Myasthenia gravis associated with Graves' disease in Japan

Neuroendocrine disruption by bisphenol A and/or di(2-ethylhexyl) phthalate after prenatal, early postnatal and lactational exposure

Bisphenol A (BPA) and di(2-ethylhexyl)phthalate (DEHP) are abundant endocrine disrupting chemicals (EDCs). In recent years, studies showed that EDCs may lead to neurodevelopmental diseases. The effects of prenatal exposure to these chemicals may have serious consequences. Moreover, exposure to EDCs as a mixture may have different effects than individual exposures. The present study aimed to determine the toxicity of BPA and/or DEHP on central nervous system (CNS) and neuroendocrine system in prenatal and lactational period in Sprague-Dawley rats. Pregnant rats were randomly divided into four groups: control (received vehicle); BPA group (received BPA at 50 mg/kg/day); DEHP group (received DEHP at 30 mg/kg/day); and combined exposure group (received both BPA at 50 mg/kg/day and DEHP at 30 mg/kg/day) during pregnancy and lactation by oral gavage. At the end of lactation, male offspring (n = 6) were randomly grouped. The alterations in the brain histopathology, neurotransmitter levels and enzyme activities in the cerebrum region, oxidative stress markers, and apoptotic effects in the hippocampus region were determined at adulthood. The results showed that exposure to EDCs at early stages of life caused significant changes in lipid peroxidation, total GSH and neurotransmitter levels, and activities of neurotransmitter-related enzymes. Moreover, BPA and/or DEHP led to apoptosis and histopathologic alterations in the hippocampus. Therefore, we can suggest that changes in oxidant/antioxidant status, as well as in neurotransmitters and related enzymes, can be considered as the underlying neurotoxicity mechanisms of BPA and DEHP. However, more mechanistic studies are needed.

Challenges in diagnosing coexisting ocular myasthenia gravis and thyroid eye disease

Ocular myasthenia gravis (OMG) and thyroid eye disease are two autoimmune conditions that have several overlapping clinical features, and these coexist with a small but not insignificant frequency. Segregating these diagnoses is typically straightforward, but, when the two diseases co-occur in the same individual, making a diagnosis of OMG can be very challenging. In this review we address what is known about the coexistence of OMG and thyroid eye disease and we highlight the clinical features that are suggestive of overlapping conditions. We also describe the major testing approaches used in the diagnosis of these two entities, with special emphasis on the potential shortcomings of individual tests in patients with overlapping disease. In patients with thyroid eye disease, securing a diagnosis of OMG may not be possible on the basis of a single positive test. A multimodal approach using clinical, serologic, imaging, and electrodiagnostic data, is typically required.

Prevalence of latent and overt polyautoimmunity in autoimmune thyroid disease: A systematic review and meta-analysis

BACKGROUND

Thyroid autoimmunity is the most frequent condition involved in polyautoimmunity (PolyA). However, the frequency of latent and overt PolyA in patients with autoimmune thyroid disease (AITD) as the index condition is unknown. Therefore, the purpose of this study was to determine the prevalence of these types of PolyA in patients with AITD as the index condition.

METHODS

This study adhered to the relevant sections of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline. Searches through MEDLINE, Embase and LILACS were done to find articles in Spanish and English. Relevant vocabulary terms and key terms related to AITD and other autoimmune diseases were used. Two investigators independently screened the eligible studies, extracted data and assessed the quality and risk of bias. Fixed and random effect models were used accordingly. Cluster analysis was used to determine similarities among diseases in the articles included (based on Jaccard index).

RESULTS

A total of 56 articles fulfilled the inclusion criteria. Of these, 25 were case-controls, 17 were cohorts, and 14 were cross-sectional studies. These studies included a total of 47 509 patients. Female was the predominant gender and included 38 950 patients (81.23%, 95% CI: 80.85-81.60). Graves' disease (GD) was the most common type of thyroid autoimmunity (69.16%, 95% CI: 68.23-70.07). Globally, overt PolyA was found in 13.46% of the patients with AITD. This type of PolyA was represented mainly by type 1 diabetes and autoimmune gastritis. Latent PolyA was presented in 17.45% of the patients, and anti-proinsulin, anti-parietal cells and dsDNA antibodies were the most common. HT had the highest frequency of overt PolyA in Europe (15.60%, 95% CI: 14.72-16.53), whereas latent PolyA was most common in patients with GD in Asia (21.03%, 95% CI: 17.76-24.71). Overt and latent PolyA were associated with gastrointestinal and endocrinological ADs in most of cases and clustered with rheumatological, dermatological and neurological ADs.

