Diagnosis Of Myasthenia Gravis Research Articles

Mitochondrial dynamics and biogenesis indicators may serve as potential biomarkers for diagnosis of myasthenia gravis.

Due to challenges in diagnosing myasthenia gravis (MG), identifying novel diagnostic biomarkers for this disease is essential. Mitochondria are key organelles that regulate multiple physiological functions, such as energy production, cell proliferation and cell death. In the present study, Mfn1/2, Opa1, Drp1, Fis1, AMPK, PGC-1α, NRF-1 and TFAM were compared between patients with MG and healthy subjects to identify potential diagnostic biomarkers for MG. Blood samples were collected from 50 patients with MG and 50 healthy subjects. The participants' demographic information and routine blood test results were recorded. Mitochondrial dynamics were evaluated and levels of Mfn1/2, Opa1, Drp1, Fis1, AMPK, PGC-1α, NRF-1 and TFAM were determined in peripheral blood mononuclear cells using western blotting and reverse transcription-quantitative PCR, respectively. Receiver operating characteristic curve analysis was used to evaluate the diagnostic accuracy of these indicators. The areas under the curve values of Mfn1/2, Opa1, Drp1, Fis1,AMPK, PGC-1α, NRF-1 and TFAM were 0.5408-0.8696. Compared with control subjects, mRNA expression levels of Mfn1/2, Opa1, AMPK, PGC-1α, NRF-1 and TFAM were lower, while those of Drp1 and Fis1 were higher in patients with MG. The protein expression levels of all these molecules were lower in patients with MG than in control subjects. These results suggested that mitochondrial dynamics and biogenesis indicators may be diagnostic biomarkers for MG.

Is Video-Oculography a Predictive Test for Myasthenia Gravis with Ocular Symptoms?

The aim of this study was to evaluate the contribution of extraocular muscle function testing with video-oculography (VOG), which is a noninvasive and easily applicable method of recording eye movement with digital cameras, to the diagnosis of myasthenia gravis (MG) in patients without any clinical eye movement abnormalities. The study included 18 patients prediagnosed with ocular MG: MG Group (N = 7) with abnormal, and non-MG Group (N = 11) with normal single-fiber electromyography. Control group included 50 healthy volunteers. Ocular movements were recorded with the EyeSeeCam VOG device. The inward latency of the 10° horizontal saccade and the downward latency of the 10° vertical saccade were significantly delayed; and the downward amplitude of the 10° vertical saccade was significantly lower in the MG group. Receiver operating characteristic curve analyses showed high specificity values for the discrimination of MG patients. This study supports the usefulness of the VOG device in revealing subclinical extraocular muscle involvement in MG.

Low Fluctuation of Symptoms May Delay Diagnosis of Myasthenia Gravis: A Case Series.

IntroductionMyasthenia gravis is an autoimmune disorder affecting neuromuscular transmission, and its hallmark is fluctuating muscular weakness affecting the ocular, bulbar, respiratory, or limb muscles. Our objective is to highlight the difficulties encountered in diagnosing this disorder in patients lacking this characteristic phenomenon.MethodsThree cases of patients presenting with progressive weakness of bulbar and ocular muscles, in whom a lack of fluctuation delayed the diagnosis of myasthenia gravis, are described.ResultsAmyotrophic lateral sclerosis was considered in two of the patients, while cavernous sinus thrombosis was initially diagnosed in the third. Electrodiagnostic, pharmacologic, and serologic testing ultimately established the diagnosis of myasthenia gravis.ConclusionWhile the typical clinical pattern of myasthenia gravis is well known and easily recognizable, there are cases when the diagnosis, and thus the treatment, is delayed because of low or absent fluctuation of symptoms. The acknowledgment of this probably underestimated presentation is important for expeditious management.

