Prevalence Of Myasthenia Gravis Research Articles

Epidemiology of seropositive myasthenia gravis in Sardinia: A population-based study in the district of Sassari.

The global incidence and prevalence of myasthenia gravis (MG) range between 6-31/million and 10-37/100,000, respectively. Sardinia is a high-risk region for different immune-mediated disorders, but the epidemiology of MG remains unclear. We determined the epidemiology of MG with acetylcholine receptor (AChR)-immunoglobulin G (IgG) and muscle-specific tyrosine kinase (MuSK)-IgG in the district of Sassari (North-Western Sardinia; population, 325,288). From the laboratory of the University Hospital of Sassari (reference for AChR/MuSK-IgG testing in Sardinia since 1998) and the main neurology units in Sardinia, we retrospectively identified MG patients with (1) AChR-IgG and/or MuSK-IgG positivity by radioimmunoprecipitation assay; and (2) residency in the district of Sassari. Incidence (January 2010-December 2019) and prevalence (December 31, 2019) were calculated. A total of 202 patients were included (incident, 107; prevalent, 180). Antibody specificities were AChR (n = 187 [93%]) and MuSK (n = 15 [7%]). The crude MG incidence (95% confidence interval) was 32.6 (26.8-39.2)/million, while prevalence was 55.3 (47.7-63.9)/100,000. After age-standardization to the world population, incidence decreased to 18.4 (14.3-22.5)/million, while prevalence decreased to 31.6 (26.1-37.0)/100,000. Among incident cases, age strata (years) at MG onset were: <18 (2%), 18-49 (14%), 50-64 (21%), and ≥65 (63%). Sardinia is a high-risk region for MG, with a prevalence that exceeds the European threshold for rare disease. Identification of the environmental and genetic determinants of this risk may improve our understanding of disease pathophysiology.

Incidence and prevalence of myasthenia gravis in the United States: A claims-based analysis.

Myasthenia gravis (MG) is a rare neuromuscular disorder with geographically variable prevalence and incidence rates. A global trend of increasing prevalence of MG has been observed in the last few decades, and this study aimed to assess the current prevalence and incidence rates of MG in the United States. Data were extracted from the Clarivate Real-World Data Repository (2016-2021), a US claims and electronic health records database. The prevalence and incidence of MG were calculated for the year 2021 for males and females who were <2, 2-5, 6-11, 12-17, 18-49, 50-64, and ≥65 years of age, using population estimates from the US Census. The diagnosed prevalence and incidence of MG in the United States in 2021 were calculated to be 37.0 per 100,000 persons and 3.1 per 100,000 persons, respectively. While the incidence and prevalence of MG increased with age in both men and women, higher prevalence and incidence of MG were observed in younger women (<50 years) compared with men of matching age, and in older men (≥65 years) compared with women of the same age group. The updated prevalence and incidence of MG in the United States in 2021 are higher than previous reports from the 1980s and early 2000s, following a global trend of increased prevalence and incidence for this disorder in the last few decades.

Epidemiology of myasthenia gravis in France: A retrospective claims database study (STAMINA)

BackgroundThe 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. MethodsA 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. ResultsThe 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)). ConclusionIn 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.

The growing burden of generalized myasthenia gravis: a population-based retrospective cohort study in Taiwan.

The prevalence of myasthenia gravis is increasing in many countries, including Asia. As treatment options expand, population-based information about the disease burden can inform health technology assessments. We conducted a population-based retrospective cohort study using the Taiwan National Healthcare Insurance Research database and Death Registry to describe the epidemiology, disease burden and treatment patterns of generalized myasthenia gravis (gMG) from 2009 to 2019. Episodes of hepatitis B virus (HBV) infection or reactivation were explored. The number of patients with gMG increased from 1,576 in 2009 to 2,638 in 2019 and the mean (standard deviation) age from 51.63 (17.32) to 55.38 (16.29) years. The female:male ratio was 1.3:1. Frequently reported co-morbidities were hypertension (32-34% of patients), diabetes mellitus (16-21%) and malignancies (12-17%). The prevalence of patients with gMG increased annually from 6.83/100,000 population in 2009 to 11.18/100,000 population in 2019 (p < 0.0001). There was no temporal trend in all-cause fatality rates (range 2.76-3.79/100 patients annually) or gMG incidence rates (2.4-3.17/100,000 population annually). First-line treatment was with pyridostigmine (82%), steroids (58%), and azathioprine (11%). There was minimal change in treatment patterns over time. Among 147 new HBV infections, 32 (22%) received ≥4 weeks of antiviral therapy suggesting chronic infection. The HBV reactivation rate was 7.2%. The epidemiology of gMG in Taiwan is evolving rapidly, with higher prevalence rates and increasing involvement of older age-groups suggesting a growing burden of disease and associated healthcare costs. HBV infection or reactivation may pose a previously unrecognized recognized risk for patients with gMG receiving immunosuppressants.

