330 results on '"William J. Mack"'
Search Results
2. Combined open revascularization and endovascular treatment of complex intracranial aneurysms: case series
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Robert C. Rennert, Vincent N. Nguyen, Aidin Abedi, Nadia A. Atai, Joseph N. Carey, Matthew Tenser, Arun Amar, William J. Mack, and Jonathan J. Russin
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cerebral revascularization ,bypass ,aneurysm ,neuroendovascular approach ,embolization ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Background and purposeThe treatment of complex intracranial aneurysms can be challenging with stand-alone open or endovascular techniques, particularly after rupture. A combined open and endovascular strategy can potentially limit the risk of extensive dissections with open-only techniques, and allow for aggressive definitive endovascular treatments with minimized downstream ischemic risk.Materials and methodsRetrospective, single-institution review of consecutive patients undergoing combined open revascularization and endovascular embolization/occlusion for complex intracranial aneurysms from 1/2016 to 6/2022.ResultsTen patients (4 male [40%]; mean age 51.9 ± 8.7 years) underwent combined open revascularization and endovascular treatment of intracranial aneurysms. The majority of aneurysms, 9/10 (90%), were ruptured and 8/10 (80%) were fusiform in morphology. Aneurysms of the posterior circulation represented 8/10 (80%) of the cases (vertebral artery [VA] involving the posterior inferior cerebellar artery [PICA] origin, proximal PICA or anterior inferior cerebellar artery/PICA complex, or proximal posterior cerebral artery). Revascularization strategies included intracranial-to-intracranial (IC-IC; 7/10 [70%]) and extracranial-to-intracranial (EC-IC; 3/10 [30%]) constructs, with 100% postoperative patency. Initial endovascular procedures (consisting of aneurysm/vessel sacrifice in 9/10 patients) were performed early after surgery (0.7 ± 1.5 days). In one patient, secondary endovascular vessel sacrifice was performed after an initial sub-occlusive embolization. Treatment related strokes were diagnosed in 3/10 patients (30%), largely from involved or nearby perforators. All bypasses with follow-up were patent (median 14.0, range 4–72 months). Good outcomes (defined as a Glasgow Outcomes Scale ≥4 and modified Rankin Scale ≤2) occurred in 6/10 patients (60%).ConclusionA variety of complex aneurysms not amenable to stand-alone open or endovascular techniques can be successfully treated with combined open and endovascular approaches. Recognition and preservation of perforators is critical to treatment success.
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- 2023
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3. Air Pollution Particulate Matter Amplifies White Matter Vascular Pathology and Demyelination Caused by Hypoperfusion
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Mikko T. Huuskonen, Qinghai Liu, Krista Lamorie-Foote, Kristina Shkirkova, Michelle Connor, Arati Patel, Axel Montagne, Hans Baertsch, Constantinos Sioutas, Todd E. Morgan, Caleb E. Finch, Berislav V. Zlokovic, and William J. Mack
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air pollution ,blood brain barrier ,hypoperfusion ,MRI ,carotid artery stenosis ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Cerebrovascular pathologies are commonly associated with dementia. Because air pollution increases arterial disease in humans and rodent models, we hypothesized that air pollution would also contribute to brain vascular dysfunction. We examined the effects of exposing mice to nanoparticulate matter (nPM; aerodynamic diameter ≤200 nm) from urban traffic and interactions with cerebral hypoperfusion. C57BL/6 mice were exposed to filtered air or nPM with and without bilateral carotid artery stenosis (BCAS) and analyzed by multiparametric MRI and histochemistry. Exposure to nPM alone did not alter regional cerebral blood flow (CBF) or blood brain barrier (BBB) integrity. However, nPM worsened the white matter hypoperfusion (decreased CBF on DSC-MRI) and exacerbated the BBB permeability (extravascular IgG deposits) resulting from BCAS. White matter MRI diffusion metrics were abnormal in mice subjected to cerebral hypoperfusion and worsened by combined nPM+BCAS. Axonal density was reduced equally in the BCAS cohorts regardless of nPM status, whereas nPM exposure caused demyelination in the white matter with or without cerebral hypoperfusion. In summary, air pollution nPM exacerbates cerebrovascular pathology and demyelination in the setting of cerebral hypoperfusion, suggesting that air pollution exposure can augment underlying cerebrovascular contributions to cognitive loss and dementia in susceptible elderly populations.
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- 2021
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4. Hemoglobin and mean platelet volume predicts diffuse T1-MRI white matter volume decrease in sickle cell disease patients
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Soyoung Choi, Adam M. Bush, Matthew T. Borzage, Anand A. Joshi, William J. Mack, Thomas D. Coates, Richard M. Leahy, and John C. Wood
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Computer applications to medicine. Medical informatics ,R858-859.7 ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Sickle cell disease (SCD) is a life-threatening genetic condition. Patients suffer from chronic systemic and cerebral vascular disease that leads to early and cumulative neurological damage. Few studies have quantified the effects of this disease on brain morphometry and even fewer efforts have been devoted to older patients despite the progressive nature of the disease. This study quantifies global and regional brain volumes in adolescent and young adult patients with SCD and racially matched controls with the aim of distinguishing between age related changes associated with normal brain maturation and damage from sickle cell disease.T1 weighted images were acquired on 33 clinically asymptomatic SCD patients (age=21.3±7.8; F=18, M=15) and 32 racially matched control subjects (age=24.4±7.5; F=22, M=10). Exclusion criteria included pregnancy, previous overt stroke, acute chest, or pain crisis hospitalization within one month. All brain volume comparisons were corrected for age and sex.Globally, grey matter volume was not different but white matter volume was 8.1% lower (p=0.0056) in the right hemisphere and 6.8% (p=0.0068) in the left hemisphere in SCD patients compared with controls. Multivariate analysis retained hemoglobin (β=0.33; p=0.0036), sex (β=0.35; p=0.0017) and mean platelet volume (β=0.27; p=0.016) as significant factors in the final prediction model for white matter volume for a combined r2 of 0.37 (p
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- 2017
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5. TARGET® Intracranial Aneurysm Coiling Prospective Multicenter Registry: Final Analysis of Peri-Procedural and Long-Term Safety and Efficacy Results
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Osama O. Zaidat, Alicia C. Castonguay, Ansaar T. Rai, Aamir Badruddin, William J. Mack, Amer K. Alshekhlee, Qaisar A. Shah, Syed I. Hussain, Mouhammed R. Kabbani, Ketan R. Bulsara, Asif M. Taqi, Vallabh Janardhan, Mary S. Patterson, Brittany L. Nordhaus, Lucas Elijovich, and Ajit S. Puri
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aneurysm ,coiling ,ruptured aneurysm ,occlusion ,target coils ,target registry ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Background and Purpose: To describe the final results of the TARGET Registry, a multicenter, real-world study of patients with intracranial aneurysms treated with new generation TARGET Coils.Methods: The TARGET Registry is a prospective, single-arm study with independent medical event monitoring and core-lab adjudication. Patients with de novo intracranial aneurysms were embolized with either TARGET-360° or helical coils in 12 US centers. The primary outcome was aneurysm packing density (PD), which was assessed immediately post-procedure. The secondary outcomes were immediate and long-term aneurysm occlusion rate using the Raymond Scale, and independent functional outcome using the modified Rankin Scale (mRS). A secondary analysis investigated the influence of the use of 100% 360-complex coils on clinical and angiographic outcomes.Results: 148 patients with 157 aneurysms met the inclusion and exclusion criteria. 58 (39.2%) patients with ruptured and 90 (61.8%) with unruptured aneurysms were treated using TARGET 360°, helical Coils, or both. Median age was 58.3 (IQR 48.1–67.4), 73% female, and 71.6% were Caucasian. Median follow-up time was 5.9 (IQR 4.0–6.9) months. The majority were treated with TARGET 360-coils (63.7%), followed by mixed and helical coils only. Peri-procedural morbidity and mortality was seen in 2.7% of patients. A good outcome at discharge (mRS 0–2) was seen in 89.9% of the full cohort, and in 84.5 and 93.3% in the ruptured and unruptured patients, respectively. The median packing density was 28.8% (IQR 20.3–41.1). Long-term complete and near complete occlusion rate was seen in 90.4% of aneurysms and complete obliteration was seen in 66.2% of the aneurysms. No significant difference in clinical and angiographic outcomes were noted between the pure 360-complex coiling vs. mixed 360-complex/Helical coiling strategies. In a multivariate analysis, predictors for long-term aneurysm occlusion were aneurysm location, immediate occlusion grade, and aneurysm size. The long-term independent functional outcome was achieved in 128/135 (94.8%) patients and all-cause mortality was seen in 3/148 (2%) patients.Conclusion: In the multicenter TARGET Registry, two-thirds of aneurysms achieved long-term complete occlusion and 91.0% achieved complete or near complete occlusion with excellent independent functional outcome.Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT01748903
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- 2019
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6. Variability in Criteria for Emergency Medical Services Routing of Acute Stroke Patients to Designated Stroke Center Hospitals
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Nikolay Dimitrov, William Koenig, Nichole Bosson, Sarah Song, Jeffrey L. Saver, William J. Mack, and Nerses Sanossian
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Medicine ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Introduction: Comprehensive stroke systems of care include routing to the nearest designated stroke center hospital, bypassing non-designated hospitals. Routing protocols are implemented at the state or county level and vary in qualification criteria and determination of destination hospital. We surveyed all counties in the state of California for presence and characteristics of their prehospital stroke routing protocols. Methods: Each county’s local emergency medical services agency (LEMSA) was queried for the presence of a stroke routing protocol. We reviewed these protocols for method of stroke identification and criteria for patient transport to a stroke center. Results: Thirty-three LEMSAs serve 58 counties in California with populations ranging from 1,175 to nearly 10 million. Fifteen LEMSAs (45%) had stroke routing protocols, covering 23 counties (40%) and 68% of the state population. Counties with protocols had higher population density (1,500 vs. 140 persons per square mile). In the six counties without designated stroke centers, patients meeting criteria were transported out of county. Stroke identification in the field was achieved using the Cincinnati Prehospital Stroke Screen in 72%, Los Angeles Prehospital Stroke Screen in 7% and a county-specific protocol in 22%. Conclusion: California EMS prehospital acute stroke routing protocols cover 68% of the state population and vary in characteristics including activation by symptom onset time and destination facility features, reflecting matching of system design to local geographic resources.
