External Validation of Predictive Models for Failed Medical Management of Spinal Epidural Abscess.

OBJECTIVE: There is limited consensus regarding management of spinal epidural abscesses (SEAs), particularly in patients without neurologic deficits. Several models have been created to predict failure of medical management in patients with SEA. We evaluate the external validity of 5 predictive models in an independent cohort of patients with SEA. METHODS: One hundred seventy-six patients with SEA between 2010 and 2019 at our institution were identified, and variables relevant to each predictive model were collected. Published prediction models were used to assign probability of medical management failure to each patient. Predicted probabilities of medical failure and actual patient outcomes were used to create receiver operating characteristic (ROC) curves, with the area under the receiver operating characteristic curve used to quantify a model's discriminative ability. Calibration curves were plotted using predicted probabilities and actual outcomes. The Spiegelhalter z-test was used to determine adequate model calibration. RESULTS: One model (Kim et al) demonstrated good discriminative ability and adequate model calibration in our cohort (ROC = 0.831, P value = 0.83). Parameters included in the model were age >65, diabetes, methicillin-resistant Staphylococcus aureus infection, and neurologic impairment. Four additional models did not perform well for discrimination or calibration metrics (Patel et al, ROC = 0.580, P ≤ 0.0001; Shah et al, ROC = 0.653, P ≤ 0.0001; Baum et al, ROC = 0.498, P ≤ 0.0001; Page et al, ROC = 0.534, P ≤ 0.0001). CONCLUSIONS: Only 1 published predictive model demonstrated acceptable discrimination and calibration in our cohort, suggesting limited generalizability of the evaluated models. Multi-institutional data may facilitate the development of widely applicable models to predict medical management failure in patients with SEA.

Clinical and socioeconomic predictors of shunt malfunction in the pediatric emergency department.

OBJECTIVE: The aim of this study was to delineate the clinical and socioeconomic variables associated with shunt revision in pediatric patients presenting to the emergency department (ED) with concerns of ventricular shunt malfunction. METHODS: A retrospective analysis of pediatric ED consultations for shunt malfunction over a 1-year period was conducted, examining clinical symptoms, radiographic findings, and socioeconomic variables. Sensitivities, specificities, and positive and negative predictive values were calculated for each presenting symptom collected. Logistic regression models were used to estimate the odds ratios for shunt revision based on these variables, and multivariate analyses were used to adjust for potential confounders. RESULTS: Of the 271 ED visits from 137 patients, 19.2% resulted in shunt revision. Increased ventricle size on imaging (OR 11.38, p < 0.001), shunt site swelling (OR 9.04, p = 0.01), bradycardia (OR 7.08, p < 0.001), and lethargy (OR 5.77, p < 0.001) were significantly associated with shunt revision. Seizure-like activity was inversely related to revision needs (OR 0.24, p < 0.001). Patients with private or self-pay insurance were more likely to undergo revision compared with those with public insurance (p = 0.028). Multivariate analysis further confirmed the significant associations of increased ventricle size, lethargy, and bradycardia with shunt revision, while also revealing that seizure-like activity inversely affected the likelihood of revision. Patients with severe cognitive and language disabilities were more likely to be admitted to the hospital from the ED but were not more likely to undergo revision. CONCLUSIONS: Clinical signs such as increased ventricle size, shunt site swelling, bradycardia, and lethargy may be strong predictors of the need for shunt revision in pediatric patients presenting to the ED with concerns of shunt malfunction. Socioeconomic factors play a less clear role in predicting shunt revision and admission from the ED; however, the nature of their influence is unclear. These findings can help inform clinical decision-making and optimize resource utilization in the ED.

Preoperative Opioid Use and Postoperative Outcomes in Patients Undergoing Microvascular Decompression for Trigeminal Neuralgia.

