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Keovilayhong S, Mulliez A, Feral L, Chenaf C, Clavelou P, Moisset X, Taithe F, Poncet Megemont L. Epidemiology of myasthenia gravis in France: Incidence, prevalence, and comorbidities based on national healthcare insurance claims data. Rev Neurol (Paris) 2024; 180:451-458. [PMID: 38582663 DOI: 10.1016/j.neurol.2024.02.392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 12/13/2023] [Accepted: 02/09/2024] [Indexed: 04/08/2024]
Abstract
BACKGROUND The European literature has reported high variability in the incidence and prevalence rates of myasthenia gravis (MG), but no specific epidemiological data for France have been published. This study aimed to assess the incidence and prevalence rates of myasthenia gravis in France based on data extracted from the French National Health Insurance Claims Database (the SNIIRAM database). METHODS We conducted a retrospective repeated cross-sectional population study from 2008 to 2018 using a representative sample of the French population (Échantillon généraliste des bénéficiaires) covered by health insurance. We calculated the incidence, prevalence, and sex ratio of MG and screened for comorbidities associated with MG (standardized to the general population). RESULTS In total, 331 MG patients were identified between 2008 and 2018. The average incidence of MG in France was 50 per million person-years, while the mean prevalence was 465 per million people. The female-to-male ratio was 1.33. The Incidence of MG gradually increased from 40years of age for women and 60 for men. Thymoma was present for 5.1% of MG patients and a thymectomy was performed for 4.7%. Thyroid disease was the most prevalent autoimmune comorbidity, affecting approximately 8.5% of cases. MG patients had an increased cancer risk, with a standardized rate ratio of 2.38 (95% CI: 1.64-3.46). CONCLUSION The incidence and prevalence rates of MG are significantly higher than those previously reported in the literature and the incidence increases with age. The excess risk of cancer raises concerns for MG patients, in particular, concerning the management of immunosuppressive drugs.
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Affiliation(s)
- S Keovilayhong
- Mittaphab Hospital, Vientiane, Lao Democratic People's Republic
| | - A Mulliez
- Université Clermont Auvergne, CHU de Clermont-Ferrand, Clermont-Ferrand, France
| | - L Feral
- Université Clermont Auvergne, CHU de Clermont-Ferrand, Clermont-Ferrand, France
| | - C Chenaf
- Université Clermont Auvergne, CHU de Clermont-Ferrand, Clermont-Ferrand, France
| | - P Clavelou
- Université Clermont Auvergne, CHU de Clermont-Ferrand, Clermont-Ferrand, France; Neuro-Dol, Inserm, Clermont-Ferrand, France
| | - X Moisset
- Université Clermont Auvergne, CHU de Clermont-Ferrand, Clermont-Ferrand, France; Neuro-Dol, Inserm, Clermont-Ferrand, France
| | - F Taithe
- Université Clermont Auvergne, CHU de Clermont-Ferrand, Clermont-Ferrand, France
| | - L Poncet Megemont
- Université Clermont Auvergne, CHU de Clermont-Ferrand, Clermont-Ferrand, France.
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Salort-Campana E, Laforet P, de Pouvourville G, Crochard A, Chollet G, Nevoret C, Emery C, Bouée S, Tard C. Epidemiology of myasthenia gravis in France: A retrospective claims database study (STAMINA). Rev Neurol (Paris) 2024; 180:202-210. [PMID: 37945494 DOI: 10.1016/j.neurol.2023.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 08/04/2023] [Accepted: 09/21/2023] [Indexed: 11/12/2023]
Abstract
BACKGROUND The objectives of this observational study were to report the incidence and prevalence of myasthenia gravis (MG) in France, describe patients' characteristics and treatment patterns, and estimate mortality. METHODS A historical cohort analysis was performed using the French National Health Data System (SNDS) database between 2008 and 2020. Patients with MG were identified based on ICD-10 codes during hospitalization and/or long-term disease (ALD) status, which leads to a 100% reimbursement for healthcare expenses related to MG. The study population was matched to a control group based on age, sex and region of residence. RESULTS The overall incidence of MG was estimated at 2.5/100,000 in 2019 and the overall prevalence at 34.2/100,000. The mean age was 58.3 years for incident patients and 58.6 for prevalent patients. Among patients with MG, 57.1% were women. In the first year after identification of MG, acetylcholinesterase inhibitors were the most commonly used treatments (87.0%). Corticosteroids were delivered to 58.3% of patients, intravenous immunoglobulin to 34.4%, and azathioprine to 29.9%. Additionally, 8% of patients underwent thymectomy. The proportions of patients with exacerbations and crises were 59.7% and 13.5% respectively in the first year after MG identification. All-cause mortality was significantly higher in patients with MG compared to matched controls (HR=1.82 (95% CI [1.74;1.90], P<0.0001)). CONCLUSION In this study, the incidence and prevalence of MG estimated in France were found to be higher than previously reported. Most exacerbations and crises occurred within the first year after MG identification. MG was associated with increased mortality compared to a control population matched on age, gender, and geographical region.
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Affiliation(s)
- E Salort-Campana
- Service du Pr Attarian, Centre de référence des maladies neuromusculaires PACA Réunion Rhône Alpes, AP-HM, Marseille, France
| | - P Laforet
- Service de Neurologie, Hôpital Raymond Poincaré, Centre de référence des maladies neuromusculaires Nord-Est-Ile de France, FHU Phenix, Garches, France
| | | | | | | | | | - C Emery
- CEMKA, Bourg-La-Reine, France
| | - S Bouée
- CEMKA, Bourg-La-Reine, France
| | - C Tard
- Service de neurologie, U1172, Centre de référence des maladies neuromusculaires Nord/Est/Ile-de-France, CHU de Lille, Lille, France
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Ye Y, Murdock DJ, Chen C, Liedtke W, Knox CA. Epidemiology of myasthenia gravis in the United States. Front Neurol 2024; 15:1339167. [PMID: 38434198 PMCID: PMC10907989 DOI: 10.3389/fneur.2024.1339167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 02/01/2024] [Indexed: 03/05/2024] Open
Abstract
Introduction Global studies of epidemiology of myasthenia gravis (MG) have pointed to increasing prevalence of this rare autoimmune disorder affecting the neuromuscular synapse; however, no new data for the USA were available for decades. We aimed to estimate the incidence rate and prevalence of MG in a large-scale insured US population. Methods We conducted a population-based retrospective cohort study to estimate the annual incidence and prevalence of MG cases in the USA during 2017. Using a previously validated algorithm, we identified cases of MG in two Truven Health MarketScan databases, which during 2017 included a sample of approximately 20 million commercially insured and Medicare recipients, plus 10 million Medicaid recipients. We report crude incidence and prevalence and calculated age-and sex-standardized estimates for the USA based on the 2017 American Community Survey. We estimated the number of adult cases during 2021 by extrapolating from the stratified estimates to the population size from the 2021 American Community Survey. Results From the US commercially/Medicare-insured cohort, we calculated an age-and sex-standardized incidence of 68.5 new cases per million person-years with an adjusted prevalence of 316.4 per million. Within the Medicaid-insured population, similar yet slightly lower numbers emerged: the adjusted incidence was 49.7 new cases per million person-years, and the adjusted prevalence rate was 203.7 cases per million. Given our results, we were able to estimate that there were approximately 82,715 US adults living with MG in 2021 (or an estimated 320.2 cases per million adults in the USA). We observed a strong effect of age and sex when stratifying the identified incidence rate and prevalence, with a pattern of female preponderance among the younger age brackets, a male preponderance for older cases in the commercially/Medicare-insured cohort, and the disease incidence and prevalence steadily increasing with age. Discussion Our updated US population-based estimates of MG epidemiology demonstrate an increase in the previously reported incidence and prevalence from over 20 years ago, in keeping with developments in westernized, industrialized countries. Notable findings of steadily increasing prevalence with age, driven by robust increases in elderly males, prompts questions for basic-translational research, therapeutics, and public health.
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Affiliation(s)
- Yun Ye
- The Division of Epidemiology, The Ohio State University, Columbus, OH, United States
| | | | - Chao Chen
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY, United States
| | | | - Caitlin A. Knox
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY, United States
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Epidemiology of myasthenia gravis in the province of Ourense (Galicia, Spain). NEUROLOGÍA (ENGLISH EDITION) 2022; 38:75-81. [PMID: 35249845 DOI: 10.1016/j.nrleng.2020.06.013] [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: 11/06/2019] [Accepted: 06/12/2020] [Indexed: 11/20/2022] Open
Abstract
INTRODUCTION Myasthenia gravis (MG) is an autoimmune disease affecting nerve transmission at the level of the neuromuscular junction, and typically causes fluctuating muscle weakness. Epidemiological studies show an increase in MG prevalence, particularly among the older population. OBJECTIVE We performed a retrospective epidemiological study to determine the incidence and prevalence of MG in the province of Ourense (Galicia, Spain), characterised by population ageing. MATERIAL AND METHODS Patients were selected from our clinical neuromuscular diseases database by searching for patients with an active prescription for pyridostigmine bromide. Incidence was estimated for the period 2009-2018. We calculated prevalence at 31/12/2018. According to census data for the province of Ourense, the population on 1/1/2019 was 307 651, of whom 96 544 (31.4%) were aged ≥ 65 years. RESULTS We identified 80 cases of MG, with a prevalence rate of 260 cases/1 000 000 population (95% CI, 202.7-316.4), rising to 517.9/1 000 000 population in those aged ≥ 65 (95% CI, 363.2-672.9). Cumulative incidence in the study period was 15.4 cases per 1 000 000 person-years. Early onset (≤ 50 years) was recorded in 29.1% of cases. CONCLUSION The prevalence of MG in our health district is one of the highest published figures, and the disease is highly prevalent in the older population.
