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 pathology which has had less than 250 reported cases since its initial description in 1830. The condition is currently limited to Level V Evidence, limiting the ability for surgeons to characterize and treat this condition.

OBJECTIVE

To report two cases of ISCAs and their surgical management: a fifty-nine-year-old female who presented with progressive right hemiparesis and a sixty-nine-year-old male 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 was screened for case reports. A logistic regression (LR) model was fit 100 times on data to retrieve predictor odds ratios.

RESULTS

200 case reports of ISCA were identified between the years of 1965 and 2022. LR determined the only variables of significance were age (p < 0.01) and antibiotics (p < 0.05).

CONCLUSION

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.

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 (V_m), conductance, and smooth muscle response. V_m includes the concepts of equilibrium potential (V_eq) for specific ions, as well as driving force (DF = V_m - V_eq). Students understood the concept of DF (~70% answered correctly), suggesting their understanding of V_m. 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.

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.

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.