Myasthenia gravis affects children and neonates as well as adults. There will be weakness noticed in children too. There might be a weak cry and difficult movement of muscles or delayed milestones.

In adults, extraocular muscle weakness is the most common affection seen in maximum patients [4]. The hallmark of the myasthenia gravis is fatiguability or tiredness of the voluntary muscles [5]. Many patients present with bulbar muscle weakness and limb weakness which is often seen first in the proximal limbs and then in distal limbs. Since it is a chronic disorder, signs and symptoms are visible only after there is 30% reduction or destruction of the receptor sites and till then there is no evident sign.

Typically, extraocular muscle weakness is asymmetric and can be noticed easily. Drooping eyelids or ptosis occurs after straining the eyes for a long time as muscles give up after continuously using them due to a deficiency of acetylcholine at the neuromuscular junction.

Other common symptoms occurring out of fatiguability are slurred speech, diplopia or blurred vision, difficulty in chewing and dysphagia, weakness in arms and legs, chronic muscle fatigue, dyspnea, unstable gait, dysarthria i.e. difficulty in speaking or talking and impaired speech.

Weakness of muscles is typically least in the morning and progresses as the day progresses. Weakness increases as there is increased exertion and gets better with rest. Proximal muscle weakness is more often seen than distal muscle weakness.

• Fatigue

  Myasthenia gravis (MG) is an autoimmune disorder that produces weakness and irregularly rapid fatigue of voluntary muscles. [muscle.ca]

  […] residual problematic fatigue. [ncbi.nlm.nih.gov]

  This results in muscle weakness and fatigue. The Myasthenia Gravis Foundation estimates the incidence of MG in the United States to be about 20 out of 100,000. At younger ages, MG occurs in women more often than men. [stanfordchildrens.org]

  Central/bulbar involvement Test the power of head/neck flexion and extension (fatigue this movement as above) Ask the patient to take a deep breath and count out loud as many numbers as they can. [oxfordmedicaleducation.com]

• Difficulty Walking

  MG may cause the following: Muscle weakness that increases with muscle use/exercise and improves with rest Drooping eyelids Double and/or blurred vision Difficulty swallowing Difficulty speaking Difficulty walking Weakness of the hand muscles Difficulty [uvahealth.com]

  […] swallowing Difficulty speaking Difficulty walking Weakness of the hand muscles Myasthenic crisis: This is a severe flare-up of symptoms. [umms.org]

  Other symptoms and signs include: Drooping eyelids and facial expressions Blurred or double vision Difficulty walking, speaking, swallowing and/or breathing Diagnostic tests may include: Blood tests: to identify the presence of abnormal antibodies Electromyography [swedish.org]

  Other symptoms include: Changes in facial expression Difficulty chewing Difficulty speaking Difficulty swallowing Difficulty walking or doing repetitive work with arms and hands Shortness of breath Diagnosis Because the diagnosis may be difficult to make [utswmed.org]

  Depending on the affected muscles, the condition can cause weakness in the neck and upper and lower extremities and difficulty walking. It may also prevent the patient from holding his or her head up straight. [docdoc.com.sg]

• Chronic Fatigue Syndrome

  Myalgic encephalomyelitis (ME) - 'chronic fatigue syndrome' - will have vague feelings of exhaustion made worse by any effort and no neurological signs to accompany it unless from disuse. The specific tests for MG will be negative. [patient.info]

• Dyspnea

  Dyspnea and muscle weakness improved gradually. Ipilimumab and nivolumab were permanently discontinued. [ncbi.nlm.nih.gov]

• Hoarseness

  This case emphasizes the need to consider systemic diseases in the differential diagnosis of hoarseness and demonstrates the need for careful follow-up in such patients. [ncbi.nlm.nih.gov]

  Symptoms of MG can include: trouble talking problems walking up stairs or lifting objects facial paralysis difficulty breathing due to muscle weakness difficulty swallowing or chewing fatigue hoarse voice drooping of eyelids double vision Not everyone [healthline.com]

  Chewing or swallowing difficulty, causing frequent gagging, choking, or drooling Difficulty climbing stairs, lifting objects, or rising from a seated position Difficulty talking Drooping head Facial paralysis or weakness of the facial muscles Fatigue Hoarseness [web.archive.org]

