Metastatic Infiltration of Nervous Tissue and Periosteal Nerve Sprouting in Multiple Myeloma-Induced Bone Pain in Mice and Human.

Multiple myeloma (MM) is a neoplasia of B plasma cells that often induces bone pain. However, the mechanisms underlying myeloma-induced bone pain (MIBP) are mostly unknown. Using a syngeneic MM mouse model, we show that periosteal nerve sprouting of calcitonin gene-related peptide (CGRP+) and growth associated protein 43 (GAP43+) fibers occurs concurrent to the onset of nociception and its blockade provides transient pain relief. MM patient samples also showed increased periosteal innervation. Mechanistically, we investigated MM induced gene expression changes in the dorsal root ganglia (DRG) innervating the MM-bearing bone of male mice and found alterations in pathways associated with cell cycle, immune response and neuronal signaling. The MM transcriptional signature was consistent with metastatic MM infiltration to the DRG, a never-before described feature of the disease that we further demonstrated histologically. In the DRG, MM cells caused loss of vascularization and neuronal injury, which may contribute to late-stage MIBP. Interestingly, the transcriptional signature of a MM patient was consistent with MM cell infiltration to the DRG. Overall, our results suggest that MM induces a plethora of peripheral nervous system alterations that may contribute to the failure of current analgesics and suggest neuroprotective drugs as appropriate strategies to treat early onset MIBP.SIGNIFICANCE STATEMENT Multiple myeloma (MM) is a painful bone marrow cancer that significantly impairs the quality of life of the patients. Analgesic therapies for myeloma-induced bone pain (MIBP) are limited and often ineffective, and the mechanisms of MIBP remain unknown. In this manuscript, we describe cancer-induced periosteal nerve sprouting in a mouse model of MIBP, where we also encounter metastasis to the dorsal root ganglia (DRG), a never-before described feature of the disease. Concomitant to myeloma infiltration, the lumbar DRGs presented blood vessel damage and transcriptional alterations, which may mediate MIBP. Explorative studies on human tissue support our preclinical findings. Understanding the mechanisms of MIBP is crucial to develop targeted analgesic with better efficacy and fewer side effects for this patient population.

RNA profiling of human dorsal root ganglia reveals sex differences in mechanisms promoting neuropathic pain.

Neuropathic pain is a leading cause of high-impact pain, is often disabling and is poorly managed by current therapeutics. Here we focused on a unique group of neuropathic pain patients undergoing thoracic vertebrectomy where the dorsal root ganglia is removed as part of the surgery allowing for molecular characterization and identification of mechanistic drivers of neuropathic pain independently of preclinical models. Our goal was to quantify whole transcriptome RNA abundances using RNA-seq in pain-associated human dorsal root ganglia from these patients, allowing comprehensive identification of molecular changes in these samples by contrasting them with non-pain-associated dorsal root ganglia. We sequenced 70 human dorsal root ganglia, and among these 50 met inclusion criteria for sufficient neuronal mRNA signal for downstream analysis. Our expression analysis revealed profound sex differences in differentially expressed genes including increase of IL1B, TNF, CXCL14 and OSM in male and CCL1, CCL21, PENK and TLR3 in female dorsal root ganglia associated with neuropathic pain. Coexpression modules revealed enrichment in members of JUN-FOS signalling in males and centromere protein coding genes in females. Neuro-immune signalling pathways revealed distinct cytokine signalling pathways associated with neuropathic pain in males (OSM, LIF, SOCS1) and females (CCL1, CCL19, CCL21). We validated cellular expression profiles of a subset of these findings using RNAscope in situ hybridization. Our findings give direct support for sex differences in underlying mechanisms of neuropathic pain in patient populations.

Predictors of syrinx presentation and outcomes in pediatric Chiari malformation type I: a single institution experience of 218 consecutive syrinx patients.

