Disease Control after Radiotherapy for Adult Craniopharyngioma: Clinical Outcomes from a Large Single-Institution Series.

PURPOSE: To report disease control and treatment-related side effects among adult patients with craniopharyngioma treated with radiotherapy. METHODS: We performed a single-institution review of adult patients (> 21 years old) with craniopharyngioma treated with radiotherapy either definitively or postoperatively for gross residual disease. We report disease control, survival, and radiotherapy-related side effects. RESULTS: A total of 49 adult patients with craniopharyngioma were included, 27 of whom were treated at initial presentation and 22 for recurrent disease following initial surgery and observation. Overall, 77% received radiotherapy postoperatively (either after primary surgery or surgery for recurrence). With a median clinical and radiographic follow-up of 4.2 (range, 0.4-21.6) years and 3.0 (range, 0-21.5) years, the 5- and 10-year local control rates were 100 and 94%, respectively. The 5- and 10-year overall survival rates were 80 and 66%, respectively. Eleven percent of patients experienced grade 2 vision deterioration and 18% suffered grade 2 endocrinopathies following radiotherapy. CONCLUSIONS: Radiotherapy provides excellent disease control with acceptable toxicity among adult patients with craniopharyngioma. These data support the use of fractionated radiotherapy in adult patients with recurrent or gross residual disease after surgery. For inoperable patients or those with moderate or high surgical risk to neurologic and/or vascular structures, we advocate for limited surgical resection and postoperative radiotherapy to balance optimal tumor control with tumor- and treatment-related morbidity.

Proton therapy for adult medulloblastoma: Acute toxicity and disease control outcomes.

PURPOSE: We report disease control, survival outcomes, and treatment-related toxicity among adult medulloblastoma patients who received proton craniospinal irradiation (CSI) as part of multimodality therapy. METHODS: We reviewed 20 adults with medulloblastoma (≥ 22 years old) who received postoperative proton CSI ± chemotherapy between 2008 and 2020. Patient, disease, and treatment details and prospectively obtained patient-reported acute CSI toxicities were collected. Acute hematologic data were analyzed. RESULTS: Median age at diagnosis was 27 years; 45% of patients had high-risk disease; 75% received chemotherapy, most (65%) after CSI. Eight (40%) patients received concurrent vincristine with radiotherapy. Median CSI dose was 36GyE with a median tumor bed boost of 54GyE. Median duration of radiotherapy was 44 days. No acute ≥ grade 3 gastrointestinal or hematologic toxicities attributable to CSI occurred. Grade 2 nausea and vomiting affected 25% and 5% of patients, respectively, while 36% developed acute grade 2 hematologic toxicity (36% grade 2 leukopenia and 7% grade 2 neutropenia). Those receiving concurrent chemotherapy with CSI had a 38% rate of grade 2 hematologic toxicity compared to 33% among those not receiving concurrent chemotherapy. Among patients receiving adjuvant chemotherapy (n = 13), 100% completed ≥ 4 cycles and 85% completed all planned cycles. With a median follow-up of 3.1 years, 4-year actuarial local control, disease-free survival, and overall survival rates were 90%, 90%, and 95%, respectively. CONCLUSIONS: Proton CSI in adult medulloblastoma patients is very well tolerated and shows promising disease control and survival outcomes. These data support the standard use of proton CSI for adult medulloblastoma.

Halo vest immobilization - an institutional review of safety in acute cervical spine injury from 2013 to 2017.

Objective: Halo vest immobilization (HVI) remains an important treatment option for occipital-cervical injuries. It provides the surgeon with a safe and effective medical treatment options for challenging patients. The aim of this study was to evaluate the safety of HVI in these patients.Methods: This retrospective study identified adult patients treated with Halo vests immobilization (HVI) for acute cervical spine injury at our metropolitan level 1 trauma center from 2013 to 2017. This heterogenous cohort included 67 consecutive patients with acute cervical spine injury secondary to trauma or iatrogenic injury following surgical intervention with a mean age of 52 and a mean injury severity score (ISS) of 18. Forty-six percent of patients were treated with HVI as an adjunct therapy to surgical fixation (both short- and long-term immobilization), 45% of patients were treated with HVI as a primary medical treatment, and 9% of patients were treated with HVI instead of failed conservative medical treatment, such as cervical braces. Results: Pneumonia during the initial hospital stay was the most common complication (25%), followed by the correction of loose pins (22%) and pin site infections (18%). Overall, 51% of patients experienced at least one of these complications. There were significant associations between low initial GCS scores and the development of pneumonia (p < 0.001), high ISS scores and the development of pneumonia (p < 0.01), and duration of HVI and the occurrence of loose pins (p < 0.05). Four patients initially treated with HVI as primary medical treatment was converted to surgical treatment due to an intolerance of HVI or non-healing injuries.Conclusions:The HVI is a safe and effective treatment modality in a subset of patients with complex cervical junction and subaxial cervical spine pathology.

