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Due to treatment associated risks, it is still debatable which unruptured aneurysm should be treated. Anatomic and morphologic characteristics may aid to predict the rupture risk of superior cerebellar artery (SCA) aneurysm and possibly support in decision- making during treatment.To identify morphologic characteristics that could predict the rupture of SCA aneurysms.A retrospective analysis of computed tomography angiography images of 81 consecutive patients harboring SCA aneurysm who were treated between 1980 to 2014 at Helsinki University Hospital was performed.Of the 81 analyzed SCA aneurysms, 30 (37%) were unruptured and remaining 51 (63%) presented with subarachnoid hemorrhage. The mean ± SD size of unruptured SCA aneurysms was 6.2 ± 6.3 mm; mean size of ruptured SCA aneurysms was 5.9 ± 5.4 mm. The mean ± SD aspect ratio was 0.9 ± 0.3 in unruptured and 1.14 ± 0.44 in ruptured SCA aneurysms. The mean ± SD degree angle between basilar artery and aneurysm was 74.7 ± 24.4 in unruptured and 65.9 ± 23 ruptured SCA aneurysms. Patients with ruptured SCA aneurysm showed significantly higher aspect ratio (Mann-Whitney U, P = 0.01) and smaller aneurysm to basilar artery angle (Mann-Whitney U, P = 0.039). Aspect ratio1.1 had 2.3 times higher risk of rupture (odds ration [OR] 2.3, 95% confidence interval [CI] 0.84-6.34). An aneurysm to basilar angle70 degrees had 2.8 times higher risk of rupture (OR 2.75, 95% CI 1.086-6.96).Ruptured SCA aneurysms are usually small in size. Higher aspect ratio and smaller angle between SCA aneurysm and basilar artery had significantly higher risk of SCA (S1 segment) aneurysm rupture.

Background Although previous studies have made significant contributions to establishing animal traumatic brain injury (TBI) models for simulation of human TBI, the accuracy, controllability, and modeling efficiency of animal TBI models need to be further improved. This study established a novel high-efficiency graded mouse TBI model induced by shock wave. Methods A total of 125 mice were randomly divided into sham, 0.7 mm, 0.6 mm, and 0.5 mm groups according to the depth of the cross groove of the aluminum sheets. The stability and repeatability of apparatus were evaluated, and the integrity of the blood-brain barrier, cerebral edema, neuropathologic immunohistochemistry, apoptosis-related protein, and behavioral tests of neurologic function were used to validate this new model. Results The results showed that 4 mice were injured simultaneously in 1 experiment. They received the same intensity of shock waves. Moreover, the mortality rates caused by 3 different aluminum sheets were consistent with the mortality rates of mild TBI, moderate TBI, and severe TBI. Compared with the sham group, mice in different injured groups significantly increased brain water content, blood-brain barrier permeability, and neuronal apoptosis. And the mice in all injured groups showed poor motor ability, balancing, spatial learning, and memory abilities. Conclusions The novel TBI apparatus has advantages in its small size, simple operation, high repeatability, high efficiency, and graded severity. Our TBI apparatus provides a novel tool to investigate the neuropathologic changes and underlying mechanisms of TBI with various levels of severities.

Background Microelectrode recording (MER)-guided deep brain stimulation (DBS) remains the standard electrophysiological procedure to place the DBS lead at the optimal target. When single-track MER or test stimulation yields suboptimal results, trajectory adjustments are needed. Intraoperative computed tomography (iCT) can be useful to visualize the microelectrode and verify possible adjustments. The aim of this study was to evaluate the effect of iCT in MER during frameless stereotactic DBS for Parkinson disease (PD). Methods We retrospectively collected 28 PD patients, of whom 19 received iCT and 9 did not, and measured intracranial volume, cerebral volume, cerebrospinal fluid volume, and pneumocephalus volume. Euclidean distance was assessed according to merged preoperative brain CT and magnetic resonance imaging and postoperative brain CT. Results Fifty-six hemispheres in the 28 patients were analyzed for MER tracks. The patients who received iCT had a significantly lower mean number of MER tracks (1.6 vs. 2.6, P = 0.013) and lower mean Euclidean distance (2.2 mm vs. 2.7 mm, P = 0.033) compared with those who did not receive iCT. Although there was a trend of a decrease in pneumocephalus using intraoperative imaging, there was no significant difference in surgical time. Conclusions iCT can reduce the number of MER tracks and increase surgical accuracy. Further studies are warranted to investigate whether iCT can reduce surgical complications and improve surgical outcomes.

Enterprise stents are widely used for intracranial aneurysms located on small arteries (2.5 mm in diameter) and change the geometry of parent arteries. The purpose of this study was to investigate the correlation between vascular geometry changes and long-term outcomes.Between May 2013 and 2018, 1065 consecutive intracranial aneurysms were treated with Enterprise stents at our institution. After inclusion and exclusion criteria were applied, 377 aneurysms with6 months of digital subtraction angiography follow-up were evaluated. The cohort comprised 101 aneurysms located on small parent arteries. After stent-assisted coiling, the vascular geometry parameters of small parent arteries were compared to explore their correlation with procedural complications, delayed stent migration, and recanalization.The rate of delayed aneurysm occlusion in patients with initial efferent artery diameter (De)2.5 mm was significantly higher than in patients with De2.5 mm (62.2% vs. 40.2%; P = 0.032). At follow-up, vascular geometry parameters significantly increased (P0.001). In multivariate analyses, larger aneurysms and initial parent artery angle (α)90° were independent predictors of procedural complications and discrepancy in vessel size (ΔD)0.5 mm was an independent predictor of delayed stent migration. Larger aneurysms and follow-up angle change (ΔAngle)30° were independent predictors for recanalization of aneurysms located on small arteries.Enterprise stent-assisted coiling of intracranial aneurysms located on small arteries is safe and effective. Our study found that Enterprise deployment in small arteries had a low procedural complication rate and high stent tolerance. Vascular geometry changes play an important role in aneurysm recanalization.

To investigate the role of transforming growth factor β1 (TGF-β1), Smad3, and phospho-Smad3 (p-Smad3) in the invasion of somatotropinomas.In total, 45 somatotropinomas were obtained from patients who underwent surgery for the first time between 2011 and 2015 at Beijing Tiantan Hospital. The expression of TGF-β1, Smad3, and p-Smad3 was examined by western blot, quantitative reverse transcription polymerase chain reaction, and immunohistochemistry in somatotropinomas, and factors correlated with tumor invasion were analyzed.A total of 13 invasive somatotropinomas and 32 noninvasive somatotropinomas were enrolled in the study. TGF-β1 protein (P0.01) and mRNA (P0.01) levels were significantly less in the invasive somatotropinomas than noninvasive somatotropinomas. There was no significant difference in Smad3 protein level or Smad3 mRNA level between invasive somatotropinomas and noninvasive somatotropinomas. However, the p-Smad3 protein level was significantly less in the invasive somatotropinomas than noninvasive somatotropinomas (P0.01). Univariate analysis demonstrated that TGF-β1 (P0.01) and p-Smad3 scores (P0.01) were associated with invasion. In multivariate analysis, p-Smad3 scores remained a significantly independent predictor of invasion (odds ratio 0.897, 95% confidence interval 0.834-0.964, P0.05).Low expression of p-Smad3 is correlated with invasion of somatotropinomas.

The coronavirus disease 2019 (COVID-19) pandemic has changed health care delivery across the United States. Few analyses have specifically looked at quantifying the financial impact of the pandemic on practicing neurosurgeons. A survey analysis was performed to address this need.A 19-question survey was distributed to practicing neurosurgeons in the United States and its territories. The questions evaluated respondents' assessments of changes in patient and procedural volume, salary and benefits, practice expenses, staffing, applications for government assistance, and stroke management. Responses were stratified by geographic region.The response rate was 5.1% (267/5224). Most respondents from each region noted a50% decrease in clinic volume. Respondents from the Northeast observed a 76% decrease in procedure volume, which was significantly greater than that of other regions (P = 0.003). Northeast respondents were also significantly more likely to have been reassigned to nonneurosurgical clinical duties during the pandemic (P0.001). Most respondents also noted decreased salary and benefits but experienced no changes in overall practice expenses. Most respondents did not experience significant reductions in nursing or midlevel staffing. These trends were not significantly different between regions.The COVID-19 pandemic has led to decreases in patient and procedural volume and physician compensation despite stable practice expenses. Significantly more respondents in the Northeast region noted decreases in procedural volume and reassignment to nonneurosurgical COVID-related medical duties. Future analysis is necessary as the pandemic evolves and the long-term clinical and economic implications become clear.

