Central neurocytomas: research trends, most cited papers, and scientometrics analysis to date.

Central neurocytoma is the most common primary intraventricular tumor in adults being classified by the World Health Organization (WHO) as a benign grade II tumor with a good prognosis. Given the recent advances with regard to this tumor, a bibliometric analysis was due to study the future direction of research for neurocytomas. A comprehensive Elsevier's Scopus database search was performed to capture all published and indexed studies to date relevant to neurocytoma. A discrete set of validated bibliometric parameters were extracted and analyzed on R v4.1.3. A total of 1002 documents were included in our analysis covering a period between 1910 and 2021 (111 years). Around 98.5% of the documents were multi-author publications with a collaboration index (CI) of 4.21. Acta Neuropathologica, The American Journal of Surgical Pathology, and Cancer were the journals to include the highest number of top ten cited articles (2 out of 10 most cited articles, 20%). Switzerland (4 out of 10, 40%) accounted for the country to have the highest number of top 10 most cited articles with the USA (5588 out of 16,395 citations, 34.1%) having the greatest number of citations. Lastly, our analysis reported an annual growth rate of 6.9% for the number of papers produced by year. This is the first bibliometric analysis to study the top 10 most cited articles with regard to neurocytomas. A shift from histopathologic and clinical symptoms towards the treatment and management of the tumor was observed in our analysis.

Immunohistochemical markers predicting long-term recurrence following clival and spinal chordoma resection: a multicenter study.

OBJECTIVE: Chordomas are rare tumors from notochordal remnants and account for 1%-4% of all primary bone malignancies, often arising from the clivus and sacrum. Despite margin-negative resection and postoperative radiotherapy, chordomas often recur. Further, immunohistochemical (IHC) markers have not been assessed as predictive of chordoma recurrence. The authors aimed to identify the IHC markers that are predictive of postoperative long-term (≥ 1 year) chordoma recurrence by using trained multiple tree-based machine learning (ML) algorithms. METHODS: The authors reviewed the records of patients who had undergone treatment for clival and spinal chordomas between January 2017 and June 2021 across the Mayo Clinic enterprise (Minnesota, Florida, and Arizona). Demographics, type of treatment, histopathology, and other relevant clinical factors were abstracted from each patient record. Decision tree and random forest classifiers were trained and tested to predict long-term recurrence based on unseen data using an 80/20 split. RESULTS: One hundred fifty-one patients diagnosed and treated for chordomas were identified: 58 chordomas of the clivus, 48 chordomas of the mobile spine, and 45 chordomas sacrococcygeal in origin. Patients diagnosed with cervical chordomas were the oldest among all groups (58 ± 14 years, p = 0.009). Most patients were male (n = 91, 60.3%) and White (n = 139, 92.1%). Most patients underwent resection with or without radiation therapy (n = 129, 85.4%). Subtotal resection followed by radiation therapy (n = 51, 33.8%) was the most common treatment modality, followed by gross-total resection then radiation therapy (n = 43, 28.5%). Multivariate analysis showed that S100 and pan-cytokeratin are more likely to predict the increase in the risk of postoperative recurrence (OR 3.67, 95% CI 1.09-12.42, p= 0.03; and OR 3.74, 95% CI 0.05-2.21, p = 0.02, respectively). In the decision tree analysis, a clinical follow-up > 1897 days was found in 37% of encounters and a 90% chance of being classified for recurrence (accuracy = 77%). Random forest analysis (n = 500 trees) showed that patient age, type of surgical treatment, location of tumor, S100, pan-cytokeratin, and EMA are the factors predicting long-term recurrence. CONCLUSIONS: The IHC and clinicopathological variables combined with tree-based ML tools successfully demonstrated a high capacity to identify recurrence patterns with an accuracy of 77%. S100, pan-cytokeratin, and EMA were the IHC drivers of recurrence. This shows the power of ML algorithms in analyzing and predicting outcomes of rare conditions of a small sample size.

The Impact of Maternal Preeclampsia and Hyperglycemia on the Cardiovascular Health of the Offspring: A Systematic Review and Meta-analysis.

