Association between interhospital transfer and increased in-hospital mortality in patients with spinal epidural abscesses.

BACKGROUND CONTEXT: Spinal epidural abscess (SEA) is an uncommon yet serious infection, associated with significant morbidity and mortality. Patients diagnosed with SEA often require surgical interventions or critical care services that are not available at community hospitals and are therefore transferred to tertiary care centers. Little is known about the effects of interhospital transfer on acute outcomes for patients with SEA. PURPOSE: To study the effects of interhospital transfer on acute outcomes for patients with SEA. STUDY DESIGN: Cross sectional analysis using the 2009 to 2017 National Inpatient Sample (NIS). PATIENT SAMPLE: Using the 2009 to 2017 NIS, we identified cases of SEA using ICD, Ninth, or Tenth Revision diagnosis codes 324.1 & G06.1. OUTCOME MEASURES: Our primary endpoint was in hospital mortality. METHODS: The association between interhospital transfer and inpatient mortality was assessed using multivariable logistic regression to adjust for potential covariates. Patient and hospital factors associated with interhospital transfer were assessed in a secondary analysis. RESULTS: A total of 21.5% of patient with SEA were treated after transfer from another hospital. After adjusting for covariates, those who presented after transfer had higher odds of death during hospitalization (OR: 1.51, 95% CI 1.27-1.78, p<.001). Transferred patients were significantly more likely to live in rural communities (11.4 % vs. 5.3 % for nontransferred patients). CONCLUSIONS: Interhospital transfer, which occurred more frequently in patients from rural hospitals, was associated with death even after controlling for disease severity. Addressing healthcare delivery disparities across the US, including across the rural-urban spectrum, will require better understanding of the observed increased mortality of interhospital transfer as a preventable source of in-hospital mortality for SEA.

Racial Disparities in Outcomes After Spine Surgery: A Systematic Review and Meta-Analysis.

OBJECTIVE: Racial disparities are a major issue in health care but the overall extent of the issue in spinal surgery outcomes is unclear. We conducted a systematic review/meta-analysis of disparities in outcomes among patients belonging to different racial groups who had undergone surgery for degenerative spine disease. METHODS: We searched Ovid MEDLINE, Scopus, Cochrane Review Database, and ClinicalTrials.gov from inception to January 20, 2021 for relevant articles assessing outcomes after spine surgery stratified by race. We included studies that compared outcomes after spine surgery for degenerative disease among different racial groups. RESULTS: We found 30 studies that met our inclusion criteria (28 articles and 2 published abstracts). We included data from 20 cohort studies in our meta-analysis (3,501,830 patients), which were assessed to have a high risk of observation/selection bias. Black patients had a 55% higher risk of dying after spine surgery compared with white patients (relative risk [RR], 1.55, 95% confidence interval [CI], 1.28-1.87; I2 = 70%). Similarly, black patients had a longer length of stay (mean difference, 0.93 days; 95% CI, 0.75-1.10; I2 = 73%), and higher risk of nonhome discharge (RR, 1.63; 95% CI, 1.47-1.81; I2 = 89%), and 30-day readmission (RR, 1.45; 95% CI, 1.03-2.04; I2 = 96%). No significant difference was noted in the pooled analyses for complication or reoperation rates. CONCLUSIONS: Black patients have a significantly higher risk of unfavorable outcomes after spine surgery compared with white patients. Further work in understanding the reasons for these disparities will help develop strategies to narrow the gap among the racial groups.

Deep Brain Stimulation for Memory Modulation: A New Frontier.

BACKGROUND: In the coming years the number of patients with cognitive disorders, such as Alzheimer disease and traumatic brain injury, is expected to dramatically increase, leading to an ever-increasing societal cost. Unfortunately, few medical and pharmacologic treatments have shown tangible benefit in the treatment of these diseases. Deep brain stimulation (DBS) is an established surgical technique to address multiple conditions, including Parkinson disease and essential tremor. Data from patients being treated with DBS, as well as those being monitored for seizures with depth electrodes, have suggested improvement in memory with electrical neuromodulation. METHODS: MEDLINE was searched from inception through March 2018 using the keywords "DBS," "Deep Brain Stimulation," "Memory," "Memory Modulation," and "Cognition." Studies evaluating the effect of DBS on memory and learning were shortlisted and reviewed. RESULTS: Efforts to stimulate various nodes within the memory circuitry suggest that the variable effects may result from different mechanisms, including alteration of neural firing patterns, increased activity across several regions, and amplification of neural plasticity. Some of these targets, such as the entorhinal cortex, hippocampus, and nucleus basalis of Meynert, have shown promising results with regards to modulation of memory. CONCLUSIONS: Given the aging population and increasing numbers of patients with memory impairment from neurodegenerative diseases, interest in neuromodulation for memory enhancement will likely expand. Further work should employ more sophisticated responsive stimulation parameters and precise spatial targeting that may lead to an effective stimulation strategy for memory enhancement.

