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1.  Ocular motor dysfunction and ptosis in ocular myasthenia gravis: effects of treatment 
The British Journal of Ophthalmology  2005;89(10):1330-1334.
Aim: The optimal treatment of ocular myasthenia gravis (OMG) remains unknown. The authors evaluated the efficacy of prednisone and pyridostigmine in reducing diplopia, ocular motor dysfunction, and ptosis in patients with OMG.
Methods: Review of records from a clinical database from one neuro-ophthalmology service of patients presenting with OMG between 1990 and 2002, excluding those who developed generalised MG within the first month after diagnosis. Institutional review board approval was obtained for this study. Participants/interventions: Non-randomised, unmasked, therapy was given. 55 patients with diplopia in primary or downward gaze and clinically demonstrable extraocular muscle dysfunction received prednisone. 34 patients who had contraindications to steroids or who refused treatment with prednisone received pyridostigmine only. Over 5 days the daily prednisone dose was increased to 50–60 mg and then gradually reduced to 10 mg, followed by further reduction as tolerated. The pyridostigmine dose was begun at 180 mg daily and increased as tolerated. Main outcome measures: Follow up evaluations, performed at 1, 3–6, 12, and 24 months, detailed the frequency of ptosis and diplopia and the amount of ocular motor deviation in primary and downward gaze.
Results: The prednisone and pyridostigmine groups were similar for age, sex, acetylcholine receptor antibody level, prism cover test results for primary and downward gaze, diplopia in primary and downward gaze, and unilateral ptosis. Bilateral ptosis was present in 32.4% of the pyridostigmine group and 10.9% of the prednisone group (p = 0.02). The prednisone group showed resolution in primary gaze diplopia, downgaze diplopia, unilateral ptosis, and bilateral ptosis in 73.5%, 75.5%, 85.7%, and 98%, respectively at 1 month. The benefit persisted at 3–6, 12, and 24 months except for the bilateral ptosis. The pyridostigmine group showed resolution in primary gaze diplopia, downgaze diplopia, unilateral ptosis, and bilateral ptosis in 6.9%, 17.2%, 50%, and 76.7% of patients after 1 month of treatment. The prism cover results improved (p = 0.003) in the prednisone group only. In the prednisone group, four patients had no response to therapy. Among the 51 prednisone responsive patients, there were 33 recurrences in 26 patients. 12 patients, all prednisone treated, had remissions. Except for three patients who developed diabetes, no patient developed a clinically significant systemic corticosteroid complication.
Conclusion: These results suggest that 50–60 mg daily prednisone followed by lower doses (10 mg or less) has the benefit of resolving ptosis and diplopia that lasts for at least 2 years in approximately 70% of patients.
PMCID: PMC1772854  PMID: 16170126
ocular myasthenia gravis; diplopia; prednisone; pyridostigmine
2.  Factors associated with depressive state in patients with myasthenia gravis: a multicentre cross-sectional study 
BMJ Open  2011;1(2):e000313.
The objective of this study was to examine clinical factors associated with depressive state in patients with myasthenia gravis (MG).
Cross-sectional study.
Setting and participants
We evaluated 287 consecutive cases of MG seen at six neurological centres located in Eastern Japan.
Outcome measures
All MG patients completed the Japanese version of the Beck Depression Inventory–Second Edition (BDI-II). Disease severity was determined according to the MG Foundation of America (MGFA) quantitative MG score, MG activities of daily living scale and MG composite scale (MG composite). Clinical state following treatment was categorised according to MGFA postintervention status. Associations between detailed clinical parameters of MG and BDI-II score were then examined statistically.
Mean BDI-II score for patients with MG (11.0±8.1) did not differ substantially from and overlapped with that reported as the Japanese standard (8.7±6.4). The mean +2 SDs for the Japanese standard is 21.5, approximately equal to the cut-off level indicative of moderate or worse depression (>20 points) in the original English version. We thus defined BDI-II >21.5 as depressive state, with a frequency of 13.6% in patients with MG. Multivariate logistic regression analysis revealed current dose of oral prednisolone (OR 1.09, 95% CI 1.02 to 1.17; p=0.01), unchanged MGFA postintervention status (OR 3.55, 95% CI 1.18 to 10.71; p=0.02), time since onset (OR 0.93, 95% CI 0.87 to 0.99; p=0.03) and MG composite (OR 1.16, 95% CI 1.00 to 1.34; p=0.046) as factors independently associated with depressive state in MG.