BACKGROUND AND OBJECTIVES: The prescription of opioid analgesics for trigeminal neuralgia (TN) is controversial, and their effect on postoperative outcomes for patients with TN undergoing microvascular decompression (MVD) has not been reported. We aimed to describe the relationship between preoperative opioid use and postoperative outcomes in patients with TN undergoing MVD. METHODS: We reviewed the records of 920 patients with TN at our institution who underwent an MVD between 2007 and 2020. Patients were sorted into 2 groups based on preoperative opioid usage. Demographic information, comorbidities, characteristics of TN, preoperative medications, pain and numbness outcomes, and recurrence data were recorded and compared between groups. Multivariate ordinal regression, Kaplan-Meier survival analysis, and Cox proportional hazards were used to assess differences in pain outcomes between groups. RESULTS: One hundred and forty-five (15.8%) patients in this study used opioids preoperatively. Patients who used opioids preoperatively were younger (P = .04), were more likely to have a smoking history (P < .001), experienced greater pain in modified Barrow Neurological Institute pain score at final follow-up (P = .001), and were more likely to experience pain recurrence (P = .01). In addition, patients who used opioids preoperatively were more likely to also have been prescribed TN medications including muscle relaxants and antidepressants preoperatively (P < .001 and P < .001, respectively). On multivariate regression, opioid use was an independent risk factor for greater postoperative pain at final follow-up (P = .006) after controlling for variables including female sex and age. Opioid use was associated with shorter time to pain recurrence on Kaplan-Meier analysis (P = .005) and was associated with increased risk for recurrence on Cox proportional hazards regression (P = .008). CONCLUSION: Preoperative opioid use in the setting of TN is associated with worse pain outcomes and increased risk for pain recurrence after MVD. These results indicate that opioids should be prescribed cautiously for TN and that worse post-MVD outcomes may occur in patients using opioids preoperatively.

Prophylactic removal of a migratory missile from the cerebral ventricles: case report.

BACKGROUND AND IMPORTANCE: Nonpowder firearm injuries to the head pose major health risks, with retained fragments potentially causing harmful sequelae that require neurosurgical intervention. CLINICAL PRESENTATION: We report the case of 2-year-old girl who sustained an accidental gunshot wound to the head. She sustained a penetrating ballistic intracranial injury caused by a BB shot from a rifle. At presentation, she was neurologically intact with a punctate laceration on her left forehead. Head CT demonstrated a small depressed left frontal skull fracture, a small intracerebral hematoma, and a 5-mm metallic bullet fragment in the deep left frontal lobe near the frontal horn of the left lateral ventricle. She was admitted to the hospital and managed nonoperatively with levetiracetam and intravenous antibiotics, and discharged home in good condition. Follow-up CT in 1 week showed slight migration of the metallic bullet fragment to the left, placing it at the anterior horn of the lateral ventricle. Six weeks later, follow-up CT showed migration of the bullet to the temporal horn of the left lateral ventricle. Intraventricular migration of the bullet raised concern that it could move further to obstruct the foramen of Monro or cerebral aqueduct. Therefore, we removed the bullet through a small left temporal craniotomy with image guidance using a microsurgical approach through a translucent tube. CONCLUSION: The authors discuss the rationale and technique for removing a nonpowder firearm bullet that has migrated within the cerebral ventricles.

Comparative Scoping Review of Prenatal Care Resources for Families of Children With Spinal Dysraphism and Hydrocephalus in High-Income Countries and Low- and Middle-Income Countries.