LEMG Findings of Vocal Fold Paresis in Voice Patients Who Play or Played Wind Instruments

Voice patients who underwent laryngeal EMG for clinically suspected vocal fold paresis between 2019 and 2021 were included in the study. Subjects were divided into two groups depending on history of playing wind instruments. Only patients with insufficient information in their medical records were excluded. All data were reviewed retrospectively. Percentage of nerve recruitment, the recruitment rating scale used in previous studies, wind instrument played, gender, age, and laryngeal Myasthenia Gravis diagnosis were variables included in the descriptive statistics, correlational, and regression analyses used for statistical analysis. Data analysis indicated that in the 103 subjects included (47 wind instrumentalists and 56 non-wind instrumentalists) that wind instrument players, past and present, experience levels of greater decreased nerve recruitment that non-instrumentalist singers do when presenting with paresis. Kind of wind instrument played was statistically significant but moderately correlated to the RRS (Recruitment Rating Scale) of the left PCA. Sex was correlated moderately and statistically significantly with right CT recruitment. Playing wind instruments in voice patients diagnosed with paresis might be associated with increased severity of laryngeal nerve damage. Further research is needed to confirm or refute these findings.

Comparative Analysis of BIOCHIP Mosaic-Based Indirect Immunofluorescence with Enzyme-Linked Immunosorbent Assay for Diagnosing Myasthenia Gravis.

Background: The detection of anti-acetylcholine receptor (AChR) and anti-muscle-specific tyrosine kinase (MuSK) antibodies is useful in myasthenia gravis (MG) diagnosis and management. BIOCHIP mosaic-based indirect immunofluorescence is a novel analytical method, which employs the simultaneous detection of anti-AChR and anti-MuSK antibodies in a single miniature incubation field. In this study, we compare, for the first time, the BIOCHIP MG mosaic with conventional enzyme-linked immunosorbent assay (ELISA) in the diagnosis of MG. Methods: A total of 71 patients with MG diagnosis were included in the study. Anti-AChR and anti-MuSK antibodies were measured separately by two different ELISA and simultaneously by BIOCHIP. The results were then compared. Results: The overall concordance between ELISA and BIOCHIP for anti-AChR reactivity was 74%. Cohen’s kappa was 0.51 (95% CI 0.32–0.71), which corresponds to 90% of the maximum possible kappa (0.57), given the observed marginal frequencies. The overall concordance for anti-MuSK reactivity was 84%. Cohen’s kappa was 0.11 (95% CI 0.00–0.36), which corresponds to 41% of the maximum possible kappa (0.27). Conclusion: The overall concordance among assays is not optimal.

Outcomes of thymoma after multimodal therapy and determinants of survival: A 16-year experience of a tertiary cancer center.

Background In this study, we aimed to evaluate the factors that contribute to survival outcomes in patients with thymoma treated with multimodal approaches. Methods A total of 203 patients (105 males, 98 females; median age: 49 years; range, 17 to 77 years) with Masaoka-Koga Stage II-IV thymoma between January 2002 and December 2018 were retrospectively analyzed. Data including diagnosis of myasthenia gravis, diagnosis of diabetes mellitus, disease stage, histological type of tumor, capsule invasion and surgical margin status, lymphadenectomy, adjuvant radiotherapy or chemotherapy, time from surgery to the first day of adjuvant treatment, length of hospital stay, and overall and disease-free survival rates were recorded. Results Of the patients, 91 had Stage II, 67 had Stage III, and 45 had Stage IV disease. A total of 123 patients (61%) had myasthenia gravis. Seventy-six patients received adjuvant radiotherapy and 48 patients received either neoadjuvant (n=35) or adjuvant (n=25) chemotherapy. Higher disease stage, presence of R1 resection, and treatment with chemotherapy were significant factors for decreased disease-free survival time. Older age, higher disease stage, longer postoperative hospital stay, chemotherapy, and disease recurrence were effective contributors to decreased overall survival time. Adjuvant radiotherapy had a statistically significant positive effect on overall survival only in patients with completely resected Stage IV disease (five-year overall survival: 94.7% vs. 79.1%, respectively; p=0.015). In the multivariate analysis, older age (hazard ratio: 4.26), higher disease stage (hazard ratio: 2.95), and longer hospitalization time (hazard ratio: 3.81) were significant prognostic factors for overall survival. Patients with local recurrence who underwent complete resection had a survival time comparable to non-recurrent patients (p=0.753). Conclusion For patients with thymoma, higher disease stage, age ≥50 years, longer hospitalization, and need for chemotherapy are associated with worse survival rates. Adjuvant chemotherapy has a positive impact on Stage IV disease. Resection of recurrent lesions has a valuable impact on survival.

