Data describing the safety/efficacy of targeted therapies in combination with stereotactic radiotherapy (SRS/SRT) for brain metastases are limited. We leverage a bicentric cohort to evaluate rates of intracranial failure and radiation necrosis in patients receiving targeted therapy and SRS. Patients with intact brain metastases at two institutions treated with SRS/SRT and concurrent central nervous system (CNS)-active targeted therapy were identified. Concurrent targeted therapy was defined as receipt of targeted therapy starting before and continuing through receipt of radiation therapy, except for a brief washout interval of 3–7 days. Patients were followed for a minimum of 3 months after SRS/SRT with brain MRI. Kaplan-Meier analysis was performed to evaluate overall survival and cumulative rates of symptomatic radiation necrosis (sRN). Variables associated with radiation necrosis on univariable analysis (p < 0.2) were included in a multivariable logistic regression model for adjusted analysis. The study included 93 patients with 306 metastases, and median follow-up was 17 months. The overall rate of sRN per-metastasis and per-patient was 16/306 (5

BACKGROUND AND PURPOSE:Cavernous sinus (CS) venous drainage patterns may affect the accuracy of inferior petrosal sinus (IPS) sampling, but descriptions of the normal venographic CS outflow patterns are scarce. We investigated CS drainage patterns using the venous phases of normal cerebral angiograms. MATERIALS AND METHODS:A retrospective review of elective cerebral angiograms was performed. Patients were included if they had no cerebrovascular abnormalities that could influence the cerebral venous flow. Patients with prior intracranial surgery, ruptured aneurysms, arteriovenous malformations, thrombectomy, idiopathic intracranial hypertension, and carotid-cavernous fistulas were excluded. Measurements of the venous sinuses were performed in the lateral views at the largest vessel diameter. RESULTS:A total of 61 elective cerebral angiograms were reviewed, performed for work-up on unruptured aneurysms (63.9%), abnormal MRI findings (16.4%), unspecified epilepsy/Wada test (16.4%), and pituitary-dependent Cushing disease (3.3%). The right and left superior petrosal sinus (SPS) had mean diameters of 1.08 mm (SD ±0.44) and 1.03 mm (SD ±0.37). The right and left IPS had mean diameters of 1.4 mm (SD ±0.51) and 1.57 mm (SD ±0.56). A total of 3 CS venous drainage patterns were identified: 1) CS to pterygoid plexus (PP), preferential on the right in 21 cases (34.4%) and on the left in 26 cases (42.6%); 2) CS to IPS, preferential on the right in 31 cases (50.8%) and on the left in 29 cases (47.5%); and 3) CS to SPS, preferential on the right in 7 cases (11.5%) and on the left in 6 cases (9.8%). The right CS could not be visualized in 2 studies (3.3%); this did not occur on the left. The lateral sinuses were right-dominant in 35 cases (57.4%), left-dominant in 14 (22.9%), and codominant in 12 patients (19.7%). No significant associations were found between dominant contralateral lateral sinus and dominant CS drainage through the PP on the right (P = .35) or left (P = .94). CONCLUSIONS:This is the first study to delineate CS drainage patterns, with IPS drainage being most common, followed by PP drainage. Based on our observations and prior studies of cavernous sinus venous anatomy, we present a classification system intended to delineate the different drainage patterns.