Proton therapy for skull-base chondrosarcoma, a single-institution outcomes study.

BACKGROUND: We sought to evaluate the effectiveness of definitive or adjuvant external-beam proton therapy on local control and survival in patients with skull-base chondrosarcoma. METHODS: We reviewed the medical records of 43 patients with a median age of 49 years (range, 23-80 years) treated with double-scattered 3D conformal proton therapy for skull-base chondrosarcomas between January 2007 and February 2016. Proton therapy-related toxicities were scored using CTCAE v4.0. RESULTS: The median radiotherapy dose was 73.8 Gy(RBE) (range, 64.5-74.4 Gy[RBE]). Thirty-six (84%) and 7 (16%) patients underwent surgical resection or biopsy alone. Tumor grade distribution included: grade 1, 19 (44%) patients; grade 2, 22 (51%); and grade 3, 2 (5%). Forty patients had gross disease at the time of radiotherapy and 7 patients were treated for locally recurrent disease following surgery. The median follow-up was 3.7 years (range, 0.7-10.1 years). There were no acute grade 3 toxicities related to RT. At 4 years following RT, actuarial rates of overall survival, cause-specific survival, local control, and RT-related grade 3 toxicity-free survival were 95%, 100%, 89%, and 95%. CONCLUSION: High-dose, double-scattered 3D conformal proton therapy alone or following surgical resection for skull-base chondrosarcoma is an effective treatment with a high rate of local control with no acute grade 3 radiation-related toxicity. Further follow-up of this cohort is necessary to better characterize long-term disease control and late toxicities.

Prospective, Multicenter, Randomized, Double-Blinded, Partial Crossover Study to Assess the Safety and Efficacy of the Novel Neuromodulation System in the Treatment of Patients With Chronic Pain of Peripheral Nerve Origin.

INTRODUCTION: Currently available central nervous system treatment strategies are often insufficient in management of peripheral neuropathic pain, prompting a resurgence of neuromodulation focused on peripheral pain. A new peripheral nerve stimulation device was investigated in a prospective, randomized, double blind, crossover study, looking specifically at efficacy and safety, with Food and Drug Administration oversight. METHODS: Prospective, multicenter, randomized, double-blind, partial crossover study to assess safety and efficacy. After IRB approval, patients were enrolled, implanted, and then followed for three months to assess efficacy and one year for safety based on Food and Drug Administration guidance. RESULTS: One hundred forty-seven patients were consented and screened for the study. Thirty-five did not meet inclusion or exclusion criteria. Ninety-four patients were implanted and then randomized to the treatment (45) or the Control group (49). The primary efficacy endpoint, three months after randomization to treatment, demonstrated that patients receiving active stimulation achieved a statistically significantly higher response rate of 38% vs. the 10% rate found in the Control group (p = 0.0048). Improvement in pain was statistically significant between the randomized groups, with the Treatment group achieving a mean pain reduction of 27.2% from Baseline to Month 3 compared to a 2.3% reduction in the Control group (p < 0.0001). During the partial crossover period, patients again demonstrated statistically significant improvement in pain relief with active stimulation compared to baseline. Further, the Treatment group had significantly better improvement than the Control group in secondary measures including but not limited to quality of life and satisfaction. Safety, assessed throughout the trial and with follow-up to one year, demonstrated no serious adverse events related to the device. All device-related adverse events were minor and self-limiting. CONCLUSION: The novel peripheral nerve stimulation device is a safe and effective treatment strategy to address neuropathic pain of peripheral nerve origin.

Utility of Anterior Atlantodens Interval Widening on Cervical Spine CT for Assessing Transverse Atlantal Ligament Injury.

