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Miller TA, Ross DC. Sciatic and tibial neuropathies. HANDBOOK OF CLINICAL NEUROLOGY 2024; 201:165-181. [PMID: 38697738 DOI: 10.1016/b978-0-323-90108-6.00003-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Abstract
The sciatic nerve is the body's largest peripheral nerve. Along with their two terminal divisions (tibial and fibular), their anatomic location makes them particularly vulnerable to trauma and iatrogenic injuries. A thorough understanding of the functional anatomy is required to adequately localize lesions in this lengthy neural pathway. Proximal disorders of the nerve can be challenging to precisely localize among a range of possibilities including lumbosacral pathology, radiculopathy, or piriformis syndrome. A correct diagnosis is based upon a thorough history and physical examination, which will then appropriately direct adjunctive investigations such as imaging and electrodiagnostic testing. Disorders of the sciatic nerve and its terminal branches are disabling for patients, and expert assessment by rehabilitation professionals is important in limiting their impact. Applying techniques established in the upper extremity, surgical reconstruction of lower extremity nerve dysfunction is rapidly improving and evolving. These new techniques, such as nerve transfers, require electrodiagnostic assessment of both the injured nerve(s) as well as healthy, potential donor nerves as part of a complete neurophysiological examination.
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Affiliation(s)
- Thomas A Miller
- Department of Physical Medicine and Rehabilitation, Schulich School of Medicine and Dentistry, Western University, St. Joseph's Health Care, Parkwood Institute, London, ON, Canada.
| | - Douglas C Ross
- Division of Plastic Surgery, Schulich School of Medicine and Dentistry, Western University, St. Joseph's Health Care, Roth McFarlane Hand and Upper Limb Centre, London, ON, Canada
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2
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Acute Flaccid Myelitis: Review of Clinical Features, Diagnosis, and Management with Nerve Transfers. Plast Reconstr Surg 2023; 151:85e-98e. [PMID: 36219869 DOI: 10.1097/prs.0000000000009788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND Acute flaccid myelitis (AFM) is a devastating neurologic condition in children, manifesting as acute limb weakness and/or paralysis. Despite increased awareness of AFM following initiation of U.S. surveillance in 2014, no treatment consensus exists. The purpose of this systematic review was to summarize the most current knowledge regarding AFM epidemiology, cause, clinical features, diagnosis, and supportive and operative management, including nerve transfer. METHODS The authors systematically reviewed the literature based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using multiple databases to search the keywords ("acute flaccid myelitis"), ('acute flaccid myelitis'/exp OR 'acute flaccid myelitis'), and (Acute AND flaccid AND myelitis). Included articles reported on (1) AFM diagnosis and (2) patient-specific data regarding epidemiology, cause, clinical features, diagnostic features, or management of AFM. RESULTS Ninety-nine articles were included in this review. The precise cause and pathophysiologic mechanism of AFM remain undetermined, but AFM is strongly associated with nonpolio enterovirus infections. Clinical presentation typically comprises preceding viral prodrome, pleocytosis, spinal cord lesions on T2-weighted magnetic resonance imaging, and acute onset of flaccid weakness/paralysis with hyporeflexia in at least one extremity. Supportive care includes medical therapy and rehabilitation. Early studies of nerve transfer for AFM have shown favorable outcomes for patients with persistent weakness. CONCLUSIONS Supportive care and physical therapy are the foundation of a multidisciplinary approach to managing AFM. For patients with persistent limb weakness, nerve transfer has shown promise for improving function in distal muscle groups. Surgeons must consider potential spontaneous recovery, patient selection, donor nerve availability, recipient nerve appropriateness, and procedure timing.
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Toopchizadeh V, Barzegar M, Ranjbar-Kiyakalayeh S, Shahidzadeh A, Khakbiz S, Jahanshahi A, Jahanjoo F. Clinical presentation, electrodiagnostic findings and outcomes of acute flaccid myelitis: A brief review and case series. J Pediatr Rehabil Med 2022; 15:369-376. [PMID: 35634814 DOI: 10.3233/prm-200798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Acute flaccid myelitis (AFM) is an acute condition occurring mostly in children. Although affected patients can show a broad spectrum of symptoms, it is mainly characterized by the progressive onset of focal limb weakness, presenting over a period of hours to a week, with or without pain, and spinal cord gray matter involvement on magnetic resonance imaging (MRI). There is compelling evidence to support the role of viruses, in particular enteroviruses. Studies describing electrodiagnostic (EDX) abnormalities and long-term outcomes in AFM are limited. In this report, the clinical presentation, EDX and MRI findings, and long-term outcomes in three children with AFM who presented with progressive and asymmetric weakness of the limbs are described. MRI showed a long segment cervicothoracic lesion with vertical expansion in all three cases. Patients do recover in time, but many continue to have permanent muscle weakness in the worst affected part(s), and complete recovery is rare. Follow-up of these three cases at 18 months demonstrated a partial recovery in the motor system.
