Surgical outcomes and risk factors for recurrence of myxopapillary ependymoma: a single-center experience.

OBJECTIVE: Myxopapillary ependymomas (MPEs) are low-grade, well-circumscribed tumors that often involve the conus medullaris, cauda equina, or filum terminale. They account for up to 5% of all tumors of the spine and 13% of spinal ependymomas, with a peak incidence between 30 and 50 years of age. Because of the rarity of MPEs, their clinical course and optimal management strategy are not well defined, and long-term outcomes remain difficult to predict. The objective of this study was to review long-term clinical outcomes of spinal MPEs and identify factors that may predict tumor resectability and recurrence. METHODS: Pathologically confirmed cases of MPE at the authors' institution were identified and medical records were reviewed. Demographics, clinical presentation, imaging characteristics, surgical technique, follow-up, and outcome data were noted. Two groups of patients-those who underwent gross-total resection (GTR) and those who underwent subtotal resection (STR)-were compared using the Mann-Whitney U-test for continuous and ordinal variables and the Fisher exact test for categorical variables. Differences were considered statistically significant at p ≤ 0.05. RESULTS: Twenty-eight patients were identified, with a median age of 43 years at the index surgery. The median postoperative follow-up duration was 107 months (range 5-372 months). All patients presented with pain. Other common presenting symptoms were weakness (25.0%), sphincter disturbance (21.4%), and numbness (14.3%). GTR was achieved in 19 patients (68%) and STR in 9 (32%). Preoperative weakness and involvement of the sacral spinal canal were more common in the STR group. Tumors were larger and spanned more spinal levels in the STR group compared with the GTR cohort. Postoperative modified McCormick Scale grades were significantly higher in the STR cohort compared with the GTR group (p = 0.00175). Seven of the 9 STR patients (77.8%) underwent reoperation for recurrence at a median of 32 months from the index operation, while no patients required reoperation after GTR, for an overall reoperation rate of 25%. CONCLUSIONS: Findings of this study emphasize the importance of tumor size and location-particularly involvement of the sacral canal-in determining resectability. Reoperation for recurrence was necessary in 78% of patients with subtotally resected tumors; none of the patients who underwent GTR required reoperation. Most patients had stable neurological status postoperatively.

Data Science and Geriatric Anesthesia Research: Opportunity and Challenges.

With an increase in geriatric population undergoing surgical procedures, research focused on enhancing their perioperative outcomes is of paramount importance. Currently, most of the evidence-based medicine protocols are driven by studies concentrating on adults encompassing all adult age groups. Given the alterations in physiology with aging, geriatric patients respond differently to anesthetics and, therefore, require specific research initiatives to further expound on the same. Large databases and the development of sophisticated analytic tools can provide meaningful insights into this. Here, we discuss a few research opportunities and challenges that data scientists face when focusing on geriatric perioperative research.

Impact of insurance status on healthcare resource utilization and outcomes in adolescent patients presenting with spinal cord injuries.

OBJECTIVE: Insurance disparities have been suggested to influence the medical and surgical outcomes of adult patients with spinal cord injury (SCI), with a paucity of studies demonstrating their impact on the outcomes of pediatric and adolescent SCI patients. The aim of this study was to assess the impact of insurance status on healthcare utilization and outcomes in adolescent patients presenting with SCI. METHODS: An administrative database study was performed using the 2017 admission year from 753 facilities using the National Trauma Data Bank. Adolescent patients (11-17 years old) with cervical/thoracic SCIs were identified using International Classification of Diseases, Tenth Revision, Clinical Modification coding. Patients were categorized by governmental insurance versus private insurance/self-pay. Patient demographics, comorbidities, imaging, procedures, hospital adverse events (AEs), and length of stay (LOS) data were collected. Multivariate regression analyses were used to determine the effect of insurance status on LOS, any imaging or procedure, or any AE. RESULTS: Of the 488 patients identified, 220 (45.1%) held governmental insurance while 268 (54.9%) were privately insured. Age was similar between the cohorts (p = 0.616), with the governmental insurance cohort (GI cohort) having a significantly lower proportion of non-Hispanic White patients than the private insurance cohort (PI cohort) (GI: 43.2% vs PI: 72.4%, p < 0.001). While transportation accident was the most common mechanism of injury for both cohorts, assault was significantly greater in the GI cohort (GI: 21.8% vs PI: 3.0%, p < 0.001). A significantly greater proportion of patients in the PI cohort received any imaging (GI: 65.9% vs PI: 75.0%, p = 0.028), while there were no significant differences in procedures performed (p = 0.069) or hospital AEs (p = 0.386) between the cohorts. The median (IQR) LOS (p = 0.186) and discharge disposition (p = 0.302) were similar between the cohorts. On multivariate analysis, with respect to governmental insurance, private insurance was not independently associated with obtaining any imaging (OR 1.38, p = 0.139), undergoing any procedure (OR 1.09, p = 0.721), hospital AEs (OR 1.11, p = 0.709), or LOS (adjusted risk ratio -2.56, p = 0.203). CONCLUSIONS: This study suggests that insurance status may not independently influence healthcare resource utilization and outcomes in adolescent patients presenting with SCIs. Further studies are needed to corroborate these findings.