Epidemiology of Antibody-positive Myasthenia Gravis in Sardinia, Italy (P2-5.027)

<h3>Objective:</h3> To determine the incidence and prevalence of myasthenia gravis (MG) associated with acetylcholine receptor (AchR)-IgG and muscle tyrosine kinase (MuSK)-IgG in the district of Sassari (Sardinia; Italy). <h3>Background:</h3> The global mean incidence and prevalence of MG have been assessed at ≈15 (range, 4–29)/million and 20 (range, 2–37)/100,000, respectively. The island of Sardinia is a recognized area at higher risk for different immune-mediated disorders (<i>e.g</i>., multiple sclerosis), but the epidemiology of MG remains unclear. <h3>Design/Methods:</h3> From the Neurochemistry Laboratory of the University-Hospital of Sassari (reference laboratory for AchR-IgG/MuSK-IgG testing in the island since 1998) we retrospectively identified patients with: 1) AchR-IgG (titer ≥0.5 nmol/L) and/or MuSK-IgG (titer ≥100 pg/ml) positivity by radioimmunoprecipitation assay; 2) available medical records; and 3) residence within the district of Sassari. Incidence (January 2010-December 2019) and prevalence (on January 1, 2020; population 325,288) were calculated. <h3>Results:</h3> Among 517 antibody-positive patients identified, 183 were included (incident, 97; prevalent, 165). We excluded 334 patients due to: 1) missing clinical information (n=65); 2) residency outside the Sassari district (n=168); 3) not classifiable as incident or prevalent (n=56); and 4) clinical phenotype not consistent with MG (n=45; median AchR-IgG titer, 0.7 [range, 0.5–5.5] nmol/L). The crude MG prevalence was 50.7/100,000 (95% CI, 43.4–58.9), whereas incidence was 29.8/1,000,000 person-years (95% CI, 24.3–36.2). Antibody specificities were AchR in 170 (92.9%; median titer 5.7 [range, 0.5–22]) and MuSK in 13 (7.1%; median titer 1,255 [range, 136–1,730]). Among incidence cases, age at disease onset was distributed as: &lt;18 years (n=2; 2%); 18–50 years (n=14; 14.4%); 51–65 years (n=25; 25.8%); and &gt;65 years (n=56; 57.7%). In 45 (46.4%) incident cases, MG was initially restricted to ocular muscles. <h3>Conclusions:</h3> We report the highest incidence and prevalence of MG worldwide. The environmental and genetic determinants of MG risk in the Sardinian population need to be investigated. <b>Disclosure:</b> Dr. Zara has nothing to disclose. Dr. DEIANA has nothing to disclose. Prof. Sotgiu has nothing to disclose. Dr. Ortu has nothing to disclose. Stefano Sotgiu has nothing to disclose. Gregorio Spagni has nothing to disclose. Dr. Damato has nothing to disclose. Dr. Solla has nothing to disclose. Dr. Sechi has nothing to disclose.

Myasthenia Gravis: Novel Findings and Perspectives on Traditional to Regenerative Therapeutic Interventions.

