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PubMed2001

[Respiratory disorders during sleep and myasthenia].

A sleep apnea syndrome is described by several studies in patients with myasthenia gravis. Apnea and hypopnea are mainly not obstructive and occur predominantly in rapid eye movement (REM) sleep. They are associated with oxygen desaturation. Although the sleep apnea index is not correlated with myasthenia gravis severity, it becomes less important as myasthenia gravis improves. Risk factors for the development of sleep apnea in myasthenia gravis patients are age, restrictive pulmonary syndrome, diaphragmatic weakness and daytime alveolar hypoventilation. Sleep apnea are not related to a central cholinergic effect in myasthenia gravis caused either by anticholinesterase used to treat myasthenia gravis or by antibodies to muscle acetylcholine receptors. Indeed acetylcholine receptors in brain are antigenically distinct from acetylcholine receptors in skeletal muscle. Sleep apneas are more likely caused by peripheral mechanisms. Correlation between sleep apnea and total lung capacity as well as the importance of diaphragmatic weakness in myasthenic patients may explain their predominance in REM sleep and their reduction with clinical improvement in the myasthenia gravis.

Diaphragm↗

PubMedDate not supplied

Study of anti-striational and anti-thyroid antibodies in patients with myasthenia gravis.

The study was carried out in 74 patients out of whom 46 with generalized myasthenia gravis and 28 with the ocular form of disease--all in acute state, ranging in Osserman's severity scale between I-IV; the age at onset of disease varied between 18-79 years. It showed anti-striational antibodies in 31% of the patients and anti-thyroid antibodies in 40%, as compared with 41 controls. Likewise it was observed that the presence of anti-striational antibodies with significant high values was associated with the presence of thymomas in 16 generalized myasthenia gravis patients and in 3 ocular myasthenia gravis patients (p < 0.001). Anti-thyroid antibodies were more frequently observed in ocular myasthenia gravis (23 cases) as compared to generalized myasthenia gravis (7 cases) with significant high levels (p < 0.001). The results obtained showed that the study of anti-striational antibodies can be of great utility in the diagnosis of thymoma, and that the study of anti-thyroid antibodies can be of great utility to sustain the clinical diagnosis of ocular myasthenia gravis. The presence of anti-striational and of anti-thyroid antibodies showed a basic alteration of immunoregulatory mechanisms of maintaining immune tolerance in myasthenia gravis patients.

Adolescent↗

PubMed1990

[Detection of erythrocyte immune function and circulatory immune complex in myasthenia gravis].

The circulating immune complexes (CIC) and erythrocyte immune function in myasthenia gravis were studied. In order to examine CIC in the patients with myasthenia gravis the complement sensitized yeast cell agglutination (CSYCA) test and anti-C3-ELISA were used. The CIC positive rate was 92.3% in the patients tested. The CIC test was all negative in the normal control subjects. The levels of CIC were remarkable elevated in the patients with myasthenia gravis (P less than 0.01). It was found that the rosette rate of red blood cell C3b receptor was 11.27 +/- 3.27% in the CIC negative patients with myasthenia gravis and 17.60 +/- 5.10% in CIC negative patients with myasthenia gravis. The erythrocyte immune function decreased remarkably in the CIC positive patients with myasthenia gravis (P less than 0.05). The relationship between the decrease of the erythrocyte immune function and myasthenia gravis is discussed.

Agglutination Tests↗

PubMed1988

"Maximal" thymectomy for myasthenia gravis. Results.