OBJECTIVES: The objective of this review was to assess the impact of maternal preeclampsia or hyperglycemia on the body composition and cardiovascular health in the offspring. STUDY DESIGN: We conducted a systematic review utilizing PubMed, EBSCO, CINAHLPlus, Cochrane Library, and Web of Science to include all studies assessing the impact of preeclampsia/eclampsia and/or gestational/pregestational diabetes mellitus on the health of the offspring (children <10 years of age). The health measures included anthropometry, cardiac dimensions and function, and vascular function. We performed a meta-analysis using Review Manager software and computed net risk ratio (RR) with 95% confidence interval (CI) for dichotomous data and mean difference (MD) with 95% CI for continuous data. RESULTS: There were 6,376 studies in total, of which 45 were included in the review and 40 in the meta-analysis. The results demonstrated higher birth weight (MD: 0.12 kg; 95% CI: 0.06-0.18) and systolic and diastolic blood pressure (BP; MD: 5.98 mm Hg; 95% CI: 5.64-6.32 and MD: 3.27 mm Hg; 95% CI: 0.65-5.89, respectively) in the offspring of mothers with gestational diabetes compared to controls. In contrast, the offspring of mothers with preeclampsia had lower birth weight (MD: -0.41 kg; 95% CI: -0.7 to -0.11); however, they had increased systolic (MD: 2.2 mm Hg; 95% CI: 1.28-3.12) and diastolic BP (MD: 1.41 mm Hg; 95% CI: 0.3-2.52) compared to controls. There is lack of data to conduct a meta-analysis of cardiac morphology, functional, and vascular imaging parameters. CONCLUSION: These findings suggest that the in-utero milieu can have a permanent impact on the body composition and vascular health of the offspring. Future work warrants multicenter prospective studies to understand the mechanism and the actual effect of exposure to maternal hyperglycemia and high BP on the cardiovascular health of the offspring and long-term outcomes. KEY POINTS: · Adverse in-utero exposures may have an impact on cardiovascular risk in children.. · Maternal hyperglycemia/preeclampsia lead to changes in birthweight and BP.. · Limited echocardiographic and vascular imaging data in these cohorts necessitates future work..

R2 advances in robotic-assisted spine surgery: comparative analysis of options, future directions, and bibliometric analysis of the literature.

Spine surgery has undergone rapid advancements over the past several decades with the emergence of robotic and minimally invasive surgery (MIS). While conventional MIS spine surgery has had relative success, its complication profile has warranted continued efforts to improve clinical outcomes. We discuss the functional, clinical, and financial aspects of four robotic options for spinal pathologies, namely ROSA, Mazor X, Da Vinci, and ExcelsiusGPS, and conduct a bibliometric analysis to better understand current trends and applications of these robots as the field of robotic spine surgery continues to grow. An extensive search of English-language published literature on robotic-assisted spinal surgery was performed in Elsevier's Scopus database. A bibliometric analysis was then performed on the top 100 most cited papers. The search yielded articles regarding robotic-assisted spine surgery application, limitations, and functional outcomes secondary to spine pathology. Accuracy analyses of 1733 screw placements were reviewed. The top 100 papers were published between 1992 and 2020, with a significant increase from 2015 onwards. The top publishing institution was John Hopkins University (n = 8). The top contributing author was Dr. Isador H. Lieberman (n = 6). The USA (n = 34) had the most articles on robotic spinal surgery, followed by Germany (n = 12). This review examines robotic applications in spine surgery, including four available options: ROSA, Mazor X, Da Vinci, and ExcelsiusGPS. Publication output over time, surgical outcomes, screw accuracy, and cost-effectiveness of these technologies have been investigated here. Certain robots have functional, clinical, and financial differences worth noting. Given the dearth of existing literature reporting postoperative complications and long-term comparative outcomes, there is a clear need for further studies on this matter.

Schwannoma: A surgical epidemiology.

OBJECTIVE: To identify the surgical incidence and prevalence of schwannoma in our region and quantify the demographic, surgical, neoplastic, and outcome characteristics of the patients diagnosed with schwannoma.. METHODS: A retrospective cross-sectional study was conducted from January 1 to December 31, 2019. Enrolled were 32 of the highest volume neurosurgical centres in Pakistan. Patients with a histopathological diagnosis of schwannoma and radiological imaging were included in the study. Medical records were reviewed for data, and SPSS version 25 was used for statistical analysis. Patients were followed up for one year, which was the duration of the study. RESULTS: From 2750 patients diagnosed with brain tumours, 148 patients had schwannomas. Out of these, 84 (56.8%) patients were male, and 64 (43.2%) patients were female. The mean age of the patients was 39 ± 14 years. The socioeconomic statuses of the enrolled patients were lower in 72 (53.3%) patients, middle in 57 (42.2%) patients, and upper middle to upper in 6 (4.4%) patients. All patients underwent surgery, 14 patients received radiotherapy, and two patients received chemotherapy. In our cohort, 115 (77.7%) patients presented to public sector hospitals, with only 33 (22.3%) patients presenting to private hospitals. At the end of the study period, 60 (40.5%) patients had been lost to follow-up. Of the remaining 88 patients, 75 (85.2%) were alive. The mortality rate on a one-year follow-up was 14.8%. CONCLUSIONS: Schwannoma comprises a larger percentage of the brain tumours in our regions than reported in the literature. The high mortality rate is of particular concern and warrants further investigation to improve patient care and outcomes.

