Illustrative resection of mixed intra- and extramedullary thoracic spinal cord capillary hemangioma.

Background: Capillary hemangiomas are typically superficial benign tumors of the cutaneous and mucosal tissues of the face and neck in pediatric patients. In adults, they typically occur in middle-aged males who present with pain, myelopathy, radiculopathy, paresthesias, and bowel/bladder dysfunction. The optimal treatment for intramedullary spinal cord capillary hemangiomas is gross total/en bloc resection. Methods: Here, we present a 63-year-old male with increasing right greater than left lower extremity numbness/ weakness, attributed to a T8-9 mixed intra- and extramedullary capillary hemangioma. Results: One year following complete lesion resection, the patient used an assistive device to ambulate and continued to improve neurologically. Conclusion: We presented a 63-year-old male whose paraparesis was attributed to a T8-9 mixed intra- and extramedullary capillary hemangioma who did well following total en bloc lesion resection. In addition to this case study/technical note, we provide a 2-D intraoperative video detailing the resection technique.

Intramedullary Spinal Cord Abscess Management: Case Series, Operative Video, and Systematic Review.

BACKGROUND: Intramedullary spinal cord abscess (ISCA) is an extremely rare disease, which has had fewer than 250 reported cases since its initial description in 1830. The condition is limited to level V evidence, limiting the ability for surgeons to characterize and treat it. OBJECTIVE: To report the cases of 2 patients with ISCA and their surgical management: a 59-year-old woman who presented with progressive right hemiparesis and a 69-old man who presented with acute gait instability and significant bilateral shoulder pain. In addition, to report findings from a systematic literature review and associated logistic regression analysis. METHODS: A MEDLINE and Embase search was conducted using the keywords "intramedullary," "spinal cord," "abscess," and "tuberculoma" and the results were screened for case reports. A logistic regression model was fit 100 times on data to retrieve predictor odds ratios. RESULTS: Two hundred case reports of ISCA were identified between 1965 and 2022. Logistic regression determined that the only variables of significance were age (P < 0.01) and antibiotics (P < 0.05). CONCLUSIONS: Treatment of ISCAs has significantly improved over the years. However, ISCAs are still poorly understood. Our recommendations can be used to guide diagnosis and treatment.

The Échancrure of the Uncovertebral Joint: A Forgotten Structure of the C3-C7 Cervical Vertebral Bodies.

Introduction The échancrure (a French term meaning "indentation") of the cervical vertebrae is the poorly defined articular part on the inferolateral aspect of the cervical spine body, which, with the uncinate processes of the associated caudal vertebra, makes up the joints of Luschka (uncovertebral joint). With no known previous studies on the échancrure, the present anatomical study aimed to better elucidate this structure, its prevalence, and its relationships to the adjacent intervertebral foramen and uncinate process. Methods We observed 50 adult cervical spines (100 sides) for the presence of an énchancrure. When an énchancrure was identified, its morphometry was documented and photographed. Measurements included the width and height of the énchancrure. The relationship with the adjacent uncinate process was also studied. Any correlation between the size and shape of the adjacent uncinate process and the énchancrure was recorded. Results Anénchancrure was found at all levels of the cervical vertebrae except at C1 and C7 and was clearly visible on 88% of the sides. The énchancrure, more or less, conformed to the reciprocal shape of the uncinate process, which was found on all sides. The shapes were roughly arched, ovoid, or linear. These structures were always in an anterolateral position on the body of the vertebra and just outside the apophyseal ring. The mean height of the énchancrure was 2.1 mm. The length of the uncinate process correlated positively (r=0.8) to the size of the adjacent énchancrure. The height of the énchancrure was inversely related to the diameter of the adjacent intervertebral foramen. The mean width was 8.3 mm. These structures tended to be largest at C3 and C4 vertebral levels and were smallest at C5 and C6 levels. The énchancrure was most in contact with the uncinate process with lateral flexion of the cervical spine and in specimens with a longer uncinate process, e.g., C6. The énchancrure was also found to be wider in cases of cervical spine degeneration involving the body of the cervical vertebrae. Degeneration of the uncovertebral joint was most often seen at the énchancrure and not at the adjacent uncinate process. Conclusions We found that the énchancrure is found in the majority of cervical spines. These structures tended to be largest at C3 and C4 vertebral levels and were smallest at C5 and C6 levels, and they had more prominence when the adjacent uncinate process was enlarged. The énchancrure should be considered a normal feature of the inferolateral aspect of the cervical vertebrae. Future clinical studies are necessary to better elucidate their functional significance.