  […] swallowing difficulty, causing frequent gagging, choking, or drooling Difficulty climbing stairs, lifting objects, or rising from a seated position Difficulty talking Drooping head and eyelids Facial paralysis or weakness of the facial muscles Fatigue Hoarseness [medlineplus.gov]

• Tachypnea

  In a patient with known myasthenia gravis, red flags of an imminent myasthenic crisis include: rapid worsening of primary symptoms or bulbar weakness, tachypnea, tachycardia, respiratory infection, or a decreased forced vital capacity. [first10em.com]

  Anxiety accompanied by tachycardia and tachypnea may be the first sign of air hunger leading to an MC.15 Inspiratory muscle function can be measured in vital capacity (VC) and negative inspiratory force (NIF); expiratory function, by positive expiratory [journals.lww.com]

• Stridor

  Importantly, vocal cord paralysis, leading to stridor, or “crowing” during attempted deep inspirations, may be a sign of severe respiratory distress requiring endotracheal intubation [5, 6]. [intechopen.com]

• Dysphagia

  “Dysphagia is a frequent symptom in patients with MG, 6% to 15% of whom present with dysphagia as the first symptom of the disease,” the research team wrote. [neurologylive.com]

  Dysphagia as a Presenting Symptom of Myasthenia Gravis—Case Report ABSTRACT Dysphagia is a common symptom in otolaryngology, but neuromuscular causes are rarely diagnostic hypotheses to be consider ed. [dx.doi.org]

  Although the presentation is typically observed with complaints of vision and bulbar symptoms such as diplopia, dystonia, and dysphagia, this article presents a case study of an elderly man with a history of increasing upper extremity weakness with complaints [ncbi.nlm.nih.gov]

• Dysphagia

  “Dysphagia is a frequent symptom in patients with MG, 6% to 15% of whom present with dysphagia as the first symptom of the disease,” the research team wrote. [neurologylive.com]

  Dysphagia as a Presenting Symptom of Myasthenia Gravis—Case Report ABSTRACT Dysphagia is a common symptom in otolaryngology, but neuromuscular causes are rarely diagnostic hypotheses to be consider ed. [dx.doi.org]

  Although the presentation is typically observed with complaints of vision and bulbar symptoms such as diplopia, dystonia, and dysphagia, this article presents a case study of an elderly man with a history of increasing upper extremity weakness with complaints [ncbi.nlm.nih.gov]

• Choking

  Myasthenia gravis symptoms can include: Breathing difficulties Fatigue Problems chewing and swallowing (choking) Facial muscle weakness or paralysis such as eyelid drooping Difficulty talking Difficulty climbing stairs A drooping head A common trait of [wakehealth.edu]

  Affected individuals may have unusual facial expressions, difficulty holding up the head, speech impairment (dysarthria), and chewing and swallowing problems (dysphagia) that may lead to choking, gagging, or drooling.Other muscles in the body are also [ncbi.nlm.nih.gov]

  Problems with swallowing (choking and coughing frequently while eating) from throat muscle problems may lead to aspiration of food into the lungs, which will lead to pneumonia. [netwellness.org]

  Severe attacks can be life‐threatening because of weakness of muscles involved in swallowing causing choking, and chest muscles causing difficulty with breathing. In MG, immunosuppressant drugs act mainly by reducing the production of antibodies. [web.archive.org]

  Swallowing, speaking and breathing If the weakness affects the muscles in the mouth, throat and chest, it can cause: difficulty chewing slurred speech a husky, quiet or nasal-sounding voice difficulty swallowing choking and accidentally inhaling bits [nhs.uk]

• Abdominal Cramps

  The side effects of pyridostigmine can include diarrhea, abdominal cramps, nausea, and vomiting. Another medication called glycopyrrolate can be used to reduce these effects. [brighamandwomens.org]

  Common side effects of pyridostigmine include abdominal cramps and diarrhea. Drugs that slow the activity of the digestive tract, such as atropine or propantheline, may be needed to counteract these effects. [msdmanuals.com]

  Potential side effects of this drug include diarrhea, abdominal cramping, and nausea, although taking it with food can reduce gastrointestinal distress. [verywellhealth.com]

• Increased Appetite

  Prednisone — a steroid medication frequently used to treat for MG — can cause increased appetite and weight gain. [rush.edu]