PURPOSE: Chiari I malformation (CM-I) in pediatric patients can impose substantial neurologic and functional impairment. Additionally, the presence of syrinx is often a harbinger of clinical compromise, but little attention has been devoted to identifying features associated with syrinx development and the clinical impact of syrinx resolution. Therefore, this study aims to identify clinical and radiographic variables associated with preoperative syrinx presence and postoperative syrinx reduction in pediatric patients with CM-I and determine the relationship between postoperative syrinx reduction and clinical symptom improvement. METHODS: The authors performed a retrospective analysis of 435 consecutive pediatric patients who underwent surgical treatment of CM-I from 2001 to 2021 at a single tertiary pediatric medical center. All patients underwent pre- and postoperative MRI, and clinical and radiographic variables were recorded and subject to inferential analysis. RESULTS: Syrinx at presentation was independently associated with symptoms of spinal cord dysfunction at presentation (OR 2.17 (95% CI 1.05-4.48); p = 0.036), scoliosis (OR 5.33 (2.34-10.86); p = 0.001), and greater pB-C2 (posterior basion to C2 distance) measurement length (OR 1.14 (95% CI 1.01-1.30); p = 0.040). Syrinx at presentation was inversely associated with tussive headaches at presentation (OR 0.27 (95% CI 0.16-0.47); p = 0.001) and cranial nerve deficits at presentation (OR 0.49 (95% CI 0.26-0.92); p = 0.025). Postoperatively, patients with radiographic evidence of syrinx improvement had greater rates of symptom improvement (93.1% vs 82.1%; p = 0.049), better CCOS scores (15.4 vs 14.2; p = 0.001), and decreased rates of readmission (6.0% vs 25.0%, p = 0.002) and reoperation (0.5% vs 35.7%; p = 0.001). The difference in syrinx resolution was similar but not statistically significant (10.3% vs 16.7%; p = 0.251). AO joint anomaly (OR 0.20, 95% CI 0.04-0.95; p = 0.026) and foramen magnum diameter (OR 1.12, 95% CI 1.00-1.25; p = 0.049) were the only independent predictors of syrinx improvement, and surgical technique was the only predictor for syrinx resolution (OR 2.44, 95% CI 1.08-5.50; p = 0.031). Patients that underwent tonsil reduction surgery whose syrinx improved had a wider foramen magnum diameter than those whose did not improve (34.3 vs 31.7; p = 0.028). CONCLUSIONS: Radiographic syrinx improvement is associated with greater rates of symptom improvement and less readmissions and reoperations for CM-I. AO joint anomalies and narrower foramen magnums were independent risk factors for the lack of syrinx improvement. These novel insights will help guide preoperative patient counseling, pre- and intraoperative surgical decision-making, and postoperative clinical prognostication in the treatment of pediatric CM-I.

Treatment of large infectious extracranial carotid artery pseudoaneurysms in children: a systematic review of the literature.

INTRODUCTION: Extracranial carotid artery pseudoaneurysm is a rare complication of deep neck space infection, and no evidence-based treatment guidelines are available in the literature. METHOD: To clarify the existing experience of the different treatment strategies, the authors performed a systematic literature search using the PubMed, Ovid EMBASE, and Scopus databases in accordance with PRISMA guidelines to review all reported cases of pediatric patients with infectious carotid pseudoaneurysms larger than 1 cm. RESULTS: Twenty-six patients with a median age of 4 years (range 6 months-15 years) were identified. Eighteen patients (69.2%) were treated with endovascular methods, 6 patients (23.1%) with surgical methods, 1 patient (3.8%) with a hybrid endovascular/surgical approach, and 1 patient (3.8%) with conservative management. Recurrence of the pseudoaneurysm occurred in 2 cases (7.7%), both of which were successfully retreated. Of the 6 patients (23.1%) who presented with pre-procedure neurologic deficits, 3 patients had complete or near complete resolution of symptoms after intervention and 3 patients had persistent deficits at last follow-up. Four patients (15.4%) experienced new neurologic deficits post-procedure that resolved at last follow-up. CONCLUSION: The endovascular treatment tends to be the preferred option to treat a large or giant infectious pseudoaneurysm of the carotid artery in the pediatric patient. However, more evidence is necessary to elucidate comparative safety and efficacy profiles of endovascular and surgical management strategies.

Surgical Site Infection After Autologous Cranioplasty for Decompressive Craniectomy in Traumatic Brain Injury: A Retrospective Review of Two Level 1 Trauma Centers.

