Diagnosis Of Ocular Myasthenia Gravis Research Articles

Diplopia in a patient presenting with “blurred vision”: a case report

BackgroundMyasthenia gravis is an autoimmune condition affecting the neuromuscular junction and causing muscle weakness along with fatigue (myasthenia). When the clinical manifestations of myasthenia gravis are isolated to the eye muscles, only causing weak eye movements, it is referred to as ocular myasthenia gravis, which can mimic a 1 and ½ syndrome.Case presentationAn African-American female in her fifties with past medical history of hypertension presented to our outpatient clinic with complaints of blurred vision for two weeks. Her symptoms were associated with facial discomfort and a generalized headache. On physical examination upon her initial presentation, there was demonstratable swelling of the left upper eyelid with drooping. Her extraocular movements revealed defects with the abduction and adduction of the right eye, and the left eye would not adduct, although the outward movement was normal. The left eye failed to lift/elevate completely when looking upwards, a pseudo 1 and ½ syndrome. A positive Cogan lid twitch was also noticed. Imaging of the brain and orbit ruled out central causes. Diagnosis of ocular myasthenia gravis was made in accordance with positive anti-acetylcholine receptor antibodies. With 120 mg pyridostigmine oral dose, the patient experienced improvement subjectively and objectively, and the patient was discharged on oral pyridostigmine and prednisone. Six months later, with prednisone having been tapered off, the patient developed a myasthenic crisis and was treated with plasmapheresis and intravenous immunoglobulins. After recovering from the myasthenic crisis, efgartigimod infusions were instituted, which helped our patient restore normal life.ConclusionOur patient who presented with “blurred vision” was discovered to have binocular diplopia due to significant dysconjugate eye movements. After diligently ruling out central etiologies, we concluded that her presentation was due to a peripheral etiology. Her serologies and her presentation helped confirm a diagnosis of ocular myasthenia gravis. Also, as in most cases, our patient also progressed to develop generalized myasthenia gravis while on pyridostigmine. Efgartigimod infusions instituted after our patient recovered from a myasthenic crisis have helped her restore a normal life.

Manifestation of Ocular Myasthenia Gravis as an Initial Symptom of Coronavirus Disease 2019: A Case Report.

For a while, coronavirus disease-2019 (COVID-19) has been a major global pandemic. It primarily affects the respiratory system but has extrapulmonary manifestations such as gastrointestinal and neurological symptoms. Data on myasthenia gravis (MG), as a complication of COVID-19, are limited. We herein report the manifestation of ocular MG as an initial symptom of COVID-19.In November 2020, a 31-year-old healthy woman was referred to Firoozgar Hospital (Tehran, Iran) with left upper eyelid ptosis and diplopia as well as general weakness, myalgia, fever, and nasal congestion for four days prior to admission. Although the acetylcholine receptor antibody in her serum was negative, increased jitter in several muscles led to the diagnosis of ocular MG. Nasal swab reverse transcription-polymerase chain reaction (RT-PCR) assay tested positive for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. Computed tomography (CT) scan of the chest revealed bilateral ground-glass opacities and some foci of consolidation formation, but the thymus was normal. The patient was successfully treated with remdesivir and dexamethasone. The patient was eventually discharged in good condition and with improved neurological symptoms.A limited number of studies have suggested a possible association between MG and COVID-19. Therefore, further data are required to substantiate the proposed association. Clinicians should be aware of ocular MG during the COVID-19 pandemic to better diagnose and manage patients with SARS-CoV-2 infection.

A computer-aided system for ocular myasthenia gravis diagnosis

The current mode of clinical aided diagnosis of Ocular Myasthenia Gravis (OMG) is time-consuming and laborious, and it lacks quantitative standards. An aided diagnostic system for OMG is proposed to solve this problem. The values calculated by the system include three clinical indicators: eyelid distance, sclera distance, and palpebra superior fatigability test time. For the first two indicators, the semantic segmentation method was used to extract the pathological features of the patient's eye image and a semantic segmentation model was constructed. The patient eye image was divided into three regions: iris, sclera, and background. The indicators were calculated based on the position of the pixels in the segmentation mask. For the last indicator, a calculation method based on the Eyelid Aspect Ratio (EAR) is proposed; this method can better reflect the change of eyelid distance overtime. The system was evaluated based on the collected patient data. The results show that the segmentation model achieves a mean Intersection-Over-Union (mIoU) value of 86.05%. The paired-sample T-test was used to compare the results obtained by the system and doctors, and the p values were all greater than 0.05. Thus, the system can reduce the cost of clinical diagnosis and has high application value.