The prevalence of myasthenia gravis (MG), an autoimmune disorder, is increasing among all subsets of the population leading to an elevated economic and social burden. The pathogenesis of MG is characterized by the synthesis of autoantibodies against the acetylcholine receptor (AChR), low-density lipoprotein receptor-related protein 4 (LRP4), or muscle-specific kinase at the neuromuscular junction, thereby leading to muscular weakness and fatigue. Based on clinical and laboratory examinations, the research is focused on distinguishing MG from other autoimmune, genetic diseases of neuromuscular transmission. Technological advancements in machine learning, a subset of artificial intelligence (AI) have been assistive in accurate diagnosis and management. Besides, addressing the clinical needs of MG patients is critical to improving quality of life (QoL) and satisfaction. Lifestyle changes including physical exercise and traditional Chinese medicine/herbs have also been shown to exert an ameliorative impact on MG progression. To achieve enhanced therapeutic efficacy, cholinesterase inhibitors, immunosuppressive drugs, and steroids in addition to plasma exchange therapy are widely recommended. Under surgical intervention, thymectomy is the only feasible alternative to removing thymoma to overcome thymoma-associated MG. Although these conventional and current therapeutic approaches are effective, the associated adverse events and surgical complexity limit their wide application. Moreover, Restivo et al. also, to increase survival and QoL, further recent developments revealed that antibody, gene, and regenerative therapies (such as stem cells and exosomes) are currently being investigated as a safer and more efficacious alternative. Considering these above-mentioned points, we have comprehensively reviewed the recent advances in pathological etiologies of MG including COVID-19, and its therapeutic management.

Application of the Technique of Extracorporeal Membrane Oxygenation in a Patient With Respiratory Distress Syndrome Associated With Myasthenia Gravis

Myasthenia gravis is an autoimmune neuromuscular disease characterized by pathologically rapid fatigue of striated muscles [1]. The main symptom of myasthenia gravis is the presence of pathological muscle weakness with involvement of the ocular, bulbar and skeletal muscles in the pathological process. The provoking factors for the development of myasthenia gravis can be infectious diseases, surgery, drugs [2, 3]. The main danger is represented by myasthenic and cholinergic crises, which are characterized by a severe course and high mortality; therefore, the problems of treating myasthenia gravis are still of high medical and social significance. The prevalence of myasthenia gravis is 17.5–20.3 per 100 thousand population, and the number of patients is increasing by 5–10% annually [4, 5]. In recent years, there has been a steady increase in morbidity with an increase in age over 50 years [6, 7]. Myasthenia gravis is a serious disease with a high mortality rate of up to 30–40% [3]. There are difficulties in the early differential diagnosis of muscle weakness in patients with respiratory failure between myasthenia gravis, myasthenic syndrome and critical illness polyneuropathy. These difficulties and insufficient awareness of patients and doctors of various specialties about myasthenia gravis can lead to the choice of the wrong treatment tactics and the development of myasthenic crisis, which is manifested by respiratory failure, requiring respiratory support. The progression of respiratory failure against the background of myasthenic crisis may require the use of extracorporeal membrane oxygenation (ECMO).It is necessary to expand the differential diagnosis of muscle weakness in a patient during the period of resolution of respiratory failure, allowing to move away from compulsory respiratory support, termination of ECMO.

Epidemiology of Myasthenia Gravis in Sweden 2006-2016.

IntroductionReported incidence and prevalence rates of Myasthenia Gravis (MG) vary widely and are assumed to have increased over the last few decades. We conducted a nationwide register‐based study on the current incidence and prevalence of MG and MG subgroups in Sweden.MethodsData were acquired from four Swedish Health Registers in order to identify patients with MG. Incidence and prevalence rates were calculated for the years 2006–2016, using population numbers provided by Statistics Sweden.ResultsIn 2016, the incidence of MG in Sweden was 2.9 per 100,000 inhabitants (95% CI: 2.5–3.2/100,000) and the crude prevalence was 36.1 per 100,000 inhabitants (95% CI: 34.9–37.3). There was a significant increase in Myasthenia Gravis prevalence from 2006 to 2016. Prevalence rates of all MG subgroups but thymoma‐associated MG increased over the same period of time.ConclusionsThe incidence and prevalence of Myasthenia Gravis have increased over time in Sweden, and the rates are high in comparison with other countries.

