High rates of blood transfusion associated with Parkinson's disease.

BACKGROUND: As evidence continues to accumulate regarding the multi-organ dysfunction associated with Parkinson's disease (PD), it is still unclear as to whether PD increases the risk of hematological pathology. In this study, the authors investigate the association between PD and hematological pathology risk factors. METHODS: This retrospective cohort analysis was conducted using 8 years of the National Readmission Database. All individuals diagnosed with PD were queried at the time of primary admission. Readmissions, complications, and risk factors were analyzed at 30-, 90-, 180-, and 300-day intervals. Statistical analysis included multivariate Gaussian-fitted modeling using age, sex, comorbidities, and discharge weights as covariates. Coefficients of model variables were exponentiated and interpreted as odds ratios. RESULTS: The database query yielded 1,765,800 PD patients (mean age: 76.3 ± 10.4; 44.1% female). Rates of percutaneous blood transfusion in readmitted patients at 30, 90, 180, and 300 days were found to be 8.7%, 8.6%, 8.3%, and 8.3% respectively. Those with anti-parkinsonism medication side effects at the primary admission had increased rates of gastrointestinal (GI) hemorrhage (OR: 1.02; 95%CI: 1.01-1.03, p < 0.0001) and blood transfusion (OR: 1.06; 95%CI: 1.05-1.08, p < 0.0001) at all timepoints after readmission. PD patients who experienced GI hemorrhage of any etiology, including as a side effect of anti-parkinsonism medication, were found to have significantly higher rates of blood transfusion at all timepoints (OR: 1.14; 95%CI: 1.13-1.16, p < 0.0001). CONCLUSIONS: Blood transfusions were found to be significantly associated with anti-parkinsonism drug side effects and GI hemorrhage of any etiology.

Citation analysis of the most influential ependymoma research articles illustrates improved knowledge of the molecular biology of ependymoma.

The history of academic research on ependymoma is expansive. This review summarizes its history with a bibliometric analysis of the 100 most cited articles on ependymoma. In March 2020, we queried the Web of Science database to identify the most cited articles on ependymoma using the terms "ependymoma" or "ependymal tumors," yielding 3145 publications. Results were arranged by the number of times each article was cited in descending order. The top 100 articles spanned across nearly a century; the oldest article was published in 1924, while the most recent was in 2017. These articles were published in 35 unique journals, including a mix of basic science and clinical journals. The three institutions with the most papers in the top 100 were St. Jude Children's Research Hospital (16%), the University of Texas MD Anderson Cancer Center (6%), and the German Cancer Research Center (5%). We analyzed the publications that may be considered the most influential in the understanding and treatment management of ependymoma. Studies focused on the molecular classification of ependymomas were well-represented among the most cited articles, reflecting the field's current area of focus and its future directions. Additionally, this article also offers a reference for further studies in the ependymoma field.

Enhancing peripheral nerve regeneration with neurotrophic factors and bioengineered scaffolds: A basic science and clinical perspective.

Despite the peripheral nervous systems (PNS) capacity to regenerate, functional restoration is highly variable following peripheral nerve injury (PNI), oftentimes leading to persistent functional deficits. In the preclinical arena, advances in the therapeutic use of exogenous neurotrophic factors and synthetic neural scaffold technology hold promise in augmenting endogenous PNS regeneration following PNI. Clinical trials utilizing neurotrophic factors for other indications (eg, peripheral neuropathy) may provide insight into their role in PNI. Here we provide an updated review of progress made toward enhancing regeneration after PNI with a focus on neurotrophic factors and bioengineered scaffolds.

The role of frailty in geriatric cranial neurosurgery for primary central nervous system neoplasms.

