4 cases of brain stem hemorrhage. The surgical technique combined with the stereotactic head frame helped the tip of the drainage tube achieve the desired position. The median surgical time was 45 (range 25-75) min. The actual head frame operating time was 10 (range 5-15) min. Target alignment performed by the surgical technique was accurate to ≤ 10.0 mm in all 42 cases. No patient experienced postoperative rebleeding. In 33 cases of supratentorial intracerebral hemorrhage, an average evacuation rate of 77.5% was achieved at postoperative 3.1 ± 1.4 days, and 29 (87.9%) cases had a residual hematoma of < 15 ml. The novel surgical technique helped to quickly and effortlessly localize hematomas and achieve satisfactory hematoma removal. Clinical application of the stereotactic head frame was feasible for intracerebral hemorrhage in various locations.

Automated neurosurgical stereotactic planning for intraoperative use: a comprehensive review of the literature and perspectives.

The creation of intracranial stereotactic trajectories, from entry point to target point, is still mostly done manually by the neurosurgeon. The development of automated stereotactic planning tools has been described in the literature. This systematic review aims to assess the effectiveness of stereotactic planning procedure automation and develop tools for patients undergoing neurosurgical stereotactic procedures. PubMed/MEDLINE, EMBASE, Google Scholar, CINAHL, PsycINFO, and Cochrane Register of Controlled Trials databases were searched from inception to September 1, 2019, at the exception of Google Scholar (from 1 January 2010 to September 1, 2019) in French and English. Eligible studies included all studies proposing automated stereotactic planning. A total of 1543 studies were screened. Forty-two studies were included in the systematic review, including 18 (42.9%) conference papers. The surgical procedures planned automatically were mainly deep brain stimulation (n = 14, 33.3%), stereoelectroencephalography (n = 12, 28.6%), and not specified (n = 10, 23.8%). The most frequently used surgical constraints to plan the trajectory were blood vessels (n = 32, 76.2%), cerebral sulci (n = 27, 64.3%), and cerebral ventricles (n = 23, 54.8%). The distance from blood vessels ranged from 1.96 to 4.78 mm for manual trajectories and from 2.47 to 7.0 mm for automated trajectories. At least one neurosurgeon was involved in 36 studies (85.7%). The automated stereotactic trajectory was preferred in 75.4% of the studied cases (range 30-92.9). Only 3 (7.1%) studies were multicentric. No study reported prospective use of the planning software. Stereotactic planning automation is a promising tool to provide valuable stereotactic trajectories for clinical applications.

Outcomes of stereoelectroencephalography exploration at an epilepsy surgery center.

OBJECTIVES: Epilepsy surgery is offered in resistant focal epilepsy. Non-invasive investigations like scalp video EEG monitoring (SVEM) help delineate epileptogenic zone. Complex cases may require intracranial video EEG monitoring (IVEM). Stereoelectroencephalography (SEEG)-based intracerebral electrode implantation has better spatial resolution, lower morbidity, better tolerance, and superiority in sampling deep structures. Our objectives were to assess IVEM using SEEG with regard to reasoning behind implantation, course, surgical interventions, and outcomes. MATERIALS AND METHODS: Seventy-two admissions for SEEG from January 2014 to December 2018 were included in the study. Demographic and clinical data were retrospectively collected. RESULTS: The cohort comprised of 69 adults of which 34 (47%) had lesional MRI. Reasons for SEEG considering all cases included non-localizing ictal onset (76%), ictal-interictal discordance (21%), discordant semiology (17%), proximity to eloquent cortex (33%), nuclear imaging discordance (34%), and discordance with neuropsychology (19%). Among lesional cases, additional reasons included SVEM discordance (68%) and dual or multiple pathology (47%). Forty-eight patients (67%) were offered resective surgery, and 41 underwent it. Twenty-three (56%) had at least one year post-surgical follow-up of which 14 (61%) had Engels class I outcome. Of the remaining 23 who were continued on medical management, 4 (17%) became seizure-free and 12 (51%) had reduction in seizure frequency. CONCLUSION: SEEG monitoring is an important and safe tool for presurgical evaluation with good surgical and non-surgical outcomes. Whether seizure freedom following non-surgical management could be related to SEEG implantation, medication change, or natural course needs to be determined.

Mechanisms and Risk Factors Contributing to Visual Field Deficits following Stereotactic Laser Amygdalohippocampotomy.