Clinical features of myasthenia gravis in elderly and senile patients

The prevalence of myasthenia gravis is 10-24 cases per 100, 000 population. The debut of the disease is possible at any age: from infancy to old age. In the literature, the definition of “myasthenia gravis with late onset” – at the age of 60 years and older, which is 20-46% of all cases. In this regard, the disease is often combined with a burdened somatic history, which makes it difficult to timely diagnosis and treatment. This group of elderly patients accounts for the majority of diagnostic errors in the diagnosis of myasthenia gravis. This study is devoted to the study of the features of the onset and course of myasthenia gravis in elderly and senile people.

Analysis of the prevalence of myasthenia gravis in Ukraine depending on the place of residency and type of settlement

Aim: to study the prevalence of myasthenia gravis among adults in certain regions of Ukraine, taking into account the type of settlement and place of residence. The biostatistical, medical-statistical and epidemiological methods was used in the study. A study of the prevalence of myasthenia gravis in Ukraine was conducted on a sample of ten regions of Ukraine. 757 cases of myasthenia gravis were studied in selected territories, of which 465 (61.43 %) were among urban residents, 292 (38.57 %) were among rural residents. The average annual prevalence of myasthenia gravis was 5.16 (95 % CI —4.79—5.53) per 100,000 population. An analysis of the prevalence of myasthenia gravis in each region showed that this indicator among rural residents was statistically signifi cantly higher than the prevalence of myasthenia gravis among urban residents in Vinnytsia, Zaporizhzhia and Kirovohrad regions (p &lt; 0.05), and in Volyn, Ivano-Frankivsk, Mykolaiv and Chernivtsi regions — without statistically significant differences (p &gt; 0.05). The highest prevalence of myasthenia gravis in rural residents compared with urban residents was in the Vinnytsia region with an excess of 5.63 times (p &lt; 0.001). The city prevalences of myasthenia in the Dnipropetrovsk (+39.14 %; p = 0.001) and Poltava regions (+35.87 %; p = 0.048) signifi cantly exceeded the average city prevalence of myasthenia gravis in Ukraine. They were signifi cantly lower in Vinnytsia (–75.07 %; p &lt; 0.001), Volyn (–51.49 %; p &lt; 0.001), Ivano-Frankivsk (–42.58 %; p = 0.004) and Chernivtsi (–37.35 %; p = 0.046) regions. The chances of rural residents to have myasthenia gravis were signifi cantly higher compared to urban residents. In general, according to the data of mya sthenia gravis prevalence rate in the context of the place of residence, it was proved that living in rural areas is associated with the presence of myasthe nia gravis. Key words: myasthenia gravis, epidemiology, prevalence, incidence, urban residents, rural residents,

Survival in a Chilean Cohort of Thymic Tumors

Introduction: Thymus neoplasm is rare tumors and it has low mortality. There are scarce publications in Latin-American about this topic. We present a Chilean casuistic. Method: Retrospective cohort of every patient’s thymic epithelial tumors diagnosed in Instituto Nacional del Torax, Santiago, Chile, between January 2007 and June 2015. Information was obtained from pathological and clinical registries. Death date was achieved from national registry. We report epidemiological data, clinical manifestations, histology type, Masaoka and WHO classification, therapies and survivor. Results: Sixty-five patients were included, with mean age 58 years and 36.9% men. Myasthenia gravis was present in 24 (36.9%) of patients. Ninety four percent of patients had a surgical biopsy. There were 60 thymomas and 5 thymic carcinomas. Most of tumors were stage I and II in Masaoka classification and type B in WHO classification. There were no deaths at 30 days. Nosocomial pneumonia was the most common complication. Conclusions: In this thymic tumor cohort there are more women and they are older than previously reported. Myasthenia gravis prevalence was similar. The survival of patients with thymomas was excellent.

Epidemiologic studies of myasthenia gravis: literature review

The review of domestic and foreign literature devoted to epidemiological studies of myasthenia gravis has been reviewed. The article presents data on the prevalence and incidence of myasthenia gravis in several regions of Russia and abroad. The prevalence of myasthenia gravis in the world varies, according to different authors, in a very wide range – from 2.17 to 32.0 per 100 thousand people. There are few epidemiological studies of myasthenia gravis in large cities and regions of Russia. Meanwhile, studies of the prevalence and incidence of myasthenia gravis are a necessary stage in the work to increase the effectiveness of diagnosis and treatment of this pathology, to determine the need for specialized types of medical care. The results of these studies can be used to optimize the management of myasthenia gravis patients.