CONCLUSIONS

Latent and overt PolyA are common in patients with AITD. These results provide insightful information for early diagnosis and management of concurrent ADs in patients with AITD. Aggregation of ADs in different clusters may help to define different phenotypes associated with thyroid autoimmunity that are critically relevant in clinical settings.

See-Saw Relationship and its Reversal after Immunotherapy in a Case of Graves' Disease with Coexisting Myasthenia Gravis

The unique association of myasthenia gravis (MG) with Graves’ disease in clinical practice emphasizes that one autoimmune disease can coexist with another or many. The relationship between these two entities has remained controversial till date. Some authors have reported a see-saw relationship between these two entities, MG waning with hyperthyroidism and waxing with treatment of hyperthyroidism. Treatment of both these disorders concurrently may be challenging at times as treatment for one entity may worsen the other. The use of beta-blockers and steroids for Graves’ disease may worsen myasthenic weakness. Antithyroid drugs can worsen myasthenia probably by immunomodulatory effects. We report a case of Graves’ disease coexisting with MG in a reciprocal relationship which was subsequently reversed after immunotherapy.

Hickam's dictum: Myasthenia Gravis presenting concurrently with Graves' disease

We present two patients with Graves' disease and concurrent myasthenia gravis. The impact of the dual diagnosis on the clinical course and the potential for a delayed diagnosis of myasthenia gravis is discussed. Patient 1, a 28-year-old man was diagnosed with Graves' disease following his second respiratory arrest. His history was strongly suggestive of a second pathology. Patient 2, a 66-year-old Cantonese woman with established Graves' disease presented with thionamide-related neutropaenia. Examination revealed bilateral ptosis and right lateral rectus palsy. Both patients had thyrotoxicosis secondary to Graves' disease with concurrent myasthenia gravis. Although neuromuscular weakness is common in Graves' disease, coexisting myasthenia gravis (MG) is rare and can cause profound morbidity. Ocular signs in both diseases may cause diagnostic confusion although ptosis suggests coexisting MG. In both cases, the thyrotoxicosis delayed the diagnosis of MG.

Diagnostic value of repeated ice tests in the evaluation of ptosis in myasthenia gravis

Twenty-six patients with ptosis related to Myasthenia gravis (MG) and 38 controls with ptosis other than MG were included. All patients were tested with the ice test 2 times on separate days in the afternoon. The margin reflex distance (MRD) was measured before and immediately after 2-minute application of ice on the eyelids. The ice test was judged positive if there was an improvement of at least 2.0 mm of MRD after the ice test. Among the patients with negative test results, 'equivocal' was defined by improvement of MRD from at least 1.0 mm to less than 2.0 mm after the ice test. Repeated ice test results showed an agreement of 61.5% in MG, and 97.4% in nonmyasthenic ptosis. Repeated ice tests increased the sensitivity by 34.6% compared to a single test. Among the patients with repeatedly negative test results, 63.6% of those who showed equivocal results at least once turned out to be MG. Of those with repeated non-equivocal negative results, nobody turned out to be MG. There was no significant difference of the ice test results between ocular MG and generalized MG (p = 0.562).

Sensorimotor Characteristics of Neuro-Ophthalmology and Oculo-Plastics Patients

BACKGROUND AND PURPOSE

Certified orthoptists are routinely required, as a standard component of outpatient care, to examine and identify the cause of double vision described by neuro-ophthalmology and oculo-plastics patients. Peer-reviewed articles in the strabismus literature describing the significance of this role of the orthoptists, especially in more complex cases of strabismus, do exist, but are outdated. The importance of creating a differential diagnosis in the understanding of the disease process is a well-recognized component of medical education and modern medicine.