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Murray C, Newsham D, Rowe F, Noonan C, Marsh IB. The Use of the Saccadometer to Identify Saccadic Characteristics in Myasthenia Gravis: A Pilot Study. J Neuroophthalmol 2022; 42:e267-e273. [PMID: 34860741 DOI: 10.1097/wno.0000000000001438] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Myasthenia gravis (MG) often presents with ocular signs that mimic other forms of ocular defects, such as isolated cranial nerve palsy. Normal velocity or even hyperfast saccadic eye movements in the presence of deficits of smooth pursuit have been well described in the literature in myasthenic patients. The reason for these paradoxical clinical findings has been reported to be due to increased postsynaptic folding of the fast-twitch fibers responsible for the execution of a saccade which is absent in those fibers responsible for slower, smooth eye movement. Saccadic characteristics therefore offer a point of differential diagnosis between patients suspected of having ocular motility deficits as a result of MG and those caused by other neuropathies. The advent of portable quantitative saccadic assessment means that previously laboratory-based assessments that require specialist equipment and training may now be undertaken clinically, providing a noninvasive test that can aid the differential diagnosis of the condition. The aim of this pilot study was to investigate the feasibility of the saccadometer (Ober Consulting, Poznan, Poland) in detecting the saccadic characteristics associated with myasthenia, specifically normal peak velocity (PV) in a group of patients confirmed with myasthenia. METHODS A group of 5 patients with a confirmed diagnosis of MG were recruited from a single site into the study along with 5 age-matched healthy volunteers. All myasthenic patients had ocular signs such as underaction or limitations of motility confirmed through ocular clinical examination. Healthy volunteers were screened for any underlying ocular motility or neurological defects before inclusion within the study. All participants undertook 100 trials of both 10 and 20° amplitude saccades, and mean PV, amplitude, and latency were recorded using the saccadometer for each individual. Overall, mean PV, amplitude, and latency were collated for both myasthenic and healthy control groups for each saccade size and compared. RESULTS The mean PV was significantly greater (481 ± 103.5 deg/seconds) for myasthenic patients compared with healthy controls (384 ± 42.8 deg/seconds) (P < 0.05) in 10° saccades. PV was also greater in myasthenics for 20° saccades; however, this difference did not reach statistical significance for patients with MG (547 ± 89.8 deg/seconds vs 477 ± 104.5 deg/seconds) (P = 0.14). The latency of participants with MG was not significantly different from those of age-matched healthy participants in 10° saccades but was significantly different for 20° saccades. There was no difference in amplitude measured between the groups. CONCLUSIONS PV for both 10 and 20° saccades was greater in myasthenic patients compared with healthy controls. All myasthenic patients produced normal velocity saccades in the presence of deficits of smooth ocular motility. The results from this small pilot study demonstrate the potential use of the saccadometer in a clinical setting to provide a noninvasive aid in the diagnosis of patients suspected with myasthenia.
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Affiliation(s)
- Craig Murray
- University of Liverpool (CM, DN, FR), Liverpool, United kingdom; and Liverpool University Hospitals NHS Foundation Trust (CN, IM), Liverpool, United kingdom
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Bharath V. Myasthenia Gravis and Thymectomy. JOURNAL OF CARDIAC CRITICAL CARE TSS 2022. [DOI: 10.1055/s-0041-1739528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
AbstractMyasthenia gravis (MG) is a rare autoimmune neuromuscular disorder. Though MG was diagnosed four centuries ago, its rational management started in 1930s. In the present era, MG is managed by multimodality care including pharmacological agents, plasmapheresis, intravenous immunoglobulins, and surgical thymectomy. Thymectomy has evolved from open trans-sternal to video-assisted thoracoscopic and robotic thymectomy. In this article, the concise history of MG, its clinical features, diagnosis, and management are described.
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Affiliation(s)
- V Bharath
- Department of Cardiothoracic and Vascular Surgery, All India Institute of Medical Sciences, New Delhi, India
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Bubuioc AM, Kudebayeva A, Turuspekova S, Lisnic V, Leone MA. The epidemiology of myasthenia gravis. J Med Life 2021; 14:7-16. [PMID: 33767779 PMCID: PMC7982252 DOI: 10.25122/jml-2020-0145] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 10/14/2020] [Indexed: 11/17/2022] Open
Abstract
Neuromuscular junction (NMJ) disorders include several dysfunctions that ultimately lead to muscle weakness. Myasthenia gravis (MG) is the most prevalent NMJ disorder with a highly polymorphic clinical presentation and many different faces. Being an autoimmune disease, MG correlates with the presence of detectable antibodies directed against the acetylcholine receptor, muscle-specific kinase, lipoprotein-related protein 4, agrin, titin, and ryanodine in the postsynaptic membrane at the NMJ. MG has become a prototype serving to understand both autoimmunity and the function of the NMJ better. The aim of this review is to synthesize some of the epidemiological data available. Epidemiological data regarding MG are important for postulating hypotheses regarding its etiology and facilitating the description of MG subtypes. Thus, adequate documentation through broad databases is essential. The incidence and prevalence of MG reported around the globe have been rising steadily and consistently over the past decades. Ethnic aspects, gender-related differences, and environmental risk factors have been described, implying that these might contribute to a specific phenotype, further suggesting that MG may be considered an umbrella term that covers several clinical entities.
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Affiliation(s)
- Ana-Maria Bubuioc
- Department of Neurology, Nicolae Testemitanu State University of Medicine and Pharmacy Chisinau, the Republic of Moldova
| | - Aigerim Kudebayeva
- Department of Neurology, Kazakh Medical University of Continuing Education, Almaty, Kazakhstan
| | - Saule Turuspekova
- Department of Nervous Diseases with course of Neurosurgery, Asfendiyarov Kazakh National Medical University, Almaty, Kazakhstan
| | - Vitalie Lisnic
- Department of Neurology, Nicolae Testemitanu State University of Medicine and Pharmacy Chisinau, the Republic of Moldova
| | - Maurizio Angelo Leone
- Neurology Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
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García Estévez DA, López Díaz LM, Pardo Parrado M, Pérez Lorenzo G, Sabbagh Casado NA, Ozaita Arteche G, Rodríguez Gómez D. Epidemiology of myasthenia gravis in the province of Ourense (Galicia, Spain). Neurologia 2020; 38:S0213-4853(20)30215-2. [PMID: 32900528 DOI: 10.1016/j.nrl.2020.06.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 05/24/2020] [Accepted: 06/12/2020] [Indexed: 10/23/2022] Open
Abstract
INTRODUCTION Myasthenia gravis (MG) is an autoimmune disease affecting nerve transmission at the level of the neuromuscular junction, and typically causes fluctuating muscle weakness. Epidemiological studies show an increase in MG prevalence, particularly among the older population. OBJECTIVE We performed a retrospective epidemiological study to determine the incidence and prevalence of MG in the province of Ourense (Galicia, Spain), characterised by population ageing. MATERIAL AND METHODS Patients were selected from our clinical neuromuscular diseases database by searching for patients with an active prescription for pyridostigmine bromide. Incidence was estimated for the period 2009-2018. We calculated prevalence at 31/12/2018. According to census data for the province of Ourense, the population on 1/1/2019 was 307,651, of whom 96,544 (31.4%) were aged ≥ 65 years. RESULTS We identified 80 cases of MG, with a prevalence rate of 260 cases/1 000 000 population (95% CI, 202.7-316.4), rising to 517.9/1 000 000 population in those aged ≥ 65 (95% CI, 363.2-672.9). Cumulative incidence in the study period was 15.4 cases per 1 000 000 person-years. Early onset (≤ 50 years) was recorded in 29.1% of cases. CONCLUSION The prevalence of MG in our health district is one of the highest published figures, and the disease is highly prevalent in the older population.
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Affiliation(s)
- D A García Estévez
- Servicio de Neurología, Complejo Hospitalario Universitario de Ourense, Ourense, España.
| | - L M López Díaz
- Servicio de Neurología, Complejo Hospitalario Universitario de Ourense, Ourense, España
| | - M Pardo Parrado
- Servicio de Neurología, Complejo Hospitalario Universitario de Ourense, Ourense, España
| | - G Pérez Lorenzo
- Servicio de Neurología, Complejo Hospitalario Universitario de Ourense, Ourense, España
| | - N A Sabbagh Casado
- Servicio de Neurología, Complejo Hospitalario Universitario de Ourense, Ourense, España
| | - G Ozaita Arteche
- Servicio de Neurología, Complejo Hospitalario Universitario de Ourense, Ourense, España
| | - D Rodríguez Gómez
- Servicio de Neurología, Complejo Hospitalario Universitario de Ourense, Ourense, España
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Rivner MH, Quarles BM, Pan JX, Yu Z, Howard JF, Corse A, Dimachkie MM, Jackson C, Vu T, Small G, Lisak RP, Belsh J, Lee I, Nowak RJ, Baute V, Scelsa S, Fernandes JA, Simmons Z, Swenson A, Barohn R, Sanka RB, Gooch C, Ubogu E, Caress J, Pasnoor M, Xu H, Mei L. Clinical features of LRP4/agrin-antibody-positive myasthenia gravis: A multicenter study. Muscle Nerve 2020; 62:333-343. [PMID: 32483837 PMCID: PMC7496236 DOI: 10.1002/mus.26985] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 05/16/2020] [Accepted: 05/18/2020] [Indexed: 12/13/2022]
Abstract
Introduction Our aim in this study was to identify the prevalence and clinical characteristics of LRP4/agrin‐antibody–positive double‐seronegative myasthenia gravis (DNMG). Methods DNMG patients at 16 sites in the United States were tested for LRP4 and agrin antibodies, and the clinical data were collected. Results Of 181 DNMG patients, 27 (14.9%) were positive for either low‐density lipoprotein receptor–related protein 4 (LRP4) or agrin antibodies. Twenty‐three DNMG patients (12.7%) were positive for both antibodies. More antibody‐positive patients presented with generalized symptoms (69%) compared with antibody‐negative patients (43%) (P ≤ .02). Antibody‐positive patients’ maximum classification on the Myasthenia Gravis Foundation of America (MGFA) scale was significantly higher than that for antibody‐negative patients (P ≤ .005). Seventy percent of antibody‐positive patients were classified as MGFA class III, IV, or V compared with 39% of antibody‐negative patients. Most LRP4‐ and agrin‐antibody–positive patients (24 of 27, 89%) developed generalized myathenia gravis (MG), but with standard MG treatment 81.5% (22 of 27) improved to MGFA class I or II during a mean follow‐up of 11 years. Discussion Antibody‐positive patients had more severe clinical disease than antibody‐negative patients. Most DNMG patients responded to standard therapy regardless of antibody status.
