Management of Atypical Teratoid/Rhabdoid Tumors in the Pediatric Population: A Systematic Review and Meta-Analysis.

BACKGROUND: Atypical teratoid/rhabdoid tumors are rare and aggressive tumors that mainly affect children <3 years of age. Despite aggressive treatment, the overall survival rate for pediatric atypical teratoid/rhabdoid tumors remains poor. Due to their rarity, little is known regarding prognostic factors, and there is no official standard of treatment. METHODS: A comprehensive database search was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Search terms included "atypical teratoid rhabdoid tumor" and "atypical (teratoid OR rhabdoid) tumor." Variables of interest included, but were not limited to, age, sex, tumor location, treatment modality, extent of resection, and overall survival. RESULTS: The study included 294 articles and 936 patients. The median age of patients was 22 months. There was a significant difference in survival among patients receiving surgery compared with patients receiving nonoperative treatment (50.3 months vs. 28 months; P < 0.005). Extent of resection did not significantly improve survival (P = 0.832 for gross total resection, P = 0.650 for partial resection). Combination therapy with surgical resection, radiotherapy, and chemotherapy demonstrated the largest median overall survival (54.9 months) and significantly improved survival on multivariate analysis (hazard ratio, 0.48; 95% confidence interval, 0.23-0.97; P = 0.042). CONCLUSIONS: The results of this study indicate that while surgery is a crucial treatment modality for pediatric atypical teratoid/rhabdoid tumors, the effect of extent of resection is unclear. Multimodal therapy including surgery, radiotherapy, and chemotherapy is effective in improving overall survival. Future studies should focus on using larger datasets to efficiently account for confounding factors and biases.

Safety & feasibility of responsive neurostimulation in children with refractory epilepsy: A single-center experience.

OBJECTIVES: Responsive neurostimulation (RNS) is a relatively recent addition to the epilepsy surgery armory, gaining FDA approval in 2013 for use in adults with intractable focal epilepsy. Data for the use of RNS system in patients less than 18 years of age is limited. We aim to determine the safety and feasibility of RNS in children with refractory epilepsy. METHODS: A retrospective chart review was conducted for all patients who underwent RNS implantation at an urban tertiary children's hospital. Demographics of the patients were obtained, including age at the time of implant, MRI findings, seizure onset zone identification, and RNS targets. RESULTS: Out of a fourteen patient cohort, one patient had a post-operative complication of infection at surgical site requiring explantation. Thirteen out of 14 patients had immediate post-operative head imaging that was negative for hemorrhage, infarction, or skull fracture; one patient did not undergo head imaging. No patients reported a worsening clinical seizure frequency at a 6-month follow up visit. In the subset of patients who were implanted with RNS and did not undergo concurrent resections, there was a statistically significant reduction in the average number of long episodes at the most recent visit when compared to the 1-month post-operative visit (p = 0.0268). CONCLUSIONS: RNS is a feasible and safe option for children as young as six years with refractory epilepsy when appropriate seizure focus identification has been performed with stereo CT and stereo EEG evaluations, and can be used in conjunction with other surgical epilepsy treatment modalities. Two canister RNS placement is achievable for patients with a broad epileptogenic network or multifocal seizure onset zones.

Using the ROSA Robot for Lesion Resection: A Novel Adapter With Added Applications.

BACKGROUND: The ROSA robot (Medtech) has been shown to be a useful instrument in the surgeon's armamentarium for accurate placement of stereotactic electroencephlography depth electrodes. However, it has not yet been used as a navigation tool for lesion resection. Here, we demonstrate a novel adapter that allows the surgeon to use the ROSA robot with the NICO BrainPath for the resection of deep lesions. OBJECTIVE: To demonstrate the utility of an adapter that allows the ROSA robot to be used in conjunction with the NICO BrainPath tube for lesion resection. METHODS: A stainless steel adapter was made based on the specifications of the ROSA pointer instrument. Two 3D printed models were used to undergo a "mock" surgery using the adapter to assess for ease of use and applicability. RESULTS: The adapter allowed for adequate accessibility and visualization of the tumors in both mock cases. In addition, the stability of the ROSA robot and the design of the adapter allowed the surgeon to rest their hands on the instrument without jeopardizing its position. CONCLUSION: The ROSA adapter allowed for accurate navigation and exposure of these lesions, combining the accuracy and stability of the ROSA robot, with the retraction of the BrainPath tube.

