Image-guidance technology and the surgical resection of spinal column tumors.

Precision imaging is paramount to achieving success in surgical resection of many spinal tumors, whether the goal involves guiding a surgical cure for primary tumors or improving neurological decompression for metastatic lesions. Pre-operatively, image visualization is intimately involved with defining a clear target and surgical planning. Intra-operatively, image-guidance technology allows for surgeons to maximize the probability for gross total resection of spinal cord tumors and minimize damage to adjacent structures. Through this review, it is evident that spinal surgery has undergone significant advancements with the continued technological progression of different modalities of imaging guided technologies. Sophisticated imaging techniques compliment the surgeon's knowledge by providing an intraoperative reference to spinal column anatomy. This review discusses research efforts focusing on immersive imaging guided interactions with subject specific medical images that could enhance a surgeon's ability to plan and perform complex spinal oncology procedures with safety and efficiency.

The Impact of Traumatic Brain Injury on the Aging Brain.

Traumatic brain injury (TBI) has come to the forefront of both the scientific and popular culture. Specifically, sports-related concussions or mild TBI (mTBI) has become the center of scientific scrutiny with a large amount of research focusing on the long-term sequela of this type of injury. As the populace continues to age, the impact of TBI on the aging brain will become clearer. Currently, reports have come to light that link TBI to neurodegenerative disorders such as Alzheimer's and Parkinson's diseases, as well as certain psychiatric diseases. Whether these associations are causations, however, is yet to be determined. Other long-term sequelae, such as chronic traumatic encephalopathy (CTE), appear to be associated with repetitive injuries. Going forward, as we gain better understanding of the pathophysiological process involved in TBI and subclinical head traumas, and individual traits that influence susceptibility to neurocognitive diseases, a clearer, more comprehensive understanding of the connection between brain injury and resultant disease processes in the aging brain will become evident.

Sports-related concussions: diagnosis, complications, and current management strategies.

Sports-related concussions (SRCs) are traumatic events that affect up to 3.8 million athletes per year. The initial diagnosis and management is often instituted on the field of play by coaches, athletic trainers, and team physicians. SRCs are usually transient episodes of neurological dysfunction following a traumatic impact, with most symptoms resolving in 7-10 days; however, a small percentage of patients will suffer protracted symptoms for years after the event and may develop chronic neurodegenerative disease. Rarely, SRCs are associated with complications, such as skull fractures, epidural or subdural hematomas, and edema requiring neurosurgical evaluation. Current standards of care are based on a paradigm of rest and gradual return to play, with decisions driven by subjective and objective information gleaned from a detailed history and physical examination. Advanced imaging techniques such as functional MRI, and detailed understanding of the complex pathophysiological process underlying SRCs and how they affect the athletes acutely and long-term, may change the way physicians treat athletes who suffer a concussion. It is hoped that these advances will allow a more accurate assessment of when an athlete is truly safe to return to play, decreasing the risk of secondary impact injuries, and provide avenues for therapeutic strategies targeting the complex biochemical cascade that results from a traumatic injury to the brain.

Hydrocephalus: the role of cerebral aquaporin-4 channels and computational modeling considerations of cerebrospinal fluid.

Aquaporin-4 (AQP4) channels play an important role in brain water homeostasis. Water transport across plasma membranes has a critical role in brain water exchange of the normal and the diseased brain. AQP4 channels are implicated in the pathophysiology of hydrocephalus, a disease of water imbalance that leads to CSF accumulation in the ventricular system. Many molecular aspects of fluid exchange during hydrocephalus have yet to be firmly elucidated, but review of the literature suggests that modulation of AQP4 channel activity is a potentially attractive future pharmaceutical therapy. Drug therapy targeting AQP channels may enable control over water exchange to remove excess CSF through a molecular intervention instead of by mechanical shunting. This article is a review of a vast body of literature on the current understanding of AQP4 channels in relation to hydrocephalus, details regarding molecular aspects of AQP4 channels, possible drug development strategies, and limitations. Advances in medical imaging and computational modeling of CSF dynamics in the setting of hydrocephalus are summarized. Algorithmic developments in computational modeling continue to deepen the understanding of the hydrocephalus disease process and display promising potential benefit as a tool for physicians to evaluate patients with hydrocephalus.

