Diagnostic accuracy and clinical utility of bed side tests versus laboratory tests in the diagnosis of ocular myasthenia

Purpose: To assess the diagnostic accuracy of forced eyelid closure test (FECT), ice pack test (IPT), repetitive nerve stimulation test (RNS), and acetylcholine receptor (AchR) antibody test in patients with suspected ocular myasthenia. To assess the clinical utility of AchR antibody test in predicting disease progression. Methods: Retrospective cohort study of patients diagnosed with ocular myasthenia at a South?Indian neuro?ophthalmology tertiary eye clinic. Baseline characteristics; ocular myasthenia symptoms; results of FECT, IPT, RNS, and AchR antibody test; and progression time to generalized myasthenia (GM) over 36 months from the time of diagnosis were recorded and analyzed using receiver operator curve analysis, multiple logistic regression, and Kaplan朚eier survival analysis. Results: FECT had a sensitivity of 96.7% (95% CI: 88.5�.6) and a specificity of 75% (95% CI: 34.9�.8). Combination of FECT and IPT, using the positivity of at least one test, increased the sensitivity to 98.3% (95% CI: 91�0), reducing the specificity to 50% (95% CI: 15.7�.3), whereas using the positivity of both tests, we obtained a sensitivity of 71.7% (95% CI: 58.6�.5) and a specificity of 100% (95% CI: 63.1�0). In the subset of patients with double negative RNS and AchR antibodies, the positive predictive value of combined FECT and IPT (double positive) was 100%. Patients who developed GM were more likely to have a positive AchR antibody test result (P = 0.001). Conclusion: Combined FECT and IPT (double positive) has high diagnostic accuracy even among patients with normal RNS and negative AchR antibodies. Despite low sensitivity, AchR?antibody test has a significant predictive value in disease progression.

Acupuncture combined with western medication for ocular myasthenia gravis: a randomized controlled trial / 中国针灸

OBJECTIVE@#To compare the clinical efficacy between acupuncture combined with western medication and simple western medication for ocular myasthenia gravis (OMG), and to explore its possible mechanism.@*METHODS@#A total of 60 patients of ocular myasthenia gravis were randomized into an acupuncture combined with western medication group (30 cases, 1 case dropped off) and a western medication group (30 cases, 2 cases dropped off). Oral pyridostigmine bromide tablet and prednisone acetate tablet were given in the western medication group. On the basis of the treatment in the western medication group, Tongdu Tiaoqi acupuncture (acupuncture for unblocking the governor vessel and regulating qi ) was applied at Baihui (GV 20), Fengfu (GV 16), Hegu (LI 4), Zusanli (ST 36), etc. in the acupuncture combined with western medication group, once a day, 6 days a week. The treatment was given 8 weeks in both groups. Before and after treatment, the OMG clinical absolute score was observed, electrophysiological indexes of orbicularis oculi (value of mean jitter, percentage of jitter >55 μs and percentage of blocks) were measured by single-fiber electromyography (SFEMG), serum levels of acetylcholine receptor antibody (AChR-Ab), interferon-gamma (IFN-γ) and interleukin-4 (IL-4) were detected by ELISA method.@*RESULTS@#After treatment, the OMG clinical absolute scores, values of mean jitter, percentages of jitter >55 μs, percentages of blocks and serum levels of AChR-Ab, IFN-γ and IL-4 were decreased compared before treatment in both groups (P<0.05), and those in the acupuncture combined with western medication group were lower than the western medication group (P<0.05).@*CONCLUSION@#Acupuncture combined with western medication can effectively improve ptosis, palpebra superior fatigability, eye movement disorder and neuromuscular junction dysfunction in patients with ocular myasthenia gravis, the therapeutic effect is superior to simple western medication. Its mechanism may be related to down-regulating serum levels of AChR-Ab, IFN-γ and IL-4 and promoting the recovery of orbicularis oculi function.