Suturing in the narrow endonasal corridor can be technically challenging. For some endonasal procedures, including inverted U-shaped nasopharyngeal flap (IUNF) harvest for cranio-cervical junction exposure, the ability to support meticulous flap resuspension offers clinical utility. Two novel suturing techniques offer promise: (1) use of barbed suture and (2) Durastat dural repair device, obviating the need for knot tying and endonasal needle driver/supination, respectively. Perform subjective and objective evaluation of IUNF resuspension with: (1) running mucosal suturing using endonasal needle driver and barbed, loop suture and (2) interrupted mucosal suturing using the Durastat device in 3 cadaveric heads. A IUNF was created and subsequently resuspended, (1) using a 3-0 monocryl barbed Stratafix with loop and endonasal needle driver. After Stratafix suture removal, (2) resuspension using interrupted sutures with the Durastat, spring loaded device was performed. Repair time was measured objectively. Suture precision was subjectively evaluated. Adequate IUNF resuspension was provided by both methods (3/3). The barbed suture required more procedural time on average (18:59 minutes), than the Durastat system (18:35 minutes). The small Durastat needle often failed to puncture the mucosal flap using spring mechanism alone, indicating that technical modification to increase needle size and spring torque could improve performance. Adequate mucosal resuspension was achieved in all specimens. Stratafix offered greater consistency with needle puncture and similar precision but was more technically challenging compared to the Durastat system. With appropriate technological modifications, the authors believe the Durastat system has greater potential to optimize IUNF resuspension.

PURPOSE:Meningiomas may express estrogen/progesterone receptors (ER/PR), but hormonal risk is poorly characterized. We characterized association between progesterone supplementation and tumor-related visual deficits in premenopausal women receiving radiation for meningioma. METHODS:We performed a retrospective case-control study with primary endpoint of visual deficit prior to radiation for intracranial meningioma in women ≤55 receiving radiation at one academic center from 2012-2025. Records were reviewed to determine risk factors including age, race, grade, neurofibromatosis / prior radiation (NF/PriorRT), gravida, unopposed progesterone use, skull base location, and time from diagnosis to radiation. All available pathology specimens were tested for ER/PR. Logistic regression was performed to analyze associations with visual deficit. RESULTS:70 women with median age 45 were included. 32 patients (44%) had meningioma grade ≥2; 51 (73%) had skull base tumors; 8 (11%) had NF/Prior RT. 30 women (43%) had used unopposed progesterone; 16 (23%) used depo-medroxyprogesterone acetate (Depo-Provera) specifically. Visual deficit was present in 38 patients (54%) and was associated with unopposed progesterone use (p=0.001, OR 8.3), black race (p=0.024, OR 5.4), and skull base location (p=0.003, OR 10.3) on multivariable analysis. Proportion using unopposed progesterone was 63% vs. 19% in patients with vs. without visual deficit, respectively (chi-sq p<0.001). 92% of progesterone exposures preceded visual deficit (in those with visual deficit). Only 5/57 (9%) original pathology reports discussed ER/PR status; 42 after pathologic re-analysis. PR was positive in 40 (95%) and ER in 1 (2%). In this subset, there was a nonsignificant trend to an association between progesterone receptor staining % and visual deficit on multivariable analysis (p=0.068, OR 1.03). CONCLUSIONS:Progesterone use was associated with meningioma-related visual deficit in women referred for radiotherapy. Providers should be aware of this potential risk factor and further study is warranted.

Background: Sporadic, unilateral pediatric-spectrum vestibular schwannomas (PSVSs), which occur in patients 21 years or younger without a diagnosis of neurofibromatosis type 2, are rare tumors with an estimated incidence of less than 0.1/100,000 children. A subset of PSVS tumors (designated Koos grade IV PSVSs) exhibits significant brainstem compression and poses unique management challenges. Methods: A systematic review of the PubMed database was conducted for all case reports, case series, meta-analyses, and clinical trials involving patients with PSVS, along with one patient from our institution. Data related to patient demographics, tumor size, Koos grading, surgical approach, number of surgical resections, preoperative and postoperative House-Brackmann (HB) grade, and postoperative complications and treatment were recorded. Results: We review the case of a 21-year-old female who presented with headaches, slight facial droop, and diplopia and was found to have a 3.7 cm Koos grade IV PSVS. Our technique of using an extended retrosigmoid craniotomy along with a navigated Sonopet ultrasonic aspirator facilitated a gross total resection with resolution of preoperative symptoms. Our literature review showed that 53.8% of Koos grade IV patients had a postoperative HB grade of III or higher, and a gross-total resection was only achieved in 57.1% of patients. Conclusion: This study illustrates the surgical complexity of Koos IV PSVS resection and underscores the need to further develop innovative surgical techniques (such as the use of a navigated ultrasonic aspirator and an extended retrosigmoid craniotomy as presented in this report) to improve surgical visualization and operative efficiency while decreasing neurologic morbidity.