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Affiliation(s)
- Vahideh Toopchizadeh
- Physical Medicine and Rehabilitation Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Barzegar
- Pediatric Health Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Sepideh Ranjbar-Kiyakalayeh
- Physical Medicine and Rehabilitation Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Azadeh Shahidzadeh
- Physical Medicine and Rehabilitation Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Saide Khakbiz
- Physical Medicine and Rehabilitation Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amirreza Jahanshahi
- Department of Radiology, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Fatemeh Jahanjoo
- Road Traffic Injury Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
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4
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Chong PF, Torisu H, Yasumoto S, Okumura A, Mori H, Sato T, Kimura J, Ohga S, Tanaka-Taya K, Kira R. Clinical and electrophysiological features of acute flaccid myelitis: A national cohort study. Clin Neurophysiol 2021; 132:2456-2463. [PMID: 34454273 DOI: 10.1016/j.clinph.2021.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 07/06/2021] [Accepted: 07/13/2021] [Indexed: 10/20/2022]
Abstract
OBJECTIVE To summarize the neurophysiological properties of acute flaccid myelitis (AFM) and evaluate limb-based motor outcomes. METHODS Nerve conduction studies (NCS) in 49 patients (21 females, 28 males; median age = 52 m) with AFM (median = 7 d after onset; range 1-122 d) were reviewed. Neurophysiological findings, together with treatment and prognosis, and neurophysiology-neuroimaging correlations were analyzed. RESULTS The findings indicated that 64% of paralytic limbs during the acute stage (≤14 d after onset) showed diminished or absent compound muscle action potentials (CMAPs), 79% showed normal motor nerve conduction velocities, 55% showed decreased persistence or absent F-waves, and 95% showed normal sensory nerve conduction velocities. The rate of CMAP abnormalities increased from 41% on days 1-2 to 83% on days 13-14. The reduction in CMAP amplitude was correlated with weaker muscle strength at both the peak neurological deficit and the last follow-up. The baseline limb-based muscle strength at nadir and anterior horn-localized magnetic resonance imaging lesions at recovery stage (>14 d) were strong predictors of outcome at the last follow-up. CONCLUSIONS AFM typically shows neurophysiological features of neuronopathy. SIGNIFICANCE NCS is probably useful in the diagnosis and evaluation of AFM.
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Affiliation(s)
- Pin Fee Chong
- Department of Pediatric Neurology, Fukuoka Children's Hospital, Fukuoka, Japan; Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Hiroyuki Torisu
- Section of Pediatrics, Department of Medicine, Fukuoka Dental College, Fukuoka, Japan
| | - Sawa Yasumoto
- Medical Education Center, Fukuoka University School of Medicine, Fukuoka, Japan
| | - Akihisa Okumura
- Department of Pediatrics, Aichi Medical University, Nagakute, Aichi, Japan
| | - Harushi Mori
- Department of Radiology, Jichi Medical University, Tochigi, Japan
| | - Tatsuharu Sato
- Department of Pediatrics, Nagasaki University Hospital, Nagasaki, Japan
| | - Jun Kimura
- Division of Clinical Electrophysiology, Department of Neurology, University of Iowa Health Care, Iowa City, IA, USA
| | - Shouichi Ohga
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Keiko Tanaka-Taya
- Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Ryutaro Kira
- Department of Pediatric Neurology, Fukuoka Children's Hospital, Fukuoka, Japan.
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5
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Abstract
Acute flaccid myelitis (AFM) is an incompletely understood neurologic disorder occurring in epidemic fashion causing weakness ranging from mild paresis to devastating paralysis in children and some adults. This article reviews the case definition of AFM as well as its epidemiology and association with enteroviral infection. The clinical presentation, diagnostic investigation with particular attention to electrodiagnostics, acute management, and surgical options are described. Clinical outcomes and considerations for acute and long-term rehabilitation management are discussed extensively based on review of current literature, highlighting avenues for further study.
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Affiliation(s)
- William Ide
- Department of Pediatric Rehabilitation, Kennedy Krieger Institute, 707 North Broadway, Ste. 232, Baltimore, MD 21205, USA; Department of Physical Medicine & Rehabilitation, Johns Hopkins University School of Medicine
| | - Michelle Melicosta
- Department of Pediatric Rehabilitation, Kennedy Krieger Institute, 707 North Broadway, Ste. 232, Baltimore, MD 21205, USA; Department of Pediatrics, Johns Hopkins University School of Medicine
| | - Melissa K Trovato
- Department of Pediatric Rehabilitation, Kennedy Krieger Institute, 707 North Broadway, Ste. 232, Baltimore, MD 21205, USA; Department of Physical Medicine & Rehabilitation, Johns Hopkins University School of Medicine.
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6
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Murphy OC, Messacar K, Benson L, Bove R, Carpenter JL, Crawford T, Dean J, DeBiasi R, Desai J, Elrick MJ, Farias-Moeller R, Gombolay GY, Greenberg B, Harmelink M, Hong S, Hopkins SE, Oleszek J, Otten C, Sadowsky CL, Schreiner TL, Thakur KT, Van Haren K, Carballo CM, Chong PF, Fall A, Gowda VK, Helfferich J, Kira R, Lim M, Lopez EL, Wells EM, Yeh EA, Pardo CA. Acute flaccid myelitis: cause, diagnosis, and management. Lancet 2021; 397:334-346. [PMID: 33357469 PMCID: PMC7909727 DOI: 10.1016/s0140-6736(20)32723-9] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 09/15/2020] [Accepted: 09/17/2020] [Indexed: 12/20/2022]
Abstract
Acute flaccid myelitis (AFM) is a disabling, polio-like illness mainly affecting children. Outbreaks of AFM have occurred across multiple global regions since 2012, and the disease appears to be caused by non-polio enterovirus infection, posing a major public health challenge. The clinical presentation of flaccid and often profound muscle weakness (which can invoke respiratory failure and other critical complications) can mimic several other acute neurological illnesses. There is no single sensitive and specific test for AFM, and the diagnosis relies on identification of several important clinical, neuroimaging, and cerebrospinal fluid characteristics. Following the acute phase of AFM, patients typically have substantial residual disability and unique long-term rehabilitation needs. In this Review we describe the epidemiology, clinical features, course, and outcomes of AFM to help to guide diagnosis, management, and rehabilitation. Future research directions include further studies evaluating host and pathogen factors, including investigations into genetic, viral, and immunological features of affected patients, host-virus interactions, and investigations of targeted therapeutic approaches to improve the long-term outcomes in this population.
