[Clinical and neurologic characteristic and principles of therapy of late-onset Myasthenia gravis]

In the present work the results of the clinic-epidemiological analysis of 223 patients with the onset of the myasthenia at 60 y. o. and later, admitted and treated in the clinic of neurology for the passed 25years are represented. A dynamic growth of incidence of the late-onset myasthenia through the passed 10 years was administered. We administered a prevalence of the generalized form of the myasthenia gravis (61,5 %). The whole clinical table of the myasthenia was developed during an year in 76,7 % of the cases. A wide range of the concomitant somatic pathology in this group of the patients (especially, with a cardio-vascular pathology - 93,3 %) was found to worsen the course of the myasthenia itself. We found that the set of the therapeutic measures in myasthenia in the elderly is determined by the course of the myasthenia and the multiple organ failure due to the concomitant diseases. The scheme of complex corrective therapy of myasthenia gravis in elderly was developed.

Epidemiology of myasthenia gravis in Ontario, Canada

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.

Treatment Outcomes and Predictive Factors in Pediatric Ocular Myasthenia Gravis

OBJECTIVE

To determine demographic data, clinical presentations, investigations, treatment regimens, and clinical outcomes in pediatric ocular myasthenia gravis patients, and to find predictive factors for clinical outcomes such as resolution of disease, development of generalized symptoms, or final amblyopia.

MATERIAL AND METHOD

This retrospective descriptive study of the medical records of 14 patients (male 6,female 8) less than 15 years that had ocular myasthenia gravis at Chiang Mai University Hospital between January 2006 and December 2012 was done. Univariate analysis was used to evaluate the predictive factors for clinical outcomes.

RESULTS

Mean age of onset was 6.96±4.65 years (range 0.58-14 years). All patients presented with ptosis (100%) and 67% with strabismus. The mean oftotalfollow-up time is 6.30±3.84 years (range 1.25-14.25 years). None ofthe patients developed generalize myasthenia gravis. Only one patient had amblyopia at final presentation. Presenting age, gender strabismus at initial presentation, and positive neostigmine or edrophonium test did not affect resolution of disease nor final amblyopia.

CONCLUSION

The most common clinical presentation in pediatric OMG was ptosis. Most patients could control the disease only by medications. There were no predictive factors affecting resolution of disease nor final amblyopia.

Association between Glucocorticoid-Induced Osteoporosis and Myasthenia Gravis: A Cross-Sectional Study

Purpose

To investigate the association between glucocorticoid-induced osteoporosis and myasthenia gravis (MG) using a cross-sectional survey in Japan.

Methods

We studied 363 patients with MG (female 68%; mean age, 57 ± 16 years) who were followed at six Japanese centers between April and July 2012. We evaluated the clinical information of MG and fractures, bone markers, and radiological assessment. Quality of life was measured using an MG-specific battery, MG-QOL15.

Results

Glucocorticoids were administered in 283 (78%) of 363 MG patients. Eighteen (6%) of 283 MG patients treated with prednisolone had a history of osteoporotic fractures. The duration of glucocorticoid therapy, but not the dose of prednisolone, was associated with the osteoporotic fractures in MG patients. Bone mineral density was significantly decreased in the MG patients with fractures. The multivariate analyses showed that the total quantitative MG score was the only independent factor associated with osteoporotic fractures (OR = 1.30, 95% CI 1.02–1.67, p = 0.03). MG patients who had experienced fractures reported more severe difficulties in activities of daily living.

Conclusion

Glucocorticoid-induced osteoporosis aggravates quality of life in patients with MG.

Higher risk of myasthenia gravis in patients with thyroid and allergic diseases: a national population-based study

The aim of this study was to determine the risk of myasthenia gravis (MG) in patients with allergic or autoimmune thyroid disease in a large cohort representing 99% of the population in Taiwan. Data from the Taiwan National Health Insurance Database were used to conduct retrospective analyses. The study comprised 1689 adult patients with MG who were 4-fold frequency matched to those without MG by sex, age, and assigned the same index year. Multivariate logistic regression models were used to calculate the odds ratios and 95% confidence intervals for the association between allergic or autoimmune thyroid disease and MG. An increased subsequent risk of MG was observed in the patients with allergic conjunctivitis (AC), allergic rhinitis, Hashimoto thyroiditis, and Graves disease. The adjusted odds ratios (aORs) were 1.93 (1.71-2.18), 1.26 (1.09-1.45), 2.87 (1.18-6.97), and 3.97 (2.71-5.83), respectively. The aORs increased from 1.63 (1.43-1.85) in a patient with only 1 allergic or autoimmune thyroid disease to 2.09 (1.75-2.49) in a patient with 2 thyroid or allergic diseases to 2.82 (2.19-3.64) in a patient with ≥3 thyroid or allergic diseases. MG was associated with the cumulative effect of concurrent allergic and autoimmune thyroid disease with combined AC and Hashimoto thyroiditis representing the highest risk (aOR = 15.62 [2.88-87.71]). This population-based case-control study demonstrates the association between allergic or autoimmune thyroid disease and the risk of MG. The highest risk of subsequent MG was associated with combined AC and Hashimoto thyroiditis.