Thymectomy has been shown to be effective in the treatment of myasthenia gravis. The logical goal of operation has been complete removal of the thymus, but there has been controversy about the surgical technique and its relation to results. Surgical-anatomic studies have shown gross and microscopic thymus widely distributed in the neck and mediastinum. We believe that an en bloc transcervical-transsternal "maximal" thymectomy is required to remove all thymic tissue predictably. Ninety-five patients with generalized myasthenia gravis underwent "maximal" thymectomy consecutively between 1977 and 1985 and were evaluated 6 months to 89 months after operation. In Group A (N = 72), myasthenia gravis without thymoma, the uncorrected data revealed that 96% (69) had benefited from operation: 79% (57) had no symptoms; 46% (33) were in remission; 33% (24) were symptom free when receiving minimal doses of pyridostigmine; and none were worse. Life table analysis yielded a remission rate of 81% at 89 months. In group B (N = 8), myasthenia gravis without thymoma for which patients underwent reexploration for incapacitating weakness after earlier transcervical or transsternal operations, residual thymus was found in all. One patient was in remission, two were symptom free when receiving medication, one was unchanged, and none were worse. In group C (N 15), myasthenia gravis and thymoma, two patients were in remission and nine were symptom free when receiving medication. Two patients in this group died 2 and 4 years postoperatively in crisis. Response to thymectomy in group A was greater in patients with mild myasthenia gravis and may have been better in patients who had symptoms for less than 60 months preoperatively, but the response did not depend on age, sex, presence or absence of thymic hyperplasia or involution, or titers of acetylcholine receptor antibodies. The response to thymectomy in group B was striking but slower than in group A, perhaps because symptoms were more severe and of longer duration. The response in group C was also less good than in group A and proportionately fewer benefited. These results support the recommendation for thymectomy in the treatment of patients with generalized myasthenia gravis and indicate the desirability of a maximal procedure. For persistent or recurrent severe symptoms after previous transcervical or submaximal transsternal resections, reoperation by this technique is also recommended.

Actuarial Analysis↗

PubMed1976

[Pseudoparalytic myasthenia gravis. Diagnostic and therapeutic aspects in 60 separate cases].

Based on 60 of our own cases and on the medical literature the authors discuss the diagnostic, pathophysiological and therapeutic aspects of myasthenia gravis. Myasthenia is suspected in cases of motor weakness of changing intensity, diminishing by rest. The weak muscles are innervated by different peripheral nerves. At the beginning a weakness of upperlid-muscles, external eye muscles and bulbar muscles is particularly frequent. There is no sensory loss or other neurological symptoms. A transitory disappearance of motor weakness after an intravenous dose of Edrophonium (Tensilon) is a typical diagnostic sign. The effect is less evident with eye-muscle weakness. A typical appearance of potentials after repetitive stimulation of peripheral nerves as well as other characteristics in electrophysiological testing of muscles are of high diagnostic value. This allows differentiation from other types of muscle weakness. In the pathogenesis of myasthenia an autoimmune process related to a persistent thymus gland plays an important part. This leads to an ultrastructural change in the postsynaptic membrane of the muscle fibre. The postsynaptic membrane no longer reacts in a normal way to acetylcholine as a transmitter substance at the level of the motor endplate. Therefore the first step in the treatment of myasthenia consists of cholinesterase-inhibitors, specially Neostigmin (Prostigmin) and Pyridostigmin (Mestinon). Thymectomy is advised in all cases of myasthenia with the exception of the pure ocular form and of myasthenia in patients older than 60 years. The thymus gland is practically always persistent or hypertrophic in myasthenia. The suprasternal access is recommended. A thymoma should always be operated upon because of the danger of malignancy. In cases where thymectomy is not performed or not successful and if cholinesterase-inhibitors are not sufficiently efficient, treatment with corticosteroids or ACTH is recommended.

Adolescent↗

PubMed1976

[Myasthenia gravis in old age. A retrospective study of 58 patients].

The course in 58 cases of myasthenia gravis in subjects over 50 years of age is reported. They total about 30% of cases in all age-groups. 36.2% of the patients died after an average period of illness of 3.4 years. 58.6% initially showed only ocular symptoms and in 58.8% of these the myasthenia was likewise located only in the eyes in the further course of the illness. The prognosis of ocular myasthenia is very good if the myasthenic process does not extend to other muscle groups in the first or second year of illness. 41.2% of primary ocular myasthenia turned into other types, in most cases a generalized type, and these had a poor prognosis. 69.2% of these patients died after an average period of illness of 1.5 years due to myasthenia-induced complications. Cases of myasthenia which initially are of the generalized type, in which the average duration is only 2.7 years until death, and to some extent the bulbar types, also have a poor prognosis. Ocular myasthenic cases generally need only small doses of cholinesterase inhibitors. Some patients had no medical treatment because there was no subjective or objective need for it. Several patients were given doses of cholinesterase inhibitors which were too large; excessive doses are to be avoided because of the proven negative influence of cholinesterase inhibitors on the myoneural system. It is recommended that types of myasthenia with a poor prognosis be treated early with corticoids, ACTH or azathioprin, if the cholinesterase inhibitors have proved ineffective or it their effect is unsatisfactory. Thymectomy is advisable only in patients under 60 years of age.

