A myasthenic crisis (MC) is a potentially fatal condition which requires intensive care and is associated with respiratory failure due to muscle weakness, caused by the autoimmune disorder myasthenia gravis (MG).
Presentation
Prior to having MC, patients with MG most often display increased generalized weakness. One study indicated that 76% of patients that had MC displayed signs of generalized asthenia before the attack [7]. Other signs of an impending MC in MG patients include bulbar weakness and decreased strength of the respiratory muscles, which in one study occurred in 19% and 5% of patients, respectively [7]. Unfortunately, the generalized symptoms displayed by patients prior to MC may hide the underlying breathing issues, which is the primary concern in these patients. Respiratory symptoms may be sudden, leading to abrupt respiratory failure, or gradual, where patients experience a relative increase in respiratory weakness compared to other muscles. Rarely, patients with MC will present with only respiratory failure [28] [29].
Entire Body System
- Weakness
Myasthenic crisis results from weakness of upper airway muscles leading to obstruction and aspiration, weakness of respiratory muscles leading to reduced tidal volumes, or from weakness of both muscle groups. [ncbi.nlm.nih.gov]
Respiratory symptoms may be sudden, leading to abrupt respiratory failure, or gradual, where patients experience a relative increase in respiratory weakness compared to other muscles. [symptoma.com]
- Falling
MG flares vary from patient to patient but may include worsened double vision, increased arm weakness, falling, unsteady walking, or having a hard time swallowing. [mg-mi.org]
In both patients, the anti-acetylcholine (anti-AChR) titer failed to fall sufficiently after completing PP. [ncbi.nlm.nih.gov]
Falls 4.) Medication side-effects Because people are asking about it, I'll be blogging about these one at a time over the next few days. Let's start with the scary one: respiratory failure. [joybenchmarks.com]
If VC falls below 15 ml/kg, respiratory failure ensues for which elective intubation is usually necessary to support ventilation so as to allow O 2 exchange and prevent muscle fatigue. [jnaccjournal.org]
- Weight Loss
It’s not clear how the two are related, but it’s important to be aware of its symptoms in case it does appear: 6 ✓ Chest pains ✓ Fever ✓ Shortness of breath ✓ Weight loss ✓ Coughing ✓ Night sweats In addition, there’s a 50 percent chance that a thymoma [articles.mercola.com]
loss Non-productive weak cough, with more secretions or having the problem to clear out secretions from the airways Having some difficulty with speaking and breathing Some pulling noted when a person tries to breath at the skin located between the ribs [healthsurgical.com]
loss Diagnosis of Myasthenic Crisis Pulmonary function tests (PFTs): An evaluation of how well your lungs are working by measuring lung volume, capacity, rate of flow, and gas exchange. [belmarrahealth.com]
If your thyroid is underactive, you may have difficulties dealing with cold, weight gain and other issues. An overactive thyroid can cause difficulties dealing with heat, weight loss and other issues. Autoimmune conditions. [mayoclinic.org]
Respiratoric
- Dyspnea
He had experienced ptosis, increased body weight with edema, and fatigue with dyspnea. He presented at our emergency department with disturbed consciousness. He was originally diagnosed with myxedema coma, and he required artificial respiration. [ncbi.nlm.nih.gov]
Sitting the patient upright may help temporize the patient’s dyspnea while preparing for intubation. Even if not intubated, patients presenting with myasthenic crises will need admission to the ICU. [wueverydayebm.blogspot.com]
Among patients with myasthenia gravis, ~16% may have myositis and ~9% may have myocarditis.(34172516) Dyspnea may be due to checkpoint pneumonitis. [emcrit.org]
Called also developmental crisis. myasthenic crisis the sudden development of dyspnea requiring respiratory support in myasthenia gravis ; the crisis is usually transient, lasting several days, and accompanied by fever. oculogyric crisis a symptom of [medical-dictionary.thefreedictionary.com]