The Effect of Timing of Intracranial Pressure Monitor Placement in Patients with Severe Traumatic Brain Injury.

BACKGROUND/OBJECTIVE: Intracranial pressure (ICP) monitor placement is indicated for patients with severe traumatic brain injury (sTBI) to minimize secondary brain injury. There is little evidence to guide the optimal timing of ICP monitor placement. METHODS: A retrospective cohort study using the National Trauma Data Bank (NTDB) from 2013 to 2017 was performed. The NTDB was queried to identify patients with sTBI who underwent external ventricular drain or intraparenchymal ICP monitor placement. Propensity score matching was used to create matched pairs of patients who underwent early compared to late ICP monitor placement using 6-h and 12-h cutoffs. The outcomes of interest were in-hospital mortality, non-routine discharge disposition, total length of stay (LOS), intensive care unit (ICU) LOS, and number of days mechanically ventilated. RESULTS: A total of 5057 patients with sTBI were included in the study. In-hospital mortality for patients with early compared to late ICP monitor placement was 33.6% and 30.4%, respectively (p = 0.049). The incidence of non-routine disposition was 92.6% in the within 6 h group and 94.4% in the late placement group (p = 0.037). Hospital LOS, ICU LOS, and number of days mechanically ventilated were significantly greater in the late ICP monitoring group. Similar results were seen when using a 12-h cutoff for late ICP monitor placement. In the Cox proportional hazards model, craniotomy (HR 1.097, 95% CI 1.037-1.160) and isolated intracranial injury (HR 1.128, 95% CI 1.055-1.207) were associated with early ICP monitor placement. Hypotension was negatively associated with early ICP monitor placement (HR 0.801, 95% CI 0.725-0.884). CONCLUSION: Despite a statistically marginal association between mortality and early ICP monitor placement, most outcomes were superior when ICP monitors were placed within 6 or 12 h of arrival. This may be due to earlier identification and treatment of intracranial hypertension.

Risk Factors and Outcomes Associated with Blunt Cerebrovascular Injury in Patients with Mild or Moderate Traumatic Brain Injury.

BACKGROUND: Blunt cerebrovascular injury (BCVI) represents a spectrum of traumatic injuries to the carotid and vertebral arteries that is an often-overlooked source of morbidity and mortality. Its incidence, risk factors, and effect on outcomes in patients with mild or moderate traumatic brain injury (mTBI) have not been studied independently. METHODS: The National Trauma Data Bank from 2013 to 2017 was queried to identify patients with mTBI who suffered blunt injuries. BCVI was identified using abbreviated injury scores and included blunt carotid artery injury (BCAI) and blunt vertebral artery injury (BVAI). A binary logistic regression was used to identify patient-related and injury-related factors associated with BCVI. Binary logistic regressions were also performed to evaluate the effect of BCVI on stroke, in-hospital mortality, nonroutine discharge disposition, total length of stay (LOS), intensive care unit LOS, and number of days mechanically ventilated. RESULTS: Of 485,880 patients with mTBI, there were 4,382 (0.9%) with BCVI. Cervical spine fracture was the strongest factor associated with BCAI (odds ratio [OR], 1.97; 95% confidence interval [95% CI], 1.77-2.19), followed by mandible fracture and basilar skull fracture. Cervical spine fracture also had the strongest association with BVAI (OR, 18.28; 95% CI, 16.47-20.28), followed by spinal cord injury and neck contusion. Stroke was more common in patients with BCAI (OR, 5.50; 95% CI, 4.19-7.21) and BVAI (OR, 7.238; 95% CI, 5.929-8.836). BVAI increased the odds of mortality, but BCAI did not. Both were associated with nonroutine discharge and increased LOS, intensive care unit LOS, and number of days mechanically ventilated. CONCLUSIONS: The incidence of BCVI in patients with mTBI is low, and it usually does not require invasive treatment. However, it is associated with greater odds of stroke and negative outcomes. Knowledge of risk factors for BCVI may tailor further investigation to aid prompt diagnosis.