Association of frailty with healthcare resource utilization after open thoracic/thoracolumbar posterior spinal fusion for adult spinal deformity.

PURPOSE: The Hospital Frailty Risk Score (HFRS) is a frailty-identifying metric developed using ICD-10-CM codes. While other studies have examined frailty in adult spinal deformity (ASD), the HFRS has not been assessed in this population. The aim of this study was to utilize the HFRS to investigate the impact of frailty on outcomes in ASD patients undergoing posterior spinal fusion (PSF). METHODS: A retrospective study was performed using the 2016-2019 National Inpatient Sample database. Adults with ASD undergoing elective PSF were identified using ICD-10-CM codes. Patients were categorized into HFRS-based frailty cohorts: Low (HFRS < 5) and Intermediate-High (HFRS ≥ 5). Patient demographics, comorbidities, intraoperative variables, and outcomes were assessed. Multivariate regression analyses were used to determine whether HFRS independently predicted extended length of stay (LOS), non-routine discharge, and increased cost. RESULTS: Of the 7500 patients identified, 4000 (53.3%) were in the Low HFRS cohort and 3500 (46.7%) were in the Intermediate-High HFRS cohort. On average, age increased progressively with increasing HFRS scores (p < 0.001). The frail cohort experienced more postoperative adverse events (p < 0.001), greater LOS (p < 0.001), accrued greater admission costs (p < 0.001), and had a higher rate of non-routine discharge (p < 0.001). On multivariate analysis, Intermediate-High HFRS was independently associated with extended LOS (OR: 2.58, p < 0.001) and non-routine discharge (OR: 1.63, p < 0.001), though not increased admission cost (OR: 1.01, p = 0.929). CONCLUSION: Our study identified HFRS to be significantly associated with prolonged hospitalizations and non-routine discharge. Other factors that were found to be associated with increased healthcare resource utilization include age, Hispanic race, West hospital region, large hospital size, and increasing number of AEs.

Geriatric relationship with inpatient opioid consumption and hospital outcomes after open posterior spinal fusion for adult spine deformity.

OBJECTIVE: As the population ages, increasing attention has been placed on identifying risk factors for poor surgical outcomes in the elderly. The aim of this study was to assess the impact of geriatric status on inpatient narcotic consumption and healthcare resource utilization in patients undergoing spinal fusion for adult spinal deformity. METHODS: A retrospective study was performed using the Premier Healthcare Database (2016-2017). All adult patients who underwent thoracic/thoracolumbar fusion for spine deformity were identified using ICD-10-CM codes. Patients were categorized by age: 18-49 years-old (Young), 50-64 years-old (Older), and 65 + years-old (Geriatric). Patient demographics, comorbidities, hospital characteristics, intraoperative variables, adverse events (AEs), and healthcare resource utilization were assessed. Increased inpatient opioid use was categorized by MME (morphine milligram equivalents) admission consumption greater than the 75th percentile of the cohort. Multivariate logistic regression analysis was used to identify independent predictors of increased opioid usage, increased cost, and non-routine discharge (NRD). RESULTS: Of the 1831 patients identified, 199 (10.9 %) were in the Young cohort, 599 (32.7 %) were in the Older cohort, and 1033 (56.4 %) were in the Geriatric cohort. The Geriatric cohort had a greater proportion of patients who were Non-Hispanic White (p < 0.001) and government-insured (p < 0.001). Comorbidities [CCI (p < 0.001)] and frailty [mFI-5 (p < 0.001)] increased with age. AEs occurred at similar rates between cohorts. A greater proportion of Older patients consumed an increased amount of MMEs during their hospital stay (Young: 24.9 % vs. Older: 33.1 % vs. Geriatric: 20.2 %, p < 0.001). A greater proportion of Geriatric patients experienced high costs (p = 0.018), longer LOS (p = 0.011), and 30-day readmission (p = 0.004) compared to other cohorts. A significantly greater proportion of the Geriatric cohort experienced NRD (Young: 25.3 % vs. Older: 58.8 % vs. Geriatric: 83.0 %, p < 0.001) On multivariate analysis, Geriatric age was independently associated with NRD (OR: 11.59, p < 0.001), and inversely associated with increased MME use (OR: 0.66, p = 0.038). However, Older age was independently associated with increased MME use (OR: 1.58, p = 0.026) and NRD (OR: 4.27, p < 0.001), though not increased cost (OR: 1.49, p = 0.077). CONCLUSION: Our study demonstrates that geriatric patients may require fewer opioids than younger patients but require greater resource utilization on discharge. Additional studies investigating the impact of aging are necessary to improve patient risk stratification, healthcare delivery, and patient outcomes.