Gastrointestinal
- Nausea
Steps for respiratory support: - No respiratory distress --> no need for respiratory support --> admit to step down - Mild/Moderate respiratroy distress --> consider BIPAP or Hiflow nasal cannula if BIPAP is contraindicated (secretions - nausea - vomiting [neurologyresidents.com]
But because of her nausea and vomiting, she has missed the last two doses. History and assessment hints Two hours after Ms. [myamericannurse.com]
[…] acute ↓ in the need for anticholinesterase medication, resulting in 'overmedication' with the customary doses; the Tensilon test exacerbates this form of myasthenic crisis; cholinergic crises may be either • Muscarinic crisis Abdominal pain, diarrhea, nausea [medical-dictionary.thefreedictionary.com]
But because of her nausea and vomiting, she has missed the last two doses. Two hours after Ms. Robbins’ admission, you enter her room to administer a pyridostigmine dose and find she has right eyelid ptosis and her head is drooping. [americannursetoday.com]
Risks and Complications Tensilon may produce side effects such as nausea, abdominal discomfort, dizziness, blurred vision, fainting, breathing failure and rapid, frequent blinking of the eyelids. [healthcommunities.com]
- Vomiting
[…] the better, in the course of an acute disease. 2. a sudden paroxysmal intensification of symptoms in the course of a disease. addisonian crisis ( adrenal crisis ) the symptoms accompanying an acute onset or worsening of addison's disease : anorexia, vomiting [medical-dictionary.thefreedictionary.com]
But because of her nausea and vomiting, she has missed the last two doses. History and assessment hints Two hours after Ms. [myamericannurse.com]
She states she has had a fever above 102° F, back pain, vomiting, and painful urination for the last 24 hours. Her urinalysis reveals bacteria. [americannursetoday.com]
Steps for respiratory support: - No respiratory distress --> no need for respiratory support --> admit to step down - Mild/Moderate respiratroy distress --> consider BIPAP or Hiflow nasal cannula if BIPAP is contraindicated (secretions - nausea - vomiting [neurologyresidents.com]
She denies infectious symptoms such as fevers, chills, cough, dysuria, vomiting, or diarrhea. Given her presentation, there is concern for myasthenic crisis. [wueverydayebm.blogspot.com]
Cardiovascular
- Tachycardia
There is bradycardia in cholinergic crisis while tachycardia in myasthenic crisis. Secretions are normal in myasthenic crisis while increased in cholinergic crisis. [allmedicalstuff.com]
Subsequent examinations showed 1) unremarkable chest film; 2) sinus tachycardia on ECG; 3) cardiac enzymes within normal range; and 4) brain, neck, and chest computer tomography revealed no abnormal organic lesions. [neuro.psychiatryonline.org]
Tachycardia, tachypnea, perspiration Use of accessory muscles and inability to lift the head from the bed Orthopnea or development of an abdominal paradoxical breathing pattern when supine Weak cough Interrupted speech (inability to perform single-breath [emblog.mayo.edu]
It starts with occurrence of short attacks of dyspnoea, frequently with inspiratory strider, increasing bulbar weakness, restlessness, insomnia, tachycardia and hypertension 1. [jpma.org.pk]
Cardiac arrhythmias seen were atrial fibrillation in one patient and narrow complex tachycardia and sinus bradycardia in another patient, this patient was also suffering from thyrotoxicosis. [annalsofian.org]
Eyes
- Diplopia
Myathenic Crisis: Seropositive myasthenia gravis (IIIb) presenting with myasthenic crisis manifested by worsening shortness of breath, dysphagia, diplopia, nasal intonation, and generalized weakness. [neurologyresidents.com]
NMJ) → decreased muscle strength Dysfunction of thymus gland or immune response to infectious antigens → abnormal thymus → often thymoma present Clinical Presentation General weakness Proximal muscles Neck extensors Facial or bulbar muscles: Ptosis, diplopia [emdocs.net]
On third post operative day, she complained of generalized weakness of neck and limbs, difficulty in getting up from bed, ptosis, diplopia, dysarthria, and dyspnea. On examination, pupils were found to be constricted. [joacc.com]