Using lectures to identify student misconceptions: a study on the paradoxical effects of hyperkalemia on vascular smooth muscle.

Medical students have difficulty understanding the mechanisms underlying hyperkalemia-mediated local control of blood flow. Such control mechanisms are crucial in the brain, kidney, and skeletal muscle vasculature. We aimed to identify medical students' misconceptions via assessment of students' in-class knowledge and, subsequently, improve future teaching of this concept. In-class polling was performed with the TurningPoint clicker response system (n = 860) to gauge students' understanding of three physiological concepts related to hyperkalemia: membrane potential (Vm), conductance, and smooth muscle response. Vm includes the concepts of equilibrium potential (Veq) for specific ions, as well as driving force (DF = Vm - Veq). Students understood the concept of DF (~70% answered correctly), suggesting their understanding of Vm. However, students misunderstood that hyperkalemia results in depolarization (~52% answered correctly) and leads to an increase in potassium conductance (~31% answered correctly). Clarification of the type of smooth muscle as vascular increased the percentage of correct responses (~51 to 73%). The data indicate that students lacked knowledge of specific potassium conductance in various muscle types, resulting in divergent responses, such as the canonical depolarization in skeletal muscle versus hyperpolarization in smooth muscle cells during hyperkalemia. Misunderstanding of this crucial concept of conductance is directly related to the students' performance. Furthermore, we connected the paradoxical effect of hyperkalemia to pathological acute and chronic hyperkalemia clinical scenarios.

Causes, Predictors, and Trends of Unplanned Readmissions after Elective Endovascular Embolization of Cerebral Aneurysms.

BACKGROUND: 30- and 90-day readmissions (dRA) are being increasingly scrutinized as quality metrics for hospital and provider performances. Little information regarding risk factors for readmission after elective endovascular treatment (EVT) of an unruptured cerebral aneurysm (UCA) is available. METHODS: The Nationwide Readmissions Database was used to identify patients who underwent elective endovascular embolization of an unruptured aneurysm between 2010 and 2014. The primary outcomes of interest were unplanned readmissions occurring within 30 or 90 days of discharge. Binary logistic regressions were used to identify variables related to patients' demographics, comorbidities, and index hospital admission that were associated with 30dRA and 90dRA. RESULTS: A total of 8588 patients met the inclusion criteria for 30dRA analysis and 7289 patients were eligible for 90dRA analysis. The 5-year 30dRA and 90dRA readmission rates were 7.1% and 13.5%, respectively. The annual incidences of 30dRAs and 90dRAs between 2010 and 2014 decreased significantly (pooled odds ratio (OR) for 30dRA: .874, 95% confidence interval (CI) .765-.998; pooled OR for 90dRA: .841, 95% CI .755-.938). Patients in higher income quartiles experienced decreased odds of 30dRA and 90dRA. Nonroutine disposition following the index admission and greater comorbidity burdens were associated with higher likelihoods of both 30dRA and 90dRA. The presence of pulmonary or cardiac complications was associated with increased odds of 90dRA. CONCLUSION: Readmission rates after elective EVT of UCAs decreased between 2010 and 2014. We identified several novel risk factors for both 30dRAs and 90dRAs that can be used to identify patients who are at highest risk of readmission.

Social media and cadaveric dissection: A survey study.

The use of social media opens content to the general public and, as a result, places images of cadaveric dissection in an open forum. This raises the question: should the general public have access to such material? A survey was conducted examining whether the general public should have access to gross cadaveric dissection images and videos for educational purposes via social media. Both medical and laypersons were queried. Questions included in the survey considered whether images were too graphic, whether online cadaveric content should be age-restricted, and whether consent by the deceased was necessary. A link to the survey was accessible to 63,562 followers through the Seattle Science Foundation's Facebookpage for 3 weeks. Among 300 responders, 89% (267/300) agreed that portrayals of cadaveric specimens/dissection on social media should be accessible by the general public for anatomical education, and 84.67% (254/300) stated that cadaveric dissection is not too graphic for untrained eyes. There was agreement by 60.33% (181/300) that an age restriction should be in place for the viewing of cadaveric dissection on social media, and 39.33% (253/300) of responders suggested restriction to 18 years and older. No statistically significant association was noted between a prior or current history of anatomy education and the frequency of positive responses to the survey questions. Social media is an innovative tool for dispensing anatomical education. The use of cadaveric images and videos provides accessibility to the general public who wish to learn more about human anatomy and their own body. Clin. Anat. 32:1033-1041, 2019. © 2019 Wiley Periodicals, Inc.

