Ocular myasthenia gravis coincident with thyroid ophthalmopathy

Graves' disease and myasthenia gravis are both auto-immune diseases and the coexistence of these two diseases is well recognized. Myasthenia gravis is more frequent in patients with thyroid disease. Here we present a case of thyroid ophthalmopathy and ocular myasthenia.     

Ocular myasthenia gravis associated with euthyroid ophthalmopathy

We report a 71-year-old woman with concomitant ocular myasthenia gravis and euthyroid Graves' ophthalmopathy. Unilateral ophthalmoplegia, including ptosis, initially was responsive to edrophonium and corticosteroids, except for diplopia on upward gaze, but refractory swelling of the inferior rectus muscle and proptosis followed. Autoantibodies to acetylcholine and thyrotropin receptors were detected. Her ophthalmopathy abated after orbital irradiation in combination with systemic steroids. There may be an immunological basis for the association of ocular myasthenia gravis with euthyroid Graves' ophthalmopathy.     

Psychosocial aspects in patients with myasthenia gravis

Journal of Neurology - Myasthenia gravis patients usually present with fluctuating, asymmetrical stress-dependent weakness in the absence of other neurological disturbances. In weak patients...     

Psychosocial aspects in patients with myasthenia gravis

Myasthenia gravis patients usually present with fluctuating, asymmetrical stress-dependent weakness in the absence of other neurological disturbances. In weak patients psychopathological disturbances are frequently reported and misdiagnosed as a psychiatric disorder. The question to what extent psychiatric symptoms are involved in MG is still open. The case report presented here shows exemplary that psychopathological disturbances in exacerbated myasthenic patients are temporary and completely reversible after adequate somatic therapy.     

Ocular myasthenia gravis: predictive value of single-fiber electromyography.

Extraocular muscle weakness is the most common presenting sign of myasthenia gravis (MG). More than half of patients presenting with symptoms isolated to these muscles (OMG) develop generalized myasthenia gravis (GMG) over the course of their illness. No clinical, laboratory, or electrophysiological features are recognized that identify these high-risk patients. We have therefore assessed the ability of single-fiber electromyography (SFEMG) to predict the development of GMG in patients presenting with OMG. Thirty-nine consecutive patients presenting with OMG underwent SFEMG of the extensor digitorum communis muscle as well as a battery of other laboratory and imaging studies at the time of diagnosis. All patients were followed prospectively for a minimum of 24 months or until they developed GMG. Two patients were excluded, leaving 37 for assessment. Twenty remained with pure OMG for the entire follow-up period (mean, 55 months). Twenty-six of the 37 had abnormal SFEMG studies at presentation. Eleven of these remained with OMG and 15 developed GMG. Fifty-eight percent of patients with an abnormal SFEMG developed GMG, whereas 82% of those with a normal study remained with OMG. Thus, a normal SFEMG was associated with MG remaining restricted to the extraocular muscles. (P = 0.036, Fisher's exact test), but an abnormal SFEMG was not predictive of subsequent development of GMG.     

Paraneoplastic myasthenia gravis: immunological and clinical aspects

Paraneoplastic myasthenia gravis (MG) is accompanied by a neoplasm, usually thymoma. In patients with thymoma and a specific genetic make‐up, the paraneoplastic immune response develops further in thymic remnant or peripheral lymphatic tissue. Paraneoplastic MG and late‐onset MG (age ≥ 50 years) share a similar immunological profile with high titin and ryanodine receptor (RyR) antibody prevalence. This profile is the most important predictor of clinical outcome in paraneoplastic MG. The presence of a thymoma per se does not cause more severe MG. MG severity is linked to the patient’s immunological profile. Paraneoplastic MG causes a distinctive non‐limb symptom profile at MG onset, characterized by bulbar, ocular, neck, and respiratory symptoms. When the diagnosis of paraneoplastic MG is established, the neoplasm should be removed surgically. Pre‐thymectomy plasmapheresis or iv‐IgG should be considered in these patients to minimize post‐thymectomy MG exacerbation risk. Paraneoplastic MG usually continues after thymectomy. The pharmacological treatment of paraneoplastic MG does not differ from non‐paraneoplastic MG, except for tacrolimus that should be considered in difficult cases. Tacrolimus is an immunosuppressant acting specifically in RyR antibody positive patients through enhancing RyR‐related sarcoplasmic calcium release that in theory might be blocked by RyR antibodies, causing symptomatic relief in paraneoplastic MG.     