STUDY DESIGN: Retrospective, cross-sectional. OBJECTIVES: To identify trauma patients with confirmed tears of the transverse atlantal ligament on cervical MRI and measure several parameters of atlanto-axial alignment on cervical CT, including the anterior atlantodens interval, to determine which method is most sensitive in predicting transverse atlantal ligament injury. METHODS: Adult trauma patients who suffered a transverse atlantal ligament tear on cervical MRI were identified retrospectively. The cervical CT and MRI exams for these patients were reviewed for the following: anterior and lateral atlantodens interval widening, lateral C1 mass offset, C1-C2 rotatory subluxation, and transverse atlantal ligament injuries on cervical MRI. RESULTS: Twenty-six patients were identified with a tear of the transverse atlantal ligament on cervical MRI. Twelve percent of these patients demonstrated an anterior dens interval measuring greater than 2 mm, 26% of patients demonstrated lateral mass offset of C1 on C2 (average offset of 2.4 mm), 18% of patients demonstrated an asymmetry greater than 1 mm between the left and right lateral atlantodens interval, and one patient demonstrated atlanto-axial rotation measuring greater than 20%. Ten patients had an accompanying C1 burst fracture and eight patients had a C2 fracture. One patient demonstrated widening of the atlanto-occipital joint space greater than 2 mm indicative of craniocervical dissociation injury. CONCLUSIONS: An anterior atlantodens interval measuring greater than 2 mm is an unreliable methodology to screen trauma patients for transverse altantal ligament injuries and atlanto-axial instability. Moreover, C1 lateral mass offset, lateral atlantodens asymmetry, and atlanto-axial rotation were all poor predictors of transverse atlantal ligament tears.

Evolution of the posterior petrosal approach.

In this article, the authors review the history of the posterior petrosal approach. The early foundation of the retrolabyrinthine lateral petrosectomy has its roots in the otolaryngology literature. These early approaches were limited in exposure by the tentorium superiorly and the sigmoid sinus posteriorly. Although the concept of a transtentorial approach was originally combined with a complete labyrinthectomy, Hakuba and colleagues described the expansive exposure afforded by sectioning the tentorium and superior petrosal sinus and mobilizing a skeletonized sigmoid sinus. This maneuver serves as the key step in allowing for the full, combined supra- and infratentorial exposure that the posterior petrosal approach provides. In contrast to Hakuba et al.'s approach, which used a partial labyrinthectomy, modern approaches often preserve the entire labyrinth (retrolabyrinthine approach). For added exposure, the latter can be combined with the anterior petrosal approach, allowing for the preservation of hearing and an enhanced view of the surgical target. The authors review the evolution of the petrosal approach and highlight its applicability.

Petrosal approaches to posterior circulation aneurysms.

Complex posterior circulation aneurysms are formidable lesions with an abysmal natural history. Their management continues to present a challenge to both endovascular and open microsurgical approaches. Affording an expansive, combined supra- and infratentorial exposure, the petrosal approaches are well suited for these challenging lesions when located along the basilar trunk or at a low-lying basilar apex. This report evaluates the evolution and application of petrosal approaches to these lesions. Excluding transsigmoid, infratentorial, or labyrinth-sacrificing approaches, the authors found 23 reports with 61 posterior circulation aneurysms treated via a petrosal approach. Although early morbidity was not negligible, rates of aneurysm occlusion (95% overall) and long-term outcome were quite laudable in light of the challenge posed by these lesions. Moreover, with accumulating experience with petrosal approaches, rates of complications are likely to wane, as neurosurgeons capitalize on the expansive exposure afforded by these indispensable approaches.

Radiologic utility of the Gehweiler and AO spine classification systems for C1 Trauma: A retrospective review from a Level I trauma center.