BACKGROUND AND OBJECTIVES: Low- and middle-income countries (LMICs) face higher incidences and burdens of care for neural tube defects (NTDs) and hydrocephalus compared with high-income countries (HICs), in part due to limited access to neurosurgical intervention. In this scoping review, we aim to integrate studies on prenatal care, counseling, and surgical management for families of children with spinal dysraphism and hydrocephalus in LMICs and HICs. METHODS: PubMed, Embase, Global Index Medicus, and Web of Science electronic databases were searched for English language articles pertaining to prenatal care, counseling, and surgical management for families of children with spinal dysraphism and hydrocephalus in HICs and LMICs. Identified abstracts were screened for full-text review. Studies meeting inclusion criteria were reviewed in full and analyzed. RESULTS: Seventy studies met the inclusion criteria. Twelve studies (16.9%) were conducted in HICs only, 50 studies (70.4%) were conducted in LMICs only, and 9 studies (12.7%) encompassed both. On thematic analysis, seven underlying topics were identified: epidemiology, folate deficiency and supplementation/fortification, risk factors other than folate deficiency, prenatal screening, attitudes and perceptions about NTDs and their care, surgical management, and recommendations for guideline implementation. CONCLUSION: NTDs have become a widely acknowledged public health problem in many LMICs. Prenatal counseling and care and folate fortification are critical in the prevention of spinal dysraphism. However, high-quality, standardized studies reporting their epidemiology, prevention, and management remain scarce. Compared with NTDs, research on the prevention and screening of hydrocephalus is even further limited. Future studies are necessary to quantify the burden of disease and identify strategies for improving global outcomes in treating and reducing the prevalence of NTDs and hydrocephalus. Surgical management of NTDs in LMICs is currently limited, but pediatric neurosurgeons may be uniquely equipped to address disparities in the care and counseling of families of children with spinal dysraphism and hydrocephalus.

Perioperative Infection After Aneurysmal Subarachnoid Hemorrhage: Risk Factors, Causative Pathogens, and Long-Term Outcomes.

BACKGROUND AND OBJECTIVES: Nosocomial infections are the most common complication among critically ill patients and contribute to poor long-term outcomes. Patients with aneurysmal subarachnoid hemorrhage (aSAH) are highly susceptible to perioperative infections, yet it is unclear what factors influence infection onset and functional recovery. The objective was to investigate risk factors for perioperative infections after aSAH and relate causative pathogens to patient outcomes. METHODS: Clinical records were obtained for 194 adult patients with aSAH treated at our institution from 2016 to 2020. Demographics, clinical course, complications, microbiological reports, and outcomes were collected. χ 2 , univariate, and multivariate logistic regression analyses were used to analyze risk factors. RESULTS: Nearly half of the patients developed nosocomial infections, most frequently pneumonia and urinary tract infection. Patients with infections had longer hospital stays, higher rates of delayed cerebral ischemia, and worse functional recovery up to 6 months after initial hemorrhage. Independent risk factors for pneumonia included male sex, comatose status at admission, mechanical ventilatory use, and longer admission, while those for urinary tract infection included older age and longer admission. Staphylococcus , Klebsiella , and Enterococcus spp. were associated with poor long-term outcome. Certain pathogenic organisms were associated with delayed cerebral ischemia. CONCLUSION: Perioperative infections are highly prevalent among patients with aSAH and are related to adverse outcomes. The risk profiles for nosocomial infections are distinct to each infection type and causative organism. Although strong infection control measures should be universally applied, patient management must be individualized in the context of specific infections.

Socioeconomic characteristics and postoperative outcomes of patients undergoing prenatal vs. postnatal repair of myelomeningoceles.