Beta-adrenoreceptor antagonists and diplopia. Lancet 1982;2(8302):826-827. 9. Choi KL, Wat MS, Kung AW, et al. Phaeochromocytoma associated with myasthenia gravis precipitated by propranolol treatment. Aust N Z J Med 1995;25:257. 10. [ispub.com]
The patient was a man in his seventies who developed symptoms of myasthenia gravis in the form of varying ptosis, diplopia and jaw claudication. [tidsskriftet.no]
- Blurred Vision
vision, bronchial hypersecretion due to parasympathetic hyperresponse • Nicotinic crisis Muscle weakness, fasciculations, cramping and dysphagia, due to overdepolarization at the neuromuscular junction. [medical-dictionary.thefreedictionary.com]
Risks and Complications Tensilon may produce side effects such as nausea, abdominal discomfort, dizziness, blurred vision, fainting, breathing failure and rapid, frequent blinking of the eyelids. [healthcommunities.com]
In over 50% of cases myasthenic patients present with ocular symptoms including blurred vision, ptosis, diplopia. 15% of patients present with bulbar symptoms including ptosis, dysarthria, dysphagia, and fatigue when chewing [2]. [nuemblog.com]
Musculoskeletal
- Muscle Weakness
PM with respiratory muscle weakness is rare. We suggest that the possibility of other neurological disorder complications should be considered when PM patients have respiratory muscle weakness out of proportion to the serum CK level. [ncbi.nlm.nih.gov]
[…] of respiratory muscle weakness and/or oropharyngeal muscle weakness leading to upper airway obstruction. 12. [slideshare.net]
Myasthenic crisis results from weakness of upper airway muscles leading to obstruction and aspiration, weakness of respiratory muscles leading to reduced tidal volumes, or from weakness of both muscle groups. [scholars.duke.edu]
- Myopathy
The unusual presentation of our patient contributes to expand the clinical phenotype of PEO1 mutations and reinforces the need to consider mitochondrial myopathy as differential diagnosis of myasthenia gravis even in the case of acute onset symptoms. [ncbi.nlm.nih.gov]
[…] restrictive lung disease, recurrent aspiration pneumonia EXAMINATION swallow functional capacity effectiveness of cough jaw closure often weak and cannot be maintained against resistance airway assessment focused RESP and CVS examination evidence of proximal myopathy [lifeinthefastlane.com]
Myasthenia gravis and steroid-induced myopathy of the respiratory muscles. Intensive Care Med 1992;18:424-426. 32. Bae JS, Go SM, Kim BJ. Clinical predictors of steroid-induced exacerbation in myasthenia gravis. [ispub.com]
For example, differential diagnoses for patients with ocular weakness may include thyroid ophthalmopathy, oculopharyngeal muscular dystrophy and mitochondrial myopathy. [clevelandclinicmeded.com]
There is also chance to develop steroid myopathy. [nnjournal.net]
- Neck Weakness
Since many thymoma patients have RyR antibodies, neck weakness and nonlimb bulbar distribution of symptoms are initial characteristic features. Such symptom distribution should raise the suspicion of thymoma2828. [scielo.br]
Neurologic
- Paresis
Accessory muscle use Expiratory function Positive expiratory force Weak cough Difficulty counting to 20 in a single breath Upper airway (bulbar) weakness: dysphagia, nasal regurgitation, nasal quality of speech, staccato speech, jaw weakness, bifacial paresis [emdocs.net]
Selective affection of the laryngeal muscles with vocal cord paresis and stridor has been reported ( 5 ). [tidsskriftet.no]
In 1879, Wilhelm Erb (Heidelberg, Germany) described three cases of myasthenia gravis in the first paper dealing entirely with this disease, whilst bringing attention to features of bilateral ptosis, diplopia, dysphagia, facial paresis, and weakness of [physio-pedia.com]
- Limb Weakness
Limb weakness is the first sign in 10 percent of patients. The arm and leg muscles may weaken, affecting activities such as lifting or walking. [medicalnewstoday.com]
Some individuals may also develop limb weakness and easy fatigability of arm and leg muscles. [rarediseases.org]
