Ocular myasthenia gravis

Refractory generalized myasthenia gravis with myasthenic incomplete ophthalmoplegia successfully treated with eculizumab

Purpose

This is a case of myasthenic incomplete ophthalmoplegia mimicking a partial cranial nerve 3 palsy both subjectively and objectively improving after treatment with eculizumab.

Observations

We chronicle a case of severe generalized myasthenia gravis including myasthenia masquerading as a partial cranial nerve 3 palsy, refractory to pyridostigmine, mycophenolate, prednisone, intravenous immunoglobulin and plasma exchange but responsive to eculizumab.

Conclusions and importance

This case demonstrates ocular and generalized myasthenia gravis refractory to several other therapies but amenable to eculizumab infusions, suggesting this medication may be of significant value in these difficult cases, and should be further explored for refractory ocular myasthenia gravis.

Myasthenia Gravis: Novel Findings and Perspectives on Traditional to Regenerative Therapeutic Interventions

The prevalence of myasthenia gravis (MG), an autoimmune disorder, is increasing among all subsets of the population leading to an elevated economic and social burden. The pathogenesis of MG is characterized by the synthesis of autoantibodies against the acetylcholine receptor (AChR), low-density lipoprotein receptor-related protein 4 (LRP4), or muscle-specific kinase at the neuromuscular junction, thereby leading to muscular weakness and fatigue. Based on clinical and laboratory examinations, the research is focused on distinguishing MG from other autoimmune, genetic diseases of neuromuscular transmission. Technological advancements in machine learning, a subset of artificial intelligence (AI) have been assistive in accurate diagnosis and management. Besides, addressing the clinical needs of MG patients is critical to improving quality of life (QoL) and satisfaction. Lifestyle changes including physical exercise and traditional Chinese medicine/herbs have also been shown to exert an ameliorative impact on MG progression. To achieve enhanced therapeutic efficacy, cholinesterase inhibitors, immunosuppressive drugs, and steroids in addition to plasma exchange therapy are widely recommended. Under surgical intervention, thymectomy is the only feasible alternative to removing thymoma to overcome thymoma-associated MG. Although these conventional and current therapeutic approaches are effective, the associated adverse events and surgical complexity limit their wide application. Moreover, Restivo et al. also, to increase survival and QoL, further recent developments revealed that antibody, gene, and regenerative therapies (such as stem cells and exosomes) are currently being investigated as a safer and more efficacious alternative. Considering these above-mentioned points, we have comprehensively reviewed the recent advances in pathological etiologies of MG including COVID-19, and its therapeutic management.

Clinical Efficacy of Immunoglobulin Combined with Glucocorticoids in the Treatment of Oculomotor Myasthenia Gravis in Children and the Effect on Serum Immunity

To investigate the effects of treatment with immunoglobulin on clinical outcomes and immune function in children with oculomotor myasthenia gravis. The clinical data of 100 pediatric patients with oculomotor myasthenia gravis treated in our hospital from January 2019 to December 2021 were selected as the subjects of this retrospective study and divided into a comparison group and a treatment group according to the different treatment methods. The comparison group was treated with glucocorticoids, and the treatment group was treated with immunoglobulin on the basis of the comparison group. The differences in the serum indexes, the effects of immune function, and the clinical efficacy of the two groups were observed and compared. It was found the comparison of immunoglobulin G (IgG), immunoglobulin A (IgA), and immunoglobulin M (IgM) after treatment was significantly different and lower in the treatment group than in the comparison group; the comparison of CD4+, CD3+, CD4+/CD8+, and NK cells after treatment was significantly different and higher in the treatment group than in the comparison group. The effective rate of 98.00% in the treatment group was significantly higher than that of 76.00% in the comparison group, and the difference was statistically significant. The clinical efficacy of the two groups showed that the fever, cough, sputum, myasthenia gravis crisis, and gastrointestinal reactions in the treatment group were significantly lower than those in the comparison group. The study indicates that comparative study of children with oculomotor myasthenia gravis treated with immunoglobulin combined with glucocorticoids is more effective, effectively improving the immune level of patients and reducing adverse reactions.