OBJECT: Surgical site infection (SSI) after cranioplasty can result in unnecessary morbidity. This analysis was designed to determine the risk factors of SSI after cranioplasty in patients who received a decompressive craniectomy with the autologous bone for traumatic brain injury (TBI). METHODS: A retrospective review was performed at two level 1 academic trauma centers for adult patients who underwent autologous cranioplasty after prior decompressive craniectomy for TBI. Demographic and procedural variables were collected and analyzed for associations with an increased incidence of surgical site infection with two-sample independent t tests and Mann Whitney U tests, and with a Bonferroni correction applied in cases of multiple comparisons. Statistical significance was reported with a P value of < 0.05. RESULTS: A total of 71 patients were identified. The mean interval from craniectomy to cranioplasty was 99 days (7-283), and 3 patients developed SSIs after cranioplasty (4.2%). Postoperative drain placement (P > 0.08) and administration of intrawound vancomycin powder (P = 0.99) were not predictive of infection risk. However, a trend was observed suggesting that administration of prophylactic preoperative IV vancomycin is associated with a reduced infection rate. CONCLUSIONS: The SSI rate after autologous cranioplasty in TBI patients is lower than previously reported for heterogeneous groups and indications, and the infection risk is comparable to other elective neurosurgical procedures. As such, the authors recommend attempting to preserve native skull and perform autologous cranioplasty in this population whenever possible.

Psychosurgery, ethics, and media: a history of Walter Freeman and the lobotomy.

At the peak of his career, Walter J. Freeman II was a celebrated physician and scientist. He served as the first chairman of the Department of Neurology at George Washington University and was a tireless advocate of surgical treatment for mental illness. His eccentric appearance, engaging personality during interviews, and theatrical demonstrations of his surgical techniques gained him substantial popularity with local and national media, and he performed more than 3000 prefrontal and transorbital lobotomies between 1930 and 1960. However, poor patient outcomes, unfavorable portrayals of the lobotomy in literature and film, and increased regulatory scrutiny contributed to the lobotomy's decline in popularity. The development of antipsychotic medications eventually relegated the lobotomy to rare circumstances, and Freeman's reputation deteriorated. Today, despite significant advancements in technique, oversight, and ethical scrutiny, neurosurgical treatment of mental illness still carries a degree of social stigma. This review presents a historical account of Walter Freeman's life and career, and the popularization of the lobotomy in the US. Additionally, the authors pay special attention to the influence of popular literature and film on the public's perception of psychosurgery. Aided by an understanding of this pivotal period in medical history, neurosurgeons are poised to confront the ethical and sociological questions facing psychosurgery as it continues to evolve.

Stereotactic radiosurgery and immunotherapy for metastatic spinal melanoma.

The management of metastatic spinal melanoma involves maximizing local control, preventing recurrence, and minimizing treatment-associated toxicity and spinal cord damage. Additionally, therapeutic measures should promote mechanical stability, facilitate rehabilitation, and promote quality of life. These objectives prove difficult to achieve given melanoma's elusive nature, radioresistant and chemoresistant histology, vascular character, and tendency for rapid and early metastasis. Different therapeutic modalities exist for metastatic spinal melanoma treatment, including resection (definitive, debulking, or stabilization procedures), stereotactic radiosurgery, and immunotherapeutic techniques, but no single treatment modality has proven fully effective. The authors present a conceptual overview and critique of these techniques, assessing their effectiveness, separately and combined, in the treatment of metastatic spinal melanoma. They provide an up-to-date guide for multidisciplinary treatment strategies. Protocols that incorporate specific, goal-defined surgery, immunotherapy, and stereotactic radiosurgery would be beneficial in efforts to maximize local control and minimize toxicity.

Prevalence of cardiomegaly and left ventricular hypertrophy in scuba diving and traffic accident victims.