PURPOSE: To investigate differences in sociodemographic characteristics and short-term outcomes between patients undergoing prenatal versus postnatal myelomeningocele repair. METHODS: Patients who underwent myelomeningocele repair at our institution were stratified based on prenatal or postnatal timing of repair. Baseline characteristics and outcomes were compared. Multivariate analysis was performed to identify whether prenatal repair was a predictor of outcomes independent of socioeconomic measures. RESULTS: 49 patients underwent postnatal repair, and 30 underwent prenatal repair. Patients who underwent prenatal repair were more likely to have private insurance (73.3% vs. 42.9%, p = 0.03) and live farther from the hospital where they received their repair (251.5 ± 447.4 vs. 72.5 ± 205.6 miles, p = 0.02). Patients who underwent prenatal repair had shorter hospital stays (14.3 ± 22.7 days vs. 25.3 ± 20.1 days, p = 0.03), fewer complications (13.8% vs. 42.9%, p = 0.01), fewer 30-day ED visits (0.0% vs. 34.0%, p < 0.001), lower CSF diversion rates (13.8% vs. 38.8%, p = 0.02), and better functional status at 3-months (13.3% vs. 57.1% delayed, p = 0.009), 6-months (20.0% vs. 56.7% delayed, p = 0.03), and 1-year (29.4% vs. 70.6% delayed, p = 0.007). On multivariate analysis, prenatal repair was an independent predictor of inpatient complication (OR(95%CI): 0.19(0.05-0.75), p = 0.02) and 3-month (OR(95%CI): 0.14(0.03-0.80) p = 0.03), 6-month (OR(95%CI): 0.12(0.02-0.73), p = 0.02), and 1-year (OR(95%CI): 0.19(0.05-0.80), p = 0.02) functional status. CONCLUSION: Prenatal repair for myelomeningocele is associated with better outcomes and developmental functional status. However, patients receiving prenatal closure are more likely to have private health insurance and live farther from the hospital, suggesting potential barriers to care.

Frailty Predicts Worse Pain Outcomes for Older TN Patients Treated with Microvascular Decompression.

BACKGROUND: Trigeminal neuralgia (TN) is a debilitating orofacial pain disorder. Recent data from a national database suggest that microvascular decompression (MVD) in frail patients is associated with more postoperative complications. However, the long-term pain outcomes for frail TN patients are not known. We aimed to elucidate the relationship between frailty and long-term pain outcomes after MVD for TN. METHODS: From 2007 to 2020, 368 TN patients aged ≥60 years underwent MVD at our institution. Patient demographics, clinical characteristics, postoperative complications, and long-term pain outcomes were recorded. Frailty was assessed using the modified 5-item frailty index (mFI-5) score, and the patients were dichotomized into nonfrail (mFI-5 <2) and frail (mFI-5 >1). Differences were assessed via the t test, χ2 test, multivariate ordinal regression, and Cox proportional hazards analysis. RESULTS: Of the 368 patients analyzed, 9.8% were frail. The frail patients were significantly older (P = 0.02) with a higher body mass index (P = 0.01) and a greater incidence of comorbidities (P < 0.001). Frail patients presented with significantly higher pain levels at the final follow-up (P = 0.04). On multivariate analysis, frailty was independently associated with more pain at follow-up (P = 0.01), as was younger age, female sex, and black race. The relationship between frailty and postoperative pain recurrence showed a trend toward significance (P = 0.06), and younger age and black race were significantly associated with recurrence. CONCLUSIONS: Frail patients undergoing MVD are at risk of worse long-term pain outcomes. Our results provide clinicians with useful information pertaining to the influence of frailty on the long-term efficacy of MVD in treating TN.

The role of multiple sclerosis subtype in microvascular decompression outcomes for patients with trigeminal neuralgia.

OBJECTIVES: While patients with concomitant trigeminal neuralgia (TN) and multiple sclerosis (MS) are understood to experience a more intractable pain phenotype, whether TN pain outcomes differ by the presenting MS subtype is not well characterized. This study's objective is to compare post-operative pain and numbness outcomes following microvascular decompression (MVD) in TN patients with either relapsing-remitting MS (RRMS) or progressive MS. METHODS: We retrospectively reviewed all TN patients who underwent MVDs at our institution from 2007 to 2020. Of the 1044 patients reviewed, 45 (4.3%) patients with MS were identified. Patient demographics, procedural characteristics, and post-operative pain and numbness scores were recorded and compared. Factors associated with pain recurrence were assessed using survival analyses and multivariate regressions. RESULTS: Of the resulting 45 MS patients, 34 (75.6%) patients presented with the RRMS subtype, whereas 11 (24.4%) patients exhibited progressive MS. Using an adjusted multivariate ordinal regression, the subtype of MS was not significantly associated with the Barrow Neurological Institute (BNI) pain score at final follow-up. Using a Kaplan-Meier survival analysis and a multivariate Cox proportional hazards regression, respectively, RRMS was significantly associated with a shorter post-operative pain-free interval (p = 0.04) as well as a greater risk for pain recurrence (p = 0.02). CONCLUSIONS: Although the degree of pain at final follow-up may not differ, RRMS patients are at increased risk for pain recurrence following MVD for TN. These results align with a growing understanding that neuroinflammation may play a significant role in TN pain.