A Nationwide Analysis of 30-Day and 90-Day Readmissions After Elective Cerebral Aneurysm Clipping in the United States: Causes, Predictors, and Trends.

BACKGROUND: Thirty-day readmissions (30dRAs) and 90-day readmissions (90dRAs) are being increasingly scrutinized as quality metrics for hospital and provider performances. Little information regarding risk factors for 30dRA and 90dRA after elective cerebral aneurysm clipping (CAC) of unruptured cerebral aneurysms is available. We sought to characterize risk factors with a nationally representative administrative database. METHODS: The Nationwide Readmissions Database was used to identify patients who underwent elective CAC between 2010 and 2014. The outcomes of interest were unplanned readmissions occurring within 30 or 90 days of discharge. Binary logistic regression was used to identify variables related to patients' demographics, comorbidities, and index hospital admission that were associated with readmission. A Cochran-Mantel-Haenszel test was used to evaluate for changes in annual readmission rates. RESULTS: A total of 1123 patients met the inclusion criteria for 30dRA analysis and 946 patients were eligible for 90dRA analysis. The 5-year 30dRA and 90dRA readmission rates were 9.1% and 14.9%, respectively. The annual rate of readmission between 2010 and 2014 did not change. Greater Charlson Comorbidity Index (odds ratio [OR], 2.68; 95% confidence interval [CI], 1.14-6.28) and nonroutine discharge after the index admission (OR, 1.81; 95% CI, 1.04-3.14) were associated with greater odds of 30dRA. Charlson Comorbidity Index (OR, 3.45; 95% CI, 1.57-7.56) and treatment at a metropolitan teaching hospital (OR, 2.21; 95% CI, 1.06-4.60) were associated with increased odds of 90dRA. Wound infection was the most common reason for readmission. CONCLUSIONS: Readmission rates after elective CAC remained unchanged between 2010 and 2014, suggesting that improved methods for reducing unplanned readmissions after CAC are needed.

Treatment of Gunshot Wounds to Spine During Late 19th Century.

BACKGROUND: The demand for neurosurgical procedures increased drastically in the late 19th century owing to advances in ballistics during the American Civil War and Crimean War. METHODS AND RESULTS: Surgical care for a gunshot wound to the spine relied on skilled identification and removal of the fractured bone. Hemorrhage control and infection prevention were also imperative for improving survival rates. CONCLUSIONS: Although new techniques were implemented, the mortality rate from spinal injuries during this period was staggering. Nevertheless, those 19th century procedural methods provided the basis for present-day treatment for spinal injury patients.

Review of Treatment of Gunshot Wounds to Head in Late 19th Century.

INTRODUCTION: During the late 19th century, the seeds of modern neurosurgery were planted to bloom into what it is now known. Wars such as the American Civil War and Crimean War drove the need to find better ways of preventing mortality from gunshot wounds to the head. However, the mortality rate from all major surgical procedures to the head, neck, and face remained staggering. Herein, we describe the surgical treatments for head and neck injuries in order to improve our understanding of neurosurgical procedures performed during the late 19th century. METHODS: A literature search was conducted using PubMed and Google Books for available articles pertaining to treatment for gunshot wounds to the head during the 19th century. Search terms included "Gunshot wounds, Treatment, Civil War," "Gunshot wound, Treatment 19th century," and "Gunshot wounds, Treatment, 1800s." Literature was excluded if not in English or if no translation was provided. Most of the information was taken from the International Encyclopedia of Surgery Volume II. RESULTS: Surgical care for gunshot wounds to the cranium were based on depth and involved finding the bullet, controlling the bleeding, and preventing further brain injury. Surgical treatment for a gunshot wound to the face or neck involved controlling the bleeding, with a focus on maintaining the airway. CONCLUSIONS: Because of improved understanding of infectious processes and technologic advances in surgical equipment, the late 19th century was a major milestone in creating modern day neurosurgery. The methodology behind today's treatments is no different from that of the late 19th century.

