Complications of Implanted Vagus Nerve Stimulation: A Systematic Review and Meta-analysis.

INTRODUCTION: Vagus Nerve Stimulation (VNS) has emerged as a promising tool in ischemic stroke rehabilitation. However, there has been no systematic review summarizing its adverse effects, critical information for patients and providers when obtaining informed consent for this novel treatment. This systematic review and meta-analysis reports the adverse effects of VNS. METHODS: A systematic review was performed in accordance with PRISMA guidelines to identify common complications after VNS therapy. The search was executed in: Cochrane Central Register of Controlled Trials, Embase, and Ovid MEDLINE. All prospective, randomized controlled trials using implanted VNS therapy in adult patients were eligible for inclusion. Case studies and studies lacking complete complication reports were excluded. Extracted data included technology name, location of implantation, follow-up duration, purpose of VNS, and adverse event rates. RESULTS: After title-and-abstract screening of 4933 studies, 21 were selected for final inclusion. Across these studies, 1474 patients received VNS implantation. VNS was used as a potential therapy for epilepsy (9), depression (8), anxiety (1), ischemic stroke (1), chronic heart failure (1), and fibromyalgia (1). The 5 most common post-implant adverse events were voice alteration/hoarseness (n=671, 45.5%), paresthesia (n = 233, 15.8%), cough (n = 221, 15.0%), dyspnea (n = 211, 14.3%), and pain (n = 170, 11.5%). CONCLUSIONS: Complications from VNS are mild and transient, with reduction in severity and number of adverse events with increasing follow-up time. In prior studies, VNS has served as treatment option in several instances of treatment-resistant conditions, such as epilepsy and psychiatric conditions, and its use in stroke recovery and rehabilitation should continue to be explored.

Body Mass Index Impacts Indication But Not Outcomes of Thoracic Endovascular Aortic Repair.

BACKGROUND: There are limited studies looking at thoracic endovascular aortic repair (TEVAR) outcomes in obese and overweight patients. Our objective was to determine the rate of complications, reintervention, and short-term mortality in normal weight, overweight, and obese patients undergoing TEVAR. METHODS: Patients undergoing TEVAR at a large tertiary hospital from October 2007 to January 2020 were analyzed. Patients were stratified into 3 cohorts based on body mass index (BMI): normal (18.5-25 kg/m2), overweight (25-30 kg/m2), and obese (>30 kg/m2). Primary outcomes were 30-day and 1-year survival. Intraoperative, in-hospital, and postdischarge complications were assessed as secondary outcomes using the Clavian-Dindo classification system. In addition, reinterventions associated with the index TEVAR procedure as a secondary outcome. RESULTS: Among 204 patients fitting the study criteria, we identified 65 with normal BMI, 78 overweight, and 61 obese patients. Obese patients were younger than the overweight and normal BMI patients (mean age 62.2 vs. 66.7 vs. 70.7, respectively, P = 0.003). In terms of TEVAR indication, the obese cohort had the highest percentage of patients with type B aortic dissection (36.4%), while the normal BMI cohort had the higher proportion of patients undergoing TEVAR for isolated thoracic aortic aneurysm (63.9%). Intraoperative complications did not significantly differ between cohorts. Postoperatively, in-hospital complications, postdischarge complications and 30-day return to the operative room did not differ significantly between study cohorts. Odds of reintervention did not differ significantly between cohorts, both on univariate and multivariate analysis. Log-rank test of Kaplan Meier analysis revealed no difference in reintervention-free survival (P = 0.22). Thirty-day mortality and 1-year overall survival were similar across cohorts. Both univariate and multivariate logarithmic regression revealed no difference in likelihood of 30-day mortality between the obese and normal cohort. CONCLUSIONS: There were no measurable differences in complications, reinterventions, or mortality, suggesting that vascular surgeons can perform TEVAR across a spectrum of BMI without compromising outcomes.

A rare case of herpes simplex virus encephalitis from viral reactivation following surgically treated traumatic brain injury.