In 1985, Kawase published an anterior petrosal approach to expose the posterior cranial fossa and to minimize retraction of the temporal lobe. However, some neurosurgeons still have difficulty with removing tumors through an anterior petrosal approach because a complete understanding of the Kawase pyramid has not been achieved. We hypothesized that if anterior petrosectomy were performed with three-dimensional understanding of the Kawase pyramid, it would have a positive effect on extent of tumor resection.We performed a retrospective study of patients who underwent surgical treatment for meningioma through an anterior petrosal approach. Patients were divided into total resection and subtotal resection groups, and statistical differences between the groups were analyzed. To identify factors predictive of complete tumor removal, univariable and multivariable logistic regression analyses were performed.Width and height of the drilled internal auditory canal of the total resection group were significantly larger than those of the subtotal resection group (P = 0.001, P = 0.033). The operative angle of the total resection group was significantly larger than that of the subtotal resection group (P0.001). Regression analyses showed only drilled internal auditory canal width to be predictive of complete tumor removal, increasing the likelihood of complete tumor removal by 2.778-fold with an increase in drilled internal auditory canal width by 1 mm (P = 0.023).Insufficient petrosectomy during an anterior petrosal approach adversely affects the extent of tumor resection. Furthering three-dimensional understanding of the Kawase pyramid could aid in complete tumor resection and better outcomes without causing damage to the surrounding organs.

Objective We aimed to evaluate the efficacy and safety of single-device flow diversion in patients with aneurysms measuring ≥15 mm in diameter. Methods For this retrospective study, we extracted medical record data for patients with unruptured intracranial aneurysms, who underwent flow diversion, at the authors’ institution between July 2014 and August 2019. The primary effectiveness outcome was defined as angiographic occlusion of the target aneurysm within 18 months without major (>50%) parent artery stenosis, major adverse events, or additional treatment. Results Thirty-five aneurysms in 35 patients were analyzed. Most aneurysms (n = 29, 82.9%) involved the anterior circulation. The median aneurysmal diameter was 18.3 mm, and the median neck size was 7.6 mm. Eleven (31.4%) aneurysms were considered giant (≥25 mm). The primary effectiveness outcome was achieved in 20 (57.1%) patients at a median of 10 months (interquartile range, 4.3–12.5) after flow diversion. Major adverse events occurred in 6 (17.1%) patients, including remote intraparenchymal hemorrhages (n = 2), a major ischemic stroke (n = 1), a delayed rupture of the target aneurysm (n = 1), and clinical deterioration caused by aggravated mass effect (n = 2). Multivariate logistic regression analysis found 2 independent predictors of the primary effectiveness outcome: the aneurysmal diameter (odds ratio, 0.71; 95% confidence interval, 0.54–0.86; P = 0.004) and the parent-vessel angle (odds ratio, 0.97; 95% confidence interval, 0.93–0.99; P = 0.017). Conclusions Single-device flow diversion was shown to be ineffective for large or giant intracranial aneurysms with a high parent vessel angle.

Background Glioma is a common primary intracranial tumor, with high infiltration and aggression. Propofol (Pro) is associated with growth and metastasis in glioma. Meanwhile, circular RNA non-SMC condensin I complex subunit G (circNCAPG; hsa_circ_0007244) has been reported to be upregulated in glioma. This study explored the role and mechanism of circNCAPG in Pro-induced glioma progression. Methods Cell viability was determined by cell counting kit-8 assay. Levels of circNCAPG, microRNA-200a-3p (miR-200a-3p), and member RAS oncogene family (RAB5A) were detected by real-time quantitative polymerase chain reaction. Colony number, apoptosis, migration, and invasion were analyzed by colony formation, flow cytometry, wound healing, and transwell assays. Matrix metallopeptidase 2, matrix metallopeptidase 9, and RAB5A protein levels were detected by Western blot assay. The binding relationship between miR-200a-3p and circNCAPG or RAB5A was predicted by starBase 2.0 and then verified by a dual-luciferase reporter and RNA immunoprecipitation assays. The biological roles of circNCAPG and Pro on glioma tumor growth were examined by the xenograft tumor model in vivo. Results Expression of circNCAPG and RAB5A was upregulated, and miR-200a-3p was decreased in glioma tissues and cells, while their expression presented an opposite trend in Pro-treated glioma cells. Moreover, circNCAPG overexpression could abolish Pro-mediated proliferation, apoptosis, migration, and invasion in glioma cells in vitro. Mechanically, circNCAPG could regulate RAB5A expression by sponging miR-200a-3p. Pro blocked glioma tumor growth in vivo by modulating circNCAPG. Conclusions Pro could inhibit glioma cell growth and metastasis through the circNCAPG/miR-200a-3p/RAB5A axis, providing a promising therapeutic strategy for glioma treatment.

Intraventricular hemorrhage (IVH) is common in premature newborns and poses a high risk for morbidity with lifelong disability. We searched the available literature for original and secondary literature regarding the epidemiology, pathogenesis, and treatment of IVH in order to trace changes in the management of this disease over time. We examined IVH pathogenesis and epidemiology and reviewed the history of medical and surgical treatment for intraventricular hemorrhage in preterm children. Initial medical management strategies aimed at correcting coagulopathy and eventually targeted mediators of perinatal instability including respiratory distress. Surgical management centered around cerebrospinal fluid diversion, initially through serial lumbar punctures, progressing to ventriculoperitoneal shunting, with more recent interventions addressing intraventricular clot burden. We provide a historical review of the evolution of treatment for IVH in newborns. While the management of IVH has grown significantly over time, IVH remains a common neurosurgical disease that continues to affect patient and caregiver quality of life and health care costs. Despite advances in treatment over more than a century, IVH remains a significant cause of morbidity and mortality in premature infants, and an understanding of past approaches may inform the development of new treatments.

Objectives To investigate the effect of surgical stabilization for patients with metastatic spinal disease on objective mobility metrics. Methods A retrospective chart review identified patients who had mechanical back pain from metastatic spinal disease and underwent spinal stabilization during 2017. Mobility metrics, the Activity Measure for Post-Acute Care (AM-PAC) inpatient mobility short form (IMSF) and the Johns Hopkins Highest Level of Mobility (JH-HLM), were reviewed. Results A total of 26 patients were included in the analysis with median hospital stay of 8 days. Preoperative JH-HLM scores were available for 17 patients with a mean score of 5.4, increasing to mean score of 6.6 at last follow-up (P = 0.036). Preoperative AM-PAC IMSF scores were available for 14 patients with a mean score of 19.4, decreasing slightly to a mean score of 18.7 at last follow-up (P = 0.367). Last follow-up with mobility metrics occurred a median of 6.5 days postoperatively (range: 3–66 days). Multivariable analysis showed that American Spinal Injury Association and Karnofsky Performance Status scores were significantly associated with both JH-HLM and AM-PAC mobility scores at last follow-up. A higher JH-HLM or AM-PAC score was significantly associated with direct home discharge and a higher AM-PAC score was associated with shorter hospital stay. Conclusions Surgical stabilization for patients with mechanical back pain secondary to metastatic spinal disease might lead to an objective improvement in JH-HLM score. JH-HLM and AM-PAC scores may be correlated with length of hospital stay and discharge disposition. Future studies are encouraged to further characterize the role of these mobility metrics in the management plan of these patients.

Cerebellar mutism syndrome (CMS) is one the most disabling postoperative neurological complications after posterior fossa surgery in children. CMS is characterized by a transient mutism with a typical onset demonstrated within 2 days postoperatively accompanied by associated ataxia, hypotonia, and irritability. Several hypotheses for the anatomical basis of pathophysiology and risk factors have been suggested. However, a definitive theory and treatment protocols have not yet been determined. Animal histological and electrophysiological studies and more recent human imaging studies have demonstrated the existence of a compartmentalized representation of cerebellar function, the understanding of which might provide more information on the pathophysiology. Damage to the dentatothalamocortical pathway and cerebrocerebellar diaschisis have been described as the anatomical substrate to the CMS. The risk factors, which include tumor type, brainstem invasion, tumor localization, tumor size, and vermal splitting technique, have not yet been clearly elucidated. The efficacy of potential pharmacological and speech therapies has been studied in small trials. Long-term motor speech deficits and associated cognitive and behavioral disturbances have now been found to be common among CMS survivors, affecting their development and requiring rehabilitation, leading to significant financial effects on the healthcare system and distress to the family. The aim of the present review was to outline the cerebellar anatomy and function and its connections in relationship to the pathophysiology and to refine the risk factors and treatment strategies for CMS.

The management of spine tumors is multimodal and personalized to each individual patient. Patients often require radiation therapy after surgical fixation. Although titanium implants are used most commonly, they produce significant artifact, leading to decreased confidence in target-volume coverage and normal tissue sparing. Carbon-based materials have been found to have minimal effects on dose perturbation in postoperative radiation therapy and have shown biostability and biocompatibility that are comparable to titanium implants. Using the PubMed and Web of Sciences databases, we conducted a systematic review of carbon-based screw and rod fixation systems in the treatment of spinal tumors. We reviewed clinical studies regarding safety of spine fixation with carbon fiber-reinforced (CFR) implants and biomechanical studies, as well as radiation and dosimetric studies. The radiolucency of CFR-polyether ether ketone implants has the potential to benefit patients with spine tumor. Clinical studies have shown no increase in complications with implementation of CFR-polyether ether ketone implants, and these devices seem to have sufficient stiffness and pullout strength. However, further trials are necessary to determine if there is a clinically significant impact on local tumor control.