False Localization of Ruptured Intracranial Dermoid Secondary to Subarachnoid Spread of Cyst Contents.

A 34-year-old right-handed female presented to the emergency department with a worsening headache, neck stiffness, intermittent abnormal sensation, and right arm weakness. Shortly after arrival, she had a generalized tonic-clonic seizure. A noncontrast head computed tomography scan revealed a right-sided, low-attenuating, lobulated mass ipsilateral to her arm symptoms. Magnetic resonance imaging revealed an abnormal signal throughout the subarachnoid space and increased fluid-attenuated inversion recovery sequence signal contralateral to the mass. This presentation suggested a false localization sign of sensory and motor disturbance ipsilateral to the mass likely caused by cyst rupture and sebum spread contralateral, causing cortical irritation (evidenced by increased fluid-attenuated inversion recovery sequence signal). During mass resection, sebum was visible throughout the subarachnoid space. The patient had an uneventful recovery from surgery and has been seizure free since the resection with steady improvement of symptoms. This case highlights the importance of avoiding cyst rupture of dermoid cysts.

Treatment of intracerebral hemorrhage: a selective review and future directions.

Intracerebral hemorrhage (ICH) is a devastating disease. Sixty percent of survivors do not function independently at one year. Treatment of ICH costs approximately US$ 12.7 billion annually. To date no intervention has demonstrated clear efficacy in improving outcomes. The goal of this selective review is to provide an understanding of current treatment and discuss future directions. After a discussion of pathophysiology and societal impact, a synopsis of treatment options is reviewed, including: 1) open craniotomy; 2) catheter-based thrombolytic therapy; 3) endoscopic evacuation; and 4) ultrasonic lysis. Amongst other studies, we will discuss the results of STICH (International Surgical Trial in ICH) and MISTIE (Minimally Invasive Surgery plus Recombinant Tissue-type Plasminogen Activator for ICH Evacuation). We hope to provide a succinct, pragmatic review for the neurosurgical community on the current state of therapy and encourage novel ways to aggressively treat this burdensome disease.

Point-of-View Recording Devices for Intraoperative Neurosurgical Video Capture.

INTRODUCTION: The ability to record and stream neurosurgery is an unprecedented opportunity to further research, medical education, and quality improvement. Here, we appraise the ease of implementation of existing point-of-view devices when capturing and sharing procedures from the neurosurgical operating room and detail their potential utility in this context. METHODS: Our neurosurgical team tested and critically evaluated features of the Google Glass and Panasonic HX-A500 cameras, including ergonomics, media quality, and media sharing in both the operating theater and the angiography suite. RESULTS: Existing devices boast several features that facilitate live recording and streaming of neurosurgical procedures. Given that their primary application is not intended for the surgical environment, we identified a number of concrete, yet improvable, limitations. CONCLUSION: The present study suggests that neurosurgical video capture and live streaming represents an opportunity to contribute to research, education, and quality improvement. Despite this promise, shortcomings render existing devices impractical for serious consideration. We describe the features that future recording platforms should possess to improve upon existing technology.

Intraarterial administration of norcantharidin attenuates ischemic stroke damage in rodents when given at the time of reperfusion: novel uses of endovascular capabilities.