Dose of oral corticosteroids appears to represent the major factor associated with depressive state in MG. Unchanged status despite treatment and early disease stage are also significant background factors for depressive state, along with disease severity.
Article summary
Article focus
Background factors associated with depressive state in MG were statistically examined.
Key messages
Dose of oral corticosteroids appears to represent the major factor associated with depressive state in MG. Unchanged status despite treatment and early disease stage are also significant background factors for depressive state, along with disease severity.
Achieving early improvement of disease by adequate MG therapy without long-term use of higher dose oral corticosteroids may be important to avoiding depressive state in patients with MG.
Strengths and limitations of this study
Strength: this study probably is the first to systematically and statistically examine the associations between detailed disease-related parameters of MG and depressive state.
Limitation: predictive modelling cannot be strictly performed on this cross-sectional sample. Weakness: the absence of social factors as variables.
PMCID: PMC3244661  PMID: 22184587
3.  Efficacy of perioperative high-dose prednisolone therapy during thymectomy in myasthenia gravis patients 
This study aimed to investigate the benefits of administering perioperative high-dose prednisolone in conjunction with thymectomy in patients with myasthenia gravis.
We retrospectively reviewed data from patients with Myasthenia Gravis Foundation of America Clinical Class I to IIIB who had undergone an extended thymectomy between 1992 and 2009. Perioperative high-dose prednisolone was administered at starting doses of 10 to 20 mg and escalated up to 100 mg on alternate days. The treatment group comprised 70 patients receiving perioperative high-dose prednisolone, whereas the control group included 61 patients not treated with preoperative steroids. The two groups were compared with respect to baseline clinical characteristics, incidence of postoperative complications, and follow-up disease status.
Prednisolone-treated patients presented with more advanced disease compared to controls (Class IIB or greater, 42 [60.0%] versus 7 [11.3%], respectively; P < 0.001). Mean preoperative%FVC was lower and FEV1.0% was higher in treated patients than in controls (%FVC: 92.4 ± 2.3% versus 99.5 ± 2.4%, respectively; P = 0.037, FEV1.0%: 85.2 ± 1.3% versus 81.4 ± 0.9%, respectively; P = 0.017). The groups were similar in other variables including presence of thymoma, and operative procedure. In the treatment group, disease status was significantly improved only by the induction of high-dose prednisolone before the surgery (P < 0.001), and these patients discontinued anti-cholinesterase therapy more frequently than controls (P < 0.001). Moreover, the treatment group demonstrated markedly lower rates of postoperative crisis (12.2% versus 2.9%, respectively; P = 0.045). The incidence of infection, wound dehiscence, and diabetes mellitus were comparable between groups. Survival analysis demonstrated higher rates of treated patients with improved disease status at three and five years (92% and 96%, respectively) compared to controls (57% and 76%, respectively; P < 0.001). Likewise, significantly greater proportions of treated patients achieved complete stable remission or pharmacologic remission at three, five, and ten years (23%, 42%, and 72%, respectively) compared to controls (10%, 20%, and 44%, respectively; P = 0.002).
Perioperative high-dose prednisolone therapy is a safe, promising strategy for managing patients with myasthenia gravis and may reduce the incidence of postoperative crisis while improving disease status.
PMCID: PMC3878862  PMID: 24321421
Myasthenia gravis; MG crisis; Prednisolone; Thymectomy
4.  Safety of prednisone for ocular myasthenia gravis 
Treatment with chronic corticosteroids has been associated with frequent significant adverse effects. We hypothesized that a long-term, low-dose prednisone regimen for OMG would have a low rate of major side effects.
Consecutive OMG patients from a single institution over a 16-year-period and treated with ≥1 month of daily prednisone were included. Steroid-related complications were defined as the development/worsening of conditions requiring alteration to medical therapy. Serious complications included conditions requiring emergency care, hospitalization, or surgery.