Selective laser amygdalohippocampotomy (SLAH) is a minimally invasive surgical treatment for medial temporal lobe epilepsy. Visual field deficits (VFDs) are a significant potential complication. The objective of this study was to determine the relationship between VFDs and potential mechanisms of injury to the optic radiations and lateral geniculate nucleus. We performed a retrospective cross-sectional analysis of 3 patients (5.2%) who developed persistent VFDs after SLAH within our larger series (n = 58), 15 healthy individuals and 10 SLAH patients without visual complications. Diffusion tractography was used to evaluate laser catheter penetration of the optic radiations. Using a complementary approach, we evaluated evidence for focal microstructural tissue damage within the optic radiations and lateral geniculate nucleus. Overablation and potential heat radiation were assessed by quantifying ablation and choroidal fissure CSF volumes as well as energy deposited during SLAH.SLAH treatment parameters did not distinguish VFD patients. Atypically high overlap between the laser catheter and optic radiations was found in 1/3 VFD patients and was accompanied by focal reductions in fractional anisotropy where the catheter entered the lateral occipital white matter. Surprisingly, lateral geniculate tissue diffusivity was abnormal following, but also preceding, SLAH in patients who subsequently developed a VFD (all p = 0.005).In our series, vision-related complications following SLAH, which appear to occur less frequently than following open temporal lobe -surgery, were not directly explained by SLAH treatment parameters. Instead, our data suggest that variations in lateral geniculate structure may influence susceptibility to indirect heat injury from transoccipital SLAH.

Biological Cardiac Tissue Effects of High-Energy Heavy Ions - Investigation for Myocardial Ablation.

Noninvasive X-ray stereotactic treatment is considered a promising alternative to catheter ablation in patients affected by severe heart arrhythmia. High-energy heavy ions can deliver high radiation doses in small targets with reduced damage to the normal tissue compared to conventional X-rays. For this reason, charged particle therapy, widely used in oncology, can be a powerful tool for radiosurgery in cardiac diseases. We have recently performed a feasibility study in a swine model using high doses of high-energy C-ions to target specific cardiac structures. Interruption of cardiac conduction was observed in some animals. Here we report the biological effects measured in the pig heart tissue of the same animals six months after the treatment. Immunohistological analysis of the target tissue showed (1.) long-lasting vascular damage, i.e. persistent hemorrhage, loss of microvessels, and occurrence of siderophages, (2.) fibrosis and (3.) loss of polarity of targeted cardiomyocytes and wavy fibers with vacuolization. We conclude that the observed physiological changes in heart function are produced by radiation-induced fibrosis and cardiomyocyte functional inactivation. No effects were observed in the normal tissue traversed by the particle beam, suggesting that charged particles have the potential to produce ablation of specific heart targets with minimal side effects.

The Origins of Human Functional Stereotaxis: A Reappraisal.

In order to shed light on the first application of human functional stereotactic neurosurgery, whether it was in the realm of movement disorders, as has been claimed repeatedly, or in the realm of psychiatry, a review of the original scholarly literature was conducted. Tracking and scrutinising original publications by Spiegel and Wycis, the pioneers of human stereotactic neurosurgery, it was found that its origin and the very incentive for its development and first clinical use were to avoid the side effects of frontal leucotomy. The first applications of functional stereotactic neurosurgery were in performing dorsomedial thalamotomies in psychiatric patients; it was only later that the stereotactic technique was applied in patients with chronic pain, movement disorders and epilepsy. Spiegel and Wycis' first functional stereotactic operations were for obsessive-compulsive disorder, schizophrenia, and other psychiatric conditions.

Clinical Perspectives on Psychiatric Neurosurgery.

INTRODUCTION: Surgical interventions such as stereotactic radiosurgery and magnetic resonance-guided focused ultrasound, and neuromodulatory interventions such as deep brain stimulation (DBS) and vagal nerve stimulation, are under investigation to remediate psychiatric conditions resistant to conventional therapies involving drugs and psychological supports. OBJECTIVE: Given the complicated history of psychiatric neurosurgery and its renaissance today, we sought to examine current perceptions and predictions about the field among practicing functional neurosurgeons. METHODS: We designed a 51-question online survey comprising Likert-type, multiple-choice, and rank-order questions and distributed it to members of the American Society for Stereotactic and Functional Neurosurgery (ASSFN). Descriptive and inferential statistical analyses were performed on the data. RESULTS: We received 38 completed surveys. Half (n = 19) of responders reported devoting at least a portion of their clinical practice to psychiatric neurosurgery, utilizing DBS and treating obsessive compulsive disorder (OCD) most frequently overall. Respondents indicated that psychiatric neurosurgery is more medically effective (OR 0, p = 0.03242, two-sided Fisher's exact test) and has clearer clinical indications for the treatment of OCD than for the treatment of depression (OR 0.09775, p = 0.005137, two-sided Fisher's exact test). Seventy-one percent of all respondents (n = 27) supported the clinical utility of ablative surgery in modern neuropsychiatric practice, 87% (n = 33) agreed that ablative procedures constitute a valid treatment alternative to DBS for some patients, and 61% (n = 23) agreed that ablative surgery may be an acceptable treatment option for patients who are unlikely to comply with postoperative care. CONCLUSIONS: This up-to-date account of practices, perceptions, and predictions about psychiatric neurosurgery contributes to the knowledge about evolving attitudes over time and informs priorities for education and further surgical innovation on the psychiatric neurosurgery landscape.