Objective Surgical treatment of advanced intracranial and extracranial communicating skull base tumors is challenging, especially for the reconstruction of the large composite defect left by tumor resection. The aim of the study is to evaluate the utility of the free flap reconstruction of the defects resulting from radical resection of these tumors in a single institution. Methods The clinical data of 17 consecutive patients who underwent free flap reconstruction for defect left by salvage resection of advanced intracranial and extracranial communicating tumors from 2013 to 2019 were retrospectively collected and analyzed. Results There were 5 squamous cell carcinomas, 4 adenoid cystic carcinomas, 2 basal cell carcinomas, 2 meningiomas, 1 anaplastic hemangiopericytoma, 1 pleomorphic adenoma, 1 osteosarcoma, and 1 chondrosarcoma. All patients had recurrent neoplasms, 2 of whom had pulmonary metastasis. A modified radical cervical dissection was performed in 6 patients. The anterolateral thigh myocutaneous flap and rectus abdominis myocutaneous flap were used in 15 patients (88.2%) and 2 patients (11.8%), respectively. Complications were seen in 3 of 17 patients (17.6%) with 1 total flap loss. The median progression-free survival duration was 31 months. The 3- and 5-year progression-free survival rates were 0.47 and 0.24, respectively. The mean overall survival duration was 66 months. The 3- and 5-year overall survival rates were 0.85 and 0.68, respectively. Conclusions Free flap transfer is a safe and effective method with acceptable complications, useful for reconstruction of large composite skull base defects after salvage resection of advanced intracranial and extracranial communicating tumors. The functional and cosmetic results are satisfying.

Background Given the significant cost and morbidity of patients undergoing lumbar fusion, accurate preoperative risk-stratification would be of great utility. We aim to develop a machine learning model for prediction of major complications and readmission after lumbar fusion. We also aim to identify the factors most important to performance of each tested model. Methods We identified 38,788 adult patients who underwent lumbar fusion at any California hospital between 2015 and 2017. The primary outcome was major perioperative complication or readmission within 30 days. We build logistic regression and advanced machine learning models: XGBoost, AdaBoost, Gradient Boosting, and Random Forest. Discrimination and calibration were assessed using area under the receiver operating characteristic curve and Brier score, respectively. Results There were 4470 major complications (11.5%). The XGBoost algorithm demonstrates the highest discrimination of the machine learning models, outperforming regression. The variables most important to XGBoost performance include angina pectoris, metastatic cancer, teaching hospital status, history of concussion, comorbidity burden, and workers’ compensation insurance. Teaching hospital status and concussion history were not found to be important for regression. Conclusions We report a machine learning algorithm for prediction of major complications and readmission after lumbar fusion that outperforms logistic regression. Notably, the predictors most important for XGBoost differed from those for regression. The superior performance of XGBoost may be due to the ability of advanced machine learning methods to capture relationships between variables that regression is unable to detect. This tool may identify and address potentially modifiable risk factors, helping risk-stratify patients and decrease complication rates.

Objective To evaluate the impact of multidisciplinary intraoperative teams on surgical complications in patients undergoing sacral tumor resection. Methods We reviewed all patients with primary or metastatic sacral tumors managed at a single comprehensive cancer center over a 7-year period. Perioperative complication rates were compared between those treated by an unassisted spinal oncologist and those treated with the assistance of at least 1 other surgical specialty. Statistical analysis involved univariable and stepwise multivariable logistic regression models to identify predictors of multidisciplinary management and 30-day complications. Results A total of 107 patients underwent 132 operations for sacral tumors; 92 operations involved multidisciplinary teams, including 54% of metastatic tumor operations and 74% of primary tumor operations. Patients receiving multidisciplinary management had higher body mass indexes (29.8 vs. 26.3 kg/m2; P = 0.008), larger tumors (258 vs. 55 cm³; P Although operations involving multidisciplinary teams were longer (467 vs. 231 minutes; P Conclusions Although patients managed with multidisciplinary teams had larger tumors and worse baseline health, 30-day complications were similar. This finding suggests that the use of multidisciplinary teams may help to mitigate surgical morbidity in those with high baseline risk.

Background Digital subtraction angiography (DSA) and computed tomographic angiography (CTA) are used to identify the cause of nontraumatic subarachnoid hemorrhage (SAH). There is no consensus on which to choose as the first diagnostic tool. We aimed to compare the cost-effectiveness of CTA versus DSA as a primary tool for identifying the cause of nontraumatic SAH. Methods A decision analysis model was built to simulate patients undergoing DSA or CTA as a primary diagnostic tool for the cause of nontraumatic SAH. The input data for the study were extracted from literature. Probabilistic and deterministic sensitivity analyses were performed to evaluate the robustness of the model. Results In the base case calculation, it cost $1261.82 less and yielded 0.0001 quality-adjusted life year (QALY) when DSA was used as a primary diagnostic imaging tool for nontraumatic SAH. Choosing DSA as a primary tool was cost-effective in more than 65% of iterations in probabilistic sensitivity analysis. Deterministic sensitivity analyses show when the probability of using endovascular treatment is >47.2%, choosing DSA is more cost-effective; otherwise, CTA is more optimal. CTA is more cost-effective when the cost for DSA >2.6 × CTA + $600. Conclusions Based on current literature and our model DSA as a primary diagnostic tool for the cause of nontraumatic SAH is more cost-effective. However, in clinical practice physicians can choose either DSA or CTA according to the scale of endovascular procedures used in their center, as well as the cost correlation between CTA and DSA, which varies among institutions.

Background The lumbar spine displays its greatest mobility in ventral flexion, which is a potential risk factor for low back pain. The relative contribution of each segment to the complete flexion is denoted the spine rhythm, which is required to distinguish between normal and abnormal spinal profiles, and as well to calculate the spinal forces in musculoskeletal models. Nevertheless, different spine rhythms have been reported in literature and the effect of arm position has not been demonstrated. We therefore aimed to investigate the effects of different arm positions on spine rhythm during ventral flexion. Methods A nonradiologic back measurement device was used to determine the real-time back lordosis during ventral flexion while participants (10 male and 10 female without low back pain) held their arms at 6 different positions. Results During flexion with the arms naturally hanging down at both sides, the lumbar range of flexion was 52.6° ± 13.1°. Different arm positions displayed nonsignificant effect on lumbar range of flexion (P > 0.05). The middle and lower levels contributed more to the whole lumbar range of flexion than the upper level (P Conclusions The lumbar spine displayed greater flexion in the middle and lower levels and its flexion rhythm remained unchanged at different arm positions. These results strike importance to explore for more reasons explaining the different lumbar flexion rhythms reported in literature.

Background The incidence of retractions has been increasing steadily, in direct proportion to the volume of scientific literature. Retraction of published articles depends on the visibility of journals and on postpublication scrutiny of published articles by peers. The possibility thus exists that not all compromised (“retractable”) articles are detected and retracted from the less-visible journals. The proportion of “retractable” articles and its converse, the proportion of published articles in each journal that are likely to be “true” (PTP), have not been estimated hitherto. Methods Three journal sets were created: pure neurosurgery journals (NS-P), the neurosurgery component of multidisciplinary journals (NS-MD), and high-impact clinical journals (HICJs). We described a new metric (the retraction gap [RGap]), defined as the proportion of retractable articles in journals that have not been retracted. We computed the expected number of retractable articles, RGap, and PTP for each journal, and compared these metrics across groups. Results Fifty-three NS-P journals, 10 NS-MD journals, and 63 HICJs were included in the analysis. The estimated number of retractable articles was 31 times the actual number of retractions in NS-P journals, 6 times higher in the NS-MD journals, and 26 times higher for the HICJs. The RGap was 96.7% for the NS-P group, 83.5% for the NS-MD group, and 96.2% for the HICJs. The PTP was 99.3% in the NS-P group, 99.2% in the NS-MD group, and 98.6% in the HICJs. Conclusions Neurosurgery as a discipline had a higher RGap but also a higher PTP than the other 2 groups.

Background Intervertebral fusions in cases of reduced bone density are a tough challenge. From a biomechanical point of view, most current studies have focused on the range of motion or have shown test setups for single-component tests. Definitive setups for biomechanical testing of the primary stability of a 360° fusion using a screw-rod system and cage on osteoporotic spine are missing. The aim of this study was to develop a test stand to provide information about the bone-implant interface under reproducible conditions. Methods After pretesting with artificial bone, functional spine units were tested with 360° fusion in the transforaminal lumbar interbody fusion technique. The movement sequences were conducted in flexion/extension, right and left lateral bending, and right and left axial rotation on a human model with osteopenia or osteoporosis under permanent maximum load with 7.5 N-m. Results During the testing of human cadavers, 4 vertebrae were fully tested and were inconspicuous even after radiological and macroscopic examination. One vertebra showed a subsidence of 2 mm, and 1 vertebra had a cage collapsed into the vertebra. Conclusions This setup is suitable for biomechanical testing of cyclical continuous loads on the spine with reduced bone quality or osteoporosis. The embedding method is stable and ensures a purely single-level setup with different trajectories, especially when using the cortical bone trajectory. Optical monitoring provides a very accurate indication of cage movement, which correlates with the macroscopic and radiological results.