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- 2015
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7. Trends in Transient Ischemic Attack Hospitalizations in the United States
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Lucas Ramirez, May A. Kim‐Tenser, Nerses Sanossian, Steven Cen, Ge Wen, Shuhan He, William J. Mack, and Amytis Towfighi
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hospitalization ,Nationwide Inpatient Sample ,transient ischemic attack ,trends ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Background Transient ischemic attack (TIA) is a major predictor of subsequent stroke. No study has assessed nation‐wide trends in hospitalization for TIA in the United States. Methods and Results Temporal trends in hospitalization for TIA (International Classification of Diseases, Ninth Revision code 435.0–435.9) from 2000 to 2010 were assessed among adults aged ≥25 years using the Nationwide Inpatient Sample. Age‐, sex‐, and race/ethnic‐specific TIA hospitalization rates were calculated using the weighted number of hospitalizations as the numerator and the US population as the denominator. Age‐adjusted rates were standardized to the 2000 US Census population. From 2000 to 2010, age‐adjusted TIA hospitalization rates decreased from 118 to 83 per 100 000 (overall rate reduction, −29.7%). Age‐specific TIA hospitalization rates increased for individuals aged 24 to 44 years (10–11 per 100 000), but decreased for individuals aged 45 to 64 (74 to 65 per 100 000), 65 to 84 (398 to 245 per 100 000), and ≥85 years (900 to 619 per 100 000). Blacks had the highest age‐adjusted yearly hospitalization rates, followed by Hispanics and whites (124, 82, and 67 per 100 000 in 2010). Rates slightly increased for blacks, but decreased for Hispanics and whites. Compared to women, age‐adjusted TIA hospitalization rates were lower and declined more steeply in men (132 to 89 per 100 000 versus 134 to 97 per 100 000). Conclusions Although overall TIA hospitalizations have decreased in the United States, the reduction has been more pronounced among older individuals, men, whites, and Hispanics. These findings highlight the need to target risk‐factor control among women, blacks, and individuals aged
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- 2016
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8. Trends in Acute Ischemic Stroke Hospitalizations in the United States
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Lucas Ramirez, May A. Kim‐Tenser, Nerses Sanossian, Steven Cen, Ge Wen, Shuhan He, William J. Mack, and Amytis Towfighi
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acute ischemic stroke ,hospitalization ,nationwide inpatient sample ,stroke ,trends ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
BackgroundPopulation‐based studies have revealed declining acute ischemic stroke (AIS) hospitalization rates in the United States, but no study has assessed recent temporal trends in race/ethnic‐, age‐, and sex‐specific AIS hospitalization rates. Methods and ResultsTemporal trends in hospitalization for AIS from 2000 to 2010 were assessed among adults ≥25 years using the Nationwide Inpatient Sample. Age‐, sex‐, and race/ethnic‐specific and age‐adjusted stroke hospitalization rates were calculated using the weighted number of hospitalizations and US census data. From 2000 to 2010, age‐adjusted stroke hospitalization rates decreased from 250 to 204 per 100 000 (overall rate reduction 18.4%). Age‐specific AIS hospitalization rates decreased for individuals aged 65 to 84 years (846 to 605 per 100 000) and ≥85 years (2077 to 1618 per 100 000), but increased for individuals aged 25 to 44 years (16 to 23 per 100 000) and 45 to 64 years (149 to 156 per 100 000). Blacks had the highest age‐adjusted yearly hospitalization rates, followed by Hispanics and whites (358, 170, and 155 per 100 000 in 2010). Age‐adjusted AIS hospitalization rates increased for blacks but decreased for Hispanics and whites. Age‐adjusted AIS hospitalization rates were lower in women and declined more steeply compared to men (272 to 212 per 100 000 in women versus 298 to 245 per 100 000 in men). ConclusionsAlthough overall stroke hospitalizations declined in the United States, the reduction was more pronounced among older individuals, women, Hispanics, and whites. Renewed efforts at targeting risk factor control among vulnerable individuals may be warranted.
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- 2016
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9. Advanced Imaging Modalities in the Detection of Cerebral Vasospasm
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Jena N. Mills, Vivek Mehta, Jonathan Russin, Arun P. Amar, Anandh Rajamohan, and William J. Mack
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Neurology. Diseases of the nervous system ,RC346-429 - Abstract
The pathophysiology of cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is complex and is not entirely understood. Mechanistic insights have been gained through advances in the capabilities of diagnostic imaging. Core techniques have focused on the assessment of vessel caliber, tissue metabolism, and/or regional perfusion parameters. Advances in imaging have provided clinicians with a multifaceted approach to assist in the detection of cerebral vasospasm and the diagnosis of delayed ischemic neurologic deficits (DIND). However, a single test or algorithm with broad efficacy remains elusive. This paper examines both anatomical and physiological imaging modalities applicable to post-SAH vasospasm and offers a historical background. We consider cerebral blood flow velocities measured by Transcranial Doppler Ultrasonography (TCD). Structural imaging techniques, including catheter-based Digital Subtraction Angiography (DSA), CT Angiography (CTA), and MR Angiography (MRA), are reviewed. We examine physiologic assessment by PET, HMPAO SPECT, 133Xe Clearance, Xenon-Enhanced CT (Xe/CT), Perfusion CT (PCT), and Diffusion-Weighted/MR Perfusion Imaging. Comparative advantages and limitations are discussed.
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- 2013
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10. Cerebral Vasospasm in Traumatic Brain Injury
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Daniel R. Kramer, Jesse L. Winer, B. A. Matthew Pease, Arun P. Amar, and William J. Mack
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Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Vasospasm following traumatic brain injury (TBI) may dramatically affect the neurological and functional recovery of a vulnerable patient population. While the reported incidence of traumatic vasospasm ranges from 19%–68%, the true incidence remains unknown due to variability in protocols for its detection. Only 3.9%–16.6% of patients exhibit clinical deficits. Compared to vasospasm resulting from aneurysmal SAH (aSAH), the onset occurs earlier and the duration is shorter. Overall, the clinical course tends to be milder, although extreme cases may occur. Traumatic vasospasm can occur in the absence of subarachnoid hemorrhage. Surveillance transcranial Doppler ultrasonography (TCD) has been utilized to monitor for radiographic vasospasm following TBI. However, effective treatment modalities remain limited. Hypertension and hypervolemia, the mainstays of treatment of vasospasm associated with aSAH, must be used judiciously in TBI patients, and calcium-channel blockers have offered mixed clinical results. Currently, the paucity of large prospective cohort studies and level-one data limits the ability to form evidence-based recommendations regarding the diagnosis and management of vasospasm associated with TBI.
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- 2013
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11. Matrix Metalloproteinases in Cerebral Vasospasm following Aneurysmal Subarachnoid Hemorrhage
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Vivek Mehta, Jonathan Russin, Alexandra Spirtos, Shuhan He, Peter Adamczyk, Arun P. Amar, and William J. Mack
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Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Delayed cerebral vasospasm is a significant cause of morbidity and mortality following aneurysmal subarachnoid hemorrhage (SAH). While the cellular mechanisms underlying vasospasm remain unclear, it is believed that inflammation may play a critical role in vasospasm. Matrix metalloproteinasees (MMPs) are a family of extracellular and membrane-bound proteases capable of degrading the blood-rain barrier (BBB). As such, MMP upregulation following SAH may result in a proinflammatory extravascular environment capable of inciting delayed cerebral vasospasm. This paper presents an overview of MMPs and describes existing data pertinent to delayed cerebral vasospasm.
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- 2013
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12. Medical Management of Cerebral Vasospasm following Aneurysmal Subarachnoid Hemorrhage: A Review of Current and Emerging Therapeutic Interventions
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Peter Adamczyk, Shuhan He, Arun Paul Amar, and William J. Mack
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Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Cerebral vasospasm is a major source of morbidity and mortality in patients with aneurysmal subarachnoid hemorrhage (aSAH). Evidence suggests a multifactorial etiology and this concept remains supported by the assortment of therapeutic modalities under investigation. The authors provide an updated review of the literature for previous and recent clinical trials evaluating medical treatments in patients with cerebral vasospasm secondary to aSAH. Currently, the strongest evidence supports use of prophylactic oral nimodipine and initiation of triple-H therapy for patients in cerebral vasospasm. Other agents presented in this report include magnesium, statins, endothelin receptor antagonists, nitric oxide promoters, free radical scavengers, thromboxane inhibitors, thrombolysis, anti-inflammatory agents and neuroprotectants. Although promising data is beginning to emerge for several treatments, few prospective randomized clinical trials are presently available. Additionally, future investigational efforts will need to resolve discrepant definitions and outcome measures for cerebral vasospasm in order to permit adequate study comparisons. Until then, definitive recommendations cannot be made regarding the safety and efficacy for each of these therapeutic strategies and medical management practices will continue to be implemented in a wide-ranging manner.
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- 2013
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13. Invasive and Noninvasive Multimodal Bedside Monitoring in Subarachnoid Hemorrhage: A Review of Techniques and Available Data
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Baback Arshi, William J. Mack, and Benjamin Emanuel
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Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Delayed-cerebral ischemia is a major cause of morbidity and mortality in the setting of aneurysmal subarachnoid hemorrhage. Despite extensive research efforts and a breadth of collective clinical experience, accurate diagnosis of vasospasm remains difficult, and effective treatment options are limited. Classically, diagnosis has focused on imaging assessment of the cerebral vasculature. Recently, invasive and noninvasive bedside techniques designed to characterize relevant hemodynamic and metabolic alterations have gained substantial attention. Such modalities include microdialysis, brain tissue oxygenation, jugular bulb oximetry, thermal diffusion cerebral blood flow, and near-infrared spectroscopy. This paper reviews these modalities and examines data pertinent to the diagnosis and management of cerebral vasospasm.