OBJECTIVE: Frailty is a clinical state of increased vulnerability due to age-associated decline and has been well established as a perioperative risk factor. Geriatric patients have a higher risk of frailty, higher incidence of brain cancer, and increased postoperative complication rates compared to nongeriatric patients. Yet, literature describing the effects of frailty on short- and long-term complications in geriatric patients is limited. In this study, the authors evaluate the effects of frailty in geriatric patients receiving cranial neurosurgery for a primary CNS neoplasm. METHODS: The authors conducted a retrospective cohort study of geriatric patients receiving cranial neurosurgery for a primary CNS neoplasm between 2010 and 2017 by using the Nationwide Readmission Database. Demographics and frailty were queried at primary admission, and readmissions were analyzed at 30-, 90-, and 180-day intervals. Complications of interest included infection, anemia, infarction, kidney injury, CSF leak, urinary tract infection, and mortality. Nearest-neighbor propensity score matching for demographics was implemented to identify nonfrail control patients with similar diagnoses and procedures. The analysis used Welch two-sample t-tests for continuous variables and chi-square test with odds ratios. RESULTS: A total of 6713 frail patients and 6629 nonfrail patients were identified at primary admission. At primary admission, frail geriatric patients undergoing cranial neurosurgery had increased odds of developing acute posthemorrhagic anemia (OR 1.56, 95% CI 1.23-1.98; p = 0.00020); acute infection (OR 3.16, 95% CI 1.70-6.36; p = 0.00022); acute kidney injury (OR 1.32, 95% CI 1.07-1.62; p = 0.0088); urinary tract infection prior to discharge (OR 1.97, 95% CI 1.71-2.29; p < 0.0001); acute postoperative cerebral infarction (OR 1.57, 95% CI 1.17-2.11; p = 0.0026); and mortality (OR 1.64, 95% CI 1.22-2.24; p = 0.0012) compared to nonfrail geriatric patients receiving the same procedure. In addition, frail patients had a significantly increased inpatient length of stay (p < 0.0001) and all-payer hospital cost (p < 0.0001) compared to nonfrail patients at the time of primary admission. However, no significant difference was found between frail and nonfrail patients with regard to rates of infection, thromboembolism, CSF leak, dural tear, cerebral infarction, acute kidney injury, and mortality at all readmission time points. CONCLUSIONS: Frailty may significantly increase the risks of short-term acute complications in geriatric patients receiving cranial neurosurgery for a primary CNS neoplasm. Long-term analysis revealed no significant difference in complications between frail and nonfrail patients. Further research is warranted to understand the effects and timeline of frailty in geriatric patients.

Gamma-band modulation in the human amygdala during reaching movements.

OBJECTIVE: Motor brain-computer interface (BCI) represents a new frontier in neurological surgery that could provide significant benefits for patients living with motor deficits. Both the primary motor cortex and posterior parietal cortex have successfully been used as a neural source for human motor BCI, leading to interest in exploring other brain areas involved in motor control. The amygdala is one area that has been shown to have functional connectivity to the motor system; however, its role in movement execution is not well studied. Gamma oscillations (30-200 Hz) are known to be prokinetic in the human cortex, but their role is poorly understood in subcortical structures. Here, the authors use direct electrophysiological recordings and the classic "center-out" direct-reach experiment to study amygdaloid gamma-band modulation in 8 patients with medically refractory epilepsy. METHODS: The study population consisted of 8 epilepsy patients (2 men; age range 21-62 years) who underwent implantation of micro-macro depth electrodes for seizure localization and EEG monitoring. Data from the macro contacts sampled at 2000 Hz were used for analysis. The classic center-out direct-reach experiment was used, which consists of an intertrial interval phase, a fixation phase, and a response phase. The authors assessed the statistical significance of neural modulation by inspecting for nonoverlapping areas in the 95% confidence intervals of spectral power for the response and fixation phases. RESULTS: In 5 of the 8 patients, power spectral analysis showed a statistically significant increase in power within regions of the gamma band during the response phase compared with the fixation phase. In these 5 patients, the 95% bootstrapped confidence intervals of trial-averaged power in contiguous frequencies of the gamma band during the response phase were above, and did not overlap with, the confidence intervals of trial-averaged power during the fixation phase. CONCLUSIONS: To the authors' knowledge, this is the first time that direct neural recordings have been used to show gamma-band modulation in the human amygdala during the execution of voluntary movement. This work indicates that gamma-band modulation in the amygdala could be a contributing source of neural signals for use in a motor BCI system.

Association of tranexamic acid with decreased blood loss in patients undergoing laminectomy and fusion with posterior instrumentation: a systematic review and meta-analysis.