Aged↗

PubMed2006

Predictive value of serum anti-C1q antibody levels in experimental autoimmune myasthenia gravis.

Components of the complement cascade and circulating immune complexes play important roles in both experimental autoimmune myasthenia gravis and myasthenia gravis in humans. Thus far, no serological factor has been identified to predict the clinical severity of either myasthenia gravis. Upon immunization with acetylcholine receptor, levels of complement factors C1q, C3 and CIC increase with time in sera from C57BL/6 (B6) mice. Both these and plasma samples from myasthenia gravis patients also contain anti-C1q antibodies. The serum levels of anti-C1q antibodies but not C1q, C3 and CIC are significantly correlated with the clinical severity in the experimental myasthenia mice. However, this correlation is not observed in myasthenia gravis patients.

Adult↗

PubMed2002

Myasthenia gravis in pregnancy: report on 69 cases.

OBJECTIVE: To review our experience with pregnancies in women with myasthenia gravis (MG). STUDY DESIGN: Sixty nine pregnancies among 65 women with MG patients managed by our department over 28 years were included. The course of the disease in pregnancy, mode of delivery and postpartal period were evaluated. RESULTS: One pregnancy miscarried. In 15% of patients the MG deteriorated in pregnancy a further 16% in the puerperium. 17% of pregnancies were delivered by cesarean section, one due to myasthenia exacerbation. All women with puerperal infections developed exacerbations. One neonatal death, not attributable to myasthenia, was recorded. Transitory neonatal myasthenia gravis (TNMG) was diagnosed in 30% infants. Its incidence was inversely associated with maternal disease duration (P < 0.05). Newborns of thymectomized mothers showed lower rate of neonatal myasthenia compared to those of non-thymectomized women (P < 0.05). CONCLUSIONS: MG patients can have normal pregnancy and delivery but the course is unpredictable. Shorter disease history and infection predispose to puerperal exacerbation. Maternal thymectomy lessens the likelihood of neonatal myasthenia. An interdisciplinary approach is required for managing the pregnant women with MG.

Adult↗

PubMed2000

Surgical correction of blepharoptosis in patients with myasthenia gravis.

PURPOSE: To describe the results of surgical correction of blepharoptosis in a series of patients with myasthenia gravis. METHODS: We reviewed the medical records of all patients with myasthenia gravis who underwent surgical correction for blepharoptosis at the Mayo Clinic between 1985 and 1999. The primary outcome measure was change in interpalpebral eyelid fissure height. RESULTS: Eighteen blepharoptosis procedures were performed on 11 patients with myasthenia gravis. Eight of the 11 patients had ocular myasthenia gravis, and 3 had systemic myasthenia gravis. Of the 18 procedures performed, 11 were external levator advancements (ELA), 6 were frontalis slings, and 1 was a tarsomyectomy. Patients were followed up postoperatively for an average of 34 months (range, 9 to 126 months). The amount of ptosis was quantified preoperatively and postoperatively for 9 of the 11 eyelids that underwent ELA. For these eyelids, there was a statistically significant improvement in the mean interpalpebral eyelid fissure height, from 4.2 mm preoperatively to 8.1 mm postoperatively, with a mean difference of 3.9 mm (95% confidence interval, 2.3 to 5.5 mm; P = .0005). Postoperative complications included worsened diplopia in 1 patient who underwent ELA and exposure keratopathy in 1 patient who underwent a frontalis sling procedure. Two of the eyelids that underwent ELA developed recurrent ptosis, requiring additional surgery more than 2 years after the initial procedure. CONCLUSION: Surgical correction of blepharoptosis is an appropriate treatment option in patients with myasthenia gravis who fail medical therapy. Potential complications include worsened diplopia and exposure keratopathy.

Adult↗

PubMed2003

[Myasthenia gravis and pregnancy. Report on 13 cases].