Objective: The purpose of our study was to identify adult trauma patients with an acute C1 burst fracture, evaluate for concomitant transverse atlantal ligament (TAL) injury, and apply the modified Gehweiler and AO spine classification systems to determine the utility of these classification systems in accurately defining C1 trauma. Materials and Methods: Adult trauma patients with an acute C1 fracture were identified retrospectively using Nuance mPower software. The C1 fracture was described based on whether the fracture involved the anterior arch, posterior arch, lateral mass, medial tubercle, and/or transverse process. If follow-up cervical magnetic resonance imaging (MRI) was performed, the presence and location of an associated TAL injury was recorded. The anatomic location of the C1 burst fracture and TAL injury, if present, were compared with the descriptive classification systems outlined by Gehweiler/Dickman (modified) and the AO Spine society. Any additional osseous trauma of the skull base and C1-C2 was also recorded along with relevant clinical history and management. Results: Thirty-nine patients were identified with an acute C1 burst fracture on cervical computed tomography (CT) with seventy-seven percent of patients undergoing follow-up cervical MRI. Observed fracture patterns were divided into five distinct types based on CT findings and further subdivided based on the integrity of the transverse altantal ligament on MRI. TAL tears were observed exclusively in type 3 fractures (anterior and posterior arch fractures) and type 4 fractures (anterior arch, posterior arch, and lateral mass fractures). The modified Gehweiler classification system failed to accurately describe the anatomic location of the C1 fracture in forty-four percent of patients, whereas the AO spine was too broad and failed to accurately describe fracture location in our cohort. Conclusions: The Gehweiler and AO spine classifications demonstrated significant shortcomings in the accurate description of patients with C1 trauma. Whereas the Gehweiler system did not accurately describe the anatomic location of the various C1 fractures, the AO spine system was too broad and failed to radiologically classify fracture location. Moreover, there was a high number of patients with AO spine type B injuries without atlantoaxial translation that nevertheless required C1-C2 fusion for atlantoaxial instability. We suggest the need for an updated classification system that takes into account both the CT (fracture location) and MRI (TAL integrity) appearance of C1 trauma. An updated classification strategy will offer a radiologic standardization of C1 trauma that will aid in future research studies and help optimize patient management.

Impact of Type of Treatment Center and Access to Care on Mortality and Survival for Skull Base Chordoma and Chondrosarcoma.

Introduction In adults with skull base chordoma or chondrosarcoma, the impact of treatment center and access to care have not been well described in regard to perioperative mortality and survival. Methods A query of the National Cancer Database (NCDB) and review of 1,102 adults-488 with chordomas and 614 with chondrosarcomas-was performed. The Kaplan-Meier's product limit method and chi-square analysis, respectively, assessed overall survival and 30-day (30D) and 90-day (90D) mortalities. Results For 925 patients who had surgery and available mortality data, the 30D and 90D mortality rates were 0.9 and 1.5%. Lower education level ( p = 0.0185) and treatment at a nonacademic facility ( p = 0.016) were associated with increased risk of 90-day mortality. Median follow-up was 52 months and analysis was dichotomized by histology. For those with skull base chordoma, patients from a larger metro size ( p = 0.002), age below the median 52 years ( p ≤ 0.001), and private insurance (<0.001) were associated with prolonged survival, whereas for skull base chondrosarcoma, the factors were treatment at an academic medical center ( p = 0.001), high-volume center ( p = 0.007), age below the median 52 years ( p ≤ 0.001), higher income ( p = 0.043), higher education ( p = 0.017), and private insurance ( p ≤ 0.001). Comparing high-, medium-, and low-volume centers, high-volume centers were most likely to be academic, deliver radiotherapy, escalate doses >70 Gy, and utilize proton radiotherapy consistent across both disease subsets. Conclusion Higher educational attainment and treatment at an academic facility were associated with decreased 90D mortality for patients with skull base chordoma and chondrosarcoma. For those with skull base chordoma, larger metro size, younger age, and private insurance were associated with prolonged survival; for those with chondrosarcoma, it was treatment at a high-volume or academic medical center, younger age, higher income or education, and private insurance.

Current Advances in the Management of Adult Craniopharyngiomas.

Craniopharyngiomas (CPs) are slow growing, histologically benign intracranial tumors located in the sellar-suprasellar region. Although known to have low mortality, their location and relationship to the adjacent neural structures results in patients having significant neurologic, endocrine, and visual comorbidities. The invasive nature of this tumor makes complete resection a challenge and contributes to its recurrence. Additionally, these tumors are bimodally distributed, being treated with surgery, and are followed by other adjuncts, such as focused radiation therapy, e.g., Gamma knife. Advances in surgical techniques, imaging tools, and instrumentations have resulted in the evolution of surgery using endoscopic techniques, with residual components being treated by radiotherapy to target the residual tumor. Advances in molecular biology have elucidated the main pathways involved in tumor development and recurrence, but presently, no other treatments are offered to patients, besides surgery, radiation, and endocrine management, as the disease and tumor evolve. We review the contemporary management of these tumors, from the evolution of surgical treatments, utilizing standard open microscopic approaches to the more recent endoscopic surgery, and discuss the current recommendations for care of these patients. We discuss the developments in radiation therapy, such as radiosurgery, being used as treatment strategies for craniopharyngioma, highlighting their beneficial effects on tumor resections while decreasing the rates of adverse outcomes. We also outline the recent chemotherapy modalities, which help control tumor growth, and the immune landscape on craniopharyngiomas that allow the development of novel immunotherapies.

