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Survey of Ophthalmology 1994Ocular myasthenia is a localized form of myasthenia clinically involving only the extraocular, levator palpebrae superioris, and/or orbicularis oculi muscles. Ocular... (Review)
Review
Ocular myasthenia is a localized form of myasthenia clinically involving only the extraocular, levator palpebrae superioris, and/or orbicularis oculi muscles. Ocular manifestations can masquerade as a variety of ocular motility disorders, including cranial nerve and gaze palsies. A history of variable and fatiguable muscle weakness suggests this diagnosis, which may be confirmed by the edrophonium (Tensilon) test and acetylcholine receptor antibody titer. Anticholinesterases, corticosteroids and other immunosuppressive agents, and other therapeutic modalities, including thymectomy and plasmapheresis, are used in treatment. As the pathophysiology of myasthenia has been elucidated in recent years, newer treatment strategies have evolved, resulting in a much more favorable prognosis than several decades ago. This review provides historical background, pathophysiology, immuno-genetics, diagnostic testing, and treatment options for ocular myasthenia, as well as a discussion of drug-induced myasthenic syndromes.
Topics: Circadian Rhythm; Humans; Myasthenia Gravis; Ocular Motility Disorders; Oculomotor Muscles
PubMed: 7878520
DOI: 10.1016/0039-6257(94)90194-5 -
SAGE Open Medical Case Reports 2023Myasthenia in the infancy and toddler age group is rare and often presents a challenge to treating pediatric neurologists. Our report addresses the challenges...
Myasthenia in the infancy and toddler age group is rare and often presents a challenge to treating pediatric neurologists. Our report addresses the challenges encountered when distinguishing myasthenia in infants and toddlers from similar illnesses, as well as the differentiation between congenital myasthenia, transient myasthenia, and autoimmune myasthenia. We present four cases of myasthenia between the ages of 10 and 30 months. The diagnosis and management of these cases were challenging due to the variability in clinical presentation. Four cases of myasthenia were diagnosed, with three having autoimmune myasthenia and one having congenital myasthenic syndrome. One patient initially tested negative for acetylcholine receptor antibodies, but later tested positive after 4 months and had a rare facial diplegia finding. The patient with congenital myasthenic syndrome had a novel genetic mutation, homozygous variants, and also had false positive acetylcholine receptor antibodies. These cases highlight the importance of genetic testing for all infants and toddlers suspected of having myasthenia.
PubMed: 38022851
DOI: 10.1177/2050313X231211047 -
Journal of Medical Case Reports Sep 2023Myasthenia gravis is an autoimmune condition affecting the neuromuscular junction and causing muscle weakness along with fatigue (myasthenia). When the clinical...
BACKGROUND
Myasthenia 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 PRESENTATION
An 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.
CONCLUSION
Our 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.
Topics: Female; Humans; Diplopia; Pyridostigmine Bromide; Prednisone; Vision Disorders; Myasthenia Gravis; Muscle Weakness
PubMed: 37679826
DOI: 10.1186/s13256-023-04089-4 -
Journal of Neurology Apr 2020To investigate the frequency and characterize the clinical features of treatment-refractory myasthenia gravis in an Austrian cohort.
BACKGROUND
To investigate the frequency and characterize the clinical features of treatment-refractory myasthenia gravis in an Austrian cohort.
METHODS
Patient charts of 126 patients with generalized myasthenia gravis and onset between 2000 and 2016 were analyzed retrospectively. Patients were classified as treatment-refractory according to strict, predefined criteria. These mandated patients being at least moderately symptomatic (i.e., MGFA class III) or needing either maintenance immunoglobulins or plasma exchange therapy for at least 1 year in spite of two adequately dosed immunosuppressive drugs. Clinical features and outcome at last follow-up were compared to treatment-responsive patients.
RESULTS
14 out of 126 patients (11.1%) met these criteria of treatment-refractory myasthenia gravis. Treatment-refractory patients had more frequent clinical exacerbations and more often received rescue treatments or a further escalation of immunosuppressive therapies. They also remained more severely affected at last follow-up. An early onset of myasthenia gravis was associated with a higher risk for a refractory course.