Ependymoma: an epidemiological perspective from a low- and middle-income country.

OBJECTIVE: To enumerate the burden of ependymoma in our region and identify the demographic, tumoural, surgical, clinical characteristics, and outcomes of patients diagnosed with ependymoma. METHODS: This retrospective cross-sectional study included patients admitted under neurosurgical service between January 1 and December 31, 2019. The inclusion criterion for the study was a histopathological diagnosis of the brain lesion. The experience of the ependymal brain tumours observed at the 32 participating sites in Pakistan is presented. RESULTS: A total of 2750 patients with brain tumours were seen in 2019 at our centres of whom 58(2.1%) had a histopathological diagnosis of ependymoma. The median age at diagnosis was nine (IQR= 4.5-24.5) years. The median time to surgery from date of radiological diagnosis was 38.5 (IQR= 4-93.8) days. The median KPS score at presentation was 70 (IQR= 60-80), and post-surgery was 90 (IQR= 70-100), showing an average increase of 20. Our population's overall mortality rate for ependymoma was 31.1%, with the 30-day mortality rate being 2.2% (lower than the 4.5% on average for all brain tumours in our cohort). CONCLUSIONS: Ependymomas were predominantly found in the paediatric population in the presented cohort. While gender distribution and histopathological grading seemed to follow international trends, this study had a much higher mortality rate and a much lower gross total resection rate than centres in high-income countries.

Modifications in lumbar facet joint are associated with spondylolisthesis in the degenerative spine diseases: a comparative analysis.

BACKGROUND: Magnetic resonance imaging (MRI) is important in the assessment of degenerative spine disease. However, its role is limited in the identification of spinal instability; therefore, weight-bearing and dynamic studies like X-rays are required. The supine position eliminates the gravitational pull, corrects the vertebral slippage, and opens the facet joints leading to the collection of the synovial fluid into the joint space, which is detected on the MRI and can serve as a marker for instability. We aim to compare the facet fluid, facet hypertrophy, facet angle, and disc degenerative changes among the patients presenting with degenerative spondylolisthesis (DS) and those without. METHODS: We performed a retrospective review for all the patients treated at our institution from January 2015 to December 2016. Facet Fluid Index (FFI) (ratio of facet fluid width and facet joint width) was calculated to assess the joint fluid. The percentage of spondylolisthesis was measured on X-rays. Each radiological parameter was compared between the two groups, i.e., patients with DS and patients without DS. A p value < 0.05 was considered significant. RESULTS: In total, 61 patients, 28 with DS and 33 without DS, were enrolled. Baseline characteristics were similar in the two groups (p > 0.05). The average values of FFI, facet fluid width, and the difference between the superior and inferior facet were significantly higher in the group with instability (p < 0.05). Multivariate analysis demonstrated a 4.44 (95% confidence interval [CI] 2.03-5.365) times increase in the odds of instability with a unit increase in FFI, p < 0.0001. CONCLUSIONS: We report a positive linear correlation between the facet joint effusion and facet hypertrophy on MRI and the percentage of vertebral translation on X-ray. Prospective studies will determine if these markers can play a role in predicting spinal instability.

Screening for malnutrition in oral cavity cancer patients prior to treatment: A cross-sectional study.

This study was conducted to assess the frequency of pre-operative malnourishment in patients being treated for oral cavity squamous cell carcinoma. A retrospective chart review was carried out at the Aga Khan University Hospital, Karachi, on 62 patients. Patients were screened pre-operatively through a standard nutritional assessment tool at the time of admission to assess for malnutrition. Mean age of presentation was 48.34±13.11 years, mean height was 165 ± 8.62cm, weight 66.09±14.98 kg and BMI of 24.09±4.84. Males were 82.3% and 17.7% were females. At the time of admission, a significant number or patients, 12 (19.4%) were prone to malnourishment, while 3 (4.8%) patients were malnourished: Assessment was done by using a standardised nutritional assessment tool.