Post-Transplant Lymphoproliferative Disorder: A Rare Case of CNS Involvement following Renal Transplant.

BACKGROUND: Post-transplant lymphoproliferative disorders (PTLD) are rare immunosuppression complications affecting 5% of transplant patients. Isolated central nervous system (CNS)-PTLD without nodal or extra-nodal organ involvement is rarely reported and is difficult to diagnose due to the non-specific clinical manifestations and imaging features overlapping with other common CNS lesions. CASE PRESENTATION: We present a case of a 72-year-old female subjected to a renal transplant 11 years ago with progressively worsening headaches and confusion. Imaging revealed vasogenic edema in the left frontal and bilateral temporal lobes. She was subjected to a craniotomy and excisional biopsy to obtain tissue for diagnostic and therapeutic interventions. Pathology examination showed atypical EBV-positive lymphoplasmacytic infiltrate, consistent with Polymorphic type PTLD. CONCLUSIONS: Patients diagnosed with PTLD need to have close monitoring of immunosuppressive medications while in the hospital. Early diagnosis is essential for patient survival with PTLD, as their health can deteriorate fast.

A Rare Case of Life-Threatening Multicompartmental Spontaneous Intracranial Hemorrhage From a Grade 1 Convexity Meningioma.

Meningiomas are slowly growing benign tumors. The incidence of hemorrhage associated with intracranial meningiomas is in the 0.5%-2.4% range. However, intracranial meningiomas with hemorrhagic presentation are associated with higher rates of overall major morbidity (36%) and mortality (21.1%). We report a case of a convexity meningioma presenting with intraparenchymal hematoma and bilateral acute subdural hematomas (SDH) in a comatose patient (Glasgow Coma Scale (GCS) score: 7) who had a history of recurrent episodes of headaches over the past few months. Hemorrhagic presentation of a meningioma is a rare but potentially devastating event. Early recognition of the potential underlying meningioma as a cause of bleeding followed by rapid appropriate additional imaging is crucial to direct treatment plans to achieve the best outcome.

Spontaneous syrinx resolution in patient with Chiari I malformation: illustrative case.

BACKGROUIND: Chiari malformations include a spectrum of congenital hindbrain herniation syndromes. In patients with the most common subtype, Chiari malformation Type I, 50% to 75% develop a syrinx. The pathogenesis of syringomyelia is not well understood, with multiple theories outlined in the literature. Although the presence of a syrinx in a patient with Chiari malformation is generally accepted as an indication for surgical intervention, there are documented cases of spontaneous resolution that support a more conservative approach to management. OBSERVATIONS: The authors reported a case of spontaneous resolution of a cervical syrinx in an adult with an unchanged Chiari malformation. LESSONS: Given the possibility of spontaneous resolution over time, the authors believe a more conservative approach of observation with periodic surveillance, magnetic resonance imaging, and neurological examination should be considered in the management of a patient with a Chiari malformation and associated syringomyelia.

Microsurgical Resection of a Parasellar Meningioma Invading the Cavernous Sinus, Bone, and Optic Canal: 2-Dimensional Operative Video.

Parasellar meningiomas, regardless of the initial origin, frequently involve the optic canal and cavernous sinus, leading to visual loss and ocular movement dysfunction.1 Hyperostotic bony invasion to the surrounding skull base is common.2 Visual acuity prognosis can be improved by surgical resection through different technical maneuvers, including opening the optic canal and the preservation of the visual apparatus vascular supply by developing the intra-arachnoidal dissection planes.1,3,4 To achieve radical dissection and reduce recurrences, the extradural invaded bone is thoroughly resected. Likewise, the soft and nonadherent invasive tumor around the cavernous carotid can be extensively removed.1,3,4 New or worsening of the ophthalmoplegia is frequent after cavernous sinus exploration and tumor resection. However, it is usually temporary and improves progressively in 80% of patients.1,3,4 Safely approaching these lesions requires extensive anatomic knowledge through cadaveric dissection and training, allowing us to achieve tumor control, preserve or improve visual function, and avoid or delay irradiation therapy.1,3,4 Pituitary function preservation is also possible in many patients through surgery, which is at higher risk with irradiation. We demonstrate the technical maneuvers through a case of a 49-yr-old woman who presented with a parasellar meningioma involving the cavernous sinus, both optic canals, and extensive bony invasion. The patient consented to the surgery and publication of her images. Image at 1:14 and middle and right image at 1:31 reprinted with permission from Al-Mefty O, Operative Atlas of Meningiomas. Vol 1, ©LWW, 1998. Left image at 1:31 reprinted from Arnautovic et al,5 by permission from JNSPG.