We sought to investigate the association between diabetes mellitus and incidence of adverse outcomes in patients who underwent meningioma surgery.The 2012-2014 National Inpatient Sample database was used. Prolonged length of stay was indicated by values greater than the 90th percentile of the sample. The Fisher exact test and analysis of variance were used to compare demographics, hospital characteristics, comorbidity, and complications among race cohorts. Logistic regression was used to analyze the independent effect of diabetes on adverse outcomes.After selecting for patients with primary diagnosis of meningioma who underwent a resection procedure, 7745 individuals were identified and divided into diabetic (n = 1518) and nondiabetic (n = 6227) cohorts. Demographics, hospital characteristics, and comorbidities were significantly different among the 2 cohorts. Average length of stay was longer in diabetic patients (8.15 vs. 6.04 days, P0.001), and total charges were higher in diabetic patients ($139,462.66 vs. $123,250.71, P0.001). Multivariate regression indicated diabetic patients have higher odds of experiencing a complication (odds ratio [OR] 1.442, 95% confidence interval [CI] 1.255-1.656, P0.001) and in-hospital mortality (OR 1.672, 95% CI 1.034-2.705, P = 0.036) after meningioma surgery. Analysis of individual postoperative complications revealed that diabetic patients experienced increased odds of pulmonary (OR 1.501, 95% CI 1.209-1.864, P0.001), neurologic (OR 1.690, 95% CI 1.383-2.065, P0.001), and urinary/renal complications (OR 2.618, 95% CI 1.933-3.545, P0.001). In addition, diabetic patients were more likely to have a prolonged length of stay (OR 1.694, 95% CI 1.389-2.065, P0.001).Diabetes is an important factor associated with complications after meningioma surgery. Preventative measures must be taken to optimize postoperative outcomes in these patients.

Objective This study aimed to investigate the safety and efficacy of endovascular embolization for very small ruptured anterior communicating artery (AcomA) aneurysms. Methods From August 2015 to June 2020, 81 patients with very small (≤3 mm) ruptured AcomA aneurysms treated endovascularly were enrolled in this study. Clinical and radiographic data were analyzed retrospectively, including the aneurysm occlusion rate, complications, and clinical outcome. Results Among 81 patients, simple coiling embolization was performed in 52 cases and stent-assisted embolization in 29 cases. Immediate angiography demonstrated complete occlusion in 59 (72.8%) aneurysms, residual neck in 20 (24.7%) aneurysms, and residual lumen in 2 (2.5%). Procedure-related complications rate was 2.5% (2 of 81), all of which were transient thromboembolic events. Angiographic follow-up outcomes of 60 patients (mean: 6.8 ± 3.2 months) revealed complete occlusion in 91.7% (55 of 60), with recurrence in 1 patient. The mean clinical follow-up time was 22.6 ± 11.4 months and good prognosis rates (6-month modified Rankin Scale score: 0–2) reached 90.2% (73 of 81). The differences in aneurysm occlusion and procedure-related complications between the simple coiling group and the stent-assisted coiling group were not statistically significant. Conclusions Coiling with or without stent-assisted technique for the treatment of very small ruptured AcomA aneurysms was safe and effective.

Objective For idiopathic normal pressure hydrocephalus (iNPH), risk stratifying patients and identifying those who are likely to fare well after ventriculoperitoneal shunt (VP) surgery may help improve quality of care and reduce unplanned readmissions. The aim of this study was to investigate the drivers of 30- and 90-day readmissions after VP shunt surgery for iNPH in elderly patients. Methods The Nationwide Readmission Database, years 2013 to 2015, was queried. Elderly patients (≥65 years old) undergoing VP shunt surgery were identified using the International Classification of Diseases, Ninth Revision, Clinical Modification coding system. Unique patient linkage numbers were used to follow patients and identify 30- and 31- to 90-day readmission rates. Patients were grouped by no readmission (Non-R), readmission within 30 days (30-R), and readmission within 31 to 90 days (90-R). Results We identified 7199 elderly patients undergoing VP shunt surgery for iNPH. A total of 1413 (19.6%) patients were readmitted (30-R: n = 812 [11.3%] vs. 90-R: n = 601 [8.3%] vs. Non-R: n = 5786). The most prevalent 30- and 90-day complications seen among the readmitted cohort were mechanical complication of nervous system device implant (30-R: 16.1%, 90-R: 12.4%), extracranial postoperative infection (30-R: 10.4%, 90-R: 7.0%), and subdural hemorrhage (30-R: 6.0%, 90-R: 16.4%). On multivariate regression analysis, age, diabetes, and renal failure were independently associated with 30-day readmission; female sex, and 26th to 50th household income percentile were independently associated with reduced likelihood of 90-day readmission. Having any complication during the index admission independently associated with both 30- and 90-day readmission. Conclusions In this study, we identify the most common drivers for readmission for elderly patients with iNPH undergoing VP shunt surgery.

Creating aneurysm sizes in animal models that resemble human aneurysms is essential to study and test neuroendovascular devices. The commonly used rabbit surgical elastase model, however, produces saccular aneurysms that are smaller than those typically treated in humans. The goal of this study was to determine whether an increased vessel stump length and the addition of calcium chloride to the incubation solution has an effect on the resulting aneurysm size.Using a modified aneurysm creation method, 32 female New Zealand White rabbits underwent aneurysm creation procedures. Subjects were equally allocated into 4 different groups based on vessel stump length (2 cm controls vs. 3 cm) and incubation solution (elastase alone controls vs. a 1:1 mixture of elastase and calcium chloride). At 4 weeks, all animals underwent angiography to determine the resulting aneurysm size by a neurointerventionalist who was blinded to treatment group.An increase in stump length from 2 cm to 3 cm resulted in a significant increase in the height of aneurysm (P0.05). Compared with control animals, the combination of a 3-cm stump length and the addition of calcium chloride to the incubation solution resulted in a significant increase in aneurysm height, width, and volume (P0.05).Creating larger aneurysms is necessary for the rabbit model to be more clinically relevant. Our study demonstrated that the utilization of a 3-cm vessel stump as well as both calcium chloride and elastase in the incubation solution results in aneurysm sizes that more closely resemble the population of aneurysms treated in humans.

Background No completely effective pharmacotherapies have been developed to improve the outcomes of traumatic brain injury (TBI). Given the reporting of cohort studies suggesting that preinjury statin use may reduce TBI-associated mortality, this study aimed to evaluate the effects of statin use in patients with TBI. Methods This study was performed according to the PRISMA guidelines. The PubMed, Embase, Cochrane Central, Web of Science, and China National Knowledge Infrastructure databases were searched from inception until April 13, 2021, using a search strategy that included 2 main terms: “statins” and “traumatic brain injury.” The outcomes were mortality, hospital length of stay, and intensive care unit length of stay, which were evaluated using a random-effects model and represented by the pooled risk ratio with 95% confidence intervals. Results The search results identified 7 eligible studies, with a total of 111,935 patients with brain injury. Preinjury statin use in patients with TBI was associated with a significantly decreased risk of mortality compared with that in nonusers (risk ratio, 0.75; 95% confidence interval, 0.59–0.94; I2 = 53%). Subgroup analysis showed that statin withdrawal might increase mortality. Sensitivity analysis showed that the results were stable and robust. Conclusions Preinjury statin use may contribute to mortality reduction in patients with TBI, whereas statin withdrawal might increase mortality. In clinical management, statin use should not be discontinued after TBI.

To examine the impact of marital status on the mortality of patients with primary malignant brain tumors excluding bias from basic characteristics and treatment.We used the Surveillance, Epidemiology, and End Results program to identify 81,277 patients diagnosed from 2000 through 2016 with the most common primary malignant brain tumors, including glioma, ependymoma, and medulloblastoma. To avoid bias, we used the propensity score matching method to match 44,854 patients with complete clinical and follow-up information. Then, we used Cox regression and Kaplan-Meier survival analysis to investigate the impact of marital status on cancer patient mortality.Married patients were more likely to receive surgery and adjuvant chemo- or radiotherapy than single and divorced, separated, and widowed (DSW) patients (all P0.001). Married patients with high grade glioma were more likely to survive longer and less likely to die of their malignance compared with single (adjusted odds ratio [OR] 1.120; 95% confidence interval [CI], 1.069 to 1.174; P0.001; OR 1.078; 95% CI, 1.025 to 1.133; P = 0.003; respectively), and DSW patients (OR 1.117; 95% CI, 1.074 to 1.161; P0.001; OR 1.090; 95% CI, 1.046 to 1.136; P0.001; respectively) (all adjusted to the married group). Similar results were identified in patients with low-grade glioma but not ependymoma and medulloblastoma.Even after adjusting for known confounders, married patients with high-grade glioma and low-grade glioma are at higher possibility to have a better outcome. This study highlights the potential significance that intimate support from spouse can improve glioma patient survival.