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Affiliation(s)
| | | | - Jin-Xiu Pan
- Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio
| | - Zheng Yu
- Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio
| | - James F Howard
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Andrea Corse
- Department of Neurology, The Johns Hopkins University, Baltimore, Maryland
| | | | - Carlayne Jackson
- Department of Neurology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Tuan Vu
- Department of Neurology, University of South Florida, Tampa, Florida
| | - George Small
- Department of Neurology, Allegheny General Hospital, Pittsburgh, Pennsylvania
| | - Robert P Lisak
- Department of Neurology, Wayne State University, Detroit, Michigan
| | - Jerry Belsh
- Department of Neurology, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey
| | - Ikjae Lee
- Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Richard J Nowak
- Department of Neurology, Yale University, New Haven, Connecticut
| | - Vanessa Baute
- Department of Neurology, Wake Forest University, Winston-Salem, North Carolina
| | - Stephen Scelsa
- Department of Neurology, Mount Sinai-Beth Israel Hospital, New York, New York
| | - J Americo Fernandes
- Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, Nebraska
| | - Zachary Simmons
- Department of Neurology, Penn State Health Milton S. Hershey Medical Center, Hershey, Pennsylvania
| | - Andrea Swenson
- Department of Neurology, University of Iowa, Iowa City, Iowa
| | - Richard Barohn
- Department of Neurology, University of Kansas, Kansas City, Kansas
| | - R Bhavaraju Sanka
- Department of Neurology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Clifton Gooch
- Department of Neurology, University of South Florida, Tampa, Florida
| | - Eroboghene Ubogu
- Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama
| | - James Caress
- Department of Neurology, Wake Forest University, Winston-Salem, North Carolina
| | - Mamatha Pasnoor
- Department of Neurology, University of Kansas, Kansas City, Kansas
| | - Hongyan Xu
- Department of Population Health Sciences, Augusta University, Augusta, Georgia
| | - Lin Mei
- Department of Neurosciences, Case Western Reserve University, Cleveland, Ohio
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Fang W, Li Y, Mo R, Wang J, Qiu L, Ou C, Lin Z, Huang Z, Feng H, He X, Wang W, Xu P, Wang L, Ran H, Liu W. Hospital and healthcare insurance system record-based epidemiological study of myasthenia gravis in southern and northern China. Neurol Sci 2020; 41:1211-1223. [PMID: 31897952 DOI: 10.1007/s10072-019-04146-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 11/07/2019] [Indexed: 12/31/2022]
Abstract
OBJECTIVE This is the first cross-region epidemiological study of myasthenia gravis (MG) in China. We estimated the incidence, prevalence, and medical costs of MG in southern China and explored the differences between the southern and northern Chinese populations. METHODS We collected and analyzed records from 20 hospitals in the southern city, Guangzhou, 13 hospitals in the northern city, Harbin, and two healthcare insurance systems: job based and residence based in Guangzhou during 2000-2017. RESULTS (1) The estimated annual incidence of MG was 1.55-3.66 per 100,000, and the estimated prevalence of MG was 2.19-11.07 per 100,000 in southern China based on insurance records. (2) The proportion of hospitalized MG patients in the south-based hospital records was three times as high as that in the north-based hospital records. (3) Female MG prevalence was significantly higher than male MG prevalence in Guangzhou, while the similar gender difference in Harbin was not statistically significant due to higher variation in earlier years. (4) The average expense was $35-42 for each outpatient service and $2526-2673 for each hospitalization expense in the south. (5) Contrary to the increase of insurance-based estimate of MG prevalence, the proportion of hospitalized MG patients did not increase over the years, suggesting rising awareness and utilization of health insurance. CONCLUSIONS The southern MG population had a significantly higher prevalence and a lower response threshold to medication than the northern MG population. These results are calling for further investigations on the genetic, cultural, and environmental variations of the Chinese MG populations between north and south.
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Affiliation(s)
- Wei Fang
- School of Earth and Environmental Sciences, Queens College, City University of New York, Queens, NY, USA
| | - Yan Li
- Department of Neurology, The First Affiliated Hospital of Sun Yat-sen University, #58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China.,Department of Neurosurgical Intensive Care Unit, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
| | - Rong Mo
- Department of Neurology, The First Affiliated Hospital of Sun Yat-sen University, #58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China
| | - Jianjian Wang
- Department of Neurology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, People's Republic of China
| | - Li Qiu
- Department of Neurology, The First Affiliated Hospital of Sun Yat-sen University, #58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China
| | - Chuangyi Ou
- Department of Neurology, The First Affiliated Hospital of Sun Yat-sen University, #58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China
| | - Zhongqiang Lin
- Department of Neurology, The First Affiliated Hospital of Sun Yat-sen University, #58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China
| | - Zhidong Huang
- Department of Neurology, The First Affiliated Hospital of Sun Yat-sen University, #58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China
| | - Huiyu Feng
- Department of Neurology, The First Affiliated Hospital of Sun Yat-sen University, #58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China
| | - Xuetao He
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong General Hospital and Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, People's Republic of China
| | - Weizhi Wang
- Department of Neurology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, People's Republic of China
| | - Peipei Xu
- Faculty of Geographical Science, Beijing Normal University, Beijing, People's Republic of China
| | - Lihua Wang
- Department of Neurology, The Second Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, People's Republic of China.
| | - Hao Ran
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, People's Republic of China.
| | - Weibin Liu
- Department of Neurology, The First Affiliated Hospital of Sun Yat-sen University, #58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China.
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Hendricks TM, Bhatti MT, Hodge DO, Chen JJ. Incidence, Epidemiology, and Transformation of Ocular Myasthenia Gravis: A Population-Based Study. Am J Ophthalmol 2019; 205:99-105. [PMID: 31077669 DOI: 10.1016/j.ajo.2019.04.017] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/23/2019] [Accepted: 04/26/2019] [Indexed: 11/15/2022]
Abstract
PURPOSE To establish the incidence of ocular myasthenia gravis (OMG) as well as identify determinants of transformation to generalized myasthenia gravis (GMG) using a population-based record-linkage system. DESIGN Population-based, retrospective cohort study. METHODS All adults (≥18 years) diagnosed with myasthenia gravis (MG) from January 1, 1990, through December 31, 2017, were identified using the Rochester Epidemiology Project. Sixty-five patients with MG were identified. Data were collected regarding symptom onset, diagnostic testing results, and conversion from OMG to GMG. RESULTS Median follow-up time was 91 months (range 17-333 months). The annual incidence of MG was 2.20/100 000 with a mean age at diagnosis of 59 years (SD=17) and 62% male sex. Thirty-three (51%) of the 65 patients presented with OMG, providing an annual incidence of 1.13/100 000. Eighteen (55%) of the 33 patients presenting with OMG converted to GMG at a median time of 13 months (range 2-180 months). Sixteen (67%) of 24 OMG patients who were seropositive for acetylcholine receptor antibody (AchR Ab) converted to GMG at 5 years compared to 11% (1/9) of those who were seronegative (hazard ratio [HR], 8.2, P = .04). Ten (77%) of 13 OMG patients with a positive single-fiber electromyography (sfEMG) at diagnosis converted to GMG at 5 years, compared with 18% (2/11) of patients who had a negative sfEMG (HR, 5.5, P = .01). CONCLUSIONS In our population-based study, 51% (33/65) of patients with MG presented with isolated ocular involvement, with 55% (18/33) of these patients converting to GMG at some point in the course of their disease. Positive sfEMG and AchR Ab seropositivity at the time of diagnosis increased the risk of conversion to GMG.
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Affiliation(s)
- Tina M Hendricks
- Mayo Clinic Alix School of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - M Tariq Bhatti
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, USA; Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | - David O Hodge
- Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota, USA
| | - John J Chen
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, USA; Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA.
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Benefits of Comprehensive Rehabilitation Therapy in Thymectomy for Myasthenia Gravis: A Propensity Score Matching Analysis. Am J Phys Med Rehabil 2017; 96:77-83. [PMID: 28099277 DOI: 10.1097/phm.0000000000000538] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To demonstrate the effectiveness of a comprehensive program of rehabilitation therapy in patients undergoing thymectomy for myasthenia gravis (MG). DESIGN From 2005 to 2010, 46 consecutive patients affected by MG underwent a rehabilitation program both before and after thymectomy. We matched each patient with a "control patient" who underwent thymectomy within the period 1999 to 2004 with no preoperative rehabilitation, who had the closest propensity score matching. RESULTS All patients but 2 were able to complete the intended program. Eighteen patients (41%) experienced mild fatigue (>25 at MG quantitative score). Propensity score selected a group of 17 patients for the matching process. The group of patients who underwent the rehabilitation program showed significant preoperative improvement associated with a reduced operative risk, a decreased early postoperative morbidity, a lower rate of postoperative intensive care unit needed (12% vs 35%; P = 0.01) and a shorter hospital stay (3 vs 5 days; P = 0.04). After the expected perioperative decline, all major myasthenic outcomes demonstrated a significant faster recovery at 3 months. Complete stable remission did not reveal significant differences. CONCLUSIONS Exercise is not necessarily a contraindication in MG, and rehabilitation can be safely performed before and after thymectomy, reducing operative risks and decreasing recovery time. TO CLAIM CME CREDITS Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCMECME OBJECTIVES: Upon completion of this article, the reader should be able to do the following: (1) appreciate the benefits of physical therapy in individuals with myasthenia gravis; (2) describe the benefits of physical therapy on postoperative morbidity in myasthenia gravis patients who undergo thymectomy; and (3) incorporate appropriate rehabilitation into the treatment plan of patient with myasthenia gravis. LEVEL AdvancedACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this activity for a maximum of 1.5 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.