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- 2013
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14. Endovascular Embolization of Intracranial Meningiomas
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Michelle Lin, Vincent Nguyen, and William J. Mack
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Surgery ,Neurology (clinical) ,General Medicine - Published
- 2023
15. ChatGPT versus the neurosurgical written boards: a comparative analysis of artificial intelligence/machine learning performance on neurosurgical board–style questions
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Benjamin S. Hopkins, Vincent N. Nguyen, Jonathan Dallas, Pavlos Texakalidis, Max Yang, Alex Renn, Gage Guerra, Zain Kashif, Stephanie Cheok, Gabriel Zada, and William J. Mack
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General Medicine - Published
- 2023
16. Interhospital transfer of pediatric patients with malignant brain tumor not associated with increased mortality, but safe routine discharge
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Shivani D, Rangwala, Jane S, Han, Li, Ding, William J, Mack, Mark D, Krieger, and Frank J, Attenello
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General Medicine - Abstract
OBJECTIVE Interhospital transfer (IHT) to obtain a higher level of care for pediatric patients requiring neurosurgical interventions is common. Pediatric patients with malignant brain tumors often require subspecialty care commonly provided at specialized centers. The authors aimed to assess the impact of IHT in pediatric neurosurgical patients with malignant brain tumors to identify areas of improvement in treatment of this patient population. METHODS Pediatric patients (age < 19 years) with malignant primary brain tumors undergoing craniotomy for resection between 2010 and 2018 were retrospectively identified in the Nationwide Readmissions Database. Patient and hospital data for each index admission provided by the Nationwide Readmissions Database was analyzed by univariate and multivariate analyses. Further analysis evaluated association of IHT on specific patient- or hospital-related characteristics. RESULTS In a total of 2279 nonelective admissions for malignant brain tumors in pediatric patients, the authors found only 132 patients (5.8%) who underwent IHT for a higher level of care. There is an increased likelihood of transfer when a patient is younger (< 7 years old, p = 0.006) or the disease process is more severe, as characterized by higher pediatric complex chronic conditions (p = 0.0004) and increased all patient refined diagnosis-related group mortality index (p = 0.02). Patients who are transferred (OR 1.87, 95% CI 1.04–3.35; p = 0.04) and patients who are treated at pediatric centers (OR 6.89, 95% CI 4.23–11.22; p < 0.0001) are more likely to have a routine discharge home. On multivariate analysis, transfer status was not associated with a longer length of stay (incident rate ratio 1.04, 95% CI 0.94–1.16; p = 0.5) or greater overall costs per patient ($20,947.58, 95% CI −$35,078.80 to $76,974.00; p = 0.50). Additionally, IHT is not associated with increased likelihood of death or major complication. CONCLUSIONS IHT has a significant role in the outcome of pediatric patients with malignant brain tumors. Transfer of this patient population to hospitals providing subspecialized care results in a higher level of care without a significant burden on overall costs, risks, or mortality.
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- 2023
17. <scp>cAMP</scp> ‐induced decrease in cell‐surface laminin receptor and cellular prion protein attenuates amyloid‐β uptake and amyloid‐β‐induced neuronal cell death
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Rayudu Gopalakrishna, Charlotte Y. Lin, Andrew Oh, Calvin Le, Seolyn Yang, Alexandra Hicks, Mark S. Kindy, William J. Mack, and Narayan R. Bhat
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Structural Biology ,Genetics ,Biophysics ,Cell Biology ,Molecular Biology ,Biochemistry - Published
- 2022
18. Feasibility of Direct Intercostal and Lumbar Artery Revascularization to Prevent Spinal Cord Ischemia Associated with Endovascular Thoracoabdominal Aortic Repair
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Anand V. Ganapathy, Alexander D. DiBartolomeo, William J. Mack, Gregory A. Magee, Anastasia Plotkin, Joseph N. Carey, Jonathan J. Russin, and Sukgu M. Han
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Surgery ,Cardiology and Cardiovascular Medicine - Published
- 2023
19. Making a case for endovascular approaches for neural recording and stimulation
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Brianna Thielen, Huijing Xu, Tatsuhiro Fujii, Shivani D Rangwala, Wenxuan Jiang, Michelle Lin, Alexandra Kammen, Charles Liu, Pradeep Selvan, Dong Song, William J Mack, and Ellis Meng
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Cellular and Molecular Neuroscience ,Biomedical Engineering - Abstract
There are many electrode types for recording and stimulating neural tissue, most of which necessitate direct contact with the target tissue. These electrodes range from large, scalp electrodes which are used to non-invasively record averaged, low frequency electrical signals from large areas/volumes of the brain, to penetrating microelectrodes which are implanted directly into neural tissue and interface with one or a few neurons. With the exception of scalp electrodes (which provide very low-resolution recordings), each of these electrodes requires a highly invasive, open brain surgical procedure for implantation, which is accompanied by significant risk to the patient. To mitigate this risk, a minimally invasive endovascular approach can be used. Several types of endovascular electrodes have been developed to be delivered into the blood vessels in the brain via a standard catheterization procedure. In this review, the existing body of research on the development and application of endovascular electrodes is presented. The capabilities of each of these endovascular electrodes is compared to commonly used direct-contact electrodes to demonstrate the relative efficacy of the devices. Potential clinical applications of endovascular recording and stimulation and the advantages of endovascular versus direct-contact approaches are presented.
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- 2023
20. Author response for 'Making a case for endovascular approaches for neural recording and stimulation'
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null Brianna Thielen, null Huijing Xu, null Tatsuhiro Fujii, null Shivani D Rangwala, null Wenxuan Jiang, null Michelle Lin, null Alexandra Kammen, null Charles Liu, null Pradeep Selvan, null Dong Song, null William J Mack, and null Ellis Meng
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- 2022
21. Air pollution nanoparticle exposure reduces neurotrophin signaling and causes hippocampal neural stem cell quiescence in mouse brain
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Hongqiao Zhang, Nathan Zhang, Andrew Li, Arnold Diaz, Kristina Shkirkova, Brandon Ge, Abigail Florentino, Constantinos Sioutas, William J Mack, Michael Anthony Bonaguidi, and Caleb E Finch
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Psychiatry and Mental health ,Cellular and Molecular Neuroscience ,Developmental Neuroscience ,Epidemiology ,Health Policy ,Neurology (clinical) ,Geriatrics and Gerontology - Published
- 2022
22. Cyclic adenosine monophosphate-elevating agents inhibit amyloid-beta internalization and neurotoxicity: their action in Alzheimer’s disease prevention
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Rayudu Gopalakrishna, Andrew Oh, Narayan R. Bhat, and William J. Mack
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Developmental Neuroscience - Published
- 2023
23. Particulate matter exposure and chronic cerebral hypoperfusion promote oxidative stress and induce neuronal and oligodendrocyte apoptosis in male mice
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Krista Lamorie‐Foote, Qinghai Liu, Kristina Shkirkova, Brandon Ge, Shannon He, Todd E. Morgan, Wendy J. Mack, Constantinos Sioutas, Caleb E. Finch, and William J. Mack
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Cellular and Molecular Neuroscience - Abstract
Chronic cerebral hypoperfusion (CCH) may amplify the neurotoxicity of nanoscale particulate matter (nPM), resulting in white matter injury. This study characterized the joint effects of nPM (diameter ≤ 200 nm) and CCH secondary to bilateral carotid artery stenosis (BCAS) exposure on neuronal and white matter injury in a murine model. nPM was collected near a highway and re-aerosolized for exposure. Ten-week-old C57BL/6 male mice were randomized into four groups: filtered air (FA), nPM, FA + BCAS, and nPM + BCAS. Mice were exposed to FA or nPM for 10 weeks. BCAS surgeries were performed. Markers of inflammation, oxidative stress, and apoptosis were examined. nPM + BCAS exposure increased brain hemisphere TNFα protein compared to FA. iNOS and HNE immunofluorescence were increased in the corpus callosum and cerebral cortex of nPM + BCAS mice compared to FA. While nPM exposure alone did not decrease cortical neuronal cell count, nPM decreased corpus callosum oligodendrocyte cell count. nPM exposure decreased mature oligodendrocyte cell count and increased oligodendrocyte precursor cell count in the corpus callosum. nPM + BCAS mice exhibited a 200% increase in cortical neuronal TUNEL staining and a 700% increase in corpus callosum oligodendrocyte TUNEL staining compared to FA. There was a supra-additive interaction between nPM and BCAS on cortical neuronal TUNEL staining (2.6× the additive effects of nPM + BCAS). nPM + BCAS exposure increased apoptosis, neuroinflammation, and oxidative stress in the cerebral cortex and corpus callosum. nPM + BCAS exposure increased neuronal apoptosis above the separate responses to each exposure. However, oligodendrocytes in the corpus callosum demonstrated a greater susceptibility to the combined neurotoxic effects of nPM + BCAS exposure.
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- 2022
24. Mortality following mechanical thrombectomy for ischemic stroke in patients with COVID-19
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Jonathan Dallas, Talia A. Wenger, Kristie Q. Liu, Li Ding, Benjamin S. Hopkins, Frank J. Attenello, and William J. Mack
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Rehabilitation ,Surgery ,Neurology (clinical) ,Cardiology and Cardiovascular Medicine - Published
- 2023
25. Urban Air Pollution Nanoparticles from Los Angeles: Recently Decreased Neurotoxicity
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Kristina Shkirkova, Mafalda Cacciottolo, Max Thorwald, Wendy J. Mack, Todd E. Morgan, Krista Lamorie-Foote, Qinghai Liu, Hongqiao Zhang, Milad Pirhadi, William J. Mack, Constantinos Sioutas, Caleb E. Finch, Carla D'Agostino, and Henry Jay Forman
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0301 basic medicine ,In Vitro Techniques ,Biology ,Pharmacology ,Mice ,03 medical and health sciences ,0302 clinical medicine ,Western blot ,Alzheimer Disease ,In vivo ,Air Pollution ,medicine ,Animals ,Humans ,Potency ,Cognitive decline ,Cells, Cultured ,integumentary system ,Microglia ,medicine.diagnostic_test ,General Neuroscience ,NF-kappa B ,Neurotoxicity ,Glutamate receptor ,In vitro toxicology ,Brain ,General Medicine ,medicine.disease ,Psychiatry and Mental health ,Clinical Psychology ,030104 developmental biology ,medicine.anatomical_structure ,Nanoparticles ,Neurotoxicity Syndromes ,Particulate Matter ,Geriatrics and Gerontology ,030217 neurology & neurosurgery - Abstract
Background: Air pollution is widely associated with accelerated cognitive decline at later ages and risk of Alzheimer’s disease (AD). Correspondingly, rodent models demonstrate the neurotoxicity of ambient air pollution and its components. Our studies with nano-sized particulate matter (nPM) from urban Los Angeles collected since 2009 have shown pro-amyloidogenic and pro-inflammatory responses. However, recent batches of nPM have diminished induction of the glutamate receptor GluA1 subunit, Iba1, TNFα, Aβ42 peptide, and white matter damage. The same methods, materials, and mouse genotypes were used throughout. Objective: Expand the nPM batch comparisons and evaluate archived brain samples to identify the earliest change in nPM potency. Methods: Batches of nPM were analyzed by in vitro cell assays for NF-κB and Nrf2 induction for comparison with in vivo responses of mouse brain regions from mice exposed to these batches, analyzed by PCR and western blot. Results: Five older nPM batches (2009–2017) and four recent nPM batches (2018, 2019) for NF-κB and Nrf2 induction showed declines in nPM potency after 2017 that paralleled declines of in vivo activity from independent exposures in different years. Conclusion: Transcription-based in vitro assays of nPM corresponded to the loss of in vivo potency for inflammatory and oxidative responses. These recent decreases of nPM neurotoxicity give a rationale for evaluating possible benefits to the risk of dementia and stroke in Los Angeles populations.