Although frequently asymptomatic, left ventricular hypertrophy (LVH) is an independent predictor of sudden cardiac death (SCD). We hypothesized that diving may increase the propensity for pre-existent LVH to cause a lethal arrhythmia (and SCD) and therefore the prevalence of LVH may be greater among scuba fatalities than among traffic fatalities. We compared autopsy data for 100 scuba fatalities with 178 traffic fatalities. Extracted data contained information on age, sex, height, body mass, heart mass (HM), left ventricular wall thickness (LVWT), interventricular wall thickness (IVWT), and degree of coronary artery stenosis. A case was classified as LVH if the LVWT was > 15 mm. Log risk models were used to compare HM and LVWT in two groups while controlling for body mass, body length, age and sex. The prevalence of LVH was compared using Pearson's test. The mean HM was 428.3 +/- 100 for divers and 387 +/- 87 for controls. The crude HM ratio for scuba fatalities vs. controls was 1.11 (1.05, 1.17), and when controlled for sex, age and body mass the ratio was 1.06 (1.01, 1.09). The mean LVWT was 15 +/- 3.5 for divers and 14 +/- 2.7 for controls (p = 0.0017). HM and LVWT measured at autopsy were greater in scuba than in traffic fatalities.

Recent modifications to the investigation of diving related deaths.

The investigation of deaths that involve diving using a compressed breathing gas (SCUBA diving) is a specialized area of forensic pathology. Diving related deaths occur more frequently in certain jurisdictions, but any medical examiner or coroner's office may be faced with performing this type of investigation. In order to arrive at the correct conclusion regarding the cause and manner of death, forensic pathologists and investigators need to have a basic understanding of diving physiology, and should also utilize more recently developed technology and ancillary techniques. In the majority of diving related deaths, the cause of death is drowning, but this more often represents a final common pathway due to a water environment. The chain of events leading to the death is just as important to elucidate if similar deaths are to be minimized in the future. Re-enactment of accident scenarios, interrogation of dive computers, postmortem radiographic imaging, and slight alterations in autopsy technique may allow some of these diving related deaths to the better characterized. The amount and location of gas present in the body at the time of autopsy may be very meaningful or may simply represent a postmortem artifact. Medical examiners, coroners, and forensic investigators should consider employing select ancillary techniques to more thoroughly investigate the factors contributing a death associated with SCUBA diving.

3D-Printed Spine Models for Planning Staged Minimally Invasive Transverse Process Resections for Bertolotti Syndrome: Technical Note.

Background: Three-dimensional (3D) printing has enabled numerous advances in spine surgery execution and education. However, few examples exist to outline how this technology can aid the performance of complex spine surgery using minimally invasive surgery (MIS) techniques. Therefore, we present a case that illustrates the benefits of 3D-printed spine model production before and after correction of a congenital lumbosacral anomaly using an MIS approach. Case Report: A 40-year-old woman with Bertolotti syndrome underwent a staged bilateral L6 MIS transverse process resection for the treatment of severe and progressive axial back pain which had repeatedly failed conservative management. 3D-printed spine models were used for pre- and post-operative surgical planning and patient counseling. Conclusion: 3D-printed spine models can aid in the planning of complex spine cases suited for an MIS approach.

Age is Associated with Level of First-Time Anterior Cervical Discectomy and Fusion: An Ordinal Analysis of Factors Influencing Timing of Cervical Degeneration.

BACKGROUND: Symptomatic cervical spondylosis is often treated with anterior cervical discectomy and fusion (ACDF). However, few factors can predict which cervical level will degenerate and require intervention. This analysis evaluates preprocedural factors associated with level of first-time single-level ACDF. METHODS: We performed a retrospective analysis of patients who underwent single-level ACDF without prior history of spine surgery. Mann Whitney U-tests and Spearman rank-order correlation were performed for analyses of associations between variables of interest and ACDF level. Adjusted odds-ratios were calculated by proportional-odds logistic regression, with age, sex, body mass index, current tobacco use, history of neck trauma, preoperative radicular symptoms, and preoperative myelopathic symptoms as covariates. RESULTS: One hundred forty-one patients met inclusion criteria, and age demonstrated a negative correlation with ACDF level, such that younger patients tended to have ACDF performed at inferior subaxial levels (P = 0.0006, rho = -0.31, moderately strong relationship). Patients with preoperative radicular symptoms and myelopathic symptoms were more likely to have ACDF performed at inferior (P = 0.0001) and superior (P < 0.0001) levels, respectively. Patient sex, body mass index, current tobacco use, and history of neck trauma were not predictive of ACDF level. When adjusting for the above variables in a proportional-odds ordinal logistic regression model, a one-year increase in age conferred a 4% increase in the odds of requiring an ACDF at a given superior level compared to the adjacent inferior level. CONCLUSIONS: Age is correlated with level of first-time single level ACDF. Individual subaxial levels may have unique biomechanical properties that influence degeneration.