Background Virtual reality (VR) use in health care has increased over the past few decades, with its utility expanding from a teaching tool to a highly reliable neuro-technology adjunct in multiple fields including neurosurgery. Generally, brain tumor surgery with the patient awake has only been performed for mapping of language and motor areas. With the rise of VR and advancing surgical techniques, neurosurgical teams are developing an increased understanding of patients’ anatomo-functional connectivity. Consequently, more specific cognitive tasks are being required for the mapping and preservation of deeper layers of cognition. Methods An extensive literature review was conducted with the inclusion criteria of manuscripts that described the use of VR during awake neurosurgery mapping. Results We identified 3 recent articles that met our inclusion criteria, yet none of them addressed the specific use of VR for cognition mapping. Consequently, a cognitive task phase was performed to search and craft the tasks and domains that better filled the spotted niche of this need inside the operating room. A proposed protocol was developed with 5 potential uses of VR for brain mapping during awake neurosurgery, each of them with a specific proposed example of use. Conclusions The authors advocate for the use of a VR protocol as a feasible functional tool in awake-patient brain tumor surgery by using it as a complement during cognitive screening in addition to language testing.

BACKGROUND Epidural hematoma (EDH) can result in a catastrophic outcome of traumatic brain injury. Current management guidelines do not consider the source of hemorrhage in decision making. The purpose of this study was to examine the relationship between EDH location and the source of hemorrhage. METHODS We report retrospectively reviewed, prospectively obtained surgical data of patients with acute traumatic cranial EDH treated between 2007 and 2018. Computed tomography (CT) scans were used to categorize EDH location as lateral or medial. The source of hemorrhage was identified intraoperatively by a single surgeon. RESULTS Overall, of 92 evacuated EDHs (in 87 patients), 71 (77.2%) were in the lateral location. Arterial bleeding was the cause of EDH in 63.4% of the lateral EDHs and 9.2% of the medial EDHs (P < 0.0001). In the cases where surgery was done primarily to treat EDH, 65.3% had an arterial bleed source (P < 0.0001). In those treated for primary reasons other than EDH evacuation, 75% had a venous bleed source (P = 0.002). CONCLUSIONS The location of EDH correlates with the source of hemorrhage. The decision to operate on EDH may be influenced by this factor.

Objective To evaluate medical and surgical complication rates between robotic-assisted versus conventional elective posterior lumbar fusions. Methods The Symphony Integrated DataVerse was queried using International Classification of Diseases, 10th Edition, Clinical Modification procedure codes to identify patients undergoing elective posterior lumbar fusions for degenerative spine pathologies between 2015 and 2018. International Classification of Diseases, 10th Edition, Clinical Modification procedure codes (8E0W4CZ, 8E0W0CZ, 8E0W3CZ) were used to identify patients undergoing a robotic-assisted spinal fusion. Outcome measures were 90-day medical and surgical complications, 1-year pseudarthrosis, and 1-year revision surgery rates. Multivariate logistic regression analyses were used to assess whether undergoing a robotic-assisted fusion (vs. conventional fusion) was associated with differences in wound complications, medical complications, pseudarthrosis, revision surgery, and readmissions within 90 days of surgery. Results A total of 39,387 patients undergoing elective posterior lumbar fusions were included in the cohort—of whom 245 (0.62%) patients underwent a robotic-assisted fusion. Multivariate analysis showed that robotic-assisted fusion (vs. conventional fusion) was not associated with significant differences in 90-day rates of wound complications (P = 0.299), urinary tract infections (P = 0.648), acute myocardial infarctions (P = 0.209), acute renal failure (P = 0.461), pneumonia (P = 0.214), stroke (P = 0.917), deep venous thrombosis (P = 0.562), pulmonary embolism (P = 0.401), and readmissions (P = 0.985). In addition, there were no significant differences in the 1-year rates of revision fusions (P = 0.316) and pseudarthrosis (P = 0.695). Conclusions Patients who underwent a robotic-assisted fusion had similar rates of surgical and medical complications compared with those who underwent a conventional fusion. Further studies are warranted to better understand the future role of robots in spine surgery.

Background Mortality rate after subarachnoid hemorrhage due to rupture of vertebral artery dissecting aneurysms (VADAs) is high; endovascular coil trapping is the first-line therapy to prevent rerupture. To select optimal treatments, the positional relationship between the VADA and posterior inferior cerebellar artery (PICA) and the morphology of the contralateral vertebral artery must be considered, and outcome predictors of different treatment methods and their possible complications must be identified. Methods We retrospectively studied 44 patients with ruptured VADAs who had undergone endovascular or surgical treatment. VADA morphology was assessed on conventional preoperative angiograms, and VADAs were categorized based on their site in relation to the PICA. VADA site, treatment method, and complications were used to identify prognostic factors. Results The sites of the 44 VADAs were PICA-proximal (n = 3), PICA-distal (n = 22), PICA-absent (n = 7), and PICA-involved (n = 12). Treatments included internal coil trapping (n = 30), proximal coil occlusion (n = 5), and stent placement (n = 3); surgical flow alteration via an occipital artery–PICA bypass and ligation at the proximal vertebral artery and the PICA origin was performed in 6 patients. Periprocedural rebleeding was associated with a poor outcome. Internal coil trapping prevented the rerupture of PICA-proximal and PICA-absent VADAs, and flow alteration prevented rerupture of PICA-involved VADAs; there were no complications directly attributable to these procedures. Conclusions Periprocedural rebleeding was a poor prognostic factor. Internal trapping of PICA-proximal and PICA-absent VADAs and flow alteration in PICA-involved VADAs prevented rerupture.

Background This study aimed to compare the effectiveness of posterior fossa decompression (PFD), posterior fossa decompression with duraplasty (PFDD), and posterior fossa decompression with resection of tonsils (PFDRT) in Chiari malformation type I (CMI). Furthermore, we aimed to evaluate the evidence supporting the efficacy of filum terminale sectioning (FTS), syringosubarachnoid shunting (SSS), and syringoperitoneal shunting (SPS) in CMI. Methods PubMed, Cochrane, and Embase databases were screened for English-language studies published from inception until August 11, 2020. A total of 3593 studies were identified through the searching process. Fifteen cohort studies were included in the systematic review and network meta-analysis. Results No studies concerning FTS, SSS, and SPS were found eligible. Therefore, only PFD, PFDD, and PFDRT were compared. PFDD showed significantly higher incidence of complications (relative risk [RR], 3.79; 95% confidence interval [CI], 2.54-5.64) cerebrospinal fluid leak (RR, 9.74; 95% CI, 2.33-40.78) and neurologic deficit (RR, 8.76; 95% CI, 2.08-36.90) than did PFD. Both PFDD and PFDRT achieved higher syringomyelia improvement (RR, 1.23, 95% CI, 1.09-1.39 and RR, 1.32, 95% CI, 1.15-1.51, respectively) and greater clinical improvement (RR, 1.24, 95% CI, 1.10-1.39 and RR, 1.24, 95% CI, 1.08-1.44, respectively) than did PFD. No differences were found between PFDD and PFDRT. Conclusions PFDD and PFDRT are superior to PFD, especially in patients with syringomyelia-Chiari complex, because of greater syringomyelia reduction and better clinical improvement. However, PFDD and PFDRT can be considered equally efficient. There is no evidence pleading in favor of SFT, SSS, and SPS over any PFD technique.

To determine postoperative complications and quality outcomes of single-stage and multistage surgical management for lumbar degenerative disease (LDD).This retrospective cohort study using a national administrative database identified patients who underwent surgery for LDD between 2007 and 2016. Patients were stratified based on whether their surgeon chose to perform single-stage or multistage LDD surgery, and these cohorts were mutually exclusive. Propensity score matching was used to mitigate intergroup differences between single-stage and multistage patients. Patients who underwent ≥3 levels of surgical correction, who were18 years old, or who had any prior history of trauma or tumor were excluded from the study. Baseline comorbidities, postoperative complication rates, and reoperation rates were determined.Primary surgery for LDD was performed in 47,190 patients; 9438 (20%) of these patients underwent multistage surgery. After propensity score matching, baseline covariates of the 2 cohorts were similar. The complication rate was 6.1% in the single-stage cohort and 11.0% in the multistage cohort. Rates of posthemorrhagic anemia, infection, wound complication, deep vein thrombosis, and hematoma all were higher in the multistage cohort. Length of stay, revisions, and readmissions were also significantly higher in the multistage cohort. Through 2 years of follow-up, multistage surgery was associated with higher payments throughout the 2-year follow-up period ($57,036 vs. $39,318, P0.05).Single-stage surgery for LDD demonstrated improved outcomes and lower health care utilization. Spine surgeons should carefully consider single-stage surgery when treating patients with LDD requiring3 levels of correction.