The Outcome and Patterns of Traumatic Brain Injury in the Paediatric Population of a Developing Country Secondary to TV Trolley Tip-Over.

BACKGROUND: Television (TV) trolley tip-over incidences are common and can cause significant morbidity and mortality in children. This study was aimed at analyzing the pattern and outcomes of head injuries resulting from TV trolley tip-over. METHOD: We conducted a medical chart review of children with TV trolley tip-over head injuries from January 2009 to April 2016. We collected data on demographics, the mechanism of injury, clinical and radiological features of the injury, and outcomes. Outcomes were measured by means of the Glasgow Outcome Scale (GOS) at 6 months (except in 1 case). A descriptive analysis was carried out using SPSS v19. RESULT: Twenty-two children were included in the study (median age 23.5 months). Sixteen children were male. Most of the children (n = 16) were aged 12-35 months. The median Glasgow Coma Scale score on admission was 15. The median Rotterdam Score for the patients was 2.0. Common symptoms upon admission were vomiting, irritability, scalp laceration, and bruises. Median length of hospital stay was 3 days. Skull bone fractures were present in 12 children. Other CT findings included contusions, extradural and subdural haematomas, intraventricular haemorrhage, and pneumocranium. Surgical intervention was required in 4 cases. Although most of the patients made a good recovery (GOS = 5), 1 patient developed a mild disability and another died in hospital. CONCLUSION: TV trolley tip-over is most common in toddlers and can lead to significant head injury and mortality. This can be avoided by parental supervision and adjustments in the household.

Awake craniotomy for brain tumours in Pakistan: An initial case series from a developing country.

Awake craniotomy offers safe resection of brain tumours in eloquent area. Aga Khan University Hospital, Karachi, recently started the programme in Pakistan, and the current study was planned to assess our experience of the first 16 procedures. The retrospective study comprised all such procedures done from November 2015 to May 2016. Pre-operative and post-operative variables were analysed. Of the 16 patients, 11(68.75%) were males and 5(31.25%) were females. The overall median age was 37 years (interquartile range[IQR]: 23-62 years). The most common presenting complaint was seizures 8(50%), followed by headache6(38%). The common pathologies operated include oligodendroglioma and glioblastoma. Pre-operative mean Karnofsky Performance Status score was 76±10, which increased to 96±7 post-operatively at discharge. Besides, 2(12.5%) intra-operative complications were observed, i.e. seizure and brain oedema, in the series. The study had median operative time of 176 minutes (IQR: 115-352) and median length of stay of 4 days (IQR: 3-7).Awake craniotomy was highly effective in maintaining post-operative functionality of the patient following glioma resection. It was also associated with shorter hospital course and so lower cost of management.

Capillary Hemangioma of the Spinal Cord: Case Report and Systematic Review of Literature.

BACKGROUND: Capillary hemangiomas are rare vascular lesions that rarely affect the central nervous system. When they present within the spinal canal, they are typically confined intradurally, with intramedullary extension rare. We present a rare case of spinal intramedullary capillary hemangioma, with a systematic review of the literature. METHODS: Medical records and imaging data were retrospectively reviewed using the health record software EPIC (Verona, Wisconsin, USA) and the radiology management software system RIS/PACS (Radiology Information System/Picture Archiving and Communication System; QREADS). The report was written in accordance with the CARE (case reports) guidelines. We also performed a systematic review of the literature on all cases of intramedullary spinal capillary hemangiomas in accordance with PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines. RESULTS: We report a case of a 54-year-old man who presented with progressive paraplegia and sensory deficits in the lower extremities. Spinal magnetic resonance imaging showed an intramedullary enhancing lesion centered at T11 with associated spinal cord compression. He underwent thoracic laminectomy and gross total resection of the lesion without complications and subsequent improvement on his neurological examination. Histological examination showed findings consistent with a capillary hemangioma. The literature review also documented 21 studies with a combined total of 38 cases of intramedullary spinal capillary hemangioma. CONCLUSIONS: Purely intramedullary capillary hemangiomas are unusual spinal lesions with only a few cases reported in the literature. These should be considered in the differential diagnosis of intramedullary tumors. Surgical management remains the first line of treatment for symptomatic patients.

Transforming Outcomes of Spine Surgery-Exploring the Power of Enhanced Recovery After Surgery Protocol: A Systematic Review and Meta-Analyses of 15 198 Patients.