BACKGROUND AND OBJECTIVES:Expandable tubular retractors have enabled microsurgical colloid cyst resection with minimal transcortical footprint, even in patients with a nondilated ventricular system. We investigated anatomic reference points to guide ideal site of transcortical entry. METHODS:Operative windows were compared in 4 cadaveric specimens using 2 sites of entry: (1) at the Kocher point and (2) at an anterolateral point located 4 cm anterior and 1 cm lateral to the Kocher point. Visualization of the third ventricular roof from both entry sites was qualitatively compared. Virtual 3-dimensional reconstructions of the ventricular system of 6 specimens were subsequently segmented using computed tomography imaging. To optimize the trajectory, the anterolateral points were shifted medially until the third ventricle roof was visible without caudate obstruction; these optimized coordinates were designated as virtual adjusted points (VAPs). Mean VAP distance from the midline was then calculated. RESULTS:The caudate head obstructed visualization of the foramen of Monro in 5 of 8 (62.5%) anterolateral entry sites, whereas no obstructions secondary to the caudate were encountered using the Kocher point. In the absence of caudate obstruction, anterolateral entry sites provided superior visualization with less line-of-sight obstruction from forniceal structures relative to Kocher entry sites. In virtual reconstruction, the VAPs offered superior visualization compared with all other entry sites, with a mean distance from the midline of 3.2 ± 0.1 cm. CONCLUSION:Both Kocher and anterolateral entries may encounter visual obstruction of the third ventricular roof in nondilated ventricles. Visualization can be optimized case-by-case as follows: (1) translation anterior, as delimited by the hairline, to minimize sagittal angle and maximize line of sight to the third ventricle roof and (2) once anterior extent is determined, use of neuronavigation to guide mediolateral transcortical access; specifically, movement of the entry site laterally until further translation would introduce visual obstruction by the caudate.

Purpose Sporadic, unilateral pediatric-spectrum vestibular schwannomas (PSVSs) are rare cerebellopontine angle tumors with an approximate incidence of 1 case per 1,000,000 children annually. A subset of PSVS tumors (designated Koos grade IV PSVSs) exhibit significant brainstem compression and pose unique management challenges. Given the more aggressive biological nature often associated with PSVSs relative to adult vestibular schwannomas, it is critical to maximize cytoreduction while preserving adjacent neurovascular structures in this young patient population. Case Report We review the case of a 21-year-old female who presented with headaches, slight facial droop, and diplopia and was found to have a 3.7 cm Koos grade IV PSVS. Following an extended retrosigmoidal craniotomy, a novel technique utilizing real-time Sonopet neuronavigation was used to enhance the efficacy of intracapsular debulking prior to extracapsular dissection. We review the literature on Koos grade IV PSVSs and discuss the utility of novel, real-time Sonopet neuronavigation in this context. Conclusion In a literature review of patients with Koos IV PSVSs, 42.9% of patients underwent subtotal resection and 53.8% of patients exhibited postoperative facial weakness of House-Brackmann grade III or higher—illustrating the surgical complexity of these tumors. We believe the novel technique presented for real-time Sonopet neuronavigation may provide useful insight for future innovations able to improve operative efficiency and decrease neurologic morbidity associated with the resection of these complex skull base tumors.