83 patients with follow-up ranging from 1-271 months (median: 58 months) were included. Fifty-eight (70%) patients had follow-up ≥24 months. The maximum prednisone dose ranged from 10-60mg. Tapering to ≤10mg per day required ≤4 months for all but two patients. Median average daily dose following the initial course was 5mg daily (interquartile range: 4-7.5 mg). During the first two years, there were 24.5 complications per 100 person-years. Only one patient had a serious complication within the first two years (2 year cumulative risk: 1%), but this individual was not following the recommended regimen.
Low-dose prednisone for OMG has an acceptable side-effect profile and causes few serious complications (∼1% two year risk). However, patients need monitoring to detect the relatively common, but less serious, complications (∼39% two year risk) in order to adjust medical therapy in a timely fashion.
PMCID: PMC3731151  PMID: 22549563
Ocular Myasthenia Gravis; Prednisone; Steroid complication
5.  Current and emerging therapies for the treatment of myasthenia gravis 
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.
PMCID: PMC3083988  PMID: 21552317
myasthenia gravis; therapy; immunosuppression; thymectomy; plasmapheresis
6.  Controversies about the treatment of myasthenia gravis. 
Clinicians treating patients with myasthenia gravis must choose cholinergic drugs, corticosteroids, immunosuppressive drugs, thymectomy, or plasmapheresis. Clinicians must decide the sequence or combination of these therapies and when to deem lack of improvement a sign for a different therapeutic approach. Because controlled trials have not been done to evaluate therapies that may require months or years before benefit is evident, controversy abounds.
PMCID: PMC490631  PMID: 7400825
7.  Multifocal Central Serous Chorioretinopathy Associated with Steroids in a Patient with Myasthenia Gravis 
We present a case of bilateral multifocal central serous chorioretinopathy in a 40-year-old male who suffered from myasthenia gravis and was receiving oral prednisolone. Due to the severity of the underlying disease, it was not possible to reduce the corticosteroid dose. After initial unsuccessful treatment with an intravitreal injection of ranibizumab, low-fluence photodynamic therapy was performed, followed by gradual tapering of the corticosteroids. Visual acuity improved significantly in both eyes. Different therapeutic approaches are discussed.
PMCID: PMC3725012  PMID: 23898284
Low-fluence photodynamic therapy; Ranibizumab; Anti-vascular endothelial growth factor; Subretinal fibrin; Central serous chorioretinopathy treatment
8.  A case of myasthenia gravis treated with steroids: some suggestions for the mechanisms underlying their effect. 
Postgraduate Medical Journal  1977;53(620):321-324.
This report deals with a patient with long standing myasthenia gravis treated with a small dose of corticosteroids. The response to treatment was prompt and the post-therapeutic deterioration in function was minimal and cholinergic in nature. It is suggested that the dose of anticholinesterases be reduced concomitantly with the institution of steroid treatment.
PMCID: PMC2496642  PMID: 887530
9.  Myasthenia gravis: a long term follow‐up study of Swedish patients with specific reference to thymic histology 
Myasthenia gravis (MG) is an autoimmune disorder of neuromuscular transmission. The majority of patients show abnormal thymic histology.
The study was performed at the Myasthenia Gravis Centre, Karolinska University Hospital, and at the Immunological Research Laboratory, Centre for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
Patients and methods
Information was collected retrospectively from 1956 and prospectively from 1975 on clinical data, concomitant diseases, concentration of serum acetylcholine receptor antibodies (AChR‐abs), immunosuppressive treatment (IS) and response to it, in 537 patients of whom 326 were thymectomised. Follow‐up time was 1.5–50 years.
Age at onset of MG increased from a median age of 24 years before 1975 to a median age of 61 years after 2000. Thymoma was found in 65, hyperplasia (HPL) in 185 and a normal thymus in 76 patients. The trans‐sternal surgical approach for thymectomy was used in 255 patients (78%). In five patients with thymoma, MG appeared after thymectomy. Of 537 patients, 466 (87%) had circulating AChR‐abs. IS was given to 300 (56%) patients, mostly those with thymoma (85%). In total, 441 patients (82%) showed an improvement. One‐third of patients with HPL, a quarter of those with thymoma, one‐fifth of those with a normal thymus and one‐seventh of those not operated on went into remission.