- Published
- 2021
26. Neurotoxicity of Diesel Exhaust Particles
- Author
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Kristina Shkirkova, Krista Lamorie-Foote, Nathan Zhang, Andrew Li, Arnold Diaz, Qinghai Liu, Max A. Thorwald, Jose A. Godoy-Lugo, Brandon Ge, Carla D’Agostino, Zijiao Zhang, Wendy J. Mack, Constantinos Sioutas, Caleb E. Finch, William J. Mack, and Hongqiao Zhang
- Subjects
Male ,General Neuroscience ,General Medicine ,Mice, Inbred C57BL ,Psychiatry and Mental health ,Clinical Psychology ,Mice ,Animals ,Dementia ,Neurotoxicity Syndromes ,Particulate Matter ,Geriatrics and Gerontology ,Peptides ,Vehicle Emissions - Abstract
Background: Air pollution particulate matter (PM) is strongly associated with risks of accelerated cognitive decline, dementia and Alzheimer’s disease. Ambient PM batches have variable neurotoxicity by collection site and season, which limits replicability of findings within and between research groups for analysis of mechanisms and interventions. Diesel exhaust particles (DEP) offer a replicable model that we define in further detail. Objective: Define dose- and time course neurotoxic responses of mice to DEP from the National Institute of Science and Technology (NIST) for neurotoxic responses shared by DEP and ambient PM. Methods: For dose-response, adult C57BL/6 male mice were exposed to 0, 25, 50, and 100μg/m3 of re-aerosolized DEP (NIST SRM 2975) for 5 h. Then, mice were exposed to 100μg/m3 DEP for 5, 100, and 200 h and assayed for amyloid-β peptides, inflammation, oxidative damage, and microglial activity and morphology. Results: DEP exposure at 100μg/m3 for 5 h, but not lower doses, caused oxidative damage, complement and microglia activation in cerebral cortex and corpus callosum. Longer DEP exposure for 8 weeks/200 h caused further oxidative damage, increased soluble Aβ, white matter injury, and microglial soma enlargement that differed by cortical layer. Conclusion: Exposure to 100μg/m3 DEP NIST SRM 2975 caused robust neurotoxic responses that are shared with prior studies using DEP or ambient PM0.2. DEP provides a replicable model to study neurotoxic mechanisms of ambient PM and interventions relevant to cognitive decline and dementia.
- Published
- 2022
27. 2022 Guideline for the Management of Patients With Spontaneous Intracerebral Hemorrhage: A Guideline From the American Heart Association/American Stroke Association
- Author
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Steven M, Greenberg, Wendy C, Ziai, Charlotte, Cordonnier, Dar, Dowlatshahi, Brandon, Francis, Joshua N, Goldstein, J Claude, Hemphill, Ronda, Johnson, Kiffon M, Keigher, William J, Mack, J, Mocco, Eileena J, Newton, Ilana M, Ruff, Lauren H, Sansing, Sam, Schulman, Magdy H, Selim, Kevin N, Sheth, Nikola, Sprigg, and Katharina S, Sunnerhagen
- Subjects
Stroke ,Advanced and Specialized Nursing ,Cerebral Amyloid Angiopathy ,Humans ,American Heart Association ,Neurology (clinical) ,Cardiology and Cardiovascular Medicine ,United States ,Cerebral Hemorrhage - Published
- 2022
28. Hospital Admissions from the Emergency Department and Subsequent Critical Care Interventions for Influenza during Pregnancy
- Author
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Nicole Krenitsky, Stephanie Cham, Kartik K. Venkatesh, William J. Mack, Frank J. Attenello, Alexander M. Friedman, Timothy Wen, and Mary E. D'Alton
- Subjects
education.field_of_study ,medicine.medical_specialty ,Pregnancy ,030219 obstetrics & reproductive medicine ,business.industry ,Public health ,Population ,Psychological intervention ,Obstetrics and Gynecology ,Emergency department ,medicine.disease ,Intensive care unit ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,law ,Relative risk ,Pediatrics, Perinatology and Child Health ,Emergency medicine ,medicine ,030212 general & internal medicine ,education ,business ,Disease burden - Abstract
OBJECTIVE The objectives of this study were to determine (1) whether obstetrical patients were more likely to be admitted from the emergency department (ED) for influenza compared with nonpregnant women, and (2) require critical care interventions once admitted. STUDY DESIGN Using data from the 2006 to 2011 Nationwide Emergency Department Sample, ED encounters for influenza for women aged 15 to 54 years without underlying chronic medical conditions were identified. Women were categorized as pregnant or nonpregnant using billing codes. Multivariable log linear models were fit to evaluate the relative risk of admission from the ED and the risk of intensive care unit (ICU)-level interventions including mechanical ventilation and central monitoring with pregnancy status as the exposure of interest. Measures of association were described with adjusted risk ratios (aRRs) with 95% confidence intervals (CIs). RESULTS We identified 15.9 million ED encounters for influenza of which 4% occurred among pregnant women. Pregnant patients with influenza were nearly three times as likely to be admitted as nonpregnant patients (aRR = 2.99, 95% CI: 2.94, 3.05). Once admitted, obstetric patients were at 72% higher risk of ICU-level interventions (aRR = 1.72, 95% CI: 1.61, 1.84). Of pregnant women admitted from the ED, 9.3% required ICU-level interventions such as mechanical ventilation or central monitoring. Older patients and those with Medicare were also at high risk of admission and ICU-level interventions (p
- Published
- 2021
29. Neuroprotective effect of minocycline against acute brain injury in clinical practice: A systematic review
- Author
-
Ben A. Strickland, Joshua Bakhsheshian, Jonathan J. Russin, William J. Mack, Steven L. Giannotta, Ben Emmanuel, and Arun P. Amar
- Subjects
Subarachnoid hemorrhage ,Traumatic brain injury ,Central nervous system ,Ischemia ,Minocycline ,Bioinformatics ,Blood–brain barrier ,Neuroprotection ,03 medical and health sciences ,0302 clinical medicine ,Physiology (medical) ,medicine ,Animals ,Humans ,Intracerebral hemorrhage ,business.industry ,General Medicine ,medicine.disease ,Neuroprotective Agents ,medicine.anatomical_structure ,Neurology ,Brain Injuries ,030220 oncology & carcinogenesis ,Surgery ,Neurology (clinical) ,business ,030217 neurology & neurosurgery ,medicine.drug - Abstract
Acute brain injury is a leading cause of morbidity and mortality worldwide. The term is inclusive of traumatic brain injury, cerebral ischemia, subarachnoid hemorrhage, and intracerebral hemorrhage. Current pharmacologic treatments have had minimal effect on improving neurological outcomes leading to a significant interest in the development neuroprotective agents. Minocycline is a second-generation tetracycline with high blood brain barrier penetrance due to its lipophilic properties. It functions across multiple molecular pathways involved in secondary-injury cascades following acute brain injury. Animal model studies suggest that minocycline might lead to improved neurologic outcomes, but few such trials exist in humans. Clinical investigations have been limited to small randomized trials in ischemic stroke patients which have not demonstrated a clear advantage in neurologic outcomes, but also have not been sufficiently powered to draw definitive conclusions. The potential neuroprotective effect of minocycline in the setting of traumatic brain injury, subarachnoid hemorrhage, and intracerebral hemorrhage have all been limited to pilot studies with phase II/III investigations pending. The authors aim to synthesize what is currently known about minocycline as a neuroprotective agent against acute brain injury in humans.
- Published
- 2021
30. Tobacco Use Is Associated With Increased 90-Day Readmission Among Patients Undergoing Surgery for Degenerative Spine Disease
- Author
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Phillip A. Bonney, John C. Liu, Li Ding, Kristina Shkirkova, Krista Lamorie-Foote, Elliot Min, Robert G. Briggs, Frank J. Attenello, Michelle Connor, and William J. Mack
- Subjects
medicine.medical_specialty ,Tobacco use ,business.industry ,medicine.medical_treatment ,Laminectomy ,Disease ,Surgical procedures ,Surgery ,Retrospective database ,03 medical and health sciences ,0302 clinical medicine ,Discectomy ,Surgical site ,medicine ,Poor wound healing ,Orthopedics and Sports Medicine ,030212 general & internal medicine ,Neurology (clinical) ,business ,030217 neurology & neurosurgery - Abstract
Study Design: Retrospective database study. Objective: Tobacco use is associated with complications after surgical procedures, including poor wound healing, surgical site infections, and cardiovascular events. We used the Nationwide Readmissions Database (NRD) to determine if tobacco use is associated with increased 30- and 90-day readmission among patients undergoing surgery for degenerative spine disorders. Methods: Patients who underwent elective spine surgery were identified in the NRD from 2010 to 2014. The study population included patients with degenerative spine disorders treated with discectomy, fusion, or decompression. Descriptive and multivariate logistic regression analyses were performed to identify patient and hospital factors associated with 30- and 90-day readmission, with significance set at P value Results: Within 30 days, 4.8% of patients were readmitted at a median time of 9 days. The most common reasons for 30-day readmission were postoperative infection (12.5%), septicemia (3.5%), and postoperative pain (3.0%). Within 90 days, 7.3% were readmitted at a median time of 18 days. The most common reasons for 90-day readmission were postoperative infection (9.6%), septicemia (3.5%), and pneumonia (2.3%). After adjustment for patient and hospital characteristics, tobacco use was independently associated with readmission at 90 days (odds ratio 1.05, 95% confidence interval 1.03-1.07, P < .0001) but not 30 days (odds ratio 1.02, 95% confidence interval 1.00-1.05, P = .045). Conclusions: Tobacco use is associated with readmission within 90 days after cervical and thoracolumbar spine surgery for degenerative disease. Tobacco use is a known risk factor for adverse health events and therefore should be considered when selecting patients for spine surgery.