OBJECTIVE: Herpes simplex virus encephalitis (HSVE) is associated with significant morbidity and mortality. Here, we present the occurrence of HSVE in a 36-year-old immunocompetent patient following craniotomy for a traumatic acute subdural hematoma (ASDH). METHODS: Imaging after four days of progressive headache following a fall with head-strike demonstrated a 1 cm thick left holohemispheric ASDH with significant cerebral compression, edema, and 8 mm of left-to-right midline shift, and an emergent craniotomy and ASDH evacuation were performed, with additional treatment needed for reaccumulation. Postoperatively, the patient developed a worsening leukocytosis, became febrile, and was hypotensive requiring vasopressor support. RESULTS: Despite empiric antibiotics, the patient remained persistently febrile with significant leukocytosis. Repeat head CT showed a new left insular hypodensity and a subsequent viral encephalitis panel was positive for HSV-1. The patient was then started on intravenous acyclovir, with progressive neurological exam improvement. Of note, the patient was noted to have a positive serum HSV-1 IgG antibody titer, indicative of prior infection. CONCLUSIONS: Given the known systemic immunosuppression in brain injury and the high prevalence of HSV seropositivity, clinicians should consider the possibility of HSVE from HSV reactivation in TBI patients with persistent fever, leukocytosis, and/or neurological deficits without an obvious etiology.

The effect of age on baseline neurocognitive performance.

OBJECTIVE: Evaluate the independent effect of age on baseline neurocognitive performance. STUDY DESIGN: Baseline ImPACT scores from tests taken by 7454 athletes aged 12-22 from 2009 to 2019 were split into three age cohorts: 12-14 years (3244), 15-17 years (3732), and 18-22 years (477). Linear regression analyses were used to evaluate the effect of age on ImPACT composite scores while controlling for demographic differences, medication-use, and symptom burden. Significance values have been set at p < 0.05. RESULTS: Linear regression analyses demonstrated that increased age does not significantly affect symptom score (ß = 0.06, p = 0.54) but does improve impulse control (ß = -0.45, p < 0.0001), verbal memory (ß = 0.23, p = 0.03), visualmotor (ß = 0.77, p < 0.0001), and reaction time (ß = -0.008, p < 0.0001) scores.  However, age did not have an effect on visual memory scores (ß = -0.25, p = 0.07). CONCLUSIONS: Age was shown to be an independent modifier of impulse control, verbal memory, visual motor, and reaction time scores but not visual memory or symptom scores.  This underscores the previous literature showing developmental differences as age increases among the adolescent athlete population.  This data also indicates the need for repeat neurocognitive baseline testing every other year as baseline scoring is likely to change as athletes become older.

Controlling Pharmaceutical Costs in a Student-Run Free Clinic in a Resource-Limited Patient Setting.

Our institution's student-run free clinic has been able to offer medication at no out-of-pocket cost to all patients since it opened in 2004. We have employed two strategies to manage prescription drug costs while simultaneously increasing medication coverage: (1) using Patient Drug Assistance Programs (PDAPs) and (2) developing an institutional-level partnership with pharmaceutical charities for medication subsidization. In this study, we aimed to analyze the financial impact of these measures on the clinic.A query of clinic data over the past 5 years identified 299 active PDAPs, corresponding to 299 fully-subsidized prescriptions. In 2017, there were 35 active PDAPs, increasing to 52 (2018), 62 (2019), and 82 (2020) before a decline to 68 PDAPs in 2021. The company affiliated with the most PDAPs varied annually: GlaxoSmithKline (2017), Lilly (2018, 2019, 2020), and both GlaxoSmithKline and Lilly (2021). The most frequent medications were sitagliptin (2017), insulin (2018, 2019), albuterol (2017, 2018), and dulaglutide (2020, 2021).In addition, data extracted from the private company subsidization program was analyzed for the year 2021. Program membership was $10,000 for institution-wide medication subsidization for all uninsured patients in the hospital system. In total, the clinic was able to acquire 220 medications with a 96% subsidy, corresponding to a direct clinic cost of $2,101.28. Comparatively, the market value of these medications was $52,401.51.Utilization of free drug acquisition programs and partnerships with pharmaceutical charities allowed for an increase in cost-savings and medications provided. Although the process for applying for medication assistance programs is complex, these programs serve as powerful tools for providing medications that may otherwise be unavailable due to cost. Other clinics and healthcare settings with uninsured patients should consider these programs as a means to ease medication cost burden.

Vagal Nerve Stimulation: A Bibliometric Analysis of Current Research Trends.