BACKGROUND AND OBJECTIVES: Enhanced recovery after surgery (ERAS) protocols aim to optimize patient outcomes by reducing the surgical stress response, expediting recovery, and reducing care costs. We aimed to evaluate the impact of implementing ERAS protocols on the perioperative surgical outcomes and financial implications associated with spine surgeries. METHODS: A systematic review and meta-analysis of peer-reviewed studies directly comparing outcome differences between spine surgeries performed with and without utilization of ERAS pathways was conducted along Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS: Of 676 unique articles identified, 59 with 15 198 aggregate patients (7748 ERAS; 7450 non-ERAS) were included. ERAS-treated patients had shorter operative times (mean difference [MD]: 10.2 mins; P < .01), shorter hospitalizations (MD: 1.41 days, P < .01), fewer perioperative complications (relative risk [RR] = 0.64, P < .01), lower postoperative opioid use (MD of morphine equivalent dose: 164.36 mg; P < .01), and more rapid mobilization/time to first out-of-bed ambulation (MD: 0.92 days; P < .01). Spine surgeries employing ERAS were also associated with lower total costs (MD: $1140.26/patient; P < .01), especially in the United States (MD: $2869.11/patient, P < .01) and lower postoperative visual analog pain scores (MD = 0.56, P < .01), without any change in odds of 30-day readmission (RR: 0.80, P = .13) or reoperation (RR: 0.88, P = .60). Subanalyses based on the region of spine showed significantly lower length of stay in both cervical and lumbar surgeries implementing ERAS. Type of procedure showed a significantly lesser time-to-initiate mobilization in fusion surgeries using ERAS protocols compared with decompression. CONCLUSION: The present meta-analysis indicates that current literature supports ERAS implementation as a means of reducing care costs and safely accelerating hospital discharge for patients undergoing spine surgery.

Transforaminal lumbar interbody fusion subsidence: computed tomography analysis of incidence, associated risk factors, and impact on outcomes.

OBJECTIVE: The aims of this study were to 1) define the incidence of transforaminal lumbar interbody fusion (TLIF) interbody subsidence; 2) determine the relative importance of preoperative and intraoperative patient- and instrumentation-specific risk factors predictive of postoperative subsidence using CT-based assessment; and 3) determine the impact of TLIF subsidence on postoperative complications and fusion rates. METHODS: All adult patients who underwent one- or two-level TLIF for lumbar degenerative conditions at a multi-institutional academic center between 2017 and 2019 were retrospectively identified. Patients with traumatic injury, infection, malignancy, previous fusion at the index level, combined anterior-posterior procedures, surgery with greater than two TLIF levels, or incomplete follow-up were excluded. Interbody subsidence at the superior and inferior endplates of each TLIF level was directly measured on the endplate-facing surface of both coronal and sagittal CT scans obtained greater than 6 months postoperatively. Patients were grouped based on the maximum subsidence at each operative level classified as mild, moderate, or severe based on previously documented < 2-mm, 2- to 4-mm, and ≥ 4-mm thresholds, respectively. Univariate and regression analyses compared patient demographics, medical comorbidities, preoperative bone quality, surgical factors including interbody cage parameters, and fusion and complication rates across subsidence groups. RESULTS: A total of 67 patients with 85 unique fusion levels met the inclusion and exclusion criteria. Overall, 28% of levels exhibited moderate subsidence and 35% showed severe subsidence after TLIF with no significant difference in the superior and inferior endplate subsidence. Moderate (≥ 2-mm) and severe (≥ 4-mm) subsidence were significantly associated with decreases in cage surface area and Taillard index as well as interbody cages with polyetheretherketone (PEEK) material and sawtooth surface geometry. Severe subsidence was also significantly associated with taller preoperative disc spaces, decreased vertebral Hounsfield units (HU), the absence of bone morphogenetic protein (BMP) use, and smooth cage surfaces. Regression analysis revealed decreases in Taillard index, cage surface area, and HU, and the absence of BMP use predicted subsidence. Severe subsidence was found to be a predictor of pseudarthrosis but was not significantly associated with revision surgery. CONCLUSIONS: Patient-level risk factors for TLIF subsidence included decreased HU and increased preoperative disc height. Intraoperative risk factors for TLIF subsidence were decreased cage surface area, PEEK cage material, bullet cages, posterior cage positioning, smooth cage surfaces, and sawtooth surface designs. Severe subsidence predicted TLIF pseudarthrosis; however, the causality of this relationship remains unclear.

Does diabetes affect outcome or reoperation rate after lumbar decompression or arthrodesis? A matched analysis of the Quality Outcomes Database data set.