She presented at a local hospital with nasal-sounding speech, difficulty chewing, dysphagia, respiratory difficulties, and limb weakness, for which she received tracheal intubation and mechanical ventilation. [frontiersin.org]
Limb weakness is usually proximal > distal. features of weakness Fatigability: ongoing effort rapidly provokes worsening weakness. Strength improves with rest. Asymmetric and fluctuating in severity over time. [emcrit.org]
- Confusion
[…] acute disease. 2. a sudden paroxysmal intensification of symptoms in the course of a disease. addisonian crisis ( adrenal crisis ) the symptoms accompanying an acute onset or worsening of addison's disease : anorexia, vomiting, abdominal pain, apathy, confusion [medical-dictionary.thefreedictionary.com]
Cholinergic Crisis: excessive anticholinesterase medication; aka too much acetylcholine Easily confused with a Myasthenia Crisis Typically not seen with doses of pyridostigmine Can differentiate by the presence of cholinergic symptoms including bradycardia [emblog.mayo.edu]
References Answer Answer One of the confusing factors in treating patients with myasthenia gravis is that insufficient medication (ie, myasthenic crisis) and excessive medication (ie, cholinergic crisis) can present in similar ways. [medscape.com]
Cardiol vol. 27n. 3 http://dx.doi.org/ Introduction: The takotsubo syndrome is a rare clinical entity commonly associated with elderly women (ratio 6:1), easily confused with an acute ischemic syndrome, strangely associated with a myasthenic crisis. [scielo.org.mx]
- Polyneuropathy
unspecified G63 Polyneuropathy in diseases classified elsewhere G64 Other disorders of peripheral nervous system G65 Sequelae of inflammatory and toxic polyneuropathies G65.0 Sequelae of Guillain-Barré syndrome G65.1 Sequelae of other inflammatory polyneuropathy [icd10data.com]
State University School of Medicine Detroit MI Divulgaciones RPL currently serves on an Advisory Board for Argenx for myasthenia gravis (MG), and was an Advisory Board member for Argenx (developing a clinical trial for chronic inflammatory demyelinating polyneuropathy [bestpractice.bmj.com]
MRI of brain and/or spine may be useful, depending on anatomic distribution of weakness Electrodiagnostic studies (these may not have excellent performance, but they offer the ability to evaluate broadly for myositis, polyneuropathy, and/or myasthenia [emcrit.org]
The differential diagnosis for MG patients with limb weakness is broader and may include motor neuron disease, Guillain-Barré syndrome, myopathy and chronic inflammatory demyelinating polyneuropathy. [clevelandclinicmeded.com]
Chronic inflammatory demyelinating polyneuropathy (CIDP): CIDP is an immune-mediated disorder of the peripheral nervous system, the patients of which experience flaccid and weakness of extremities, hypoesthesia, reduction or loss of deep tendon reflexes [nnjournal.net]
- Slurred Speech
Severe slurred speech and difficulty managing secretions are also signs of potential impending MG crisis. [myasthenia.org]
Call your doctor if any of these occur: Drooping eyelid Blurred or double vision Slurred speech Problems chewing and swallowing Weakness in the arms and legs Chronic fatigue Trouble breathing [hopkinsmedicine.org]
The first symptoms of myasthenia gravis in most people with the disease is weakness of the eye muscles while others may have signs and symptoms of swallowing problems and slurred speech. [medicinenet.com]
Workup
The respiratory failure associated with MC is often serious enough to require intubation. Patients who experience MC during surgery should remain intubated if respiratory failure persists after surgery is completed. If a patient who has not been diagnosed with MG present with MC, diagnosis of MG should be established, using physiological or immunological assays, to rule out other causes of respiratory failure. Imminent ventilation failure can be verified using lung function tests and diagnosis of MC can be confirmed in patients with MG using single-fiber electromyography or repetitive motor neuron stimulation. Edrophonium tests should be avoided due to the chances of increasing muscle fatigue.