OBJECTIVES: To evaluate our experience of myasthenia during pregnancy. MATERIALS AND METHODS: Retrospective study in a tertiary care university hospital including pregnant women affected by myasthenia gravis and who delivered in the obstetrical tertiary center. Medical and delivery reports were analyzed. RESULTS: Between 1994 and 2002, 12 women, age 31 (25-36), delivered 14 children. One women delivered twice, and there was one twin pregnancy. Clinical symptoms of myasthenia worsened in five. One was admitted twice to the intensive care unit during her pregnancy. Two were admitted to intensive care unit during the first month of post-partum. Gestational age at birth was 39.3 weeks (38-40.6), all birth weights were normal: 3329 g (2660-4520). Six women delivered vaginally, two by instrumental extraction and five by cesarean section. Apgar score was normal for all infants: 9/10. The level of anti-acetylcholine receptor antibodies (anti AchR) was high: 36.4 nM/L (0-46.8) (normal below 0.6 nM/L), but was not related to neonatal outcome. Three children presented neonatal myasthenia. CONCLUSION: We recommend obstetrical monitoring in tertiary centers for pregnant women with myasthenia gravis because of the risk of neonatal myasthenia. Measurement of anti-acetylcholine receptor antibodies may be useful. Pediatric and maternal observation is necessary in the first days of post partum.

Adult↗

PubMed1996

Beneficial effects of corticosteroids on ocular myasthenia gravis.

OBJECTIVE: To determine if moderate-or low-dose corticosteroid therapy can reduce the diplopia and frequency of deterioration to generalized disease in ocular myasthenia gravis. DESIGN: Retrospective record review. SETTING: Two university-based neuro-ophthalmology services. PATIENTS: All 32 patients with ocular myasthenia gravis, treated with prednisone, followed up for a minimum of 2 years were included. Patients were treated with 1 or more courses of daily prednisone (highest initial dose, 40-80 mg) gradually withdrawn over 4 to 6 weeks. Subsequently, in 6 patients, 2.5 to 20 mg of prednisone was given on alternate day. OUTCOME MEASURES: Diplopia in the primary position or downgaze diplopia and generalized myasthenia gravis after 2 years of follow-up. RESULTS: Diplopia, which was initially found in the primary position in 29 patients and in the downgaze position in 26 patients, was absent in 21 patients at 2 years. Generalized myasthenia gravis occurred in 3 patients at 2 years. Elevated serum acetylcholine receptor antibody levels and abnormal electromyography findings were not predictive of worsening. No patient experienced a major steroid complication. CONCLUSIONS: Moderate-dose daily prednisone for 4 to 6 weeks, followed by low-dose alternate-day therapy as needed, can control the diplopia in patients with ocular myasthenia gravis. The frequency of deterioration to generalized myasthenia gravis at 2 years may be reduced; 9.4% in this study compared with more than 40% previously reported frequency. Corticosteroids may be useful even when ocular motor dysfunction is not normalized.

Adrenal Cortex Hormones↗

PubMed1991

Seronegative myasthenia gravis: a plasma factor inhibiting agonist-induced acetylcholine receptor function copurifies with IgM.

Anti-acetylcholine receptor antibodies cannot be detected by standard radioimmunoassay in 10 to 15% of patients with generalized myasthenia gravis (seronegative myasthenia gravis). We investigated the effect of seronegative myasthenia gravis plasma on 22Na+ flux through acetylcholine receptors and voltage-gated sodium channels in the human rhabdomyosarcoma cell line, TE671. Fourteen of 19 seronegative MG plasmas inhibited acetylcholine receptor 22Na+ flux; none inhibited voltage-gated sodium channel flux. The inhibitory activity was found in the IgG-depleted fraction, and copurified with IgM after gel-filtration chromatography. Inhibitory activity was absent from the plasma of 8 healthy control subjects and of 6 patients with the Lambert-Eaton myasthenic syndrome, but was present in the IgG-depleted plasma fraction of 4 of 6 seropositive patients with myasthenia gravis and all 5 patients with demyelinating polyneuropathy. We conclude that a low-affinity serum factor, probably an IgM antibody, found in a high proportion in patients with seronegative and those with seropositive myasthenia gravis may contribute to the muscle weakness in myasthenia gravis, but its role in these and other neuroimmunological disorders requires further investigation.

Autoantibodies↗

PubMed1995

Acetylcholine release in myasthenia gravis: regulation at single end-plate level.