Neurologic Quality of Life Outcomes in Patients with Normal Pressure Hydrocephalus After Ventriculoperitoneal Shunt Placement: A Prospective Assessment of Cognition, Mobility, and Social Participation.

BACKGROUND: Idiopathic normal pressure hydrocephalus (iNPH) typically presents with gait disturbances, cognitive decline, and urinary incontinence. Symptomatic improvement generally occurs following shunt placement, but limited evidence exists on the quality of life (QOL) metrics in iNPH. Therefore, we conducted a prospective study of the effect of shunt placement on QOL in iNPH patients, using Quality of Life in Neurologic Disorders (Neuro-QOL) metrics. METHODS: Eligible patients underwent shunt placement after evidence of symptomatic improvement following temporary CSF diversion via inpatient lumbar drain trial. Patients were administered short- and long-form Neuro-QOL assessments prior to shunt placement and at six-month and one-year postoperative timepoints to evaluate lower extremity mobility, cognitive function, and social roles and activities participation. Changes in QOL measures were analyzed using a repeated measures linear mixed effects model. RESULTS: There were forty-eight patients with a mean age of 75.4 ± 6.3 years. Average short-form mobility scores improved by 3.9 points (14.6%) at six-month follow-up and by 6.2 points (23.2%) at one-year follow-up compared to preoperative baseline (p = 0.027 and p = 0.0002, respectively). Short-form cognition scores increased by 5.2 points (22.4%) at six months and 10.9 points (47.0%) at one year postoperatively (p = 0.007 and p < 0.0001, respectively). On long-form assessment, social roles and activity participation scores improved by 29.3 points (23.4%) at six months and 31.6 points (25.2%) at one year after surgery compared to baseline (p = 0.028 and p = 0.02, respectively). CONCLUSION: Our findings demonstrate that shunt placement leads to improved QOL in iNPH patients across multiple domains. Significant improvements in mobility, cognition, and social roles and activity participation are realized within the first six months and are sustained on one-year follow-up.

Basilar Impression: A Systematic Review and Meta-Analysis of Clinical Features, Operative Strategies, and Outcomes.

OBJECTIVE: Basilar impression (BI) is a rare yet debilitating abnormality of the craniovertebral junction, known to cause life-threatening medullary brainstem compression. Our study analyzes surgical approaches for BI and related outcomes. METHODS: A systematic review was conducted using PubMed, Google Scholar, and Web of Science electronic databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to critically assess primary articles examining BI. RESULTS: We analyzed 87 patients from 65 articles, mostly female (55.17%) with a mean age of 46.31 ± 17.94 years, commonly presenting with motor (59.77%) and sensory deficits (55.17%). Commonly employed procedures included posterior occipitocervical fusion (24.14%), anterior decompression (20.69%), and combined anterior decompression with posterior fusion (21.84%). Patients who underwent anterior approaches were found to be older (55.38 ± 17.67 vs. 45.49 ± 18.78 years, P < 0.05) and had a longer duration from symptom onset to surgery (57.39 ± 64.33 vs. 26.02 ± 29.60 months, P < 0.05) compared to posterior approaches. Our analysis revealed a significant association between a longer duration from symptom onset to surgery and an increased likelihood of undergoing odontoidectomy and decompression (odds ratio: 1.02, 95% confidence interval: 1.00-1.03, P < 0.05). Furthermore, after adjusting for all other covariates, a history of rheumatoid arthritis and the use of a posterior approach were significantly associated with an elevated risk of postoperative complications (P < 0.05). CONCLUSIONS: The treatment approach to complex craniovertebral junction disease should be tailored to the surgeon's experience and the nature of the compressive pathology.

Stereo-EEG Evaluation and Surgical Treatment in Patients With Drug-Resistant Focal Epilepsy Associated With Nodular Heterotopia.