PATIENTS AND METHOD

This work was a retrospective chart review and descriptive study of the most common clinical characteristics of adult neuro-ophthalmology and oculo-plastics patients seen over a 9-year period by an orthoptist in a large, urban academic institution in the United States. History and clinical data obtained included demographic information; whether the subjects were neuro-ophthalmology or oculo-plastic patients or both; chief complaint; past medical history and associated medical risk factors; past ocular history of strabismus or amblyopia; whether reported diplopia was monocular or binocular; visual acuities; sensorimotor examination and fusion status information; presence or absence of ptosis; pupil size and reactivity; basic accommodative function; orthoptist and physician diagnoses; and suggested treatment of diplopia.

RESULTS

Five hundred seventy-five subjects were identified based on inclusion criteria. Racial demographics matched that of the state of Maryland, with the majority of the patients being Caucasian. The minority were of Hispanic origin. Ninety-one percent of the study cohort was referred by the department of neuro-ophthalmology at the institution. Hypertension was a statistically significant medical risk factor for acquired strabismus and diplopia in this adult cohort. Etiology for the strabismus and associated diplopia suggested by the orthoptist was in close agreement with the final diagnosis made by the referring physician. Pupil-sparing oculomotor palsy (third cranial nerve, CN3) occurred as frequently as pupil-involving CN3, with tumor occurring more frequently as an etiology than aneurysm in both groups. Trochlear nerve palsy (CN4) was more often associated with hydrocephalus than abducens nerve palsy (CN6), and trauma remained a common association with acquired CN4 palsy. In patients with thyroid eye disease (TED), eso- and exo-deviations occurred with similar frequency. As has been reported in the literature, concomitant myasthenia gravis (MG) remained rare in these patients, although occurring with similar frequency in patients with both types of horizontal deviation. In patients with ptosis, asymmetry was not statistically more predictive of MG than symmetry. Prism was used most frequently, followed by surgery, to address diplopia symptoms. Lastly, there was a statistically significant association of acquired strabismus and diplopia in female subjects with breast cancer and no past ocular history of childhood strabismus or amblyopia.

CONCLUSION

The thorough assessment of sensorimotor function, fusion, and visual acuity provided by the orthoptist is an important clinical adjunct in developing the differential required to make an accurate final diagnosis, which sometimes may not subscribe to accepted clinical norms reported in the literature. The orthoptist also plays an important role in the nonsurgical treatment of acquired diplopia due to strabismus. Fresnel Press-On™ or ground-in spectacle prism was a commonly used treatment for diplopia.

Clinical features of myasthenia gravis patients with autoimmune thyroid disease in Taiwan

OBJECTIVES

The aim of this study was to analyze the prevalence and clinical features of myasthenia gravis (MG) patients with and without autoimmune thyroid disease (ATD).

MATERIALS AND METHODS

Between 1999 and 2009, we reviewed a total of 1482 patients with MG. On the basis of thyroid evaluations, as well as neurological, clinical, and serological findings, the patients were divided into group A (MG patients with ATD) or group B (MG patients without ATD). The patients were categorized as having ocular myasthenia when symptoms restricted to the ocular system were present for 2 years or more.

RESULTS

Of the 1482 MG patients, 121 (8.2%) patients were classified into group A. Graves' disease was more predominant (5.7%) than Hashimoto's thyroiditis (1.1%) and antibody-positive thyroid disease (1.4%). MG patients with ATD were predominantly female, were younger at the onset of MG symptoms, had a higher frequency of mild MG (ocular and mild generalized MG) and thymic hyperplasia, and had lower levels of seropositive anti-acetylcholine receptor antibodies. Compared to patients without thyroid eye disease, ATD patients with thyroid eye disease had a higher frequency of ocular MG.

CONCLUSIONS

This is the largest review of the clinical features of MG patients with and without ATD to date. We found that compared to ocular MG, mild MG is more commonly associated with ATD. Furthermore, we observed that thymic hyperplasia is more common in MG patients with ATD, while thymoma is more common in MG patients without ATD.