Impact of Powdered Vancomycin on Preventing Surgical Site Infections in Neurosurgery: A Systematic Review and Meta-analysis.

BACKGROUND: Surgical site infections (SSIs) after spine and brain surgery present a major burden to patients and hospitals by increasing morbidity, mortality, and healthcare costs. OBJECTIVE: To review available literature investigating the role of intrawound powdered vancomycin against SSIs after neurosurgical operations. METHODS: All randomized and observational English language studies of intrawound powdered vancomycin use in spinal and cranial surgery were included and analyzed using random-effects modeling. RESULTS: In spine surgery (25 studies with 16 369 patients), patients in the vancomycin group had a significantly lower risk for any SSI (odds ratio [OR]: 0.41; 95% confidence interval [CI]: 0.30-0.57; P < .001; I2 = 47%). However, when separate analyses were conducted for superficial and deep SSIs, a significant difference was found only for deep (OR: 0.31; 95% CI: 0.22-0.45; P < .001; I2 = 29%). Subgroup analyses for different vancomycin powder dosages (1 g vs 2 g vs composite dose) did not point to any dose-related effect of vancomycin. In cranial surgery (6 studies with 1777 patients), use of vancomycin was associated with a significantly lower risk for SSIs (OR: 0.33; 95% CI: 0.18-0.60; P = .0003; I2 = 45%). In meta-regression analysis, trial-level variability of diabetes had no influence on the association of vancomycin powder use with SSIs. CONCLUSION: Use of vancomycin powder in spinal and cranial surgery might be protective against SSIs, especially against deep SSIs. No dose-related effect of vancomycin powder was identified. However, caution is needed in the clinical interpretation of these results, owing to the observational design of the included studies in this meta-analysis.

Improvement of Hypothalamic Hamartoma-Related Psychiatric Disorder After Stereotactic Laser Ablation: Case Report and Review of Literature.

BACKGROUND: Hypothalamic hamartomas (HHs) are nonneoplastic congenital malformations associated with refractory epilepsy and behavioral disorders. Improvement in behavioral functioning following resection of HHs has been reported. Stereotactic laser ablation (SLA), a minimally invasive technique, has been used for the treatment of HH-related epilepsy. We report the case of child with an HH, gelastic seizures, and severe psychiatric dysfunction who was successfully treated via SLA therapy. CASE DESCRIPTION: The patient was an 11-year-old female with a history of central hypothyroidism, precocious puberty, and localization-related epilepsy thought to be secondary to an HH. She had a significant psychiatric history including attention deficit hyperactivity disorder, depressed mood, impulsivity, threatening behavior, and suicidal ideation requiring management with dexmethylphenidate, bupropion, and aripiprazole. Seizure onset occurred at age 7, and her semiology included nighttime hypermotor seizures and uncontrollable laughing spells thought to be gelastic seizures. Her hypermotor seizures were successfully managed with oxcabazepine monotherapy, but she continued to have several weekly laughing spells and self-harming behavior. Her HH was successfully treated via SLA. Postoperatively, she remained neurologically intact and was discharged the next day. At her 6-month follow-up, she had a markedly improved affect and general mood. At 3 years postprocedure, she remains seizure free and has been weaned off her antiepileptic and antipsychotic medications. CONCLUSIONS: Severe behavioral dysfunction in the setting of an HH may constitute an indication for surgical intervention. The outcome of this case suggests there may be a role for SLA in the management of HH-related psychiatric dysfunction, even in patients with good seizure control.

Stereotaxy in rat models: Current state of the art, proposals to improve targeting accuracy and reporting guideline.