Ocular myasthenia gravis — clinical diagnosis and treatment

The ocular myasthenia gravis has a variable clinical presentation and imitates many diseases with ocular region damaged. The diagnosis of ocular myasthenia gravis is complicated due to low sensitivity of the diagnostic approaches. The article introduces the features of the examination of patients with the ocular myasthenia gravis. The article describes the study methodology and interpretation of Simpson, Gorelick, Cogan`s lid twitch sign, rest and sleep tests, ice test. The article considered features of the treatment of the disease in order to achieve remission and prevent the generalization of the process. Timely diagnosis and optimal choice of treatment strategy can significantly change the quality of patients life and influence the subsequent prognosis of the disease.

Reader Response: Comparison of Ice Pack Test and Single-Fiber EMG Diagnostic Accuracy in Patients Referred for Myasthenic Ptosis.

Giannoccaro et al.1 reported their findings on the sensitivity and specificity of the ice pack test and single-fiber electromyography (SF-EMG) in the diagnosis of ocular myasthenia gravis. It is interesting—and perhaps humbling—that such a straightforward test as cooling muscle with ice has very similar diagnostic accuracy compared with a technically complex and sophisticated test as SF-EMG in patients presenting with eyelid ptosis. These findings are largely in line with previous research evaluating the positive and negative predictive values of the ice pack test in ocular myasthenia gravis.2-5

Repetitive ocular vestibular evoked myogenic potential stimulation for the diagnosis of myasthenia gravis: Optimization of stimulation parameters

ObjectiveTo determine the most effective stimulation parameters for the diagnosis of ocular myasthenia gravis (MG) using repetitive ocular vestibular evoked myogenic potentials (oVEMP) for quantification of the extraocular muscle response decrement. MethodsRepetitive bone-conducted oVEMPs were elicited in 18 MG patients and 20 healthy subjects. We compared four different stimulus repetition rates (20 Hz, 30 Hz, 40 Hz, 50 Hz) and 100 Hz continuous stimulation, as well as recordings from the inferior oblique muscles and the lateral rectus muscles to determine the most sensitive and specific oVEMP parameters for decrement detection. ResultsRepetitive stimulation at all tested repetition rates with recordings from inferior oblique muscles allowed for effective differentiation between MG patients and healthy subjects. Among all repetition rates, 30 Hz showed a trend towards superiority, with a sensitivity of 71% and a specificity of 94% (area under the curve (AUC) 0.88) when using the smaller decrement of the two eyes and −10% as cutoff. Considering the larger decrement for analysis (−9% as cutoff), sensitivity increased to 82%, but specificity decreased to 78% (AUC 0.81). ConclusionsOur study demonstrates, that repetitive oVEMP stimulation elicits a robust decrement in the inferior oblique muscles of MG patients at repetition rates between 20 Hz and 50 Hz, with a probable optimum at 30 Hz. SignificanceRepetitive inferior oblique oVEMP stimulation with optimal stimulus parameters facilitates early and accurate diagnosis of ocular MG.

Ocular myasthenia gravis: an update on diagnosis and treatment.

Myasthenia gravis is an autoimmune disease that commonly affects the palpebral and extraocular muscles. Ocular myasthenia gravis (OMG) is a variant of the disease that is confined to the ocular muscles but frequently becomes generalized over time. The diagnosis of OMG is often challenging but both clinical and laboratory findings are helpful in confirming the clinical suspicion. This review provides an update on the diagnostic approach and therapeutic options for OMG. Antimuscle-specific tyrosine kinase and LDL-related receptor-related protein 4 are newly available serologic testing for myasthenia gravis that can help in increasing the diagnostic sensitivity of OMG. They should be included to the diagnostic algorithm of OMG in appropriate clinical situations. OMG remains a primarily clinical diagnosis, but recent advances in laboratory testing can improve the diagnostic accuracy and should be used in appropriate clinical settings. The mainstay of treatment for OMG has not significantly changed over the past years, but the increasing availability of steroid-sparing agents improved the disease control while minimizing steroid-induced complications.