Preoperative Characteristics and Postoperative Pain Outcomes in Trigeminal Neuralgia With Concomitant Autoimmune Disease.

BACKGROUND AND OBJECTIVES: Although the association between multiple sclerosis and trigeminal neuralgia (TN) is well established, little is known about TN pain characteristics and postoperative pain outcomes after microvascular decompression (MVD) in patients with TN and other autoimmune diseases. In this study, we aim to describe presenting characteristics and postoperative outcomes in patients with concomitant TN and autoimmune disease who underwent an MVD. METHODS: A retrospective review of all patients who underwent an MVD at our institution between 2007 and 2020 was conducted. The presence and type of autoimmune disease were recorded for each patient. Patient demographics, comorbidities, clinical characteristics, postoperative Barrow Neurological Institute (BNI) pain and numbness scores, and recurrence data were compared between groups. RESULTS: Of the 885 patients with TN identified, 32 (3.6%) were found to have concomitant autoimmune disease. Type 2 TN was more common in the autoimmune cohort ( P = .01). On multivariate analysis, concomitant autoimmune disease, younger age, and female sex were found to be significantly associated with higher postoperative BNI score ( P = .04, <0.001, and <0.001, respectively). In addition, patients with autoimmune disease were more likely to experience significant pain recurrence ( P = .009) and had shorter time to recurrence on Kaplan-Meier analysis ( P = .047), although this relationship was attenuated on multivariate Cox proportional hazards regression. CONCLUSION: Patients with concomitant TN and autoimmune disease were more likely to have Type 2 TN, had worse postoperative BNI pain scores at the final follow-up after MVD, and were more likely to experience recurrent pain than patients with TN alone. These findings may influence postoperative pain management decisions for these patients and support a possible role for neuroinflammation in TN pain.

Machine learning predictive models in neurosurgery: an appraisal based on the TRIPOD guidelines. Systematic review.

OBJECTIVE: In recent years, machine learning models for clinical prediction have become increasingly prevalent in the neurosurgical literature. However, little is known about the quality of these models, and their translation to clinical care has been limited. The aim of this systematic review was to empirically determine the adherence of machine learning models in neurosurgery with standard reporting guidelines specific to clinical prediction models. METHODS: Studies describing the development or validation of machine learning predictive models published between January 1, 2020, and January 10, 2023, across five neurosurgery journals (Journal of Neurosurgery, Journal of Neurosurgery: Spine, Journal of Neurosurgery: Pediatrics, Neurosurgery, and World Neurosurgery) were included. Studies where the TRIPOD (Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis or Diagnosis) guidelines were not applicable, radiomic studies, and natural language processing studies were excluded. RESULTS: Forty-seven studies featuring a machine learning-based predictive model in neurosurgery were included. The majority (53%) of studies were single-center studies, and only 15% of studies externally validated the model in an independent cohort of patients. The median compliance across all 47 studies was 82.1% (IQR 75.9%-85.7%). Giving details of treatment (n = 17 [36%]), including the number of patients with missing data (n = 11 [23%]), and explaining the use of the prediction model (n = 23 [49%]) were identified as the TRIPOD criteria with the lowest rates of compliance. CONCLUSIONS: Improved adherence to TRIPOD guidelines will increase transparency in neurosurgical machine learning predictive models and streamline their translation into clinical care.