Evaluating vagus nerve stimulation treatment with heart rate monitoring in pediatric patients with intractable epilepsy.

PURPOSE: Vagus nerve stimulators (VNS) have emerged as an effective treatment modality for pediatric patients suffering from intractable, drug-resistant epilepsy. Newer devices, AspireSR™ Model 106 and the SenTiva™ Model 1000 (VNS TherapyⓇ, LivaNova™), contain an "auto-stimulation" feature that detects ictal tachycardia and transmits pulsations to attenuate seizures. However, the exact benefits of auto-stimulation compared to its risks still merit further exploration. This study evaluates the utility of these specific devices in a heterogeneous population of pediatric and young adult patients with intractable epilepsy. METHODS: This is a retrospective chart review of 55 patients who underwent either VNS insertion with or without an auto-stimulation-enabled VNS device at a single level four epilepsy center. Seizure frequency, seizure subtype, side effects, and change in anti-seizure medication load both before and after VNS implantations were collected from patient self-reporting at the time of VNS insertion and 12 months following implantation. Information regarding output current, auto-stimulation current, duty cycling, and auto-stimulation threshold of the device was obtained from documented VNS interrogation for patients with auto-stimulation-enabled VNS devices. RESULTS: Patients with auto-stimulation-enabled VNS devices had a mean 56.0% (SD = 0.414) seizure frequency reduction 12 months post-VNS insertion, while patients without auto-stimulation-enabled VNS devices had a mean 41.6% (SD = 0.456) seizure frequency reduction during the same interval. The mean seizure frequency reduction 12 months post-VNS insertion for patients with a SenTiva™ 1000 model was 66.0% (SD = 0.426). For patients with auto-stimulation-enabled VNS devices, post-treatment seizure reduction was significantly correlated with daily auto-stimulation activation (R = 0.432, p = 0.025). CONCLUSION: This study supports the clinical safety and utility of auto-stimulation-enabled VNS models, specifically the SenTiva™ 1000, in treating pediatric patients with intractable epilepsy of various subtypes and etiologies. Further research is needed to evaluate the sustained impact of auto-stimulation on long-term outcomes (≥ 2 years follow-up post-VNS).

Laser interstitial thermal therapy for gyrus rectus cortical dysplasia in a child: a technical note.

Laser interstitial thermal therapy (LITT) has become a popular tool in the treatment of tumors and epilepsy. While most commonly used for the treatment of mesial temporal lobe epilepsy, it can be used as a minimally invasive option for the treatment of any seizure focus but has very rarely been discussed in the setting of cortical dysplasia. Here, we discuss the case of a 5-year-old girl with medically refractory epilepsy secondary to a right medial orbital gyrus and gyrus rectus cortical dysplasia successfully treated with LITT. After confirmation of seizure focus using stereo electroencephalography (SEEG), the patient underwent thermal ablation of the focus through an eyebrow incision with use of a single laser fiber. She has been seizure-free 6 months postoperatively, only on one anti-seizure medication, with normal EEG. The use of LITT in this case was successful because of the cylindrical shape of the cortical dysplasia, making it easily accessible via a single laser fiber in the absence of a yet to develop fontal sinus. While open resection would have also been appropriate, the use of LITT provided a minimally invasive alternative approach that allowed for an excellent outcome with limited risks.

Robot-assisted stereoelectroencephalography electrode placement in twenty-three pediatric patients: a high-resolution analysis of individual lead placement time and accuracy at a single institution.