Concentric or monopolar electrode for jitter determination in orbicularis oculi

ObjectivesTo investigate if monopolar (MN) and concentric (CN) electrodes are equivalent for volitional contraction jitter estimation in orbicularis oculi (OO), and to study the effect of selecting a specific high-pass filter. MethodsWe studied neuromuscular jitter in OO on both sides in 100 consecutive patients with a clinical diagnosis of ocular myasthenia gravis (MG). We used either MN (50 patients) or CN (50 patients) electrodes in individual patients, according to a randomised protocol, with a 1kH high pass filter on one side and a 3kH filter on the other. Ten or more potential pairs were studied on each side. Results48 patients had a definite clinical diagnosis of ocular MG, and 52 of mimicking-disorders, who were analysed as controls. In controls, jitter (MCD) showed a normal distribution independent of the electrode type or filter settings. The mean jitter value and the number of abnormal pairs (>10%) was similar in MN and CN recordings, with both 1 kHz and 3 kHz filters. Sensitivity was 73% for mean jitter and 94% for number of abnormal pairs. Specificity was 100%. ConclusionsThe jitter in OO using MN or CN was similar in controls and the diagnostic sensitivity was similar using either electrode in patients with ocular MG. The use of high-pass filters of 1 or 3 kHz did not influence these results. SignificanceMN and CN are both suitable for determining volitional jitter in OO.

A TYPICAL CASE OF CHILDHOOD OCULAR MYASTHENIA GRAVIS: A LITERATURE REVIEW FROM OPHTHALMOLOGY PERSPECTIVE

ABSTRACT Background: Childhood ocular myasthenia gravis (MG) is a rare autoimmune disease that has a benign course and provide a good overall prognosis. Diagnosis of ocular MG especially in children is often difficult especially in younger age group as the symptoms may be subtle and may mimic other pathology. There are many articles discussing MG in general, but only a handful elaborating on childhood ocular MG. This article is discussing a typical case of childhood MG and a review of current clinical approach particularly from ophthalmology point of view. Case Report: A one-year-old Malay girl who was previously well, presented with 2 weeks history of left eye ptosis and intermittent exotropia following a brief episode of fever. A provisional diagnosis of ocular MG was made. Unfortunately, the patient defaulted pediatric neurology follow up for confirmatory investigations. She came back 2 years later with bilateral ptosis. Upon her second presentation, blood investigation for acetylcholine receptor antibody showed positive result and finally she was diagnosed to have ocular MG. She was co-managed with a pediatric neurologist and was treated with oral pyridostigmine. Satisfactory improvement of ptosis was achieved with no amblyopia. There was no features of systemic MG during 2 years follow up. Conclusion: Although this is a typical presentation of childhood ocular MG, there are many interesting and useful learning points particularly from an ophthalmology point of view.

Diagnostic value of low-frequency repetitive nerve stimulation in patients with ocular myasthenia gravis

Objective To investigate the diagnostic value of low-frequency repetitive nerve stimulation(RNS) in patients with ocular myasthenia gravis(MG). Methods The clinical data of the low-frequency RNS of 54 in-patients with ocular MG were analyzed. Results The positive rate of low-frequency RNS was 53.7% in 54 patients.The abnormal rate of the facial nerve and the proximal limb nerve was significantly higher than that of low limb distal nerve.The differences were statistically significant(χ2=6.783, P=0.009; χ2=4.167, P=0.041). In all the examined nerves, the abnormal rate of right facial nerve was the highest(46.3%), and the lowest on the ulnar nerve(11.1%). The abnormal rate was statistically significant in all these nerves(χ2=21.995, P=0.001). Conclusion Low-frequency RNS plays an important role in the diagnosis of ocular MG, and the facial nerve should be the first choice in this examination. Key words: Ocular myasthenia gravis; Low-frequency repetitive nerve stimulation

Positive ice test in a patient with a lymphomatous infiltration of the levator palpebrae superioris

The ice test is known to be specific for the diagnosis of ocular myasthenia gravis in patients with ptosis, with reported specificities of 97%-100%. We report a patient with diffuse large B-cell lymphoma who showed a positive result to the ice test. A 53-year-old woman presented with left eyelid ptosis of 3weeks' duration. She had finished chemotherapy and radiotherapy for diffuse large B-cell lymphoma a year previously. On ophthalmological examination, her best-corrected visual acuity was 20/20 in each eye. Marginal reflex distances were +4 in the right eye and -1 in the left eye. Levator palpebrae superioris functions were 11mm in the right eye and 8mm in the left eye. Ptosis improved after 5minutes' application of ice to both eyelids, after which marginal reflex distances were +4 in the right eye and +1 in the left eye. Thyroid function tests, anti-acetylcholine receptor antibody test, and the repetitive nerve stimulation test were all negative. Magnetic resonance imaging showed fusiform masslike enlargement of the left superior rectus muscle and left levator palpebrae superioris muscles, with enhancement suggesting metastatic infiltration.

Necessary number of records for the diagnosis of ocular myasthenia gravis during single fiber electromyography

Background: Single fiber electromyography (SFEMG) is the most sensitive diagnostic tool for diagnosis of myasthenia gravis.