CONCLUSION
A small subgroup of patients with generalized myasthenia gravis do not respond sufficiently to standard therapies. Refractory disease has considerable implications for both patients and health care providers and highlights an unmet need for new treatment options.
Topics: Adolescent; Adult; Age of Onset; Aged; Aged, 80 and over; Female; Follow-Up Studies; Humans; Immunosuppressive Agents; Male; Middle Aged; Myasthenia Gravis; Outcome Assessment, Health Care; Plasma Exchange; Retrospective Studies; Severity of Illness Index; Symptom Flare Up; Young Adult
PubMed: 31828474
DOI: 10.1007/s00415-019-09667-5 -
Neurosciences (Riyadh, Saudi Arabia) Jan 2021To evaluate the prevalence and the factors associated with recurrence of myasthenia gravis following thymectomy.
OBJECTIVES
To evaluate the prevalence and the factors associated with recurrence of myasthenia gravis following thymectomy.
METHODS
Six electronic databases which reported on recurrence of myasthenia gravis following thymectomy and/or its risk factors from 1985 to 2018 were searched. Summary prevalence and risk values obtained based on the random effect models were reported.
RESULTS
Seventy (70) papers containing 7,287 individuals with myasthenia gravis who received thymectomy as part of their management were retrieved. The patients had a mean follow-up of 4.65 years post-thymectomy. The prevalence of myasthenia gravis recurrence post-thymectomy was 18.0% (95% CI 14.7-22.0%; 1865/7287). Evident heterogeneity was observed (I=93.6%; <0.001). Recurrence rate was insignificantly higher in male compared with female patients (31.3 vs. 23.8%; =0.104). Pooled recurrence rates for thymomatous (33.3%) was higher than the rate among non-thymomatous (20.8%) myasthenia gravis patients (Q=4.19, =0.041). Risk factors for recurrence include older age, male sex, disease severity, having thymomatous myasthenia gravis, longer duration of the myasthenia gravis before surgery, and having an ectopic thymic tissue.
CONCLUSION
A fifth of individuals with myasthenia gravis experience recurrence after thymectomy. Closer monitoring should be given to at-risk patients and further studies are needed to understand interventions to address these risks.
Topics: Databases, Factual; Humans; Myasthenia Gravis; Prevalence; Recurrence; Risk Factors; Thymectomy; Time Factors; Treatment Outcome
PubMed: 33530037
DOI: 10.17712/nsj.2021.1.20190041 -
Autoimmunity 2015Myasthenia gravis (MG) is a rare autoimmune disease of skeletal muscle endplates. MG subgroup is relevant for comorbidity, but usually not accounted for. MG patients... (Review)
Review
Myasthenia gravis (MG) is a rare autoimmune disease of skeletal muscle endplates. MG subgroup is relevant for comorbidity, but usually not accounted for. MG patients have an increased risk for complicating autoimmune diseases, most commonly autoimmune thyroid disease, systemic lupus erythematosus and rheumatoid arthritis. In this review, we present concomitant autoimmune disorders associated with the different MG subgroups, and show how this influences treatment and prognosis. Concomitant MG should always be considered in patients with an autoimmune disorder and developing new neuromuscular weakness, fatigue or respiratory failure. When a second autoimmune disorder is suspected, MG should be included as a differential diagnosis.
Topics: Animals; Autoantibodies; Autoantigens; Autoimmune Diseases; Autoimmunity; Genetic Predisposition to Disease; Humans; LDL-Receptor Related Proteins; Myasthenia Gravis; Receptor Protein-Tyrosine Kinases; Receptors, Cholinergic; Receptors, Nicotinic; Thymoma
PubMed: 25915571
DOI: 10.3109/08916934.2015.1030614 -
Frontiers in Bioscience (Landmark... Mar 2017Properly sustained impulse transmission at the neuromuscular junction (NMJ) is crucial for successful muscle contraction. To guarantee this, NMJs not only possess a... (Review)
Review
Properly sustained impulse transmission at the neuromuscular junction (NMJ) is crucial for successful muscle contraction. To guarantee this, NMJs not only possess a considerable safety factor in transmission but also have the ability to adjust the presynaptic acetylcholine release level to cope with any changes in the postsynaptic neurotransmitter sensitivity. This review will provide overview on the discovery and characterization of this synaptic homeostatic mechanism, especially in the condition of the neuromuscular disorder myasthenia gravis (MG) where the postsynaptic transmitter sensitivity at the NMJ becomes severely reduced due to autoimmune attack of acetylcholine receptors. Because homeostatic signalling and adaptation is presumably maximally active in this condition, NMJs from MG animal models are important study objects. Although candidate post- and presynaptic factors as well as the retrograde signals have been proposed, the homeostatic mechanism at the MG NMJ is still incompletely understood. Further identification and functional characterization of key factors is important because these may form new therapeutic targets in MG.