OBJECT Matrix metalloprotease-9 (MMP-9) plays a critical role in infarct progression, blood-brain barrier (BBB) disruption, and vasogenic edema. While systemic administration of MMP-9 inhibitors has shown neuroprotective promise in ischemic stroke, there has been little effort to incorporate these drugs into endovascular modalities. By modifying the rodent middle cerebral artery occlusion (MCAO) model to allow local intraarterial delivery of drugs, one has the ability to mimic endovascular delivery of therapeutics. Using this model, the authors sought to maximize the protective potential of MMP-9 inhibition by intraarterial administration of an MMP-9 inhibitor, norcantharidin (NCTD). METHODS Spontaneously hypertensive rats were subjected to 90-minute MCAO followed immediately by local intraarterial administration of NCTD. The rats' neurobehavioral performances were scored according to the ladder rung walking test results and the Garcia neurological test for as long as 7 days after stroke. MRI was also conducted 24 hours after the stroke to assess infarct volume and BBB disruption. At the end of the experimental protocol, rat brains were used for active MMP-9 immunohistochemical analysis to assess the degree of MMP-9 inhibition. RESULTS NCTD-treated rats showed significantly better neurobehavioral scores for all days tested. MR images also depicted significantly decreased infarct volumes and BBB disruption 24 hours after stroke. Inhibition of MMP-9 expression in the ischemic region was depicted on immunohistochemical analysis, wherein treated rats showed decreased active MMP-9 staining compared with controls. CONCLUSIONS Intraarterial NCTD significantly improved outcome when administered at the time of reperfusion in a spontaneously hypertensive rat stroke model. This study suggests that supplementing endovascular revascularization with local neuroprotective drug therapy may be a viable therapeutic strategy.

Intracerebral Hemorrhage: A Common and Devastating Disease in Need of Better Treatment.

OBJECTIVE: To review the poor natural history of intracerebral hemorrhage (ICH), current treatment options for ICH, discuss ongoing trials evaluating minimally invasive techniques for clot evacuation, and offer future directions of investigation for the management of this devastating disease. METHODS: A selective review of recent trials regarding treatment of ICH was performed. RESULTS: Completed trials of medical and surgical management are reviewed. The supportive research for clot evacuation to limit secondary injury is surveyed. We also provide a comprehensive discussion of current data evaluating minimally invasive techniques to achieve clot removal, including Minimally Invasive Surgery plus tPA for ICH Evacuation (MISTIE), Clot Lysis: Evaluating Accelerated Resolution (CLEAR), and endoscopic evacuation. CONCLUSION: We encourage the neurosurgical community to pursue improved therapies for ICH. PRACTICE: New minimally invasive treatments for ICH are being developed. IMPLICATIONS: Treatment of ICH is an important area of research and should continue to be aggressively pursued because of the significant societal burden and poor outcomes associated with ICH.

Imaging of amide proton transfer and nuclear Overhauser enhancement in ischemic stroke with corrections for competing effects.

Chemical exchange saturation transfer (CEST) potentially provides the ability to detect small solute pools through indirect measurements of attenuated water signals. However, CEST effects may be diluted by various competing effects, such as non-specific magnetization transfer (MT) and asymmetric MT effects, water longitudinal relaxation (T1 ) and direct water saturation (radiofrequency spillover). In the current study, CEST images were acquired in rats following ischemic stroke and analyzed by comparing the reciprocals of the CEST signals at three different saturation offsets. This combined approach corrects the above competing effects and provides a more robust signal metric sensitive specifically to the proton exchange rate constant. The corrected amide proton transfer (APT) data show greater differences between the ischemic and contralateral (non-ischemic) hemispheres. By contrast, corrected nuclear Overhauser enhancements (NOEs) around -3.5 ppm from water change over time in both hemispheres, indicating whole-brain changes that have not been reported previously. This study may help us to better understand the contrast mechanisms of APT and NOE imaging in ischemic stroke, and may also establish a framework for future stroke measurements using CEST imaging with spillover, MT and T1 corrections.

Surgical management of large scalp infantile hemangiomas.

BACKGROUND: Infantile Hemangiomas (IH) are the most common benign tumor of infancy, occurring in over 10% of newborns. While most IHs involute and never require intervention, some scalp IHs may cause severe cosmetic deformity and threaten tissue integrity that requires surgical excision. CASE DESCRIPTION: We present our experience with two infants who presented with large scalp IH. After vascular imaging, the patients underwent surgical resection of the IH and primary wound closure with excellent cosmetic outcome. We detail the surgical management of these cases and review the relevant literature. CONCLUSION: In some cases the IHs leave behind fibro-fatty residuum causing contour deformity. Surgery is often required for very large lesions causing extensive anatomical and/or functional disruption. The goal of surgical intervention is to restore normal anatomic contour and shape while minimizing the size of the permanent scar.