BACKGROUND: Stereotaxy is frequently employed in rodent models for precise brain injections or implantations. We intended to map the current practice in rat stereotaxy and list proposals to improve targeting accuracy. METHODS: We selected 235 publications on rat stereotaxy from the last 5 years. We collected data on the subjects, targets, coordinate system used, postoperative implant verification and analysis of subjects with off-target implants. RESULTS: Approximately 10,000 rats, mostly Sprague-Dawley and Wistar, were subjected to stereotaxy. Although referenced in 57% of the studies, only 10% of the subjects resembled those used in the Paxinos atlas. Popular procedures were injections (62%) and implantation of cannulas (20%) and electrodes (8%). Right-sided and bilateral targets were more often used than left-sided targets. Bregma served as a stereotaxic origin in 96% of the publications, although for 27% of the targets, the entry was closer to lambda. The Euclidian distance from the target to the interaural line midpoint and to lambda was shorter than to bregma in 38% and 5% of the cases, respectively. Bregma and the dura/brain surface were the most popular dorsoventral References Implantation accuracy was assessed almost exclusively histologically. 39% of the studies did not perform any accuracy check. The number of on-target implants was reported in only 8% of the studies. Only 15% of the publications reported that they excluded subjects with off-target implants. CONCLUSIONS: Although well-established, rat stereotaxy could be improved, mainly in acquiring target coordinates, selecting a stereotaxic origin and verifying and reporting accuracy.

How is stereotactic brain biopsy evolving? A multicentric analysis of a series of 421 cases treated in Rome over the last sixteen years.

OBJECTIVE: In recent decades, frame-based (FBB) and frame-less stereotactic brain biopsy (FLB) have played a crucial role in defining the diagnosis and management of expanding intracranial lesions in critical areas. During the same period, there have been significant advances in diagnostic imaging, a shift in surgical strategies towards extensive resection in gliomas and new molecular classification of brain tumors. Taking these advances into account, we have evaluated whether significant changes have occurred over the last sixteen years of our clinical practice in terms of frequency, indications, target selection, and the histologic results of stereotactic brain biopsy (SBB) procedures. PATIENTS AND METHODS: We analyzed a series of 421 SBB cases treated between January 2002 and June 2017 in three major neurosurgical institutes in Rome, serving a total of 1.5 million people. Within this series, 94.8% of patients underwent FBB, while, more recently, FLB was performed in 5.2% of cases. The entire period under consideration, running from 2002 to 2017, has been further stratified into four-year time-frames (2002-2005, 2006-2009, 2010-2013, 2014-2017) for the purpose of analysis. RESULTS: The diagnostic yield was 97%. Final diagnoses revealed tumors in 90% of cases and non-neoplastic masses in 7%, while 3% of cases were not conclusive. The morbidity rate was 3% (12 cases) and mortality was 0.7% (3 cases). Intra-operative frozen sections were made in 78% of biopsies. In our three institutes, the number of SBBs decreased steadily throughout the time-frames under consideration. We have also observed a statistically significant reduction in biopsy procedures in lobar lesions, while those performed on the basal ganglia increased and the number of SBBs of multiple masses and lesions of the corpus callosum remained stable. Primary central nervous system diagnosis of lymphomas (PCNSL) was the sole diagnosis whose incidence increased significantly. CONCLUSIONS: Over the last sixteen years, we have witnessed a significant decrease in SBB procedures and a modification in target selection and histologic results. Despite the significant evolution of neuroimaging, an accurate non-invasive diagnosis of intracranial expanding lesions has not yet been achieved. Furthermore, the most recent WHO classification of brain tumors (2016), which incorporates molecular and morphological features, has boosted the need for molecular processing of tissue samples in all expanding brain lesions. For these reasons, it is likely that SBBs will continue to be performed in specific cases, playing a significant role in diagnostic confirmation by providing tissue samples, so as to better assess the biology and the prognosis of cerebral lesions, as well as their sensitivity to standard radio-chemotherapy or to new molecular target therapies.

Value of Diffusion-Weighted Imaging in the Diagnosis of Postoperative Intracranial Infections.