OBJECTIVE: Tranexamic acid (TXA) is an antifibrinolytic agent associated with reduced blood loss and mortality in a wide range of procedures, including spine surgery, traumatic brain injury, and craniosynostosis. Despite this wide use, the safety and efficacy of TXA in spine surgery has been considered controversial due to a relative scarcity of literature and lack of statistical power in reported studies. However, if TXA can be shown to reduce blood loss in laminectomy with fusion and posterior instrumentation, more surgeons may include it in their armamentarium. The authors aimed to conduct an up-to-date systematic review and meta-analysis of the efficacy of TXA in reducing blood loss in laminectomy and fusion with posterior instrumentation. METHODS: A systematic review and meta-analysis, abiding by PRISMA guidelines, was performed by searching the databases of PubMed, Web of Science, and Cochrane. These platforms were queried for all studies reporting the use of TXA in laminectomy and fusion with posterior instrumentation. Variables retrieved included patient demographics, surgical indications, involved spinal levels, type of laminectomy performed, TXA administration dose, TXA route of administration, operative duration, blood loss, blood transfusion rate, postoperative hemoglobin level, and perioperative complications. Heterogeneity across studies was evaluated using a chi-square test, Cochran's Q test, and I2 test performed with R statistical programming software. RESULTS: A total of 7 articles were included in the qualitative study, while 6 articles featuring 411 patients underwent statistical analysis. The most common route of administration for TXA was intravenous with 15 mg/kg administered preoperatively. After the beginning of surgery, TXA administration patterns were varied among studies. Blood transfusions were increased in non-TXA cohorts compared to TXA cohorts. Patients administered TXA demonstrated a significant reduction in blood loss (mean difference -218.44 mL; 95% CI -379.34 to -57.53; p = 0.018). TXA administration was not associated with statistically significant reductions in operative durations. There were no adverse events reported in either the TXA or non-TXA patient cohorts. CONCLUSIONS: TXA can significantly reduce perioperative blood loss in cervical, thoracic, and lumbar laminectomy and fusion procedures, while demonstrating a minimal complication profile.

Getting Down to the Bare Bones: Does laminoplasty or laminectomy With Fusion Provide Better Outcomes for Patients With Multilevel Cervical Spondylotic Myelopathy?

OBJECTIVE: Cervical spondylotic myelopathy (CSM) is a degenerative disorder leading to progressive decline in spinal cord function. Cervical laminoplasty (CLP) and cervical laminectomy with fusion (CLF) are standard treatments for multilevel CSM. However, it is still unclear whether one procedure over the other provides better outcomes. Here, we performed a comprehensive review of published articles that compare the clinical outcomes and costs between CLP and CLF for CSM. METHODS: A literature search was performed using PubMed, Web of Science, and Cochrane databases. Strict exclusion criteria were applied, and included articles were then assessed for publication year, study design, and significant differences in outcome variables. RESULTS: From 519 studies identified with search terms, 38 studies were included for the qualitative analysis. Statistically significant differences in the clinical outcomes and costs were found in 18 studies. Eleven studies were prospective or retrospective, and 8 studies were meta-analyses. For the outcome variables of interest, results were reported by classifying into prospective studies, retrospective studies, and meta-analyses. CONCLUSION: CLP and CLF are 2 of the most commonly performed surgical procedures for the treatment of CSM. Although CLP and CLF each provide satisfactory clinical outcomes for patients with CMS, CLP may result in better cervical range of motion and less cost, length of stay, operation time, blood loss, paraspinal muscular atrophy, and rate of nerve palsies as compared to CLF. The major limitation of CLP versus CLF comparison studies includes the heterogeneity in techniques and preoperative criteria. Thus, further validation and investigations in larger cohorts will be required.

Indication-based analysis of patient outcomes following deep brain stimulation surgery.