BACKGROUND: Vagal nerve stimulation (VNS) has become established as an effective tool for the management of various neurologic disorders. Consequently, a growing number of VNS studies have been published over the past four decades. This study presents a bibliometric analysis investigating the current trends in VNS literature. MATERIALS AND METHODS: Using the Web of Science collection data base, a search was performed to identify literature that discussed applications of VNS from 2000 to 2021. Analysis and visualization of the included literature were completed with VOSviewer. RESULTS: A total of 2895 publications were identified. The number of articles published in this area has increased over the past two decades, with the most citations (7098) occurring in 2021 and the most publications (270) in 2020. The h-index, i-10, and i-100 were 97, 994, and 91, respectively, with 17.0 citations per publication on average. The highest-producing country and institution of VNS literature were the United States and the University of Texas, respectively. The most productive journal was Epilepsia. Epilepsy was the predominant focus of VNS research, with the keyword "epilepsy" having the greatest total link strength (749) in the keyword analysis. The keyword analysis also revealed two major avenues of VNS research: 1) the mechanisms by which VNS modulates neural circuitry, and 2) therapeutic applications of VNS in a variety of diseases beyond neurology. It also showed a significant prevalence of noninvasive VNS research. Although epilepsy research appears more linked to implanted VNS, headache and depression specialists were more closely associated with noninvasive VNS. CONCLUSION: VNS may serve as a promising intervention for rehabilitation beyond neurologic applications, with an expanding base of literature over the past two decades. Although epilepsy researchers have produced most current literature, other fields have begun to explore VNS as a potential treatment, likely owing to the rise of noninvasive forms of VNS.

Risk Factors for Opioid Utilization in Patients with Intracerebral Hemorrhage.

BACKGROUND: Headache is a common presenting symptom of intracerebral hemorrhage (ICH) and often necessitates treatment with opioid medications. However, opioid prescribing patterns in patients with ICH are not well described. We aimed to characterize the prevalence and risk factors for short and longer-term opioid use in patients with ICH. METHODS: We conducted a retrospective cohort study using data from a single-center registry of patients with nontraumatic ICH. This registry included data on demographics, ICH-related characteristics, and premorbid, inpatient, and postdischarge medications. After excluding patients who died or received end-of-life care, we used multivariable regression models adjusted for premorbid opioid use to determine demographic and ICH-related risk factors for inpatient and postdischarge opioid use. RESULTS: Of 468 patients with ICH in our cohort, 15% (n = 70) had premorbid opioid use, 53% (n = 248) received opioids during hospitalization, and 12% (n = 53) were prescribed opioids at discharge. The most commonly used opioids during hospitalization were fentanyl (38%), oxycodone (30%), morphine (26%), and hydromorphone (7%). Patients who received opioids during hospitalization were younger (univariate: median [interquartile range] 64 [53.5-74] vs. 76 [67-83] years, p < 0.001; multivariable: odds ratio [OR] 0.96 per year, 95% confidence interval [CI] 0.94-0.98) and had larger ICH volumes (univariate: median [interquartile range] 10.1 [2.1-28.6] vs. 2.7 [0.8-9.9] cm3, p < 0.001; multivariable: OR 1.05 per cm3, 95% CI 1.03-1.08) than those who did not receive opioids. All patients who had external ventricular drain placement and craniotomy/craniectomy received inpatient opioids. Additional risk factors for increased inpatient opioid use included infratentorial ICH location (OR 4.8, 95% CI 2.3-10.0), presence of intraventricular hemorrhage (OR 3.9, 95% CI 2.2-7.0), underlying vascular lesions (OR 3.0, 95% CI 1.1-8.1), and other secondary ICH etiologies (OR 7.5, 95% CI 1.7-32.8). Vascular lesions (OR 4.0, 95% CI 1.3-12.5), malignancy (OR 5.0, 95% CI 1.5-16.4), vasculopathy (OR 10.0, 95% CI 1.8-54.2), and other secondary etiologies (OR 7.2, 95% CI 1.8-29.9) were also risk factors for increased opioid prescriptions at discharge. Among patients who received opioid prescriptions at discharge, 43% (23 of 53) continued to refill their prescriptions at 3 months post discharge. CONCLUSIONS: Inpatient opioid use in patients with ICH is common, with some risk factors that may be mechanistically connected to primary headache pathophysiology. However, the lower frequency of opioid prescriptions at discharge suggests that inpatient opioid use does not necessarily lead to a high rate of long-term opioid dependence in patients with ICH.