[Myasthenia gravis in adults of institutions pertaining to the Mexican public health system: an analysis of hospital discharges during 2010]

INTRODUCTION

Epidemiological studies on myasthenia gravis (MG) in Mexico is mainly derived from experiences in referral centers.

OBJECTIVE

To describe the epidemiological characteristics of hospital discharges during 2010 with the diagnosis of MG in adults hospitalized in the Mexican public health system.

METHODS

We consulted the database of hospital discharges during 2010 of the National Health Information System (Ministry of Health, IMSS, IMSS oportunidades, ISSSTE, PEMEX, and the Ministry of Defense). The MG records were identified by the code G70.0 of the International Classification of Diseases 10th revision.

RESULTS

During 2010 there were 5,314,132 hospital discharges (4,254,312 adults). Among them, 587 (0.01%) were adults with MG (median age: 47 years, 60% women). Women with MG were significantly younger than men (median age: 37 vs. 54 years, respectively; p < 0.001). The median hospital stay was six days. The case fatality rate was 3.4%, without gender differences. Age was associated with the probability of death.

CONCLUSIONS

We confirmed the bimodal age-gender distribution in MG. The in-hospital case fatality rate in Mexico is consistent with recent reports around the world.

High prevalence of myasthenia gravis among rural adult populations

OBJECTIVE

There is no evidence of an increased prevalence of myasthenia gravis (MG) in rural agricultural communities. We conducted a prevalence study to examine the prevalence of MG in populations living in rural versus urban areas.

METHODS

We retrieved the electronic medical records of all members of the Health Maintenance Organization to detect patients who had the diagnosis of MG of the district in the year 2012. Main outcome measured the relative risk (RR) of patients with MG compared with controls.

RESULTS

A total of 248 total MG cases were found in the 527,258 individuals in the region, with a male to female ratio of 118 (47.6%) to 130 (52.4%). Two hundred twenty-three of these patients with MG (89.9%) lived in urban settlements, whereas 25 (10.1%) came from rural areas. A borderline RR was found in rural areas of 1.61 (95% confidence interval, 0.98-2.66) for men, and a significantly RR in patients aged 55 years and older (RR = 2.85; 95% confidence interval, 1.68-4.84).

CONCLUSIONS

There is an increased prevalence of MG among rural male adults. A possible association of MG with agricultural pesticides exposure is discussed.

Diagnostic and clinical classification of autoimmune myasthenia gravis

Myasthenia gravis is characterized by muscle weakness and abnormal fatigability. It is an autoimmune disease caused by the presence of antibodies against components of the muscle membrane localized at the neuromuscular junction. In most cases, the autoantibodies are against the acetylcholine receptor (AChR). Recently, other targets have been described such as the MuSK protein (muscle-specific kinase) or the LRP4 (lipoprotein related protein 4). Myasthenia gravis can be classified according to the profile of the autoantibodies, the location of the affected muscles (ocular versus generalized), the age of onset of symptoms and thymic abnormalities. The disease generally begins with ocular symptoms (ptosis and/or diplopia) and extends to other muscles in 80% of cases. Other features that characterize MG include the following: variability, effort induced worsening, successive periods of exacerbation during the course of the disease, severity dependent on respiratory and swallowing impairment (if rapid worsening occurs, a myasthenic crisis is suspected), and an association with thymoma in 20% of patients and with other autoimmune diseases such as hyperthyroidism and Hashimoto's disease. The diagnosis is based on the clinical features, the benefit of the cholinesterase inhibitors, the detection of specific autoantibodies (anti-AChR, anti-MuSK or anti-LRP4), and significant decrement evidenced by electrophysiological tests. In this review, we briefly describe the history and epidemiology of the disease and the diagnostic and clinical classification. The neonatal form of myasthenia is explained, and finally we discuss the main difficulties of diagnosis.

Anti-citrullinated protein antibody-positive rheumatoid arthritis associated with RS3PE syndrome-like symptoms and an elevated serum vascular endothelial growth factor level in a patient with myasthenia gravis

A 73-year-old man with a history of myasthenia gravis (MG) was diagnosed with rheumatoid arthritis (RA) based on a history of polyarthritis and positivity for anti-citrullinated protein antibodies (ACPA). He presented with a high level of serum vascular endothelial growth factor (VEGF) and RS3PE syndrome-like pitting edema in the extremities, which improved following treatment with low-dose prednisolone. This is an interesting case of ACPA-positive RA associated with RS3PE syndrome-like pitting edema and a high VEGF level.