Risk for generalization in ocular onset myasthenia gravis: experience from a neuro-ophthalmology clinic

Conversion to generalized myasthenia gravis (GMG) within the first 2 years has been reported in 18-85% of patients with ocular myasthenia gravis (OMG). The aim of the study was to investigate the risk factors for generalization in patients with OMG admitted to a neuro-ophthalmology clinic and to determine if there were differences between patients with GMG with predominant bulbar (GMG-B) or extremity muscle (GMG-E) involvement according to the 6th and 24th-month Myasthenia Gravis Foundation of America classification ranks. Patients with OMG who were followed-up for at least 24 months were retrospectively analyzed. Demographic, clinical, laboratory features and treatment strategies that can be associated with generalization and time to generalization were evaluated. Of the 139 patients with OMG, 54 (39%) showed generalization with a mean time of 10.3 (range 2-24) months. GMG-B and GMG-E were diagnosed in 31 (22.3%) and 23 patients (16.5%), respectively. Seropositivity for acetylcholine receptor and muscle-specific tyrosine kinase antibodies, abnormal single-fiber electromyography (SFEMG), and the presence of thymic abnormalities (thymoma and hyperplasia) were factors associated with generalization on multivariate analysis without a significant difference between the GMG-B and GMG-E groups. In addition, an abnormal repetitive nerve stimulation test was related to a shortened time to generalization. Bilateral ptosis at onset was found as a risk factor for generalization. In a neuro-ophthalmology clinic, bilateral ptosis as an initial feature of OMG must be approached cautiously because it may be the first sign of impending GMG.

Interobserver and Intra-Observer Reliability of Eyelid Tests for Ocular Myasthenia Gravis

BACKGROUND

Lid fatigability test (LFT), Cogan lid twitch (CLT), and forced eyelids closure test (FECT) are simple clinical screening tests for ocular myasthenia gravis (OMG). However, these tests are subjectively interpreted. We thus evaluated the interobserver and intra-observer reliability of each test.

METHODS

The 3 eyelid tests were performed in ptotic patients associated with various conditions, including OMG and others. Video clips of all tests were recorded using smartphone with built-in camera in the following order; LFT, CLT, and FECT. All video clips were distributed to 3 neuro-ophthalmologists and 3 general ophthalmologists, who were trained to evaluate the tests using a single standard instruction. After 3 months, all video clips were re-organized for the second evaluation. Interobserver and intra-observer reliability were calculated using Cohens' Kappa coefficient and Fleiss Kappa statistic.

RESULTS

The 3 eyelid tests were performed and recorded in 35 patients, which included the diagnosis of OMG, levator muscle dehiscence, partial oculomotor nerve palsy, and Horner syndrome. CLT received moderate-to-substantial interobserver reliability in neuro-ophthalmologist group (Fleiss Kappa 0.77 [95% CI 0.60-0.94] and 0.66 [95% CI 0.46-0.85] in first and second evaluation respectively), but the results varied in general ophthalmologist group (Fleiss Kappa 0.58 [95% CI 0.37-0.79] and 0.54 [95% CI 0.33-0.76] in first and second evaluation respectively). FECT and LFT received lower interobserver reliability in both groups. CLT also received moderate-to-almost perfect intra-observer reliability in neuro-ophthalmologist group (Cohen Kappa 0.55, 0.58, and 0.92), whereas FECT and LFT received lower intra-observer reliability. The intra-observer reliability varied among general ophthalmologists for all 3 eyelid tests.

CONCLUSIONS

CLT is the most reliable test among the 3 eyelid tests. However, all tests should be interpreted with caution by general ophthalmologists.

