Publications by authors named "Mark Keegan"

Spinal cord disease is important in most people with multiple sclerosis, but assessment remains less emphasized in patient care, basic and clinical research and therapeutic trials. The North American Imaging in Multiple Sclerosis Spinal Cord Interest Group was formed to determine and present the contemporary landscape of multiple sclerosis spinal cord evaluation, further existing and advanced spinal cord imaging techniques, and foster collaborative work. Important themes arose: (i) multiple sclerosis spinal cord lesions (differential diagnosis, association with clinical course); (ii) spinal cord radiological-pathological associations; (iii) 'critical' spinal cord lesions; (iv) multiple sclerosis topographical model; (v) spinal cord atrophy; and (vi) automated and special imaging techniques.

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Background: Differences in the MS course between White and Black populations is well accepted. The existence of a large Somali immigrant population in Minnesota facilitates a study of MS characteristics in this immigrant native African population. The objective of this study was to compare Somali American (SA), African American (AA), and White American (WA) persons with MS (pwMS) regarding clinical features and disease modifying therapy (DMT) use.

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In response to the COVID-19 pandemic, the American Board of Anesthesiology transitioned from in-person to virtual administration of its APPLIED Examination, assessing more than 3000 candidates for certification purposes remotely in 2021. Four hundred examiners were involved in delivering and scoring Standardized Oral Examinations (SOEs) and Objective Structured Clinical Examinations (OSCEs). More than 80% of candidates started their exams on time and stayed connected throughout the exam without any problems.

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Purpose: The COVID-19 pandemic prompted training institutions and national credentialing organizations to administer examinations virtually. This study compared task difficulty, examiner grading, candidate performance, and other psychometric properties between in-person and virtual standardized oral examinations (SOEs) administered by the American Board of Anesthesiology.

Method: This retrospective study included SOEs administered in person from March 2018 to March 2020 and virtually from December 2020 to November 2021.

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Background And Purpose: Progressive MS is typically heralded by a myelopathic pattern of asymmetric progressive motor weakness. Focal individual "critical" demyelinating spinal cord lesions anatomically associated with progressive motor impairment may be a compelling explanation for this clinical presentation as described in progressive solitary sclerosis (single CNS demyelinating lesion), progressive demyelination with highly restricted MR imaging lesion burden (2-5 total CNS demyelinating lesions; progressive paucisclerotic MS), and progressive, exclusively unilateral hemi- or monoparetic MS (>5 CNS demyelinating progressive unilateral hemi- or monoparetic MS [PUHMS] lesions). Critical demyelinating lesions appear strikingly similar across these cohorts, and we describe their specific spinal cord MR imaging characteristics.

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Background: The purpose of this study was to evaluate relationships between demographics, professional characteristics, and perceived challenges facing the specialty of anesthesiology among physicians who entered a fellowship and those who started independent practice immediately after finishing a U.S. anesthesiology residency.

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Background: The American Board of Anesthesiology's Objective Structured Clinical Examination (OSCE), as a component of its initial certification process, had been administered in-person in a dedicated assessment center since its launch in 2018 until March 2020. Due to the COVID-19 pandemic, a virtual format of the exam was piloted in December 2020 and was administered in 2021. This study aimed to compare candidate performance, examiner grading severity, and scenario difficulty between these two formats of the OSCE.

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Cerebellar dysfunction is likely to cause severe and treatment-resistant disability in multiple sclerosis (MS). Certain spinocerebellar ataxia (SCA)-related alleles can increase MS susceptibility, and channel polymorphisms can impact disability measures. Following an index patient with the coexistence of MS and SCA Type-8 (SCA8) in the MS clinic, an institutional engine search for MS and hereditary ataxia coexistence was conducted but did not reveal any other cases.

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Study Objective: This study sought to understand the timing and important factors identified by residents regarding their decision to pursue a career in anesthesiology, training areas deemed important to their future success, perceived greatest challenges facing the profession of anesthesiology, and their post-residency plans.

Design: The American Board of Anesthesiology administered voluntary, anonymous, repeated cross-sectional surveys to residents who began clinical anesthesia training in the U.S.

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Background: Spinal cord lesions have been associated with progressive disease in individuals with typical relapsing remitting MS (RRMS).

Objective: In the current study, we aimed to determine if progressive disease is associated with spinal cord lesions in those with tumefactive multiple sclerosis (MS).

Methods: Retrospective chart review of individuals presenting to Mayo Clinic with tumefactive MS with spinal cord MRIs available (n=159).

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Background: Progressive motor impairment anatomically associated with a "critical" lesion has been described in primary demyelinating disease. Most "critical" lesions occur within the spinal cord.

Objective: To describe the clinical and radiological features of "critical" lesions of the cervicomedullary junction (CMJ).

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Among people with multiple sclerosis, cognitive impairment occurs commonly and is a potent predictor of disability. Some multiple sclerosis patients present with severe cognitive impairment, and distinguishing multiple sclerosis-related cognitive impairment from co-existent progressive neurodegenerative diseases such as Alzheimer disease poses a diagnostic challenge. The use of biomarkers such as PET and CSF proteins may facilitate this distinction.