Accuracy of artificial intelligence for the detection of intracranial hemorrhage and chronic cerebral microbleeds: a systematic review and pooled analysis.

BACKGROUND: Artificial intelligence (AI)-driven software has been developed and become commercially available within the past few years for the detection of intracranial hemorrhage (ICH) and chronic cerebral microbleeds (CMBs). However, there is currently no systematic review that summarizes all of these tools or provides pooled estimates of their performance. METHODS: In this PROSPERO-registered, PRISMA compliant systematic review, we sought to compile and review all MEDLINE and EMBASE published studies that have developed and/or tested AI algorithms for ICH detection on non-contrast CT scans (NCCTs) or MRI scans and CMBs detection on MRI scans. RESULTS: In total, 40 studies described AI algorithms for ICH detection in NCCTs/MRIs and 19 for CMBs detection in MRIs. The overall sensitivity, specificity, and accuracy were 92.06%, 93.54%, and 93.46%, respectively, for ICH detection and 91.6%, 93.9%, and 92.7% for CMBs detection. Some of the challenges encountered in the development of these algorithms include the laborious work of creating large, labeled and balanced datasets, the volumetric nature of the imaging examinations, the fine tuning of the algorithms, and the reduction in false positives. CONCLUSIONS: Numerous AI-driven software tools have been developed over the last decade. On average, they are characterized by high performance and expert-level accuracy for the diagnosis of ICH and CMBs. As a result, implementing these tools in clinical practice may improve workflow and act as a failsafe for the detection of such lesions. REGISTRATION-URL: https://www.crd.york.ac.uk/prospero/ Unique Identifier: CRD42021246848.

Portable stroke detection devices: a systematic scoping review of prehospital applications.

BACKGROUND: The worldwide burden of stroke remains high, with increasing time-to-treatment correlated with worse outcomes. Yet stroke subtype determination, most importantly between stroke/non-stroke and ischemic/hemorrhagic stroke, is not confirmed until hospital CT diagnosis, resulting in suboptimal prehospital triage and delayed treatment. In this study, we survey portable, non-invasive diagnostic technologies that could streamline triage by making this initial determination of stroke type, thereby reducing time-to-treatment. METHODS: Following PRISMA guidelines, we performed a scoping review of portable stroke diagnostic devices. The search was executed in PubMed and Scopus, and all studies testing technology for the detection of stroke or intracranial hemorrhage were eligible for inclusion. Extracted data included type of technology, location, feasibility, time to results, and diagnostic accuracy. RESULTS: After a screening of 296 studies, 16 papers were selected for inclusion. Studied devices utilized various types of diagnostic technology, including near-infrared spectroscopy (6), ultrasound (4), electroencephalography (4), microwave technology (1), and volumetric impedance spectroscopy (1). Three devices were tested prior to hospital arrival, 6 were tested in the emergency department, and 7 were tested in unspecified hospital settings. Median measurement time was 3 minutes (IQR: 3 minutes to 5.6 minutes). Several technologies showed high diagnostic accuracy in severe stroke and intracranial hematoma detection. CONCLUSION: Numerous emerging portable technologies have been reported to detect and stratify stroke to potentially improve prehospital triage. However, the majority of these current technologies are still in development and utilize a variety of accuracy metrics, making inter-technology comparisons difficult. Standardizing evaluation of diagnostic accuracy may be helpful in further optimizing portable stroke detection technology for clinical use.

Effects of a history of headache and migraine treatment on baseline neurocognitive function in young athletes.