Upper midwest climate variations: farmer responses to excess water risks.

Persistent above average precipitation and runoff and associated increased sediment transfers from cultivated ecosystems to rivers and oceans are due to changes in climate and human action. The US Upper Midwest has experienced a 37% increase in precipitation (1958-2012), leading to increased crop damage from excess water and off-farm loss of soil and nutrients. Farmer adaptive management responses to changing weather patterns have potential to reduce crop losses and address degrading soil and water resources. This research used farmer survey ( = 4778) and climate data (1971-2011) to model influences of geophysical context, past weather, on-farm flood and saturated soils experiences, and risk and vulnerability perceptions on management practices. Seasonal precipitation varied across six Upper Midwest subregions and was significantly associated with variations in management. Increased warm-season precipitation (2007-2011) relative to the past 40 yr was positively associated with no-till, drainage, and increased planting on highly erodible land (HEL). Experience with saturated soils was significantly associated with increased use of drainage and less use of no-till, cover crops, and planting on HEL. Farmers in counties with a higher percentage of soils considered marginal for row crops were more likely to use no-till, cover crops, and plant on HEL. Respondents who sell corn through multiple markets were more likely to have planted cover crops and planted on HEL in 2011.This suggests that regional climate conditions may not well represent individual farmers' actual and perceived experiences with changing climate conditions. Accurate climate information downscaled to localized conditions has potential to influence specific adaptation strategies.

EGFR expression stratifies oligodendroglioma behavior.

Epidermal growth factor receptor (EGFR) expression and signaling contribute to glioma biological features and, thus, are a target for new drug development. The role, if any, of EGFR in routine surgical neuropathological diagnostics is less clear. Herein, we describe prospective EGFR IHC analysis in an adult cohort comprising 750 infiltrative gliomas. EGFR expression increased with World Health Organization grade but did not significantly differ between grade-matched astrocytic and oligodendroglial tumors. Survival did not significantly differ by EGFR expression among astrocytic tumors adjusted for World Health Organization grade. However, grade II oligodendrogliomas with strong EGFR expression and 1p/19q codeletion showed reduced survival, compared with their codeleted counterparts with weaker EGFR expression. Surprisingly, an inverse phenomenon was found with grade III anaplastic oligodendrogliomas, in which stronger EGFR expression was a favorable marker for survival. Among all gliomas, the likelihood of EGFR amplification, as viewed by fluorescence in situ hybridization, increased with the strength of EGFR expression, and <1% of cases with weak or no EGFR immunostaining showed amplification. These data suggest that EGFR IHC is useful in certain circumstances (ie, it may help supplement 1p/19q prognostic information in oligodendroglial tumors and screen out cases that would not benefit from more costly EGFR fluorescence in situ hybridization analysis).

Association of Neurosurgical Work Relative Value Units with Objective Markers of Operative Complexity.

OBJECTIVE: Relative value units (RVUs) form the backbone of health care service reimbursement calculation in the United States. However, it remains unclear how well RVUs align with objective measures of procedural complexity within neurosurgery. METHODS: The 2018 American College of Surgeons National Surgical Quality Improvement Program database was queried for neurosurgical procedures with >50 patients, using Current Procedural Terminology (CPT) codes. Length of stay (LOS), operative time, mortality, and readmission and reoperation rates were collected for each code and a univariate correlation analysis was performed, with significant predictors entered into a multivariate logistic regression model, which generated predicted work RVUs, which were compared with actual RVUs to identify undervalued and overvalued procedures. RESULTS: Among 64 CPT codes, LOS, operative time, mortality, readmission, and reoperation were significant independent predictors of work RVUs and together explained 76% of RVU variance in a multivariate model (R2 = 0.76). Using a difference of >1.5 standard deviations from the mean, procedures associated with greater than predicted RVU included surgery for intracranial carotid circulation aneurysms (CPTs 61697 and 61700; residual RVU = 12.94 and 15.07, respectively), and infratemporal preauricular approaches to middle cranial fossa (CPT 61590; residual RVU = 15.39). Conversely, laminectomy/foraminotomy for decompression of additional spinal cord, cauda equina, and/or nerve root segments (CPT 63048; residual RVU = -21.30), transtemporal craniotomy for cerebellopontine angle tumor resection (CPT 61526; residual RVU = -9.95), and brachial plexus neuroplasty (CPT 64713; residual RVU = -11.29) were associated with lower than predicted RVU. CONCLUSIONS: Work RVUs for neurosurgical procedures are largely predictive of objective measures of surgical complexity, with few notable exceptions.