Acquired myasthenia gravis in a domestic shorthair cat with cranial mediastinal mass

A 7-year-old castrated male domestic short-hair cat presented with anorexia, constipation, depression, and voice alteration. Physical and neurological examinations revealed hyperthermia (40.5℃), ventroflexion of the neck, reduced responses to external stimuli, generalized muscle weakness, and exercise intolerance. Thoracic radiographs revealed the presence of a cranial mediastinal mass. The history, clinical signs, and other examination results were compatible with acquired myasthenia gravis (MG). Acetylcholine receptor (AChR) antibody titers were determined to confirm MG and the serum AChR antibody concentration was 1.24 nmol/L (reference interval, < 0.3 nmol/L). This is the first diagnosis of acquired MG in a cat in Korea.

Focal form of acquired myasthenia gravis with megaesophagus in a Yorkshire terrier dog / 대한수의학회지

A 12-year-old, castrated male Yorkshire terrier dog presented with frequent regurgitations that had begun 45 days earlier and become more progressive. Radiographs revealed an air-trap region behind the cranial esophageal sphincter muscle in the esophagus and esophagographies with barium contrast showed mild esophageal dilation with decreased motility. Esophageal motility increased within 5 min of neostigmine methylsulfate administration and acetylcholine receptor antibodies titer increased to beyond the normal range. Based on these findings, acquired myasthenia gravis with focal form was diagnosed, making this the first such case diagnosed by an acetylcholine receptor antibody test in Korea.

Seropositive Myasthenia Gravis Associated with Small-Cell Lung Carcinoma

BACKGROUND: Lambert-Eaton myasthenic syndrome is well known to be a classical paraneoplastic syndrome of small cell lung carcinoma (SCLC). Three cases of seronegative myasthenia gravis (MG) and SCLC were previously reported. CASE REPORT: A 65-year-old man developed a severe progressive respiratory failure with clinical features of MG. Tests showed a decremental response in the repetitive nerve stimulation test, abnormal single-fiber electromyography, and positive acetylcholine receptor antibody. SCLC was confirmed by the lung biopsy. CONCLUSIONS: This case represents the first case of seropositive MG and SCLC.

Isaacs' Syndrome Associated With Acetylcholine Receptor Antibodies Developed After Removal of Malignant Thymoma

Isaacs' syndrome is a rare and heterogeneous syndrome of continuous muscle fiber activity that originates from peripheral nerves. We report a 56-year-old male patient who showed symptoms of Isaacs' syndrome after the removal of a malignant thymoma. Needle electromyography revealed spontaneously occurring repetitive myokymic discharge in the affected muscles. Acetylcholine receptor (AChR) antibodies were significantly elevated, but clinical and electrophysiologic findings did not indicate the presence of myasthenia gravis. We deduce that in Isaacs' syndrome, raised AChR antibodies may facilitate rather than inhibit cholinergic action.

Changes and correlation between the concentration of complement and titer of anti-acetylcholine receptor antibody in the sera of patients with myasthenia gravis / 临床神经病学杂志

0.05).Conclusions The serum concentration of C_3 rises and the titer of AChRAb decreases in MG patients after treatment with glucocorticoid. There is no correlation between C_3 concentration and titer of AChRAb. The complement possibly cooperates with AChRAb in pathogenesis of MG.

AChR subunit mRNA expression in human muscles of patients with myasthenia gravis / 中国免疫学杂志

Objective:To investigate extraocular muscles(EOM) susceptibility to myasthenia gravis(MG).Methods:Acetylcholine receptor(AChR) ?, ?, ?, ? and ? subunits from human EOM and other different muscle groups from 8 health controls and intercostal muscles from 10 MG patients were studied by RT-PCR System. Serum AChR antibodies from 83 patients with MG were assayed by ELISA.Results:①AChR?, ?, ?, ? and ? subunit mRNA could be amplified from normal human EOM and all muscle groups studied. ②AChR? P3A+/?-actin mRNA was expressed at higher level in general MG than in health controls(P=0.028). ③Ocular and general MG patients had higher AChR antibodies against AChR from adult gastrocnemius muscle than that from fetus(P=0.001,0.016).Conclusion:Susceptibility of EOM to MG is likely associated with muscle AChR subunit mRNA expression and intrinsic susceptivity of EOM.