Association of inpatient opioid consumption on postoperative outcomes after open posterior spinal fusion for adult spine deformity.

INTRODUCTION: Opioids are the most commonly used analgesic in the postoperative setting. However, few studies have analyzed the impact of high inpatient opioid use on outcomes following surgery, with no current studies assessing its effect on patients undergoing spinal fusion for an adult spinal deformity (ASD). Thus, the aim of this study was to investigate risk factors for high inpatient opioid use, as well as to determine the impact of high opioid use on outcomes such as adverse events (AEs), hospital length of stay (LOS), cost of hospital admission, discharge disposition, and readmission rates in patients undergoing spinal fusion for ASD. METHODS: A retrospective cohort study was performed using the Premier healthcare database from the years 2016 and 2017. All adult patients > 40 years old who underwent thoracic or thoracolumbar fusion for ASD were identified using the ICD-10-CM diagnostic and procedural coding system. Patients were then categorized into three cohorts based on inpatient opioid use: Low MME (morphine milligram equivalents), Medium MME, and High MME. Patient demographics, comorbidities, treating hospital characteristics, intraoperative variables, postoperative AEs, LOS, discharge disposition, and total cost of hospital admission were assessed in the analysis. Multivariate regression analysis was done to determine independent predictors of high inpatient MME, prolonged LOS, and increased hospital cost. RESULTS: Of 1673 patients included, 417 (24.9%) were classified as Low MME, 840 (50.2%) as Medium MME, and 416 (24.9%) as High MME. Age significantly decreased with increasing MME (Low: 71.0% 65 + years vs Medium: 62.0% 65 + years vs High: 47.4% 65 + years, p < 0.001), while the proportions of patients presenting with three or more comorbidities were similar across the cohorts (Low: 20.1% with 3 + comorbidities vs Medium: 18.0% with 3 + comorbidities vs High: 24.3% with 3 + comorbidities, p = 0.070). With respect to postoperative outcomes, the proportion of patients who experienced any AE (Low: 60.2% vs Medium: 68.8% vs High: 70.9%, p = 0.002), extended LOS (Low: 6.7% vs Medium: 20.7% vs High: 45.4%, p < 0.001), or non-routine discharge (Low: 66.6% vs Medium: 73.5% vs High: 80.1%, p = 0.003) each increased along with total MME. In addition, rates of 30-day readmission were greatest among the High MME cohort (Low: 8.4% vs Medium: 7.9% vs High: 12.5%, p = 0.022). On multivariate analysis, medium and high MME were associated with prolonged LOS [Medium: OR 4.41, CI (2.90, 6.97); High: OR 13.99, CI (8.99, 22.51), p < 0.001] and increased hospital cost [Medium: OR 1.69, CI (1.21, 2.39), p = 0.002; High: OR 1.66, CI (1.12, 2.46), p = 0.011]. Preadmission long-term opioid use [OR 1.71, CI (1.07, 2.7), p = 0.022], a prior opioid-related disorder [OR 11.32, CI (5.92, 23.49), p < 0.001], and chronic pulmonary disease [OR 1.39, CI (1.06, 1.82), p = 0.018] were each associated with a high inpatient MME on multivariate analysis. CONCLUSION: Our study demonstrated that increasing inpatient MME consumption was associated with extended LOS and increased hospital cost in patients undergoing spinal fusion for ASD. Further studies identifying risk factors for increased MME consumption may provide better risk stratification for postoperative opioid use and healthcare resource utilization.

Impact of Affective Disorders on Inpatient Opioid Consumption and Hospital Outcomes Following Open Posterior Spinal Fusion for Adult Spine Deformity.