• Hypersalivation

  The most common systemic side effects are sweating, hypersalivation, lacrimation, bronchial constriction and nightmares. [doi.org]

  Features suggestive of a cholinergic crisis (too much medication) include muscle fasciculation, pallor, sweating, hypersalivation and small pupils. If in doubt, perform an edrophonium test. [patient.info]

  An alternative diagnosis should be entertained when muscarinic symptoms (e.g., hypersalivation, sweating, increased secretions, nausea, vomiting, and diarrhea) are present, when symptoms worsen with a Tensilon test, when upper motor neuron signs are noted [pulmonologyadvisor.com]

• Chewing Problem

  If myasthenia gravis affects the throat and face muscles, the person may display symptoms, such as altered speaking, chewing problems, swallowing problems, or limited facial expressions. [docdoc.com.sg]

• Orthostatic Hypotension

  hypotension, impaired heart-rate variability (HRV)[18,19]). [oaepublish.com]

  This may be experienced as a dry mouth, constipation, blurred vision, impaired sweating, and orthostatic hypotension (falls in blood pressure on standing, potentially leading to blackouts). [en.wikipedia.org]

  The most frequent symptoms found in LEMS include abnormal fatigue, weakness of the proximal muscles (particularly in the legs), hyporeflexia, and, dysautonomic manifestations (dry mouth, orthostatic hypotension constipation, and impotence). [intechopen.com]

• Diplopia

  Diplopia or ptosis eventually occur in 90% of patients with MG and account for the initial complaint in 75%. [myasthenia.puhs.org]

  The first noticeable symptom is often eye muscle weakness, resulting in droopy eyelids (ptosis) or double vision (diplopia). [muscle.ca]

  Patients of MG usually present with bilateral ptosis, diplopia and fatigability, which may or may not coexist with generalised weakness, dysphagia and dysarthria. A46-year male presented with unilateral ptosis and diplopia. [ncbi.nlm.nih.gov]

• Blurred Vision

  MG may cause the following: Muscle weakness that increases with muscle use/exercise and improves with rest Drooping eyelids Double and/or blurred vision Difficulty swallowing Difficulty speaking Difficulty walking Weakness of the hand muscles Difficulty [uvahealth.com]

  Case report A 63-year-old male presented with right eyelid drooping, puffiness, blurred vision, and shortness of breath two weeks after an initial infusion of pembrolizumab. [ncbi.nlm.nih.gov]

  DO call your health care provider if you have shortness of breath or your symptoms worsen to include double vision, blurred vision, or weakness. DON’T gain weight and become inactive. DON’T use tobacco. It may worsen shortness of breath. [spectrumhealth.org]

  Common symptoms of MG are a droopy eyelid; blurred vision; and muscle fatigue in the arms, neck, and legs. Shortness of breath; facial paralysis; and difficulty speaking, chewing, or swallowing also may occur. [kidshealth.org]

  People with myasthenia gravis may notice that their eyelids droop, that they develop blurred or double vision or difficulties with chewing, talking or swallowing. Sometimes the muscles of the limbs or the neck can be affected. [ada.com]

• Blepharoptosis

  Blepharoptosis surgery: In some cases, medication or other therapies may not be effective for treating ptosis. [eyehealthweb.com]

  Surgical correction of blepharoptosis in patients with myasthenia gravis. Ophthal Plast Reconstr Surg. 2001 Mar. 17(2):103-10. [Medline]. Bernardini FP, de Conciliis C, Devoto MH. [emedicine.com]

  Effect of local heat versus ice on blepharoptosis resulting from ocular myasthenia. Ophathalmology 2000 ; 107: 2209 – 14. Google Scholar 9. Engstrom, JW. Myasthenia gravis: diagnostic mimics. Semin Neurol 2004 ; 24: 141 – 7. Google Scholar [doi.org]

  Effect of local heat versus ice on blepharoptosis resulting from ocular myasthenia. Ophthalmology. 2000 Dec. 107(12):2209-14. [Medline]. Benatar M. A systematic review of diagnostic studies in myasthenia gravis. [medscape.com]

• Unilateral Ptosis

  Except for unilateral moderate ptosis and restriction of extraocular movements, ocular and systemic examination was normal. Both ice pack and tensilon tests revealed improvement in ptosis. [ncbi.nlm.nih.gov]