Topics: Acetylcholine; Animals; Homeostasis; Humans; Muscle Contraction; Myasthenia Gravis; Myasthenia Gravis, Autoimmune, Experimental; Neuromuscular Junction; Signal Transduction; Synaptic Transmission
PubMed: 28199191
DOI: 10.2741/4532 -
Seminars in Thoracic and Cardiovascular... Jan 1999Myasthenia gravis is a disorder characterized by weakness and fatigue of voluntary muscles. The muscular disorder is generalized in 85% and confined to extraocular... (Review)
Review
Myasthenia gravis is a disorder characterized by weakness and fatigue of voluntary muscles. The muscular disorder is generalized in 85% and confined to extraocular muscles in 15% of patients. The disease is graded based on pattern and severity of muscular involvement. Myasthenia gravis is an autoimmune disease which leads to a reduction of the number of acetylcholine receptors (Ach-R) at the muscular motor endplate. This results in less receptors available for stimulation, lower amplitude stimulations, less muscle fiber activation, and the resultant clinical findings of weakness in the affected muscles. The work-up and treatment of this disease originated from an understanding of its pathogenesis. Diagnostic tests include use of anticholinesterase agents (tensilon test), curare test, repetitive nerve stimulation, Ach-R antibody assay, and single fiber electromyography. Medical therapy includes use of anticholinesterase agents, immunotherapy, and plasmapheresis.
Topics: Adrenal Cortex Hormones; Autoimmune Diseases; Azathioprine; Cholinesterase Inhibitors; Humans; Immunosuppressive Agents; Myasthenia Gravis; Plasmapheresis
PubMed: 9930711
DOI: 10.1016/s1043-0679(99)70018-3 -
Pediatric Neurology Briefs Dec 2020Investigators from Oxford John Radcliff Hospital and Great Ormond Street Hospital for Children performed a retrospective study of myasthenia patients diagnosed before...
Investigators from Oxford John Radcliff Hospital and Great Ormond Street Hospital for Children performed a retrospective study of myasthenia patients diagnosed before the age of 16 years.
PubMed: 33376293
DOI: 10.15844/pedneurbriefs-34-24 -
Revista de NeurologiaIn the newborn, myasthenia can present either as transient neonatal myasthenia or as a congenital syndrome. At present at least 8 syndromes involving neonatal... (Review)
Review
INTRODUCTION
In the newborn, myasthenia can present either as transient neonatal myasthenia or as a congenital syndrome. At present at least 8 syndromes involving neonatal neuromuscular junction (NMJ) malfunction have been described; one caused by the passage of transplacental antibodies from mother to child, while all but one of the rest are inherited. Inheritance in all but two syndromes is autosomal recessive. One is an autosomal dominantly inherited illness; in another the mode of inheritance is not clear. The deficit in function of the NMJ is presynaptic in 3 instances, at the junctional gap in 1, and postsynaptic in at least 3 other syndromes.
DEVELOPMENT
We will review the clinical symptoms, as well as neurophysiologic and genetic testing available for diagnosis. We explain how, at least, in some of the syndromes, one can begin appropriate therapy based on clinical, neurophysiological and simple pharmacological testing.
CONCLUSION
However, in many cases, it becomes necessary to refer the patient or a tissue sample, usually an intercostal nerve muscle preparation, to one of the very few centers in the world where in vitro neurophysiologic, microstructural and genetic procedures leading to a more precise diagnosis can be performed.
Topics: Acetylcholine; Humans; Infant, Newborn; Myasthenia Gravis, Neonatal; Myasthenic Syndromes, Congenital; Neuromuscular Junction
PubMed: 11988891
DOI: No ID Found