Steroid Use Associated With Increased Odds of 30-Day Mortality in Surgical Patients With Metastatic Spinal Tumors in the Setting of Disseminated Disease.

BACKGROUND: Steroid administration is part of a standard treatment regimen in metastatic spinal cord compression, though the appropriate dose, duration, efficacy, and risks remain controversial. OBJECTIVE: To analyze the risk of preoperative steroid use on 30-d mortality in surgical metastatic spinal tumors with dissemination disease using a large multicenter national database. METHODS: Adult patients who underwent surgical treatment for metastatic spine tumors between 2005 and 2014 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Demographic, preoperative risk factors, operative information, and postoperative events were extracted. Multivariate logistical regression modeling was used to investigate the association with preoperative steroid use with the outcome of interest, 30-d mortality. Other independent risk factors associated with 30-d mortality were also identified. RESULTS: Five hundred fifty-two patients underwent surgical treatment of spinal metastases with disseminated cancer present at time of surgery. Independent risk factors of 30-d mortality included prolonged steroid use (odds ratio [OR] 2.48, 95% confidence interval [CI]: 1.22-5.04, P = .012), dependent functional status (OR 2.91, 95% CI: 1.68-5.04, P < .001), history of bleeding disorder (OR 2.80, 95% CI: 1.16-6.74, P = .021), history of smoking (OR 2.26, 95% CI: 1.11-4.61, P = .024), preoperative transfusions (OR 2.91, 95% CI: 1.02-8.29, P = .049), and preoperative infection/sepsis (OR 2.67, 95% CI: 1.18-6.08, P = .02). Our model demonstrates very strong predictive capabilities, with an area under the receiver operating characteristic curve of 0.7447. CONCLUSION: Steroid use is associated with a significant increased risk of 30-d mortality in surgical metastatic spine tumor patients with disseminated disease. These findings warrant further investigation in controlled experimental environments.

Pediatric tethered cord release: an epidemiological and postoperative complication analysis.

BACKGROUND: Tethered cord release (TCR) is a common procedure in pediatric neurosurgery. Despite a reputation for being relatively safe, the risk factors for postoperative complications are poorly understood. METHODS: In this study, the American College of Surgeons-National Surgical Quality Improvement Program Pediatric Database (ACS-NSQIP-P) was reviewed to identify the demographics, risk factors, and 30-day postoperative complications for tethered cord release using univariate and multivariate analysis. A detailed analysis of reasons for readmission and reoperation was also performed. RESULTS: Three thousand and six hundred eighty-two pediatric patients were studied. Males undergoing TCR were younger (5.6 vs. 6.1 years) and had a higher rate of pre-operative comorbidities but lower 30-day complication rate versus females. Patients who later developed complications were more likely to require a microscope intraoperatively, had longer operative times, and worse preoperative American Society of Anesthesiologists (ASA) class. CONCLUSIONS: Despite being a relatively safe procedure, TCR in the pediatric population carries a finite risk of complications. In this large, international database study, males were found to have a greater number of risk factors prior to TCR, while females exhibit a higher risk of developing postoperative complications. This paper provides a large sample size of multi institutional pediatric patients undergoing TCR and may serve as a contemporary "snapshot" for future studies.

Supratentorial and Infratentorial Approaches to Pineal Surgery: A Database Analysis.