Evaluation of Metabolic and Synaptic Dysfunction Hypotheses of Alzheimer's Disease (AD): A Meta-Analysis of CSF Markers.

BACKGROUND: Alzheimer's disease (AD) is currently incurable and a majority of investigational drugs have failed clinical trials. One explanation for this failure may be the invalidity of hypotheses focusing on amyloid to explain AD pathogenesis. Recently, hypotheses which are centered on synaptic and metabolic dysfunction are increasingly implicated in AD. OBJECTIVE: Evaluate AD hypotheses by comparing neurotransmitter and metabolite marker concentrations in normal versus AD CSF. METHODS: Meta-analysis allows for statistical comparison of pooled, existing cerebrospinal fluid (CSF) marker data extracted from multiple publications, to obtain a more reliable estimate of concentrations. This method also provides a unique opportunity to rapidly validate AD hypotheses using the resulting CSF concentration data. Hubmed, Pubmed and Google Scholar were comprehensively searched for published English articles, without date restrictions, for the keywords "AD", "CSF", and "human" plus markers selected for synaptic and metabolic pathways. Synaptic markers were acetylcholine, gamma-aminobutyric acid (GABA), glutamine, and glycine. Metabolic markers were glutathione, glucose, lactate, pyruvate, and 8 other amino acids. Only studies that measured markers in AD and controls (Ctl), provided means, standard errors/deviation, and subject numbers were included. Data were extracted by six authors and reviewed by two others for accuracy. Data were pooled using ratio of means (RoM of AD/Ctl) and random effects meta-analysis using Cochrane Collaboration's Review Manager software. RESULTS: Of the 435 identified publications, after exclusion and removal of duplicates, 35 articles were included comprising a total of 605 AD patients and 585 controls. The following markers of synaptic and metabolic pathways were significantly changed in AD/controls: acetylcholine (RoM 0.36, 95% CI 0.24-0.53, p<0.00001), GABA (0.74, 0.58-0.94, p<0.01), pyruvate (0.48, 0.24-0.94, p=0.03), glutathione (1.11, 1.01- 1.21, p=0.03), alanine (1.10, 0.98-1.23, p=0.09), and lower levels of significance for lactate (1.2, 1.00-1.47, p=0.05). Of note, CSF glucose and glutamate levels in AD were not significantly different than that of the controls. CONCLUSION: This study provides proof of concept for the use of meta-analysis validation of AD hypotheses, specifically via robust evidence for the cholinergic hypothesis of AD. Our data disagree with the other synaptic hypotheses of glutamate excitotoxicity and GABAergic resistance to neurodegeneration, given observed unchanged glutamate levels and decreased GABA levels. With regards to metabolic hypotheses, the data supported upregulation of anaerobic glycolysis, pentose phosphate pathway (glutathione), and anaplerosis of the tricarboxylic acid cycle using glutamate. Future applications of meta-analysis indicate the possibility of further in silico evaluation and generation of novel hypotheses in the AD field.

A Rare Case of Double-Headed Psoas Minor Muscle with Review of its Known Variants.

Variations of the muscles of humans are important to remember for those who interpret imaging and for those who operate near these anomalies. Herein, we describe a rare two-headed psoas minor muscle found incidentally during dissection of the posterior abdominal wall. This case is presented with a detailed review of all known variations of the minor psoas and is analyzed through a literature review.

Cervical Spine Aneurysmal Bone Cysts in the Pediatric Population: A Systematic Review of the Literature.

Cervical spine aneurysmal bone cysts (ABCs) in pediatric patients have not been thoroughly studied. Using PubMed and Google Scholar, a systematic review of the literature was conducted for publications that included patients aged ≤15 years with a confirmed diagnosis of ABC in the cervical spine. Thirty-five studies with a total of 71 patients met the inclusion criteria. Nearly 80% of patients presented with neck or shoulder pain. The axis was the level most frequently involved (34.28%), followed by C5 (24.28%). Posterior elements were most likely to be affected (88.46%) while exclusive involvement of the body was uncommon. To our knowledge, this is the first systematic review of the literature regarding ABCs of the cervical spine in a pediatric population. Spinal ABCs are rarely found in the cervical region, and their treatment remains challenging due to their location, vascularization, and a high overall recurrence rate even with surgical resection.