Treatment
MC requires intensive care, including ventilation, to address respiratory failure and should be treated with immunoglobulin (Ig) administration or plasma exchange (PE) [10] [11]. Ig should be administered intravenously each day for five days at a dose of 400 mg/kg [30] concurrently with high doses enteral administration of corticosteroids (eg. prednisone 1-1.5 mg/kg/day). PE to treat MC involves the administration of 1 volume of plasma (approximately 3-4 L) every other day for 10 days (5 exchanges total) [31]. High-dose corticosteroids should also be administered with PE and fluids can be replaced with normal saline supplemented with five percent albumin [32] [33]. Patients who cannot tolerate corticosteroids may be administered cyclosporine although cyclosporine requires at least a month to produce desired effects [32] [24]. Patients who experience MC that have pneumonia should be closely monitored due to their increased risk of developing aspiration pneumonia because of their immune suppressed state [34]. If patients develop an acute MG attack, plasmapheresis to remove autoantibodies may be performed.
Patients that develop MC in developing countries, without access to intensive care units, have a severely decreased survival rate. One study on outcomes of MC in developing countries revealed that patients who were treated in an intensive care unit had a 100% survival rate whereas only a 50% survival rate was observed in patients that did not receive intensive care. Most patients with MC that receive a thymectomy display a partial reduction in symptoms and 35% of patients no longer experience any symptoms [35], therefore, if possible patients with MC should receive a thymectomy after puberty [36].
Prognosis
The mortality rates associated with MC have dramatically declined over time from a 75% mortality rate in the mid-1900s to only 5% since the 1990s [24] [25] [26] [27]. This decline in mortality is due to improvements in therapy along with better intensive care. Although mortality rates have dropped significantly, patients who experience MC have considerable morbidity due to this condition.
Etiology
A number of factors have been identified as contributors to a myasthenic crisis, although this condition may spontaneously occur in patients with MG [7] [8] [9]. The most common precipitating factor is an infection in patients with MG [7] [8]. Other contributing factors include surgery, reducing immunosuppressives, pregnancy, elevated body temperature, hyperthyroidism, stress, drugs or medications associated with weakness and drug withdrawal. Medications that may increase weakness in patients with MG include medications for dysrhythmia (beta-blockers, quinidine, procainamide), specific antibiotics (tetracycline, macrolides, aminoglycosides, fluoroquinolones, chloroquine), muscle relaxants and some antipsychotic drugs [9] [10] [11] [12].
Epidemiology
Of all patients with MG, approximately 10 to 20 percent will develop a myasthenic crisis and this will be the first sign of MG in roughly 13 to 20 percent of patients [7] [13] [14] [15] [16] [17] [18] [19] [20]. Each year close to three percent of individuals with MG experience such a crisis [7]. Patients diagnosed with MG who develop a myasthenic crisis will generally have this condition soon after diagnosis (median time around 8 months to one year after diagnosis) [18] [19]. Myasthenic crises are two times more likely to occur in women than men with the highest incidence in women between the ages of 30 to 50 years old. The age of onset of MC follows a bimodal distribution with early onset mainly affecting women and late onset occurring at similar levels in both genders [21] [22] [23].