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Affiliation(s)
- Olwen C Murphy
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kevin Messacar
- Department of Pediatric Infectious Diseases, Children's Hospital Colorado, Aurora, CO, USA
| | - Leslie Benson
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Riley Bove
- Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Jessica L Carpenter
- Department of Neurology, Children's National Health System, Washington, DC, USA
| | - Thomas Crawford
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Janet Dean
- International Center for Spinal Cord Injury, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Roberta DeBiasi
- Department of Pediatric Infectious Diseases, Children's National Health System, Washington, DC, USA
| | - Jay Desai
- Division of Neurology, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Matthew J Elrick
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Raquel Farias-Moeller
- Department of Neurology, Children's Hospital of Wisconsin and the Medical College of Wisconsin, Milwaukee, WI, USA
| | - Grace Y Gombolay
- Department of Neurology, Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, GA, USA
| | - Benjamin Greenberg
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Matthew Harmelink
- Department of Neurology, Children's Hospital of Wisconsin and the Medical College of Wisconsin, Milwaukee, WI, USA
| | - Sue Hong
- Division of Pediatric Critical Care, Ann & Robert H Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Sarah E Hopkins
- Division of Neurology, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Joyce Oleszek
- Department of Physical Medicine and Rehabilitation, Children's Hospital Colorado, Aurora, CO, USA
| | - Catherine Otten
- Department of Pediatric Neurology, Seattle Children's Hospital, Seattle, WA, USA
| | - Cristina L Sadowsky
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD, USA; International Center for Spinal Cord Injury, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Teri L Schreiner
- Department of Child Neurology, Children's Hospital Colorado, Aurora, CO, USA
| | - Kiran T Thakur
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
| | - Keith Van Haren
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA
| | - Carolina M Carballo
- Department of Infectious Diseases, Hospital de Niños "Ricardo Gutiérrez", Buenos Aires, Argentina
| | - Pin Fee Chong
- Department of Pediatric Neurology, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Amary Fall
- Institut Pasteur de Dakar, Département de Virologie, Dakar, Senegal
| | - Vykuntaraju K Gowda
- Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, Karnataka, India
| | - Jelte Helfferich
- Department of Neurology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Ryutaro Kira
- Department of Pediatric Neurology, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Ming Lim
- Children's Neuroscience Center, Evelina London Children's Hospital, Guy's and St Thomas' NHS Trust, and Faculty of Life Sciences, King's College, London, UK
| | - Eduardo L Lopez
- Department of Infectious Diseases, Hospital de Niños "Ricardo Gutiérrez", Buenos Aires, Argentina
| | - Elizabeth M Wells
- Department of Neurology, Children's National Health System, Washington, DC, USA
| | - E Ann Yeh
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, ON, Canada
| | - Carlos A Pardo
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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7
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Elrick MJ, Pekosz A, Duggal P. Enterovirus D68 molecular and cellular biology and pathogenesis. J Biol Chem 2021; 296:100317. [PMID: 33484714 PMCID: PMC7949111 DOI: 10.1016/j.jbc.2021.100317] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 12/13/2022] Open
Abstract
In recent years, enterovirus D68 (EV-D68) has advanced from a rarely detected respiratory virus to a widespread pathogen responsible for increasing rates of severe respiratory illness and acute flaccid myelitis (AFM) in children worldwide. In this review, we discuss the accumulating data on the molecular features of EV-D68 and place these into the context of enterovirus biology in general. We highlight similarities and differences with other enteroviruses and genetic divergence from own historical prototype strains of EV-D68. These include changes in capsid antigens, host cell receptor usage, and viral RNA metabolism collectively leading to increased virulence. Furthermore, we discuss the impact of EV-D68 infection on the biology of its host cells, and how these changes are hypothesized to contribute to motor neuron toxicity in AFM. We highlight areas in need of further research, including the identification of its primary receptor and an understanding of the pathogenic cascade leading to motor neuron injury in AFM. Finally, we discuss the epidemiology of the EV-D68 and potential therapeutic approaches.
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Affiliation(s)
- Matthew J Elrick
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.
| | - Andrew Pekosz
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Priya Duggal
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
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8
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Patel R, Gombolay GY, Peljovich AE, Conklin J, Blackwell LS, Howarth R, Wolf DS, Upadhyayula SR, Verma S. Acute Flaccid Myelitis: A Single Pediatric Center Experience From 2014 to 2019. J Child Neurol 2020; 35:912-917. [PMID: 32677590 DOI: 10.1177/0883073820939392] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
BACKGROUND Acute flaccid myelitis has emerged as the leading cause of acute flaccid paralysis in children. Acute flaccid myelitis leads to significant physical disability; hence, objective outcome measures to study disease severity and progression are desirable. In addition, nerve transfer to improve motor function in affected children needs further study. METHODS Retrospective study of acute flaccid myelitis subjects managed at Children's Healthcare of Atlanta from August 2014 to December 2019. Clinical, electromyography and nerve conduction study, neuropsychological functional independence (WeeFIM), and nerve transfer data were reviewed. RESULTS Fifteen children (11 boys and 4 girls) mean age 5.1±3.2 years (range 14 months to 12 years) were included. All subjects (n = 15) presented with severe asymmetric motor weakness and absent tendon reflexes. Motor nerve conduction study of the affected limbs in 93% (n = 14) showed absent or markedly reduced amplitude. Ten patients received comprehensive inpatient rehabilitation and neuropsychological evaluation. Admission and discharge WeeFIM scores showed deficits most consistent and pronounced in the domains of self-care and mobility. Multiple nerve transfer surgery was performed on 13 limbs (9 upper and 4 lower extremities) in 6 children. Postsurgery (mean duration of 10.4 ± 5.7 months) follow-up demonstrated improvement on active movement scale (AMS) in 4 subjects. CONCLUSION Acute flaccid myelitis affects school-age children with asymmetric motor weakness, absent tendon reflexes, and reduced or absent motor amplitude on nerve conduction study. Comprehensive rehabilitation and nerve transfer led to improvement in motor function on neuropsychology WeeFIM and AMS scores.