OBJECTIVE: Diabetes mellitus (DM) is a known risk factor for postsurgical and systemic complications after lumbar spinal surgery. Smaller studies have also demonstrated diminished improvements in patient-reported outcomes (PROs), with increased reoperation and readmission rates after lumbar surgery in patients with DM. The authors aimed to examine longer-term PROs in patients with DM undergoing lumbar decompression and/or arthrodesis for degenerative pathology. METHODS: The Quality Outcomes Database was queried for patients undergoing elective lumbar decompression and/or arthrodesis for degenerative pathology. Patients were grouped into DM and non-DM groups and optimally matched in a 1:1 ratio on 31 baseline variables, including the number of operated levels. Outcomes of interest were readmissions and reoperations at 30 and 90 days after surgery in addition to improvements in Oswestry Disability Index, back pain, and leg pain scores and quality-adjusted life-years at 90 days after surgery. RESULTS: The matched decompression cohort comprised 7836 patients (3236 [41.3] females) with a mean age of 63.5 ± 12.6 years, and the matched arthrodesis cohort comprised 7336 patients (3907 [53.3%] females) with a mean age of 64.8 ± 10.3 years. In patients undergoing lumbar decompression, no significant differences in nonroutine discharge, length of stay (LOS), readmissions, reoperations, and PROs were observed. In patients undergoing lumbar arthrodesis, nonroutine discharge (15.7% vs 13.4%, p < 0.01), LOS (3.2 ± 2.0 vs 3.0 ± 3.5 days, p < 0.01), 30-day (6.5% vs 4.4%, p < 0.01) and 90-day (9.1% vs 7.0%, p < 0.01) readmission rates, and the 90-day reoperation rate (4.3% vs 3.2%, p = 0.01) were all significantly higher in the DM group. For DM patients undergoing lumbar arthrodesis, subgroup analyses demonstrated a significantly higher risk of poor surgical outcomes with the open approach. CONCLUSIONS: Patients with and without DM undergoing lumbar spinal decompression alone have comparable readmission and reoperation rates, while those undergoing arthrodesis procedures have a higher risk of poor surgical outcomes up to 90 days after surgery. Surgeons should target optimal DM control preoperatively, particularly for patients undergoing elective lumbar arthrodesis.

Cerebellar Liponeurocytoma: Publication Trends, Scientometrics Analysis, and Critical Review.

BACKGROUND: The literature on cerebellar liponeurocytoma (CL) has never been systematically assessed using bibliometric analytic methodologies. We quantitatively analyzed the major trends and scientific output regarding CL, highlighting potential avenues for research. METHODS: Elsevier's Scopus database was used to collect all published studies relevant to cerebellar liponeurocytoma from 1978 to 2021. The specific bibliometric parameters were extracted and analyzed with R v4.1.2. RESULTS: Our search yielded 108 documents published in 67 sources from 1978 to 2021. The annual growth rate of publications regarding CL has been 7.47% per year since 1978. Journals with the most publications on CL include Clinical Neuropathology and Neurology India (n = 5), followed by Acta Neuropathologica and Journal of Neuro-oncology (n = 4). A total of 529 authors have published on CL and they have been cited 598 times. The 10 most influential authors in the field were determined using their total number of citations and the local H-index. Kleihues P has the highest number of citations (n = 177) with a local H index of 3, followed by Chimelli L with 167 citations and a local H index of 4. Davis DG has 149 citations and a local H index of 3. China had the most single country publications followed by India, Italy, and the USA. France and Austria have the most multiple country publications followed by China, Tunisia, Brazil, United Kingdom, Egypt, and Israel. CONCLUSIONS: Our study is the first bibliometric analysis evaluating the present literature and publication trends in CL. Generally, the current literature has a few studies regarding CL relative to other neuro-oncological pathologies. This can be due to the low incidence of the disease and highlights a need for high volume database studies that can offer high quality evidence on the subject.

Bone morphogenetic proteins in spine surgery: a scientometric analysis to date.