Objectives Neoplasms involving the pineal gland are rare. When they do occur, tumor resection is anatomically challenging and is traditionally addressed by either a supratentorial or an infratentorial approach. To date, no large, multicenter studies have been performed that systematically analyze outcomes comparing these two approaches. This study aimed to evaluate outcomes for patients undergoing pineal neoplasm resection, comparing supratentorial and infratentorial approaches. Design Retrospective database review. Setting Multi-institutional database. Participants From 2005 to 2016, 60 patients were identified, with 13 undergoing a supratentorial approach and 47 undergoing an infratentorial approach. Main Outcome Measures Patient demographics, comorbidities, and 30-day postoperative outcomes were investigated using the American College of Surgeons National Surgical Quality Improvement Program database. Demographics, readmission, reoperation, and complication rates were analyzed and compared with previous studies. Results Patient demographics were similar between these two groups. The overall complication rates for the supratentorial and infratentorial approaches were 30.8 and 17%, respectively, and the difference was not statistically significant. The most common medical complications encountered were respiratory and hematological. Conclusion As the first multi-institutional database analysis of approaches to the pineal gland, this study provides an analysis of patient demographics, comorbidities, and postoperative complications. After controlling for preoperative risk factors and demographic characteristics, no statistically significant differences in postoperative outcomes were found between infratentorial and supratentorial approaches. The mean readmission, reoperation, and complication rates were found to be 2.1, 8.3, and 20%, respectively. The lack of significant difference between approaches suggests that clinical decision-making should depend upon anatomical considerations and physician preference, although the complications illustrated here may provide some preoperative guidance.

Acute Surgical Risk Profile of Intramedullary Spinal Cord Tumor Resection in Pediatric Patients: A Pediatric National Surgical Quality Improvement Program Analysis.

OBJECTIVE: The purpose of the present study was to characterize the acute (30-day) surgical risk profile of pediatric patients undergoing surgical resection of intramedullary spinal cord tumors (IMSCTs). METHODS: Preoperative factors were collected from the Pediatric American College of Surgeons National Surgical Quality Improvement Program database for patients identified by Current Procedural Terminology codes for laminectomy and International Classification of Diseases codes for IMSCTs from 2012 to 2016. The postoperative outcomes were compared by tumor location and type. RESULTS: The mean age of the 139 patients meeting all inclusion criteria was 8.7 years, with a male predominance (58.7%). The cervical and thoracic IMSCT populations had worst preoperative health status, as indicated by American Society of Anesthesiologists class, and a greater proportion of malignant tumors compared with the lumbar IMSCT population. No patient died; 8.6% of the patients were readmitted, and 6.5% required reoperation. Of the 12 readmissions, 8 were required for patients with malignant tumors. The patients with cervical IMSCTs returned to the operating room at a significantly greater rate than did the thoracic and lumbar IMSCT populations. Two common reasons for reoperation in the cervical population were issues related to respiration and hydrocephalus management. The complications included 13 cases of infection, 6 of urinary tract infection, and 5 cases of surgical site infection. CONCLUSIONS: Resection of IMSCTs in the pediatric population is a relatively low-risk procedure in terms of acute surgical complications. However, surgeons operating in the cervical spine should be aware of the increased risk of reoperation, in particular as it pertains to respiratory issues and hydrocephalus.

Opioid Dependence and Prolonged Length of Stay in Lumbar Fusion: A Retrospective Study Utilizing the National Inpatient Sample 2003-2014.

STUDY DESIGN: Retrospective cohort utilizing the National Inpatient Sample (NIS) 2003 to 2014. OBJECTIVE: To investigate the association of opioid dependence with prolonged length of stay (LOS), costs, and surgical complications in elective one-to-two level lumbar fusion. SUMMARY OF BACKGROUND DATA: Opioids are the most commonly prescribed drug class to treat back pain. Few studies have examined the impact of opioid dependence on spinal fusion outcomes. The data available show inconsistent conclusions regarding the association between opioid dependence and LOS. METHODS: Data from 1,826,868 adult elective one-to-two level lumbar fusion discharges in the NIS from 2003 to 2014 were included. Discharges were categorized into an opioid-dependent or unaffected cohort based on the presence or absence of an International Classification of Disease, Ninth Revision-Clinical Modification (ICD-9-CM) code for opioid dependence. Incidence of opioid dependence was compared between 2003 and 2014 via adjusted Wald tests. Patient and surgical characteristics, costs, and complications were compared between cohorts via chi-square tests or adjusted Wald tests for categorical and continuous variables, respectively. Patient and surgical factors were tested for association with prolonged LOS via univariable logistic regressions, and significant (P ≤ 0.01) factors were included in a multivariable logistic regression. RESULTS: Seven thousand nine hundred sixty-four (0.44%) discharges included a diagnosis of opioid dependence. The incidence of opioid dependence increased from 2003 to 2014. Opioid dependence was associated with an adjusted 2.11 times higher odds of prolonged LOS. Opioid-dependent discharges accrued higher costs and had higher frequencies of infection, device-related complications, hematoma- or seroma-related complications, acute posthemorrhagic anemia, and pulmonary insufficiency. CONCLUSION: This nationally-representative study suggests that opioid dependence is associated with prolonged LOS in lumbar fusion, as well as higher costs and higher frequencies of surgical complications. Further investigations are needed to determine the optimal method to treat opioid-dependent patients who require lumbar fusion. LEVEL OF EVIDENCE: 3.