  Ptosis may be unilateral or bilateral or may alternate sides. [emedicine.com]

  Case Report A 40-year-old woman, with no psychiatric history but previously diagnosed with generalized MG, presented to the emergency department 18 days after she delivered her first child with fatigue, diplopia, unilateral ptosis, progressive shortness [psychiatrist.com]

  Alternating ptosis, i.e., unilateral ptosis that remits and is followed a variable interval by ptosis of the other eye, is highly suggestive, as is diurnal fatigue of an extraocular muscle causing diplopia to develop and worsen as the day progresses. [myasthenia.puhs.org]

• Muscle Weakness

  The muscle weakness usually causes symptoms of double vision and drooping eyelids (ptosis). What are typical problems with muscle weakness and Myasthenia Gravis? Muscle weakness typically worsens as the muscle is used. [netwellness.org]

  Myasthenia gravis (MG) is an autoimmune disorder that produces weakness and irregularly rapid fatigue of voluntary muscles. [muscle.ca]

  The degree of muscle weakness depends on the severity of the disease. Weakness occurs in the muscles under voluntary control, especially in the eyes, mouth, throat, and limbs. [stanfordchildrens.org]

  Myasthenia gravis (MG) is a neuromuscular disorder that causes muscle weakness because nerve impulses are not adequately transmitted to muscles. [wakehealth.edu]

  The name myasthenia gravis, which is Latin and Greek in origin, means "grave, or serious, muscle weakness." The hallmark of myasthenia gravis is muscle weakness that worsens after periods of activity and improves after periods of rest. [ninds.nih.gov]

• Proximal Muscle Weakness

  CASE PRESENTATION: This report presents a case-vignette of a 72-year-old woman with progressive proximal muscle weakness and myalgias, diagnosed with thymoma-associated myasthenia and bioptically verified granulomatous myositis, with positive autoantibody [ncbi.nlm.nih.gov]

  Proximal muscle weakness is a common symptom of MG and in DM, appearing with bulbar symptoms such as dysphagia or dysarthria. Treatment of MG includes anticholinesterase although not all patients respond. [reumatologiaclinica.org]

  Infection Surgery, anesthesia Pregnancy [5] Medications Stress, heat Diagnostics Differential diagnoses Lambert-Eaton myasthenic syndrome (LEMS) [9] Definition: rare neuromuscular junction disorder characterized by proximal muscle weakness and autonomic [amboss.com]

  Weakness of muscles is typically least in the morning and progresses as the day progresses. Weakness increases as there is increased exertion and gets better with rest. Proximal muscle weakness is more often seen than distal muscle weakness. [symptoma.com]

• Neck Weakness

  An 82-year-old woman developed neck weakness and dysarthria with antibodies against acetylcholine receptor (AChR) and low-density lipoprotein receptor-related protein 4 (LRP4). [ncbi.nlm.nih.gov]

  Other less common presentations may include isolated neck weakness (drop head syndrome), distal limb weakness or isolated respiratory muscle weakness. [minneapolisclinic.com]

  Although symptoms vary slightly from one person to the next, most people with myasthenia gravis will experience at least some of the following: Weakness of the arms, hands, fingers, legs, and neck Weakness of the eye muscles (a condition called ocular [everydayhealth.com]

  Strength: Trends in weakness (e.g. especially neck weakness, which may function as a surrogate of oropharyngeal musculature). FVC: Trends in forced vital capacity. Oxygenation: Generally, myasthenia shouldn't cause significant hypoxemia. [emcrit.org]

• Muscular Atrophy

  MDA addresses the muscular dystrophies, spinal muscular atrophy, ALS, Charcot-Marie-Tooth disease, myasthenia gravis, Friedreich's ataxia, metabolic diseases of muscle, and inflammatory diseases of muscle, for a total of more than 40 neuromuscular diseases [brainfacts.org]

  There is no muscular atrophy or loss of sensation. It characteristically affects the ocular and other cranial muscles and tends to fluctuate in severity. [medical-dictionary.thefreedictionary.com]