PURPOSE: We describe a detailed evaluation of predictors associated with individual lead placement efficiency and accuracy for 261 stereoelectroencephalography (sEEG) electrodes placed for epilepsy monitoring in twenty-three children at our institution. METHODS: Intra- and post-operative data was used to generate a linear mixed model to investigate predictors associated with three outcomes (lead placement time, lead entry error, lead target error) while accounting for correlated observations from the same patients. Lead placement time was measured using electronic time-stamp records stored by the ROSA software for each individual electrode; entry and target site accuracy was measured using postoperative stereotactic CT images fused with preoperative electrode trajectory planning images on the ROSA computer software. Predictors were selected from a list of variables that included patient demographics, laterality of leads, anatomic location of lead, skull thickness, bolt cap device used, and lead sequence number. RESULTS: Twenty-three patients (11 female, 48%) of mean age 11.7 (± 6.1) years underwent placement of intracranial sEEG electrodes (median 11 electrodes) at our institution over a period of 1 year. There were no associated infections, hemorrhages, or other adverse events, and successful seizure capture was obtained in all monitored patients. The mean placement time for individual electrodes across all patients was 6.56 (± 3.5) min; mean target accuracy was 4.5 (± 3.5) mm. Lesional electrodes were associated with 25.7% (95% CI: 6.7-40.9%, p = 0.02) smaller target point errors. Larger skull thickness was associated with larger error: for every 1-mm increase in skull thickness, there was a 4.3% (95% CI: 1.2-7.5%, p = 0.007) increase in target error. Bilateral lead placement was associated with 26.0% (95% CI: 9.9-44.5%, p = 0.002) longer lead placement time. The relationship between placement time and lead sequence number was nonlinear: it decreased consistently for the first 4 electrodes, and became less pronounced thereafter. CONCLUSIONS: Variation in sEEG electrode placement efficiency and accuracy can be explained by phenomena both within and outside of operator control. It is important to keep in mind the factors that can lead to better or worse lead placement efficiency and/or accuracy in order to maximize patient safety while maintaining the standard of care.

Virtual Planning for Exchange Cranioplasty in Cranial Vault Remodeling.

ABSTRACT: The use of virtual surgical planning and computer-aided design/computer-aided manufacturing has gained popularity in the surgical correction of craniosynostosis. This study expands the use of virtual surgical planning and computer-aided design/computer-aided manufacturing in cranial vault reconstruction by using these methods to reconstruct the anterior vault using a single endocortically-plated unit constructed from the posterior calvarium. This technique was designed to reduce the risk of undesirable contour deformities that can occur when multiple bone grafts are used to reconstruct the anterior vault and fronto-orbital rim. Six patients were included in this study, all of which had nonsyndromic craniosynostosis. Excellent aesthetic outcomes were obtained in all patients, without complication. Additionally, the placement of a single reconstructive unit constructed from the posterior calvarium was efficient, aesthetically pleasing, and minimized postoperative contour deformities secondary to bone gaps, resorption, and often palpable resorbable plates.

Improved seizure burden and cognitive performance in a child treated with responsive neurostimulation (RNS) following febrile infection related epilepsy syndrome (FIRES).

Responsive neurostimulation (RNS) is an emerging therapy for patients with refractory focal epilepsy who are not candidates for surgical resection, with limited published experience in the pediatric population. We report a case of refractory multifocal epilepsy following febrile infection related epilepsy syndrome (FIRES) in which surgical resection was not feasible due to multifocal independent seizures and risk of cognitive deficit, and RNS was pursued. Relevant RNS data and neuropsychological testing results were reviewed. By eight months after implantation, decreased frequency and severity of clinical seizures were noted, and RNS data revealed decreased "long episodes," reduced spread of electrographic seizures, and fewer detections. Neuropsychological assessment, though potentially confounded by stimulant medication, revealed significant improvement in multiple cognitive domains, particularly working memory and processing speed, at six months. These findings illustrate success in detecting and aborting seizures, and additionally suggest a neuromodulatory effect of RNS stimulation. Our case demonstrates feasibility, efficacy and safety of RNS in a pediatric patient with FIRES, with evidence to also suggest cognitive improvement.

Comparison of surgical outcomes in patients with Chiari Type I malformation receiving posterior fossa decompression with and without duraplasty.

PURPOSE: The goals of this study were to compare clinical outcomes in patients with Chiari Malformation Type I (CMI) receiving posterior fossa decompression with (PFDD) or without duraplasty (PFD). METHODS: We conducted a retrospective analysis of 178 consecutive cases of 157 patients undergoing PFDD or PFD for CMI at Cohen Children's Medical Center between 2007 and 2017. Clinical improvement was defined as a clear reduction of preoperative symptoms after surgery as reported by patients and parents. An improvement of syrinx was derived from radiologic comparison of pre- and postoperative MR imaging. Chi-square analysis was performed to analyze the association between duraplasty and clinical parameters (alpha = 0.05). RESULTS: The primary presenting complaint was headache (142/178; 80%), followed by neck, back, and upper extremity pain, and numbness or tingling (49/178; 28%). Seventy patients (78/178; 44%) underwent PFD, and 100 patients (100/178; 56%) underwent PFDD. Overall, 143 patients (143/178; 80%) experienced subjective improvement with no statistically significant difference between the two surgical techniques (p = 0.705). The number of patients receiving PFDD with syrinx improvement or stabilization (55/59; 93%) was statistically larger than those that received PFD (8/13; 62%) (p = 0.008). PFDD was associated with greater complications than PFD alone. There were 35 cases of reoperation overall (35/178; 19%), and there was no statistically significant difference in reoperation rate between PFD and PFDD (p = 0.255). CONCLUSIONS: There appears to be a role for PFDD in patients with severe syringomyelia, but overall, PFD alone may be safely offered as the initial surgical intervention for symptomatic CMI patients.