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Affiliation(s)
- Rifali Patel
- Pediatric Neurology, MercyOne, Des Moines, IA, USA
| | - Grace Y Gombolay
- Division of Pediatric Neurology, Department of Pediatrics and Neurology, 1371Emory University School of Medicine, Atlanta, GA, USA
| | - Allan E Peljovich
- The Hand and Upper Extremity Center of Georgia, Department of Orthopaedic Surgery, 1367Children's Healthcare of Atlanta, Atlanta Medical Center Orthopaedic Residency Program, Atlanta, GA, USA
| | - Jessica Conklin
- Division of Neuropsychology, 1367Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - Laura S Blackwell
- Division of Neuropsychology, 1367Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - Robyn Howarth
- Division of Neuropsychology, 1367Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - David S Wolf
- Division of Pediatric Neurology, Department of Pediatrics and Neurology, 1371Emory University School of Medicine, Atlanta, GA, USA
| | - Saila R Upadhyayula
- Division of Pediatric Neurology, Department of Pediatrics and Neurology, 1371Emory University School of Medicine, Atlanta, GA, USA
| | - Sumit Verma
- Division of Pediatric Neurology, Department of Pediatrics and Neurology, 1371Emory University School of Medicine, Atlanta, GA, USA
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9
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Majer A, McGreevy A, Booth TF. Molecular Pathogenicity of Enteroviruses Causing Neurological Disease. Front Microbiol 2020; 11:540. [PMID: 32328043 PMCID: PMC7161091 DOI: 10.3389/fmicb.2020.00540] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 03/12/2020] [Indexed: 12/12/2022] Open
Abstract
Enteroviruses are single-stranded positive-sense RNA viruses that primarily cause self-limiting gastrointestinal or respiratory illness. In some cases, these viruses can invade the central nervous system, causing life-threatening neurological diseases including encephalitis, meningitis and acute flaccid paralysis (AFP). As we near the global eradication of poliovirus, formerly the major cause of AFP, the number of AFP cases have not diminished implying a non-poliovirus etiology. As the number of enteroviruses linked with neurological disease is expanding, of which many had previously little clinical significance, these viruses are becoming increasingly important to public health. Our current understanding of these non-polio enteroviruses is limited, especially with regards to their neurovirulence. Elucidating the molecular pathogenesis of these viruses is paramount for the development of effective therapeutic strategies. This review summarizes the clinical diseases associated with neurotropic enteroviruses and discusses recent advances in the understanding of viral invasion of the central nervous system, cell tropism and molecular pathogenesis as it correlates with host responses.
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Affiliation(s)
- Anna Majer
- Viral Diseases Division, National Microbiology Laboratory, Winnipeg, MB, Canada
| | - Alan McGreevy
- Viral Diseases Division, National Microbiology Laboratory, Winnipeg, MB, Canada.,Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada.,Department of Biology, University of Winnipeg, Winnipeg, MB, Canada
| | - Timothy F Booth
- Viral Diseases Division, National Microbiology Laboratory, Winnipeg, MB, Canada.,Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, MB, Canada
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10
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Bove R, Rowles W, Carleton M, Olivera E, Sheehan M, Werdal HP, Scott R, Axton L, Benson L. Unmet Needs in the Evaluation, Treatment, and Recovery for 167 Children Affected by Acute Flaccid Myelitis Reported by Parents Through Social Media. Pediatr Neurol 2020; 102:20-27. [PMID: 31630913 DOI: 10.1016/j.pediatrneurol.2019.08.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/13/2019] [Accepted: 08/17/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND We aimed to characterize the outcomes of 167 children affected by acute flaccid myelitis by leveraging the power of social media. METHODS Members of a closed social media (Facebook) group were invited to participate in an anonymous online survey. Descriptive statistics were applied to quantitative responses, and free-text responses were grouped into themes using a grounded theory approach. RESULTS Caregivers provided information about 167 affected children; 77% were at least 6 months since onset. Clinical features matched those of larger published case series (e.g., walking impairment in 76.7%, intravenous immunoglobulin treatment in 80.8%; 28.2% tested positive for Enterovirus D68; 17% children had asthma before acute flaccid myelitis onset). Mean duration of initial hospitalization was 49.1 (S.D., 74.0) days, and of initial inpatient rehabilitation was 42.3 (S.D., 67.6) days. Among challenges, parents frequently reported delays in diagnosis, including lack of neurological examination at initial medical evaluation for weakness. Other challenges included familial and professional impact of protracted hospitalizations, uncertainty about cause or prognosis of acute flaccid myelitis, and the dynamic nature of care needs in growing children. The social media group played a critical role not only for social support but also for dissemination of rehabilitation approaches and of networks of expert clinicians. CONCLUSIONS Children with acute flaccid myelitis have persistent and dynamic deficits, but many continue to show ongoing functional improvements beyond the initial expected window of recovery. In an emerging disease paralyzing young children, social media can strengthen knowledge networks and focus on rehabilitation.