- Published
- 2020
31. Effects of ambient particulate matter on vascular tissue: a review
- Author
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Todd E. Morgan, Arati Patel, Giuseppe Barisano, William J. Mack, Kristina Shkirkova, Michelle Connor, Constantinos Sioutas, Qinghai Liu, Hans Baertsch, and Krista Lamorie-Foote
- Subjects
Health, Toxicology and Mutagenesis ,Physiology ,Inflammation ,030204 cardiovascular system & hematology ,010501 environmental sciences ,Toxicology ,medicine.disease_cause ,01 natural sciences ,Article ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Animals ,Humans ,Vascular tissue ,0105 earth and related environmental sciences ,Air Pollutants ,Inhalation Exposure ,Vasomotor ,business.industry ,Particulates ,Plaque, Atherosclerotic ,Vascular tone ,Vasomotor System ,Oxidative Stress ,Blood Vessels ,Particulate Matter ,medicine.symptom ,business ,Oxidative stress - Abstract
Fine and ultra-fine particulate matter (PM) are major constituents of urban air pollution and recognized risk factors for cardiovascular diseases. This review examined the effects of PM exposure on vascular tissue. Specific mechanisms by which PM affects the vasculature include inflammation, oxidative stress, actions on vascular tone and vasomotor responses, as well as atherosclerotic plaque formation. Further, there appears to be a greater PM exposure effect on susceptible individuals with pre-existing cardiovascular conditions.
- Published
- 2020
32. Predictors of readmission after craniotomy for meningioma resection: a nationwide readmission database analysis
- Author
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Michelle Lin, Steven L. Giannotta, Elliott A Orloff, Li Ding, William J. Mack, Frank J. Attenello, James S. Hu, Elliot Min, and Kerolos S R Youssef
- Subjects
Adult ,Male ,medicine.medical_specialty ,Adolescent ,Databases, Factual ,medicine.medical_treatment ,Medicare ,Logistic regression ,Patient Readmission ,030218 nuclear medicine & medical imaging ,Benign tumor ,Meningioma ,Young Adult ,03 medical and health sciences ,Sex Factors ,0302 clinical medicine ,Risk Factors ,Meningeal Neoplasms ,medicine ,Humans ,Surgical Wound Infection ,Craniotomy ,Aged ,Neuroradiology ,Aged, 80 and over ,medicine.diagnostic_test ,business.industry ,Interventional radiology ,Perioperative ,Middle Aged ,medicine.disease ,Patient Discharge ,United States ,Surgery ,Female ,Neurology (clinical) ,Neurosurgery ,business ,030217 neurology & neurosurgery - Abstract
Meningiomas are the most common benign primary brain tumors. The mainstay of treatment, surgical resection, is often curative. Given the excellent prognosis of these lesions, minimizing perioperative complications is of the utmost importance. With the establishment of the National Readmissions Database (NRD), researchers are now able to identify variables associated with postoperative complications beyond the index admission. In this study, we sought to identify the leading causes for non-elective readmission and variables associated with increased likelihood of readmission at 30 and 90 days after discharge following a craniotomy for meningioma resection. Adult inpatients who underwent craniotomy for meningioma resection between 2010 and 2014 were queried from the NRD. All-cause readmissions following craniotomy at 30 and 90 days were identified, and a multivariable logistic regression model was used to characterize independent risk factors. Among 26,034 patients who received craniotomy for meningioma resection, 2825 (10.9%) were readmitted at 30 days and 3436 (16.1%) were readmitted at 90 days. Postoperative wound infection was the most common readmission diagnosis, occurring in 9.32% and 10.2% of 30- and 90-day readmissions respectively. Patient factors associated with increased likelihood of readmission included male gender, greater illness severity, non-routine discharge, index length of hospitalization, and having Medicare or Medicaid insurance. Readmission following craniotomy for meningioma resection occurs at a clinically significant rate. Several patient factors were identified in association with all-cause 30- and 90-day readmissions. Further studies are required to identify means for preventing complications following discharge in these vulnerable patient populations.
- Published
- 2020
33. Increased 30-day readmission rate after craniotomy for tumor resection at safety net hospitals in small metropolitan areas
- Author
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Saman Sizdahkhani, William J. Mack, Li Ding, Neal H. Nathan, Michelle Connor, and Frank J. Attenello
- Subjects
Adult ,Male ,Cancer Research ,medicine.medical_specialty ,Multivariate analysis ,Adolescent ,Databases, Factual ,medicine.medical_treatment ,Brain tumor ,Logistic regression ,Patient Readmission ,Article ,Benign tumor ,Young Adult ,03 medical and health sciences ,Postoperative Complications ,0302 clinical medicine ,medicine ,Humans ,Craniotomy ,Aged ,Brain Neoplasms ,business.industry ,Middle Aged ,medicine.disease ,Metropolitan area ,Neurology ,Oncology ,Quartile ,030220 oncology & carcinogenesis ,Emergency medicine ,Female ,Neurology (clinical) ,business ,Medicaid ,Safety-net Providers ,030217 neurology & neurosurgery - Abstract
PURPOSE: Unplanned readmission of post-operative brain tumor patients is often attributed to hospital and patient characteristics and is associated with higher mortality and cost. Previous studies demonstrate multiple patient outcome disparities in safety net hospitals (SNHs) when compared to non-SNHs. This study uses the Nationwide Readmissions Database (NRD) to determine if initial brain tumor resection at SNHs is associated with increased 30-day non-elective readmission rates. METHODS: Patients with benign or malignant primary or metastatic brain tumor undergoing craniotomy for surgical resection were retrospectively identified in the NRD from 2010–2014. SNHs were defined as hospitals with Medicaid and uninsured patient burden in the top quartile. Descriptive and multivariate analyses employing survey-adjusted logistic regression evaluated patient and hospital level factors influencing 30-day readmissions. RESULTS: During the study period, 83367 patients met inclusion criteria. 44.7% of patients had a benign tumor, and 55.3% had a malignant tumor. Secondary CNS neoplasm (5.99%), post-operative infection (5.96%), and septicemia (4.26%) caused most readmissions within 30 days. Patients had increased unplanned readmission rates if they underwent craniotomy for tumor resection at a SNH in a small metropolitan area (OR 1.11, 95% CI 1.02–1.21, p=0.01), but not at a SNH in a large metropolitan area (OR 0.99, 95% CI 0.93–1.05, p=0.73). CONCLUSION: This finding may reflect differences in access to care and disparities in neurosurgical resources between small and large metropolitan areas. Inequities in expertise and capacity are relevant as surgical volume was also related to readmission rates. Further studies may be warranted to address such disparities.
- Published
- 2020
34. Cyclic-AMP induces Nogo-A receptor NgR1 internalization and inhibits Nogo-A-mediated collapse of growth cone
- Author
-
Rayudu Gopalakrishna, William J. Mack, Andrew Oh, Charlotte Lin, Aubree Mades, Mark S. Kindy, Angela Zhu, and Julie Nguyen
- Subjects
0301 basic medicine ,Neurite ,Nogo Proteins ,media_common.quotation_subject ,Growth Cones ,Biophysics ,PC12 Cells ,Biochemistry ,Adenylyl cyclase ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Nogo Receptor 1 ,Cyclic AMP ,Animals ,Guanine Nucleotide Exchange Factors ,Internalization ,Growth cone ,Protein kinase A ,Molecular Biology ,media_common ,Neurons ,Forskolin ,Cell Biology ,Rats ,Cell biology ,Protein Transport ,030104 developmental biology ,chemistry ,030220 oncology & carcinogenesis ,Growth inhibition ,Intracellular - Abstract
The promotion of axonal regeneration is required for functional recovery from stroke and various neuronal injuries. However, axonal regeneration is inhibited by diverse axonal growth inhibitors, such as Nogo-A. Nogo-66, a C-terminal domain of Nogo-A, binds to the Nogo-A receptor 1 (NgR1) and induces the collapse of growth cones and inhibits neurite outgrowth. NgR1 is also a receptor for additional axonal growth inhibitors, suggesting it is an important target for the prevention of axonal growth inhibition. By using the indirect immunofluorescence method, we show for the first time that a cell-permeable cAMP analog (dibutyryl-cAMP) induced a rapid decrease in the cell surface expression of NgR1 in Neuroscreen-1 (NS-1) cells. The biotinylation method revealed that cAMP indeed induced internalization of NgR1 within minutes. Other intracellular cAMP-elevating agents, such as forskolin, which directly activates adenylyl cyclase, and rolipram, which inhibits cyclic nucleotide phosphodiesterase, also induced this process. This internalization was found to be reversible and influenced by intracellular levels of cAMP. Using selective activators and inhibitors of protein kinase A (PKA) and the exchange protein directly activated by cAMP (Epac), we found that NgR1 internalization is independent of PKA, but dependent on Epac. The decrease in cell surface expression of NgR1 desensitized NS-1 cells to Nogo-66-induced growth cone collapse. Therefore, it is likely that besides axonal growth inhibitors affecting neurons, neurons themselves also self-regulate their sensitivity to axonal growth inhibitors, as influenced by intracellular cAMP/Epac. This normal cellular regulatory mechanism may be pharmacologically exploited to overcome axonal growth inhibitors, and enhance functional recovery after stroke and neuronal injuries.
- Published
- 2020
35. HTU
- Author
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Aviva Abosch, Lola B. Chambless, Edward Chang, Michael T. Lawton, Michael Lim, William J. Mack, Alfredo Quiñones-Hinojosa, James T. Rutka, Daniel M. Sciubba, and Nicholas Theodore
- Published
- 2022
36. Failure of Flow Diverter Therapy: Predictors and Management Strategies
- Author
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Brian P. Walcott, Christopher J Stapleton, Parampreet Singh, Tatsuhiro Fujii, Phillip A. Bonney, Michelle Connor, Matthew J. Koch, and William J. Mack
- Subjects
medicine.medical_specialty ,Subarachnoid hemorrhage ,Flow diversion ,business.industry ,Endovascular Procedures ,Intracranial Aneurysm ,medicine.disease ,Embolization, Therapeutic ,Treatment Outcome ,Aneurysm ,Treatment modality ,medicine ,Humans ,Initial treatment ,Effective treatment ,Surgery ,cardiovascular diseases ,Neurology (clinical) ,Intensive care medicine ,business ,After treatment ,Retrospective Studies ,Flow diverter - Abstract
Flow diversion is a safe and effective treatment for many types of brain aneurysms. Even so, there remain some aneurysms that persist despite initial treatment. In studies with the longest follow-up (5 yr), at least 5% of aneurysms persist with this treatment modality. As the cumulative experience and clinical indications for flow diversion continue to expand, the anatomic and functional characteristics that are associated with aneurysm persistence are increasingly described. Identification of these factors preoperatively can help to guide initial treatment decisions, enhance monitoring protocols in the follow-up period, and establish best practices for re-treatment when necessary. Herein, we review published clinical series and provide examples to highlight variables implicated in aneurysm persistence after treatment with flow diversion.