Pedicled nasoseptal flap reconstruction for craniopharyngiomas in pediatric patients.

PURPOSE: Though the use of the pedicled nasoseptal flap (NSF), a reconstructive technique used after endoscopic endonasal approaches (EEA) for resection of craniopharyngiomas, has been shown to reduce the occurrence of post-operative cerebrospinal fluid (CSF) leaks in adults, less is known about its use in pediatric populations, specifically in children under the age of 7. The goal of this retrospective cohort study is to determine the viability of the pedicled NSF for pediatric patients. METHODS: Retrospective review of 12 pediatric patients (ages 2-16) undergoing 13 NSF reconstructions after resection of craniopharyngiomas. Radioanatomic analysis of computed tomography (CT) scans was utilized to classify the pneumatization of the sphenoid sinus depending on the thickness of the sphenoid bone margin. Intercarotid distances were measured from magnetic resonance imaging (MRI) scans to assess the feasibility of this reconstruction technique in pediatric patients. RESULTS: At the time of surgery, all patients were noted to have adequate NSF length and width. No post-operative high-flow CSF leaks were found within the group. Lack of pneumatization of the sphenoid sinus and narrow intercarotid distances in the youngest of patients did not lead to negative clinical outcomes. CONCLUSIONS: Based on our results and experience, the pedicled nasoseptal flap is a viable reconstructive option after EEA in the pediatric population, including even the youngest of patients. In these patients, a narrowed window between the intercarotid arteries and the lack of pneumatization of the sphenoid sinus present a challenge that can be overcome by using stereotactic navigation and advanced endoscopic techniques.

Robotic Surgical Assistant Rehearsal: Combining 3-Dimensional-Printing Technology With Preoperative Stereotactic Planning for Placement of Stereoencephalography Electrodes.

BACKGROUND: The use of frameless stereotactic robotic technology has rapidly expanded since the Food and Drug Administration's approval of the Robotic Surgical Assistant (ROSA) in 2012. Although the use of the ROSA robot has greatly augmented stereotactic placement of intracerebral stereoelectroencephalography (sEEG) for the purposes of epileptogenic focus identification, the preoperative planning stages remain limited to computer software. OBJECTIVE: To describe the use of a 3-dimensionally (3D)-printed patient model in the preoperative planning of ROSA-assisted depth electrode placement for epilepsy monitoring in a pediatric patient. METHODS: An anatomically accurate 3D model was created and registered in a preoperative rehearsal session using the ROSA platform. After standard software-based electrode trajectory planning, sEEG electrodes were sequentially placed in the 3D model. RESULTS: Utilization of the 3D-printed model enabled workflow optimization and increased staff familiarity with the logistics of the robotic technology as it relates to depth electrode placement. The rehearsal maneuvers enabled optimization of patient head positioning as well as identification of physical conflicts between 2 electrodes. This permitted revision of trajectory planning in anticipation of the actual case, thereby improving patient safety and decreasing operative time. CONCLUSION: Use of a 3D-printed patient model enhanced presurgical positioning and trajectory planning in the placement of stereotactic sEEG electrodes for epilepsy monitoring in a pediatric patient. The ROSA rehearsal decreased operative time and increased efficiency of electrode placement.

Robotic Surgical Assistant (ROSA™) Rehearsal: Using 3-Dimensional Printing Technology to Facilitate the Introduction of Stereotactic Robotic Neurosurgical Equipment.