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.     

Immunological and therapeutic aspects of myasthenia gravis (author's transl)

In the treatment of Myasthenia Gravis (M.G.) new therapeutic techniques have been gradually added to the usual anticholinesterase drugs. Steroids, immunosuppressive drugs, plasma exchange have been employed whereas thymectomy is still the most useful surgical treatment. On the basis of both personal experience and data from the literature the AA. reviewed the therapeutic techniques. Thymectomy is practically indicated for all patients particularly young ones. However there are some reserves in the presence of thymomas as sometimes deterioration may occur. Steroids are mostly employed in cases resistant to other therapies. Immunosuppressive drugs are usually associated with plasma-exchange. The latter has been recently preferred because of the absence of side effects; however its real therapeutic value has not yet been fully assessed.     

Seronegative myasthenia gravis

Of 221 patients with myasthenia gravis, 18.5% had no detectable antibodies to acetylcholine receptor. Seven of 14 patients (50%) with only ocular symptoms for more than 2 years were seronegative, and 25 of 145 (17%) patients with generalized myasthenia were seronegative. The clinical characteristics of seronegative patients did not differ from patients with high antibody titers. No seronegative patient had a thymoma, but that difference did not reach statistical significance. Lack of serum antibodies did not preclude favorable response to thymectomy or plasmapheresis.     

Juvenile myasthenia gravis

Juvenile myasthenia gravis shares a similar pathophysiologic origin with adult myasthenia gravis, but there are important differences, mostly relating to epidemiology, presentation, and therapeutic decision making. Gender ratios and the proportion of seropositive patients differ in the pre‐ and postpubertal age groups. The diagnostic evaluation is similar to that in adults, although special techniques are sometimes necessary to perform single‐fiber electromyography in younger patients. Therapeutic decisions in affected children and adolescents are complicated by the greater long‐term consequences of using steroids, and thus other interventions, such as intravenous immunoglobulin (IVIg) and plasmapheresis, may play a greater therapeutic role in this population than in adults. Steroid‐sparing agents may contribute to the management of refractory cases, but they should be used with caution due to the risk of malignancy. Muscle Nerve, 2008     

Ocular myasthenia gravis: treatment successes and failures in patients with long-term follow-up

We previously reported that prednisone reduced the frequency of generalized myasthenia (GMG) and controlled diplopia without major adverse effects at 2 years in patients with ocular myasthenia gravis (OMG). Questions remain as to whether study subjects had long-standing disease, biasing results towards a steroid benefit, and if prednisone merely delayed GMG onset. Here, we performed a record review of a referral neuro-ophthalmology service OMG database for patients who were followed-up for ≥4 years or until GMG developed. We studied the effect of prednisone on GMG incidence and control of ocular symptoms. Generally, patients with diplopia were recommended for prednisone therapy. Most remained on daily 2.5–10 mg for diplopia control. We compared the results for prednisone-treated and “untreated” (pyridostigmine only) patients. Of 87 patients, 55 were in the prednisone-treated and 32 were in the untreated groups. GMG developed in 7 (13%) of the prednisone-treated (OR 0.41; 95% CI 0.22–0.76) and in 16 (50%) of the untreated (OR 2.78; 95% CI 1.68–4.60) patients. After OMG onset, GMG developed at a mean 5.8 and 0.22 years in prednisone and untreated groups. Diplopia was present at the last exam in 27% of the prednisone-treated (mean 7.2 years) and in 57% of the untreated (mean 4.6 years) OMG patients. For 48 prednisone-treated patients who did not develop GMG, OMG treatment failure occurred in 13. Thus, prednisone delays the onset of GMG and has sustained benefit in reducing the incidence of GMG and controlling diplopia. Without prednisone, GMG develops in 50% of OMG patients, typically within 1 year.