Validity of Forced Eyelid Closure Test: A Novel Clinical Screening Test for Ocular Myasthenia Gravis

Forced eyelid closure test (FECT) is a clinical screening test developed from the original Cogan lid twitch (CLT) sign to assist in the diagnosis of ocular myasthenia gravis (OMG), We evaluated the sensitivity and specificity of FECT compared with CLT and benchmarked to standard diagnostic tests. This study was a retrospective chart review of 48 patients using electronic medical records of those that presented with ptosis and/or diplopia at Doheny Eye Institute, University of California, Los Angeles between February 2015 and April 2016. Patients without FECT testing were excluded. FECT and CLT results, and final diagnosis were recorded. To perform FECT, the patient was asked to squeeze his or her eyelids shut for 5-10 seconds then open quickly and fixate in primary position. The excessive upward overshoot of eyelids movement indicated a positive FECT. The test was performed by a neuro-ophthalmologist before establishing the diagnosis. Patients who had equivocal test results and/or inconclusive final diagnosis were excluded. Of the 48 patients studied, 18 patients (37.5%) had positive FECT; 15 of whom had a final diagnosis of OMG (83.3%). Of the 30 patients with negative FECT, 1 had OMG (3.3%). Of the 48 patients, 35 patients also had a documented CLT result (72.9%). CLT was positive in 11 of these 35 patients (31.4%), and 9 of these 11 had OMG (81.8%). Of the 24 patients with negative CLT, 2 of them had OMG (8.3%). Sensitivity and specificity of FECT were 94% and 91% (joint 95% confidence region: sensitivity × specificity = [0.70, 1] × [0.75, 1]). The relative true-positive fraction (rTPF) between FECT and CLT was 1.15; the relative false-positive fraction was 1.31. FECT is a simple clinical screening test with good sensitivity and specificity for OMG.

Comparative study on the value of accessory examinations in the diagnosis of ocular myasthenia gravis

Objective To compare the sensitivity and specificity of ice test, neostigmine test and single fiber electromyography (SFEMG) in the diagnosis of ocular myasthenia gravis (OMG), so as to establish an appropriate process for the diagnosis of OMG. Methods A total of 116 patients with newly onset ptosis and/or diplopia were detected by ice test, neostigmine test and SFEMG. Patients were followed up for 6 months to observe the disease changes and experimental treatment effects. Results Apart from patients whose diagnosis was in doubt or lost to follow - up, and who were diagnosed as generalized myasthenia gravis (GMG), the definite diagnosis was finally made in 81 patients, including 21 OMG patients and 60 patients with ptosis and/or diplopia caused by other diseases. The sensitivity of ice test for diagnosis of OMG was 95.24% (20/21), and specificity was 98.33%(59/60). The sensitivity of neostigmine test for diagnosis of OMG was 90.48% (19/21), and specificity was 85% (51/60). The sensitivity of SFEMG for diagnosis of OMG was 95.24% (20/21), and specificity was 80% (48/60). Among 3 tests, only specificity was found significant difference ( χ 2 = 5.232, P = 0.022). The specificity of ice test was better than that of neostigmine test ( χ 2 = 5.707, P = 0.017) and SFEMG ( χ 2 = 6.023, P = 0.014). Conclusions The ice test achieved high sensitivity and specificity in the diagnosis of OMG. The combination of ice test, neostigmine test and SFEMG may have important clinical value for the early diagnosis of OMG. DOI: 10.3969/j.issn.1672-6731.2016.10.008

Sensitivity of Acetylcholine Receptor Antibody in the Diagnosis of Ocular Myasthenia Gravis

Acetylcholine receptor (AChR) binding antibodies are present in approximately 80% of patients with generalized myasthenia gravis (MG), but in only 55%

Retroperitoneal teratoma causing ptosis: A case report.

The present study reports the case of a patient who had undergone unsuccessful hormone therapy for ocular myasthenia gravis 14-years prior to the current presentation. The diagnosis of ocular myasthenia gravis was once again confirmed by a neostigmine test and repeat nerve stimulation study. Computed tomography scans in an external institution revealed a retroperitoneal cystic tumor with calcification above the left adrenal gland. The tumor was removed via a transperitoneal laparoscopic resection and was diagnosed as a mature cystic teratoma upon pathological examination. A teratoma is a common form of germ cell tumor, but primary teratomas of the retroperitoneum are quite rare in the adult population. Post-operative observation of the patient showed resolution of the ptosis and improved movement of the eyeballs. The potential mechanism was unclear, but the patient's teratoma was mature and may have contained myoid cells with antigenicity for anti-acetylcholine receptor (anti-AchR), as has been established in the thymus. Therefore, the anti-AchR antibody may have been involved.