OBJECTIVE/BACKGROUND: Despite the prevalence of concussions in young athletes, the impact of headaches on neurocognitive function at baseline is poorly understood. We analyze the effects of a history of headache treatment on baseline ImPACT composite scores in young athletes. METHODS: A total of 11,563 baseline ImPACT tests taken by 7,453 student-athletes ages 12-22 between 2009 and 2019 were reviewed. The first baseline test was included. There were 960 subjects who reported a history of treatment for headache and/or migraine (HA) and 5,715 controls (CT). The HA cohort included all subjects who self-reported a history of treatment for migraine or other type of headache on the standardized questionnaire. Chi-squared tests were used to compare demographic differences. Univariate and multivariate regression analyses were used to assess differences in baseline composite scores between cohorts while controlling for demographic differences and symptom burden. RESULTS: Unadjusted analyses demonstrated that HA was associated with increased symptoms (ß=2.30, 95% CI: 2.18-2.41, p<.0001), decreased visual memory (ß=-1.35, 95% CI: -2.62 to -0.43, p=.004), and increased visual motor speed (ß=0.71, 95% CI: 0.23-1.19, p=.004) composite scores. Baseline scores for verbal memory, reaction time, and impulse control were not significantly different between cohorts. Adjusted analyses demonstrated similar results with HA patients having greater symptom burden (ß=1.40, 95% CI: 1.10-1.70, p<.0001), lower visual memory (ß=-1.25, 95% CI: -2.22 to -0.27, p=.01), and enhanced visual motor speed (ß=0.60, 95% CI: 0.11-1.10, p=.02) scores. CONCLUSION: HA affected symptom, visual motor speed, and visual memory ImPACT composite scores. Visual memory scores and symptom burden were significantly worse in the HA group while visual motor speed scores were better, which may have been due to higher stimulant use in the HA group. The effects of HA on visual motor speed and visual memory scores were independent of the effects of the increased symptom burden.

Gender Disparities in Stroke Code Activation in Patients with Intracerebral Hemorrhage.

OBJECTIVES: Routine implementation of protocol-driven stroke "codes" results in timelier and more effective acute stroke management. However, it is unclear if patient demographics contribute to disparities in stroke code activation. We aimed to explore these demographic factors in a retrospective cohort study of patients with intracerebral hemorrhage (ICH). MATERIALS AND METHODS: We identified consecutive patients with non-traumatic ICH who presented directly to our Comprehensive Stroke Center over 2 years and collected data on demographics, clinical features, and stroke code activation. We used multivariable logistic regression to examine differences in stroke code activation based on patient demographics while adjusting for initial clinical features (NIH Stroke Scale, FAST [facial drooping, arm weakness, speech difficulties] vs. non-FAST symptoms, time from last-known-well [LKW], and systolic blood pressure [SBP]). RESULTS: Among 265 patients, 68% (n=179) had a stroke code activation. Stroke codes occurred less frequently in women (62%) than men (72%) and in non-white (57%) vs. white patients (70%). Non-stroke code patients were less likely to have FAST symptoms (37% vs. 87%) and had lower initial SBP (mean±SD 159.3±34.2 vs. 176.0±31.9 mmHg) than stroke code patients. In our primary multivariable models, neither age nor race were associated with stroke code activation. However, women were significantly less likely to have stroke codes than men (OR 0.49 [95% CI 0.24-0.98]), as were non-FAST symptoms (OR 0.11 [95% CI 0.05-0.22]). CONCLUSIONS: Our data suggest gender disparities in emergency stroke care that should prompt further investigations into potential systemic biases. Increased awareness of atypical stroke symptoms is also warranted.

H-index and academic rank in general surgery and surgical specialties in the United States.

BACKGROUND: H-index serves as an alternative to measure academic achievement. Our objective is to study the h-index as a measure of academic attainment in general surgery and surgical specialties. METHODS: A database of all surgical programs in the United States was created. Publish or Perish software was used to determine surgeons h-index. RESULTS: A total of 134 hospitals and 3712 surgeons (79% male) were included. Overall, mean h-index was 14.9 ± 14.8. H-index increased linearly with academic rank: 6.8 ± 6.4 for assistant professors (n = 1557, 41.9%), 12.9 ± 9.3 for associate professors (n = 891, 24%), and 27.9 ± 17.4 for professors (n = 1170, 31.5%); P < 0.001. Thoracic surgery and surgical oncology had the highest subspecialty mean h-indices (18.7 ± 16.7 and 18.4 ± 17.6, respectively). Surgeons with additional postgraduate degrees, university affiliations and male had higher mean h-indices; P < 0.001. Scatterplot analysis showed a strong correlation between h-index and the number of publications (R2 = 0.817) and citations (R2 = 0.768). CONCLUSIONS: The h-index of academic surgeons correlates with academic rank and serves a potential tool to measure academic productivity.

Identifying Predictors of Initial Surgical Failure during Minimally Invasive Endoscopic Intracerebral Hemorrhage Evacuation.