Diagnostic yields and clinical features of ocular myasthenia gravis

To investigate clinical features and diagnosis process of ocular myasthenia gravis (OMG) in ophthalmology department.A total of 36 patients with ptosis or diplopia who had follow-up for at least 3 months between March 2016 and December 2019 were included in this study. Clinical symptoms of patients and the test results were analyzed. According to the positivity of serologic test, these patients were divided into 2 groups (confirmed OMG and possible OMG with relief of symptoms after antimyasthenic treatment) for comparison.Ptosis was present in 12 (33.33%) patients, diplopia was present in 14 (38.89%) patients, and both ptosis and diplopia were present in 10 (27.78%) patients. Acetylcholine receptor auto-antibody (AchR Ab) was positive in 14 (38.89%) of 36 patients and ice test was positive in 15 (71.43%) of 21 patients with ptosis. Unequivocal response to pyridostigmine was observed in 31 (86.11%) patients. For seropositive cases, AchR Ab titer was significantly higher in the group with 2 clinical symptoms than that in the 1 clinical symptom (P = .011).This study presents the usefulness and diagnostic validity of antimyasthenic treatment for OMG, especially seronegative OMG, with detailed symptom analysis.

Differential Gut Microbiota and Fecal Metabolites Related With the Clinical Subtypes of Myasthenia Gravis

Myasthenia gravis (MG) is a devastating acquired autoimmune disease. Previous studies have observed that disturbances of gut microbiome may attribute to the development of MG through fecal metabolomic signatures in humans. However, whether there were differential gut microbial and fecal metabolomic phenotypes in different subtypes of MG remains unclear. Here, our objective was to explore whether the microbial and metabolic signatures of ocular (OMG) and generalized myasthenia gravis (GMG) were different, and further identify the shared and distinct markers for patients with OMG and GMG. In this study, 16S ribosomal RNA (rRNA) gene sequencing and gas chromatography-mass spectrometry (GC/MS) were performed to capture the microbial and metabolic signatures of OMG and GMG, respectively. Random forest (RF) classifiers was used to identify the discriminative markers for OMG and GMG. Compared with healthy control (HC) group, GMG group, but not OMG group, showed a significant decrease in α-phylogenetic diversity. Both OMG and GMG groups, however, displayed significant gut microbial and metabolic disorders. Totally, we identified 20 OTUs and 9 metabolites specific to OMG group, and 23 OTUs and 7 metabolites specific to GMG group. Moreover, combinatorial biomarkers containing 15 discriminative OTUs and 2 differential metabolites were capable of discriminating OMG and GMG from each other, as well as from HCs, with AUC values ranging from 0.934 to 0.990. In conclusion, different subtypes of MG harbored differential gut microbiota, which generated discriminative fecal metabolism.

Factors Affecting Generalization of Ocular Myasthenia Gravis in Patients With Positive Acetylcholine Receptor Antibody

PURPOSE

To evaluate the associated factors of conversion of ocular myasthenia gravis (OMG) to generalized myasthenia gravis (GMG) among patients with seropositive acetylcholine receptor antibody (AchR Ab).

DESIGN

Retrospective cohort study.

METHODS

Setting: Retrospective chart review.

PATIENT

Seventy-one OMG patients with seropositive AchR Ab presented during July 2009 and December 2016. The exclusion criteria were patients who (1) first presented with GMG, (2) were unable to identify the time of onset of OMG or GMG, (3) were unable to provide information about previous treatments before the onset of GMG, and (4) had incomplete or lost medical records.

OBSERVATION PROCEDURE

We collected demographic and clinical characteristics, including onset of OMG and GMG, presence of other autoimmune disorders, history of smoking, presence of thymic abnormalities, and medications received.

MAIN OUTCOME MEASURES

Conversion to GMG and time to conversion.