PURPOSE: Nodular heterotopia (NH) is a common cause of drug-resistant epilepsy. Only limited studies detail the treatment of NH with laser interstitial thermal therapy and none analyze the relation between epileptogenicity and NH location. METHODS: We retrospectively studied nine patients with drug-resistant epilepsy and NH who underwent stereoelectroencephalography and subsequent epilepsy surgery. Nodular heterotopia in the frontal lobes or along the bodies of the lateral ventricles was classified as anterior NH. Nodular heterotopia in the trigones, temporal or occipital horns, or temporal lobes was classified as posterior NH. Nodular heterotopia in both anterior and posterior locations was classified as diffuse NH. Interictal and ictal stereoelectroencephalography were analyzed, and patients were followed postoperatively to assess outcomes. RESULTS: Of the six patients who underwent nine laser interstitial thermal therapy procedures either in isolation or in combination with other surgical therapies, four patients were Engel Ia, one was Engel IIb, and one was Engel IIIa, with an average follow-up of 22.8 months. All patients with posterior NH had interictal epileptiform abnormalities and seizures originating from the posterior NH. None of the patients with anterior NH had epileptiform activity recorded from their NH. CONCLUSION: Laser interstitial thermal therapy alone or in combination with other surgical therapies is an effective treatment in those with drug-resistant epilepsy because of NH, even in those with extensive NH and broad seizure onset. We observed a trend suggesting that posterior NH are more likely to be epileptogenic compared with anterior NH and recommend that in patients with anterior NH, alternative epilepsy etiologies and stereoelectroencephalography implantation strategies be considered.

Single Nucleotide Polymorphisms and Adolescent Idiopathic Scoliosis: A Systematic Review and Meta-Analysis of the Literature.

STUDY DESIGN: Meta-analysis. OBJECTIVE: To determine the single nucleotide polymorphisms (SNPs) that are related to adult idiopathic scoliosis. SUMMARY AND BACKGROUND DATA: Adolescent idiopathic scoliosis (AIS) is considered one of the most prevalent spinal diseases. Even though the cause of AIS is yet to be determined, family history and sex have shown conclusive associations. Multiple studies have indicated that AIS is more prevalent in families where at least one other first-degree relative is similarly affected, indicating a possible genetic etiology to AIS. MATERIALS AND METHODS: Articles were collected from 3 different search engines and then processed in 2 stages for final article selection for quantitative analysis. Five different genetic models were represented to show the association between the different SNPs and AIS. The Hardy-Weinberg equilibrium was examined using Fisher exact test, with significance set at P <0.05. The final analysis paper's quality was evaluated using the Newcastle Ottawa Scale. Kappa interrater agreement was calculated to evaluate the agreement between authors. RESULTS: The final analysis comprised 43 publications, 19412 cases, 22005 controls, and 25 distinct genes. LBX1 rs11190870 T>C and MATN-1 SNPs were associated with an increased risk of AIS in one or all of the 5 genetic models. IGF-1 , estrogen receptor alfa, and MTNR1B , SNPs were not associated with AIS in all 5 genetic models. Newcastle Ottawa Scale showed good quality for the selected articles. Cohen k = 0.741 and Kappa interrater agreement of 84% showed that the writers were in strong agreement. CONCLUSIONS: There seem to be associations between AIS and genetic SNP. Further larger studies should be conducted to validate the results.

Image-Guided Percutaneous Multilevel Pediculosynthesis for Treatment of Contiguous Pedicle Stress Fractures: Technical Case Report.

BACKGROUND: Nontraumatic pedicle fracture is uncommon, with sparsely described cases of conservative management versus surgical treatment by open fusion or percutaneous fixation. METHODS: We report the case of a 60-year-old woman with nontraumatic L4 and L5 pedicle fracture who developed additional pedicle fractures at L3 while undergoing conservative management in a brace. The patient underwent percutaneous pediculosynthesis with screw fixation without fusion at L3-5 bilaterally. RESULTS: The treatment led to fracture healing with good radiographic result and resolution of her symptoms. CONCLUSIONS: A trial of conservative management is typically warranted in most cases of nontraumatic pedicle fracture, but there is risk of refractory or progressive symptoms and subsequent fracture. Minimally invasive fixation is a viable surgical option that can be used in multilevel fractures.

Development and Internal Validation of the Postoperative Analgesic Intake Needs Score: A Predictive Model for Post-Operative Narcotic Requirement after Spine Surgery.