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Affiliation(s)
- Riley Bove
- Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, California.
| | - William Rowles
- Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, California
| | - Mia Carleton
- Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, California
| | - Erin Olivera
- Ventura County Medical Center, Simi Valley, California
| | | | | | | | | | - Leslie Benson
- Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
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11
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Matsuo K, Koga M, Shiraishi M, Hasegawa M, Kanda T, Fukusako T. [A case of severe acute flaccid myelitis requiring continuous mechanical ventilation]. Rinsho Shinkeigaku 2019; 59:579-583. [PMID: 31474644 DOI: 10.5692/clinicalneurol.cn-001319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Many cases of acute flaccid paralysis occurred during an enterovirus D68 (EV-D68) outbreak in North America in the fall of 2014, and this epidemic has been newly defined as a distinct disease entity named acute flaccid myelitis (AFM). This disease entity is relatively popular among pediatricians, whereas it remains little-known among neurologists in Japan. We reported a 7-year-old girl with AFM, in whom severe limb weakness and respiratory failure developed five days after appearance of respiratory symptoms. Clinical features of our case were mimicked by those of acute axonal motor neuropathy at early stage of the disease, and this resulted in delayed diagnosis of AFM. DNA of EV-D68 was not detected. There are few reported cases of severe AFM, in which artificial ventilation is needed for a long time including both acute and recovery phases of the illness, and functional prognosis of AFM is discussed by literature.
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Affiliation(s)
- Kinya Matsuo
- Department of Neurology, Yamaguchi Prefectural Grand Medical Center.,Department of Neurology and Clinical Neuroscience, Yamaguchi University Graduate School of Medicine
| | - Michiaki Koga
- Department of Neurology and Clinical Neuroscience, Yamaguchi University Graduate School of Medicine
| | | | - Masanari Hasegawa
- Department of Pediatrics, Yamaguchi Prefectural Grand Medical Center
| | - Takashi Kanda
- Department of Neurology and Clinical Neuroscience, Yamaguchi University Graduate School of Medicine
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12
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Hixon AM, Frost J, Rudy MJ, Messacar K, Clarke P, Tyler KL. Understanding Enterovirus D68-Induced Neurologic Disease: A Basic Science Review. Viruses 2019; 11:E821. [PMID: 31487952 PMCID: PMC6783995 DOI: 10.3390/v11090821] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/28/2019] [Accepted: 08/29/2019] [Indexed: 12/28/2022] Open
Abstract
In 2014, the United States (US) experienced an unprecedented epidemic of enterovirus D68 (EV-D68)-induced respiratory disease that was temporally associated with the emergence of acute flaccid myelitis (AFM), a paralytic disease occurring predominantly in children, that has a striking resemblance to poliomyelitis. Although a definitive causal link between EV-D68 infection and AFM has not been unequivocally established, rapidly accumulating clinical, immunological, and epidemiological evidence points to EV-D68 as the major causative agent of recent seasonal childhood AFM outbreaks in the US. This review summarizes evidence, gained from in vivo and in vitro models of EV-D68-induced disease, which demonstrates that contemporary EV-D68 strains isolated during and since the 2014 outbreak differ from historical EV-D68 in several factors influencing neurovirulence, including their genomic sequence, their receptor utilization, their ability to infect neurons, and their neuropathogenicity in mice. These findings provide biological plausibility that EV-D68 is a causal agent of AFM and provide important experimental models for studies of pathogenesis and treatment that are likely to be difficult or impossible in humans.
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Affiliation(s)
- Alison M Hixon
- Medical Scientist Training Program, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Joshua Frost
- Department of Immunology & Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Michael J Rudy
- Department of Neurology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Kevin Messacar
- Hospital Medicine and Pediatric Infectious Disease Sections, Department of Pediatrics, University of Colorado, Aurora, CO 80045, USA.
- Children's Hospital Colorado, Aurora, CO 80045, USA.
| | - Penny Clarke
- Department of Neurology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
| | - Kenneth L Tyler
- Department of Immunology & Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, USA
- Department of Neurology, University of Colorado School of Medicine, Aurora, CO 80045, USA
- Division of Infectious Disease, Department of Medicine, University of Colorado School of Medicine, Aurora, CO 80045, USA
- Neurology Service, Rocky Mountain VA Medical Center, Aurora, CO 80045, USA
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Acute Flaccid Myelitis With Early, Severe Compound Muscle Action Potential Amplitude Reduction: A 3-Year Follow-up of a Child Patient. J Clin Neuromuscul Dis 2019; 20:100-101. [PMID: 30439757 DOI: 10.1097/cnd.0000000000000217] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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14
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Contemporary Circulating Enterovirus D68 Strains Infect and Undergo Retrograde Axonal Transport in Spinal Motor Neurons Independent of Sialic Acid. J Virol 2019; 93:JVI.00578-19. [PMID: 31167912 DOI: 10.1128/jvi.00578-19] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 06/01/2019] [Indexed: 12/25/2022] Open
Abstract
Enterovirus D68 (EV-D68) is an emerging virus that has been identified as a cause of recent outbreaks of acute flaccid myelitis (AFM), a poliomyelitis-like spinal cord syndrome that can result in permanent paralysis and disability. In experimental mouse models, EV-D68 spreads to, infects, and kills spinal motor neurons following infection by various routes of inoculation. The topography of virus-induced motor neuron loss correlates with the pattern of paralysis. The mechanism(s) by which EV-D68 spreads to target motor neurons remains unclear. We sought to determine the capacity of EV-D68 to spread by the neuronal route and to determine the role of known EV-D68 receptors, sialic acid and intracellular adhesion molecule 5 (ICAM-5), in neuronal infection. To do this, we utilized a microfluidic chamber culture system in which human induced pluripotent stem cell (iPSC) motor neuron cell bodies and axons can be compartmentalized for independent experimental manipulation. We found that EV-D68 can infect motor neurons via their distal axons and spread by retrograde axonal transport to the neuronal cell bodies. Virus was not released from the axons via anterograde axonal transport after infection of the cell bodies. Prototypic strains of EV-D68 depended on sialic acid for axonal infection and transport, while contemporary circulating strains isolated during the 2014 EV-D68 outbreak did not. The pattern of infection did not correspond with the ICAM-5 distribution and expression in either human tissue, the mouse model, or the iPSC motor neurons.IMPORTANCE Enterovirus D68 (EV-D68) infections are on the rise worldwide. Since 2014, the United States has experienced biennial spikes in EV-D68-associated acute flaccid myelitis (AFM) that have left hundreds of children paralyzed. Much remains to be learned about the pathogenesis of EV-D68 in the central nervous system (CNS). Herein we investigated the mechanisms of EV-D68 CNS invasion through neuronal pathways. A better understanding of EV-D68 infection in experimental models may allow for better prevention and treatment strategies of EV-D68 CNS disease.