In myasthenia gravis, loss of acetylcholine receptors at motor end-plates is induced by antireceptor autoantibodies. At end-plates in rats in which myasthenia gravis-like symptoms are induced by chronic treatment with alpha-bungarotoxin, acetylcholine release is increased. Within muscles from such rats there is a strong correlation between the increase of acetylcholine release at an end-plate and the loss of postsynaptic acetylcholine receptors, caused by the toxin. The question is whether upregulation of acetylcholine release is a clinically relevant compensatory mechanism in myasthenia gravis or only a feature of the animal model using alpha-bungarotoxin. We investigated electrophysiologically the in vitro acetylcholine release at end-plates of muscles from patients with myasthenia gravis and rats with experimental autoimmune myasthenia gravis where acetylcholine receptor reduction is caused by autoantibody attack. In both human and rat autoimmune myasthenic muscle, the mean quantal content was considerably increased compared with control levels. At each individual myasthenic end-plate, the increase in quantal content appeared to be correlated with the reduction of the amplitude of the miniature end-plate potential. This finding suggests the existence of an important compensatory mechanism in myasthenia gravis, in which retrograde acting factors (i.e., from muscle fiber to nerve terminal) upregulate acetylcholine release.

Acetylcholine↗

PubMed1998

Postoperative infection after transsternal thymectomy for myasthenia gravis: a retrospective analysis of 125 cases.

The present study was conducted in an attempt to clarify the extent to which the preoperative severity of myasthenia gravis and immunosuppression favor postoperative infection. A retrospective analysis was carried out on 125 consecutive patients who had undergone transsternal thymectomy for myasthenia gravis between 1976 and 1995. The preoperative severity of myasthenia was graded by a modified version of Osserman's classification. The incidence of postoperative pneumonia among patients with Osserman's class 1, class 2, class 3, and class 4 disease were 0%, 10%, 21%, and 44%, respectively, showing a marked increase with the preoperative severity of myasthenia; however, postoperative wound infection and mediastinitis were unrelated to the preoperative severity of myasthenia. With every increment in Osserman class, there was an appreciable, though insignificant, rise in the frequency of preoperative immunosuppression. There was no significant association between postoperative infection and preoperative immunosuppression. These findings indicate that a poor preoperative clinical status has a greater impact on the risk of postoperative pneumonia than immunosuppression, and therefore, every effort should be made to decrease the preoperative severity of myasthenia. Promoting the widespread use of plasmapheresis seems particularly important for this purpose.

Adult↗

PubMed2004

Experience with programmed steroid treatment with thymectomy in nonthymomatous myasthenia gravis.

BACKGROUND: The benefit of thymectomy in myasthenia gravis management is recognized but the perioperative course can fluctuate. The goal of this study was to assess the feasibility and clinical benefit of dose-escalated steroid therapy with thymectomy for nonthymomatous myasthenia gravis. METHODS: We reviewed the records of 69 myasthenia gravis patients who were followed up after undergoing transsternal thymectomy with extended anterior mediastinal dissection in our hospital between 1976-2000. Forty-eight patients in the programmed treatment group who had dose-escalated and de-escalated steroid therapy during the perioperative period comprised 17 patients with ocular myasthenia gravis and 31 patients with generalized myasthenia gravis. Clinical benefits and clinical remission, which was diagnosed when the patients were symptom-free without medications for at least 1 year, were compared with those of 21 patients in the occasional treatment group who received medications occasionally over the perioperative period. RESULTS: Postoperative respiratory failure and myasthenic crisis did not occur in the programmed treatment group but did occur in 6 patients in the occasional treatment group. Remission rates in the programmed treatment group (mean follow-up, 6.4 years) were 30% at 3 years, 38% at 5 years, and 46% at 10 years; rates in the occasional treatment group (mean follow-up, 9.6 years) were 25% at 3 years, 25% at 5 years, and 45% at 10 years. CONCLUSIONS: Programmed steroid therapy in patients with nonthymomatous myasthenia gravis is feasible and it provides clinical benefit when fluctuating symptoms occur during the perioperative period.

Adult↗

PubMed2005

Role of positive selection of thymoma-associated T cells in the pathogenesis of myasthenia gravis.