- Published
- 2019
37. Outcomes After Minimally Invasive Parafascicular Surgery for Intracerebral Hemorrhage: A Single-Center Experience
- Author
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Gabriel Zada, William J. Mack, Martin J. Rutkowski, and Ivy Song
- Subjects
Adult ,Male ,medicine.medical_specialty ,Single Center ,Left sided ,03 medical and health sciences ,0302 clinical medicine ,Hematoma ,Modified Rankin Scale ,medicine ,Humans ,Minimally Invasive Surgical Procedures ,cardiovascular diseases ,Spontaneous intracerebral hemorrhage ,Neuronavigation ,Aged ,Cerebral Hemorrhage ,Retrospective Studies ,Thrombectomy ,Intracerebral hemorrhage ,business.industry ,Glasgow Coma Scale ,Middle Aged ,medicine.disease ,Surgery ,Intraventricular hemorrhage ,030220 oncology & carcinogenesis ,Female ,Neurology (clinical) ,business ,Craniotomy ,030217 neurology & neurosurgery - Abstract
Background Spontaneous intracerebral hemorrhage (ICH) comprises 10%–15% of strokes with a high mortality (40%) and low rates of functional independence within 6 months (25%). Minimally invasive parafascicular surgery has emerged as a potentially safer option for ICH management. Methods Data from 25 patients who underwent channel-based ICH evacuation were retrospectively collected regarding demographics, clinical presentation, neuroimaging characteristics, follow-up modified Rankin Scale (mRS) score, Glasgow Coma Scale (GCS) score, and disposition. Results Sixteen patients were male (64%) and 9 were female (36%), with a mean age of 52 years. There were 4 frontal, 1 occipital, and 20 basal ganglia hemorrhages; 15 (60%) showed intraventricular extension. Seventeen ICHs (68%) and 6 of 7 patient deaths (86%) were left sided. The mean volume was 46 cm3 (range, 13.1–101.2 cm3), and the mean clot reduction was 92%. Left-sided ICH (P = 0.014) and the presence of intraventricular hemorrhage (P = 0.038) were associated with worsened postoperative GCS score. Larger hemorrhages were associated with mortality (66 cm3 vs. 38 cm3; P Conclusions BrainPath-mediated transsulcal approaches are associated with improved mRS and GCS scores, with low rates of residual hematoma, although further data are needed via controlled studies to determine the importance of hemorrhage location and size, timing of surgical intervention, and long-term patient outcomes.
- Published
- 2019
38. Getting ahead of stroke
- Author
-
William J, Mack
- Subjects
Stroke ,Humans ,Surgery ,Neurology (clinical) ,General Medicine - Published
- 2022
39. Interhospital transfer of patients with malignant brain tumors undergoing resection is associated with routine discharge
- Author
-
Jane S, Han, Edith, Yuan, Phillip A, Bonney, Michelle, Lin, Katherine, Reckamp, Li, Ding, Gabriel, Zada, William J, Mack, and Frank J, Attenello
- Subjects
Hospitalization ,Male ,Patient Transfer ,Brain Neoplasms ,Humans ,Female ,Surgery ,Comorbidity ,Neurology (clinical) ,General Medicine ,Patient Discharge ,Retrospective Studies - Abstract
Neurosurgical patients often undergo interhospital transfer (IHT) for specialized care. While IHT is often associated with worse outcomes in emergent neurosurgical conditions, less is known about patient outcomes after IHT for urgent diagnoses such as brain tumors. We sought to evaluate patient outcomes after IHT for malignant brain tumor resection.Patients hospitalized for resection of malignant brain tumor resections were analyzed from the Nationwide Readmissions Database (NRD) from 2016 to 2018. Multivariate regression analyses were conducted to determine associations between transfer status and routine disposition, mortality index, and length of stay.Among 13,173 patients with non-elective admissions for malignant brain tumor resection, 1583 (12.0%) were transferred from another facility. In comparison to non-transferred patients, IHT patients were more likely to be male (53.8% vs. 51.1%, p 0.04), older (rates of age ≥60 64.0% vs. 58.9%, p 0.001), and had greater Elixhauser comorbidity scores (≥3: 75.0% vs. 56.1%, p 0.0001). After adjustment for comorbidity burden, transfer status was associated with increased likelihood of routine discharge (OR 1.35, 95% CI 1.18-1.55, p 0.0001). Mortality was similar for IHT patients compared to non-transferred patients (OR 0.87, CI 0.62-1.22, p = 0.405). Transfer status was associated with increased length of stay (incident rate ratio [IRR] 1.41, 95% CI 1.34-1.48, p 0.0001).IHT for malignant brain tumor resection was not associated with worse patient outcomes with respect to discharge disposition and mortality. Length of stay was greater for IHT patients. Further research is needed to determine which patients will benefit from IHT for malignant brain tumor resection.
- Published
- 2022
40. Air Pollution Particulate Matter Exposure and Chronic Cerebral Hypoperfusion and Measures of White Matter Injury in a Murine Model
- Author
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Kristina Shkirkova, Caleb E. Finch, Constantinos Sioutas, Qinghai Liu, Jiu Chiuan Chen, William J. Mack, Todd E. Morgan, Wendy J. Mack, Michelle Connor, Berislav V. Zlokovic, Mikko T Huuskonen, Arati Patel, Hans Baertsch, Hongqiao Zhang, Axel Montagne, Brian P. Walcott, Robin Babadjouni, and Krista Lamorie-Foote
- Subjects
Male ,medicine.medical_specialty ,Health, Toxicology and Mutagenesis ,Air pollution ,medicine.disease_cause ,Mice ,Air Pollution ,Internal medicine ,medicine ,Animals ,Dementia ,Science Selection ,Cerebral hypoperfusion ,Ambient air pollution ,business.industry ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,Public Health, Environmental and Occupational Health ,White Matter Injury ,Particulates ,medicine.disease ,White Matter ,Mice, Inbred C57BL ,Disease Models, Animal ,Increased risk ,Murine model ,ComputerSystemsOrganization_MISCELLANEOUS ,Data_GENERAL ,Cerebrovascular Circulation ,Cardiology ,Particulate Matter ,business - Abstract
Exposure to ambient air pollution particulate matter (PM) is associated with increased risk of dementia and accelerated cognitive loss. Vascular contributions to cognitive impairment are well recognized. Chronic cerebral hypoperfusion (CCH) promotes neuroinflammation and blood-brain barrier weakening, which may augment neurotoxic effects of PM.This study examined interactions of nanoscale particulate matter (nPM; fine particulate matter with aerodynamic diameternPM was collected using a particle sampler near a Los Angeles, California, freeway. Mice were exposed to 10 wk of reaerosolized nPM or filtered air (FA) for 150 h. CCH was induced by BCAS surgery. Mice (C57BL/6J males) were randomized to four exposure paradigms:The jointOur data suggest that nPM and CCH contribute to white matter injury in a synergistic manner in a mouse model. Adverse neurological effects may be aggravated in a susceptible population exposed to air pollution. https://doi.org/10.1289/EHP8792.
- Published
- 2021
41. Transcranial eddy current damping sensors for detection and imaging of hemorrhagic stroke: feasibility in benchtop experimentation
- Author
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Nerses Sanossian, Yu-Chong Tai, Gabriel Zada, Shane Shahrestani, William J. Mack, Ben A Strickland, Arthur W. Toga, and Joshua Bakhsheshian
- Subjects
Intracerebral hemorrhage ,business.industry ,General Medicine ,Bleed ,medicine.disease ,Imaging phantom ,law.invention ,Brain Ischemia ,Stroke ,Hemorrhagic Stroke ,Neuroimaging ,law ,Eddy current ,medicine ,Feasibility Studies ,Humans ,Surgery ,Neurology (clinical) ,business ,Image resolution ,Biomedical engineering ,Point of care ,Cerebral Hemorrhage - Abstract
OBJECTIVE Spontaneous intracerebral hemorrhage occurs in an estimated 10% of stroke patients, with high rates of associated mortality. Portable diagnostic technologies that can quickly and noninvasively detect hemorrhagic stroke may prevent unnecessary delay in patient care and help rapidly triage patients with ischemic versus hemorrhagic stroke. As such, the authors aimed to develop a rapid and portable eddy current damping (ECD) hemorrhagic stroke sensor for proposed in-field diagnosis of hemorrhagic stroke. METHODS A tricoil ECD sensor with microtesla-level magnetic field strengths was constructed. Sixteen gelatin brain models with identical electrical properties to live brain tissue were developed and placed within phantom skull replicas, and saline was diluted to the conductivity of blood and placed within the brain to simulate a hemorrhage. The ECD sensor was used to detect modeled hemorrhages on benchtop models. Data were saved and plotted as a filtered heatmap to represent the lesion location. The individuals performing the scanning were blinded to the bleed location, and sensors were tangentially rotated around the skull models to localize blood. Data were also used to create heatmap images using MATLAB software. RESULTS The sensor was portable (11.4-cm maximum diameter), compact, and cost roughly $100 to manufacture. Scanning time was 2.43 minutes, and heatmap images of the lesion were produced in near real time. The ECD sensor accurately predicted the location of a modeled hemorrhage in all (n = 16) benchtop experiments with excellent spatial resolution. CONCLUSIONS Benchtop experiments demonstrated the proof of concept of the ECD sensor for rapid transcranial hemorrhagic stroke diagnosis. Future studies with live human participants are warranted to fully establish the feasibility findings derived from this study.
- Published
- 2021
42. National Institutes of Health grant opportunities for the neurointerventionalist: preparation and choosing the right mechanism
- Author
-
Robert M. Starke, William J. Mack, Michael R. Levitt, Peter Kan, Felipe C. Albuquerque, Kevin N. Sheth, and Maxim Mokin
- Subjects
Medical education ,Preparation stage ,business.industry ,General Medicine ,Time based ,Article ,Grant writing ,03 medical and health sciences ,Intervention (law) ,0302 clinical medicine ,Premise ,Medicine ,Surgery ,030212 general & internal medicine ,Neurology (clinical) ,Early career ,business ,030217 neurology & neurosurgery ,Mechanism (sociology) - Abstract
ObjectiveThe goal of this article is to provide recommendations for the early career neurointerventionalist in writing a successful grant application to the National Institutes of Health (NIH) and similar funding agencies.MethodsThe authors reviewed NIH rules and regulations and also reflected on their own collective experience in writing NIH grant proposals in the area of cerebrovascular disease and neurointerventional surgery.ResultsA strong proposal should address an important scientific problem where there is a gap in knowledge. The solution offered needs to be innovative but at the same time based on a strong scientific premise. The proposed research must be feasible to implement and investigate in the researcher’s environment.ConclusionSuccessful grant writing is critical in funding and enhancing research. The information in the article may aid in the preparation stage of grant writing for early career neurointerventionalists.