Sequential onset of bilateral trigeminal neuralgia: clinical presentation and outcomes.

PURPOSE: Sequential onset of bilateral trigeminal neuralgia (TN) is rare and not well-described in the literature. The objective of this study was to characterize demographic, clinical, and procedural characteristics of patients with sequential onset bilateral TN. METHODS: We retrospectively reviewed patients presenting with sequential onset bilateral TN at our institution from 2007 to 2020. Patient demographics, clinical diagnoses, pain outcomes, and procedural characteristics were recorded and compared. Factors associated with pain recurrence were assessed using survival analyses and multivariate regressions. RESULTS: We identified 34 patients who presented with sequential onset bilateral TN. The average age of onset for the index case was 49.9 ± 15.5 years, and 58.0 ± 16.8 years for the contralateral case. In total for our cohort, 91 surgical procedures were performed for the index case, and 70 for the contralateral case. With each additional surgical intervention, pain-free survival was more likely to decrease, p = 0.05. When controlled for order of intervention, glycerin rhizotomy (p = 0.01) and glycerin-radiofrequency rhizotomy (p = 0.05) were more likely associated with pain recurrence compared to microvascular decompression. While pain outcomes were significantly decreased in our cohort at final follow-up, 82.4% of patients were still dependent on medication for pain management after an average of 5.03 ± 7.74 years. CONCLUSION: Our results represent one of the largest series of sequential onset bilateral TN in North America. Our study demonstrates the high treatment burden and chronicity of pain encountered in this population.

H3 K27-altered diffuse midline glioma presenting as massive cerebellopontine hemorrhage.

We report the case of a 14-year-old boy who presented with extensive cerebellar and brainstem hemorrhage. Our presumptive diagnosis was a ruptured arteriovenous malformation (AVM), but two cerebral angiograms showed no significant vascular abnormalities. The patient underwent posterior fossa craniotomy and microsurgical evacuation of the hematoma. Pathological analysis of the hemorrhagic tissue made the diagnosis of diffuse midline glioma, H3 K27-altered (WHO grade 4), based on immunohistochemistry. He subsequently developed diffuse craniospinal leptomeningeal disease and progressed rapidly, with respiratory failure followed by severe neurologic decline without further hemorrhage. He was compassionately extubated at the request of the family and died before initiation of adjuvant therapy. This unusual case of a diffuse midline glioma presenting with massive hemorrhage underscores the importance of searching for an underlying etiology of hemorrhage in a child when a vascular lesion cannot be identified.

A racial analysis of pain outcomes following microvascular decompression for trigeminal neuralgia.

OBJECTIVE: Pain outcomes by race in trigeminal neuralgia (TN) are not well investigated. The authors aimed to compare microvascular decompression (MVD) outcomes in TN patients on the basis of self-identified race. METHODS: The authors retrospectively reviewed all patients with TN who underwent MVD at their institution from 2007 to 2020. Each patient's self-reported race was recorded, and Barrow Neurological Institute (BNI) scores for pain and numbness were compared. Factors associated with pain recurrence were assessed using survival analyses and multivariate regressions. RESULTS: Of 1011 patients, 925 reported their racial demographic characteristics, and patients who identified as Native American or American Indian and Native Hawaiian or Pacific Islander were excluded due to small sample sizes. Of the resulting 921 patients, 697 (75.7%) patients identified as White, 108 (11.7%) as Black or African American, 39 (4.2%) as Asian, and 77 (8.4%) as other. Compared with White patients, Black TN patients were more likely to present with type 1 TN (p = 0.02). At final follow-up, the mean BNI pain score of Black patients was significantly higher (p < 0.001) compared with that of White patients, although pain scores did not differ preoperatively. The adjusted multivariate ordinal regression model showed that Black patients were associated with higher BNI pain scores at final follow-up (p = 0.01). Furthermore, compared with White patients, Black patients were at increased risk for postoperative pain recurrence (p = 0.04), which additionally occurred after a shorter median pain-free duration (p = 0.03). CONCLUSIONS: TN patients who identify as Black or African American exhibit worse postoperative pain outcomes after MVD compared with White patients. Future studies investigating the factors driving these racial differences are warranted.