  Aird RB Muscular atrophies and dystrophies. Baker ABed. Clinical Neurology. Vol 3 New York, NY Hoeber & Harper1955;1498- 1562Google Scholar 3. Schwab RSLeland CC Sex and age in myasthenia gravis as critical factors in incidence and remission. [jamanetwork.com]

• Neck Muscle Weakness

  Muscles of extremities, neck, and torso are affected symmetrically and muscle weakness isn’t equal when comparing musculature of different parts of patient’s body. [neuroimmunology.lv]

• Dysarthria

  Patients of MG usually present with bilateral ptosis, diplopia and fatigability, which may or may not coexist with generalised weakness, dysphagia and dysarthria. A46-year male presented with unilateral ptosis and diplopia. [ncbi.nlm.nih.gov]

  His initial exam revealed labial and lingual dysarthria with prolonged speech and bilateral ptosis which improved with ice pack test. There was no fatigability of his axial muscles or ophthalmoplegia. [n.neurology.org]

• Slurred Speech

  It causes fluctuating weakness of the voluntary muscles of the body and can include a drooping eyelid, blurred or double vision, slurred speech, difficulty chewing and swallowing, weakness in the arms and legs, and difficulty breathing. [myastheniagravis.org]

  DIAGNOSES: The patient firstly suffered from fluctuant symptoms, including slurred speech, double eyelid ptosis, and weakness of limbs. [ncbi.nlm.nih.gov]

  The first symptoms of myasthenia gravis may be: Weakness of the eye muscles Difficulty in swallowing Slurred speech Myasthenia gravis is an autoimmune disease because the immune system--which normally protects the body from foreign organisms--mistakenly [mercyhealth.org]

  Main complains are slurred speech, chewing difficulty, inability to swallow, liquids are flowing back through the nose (caused by paresis of soft palate). [neuroimmunology.lv]

• Nasal Speech

  Dysarthria: Speech difficulties manifesting as dysarthria and nasality are commonly seen in MG. [intechopen.com]

  With weakness of palatal muscles, nasal speech develops as air escapes through the nose. This may become increasingly apparent with prolonged speaking. Liquid may also escape through the nose during attempted swallowing with nasal regurgitation. [ncbi.nlm.nih.gov]

• Chronic Progressive External Ophthalmoplegia

  This includes: an intracranial lesion, tumor, pituitary adenoma, aneurysm, fascicular lesion of CN 3, evolving CN 3 palsy, post-viral neuropathy, thyroid disorders *, migraines, meningitis, Horner's syndrome, levator aponeurosis, chronic progressive external [eyewiki.aao.org]

  Chronic progressive external ophthalmoplegia (CPEO) may manifest as ptosis and decreased eye movements. [emedicine.com]

  See ocular dysmetria ; chronic progressive external ophthalmoplegia ; Cogan's lid twitch sign. my·as·the·ni·a gra·vis ( mīas-thēnē-ă grāvis ) [MIM*254200] Disorder of neuromuscular transmission marked by fluctuating weakness and fatigue of some voluntary [medical-dictionary.thefreedictionary.com]

• Cranial Nerve Involvement

  […] polyneuropathy No clear association Acute motor axonal neuropathy (AMAN) Isolated muscle weakness without sensory symptoms in less than 10%; cranial nerve involvement uncommon Rare in Europe and North America, substantial proportion (30-65%) in Asia [en.wikipedia.org]

The anti-acetylcholine receptor antibody test is a very specific test which is done to diagnose myasthenia gravis [7]. This is a very reliable test and is positive in almost 90% of the patients. Antistriated muscle antibody is another sensitive test to be diagnose myasthenia gravis. Muscle weakness should be tested for different parts of the body:

• Looking upward and sideways for 30 seconds.
• Walking 30 steps on both the toes or heels.
• Keeping arms stretched for 60 seconds.

If any of the above tests is positive, i.e. there is fatigue at the end of the set time, it reveals that the patient is suffering from myasthenia gravis.

Single fiber electromyography might be performed [6] [8]. Repeated electrical impulses are given to the muscle fibers of the patient and electrodes are placed in to the muscle fiber to check for action potentials changes of the muscle fiber. This is a very specific test for myasthenia gravis and helps confirm the diagnosis.

Ice test: Application of ice will characteristically improve the weakness in the patients muscle and this is a very important non-invasive test to be performed. The basis of performing this test is that at lower temperatures acetylcholinesterase is inhibited, leaving more acetylcholine available at the junctions. Thus the patient can perform better as weakness is less [9].