BACKGROUND: A human thymoma is a thymic epithelial neoplasm and is characterized by its frequent association with myasthenia gravis. The histological characteristic of thymoma is coexistence of a large number of lymphocytes, including CD4(+)CD8(+) double positive T cells, phenotypes of the cortical thymocytes. To elucidate the role of these T lymphocytes in the pathogenesis of thymoma-associated myasthenia gravis, we examined the usage of alphabeta or gammadelta T cell receptor of the T lymphocytes in thymoma in conjunction with the positive selection event. MATERIALS AND METHODS: Thymomas were obtained from 28 patients. Nine patients were associated with myasthenia gravis. Lymphocytes were freshly isolated from the tumor tissue and were subjected to four-color flow cytometric analysis. RESULTS: The average proportion of TCRalphabeta(+) cells in thymomas associated with myasthenia gravis was 47.0% and was significantly higher (P = 0.0008) than that without myasthenia gravis (23.4%). Positive selection event was then examined in terms of CD69, a positive selection marker. The mean proportion of TCRalphabeta(+)CD69(+)CD4(+)CD8(-) cells in the myasthenic thymomas (8.22%) was significantly greater (P = 0.015) than the nonmyasthenic thymomas (2.99%). On the other hand, there was not a significant difference in the mean proportion of TCRalphabeta(+)CD69(+)CD4(-)CD8(+) cells between the myasthenic and the nonmyasthenic thymomas. CONCLUSIONS: The possible role of development of TCRalphabeta(+) T cells, especially the role of positive selection of TCRalphabeta(+)CD4(+)CD8(-) T cells in thymoma, was suggested in the pathogenesis of thymoma-associated myasthenia gravis.

Adult↗

PubMed2005

[Myasthenia in elderly patients: a series of 23 cases].

PURPOSE: There is evidence that myasthenia gravis is substantially underdiagnosed in older people, for which diagnosis and treatment may be difficult. METHOD: We report on a series of 23 cases of myasthenia gravis diagnosed after the age of 65. Diagnosis was ascertained by compatible symptoms, associated with electrophysiological evidence and/or presence of antibodies to the acetylcholine receptor (AchRAb) and/or positive prostigmine test. RESULTS: Twelve female and 11 male patients were identified, with a mean age of 77 (range: 66-89). Initial symptoms were ocular in 8 cases (35%), bulbar and ocular in 9 cases (39%), generalized in 6 cases (26%). Diagnosis was delayed in many patients (mean delay 31+/-47 months). Prostigmine test was positive in 16 cases (100%), AchRAb were positive in 19/23 cases (83%). Only one thymoma was found. Other diagnoses than myasthenia gravis, mainly stroke, were often considered. Treatment with anticholinesterase drugs, prescribed in all cases, has been able to control symptoms in only 3 cases. Corticosteroids were used in 10 cases, azathioprine or mycophenolate mofetil in 14 cases, intravenous immunoglobulins in 8 cases, and plasma exchanges in 2 cases. Thymectomy was performed on one patient with thymoma. Three patients were hospitalized in intensive care units for several weeks, and 3 patients died from their myasthenia. CONCLUSION: Diagnosis of myasthenia gravis is often missed or delayed in the elderly, because of a broad differential diagnosis in older people, and because the high incidence of the disease in middle and old age is often overlooked. The outcome of myasthenia gravis in older people is far from simple, and immunomodulation proves to be necessary in most cases. However, quality of life of surviving patients appears good.

Adrenal Cortex Hormones↗

PubMed2001

Myasthenia gravis with ocular involvement in older patients.

BACKGROUND: There has been little previous study reporting the eye findings and presentation of elderly patients with myasthenia gravis. The purpose of this study was to review the findings and course of myasthenia gravis after the sixth decade of life. METHODS: Retrospective observational case series. The authors reviewed the clinical records of 27 patients with onset of myasthenia gravis at age 60 years or more who were seen at a tertiary care academic ophthalmology centre in Houston between January 1992 and March 1999. The diagnosis of myasthenia gravis was based on conventional clinical and laboratory criteria. RESULTS: Twenty patients (74%) were men. Of the 16 patients who underwent testing for anti-acetylcholine receptor antibodies, 11 (69%) were seropositive. Concurrent thyroid disease was found in seven patients (26%), including five (71%) of the seven women. No patient had thymoma. Sixteen patients (59%) manifested generalized symptoms during follow-up; 12 did so within 1 year of disease onset. Patients responded well to both anticholinesterase and corticosteroid therapy. At the most recent follow-up visit 18 patients (67%) were clinically improved, and no patient was clinically worse. INTERPRETATION: Myasthenia gravis in this study was characterized by a male predominance, high rate of concurrent thyroid disease, high rate of progression to mild generalized symptoms, absence of thymoma, good response to medical therapy and minimal life-threatening complications. Clinicians should consider the diagnosis of myasthenia gravis in an older patient presenting with diplopia or ptosis.

Aged↗