Sex-Specific Pain Outcomes Following Microvascular Decompression for Trigeminal Neuralgia.

BACKGROUND: Trigeminal neuralgia (TN) is more prevalent among women. However, while microvascular decompression (MVD) is the most effective long-term surgical treatment for TN, it is unclear whether it is equally efficacious for men and women. We sought to characterize the relationship between sex and pain outcomes following MVD for TN. METHODS: From 2007 to 2020, 938 unilateral TN patients were treated with MVD at our institution. Patient demographics, clinical characteristics, operative features, and pain outcomes were recorded. Differences between men and women were analyzed via t-test and chi-squared analyses. A multivariate ordinal regression was used to establish significant predictors of pain outcome. Differences in time to pain recurrence were assessed via Cox proportional hazards and Kaplan-Meier nonparametric survival analysis. RESULTS: A majority (67%) of the 938 patients analyzed were female. Men and women presented with similar preoperative pain severity (P = 0.17). Female sex (P = 0.048) and younger age (P = 0.03) were independently associated with worsened Barrow Neurological Institute pain scores at 3-month follow-up on multivariate analysis. Women were also more likely to experience recurrence than men (P = 0.01), and time to recurrence was shorter among women (P = 0.02). Only female sex was independently associated with increased risk of postoperative pain recurrence on multivariate Cox proportional hazards regression (P = 0.01). CONCLUSIONS: Female TN patients undergoing MVD had worse pain outcomes, more frequent pain recurrence, and shorter time to recurrence. Our results indicate a sex-specific dimorphism in response to MVD among TN patients.

The Tumor Immune Microenvironment in Primary CNS Neoplasms: A Review of Current Knowledge and Therapeutic Approaches.

Primary CNS neoplasms are responsible for considerable mortality and morbidity, and many therapies directed at primary brain tumors have proven unsuccessful despite their success in preclinical studies. Recently, the tumor immune microenvironment has emerged as a critical aspect of primary CNS neoplasms that may affect their malignancy, prognosis, and response to therapy across patients and tumor grades. This review covers the tumor microenvironment of various primary CNS neoplasms, with a focus on glioblastoma and meningioma. Additionally, current therapeutic strategies based on elements of the tumor microenvironment, including checkpoint inhibitor therapy and immunotherapeutic vaccines, are discussed.

Multiple Vessel Compression of the Trigeminal Nerve Is Associated With Worse Outcomes in Trigeminal Neuralgia After Microvascular Decompression.

BACKGROUND: Whether the total number of compressive vessels in trigeminal neuralgia (TN) affects outcomes after microvascular decompression (MVD) is unknown. OBJECTIVE: To investigate whether the number of compressive vessels is associated with outcomes after MVD. METHODS: We retrospectively reviewed all patients with TN who underwent MVDs at our institution from 2007 to 2020. The number and identity of compressive vessels on the trigeminal nerve were recorded. Preoperative and postoperative pain and numbness Barrow Neurological Institute scores were compared. Factors associated with pain recurrence were assessed using survival analyses and multivariate regressions. RESULTS: We identified 496 patients with a single vessel and 381 patients with multiple vessels compressing the trigeminal nerve. Compared with patients with a single compressive vessel, patients with multiple sources of compression exhibited increased Barrow Neurological Institute pain scores preoperatively ( P = .01). In addition, pain recurrence was more frequent ( P < .001) and occurred after a significantly shorter pain-free duration ( P < .001) for the multiple compression group. Using multivariate ordinal regression, a greater number of arteries ( P = .03) and veins ( P = .03) were both significantly associated with higher pain scores at final follow-up. Furthermore, the number of arteries ( P = .01) and of veins ( P = .01) was significantly associated with a higher risk for pain recurrence. CONCLUSION: TN patients with a single compressive vessel exhibited better pain outcomes after an MVD. Patients with multiple compressive vessels exhibited higher pain scores preoperatively and incurred a higher risk for pain recurrence, which occurred after a shorter pain-free interval compared with the single compression cohort.