The prognosis for the majority of patients with MG is favourable, irrespective of thymic histology. The cause may be the use of immunomodulating therapy.
PMCID: PMC2117543  PMID: 17353257
10.  Extraocular muscle responses to high dose intravenous methylprednisolone in myasthenia gravis 
Three patients with generalised myasthenia gravis and three with ocular myasthenia gravis received two to five courses of high dose intravenous methylprednisolone because of the failure of standard immunomodulating therapies. Changes in myasthenic signs were assessed using a four step system for grading muscle weakness and fatiguability in 10 test items. Although a brief and modest amelioration was found from day 1 to day 2 after the initial infusion in two patients with generalised myasthenia gravis, all three experienced a prolonged phase of worsening followed by improvement before the next course. Conversely, for two of the patients with ocular myasthenia gravis, a transient but dramatic improvement of ptosis and ocular immobility was noted from 90minutes to 5 hours after initiating the first infusion, followed by mild or no exacerbation. This 3 hour improvement may be related not only to possible differences in the neuromuscular junction, but also to corticosteroids unmasking the central adaptation for the peripheral ocular muscle weakness by increasing the acetylcholine release.

PMCID: PMC1736793  PMID: 10644791
11.  Treatment of Myasthenia Gravis Based on Its Immunopathogenesis 
The prognosis of myasthenia gravis (MG) has improved dramatically due to advances in critical-care medicine and symptomatic treatments. Its immunopathogenesis is fundamentally a T-cell-dependent autoimmune process resulting from loss of tolerance toward self-antigens in the thymus. Thymectomy is based on this immunological background. For MG patients who are inadequately controlled with sufficient symptomatic treatment or fail to achieve remission after thymectomy, remission is usually achieved through the addition of other immunotherapies. These immunotherapies can be classified into two groups: rapid induction and long-term maintenance. Rapid induction therapy includes intravenous immunoglobulin (IVIg) and plasma exchange (PE). These produce improvement within a few days after initiation, and so are useful for acute exacerbation including myasthenic crisis or in the perioperative period. High-dose prednisone has been more universally preferred for remission induction, but it acts more slowly than IVIg and PE, commonly only after a delay of several weeks. Slow tapering of steroids after a high-dose pulse offers a method of maintaining the state of remission. However, because of significant side effects, other immunosuppressants (ISs) are frequently added as "steroid-sparing agents". The currently available ISs exert their immunosuppressive effects by three mechanisms: 1) blocking the synthesis of DNA and RNA, 2) inhibiting T-cell activation and 3) depleting the B-cell population. In addition, newer drugs including antisense molecule, tumor necrosis factor alpha receptor blocker and complement inhibitors are currently under investigation to confirm their effectiveness. Until now, the treatment of MG has been based primarily on experience rather than gold-standard evidence from randomized controlled trials. It is hoped that well-organized studies and newer experimental trials will lead to improved treatments.
PMCID: PMC3259491  PMID: 22259613
myasthenia gravis; immunosuppressive agents; immunotherapy
12.  Progress in the Treatment of Myasthenia Gravis 
Substantial therapeutic progress has been made in myasthenia gravis (MG) even before the era of molecular medicine. Here we characterize modern treatment algorithms that are adapted to disease severity and introduce the principle of escalating treatment strategies for MG. In very mild cases and in some ocular forms of MG, treatment with acetylcholinesterase inhibitors may be sufficient, at least temporarily, but commonly some kind of immunologically active treatment is needed. In generalized MG, a wide array of immunosuppressive treatments has been established through observational studies, some prospective, but most of them have never been tested in a double-blind, prospective and randomized trial. Within the immunologically active drugs, glucocorticosteroids (GCS) and the immunosuppressive drug azathioprine (Aza) have