Background and Purpose: Intracerebral hemorrhage (ICH) is a common and severe disease with high rates of morbidity and mortality; however, minimally invasive surgical (MIS) hematoma evacuation represents a promising avenue for treatment. In February of 2019, the MISTIE III study found that stereotactic thrombolysis with catheter drainage did not benefit patients with supratentorial spontaneous ICH but that a clinical benefit may be present when no more than 15 mL of hematoma remains at the end of treatment. Intraoperative CT (iCT) imaging has the ability to assess whether or not this surgical goal has been met in real time, allowing for operations to add additional CT-informed 'evacuation periods' (EPs) to achieve the surgical goal. Here, we report on the frequency and predictors of initial surgical failure on at least one iCT requiring additional EPs in a large cohort of patients undergoing endoscopic minimally invasive ICH evacuation with the SCUBA technique. Methods: All patients who underwent minimally invasive endoscopic evacuation of supratentorial spontaneous ICH in a major health system between December 2015 and October 2018 were included in this study. Patient demographics, clinical and radiographic features, procedural details, and outcomes were analyzed retrospectively from a prospectively collected database. Procedures were characterized as initially successful when the first iCT demonstrated that surgical success had been achieved and initially unsuccessful when the surgical goal was not achieved, and additional EPs were performed. The surgical goal was prospectively identified in December of 2015 as leaving no more than 20% of the preoperative hematoma volume at the end of the procedure. Descriptive statistics and regression analyses were performed to identify predictors of initial failure and secondary rescue. Results: Patients (100) underwent minimally invasive endoscopic ICH evacuation in the angiography suite during the study time period. In 14 cases, the surgical goal was not met on the first iCT and multiple Eps were performed; in 10 cases the surgical goal was not met, and no additional EPs were performed. In 14 cases, the surgical goal was never achieved. When additional EPs were performed, a rescue rate of 71.4% (10/14) was seen, bringing the total percentage of cases meeting the surgical goal to 86% across the entire cohort. Cases in which the surgical goal was not achieved were significantly associated with older patients (68 years vs. 60 years; p = 0.0197) and higher rates of intraventricular hemorrhage (34.2% vs. 70.8%; p = 0.0021). Cases in which the surgical goal was rescued from initial failure had similar levels of IVH, suggesting that these additional complexities can be overcome with the use of additional iCT-informed EPs. Conclusions: Initial and ultimate surgical failure occurs in a small percentage of patients undergoing minimally invasive endoscopic ICH evacuation. The use of intraoperative imaging provides an opportunity to evaluate whether or not the surgical goal has been achieved, and to continue the procedure if the surgeon feels that more evacuation is achievable. Now that level-one evidence exists to target a surgical evacuation goal during minimally invasive ICH evacuation, intraoperative imaging, such as iCT, plays an important role in aiding the surgical team to achieve the surgical goal.

Vagus nerve stimulation for enhanced stroke recovery after intracerebral hemorrhage: illustrative case.

BACKGROUND: Randomized controlled trial (RCT) evidence has revealed the efficacy of vagus nerve stimulation (VNS) paired with rehabilitation therapy, over therapy alone, for upper-limb functional recovery after ischemic stroke. However, this technique has not yet been described for the recovery of chronic motor deficits after hemorrhagic stroke. OBSERVATIONS: Three years after left putaminal intracerebral hemorrhagic stroke with chronic upper-limb functional deficits, a patient was treated with VNS for enhanced stroke recovery. VNS was paired with 6 weeks of in-clinic physical therapy, resulting in upper-limb functional improvement of 14 points on the Fugl-Meyer Assessment Upper Extremity (FMA-UE) index for stroke recovery (maximum score of 66 equating to normal function). This improvement was more than 1 standard deviation above the improvement documented in the first successful RCT of VNS paired with therapy for ischemic stroke (5.0 ± 4.4 improvement on FMA-UE). LESSONS: VNS is a promising therapy for enhanced recovery after hemorrhagic stroke and may offer greater improvement in function compared to that after ischemic stroke. Improvement in function can occur years after the time of intracerebral hemorrhage.

Clinical Considerations and Outcomes for Spine Surgery Patients with a History of Transplant: A Systematic Scoping Review.