OBJECTIVE: Affective disorders (ADs) are common and have a profound impact on surgical recovery, though few have studied the impact of ADs on inpatient narcotic consumption. The aim of this study was to assess the impact of ADs on inpatient narcotic consumption and healthcare resource utilization in patients undergoing spinal fusion for adult spinal deformity. METHODS: A retrospective cohort study was performed using the 2016-2017 Premier Healthcare Database. Adults who underwent adult spinal deformity surgery were identified using International Classification of Disease, Tenth Revision, codes. Patients were grouped based on comorbid diagnosis of an AD. Demographics, comorbidities, intraoperative variables, complications, length of stay, admission costs, and nonroutine discharge rates were assessed. Increased inpatient opioid use was categorized by morphine milligram equivalents consumption greater than the 75th percentile. Multivariate regression analysis was used to identify predictors of increased healthcare recourse utilization. RESULTS: Of the 1831 study patients, 674 (36.8%) had an AD. A smaller proportion of patients in the AD cohort were 65+ years of age (P = 0.001), while a greater proportion of patients in the AD cohort identified as non-Hispanic White (P < 0.001). A greater proportion of patients in the AD cohort had increased morphine milligram equivalents consumption (P < 0.001). The AD cohort also had a longer mean length of stay (P < 0.001). A greater proportion of patients in the AD cohort had nonroutine discharges (P = 0.039) and unplanned 30-day readmission (P = 0.041). On multivariate analysis, AD was significantly associated with increased cost (odds ratio: 1.61, P < 0.001) and nonroutine discharge (odds ratio: 1.36, P = 0.035). CONCLUSIONS: ADs may be associated with increased inpatient opioid consumption and healthcare resource utilization.

Leveraging HFRS to assess how frailty affects healthcare resource utilization after elective ACDF for CSM.

BACKGROUND CONTEXT: Frailty is a common comorbidity associated with worsening outcomes in various medical and surgical fields. The Hospital Frailty Risk Score (HFRS) is a recently developed tool which assesses frailty using 109 International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) comorbidity codes to assess severity of frailty. However, there is a paucity of studies utilizing the HFRS with patients undergoing anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy (CSM). PURPOSE: The aim of this study was to investigate the impact of HFRS on health care resource utilization following ACDF for CSM. STUDY DESIGN: A retrospective cohort study was performed using the Nationwide Inpatient Sample (NIS) database from 2016-2019. PATIENT SAMPLE: All adult (≥18 years old) patients undergoing primary, ACDF for CSM were identified using the ICD-10 CM codes. OUTCOME MEASURES: Weighted patient demographics, comorbidities, perioperative complications, LOS, discharge disposition, and total admission costs were assessed. METHODS: The 109 ICD-10 codes with pre-assigned values from 0.1 to 7.1 pertaining to frailty were queried in each patient, with a cumulative HFRS ≥5 indicating a frail patient. Patients were then categorized as either Low HFRS (HFRS<5) or Moderate to High HFRS (HFRS≥5). A multivariate stepwise logistic regression was used to determine the odds ratio for risk-adjusted extended LOS, non-routine discharge disposition, and increased hospital cost. RESULTS: A total of 29,305 patients were identified, of which 3,135 (10.7%) had a Moderate to High HFRS. Patients with a Moderate to High HFRS had higher rates of 1 or more postoperative complications (Low HFRS: 9.5% vs. Moderate-High HFRS: 38.6%, p≤.001), significantly longer hospital stays (Low HFRS: 1.8±1.7 days vs. Moderate-High HFRS: 4.4 ± 6.0, p≤.001), higher rates of non-routine discharge (Low HFRS: 5.8% vs. Moderate-High HFRS: 28.2%, p≤.001), and increased total cost of admission (Low HFRS: $19,691±9,740 vs. Moderate-High HFRS: $26,935±22,824, p≤.001) than patients in the Low HFRS cohort. On multivariate analysis, Moderate to High HFRS was found to be a significant independent predictor for extended LOS [OR: 3.19, 95% CI: (2.60, 3.91), p≤.001] and non-routine discharge disposition [OR: 3.88, 95% CI: (3.05, 4.95), p≤.001] but not increased cost [OR: 1.10, 95% CI: (0.87, 1.40), p=.418]. CONCLUSIONS: Our study suggests that patients with a higher HFRS have increased total hospital costs, a longer LOS, higher complication rates, and more frequent nonroutine discharge compared with patients with a low HFRS following elective ACDF for CSM. Although frail patients should not be precluded from surgical management of cervical spine pathology, these findings highlight the need for peri-operative protocols to medically optimize patients to improve health care quality and decrease costs.