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Lee JI, Jander S. Myasthenia gravis: recent advances in immunopathology and therapy. Expert Rev Neurother 2016; 17:287-299. [PMID: 27690672 DOI: 10.1080/14737175.2017.1241144] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- John-Ih Lee
- Department of Neurology, Heinrich-Heine-University, Medical Faculty, Duesseldorf, Germany
| | - Sebastian Jander
- Department of Neurology, Heinrich-Heine-University, Medical Faculty, Duesseldorf, Germany
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Santos E, Coutinho E, Moreira I, Silva AM, Lopes D, Costa H, Silveira F, Nadais G, Morais H, Martins J, Branco MC, Veiga A, Silva RS, Ferreira A, Sousa F, Freijo M, Matos I, André R, Negrão L, Fraga C, Santos M, Sampaio M, Lopes C, Leite MI, Gonçalves G. Epidemiology of myasthenia gravis in Northern Portugal: Frequency estimates and clinical epidemiological distribution of cases. Muscle Nerve 2016; 54:413-21. [PMID: 26851892 DOI: 10.1002/mus.25068] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 01/25/2016] [Accepted: 02/01/2016] [Indexed: 12/22/2022]
Abstract
INTRODUCTION In this study we estimated the prevalence, incidence, and mortality of myasthenia gravis (MG) in northern Portugal and characterized the clinical features of the patients identified. METHODS We used 2 data sources: clinical records from the hospitals and pyridostigmine prescription registers. RESULTS On December 31, 2013, we estimated a point prevalence of 111.7 patients per million population. The highest prevalence was observed in the group >65 years of age, especially in men (288.1 per million). During 2013, we estimated an incidence rate of 6.3 per million per year. Among women, the incidence rate was highest in the 15-49-year age group; in men, incidence increased with age up to 22.1 per million in those >65 years old. The MG-related mortality rate was 0.5 per million. CONCLUSIONS These figures are in keeping with similar studies and emphasize the importance of diagnosis and management of MG in elderly populations. Muscle Nerve 54: 413-421, 2016.
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Affiliation(s)
- Ernestina Santos
- Neurology Department, Hospital Santo Antonio, Centro Hospitalar Porto, Porto, Portugal.,Unit for Multidisciplinary Research in Biomedicine, Instituto de Ciencias Biomedicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Ester Coutinho
- Nuffield Department of Clinical Neurosciences, Oxford University Hospitals, University of Oxford, UK
| | - Isabel Moreira
- Neurology Department, Hospital Santo Antonio, Centro Hospitalar Porto, Porto, Portugal
| | - Ana Martins Silva
- Neurology Department, Hospital Santo Antonio, Centro Hospitalar Porto, Porto, Portugal.,Unit for Multidisciplinary Research in Biomedicine, Instituto de Ciencias Biomedicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Dina Lopes
- Centro Hospitalar do Porto, Porto, Portugal
| | - Henrique Costa
- Neurology Department, Hospital Sao Joao, Porto, Portugal
| | | | - Goreti Nadais
- Neurology Department, Hospital Sao Joao, Porto, Portugal
| | - Hugo Morais
- Neurology Department, Centro Hospitalar de Vila Nova de Gaia e Espinho, Gaia, Portugal
| | - João Martins
- Neurology Department, Hospital Pedro Hispano, Matosinhos, Portugal
| | - Maria Ceu Branco
- Neurology Department, Hospital Pedro Hispano, Matosinhos, Portugal.,Neurology Department, Hospital de Sao Pedro, Centro Hospitalar do Trás-os-Montes e Alto Douro, Vila Real, Portugal
| | - Andreia Veiga
- Neurology Department, Hospital de Sao Pedro, Centro Hospitalar do Trás-os-Montes e Alto Douro, Vila Real, Portugal
| | - Rosa Santos Silva
- Neurology Department, Centro Hospitalar do Alto Minho, Viana do Castelo, Portugal
| | - Augusto Ferreira
- Neurology Department, Centro Hospitalar Entre Douro e Vouga, Feira, Portugal
| | - Filipa Sousa
- Neurology Department, Hospital de Braga, Braga, Portugal
| | - Marta Freijo
- Neurology Department, Centro Hospitalar do Nordeste, Mirandela, Portugal
| | - Ilda Matos
- Neurology Department, Centro Hospitalar do Nordeste, Mirandela, Portugal
| | - Rui André
- Neurology Department, Hospital de São Teotonio, Viseu, Portugal
| | - Luís Negrão
- Neurology Department, Centro Hospitalar Universitario de Coimbra, Coimbra, Portugal
| | - Carla Fraga
- Neurology Department, Centro Hospitalar do Vale do Sousa, Penafiel, Portugal
| | - Manuela Santos
- Neuropediatrics Department, Centro Materno Infantil Norte, Centro Hospitalar Porto, Porto, Portugal
| | - Mafalda Sampaio
- Neuropediatrics Department, Hospital de Sao Joao, Porto, Portugal
| | - Carlos Lopes
- Instituto de Ciencias Biomedicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Maria Isabel Leite
- Nuffield Department of Clinical Neurosciences, Oxford University Hospitals, University of Oxford, UK
| | - Guilherme Gonçalves
- Unit for Multidisciplinary Research in Biomedicine, Instituto de Ciencias Biomedicas de Abel Salazar, Universidade do Porto, Porto, Portugal
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Park SY, Lee JY, Lim NG, Hong YH. Incidence and Prevalence of Myasthenia Gravis in Korea: A Population-Based Study Using the National Health Insurance Claims Database. J Clin Neurol 2016; 12:340-4. [PMID: 27165426 PMCID: PMC4960219 DOI: 10.3988/jcn.2016.12.3.340] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 12/28/2015] [Accepted: 12/30/2015] [Indexed: 11/24/2022] Open
Abstract
Background and Purpose There have been a few national population-based epidemiological studies of myasthenia gravis (MG) with wide variation of incidence and prevalence rates worldwide. Herein we report the first nationwide population-based epidemiological study of MG in Korea. Methods We attempted to estimate the incidence and prevalence rates of MG using the Korean National Health Insurance claims database for 2010 to 2013. Cases with MG were defined as those having claim records with a principal diagnosis of MG and the prescription of acetylcholinesterase inhibitors or immunosuppressive agents including corticosteroids and azathioprine within 2 years after the diagnosis. The year 2010 was set as a washout period, such that patients were defined as incident cases if their first records of MG were observed in 2011. Results In 2011 there were 1,236 incident cases, and the standardized incidence rate was 2.44 per 100,000 person-years. The standardized prevalence rates were 9.67 and 10.66 per 100,000 persons in 2010 and 2011, respectively. The incidence and prevalence rates peaked in the elderly population aged 60 to 69 years for both sexes. Conclusions This is one of the largest national population-based epidemiological studies of MG, and it has confirmed the high incidence and prevalence rates of MG in the elderly population of South Korea.
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Affiliation(s)
- Su Yeon Park
- Department of Neurology, Korea Cancer Center Hospital, Seoul, Korea
| | - Jin Yong Lee
- Public Health Medical Service, Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea
| | - Nam Gu Lim
- Department of Medical Administration, Daejeon Health Sciences College, Daejeon, Korea.
| | - Yoon Ho Hong
- Department of Neurology, Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea.
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Binks S, Vincent A, Palace J. Myasthenia gravis: a clinical-immunological update. J Neurol 2015; 263:826-34. [PMID: 26705120 PMCID: PMC4826656 DOI: 10.1007/s00415-015-7963-5] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 10/06/2015] [Indexed: 12/13/2022]
Abstract
Myasthenia gravis (MG) is the archetypic disorder of both the neuromuscular junction and autoantibody-mediated disease. In most patients, IgG1-dominant antibodies to acetylcholine receptors cause fatigable weakness of skeletal muscles. In the rest, a variable proportion possesses antibodies to muscle-specific tyrosine kinase while the remainder of seronegative MG is being explained through cell-based assays using a receptor-clustering technique and, to a lesser extent, proposed new antigenic targets. The incidence and prevalence of MG are increasing, particularly in the elderly. New treatments are being developed, and results from the randomised controlled trial of thymectomy in non-thymomatous MG, due for release in early 2016, will be of particular clinical value. To help navigate an evidence base of varying quality, practising clinicians may consult new MG guidelines in the fields of pregnancy, ocular and generalised MG (GMG). This review focuses on updates in epidemiology, immunology, therapeutic and clinical aspects of GMG in adults.
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Affiliation(s)
- Sophie Binks
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Angela Vincent
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Jacqueline Palace
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DU, UK.