RESULTS

Thirty-six patients experienced conversion to GMG. Overall incidence of GMG was 14 (95% confidence interval [CI] 10.09-19.4) per 100 patient-years. Probability of conversion at 2 years was .37 (95% CI .27-.49). Overall median conversion time was 4.97 years. Cox proportional hazard model showed that risk factors were female sex (HR 2.52, 95% CI 1.04-6.10), history of smoking (HR 3.42, 95% CI 1.40-8.45), and thymic abnormalities (HR 1.82, 95% CI 0.91-3.67). Protective factors against conversion to GMG were receiving immunosuppressive agents (HR 0.42, 95% CI 0.19-0.97) and pyridostigmine (HR 0.37, 95% CI 0.14-0.93).

CONCLUSIONS

OMG patients with seropositive AchR Ab should be informed that taking pyridostigmine and/or immunosuppressive agents as well as smoking cessation might prevent conversion to GMG.

Efficacy and Safety of Low-to-Moderate Dose Oral Corticosteroid Treatment in Ocular Myasthenia Gravis

PURPOSE

To evaluate the response to corticosteroid therapy as a primary treatment for ocular myasthenia gravis.

METHODS

Patients diagnosed as having ocular myasthenia gravis by an acetylcholine receptor binding antibody test between January 2011 and September 2015 were included in the study and started receiving treatment with a corticosteroid. Patients with a blowout fracture, hyperthyroidism, diabetes mellitus, hypertension, cardiovascular disease, or history of strabismus surgery were excluded. Disappearance of diplopia and ptosis were considered a response to treatment.

RESULTS

Methylprednisolone therapy was administered to 29 patients (19 men and 10 women; average age: 49 ± 16.5 years) as an initial treatment. A total of 6 patients were lost to follow-up. Twenty-three of 29 patients (82.6%) were regarded as having presented a response to treatment. The average treatment duration was 3 weeks for patients responding to primary treatment. Eight patients complained of adverse effects from steroid therapy such as heartburn, insomnia, weight gain, and myalgia.

CONCLUSIONS

A corticosteroid could be considered as an initial treatment for patients diagnosed as having ocular myasthenia gravis by an acetylcholine receptor binding antibody test. [J Pediatr Ophthalmol Strabismus. 2018;55(5):339-342.].

Antibody profile may predict outcome in ocular myasthenia gravis

An unsolved issue remains whether there are clinical and immunological features to predict in a single patient the risk of conversion from ocular Myasthenia Gravis (OMG) to generalized disease (GMG) as 50-60% of patients may progress within 1-2 years since onset. Anti-acetylcholine receptor antibodies (AChR Abs) are found in up to 50% of OMG patients; muscle-specific tyrosine kinase antibodies (MuSK-Abs) are present in about 70% of the whole seronegative (SN), who usually develop a severe disease with bulbar involvement. We surveyed a cohort of 175 OMG patients with purely ocular symptoms and we compare the outcome of patients with antibodies to AChR or to MuSK with those seronegative for both Abs (DSN). All patients had purely ocular signs for at least 24 months. Gender, age at onset, time to generalization or to worsening in quantitative ocular QMG scores, electrophysiological results were analyzed. Males were 58.9%, females 41.1%. Patients with late onset of symptoms after 50 years (LOMG) were 78.3%. We assayed anti-MuSK-Abs in 4.7%, anti-AChR Abs in 38.5%; 57.3% were defined DSN. Thirty-seven patients (21.1%) progressed to GMG during the observational time: 23 were females, 62% of the whole group of the generalized subjects, 75% of MuSK-positive OMG converted to GMG versus the 26.2% of AChR positive and 13.7% of DSN. Statistical analysis showed that gender and presence of antibodies either to AChR or to MuSK were independent predictors of worse outcome; the DSN subjects had lower risk of conversion to GMG.