- Published
- 2020
43. Fusiform vertebral artery aneurysms involving the posterior inferior cerebellar artery origin associated with the sole angiographic anterior spinal artery origin: technical case report and treatment paradigm proposal
- Author
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Kristine Ravina, William J. Mack, Robert C. Rennert, Arun P. Amar, Mark Chien, Joshua Bakhsheshian, Vance L Fredrickson, Jonathan J. Russin, and Ben A. Strickland
- Subjects
medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Vertebral artery ,Anterior spinal artery ,Fusiform Aneurysm ,General Medicine ,medicine.disease ,Revascularization ,Surgery ,surgical procedures, operative ,Aneurysm ,Posterior inferior cerebellar artery ,medicine.artery ,cardiovascular system ,Medicine ,cardiovascular diseases ,Embolization ,Medial medullary syndrome ,business - Abstract
Fusiform aneurysms of the vertebral artery (VA) involving the posterior inferior cerebellar artery (PICA) origin are uncommon and challenging. The anterior spinal artery (ASA) commonly originates from a unilateral ramus just distal to the PICA. Occlusion of an unpaired ASA can result in bilateral medial medullary syndrome. The authors propose a treatment paradigm for ASA preservation based on the artery’s proximity to fusiform VA aneurysms, and they present 3 representative cases. In the first case, they performed a V3-PICA bypass using an interposition graft and then performed endovascular coil embolization of the parent VA. A complete occlusion of the aneurysm and VA was complicated by ASA thrombosis. The subsequent cases were treated with PICA-PICA bypass and subsequent endovascular embolization of the VA. Filling of the sole angiographic ASA remote from the aneurysm was preserved in both cases. The anatomy of the ASA is the most critical determinant of treatment recommendations for fusiform VA aneurysms involving PICA. When the ASA originates from the aneurysm, proximal occlusion with or without a PICA bypass is suggested. In cases in which the ASA is removed from the aneurysm, the authors recommend revascularization followed by endovascular sacrifice. When the aneurysm is immediately adjacent to the ASA, revascularization and open trapping should be considered.
- Published
- 2019
44. Nonindex Readmission After Ruptured Brain Aneurysm Treatment Is Associated with Higher Morbidity and Repeat Readmission
- Author
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Li Ding, Ben A. Strickland, Steven L. Giannotta, Casey A. Jarvis, Austin M. Tang, Edith Yuan, William J. Mack, Joshua Bakhsheshian, Frank J. Attenello, and Arun P. Amar
- Subjects
Adult ,Male ,Brain aneurysm ,medicine.medical_specialty ,Subarachnoid hemorrhage ,Adolescent ,Aneurysm, Ruptured ,Logistic regression ,Patient Readmission ,Article ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Aneurysm ,Risk Factors ,medicine ,Humans ,Aged ,Retrospective Studies ,Aged, 80 and over ,Hospital readmission ,business.industry ,Intracranial Aneurysm ,Odds ratio ,Middle Aged ,medicine.disease ,Confidence interval ,Treatment Outcome ,030220 oncology & carcinogenesis ,Emergency medicine ,Female ,Surgery ,Continuity of care ,Neurology (clinical) ,Morbidity ,business ,030217 neurology & neurosurgery - Abstract
Background Aneurysmal subarachnoid hemorrhage (aSAH) requires complex multidisciplinary care. After initial treatment (index hospital), readmission to a different hospital (nonindex) can compromise quality of care, resulting in increased morbidity. We aimed to evaluate factors associated with nonindex readmission and evaluate association of nonindex hospital readmission on outcomes in patients with ruptured aneurysm. Methods Readmissions within 90 days after aSAH treatment were identified in the 2010–2014 Nationwide Readmissions Database. Multivariable logistic regression identified patient and hospital characteristics associated with nonindex readmission. Separate multivariable models determined increased morbidity or risk of second readmission for nonindex readmissions. Results A total of 9254 patients who underwent treatment of ruptured aneurysms from 2010 to 2014 were identified. Of these, 1985 (21.5%) were readmitted within 90 days. Three hundred and fifty-five of these readmissions (17.9%) occurred to nonindex hospitals. Patients that were discharged to a skilled nursing or other facility (odds ratio [OR], 1.70; 95% confidence interval [CI], 1.27–2.28]) had higher odds of nonindex readmission, whereas patients with private insurance were associated with lower odds of nonindex readmission (OR, 0.65; 95% CI, 0.46–0.92). Patients readmitted to a nonindex (vs. index) hospital were associated with increased likelihood of major complications (OR, 1.71; 95% CI, 1.18–2.48) and second readmissions (OR, 1.51; 95% CI, 1.17–1.96). Conclusions After treatment of a ruptured cerebral aneurysm, 17.9% of readmissions occurred at a nonindex hospital. These patients were at increased risk for major complications or subsequent readmissions, which may be because of care fragmentation. Interventions aimed at improving continuity of care may reduce higher morbidity associated with nonindex readmission.
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- 2019
45. Postpartum Psychiatric Admissions in the United States
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Jason D. Wright, Alexander M. Friedman, William J. Mack, Frank J. Attenello, Timothy Wen, Arielle W. Fein, and Mary E. D'Alton
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Adult ,medicine.medical_specialty ,Younger age ,Adolescent ,Databases, Factual ,Comorbidity ,Medicare ,Patient Readmission ,Depression, Postpartum ,Young Adult ,03 medical and health sciences ,Psychiatric comorbidity ,0302 clinical medicine ,Pregnancy ,Risk Factors ,Humans ,Medicine ,030212 general & internal medicine ,Psychiatry ,Lower income ,030219 obstetrics & reproductive medicine ,Medicaid ,business.industry ,Mental Disorders ,Postpartum Period ,Obstetrics and Gynecology ,Middle Aged ,United States ,Quartile ,Pediatrics, Perinatology and Child Health ,Psychiatric diagnosis ,Linear Models ,Female ,business - Abstract
Objective This study aimed to assess risk for postpartum psychiatric admissions in the United States. Study Design This study used the 2010 to 2014 Nationwide Readmissions Database to identify psychiatric admissions during the first 60 days after delivery hospitalization. Timing of admission after delivery discharge was determined. We fit multivariable log-linear regression models to assess the impact of psychiatric comorbidity on admission risk, adjusting for patient, obstetrical, and hospital factors. Results Of 15.7 million deliveries from 2010 to 2014, 11,497 women (0.07%) were readmitted for a primary psychiatric diagnosis within 60 days postpartum. Psychiatric admissions occurred relatively consistently across 10-day periods after delivery hospitalization discharge. Psychiatric diagnoses were present among 5% of women at delivery but 40% of women who were readmitted postpartum for a psychiatric indication. In the adjusted model, women with psychiatric diagnoses at delivery hospitalization were 9.7 times more likely to be readmitted compared with those without psychiatric comorbidity. Women at highest risk for psychiatric admission were those with Medicare and Medicaid, in lower income quartiles, and of younger age. Conclusion While a large proportion of psychiatric admissions occurred among a relatively small proportion of at-risk women, admissions occurred over a broad temporal period relative to other indications for postpartum admission.
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- 2019
46. Early Readmission After Ventricular Shunting in Adults with Hydrocephalus: A Nationwide Readmission Database Analysis
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Timothy Wen, Daniel A. Donoho, Steven Cen, Ian A. Buchanan, Li Ding, Frank J. Attenello, Steven L. Giannotta, Arati Patel, and William J. Mack
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Adult ,Male ,Shunt placement ,medicine.medical_specialty ,Younger age ,Adolescent ,Database analysis ,Comorbidity ,Insurance type ,Medicare ,Patient Readmission ,Ventriculoperitoneal Shunt ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Risk Factors ,Odds Ratio ,medicine ,Humans ,Heart Atria ,Spinal Dysraphism ,Aged ,Insurance, Health ,Brain Neoplasms ,Medicaid ,business.industry ,Age Factors ,Length of Stay ,Middle Aged ,Ventricular shunt ,medicine.disease ,Cerebrospinal Fluid Shunts ,Hydrocephalus, Normal Pressure ,United States ,Hydrocephalus ,Shunting ,030220 oncology & carcinogenesis ,Emergency medicine ,Pleura ,Female ,Surgery ,Neurology (clinical) ,business ,030217 neurology & neurosurgery ,Shunt (electrical) - Abstract
Background Ventricular shunting is one of the primary modalities for addressing hydrocephalus in both children and adults. Despite advances in shunt technology and surgical practices, shunt failure is a persistent challenge for neurosurgeons, and shunt revisions account for a substantial proportion of all shunt-related procedures. There are a wealth of studies elucidating failure patterns and patient demographics in pediatric cohorts; however, data in adults are less uniform. We sought to determine the rates of all-cause and shunt failure readmission in adults who underwent the insertion of a ventricular shunt. Methods We queried the Nationwide Readmissions Database from 2010 to 2014 to evaluate new ventricular shunts placed in adults with hydrocephalus. We sought to determine the rates of all-cause and shunt revision-related readmissions and to characterize factors associated with readmissions. We analyzed predictors including patient demographics, hospital characteristics, shunt type, and hydrocephalus cause. Results Analysis included 24,492 initial admissions for shunt placement in patients with hydrocephalus. Of patients, 9.17% required a shunt revision within the first 6 months; half of all revisions occurred within the first 41 days. There were 4044 (16.50%) 30-day and 5758 (28.8%) 90-day all-cause readmissions. In multivariable analysis, patients with a ventriculopleural shunt, Medicare insurance, and younger age had increased likelihood for shunt revision. Notable predictors for all-cause readmission were insurance type, length of hospitalization, age, comorbidities, and hydrocephalus cause. Conclusions Most shunt revisions occurred during the first 2 months. Readmissions occurred frequently. We identified patient factors that were associated with all-cause and shunt failure readmissions.