BACKGROUND: The use of frameless stereotactic robotic technology has rapidly expanded since the Food and Drug Administration's approval of the Robotic Surgical Assistant (ROSA™) in 2012. Although the safety and accuracy of the ROSA platform has been well-established, the introduction of complex robotic technology into an existing surgical practice poses technical and logistical challenges particular to a given institution. OBJECTIVES: To better facilitate the integration of new surgical equipment into the armamentarium of a thriving pediatric neurosurgery practice by describing the use of a three-dimensional (3D)-printed patient model with in situ 3D-printed tumor for presurgical positioning and trajectory optimization in the stereotactic biopsy of a pontine lesion in a pediatric patient. METHODS: A 3D model was created with an added silicone mock tumor at the anatomical position of the lesion. In a preoperative rehearsal session, the patient model was pinned and registered using the ROSA platform, and a mock biopsy was performed targeting the in Situ silicone tumor. RESULTS: Utilization of the 3D-printed model enabled workflow optimization and increased staff familiarity with the logistics of the robotic technology. Biopsy trajectory successfully reached intralesional tissue on the 3D-printed model. The rehearsal maneuvers decreased operative and intubation time for the patient and improved operative staff familiarity with the robotic setup. CONCLUSION: Use of a 3D-printed patient model enhanced presurgical positioning and trajectory planning in the biopsy of a difficult to reach pontine lesion in a pediatric patient. The ROSA rehearsal decreased operative time and increased staff familiarity with a new complex surgical equipment.

Outcomes following endoscopic endonasal resection of sellar and supresellar lesions in pediatric patients.

PURPOSE: The endoscopic endonasal approach (EEA) is a credible surgical alternative for the resection of sellar and suprasellar lesions such as pituitary adenomas, craniopharyngiomas, and Rathke cleft cysts. However, its application to pediatric patients poses several unique challenges that have not yet been well evaluated. The authors evaluate the safety, efficacy, and outcomes associated with the use of the EEA for treatment of these pathologic entities in pediatric patients. METHODS: Retrospective review of 30 patients between the ages of two and 24 who underwent endoscopic endonasal resection of sellar or suprasellar lesions between January 2010 and December 2015. Endocrinological and ophthalmological outcomes, as well as extent of resection and complications were all evaluated. RESULTS: Gross total resection was achieved in eight of the nine pituitary adenomas, nine of the 12 craniopharyngiomas, and six of the nine Rathke cleft cysts. Of the 30 patients, 22 remained disease free at last follow-up. A total of six patients developed hypopituitarism and five developed diabetes insipidus. Eleven patients experienced improved vision, sixteen experienced no change, and one patient experienced visual worsening. Postoperative cerebrospinal fluid leak was seen in a single case and later resolved, vasospasm/stroke was experienced by 10% of patients, and new obesity was recorded in 10% of patients. There were no perioperative deaths. CONCLUSIONS: Endoscopic endonasal resection is a safe and effective surgical alternative for the management of sellar and suprasellar pathologies in pediatric populations with excellent outcomes, minimal complications, and a low risk of morbidity.

A Cryptic Cause of Cardiac Arrest.

BACKGROUND: RIPPLY2-associated spondylocostal dysostosis is a rare disorder that leads to segmentation defects of the vertebrae. These vertebral defects can result in severe instability of the cervical spine, leading to cardiac arrest after only minor whiplash injury. CASE REPORT: We present the case of a healthy 7-year-old child who experienced an out-of-hospital cardiac arrest. He was reported to have profound respiratory distress and collapsed after going down a slide, without trauma. He was resuscitated in the field, and presented to the emergency department, where return of spontaneous circulation was achieved. Imaging of his cervical spine revealed multiple abnormalities. It was determined that a whiplash injury led to hypoxia and bradycardia due to the anatomic abnormalities of his cervical spine, resulting in cardiovascular collapse. He recovered fully and was later diagnosed with SCDO6, an autosomal recessive inherited disorder caused by a mutation in the RIPPLY2 gene. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Unfamiliarity of providers with this mechanism of cardiac arrest, and the rarity of the syndrome itself, make early recognition very difficult. Late diagnosis and lack of preventative measures, including immediate cervical spine stabilization, can lead to catastrophic outcomes. In patients with cardiac arrest of unclear etiology, early consideration of cervical spine immobilization and evaluation can be lifesaving.

Tuberous Sclerosis Health Care Utilization Based on the National Inpatient Sample Database: A Review of 5655 Hospitalizations.