OBJECTIVE: Bone morphogenetic proteins (BMPs) are part of the transforming growth factor-beta superfamily and are involved in bone formation and repair. In spine surgery, recombinant human BMP (rhBMP) is used as an alternative to autografts for spinal fusions. This study aimed to evaluate bibliometric parameters and citations of the literature on BMPs to provide an overview of how the field has evolved. METHODS: A comprehensive search of the literature was conducted using Elsevier's Scopus database to capture all the published and indexed studies relevant to BMPs from 1955 to the present. A discrete set of validated bibliometric parameters was extracted and analyzed. All statistical analyses were performed using R 4.1.1. RESULTS: The 100 most cited articles were published between 1994 and 2018 by 472 unique authors in 40 sources (e.g., journals and books). On average, there were 279 citations per publication and 17.69 citations per publication per year. The United States had the publications with the most citations (n = 23,761), followed by Hong Kong (n = 580) and the United Kingdom (n = 490). The three institutions in the United States with the greatest number of publications in the field were Emory University (n = 14), Hughston Clinic (n = 9), Hospital for Special Surgery (n = 6), and University of California (n = 6). CONCLUSIONS: The authors evaluated and characterized the 100 most cited articles about BMP. Most of the publications were clinical in nature and focused on BMP's application in spine surgery. While early scientific efforts focused on basic science research to advance the understanding of BMP's mechanism of action in promoting bone formation, the majority of the more recent publications are clinically focused. It will be beneficial to conduct more controlled clinical trials to compare the outcomes of BMP use with other methods.

Utilizing pre- and postoperative radiological parameters to predict surgical outcomes following untethering for tethered cord syndrome in a pediatric population.

OBJECTIVE: Tethered cord syndrome (TCS) can lead to significant downstream neurological deficits including gait deterioration, incontinence, and often unexplained chronic low-back pain. Surgical intervention may relieve symptoms, but there are no defined radiological parameters associated with surgical outcomes and functional status. The authors aimed to define pre- and postoperative radiological parameters for assessing surgical outcomes in TCS. METHODS: The authors performed a single-center retrospective review of all pediatric patients treated for TCS between 2016 and 2021. Patient baseline characteristics and operative metrics included age, sex, level of conus, level of procedure, tethering pathology, symptoms at presentation, complications, improvement of symptoms, and reoperation rate. MRI measurements included pre- and postoperative anterior canal distance (ACD) and bending angle (BA). RESULTS: Thirty-three pediatric patients were identified who underwent untethering of the spinal cord and had pre- and postoperative MRI between 2016 and 2021. The mean patient age was 5.64 ± 5.33 years. Twenty patients (60.60%) were female. Regarding the site of untethering, 31 procedures (93.93%) were performed at the lumbosacral region and 2 (6.06%) were performed at the thoracolumbar region. The conus medullaris was found above L3 in 21.21% of patients. Postoperatively, 18.18% of patients experienced complications, 48.48% showed improvement in their symptoms, and 48.48% were equivocal or had persistent symptoms. The mean preoperative ACD0 (measured from the posterior vertebral body margin [middle] to the anterior margin of the conus medullaris) was 6.15 ± 3.18 mm, the postoperative ACD0 was 2.25 ± 2.72 mm, and the average change in ACD0 was -0.90 ± 1.31 mm. The mean preoperative BA was 26.00° ± 11.56°, the mean postoperative BA was 15.92° ± 9.81°, and the average change in BA was -10.08° ± 8.80°. An optimal cutoff value for preoperative BA to predict reoperation in pediatric patients with complex TCS undergoing surgery was ≥ 31.70° (area under the curve = 0.83). CONCLUSIONS: In surgically treated patients with TCS, certain preoperative radiological parameters may be important in predicting postoperative surgical outcomes; these parameters can be evaluated and reported to indicate patients at high risk for complications. Further prospective multicenter research is warranted to offer robust evidence of association of patient outcomes with preoperative radiological parameters in TCS.

Redundant nerve roots indicate higher degree of stenosis in lumbar spine stenotic patients.

OBJECTIVES: Redundant Nerve Root (RNR) is a tortuous and elongated radiological appearance of cauda equina on Magnetic Resonance Imaging (MRI) in Lumbar Spinal Canal Stenosis (LSCS) patients. This study evaluated preoperative spinal morphometry associated with the development of RNR. METHODS: The retrospective cohort was conducted at The Aga Khan University Hospital, and included patients undergoing decompressive spinal surgery secondary to degenerative LSCS in 2015. The patients were divided into two groups with respect to the presence of preoperative RNR. Spinal morphometry was defined by several radiological parameters, including areas of dural sac (DSA), spinal canal, spinal foramen, facets, and spinal joints, and bilateral angles based on vertebral anatomy. RESULTS: A total of 55 patients were enrolled with a mean age of 57.1 years, in which 22 (40%) expressed RNR in their MRI. The RNR group had significantly lower mean DSA (59.64 vs 84.01 mm2; p = 0.028), bilateral posterior facet angle (Right: 33.84 vs 46.21, p = 0.004; Left: 36.43 vs 43.80, p = 0.039) and higher bilateral anterior facet angles (Right: 54.85 vs 44.57, p = 0.026; Left: 55.27 vs 46.36, p = 0.050) compared to the non-RNR group. The other bidimensional and angular parameters did not observe any statistical difference between the two groups. CONCLUSION: RNR was associated with a higher degree of stenosis in patients with LSCS. Bilateral anterior and posterior facets angles contribute to its development, indicating particular spinal morphology to be vulnerable to the stenotic disease.