Ice-on-Eyes Test in the Diagnosis of Myasthenia Gravis

Myasthenia gravis is the most frequent autoimmune neuromuscular transmission disorder with incidence of 2-20 patients per million. Its pathophysiology is autoimmune, with acetylcholine receptor auto antibodies damaging the post-synaptic fold at the muscle membrane. The diagnostic confirmation of myasthenia gravis is often challenging. Ice-oneyes test can be used to diagnose this disease for its simplicity, safety and cost-effectiveness. Here we report a case of myasthenia gravis in Enam Medical College Hospital, Savar, Dhaka where ice-on-eyes test was done with improvement of ptosis of the patient. Aim of this case report is to make aware our physicians to apply this simple bed side test instead of common traditional edrophonium (tensilon test) test for confirmation of the diagnosis of ocular myasthenia gravis. DOI: http://dx.doi.org/10.3329/jemc.v2i2.12845 J Enam Med Col 2012; 2(2): 92-93

Miller Fisher Syndrome Mimicking Ocular Myasthenia Gravis

PURPOSE.: Miller Fisher syndrome (MFS) is a rare immune-mediated neuropathy that commonly presents with diplopia after the acute onset of complete bilateral external ophthalmoplegia. Ophthalmoplegia is often accompanied by other neurological deficits such as ataxia and areflexia that characterize MFS. Although MFS is a clinical diagnosis, serological confirmation is possible by identifying the anti-GQ1b antibody found in most of the affected patients. We report a patient with MFS who presented with clinical signs suggestive of ocular myasthenia gravis but in whom the correct diagnosis was made on the basis of serological testing for the anti-GQ1b antibody. CASE REPORT.: An 81-year-old white man presented with an acute onset of diplopia after a mild gastrointestinal illness. Clinical examination revealed complete bilateral external ophthalmoplegia and left-sided ptosis. He developed more marked bilateral ptosis, left greater than right, with prolonged attempted upgaze. He was also noted to have a Cogan lid twitch. Same day evaluation by a neuro-ophthalmologist revealed mild left-sided facial and bilateral orbicularis oculi weakness. He had no limb ataxia but exhibited a slightly wide-based gait with difficulty walking heel-to-toe. A provisional diagnosis of ocular myasthenia gravis was made, and anticholinesterase inhibitor therapy was initiated. However, his symptoms did not improve, and serological testing was positive for the anti-GQ1b immunoglobulin G antibody, supporting a diagnosis of MFS. CONCLUSIONS.: Although the predominant ophthalmic feature of MFS is complete bilateral external ophthalmoplegia, it should be recognized that MFS has variable associations with lid and pupillary dysfunction. Such confounding neuro-ophthalmic features require a thorough history, neurological examination, neuroimaging, and serological testing for the anti-GQ1b antibody to arrive at a diagnosis of MFS.

Myasthenia gravis masquerading as acute sixth nerve paresis following head trauma – or vice versa? A case report

Aim: To report a case of sudden-onset diplopia, blurred vision and an inability of the left eye to fully abduct following trauma. Subsequent examinations showed significant variability leading to a possible diagnosis of myasthenia gravis. Methods: This is a case report of a 7-year-old boy with a 2-day history of blurred vision, horizontal diplopia and headaches following a bump to the left side of his head that presented as a left sixth nerve paresis. The history, orthoptic findings, investigations and possible aetiologies are discussed. Results: Orthoptic assessments initially revealed a marked left esotropia with restriction on left abduction. Computed tomography (CT) scans and magnetic resonance imaging (MRI) were both normal, as was monitoring of the patient’s intracranial pressures. Further orthoptic assessments demonstrated normal ocular movements on some visits whilst on other visits a restriction of left abduction was still shown. The patient then developed a vertical element with ptosis with significant variability at each visit, leading to a possible diagnosis of ocular myasthenia gravis. He was started on pyridostigmine and improvement was observed. However, low-affinity acetylcholine receptor antibodies, MuSK antibodies, Tensilon test and nerve fibre stimulation were negative and pyridostigmine was stopped. Conclusion: A question mark still hangs over the aetiology of this case. After a year of monitoring it was decided that the most suitable management for this patient was botulinum toxin. Following one injection the patient is currently straight and demonstrating stereopsis.

P34-21 Utility of various tests in diagnosis of ocular myasthenia gravis

P34-21 Utility of various tests in diagnosis of ocular myasthenia gravis