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Breiner A, Widdifield J, Katzberg HD, Barnett C, Bril V, Tu K. Epidemiology of myasthenia gravis in Ontario, Canada. Neuromuscul Disord 2015; 26:41-6. [PMID: 26573434 DOI: 10.1016/j.nmd.2015.10.009] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 10/05/2015] [Accepted: 10/19/2015] [Indexed: 12/19/2022]
Abstract
Incidence and prevalence estimates in myasthenia gravis have varied widely. Recent studies based on administrative health data have large sample sizes but lack rigorous validation of MG cases, and have not examined the North American population. Our aim was to explore trends in MG incidence and prevalence for the years 1996-2013 in the province of Ontario, Canada (population 13.5 million). We employed a previously validated algorithm to identify MG cases. Linking with census data allowed for the calculation of crude- and age/sex-standardized incidence and prevalence rates for the years 1996-2013. The regional distribution of MG cases throughout the province was examined. Mean age at the first myasthenia gravis encounter was 60.2 ± 17.1 years. In 2013, there were 3611 prevalent cases in Ontario, and the crude prevalence rate was 32.0/100,000 population. Age- and sex-standardized prevalence rates rose consistently over time from 16.3/100,000 (15.4-17.1) in 1996 to 26.3/100,000 (25.4-27.3) in 2013. Standardized incidence rates remained stable between 1996 (2.7/100,000; 95% CL 2.3-3.0) and 2013 (2.3/100,000; 2.1-2.6). Incidence was highest in younger women and older men, and geographic variation was evident throughout the province. In conclusion, this large epidemiological study shows rising myasthenia gravis prevalence with stable incidence over time, which is likely reflective of patients living longer, possibly due to improved disease treatment. Our findings provide accurate information on the Canadian epidemiology of myasthenia gravis and burden for health care resources planning for the province, respectively.
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Affiliation(s)
- Ari Breiner
- Department of Medicine, Division of Neurology, University of Toronto, Toronto, Ontario, Canada.
| | - Jessica Widdifield
- Institute for Clinical Evaluative Sciences (ICES), Toronto, Ontario, Canada; McGill University, Montreal, Quebec, Canada
| | - Hans D Katzberg
- Department of Medicine, Division of Neurology, University of Toronto, Toronto, Ontario, Canada
| | - Carolina Barnett
- Department of Medicine, Division of Neurology, University of Toronto, Toronto, Ontario, Canada
| | - Vera Bril
- Department of Medicine, Division of Neurology, University of Toronto, Toronto, Ontario, Canada
| | - Karen Tu
- Institute for Clinical Evaluative Sciences (ICES), Toronto, Ontario, Canada; Department of Family and Community Medicine, University of Toronto, Toronto, Ontario, Canada; University Health Network, Toronto Western Hospital Family Health Team, Toronto, Ontario, Canada
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Mourão AM, Barbosa LSM, Comini-Frota ER, Freitas DDS, Gomez RS, Burns TM, Lemos SMA, Teixeira AL. Clinical profile of patients with myasthenia gravis followed at the University Hospital, Federal University of Minas Gerais. Rev Assoc Med Bras (1992) 2015; 61:156-60. [PMID: 26107366 DOI: 10.1590/1806-9282.61.02.156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 10/21/2014] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE to determine the clinical profile of patients with myasthenia gravis (MG); followed at the Neuromuscular Diseases Clinic of the University Hospital, Federal University of Minas Gerais, Brazil, and to compare it with other Brazilian case series. METHODS sociodemographic and clinical data were collected from patients, and a systematic literature review performed, focusing on national studies on the clinical profile of MG patients. RESULTS sixty nine patients were enrolled in the study. Fifty five (91%) subjects were female and the mean age (SD) was 37.6 (± 11.4) years. The mean disease duration was 14.1 years. Regarding treatment, prednisone was the most used strategy (64%), followed by the use of azathioprine (43%). There was no difference between thymectomized (42) and non-thymectomized (27) patients regarding disease severity and medication use. CONCLUSION clinical and socio-demographic features of this MG sample from a University-based clinic resemble those reported in other Brazilian series and in the international literature.
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Affiliation(s)
| | | | | | - Denise da Silva Freitas
- Neurology Service, Clinics Hospital, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Rodrigo Santiago Gomez
- Neurology Service, Clinics Hospital, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Ted M Burns
- University of Virginia, Charlottesville, Virginia, USA
| | - Stela Maris Aguiar Lemos
- Department of Speech Pathology and Audiology, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
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Breiner A, Young J, Green D, Katzberg HD, Barnett C, Bril V, Tu K. Canadian Administrative Health Data Can Identify Patients with Myasthenia Gravis. Neuroepidemiology 2015; 44:108-13. [DOI: 10.1159/000375463] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 01/22/2015] [Indexed: 11/19/2022] Open
Abstract
Introduction: Incidence and prevalence estimates for myasthenia gravis (MG) have varied widely, and the ability of administrative health data (AHD) records to accurately identify cases of MG is yet to be ascertained. The goal of the current study was to validate an algorithm to identify patients with MG in Ontario, Canada using AHD - thereby enabling future disease surveillance. Methods: A reference standard population was established using automated key word searching within EMRALD (Electronic Medical Record Administrative data Linked Database) and chart review of potential cases. AHD algorithms were generated and tested against the reference standard. The data was used to calculate MG prevalence rates. Results: There were 123,997 eligible adult patients, and 49 patients had definite MG (forming the reference standard). An algorithm requiring: (1 hospital discharge abstract with MG listed as a reason for hospitalization or a comorbid condition), or (5 outpatient MG visits and 1 relevant diagnostic test, within 1 year), or (3 pyridostigmine prescriptions, within 1 year) identified MG with sensitivity = 81.6%, specificity = 100%, positive predictive value = 80.0% and negative predictive value = 100%. The population prevalence within our cohort was 0.04%. Conclusions: This novel validation method demonstrates the feasibility of using administrative health data to identify patients with myasthenia gravis among the Ontario population.
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Szczudlik P, Szyluk B, Lipowska M, Ryniewicz B, Kubiszewska J, Dutkiewicz M, Gilhus NE, Kostera-Pruszczyk A. Antititin antibody in early- and late-onset myasthenia gravis. Acta Neurol Scand 2014; 130:229-33. [PMID: 24947881 DOI: 10.1111/ane.12271] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2014] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Myasthenia gravis (MG) is an autoimmune disease caused by antibodies against neuromuscular junction proteins, 85% of patients have antibodies against acetylcholine receptor (AChR-MG). Antititin antibodies are present in a subset of patients with MG. We aimed to determine the value of antititin antibodies as severity markers and thymoma predictors in early- and late-onset MG. MATERIALS & METHODS Two-hundred and ninety-five consecutive MG patients (188 F and 107 M) aged 12-89 years (mean 50y) were included. 164 patients had early-onset (EOMG, ≤50 years of age), 131 had late-onset MG (LOMG). Twenty-six patients had thymoma. symptoms, severity graded with MGFA scale, thymus histology, medications, and treatment results were analyzed. RESULTS Antititin antibodies were present in 81 (27%) of all patients: 54% of thymoma MG, 0.6% of non-thymomatous EOMG, and 55% of LOMG, with proportion of titin-positive patients increasing linearly from 40% in the 6th to 88% in the 9th decade of life. Titin-positive patients had more bulbar symptoms (P = 0.003). Severity of MG, need for immunosuppression, myasthenic crisis risk or treatment results were not related to its presence. Antititin antibodies had 56% sensitivity, 99% specificity, 90% positive predictive value (PPV), and 95% negative predictive value (NPV) for thymoma diagnosis in EOMG, and 50% sensitivity, 75% specificity, 71% PPV and 55% NPV in LOMG. CONCLUSIONS Antititin antibodies have high PPV and NPV for thymoma in EOMG. In MG without thymoma, antititin antibodies can be considered as markers of LOMG, but not of a severe course in our MG cohort.
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Affiliation(s)
- P. Szczudlik
- Department of Neurology; Medical University of Warsaw; Warsaw Poland
| | - B. Szyluk
- Department of Neurology; Medical University of Warsaw; Warsaw Poland
| | - M. Lipowska
- Department of Neurology; Medical University of Warsaw; Warsaw Poland
| | - B. Ryniewicz
- Department of Neurology; Medical University of Warsaw; Warsaw Poland
| | - J. Kubiszewska
- Department of Neurology; Medical University of Warsaw; Warsaw Poland
| | - M. Dutkiewicz
- Department of Immunology, Biochemistry and Nutrition; Medical University of Warsaw; Warsaw Poland
| | - N. E. Gilhus
- Department of Neurology; Haukeland University Hospital; Bergen Norway
- Department of Clinical Medicine; University of Bergen; Bergen Norway
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Increased subsequent risk of myasthenia gravis in children with allergic diseases. J Neuroimmunol 2014; 276:202-6. [PMID: 25227584 DOI: 10.1016/j.jneuroim.2014.08.627] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 08/28/2014] [Accepted: 08/31/2014] [Indexed: 12/30/2022]
Abstract
Myasthenia gravis (MG) is an autoimmune disorder that affects the neuromuscular junction. The initiating factors of MG remain unclear. However, allergy has been regarded as a potential risk factor. We included 410 children with MG diagnosed between 2000 and 2008, as well as 1640 randomly selected controls. The odds ratios of MG were calculated to determine the association between MG and preexisting allergic diseases. The children with allergic diseases were at increased subsequent risk of MG, which was associated with the cumulative effect of the concurrent allergic diseases and the frequency of seeking medical care.