To do a comparative surgical outcome and cost-benefit analysis of our simple modified Taylor retractor with both open and tubular techniques in lumbar discectomy.We retrospectively divided 52 lumbar disc patients operated by 2 different techniques between January 2019 and June 2020 into 2 groups- group 1 (n = 20): standard open macrodiscectomy (4-5 cm incision); group 2 (n = 32): unilateral translaminar microdiscectomy using our modified Taylor retractor with a small incision (18-20 mm, comparable to the tubular retractor). We compared both groups in terms of surgical outcomes and cost-benefit analysis. In addition, a cost-benefit comparison between our modified Taylor technique and that of the already published tubular microdiscectomy cohort was done.Complete symptom resolution occurred in 85% group 1 and 84.4% group 2 patients, with no difference in complication rates. Mean hospital stay was significantly less in group 2 (1.2 ± 0.37 days) as compared with group 1 (2.4 ± 1.15, P0.001). The mean total cost per patient was $2253.17 ± 69.16 in the modified Taylor microdiscectomy group compared with $2495.76 ± 214.85 (P0.001) in standard macrodiscectomy. Compared with the previously published tubular microdiscectomy cohort ($3069.91 ± 69.16), the modified Taylor retractor was $816.74 cheaper per patient with similar length of incision, surgical outcome, and hospital stay.Similar clinical outcomes at decreased costs are obtained using the modified Taylor retractor compared with the tubular retractor. The modified Taylor retractor has a simple design, is user-friendly, and frugal alternative to the tubular retractor system for microscopic discectomy, especially in the resource-constrained countries.

Previous studies have shown that deep brain stimulation (DBS) can improve the level of consciousness of comatose patients with traumatic brain injuries (TBIs). However, the most suitable targets for DBS are unknown, and the mechanisms underlying recovery remain to be determined. The aim of the present study was to assess the effects of lateral hypothalamic area-DBS (LHA-DBS) in comatose rats with TBIs.A total of 55 Sprague-Dawley rats were randomly assigned to 5 groups: the control group, TBI group, stimulated (TBI+LHA-DBS) group, antagonist (TBI+SB334867+LHA-DBS) group, and antagonist control (TBI+saline+LHA-DBS) group. The rats in the control group had undergone a sham operation and anesthesia, without coma induction. Coma was induced using a free-fall drop method. The rats in the stimulated group received bilateral LHA stimulation (frequency, 200 Hz; voltage, 2-4 V; pulse width, 0.1 ms) for 1 hour, with 5-minute intervals between subsequent stimulations, which were applied alternately to the left and right sides of the lateral hypothalamus. The comatose rats in the antagonist group received an intracerebroventricular injection with an orexins receptor type 1 (OX1R) antagonist (SB334867) and then received LHA-DBS. A I-VI consciousness scale and electroencephalography were used to assess the level of consciousness in each group of rats after LHA-DBS. Western blotting and immunofluorescence were used to detect OX1R expression in the LHA and α1-adrenoceptor (α1-AR) subtype and gamma-aminobutyric acid β receptor (GABABR) expression in the prefrontal cortex.In the TBI, stimulated, antagonist, and antagonist control groups, 5, 10, 6, and 9 rats were awakened. The electroencephalographic readings indicated that the proportion of δ waves was lower in the stimulated group than in the TBI and antagonist groups (P0.05). Western blotting and immunofluorescence analysis showed that OX1R expression was greater in the stimulated group than in the TBI group (P0.05). The expression of α1-AR was also greater in the stimulated group than in the TBI and antagonist groups (P0.05). In contrast, the GABABR levels in the stimulated group were lower than those in the TBI and antagonist groups (P0.05). A statistically significant difference was found between the antagonist and antagonist control groups.Taken together, these results suggest that LHA-DBS promotes the recovery of consciousness in comatose rats with TBIs. Upregulation of α1-AR expression and downregulation of GABABR expression in the prefrontal cortex via the orexins and OX1R pathways might be involved in the wakefulness-promoting effects of LHA-DBS.

Objective We sought to examine the conservative treatment of symptomatic spinal cavernomas and evaluate the efficacy and safety of surgical management of spinal cord cavernous malformations. Methods This meta-analysis included articles comparing outcomes of conservative treatment and surgical management of spinal cavernomas, published in the full-text form (from 2000 to June 31, 2020). Collected variables included first author name, country, covered study period, publication year, the total number of patients and at follow-up, bleeding, motor weakness, pain, bladder and/or bowel dysfunction neurologic improvement or deterioration after discharge, and the need for reintervention after subtotal surgical resection or hemorrhage. Results After the initial searching and applying all exclusion and inclusion criteria, there were 9 articles left in the final article pool. The total number of patients was 396 with 264 (66.6%) undergoing surgical resection and 132 (33.4%) electing conservative management. Regarding motor weakness, bladder/bowel dysfunction, deterioration, and reintervention, the final results demonstrated no potential significant difference between the 2 groups. In regard to the subgroup of patients with bleeding, improvement, and pain, the results of the analysis showed a statistically significant difference between the 2 groups. Conclusions Patients who have experienced a hemorrhagic episode should consider surgical intervention, which decreases the risk of recurrent hemorrhage and further neurologic deterioration. In addition, surgical decompression obtained by resection of the hemorrhage and cavernoma seems to lead to slight neurologic improvement in some patients. In nonhemorrhagic cavernomas, conservative treatment might be optimal due to surgery-related morbidity risks.

Background Diffusion tensor imaging (DTI) application in Chiari malformation type I (CMI) is still poorly defined. This study aimed to systematically review the literature and propose perspectives toward the clinical application of DTI in CMI. Methods PubMed and Embase were searched for English-language articles published until October 20, 2020. Clinical studies and case series, evaluating fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), or radial diffusivity values in patients with CMI, were included. Results Eight articles were included. Lower FA values were found at the syrinx level, which decreased with syrinx extent and intensity of symptoms, reflecting myelopathy severity. Decreased AD and MD in the middle cerebellar peduncles in symptomatic patients with CMI might explain the presence of cerebellar signs. Increased FA in various supratentorial structures positively correlated with pain severity. Worse performance in neuropsychological tests correlated with decreased FA, increased MD, and radial diffusivity, reflecting axonal degeneration. Postoperative FA decrease in the brainstem compression area reflects successful decompression. A positive correlation was found between the extent of tonsillar ectopia and increased FA, MD, and AD values, which could act as an early indicator of acute brainstem compression. Conclusions DTI might provide a valuable insight into the neurobiological foundation of symptomatic CMI presentation. The severity of white matter injury evident on DTI could serve as a reliable predictor of postoperative outcomes, therefore facilitating selection of appropriate surgical candidates. Postinterventional DTI reassessment might enable differentiation between unsuccessful surgical technique and irreversible myelopathy. The extent of tonsillar ectopia reflects the severity of microstructural brainstem injury.

Objective A review of endovascular cerebral mycotic aneurysm treatment with Onyx liquid embolic, N-butyl-2-cyanoacrylate (NBCA), or coil embolization has not been reported. The authors conduct a systematic review on endovascular treatment methods of mycotic aneurysms. Methods A systematic literature review was performed using the PubMed and MEDLINE databases for studies published between 1986 and 2020. All studies assessing outcomes related to endovascular Onyx embolization, NBCA embolization, or coiling were included. Results A total of 74 studies were ultimately selected, including 180 (67% male) patients comprising 243 aneurysms treated endovascularly. The mean age was 38.2 ± 17.6 years, and the most common symptom on presentation was headache (31%). Most aneurysms were located on the middle cerebral artery (52.5%), and over half presented with rupture (53.8%). Coiling was the most commonly employed technique (50.4%), and obliteration rates were comparable across coiling, NBCA, and Onyx (99.1%, 100%, 100%, respectively). Complication rates were also comparable (4.3% vs. 15.2% vs. 8.1%). Conclusion Embolization for infectious intracranial aneurysm appears to be an effective treatment option for mycotic aneurysms. Embolization rates were comparable between coiling, NBCA, and Onyx embolization. Noninferiority among these modalities cannot be demonstrated given the retrospective nature of this review, evolution of endovascular techniques over the years, and changes in treatment paradigms in the last 2 decades. Ideally, further prospective research will be needed to find which treatment method offers the lowest complication rates and the best outcomes for patients with mycotic aneurysms.

Background Pituitary apoplexy (PA) is a rare, but life-threatening, condition characterized by pituitary infarction and hemorrhage, most often in the setting of a preexisting adenoma. The risk factors and mechanisms associated with PA are poorly understood. Although neurovascular manifestations of coronavirus disease 2019 (COVID-19) infection have been documented, its association with PA has not yet been determined. Methods From a prospectively collected database of patients treated at a tertiary care center for pituitary adenoma, we conducted a retrospective medical record review of PA cases during the COVID-19 pandemic from March 2020 to December 2020. We also conducted a literature review to identify other reported cases. Results We identified 3 consecutive cases of PA and concomitant COVID-19 infection. The most common symptoms at presentation were headache and vision changes. The included patients were successfully treated with surgical decompression and medical management of the associated endocrinopathy, ultimately experiencing improvement in their visual symptoms at the latest follow-up examination. COVID-19 infection in the perioperative period was corroborated by polymerase chain reaction test results in all the patients. Conclusions With the addition of our series to the literature, 10 cases of PA in the setting of COVID-19 infection have been confirmed. The present series was limited in its ability to draw conclusions about the relationship between these 2 entities. However, COVID-19 infection might represent a risk factor for the development of PA. Further studies are required.