been studied the longest. Aza is still the standard base-line treatment, in particular in cases where high doses of GCS would be needed to maintain remission. If Aza is not tolerated, several alternatives are available including cyclosporine A (Cic A), mycophenolate mofetil, cyclophosphamide, and methotrexate, all of them off-label in most western countries. Tacrolimus is under investigation. More severe cases may profit from drug combinations in which compounds with more rapidly acting drugs (GCS, Cic A) are combined with others showing a more delayed action (Aza). All such combination therapies need to be supervised by an experienced neuroimmunological center because of potentially serious adverse reactions. Serial measurements of anti-acetylcholine receptor antibodies, once these are elevated, is a useful adjunct for monitoring long-term treatment success and may help in weaning from higher to lower doses or to single drugs rather than combinations. For very severe and treatment-resistant cases, co-treatment with intravenous immunoglobulins or different modalities of plasmapheresis may be considered on the short term while the humanized monoclonal anti-CD 20 antibody (rituximab) is a candidate for the long term. In highly refractory cases also immuno-ablation via high-dose cyclophosphamide, followed by hematologic trophic factors such as G-CSF, has been tried successfully. Future developments may include other immunologically active monoclonal antibodies (e.g., anti-CD 52, Campath-1). Up to 10% of patients with MG are associated with a malignant thymoma, often referred to as paraneoplastic MG, as detected by CT scan or MRI, and these patients require thymomectomy and sometimes postsurgical chemotherapy and radiation treatment. In nonthymoma patients with generalised MG, including older children and adults up to the 5th decade, a complete transsternal thymectomy is recommended based on available open trials and expert opinion, preferentially during the first year of disease. Endoscopic surgery may also be effective. Before surgery, pretreatment with immunosuppressive medication or plasmapheresis is usually recommended to ameliorate MG and subsequently reduce perioperative morbidity and mortality which is now near zero in experienced centers. Myasthenic crisis is the life-threatening exacerbation of MG and is best treated by plasmapheresis, mostly combined with immunoadsorption techniques. Intravenous immunoglobulins are a reasonable alternative, but a shortage in supplies and high prices limit its use.
PMCID: PMC3002545  PMID: 21180568
immunosuppression; immunoglobulins; plasmapheresis; immuno-adsorption; acetylcholine receptor; muscle specific kinase; thymoma
13.  The relationship of plasma levels of pyridostigmine to clinical effect in patients with myasthenia gravis 
The relationship between plasma levels of pyridostigmine to clinical evaluation of muscle power was examined in nine patients with myasthenia gravis during treatment with pyridostigmine in doses of 60 to 1040 mg daily. Five of the nine subjects demonstrated a trend towards a positive correlation, but in only two of them was this statistically significant at p < 0.05. In addition, the presence or absence of a possible correlation between muscle power and plasma concentration was not related to the duration of the disease, additional prednisolone therapy or thymectomy.
PMCID: PMC491235  PMID: 7334410
14.  Effects of alternate-day prednisone therapy on respiratory function in myasthenia gravis. 
Thorax  1976;31(4):410-413.
To determine the effects of alternate-day prednisone therapy on respiratory function in myasthenia gravis, eight patients were evaluated during "days on" and "days off" prednisone. The patients were treated with long-term (up to three years), high-single-dose, alternate-day oral prednisone. After patients had been controlled with alternate-day prednisone they had no episodes of acute respiratory insufficiency or myasthenic crises. Although a small reduction in respiratory function during the day off prednisone was seen in some patients, the change was not statistically significant for the group and was probably physiologically unimportant in most patients. The data indicate that in myasthenic patients who have no underlying lung disease respiratory function is not significantly compromised by administering the prednisone on alternate days.