OBJECTIVE: The objective of this study was to investigate the perioperative management and outcomes of patients with a prior history of successful transplantation undergoing spine surgery. METHODS: We searched Medline, Embase, and Cochrane Central Register of Controlled Trials for matching reports in July 2021. We included case reports, cohort studies, and retrospective analyses, including terms for various transplant types and an exhaustive list of key words for various forms of spine surgery. RESULTS: We included 45 studies consisting of 34 case reports (published 1982-2021), 3 cohort analyses (published 2005-2006), and 8 retrospective analyses (published 2006-2020). The total number of patients included in the case reports, cohort studies, and retrospective analysis was 35, 48, and 9695, respectively. The mean 1-year mortality rate from retrospective analyses was 4.6% ± 1.93%, while the prevalence of perioperative complications was 24%. Cohort studies demonstrated an 8.5% ± 12.03% 30-day readmission rate. The most common procedure performed was laminectomy (38.9%) among the case reports. Mortality after spine surgery was noted for 4 of 35 case report patients (11.4%). CONCLUSIONS: This is the first systematic scoping review examining the population of transplant patients with subsequent unrelated spine surgery. There is significant heterogeneity in the outcomes of post-transplant spine surgery patients. Given the inherent complexity of managing this group and elevated mortality and complications compared to the general spine surgery population, further investigation into their clinical care is warranted.

Effects of hours of sleep on ImPACT concussion testing: comparing baseline with postinjury scores.

OBJECTIVE: The influence of sleep on baseline and postconcussion neurocognitive performance prior to Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) is poorly understood. Since ImPACT is widely used in youth sport to assess neurocognitive performance before and after head injury, it is important to delineate factors that affect testing performance. While some have reported correlations between fewer hours of sleep and lower scores on baseline tests, others have not observed any such associations. Therefore, the authors sought to compare the relationship between sleep and neurocognitive performance on ImPACT at both baseline and postinjury. METHODS: The authors queried a database of 25,815 ImPACT tests taken from 2009 to 2019 by athletes aged 12-22 years. There were 11,564 baseline concussion tests and 7446 postinjury concussion ImPACT tests used in the analysis. Linear regression was used to model the effect of sleep on baseline and postconcussion ImPACT scores adjusting for sex, age, learning disability, attention-deficit/hyperactivity disorder, number of prior concussions, number of games missed, and strenuous exercise before testing. RESULTS: Mean composite scores expectedly were all significantly lower in the post-head injury group compared with the baseline group. In the multivariable analysis, at baseline, hours of sleep significantly affected symptom scores (ß = -1.050, 95% CI -1.187 to -0.9138; p < 0.0001). In the postinjury multivariable analysis, verbal memory (ß = 0.4595, 95% CI 0.2080-0.7110; p = 0.0003), visual memory (ß = 0.3111, 95% CI 0.04463-0.5777; p = 0.0221), impulse control (ß = -0.2321, 95% CI -0.3581 to -0.1062; p = 0.0003), and symptom scores (ß = -0.9168, 95% CI -1.259 to -0.5750; p < 0.0001) were all affected by hours of sleep. CONCLUSIONS: Hours of sleep did not alter neurocognitive metrics at baseline but did have an impact on post-head injury metrics. These findings suggest that individuals may be able to compensate for lack of sleep at baseline but not immediately after concussion. Concussions may reduce cognitive reserve or detract from the brain's resources, making sleep even more important for proper neurocognitive functioning postconcussion. Future work will analyze the effects of sleep on postconcussion test performance.

Application of the Robotic-Assisted Digital Exoscope for Resection of Posterior Fossa Tumors in Adults: A Series of 45 Cases.