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Background: Preoperative risk scores facilitate patient selection, but postoperative risk scores may offer valuable information for predicting outcomes. We hypothesized that the postoperative Sequential Organ Failure Assessment (SOFA) score would predict mortality after left ventricular assist device (LVAD) implantation.

Methods: We retrospectively reviewed data from 294 continuous-flow LVAD implantations performed at Mayo Clinic Rochester during 2007 to 2015.

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Background: Elevated intrathecal immunoglobulin G (IgG; oligoclonal bands (OCBs)) or IgG in people with progressive motor impairment due to "critical" demyelinating lesions are of uncertain significance.

Objective: Compare clinical/radiological features of people with "critical" demyelinating lesion-induced progressive motor impairment with/without elevated intrathecal IgG synthesis.

Methods: A total of 133 people with progressive motor impairment attributable to "critical" demyelinating lesions (corticospinal tract location, consistent with the progressive motor deficit) were compared regarding clinical and radiological presentation with and without ≥2 unique cerebrospinal fluid (CSF) OCB and/or IgG index ≥0.

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In 2020, the coronavirus disease 2019 (COVID-19) pandemic interrupted the administration of the APPLIED Examination, the final part of the American Board of Anesthesiology (ABA) staged examination system for initial certification. In response, the ABA developed, piloted, and implemented an Internet-based "virtual" form of the examination to allow administration of both components of the APPLIED Exam (Standardized Oral Examination and Objective Structured Clinical Examination) when it was impractical and unsafe for candidates and examiners to travel and have in-person interactions. This article describes the development of the ABA virtual APPLIED Examination, including its rationale, examination format, technology infrastructure, candidate communication, and examiner training.

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Background And Objective: There are few studies comparing lesion evolution across different CNS demyelinating diseases, yet knowledge of this may be important for diagnosis and understanding differences in disease pathogenesis. We sought to compare MRI T2 lesion evolution in myelin oligodendrocyte glycoprotein immunoglobulin G (IgG)-associated disorder (MOGAD), aquaporin 4 IgG-positive neuromyelitis optica spectrum disorder (AQP4-IgG-NMOSD), and multiple sclerosis (MS).

Methods: In this descriptive study, we retrospectively identified Mayo Clinic patients with MOGAD, AQP4-IgG-NMOSD, or MS and (1) brain or myelitis attack; (2) available attack MRI within 6 weeks; and (3) follow-up MRI beyond 6 months without interval relapses in that region.

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Background: A temporary decrease in anesthesiology residency graduates that occurred around the turn of the millennium may have workforce implications. The aims of this study are to describe, between 2005 and 2015, (1) demographic changes in the workforce of physicians trained as anesthesiologists; (2) national and state densities of these physicians, as well as temporal changes in the densities; and (3) retention of medical licenses by mid- and later-career anesthesiologists.

Methods: Using records from the American Board of Anesthesiology and state medical and osteopathic boards, the numbers of licensed physicians aged 30-59 years who had completed Accreditation Council for Graduate Medical Education-accredited anesthesiology residency training were calculated cross-sectionally for 2005, 2010, and 2015.

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Background: Anesthesiology residents' experiences and perspectives about their programs may be helpful in improving training. The goals of this repeated cross-sectional survey study are to determine: (1) the most important factors residents consider in choosing an anesthesiology residency, (2) the aspects of the clinical base year that best prepare residents for anesthesia clinical training, and what could be improved, (3) whether residents are satisfied with their anesthesiology residency and what their primary struggles are, and (4) whether residents believe their residency prepares them for proficiency in the 6 Accreditation Council for Graduate Medical Education (ACGME) Core Competencies and for independent practice.

Methods: Anesthesiologists beginning their US residency training from 2013 to 2016 were invited to participate in anonymous, confidential, and voluntary self-administered online surveys.

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In 2018, the American Board of Anesthesiology (ABA) became the first US medical specialty certifying board to incorporate an Objective Structured Clinical Examination (OSCE) into its initial certification examination system. Previously, the ABA's staged examination system consisted of 2 written examinations (the BASIC and ADVANCED examinations) and the Standardized Oral Examination (SOE). The OSCE and the existing SOE are now 2 separate components of the APPLIED Examination.

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Background: New inflammatory activity is of unclear frequency and clinical significance in progressive multiple sclerosis (MS); it is uncertain in patient cohorts with motor progression due to critical demyelinating lesions.

Objectives: The aim of this study is to determine the likelihood of central nervous system (CNS) inflammatory activity, assessed by new clinical relapses or active magnetic resonance imaging (MRI) lesions, following onset of motor progression due to critical demyelinating lesions.

Methods: Patients with progressive upper motor neuron impairment for ⩾1 year attributable to critical demyelinating lesions with single CNS lesion (progressive solitary sclerosis (PSS)), 2 to 5 total CNS demyelinating lesions (progressive "pauci-sclerosis" (PPS)), or >5 CNS demyelinating lesions and progressive exclusively unilateral monoparesis or hemiparesis (PUHMS) were identified.

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