Hospital Frailty Risk Score Predicts Adverse Events and Readmission Following a Ventriculoperitoneal Shunt Surgery for Normal Pressure Hydrocephalus.

OBJECTIVE: The aim of this study was to evaluate the impact of a Hospital Frailty Risk Score (HFRS) on unplanned readmission and health care resource utilization in normal pressure hydrocephalus (NPH) patients undergoing a ventriculoperitoneal (VP) shunt surgery. METHODS: A retrospective cohort study was performed using the 2016-2019 Nationwide Readmission Database. All NPH patients (≥60 years) undergoing a VP shunt surgery were identified using ICD-10-CM diagnostic and procedural codes. Patients were dichotomized into 2 cohorts as follows: Low HFRS (<5) and Intermediate-High HFRS (≥5). A multivariate logistic regression analysis was then used to identify independent predictors of adverse event (AE) and 30- and 90-day readmission. RESULTS: Of 13,262 patients, 4386 (33.1%) had an Intermediate-High HFRS score. A greater proportion of the Intermediate-High HFRS cohort experienced at least one AE (1.9 vs. 22.1, P < 0.001). The Intermediate-High HFRS cohort also had a longer length of stay (2.3 ± 2.4 days vs. 7.0 ± 7.7 days, P < 0.001), higher non-routine discharge rate (19.9% vs. 39.9%, P < 0.001), and greater admission cost ($14,634 ± 5703 vs. $21,749 ± 15,234, P < 0.001). The Intermediate-High HFRS cohort had higher rates of 30- (7.6% vs. 11.0%, P < 0.001) and 90-day (6.8% vs. 8.3%, P < 0.001) readmissions. On a multivariate regression analysis, Intermediate-High HFRS compared to Low HFRS was an independent predictor of any AE (odds ratio, 16.6; 95% confidence interval, [12.9-21.5]; P < 0.001) and 30-day readmission (odds ratio, 1.4; 95% confidence interval, [1.2-1.7]; P < 0.001). CONCLUSIONS: Our study suggests that frailty, as defined by HFRS, is associated with increased resource utilization in NPH patients undergoing VP shunt surgery. Furthermore, HFRS was an independent predictor of adverse events and 30-day hospital readmission.

Neurosurgical Education for Medical Students: A Scoping Review.

Neurosurgeons have a rich history of involvement in medical student education. We review the scope of related published works with the goal of highlighting recently increased efforts to innovate in neurosurgical education and discuss where future efforts must go. A scoping review was performed after comprehensive search of PubMed MEDLINE and Embase databases. Among the 2314 articles returned in the search, 54 were selected for inclusion and review. Articles are discussed in the context of neurosurgery electives, American Association of Neurological Surgeons chapters and medical school programs, national neurosurgery courses, neurosurgery education materials, neurosurgery career perceptions, and the impact of coronavirus disease 2019. Despite increasing need for neurosurgical education in medical school, available experiences in formal curricula are diminishing. Longitudinal exposure to neurosurgery throughout medical school will help ensure a foundational understanding of neurosurgical disease management for all physicians and provide a pathway of exploration, education, and mentorship for the most suitable candidates. Neurosurgery faculty mentorship is particularly important to ensure that the next generation of neurologic surgeons is well equipped to treat patients, catalyze innovative research, and espouse both diverse perspectives and novel ideas.

Increasing Equity in Medical Student Neurosurgery Education Through Distance Learning.

