bluuebunny/crossref_metadata_2025 huggingface dataset:
Wettability-dependent wave velocities and attenuation in granular porous media
Authors: Li Jimmy Xuekai , Rezaee Reza , Müller Tobias M. , Madadi Mahyar , Ma Rupeng , Sarmadivaleh Mohammad
Published: March 2022

Understanding seismic wave propagation in granular porous media is important for subsurface characterization. The presence of fluids, their distribution, and the prevailing wettability condition result in additional complexities. Although it is known that wave propagation in dry granular porous media is dominated by the presence of force chains, their influence in (partially) saturated granular porous media with different wettability conditions remains largely unexplored. To make progress in this direction, we have designed laboratory experiments by combining core flooding and ultrasonic measurements in glass bead packings that are chemically treated to alternate the wettability. The P- and S-wave velocity-saturation relation and attenuation-saturation relation are retrieved from the waveforms for water- and gas-wetting samples. The results demonstrate that there is a transition from an attenuating but stable P-wave pulse at low and moderate saturation to a set of incoherently scattered waves at high saturation. The incoherent scattering in the gas-wetting case is negligibly small, whereas it is more pronounced in the water-wetting case. We interpret these observations in terms of the wettability-dependent ability for water to penetrate into grain contacts. In the water-wetting case, liquid bridges are thought to locally reinforce the force chains and to increase their characteristic length scale. This leads to an increase in P-wave velocity and promotes incoherent scattering because the ratio of dominant wavelength to characteristic length scale decreases. In the gas-wetting case, however, the presence of gas prevents the water from direct contact with the glass beads and therefore stops the formation and growth of the liquid bridges within the force-chain network.
Sorafenib in Combination With Standard Chemotherapy for Children With High Allelic Ratio FLT3/ITD+ Acute Myeloid Leukemia: A Report From the Children's Oncology Group Protocol AAML1031
Authors: Pollard Jessica A. , Alonzo Todd A. , Gerbing Robert , Brown Patrick , Fox Elizabeth , Choi John , Fisher Brian , Hirsch Betsy , Kahwash Samir , Getz Kelly , Levine John , Brodersen Lisa Eidenschink , Loken Michael R. , Raimondi Susana , Tarlock Katherine , Wood Andrew , Sung Lillian , Kolb E. Anders , Gamis Alan , Meshinchi Soheil , Aplenc Richard
Published: March 2022

PURPOSE

High allelic ratio (HAR) FLT3/ITD (AR > 0.4) mutations confer poor prognosis in pediatric acute myeloid leukemia (AML). COG AAML1031 studied the feasibility and efficacy of adding sorafenib, a multikinase tyrosine kinase inhibitor to standard chemotherapy and as single-agent maintenance therapy in this population.

MATERIALS AND METHODS

Patients were treated in three cohorts. The initial safety phase defined the maximum tolerated dose of sorafenib starting in induction 2. Cohorts 2 and 3 added sorafenib in induction and as single-agent maintenance. Clinical outcome analysis was limited to n = 72 patients in cohorts 2/3 and compared with n = 76 HAR FLT3/ITD+ AML patients who received identical chemotherapy without sorafenib. Sorafenib pharmacokinetics and plasma inhibitory activity were measured in a subset of patients.

RESULTS

The maximum tolerated dose of sorafenib was 200 mg/m2 once daily; dose-limiting toxicities included rash (n = 2; 1 grade 3 and 1 grade 2), grade 2 hand-foot syndrome, and grade 3 fever. Pharmacokinetics/plasma inhibitory activity data demonstrated that measured plasma concentrations were sufficient to inhibit phosphorylated FLT3. Although outcomes were superior with sorafenib in cohorts 2 and 3, patients treated with sorafenib also underwent hematopoietic stem-cell transplant more frequently than the comparator population. Multivariable analysis that accounted for both hematopoietic stem-cell transplant and favorable co-occurring mutations confirmed sorafenib's benefit. Specifically, risk of an event was approximately two-fold higher in HAR FLT3/ITD+ patients who did not receive sorafenib (event-free survival from study entry: hazard ratio [HR] 2.37, 95% CI, 1.45 to 3.88, P < .001, disease-free survival from complete remission: HR 2.28, 95% CI, 1.08 to 4.82, P = .032, relapse risk from complete remission: HR 3.03, 95% CI 1.31 to 7.04, P = .010).

CONCLUSION

Sorafenib can be safely added to conventional AML chemotherapy and may improve outcomes in pediatric HAR FLT3/ITD+ AML.
Early Warning of Ischemic Stroke Based on Atherosclerosis Index Combined With Serum Markers
Authors: Zhou Wenjie , Li Shanze , Sun Guijiang , Song Lili , Feng Wenjun , Li Rui , Liu Hui , Dong Yaqian , Chen Siyu , Yang Shenshen , Li Jing , Li Yubo
Published: March 2022

Context

Ischemic stroke (IS) is a serious public health problem worldwide, threatening human life and health. Atherosclerosis is the cause of stroke. At present, there are few selective indexes that can be used to evaluate atherosclerosis in the clinic; providers rely mainly on the atherosclerotic index (AI). Disturbance of lipid metabolism is considered to be a key event leading to IS.

Objective

The purpose of this study was to discover potential biomarkers in the serum of atherosclerosis-induced IS, combined with the AI to provide early warning for the diagnosis of IS.

Methods

In this study, we used nontargeted metabolomics based on ultra-high performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS) to measure the changes in serum metabolites in a group of patients with IS. To verify the reproducibility of candidate biomarkers in the population, we expanded the sample size.