Update on ocular myasthenia gravis in Taiwan

Myasthenia gravis (MG) is an autoimmune disease involving the neuromuscular junction. Autoantibodies to the acetylcholine receptor or, less frequently, to muscle-specific kinase, attack against the postsynaptic junctional proteins, resulting in fluctuating and variable weakness of muscles. Extraocular, levator palpebrae superioris, and orbicularis oculi muscles are particularly susceptible. The majority of patients with MG present with purely ocular symptoms including ptosis and diplopia initially. About half of these patients progress to generalized disease within 2 years. The prevalence of MG in Taiwan is 140 per million with male to female ratio of 0.7. The incidence rate is higher in the elderly. Several immune-related diseases such as lymphoid malignancy, diabetes, and thyroid diseases are associated with MG in the national population-based studies in Taiwan. Ice pack test, rest test, Tensilon/neostigmine test, circulating antibody measurement, and electrophysiological studies are useful diagnostic tools with variable sensitivity and specificity. For the patients with ocular MG, acetylcholinesterase inhibitors are usually the first-line treatment. Corticosteroids and immunosuppressant could provide better disease control and may reduce the risk of conversion to generalized form although there is still some controversy. A thymectomy is also beneficial for ocular MG, especially in refractory cases. The correction of ptosis and strabismus surgery could improve the visual outcome but should be performed only in stable disease.

Factors affecting outcome in ocular myasthenia gravis

AIM OF THE STUDY

50%-60% of patients with ocular myasthenia gravis (OMG) progress to generalized myasthenia gravis (GMG) within two years. The aim of our study was to explore factors affecting prognosis of OMG and to test the predictive role of several independent clinical variables.

MATERIALS AND METHODS

We reviewed a cohort of 168 Caucasian patients followed from September 2000 to January 2016. Several independent variables were considered as prognostic factors: gender, age of onset, results on electrophysiological tests, presence and level of antibodies against acetylcholine receptors (AChR Abs), treatments, thymic abnormalities. The primary outcome was the progression to GMG and/or the presence of bulbar symptoms. Secondary outcomes were either achievement of sustained minimal manifestation status or worsening in ocular quantitative MG subscore (O-QMGS) or worsening in total QMG score (T-QMGS), assessed by Myasthenia Gravis Foundation of America (MGFA) quantitative scores. Changes in mental and physical subscores of health-related quality of life (HRQoL) were assessed with SF-36 questionnaire. Variance analysis was used to interpret the differences between AChR Ab titers at different times of follow up among the generalized and non-generalized patients.

RESULTS

Conversion to GMG occurred in 18.4% of patients; it was significantly associated with sex, later onset of disease and anti-AChR Ab positivity. Antibody titer above the mean value of 25.8 pmol/mL showed no significant effect on generalization. Sex and late onset of disease significantly affected T-QMGS worsening. None of the other independent variables significantly affected O-QMGS and HRQoL.

CONCLUSIONS

Sex, later onset and anti-AChR Ab positivity were significantly associated with clinical worsening.

Diagnosis of Ocular Myasthenia Gravis by means of tracking eye parameters

Ptosis of the eyelids is a common condition with a myriad of causes. Its management depends on the underlying cause, which can be challenging to diagnose in some cases. Current diagnosis methods include serum antibodies, tensilon test, and electromyography (EMG). Each has its own set of limitations such as invasiveness and lack of sensitivity. To overcome these limitations, we have developed a Portable Realtime Infrared Lids, Iris and Blink (PRILIB) monitoring system, with a long-term goal to improve clinical diagnosis of ptosis. In this paper, we present the algorithms to detect and analyze eye parameters and report experimental results. From experiments conducted on normal volunteers and myasthenic patients, we found 1. Partial blinks happen when Ocular Myasthenia Gravis (OMG) patients are tired or engaged in an activity; 2. Blink rate is significantly higher for OMG patients due to failure to blink fully; 3. There are noticeably more fluctuations of palpebral aperture of OMG patients due to rising and falling of the eyelid height. These experimental findings suggest new diagnostic features for OMG patients and have implications for disease management.