BACKGROUND: While considered a safe operation, deep brain stimulation (DBS) has been associated with various morbidities. We assessed differences in postsurgical complication rates in patients undergoing the most common types of neurostimulation surgery. METHODS: The National Readmission Database (NRD) was queried to identify patients undergoing neurostimulation placement with the diagnosis of Parkinson disease (PD), epilepsy, dystonia, or essential tremor (ET). Demographics and complications, including infection, pneumonia, and neurostimulator revision, were queried for each cohort and compiled. Readmissions were assessed in 30-, 90-, and 180-day intervals. We implemented nearest-neighbor propensity score matching to control for demographic and sample size differences between groups. RESULTS: We identified 3230 patients with Parkinson disease, 1289 with essential tremor, 965 with epilepsy, and 221 with dystonia. Following propensity score matching, 221 patients remained in each cohort. Readmission rates 30-days after hospital discharge for PD patients (15.5 %) were significantly greater than those for ET (7.8 %) and seizure patients (4.4 %). Pneumonia was reported for PD (1.6 %), seizure (3.3 %) and dystonia (1.7 %) patients but not individuals ET. No PD patients were readmitted at 30-days due to dysphagia while individuals treated for ET (6.5 %), seizure (1.6 %) and dystonia (5.2 %) were. DBS-revision surgery was performed for 11.48 % of PD, 6.52 % of ET, 1.64 % of seizure and 6.90 % of dystonia patients within 30-days of hospital discharge. CONCLUSION: 30-day readmission rates vary significantly between indications, with patients receiving DBS for PD having the highest rates. Further longitudinal studies are required to describe drivers of variation in postoperative outcomes following DBS surgery for different indications.

The 100 Most Influential Publications on Medulloblastoma: Areas of Past, Current, and Future Focus.

BACKGROUND: This article is the first to identify the most influential articles on medulloblastoma using the citation analysis methodology. OBJECTIVE: To perform a bibliometric analysis of the 100 most-cited articles on medulloblastoma. METHODS: Using the Web of Science database, search criteria included the title-specific keyword "medulloblastoma" OR "cerebellar primitive neuroectodermal tumor (PNET)" OR "cerebellar PNET." Publications from 1900 to 2020 labeled "article," "review," "data set," or "clinical trial" were chosen and ranked based on total number of citations in descending order. Each article was evaluated based on the following variables: total citations, average citations per year, first author, institution of first author, title, publication year, country of origin, SCImago Journal Rank, and Scopus SNIP (Source Normalized Impact per Paper). RESULTS: Our search yielded 4928 articles on medulloblastoma. The 100 most-cited articles ranged from 192 to 2017 across 42 unique journals; Journal of Clinical Oncology accounted for the most publications (16%). Paul A. Northcott was first author of the most articles on the list (n = 7.7%), and the most widely cited article was "Altered neural cell fates and medulloblastoma in mouse patched mutants" by Goodrich et al., published in Science (1997). CONCLUSIONS: Because medulloblastoma represents the most common form of pediatric cancerous brain tumor, it is important to identify works that have significantly contributed to the body of knowledge regarding this disease. The 100 most-cited medulloblastoma articles comprise a significant collection of data regarding the histopathologic and molecular classification of medulloblastoma as well as clinical outcomes of therapeutics used to treat this disease.

Predictors of Patient Satisfaction in Spine Surgery: A Systematic Review.

BACKGROUND: Recently, there has been increased interest in patient satisfaction measures such as Press Ganey and Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) surveys. In this systematic review, the spine surgery literature is analyzed to evaluate factors predictive of patient satisfaction as measured by these surveys. METHODS: A thorough literature search was performed in PubMed/MEDLINE, Google Scholar, and Cochrane databases. All English-language articles from database inception to July 2020 were screened for study inclusion according to PRISMA guidelines. RESULTS: Twenty-four of the 1899 published studies were included for qualitative analysis. There has been a statistically significant increase in the number of publications across years (P = 0.04). Overall, the studies evaluated the relationship between patient satisfaction and patient demographics (71%), preoperative and intraoperative clinical factors (21%), and postoperative factors (33%). Top positive predictors of patient satisfaction were patient and nursing/medical staff relationship (n = 4; 17%), physician-patient relationship (n = 4; 17%), managerial oversight of received care (n = 3; 13%), same sex/ethnicity between patient and physician (n = 2; 8%), and older age (n = 2; 8%). Top negative predictors of patient satisfaction were high Charlson Comorbidity Index/high disability/worse overall health functioning (n = 7; 29%), increased length of hospital stay (n = 4; 17%), high rating for pain/complications/readmissions (n = 4; 17%), and psychosocial factors (n = 3; 13%). CONCLUSIONS: There is heterogeneity in terms of different factors, both clinical and nonclinically related, that affect patient satisfaction ratings. More research is warranted to investigate the role of hospital consumer surveys in the spine surgical patient population.