Double motion of upper eyelids in Graves' orbitopathy: an additional sign for detection of thyroid dysfunction or positive thyroid autoantibodies

Purpose:

To assess the effectiveness of the upper eyelid double motion sign in Graves’ orbitopathy (GO) in detecting thyroid dysfunction or a positive level of thyroid-related autoantibodies.

Methods:

GO was defined when more than two GO-related eyelid symptoms, including the double motion sign, existed with at least one positive thyroid-related blood test. Blood tests were performed in patients with more than two GO-related eyelid symptoms. The double motion was defined when the upper eyelid stopped at least once during downward eye movement. Fifty patients without GO or other eyelid diseases were used as controls.

Results:

There were 353 patients who showed more than two GO-related eyelid symptoms including the upper eyelid double motion sign. Of these, 300 patients were diagnosed with GO (300/353, 85.0%). The double motion sign was demonstrated in 267 patients (75.6%). A pause in double motion was typically seen around the anterosuperior direction of gaze. Double motion was not seen in any of the control eyelids. Although only 7.0% were hyperthyroid and 8.6% were hypothyroid, thyroid related autoantibodies were shown in 73.9% of patients. When the double motion sign was removed from the diagnostic criteria of GO, 263 patients had more than two thyroid-related eyelid symptoms, including 223 patients diagnosed as GO (25.7% reduction), although the rate of a correct diagnosis was almost the same (84.8%).

Conclusions:

The double motion sign of the upper eyelids is frequently demonstrated in GO patients. This previously unreported sign can help in detecting thyroid dysfunction states with positive levels of autoantibodies.

Concurrent Graves disease thyrotoxicosis and myasthenia gravis: the treatment of the former may dangerously reveal the latter

Autoimmune thyroxicosis and myasthenia gravis are often associated. In both diseases, clinical features may include neuromuscular weakness, making their distinction challenging. We report a patient with known Graves disease who presented with generalised fatigue, initially attributed solely to thyrotoxicosis, and who experienced severe respiratory failure linked to associated myasthenia gravis that was unmasked by medication used in the perioperative management of his thyroxicosis. Anaesthetists should always consider myasthenia gravis in cases of hyperthyroidism presenting with neuromuscular features.

Clinical features of patients with myasthenia gravis associated with autoimmune diseases

We investigated the incidence and clinical features of patients with myasthenia gravis (MG) associated with autoimmune diseases. Associated autoimmune diseases were found in 28 of 142 consecutive Japanese MG patients (19.7%), amongst which Graves' disease (7.7%) and Hashimoto's thyroiditis (4.2%) were predominant. The clinical features of MG patients with Graves' disease were different from those of MG patients without autoimmune diseases in terms of age at onset of MG symptoms (35.5 +/- 4.0 years and 49.0 +/- 1.7 years; P < 0.05), positivity for the anti-acetylcholine receptor antibody (44.4% and 89.8%; P < 0.05), and association with thymic hyperplasia (72.7 and 17.9%; P < 0.05). The therapeutic outcome of MG patients with Graves' disease and that of those without autoimmune diseases were not significantly different. Further studies should be performed to investigate whether MG associated with Graves' disease is a distinct subtype of MG.

Double vision in a patient with thyroid disease: what's the big deal?

A 70-year-old woman with a 46-year history of Graves disease had significant thyroid related orbitopathy (TRO) requiring previous bilateral orbital decompressions and one previous strabismus procedure for an exotropia of 60 PD. At the initial neuro-ophthalmology assessment, she had an exotropia of 20 PD and was scheduled for further surgery, but at the time of a second assessment a few weeks later, her strabismus had markedly changed. Accordingly, the patient underwent a neostigmine bromide test that demonstrated evidence of co-existing myasthenia gravis.