INTRODUCTION: Tuberous sclerosis complex (TSC) has an incidence of 1/6000 in the general population. Overall care may be complex and costly. We examine trends in health care utilization and outcomes of patients with TSC over the last decade. METHODS: The National Inpatient Sample (NIS) database for inpatient hospitalizations was searched for admission of patients with TSC. RESULTS: During 2000-2010, the NIS recorded 5655 patients with TSC. Most patients were admitted to teaching hospitals (71.7%). Over time, the percentage of craniotomies performed per year remained stable (P = 0.351). Relevant diagnoses included neuro-oncologic disease (5.4%), hydrocephalus (6.5%), and epilepsy (41.2%). Hydrocephalus significantly increased length of stay and hospital charges. A higher percentage of patients who underwent craniotomy had hydrocephalus (29.8% vs. 5.3%; P < 0.001), neuro-oncologic disease (43.5% vs. 3.4%; P < 0.001), other cranial diseases (4.2% vs. 1.2%; P < 0.001), and epilepsy (61.4% vs. 40.1%; P < 0.001). CONCLUSIONS: Our study identifies aspects of inpatient health care utilization, outcomes, and cost of a large number of patients with TSC. These aspects include related diagnoses and procedures that contribute to longer length of stay, increased hospital cost, and increased in-hospital mortality, which can inform strategies to reduce costs and improve care of patients with TSC.

Resective Epilepsy Surgery for Tuberous Sclerosis in Children: Determining Predictors of Seizure Outcomes in a Multicenter Retrospective Cohort Study.

BACKGROUND: There are no established variables that predict the success of curative resective epilepsy surgery in children with tuberous sclerosis complex (TSC). OBJECTIVE: We performed a multicenter observational study to identify preoperative factors associated with seizure outcome in children with TSC undergoing resective epilepsy surgery. METHODS: A retrospective chart review was performed in eligible children at New York Medical Center, Miami Children's Hospital, Cleveland Clinic Foundation, BC Children's Hospital, Hospital for Sick Children, and Sainte-Justine Hospital between January 2005 and December 2013. A time-to-event analysis was performed. The "event" was defined as seizures after resective epilepsy surgery. RESULTS: Seventy-four patients (41 male) were included. The median age of the patients at the time of surgery was 120 months (range, 3-216 months). The median time to seizure recurrence was 24.0 ± 12.7 months. Engel Class I outcome was achieved in 48 (65%) and 37 (50%) patients at 1- and 2-year follow-up, respectively. On univariate analyses, younger age at seizure onset (hazard ratio [HR]: 2.03, 95% confidence interval [CI]: 1.03-4.00, P = .04), larger size of predominant tuber (HR: 1.03, 95% CI: 0.99-1.06, P = .12), and resection larger than a tuberectomy (HR: 1.86, 95% CI: 0.92-3.74, P = .084) were associated with a longer duration of seizure freedom. In multivariate analyses, resection larger than a tuberectomy (HR: 2.90, 95% CI: 1.17-7.18, P = .022) was independently associated with a longer duration of seizure freedom. CONCLUSION: In this large consecutive cohort of children with TSC and medically intractable epilepsy, a greater extent of resection (more than just the tuber) is associated with a greater probability of seizure freedom. This suggests that the epileptogenic zone may include the cortex surrounding the presumed offending tuber.

Intraoperative fat placement in surgically refractory parasellar neoplasms to facilitate stereotactic radiosurgery.

BACKGROUND: In this article, we report on the technique of placing fat in between a sellar or parasellar neoplasm and the optic chiasm to possibly protect the optic chiasm from sequelae of radiation. METHODS: A review was performed on three patients, each of whom had planned subtotal resection with fat placed near their optic chiasm to facilitate future radiosurgery. RESULTS: Follow-up on our three patients varied from 6 months to 3 years post-stereotactic radiosurgery. The fat remained stable and in place. The tumors either remained stable or reduced in size. No infections, postoperative marker dependent neurological complications or unusual symptoms were encountered. CONCLUSIONS: Placement of fat between a parasellar neoplasm and the optic chiasm appears to be a safe approach to help define the tumor chiasm space, helping to facilitate radiosurgery. Future experience is warranted to determine the efficacy of this technique.

Partial labyrinthectomy presigmoid transpetrosal resection of petroclival meningioma.

A petroclival meningioma represents a challenging tumor to resect in the cerebellopontine angle and ventral to the brain stem. Multiple cranial nerves and blood vessels may be intimately involved with the tumor. A partial labyrinthectomy presigmoid transpetrosal approach can facilitate resection while preserving hearing. This approach allows for a direct line of sight along the petrous bone while sealing the canals can preserve hearing. In this video operative manuscript, we demonstrate a step-by-step illustration of a partial labyrinthectomy presigmoid transpetrosal resection of a petroclival meningioma. This approach affords the best chance of hearing preservation and an opportunity for maximum tumor resection. The video can be found here: http://youtu.be/29I4KEXz1vY .