Myasthenia gravis

Myasthenia gravis (MG) is a chronic neuromuscular disorder characterized by fluctuating skeletal muscle weakness and fatigue. This rare autoimmune condition can present a diagnostic challenge for the advanced practice nurse (APN). Because of its low incidence in clinical practice and frequently unrecognized symptoms, a delay of 1 to 2 years prior to diagnosis is not uncommon. Recognition of the clinical features is a key component of prompt diagnosis. To avoid delay in treatment, APNs should be aware of variations in MG symptoms and the tools used to confirm a suspected diagnosis. Because patients benefit from the care of neuromuscular specialists, APNs are not expected to be experts within MG treatment. But knowledge of general treatment principles affords the APN an opportunity to collaborate with the neuromuscular specialist to provide care for patients with MG. Using an individual example, this article reviews the experience of an older adult with MG from clinical presentation through treatment.

Clinical characteristics of refractory myasthenia gravis patients

BACKGROUND

A subset of myasthenia gravis (MG) patients is refractory to standard therapies. Identifying the characteristics of this population is essential as newer treatment strategies emerge that may be more effective in this group.

OBJECTIVE

The aim of our study is to describe the clinical features of refractory MG patients and compare them to those of non-refractory patients.

METHODS

A retrospective chart review was completed of 128 MG patients referred to a tertiary neuromuscular clinic from 2003 to 2011. Patients were classified as refractory or non-refractory based on predefined criteria, and clinical features were compared.

RESULTS

Nineteen out of 128 patients were classified as refractory (14.8 percent). Compared to the non-refractory patients, the refractory patients were more likely to be younger at onset, female, thymomatous, and MuSK-antibody positive.

CONCLUSION

Refractory MG patients represent a small but distinct group for whom exploring newer therapeutic approaches and immunopathologic differences is warranted.

Fracture rate in patients with myasthenia gravis: the general practice research database

SUMMARY

The aim of this study was to evaluate fracture risk after onset of myasthenia gravis using the UK General Practice Research Database. Overall fracture risk is not statistically increased compared with age- and gender-matched controls irrespective of glucocorticoid use, but was increased in those using antidepressants, anxiolytics or anticonvulsants.

INTRODUCTION

Myasthenia gravis (MG) is a neuromuscular disease which has been associated with an increased falls risk and glucocorticoid-induced osteoporosis, recognized determinants of increased fracture risk. The aim of this study was to evaluate the risk of fracture after onset of MG.

METHODS

We conducted a retrospective cohort study using the UK General Practice Research Database (1987-2009). Each MG patient was matched by age, sex, calendar time and practice to up to six patients without a history of MG and we identified all fractures and those associated with osteoporosis.

RESULTS

Compared to the control cohort, there was no statistically significant increased risk observed in patients with MG for any fracture (adjusted hazard ratio [AHR] 1.11; 95 % confidence interval [CI], 0.84-1.47) or osteoporotic fractures (AHR 0.98 [95 % CI 0.67-1.41]). Further, use of oral glucocorticoids up to a cumulative dose exceeding 5 g prednisolone equivalents did not increase risk of osteoporotic fracture (AHR 0.99 [95 % CI, 0.31-3.14]) compared with MG patients without glucocorticoid exposure. However, fracture risk was higher in patients with MG prescribed antidepressants (AHR 3.27 [95 % CI, 1.63-6.55]), anxiolytics (AHR 2.18 [95 % CI, 1.04-4.57]) and anticonvulsants (AHR 6.88 [95 % CI, 2.91-16.27]).

CONCLUSION

Overall risk of fracture in patients with MG is not statistically increased compared with age- and gender-matched controls irrespective of glucocorticoid use but was increased in those using antidepressants, anxiolytics or anticonvulsants. These findings have implications in strategies preserving bone health in patients with MG.

[Clinical study and case follow-up of 61 cases of familial myasthenia gravis in 28 families]

OBJECTIVE

To explore the clinical features and prognosis of familial myasthenia gravis (FMG).

METHODS

The clinical data were collected and analyzed for 61 FMG patients from 28 families from February 1998 to March 2009 at the department of neurology, First Affiliated Hospital, Sun Yat-sen University. And they were compared with 257 cases of sporadic myasthenia gravis (MG) by case-control method. Age at onset, gender, Osserman clinical classification, diagnosis, treatment, thymus imaging examination, prognosis and other family members were measured retrospectively.