A Case Series of Trigeminal Neuralgia With Pure Venous Compression: Postoperative Outcomes Associated With Intraoperative Venous Transposition Versus Coagulation.

BACKGROUND: Microvascular decompressions (MVDs) are effective open-surgical procedures for trigeminal neuralgia (TN). Intraoperative management of compressive veins may include either venous transposition or coagulation. Although both are generally considered safe, which technique results in optimal postoperative outcomes remains unclear. OBJECTIVE: To compare postoperative pain and numbness outcomes after an MVD in patients with TN of exclusive venous compression. METHODS: We retrospectively reviewed all patients with TN who underwent MVDs at our institution from 2007 to 2020. Patients with TN of pure venous compression were identified using MRI imaging, which was subsequently confirmed intraoperatively. Patient demographics, procedural characteristics, and postoperative pain and numbness scores were recorded and compared. Factors associated with pain recurrence were assessed using survival analyses and multivariate regressions. RESULTS: We identified 181 patients who presented with TN of pure venous compression. Using a multivariate linear regression, adjusted for age, sex, and presence of multiple sclerosis, use of venous transposition vs coagulation was not significantly associated with the Barrow Neurological Institute pain score at final follow-up, although venous transposition was significantly predictive of a worse postoperative Barrow Neurological Institute numbness score ( P = .003). Using a Kaplan-Meier survival analysis and a multivariate Cox proportional hazards regression, respectively, venous transposition was significantly associated with faster ( P = .01) as well as higher risk for pain recurrence ( P = .01). CONCLUSION: The use of venous coagulation during an MVD is associated with better postoperative pain and numbness outcomes. The results of our study may help inform preoperative patient counseling and surgical management for TN cases that involve pure venous compression.

Elongated, finger-like ophthalmic segment aneurysms: Implications for selection of treatment modality.

BACKGROUND: Microsurgical treatment of ophthalmic segment aneurysms often requires anterior clinoidectomy and optic nerve mobilization prior to successful clipping. OBJECTIVE: We hypothesize that ophthalmic segment aneurysms that are elongated and finger-like grow unconstrained, lateral to the optic nerve. We note that this avoids the need for clinoid resection and optic nerve mobilization. METHODS: Three cases with up-pointing aneurysms were reviewed. Patient and aneurysm characteristics were collected. RESULTS: The first two patients with elongated ophthalmic segment aneurysms were found to have aneurysms growing lateral to the optic nerve. This allowed for straightforward treatment via microsurgical clipping without anterior clinoidectomy or division of the falciform ligament. The third patient presented with distortion of the optic chiasm superiorly and medially by a giant ventral ICA aneurysm. A concomitant ophthalmic aneurysm in this patient exhibited elongated morphology, with a high-resolution MRI demonstrating the patient's optic nerve was located inferior and medial to the ophthalmic artery aneurysm dome. This supports our hypothesis that an overriding optic nerve normally impedes vertical growth of ophthalmic segment aneurysms. CONCLUSIONS: Ophthalmic segment aneurysms may acquire a round morphology when their growth is constrained superiorly by the optic nerve. Elongated ophthalmic segment aneurysms may be the result of growth lateral to the optic nerve. For these aneurysms, an anterior clinoidectomy is not required, and microsurgical clipping represents a straightforward treatment option.