Results

Five metabolites were identified, including sphingomyelin (18:0/14:0), 1-Methylpyrrolinium, PC (18:0/18:0), LysoPC (18:0/0:0), and PC (18: 2/18:2). The combination of these 5 metabolic markers has good diagnostic and predictive ability, and the change level of these metabolites is significantly related to IS. Our results also indicate that changes in glycerophospholipid metabolism may indicate an early risk of IS development.

Conclusion

These findings may contribute to the development of new diagnostic methods of potential biomarkers in serum combined with the AI, thereby providing early warning for the diagnosis of atherosclerosis-induced IS, and may provide a new insights for pathogenesis in IS.
Reports on Philippine Industrial Crops in World War II from Japan’s English Language Press
Authors: Danquah Francis K.
Published: March 2022

Japan’s occupation of Southeast Asia placed enormous stocks of the region’s industrial crops under Japanese control. English language Japanese newspaper reports from the Philippines suggest that the invaders grossly under-utilized this vast storehouse of agricultural wealth. Washington’s pre-war oil embargo severely crippled military and civilian transport services throughout the war, and Japan’s conversion of cane sugar into fuel alcohol and butane for aviation fuel failed to generate successful outcomes. Also, as the Pacific War eliminated cotton imports from the United States, India, and Egypt, placing numerous Japanese textile factories in jeopardy, Tokyo attempted to replace Philippine cane sugar plantings that previously served US markets with raising raw cotton for Japanese textile interests. In the Philippines, however, multifarious bottlenecks crippled all of Tokyo’s wartime farm projects. Though the Japanese occupation was short-lived, it demonstrated Tokyo’s intention to adjust the Philippine economy into a dependent relationship with Japanese industries.
Vanishing Earth: Soil Erosion in the Palouse, 1930-1945
Authors: Duffin Andrew P.
Published: March 2022

This article examines the environment and agricultural activity in the Palouse, a fertile, hilly prairie in the inland Northwest, during the Great Depression and World War II. This area is home to some of the most productive wheatland in the nation, but because of constant farming activity on its steep slopes, soil erosion has been a problem since the turn of the twentieth century. Erosion threatened the long-term viability of farming in the Palouse and the economic health of greater eastern Washington. Local efforts at stemming the problem were nonexistent in the 1910s and 1920s, but after the depression began, New Deal erosion control programs attempted to improve the erosion situation in the Palouse and countless other areas in the United States. A great deal of time and money were devoted to the problem, including the construction of a USDA erosion experiment station in Pullman, Washington. However, federal erosion control efforts were only minimally successful, in part because programs to stop erosion were voluntary, not compulsory. Not enough farmers initiated or maintained soil conservation techniques, and Palouse farmers continued to endanger their most crucial natural resource.
The Agricultural Settlement of Refugees: A Source of Productive Work and Stability in Greece, 1923–1930
Authors: Kritikos Georgios
Published: March 2022

The case of the Greek Orthodox refugees transferred from Turkey to Greece after 1923 is unique as the first obligatory exchange of populations in world history. Overall, the Greek government succeeded in incorporating these refugees economically and politically into the extant population. This paper explores rural refugee settlement as a productive force on the domestic economy and examines its impact on the rural markets of Greece. It also investigates how a poor, war-weary country with a population barely over five million provided land and employment in a largely successful effort to integrate almost six hundred thousand refugees into its agricultural labor market. The author further evaluates how Greece preempted the potential radicalization of the refugee vote through reform, repression, and the involvement of refugees in the hierarchical Greek political system.
Dependent Harvests: Grain Production on the American and Canadian Plains and the Double Dependency with Mexico, 1880–1950
Authors: Evans Sterling
Published: March 2022

For nearly sixty years, roughly 1880 to 1950, before the affordability and wide-spread use of combines, grain production in the American and Canadian Great Plains was dependent on harvesting with binders. Binders cut the grain stalks and then tied them into bundles with twine that farmhands later would gather into shocks to await threshing. The majority of the twine used was made from fiber from agave plants (sisal and henequen) from Mexico’s Yucatan Peninsula. The dependency on this Mexican commodity is illustrated by the fact that for the first two decades of the twentieth century, the United States and Canada consumed an estimated 230,000 tons of the fiber a year for the production of binder twine. Thus, a double agricultural dependency developed between these regions that this essay seeks to explore. Along with this international dependency, corporate, social, and labor issues are integral aspects of the grain/twine story. International Harvester of Chicago came to dominate the twine industry in the United States, but faced stiff competition from American and Canadian penitentiaries that developed their own twine mills using low-wage inmate labor. And in Mexico, wealthy henequen estate owners enslaved Yaqui Indians from Sonora to work in their fields in the Yucatan. "Dependent Harvests" seeks to introduce these themes and to cast them into their proper transnational and agricultural history perspectives.
“Like Ribbons of Green and Gold”: Industrializing Lettuce and the Quest for Quality in the Salinas Valley, 1920–1965
Authors: Petrick Gabriella M.
Published: March 2022