Microfluidic 'brain-on chip' systems to supplement neurological practice: development, applications and considerations.

Among the greatest general challenges in bioengineering is to mimic human physiology. Advanced efforts in tissue engineering have led to sophisticated 'brain-on-chip' (BoC) microfluidic devices that can mimic structural and functional aspects of brain tissue. BoC may be used to understand the biochemical pathways of neurolgical pathologies and assess promising therapeutic agents for facilitating regenerative medicine. We evaluated the potential of microfluidic BoC devices in various neurological pathologies, such as Alzheimer's, glioblastoma, traumatic brain injury, stroke and epilepsy. We also discuss the principles, limitations and future considerations of BoC technology. Results suggest that BoC models can help understand complex neurological pathologies and augment drug testing efforts for regenerative applications. However, implementing organ-on-chip technology to clinical practice has some practical limitations that warrant greater attention to improve large-scale applicability. Nevertheless, they remain to be versatile and powerful tools that can broaden our understanding of pathophysiological and therapeutic uncertainties to neurological diseases.

In this paper, the authors describe the role of microfluidic 'brain-on-chip' systems as a tool to model and study the human brain. While animal studies have provided significant insights, they lack the complexity of human brain tissue in order to verify the effects of drugs on patients, study complex physiological pathways or personalize regenerative therapies. This makes studying diseases of complex human organs challenging. Microfluidics is a field of study that can address these challenges by developing sophisticated and miniaturized devices that can chamber human tissue. These devices could allow scientists to better study diseases on a model that is accurate and controllable, allowing researchers to better understand complex diseases, assess drug efficacy to specific areas of the brain and potentially accelerate the development of new therapies. Herein, we characterize the principles, development and challenges of microfluidics and the role they have served in different neurological diseases.

Immunohistochemical markers predicting recurrence following resection and radiotherapy in chordoma patients: insights from a multicenter study [RETRACTED].

OBJECTIVE: Chordomas are rare tumors that often recur regardless of surgery with negative margins and postoperative radiotherapy. The predictive accuracy of widely used immunohistochemical (IHC) markers in addressing the recurrence of skull base chordomas (SBCs) is yet to be determined. This study aimed to investigate IHC markers in the prediction of recurrence after SBC resection with adjuvant radiation therapy. METHODS: The authors reviewed the records of patients who had treatment for SBC between January 2017 and June 2021 across the Mayo Clinic in Minnesota, Florida, and Arizona. Exclusion criteria included patients who had no histopathology or recurrence as an outcome. Histopathological markers included cytokeratin A1/A3 only, epithelial membrane antigen (EMA), S100 protein, pan-cytokeratin, IN1, GATA3, CAM5.2, OSCAR, and chondroid. Information from patient records was abstracted, including treatment, clinical and radiological follow-up duration, demographics, and histopathological factors. Decision tree and random forest classifiers were trained and tested to predict the recurrence based on unseen data using an 80/20 split. RESULTS: A total of 38 patients with a diagnosis of SBC who underwent resection (gross-total resection: 42.1%; and subtotal resection: 57.9%) and radiation therapy were extracted from the medical records. The mean patient age was 48.2 (SD 19.6) years; most patients were male (n = 23; 60.5%) and White (n = 36; 94.7%). Pan-cytokeratin was associated with an increased risk of postoperative recurrence (OR 14.67, 95% CI 2.44-88.13; p = 0.00517) after resection and adjuvant radiotherapy. The decision tree analysis found pan-cytokeratin-positive tumors to have a 78% chance of being classified as a recurrence, with an accuracy of 75%. The distribution of minimal depth in the prediction of postoperative recurrence indicates that the most important variables were pan-cytokeratin, followed by cytokeratin A1/A3 and EMA. CONCLUSIONS: The authors' machine learning algorithm identified pan-cytokeratin as the largest contributor to recurrence among other IHC markers after SBC resection. Machine learning may facilitate the prediction of outcomes in rare tumors, such as chordomas.