Inferior oblique muscle paresis as a sign of myasthenia gravis

Myasthenia gravis may affect any of the six extra-ocular muscles, masquerading as any type of ocular motor pathology. The frequency of involvement of each muscle is not well established in the medical literature. This study was designed to determine whether a specific muscle or combination of muscles tends to be predominantly affected. This retrospective review included 30 patients with a clinical diagnosis of myasthenia gravis who had extra-ocular muscle involvement with diplopia at presentation. The diagnosis was confirmed by at least one of the following tests: Tensilon test, acetylcholine receptor antibodies, thymoma on chest CT scan, or suggestive electromyography. Frequency of involvement of each muscle in this cohort was inferior oblique 19 (63.3%), lateral rectus nine (30%), superior rectus four (13.3%), inferior rectus six (20%), medial rectus four (13.3%), and superior oblique three (10%). The inferior oblique was involved more often than any other muscle (p<0.01). Eighteen (60%) patients had ptosis, six (20%) of whom had bilateral ptosis. Diagnosing myasthenia gravis can be difficult, because the disease may mimic every pupil-sparing pattern of ocular misalignment. In addition diplopia caused by paresis of the inferior oblique muscle is rarely encountered (other than as a part of oculomotor nerve palsy). Hence, when a patient presents with vertical diplopia resulting from an isolated inferior oblique palsy, myasthenic etiology should be highly suspected.

Detection of third and sixth cranial nerve palsies with a novel method for eye tracking while watching a short film clip

OBJECT

Automated eye movement tracking may provide clues to nervous system function at many levels. Spatial calibration of the eye tracking device requires the subject to have relatively intact ocular motility that implies function of cranial nerves (CNs) III (oculomotor), IV (trochlear), and VI (abducent) and their associated nuclei, along with the multiple regions of the brain imparting cognition and volition. The authors have developed a technique for eye tracking that uses temporal rather than spatial calibration, enabling detection of impaired ability to move the pupil relative to normal (neurologically healthy) control volunteers. This work was performed to demonstrate that this technique may detect CN palsies related to brain compression and to provide insight into how the technique may be of value for evaluating neuropathological conditions associated with CN palsy, such as hydrocephalus or acute mass effect.

METHODS

The authors recorded subjects' eye movements by using an Eyelink 1000 eye tracker sampling at 500 Hz over 200 seconds while the subject viewed a music video playing inside an aperture on a computer monitor. The aperture moved in a rectangular pattern over a fixed time period. This technique was used to assess ocular motility in 157 neurologically healthy control subjects and 12 patients with either clinical CN III or VI palsy confirmed by neuro-ophthalmological examination, or surgically treatable pathological conditions potentially impacting these nerves. The authors compared the ratio of vertical to horizontal eye movement (height/width defined as aspect ratio) in normal and test subjects.

RESULTS

In 157 normal controls, the aspect ratio (height/width) for the left eye had a mean value ± SD of 1.0117 ± 0.0706. For the right eye, the aspect ratio had a mean of 1.0077 ± 0.0679 in these 157 subjects. There was no difference between sexes or ages. A patient with known CN VI palsy had a significantly increased aspect ratio (1.39), whereas 2 patients with known CN III palsy had significantly decreased ratios of 0.19 and 0.06, respectively. Three patients with surgically treatable pathological conditions impacting CN VI, such as infratentorial mass effect or hydrocephalus, had significantly increased ratios (1.84, 1.44, and 1.34, respectively) relative to normal controls, and 6 patients with supratentorial mass effect had significantly decreased ratios (0.27, 0.53, 0.62, 0.45, 0.49, and 0.41, respectively). These alterations in eye tracking all reverted to normal ranges after surgical treatment of underlying pathological conditions in these 9 neurosurgical cases.