Ethical considerations and patient safety concerns for cancelling non-urgent surgeries during the COVID-19 pandemic: a review.

At the time of writing of this article, there have been over 110 million cases and 2.4 million deaths worldwide since the start of the Coronavirus Disease 2019 (COVID-19) pandemic, postponing millions of non-urgent surgeries. Existing literature explores the complexities of rationing medical care. However, implications of non-urgent surgery postponement during the COVID-19 pandemic have not yet been analyzed within the context of the four pillars of medical ethics. The objective of this review is to discuss the ethics of elective surgery cancellation during the COVID-19 pandemic in relation to beneficence, non-maleficence, justice, and autonomy. This review hypothesizes that a more equitable decision-making algorithm can be formulated by analyzing the ethical dilemmas of elective surgical care during the pandemic through the lens of these four pillars. This paper's analysis shows that non-urgent surgeries treat conditions that can become urgent if left untreated. Postponement of these surgeries can cause cumulative harm downstream. An improved algorithm can address these issues of beneficence by weighing local pandemic stressors within predictive algorithms to appropriately increase surgeries. Additionally, the potential harms of performing non-urgent surgeries extend beyond the patient. Non-maleficence is maintained through using enhanced screening protocols and modifying surgical techniques to reduce risks to patients and clinicians. This model proposes a system to transfer patients from areas of high to low burden, addressing the challenge of justice by considering facility burden rather than value judgments concerning the nature of a particular surgery, such as cosmetic surgeries. Autonomy can be respected by giving patients the option to cancel or postpone non-urgent surgeries. However, in the context of limited resources in a global pandemic, autonomy is not absolute. Non-urgent surgeries can ethically be postponed in opposition to the patient's preference. The proposed algorithm attempts to uphold the four principles of medical ethics in rationing non-urgent surgical care by building upon existing decision models, using additional measures of resource burden and surgical safety to increase health care access and decrease long-term harm as much as possible. The next global health crisis will undoubtedly present its own unique challenges. This model may serve as a comprehensive starting point in determining future guidelines for non-urgent surgical care.

Spinal pathologies and management strategies associated with cervical angina (pseudoangina): a systematic review.

OBJECTIVE: Cervical angina, or pseudoangina pectoris, is a noncardiac syndrome of chest pain that often mimics angina pectoris but is a disease of the spine. Diagnosis of cervical angina can be difficult and is often overlooked, although once identified, it can be successfully managed through conservative therapies and/or a variety of surgical interventions. Ultimately, cervical angina is an important component of the list of differential diagnoses in noncardiac chest pain. In the present study, the authors report the first comprehensive systematic review of the range of cervical and thoracic pathologies associated with cervical angina, as well as the different treatment methods used to manage this condition. METHODS: A systematic review was performed according to PRISMA guidelines and using PubMed, Web of Science, and Cochrane databases from database inception to April 29, 2020, to identify studies describing spinal pathologies related to cervical angina. The following Boolean search was performed: ("cervical" OR "thoracic") AND ("angina" OR "chest pain") AND ("herniation" OR "OPLL"). Variables extracted included patient demographics, cervical angina pain location, pathology and duration of symptoms, treatment and/or management method, and posttreatment pain relief. RESULTS: Upon careful screening, 22 articles published between 1976 and 2020 met the study's inclusion/exclusion criteria, including 5 case series, 12 case reports, and 5 retrospective cohort studies. These studies featured a total of 1100 patients, of which 95 met inclusion criteria (mean patient age 51.7 years, age range 24-86 years; 53.6% male). Collectively, symptom durations ranged from 1.5 days to 90 months. Cervical herniation (72.6%) accounted for the majority of cervical angina cases, and surgical interventions (84.4%) predominated over physical therapy (13.0%) and medical management strategies (9.1%). Every patient assessed at follow-up reported relief from symptoms related to cervical angina. CONCLUSIONS: Cervical angina is a noncardiac syndrome of chest pain associated with a broad range of cervical and thoracic spinal pathologies, the most common of which is cervical disc herniation. Although difficult to diagnose, it can be successfully treated when identified through first-line conservative management or surgical interventions in refractory cases.