Background:Presigmoid approaches provide access to several structures anterior to the sigmoid sinus (SS) and may be intended for the treatment of lesions located in the middle and posterior fossa. We conducted a morphometric cadaveric study investigating the infratentorial presigmoid retrolabyrinthine suprameatal approach (PRSA) as a unique operative corridor. The typical anatomic-radiological characteristics and variations were evaluated and analyzed to predict surgical accessibility. Methods:A total of 10 surgical dissections were performed on both sides of five adults, injected, and cadaveric heads. Fifteen morphometric parameters were measured, analyzed, and categorized into pre-procedural, intra-procedural, and additional parameters. Results:Preoperative anatomic-radiological parameters provide valuable information to select patients with favorable anatomy that may offer appropriate surgical accessibility to the medial part of cerebellopontine angle cistern, lateral pons, and prepontine cistern through a PRSA corridor. An obtuse petroclival angle of ≥144° with a more horizontally oriented petrous bone, a posterior SS position, and a large mastoid cavity provided the greatest surgical accessibility through the PRSA corridor. The superior petrosal sinus drainage and the degree of petrous apex pneumatization were important factors affecting surgical fluency and speed. However, they were not determinant factors for selecting the most appropriate patients eligible for the PRSA. Conclusion:The PRSA represents a minimally invasive modification of the trans-labyrinthine approach that may be offered in patients with lesions medial to the internal auditory canal or anterior/lateral to the brainstem, with the goal of preserving vestibulocochlear functions. Preoperative anatomic-radiological parameters are mandatory for a patient-tailored selection of the most effective surgical approach.

Objectives:Elevated intracranial pressure (ICP) secondary to idiopathic intracranial hypertension (IIH) is a recognized risk factor for anterior and lateral skull base cerebrospinal fluid (CSF) leaks. A recent randomized controlled trial (Mitchell et al) demonstrated a significant reduction of ICP in IIH with the use glucagon-like peptide-1 (GLP-1) receptor agonists. This retrospective population study aims to evaluate the role of GLP-1 agonists in reducing CSF leaks. Design:Retrospective cohort database study. Setting:A collaborative global database (TriNetX) sourced from electronic medical records from 99 large healthcare organizations across the world. Participants:Adults (≥18 years old) with a diagnosis of IIH, stratified into groups based on the presence or absence of concurrent GLP-1 agonist use. Main Outcome Measures:The rate of spontaneous cranial CSF leak and the rate of anterior/lateral skull base CSF leak repair between GLP-1 users versus non-users over 3 years. Results:Compared with IIH patients not taking GLP-1 agonists ( n  = 11,825), IIH patients on GLP-1 agonists ( n  = 11,825) were 24% less likely to develop a spontaneous cranial CSF leak (OR 0.76, 95% CI, 0.61-0.94) and 72% less likely to undergo skull base CSF leak repair (OR 0.28, 95% CI, 0.15-0.51). Conclusions:GLP-1 agonist use in IIH patients is associated with a lower incidence of spontaneous cranial CSF leaks and a decreased rate of undergoing anterior and/or lateral skull base CSF leak repairs. These promising findings suggest that GLP-1 agonists may be an effective adjuvant therapeutic agent in preventing recurrence following CSF leak repair in IIH patients.

OBJECTIVE:The ongoing war in Ukraine has introduced many challenges to an already overburdened and resource-limited medical system. Longitudinal collaborations, material support, educational outreach, and surgical mentorship are essential for improving outcomes and standards of neurosurgical care in extreme settings such as in times of war. METHODS:Operating in Ukraine since 2016 through the coordination of Razom, the Co-Pilot Project has organized multiple United States-based mission trips to Ukraine to support local physicians during wartime, including a trip between April and May of 2023. RESULTS:A team of two anesthesiologists, two neurosurgeons, a neurointerventional radiologist, and an industry representative providing technical expertise aided in the instruction and performance of complex neurosurgical and neurovascular procedures by Ukrainian physicians at St. Panteleimon Hospital and St. Nicholas Children's Hospital in Lviv. Such efforts are crucial for helping to address the sharp rise in elective neurosurgical volume caused by the increase in internally displaced persons in Western Ukraine since February 2022. In an illustrative case, the authors provide an in-depth description of a foramen magnum meningioma resection via a far lateral craniotomy in a 48-year-old female. CONCLUSIONS:Despite the supply shortages and logistical challenges brought on by war, the Co-Pilot Project continues to utilize a long-term approach to continually improve the operative capabilities of Ukrainian neurosurgeons through both in-person and virtual collaborations. It is hoped that the lessons learned from a recent trip to Ukraine will help to inform and inspire other global neurosurgery initiatives in the future.