The development of large-scale lettuce production in California’s Salinas Valley illustrates the tensions between technology and nature and provides a starting point for understanding the complexities of supplying vast quantities of quality fresh produce to consumers in distant markets. The case of iceberg lettuce shows that the industrialization of agriculture was largely idiosyncratic, and the level of industrialization possible for any specific crop varied, depending equally on the nature of the commodity and the willingness of consumers to purchase it. The emergence of lettuce cultivation in the Salinas Valley during the inter-war period highlights how early growers harnessed organizational techniques, transportation infrastructures, and technological and scientific knowledge to transcend both the ephemeral nature of lettuce and consumer taste. Yet, these very same factors also limited the success of valley growers after World War II, despite the best efforts of growers and agricultural researchers to improve lettuce quality.
Fescue to the Rescue: Chewings Fescue, Paspalum, and the Application of Non-British Experience to Pastoral Practice in New Zealand, 1880–1920
Authors: Star Paul , Brooking Tom
Published: March 2022

Under British settlement, New Zealand’s export income became increasingly dependent upon new and improved pasture for sheep and cattle. While the introduction of familiar pasture plants--such as ryegrass and cocksfoot--was preferred, from the 1880s farmers also experimented with different grass species to suit newly experienced environmental conditions. Both Chewings fescue (Festuca rubra var. commutata) and paspalum (Paspalum dilatatum) were experimented with and adopted for pasture up to the 1920s. While the discovery of ecological limits partly determined the chain of events, the story of these adoptions equally reflects the influence of human and social factors upon the pattern of agricultural change. Individuals and newspapers were more integral to the process of investigating the uses of Chewings fescue and paspalum than departments and government reports. This case study emphasizes Australian and American influences more than British ones, which necessitates the reassessment of all external knowledge in the light of New Zealand’s experience.
Rural America on the Silent Screen
Authors: Barron Hal S.
Published: March 2022

This article analyzes American silent film depictions of rural life in order to understand their role in the creation of new conceptions of the countryside during the first third of the twentieth century. The rise of motion pictures during the 1910s and 1920s was a critical component of an emerging consumer culture in the United States that coincided with its broader transformation from a rural to an urban society. Because of this conjuncture, silent movies depicting agrarian life were instrumental in establishing new understandings of rural society for a modern, urban nation. They resonated with city audiences, particularly those who had been raised on the farm, as well as with rural and small-town moviegoers, and they helped to reconcile both groups to vexing social changes. Besides providing comfort in a time of transition, however, these films also facilitated the new order by subverting traditional understandings of agrarian life and distancing it from its previous position at the core of American culture.
"Not to Intrude": A Danish Perspective on Gender and Class in Nineteenth-Century Dairying
Authors: FINK DEBORAH
Published: March 2022

This study follows the thread of gender divisions in dairying in Denmark and the American Midwest in the late nineteenth and early twentieth centuries.Gender organization of dairying shifted at this time in diverse European and North American contexts. As agriculture mechanized and production scale increased, access to advanced education and international markets became critical. Women, who had been in the forefront of the development of dairying, ceded their leadership to men as these changes occurred. While some scholars see this shift as a strategic loss for women, this study finds that variables of class, marital status, rural demographics, and alternative occupations mediated the rural women’s experience of change. Not all women experienced the change as a loss. The question of which women were invested in dairying is critical to understanding the course of change. Increasingly, middle-class farm women were turning away from the hard work of dairying and investing themselves in new ways in the upward mobility of their family farms. Rural life shaped distinct gender patterns in European and American history, and the rural experience shaped the larger trajectory of women’s economic and political evolution, even though few rural women were involved in the organized women’s movement.
104 Myelopathy and Increased Costs of Care After Hip Fracture
Authors: Zhang Hans , Buell Thomas , Baldwin Edward , Crutcher Clifford , Dalton Tara E. , Price Meghan , Karikari Isaac O. , Abd-El-Barr Muhammad M. , Goodwin C. Rory , Erickson Melissa
Published: March 2022

INTRODUCTION:

Cervical myelopathy, as a common cause of disability and falls in the elderly, places patients at risk for hip fracture and increased complications after hip surgery. Myelopathy’s co-incidence with hip fractures, however, is not well understood.

METHODS:

Medicare hip fracture and cervical myelopathy patients between 2005 and 2012 were retrospectively identified using the PearlDiver Patient Records Database (PearlDiver Technologies, Inc., CO) with ICD-9 CPT codes. Myelopathic and non-myelopathic hip fracture patients were compared by age, comorbidities, average payments, and average lengths of stay (LOS). Myelopathic patients who were treated with cervical decompression prior to hip fracture were also compared with those without prior decompression. Statistical analysis with t-test and Chi-squared test was performed, with statistical significance set at p<0.05.

RESULTS:

A total of 2,309,972 patients with hip fractures were identified, with 22,884 (1.0%) also having cervical myelopathy. Hip fracture patients with myelopathy were significantly younger (p<0.001) but had significantly greater incidence of medical co-morbidities (hypertension, osteoporosis) (p<0.001). Patients with concomitant myelopathy also had significantly greater average payments ($16,549.21 v. $10,300.88, p<0.001) and longer average LOS (6.66 v. 6.38 days, p<0.001). Of the myelopathic patients, 461 (2.0%) underwent cervical decompression prior to hip fracture. When compared with non-operative myelopathic patients (98%), post-decompression myelopathic hip fracture patients were seen to have increased incidence of medical comorbidities (p<0.001) but also decreased average payments ($7,376.97v. $16,607.81 p<0.001) and LOS (6.04 v. 6.67 days, p=0.011).