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15
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Hurst BL, Evans WJ, Smee DF, Van Wettere AJ, Tarbet EB. Evaluation of antiviral therapies in respiratory and neurological disease models of Enterovirus D68 infection in mice. Virology 2019; 526:146-154. [PMID: 30390563 PMCID: PMC6309259 DOI: 10.1016/j.virol.2018.10.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 10/14/2018] [Accepted: 10/15/2018] [Indexed: 01/19/2023]
Abstract
Enterovirus D68 (EV-D68) is unique among enteroviruses because of the ability to cause severe respiratory disease as well as neurological disease. We developed separate models of respiratory and neurological disease following EV-D68 infection in AG129 mice that respond to antiviral treatment with guanidine. In four-week-old mice infected intranasally, EV-D68 replicates to high titers in lung tissue increasing the proinflammatory cytokines MCP-1 and IL-6. The respiratory infection also produces an acute viremia. In 10-day-old mice infected intraperitoneally, EV-D68 causes a neurological disease with weight-loss, paralysis, and mortality. In our respiratory model, treatment with guanidine provides a two-log reduction in lung virus titers, reduces MCP-1 and IL-6, and prevents histological lesions in the lungs. Importantly, viremia is prevented by early treatment with guanidine. In our neurological model, guanidine treatment protects mice from weight-loss, paralysis, and mortality. These results demonstrate the utility of these models for evaluation of antiviral therapies for EV-D68 infection.
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Affiliation(s)
- Brett L Hurst
- Institute for Antiviral Research, Utah State University, Logan, UT, United States; Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT, United States
| | - W Joseph Evans
- Institute for Antiviral Research, Utah State University, Logan, UT, United States; Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT, United States
| | - Donald F Smee
- Institute for Antiviral Research, Utah State University, Logan, UT, United States; Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT, United States
| | - Arnaud J Van Wettere
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT, United States; Utah Veterinary Diagnostic Laboratory, Logan, UT, United States
| | - E Bart Tarbet
- Institute for Antiviral Research, Utah State University, Logan, UT, United States; Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT, United States; Utah Veterinary Diagnostic Laboratory, Logan, UT, United States.
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16
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Acute flaccid myelitis and enterovirus D68: lessons from the past and present. Eur J Pediatr 2019; 178:1305-1315. [PMID: 31338675 PMCID: PMC6694036 DOI: 10.1007/s00431-019-03435-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 07/11/2019] [Accepted: 07/16/2019] [Indexed: 12/20/2022]
Abstract
Acute flaccid myelitis is characterized by the combination of acute flaccid paralysis and a spinal cord lesion largely restricted to the gray matter on magnetic resonance imaging. The term acute flaccid myelitis was introduced in 2014 after the upsurge of pediatric cases in the USA with enterovirus D68 infection. Since then, an increasing number of cases have been reported worldwide. Whereas the terminology is new, the clinical syndrome has been recognized in the past in association with several other neurotropic viruses such as poliovirus.Conclusion: This review presents the current knowledge on acute flaccid myelitis with respect to the clinical presentation and its differential diagnosis with Guillain-Barré syndrome and acute transverse myelitis. We also discuss the association with enterovirus D68 and the presumed pathophysiological mechanism of this infection causing anterior horn cell damage. Sharing clinical knowledge and insights from basic research is needed to make progress in diagnosis, treatment, and prevention of this new polio-like disease. What is Known: • Acute flaccid myelitis (AFM) is a polio-like condition characterized by rapid progressive asymmetric weakness, together with specific findings on MRI • AFM has been related to different viral agents, but recent outbreaks are predominantly associated with enterovirus D68. What is New: • Improving knowledge on AFM must increase early recognition and adequate diagnostic procedures by clinicians. • The increasing incidence of AFM urges cooperation between pediatricians, neurologists, and microbiologists for the development of treatment and preventive options.