OBJECTIVE: Addressing equitable opportunities for medical student (MS) education is important for minimizing disparities in neurosurgical care. However, international MSs, particularly from low- and middle-middle income countries (LMICs) may lack access to educational opportunities compared with their contemporaries in high-income countries. We compare the usefulness of virtual neurosurgery training camps (VNTC) between U.S. and international MSs. METHODS: A survey assessing demographics, baseline interests, and ratings of usefulness was sent to attendees after the VNTC. Ratings were compared between international and U.S. MSs. RESULTS: Thirty-three (27.7%) of 119 attendees were international MSs, of whom 24 (72.7%) were from LMICs. International MSs were more likely to hold an advanced degree (P = 0.0009), more likely to be MS3/MS4s (P = 0.0111) or postdoctoral (P < 0.0001), and less likely to be MS1/MS2s (P = 0.0059). After the VNTC, international MSs reported greater increase in interest in neurosurgery in general (P = 0.0009) and subspecialties of spine (P = 0.0002), peripheral nerve (P = 0.002), vascular (P = 0.0468), functional/epilepsy (P = 0.001), pediatric (P = 0.0285), and trauma/neurocritical care (P = 0.0067). International MSs reported greater post-VNTC willingness to pursue a career in neurosurgery (P = 0.0001), likelihood of taking a year off during medical school (P = 0.0363), and preparedness for subinternships (P = 0.0003). International MSs reported greater increases in awareness of burnout (P = 0.0157) and work-life balance in neurosurgery (P = 0.0249). CONCLUSIONS: International MSs experience prolonged periods of education before applying to residency and have unmet informational needs. Distance learning is useful for international MSs. MS neurosurgery education, through online platforms, represents a long-term strategy for addressing disparities in neurosurgical care worldwide.

Assessment of Frailty Indices and Charlson Comorbidity Index for Predicting Adverse Outcomes in Patients Undergoing Surgery for Spine Metastases: A National Database Analysis.

OBJECTIVE: The aim of this study was to assess the predictive ability of Metastatic Spinal Tumor Frailty Index (MSTFI) and the Modified 5-Item Frailty Index (mFI-5) on adverse outcomes, compared with the known Charlson Comorbidity Index (CCI). METHODS: A retrospective cohort study was performed using National Surgical Quality Improvement Program database from 2011 to 2019. All adult patients undergoing various procedures for extradural spinal metastases were identified. Patients were stratified into frail and nonfrail cohorts based on CCI, mFI-5, and MSTFI scores. A multivariate logistic regression analysis was used to identify independent predictors of prolonged length of stay, nonroutine discharge, adverse events, and unplanned readmission. RESULTS: Of the 1613 patients included in this study, 21.4% had a CCI >0, 56.6% had an mFI-5 >0, and 76.7% of patients had an MSTFI >0. On multivariate analysis, all 3 indices were found to be predictive of nonroutine discharge (CCI: adjusted odds ratio [aOR], 1.41 vs. mFI-5: aOR, 1.37 vs. MSTFI: aOR, 1.5) and adverse events (CCI: aOR, 1.53 vs. mFI-5: aOR, 1.23 vs. MSTFI: aOR, 1.43). High CCI (adjusted relative risk, 1.67) and MSTFI (adjusted relative risk, 1.14), but not mFI-5, were also associated with a prolonged length of stay, whereas MSTFI was found to be the only significant predictor of unplanned readmission (aOR, 1.22). CONCLUSIONS: Our study suggests that MSTFI frailty index may be more sensitive than both CCI and mFI-5 in identifying adverse outcomes after spine surgery for metastases.

Impact of Frailty on Morbidity and Mortality in Adult Patients Undergoing Surgical Evacuation of Acute Traumatic Subdural Hematoma.

OBJECTIVE: To determine whether baseline frailty is an independent predictor of extended hospital length of stay (LOS), nonroutine discharge, and in-hospital mortality after evacuation of an acute traumatic subdural hematoma (SDH). METHODS: A retrospective cohort study was performed. All adult patients who underwent surgery for an acute traumatic SDH were identified using the National Trauma Database from the year 2017. Patients were categorized into 3 cohorts based on the criteria of the 5-item modified frailty index (mFI-5): mFI = 0, mFI = 1, or mFI = 2+. A multivariate logistic regression analysis was used to identify independent predictors of extended LOS, nonroutine discharge, and in-hospital mortality. RESULTS: Of the 2620 patients identified, 41.7% were classified as mFI = 0, 32.7% as mFI = 1, and 25.6% as mFI = 2+. Rates of extended LOS and in-hospital mortality did differ significantly between the cohorts, with the mFI = 0 cohort most often experiencing a prolonged LOS (mFI = 0: 29.41% vs. mFI = 1: 19.45% vs. mFI = 2+: 19.73%, P < 0.001) and in-hospital mortality (mFI = 0: 24.66% vs. mFI = 1: 18.11% vs. mFI = 2+: 21.58%, P = 0.002). On multivariate regression analysis, when compared with mFI = 0, mFI = 2+ (odds ratio 1.4, P = 0.03) predicted extended LOS and nonroutine discharge (odds ratio 1.61, P = 0.001). CONCLUSIONS: Our study demonstrates that baseline frailty may be an independent predictor of extended LOS and nonroutine discharge, but not in-hospital mortality, in patients undergoing evacuation for an acute traumatic SDH. Further investigations are warranted as they may guide treatment plans and reduce health care expenditures for frail patients with SDH.