Global neurosurgery: a scoping review detailing the current state of international neurosurgical outreach.

OBJECTIVE: Global neurosurgery is a rapidly emerging field that aims to address the worldwide shortages in neurosurgical care. Many published outreach efforts and initiatives exist to address the global disparity in neurosurgical care; however, there is no centralized report detailing these efforts. This scoping review aims to characterize the field of global neurosurgery by identifying partnerships between high-income countries (HICs) and low- and/or middle-income countries (LMICs) that seek to increase neurosurgical capacity. METHODS: A scoping review was conducted using the Arksey and O'Malley framework. A search was conducted in five electronic databases and the gray literature, defined as literature not published through traditional commercial or academic means, to identify studies describing global neurosurgery partnerships. Study selection and data extraction were performed by four independent reviewers, and any disagreements were settled by the team and ultimately the team lead. RESULTS: The original database search produced 2221 articles, which was reduced to 183 final articles after applying inclusion and exclusion criteria. These final articles, along with 9 additional gray literature references, captured 169 unique global neurosurgery collaborations between HICs and LMICs. Of this total, 103 (61%) collaborations involved surgical intervention, while local training of medical personnel, research, and education were done in 48%, 38%, and 30% of efforts, respectively. Many of the collaborations (100 [59%]) are ongoing, and 93 (55%) of them resulted in an increase in capacity within the LMIC involved. The largest proportion of efforts began between 2005-2009 (28%) and 2010-2014 (17%). The most frequently involved HICs were the United States, Canada, and France, whereas the most frequently involved LMICs were Uganda, Tanzania, and Kenya. CONCLUSIONS: This review provides a detailed overview of current global neurosurgery efforts, elucidates gaps in the existing literature, and identifies the LMICs that may benefit from further efforts to improve accessibility to essential neurosurgical care worldwide.

Staged Cranial Surgery for Intracranial Lesions: Historical Perspective.

We follow the development of staged resection from its first description by Walter E. Dandy, one of the founding fathers of neurosurgery, in 1925 in which he removed a large vestibular schwannoma.This historical vignette cites neurosurgical case reports and literature to demonstrate the evolution of staged resection of intracranial lesions, from Dandy's initial use to its becoming a more viable and safe option for the treatment of meningiomas, vestibular schwannomas, and skull base lesions (among numerous other intracranial pathologies). We also discuss the current advancements and future perspectives of staged resection that may show promise in effectively treating a wide range of pathologies while simultaneously reducing morbidity rates-a warrant for further exploration of staged cranial surgery as an important tool in neurosurgery.

Translational Approaches to Electrical Stimulation for Peripheral Nerve Regeneration.

BACKGROUND: Achieving functional repair after peripheral nerve injury (PNI) remains problematic despite considerable advances in surgical technique. Therein, questions lie regarding the variable capacity of peripheral nerves to regenerate based on environmental influence. In-depth analyses of multiple therapeutic strategies have ensued to overcome these natural obstacles. Of these candidate therapies, electrical stimulation has emerged a frontrunner. Extensive animal studies have reported the ability of brief intraoperative electrical stimulation (BES) to enhance functional regeneration after PNI. Despite these reports, the exact mechanisms by which BES enhances regeneration and its effects on long nerve lesions are largely unknown. Indeed, clinical translation of this seemingly simple therapeutic has not been so simple, but a few studies performed in humans have yielded highly encouraging results. OBJECTIVE: We aimed to help bridge this translational gap by presenting the latest clinical trials on electrical stimulation for PNIs in combination with relevant etiologies, treatments and nonclinical findings. METHODS: To do so, a systematic search was performed on PubMed, IEEE, and Web of Science databases up to February 2020 using keywords significant to our study. References of each manuscript were screened for additional manuscripts of relevance to our study. RESULTS: We found multiple BES clinical studies reporting enhanced functional recovery or increased nerve regeneration. Although improved outcomes were reported, high variability after BES is seen between and within species likely due to injury severity, location and timeline along with other factors. CONCLUSION: Further clinical studies and introduction of novel delivery platforms are vital to uncover the true regenerative potential of electrical stimulationtherapy.

Development and clinical validation of a grading system for pituitary adenoma consistency.