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Mourao AM, Araujo CM, Barbosa LSM, Gomez RS, Burns TM, Lemos SMA, Teixeira AL. Brazilian cross-cultural translation and adaptation of the "Questionnaire of Life Quality Specific for Myasthenia Gravis - 15 items". ARQUIVOS DE NEURO-PSIQUIATRIA 2013; 71:955-8. [DOI: 10.1590/0004-282x20130180] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 07/17/2013] [Indexed: 11/22/2022]
Abstract
Objective To translate and to perform the cross-cultural adaptation of the “Questionnaire of Life Quality Specific for Myasthenia Gravis - 15 items” (MG-QOL15). Method The original English version of the questionnaire was translated into Portuguese. This version was revised and translated back into English. Later, both English versions were compared and the divergences were corrected in the Portuguese text. At a second stage, ten patients with MG followed at the Neuromuscular Diseases Clinic from the University Hospital, Universidade Federal de Minas Gerais answered the questionnaire. The authors analyzed the difficulties and misunderstandings in the application of the questionnaire. Results The questions 8, 13 and 15 were considered difficult to understand and were modified in the final Portuguese version. Most patients (70%) had a total score above 25, and the statements 3, 8 and 9 showed the highest scores. Conclusion The Brazilian version of the questionnaire MG-QOL15 seems to be a promising tool for the assessment of Brazilian patients with MG.
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Jiang L, Wu W, Guan W, Wu Z, Nie Y. Overlooked myasthenia gravis in an elderly adult. J Am Geriatr Soc 2013; 61:840-1. [PMID: 23672558 DOI: 10.1111/jgs.12228] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
OBJECTIVES To find the characteristic phenotypes of 3 different types of myasthenia gravis (MG). METHODS The clinical and electrophysiological features among 15 cases of muscle-specific kinase antibody positive (MuSK Ab+) MG, 59 cases of double seronegative (DSN) MG, and 161 cases of acetylcholine receptor antibody (AChR Ab)+ MG in the University of Alabama at Birmingham were compared. RESULTS AChR Ab was positive in 69% of cases and MuSK Ab in 6% of cases. MuSK Ab+ MG was more common (14%) in African Americans compared with whites (4%). AChR Ab+ MG is characterized by male predominance, later onset, a fewer cases of ocular MG, and a higher association with thymoma. DSN-MG is characterized by a greater prevalence of ocular MG, milder forms of MG with less number of crisis, and fewer abnormalities in the repetitive nerve stimulation test. MuSK Ab+ MG is characterized by younger age at onset, severe and bulbar forms of MG, predominant faciobulbar neck weakness, and a poor response to edrophonium, anticholinesterase, and intravenous immunoglobulin. Long-term outcome showed no difference among 3 types of MG. CONCLUSIONS AChR Ab+ MG and DSN-MG are similar, with the exception of less severity in the latter. MuSK Ab+ MG has distinct clinical and electrophysiological features.
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Cetin H, Fülöp G, Zach H, Auff E, Zimprich F. Epidemiology of myasthenia gravis in Austria: rising prevalence in an ageing society. Wien Klin Wochenschr 2012; 124:763-8. [PMID: 23129486 DOI: 10.1007/s00508-012-0258-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 10/01/2012] [Indexed: 10/27/2022]
Abstract
OBJECTIVE The purpose of this study was to investigate recent epidemiological trends of myasthenia gravis (MG) in Austria. METHODS We used the national hospital discharge register, which records the discharge diagnoses of all inpatient stays in Austria to calculate the yearly inpatient prevalence of MG from 1992 to 2009 (main or secondary diagnosis of MG). The population prevalence was indirectly estimated. The temporal and geographical variability of the inpatient prevalence was correlated with the number of practicing neurologists. RESULTS The inpatient prevalence of 2009 was calculated as 8.0 and the population prevalence as 15.69 (95 % CI 13.16-19.42) per 100,000. We observed a 2.2 fold increase in the inpatient prevalence between 1992 and 2009, which was mainly due to a rise in the number of older patients (³ 50 years). Partly this could be accounted for by an ageing of the population as a whole and a rise in the age of hospitalised patients. However, after adjusting for demographic factors an unexplained average yearly rise of 3.7-3.9 % remained. We found a significant spatial and temporal correlation of MG inpatient prevalence rates with the number of practicing neurologists, which increased over the same period. CONCLUSIONS The results from this study support the notion that the prevalence rate of MG in Austria is rising and near the higher end of the wide range discussed in the literature. Our data argue for the importance of specialist neurological care for the diagnosis of this disease.
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Affiliation(s)
- Hakan Cetin
- Department of Clinical Neurology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
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Živković SA, Clemens PR, Lacomis D. Characteristics of late-onset myasthenia gravis. J Neurol 2012; 259:2167-71. [DOI: 10.1007/s00415-012-6478-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 03/04/2012] [Accepted: 03/05/2012] [Indexed: 12/27/2022]
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Updated assessment of the prevalence, spectrum and case definition of autoimmune disease. Autoimmun Rev 2012; 11:754-65. [PMID: 22387972 DOI: 10.1016/j.autrev.2012.02.001] [Citation(s) in RCA: 287] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 01/31/2012] [Indexed: 12/13/2022]
Abstract
Autoimmune diseases are heterogeneous with regard to prevalence, manifestations, and pathogenesis. The classification of autoimmune diseases has varied over time. Here, we have compiled a comprehensive up-to-date list of the autoimmune diseases, and have reviewed published literature to estimate their prevalence. We identified 81 autoimmune diseases. The overall estimated prevalence is 4.5%, with 2.7% for males and 6.4% for females. For specific diseases, prevalence ranges from 1% to <1/10(6). Considering all diseases in the class, the most common mean age-of-onset was 40-50 years. This list of autoimmune diseases has also yielded information about autoantigens. Forty-five autoimmune diseases have been associated with well-defined autoantigens. Of the diseases with known autoantigens, 33.3% had highly repetitive sequences, 35.6% had coiled-coil arrangements and 57.8% were associated with cellular membranes, which means that based on these structural motifs alone, autoantigens do not appear to be a random sample of the human proteome. Finally, we identified 19 autoimmune diseases that phenocopy diseases arising from germline mutations in the corresponding autoantigen. Collectively, our findings lead to a tentative proposal for criteria for assigning autoimmune pathogenesis to a particular disease.
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Liu CJ, Chang YS, Teng CJ, Chen TJ, Ou SM, Tzeng CH, Wang SJ. Risk of extrathymic cancer in patients with myasthenia gravis in Taiwan: a nationwide population-based study. Eur J Neurol 2012; 19:746-51. [DOI: 10.1111/j.1468-1331.2011.03621.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Neuromuscular Disorders. Neurology 2012. [DOI: 10.1007/978-0-387-88555-1_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Abstract
Myasthenia gravis is an autoimmune neuromuscular disorder. There are several treatment options, including symptomatic treatment (acetylcholinesterase inhibitors), short-term immunosuppression (corticosteroids), long-term immunosuppression (azathioprine, cyclosporine, cyclophosphamide, methotrexate, mycophenolate mofetil, rituximab, tacrolimus), rapid acting short-term immunomodulation (intravenous immunoglobulin, plasma exchange), and long-term immunomodulation (thymectomy). This review explores in detail these different treatment options. Potential future treatments are also discussed.
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Pallaver F, Riviera AP, Piffer S, Ricciardi R, Roni R, Orrico D, Bonifati DM. Change in myasthenia gravis epidemiology in Trento, Italy, after twenty years. Neuroepidemiology 2011; 36:282-7. [PMID: 21757957 DOI: 10.1159/000328863] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2010] [Accepted: 04/21/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The recent literature suggests that the incidence and prevalence of myasthenia gravis (MG) are changing. We performed a population-based study of MG in the province of Trentino (524,826 inhabitants) and compared the results with those collected 20 years ago. METHODS Multiple sources of information (discharge diagnosis, antibody tests and anticholinesterase drugs) were analyzed. Incidence was calculated from 2005 to 2009. Prevalence was calculated on December 31, 2009. Comparison was made with descriptive statistics for 1981-1990 for the identical region. RESULTS Incidence and prevalence greatly increased in comparison with 1981-1990 data. The prevalence rate increased from 82.9 (95% confidence interval, CI, 58.4-114.3) in 1990 to 129.6 (95% CI 100.6-164.3) per million population, whereas the average annual incidence increased from 7.4 (95% CI 5-10.4) per million person-years in 1981-1990 to 14.8 (95% CI 10.5-20.3) in 2005-2009. This increase was mainly due to male patients with late-onset MG. CONCLUSIONS The study confirms the increase in incidence and prevalence of late-onset MG in the same region 20 years apart. So we should consider MG also as a disease of the elderly.
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Affiliation(s)
- Fabrizio Pallaver
- Department of Neurological Disorders, Santa Chiara Hospital, Trento, Italy
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Andersen JB, Engeland A, Owe JF, Gilhus NE. Myasthenia gravis requiring pyridostigmine treatment in a national population cohort. Eur J Neurol 2011; 17:1445-50. [PMID: 20491896 DOI: 10.1111/j.1468-1331.2010.03089.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Pyridostigmine is the first drug of choice for patients with myasthenia gravis (MG). The drug is not prescribed regularly to any other patient groups. We aimed to determine the prevalence, incidence and gender-specific characteristics of patients with MG needing drug treatment in a well-defined population cohort. METHODS Data were retrieved from the Norwegian Prescription Database (NorPD) 2004-2007, containing information on all dispensed drugs in Norway. The study population comprised 677 recipients of pyridostigmine who met the following inclusion criteria (one or more): (i) More than one prescription 1 January 2004-31 December 2007, (ii) prescription from a specialist in neurology, (iii) prescription for MG being specified in NorPD. RESULTS A total of 435 (64%) women and 242 men were included; female:male ratio 1.8:1. Point prevalence (1 January 2008) of symptomatic MG was 131 per million; 92 for men, 170 for women. Seventy-four new users of pyridostigmine were registered in 2007 (42 women, 32 men), i.e. the incidence rate for 2007 being 16 per million; 14 for men, 18 for women. Mean age of incident cases was 59 years; 64 and 55 years, respectively. Prevalence and incidence were significantly higher in the age group ≥ 50 years than < 50 years (P < 0.001), and highest at 70-79 years. Prevalence and incidence did not differ in the five geographical health regions in Norway. CONCLUSIONS Reported prevalence and incidence are amongst the highest found in similar studies. This may be explained by optimal case identification, higher incidence of drug requiring MG amongst the elderly, and recurrences of previous MG.