Edrophonium test: Intravenous edrophonium bromide or tensilon will cause inhibition of breakdown of acetylcholine and thus improve weakness temporarily [10]. This test is usually performed only after all the other tests have failed to give an accurate result.

Radiography and CT scan or MRI will help confirm the diagnosis and show if a thymoma or any other tumor is leading to myasthenia gravis.

• Anterior Mediastinal Mass

  Video-assisted thoracoscopy is become a widely accepted approach for the resection of anterior mediastinal masses, including thymoma. [ncbi.nlm.nih.gov]

  Anterior mediastinal mass surgically resected. Hematoxylin & eosin stain. Histopathological image of thymoma type B1. Anterior mediastinal mass surgically resected. Cytokeratin CAM5.2 immunostain. [en.wikipedia.org]

  The front of the mediastinum is called the anterior mediastinum, so abnormalities in the thymus gland are often called Anterior Mediastinal Masses. [pennmedicine.org]

  CT scan of chest showing an anterior mediastinal mass (thymoma) in a patient with myasthenia gravis. Increasing left ptosis developing upon sustained upward gaze in patient with myasthenia gravis (A through F). [web.archive.org]

  mediastinal mass and suspected thymoma, and also to exclude brain and orbit mass lesion inducing cranial nerve palsies in ocular MG. 8.4 Pharmacological tests In MG, the number of AChRs at the NMJ is low due to inhibition by the autoantibody. [intechopen.com]

• Hypercapnia

  Hypercapnia is an extremely late finding in this context. [emcrit.org]

  Preliminary studies suggest that bilevel positive airway pressure (BiPAP) can prevent intubation in patients with myasthenic crisis without overt hypercapnia and should be considered in the patient who can be closely monitored. [9, 14] Hypercapnia present [emedicine.medscape.com]

  Hypercapnia is a late sign. An FVC of less than 15 mL/kg or a declining negative inspiratory force (NIF) usually indicate the need for intubation. Aggressive chest physiotherapy and pulmonary toilet are key in management. [pulmonologyadvisor.com]

• Decreased Vital Capacity

  Pulmonary function testing usually reveals a decreased vital capacity (VC) and decreases in inspiratory and expiratory muscle strength, which improve after administration of mestinon. [pulmonologyadvisor.com]

• Thymus Hyperplasia

  hyperplasia HLA-DRB1 DR3  DR7# Caucasian 192 <1  −6  <1  −6 [9] Thymus hyperplasia HLA-DRB1 DR16 Caucasian 192 −5 [9] Thymus hyperplasia HLA-DRB1 DR9 Caucasian 192 −3 [9] ATA (+) with no thymic abnormalities HLA-DRB1 DR7 Caucasian 59 [9] ATA (−) with [hindawi.com]

  The thymus gland plays a role in the origin and development of MG. It is known that about 50% of anti-AchR positive patients have thymus hyperplasia and 10-15% have a thymic tumor. [minneapolisclinic.com]

  Palabras clave : Myasthenia Gravis; Thoracic Surgery; Thymectomy; Thymus Hyperplasia. [scielo.conicyt.cl]

  Rudimentary thymus’ tissues have an important role in pathogenesis of myasthenia; those tissues are promoting autoimmune reactions. 65% of patients with myasthenia have thymus’ hyperplasia and 10-15% have thymus tumor – thymoma. [neuroimmunology.lv]

  These antibodies are found in serum samples from 85% of patients with MG with thymoma and from approximately 50% of those with late-onset MG, but are extremely rare in samples from those with early-onset MG (MG with thymus hyperplasia).19 The presence [jamanetwork.com]

• HLA-B8

  People with certain genetic markers (called HLA-B8, DR3) are more likely to develop MG. Infants of mothers with MG are more likely to develop a temporary form of the condition, called neonatal MG. [umms.org]

  This suggests an association of MG with HLA B8 and DR3. In terms of underlying genetic abnormalities, work is ongoing[8]. Presentation Almost all MG patients will have ocular manifestations at some point during the course of their disease. [patient.info]

  The early peak shows a female predominance, approximately 3:1, and an association with HLA-B8, HLA-DR3, and HLA-DR1, the latter being more specific for ocular MG. [eyewiki.aao.org]