Traumatic Brain Injury (TBI) is a significant global health concern, particularly in low- and middle-income countries (LMICs) where access to medical resources is limited. Decompressive craniectomy (DHC) is a common procedure to alleviate elevated intracranial pressure (ICP) following TBI, but the cost of subsequent cranioplasty can be prohibitive, especially in resource-constrained settings. We describe challenges encountered during the beta-testing phase of CranialRebuild 1.0, an automated software program tasked with creating patient-specific cranial implants (PSCIs) from CT images. Two pilot clinical teams in the Philippines and Ukraine tested the software, providing feedback on its functionality and challenges encountered. The constructive feedback from the Philippine and Ukrainian teams highlighted challenges related to CT scan parameters, DICOM file arrays, software limitations, and the need for further software improvements. CranialRebuild 1.0 shows promise in addressing the need for affordable PSCIs in LMICs. Challenges and improvement suggestions identified throughout the beta-testing phase will shape the development of CranialRebuild 2.0, with the aim of enhancing its functionality and usability. Further research is needed to validate the software’s efficacy in a clinical setting and assess its cost-effectiveness.

Objectives This study seeks to comprehensively analyze the impact of smoking history on outcomes after endoscopic transsphenoidal hypophysectomy (TSH) for pituitary adenoma.Design This was a retrospective study.Setting This study was done at the tertiary care center.Participants Three hundred and ninety-eight adult patients undergoing TSH for a pituitary adenoma.Main Outcome Measures Clinical and tumor characteristics and operative factors were collected. Patients were categorized as never, former, or active smokers, and the pack-years of smoking history was collected. Years since cessation of smoking was obtained for former smokers. Specific outcomes included postoperative cerebrospinal fluid (CSF) leak, length of hospitalization, 30-day return to the operating room, and 30-day readmission. Smoking history details were comprehensively analyzed for association with outcomes.Results Any history of smoking tobacco was associated with return to the operating room (odds ratio [OR] = 2.67, 95% confidence interval [CI]: 1.05-6.76, p = 0.039), which was for persistent CSF leak in 58.3%. Among patients with postoperative CSF leak, any history of smoking was associated with need for return to the operating room to repair the CSF leak (OR = 5.25, 95% CI: 1.07-25.79, p = 0.041). Pack-years of smoking was positively associated with a return to the operating room (OR = 1.03, 95% CI: 1.01-1.06, p = 0.048). In all multivariable models, all negative outcomes were significantly associated with the covariate: occurrence of intraoperative CSF leak.Conclusion This is the first study to show smoking may have a negative impact on healing of CSF leak repairs after TSH, requiring a return to the operating room. This effect appears to be dose dependent on the smoking history. Secondarily, intraoperative CSF leak as covariate in multivariable models was significantly associated with all negative outcomes.

OBJECTIVE: To evaluate the feasibility of a novel method for occipitocervical fixation (OCF) through the endonasal corridor. METHODS: Thin-cut computed tomography scans were obtained for 5 cadaveric specimens. Image segmentation was used to reconstruct 3D models of each O-C1 joint complex. Using computer-aided design software, plates were custom-designed to span each O-C1 joint, sit flush onto the bony surface, and accommodate screws. The final models were 3D-printed in titanium. For implantation, specimens were held in pin-fixation and registered to neuronavigation. A rigid 0o endoscope was used for endonasal visualization. An inverted U-shaped nasopharyngeal flap was raised to expose the occipital condyles and C1. The plates were introduced and fixed with bone screws. Computed tomography scans were obtained to assess screw accuracy and proximity to critical neurovascular structures. Screw entry points and trajectories were recorded. RESULTS: Endonasal OCF was performed on 5 cadaveric specimens. The mean starting point for occipital condyle screws was 6.17 mm lateral and 5.38 mm rostral to the medial O-C1 joint. Mean axial and sagittal trajectories were 7.98 degrees degrees and 6.71 degrees, degrees , respectively. The mean starting point for C1 screws was 16.11 mm lateral to the C1 anterior tubercle and 6.39 mm caudal to the medial O-C1 joint. Mean axial and sagittal trajectories were 10.97 degrees degrees and L 9.91 degrees , respectively. CONCLUSIONS: Endonasal OCF is technically and anatomically feasible. The application of this technique may allow for same-stage endonasal decompression and fixation, offering a minimally invasive alternative to current methods of fixation and advancing surgeons' ability to treat pathology of the craniovertebral junction. Next steps will focus on biomechanical testing.