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Affiliation(s)
- J B Andersen
- Department of Clinical Medicine, Section for Neurology, University of Bergen, Bergen, Norway.
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Psychosocial aspects in myasthenic patients treated by plasmapheresis. J Neurol 2011; 258:1240-6. [DOI: 10.1007/s00415-011-5913-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 01/10/2011] [Accepted: 01/11/2011] [Indexed: 11/29/2022]
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Mantegazza R, Bonanno S, Camera G, Antozzi C. Current and emerging therapies for the treatment of myasthenia gravis. Neuropsychiatr Dis Treat 2011; 7:151-60. [PMID: 21552317 PMCID: PMC3083988 DOI: 10.2147/ndt.s8915] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Indexed: 11/23/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmmune disease in which autoantibodies to different antigens of the neuromuscular junction cause the typical weakness and fatigability. Treatment includes anticholinesterase drugs, immunosuppression, immunomodulation, and thymectomy. The autoimmune response is maintained under control by corticosteroids frequently associated with immunosuppressive drugs, with improvement in the majority of patients. In case of acute exacerbations with bulbar symptoms or repeated relapses, modulation of autoantibody activity by plasmapheresis or intravenous immunoglobulins provides rapid improvement. Recently, techniques removing only circulating immunoglobulins have been developed for the chronic management of treatment-resistant patients. The rationale for thymectomy relies on the central role of the thymus. Despite the lack of controlled studies, thymectomy is recommended as an option to improve the clinical outcome or promote complete remission. New videothoracoscopic techniques have been developed to offer the maximal surgical approach with the minimal invasiveness and hence patient tolerability. The use of biological drugs such as anti-CD20 antibodies is still limited but promising. Studies performed in the animal model of MG demonstrated that several more selective or antigen-specific approaches, ranging from mucosal tolerization to inhibition of complement activity or cellular therapy, might be feasible. Investigation of the transfer of these therapeutic approaches to the human disease will be the challenge for the future.
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Affiliation(s)
- Renato Mantegazza
- Department of Neuromuscular Diseases and Neuroimmunology, Fondazione Istituto Neurologico Carlo Besta, Milan, Italy
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Aguiar ADAX, Carvalho AF, Costa CMDC, Fernandes JMA, D'Almeida JAC, Furtado LETDA, Cunha FMBD. Myasthenia gravis in Ceará, Brazil: clinical and epidemiological aspects. ARQUIVOS DE NEURO-PSIQUIATRIA 2010; 68:843-8. [DOI: 10.1590/s0004-282x2010000600003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Accepted: 06/08/2010] [Indexed: 11/22/2022]
Abstract
A retrospective chart review was performed on patients diagnosed as having myasthenia gravis in Ceará State, Brazil and who were followed from October 1981 to June 2009. Clinical and epidemiologic aspects were evaluated. In this work, 122 patients were studied, of whom 85 (69.7%) were females and 37 (30.3%) were males. The disease duration ranged from five months to 50 years (8.9±8.1 years). Age at the first symptoms varied from 0 to 74 years (31.9±14.4 years). The first main symptoms and signs were ptosis, diplopia and limb weakness. Generalized myasthenia was the most common clinical presentation, but 5.1% (n=6) persisted as ocular myasthenia. Thymectomy was performed in 42.6% (n=52) of myasthenic patients. A thymoma was present in 10 patients. Serum acetylcholine receptor (AChR) antibodies were present in 80% (n=20) of specimens tested. The data presented are similar to those of studies performed in other countries.
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Carr AS, Cardwell CR, McCarron PO, McConville J. A systematic review of population based epidemiological studies in Myasthenia Gravis. BMC Neurol 2010; 10:46. [PMID: 20565885 PMCID: PMC2905354 DOI: 10.1186/1471-2377-10-46] [Citation(s) in RCA: 394] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Accepted: 06/18/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aim was to collate all myasthenia gravis (MG) epidemiological studies including AChR MG and MuSK MG specific studies. To synthesize data on incidence rate (IR), prevalence rate (PR) and mortality rate (MR) of the condition and investigate the influence of environmental and technical factors on any trends or variation observed. METHODS Studies were identified using multiple sources and meta-analysis performed to calculate pooled estimates for IR, PR and MR. RESULTS 55 studies performed between 1950 and 2007 were included, representing 1.7 billion population-years. For All MG estimated pooled IR (eIR): 5.3 per million person-years (C.I.:4.4, 6.1), range: 1.7 to 21.3; estimated pooled PR: 77.7 per million persons (C.I.:64.0, 94.3), range 15 to 179; MR range 0.1 to 0.9 per millions person-years. AChR MG eIR: 7.3 (C.I.:5.5, 7.8), range: 4.3 to 18.0; MuSK MG IR range: 0.1 to 0.32. However marked variation persisted between populations studied with similar methodology and in similar areas. CONCLUSIONS We report marked variation in observed frequencies of MG. We show evidence of increasing frequency of MG with year of study and improved study quality. This probably reflects improved case ascertainment. But other factors must also influence disease onset resulting in the observed variation in IR across geographically and genetically similar populations.
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Affiliation(s)
- Aisling S Carr
- Department of Neurology, Royal Victoria Hospital, Belfast, Northern Ireland, UK
| | - Chris R Cardwell
- Department of Epidemiology and Medical Statistics, Queens University, Belfast, Northern Ireland, UK
| | - Peter O McCarron
- Department of Epidemiology and Medical Statistics, Queens University, Belfast, Northern Ireland, UK
| | - John McConville
- Department of Neurology, Royal Victoria Hospital, Belfast, Northern Ireland, UK
- Department of Neurology, Ulster Hospital, Dundonald, Northern Ireland, UK
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Lai CH, Tseng HF. Nationwide population-based epidemiological study of myasthenia gravis in taiwan. Neuroepidemiology 2010; 35:66-71. [PMID: 20523074 DOI: 10.1159/000311012] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2009] [Accepted: 03/18/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The purpose of this study is to investigate the epidemiology and medical expenses of myasthenia gravis (MG) in Taiwan. METHODS Cases of MG were identified from the National Health Insurance Research Database with corresponding codes of the International Classification of Diseases, ninth revision (ICD-9), from January 2000 to December 2007. Age- and sex-specific incidences were estimated by dividing the incidence number by population data obtained from the Department of Statistics, Ministry of the Interior. RESULTS During the study period, 5,211 cases were identified. The incidence ratio of males to females was 0.68. The average annual incidence rate was 2.1/100,000. MG occurred in all age groups with a higher incidence in older individuals and the lowest incidence in the 10- to 14-year-olds for both sexes. Among the 5,211 cases, 615 (12%) had a neoplasm of the thymus. The prevalence increased steadily during the study period from 8.4/100,000 in 2000 to 14.0/ 100,000 in 2007. CONCLUSIONS This is the first population-based epidemiological study of MG in Taiwan. The incidence rate and prevalence were higher than in most published studies, especially in old age groups.
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Affiliation(s)
- Chien-Hsu Lai
- Department of Neurology, Changhua Christian Hospital, Changhua, Taiwan, ROC
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Abstract
Myasthenia gravis is a rare, chronic, autoimmune disorder characterized by postsynaptic dysfunction at the neuromuscular junction. The disease affects more females than males. We describe the case of a 17-year-old female adolescent with recurrent episodes of dysarthria and dysphagia and a history of aspiration pneumonia. A bedside edrophonium (Tensilon) test in our emergency department confirmed the diagnosis of myasthenia gravis.
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Mao ZF, Mo XA, Qin C, Lai YR, Olde Hartman TC. Course and prognosis of myasthenia gravis: a systematic review. Eur J Neurol 2010; 17:913-21. [PMID: 20402761 DOI: 10.1111/j.1468-1331.2010.03017.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Z-F Mao
- Institute of Neurology, First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi, China
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Abstract
Myasthenia gravis (MG) is an autoimmune disease that affects the post-synaptic area of the neuromuscular junction. Its hallmark is weakness that worsens with activity. MG incidence is rising in the recent decades, mostly the late onset subtype, which is considered to be due to the aging population or unknown environmental factors. The disease has several subtypes which defer slightly in the clinical characteristics, immunological markers, population distribution and the suitable treatments. The autoimmune nature of the disease is manifested by a decrease in the number of acetylcholine receptors in the muscle receptors which makes the endplate potential to be lower than the threshold needed to activate muscle fiber action potential. In our review we try to find the environmental influence on the disease.
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Affiliation(s)
- Avraham Meyer
- Department of Medicine E, Meir Medical Center, Kfar-Saba, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
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Wen JC, Liu TC, Chen YH, Chen SF, Lin HC, Tsai WC. No increased risk of adverse pregnancy outcomes for women with myasthenia gravis: a nationwide population-based study. Eur J Neurol 2009; 16:889-94. [PMID: 19486132 DOI: 10.1111/j.1468-1331.2009.02689.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND This study aims to examine the risk of adverse pregnancy outcomes [low birthweight (LBW), preterm birth, cesarean sections (CS) and babies born small for gestational age (SGA)] in pregnant women with myasthenia gravis (MG), using a 3-year population-based database, taking characteristics of infant and mother into consideration. METHODS This study used two nationwide population-based datasets: the Taiwan National Health Insurance Research Dataset and the Taiwan birth certificate registry. We identified 163 pregnant women with MG during 2001-2003 as the study cohort and 815 randomly selected pregnant women as a comparison cohort. Conditional logistic regression analyses were performed. RESULTS The results showed that, although these patterns did not reach a statistically significant level, mothers with MG had higher percentages of LBW (6.8%, vs. 5.6%), SGA (17.8%, vs. 14.1%) and cesarean deliveries (44.8%, vs. 37.4%), except for preterm births (8.1%, vs. 8.1%). After adjusting for highest maternal education level, marital status, family monthly income and infant gender and parity, the odds ratios (OR) of LBW, preterm birth, SGA infants, and cesarean delivery for mothers with MG were 1.19 (95% CI = 0.60-2.38), 1.00 (95% CI = 0.54-1.87), 1.30 (95% CI = 0.83-2.04), and 1.33 (95% CI = 0.94-1.88), respectively, as compared to unaffected mothers. CONCLUSIONS We conclude that there were no statistically significant differences in the risk of having preterm, LBW, SGA infants and cesarean deliveries between women with and without MG.