The importance of single-fiber electromyography in myasthenia gravis diagnosis and prognosis: A systematic review

Myasthenia gravis (MG) is a serious neuromuscular impairment in the communication between nerve cells and muscles. It causes weakness in skeletal muscles, hindering their movement and control. A single-fiber electromyography (SF-EMG) is the most sensitive test for diagnosing MG. The diagnosis is confirmed with an altered SF-EMG of a clinically weak muscle. We have systematically reviewed the current application of SF-EMG techniques in the diagnosis of myasthenia gravis.

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.

The prognostic value of diagnostic tools in patients with seropositive myasthenia gravis: a retrospective study of 31 cases

To confirm the diagnosis of myasthenia gravis (MG), in addition to clinical observation of the muscle weakness dynamics, pharmacological and functional tests, Computed tomography/Magnetic resonance imaging (CT/MRI) of the mediastinum, detection of antibodies to acetylcholine receptors (AChR) and to muscle specific tyrosine kinase (MuSK)/; electrophysiological tests are used: rhythmic nerve stimulation (RNS)/decrement test and electro­myography of a single muscle fiber (single-fiber EMG (SF-EMG)/jitter). The aim of our study is to determine the possible relationship between the level of antibodies to AChR and the decrement test value, to verify a correlation between SF-EMG and the severity of MG seropositive to AChR. To evaluate the effectiveness of pathogenetic treatment and prediction of the duration of remission according to the results of the study. A total of 31 patients with myasthenia gravis seropositive to AChR were examined, among whom there were 19 (61.3%) women aged 19 to 74 years. The pattern of muscle weakness was evaluated by a score of the International Clinical Classification of Severity of Myasthenia gravis scale (MGFA). The presence of respiratory failure and its degree was assessed by spirography. The number of antibodies to AChR was determined using enzyme-linked immunosorbent assay (ELISA). The criteria for inclusion in the study were the confirmed diagnosis of seropositive myasthenia gravis with an AChR antibody level of more than 0.5 nmol/L. All patients underwent electrophysiological studies. Patients were examined three times: 1) at the time of visiting the doctor (in the hospital or on an outpatient basis); 2) in 16 and 3) in 24 weeks from the start of the study. Depending on the clinical condition of the patients the following treatment was prescribed: pyridostigmine, methylprednisolone, azathioprine. Statistical analyses were performed using the statistical computing environment R (R Core Team). In the dynamics of observation, a decrease in the level of antibodies to AChR and an improvement in the condition of patients according to the MGFA classification were generally observed but no correlation was found between the severity of MG and the level of antibodies to AChR during the first visit (Kruskal-Wallis test: H (4, N=31)=2.23 p=0.69); during the second visit (Kruskal-Wallis test: H (5, N=31)=9.44 p=0.09), as well as during the third visit (Kruskal-Wallis test: H (2, N=30)=2.74 p=0.25). A correlation was found between the concentration of antibodies to AChR and a thymectomy in the clinical history (Kruskal-Wallistest: H (1, N=7)=3.153752 p=0.07): over time, the level of antibodies decreased. Decrement test deviations were detected in 23 (74.2%) of the 31 patients, SF-EMG – in 20 (95%) of 21 patients. Abnormal jitter was recorded in 100% of cases with a generalized form of myasthenia gravis. During all three visits, a correlation was determined between the highest decrement test of symptomatic muscle and MG severity according to MGFA (r=0.39; p=0.042), (r=0.35; p=0.048), (r=0.41; p=0.039); and also between the jitter value and MG severity (r=0.54; p=0.032) (r=0.35; p=0.048), (r=0.61; p=0.034 respectively). Analysis of the contingency tables using the exact Fisher test provided information on the best method of treating patients. We consider that the most effective prognostic test that may affect the choice of further treatment is SF-EMG. However, due to the difficulties of using this method in routine practice, rhythmic nerve stimulation (RNS) test in clinically weak muscles should be recommended. It is not recommended to monitor antibodies to AChR in order to predict the course of the disease, it is better to use this test only for the diagnosis of seropositive myasthenia gravis.