Incidence and Prevalence of Myasthenia Gravis in Korea: A Population-Based Study Using the National Health Insurance Claims Database

Background and PurposeThere 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.MethodsWe 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.ResultsIn 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.ConclusionsThis 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.

Main clinic and epidemiological factors of myasthenia in Leningrad region

Objective: to conduct a study of the basic epidemiological and clinical data of myasthenia in Leningrad region. The analysis of inpatient and outpatient charts of all patients with myasthenia, who were treated at the neurology department of the Leningrad Regional Clinical Hospital (LOKB) from 2003 to 2012. The estimation of incidence and prevalence of the disease per 100 000 population, the basic gender-age characteristics and clinical features of myasthenia in Leningrad region. According to the findings myasthenia gravis is not a rare disease, the prevalence of myasthenia gravis in the whole area is 4.6 cases, the average incidence was 0.29 cases per 100 000 population. The prevalence of myasthenia gravis in Leningrad region is lower than in other regions of Russia. Among patients women predominate in the age group 45-59 years, and there is a significant number of patients with disease onset in middle and old age.

Estimation of incidence, prevalence, and age-at-diagnosis of myasthenia gravis among adults by hospital discharge records.

The Hungarian Health Insurance Fund, using appropriate information technology, covers all of the secondary care of the country and maintains a database of Hospital Discharge Records (HDR). Our study aimed to determine the incidence, average age-at-diagnosis (AaD), and prevalence of myasthenia gravis (MG) among adults and the regional heterogeneity of these measures to assess the potential usefulness of HDRs for monitoring. The nationwide database of 336,679 HDRs from 2004 to 2009 was analyzed. The incidence and prevalence were determined for adults in 2007. Patients with MG code in 2007, 2008, and 2009 but without that in 2004-2006 were defined as incident. Distribution of AaD was described for these cases. Patients with an MG code in 2007, 2008, and 2009 were defined as prevalent in 2007. The heterogeneity of regional age-standardized indices was tested. The observed incidence and prevalence was 2.76/100,000 (men: 2.37/100,000; women: 3.11/100,000) and 17.42/100,000 (male: 13.08/100,000; female: 21.28/100,000), respectively. These estimates were within published ranges. The mean AaD was significantly higher for men than for women (63.60 vs. 51.92; p < 0.001). Significant regional heterogeneity was observed for all measures. HDRs seem to be useful for developing MG indicators because they adequately estimate epidemiological parameters of MG occurrence.

Prevalence of myasthenia gravis and associated autoantibodies in paraneoplastic pemphigus and their correlations with symptoms and prognosis.

Paraneoplastic pemphigus (PNP) involves multiple organs, but little is known about its neurological involvement. To investigate the symptoms, prognosis and profiles of associated autoantibodies in myasthenia gravis (MG), and their correlations in patients with PNP. Fifty-eight patients with PNP were assessed for myasthenic symptoms and laboratory evidence. Serum autoantibodies against acetylcholine receptor (AChR), acetylcholinesterase (AChE), titin, ryanodine receptor (RyR) and muscle-specific kinase (MuSK) were measured by enzyme-linked immunosorbent assay. Patients with pemphigus vulgaris (PV), pemphigus foliaceus (PF), connective tissue disease (CTD) and non-PNP MG (NP-MG), and healthy donors, served as controls. These autoantibodies in PNP were also compared in the presence or absence of dyspnoea or muscle weakness. Cox regression and log-rank tests were used for survival analysis. Overall 39% of patients with PNP experienced muscle weakness, and 35% were diagnosed with MG. Moreover, 35% had positive anti-AChR and 28% had anti-AChE antibodies, similarly to NP-MG (33% and 17%, respectively, P>0·05). However, both were negative in all patients with PV, PF and CTD and healthy donors (P<0·005). No other antibodies showed significant differences among groups. Anti-AChR and anti-AChE antibody levels were significantly increased in patients with PNP with dyspnoea, while anti-AChR, anti-titin and anti-RyR were significantly increased in patients with PNP with muscle weakness (P<0·05). Nevertheless, levels and positive rates of these autoantibodies showed no significant differences between PNP with Castleman disease and thymoma. Although anti-AChE levels impacted survival duration (P = 0·027, odds ratio 3·14), MG complications did not affect the overall survival percentage in PNP. MG is a complication of PNP. Anti-AChR and anti-AChE antibodies are prominent in patients with PNP, especially those with dyspnoea.