Intracranial hemorrhage as initial manifestation of plasma cell myeloma: A case report.

This is the case of a previously healthy 48 year-old male whom presented with mild confusion, low-grade headache, and left sided weakness. Computed tomography of the head revealed a large acute right frontal lobe intracranial hemorrhage (ICH) and intraventricular extension, with normal vascular imaging. Initial laboratory testing was inconsequential. The patient required emergent evacuation, with pathology revealing only elements of a hematoma. Further laboratory testing and bone marrow biopsy results confirmed the diagnosis of plasma cell myeloma. Other systemic signs/symptoms of this disease were notably absent. This report provides the first description of an ICH as the presenting manifestation of plasma cell myeloma (PCM; multiple myeloma).

C1-C2 Fusion Versus Occipito-Cervical Fusion for High Cervical Fractures: A Multi-Institutional Database Analysis and Review of the Literature.

OBJECTIVE: Type II odontoid fractures of the axis (C2) account for more than 20% of all cervical fractures. If an odontoid screw is contraindicated, the treatment approach for type II C2 fractures typically involves C1-C2 posterior fusion or occipito-cervical (O-C) fusion, each of which has distinct advantages and disadvantages. In this study, postoperative outcomes of C1-C2 fusion and O-C fusion for high cervical fractures were compared. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried to determine 30-day surgical outcomes of posterior C1-C2 fusion versus O-C fusion for adult patients with C2 fractures between 2005 and 2016. Demographics, operative factors, and postoperative events were analyzed, including returns to the operating room, readmission, and death. RESULTS: In total, 165 patients were identified. A majority of the patients (142, 86.1%) had independent functional status, although 133 (80.6%) had an American Society of Anesthesiologists classification ranging from 3 to 5, representing poor preoperative health. A significantly greater proportion of O-C (9.1%) versus C1-C2 fusion (1.7%) returned to the operating room (odds ratio 6.465, confidence interval 1.079-38.719, P = 0.041). The length of operation approached statistical significance (P = 0.053) between the 2 groups, with O-C fusion group having a longer average length of operation (196.4 minutes) versus the C1-C2 group (164.0 minutes). CONCLUSIONS: This study provides a snapshot of the risk profiles of C1-C2 and O-C fusion for C2 fracture, demonstrating a statistically higher risk of reoperation in O-C fusion versus C1-C2 fusion. Future randomized trials are needed to identify the preferred technique to improve patient outcomes.

Epidural Abscess: A Propensity Analysis of Surgical Treatment Strategies.