RESULTS

(1) The proportion of FMG in Southern China was 2.03% and it was lower than the other countries. (2) Onset age was younger in FMG than in sporadic MG. Juvenile MG was more common in FMG than in sporadic MG (70.5% vs 52.1%, P = 0.009). (3) Ocular MG was more common in FMG than in sporadic MG (83.6% vs 62.7%, P = 0.002). (4) There was a higher proportion in FMG with thymic hyperplasia than in sporadic MG (98.3% vs 83.7%, P = 0.014). (5) Better prognosis was found in FMG than in sporadic MG. FMG patients had a higher proportion of completely stable remission than sporadic MG (24.5% vs 11.7%, P = 0.009). (6) The so-called "consistency of the same disease" could only be found in families with pure ocular diseases. If the patients with general type MG were present in the family, their pathogenetic conditions and prognosis might vary greatly.

CONCLUSION

There characteristics of FMG in south China are different from those of other countries. Their exact inheritance patterns await further explorations.

A case of Lambert-Eaton myasthenic syndrome with possible myasthenia gravis

Lambert-Eaton myasthenic syndrome (LEMS) is a rare autoimmune disorder of neuromuscular transmission (NMJ) that shares many clinical features with myasthenia gravis (MG). We report a 73 year-old lady who presented 10 years previously with stiffness of both calves, dry mouth, fatigue, proximal weakness and areflexia in lower limbs. Neurophysiological studies were consistent with LEMS. Her work up for an underlying neoplasm was negative. She recently developed unilateral ptosis and diplopia which dramatically improved with pyridostigmine suggesting concomitant MG.

Late onset myasthenia gravis is associated with HLA DRB1*15:01 in the Norwegian population

Background

Acquired myasthenia gravis (MG) is a rare antibody-mediated autoimmune disease caused by impaired neuromuscular transmission, leading to abnormal muscle fatigability. The aetiology is complex, including genetic risk factors of the human leukocyte antigen (HLA) complex and unknown environmental factors. Although associations between the HLA complex and MG are well established, not all involved components of the HLA predisposition to this heterogeneous disease have been revealed. Well-powered and comprehensive HLA analyses of subgroups in MG are warranted, especially in late onset MG.

Methodology/Principal Findings

This case-control association study is of a large population-based Norwegian cohort of 369 MG patients and 651 healthy controls. We performed comprehensive genotyping of four classical HLA loci (HLA-A, -B, -C and -DRB1) and showed that the DRB1*15:01 allele conferred the strongest risk in late onset MG (LOMG; onset ≥60years) (OR 2.38, p_c7.4×10⁻⁵). DRB1*13:01 was found to be a protective allele for both early onset MG (EOMG) and LOMG (OR 0.31, p_c 4.71×10⁻⁴), a finding not previously described. No significant association was found to the DRB1*07:01 allele (p_nc = 0.18) in a subset of nonthymomatous anti-titin antibody positive LOMG as reported by others. HLA-B*08 was mapped to give the strongest contribution to EOMG, supporting previous studies.

Conclusion

The results from this study provide important new information concerning the susceptibility of HLA alleles in Caucasian MG, with highlights on DRB1*15:01 as being a major risk allele in LOMG.

Clinical profile of coexisting conditions in type 1 diabetes mellitus patients

AIMS

Type 1 diabetes mellitus (T1DM) is associated with various genetic and autoimmune diseases implicated in its etiopathogenesis. We hereby profile the clinical association of such diseases among patients from our center.

METHODS

Consecutive patients of T1DM presenting to department of Endocrinology from May 1997 to December 2011 were retrospectively analyzed in context of associated clinical profile.

RESULTS

Among 260 patients diagnosed as T1DM, 21 (8%) had hypothyroidism, 4 (1.5%) had hyperthyroidism and 2 (0.7%) had primary adrenal insufficiency. Eighteen patients (7%) had celiac disease, 9 (3.5%) had Turner's syndrome, 5 patients (1.9%) had Klinefelter's syndrome, whereas Down's syndrome and Noonan's syndrome was present in 2 and 1 patients (0.7%) respectively. One patient had Wolframs' syndrome and 1 patients had myasthenia gravis. Systemic lupus erythematosus and rheumatoid arthritis were present in 3 and 1 patients respectively. Total of 5 patients with cerebral palsy, 4 cases with deaf mutism, 4 cases with acute psychosis and 16 patients with depression were noted. Mean age of study patients was 20.8±9.8 years (range, 3-23 years).

CONCLUSION

Various conditions including genetic (Down, Turner, Noonan, and Klinefelter's), autoimmune (thyroid and adrenal disorders, myasthenia gravis, SLE, rheumatoid arthritis) and central nervous system diseases were the associated diseases encountered in our patients. Routine screening is required for early diagnosis and treatment of associated co morbidities.