Radical Resection of a Giant Epidermoid Tumor Associated With Miniature Chordoma Utilizing a Combined Endoscopic-Microscopic Technique: 2-Dimensional Operative Video.

Epidermoid tumors arise from misplaced squamous epithelium and enlarge through the accumulation of desquamated cell debris.1 Notwithstanding the prevailing conservative attitudes to minimize morbidity, optimal treatment consists of total removal of the capsule2,3; therefore, giant and multicompartmental tumors are particularly challenging. The utilization of simultaneous endoscopic microscopic techniques by tandem endoscopic and microscopic dissection to overcome the shortcomings of both modalities, markedly enhances the ability of radical removal,4 thus eliminating or at least long-delaying inevitable recurrences with subsequent accumulated morbidity. The transmastoid approach by skeletonizing and reflexing the transverse-sigmoid sinus offers wide exposure of the cerebellopontine angle avoiding cerebellar retraction and allowing 4-hands dissection.5 The patient is a 17-yr-old male with a giant epidermoid tumor in the cerebellopontine angle, extending through the incisura. The patient underwent surgical resection with maximum pursuit of the epithelial capsule. After removing the epidermoid tumor, a miniature intra and extradural midclival tumor was encountered and removed with a proven pathology of chordoma. Patient did well postoperatively with relief of his hemifacial spasms. Patient consented for surgery and photograph publication. Image at 1:23, ©1997, O. Al-Mefty, used with permission. All rights reserved.

Falx Cerebelli Meningioma: Case Report of a Rarely Occurring Tumor, Management Nuances, and Literature Review.

The falx cerebelli is a small crescent fold of dura mater that is attached to the internal occipital crest and projects forward into the posterior cerebellar notch between the cerebellar hemispheres. We report a rare case of a 61-year-old female who presented with a 1-month history of headache and gait instability. Imaging findings were suggestive of a meningioma arising from the falx cerebelli. Complete surgical resection was achieved with a standard posterior fossa midline approach. Duraplasty was performed using animal allograft dura (Duraguard) and additional layers of oxidized cellulose preparation (Surgicel), fibrin sealant, and nonsuturable collagen matrix (Duragen) were utilized to reduce the risk of a cerebrospinal fluid leak. Pathology confirmed a World Health Organization (WHO) grade-I meningioma. Postoperatively, patient with asymptomatic thrombosis of the left transverse/sigmoid sinuses and later with a pseudomeningocele managed with a lumbar drain. To our knowledge, this is the second documented case in the literature. We discuss intraoperative nuances and unique aspects in the postoperative care and management of these patients.

Current Management and Image Review of Skull Base Chordoma: What the Radiologist Needs to Know.

Chordomas of the skull-base are typically slow-growing, notochord-derived tumors that most commonly originate along the clivus. Skull base chordoma is treated with surgery and radiotherapy. Local recurrence approaches 50% at 10 years. Radiologists play a critical role in diagnosis, treatment planning, and follow-up. Surgeons and radiation oncologists rely on radiologists for pre-operative delineation of tumor and adjacent anatomy, identification of post-treatment changes and disease recurrence, and radiation treatment effects. This review provides an overview of clinical characteristics, surgical anatomy, indications for radiotherapy, identification of treatment complications, and patterns of disease recurrence for radiologists to provide value in the management of these lesions.

False Localizing Trigeminal V2 Sensory Loss in Vestibular Schwannoma.

False localizing signs involving cranial nerves are rare, even more so when involving the trigeminal nerve. Here we present the first case of trigeminal V2 sensory loss as a false localizing sign. The sensory dysfunction was caused by a large contralateral cystic vestibular schwannoma and subsequently improved after tumor resection. The clinical and radiographic features are described, and proposed mechanisms for this false localizing sign are discussed.