STUDY DESIGN: Observational analysis of retrospectively collected data. OBJECTIVE: A retrospective study was performed in order to compare the surgical profile of risk factors and perioperative complications for laminectomy and laminectomy with fusion procedures in the treatment of spinal epidural abscess (SEA). SUMMARY OF BACKGROUND DATA: SEA is a highly morbid condition typically presenting with back pain, fever, and neurologic deficits. Posterior fusion has been used to supplement traditional laminectomy of SEA to improve spinal stability. At present, the ideal surgical strategy-laminectomy with or without fusion-remains elusive. METHODS: Thirty-day outcomes such as reoperation and readmission following laminectomy and laminectomy with fusion in patients with SEA were investigated utilizing the American College of Surgeons National Quality Improvement Program database. Demographics and clinical risk factors were collected, and propensity matching was performed to account for differences in risk profiles between the groups. RESULTS: Seven hundred thirty-eight patients were studied (608 laminectomy alone, 130 fusion). The fusion population was in worse health. The fusion population experienced significantly greater rate of return to the operating room (odds ratio [OR] 1.892), with the difference primarily accounted for by cervical spine operations. Additionally, fusion patients had significantly greater rates of blood transfusion. Infection was the most common reason for reoperation in both populations. CONCLUSION: Both laminectomy and laminectomy with fusion effectively treat SEA, but addition of fusion is associated with significantly higher rates of transfusion and perioperative return to the operating room. In operative situations where either procedure is reasonable, surgeons should consider that fusion nearly doubles the odds of reoperation in the short-term, and weigh this risk against the benefit of added stability. LEVEL OF EVIDENCE: 3.

Anterior Versus Posterior Approach for Thoracic Corpectomy: An Analysis of Risk Factors, Outcomes, and Complications.

BACKGROUND: Thoracic corpectomies are performed for various reasons, including spinal deformity, trauma, neoplasms, and infection. Regardless of indication, both anterior and posterior approaches are surgical options, selected based on pathology, anatomy, patient characteristics, and surgical experience. Risk profiles and outcomes for these procedures are poorly characterized, however, and the choice between the 2 approaches remains inconclusive. OBJECTIVE: To compare risk factors and complications for adult patients undergoing anterior and posterior thoracic corpectomies. METHODS: A review of the American College of Surgeons National Quality Improvement Program database was performed, with 30-day patient outcomes after anterior or posterior thoracic corpectomy queried from 2005 to 2016. Preoperative risk factors and postoperative outcomes (e.g., deaths, reoperations, readmissions) were identified and compared. RESULTS: In total, 1327 corpectomies were studied, 861 (64.9%) by an anterior approach and 465 (35.1%) by a posterior approach. Patients undergoing a posterior approach were generally male, older, and had a greater American Association of Anesthesiologists class, whereas those subject to anterior approaches had a greater average body mass index. After we controlled for these baseline characteristics, no significant difference in postoperative events was observed, with 9.3% of anterior approach patients and 7.1% of posterior approach patients returning to the operating room within 30 days. CONCLUSIONS: No significant difference in rates of reoperation, readmission, death, average length of stay, or medical complications exists between anterior and posterior thoracic corpectomy approaches. Both have relatively low-risk profiles and, in situations in which either strategy is reasonable, each can be selected at the surgeon's discretion with comparable risk.

Targeted Blockade of TARP-γ8-Associated AMPA Receptors: Anticonvulsant Activity with the Selective Antagonist LY3130481 (CERC-611).

BACKGROUND & OBJECTIVE: 6-[(1S)-1-[1-[5-(2-hydroxyethoxy)-2-pyridyl]pyrazol-3-yl]ethyl]- 3H-1,3-benzothiazol-2-one (LY3130481 or CERC-611) is a selective antagonist of AMPA receptors containing transmembrane AMPA receptor regulatory protein (TARP) γ-8 that is under development for epilepsy. The present study provided a broad inquiry into its anticonvulsant properties. LY3130481 was anticonvulsant in multiple acute seizure provocation models in mice and rats. In addition, LY3130481 was effective against absence seizures in the GAERS genetic model and in the Frings mouse model. Likewise, LY3130481 attenuated convulsions in mice and rats with long-term induction of seizures (e.g., corneal, pentylenetetrazole, hippocampal, and amygdala kindled seizures). In slices of epileptic human cortex, LY3130481 significantly decreased neuronal firing frequencies. LY3130481 displaced from rat brain a radioligand specific for AMPA receptors associated with TARP γ-8 whereas non-TARP-selective molecules did not. Binding was also observed in hippocampus freshly transected from a patient. RESULTS & CONCLUSION: Taken as a whole, the findings reported here establish the broad anticonvulsant efficacy of LY3130481 indicating that blockade of AMPA receptors associated with TARP γ-8 is sufficient for these protective effects.