CONCLUSION:

Hip fractures in myelopathic patients are significantly more complex than hip fractures in non-myelopathic counterparts and incur significantly greater costs and longer admissions. Cervical decompression prior to hip fracture appears to decrease costs and lengths of stay in this population, suggesting faster recovery from hip fracture despite medical complexity.
105 Patient Satisfaction Reviews for 967 Spine Neurosurgeons
Authors: Agarwal Nitin , Gupta Arjun , Gupta Radhika , White Michael D. , Reddy Vamsi , Chang Yue-Fang , Agarwal Prateek , Alan Nima
Published: March 2022

INTRODUCTION:

Patients are increasingly relying on independent physician-rating websites (PRWs) to obtain information about healthcare providers. Healthgrades.com is a widely used PRW which allows patients to rate physicians on various metrics of performance and quality-of-care.

METHODS:

This study categorically investigated the correlations between demographics of spine neurosurgeons and online ratings on Healthgrades to better understand the factors driving patient satisfaction in spine surgery in the United States.

RESULTS:

A total of 967 spine neurosurgeons were included in the study cohort. Patient satisfaction did not correlate with gender, Ph.D. acquisition, academic status, or academic rank. Among those who were academic surgeons, completion of fellowship training was associated with higher ratings. Geographical location of practice did not influence patient satisfaction. Prolonged wait time was an independent predictor of decreased patient satisfaction and was a key confounding variable underlying trends seen with advanced career duration and age.

CONCLUSION:

Overall, patients rated spine neurosurgeons highly favorably on Healthgrades.com. Due to the emerging role of PRWs in locating and assessing providers, it is important for both patients and clinicians to understand the factors that impact patient experience.
106 Lack of Insurance Leads to Increased Mortality After Craniotomy
Authors: Cua Santino , Shah Varun , Dornbos David L. , Hoang Nguyen , Kreatsoulas Daniel C. , Eaton Ryan , Rodgers Brandon , Pezzutti Dante , Duenas Helen , Nimjee Shahid M.
Published: March 2022

INTRODUCTION:

Socioeconomic status directly impacts outcomes in healthcare. Prior studies have demonstrated the impact of insurance type and status on postoperative outcomes in subspecialty populations, including peripheral tumor and spine. There is a paucity of literature addressing the impact of socioeconomic status on neurosurgical outcomes. This study seeks to investigate socioeconomic factors, namely insurance status, and their impact on adverse events and outcomes in patients undergoing a craniotomy.

METHODS:

A single center, retrospective cohort study was conducted on neurosurgical patients undergoing a craniotomy from 2013-2018. Preoperative demographics, comorbidities, surgical variables, postoperative adverse events, and mortality within 90-days of surgery were collected. Socioeconomic variables include insurance, employment, and disability statuses. Statistical analysis utilizing the Mann-Whitney U test, independent sample t-test and multivariate logistic regression analyses with an alpha of 0.05 were used to compare differences in demographic baseline, adverse event rates and outcomes between patients with and without insurance.

RESULTS:

2445 patients who underwent a craniotomy were included in the analysis with 5.4% being uninsured. Baseline demographic analysis found an increased prevalence of unemployment among uninsured patients (38.3% v 50.0%, p = 0.007). Uninsured patients were significantly younger (p < 0.001) and had higher prevalence of non-opioid substance use (p = 0.027). Adverse events were higher in uninsured patients, including higher rate of acute respiratory insufficiency (p=0.002), delirium (p=0.039) and non-surgical site related infections (p=0.001) compared to insured patients. After controlling for confounders (including age, sex, employment status, disability, substance use, tobacco use, hyperlipidemia, supratentorial patholoy, surgical time), uninsured patients had higher odds of 90-day mortality (OR 2.393, 95% CI 1.321 – 4.334, p = 0.004).

CONCLUSION:

Lower socioeconomic status negatively impact postoperative outcomes in patients undergoing craniotomy. Namely, uninsured patients experienced significantly increased 90-day mortality following craniotomy. It is imperative that insurance status be considered in developing comprehensive treatment plans for each patient in order to minimize the risk of disparate outcomes after undergoing a craniotomy.
107 Composition and Gender Distribution of Editorial Boards for Top Neurosurgical Journals
Authors: Kearns Kathryn , Rabinovich Emily , Shabo Leah , Shaffrey Mark E. , Jane John A. , Park Min S.
Published: March 2022

INTRODUCTION:

Women are underrepresented in academic medicine, most notably in surgical subspecialties. Despite increasing numbers of female neurosurgery residents, female neurosurgeons are not obtaining competitive national positions at comparable rates. Serving as a journal editor is one measure of academic success.

METHODS:

This is a cross-sectional study of editorial boards for the top 10 English-language neurosurgical journals (Journal of Neurosurgery, Neurosurgery, JNS: Spine, World Neurosurgery, Neurosurgical Focus, JNS: Pediatrics, Acta Neurochirurgica, Surgical Neurology International, Neurosurgical Review, and Neurosurgical Clinics). Board members were identified from journal websites. Data was obtained from journal websites, program faculty lists, or physician online profiles. Editors with medical degrees (MD or equivalent) were included. Gender differences were compared using Student’s t-test and chi-squared analysis.

RESULTS:

722 board members were examined (female n=65; male n=650; unidentified n=7). Overall, women had fewer years in practice (p=0.002) while men were more likely to have additional degrees (p=0.009) and to have higher h-indices (p<0.0001). Within the editorial boards of Neurosurgery and Acta Neurochirurgica, men were more likely to have been in practice longer (p=0.014;p=0.023), and to have higher h-indices (p=0.003;p=0.025). Male editors for JNS: Spine and World Neurosurgery were more likely to have higher h-indices (p=0.007;p=0.018).