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17
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Twenty-nine Cases of Enterovirus-D68-associated Acute Flaccid Myelitis in Europe 2016: A Case Series and Epidemiologic Overview. Pediatr Infect Dis J 2019; 38:16-21. [PMID: 30234793 PMCID: PMC6296836 DOI: 10.1097/inf.0000000000002188] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Enterovirus-D68 (EV-D68) is a respiratory virus within the genus Enterovirus and the family of Picornaviridae. Genetically, it is closely related to rhinovirus that replicates in the respiratory tract and causes respiratory disease. Since 2014, EV-D68 has been associated with the neurologic syndrome of acute flaccid myelitis (AFM). METHODS In October 2016, questionnaires were sent out to a European network including 66 virologists and clinicians, to develop an inventory of EV-D68-associated AFM cases in Europe. Clinical and virologic information of case patients was requested. In addition, epidemiologic information on EV testing was collected for the period between March and October 2016. RESULTS Twenty-nine cases of EV-D68-associated AFM were identified, from 12 different European countries. Five originated from France, 5 from Scotland and 3 each from Sweden, Norway and Spain. Twenty-six were children (median age 3.8 years), 3 were adults. EV-D68 was detected in respiratory materials (n = 27), feces (n = 8) and/or cerebrospinal fluid (n = 2). Common clinical features were asymmetric flaccid limb weakness, cranial nerve deficits and bulbar symptoms. On magnetic resonance imaging, typical findings were hyperintensity of the central cord and/or brainstem; low motor amplitudes with normal conduction velocities were seen on electromyography. Full clinical recovery was rare (n = 3), and 2 patients died. The epidemiologic data from 16 European laboratories showed that of all EV-D68-positive samples, 99% was detected in a respiratory specimen. CONCLUSIONS For 2016, 29 EV-D68-related AFM cases were identified in mostly Western Europe. This is likely an underestimation, because case identification is dependent on awareness among clinicians, adequate viral diagnostics on respiratory samples and the capability of laboratories to type EVs.
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18
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Neurologische Komplikationen bei Infektionen mit (neuen) Enteroviren. DER NERVENARZT 2018; 89:1320-1331. [DOI: 10.1007/s00115-018-0619-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Messacar K, Asturias EJ, Hixon AM, Van Leer-Buter C, Niesters HGM, Tyler KL, Abzug MJ, Dominguez SR. Enterovirus D68 and acute flaccid myelitis-evaluating the evidence for causality. THE LANCET. INFECTIOUS DISEASES 2018; 18:e239-e247. [PMID: 29482893 PMCID: PMC6778404 DOI: 10.1016/s1473-3099(18)30094-x] [Citation(s) in RCA: 141] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 09/19/2017] [Accepted: 11/09/2017] [Indexed: 01/11/2023]
Abstract
Increased circulation of enterovirus D68 in 2014 and 2016 temporally and geographically coincided with increases in cases of acute flaccid myelitis, an uncommon condition of paralysis due to lesions in the anterior horn of the spinal cord. The identification of enterovirus D68 in respiratory specimens from cases of acute flaccid myelitis worldwide further supports an association, yet the absence of direct virus isolation from affected tissues, infrequent detection in cerebrospinal fluid, and the absence, until recently, of an animal model has left the causal nature of the relationship unproven. In this Personal View we evaluate epidemiological and biological evidence linking enterovirus D68 and acute flaccid myelitis. We applied the Bradford Hill criteria to investigate the evidence for a causal relationship and highlight the importance of comprehensive surveillance and research to further characterise the role of enterovirus D68 in acute flaccid myelitis and pursue effective therapies and prevention strategies.
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Affiliation(s)
- Kevin Messacar
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA; Department of Neurology, University of Colorado School of Medicine, Aurora, CO, USA; Children's Hospital Colorado, Aurora, CO, USA.
| | - Edwin J Asturias
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA; Children's Hospital Colorado, Aurora, CO, USA; Center for Global Health and Department of Epidemiology, Colorado School of Public Health, Aurora, CO, USA
| | - Alison M Hixon
- University of Colorado School of Medicine Medical Scientist Training Program, Aurora, CO, USA
| | - Coretta Van Leer-Buter
- Division of Clinical Virology, Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Hubert G M Niesters
- Division of Clinical Virology, Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, Netherlands
| | - Kenneth L Tyler
- Department of Neurology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Mark J Abzug
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA; Children's Hospital Colorado, Aurora, CO, USA
| | - Samuel R Dominguez
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA; Children's Hospital Colorado, Aurora, CO, USA
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20
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Abstract
PURPOSE OF REVIEW The focus of this review is on enterovirus (EV)-associated acute flaccid paralysis (AFP) due to spinal cord anterior horn cell disease. Emphasis is placed on the epidemiology, pathogenesis, diagnosis, treatment, and outcome of AFP caused by polioviruses, vaccine-derived polioviruses, EV-D68, and EV-A71. RECENT FINDINGS Since the launch of The Global Polio Eradication Initiative in 1988, the worldwide incidence of polio has been reduced by 99.9%, with small numbers of poliomyelitis cases being reported only in Afghanistan, Pakistan, and Nigeria. With the planned phaseout of oral polio vaccine, vaccine-associated poliomyelitis is also expected to be eliminated. In their place, other EVs, chiefly EV-D68 and EV-A71, have emerged as the principal causes of AFP. There is evidence that the emergence of EV-D68 as a cause of severe respiratory disease and AFP was due to recent genetic virus evolution. Antiviral medications targeting EV-D68, EV-A71, and other EVs will likely be available in the near future. An effective EV-A71 vaccine has been developed, and preliminary investigations suggest an EV-D68 vaccine could be on the horizon. The eradication of poliomyelitis and vaccine-associated poliomyelitis is near, after which other EVs, presently EV-D68 and EV-A71, will be the principle viral causes of AFP. Moving forward, it is essential that EV outbreaks, in particular those associated with neurologic complications, be investigated carefully and the causal strains identified, so that treatment and prevention efforts can be rapidly developed and implemented.