PMCID: PMC470450  PMID: 968798
15.  Ocular myasthenia gravis: response to long-term immunosuppressive treatment. 
OBJECTIVE: Ocular myasthenia gravis is a subtype of myasthenia gravis that causes relatively mild disability, but may convert into severe generalised muscle weakness. A universal management plan for ocular myasthenia gravis has not been established. This study was performed to determine the outcome of ocular myasthenia gravis with the currently available therapeutic options. METHODS: Retrospective analysis of 78 patients with ocular myasthenia gravis with a mean disease duration of 8.3 (range 0.5-58.3) years. RESULTS: In 54 patients (69%) symptoms and signs remained confined to the extraocular muscles during the observation period. The remaining 24 patients (31%) developed symptoms of generalised myasthenia gravis; 50% of them within two years, 75% within four years after onset. A somewhat reduced risk of generalisation was found in those with mild symptoms, normal repetitive nerve stimulation test, and low or absent antiacetylcholine receptor (AChR) antibodies at the time of diagnosis. Patients receiving immunosuppressive treatment (corticosteroids and/or azathioprine) rarely developed generalised myasthenia gravis (six of 50, 12%). Those without such treatment, usually due to uncertain diagnosis and late referral, converted into generalised myasthenia gravis significantly more often (18 of 28, 64%). CONCLUSIONS: The prognosis of ocular myasthenia gravis is good. A conventional scheme with short-term corticosteroids and long-term azathioprine seems adequate to achieve remission in most patients. The proportion of patients developing generalised myasthenia gravis was smaller in this population compared with previously published groups (usually 50%-70%). Early immunosuppressive treatment is at least partially responsible for this finding. Thymectomy (performed here in 12 patients with an abnormal chest CT) also correlated with a good outcome, but had no apparent advantage over medical treatment alone.
PMCID: PMC486727  PMID: 9048716
16.  Acute myopathy associated with large parenteral dose of corticosteroid in myasthenia gravis. 
A 13 year old Greek girl with myasthenia gravis developed widespread muscle paralysis and atrophy after large parenteral doses of corticosteroids (5.48 g methylprednisolone). An electromyogram showed myopathy, creatine kinase concentration below normal, and a muscle biopsy showed severe myopathy with selective loss of the thick filaments (myosin). Previous reports of myopathy associated with large steroid doses have mostly been in patients who were also receiving non-depolarising neuromuscular blocking drugs. This patient is unique in that severe myopathy was associated with neuromuscular blockade caused by antibodies to acetylcholine receptors. The findings in this case suggest that high doses of parenteral corticosteroids in patients with myasthenia gravis may be dangerous and that blocking the neuromuscular junction with drugs or antibodies predisposes skeletal muscles to the injurious effects of corticosteroids.
PMCID: PMC489625  PMID: 8509789
17.  Current and emerging treatments for the management of myasthenia gravis 
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.
PMCID: PMC3150477  PMID: 21845054
acetylcholinesterase inhibition; immunosuppression; immunomodulation; thymectomy
18.  Juvenile Myasthenia Gravis: A Paediatric Perspective 
Autoimmune Diseases  2011;2011:404101.
Myasthenia gravis (MG) is an autoimmune disease in which antibodies are directed against the postsynaptic membrane of the neuromuscular junction, resulting in muscle weakness and fatigability. Juvenile myasthenia gravis (JMG) is a rare condition of childhood and has many clinical features that are distinct from adult MG. Prepubertal children in particular have a higher prevalence of isolated ocular symptoms, lower frequency of acetylcholine receptor antibodies, and a higher probability of achieving remission. Diagnosis in young children can be complicated by the need to differentiate from congenital myasthenic syndromes, which do not have an autoimmune basis. Treatment commonly includes anticholinesterases, corticosteroids with or without steroid-sparing agents, and newer immune modulating agents. Plasma exchange and intravenous immunoglobulin (IVIG) are effective in preparation for surgery and in treatment of myasthenic crisis. Thymectomy increases remission rates. Diagnosis and management of children with JMG should take account of their developmental needs, natural history of the condition, and side-effect profiles of treatment options.
PMCID: PMC3206364  PMID: 22110902
19.  Localized Thymic Amyloidosis Presenting with Myasthenia Gravis: Case Report 
Journal of Korean Medical Science  2013;29(1):145-148.
A mediastinal mass was incidentally found on chest radiography in a 46-yr-old woman who had had myasthenia gravis (MG) for 2 months. Computed tomography revealed a 4-cm in size, well-defined, and lobulating mass with nodular calcification that was located in the thymus. Microscopically, the mass consisted of diffuse amorphous eosinophilic materials. These deposits exhibited apple-green birefringence under polarized light microscopy after Congo red staining. Immunohistochemical analysis revealed that they were positive for both kappa and lambda light chains and negative for amyloid A. A diagnosis of localized primary thymic amyloidosis was finally made. After thymectomy, the symptoms of MG were controlled with reduced corticosteroid requirements. Localized thymic amyloidosis associated with MG has not been reported to date.