CONCLUSION:

Women constitute ∼8% of the editorial boards for top neurosurgical journals. While this is comparable to the amount of practicing female academic neurosurgeons, much needs to be done to achieve gender parity in competitive, high-ranking positions. The differences in years in practice and h-index suggest that this discrepancy may improve with time as more women enter practice and produce scientific literature. Efforts to recruit and retain women in neurosurgery should be pursued to rectify this discrepancy.
108 Cost-Effectiveness Analysis on Screening Females Who Smoke Cigarettes for Unruptured Intracranial Aneurysms
Authors: Salih Mira , Salem Mohamed M. , Moore Justin M. , Ogilvy Christopher S.
Published: March 2022

INTRODUCTION:

Screening for intracranial aneurysms (IA) in asymptomatic patients is recommended for certain high-risk patients with autosomal dominant polycystic kidney and those with a family history of intracranial aneurysm. The prevalence of IAs among smokers and the female population has been studied, yet the cost-effectiveness of screening this risk group has not yet been explored.

METHODS:

A decision analytical study was performed with a Markov model to compare screening with no screening in female smokers. Input data for the model was extracted from Meta-analysis, cohort studies and multi-center studies. A single screening was performed for 30, 35, 40, 45, 50, 55, 60, 65, 70-, or 75-years old female smokers in a lifetime horizon. Costs, effects, and incremental cost-effectiveness ratios were analyzed. Probabilistic, one-way, and two-way sensitivity analyses were performed to evaluate the robustness of the Model.

RESULTS:

A single screening at any age yields extra QALYs and screening always cost more than not screening. A single screening at age 30, 35, 40, 45, 50, 55, 60, 65-, or 70-years old is cost-effective. The finding is robust in probabilistic, one- and two-way sensitivity analyses. One-way and Two-way sensitivity analyses show that the upper age limit for a single screening is 72.

CONCLUSION:

Given the current literature and our model, a single screening of female smokers at any age up to 72 years is justifiable and gains extra QALYs. Screening at a younger age brings more health benefit.
115 Minimally Invasive Versus Open Lumbar Spinal Fusion: A Matched Study Investigating Patient-Reported and Surgical Outcomes
Authors: Mooney James Henry , Michalopoulos Giorgos , Alvi Mohammed , Zeitouni David , Chan Andrew K. , Mummaneni Praveen V. , Bisson Erica F. , Haid Regis W. , Knightly John J. , Devin Clinton J. , Pennicooke Brenton H. , Asher Anthony L. , Bydon Mohamad
Published: March 2022

INTRODUCTION:

With the expanding indications for and increasing popularity of minimally invasive spine surgery (MIS) for lumbar spinal fusion, large-scale analysis of patient outcomes after MIS approaches compared to traditional open procedures is warranted.

METHODS:

Patients undergoing MIS and open lumbar fusion were matched at a 1:2 ratio on 33 baseline variables to create two highly homogeneous groups. Primary endpoints of interest were overall satisfaction and a decrease in Oswestry Disability Index (ODI) at 3 months postoperatively. Satisfaction was defined as score 1-2 in the North American Spine Association index; minimal clinically important disease (MCID) for ODI was defined as = 30% decrease from baseline. Secondary endpoints were satisfaction and decrease in ODI at 12 months, length of stay (LOS), operative time, and incidental durotomy rate.

RESULTS:

The MIS and open groups consisted of 1,483 and 2,966 patients, respectively. MIS fusion patients had a higher odds of satisfaction compared to open surgery at 3 months (OR = 1.4, p = 0.004), while maintaining non-inferior odds of satisfaction at 12 months (OR = 1.04, p = 0.67). Lumbar stenosis, single-level fusion, predominant back pain, higher ASA grade, and absence of spondylolisthesis were associated with higher odds of satisfaction with MIS compared to open surgery. Patients in the MIS group had slightly lower ODI scores at 3 months (mean difference=1.61, p = 0.006; MCID OR = 1.14, p = 0.0495), and 12 months (mean difference=2.35, p < 0.001; MCID OR = 1.29, p < 0.001). The groups did not differ in terms of operative time and incidental durotomy rate; however, LOS was shorter for the MIS group.

CONCLUSION:

These results demonstrate that MIS fusion is associated with higher odds of satisfaction and, possibly, a greater decrease in ODI than open fusion at 3 months postoperatively while maintaining a greater ODI improvement and performing non-inferiorly to open in regards to satisfaction at 12 months.
116 OpEyes-Augmented Reality Surgical Navigation and Advanced Minimally Invasive Pedicle Screw Navigation
Authors: Parr Ryan , Felix Brent , Cvetko Steve , Gibby Wendell
Published: March 2022

INTRODUCTION:

The spine surgery market is moving away from open dissection to minimally invasive spine surgery (MISS). Precise operative navigation is imperative for MISS to achieve its potential. Guidance systems have been available for years, but adoption is limited by laborious set-up, costs and intraoperative imaging requirements. Herein is described the use of OpEyes-Augmented Reality (Novarad, American Fork, UT) for navigation and guidance of MISS for highly accurate insertion of pedicle screws.

METHODS:

A Microsoft HoloLens 2 (Microsoft, Redmond, WA) was used as the hardware platform for OpEyes-AR software. AprilTags, printed with CT visible ink, were either adhered to the skin, anchored to the iliac crests, or a vertebra. Following CT, the radiologist identified virtual pathways for ideal placement of pedicle screws for each vertebra.The annotated studies were wirelessly uploaded to the software/visor combination by viewing an encrypted QR code assigned by the pre-op system. The studies were registered to the AprilTags captured during CT. The virtual pathways were called by voice command for each vertebra and were used to establish skin entry point, trajectory, and depth with target bullseyes. Fluoroscopy was not required for navigation. Excella MIS hardware was used for placement of the screws into the pedicles of a donor torso (Innovasis, Salt Lake City, UT).