Optimizing the surgical management of MRI-negative epilepsy in the neuromodulation era.

OBJECTIVE: To evaluate the role of intracranial electroencephalography monitoring in diagnosing and directing the appropriate therapy for MRI-negative epilepsy and to present the surgical outcomes of patients following treatment. METHODS: Retrospective chart review between 2015-2021 at a single institution identified 48 patients with no lesion on MRI, who received surgical intervention for their epilepsy. The outcomes assessed were the surgical treatment performed and the International League Against Epilepsy seizure outcomes at 1 year of follow-up. RESULTS: Eleven patients underwent surgery without invasive monitoring, including vagus nerve stimulation (10%), deep brain stimulation (8%), laser interstitial thermal therapy (2%), and callosotomy (2%). The remaining 37 patients received invasive monitoring followed by resection (35%), responsive neurostimulation (21%), and deep brain stimulation (15%) or no treatment (6%). At 1 year postoperatively, 39% were Class 1-2, 36% were Class 3-4 and 24% were Class 5. More patients with Class 1-2 or 3-4 outcomes underwent invasive monitoring (100% and 83% respectively) compared with those with poor outcomes (25%, P < .001). Patients with Class 1-2 outcomes more commonly underwent resection or responsive neurostimulation: 69% and 31%, respectively (P < .001). SIGNIFICANCE: The optimal management of MRI-negative focal epilepsy may involve invasive monitoring followed by resection or responsive neurostimulation in most cases, as these treatments were associated with the best seizure outcomes in our cohort. Unless multifocal onset is clear from the noninvasive evaluation, invasive monitoring is preferred before pursuing deep brain stimulation or vagal nerve stimulation directly.

Perspectives on Understanding Aberrant Brain Networks in Epilepsy.

Epilepsy is a neurological disorder affecting approximately 70 million people worldwide. It is characterized by seizures that are complex aberrant dynamical events typically treated with drugs and surgery. Unfortunately, not all patients become seizure-free, and there is an opportunity for novel approaches to treat epilepsy using a network view of the brain. The traditional seizure focus theory presumed that seizures originated within a discrete cortical area with subsequent recruitment of adjacent cortices with seizure progression. However, a more recent view challenges this concept, suggesting that epilepsy is a network disease, and both focal and generalized seizures arise from aberrant activity in a distributed network. Changes in the anatomical configuration or widespread neural activities spanning lobes and hemispheres could make the brain more susceptible to seizures. In this perspective paper, we summarize the current state of knowledge, address several important challenges that could further improve our understanding of the human brain in epilepsy, and invite novel studies addressing these challenges.

Oral glutamine supplementation increases seizure severity in a rodent model of mesial temporal lobe epilepsy.

Background: Glutamine synthetase (GS) is the only enzyme known to synthesize significant amounts of glutamine in mammals, and loss of GS in the hippocampus has been implicated in the pathophysiology of medication refractory mesial temporal lobe epilepsy (MTLE). Moreover, loss-of-function mutations of the GS gene causes severe epileptic encephalopathy, and supplementation with glutamine has been shown to normalize EEG and possibly improve the outcome in these patients. Here we examined whether oral glutamine supplementation is an effective treatment for MTLE by assessing the frequency and severity of seizures after supplementation in a translationally relevant model of the disease.Methods: Male Sprague Dawley rats (380-400 g) were allowed to drink unlimited amounts of glutamine in water (3.6% w/v; n = 8) or pure water (n = 8) for several weeks. Ten days after the start of glutamine supplementation, GS was chronically inhibited in the hippocampus to induce MTLE. Continuous video-intracranial EEG was collected for 21 days to determine the frequency and severity of seizures.Results: While there was no change in seizure frequency between the groups, the proportion of convulsive seizures was significantly higher in glutamine treated animals during the first three days of GS inhibition.Conclusion: The results suggest that oral glutamine supplementation transiently increases seizure severity in the initial stages of an epilepsy model, indicating a potential role of the amino acid in seizure propagation and epileptogenesis.

Management of patients with medically intractable epilepsy and anterior temporal lobe encephaloceles.