OBJECTIVE: Pituitary adenoma (PA) consistency, or texture, is an important intraoperative characteristic that may dictate operative dissection techniques and/or instruments used for tumor removal during endoscopic endonasal approaches (EEAs). The impact of PA consistency on surgical outcomes has yet to be elucidated. METHODS: The authors developed an objective 5-point grading scale for PA consistency based on intraoperative characteristics, including ease of tumor debulking, manipulation, and instrument selection, ranging from cystic/hemorrhagic tumors (grade 1) to calcified tumors (grade 5). The proposed grading system was prospectively assessed in 306 consecutive patients who underwent an EEA for PAs, and who were subsequently analyzed for associations with surgical outcomes, including extent of resection (EOR) and complication profiles. RESULTS: Institutional database review identified 306 patients who underwent intraoperative assessment of PA consistency, of which 96% were macroadenomas, 70% had suprasellar extension, and 44% had cavernous sinus invasion (CSI). There were 214 (69.9%) nonfunctional PAs and 92 functional PAs (31.1%). Distribution of scores included 15 grade 1 tumors (4.9%), 112 grade 2 tumors (36.6%), 125 grade 3 tumors (40.8%), 52 grade 4 tumors (17%), and 2 grade 5 tumors (0.7%). Compared to grade 1/2 and grade 3 PAs, grade 4/5 PAs were significantly larger (22.5 vs 26.6 vs 27.4 mm, p < 0.01), more likely to exhibit CSI (39% vs 42% vs 59%, p < 0.05), and trended toward nonfunctionality (67% vs 68% vs 82%, p = 0.086). Although there was no association between PA consistency and preoperative headaches or visual dysfunction, grade 4/5 PAs trended toward preoperative (p = 0.058) and postoperative panhypopituitarism (p = 0.066). Patients with preoperative visual dysfunction experienced greater improvement if they had a grade 1/2 PA (p < 0.05). Intraoperative CSF leaks were noted in 32% of cases and were more common with higher-consistency-grade tumors (p = 0.048), although this difference did not translate to postoperative CSF leaks. Gross-total resection (%) was more likely with lower PA consistency score as follows: grade 1/2 (60%), grade 3 (50%), grade 4/5 (44%; p = 0.045). Extracapsular techniques were almost exclusively performed in grade 4/5 PAs. Assignment of scores showed low variance and high reproducibility, with an intraclass correlation coefficient of 0.905 (95% CI 0.815-0.958), indicating excellent interrater reliability. CONCLUSIONS: These findings demonstrate clinical validity of the proposed intraoperative grading scale with respect to PA subtype, neuroimaging features, EOR, and endocrine complications. Future studies will assess the relation of PA consistency to preoperative MRI findings to accurately predict consistency, thereby allowing the surgeon to tailor the exposure and prepare for varying resection strategies.

Differential Clinical Presentation, Intraoperative Management Strategies, and Surgical Outcomes After Endoscopic Endonasal Treatment of Cystic Sellar Masses.

BACKGROUND: Cystic sellar masses (CSMs) pose diagnostic and therapeutic challenges associated with subtotal cyst wall resection, cerebrospinal fluid (CSF) leak repair, and disease recurrence. Current magnetic resonance imaging (MRI) interpretation often cannot reliably differentiate CSMs, mandating adaptable intraoperative strategies. We reviewed our diagnostic and therapeutic experience after endoscopic endonasal approaches (EEAs) for CSMs. METHODS: A retrospective record review of patients with CSM managed via EEA at the University of Southern California from 2011 to 2018 was conducted. Patient demographics, preoperative characteristics, surgical details, pathologic findings, and postoperative outcomes were assessed. RESULTS: Analysis included 47 patients (mean age, 43.2 years); of these, 78.7% were women. Preoperative symptoms included headache (76.6%) and vision loss (42.6%). Histologically verified sellar pathology included 27 Rathke cleft cysts (RCCs) (57.4%), 17 cystic pituitary adenomas (CPAs) (36.2%), 2 arachnoid cysts (4.3%), and 1 xanthogranuloma (2.1%). Twelve patients (70.6%) with CPAs underwent complete resection and 5 (29.4%) underwent subtotal resection. All 27 patients with RCC and 2 patients with arachnoid cyst underwent complete fenestration and drainage. One xanthogranuloma was completely resected. There were 14 intraoperative (29.8%) and 4 postoperative CSF leaks (8.5%). Headaches, vision, and endocrinopathy improved in 69.2%, 80.0%, and 33.3% of patients with CPA and 73.9%, 71.4%, and 40.9% of patients with RCC, respectively. There were 2 RCC recurrences and 1 CPA recurrence over the follow-up period. CONCLUSIONS: Surgeons must prepare for versatile management strategies of CSMs based on pretest probability associated with MRI and intraoperative findings. Outcomes after EEA for CSMs show low complication profiles and excellent rates of headache and visual improvement, albeit lower rates of endocrine normalization.