CONCLUSIONS

This proof of concept series of cases suggests that the use of eye tracking to detect CN palsy while the patient watches television or its equivalent represents a new capacity for this technology. It may provide a new tool for the assessment of multiple CNS functions that can potentially be useful in the assessment of awake patients with elevated intracranial pressure from hydrocephalus or trauma.

A case of ocular myasthenia gravis presenting as double depressor palsy

A 65-year-old man who had been experiencing diplopia in front and down gaze for 15 days visited our hospital. Hypertropia was noted in the patient's left eye, and limitation of depression was found in the adduction, primary gaze, and abduction. Brain magnetic resonance imaging showed no remarkable findings. Two weeks after the first visit, the patient complained of ptosis in the left eye. An ice test was performed and the ptosis was resolved after the test. Then, anti-acetylcholine receptor binding antibody levels were checked and found to be slightly elevated. We prescribed methylprednisolone per os 24 mg for 2 weeks, and his symptoms improved after the 2-week treatment. Five weeks after his first visit, the patient showed an ortho result in the alternate prism cover test and normal ocular movements. This may be the first case in which ocular myasthenia gravis presented as double depressor palsy, and in such cases, the possibility of ocular myasthenia gravis should be considered to rule out double depressor palsy.

Neuro-Ophthalmology Annual Review

The aim of this study was to update the practicing ophthalmologist on the English-language neuro-ophthalmology literature from the prior year. This study is a review of English-language literature from August 1, 2012, to August 1, 2013. The authors searched PubMed articles published from August 1, 2012, to August 1, 2013, limited to English-language publications including original articles, review articles, and case reports and excluding letters to the editor, unpublished work, and abstracts. We researched the following topics: pupillary abnormalities, eye movement dysfunction, neuromuscular diseases, optic neuropathies, optic neuritis and demyelinating disease including multiple sclerosis, lesions of the chiasm and posterior primary visual pathways, elevated intracranial pressure, tumors and aneurysms affecting the visual pathways, vascular diseases, higher visual functions, and neuroimaging advances. We intend to share clinically relevant literature of the past year with the practicing ophthalmologist. We aimed to highlight remarkable and interesting literature rather than exhaustively including all new neuro-ophthalmological publications of the year. We reviewed literature in the past year with a focus on relevance and novelty. This review updates the comprehensive ophthalmologist on neuro-ophthalmic topics.

Monitoring of neuromuscular blockade in one muscle group alone may not reflect recovery of total muscle function in patients with ocular myasthenia gravis

PURPOSE

We report on two patients with ocular myasthenia gravis who received rocuronium, followed later by sugammadex to reverse neuromuscular blockade. Recovery was monitored simultaneously at the adductor pollicis muscle (APM) and the corrugator supercilii muscle (CSM).

CLINICAL FEATURES

Two patients with ocular myasthenia gravis (case 1: 74 yr-old female, 54 kg; case 2: 71 yr-old male, 72 kg) were scheduled for surgery under general anesthesia. Neuromuscular blockade was induced with rocuronium 0.3 mg·kg(-1) after placing two separate monitors at the APM and the CSM, respectively. Additional doses of rocuronium 0.1-0.2 mg·kg(-1) were given to maintain neuromuscular blockade at fewer than two twitches at the APM during surgery. Train-of-four response at the CSM did not show recovery of the twitch after its initial disappearance. At the end of surgery, sugammadex was administered. Twitch height at the APM recovered to the control value in 12 min (case 1) and 13 min (case 2) after sugammadex administration; however, twitch height at the CSM took 26 min (case 1) and 14 min (case 2) to recover to the control value.

CONCLUSION

After rocuronium-induced paralysis in both patients with ocular myasthenia, spontaneous recovery and sugammadex-assisted recovery were slower at the CSM than at the APM. In patients without the disorder, CSM recovery is faster than APM recovery. Thus, in ocular myasthenia gravis, neuromuscular recovery at the APM may not reflect recovery of all muscles.