A patient with Graves' disease, myasthenia gravis, and polymyositis

Graves' disease (GD), myasthenia gravis (MG), and polymyositis (PM) are organ-specific autoimmune diseases. The association between GD and MG is well known, and an association between MG and PM has been reported. However, only one patient with all three diseases has been reported. We describe a patient with GD and PM developing 6 and 29 years, respectively after the onset of MG. This case suggests that the expression of autoimmunity occurred over a prolonged period of time and these organ-specific autoimmune diseases may be induced by a similar mechanism.

Schwannomatosis: a clinical and pathologic study

Schwannomas are benign nerve sheath tumors that most commonly occur singularly in otherwise normal individuals. Multiple schwannomas in a single patient are most often seen in neurofibromatosis 2 (NF2), but several recent reports suggest that schwannomatosis may also be a distinct clinical entity. We studied the clinical, radiographic, and pathologic features of 14 patients with multiple schwannomas who did not have vestibular schwannoma diagnostic of NF2. Most patients had peripheral nerve tumors that presented with pain. Many also had spinal nerve root and cranial nerve tumors. Three had multiple tumors limited to a single limb. We found that these 14 individuals did not exhibit phenotypic overlap with the neurofibromatoses. Only 1 of 14 patients had a positive family history. We conclude that patients with multiple schwannomas, who do not have vestibular schwannoma, comprise a distinct clinical problem, but further molecular genetic analysis is needed to define the pathophysiology of this disorder.

Antibodies to acetylcholinesterase cross-reacting with thyroglobulin in myasthenia gravis and Graves's disease

In the present study we analysed by ELISA the ability of sera from 50 patients with myasthenia gravis (MG), 20 with Hashimoto's thyroiditis (HT), 53 with Graves' disease (GD) and 36 healthy controls (CR) to react with acetylcholinesterase (AChE) from Electrophorus electricus and human thyroglobulin (Tg). Significantly increased anti-AChE activity was exhibited by a high proportion of MG (IgG 36%) and GD (IgG 21%) sera, while increased anti-Tg activity was detected in all three patient groups (MG, IgG 26% and IgA 26%; HT, IgG 85% and IgA 40%; and GD, IgG 51%). Interestingly, a significant proportion of MG and GD sera exhibited both IgG anti-AChE and anti-Tg activities (MG, 18%; P < 0.001; and GD, 15%; P < 0.001, versus CR, 0%). This bi-reactivity was exhibited by anti-AChE antibodies cross-reacting with Tg (anti-AChE/Tg activity); (i) serum anti-AChE activity was effectively inhibited by soluble Tg, and (ii) affinity-purified anti-Tg antibodies cross-reacted with AChE. Cross-reactivity seems to be a property of pathological (auto)antibodies; induced (rabbit) antibodies to AChE or Tg were highly monospecific. Analysis of clinical data showed that increased IgG anti-AChE/Tg activity was well associated with: (i) overlapping GD in MG (P < 0.02), and (ii) ophthalmopathy in GD (P < 0.01). In contrast, no correlation was noted in MG between anti-AChE activity units and anti-Tg activity units or acetylcholine receptor antibody titres. The clinical significance of anti-AChE/Tg antibodies remains to be elucidated.

Myasthenia gravis with thymoma associated with occult thyroid carcinoma

We report herein a case of myasthenia gravis associated with thymoma and occult thyroid carcinoma with metastasis to a cervical lymph node, which was treated in two stages by a total thymectomy and radical dissection of the bilateral neck after a total thyroidectomy. A 48 year old woman was admitted with right blepharoptosis and hypodynamia of the proximal muscles. After various examinations, a diagnosis of myasthenia gravis was made. The association of thymoma was clarified upon CT scanning and a total thymectomy performed. However, after surgery, swelling of the cervical lymph nodes became apparent and a biopsy revealed metastasis of thyroid carcinoma in the lymph nodes. A diagnosis of occult thyroid carcinoma with metastasis to a cervical lymph node was subsequently made and a total thyroidectomy and radical dissection of the bilateral neck performed 37 days after the total thymectomy. The patient's postoperative course was uneventful and for the time being, no recurrence is expected. It is considered better to perform two-stage operations for easier and safer postoperative management when myasthenia gravis associated with occult thyroid carcinoma is treated, although it depends on the development of thyroid carcinoma being occult.