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Affiliation(s)
- J-C Wen
- Department of Internal Medicine, PoJen General Hospital, Taipei, Taiwan
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Abstract
Acquired myasthenia gravis (MG) is an autoimmune disorder of the neuromuscular junction in which patients experience fluctuating skeletal muscle weakness that often affects selected muscle groups preferentially. The target of the autoimmune attack in most cases is the skeletal muscle acetylcholine receptor (AChR), but in others, non-AChR components of the neuromuscular junction, such as the muscle-specific receptor tyrosine kinase, are targeted. The pathophysiological result is muscle endplate dysfunction and consequent fatigable muscle weakness. Clinical presentations vary substantially, both for anti-AChR positive and negative MG, and accurate diagnosis and selection of effective treatment depends on recognition of less typical as well as classic disease phenotypes. Accumulating evidence suggests that clinical MG subgroups might respond differently to treatment. In this Review, we provide current information about the epidemiology, immunopathogenesis, clinical presentations, diagnosis, and treatment of MG, including emerging therapeutic strategies.
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Affiliation(s)
- Matthew N Meriggioli
- Department of Neurology and Rehabilitation, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA.
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Oh SJ, Morgan MB, Lu L, Hatanaka Y, Hemmi S, Young A, Claussen GC. Racial differences in myasthenia gravis in Alabama. Muscle Nerve 2009; 39:328-32. [PMID: 19127534 PMCID: PMC2814330 DOI: 10.1002/mus.21191] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Demographic, clinical, and laboratory features were compared in 235 white and African-American (AA) patients with myasthenia gravis (MG) at the University of Alabama at Birmingham Neuromuscular Disease Clinic from May 2003 to January 2008. Seventy nine percent of patients were white. Acetylcholine receptor antibody was positive in 71% of white patients and in 59% of AA. In patients with seronegative generalized MG, the rate of positive muscle-specific tyrosine kinase antibody (MuSK-Ab) was significantly higher in AA than it was in whites (50% in AA vs. 17% in whites). Ocular MG was seronegative in 75% of AA patients. In AA, MG occurred earlier and more frequently in females, whereas, in whites, disease onset was later and more common in males. Another significant difference was a higher percentage of abnormality on repetitive nerve stimulation in AA. There was also a tendency for more severe forms of MG in AA. There are racial differences in MG between whites and AA in Alabama. These racial differences highlight the need to study biological factors in the pathogenesis of MG and to assess different approaches in diagnosis and treatment.
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Affiliation(s)
- Shin J Oh
- Department of Neurology, University of Alabama at Birmingham Veterans Affairs Medical Center, University Station, Birmingham, Alabama 35294, USA.
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Feyma T, Carter GT, Weiss MD. Myotonic dystrophy type 1 coexisting with myasthenia gravis and thymoma. Muscle Nerve 2008; 38:916-20. [DOI: 10.1002/mus.21046] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
PURPOSE OF REVIEW Increasing rigor is being applied to medical decision making, but myasthenia gravis, commonly considered the best understood autoimmune disorder from a pathophysiological basis, lags other disciplines in the evidence base used to make clinical decisions. The review attempts to provide a focused, practical guideline for the diagnosis and treatment of ocular myasthenia within the limits of largely retrospective case series and expert opinion. RECENT FINDINGS Confirmation of clinical diagnosis continues to be challenging for ocular myasthenia. Despite the recognition of a new autoantigen, the muscle-specific kinase protein in generalized myasthenia gravis, it has been found to be only rarely identified in ocular myasthenia patients and therefore the majority of patients lack detectable autoantibodies and confirmation of a neuromuscular transmission disorder relies on specialized testing of single-fiber electromyography. The visual compromise of ocular myasthenia responds poorly to nonpharmacological and cholinesterase inhibitor therapy, and although corticosteroids are thought to be extremely effective, their toxicity is poorly defined in ocular myasthenia patients and whether they reduce the risk of development of generalized disease is not known. SUMMARY Rigorous clinical trials or large databases with outcome assessments are necessary in order to allow development of rational treatment strategies.
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Furukawa Y, Yoshikawa H, Iwasa K, Yamada M. Clinical efficacy and cytokine network-modulating effects of tacrolimus in myasthenia gravis. J Neuroimmunol 2008; 195:108-15. [PMID: 18262659 DOI: 10.1016/j.jneuroim.2007.12.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2007] [Revised: 11/09/2007] [Accepted: 12/04/2007] [Indexed: 11/29/2022]
Abstract
To clarify the long-term efficacy, safety and the cytokine network-modulating effects of tacrolimus in myasthenia gravis, medical records of 86 newly diagnosed consecutive patients and nine steroid-dependent patients were retrospectively reviewed, and peripheral blood mononuclear cells (PBMC) were cultured for the cytokine profile. Steroid reduction effects were observed by using tacrolimus, and no serious adverse effects were observed. The culture study showed reduced IL-12, IL-17, IFN-gamma, GM-CSF, TNF-alpha and MIP-1beta, and elevated IL-10 in the PBMC from patients who received tacrolimus, which suggests inhibition of T cells and macrophages, and enhancement of type 1 regulatory T cells.
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Affiliation(s)
- Yutaka Furukawa
- Department of Neurology and Neurobiology of Aging, Kanazawa University, Kanazawa Japan
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Sommer N, Tackenberg B, Hohlfeld R. The immunopathogenesis of myasthenia gravis. HANDBOOK OF CLINICAL NEUROLOGY 2008; 91:169-212. [PMID: 18631843 DOI: 10.1016/s0072-9752(07)01505-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- Norbert Sommer
- Clinical Neuroimmunology Group, Philipps-University, Marburg, Germany
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Abstract
Myasthenia gravis (MG) is a rare, autoimmune neuromuscular junction disorder. Contemporary prevalence rates approach 1/5,000. MG presents with painless, fluctuating, fatigable weakness involving specific muscle groups. Ocular weakness with asymmetric ptosis and binocular diplopia is the most typical initial presentation, while early or isolated oropharyngeal or limb weakness is less common. The course is variable, and most patients with initial ocular weakness develop bulbar or limb weakness within three years of initial symptom onset. MG results from antibody-mediated, T cell-dependent immunologic attack on the endplate region of the postsynaptic membrane. In patients with fatigable muscle weakness, the diagnosis of MG is supported by: 1. pharmacologic testing with edrophonium chloride that elicits unequivocal improvement in strength; 2. electrophysiologic testing with repetitive nerve stimulation (RNS) studies and/or single-fiber electromyography (SFEMG) that demonstrates a primary postsynaptic neuromuscular junctional disorder; and 3. serologic demonstration of acetylcholine receptor (AChR) or muscle-specific tyrosine kinase (MuSK) antibodies. Differential diagnosis includes congenital myasthenic syndromes, Lambert Eaton syndrome, botulism, organophosphate intoxication, mitochondrial disorders involving progressive external ophthalmoplegia, acute inflammatory demyelinating polyradiculoneuropathy (AIDP), motor neuron disease, and brainstem ischemia. Treatment must be individualized, and may include symptomatic treatment with cholinesterase inhibitors and immune modulation with corticosteroids, azathioprine, cyclosporine, and mycophenolate mofetil. Rapid, temporary improvement may be achieved for myasthenic crises and exacerbations with plasma exchange (PEX) or intravenous immunoglobulin (IVIg). Owing to improved diagnostic testing, immunotherapy, and intensive care, the contemporary prognosis is favorable with less than five percent mortality and nearly normal life expectancy.
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Affiliation(s)
- Vern C Juel
- Division of Neurology, Box 3403, Duke University Medical Center, Durham, North Carolina, 27710, USA
| | - Janice M Massey
- Division of Neurology, Box 3403, Duke University Medical Center, Durham, North Carolina, 27710, USA
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Verschuuren JJGM, Wirtz PW, Titulaer MJ, Willems LNA, van Gerven J. Available treatment options for the management of Lambert-Eaton myasthenic syndrome. Expert Opin Pharmacother 2007; 7:1323-36. [PMID: 16805718 DOI: 10.1517/14656566.7.10.1323] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Lambert-Eaton myasthenic syndrome is a rare, but reasonably well-understood, antibody-mediated autoimmune disease that is caused by serum auto-antibodies and results in muscle weakness and autonomic dysfunction. One half of the patients have an idiopathic form, the other half a tumour-associated form of the disease. Three randomised trials and a large number of smaller clinical studies have resulted in a number of drugs becoming available for the treatment of Lambert-Eaton myasthenic syndrome. Several drugs are available for the symptomatic treatment of the disease, including guanidine, aminopyridines or acetylcholinesterase inhibitors. Other therapies aim to deplete the serum autoantibodies or to suppress the immune system. For this purpose, immunomodulating strategies, such as intravenous immunoglobulins or plasmapheresis, or several immunosuppressive agents are available. Chemotherapy has successfully ameliorated the course of disease in Lambert-Eaton myasthenic syndrome patients with an underlying tumour.
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Affiliation(s)
- Jan J G M Verschuuren
- Leiden University Medical Centre, Department of Neurology, PO Box 9600, 2300 RC Leiden, Leiden, The Netherlands.
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