Revisiting two clinical techniques for diagnosing myasthenia gravis in Covid times: Pointing to semiology

As it has been evident in these times of the Covid-19 pandemic, the majority of health resources have been focused to the acute treatment, vaccination or research to this condition. By these reasons, some confirmatory complementary tests in many pathologies cannot be made or are postponed, including Myasthenia Gravis. Two clinical neurological signs useful for diagnosis of Myasthenia Gravis are revised: the “Curtain Sign” (also called paradoxical ptosis), that is evoked opening the more closed eye, which results in a dropping of the contralateral eyelid; and the Mary-Walker maneuver, which results from repetitive pronation-supination exercise under anaerobic conditions in one or both arms resulting in increasing of bilateral ptosis. The importance of a presumptive early diagnosis of Myasthenia Gravis is the early onset of specific treatment even when it’s impossible to carry out complementary studies like single-fiber electromyography, thoracic images, or specific immune studies. .

Myasthenia Gravis in Patients with Histopathologically Diagnosed Thymoma at Sanglah General Hospital: A Case Series

Introduction: Thymoma is a neoplasm of the thymus gland which arises from the epithelial tissue. Thymoma is frequently related to various paraneoplastic syndromes, most commonly myasthenia gravis. Up to 50% of patients with thymoma are reported to develop myasthenia gravis, whereas 10–15% of patients with myasthenia gravis are found to have thymoma. Case Presentation: This case series reported 3 patients with myasthenia gravis which co-occurred with thymoma at Sanglah General Hospital from 2018 to 2019. The patients’ ages range from 33 to 61 years (mean age 46 ± 11 years) with a 2:1 male-to-female ratio. The diagnosis of myasthenia gravis was made by the presentation of typical myasthenia gravis appearances, the fluctuating intensity of ocular and bulbar muscle weakness (all three cases), and limbs and axial muscle weakness (one case); no respiratory muscle involvement was found. Physical and supporting examinations including electroneuromyography results were coherent with myasthenia gravis. The diagnosis of thymoma was made by highly suggestive appearance in Thorax Multi Sliced Computed Tomography (MSCT) scan examination and histopathologic findings. MSCT scan examination showed a well-circumscribed ovoid solid mass in the mediastinum (left anterosuperior, superior, and anterior to middle right mediastinum) sized from 1.8x1.5x2.9 cm to 8.1x9.9x9.7 cm, enhanced with contrast injection with areas of calcification and central necrotic (1 case) and no dissemination to regional lymph node and neighboring organs. All cases received acetylcholinesterase inhibitors and underwent extended thymectomy. Histopathological examination showed accordance with thymoma features of subtype A, AB, and B1.Conclusions: Clinicians should be aware of the thymoma and myasthenia gravis co-existence possibility to ensure early recognition and appropriate management.

Bioengineered optogenetic model of human neuromuscular junction

Functional human tissues engineered from patient-specific induced pluripotent stem cells (hiPSCs) hold great promise for investigating the progression, mechanisms, and treatment of musculoskeletal diseases in a controlled and systematic manner. For example, bioengineered models of innervated human skeletal muscle could be used to identify novel therapeutic targets and treatments for patients with complex central and peripheral nervous system disorders. There is a need to develop standardized and objective quantitative methods for engineering and using these complex tissues, in order increase their robustness, reproducibility, and predictiveness across users. Here we describe a standardized method for engineering an isogenic, patient specific human neuromuscular junction (NMJ) that allows for automated quantification of NMJ function to diagnose disease using a small sample of blood serum and evaluate new therapeutic modalities. By combining tissue engineering, optogenetics, microfabrication, optoelectronics and video processing, we created a novel platform for the precise investigation of the development and degeneration of human NMJ. We demonstrate the utility of this platform for the detection and diagnosis of myasthenia gravis, an antibody-mediated autoimmune disease that disrupts the NMJ function.