Background Mechanical thrombectomy is a proven treatment for large-vessel ischemic stroke with improved functional outcomes compared with intravenous thrombolytics. Access to thrombectomy-capable sites varies greatly by geography, often necessitating interhospital transfer of patients who first present to hospitals unable to provide thrombectomy. The purpose of this meta-analysis was to examine the impact of interhospital transportation on patient outcomes to better inform recommendations for prehospital protocols. Methods A meta-analysis was performed following systematic literature searches. Outcomes of interest included successful reperfusion, symptomatic intracranial hemorrhage, 90-day modified Rankin Scale score 0–2, 90-day mortality, onset-to-puncture times, and door-to-puncture times. Results Pooled analysis comprised >27,000 patients. Door-to-puncture time was 35.6 minutes shorter among transferred patients; however, symptom onset-to-puncture time was 91.6 minutes longer. Rate of reperfusion or symptomatic intracranial hemorrhage as well as 90-day mortality did not differ significantly between transferred and directly admitted patients. While the proportion of patients achieving good functional outcome at 90 days with modified Rankin Scale score 0–2 did not differ by admission type, when modified Rankin Scale score was narrowed to 0–1, direct transport showed 20% greater probability of achieving excellent functional outcome (P Conclusions This meta-analysis represents the largest pooled population examined to date to assess how interfacility transportation to thrombectomy-capable sites affects patient outcomes. Our results indicate that direct admission is a significant predictor of excellent functional outcome. The findings presented here can be used to better inform quality improvement projects to streamline access to facilities providing endovascular mechanical thrombectomy capabilities.

OBJECTIVE Electrophysiologic mapping (EM) has been instrumental in advancing neuroscience and ensuring accurate lead placement for deep brain stimulation. However, EM is associated with increased operative time, expense, and potential risk. Intraoperative imaging to verify lead placement provides an opportunity to reassess the clinical role of EM. We investigated whether EM 1) provides new information that corrects suboptimal preoperative target selection by the physician or 2) simply corrects intraoperative stereotactic error, which can instead be quickly corrected with intraoperative imaging. METHODS Deep brain stimulation lead location errors were evaluated by measuring whether repositioning leads based on EM directed the final lead placement 1) away from or 2) toward the original target. We retrospectively identified 50 patients with 61 leads that required repositioning directed by EM. The stereotactic coordinates of each lead were determined with intraoperative computed tomography. RESULTS In 45 of 61 leads (74%), the electrophysiologically directed repositioning moved the lead toward the initial target. The mean radial errors between the preoperative plan and targeted contact coordinates before and after repositioning were 2.2 and 1.5 mm, respectively (P < 0.001). Microelectrode recording was more likely than test stimulation to direct leads toward the initial target (88% vs. 63%; P = 0.03). The nucleus targeted was associated with the likelihood of moving toward the initial target. CONCLUSIONS Electrophysiologic mapping corrected primarily for errors in lead placement rather than providing new information regarding errors in target selection. Thus, intraoperative imaging and improvements in stereotactic techniques may reduce or even eliminate dependence on EM.

Background Neurosurgery in Pakistan is an advanced field with significant challenges. The training program tests one’s endurance, knowledge, empathy, and dedication. The training structure in Pakistan consists of 5 years, of which 2 years are spent in general surgery followed by 3 years of dedicated neurosurgery. This study aimed to conduct a survey to address the quality of neurosurgery training in Pakistan so that its strengths and deficiencies could be identified, recommendations could be made, and actions could be taken toward improvement. Methods A nationwide survey was conducted of neurosurgery residents from all over Pakistan. An e-mail invitation was sent to 177 neurosurgery residents certified by the College of Physicians and Surgeons Pakistan from 22 institutes in all provinces of Pakistan. The questionnaire was divided into the following sections: sociodemographics of participants, infrastructure of training site, clinical skills training and exposure, and knowledge-based education. Data were collected through Google Forms and analyzed using statistical software. Results A total of 151 residents responded to the survey. More than half of the institutes had >10 neurosurgery residents in their department (59.6%). More than half of the residents did not attend any international conference during their residency (51%). More than one fourth of the residents did not participate in any hands-on workshop during their residency tenure. Conclusions The neurosurgical training program in Pakistan requires updating of the curriculum with better implementation. These data will help the College of Physicians and Surgeons Pakistan in standardizing neurosurgical training across Pakistan to improve competence among trainees.

Background Adjacent segmental degeneration (ASD) is one of the common complications after posterior lumbar interbody fusion (PLIF). Both whole body vibration (WBV) and osteoporosis are important factors associated with the biomechanics of the lumbar spine. However, to the best of our knowledge, no studies have investigated the effects of osteoporosis on ASD after PLIF under WBV. Methods In the present study, using one normal model, one PLIF model and one PLIF with osteoporosis model of the L1–S1 segment were developed. A 5-Hz, 40-N sinusoidal vertical load was imposed on the superior surface of L1 of each model to simulate WBV, and the dynamic responses and maximal values of intradiscal pressure, shear stress on annulus fibrosus, total deformation, and disc bulge were evaluated in the L1-L2, L2-L3, L3-L4, and L5-S1 segments. Results At the L1-L2, L2-L3, and L3-L4 levels, the differences in the dynamic responses and maximal values in intradiscal pressure, shear stress, total deformation, and disc bulge between the PLIF and PLIF with osteoporosis models were slight. However, at the L5-S1 level, the dynamic response curves and maximal intradiscal pressure, shear stress, and disc bulge values in the PLIF with osteoporosis model were significantly lower than those in the PLIF model. Conclusions Osteoporosis can mitigate the development of ASD in the lower adjacent segment but has no obvious influence on the upper adjacent segments during WBV.

Hormone and human epidermal growth factor receptor 2 (HER2/neu) receptor status is prognostic and predictive in breast cancer (BC) and guides the choice of therapy. However, owing to receptor conversion, the receptor status can differ in metastases compared with that of the primary tumor. The aim of the present study was to analyze the prognostic value of receptor status, receptor conversion, and clinical parameters in patients with resected BC brain metastases (BMs).Patients with BCBMs treated at our institution from July 2007 to December 2019 were eligible for the present study. The receptor status of the BC and corresponding BMs and the occurrence of receptor conversion were separately recorded for 3 common receptors: HER2/neu, estrogen receptor, and progesterone receptor. The association between the receptor status or receptor conversion and clinical parameters was adjusted for outcome-relevant patient and tumor characteristics.The final analysis included 78 patients. HER2/neu receptor status in BMs was associated with overall survival (P = 0.033). Receptor conversion was identified in 39 patients (50.0%): HER2/neu, n = 9 (11.5%); estrogen receptor, n = 22 (28.2%); and progesterone receptor, n = 25 (32.1%). In the final multivariate Cox regression analysis, HER2/neu receptor conversion (adjusted hazard ratio [aHR], 3.58; P = 0.006), Karnofsky performance status score70% (aHR, 3.11; P = 0.048), infratentorial BM location (aHR, 2.49; P = 0.007), and age ≥55 years at BM diagnosis (aHR, 2.20; P = 0.046) were independently associated with poorer survival.Of the 3 common BC receptors, only HER2/neu receptor conversion was strongly associated with the prognosis of patients with surgically treated BCBMs. The clinical relevance of the reevaluation of receptor status in BMs favors surgical treatment of patients with noneloquent BCBMs.

Objective Lumbar spinal stenosis (LSS) is a common disease in spinal surgery. Many related treatment methods have been reported, but their effectiveness still lacks a systematic comparison. We aimed to evaluate the clinical outcomes related to the efficacy and safety of these treatment strategies via a network meta-analysis. Methods Relevant clinical studies were retrieved from the databases of PubMed, Embase, Web of Science, and Cochrane library updated to July 29, 2020. The data were extracted from the eligible literature and the results were presented as standardized mean differences with 95% confidence intervals (CIs). A network meta-analysis was executed using the netmeta, rjags, and gemtc packages in R software, and Begg and Egger tests were used to assess the publication bias within the included studies. Results A total of 21 eligible studies based on 2890 patients with degenerative LSS were included. The newer microdecompression technique (bilateral decompression via unilateral laminotomy [BDUL]) performed better in decreasing the visual analog scale (VAS) score compared with conventional decompressive laminectomy (VAS score back pain, 1.22; 95% CI, 0.28–2.17; VAS score leg pain, 1.39; 95% CI, 0.82–1.96), but its Oswestry Disability Index improvement was slightly inferior to that of posterolateral fusion. Conclusions BDUL could effectively alleviate VAS pain of patients, and had a lower incidence of complications. Although BDUL was slightly inferior to posterolateral fusion in terms of Oswestry Disability Index improvement, the postoperative quality of life of patients treated with BDUL had been significantly improved compared with that before surgery.