BACKGROUND: Magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI), is an excellent tool for diagnosing intracranial infection, with limitations in previous neurosurgical intervention. This study aimed to evaluate the accuracy of DWI in the diagnosis of postoperative intracranial infection. METHODS: We retrospectively evaluated all consecutive patients with intracranial infection undergoing a neurosurgical intervention who had preoperative MRI, including DWI. Patients were divided into 2 groups: spontaneous intracranial infection (SI) and postoperative intracranial infection (PI). A control group (CG) of patients who had undergone brain surgery without any signs of subsequent infection was also included. Qualitatively, MRI data were evaluated for the presence of intracranial infection. Sensitivity, specificity, and positive and negative predictive values for PI as opposed to no infection were determined. Quantitatively, areas with diffusion restriction within the surgery/abscess cavity were identified for the 3 groups using semiautomated segmentation. Group differences regarding apparent diffusion coefficient (ADC) ratios were evaluated. Receiver operating characteristic curve analysis was used to identify a point in time beyond which ADC ratios might show reasonable discriminatory power between the PI and CG groups. RESULTS: A total of 78 patients were included (38 in the SI group, 20 in the PI group, 20 in the CG group). Sensitivity, specificity, and positive and negative predictive values in the diagnosis of PI were 80%, 95%, 4%, and 100%, respectively. Median ADC was significantly higher in the PI group compared with the SI group (0.98 vs. 0.69; P < 0.001) but lower compared with the CG group (1.24; P = 0.16). The analysis suggested a possible differentiation of PI and CG after a time interval of approximately 100 days/3 months. CONCLUSIONS: DWI is of limited value in evaluating postoperative brain infection. Our data show a trend toward DWI regaining its validity at approximately 3 months after surgery.

Long-Term Follow-Up After Radiosurgery of Papillary Tumor of Pineal Region: 2 Case Reports and Review of Literature.

BACKGROUND: Tumors of the pineal region are rare in adulthood, accounting for approximately 1% of intracranial neoplasms in this age range. Because of their rarity, it has proven to be difficult to establish the optimal therapy. Furthermore, microsurgical total resection in this eloquent location is associated with not low rates of morbidity. CASE DESCRIPTION: We describe 2 patients diagnosed with papillary tumors of the pineal region by stereotactic biopsy and referred for Gamma Knife radiosurgery after shunting for hydrocephalus. We report a long-term follow-up of 15 and 20 years, respectively, showing a good response to the treatment. CONCLUSIONS: After a diagnosis of papillary tumors of the pineal region, radiosurgery is an alternative treatment, with high local control and low morbidity.

Patterns of Clinical Use of Stereotactic Laser Ablation: Analysis of a Multicenter Prospective Registry.

BACKGROUND: Stereotactic laser ablation (SLA), also termed laser interstitial thermal therapy, is a minimally invasive procedure that is increasingly used in neurosurgery. We wished to examine how and whether SLA is changing the landscape of treatment options for neurosurgical patients. METHODS: Patients undergoing stereotactic laser ablation were prospectively enrolled in the Laser Ablation of Abnormal Neurological Tissue (LAANTERN) registry. Data from the first 100 enrolled patients are presented here. RESULTS: Clinical indications for SLA include treatment of primary intracranial tumors (48%; 81% being high-grade gliomas [HGGs]), brain metastases (BMs, 34%), epilepsy (16%), and other (2%). For HGGs, SLA was equally likely used for newly diagnosed (45%) or previously treated/recurrent lesions (55%, P = 0.54). By contrast, SLA was predominantly used as treatment for BMs in which radiation therapy/radiosurgery had failed (91%), with only 9% of SLAs performed as initial treatment for newly diagnosed lesions (P < 0.001). Of all SLAs performed, 45% of the procedures were in lieu of surgical resection, with 43% performed because the lesion was not accessible by conventional neurosurgical techniques. CONCLUSION: HGGs and BMs are the leading indications for SLA in the LAANTERN study. For HGGs, SLA is equally used in the presenting or previously treated/recurrent setting. For BMs, SLA is typically used in the recurrent setting. SLAs are equally likely to be performed for difficult-to-access lesions or in lieu of conventional open surgery.

Techniques for Stereotactic Neurosurgery: Beyond the Frame, Toward the Intraoperative Magnetic Resonance Imaging-Guided and Robot-Assisted Approaches.