• HLA-DR3

  The early peak shows a female predominance, approximately 3:1, and an association with HLA-B8, HLA-DR3, and HLA-DR1, the latter being more specific for ocular MG. [eyewiki.aao.org]

  HLA-B8, and non-HLA genes late-onset myasthenia gravis1,2 onset on or after age 50 years with disease characterized by thymic atrophy presence of AChR antibodies associated with HLA-DR2, HLA-B7, and HLA-DRB115.01 genes thymoma-associated myasthenia [dynamed.com]

  This family-based association test determined the presence of genetic linkage between the HLA-DR3 allele and MG with thymus hyperplasia [9]. [hindawi.com]

  […] associated with the likelihood of encouraging other women with myasthenia gravis to abstain from having children. [5] Etiology Genetic studies have revealed a correlation between early-onset myasthenia gravis, which affects women of childbearing age, and the HLA-DR3 [emedicine.com]

• HLA-A1

  In the sequel study, Garchon and coworkers reevaluated the contribution of the extended 8.1 HLA haplotype, including Class I HLA-A1 and B8 loci and Class II HLA-DR3 allele, to the occurrence of MG with thymus hyperplasia. [hindawi.com]

  The histocompatibility complex profile includes HLA-A1, -A3, -B7, -B8, -DRw3, and -DQw2 (though these have not been shown to be associated with the strictly ocular form of MG). [emedicine.com]

• HLA-B7

  HLA-B8, and non-HLA genes late-onset myasthenia gravis1,2 onset on or after age 50 years with disease characterized by thymic atrophy presence of AChR antibodies associated with HLA-DR2, HLA-B7, and HLA-DRB115.01 genes thymoma-associated myasthenia [dynamed.com]

• HLA-DRw3

  The histocompatibility complex profile includes HLA-B8, HLA-DRw3, and HLA-DQw2 (though these have not been shown to be associated with the strictly ocular form of MG). Both SLE and RA may be associated with MG. [web.archive.org]

Pharmacology includes medication and immunosuppressive agents like corticosteroids, cyclosporine, plasmapheresis and intravenous immunoglobulin. Thymectomy is another option for people who have thymoma.

Acetylcholineesterase inhibitors and immunomodulations are the most important modalities of treating patients with myasthenia gravis. They mostly prevent the acetylcholine from degrading and the weakness of the muscles thus reduces. This remains the initial line of treatment followed by corticosteroids as per need. Long term corticosteroids should be avoided as they may lead to further complications like osteoporosis, weight gain, diabetes etc.

Plasmapheresis is a procedure where the plasma is exchanged with fresh plasma which helps in removing out the circulating antibodies from the body. The new plasma contains lesser acetylcholine antibodies, reducing muscle weakness and fatiguability. This is short term relief for the patient especially if they undergo surgery. Exercise helps in a better prognosis.

The prognosis is good today as science has advanced a lot. Patients earlier had 3 to 4 % morbidity but now it has reduced further. Long term use of medications will give these patients a near normal life with very minimal complications. The only threat for these patients is the weakness affecting their respiratory muscles. This might lead to a need for supportive respiration i.e. ventilator support.

Myasthenia gravis is an autoimmune disorder. It is the result of antibodies against the acetylcholinesterase receptors present at neuromuscular junctions which are responsible for muscular movements. These circulating antibodies cause weakness of the body by blocking acetylcholine receptors at the neuromuscular junctions.

Thymus gland abnormality is seen in 75% of the patients with myasthenia gavis. Very few patients may have a thymus tumor called as thymoma.

Certain drugs may induce myasthenia gravis e.g. Penicillamine, Antibiotics, lithium, Beta-adrenergic receptor blocking agents.

Myasthenia gravis affects people of both the sexes but is more commonly seen in women of the age group 20 to 40 years. It also affects people who have thymus gland abnormalities. More commonly, it is seen in people who have other autoimmune disorders. The female to male ratio is 3:2 whereas in children the ratio is typically 5:1.

Voluntary muscles of the body move by the excitatory impulses sent by nerves to the muscle through the neuromuscular junctions. In myasthenia gravis, the circulating antibodies block the receptors for acetylcholine at the neuromuscular junction leading to failure of transmission of efferent impulses to the muscle.