Objective Single-stage spinal correction without previous neurosurgical intervention has been attempted in patients with scoliosis associated with syringomyelia (SM). However, evidence to demonstrate its potential influence on associated SM from direct spinal correction is still lacking. The aim of the present study was to explore the role of spinal shortening in the prognosis of SM-associated scoliosis after single-stage spinal correction without previous neurosurgical intervention. Methods Patients with SM-associated scoliosis without previous neurological intervention, who had undergone posterior direct instrumental correction (PDIC) without osteotomy and posterior vertebral column resection (PVCR) at a single center, were selected for comparative analysis. The basic demographic and pre- and postoperative imaging data of the spinal deformity and SM at the final follow-up were compared separately for the 2 different spinal correction procedures. Results A total of 23 patients were included in the final analysis: 13 had undergone PDIC and 10 had undergone PVCR. The mean follow-up period was 6.2 years (range, 5–9 years). At the final follow-up, the mean corrective rate of scoliosis and kyphosis was 65.7% and 48.4%, respectively. Obvious SM reduction was achieved in 11 patients (47.8%), with an average reduction of 37.3%. No patient experienced neurologic deterioration or had required further neurosurgical intervention for SM during follow-up. The patients who had undergone PVCR had had much more severe scoliosis (98.8° vs. 60.5°; P = 0.000) and kyphosis (74.8° vs. 43.6°; P = 0.032). Moreover, 80.0% of the patients who had undergone PVCR had experienced obvious SM improvement compared with 23.1% of those who had undergone PDIC (P = 0.007). Conclusions The reduction of spinal cord tension is an important factor influencing SM improvement. As the most powerful spinal-shortening osteotomy, PVCR can effectively correct severe spinal deformities and improve associated SM. Single-stage posterior spinal correction can be a potential choice for selected patients with scoliosis and untreated SM using strict inclusion criteria, which will not only achieve safe spinal correction but could also steadily improve and stabilize SM.

BACKGROUND: The thin-walled regions (TIWRs) of intracranial aneurysms have a high risk of rupture during surgical manipulation. They have been reported to be predicted by wall shear stress and pressure (PS) based on computational fluid dynamics analysis, although this remains controversial. In this study, we investigated whether the oscillatory shear index (OSI) can predict TIWRs. METHODS: Twenty-five unruptured aneurysms were retrospectively analyzed; the position and orientation of the computational fluid dynamics color maps were adjusted to match the intraoperative micrographs. The red area on the aneurysm wall was defined as TIWR, and if most of the regions on the color map corresponding to TIWR were OSI low (lower quartile range), time-averaged wall shear stress (TAWSS) high, or PS high (upper quartile range), each region was defined as a matched region and divided by the total number of TIWRs to calculate the match rate. In addition, the mean values of OSI, TAWSS, and PS corresponding to TIWRs were quantitatively compared with those in adjacent thick-walled regions. RESULTS: Among 27 TIWRs of 25 aneurysms, 23, 10, and 14 regions had low OSI, high TAWSS, and high PS regions (match rate: 85.2%, 37.0%, and 51.9%), respectively. Receiver operating characteristic curve analysis demonstrated that OSI was the most effective hemodynamic parameter (area under the curve, 0.881), followed by TAWSS (0.798). Multivariate analysis showed that OSI was a significant independent predictor of TIWRs (odds ratio, 18.30 [95% CI, 3.2800e102.00], P < 0.001). CONCLUSIONS: OSI may be a unique predictor for TIWRs. Low OSI strongly corresponds with TIWRs of intracranial aneurysms.

Meeting patient expectations is believed to impact satisfaction scores; however, the influence of achieving a minimum clinically important difference (MCID) is scarcely reported. This study aims to evaluate meeting patient expectations or MCID achievement for pain and disability as predictors of patient satisfaction.A retrospective review of single or multilevel lumbar fusion patients was performed. Patients with missing preoperative Oswestry Disability Index (ODI) expectation questionnaires were excluded. Preoperative expectations and postoperative satisfaction scores for visual analog scale (VAS) back, VAS leg, and ODI were collected. Meeting expectations was defined as scores less than or equal to preoperative expectations. Achievement of MCID was evaluated. Improvement of all outcomes and correlations with satisfaction scores were evaluated using the Student's t-test and Pearson coefficient. Achievement of MCID or meeting expectations as predictors of satisfaction were evaluated and compared using linear regression and Suest test.The study included 144 patients. All outcomes significantly improved and demonstrated significant correlations with satisfaction scores (P0.001, all). Patients reported a mean expectation of 17.7 (ODI), 1.7 (VAS back), and 0.9 (VAS leg). The majority had their expectations met and achieved MCID. Meeting expectations and MCID achievement demonstrated significant associations with satisfaction scores for all outcomes and time points. Achievement of MCID was a stronger predictor of satisfaction for ODI and VAS back.Meeting preoperative expectations and achievement of an MCID for pain and disability measures was significantly associated with satisfaction. Achievement of MCID may be a more consistent and suitable replacement as a predictor of satisfaction over meeting patient expectations.

Objective The American Medical Association and National Institutes of Health have recommended that patient education materials should be written at the sixth-grade reading level to maximize patient comprehension. The objective of the present study was to evaluate the readability of Internet information for the 9 most common spinal surgeries. Methods We reviewed 90 online patient educational materials regarding the 9 most common spinal surgeries as reported by the North American Spine Society. A Google search was performed on March 23, 2019 for each surgery, and the top 10 most visited websites for each surgery were assessed for reading level using the Flesch-Kincaid formula. Results Using the Flesch-Kincaid formula, the average grade reading level of the 90 websites included was 12.82, with a reading ease of 37.04 (“difficult college”). Only 6 websites relayed information to patients at or below the national average of an eighth-grade reading level. The websites for bone morphogenic protein had the highest average grade reading level at 15.88 ± 2.6. Lumbar microscopic discectomy had the lowest average grade reading level at 10.37 ± 2.89. All surgical options discussed had an average readability above the recommended sixth-grade reading level. Conclusions The most accessed online materials for common spinal surgeries, not only exceeded the readability limits recommended by both the American Medical Association and the National Institutes of Health, but they also exceeded the average reading ability of most adults in the United States. Patients, therefore, might not fully comprehend the information from commonly accessed websites regarding surgical spine treatment options.

Acute hemorrhage caused by cerebral arteriovenous malformation (cAVM) during pregnancy is uncommon but life-threatening for both mother and fetus and presents a great challenge to clinical management. However, there is still no consensus on the treatment strategy and the treatment timing of acute hemorrhage from cAVM during pregnancy. The aim of this study was to amalgamate reported case series and our cases regarding the clinical management of pregnant patients under this special condition.We report a case series of 3 pregnant patients with acute hemorrhage caused by cAVM in our hospital. A systematic PubMed search of the English-language literature published between 1970 and 2020 was carried out. Clinical information including patients' age, gestational age, imaging studies, treatment strategy, treatment timing, delivery mode, and outcomes were collected and analyzed.The rebleed rate is about 7.1% and the mortality from rebleeding is up to 25%. Treatment modalities included radical surgery, endovascular embolization, radiosurgery/stereotactic radiosurgery, palliative surgery, and conservative treatment. There were no maternal deaths in either the intrapartum intervention group and the postpartum intervention subgroup of gestational age34 weeks.A high rebleed rate and high mortality from rebleeding indicate that the intervention of ruptured cAVM should not be delayed. Intervention of ruptured cAVM within 2 weeks after initial hemorrhage is advisable in patients at gestational age34 weeks, whereas termination of pregnancy as soon as possible followed by timely intervention of ruptured cAVM is practicable in patients at gestational age ≥34 weeks.

Background The use of balloon guide catheters (BGCs) for proximal flow arrest during neurointerventional procedures has been limited owing to the incompatibility of BGCs with large-bore aspiration catheters and difficulty in device navigation. The objective of our study was to describe the use of the Walrus catheter (Q'Apel Medical, Fremont, California, USA), a new 8F BGC, with a variety of aspiration catheters and procedures requiring flow arrest. Methods Consecutive cases using Walrus BGCs for proximal flow arrest during mechanical thrombectomy for acute stroke cases were recorded. The procedure indication, vessel occlusion site, technique, first-pass effect (modified thrombolysis in cerebral infarction score of 2C or 3 after the first recanalization attempt), and complications were recorded and evaluated statistically. Results Our study included 57 patients who had undergone mechanical thrombectomy. In addition to mechanical thrombectomy, the Walrus BGC was used in conjunction with the following techniques: stent retrieval in 2 patients (3.5%), stent retrieval followed by aspiration (Solumbra technique) in 41 (71.9%), and aspiration followed by stent retrieval in 14 patients (24.6%). Eight different aspiration catheters were used in 56 of these 57 procedures. The first-pass effect (modified thrombolysis in cerebral infarction score of 2C and 3) was achieved in 36 (63.2%) of 57 procedures. Two patients (3.5%) had experienced intraoperative complications (symptomatic intracerebral hemorrhage) and one patient (1.8%) had died in-hospital. Conclusions Our results have demonstrated that the Walrus BGC is a highly navigable 8F guide catheter compatible with most available aspiration catheters. Owing to its compatibility with most available aspiration catheters and ease of use, the Walrus BGC is a valuable addition to the tools available for mechanical thrombectomy.