A rare case of combined thymoma and a multilocular thymic cyst discovered due to chest pain

BackgroundA thymoma with chest pain and multilocular thymic cysts (MTCs) is very rare.Case presentationA 49-year-old man presented to another hospital complaining of an anterior chest pain. Chest computed tomography (CT) showed an anterior mediastinal tumor 60 × 30 × 55 mm in size. The boundary with the pericardium or left brachiocephalic vein seemed to be partially unclear while enhanced by the contrast medium, and so the tumor could have invaded them. No definitive diagnosis of myasthenia gravis was made although the serum anti-acetylcholine receptor antibody count was high. We performed an extended thymectomy with combined partial resection of left brachiocephalic vein, left upper lobe, and left phrenic nerve. He was discharged with no chest pain and no complications post-surgery. The tumor was pathologically type B2 thymoma with hemorrhage necrosis and MTCs, and we diagnosed Masaoka stage II because of no histological infiltration to the organs.Conclusions We speculated that hemorrhagic necrosis due to infarction in tumor caused the inflammation to spread to the surrounding organs, which was related to the chest pain and the development of MTCs.

Quantification of Cover Test Prior and Post Pyridostigmine in Diagnosis of Myasthenia Gravis

ABSTRACT Objective: To assess the value of measuring diplopia before and after pyridostigmine intake to differentiate myasthenia gravis from sagging eye syndrome. To establish a threshold for a positive response to pyridostigmine in the diagnosis of myasthenia gravis. Methods: 15 patients with myasthenia gravis and 15 with sagging eye syndrome diplopia were evaluated. Diplopia was measured in five positions (upgaze, downgaze, right gaze, left gaze, and primary position). After baseline measurements, the patient received a single dose (60 mg) of pyridostigmine. After 60 minutes the prism measure was performed again in five positions. Horizontal deviation, vertical deviation at distance was compared before and after a single dose of pyridostigmine in each gaze. Ocular deviations were compared between the two groups to identify the threshold with the highest sensitivity and specificity. Results: Differences between pretest deviations and posttest deviations in any gaze were found to be statistically significant only in the MG group. The optimum threshold for a positive response to pyridostigmine was a reduction of 2 prism diopters in any component in any gaze. Sensitivity for the detection of myasthenia diplopia was 80.00% and specificity was 86.67%. Conclusions: Our results suggest that measuring diplopia with prisms before and after pyridostigmine administration can help to detect patients with suspected myasthenia.

Evaluating an In-House Cell-Based Assay for Detecting Antibodies Against Muscle-Specific Tyrosine Kinase in Myasthenia Gravis.

Background and PurposeDetecting antibodies against muscle-specific tyrosine kinase (MuSK Abs) is essential for diagnosing myasthenia gravis (MG). We applied an in-house cell-based assay (CBA) to detect MuSK Abs.MethodsA stable cell line was generated using a lentiviral vector, which allowed the expression of MuSK tagged with green fluorescent protein in human embryonic kidney 293 (HEK293) cells. Serum and anti-human IgG antibody conjugated with red fluorescence were added. The presence of MuSK Abs was determined based on the fluorescence intensity and their colocalization in fluorescence microscopy. Totals of 218 serum samples collected from 177 patients with MG, 31 with other neuromuscular diseases, and 10 healthy controls were analyzed. The CBA results were compared with those of a radioimmunoprecipitation assay (RIPA) and an enzyme-linked immunosorbent assay (ELISA).ResultsThe MuSK-HEK293 cell line stably expressed MuSK protein. The CBA detected MuSK Abs in 34 (19.2%) of 177 samples obtained from patients with MG and in none of the participants having other neuromuscular diseases or in the healthy controls. The clinical characteristics of the patients with MuSK MG determined based on the CBA were strongly correlated with known clinical features of MuSK MG. There was an almost perfect agreement between the results of the CBA and those of the RIPA (Cohen's kappa=0.880, p<0.001) and ELISA (Cohen's kappa=0.982, p<0.001).ConclusionsThe results of the in-house CBA showed excellent agreement with both the RIPA and ELISA. Our in-house CBA can be considered a reliable method for detecting MuSK Abs.

Detecting myasthenia gravis as a cause of unclear dysphagia with an endoscopic tensilon test.