BACKGROUND AND OBJECTIVES: Complete safe resection is the goal when pursuing surgical treatment for posterior fossa (PF) tumors. Efforts have led to the development of the exoscope that delineates tumors from non-neoplastic brain. This investigation aims to assess patient outcomes where PF tumor resection is performed with the exoscope by a retromastoid or suboccipital approach. METHODS: A retrospective analysis was conducted for patients with PF tumors who underwent exoscope resection from 2017 to 2022. Patient demographics, clinical, operative, and outcome findings were collected. Extent of resection studies were also performed. Associations between perioperative data, discharge disposition, progression-free survival (PFS), and overall survival (OS) were evaluated. RESULTS: A total of 45 patients (22 male patients) with a median age of 57 years were assessed. Eighteen (40%) and 27 patients (60%) were diagnosed with malignant and benign tumors, respectively. Tumor neurovascular involvement was found in 28 patients (62%). Twenty-four (53%) and 20 (44%) tumors formed in the cerebellum and cerebellopontine angle cistern, respectively. One tumor (2%) was found in the cervicomedullary junction. The mean extent of resection was 96.7% for benign and malignant tumors. The PFS and OS rate at 6 months (PFS6, OS6) was 89.7% and 95.5%, respectively. Neurological complications included sensory loss and motor deficit, with 11 patients reporting no postoperative symptoms. Of the neurological complications, 14 were temporary and 9 were permanent. CONCLUSION: The exoscope is an effective intraoperative visualization tool for delineating PF tumors. In our series, we achieved low postoperative tumor volumes and a high gross total resection rate.

External Ventricular Drain Placement Teleproctoring Using a Novel Camera-Projector Navigation System: A Proof-of-Concept Study.

BACKGROUND: Teleproctoring is an emerging method of bedside clinical teaching; however, its feasibility has been limited by the available technologies. The use of novel tools that incorporate 3-dimensional environmental information and feedback might offer better bedside teaching options for neurosurgical procedures, including external ventricular drain placement. METHODS: A platform with a camera-projector system was used to proctor medical students on placing external ventricular drains on an anatomic model as a proof-of-concept study. Three-dimensional depth information of the model and surrounding environment was captured by the camera system and provided to the proctor who could provide projected annotations in a geometrically compensated manner onto the head model in real time. The medical students were randomized to identify Kocher's point on the anatomic model with or without the navigation system. The time required to identify Kocher's point and the accuracy were measured as a proxy for determining the effectiveness of the navigation proctoring system. RESULTS: Twenty students were enrolled in the present study. Those in the experimental group identified Kocher's point an average of 130 seconds faster than did the control group (P < 0.001). The mean diagonal distance from Kocher's point was 8.0 ± 4.29 mm for the experimental group compared with 23.6 ± 21.98 mm for the control group (P = 0.053). Of the 10 students randomized to the camera-projector system arm, 70% were accurate to within 1 cm of Kocher's point compared with 40% of the control arm (P > 0.05). CONCLUSIONS: Camera-projector systems for bedside procedure proctoring and navigation are a viable and valuable technology. We demonstrated its viability for external ventricular drain placement as a proof-of-concept. However, the versatility of this technology indicates that that it could be useful for a variety of even more complex neurosurgical procedures.

Novel Grading Scales for Static and Flexion-Extension Magnetic Resonance Imaging in Patients with Cervical Spondylotic Myelopathy.

BACKGROUND: Flexion-extension magnetic resonance imaging (MRI) has potential to identify cervical pathology not detectable on conventional static MRI. Our study evaluated standard quantitative and novel subjective grading scales for assessing the severity of cervical spondylotic myelopathy in dynamic sagittal MRI as well as in static axial and sagittal images. METHODS: Forty-five patients underwent both conventional and flexion-extension MRI prior to anterior cervical discectomy and fusion from C4 through C7. In addition to measuring Cobb angles and cervical canal diameter, grading scales were developed for assessment of vertebral body translation, loss of disc height, change in disc contour, deformation of cord contour, and cord edema. Data were collected at all levels from C2-C3 through C7-T1. Variations in measurements between cervical levels and from flexion through neutral to extension were assessed using Mann-Whitney, Kruskal-Wallis, and two-way ANOVA tests. RESULTS: Cervical canal diameter, vertebral translation, and posterior disc opening changed significantly from flexion to neutral to extension positions (P < 0.01). When comparing operative versus nonoperative cervical levels, significant differences were found when measuring sagittal cervical canal dimensions, vertebral translation, and posterior disc opening (P < 0.01). Degenerative loss of disc height, disc dehydration, deformation of ventral cord contour, and cord edema were all significantly increased at operative levels versus nonoperative levels (P < 0.01). CONCLUSIONS: Flexion-extension MRI demonstrated significant changes not available from conventional MRI. Subjective scales for assessing degenerative changes were significantly more severe at levels with operative cervical spondylotic myelopathy. The utility of these scales for planning surgical intervention at specific and adjacent levels is currently under investigation.