Resolution of trigeminal neuralgia by coil embolization of a persistent primitive trigeminal artery aneurysm.

The persistent primitive trigeminal artery (PTA) is a rare anastomosis between the carotid artery and basilar artery. While most PTAs are asymptomatic, lateral variants can occasionally compress the trigeminal nerve and precipitate trigeminal neuralgia. Aneurysms of the PTA are exceptionally rare in the literature and have not previously been associated with trigeminal neuralgia. We present the first case of an aneurysm of the PTA causing trigeminal neuralgia. The patient underwent coil embolization of the aneurysm which relieved her symptoms. We propose embolization as a viable therapeutic option for the resolution of trigeminal neuralgia when the condition is secondary to irritation by the high velocity pulsatile flow of an aneurysm.

Prototyping of cerebral vasculature physical models.

BACKGROUND: Prototyping of cerebral vasculature models through stereolithographic methods have the ability to accurately depict the 3D structures of complicated aneurysms with high accuracy. We describe the method to manufacture such a model and review some of its uses in the context of treatment planning, research, and surgical training. METHODS: We prospectively used the data from the rotational angiography of a 40-year-old female who presented with an unruptured right paraclinoid aneurysm. The 3D virtual model was then converted to a physical life-sized model. RESULTS: The model constructed was shown to be a very accurate depiction of the aneurysm and its associated vasculature. It was found to be useful, among other things, for surgical training and as a patient education tool. CONCLUSION: With improving and more widespread printing options, these models have the potential to become an important part of research and training modalities.

Inverse Z-spectrum analysis for spillover-, MT-, and T1 -corrected steady-state pulsed CEST-MRI--application to pH-weighted MRI of acute stroke.

Endogenous chemical exchange saturation transfer (CEST) effects are always diluted by competing effects, such as direct water proton saturation (spillover) and semi-solid macromolecular magnetization transfer (MT). This leads to unwanted T2 and MT signal contributions that lessen the CEST signal specificity to the underlying biochemical exchange processes. A spillover correction is of special interest for clinical static field strengths and protons resonating near the water peak. This is the case for all endogenous CEST agents, such as amide proton transfer, -OH-CEST of glycosaminoglycans, glucose or myo-inositol, and amine exchange of creatine or glutamate. All CEST effects also appear to be scaled by the T1 relaxation time of water, as they are mediated by the water pool. This forms the motivation for simple metrics that correct the CEST signal. Based on eigenspace theory, we propose a novel magnetization transfer ratio (MTRRex ), employing the inverse Z-spectrum, which eliminates spillover and semi-solid MT effects. This metric can be simply related to Rex , the exchange-dependent relaxation rate in the rotating frame, and ka , the inherent exchange rate. Furthermore, it can be scaled by the duty cycle, allowing for simple translation to clinical protocols. For verification, the amine proton exchange of creatine in solutions with different agar concentrations was studied experimentally at a clinical field strength of 3 T, where spillover effects are large. We demonstrate that spillover can be properly corrected and that quantitative evaluation of pH and creatine concentration is possible. This proves that MTRRex is a quantitative and biophysically specific CEST-MRI metric. Applied to acute stroke induced in rat brain, the corrected CEST signal shows significantly higher contrast between the stroke area and normal tissue, as well as less B1 dependence, than conventional approaches.

Endovascular thrombolysis for pediatric cerebral sinus venous thrombosis with tissue plasminogen activator and abciximab.

Cerebral sinus venous thrombosis (CSVT) is a relatively rare but potentially devastating disease. Medical management of CSVT with systemic anticoagulation has been the mainstay treatment strategy with these patients. However, some patients may not respond to this treatment or may present with very severe symptoms indicating more aggressive management strategies. The authors present the case of a pediatric patient who presented with severe CSVT, who underwent successful recanalization with endovascular tissue plasminogen activator (tPA) and abciximab. To the authors' knowledge there are no cases of endovascular thrombolysis for CSVT described in the literature in which abciximab has been used in conjunction with tPA. The authors also review the literature regarding the agents used and outcome in pediatric patients with CSVT after endovascular thrombolysis. The use of abciximab in conjunction with tPA may be considered in patients whose blood is hypercoagulable and in whom the treatment strategy is to obtain acute recanalization and long-term venous patency. However, the use of adjunctive agents increases the risk of hemorrhagic complications and must be done judiciously.