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- 2019
47. Frequency, predictors, and outcomes of readmission to index versus non-index hospitals after mechanical thrombectomy in patients with ischemic stroke
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Arati Patel, Li Ding, Michelle Connor, Arun P. Amar, Qinghai Liu, Kristina Shkirkova, William J. Mack, Nerses Sanossian, Frank J. Attenello, and Krista Lamorie-Foote
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Adult ,Male ,medicine.medical_specialty ,Time Factors ,Index (economics) ,Adolescent ,Databases, Factual ,Logistic regression ,Patient Readmission ,Brain Ischemia ,Cohort Studies ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,In patient ,030212 general & internal medicine ,Stroke ,Aged ,Retrospective Studies ,Thrombectomy ,Aged, 80 and over ,business.industry ,Atrial fibrillation ,General Medicine ,Middle Aged ,medicine.disease ,Hospitals ,Mechanical thrombectomy ,Treatment Outcome ,Ischemic stroke ,Emergency medicine ,Female ,Surgery ,Neurology (clinical) ,business ,Complication ,030217 neurology & neurosurgery - Abstract
BackgroundStroke systems of care employ a hub-and-spoke model, with fewer centers performing mechanical thrombectomy (MT) compared with stroke-receiving centers, where a higher number offer high-level, centralized treatment to a large number of patients.ObjectiveTo characterize rates and outcomes of readmission to index and non-index hospitals for patients with ischemic stroke who underwent MT.MethodsThis study leveraged a population-based, nationally representative sample of patients with stroke undergoing MT from the Nationwide Readmissions Database between 2010 and 2014. Descriptive, logistic regression analyses, and univariate and multivariate logistic regression models were carried out to determine patient- and hospital-level factors, mortality, complications, and subsequent readmissions associated with index and non-index hospitals' 90-day readmissions.ResultsIn the study, 2111 patients with a stroke were treated with MT, of whom 534 were readmitted within 90 days. The most common reasons for readmission were: septicemia (5.9%), atrial fibrillation (4.8%), and cerebral artery occlusion with infarct (4.8%). Among readmitted patients, 387 (74%) were readmitted to index and 136 (26%) to non-index hospitals. On multivariable logistic regression analysis, non-index hospital readmission was not independently associated with major complications (p=0.09), mortality (p=0.34), neurological complications (p=0.47), or second readmission (p=0.92).ConclusionOne-quarter of patients with a stroke treated with MT were readmitted within 90 days, and one quarter of these patients were readmitted to non-index hospitals. Readmission to a non-index hospital was not associated with mortality or increased complication rates. In a hub-and-spoke model it is important that follow-up care for a specialized procedure can be performed effectively at a vast number of non-index hospitals covering a large geographic area.
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- 2019
48. Risk for postpartum readmissions and associated complications based on maternal age
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Eve Overton, Timothy Wen, Jean-Ju Sheen, Mary E. D'Alton, Alexander M. Friedman, William J. Mack, and Frank J. Attenello
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Adult ,Pediatrics ,medicine.medical_specialty ,Patient Readmission ,Article ,03 medical and health sciences ,0302 clinical medicine ,Pregnancy ,Risk Factors ,Humans ,Medicine ,030212 general & internal medicine ,Advanced maternal age ,Retrospective Studies ,030219 obstetrics & reproductive medicine ,business.industry ,Postpartum Period ,Obstetrics and Gynecology ,Retrospective cohort study ,Patient Discharge ,humanities ,Pediatrics, Perinatology and Child Health ,Severe morbidity ,Female ,business ,Maternal Age - Abstract
BACKGROUND: Recent recommendations support more intensive postpartum care for women at risk for complications. Advanced maternal age (AMA) is associated with risk for adverse outcomes, but readmission risk based on maternal age is not well characterized. OBJECTIVE: To evaluate risk for postpartum readmissions and associated severe morbidity by maternal age. METHODS: This retrospective cohort study used the Nationwide Readmission Database to analyze 60-day all-cause postpartum readmission risk from 2010 to 2014. Risk for severe maternal morbidity (SMM) during readmission was ascertained using criteria from the Centers for Disease Control and Prevention. The primary exposure of interest was maternal age. Outcomes included time to readmission, risk of readmission, and risk for SMM during readmission. Multivariable log linear analyses adjusting for patient, obstetric, and hospital factors were conducted to assess readmission and SMM risk with adjusted risk ratios (aRR) with 95% confidence intervals (CI) as measures of effect. RESULTS: Between 2010-2014, we identified 15.7 million deliveries, 15% of which were to women aged 35 or older. The 60-day all-cause readmission rate was 1.7%. Of these, 13% were complicated by SMM. Age-stratification revealed that women 35 and older were at increased risk for readmission and increased risk for SMM. The majority of readmissions occurred within the first 20 days regardless of age, although women 35 and older were more likely to be admitted within the first 10 days of discharge. Patients ages 35-39, 40-44, and >44 years had 9% (95% CI 7-10%), 37% (95% CI 34-39%), and 66% (95% CI 55-79%) significantly higher rates of postapartum readmission when compared to women age 25-29. Women 35-39, 40-44, and >44 years of age had a 15% (95% CI 10-21%), 26% (95% CI 18-34%), and 56% (95% CI 25-94%) higher risk of a readmission with SMM than women 25-29. CONCLUSIONS: AMA women are at higher risk for both postpartum readmission and severe morbidity during readmission. Women older than 35 years represent the group most likely to experience complications requiring readmission, with the highest risk age 40 and older.
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- 2019
49. Venous Thromboembolism After Degenerative Spine Surgery: A Nationwide Readmissions Database Analysis
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Daniel A. Donoho, Ian A. Buchanan, Frank J. Attenello, Li Ding, John C. Liu, Michelle Lin, Steven L. Giannotta, and William J. Mack
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Adult ,Male ,medicine.medical_specialty ,Time Factors ,Multivariate analysis ,Adolescent ,Intervertebral Disc Degeneration ,Logistic regression ,Patient Readmission ,Article ,Thoracic Vertebrae ,Young Adult ,03 medical and health sciences ,Postoperative Complications ,0302 clinical medicine ,Adrenal Cortex Hormones ,Risk Factors ,Acute care ,medicine ,Humans ,cardiovascular diseases ,Aged ,Lumbar Vertebrae ,business.industry ,Incidence (epidemiology) ,Venous Thromboembolism ,Odds ratio ,Perioperative ,Length of Stay ,Middle Aged ,equipment and supplies ,medicine.disease ,Deep vein thrombosis (DVT) ,030220 oncology & carcinogenesis ,Emergency medicine ,Chemoprophylaxis ,Surgery ,Neurology (clinical) ,business ,030217 neurology & neurosurgery - Abstract
Venous thromboembolism (VTE) is an appreciable burden on health care. The protracted recumbency experienced by many spinal patients juxtaposed with concerns for postoperative hemorrhage from early anticoagulation results in conflicting stances regarding chemoprophylaxis. Identifying risk factors associated with VTE is therefore instrumental in guiding management.To identify VTE risk factors in patients undergoing degenerative spine surgery.The Nationwide Readmissions Database was searched for adults undergoing spine surgery for degenerative diseases between 2010 and 2014. The 30-day and 90-day VTE incidence was estimated from readmissions with new VTE diagnoses. A multivariate survey-adjusted logistic regression model was used to identify variables associated with VTE diagnoses on readmission.Of 838,507 degenerative spine cases queried, 3499 patients (0.42%) were readmitted with a VTE diagnosis within 30 days and 4321 patients (0.62%) were readmitted within 90 days. In multivariate analysis, steroids were independently associated with a higher likelihood of readmission with VTE at both 30 days (odds ratio, 1.58; P0.001) and 90 days (odds ratio, 1.97; P0.001). Significant associations were also identified with thoracolumbar surgery, length of stay, and discharge to institutional care.The incidence of readmission with VTE diagnoses in spine surgery is low. However, their devastating consequences underscore the need to identify those patients deemed high risk. These patients include those having thoracolumbar surgery, of advanced age, with prolonged length of stay, using corticosteroids, and with a disposition to institutional care (e.g., skilled nursing facility or long-term acute care). Given the association between steroids and VTE, clinicians should be judicious about perioperative administration despite their obvious antiinflammatory benefits.
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- 2019
50. Treatment at Safety-Net Hospitals Is Associated with Delays in Coil Embolization in Patients with Subarachnoid Hemorrhage
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Daniel A. Donoho, Arun P. Amar, Ian A. Buchanan, Frances Chow, William J. Mack, Arati Patel, Frank J. Attenello, and Li Ding
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Adult ,Male ,medicine.medical_specialty ,Multivariate analysis ,Subarachnoid hemorrhage ,Databases, Factual ,medicine.medical_treatment ,Psychological intervention ,Article ,Time-to-Treatment ,03 medical and health sciences ,0302 clinical medicine ,Aneurysm ,medicine ,Humans ,030212 general & internal medicine ,Healthcare Disparities ,Aged ,Coil embolization ,Medically Uninsured ,Endovascular coiling ,Medicaid ,business.industry ,Endovascular Procedures ,Middle Aged ,Subarachnoid Hemorrhage ,medicine.disease ,Embolization, Therapeutic ,United States ,Quartile ,Multivariate Analysis ,Emergency medicine ,Female ,Surgery ,Neurology (clinical) ,business ,Safety-net Providers ,030217 neurology & neurosurgery - Abstract
INTRODUCTION: Successful endovascular management of aneurysmal subarachnoid hemorrhage (aSAH) requires timely access to significant resources. Prior studies suggest an association between time to treatment and patient outcome. Patients treated at safety- net hospitals are thought to be particularly vulnerable to disparities in access to interventions that require substantial technological resources. We hypothesize that patients treated at safety-net hospitals are at greater risk for delayed access to endovascular treatment. MATERIALS AND METHODS: Adults undergoing endovascular coiling procedures between 2002–2011 in the Nationwide Inpatient Sample were included. Hospitals in the quartile with the highest proportion of Medicaid or uninsured patients were defined as safety-net hospitals. A multivariable model including patient and hospital-level factors was constructed to permit analysis of delays in endovascular treatment (defined as time to treatment greater than 3 days). RESULTS: Analysis included 7,109 discharges of patients with aSAH undergoing endovascular coil embolization procedures from 2002–2011. The median time to coil embolization in all patients was 1 day; 10.1% of patients waited more than three days until treatment. In multivariable analysis, patients treated at safety-net hospitals were more likely to have a prolonged time to coil embolization (OR 1.32, p
- Published
- 2018
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