RESULTS:

Pedicle screws were instrumented through levels L5-T9 for a total of 15 screws. There were no breaches. Many of the thoracic pedicles were narrow with little or no tolerance. Guidance and navigation were performed solely with OpEyes-AR.

CONCLUSION:

OpEyes-AR is a tether-less, holographic visor and software combination offering the potential for precise navigation of MISS percutaneous insertion of pedicle screws with a nominal OR footprint and elimination of OR imaging.
119 Impact of an Early Mobilization Protocol on the Reduction of Medical Complications After Surgery for Chronic Subdural Hematoma – GET-UP Trial Interim 1 Year Overview
Authors: Sousa Sérgio , Pinto Vasco S. , Vaz da Silva Filipe , Costa Tiago , Fernandes Armindo Picão , Rangel Rui , Calheiros Alfredo
Published: March 2022

INTRODUCTION:

Timing for mobilization after chronic subdural hematoma (CSDH) surgery is highly heterogeneous among neurosurgical centers. No high-quality evidence addresses this question.

METHODS:

Our aim is to recruit a total of 208 patients. Patients are randomized to either an early mobilization group (EMG) where mobilization is required within the first 12 hours post-surgery; or to a bed rest group (BRG) where they remain recumbent for 48 hours after surgery. The primary outcome is medical complications after surgery and until discharge. Secondary outcomes include evaluation of the functional status at 1 year post-op, using Glasgow Outcome Scale Extended (GOS-E) and Short Form 36 Health Survey (SF-36).

RESULTS:

We present results of the interim analysis at one year post-op referring to the first 104 randomized patients. A total of 52 patients were randomized to each group. Two patients were lost to follow up at one year. No significant baseline demographic differences were observed. A good outcome was considered when patients achieved GOS-E 5 or higher. At one year we observed a tendency towards better outcome in the EMG group with 71% of the patients having a GOS E = 5 against 54% in the BRG group (p = 0.073). Mortality at 1 year demonstrated a tendency to be lower in the EMG group (21% against 30% in the BRG group, p = 0.305). When we analyze our results based on the SF-36 questionnaire, a tendency toward better performance in the EMG is apparent, especially in the physical performance (p = 0.048), mental health (p = 0.037), vitality (p = 0.043) and general health (p = 0.002) subdivisions.

CONCLUSION:

GET-UP Trial is performing in accordance with the established protocol. This interim analysis’ results validate the methodology and do not pose security concerns even after 1 year follow-up. Active recruitment is ongoing.
121 Analysis of Post-traumatic Epilepsy After Severe Traumatic Brain Injury in a Modern Series Identifies an Increasing Incidence and Novel Risk Factors
Authors: Pease Matthew , Elmer Jonathan , Nwachuku Enyinna L. , González-Martínez Jorge A. , Puccio Ava , Castellano James , Okonkwo David O.
Published: March 2022

INTRODUCTION:

Post-traumatic epilepsy (PTE) accounts for 20% of symptomatic epilepsy with rates highest after severe Traumatic Brain Injury (TBI). PTE has not been well studied in modern cohorts and its risk factors are poorly understood.

METHODS:

We retrospectively reviewed severe TBI patients from a prospective database treated from 2002 through 2018 at a single level 1 trauma center, excluding those with alcohol withdrawal seizures, prior epilepsy, or death at discharge. Using definitions from the International League Against Epilepsy, a seizure was defined as a witnessed clinical event confirmed to be a seizure by the treating healthcare team or electroencephalography, and PTE as two or more seizures. We collected timing of seizures, follow up, demographic, clinical information, and Glasgow Outcomes Scale (GOS). Because more severe injury predisposes to both death and PTE, we developed a competing hazards model to identify independent predictors of PTE.

RESULTS:

We identified 393 patients after exclusions. The rate of early seizures within 7 days was 2.8% (11). The cumulative incidence of PTE was 11% by one year and 25% overall, with 29% of PTE patients requiring multiple anti-seizure medications.Patients with PTE had more severe injuries with higher rates of unreactive pupils, subdural hematomas, obliteration of the basal cisterns, skull fractures, Marshall CT classification, decompressive hemicraniectomies (DHC), lobectomies, and shunting, as well as increased length of stay (LOS), younger age, and intracranial infections (all p < 0.01). Our adjusted model identified age (subdistribution hazard 0.75; 95% confidence interval [95% CI]: 0.62 – 0.93]), DHC (3.3; 95% CI: 2.0-5.5), lobectomy (2.2; 95% CI: 2.6 – 4.2), and infection (1.9; 95% CI: 1.1 – 3.3) as predictors of PTE. Patients with PTE had worse functional outcomes (GOS 1-3 versus 4-5) at 6, 12, and 24 months (p < 0.03).