Pathophysiology
MG is an autoimmune disorder most commonly associated with autoantibodies against the acetylcholine receptors (AChR-MG) found at the motor end plate of the neuromuscular junction. Decreased sensitivity of skeletal muscles to acetylcholine occurs through direct blocking of the acetylcholine receptors by antibodies and through the accumulation of immune complexes and activation of complement at the motor end plate. Due to the decreased numbers of available AChRs and other changes at the motor end plate caused by inflammation, normal levels of ACh aren't sufficient to reach the threshold necessary to induce an action potential. Therefore, neural impulses that would normally induce muscle contraction in healthy individuals may fail to produce a response in individuals with MG. This causes muscle dysfunction and subsequent weakness in patients with MG. MC is a health crisis that may occur in patients with MG associated with a weakening of the muscles needed for respiration leading to respiratory distress. There are two distinct types of active MG with the most common type characterized by the presence of AChR-MG autoantibodies. The majority of studies focus on patients with AChR-MG autoantibodies. MG may also occur due to passive immunity when AChR-MG autoantibodies are passed through the placenta leading to neonatal MG. Neonatal MG caused by the passive immunity should resolve on its own.
Prevention
Around 50% of patients with MC will not present any precipitating factors, however, factors, such as infection, should be identified and treated quickly if present. Patients with MG can do a number of things to decrease the risk of developing MC including, closely following a physician’s instructions regarding the use of anticholinesterases which will help to strengthen breathing muscles and prevent aspiration of food. Patients should maintain optimal nutrition to sustain strength and reduce stress. During exercise, rest should be taken intermittently. Medications that negatively affect MG should be avoided especially in individuals who have infections of the respiratory tract.
Summary
A myasthenic crisis is a condition characterized by respiratory failure in patients with myasthenia gravis [1]. In MG, patients have generalized muscle weakness due to the presence of acetylcholine receptor (AChR) autoantibodies which target the motor end plate through direct inhibition of AChRs or by recruiting immune cells, thereby disrupting neuromuscular transmission. During MC, the already weakened muscles of individuals suffering from MG are severely incapacitated to the point where a respiratory failure occurs. Patients suffering from MC will need to be intubated and require mechanical ventilation. 15-30% of patients with MG will experience a myasthenic crisis [2] [3] [4]. Moreover, the patients may also develop quadriparesis and severe weakness of the oropharyngeal muscles during the crisis [4] [5] [6]. The crisis itself is often activated by an infection that stimulates the immune response.
The typical immunotherapy administered to treat a myasthenic crisis includes steroids, immunoglobulins and plasma exchange, which have helped to decrease the mortality rate of this serious disease to below 5% [4] [5] [6].
Patient Information
Patients with myasthenia gravis may develop myasthenic crisis, which is a life-threatening condition associated with respiratory failure, that requires intensive care. Respiratory failure in MC is caused by weakening of the respiratory muscles, such as that of the diaphragm and chest muscles and this condition has to be treated with a ventilator. Approximately 15-20% of patients affected with MG develop MC. During MC, patients often experience extreme weakness of the legs and arms followed by the respiratory failure. Causes of MC include infection, stress, surgery or failure to take medications for MG. Along with ventilation in extreme cases of MC, patients may require treatment with immunoglobulin or plasma exchange along with corticosteroids.
References
- Bedlack RS, Sanders DB. On the concept of myasthenic crisis. J Clin Neuromuscul Dis. 2002; 4:40.
- Fink ME. Treatment of the critically ill patient with myasthenia gravis. In: Ropper AH, editor. Neurological and neurosurgical intensive care. 3rd ed. New York: Raven Press; 1993; 351–62.
- Thomas CE, Mayer SA, Gungor Y, et al. Myasthenic crisis: clinical features, mortality, complications, and risk factors for prolonged intubation. Neurology. 1997; 48(5):1253-60.
- Cohen MS, Younger D. Aspects of the natural history of myasthenia gravis: crisis and death. Ann N Y Acad Sci. 1981; 377:670-7.
- Juel VC. Myasthenia gravis: management of myasthenic crisis and perioperative care. Semin Neurol. 2004; 24(1):75-81.
- Watanabe A, Watanabe T, Obama T, et al. Prognostic factors for myasthenic crisis after transsternal thymectomy in patients with myasthenia gravis. J Thorac Cardiovasc Surg. 2004; 127(3):868-76.