A Phantom Study of the Spatial Precision and Accuracy of Stereotactic Localization Using Computed Tomography Imaging with the Leksell Stereotactic System.

BACKGROUND: Stereotactic localization of neurosurgical targets traditionally relies on computed tomography (CT), which is considered the optimal imaging modality for geometric accuracy. However, in-depth investigations that characterize the precision and accuracy of CT images are lacking. We used a CT phantom to examine interscanner precision and interprotocol accuracy in coordinate localization. METHODS: A polymethylacrylate phantom was scanned with Toshiba Aquilion 64 and GE Healthcare LightSpeed 16 CT scanners, using both helical and incremental single-slice (SS) image acquisition protocols. The X, Y, and Z coordinates of 94 points across 6 surfaces of the phantom were physically measured. The CT scan-derived coordinates were compared with the phantom coordinates and with each other to determine accuracy and precision, respectively. RESULTS: Using the SS imaging protocol, the mean (SD) interscanner disparity in localization was 0.93 (0.39) mm, given by the average Euclidean distance between the coordinates of the 2 scanners. This discrepancy significantly varied by axis and surface, with the greatest discrepancy in the Z-axis of 0.30 mm (95% confidence interval, 0.25-0.35; P = 0.05) and on the superior surface of 1.30 mm (95% confidence interval, 1.15-1.45; P = 0.05). SS acquisition was significantly more accurate than the helical protocol. CONCLUSIONS: We found evidence of clinically relevant inconsistency between 2 CT scanners used for stereotactic localization. SS image acquisition was superior to helical scanning with respect to localization accuracy. Interscanner consistency cannot be assumed. Institutions would benefit from identifying the errors inherent in their CT scanners.

Extended-Release Amantadine for Levodopa-Induced Dyskinesia.

INTRODUCTION: Levodopa-induced dyskinesia (LID) is a significant impediment to the long-term use of levodopa for Parkinson's disease (PD). Relatively few studies exist that have described safe and effective therapy for LID. There is thus a significant need for therapy that can control LID to allow for greater sustainability of levodopa therapy. Amantadine extended release (ER) is currently the only FDA-approved medication for the treatment of LID. While other medications have demonstrated efficacy in treating the motor symptoms of PD, amantadine ER is the only one that has been shown, in several clinical trials, to reduce LID and reduce OFF time. Areas Covered: In this review, the authors present the findings of amantadine ER including its efficacy and safety. The authors also provide their expert perspectives on its use and its future prospects. Expert opinion: Several therapies are currently being used and studied for controlling LID, an unmet need in therapy for PD. Amantadine ER has potential to supplement levodopa therapy in PD and improve patient therapeutic outcomes.

Usefulness of Statins for Prevention of Venous Thromboembolism.

Venous thromboembolism (VTE), including deep venous thrombosis and pulmonary embolism, is common with an annual incidence of 1 to 5 per 1,000, resulting in major morbidity, mortality, and increased health care costs. It is more common in the elderly, obese, those with cancer, those undergoing surgery, and those with previous VTE. Strategy to reduce its occurrence has important public health implications. Pleotropic effects of statins may have beneficial effects on a number of potential targets associated with VTE. Statins have excellent safety profile and seem to be associated with beneficial effects in VTE in case-control studies, large observational studies, meta-analyses, and a randomized trial. In conclusion, after critically reviewing the clinical data supporting statin use in the prevention of VTE, we presented clinical recommendations for the use of statins in reducing VTE occurrence, especially in high-risk situations.