The acetylcholine receptor present in the motor end plate is called nicotinic acetylcholine receptor. Myasthenia gravis usually causes blocking or destruction of this receptor sites placed all over the body leading to weakness of varying degrees in voluntary muscles [2]. In a healthy person, the nerve carries impulses from the brain and passes on to the muscles through the neuromuscular junction where the neurotransmitter acetylcholine is released. This neurotransmitter then causes excitation of the receptor sites present on the muscular end of the junction.

In a myasthenia gravis patient, the nicotinic receptor sites are destroyed much faster than the body can repair and there is around 80% reduction in the receptor sites [3]. Even though acetylcholine is present, there aren’t enough receptor sites to bring about purposeful muscle movements.

Myasthenia gravis might be prevented by avoiding ingestion of certain drugs which may cause this disease. However, it is essentially an autoimmune disorder and there is no exact way of preventing it.

Myasthenia gravis is an autoimmune disorder affecting the neuromuscular junctions between nerves and muscles affecting voluntary movements. It causes muscle weakness in varying proportions depending on the degree of affection.

It is also known as Goldflam disease and affects the voluntary group of muscles [1]. The term “Myasthenia gravis” literally originates from the Greek and Latin words which mean “grave muscular weakness.”

Myasthenia gravis is an autoimmune disorder which affects the neuromuscular junction (the junction where the nerve synapses meet the muscle fiber and transmits the impulse carried from the brain to the muscle). There are circulating antibodies that block the receptors for the neurotransmitter acetylcholine which are present at the junction and thereby do not allow the voluntary muscle to contract and produce movement.

This is a chronic disorder and gradually many of the receptor sites are destroyed leading to fatigability. There is drooping of eyelids on repeated eye strain, difficulty in swallowing or chewing, slurred or impaired speech, weakness of hands, fingers, legs. There may be weakness of head and difficulty in holding the head up straight. The weakness is least in the morning and keeps on increasing as the day progresses and the most important aspect of this weakness is that there is amelioration of weakness on rest.

This disease also affects children and neonates if the mother has the disease at the time of conception. Ice test, tensilon test and electromyography are the basic tests done for investigating this disease. Prognosis is good and patients are kept on long term acetylcholinesterase inhibitors, intravenous immunoglobulin and plasmapheresis.

1. ContiFine B, Milani M, Kaminski H et al. Myasthenia Gravis: past, present and future. J Clin Invest. 2006 Nov 1; 116(11):2843-54.
2. Mc Grogan, Sneddon S, de Vries CS. The incidence of myasthenia gravis: a systematic literature review. Neuroepidemiology. 2010;34(3):171-83.
3. Bedlack RS, Sanders DB. How to handle myasthenia crisis. Essential steps in patient care. Postgrad Med. 2004 Apr;107(4):211-4,220-2.
4. Patrick J, Lindstrom J. Autoimmune response to acetylcholine receptor. Science. 1973 May 25;180(4088):871-2.
5. Téllez-Zenteno JF, Hernández-Ronquillo L, Salinas V, Estanol B, et al. Myasthenia gravis and pregnancy: clinical implications and neonatal outcome. BMC Musculoskelet Disord. 2004 Nov 16;5:42.
6. Selvan VA. Single-fiber EMG: A review. Ann Indian Acad Neurol.2011 Jan; 14(1): 64–67.
7. Losen M, Stassen MH, Martínez-Martínez P, Machiels BM et al. Increased expression of rapsyn in muscles prevents acetylcholine receptor loss in experimental autoimmune myasthenia gravis. Brain. 2005 Oct; 128 (Pt 10): 2327–37.
8. Juel VC. Myasthenia gravis: management of myasthenic crisis and perioperative care. Semin Neurol. 2004 Mar; 24 (1): 75–81.
9. Cup EH, Pieterse AJ, Ten Broek-Pastoor JM, Munneke M, et al. Exercise therapy and other types of physical therapy for patients with neuromuscular diseases: a systematic review. Arch Phys Med Rehabil. 2007 Nov; 88 (11): 1452-64.
10. Seybold ME. The office Tensilon test for ocular myasthenia gravis. Arch Neurol. 1986 Aug; 43 (8): 842–3.