Resolution of trigeminal neuralgia by coil embolization of a persistent primitive trigeminal artery aneurysm.

The persistent primitive trigeminal artery (PTA) is a rare anastomosis between the carotid artery and basilar artery. While most PTAs are asymptomatic, lateral variants can occasionally compress the trigeminal nerve and precipitate trigeminal neuralgia. Aneurysms of the PTA are exceptionally rare in the literature and have not previously been associated with trigeminal neuralgia. We present the first case of an aneurysm of the PTA causing trigeminal neuralgia. The patient underwent coil embolization of the aneurysm which relieved her symptoms. We propose embolization as a viable therapeutic option for the resolution of trigeminal neuralgia when the condition is secondary to irritation by the high velocity pulsatile flow of an aneurysm.

The role of the CXCR4 cell surface chemokine receptor in glioma biology.

CXCR4, a cell surface chemokine receptor, mediates cellular dissemination, invasion, and proliferation in a wide range of cancers including gliomas. It is over-expressed in glioma progenitor cells, and its protein ligand, CXCL12, has been shown to mediate a specific proliferative response in these cells thereby implicating a role for CXCR4 in glioma initiation and renewal. Given the failure of currently employed therapies to meaningfully impact prognosis in patients with high-grade gliomas, the CXCR4-CXCL12 axis represents a novel biologically relevant mechanism that could be specifically targeted for therapy. From this perspective, this review summarizes the biological effects of CXCR4 activity and its implications for glioma pathogenesis. Ultimately, the development of effective treatment approaches for malignant glioma must be based on a rational mechanistic understanding of tumor cell biology. As such, this article presents such a framework with regard to the CXCR4 pathway in glioma thereby supporting the further investigation of CXCR4 as a therapeutic target in patients with this disease.

Primary calvarial angiosarcoma: A case report and review of the literature.

BACKGROUND: Angiosarcomas are high-grade endothelial tumors remarkable for their rarity and malignant behavior. Primary calvarial angiosarcoma is an extremely rare entity and its behavior usually sets it apart from other angiosarcoma types. We highlight the successful management of cranial angiosarcoma using a multidisciplinary approach. CASE DESCRIPTION: We present a 16-year-old male who was first noted to have a right-sided parietal cranial mass that was biopsied in 2008. Pathology was initially thought to be Kaposiform hemangioendothelioma. The patient subsequently underwent chemotherapy with vincristine. The patient did well until early 2010, when he suffered a right-sided intraparenchymal intratumoral hemorrhage. At this time, the original pathologic diagnosis was revisited and the diagnosis was upgraded to an angiosarcoma. The patient underwent a second round of chemotherapy using vincristine, cyclophosphamide, and actinomycin. The tumor continued to progress despite this treatment and he developed extensive skull deformity. At this point more definitive surgical intervention was reconsidered. Preoperative embolization of the mass was performed followed by aggressive surgical resection of the bony disease. The patient tolerated the procedure well and was discharged 6 days postoperatively without any new deficits. The patient is currently in the process of completing radiation therapy to entire tumor bed. He has clinically done well with no neurologic deterioration and has demonstrated long-term survival (>3 years). CONCLUSION: With the combined efforts of pediatric oncology, radiation oncology, interventional neuroradiology, and neurosurgery, a survival of greater than 3 years is possible with this aggressive pathology.

XDR tuberculosis and the Indian-subcontinent: effective prevention strategies needed.

The Indian-subcontinent is becoming, what could be, the next big battle ground for the control of Extensively Drug Resistant Tuberculosis (XDR-TB). The region caters to not only an ever-increasing incidence of new TB cases, but also a huge burden of already existing TB cases, thereby facing a dual threat for spread of XDR-TB. Most of the health-care facilities are devoid of essential laboratory-based infra-structure which is essential for diagnosing XDR-TB. Coupled to this is the lack of knowledge regarding TB diagnosis and treatment amongst the General Practitioners of India and Pakistan, who still treat the bulk of the TB cases. The element of AIDS is also slowly creeping into the equation. Questions have already been raised about the effectiveness of the governmental responses to curb the TB threat. What is needed right away is an effective strategy, incorporating a broad-tiered approach between the government and social sector. This can facilitate greatly in preventing further spread of these resistant strains.