PMCID: PMC3890467  PMID: 24431920
Amyloidosis; Thymus; Mediastinum; Myasthenia Gravis
20.  Myasthenia Gravis—Current Concepts 
Western Journal of Medicine  1985;142(6):797-809.
An edited summary of an Interdepartmental Conference arranged by the Department of Medicine of the UCLA School of Medicine, Los Angeles. The Director of Conferences is William M. Pardridge, MD, Associate Professor of Medicine.
Current findings indicate that autoimmune myasthenia gravis is an acquired immune complex disorder of neuromuscular transmission in voluntary striated muscle. There is a break in immunologic tolerance leading to blocking and degradation of acetylcholine receptors, together with widening of the synaptic cleft associated with partial destruction, simplification and shortening of the postjunctional membrane. Thymic hyperplasia and thymoma may be present. A decremental response to nerve-muscle stimulation, blocking and jitter on single-fiber electromyography and circulating antibodies to acetylcholine receptor are detectable in most patients with generalized weakness. Although the cause of this abnormal immunologic mechanism remains to be discovered, anticholinesterases, corticosteroids, immunosuppressants, plasmapheresis or thymectomy (individually or in combination) provide control and better prognosis in most patients.
PMCID: PMC1306182  PMID: 3895751
21.  Actuarial analysis of the occurrence of remissions following thymectomy for myasthenia gravis in 400 patients. 
The role of thymectomy in the treatment of myasthenia gravis (MG) was analysed in 400 patients affected with generalised MG operated on between 1974-83, and prospectively followed up for five years after surgery. The occurrence of stable remission (SR) (that is, complete clinical drug-free remission that remains stable for all the subsequent follow up) was the endpoint of survival analyses and the distribution of SR time (SRT, that is, the interval from thymectomy to the occurrence of SR) was assessed by actuarial and Cox multivariate analyses. SRT distribution after surgery showed a slow progressive increase of cumulative SR rate that could both be ascribed to a delayed effect of thymectomy as well as reflect the natural history of MG, itself characterised by an increasing probability of spontaneous remission with time. SRT distribution was similar after stratification for all variables studied except when patients without thymoma were stratified for the need for immunosuppressive treatment in addition to thymectomy. Patients without thymoma who did not require additional immunosuppressive therapy (n = 130) had the highest SR rate occurring in the two years after thymectomy, and differed from patients treated with immunosuppressive drugs who showed the highest SR rate five years after surgery. Actuarial analysis has therefore identified a subgroup of patients where SR, occurring in the first years after surgery, is more likely to be ascribed to thymectomy than merely reflect the natural course of the disease.
PMCID: PMC488538  PMID: 1865202
22.  Frequency of myasthenic crisis in relation to thymectomy in generalized myasthenia gravis: A 17-year experience 
BMC Neurology  2004;4:12.
Myasthenic crisis is the most serious life-threatening event in generalized myasthenia gravis (MG) patients. The objective of this study was to assess the long-term impact of thymectomy on rate and severity of these attacks in Iranian patients.
We reviewed the clinical records from 272 myasthenic patients diagnosed and treated in our neurology clinic during 1985 to 2002. Fifty-three patients were excluded because of unconfirmed diagnosis, ocular form of MG, contraindication to surgery, concomitant diseases and loss to follow-up. The Osserman classification was used to assess the initial severity of the disease. Frequency and severity of the attacks were compared between two groups with appropriate statistical tests according to the nature of variables. Multivariate logistic regression analysis was used to assess the predictors of myasthenic crisis in the group of patients without thymoma.
110 patients were in thymectomy group and the other 109 patients were on medical therapy. These two groups had no significant differences with respect to age at onset, gender, Osserman score in baseline and follow up period. 62 patients (28.3% of all 219 patients) had reported 89 attacks of myasthenic crisis. 20 patients of 62 (32%) were in thymectomy group and 42 (68%) were in the other group. There was significant difference between the two groups in number of patients with crisis (P = 0.001; odds ratio = 2.8 with 95% CI of 1.5 to 5.2). In addition, these attacks were more severe in group of non-thymectomized patients as the duration of ICU admission was longer and they needed more ventilatory support during their attacks. Regression model showed thymectomy and lower age at onset as two predictors of decrement in myasthenic crisis rate in non-thymomatous MG patients.