STUDY DESIGN: Retrospective Cohort. OBJECTIVE: The aim of this study was to develop a clinical tool to pre-operatively risk-stratify patients undergoing spine surgery based on their likelihood to have high postoperative analgesic requirements. METHODS: A total of 1199 consecutive patients undergoing elective spine surgery over a 2-year period at a single center were included. Patients not requiring inpatient admission, those who received epidural analgesia, those who had two surgeries at separate sites under one anesthesia event, and those with a length of stay greater than 10 days were excluded. The remaining 860 patients were divided into a derivation and validation cohort. Pre-operative factors were collected by review of the electronic medical record. Total postoperative inpatient opioid intake requirements were converted into morphine milligram equivalents to standardize postoperative analgesic requirements. RESULTS: The postoperative analgesic intake needs (PAIN) score was developed after the following predictor variables were identified: age, race, history of depression/anxiety, smoking status, active pre-operative benzodiazepine use and pre-operative opioid use, and surgical type. Patients were risk-stratified based on their score with the high-risk group being more likely to have high opioid consumption postoperatively compared to the moderate and low-risk groups in both the derivation and validation cohorts. CONCLUSION: The PAIN Score is a pre-operative clinical tool for patients undergoing spine surgery to risk stratify them based on their likelihood for high analgesic requirements. The information can be used to individualize a multi-modal analgesic regimen rather than utilizing a "one-size fits all" approach.

Standard of Care During a Crisis: What Should a Surgeon Know (and Do)?

Numerous catastrophic events in the 21st century have motivated renewed discussion regarding whether the traditional definition of standard of care appropriately applies to clinical decision-making in crisis scenarios. Some authorities have proposed the adoption of a crisis standard of care, which refines physician responsibilities during a crisis event in accordance with population health principles. However, this proposal is fraught with controversy, and current medical and legal scholarship on this topic remains complex and conflicted. To clarify these points and provide practicing neurosurgeons with guidance, we provide a review of current literature on the evolving definitions of crisis standard of care. Additionally, we provide an assessment of the implications of a crisis standard of care, as it relates to legal liability, clinical ethics, and neurosurgical practice.

Imaging as a Pain Biomarker.

In recent years, the hunt for objective biomarkers in chronic pain has intensified, as interest has grown in precision medicine techniques, and the global opioid crisis has underscored the need to accelerate the pace of pain research. A growing body of neuroimaging literature suggests that chronic pain is associated with various alterations in regional brain areas as well as whole-brain networks, which may represent unique radiological pain signatures or biomarkers to guide diagnosis, response, and treatment. Here, we provide a comprehensive and updated literature review on investigative efforts to identify neuroimaging biomarkers for pain.

Relative Citation Ratios of Global Surgery, Obstetrics, Trauma, and Anesthesia: Implications and Lessons for Global Neurosurgery.

BACKGROUND: The National Institutes of Health has developed a new metric, the Relative Citation Ratio (RCR), to assess the impact of research articles and compare academic productivity across different fields. Global surgery, obstetrics, trauma, and anesthesia (SOTA) are young and increasingly popular fields attracting researchers and funding. This study analyzed the RCR of global neurosurgery; compared it with other global SOTA specialties; and discussed the implications for researchers, academic institutions, and aspiring global neurosurgeons. METHODS: Metadata were downloaded from the National Institutes of Health RCR website for 12 established global surgery specialties, including global neurosurgery. The authors performed descriptive and bivariable inferential analyses to evaluate differences in the number of total publications, median number of citations per year, and median RCR for each specialty for which data were available. RESULTS: Global pediatric surgery had the highest median citations per year (2.00, interquartile range: 0.63-3.50; P = 0.048) and median relative citation ratio (1.36, interquartile range: 0.33-1.95; P = 0.693). In comparison, global neurosurgery articles had 0.20 median citations per year (IQR: 0-1.5) and 0.54 (IQR: 0.12-1.30) median relative citations. The median expected citations per year for all SOTA articles was 1.77. CONCLUSIONS: We observed strong development of global neurosurgery and SOTA research. Overall, the use of the RCR will facilitate standardized interfield and intrafield academic productivity comparisons. Based on the results presented in this study, global neurosurgery is a promising career route for young and aspiring academic neurosurgeons.