Diastematomyelia is a rare congenital disorder characterized by the separation of the spinal cord by an osseocartilaginous or fibrous septum. While diastematomyelia has been reported to be more common in the thoracic and lumbar regions, the true incidence of cervical diastematomyelia is currently unknown. In this study, we conducted the most comprehensive systematic review to date of all other case reports of diastematomyelia to better characterize the incidence of cervical diastematomyelia and provide comprehensive statistics on the clinical characteristics of diastematomyelia generally. Ninety-one articles were included in our study, which comprised 252 males (27.9%) and 651 females (72.0%) (and one patient with unspecified gender). In 507 cases, the vertebral level of the diastematomyelia was described, and we recorded those levels as either cervical ( n = 8, 1.6%), thoracic ( n = 220, 43.4%), lumbar ( n = 277, 54.6%), or sacral ( n = 2, 0.4%). In 719 cases, the type of diastematomyelia was specified as either Type I ( n = 482, 67.0%) or Type II ( n = 237, 33.0%). Our study found that diastematomyelia has been reported in the cervical region in only 1.6% of cases, and we provide comprehensive data that this disorder occurs in female-to-male ratio of approximately 2.6:1 and Type I versus Type II diastematomyelia in an estimated ratio of 2:1.

Purpose/Objective(s) The use of pre-radiation therapy (RT) planning MRI for glioblastoma (GBM) is inconsistent. Current NCCN guidelines recommend treatment planning on preoperative or immediate postoperative MRI. We characterized and investigated implications of rapid early progression (REP) on pre-RT planning MRIs standardly performed at our institution. We hypothesized that REP is associated with worse survival, earlier need for intervention, and performs better than extent of resection as a prognostic variable for risk stratification. Materials/Methods We reviewed patients with a new pathologic diagnosis of IDH-wildtype GBM who received ≥40 Gy RT between 2016-2024. Inclusion required a pre-RT planning MRI ≥2 weeks after postoperative MRI. REP was defined as >1cm thickness of new enhancing disease between postoperative and pre-RT MRI. Extent of surgical resection was scored 1-4 as an ordinal variable, 1: gross total resection (GTR, >95%); 2: near total resection (NTR, 90-95%); 3: subtotal resection (STR); 4: biopsy only. Endpoints included overall survival (OS) and bevacizumab/re-resection. Cox proportional hazards model was used to analyzed age, extent of resection, MGMT methylation, short course RT, and presence of REP. Significant covariates were included in the multivariate analysis. Results The final cohort included 84 patients (median age 63). The median number of days from postoperative MRI to pre-RT MRI was 27 days, and 10 patients (12%) received short course RT. Surgical extent was GTR in 45 (54%), NTR in 15 (18%), STR in 17 (20%), and biopsy only in 7 (8%). REP occurred in 46% of patients and was less frequent after GTR (31%) vs. NTR (73%), STR (59%), or biopsy (57%). On univariate analysis, MGMT methylation, REP, and extent of resection were prognostic for OS and freedom from bevacizumab/re-resection (Table). On multivariate analysis, REP remained significant (HR = 2.2, P = 0.005 for OS; HR = 2.7, P = 0.002 for bevacizumab/re-resection) while extent of resection lost significance. Median OS was 1.1 years with REP vs. 1.7 years without. Conclusion REP occurs frequently in GBM patients, adds a measure of "growth rate", and may perform equal or better than surgical resection in predicting survival and need for bevacizumab or re-resection for fast progressing GBM's. These data have implications for clinical trial design and support pre-RT planning MRIs as standard of care for accurate tumor delineation, risk stratification, and identification of high-risk patients who may need earlier intervention.