OBJECTIVE: Temporal lobe encephaloceles (TLENs) are a significant cause of medically refractory epilepsy, but there is little consensus regarding their workup and treatment. This study characterizes these lesions and their role in seizures and aims to standardize preoperative evaluation and surgical management. METHODS: Patients with TLEN who had undergone resective epilepsy surgery from December 2015 to August 2020 at a single institution were included in the study. Medical records were reviewed for each patient to collect relevant seizure workup information including demographics, radiological findings, surgical data, and neuropsychological evaluation. RESULTS: For patients who presented to the authors' program with suspected medically intractable temporal lobe epilepsy (219 patients), TLEN was considered to be the epileptogenic focus in 5.5%. Ten patients with TLEN had undergone resection and were included in this study. Concordance between ictal scalp electroencephalography (EEG) lateralization and TLEN was found in 9/10 patients (90%), and 4/10 patients (40%) had signs suggestive of idiopathic intracranial hypertension (IIH). Surgical outcome was reported in patients with at least 12 months of follow-up (9/10). Patients with scalp EEG findings concordant with the TLEN side had a good outcome (Engel class I: 7 patients, class II: 1 patient). One patient with discordant EEG findings had a bad outcome (Engel class III). No significant neuropsychological deficits were observed after the surgery. CONCLUSIONS: TLENs are epileptogenic lesions that should be screened for in patients with medically refractory epilepsy who have signs of IIH and no other lesions on MRI. Restricted resection is safe and effective in patients with scalp EEG findings concordant with TLEN.

Small loci of astroglial glutamine synthetase deficiency in the postnatal brain cause epileptic seizures and impaired functional connectivity.

OBJECTIVE: The astroglial enzyme glutamine synthetase (GS) is deficient in small loci in the brain in adult patients with different types of focal epilepsy; however, the role of this deficiency in the pathogenesis of epilepsy has been difficult to assess due to a lack of sufficiently sensitive and specific animal models. The aim of this study was to develop an in vivo approach for precise and specific deletions of the GS gene in the postnatal brain. METHODS: We stereotaxically injected various adeno-associated virus (AAV)-Cre recombinase constructs into the hippocampal formation and neocortex in 22-70-week-old GSflox/flox mice to knock out the GS gene in a specific and focal manner. The mice were subjected to seizure threshold determination, continuous video-electroencephalographic recordings, advanced in vivo neuroimaging, and immunocytochemistry for GS. RESULTS: The construct AAV8-glial fibrillary acidic protein-green fluorescent protein-Cre eliminated GS in >99% of astrocytes in the injection center with a gradual return to full GS expression toward the periphery. Such focal GS deletion reduced seizure threshold, caused spontaneous recurrent seizures, and diminished functional connectivity. SIGNIFICANCE: These results suggest that small loci of GS deficiency in the postnatal brain are sufficient to cause epilepsy and impaired functional connectivity. Additionally, given the high specificity and precise spatial resolution of our GS knockdown approach, we anticipate that this model will be extremely useful for rigorous in vivo and ex vivo studies of astroglial GS function at the brain-region and single-cell levels.

Incidence and characteristics of metastatic intracranial lesions in stage III and IV melanoma: a single institute retrospective analysis.

INTRODUCTION: The study aimed to describe the brain metastases (BM) incidence, at diagnosis and follow-up, in patients initially presenting with stage III or IV melanoma and characterize their metastatic brain lesions. We also sought to describe the association of common genetic mutations and immunotherapy with BM development in advanced melanoma. METHODS: Using our institution's tumor registry, we identified patients with initial diagnoses of stage III and stage IV melanoma. In this cohort, we obtained BM incidence at diagnosis and follow-up, characterized the metastatic brain lesions and primary tumor's genetic profile. RESULTS: During the follow-up period, 22.9% of patients with an initial diagnosis of stage III developed BM. In this cohort, the median time for BM occurrence was 20 months; [95% CI (14-29)]. Likewise, 37.7% of patients with Stage IV melanoma presented with BM at the time of diagnosis, and 22.7% of remaining patients developed BM at follow-up over a median duration of 6 months [95% CI (4-11)]. Therefore, suggesting an overall incidence of 51.9% in stage IV melanoma. Next, we observed that the incidence of BM development during the follow-up period significantly decreased from 2012 to 2017 (p < 0.001). Lastly, we found a significantly higher frequency of mutational BRAF in the primary tumor of patients with BM (68.7% vs. 31.2%; p = 0.02). CONCLUSIONS: While the overall incidence of BM remains high, the decreasing incidence of BM over the follow-up period is promising. Similar BM incidence in patients with an initial diagnosis of stage III or stage IV warrants appropriate imaging surveillance regimen for stage III patients.