Aims:The flexible endoscopic evaluation of swallowing-tensilon test (FTT) was developed to diagnose myasthenia gravis (MG) in patients with unclear pharyngeal dysphagia. The purpose of this study was to determine sensitivity and specificity of the FTT and compare its diagnostic validity with that of other diagnostic markers.Methods:In this single-centre pragmatic clinical cohort study, a total of 100 patients with unclear pharyngeal dysphagia were eligible to undergo FTT. All patients were subjected to FTT and subsequently followed up clinically. FTT was considered positive if a significant improvement of pharyngeal swallowing function could be objectified endoscopically upon administration of edrophonium chloride. In addition, repetitive nerve stimulation test and serum MG antibody analysis were conducted.Results:All subjects (mean age 62.5 ± 14.1 years, female 33) underwent FTT without any complications. According to the results of the diagnostic procedures and based on long-term clinical follow-up for at least 3 years, 51 patients were finally diagnosed with MG. The sensitivity and specificity for the FTT was 88.2% and 95.9%, respectively. Application of the Cochran’s Q test showed statistically significant heterogeneity among the diagnostic tests, with results indicating FTT performance to be more accurate than the repetitive nerve stimulation results (p < 0.001) and comparable with serum antibody tests (p > 0.99).Conclusion:FTT has excellent clinical properties to be used routinely in the assessment of dysphagia with isolated or predominant pharyngeal muscle involvement allowing rapid and accurate diagnosis of MG.

Distinctive Disease Entity of Neurological Adverse Events Associated with Immune Checkpoint Inhibitors

Neurological immune-related adverse events (irAEs) associated with cancer treatment with immune checkpoint inhibitors (ICIs) are infrequent but are sometimes serious and require prompt diagnosis and management. Among diverse clinical subsets, meningoencephalitis, polyradiculoneuropathy, myasthenia gravis, and myositis are particularly important. The clinical presentation may be different from that of patients with those conditions unrelated to ICIs. A broad range of clinical symptoms complicates the diagnosis of autoimmune encephalitis. The clinical features of aseptic meningitis induced by classical drugs and ICIs are different. Polyradiculoneuropathy, usually diagnosed as Guillain-Barré syndrome or chronic inflammatory demyelinating polyneuropathy, requires prompt diagnosis. However, the clinical manifestations and laboratory findings of patients with polyradiculoneuropathy may be unique and differ from those in the preexisting disease subset. Although myasthenia gravis and myositis are usually independent diseases, it is often difficult to diagnose myasthenia gravis or myositis independently when the disease is associated with irAEs. We believe that inflammatory myopathy associated with ICIs is a novel disease entity accompanied by possible biomarkers of anti-striational antibodies. Discontinuation of immune checkpoint inhibitors and steroid treatment is recommended with a good response. A correct understanding of neurological adverse events is required for the best management of cancer patients.

Myasthenia gravis – czyli objawy okulistyczne jako manifestacja choroby układowej

Terminem ptoza określamy nieprawidłowe ustawienie powieki górnej mogące w różnym stopniu ograniczać pole widzenia. Opadnięcie powieki górnej bardzo często jest pierwszym symptomem miastenii (inaczej nużliwości mięśni), choroby autoimmunologicznej, w której przebiegu autoprzeciwciała uszkadzają receptory w płytce nerwowo-mięśniowej. W takim przypadku postępowanie z wyboru stanowi terapia farmakologiczna, a leczenie chirurgiczne jest względnie przeciwwskazane. Operacje wykonuje się w rzadkich przypadkach stabilnej ptozy, przy braku skuteczności działania leków. Ze względu na to, że większość przypadków izolowanej ptozy o innej etiologii możemy skutecznie korygować chirurgicznie, prawidłowa diagnostyka i wykluczenie obecności miastenii są kluczowe przed podjęciem decyzji o wdrożeniu odpowiedniej terapii.