Background: Previous authors have reported on cadaveric models of endonasal CSF leakage to assess a surgeon’s ability to repair interrupted dura. However, to date, there are no models able to quantitatively and precisely assess the pressure associated with acute burst failure of various methods of skull base repair. This project is the first step in confirming the reliability of the perfusion pump system in cadaveric specimens.

Abstract BACKGROUND Meningiomas express ER/PR, but hormonal risk is poorly characterized and not always considered. We hypothesized that hormonal contraceptives lead to tumor-related visual deficits in premenopausal women referred for radiation. METHODS We conducted a retrospective case-control study with primary endpoint visual deficit prior to radiation for meningioma in women age ≤55. Key risk factors determined included age, grade, skull base location, hormonal supplementation / contraception, and neurofibromatosis / prior radiation (NF/priorRT). Univariate and multivariate (including factors with p<0.05 on univariate) logistic regression was performed to analyze associations with visual deficit. RESULTS 64 women (median age 46) receiving RT from 2012-2024 at a single academic institution were included. 45 (70%) had skull base tumors, 33 (52%) used estrogen or progesterone, and 23 (36%) used unopposed progesterone only, 15 specifically medroxyprogesterone acetate (Provera). Visual deficit was present in 35 patients (55%) and was independently associated with both skull base location (p=0.002, OR 11.5) and unopposed progesterone only use (p=0.008, OR 12) but not estrogen or progesterone use on multivariate analysis. Proportion with progesterone only use was 57% vs. 11% in patients with vs. without visual deficit (chi-sq p<0.001). In 5 with ER/PR testing, 3 were PR+ (all with visual deficits and history of medroxyprogesterone acetate) and 2 were PR- (neither with visual deficits nor hormone use). 13 women (20%) were actively using progesterone during RT. 17 women have been contacted at time of analysis, and 4 discontinued progesterone. CONCLUSIONS Progesterone increases risk for meningioma-related visual deficits in premenopausal women referred for radiotherapy, with a disproportionate number on Provera specifically. These data highlight the importance of age-appropriate counseling, consistent pathologic assessment of ER/PR status, and greater awareness of this issue amongst neurosurgeons and radiation oncologists.

BACKGROUND AND OBJECTIVE:Radiofrequency lesioning (RFL) is a safe and effective treatment for medically refractory trigeminal neuralgia. Despite gaining mainstream neurosurgical acceptance in the 1970s, the technique has remained relatively unchanged, with the majority of series using lateral fluoroscopy over neuronavigation for cannula guidance. To date, there are no studies describing neuronavigation-specific parameters to help neurosurgeons selectively target individual trigeminal rootlets. In this cadaveric study, we sought to provide a neuronavigation-specific morphometric roadmap for selective targeting of individual trigeminal rootlets.METHODS:Embalmed cadaveric specimens were registered to cranial neuronavigation. Frontotemporal craniotomies were then performed to facilitate direct visualization of the Gasserian ganglion. A 19-gauge cannula was retrofit to a navigation probe, permitting real-time tracking. Using preplanned trajectories, the cannula was advanced through foramen ovale (FO) to the navigated posterior clival line (nPCL). A curved electrode was inserted to the nPCL and oriented inferolaterally for V3 and superomedially for V2. For V1, the cannula was advanced 5 mm distal to the nPCL and the curved electrode was reoriented inferomedially. A surgical microscope was used to determine successful contact. Morphometric data from the neuronavigation unit were recorded.RESULTS:Twenty RFL procedures were performed (10R, 10L). Successful contact with V3, V2, and V1 was made in 95%, 90%, and 85% of attempts, respectively. Mean distances from the entry point to FO and from FO to the clival line were 7.61 cm and 1.26 cm, respectively.CONCLUSION:In this proof-of-concept study, we found that reliable access to V1-3 could be obtained with the neuronavigation-specific algorithm described above. Neuronavigation for RFL warrants further investigation as a potential tool to improve anatomic selectivity, operative efficiency, and ultimately patient outcomes.