The development of stereotaxy can be dated back 100 years. However, most stereotactic neurosurgery still relies on the workflow established about half a century ago. With the arrival of computer-assisted navigation, numerous studies to improve the neurosurgical technique have been reported, leading to frameless and magnetic resonance imaging (MRI)-guided/verified techniques. Frameless stereotaxy has been proved to be comparable to frame-based stereotaxy in accuracy, diagnostic yield, morbidity, and mortality. The incorporation of intraoperative MRI guidance in frameless techniques is considered an appealing method that could simplify workflow by reducing coregistration errors in different imaging modalities, conducting general anesthesia, and monitoring the surgical progress. In light of this situation, manually operated platforms have emerged for MRI-guided frameless procedures. However, these procedures could still be complicated and time-consuming because of the intensive manual operation required. To further simplify the procedure and enhance accuracy, robotics was introduced. Robots have superior capabilities over humans in certain tasks, especially those that are limited by space, accuracy demanding, intensive, and tedious. Clinical benefits have been shown in the recent surge of robot-assisted surgical interventions. We review the state-of-the-art intraoperative MRI-guided robotic platforms for stereotactic neurosurgery. To improve the surgical workflow and achieve greater clinical penetration, 3 key enabling techniques are proposed with emphasis on their current status, limitations, and future trends.

Laser ablation is effective for temporal lobe epilepsy with and without mesial temporal sclerosis if hippocampal seizure onsets are localized by stereoelectroencephalography.

OBJECTIVE: Selective laser amygdalohippocampotomy (SLAH) using magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) is emerging as a treatment option for drug-resistant mesial temporal lobe epilepsy (MTLE). SLAH is less invasive than open resection, but there are limited series reporting its safety and efficacy, particularly in patients without clear evidence of mesial temporal sclerosis (MTS). METHODS: We report seizure outcomes and complications in our first 30 patients who underwent SLAH for drug-resistant MTLE between January 2013 and December 2016. We compare patients who required stereoelectroencephalography (SEEG) to confirm mesial temporal onset with those treated based on imaging evidence of MTS. RESULTS: Twelve patients with SEEG-confirmed, non-MTS MTLE and 18 patients with MRI-confirmed MTS underwent SLAH. MTS patients were older (median age 50 vs 30 years) and had longer standing epilepsy (median 40.5 vs 5.5 years) than non-MTS patients. Engel class I seizure freedom was achieved in 7 of 12 non-MTS patients (58%, 95% confidence interval [CI] 30%-86%) and 10 of 18 MTS patients (56%, 95% CI 33%-79%), with no significant difference between groups (odds ratio [OR] 1.12, 95% CI 0.26-4.91, P = .88). Length of stay was 1 day for most patients (range 0-3 days). Procedural complications were rare and without long-term sequelae. SIGNIFICANCE: We report similar rates of seizure freedom following SLAH in patients with MTS and SEEG-confirmed, non-MTS MTLE. Consistent with early literature, these rates are slightly lower than typically observed with surgical resection (60%-80%). However, SLAH is less invasive than open surgery, with shorter hospital stays and recovery, and severe procedural complications are rare. SLAH may be a reasonable first-line surgical option for patients with both MTS and SEEG confirmed, non-MTS MTLE.

The Pioneering and Unknown Stereotactic Approach of Roeder and Orthner from Göttingen. Part II: Long-Term Outcome and Postmortem Analysis of Bilateral Pallidotomy in the Pre-Levodopa Era.

Before the advent of levodopa, pallidotomy was initially the most effective treatment for Parkinson disease, but it was soon superseded by thalamotomy. It is widely unknown that, similar to Leksell, 2 neurologists from Göttingen, Orthner and Roeder, perpetuated pallidotomy against the mainstream of their time. Postmortem studies demonstrated that true posterior and ventral pallidoansotomy sparing the overwhelming mass of the pallidum was accomplished. This was due to a unique and individually tailored stereotactic technique even allowing bilateral staged pallidotomies. In 1962, the long-term effects (3-year follow-up on average) of the first 18 out of 36 patients with staged bilateral pallidotomies were reported in great detail. Meticulous descriptions of each case indicate long-term improvements in parkinsonian rigidity and associated pain, as well as posture, gait, and akinesia (e.g., improved repetitive movements and arm swinging). Alleviation of tremor was found to require larger lesions than needed for suppression of rigidity. No improvement in speech, drooling, or seborrhea was observed. By 1962, the team had operated 13 patients with postencephalitic oculogyric crises with remarkable results (mean follow-up: 5 years). They also described alleviation of nonparkinsonian hyperkinetic disorders (e.g., hemiballism and chorea) with pallidotomy. The reported rates for surgical mortality and other complications had been remarkably low, even if compared to those reported after the revival of pallidotomy by Laitinen in the post-levodopa era. This applies also to bilateral pallidotomy performed with a positive risk-benefit ratio that has remained unparalleled to date. The intricate history of pallidotomy for movement disorders is incomplete without an appreciation of the achievements of the Göttingen group.