It is suggested that frequency and severity of myasthenic attacks as important endpoints in evaluation of MG patients. Thymectomy seems to have a preventive role on rate and severity of these attacks.
PMCID: PMC518967  PMID: 15361260
23.  Anesthesia for patients undergoing transsternal thymectomy for juvenile myasthenia gravis 
Saudi Journal of Anaesthesia  2011;5(1):25-30.
Juvenile myasthenia gravis (JMG) is the rare form of myasthenia gravis presenting in childhood and adolescence. When medical management fails, thymectomy is offered for these patients. Complete resection of the thymus is best achieved through transsternal thymectomy. Anesthetic management of patients with JMG is challenging, particularly in regards to the goals of postoperative pain control, respiratory function, and extubation.
We retrospectively reviewed the medical records of 13 patients, ranging in age from 6 to 22 years, who underwent transsternal thymectomy for JMG. Information on patient demographics, characteristics of their disease and treatment, anesthetic management, and postoperative course were collected.
All patients had undergone multiple treatment modalities and presented for surgery because of inadequate symptom control with medical management. As expected for a pediatric population, anesthesia induction was age dependent. 40% of the patients underwent an inhalation induction and 60% underwent an intravenous induction. Anesthesia was maintained with a low-dose inhalation agent in all patients, supplemented in 84% of patients with a remifentanil infusion, and in 69% of patients with an epidural infusion. Muscle relaxants were avoided in all patients. With this regimen, 92% of patients could be extubated successfully in the operating room.
We found that avoidance of muscle relaxants and use of remifentanil with a low-dose hypnotic agent provided a stable intraoperative course, facilitated rapid emergence, and allowed early extubation in patients with JMG undergoing transsternal thymectomy. Epidural analgesia reduced the need for intra- and postoperative intravenous opioids and did not have an adverse effect on respiratory strength.
PMCID: PMC3101749  PMID: 21655012
Epidural anesthesia; juvenile myasthenia gravis; pediatric anesthesia; remifentanil
24.  Thymectomy for myasthenia gravis 
Thorax  1972;27(5):513-516.
Between 1951 and 1971 thymectomy was performed on 41 patients with myasthenia gravis. They were selected from a total group of 95 myasthenic patients receiving anticholinesterase therapy. The criteria for selecting patients for thymectomy and the assessment of their progress after operation are described. All the patients have been examined by us at intervals and the results of this follow-up are presented. The survey has shown that substantial improvement after thymectomy occurred in 21 patients (group A), seven of whom had complete remissions without medication for periods of up to 12 years after operation. Considerable benefit from the operation was also observed in seven patients (group B); although their response was less spectacular, in that their daily requirement of anticholinesterase drugs was not changed, their functional activities were significantly enhanced. The most favourable results were seen in female patients aged 15 to 40 years, six of whom had one or more successful pregnancies. Thymectomy did not improve the general condition or progress of six patients (group C). There were three deaths within 16 days of operation, and two patients died within one year. Eight patients survived for periods of 3 to 16 years; six of these died from causes other than directly from myasthenia, and two died at home without established cause.
PMCID: PMC470538  PMID: 5083719
25.  Cervical thymectomy in the treatment of myasthenia gravis. 
A retrospective review of 22 patients undergoing cervical thymectomy for myasthenia gravis is presented. Their ages ranged from 19 to 67 years. The male and female ratio as well as the severity of illness prior to operation were similar to other reported series. All patients were evaluated from the standpoint of clinical response to thymectomy, and the number and dosage of anti-myasthenic drugs required after operation. There was a statistically significant improvement in clinical status in the immediate postoperative period (P less than 0.05) and a further significant improvement was noted at six months (P less than 0.05). In addition, significant reductions in postoperative drug therapy were noted (P less than 0.05). Complications from cervical thymectomy were minimal and mortality was zero. An attempt was made to correlate histological findings with clinical results. Comparison is made to other series in the literature and the advantages of the cervical technique as the initial surgical approach are described. The data presented support a useful role for cervical thymectomy in the treatment of myasthenia gravis.
PMCID: PMC2493678  PMID: 6486664

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