Generalized form and duration of myasthenia gravis as predictors of cognitive impairment

We performed a clinical, neurological, neuropsychological and laboratory examination of 30 patients with a confirmed diagnosis of myasthenia gravis, aged 25 to 69 years (49.0 ± 14.6 years), 11 men and 19 women. Among the examined patients, the generalized form of myasthenia was diagnosed in 20 (66.7%) patients: 4 (20.0%) cases of severe and 16 (80.0%) of moderate forms. The ocular form of myasthenia was found in 10 (33.3%) cases. Neuropsychological testing revealed memory impairment in 15 (50.0%), attention – 11 (36.7%), emotional disturbances – 13 (43.3%) patients with myasthenia gravis. A significant decrease in the concentration of brain-derived neurotrophic factor (BDNF) in the blood serum of patients with myasthenia was noted, compared with the control group (p &lt; 0.01). When comparing the data of neuropsychological testing, the level of BDNF and the history of the disease, it was found that patients with a generalized form of myasthenia gravis and a disease duration of more than three years have a lower level BDNF, which has a reliable correlation with lower cognitive function scores.

DON’T JUDGE A BOOK BY ITS COVER: UNUSUAL CASE OF MYASTHENIA GRAVIS

SESSION TITLE: Medical Student/Resident Pulmonary Manifestations of Systemic Disease Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Myasthenia gravis is an autoimmune disorder where auto-antibodies bind to the acetylcholine receptors present in the post-synaptic membrane of the neuromuscular junction. It typically presents with limb weakness but may also include ocular symptoms such as diplopia and ptosis or bulbar symptoms including dysphagia, dysphonia and dysarthria. We report an atypical case of myasthenia gravis that initially appeared to be consistent with the diagnosis of asthma. CASE PRESENTATION: The patient is a 78-year old female with a past medical history of remote deep venous thrombosis associated with pulmonary embolism, hypertension, rheumatoid arthritis, and polymyalgia rheumatica who was referred to pulmonology for eight months of exertional dyspnea and fatigue. Besides her progressive dyspnea, additional respiratory symptoms included chest tightness, non-productive cough, and wheezing. Her pulmonary function tests indicated a mixed obstructive and restrictive defect with FEV1/FVC ratio of 69% with FVC of 1.63L (62 % predicted) as well as a positive bronchodilatory response. She was started on a regimen of ICS/LABA, leukotriene inhibitor, and an as needed ß2-recptor agonist for presumed late-onset asthma in which her symptoms only partially improved. Given both the severity of her dyspnea and restrictive physiology on her pulmonary function testing in absence of parenchymal lung disease, the patient underwent additional neuromuscular evaluation. Her maximal inspiratory pressure (MIP) was 15% predicted and her maximal expiratory pressure (MEP) was 16% predicted in setting of a normal diaphragmatic fluoroscopy (SNIFF test). She subsequently underwent serological evaluation for neuromuscular weakness in which her acetylcholine binding antibody was positive, confirming the diagnosis of myasthenia gravis. The patient was started on acetylcholinesterase inhibitor and steroids with a mixed response. Due to progression of her illness, she eventually required ICU admission and was started on plasmapheresis with positive clinical response. DISCUSSION: Acetylcholine receptor antibody myasthenia gravis has a bimodal pattern with early onset prior to age of 50. It uncommonly can be seen in setting of other autoimmune disorders such as systemic lupus, thyroiditis, or as seen in our patient, rheumatoid arthritis. Our case is unique given the fact that patient initially presented with clinical features suggestive of late-onset asthma. However, given only partial improvement in symptoms and unexplained restrictive physiology on spirometry, further testing revealed diagnosis of myasthenia gravis. CONCLUSIONS: This case stresses the need for thorough evaluation for all patients with unexplained progressive dyspnea. Reference #1: Gilhus NE. Myasthenia Gravis. Longo DL, ed. N Engl J Med. 2016;375(26):2570-2581. doi:10.1056/NEJMra1602678 Reference #2: Marlowe FI, D’Angelo AJ. Respiratory failure as the initial presentation of myasthenia gravis. Ear Nose Throat J. 1989;68(6):472-473. Reference #3: Qureshi AI, Choundry MA, Mohammad Y, et al. Respiratory failure as a first presentation of myasthenia gravis. Med Sci Monit. 2004;10(12):CR684-689. DISCLOSURES: No relevant relationships by Shubham Adroja, source=Web Response No relevant relationships by Anthony Cucci, source=Admin input No relevant relationships by Urbee Haque, source=Web Response