CONCLUSION:

The incidence of PTE after severe TBI is higher than historical cohorts suggest and continues to increase though fifteen years post-trauma. Patients with PTE have more severe injuries with worse functional outcomes.
124 Feasibility of Spinal Motor Mapping Using High-resolution Spinal Cord Stimulation Paddles in Patients with Chronic Pain
Authors: Telkes Ilknur , Hadanny Amir , DiMarzio Marisa D. , Chitnis Girish , Staudt Michael D. , Paniccioli Steven , O'Connor; Rachael Grey Katherine , Gillogly Michael , Khazen Olga , McLaughlin Bryan , Pilitsis Julie G.
Published: March 2022

INTRODUCTION:

High-resolution spinal cord stimulation (HR-SCS) paddles, which have the ability to target both medially and laterally oriented spinal targets (dorsal columns and dorsal horns respectively), may provide improved options for treating chronic pain. The physical rigidity of existing technologies often either precludes lateral placement due to compression of nerve roots or lacks the ability to concurrently stimulate the medial targets.

METHODS:

During standard of care SCS placement, intraoperative neuromonitoring (IONM) recordings were performed with the HR-SCS paddle. Spinal motor mapping was performed at 18 muscle groups at 60 Hz/300 µs at increasing amplitudes from 0-to-10 mA. EMGs were acquired by Cadwell CascadePro IONM system and analyzed in MATLAB. For feature extraction, root-mean-square values of denoised EMGs were computed and normalized to baseline (stimulationOFF). Data from left and right sided data were not significantly different (p > 0.05) and combined for analysis.

RESULTS:

Electrophysiological signals were recorded in twelve subjects (7 women) with chronic pain. The testing was performed between T9-12 depending on the patients’ trial response. Based on overlayed images of HR-SCS paddles, all contacts were aligned with respect to anatomical midline (in one case, to electrophysiological middle). Distribution of EMGs above 50% change revealed stronger responses in adductor magnus, medial gastrocnemius (MG), and tibialis anterior (TA) when stimulation was delivered from the lateral contacts. Responses were higher in gluteus maximus when stimulation was delivered from the medial contacts. Statistical analysis showed significance difference between contacts in MG (p = 0.041) while it was marginal in TA (p = 0.072). Laterality was not observed in the abdominal muscles in either condition.

CONCLUSION:

By using our routine IONM setup and offline signal processing techniques, we showed that the HR-SCS paddle with 8-columns was able to trigger distinct motor responses at thoracic levels of T9-12 in 12 subjects in accordance with the dorsal column fibers spatial organization.
130 Development of an Integrated Risk Scale for Prediction of Shunt Placement After Neonatal Intraventricular Hemorrhage
Authors: Jin Michael C. , Parker Jonathon J. , Rodrigues Adrian , Colon Gabriela R. , Garcia Cesar A. , Mahaney Kelly B. , Grant Gerald A. , Prolo Laura M.
Published: March 2022

INTRODUCTION:

Neonatal intraventricular hemorrhage (IVH) is a major source of mortality and morbidity in infants, particularly following premature birth. Even after the acute phase, post-hemorrhagic hydrocephalus is a long-term complication, frequently requiring permanent ventriculoperitoneal shunt placement (VPS). Currently, there are no risk classification methods integrating the constellation of clinical data to predict short- and long-term prognosis in neonatal IVH.

METHODS:

Neonates with IVH were identified from the Optum Clinformatics DataMart administrative claims database using ICD-9/10 codes. Matched maternal-childbirth characteristics were obtained. Primary endpoints were short-term (30-day) mortality and long-term VPS placement. Classification of short-term mortality risk was evaluated using five different machine learning approaches and the best-performing method was validated using a withheld validation subset. Prediction of long-term shunt risk was performed using a multivariable Cox regression model with stepwise variable selection, which was subsequently converted to an easily applied integer risk scale.

RESULTS:

A total of 5,926 neonate-maternal pairs were included. Empiric 30-day neonatal mortality risk was 10.9% across all IVH grades and highest among grade IV IVH (34.3%). Among those surviving beyond 30 days, actuarial 12-month risk of shunt placement was 5.4% across all IVH grades and 31.3% for grade IV IVH. The optimal short-term risk classifier was a random forest model achieving an AUROC of 0.882 with important predictors ranging from gestational age to diverse comorbid medical conditions. The final multivariable Cox regression model for long-term shunt risk stratification following stepwise feature selection included IVH grade, respiratory distress syndrome, disseminated intravascular coagulation, and maternal preeclampsia/eclampsia. An integer risk scale termed the Shunt Prediction After IVH in Neonates (SPAIN) scale was developed from these four features which, evaluated on withheld validation cases, demonstrated improved risk stratification compared to IVH grade alone (Harrell’s concordance index 0.869 vs 0.852).

CONCLUSION:

We developed an integrated risk classification approach to anticipate short-term mortality and long-term shunt risk. Application of such approaches may improve outcome prognostication and identification of higher risk individuals warranting careful surveillance and early intervention.
138 Neuroprotection in the Facial Nerve
Authors: Hafez Daniel , Kim Albert H. , Millbrandt Jeffrey , Sasaki Yo
Published: March 2022

INTRODUCTION:

Facial nerve injury is disabling for patients with skull base brain tumors or head trauma. NAD+ is a key cofactor in metabolism and is an important component in axonal survival. Exogenous NAD+ prolongs axonal survival after axotomy in both in vitro and in vivo studies. Additionally, axonal survival is improved by blocking enzymes that decrease NAD+ levels (ex SARM1). Nicotinamide precursors like nicotinamide mononucleotide (NMN) have demonstrated neuroprotective benefits in aging and cellular death.