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Affiliation(s)
- Ari Bitnun
- Division of Infectious Diseases, The Hospital for Sick Children and Department of Pediatrics, University of Toronto, Toronto, ON, M5G 1X8, Canada.
| | - E Ann Yeh
- Division of Neurology, The Hospital for Sick Children and Department of Pediatrics, Division of Neurosciences and Mental Health, SickKids Research Institute, University of Toronto, Toronto, Canada
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21
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Hixon AM, Clarke P, Tyler KL. Evaluating Treatment Efficacy in a Mouse Model of Enterovirus D68-Associated Paralytic Myelitis. J Infect Dis 2017; 216:1245-1253. [PMID: 28968718 DOI: 10.1093/infdis/jix468] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 09/07/2017] [Indexed: 12/17/2022] Open
Abstract
Background Enterovirus D68 (EV-D68)-associated acute flaccid myelitis (AFM) is a devastating neurological disease for which there are no treatments of proven efficacy. The unpredictable temporal and geographic distribution of cases and the rarity of the disease make it unlikely that data from randomized controlled trials will be available to guide therapeutic decisions. We evaluated the following 3 widely used empirical therapies for the ability to reduce the severity of paralysis in a mouse model of EV-D68 infection: (1) human intravenous immunoglobulin (hIVIG), (2) fluoxetine, and (3) dexamethasone. Methods Neonatal mice were injected intramuscularly with a human 2014 EV-D68 isolate that reliably induces paralysis in mice due to infection and loss of spinal cord motor neurons. Mice receiving treatments were evaluated for motor impairment, mortality, and spinal cord viral load. Results hIVIG, which contained neutralizing antibodies to EV-D68, reduced paralysis in infected mice and decreased spinal cord viral loads. Fluoxetine had no effect on motor impairment or viral loads. Dexamethasone treatment worsened motor impairment, increased mortality, and increased viral loads. Conclusion Results in this model of EV-D68-associated AFM provide a rational basis for selecting empirical therapy in humans and establish this model as a useful system for evaluating other potential therapies.
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Affiliation(s)
- Alison M Hixon
- Medical Scientist Training Program.,Neuroscience Program
| | | | - Kenneth L Tyler
- Department of Neurology.,Department of Medicine.,Department of Immunology and Microbiology, University of Colorado School of Medicine Aurora
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22
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Messacar K, Schreiner TL, Van Haren K, Yang M, Glaser CA, Tyler KL, Dominguez SR. Acute flaccid myelitis: A clinical review of US cases 2012-2015. Ann Neurol 2016; 80:326-38. [PMID: 27422805 DOI: 10.1002/ana.24730] [Citation(s) in RCA: 139] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 07/01/2016] [Accepted: 07/10/2016] [Indexed: 01/24/2023]
Abstract
This review highlights clinical features of the increasing cases of acute flaccid paralysis associated with anterior myelitis noted in the United States from 2012 to 2015. Acute flaccid myelitis refers to acute flaccid limb weakness with spinal cord gray matter lesions on imaging or evidence of spinal cord motor neuron injury on electrodiagnostic testing. Although some individuals demonstrated improvement in motor weakness and functional deficits, most have residual weakness a year or more after onset. Epidemiological evidence and biological plausibility support an association between enterovirus D68 and the recent increase in acute flaccid myelitis cases in the United States. Ann Neurol 2016;80:326-338.
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Affiliation(s)
- Kevin Messacar
- Department of Pediatrics, Section of Hospital Medicine, Children's Hospital Colorado and University of Colorado School of Medicine, Aurora, CO. .,Department of Pediatrics, Section of Pediatric Infectious Diseases, Children's Hospital Colorado and University of Colorado School of Medicine, Aurora, CO.
| | - Teri L Schreiner
- Department of Pediatrics, Section of Neurology, Children's Hospital Colorado and University of Colorado School of Medicine, Aurora, CO
| | - Keith Van Haren
- Department of Neurology, Stanford University School of Medicine, Stanford, CA
| | - Michele Yang
- Department of Pediatrics, Section of Neurology, Children's Hospital Colorado and University of Colorado School of Medicine, Aurora, CO
| | - Carol A Glaser
- Kaiser Permanente Medical Center, Oakland, CA, and University of California San Francisco, San Francisco, CA
| | - Kenneth L Tyler
- Departments of Neurology, Medicine and Immunology-Microbiology at the University of Colorado School of Medicine and Neurology Service at the Denver Veterans Affairs Medical Center, Denver, CO
| | - Samuel R Dominguez
- Department of Pediatrics, Section of Pediatric Infectious Diseases, Children's Hospital Colorado and University of Colorado School of Medicine, Aurora, CO
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23
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Genetic divergence of enterovirus D68 in China and the United States. Sci Rep 2016; 6:27800. [PMID: 27278628 PMCID: PMC4899779 DOI: 10.1038/srep27800] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 05/25/2016] [Indexed: 02/08/2023] Open
Abstract
The largest outbreak of human enterovirus 68 (EV-D68) infections associated with severe respiratory illness and neurological complications emerged from the United States in 2014. China reported the circulation of EV-D68 since 2006, but these cases were sporadic and did not display neurological symptoms. Yet viral determinants responsible for the difference in prevalence between China and the U.S. were not clear. We analyzed the genome of 64 reported Chinese EV-D68 strains and found that genogroup replacement has occurred in China since 2006. The six coding mutations (M291T, V341A, T860N, D927N, S1108G and R2005K) associated with neurovirulence reported in American strains were not found in Chinese strains. Moreover, 2014 Chinese strains had a unique R220A mutation in the puff region of VP2 while R220E mutation occurred in other strains. Like other enteroviruses, the loop sequences of the domain X and Y in the 3'-UTR of the Chinese strains are complementary. However, the X loop sequences of the 2014 American strains were not complementary but identical to Y loop sequences. These results indicate that different EV-D68 strains circulated in China and America and the mutations might be responsible for different prevalence. Our findings also provide new evidence for the sequence diversity of EV-D68.
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