Two patients with co-morbid myasthenia gravis in a Brazilian cohort of inflammatory bowel disease

Co-morbid auto-immune disorders may affect 0.2% of the population. We present the clinical and electrodiagnostic findings of 2 patients with inflammatory bowel disease and myasthenia gravis from a Brazilian cohort of 218 inflammatory bowel disease patients. Patient 1: A 40year-old man was diagnosed with ulcerative colitis at age 37 and underwent total colectomy 3years later. After prednisone was tapered, he experienced a clinical relapse and was diagnosed with Crohn’s disease. He then developed quadriparesis, bilateral ptosis, dysphagia and dysarthria. Patient 2: A 41year-old woman (diagnosed with ulcerative colitis and primary sclerosing cholangitis at age 35) developed speech impairment and ptosis. On both patients, symptoms quickly progressed over few weeks. Myasthenia gravis was diagnosed and confirmed by abnormal repetitive nerve stimulation and elevated anti-acetylcholine receptor antibody titers. Pyridostigmine and prednisone successfully treated both patients. Myasthenia gravis prevalence over 9years was 0.9%. Myasthenia gravis clinical course was not significantly modified by inflammatory bowel disease relapses and should be suspected with new onset weakness.

Robot-Assisted Thoracoscopic Thymectomy for Treating Myasthenia Gravis in Children

In the United States, the prevalence of myasthenia gravis (MG) is approximately 14-20 per 100,000. One treatment option involves a thymectomy, which can lead to remission of symptoms. The amount of thymic tissue removed is correlated with a better outcome for patients. Thus, it is critical that the procedure used when performing a thymectomy maximize the resection of thymic tissue. Robotic-assisted thoracoscopic thymectomy provides a minimally invasive platform that avoids the mortality and morbidity of a median sternotomy while providing better visualization and a more delicate dissection than is available in a standard thoracoscopic procedure. Following Institutional Review Board approval, in total, 9 patients who underwent robotic thymectomy were reviewed. Intraoperative statistics such as operative time and blood loss were reviewed from operative records. Postoperative outcomes such as hospital stay, discharge medications, and complications were reviewed from hospital charts. Lastly, disease response was evaluated in consultation with a pediatric neurologist who specializes in MG. Age at operation ranged from 2 to 15 years of age (average, 9.4 years). A majority of patients had an MGFA classification of II or greater (n=5). All patients were on pyridostigmine preoperatively, and 7 of 9 (77%) were taking prednisone. Mean operative time was 160.1±6.1 minutes. Average postoperative hospital stay was 1.1±0.3 days. One patient had a documented persistent pneumothorax on postoperative Day 1, which was treated with nasal cannula oxygen for an additional day. There were no additional operative complications, and all patients were discharged home on acetaminophen with codeine for pain control. Eight of 9 patients had improvement in MG symptoms after the procedure. Robotic-assisted thoracoscopic thymectomy is a safe and effective operation for children with MG. Robotic assistance allows for articulating instruments, three-dimensional visualization, and minimal blood loss. These factors may allow for a more complete resection compared with a standard thoracoscopic thymectomy.

Change in Myasthenia Gravis Epidemiology in Trento, Italy, after Twenty Years

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.

Myasthenia Gravis in the Elderly

The prevalence of myasthenia gravis (MG) in people over 50 years of age is increasing, mainly because of the increase in the percentage of people aged 65 years and over in society. The clinical symptoms are the same as in early onset, but may be more difficult to detect in the elderly. Most MG patients with symptom onset after 50 years of age have thymic atrophy. Approximately 10–15% of all patients with MG have a thymoma. Antibodies to non-acetylcholine receptors, such as titin and the ryanodine receptor, are common in early-onset MG thymoma, and more than 40% of patients with late-onset MG have such antibodies. The outcome after thymectomy in MG is generally less favorable in patients over 45 years of age. Standard nonsurgical therapy for late-onset MG follows a similar pattern as for early onset.