METHODS:

We developed a model of facial nerve injury by subjecting mice to 200 Hz of vibratory injury to the facial nerve distal to the stylomastoid foramen using SARM1KO and littermate controls, as well as mice implanted with intraventricular pumps containing 400 mM NMN or saline one week before facial nerve injury. EMG was performed using the NIM Nerve Monitoring System. Whisker movements were recorded and scored daily using Vibrissae observation scale. NAD+ metabolite levels were measured using liquid-chromatography/mass-spectrometry. NF200 immunofluorescence of facial nerves was performed.

RESULTS:

SARM1KO mice demonstrated robust axoprotection to vibratory injury for both 15 and 30 second durations and regained normal whisker movement in significantly less time compared to controls. Post-injury, SARM1 KO facial nerves required a lower stimulus current to elicit electrical responses in vibrissae muscles. We then used intracranial NMN delivery to test if raising NAD+ levels is axoprotective. NMN delivery increased brain NAD+ 1.5-fold. NMN significantly shortened the time to normal whisker movement, required a lower stimulus current for muscle response, and showed increased axonal integrity by NF200 staining.

CONCLUSION:

Continuous delivery of the NAD+ metabolite, NMN, allows for neuroprotective benefits in the vibratory neuropraxia nerve injury model, likely through sustained elevated NAD+ levels. These benefits are magnified through inhibition of the NADase enzyme, SARM1. This research demonstrates NMN as a neuroprotective pretreatment adjuvant in patients undergoing planned surgical invention where facial nerve injury is a possible outcome.
144 Interstitial Laser Anterior Capsulotomy for Obsessive-compulsive Disorder: Lesion Size and Tractography Correlate with Outcome
Authors: Satzer David I. , Mahavadi Anil , Lacy Maureen , Grant Jon , Warnke Peter C.
Published: March 2022

INTRODUCTION:

Anterior capsulotomy is a well-established treatment for refractory obsessive-compulsive disorder (OCD) and has been performed with radiofrequency ablation, stereotactic radiosurgery, and focused ultrasound. MRI-guided laser interstitial thermal therapy (LITT) allows creation of larger, more demarcated lesions with the safety conferred by real-time imaging of the ablation volume.

METHODS:

Patients with severe OCD refractory to pharmacotherapy and cognitive-behavioral therapy underwent bilateral anterior capsulotomy via LITT. The primary outcome was percent reduction in Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score over time. Lesion size was measured on post-ablation MRI. Disconnection of the anterior limb of the internal capsule (ALIC) was assessed via individual and normative tractography.

RESULTS:

Eighteen patients underwent laser anterior capsulotomy. Median follow-up was 6 months (range 3-51 months). Time occupied by obsessions improved immediately (median Y-BOCS item 1 score 4 to 1, P = 0.0002). Mean (± standard deviation) decrease in Y-BOCS score at last follow-up was 46 ± 32% (16 ± 11 points; P = 0.0002). Sixty-one percent of patients were responders. One patient had an asymptomatic intracerebral hemorrhage. Reduction in Y-BOCS score was positively associated with ablation volume (P = 0.006). Individual tractography demonstrated durable ALIC disconnection. Normative tractography revealed a dorsal-ventral gradient, with disconnection of orbitofrontal streamlines most strongly associated with a positive response to surgery (P < 0.0001).

CONCLUSION:

Laser anterior capsulotomy resulted in immediate, marked improvement in OCD symptom severity. Larger lesions can be created safely and permit greater disconnection of the prefrontal-subcortical pathways involved in OCD. The importance of greater disconnection is presumably related to variation in ALIC structure and the complex role of the PFC in OCD.
146 Human Interictal Epileptiform Discharges are Traveling Waves Reflecting Ictal Self-organization
Authors: Smith Elliot , Liou Jyun-you , Merricks Edward , Davis Tyler , Thomson Kyle , Greger Bradley , House Paul A. , Emerson Ronald , Goodman Robert R. , McKhann Guy M. , Schevon Catherine , Rolston John D.
Published: March 2022

INTRODUCTION:

Interictal epileptiform discharges (IEDs), are large intermittent electrophysiological events observed between seizures in epileptic patients. While seizures are infrequent and unpredictable, IEDs are far more common, occurring several times per minute (0.67 IEDs per minute in this dataset). The relative frequency of IEDs makes them an alluring indicator of epileptogenic brain, especially when compared to more scarce and unpredictable seizures. Yet despite the relative abundance of IEDs, it remains unknown how they relate to seizures.

METHODS:

To better understand this relationship, we examined semi-chronic, multi-day recordings of 96-channel microelectrode arrays implanted in human epilepsy patients. These recordings—spanning single cell action potentials to local field potentials—allowed us to study the microscale spatiotemporal organization of over 45,000 IEDs across 10 patients. We used ordinary multivariate linear regression to estimiate IED speed and direction, and vonMises Mixture models to cluster bimodal IED directions in to sub-distributions.

RESULTS:

These recordings showed that the majority (66.4%) of IEDs propagate across neocortex as traveling waves with a dominant direction (Hermans-Rasson Tests, all p < 10-3). IED traveling wave direction distributions were bimodal in 8 of the 10 subjects, with a median difference between sub-distributions of 178 degrees. Firing rates and voltages of IEDs in each sub distribution were not significantly different, however, the proportion of IEDs in each sub-distrbution and their speeds and directions were different among sub-distributions, and mimicked sub-distributions of ictal discharges.

CONCLUSION:

These results show that IEDs propagate across the surface of the brain as traveling waves, and the that their directions mimic those of discharges occuring during seizures. Furthermore, these results provide a new understanding of epileptic brian tissue, and suggest that spatial features of IEDs may be used to help diagnose and treat medically refractory epilepsy.