- Berrouschot J, Baumann I, Kalischewski P, et al. Therapy of myasthenic crisis. Crit Care Med 1997; 25:1228.
- Bershad EM, Feen ES, Suarez JI. Myasthenia gravis crisis. South Med J. 2008; 101(1):63-9.
- Godoy DA, Mello LJ, Masotti L, et al. The myasthenic patient in crisis: an update of the management in Neurointensive Care Unit. Arq Neuropsiquiatr. 2013; 71(9A):627-39.
- Keesey JC. Clinical evaluation and management of myasthenia gravis. Muscle Nerve. 2004; 29(4):484-505.
- Schneider-Gold C, Gajdos P, Toyka KV, et al. Corticosteroids for myasthenia gravis. Cochrane Database Syst Rev. 2005; CD002828.
- Oosterhuis Hans JGH. Myasthenia Gravis. New York: Churchill Livingstone. 1984.
- Wendell LC, Levine JM. Myasthenic crisis. Neurohospitalist. 2011; 1:16.
- Rabinstein AA, Mueller-Kronast N. Risk of extubation failure in patients with myasthenic crisis. Neurocrit Care. 2005; 3:213.
- O'Riordan JI, Miller DH, Mottershead JP, et al. The management and outcome of patients with myasthenia gravis treated acutely in a neurological intensive care unit. Eur J Neurol. 1998; 5:137.
- Spillane J, Higham E, Kullmann DM. Myasthenia gravis. BMJ. 2012; 345:e8497.
- Patient With Myasthenia Gravis. Neurological and Neurosurgical Intensive Care. 4th ed. Philadelphia, PA: Lipincott Williams & Wilkins. 2004; 299–311
- Thomas CE, Mayer SA, Gungor Y, et al. Myasthenic crisis: clinical features, mortality, complications, and risk factors for prolonged intubation. Neurology. 1997; 48(5):1253-60.
- Rabinstein AA, Mueller-Kronast N. Risk of extubation failure in patients with myasthenic crisis. Neurocrit Care. 2005; 3(3):213-5.
- O'Riordan JI, Miller DH, Mottershead JP, et al. The management and outcome of patients with myasthenia gravis treated acutely in a neurological intensive care unit. Eur J Neurol. 1998; 5(2):137-142.
- Cohen MS, Younger D. Aspects of the natural history of myasthenia gravis: crisis and death. Ann N Y Acad Sci. 1981; 377:670-7.
- Ferguson IT, Murphy RP, Lascelles RG. Ventilatory failure in myasthenia gravis. J Neurol Neurosurg Psychiatry. 1982; 45(3):217-22.
- Perlo VP, Poskanzer DC, Schwab RS, et al. Myasthenia gravis: evaluation of treatment in 1,355 patients. Neurology. 1966; 16(5):431-9.
- Li Y, Arora Y, Levin K. Myasthenia gravis: newer therapies offer sustained improvement. Cleve Clin J Med. 2013; 80(11):711-21.
- Juel VC. Myasthenia gravis: management of myasthenic crisis and perioperative care. Semin Neurol 2004; 24:75.
- Mandawat A, Kaminski HJ, Cutter G, et al. Comparative analysis of therapeutic options used for myasthenia gravis. Ann Neurol 2010; 68:797.
- Alshekhlee A, Miles JD, Katirji B, et al. Incidence and mortality rates of myasthenia gravis and myasthenic crisis in US hospitals. Neurology. 2009; 72:1548.
- Mier A, Laroche C, Green M. Unsuspected myasthenia gravis presenting as respiratory failure. Thorax. 1990; 45:422.
- Dushay KM, Zibrak JD, Jensen WA. Myasthenia gravis presenting as isolated respiratory failure. Chest. 1990; 97:232.
- Ahmed S, Kirmani JF, Janjua N, et al. An Update on Myasthenic Crisis. Curr Treat Options Neurol. 2005; 7(2):129-141.
- Shemin D, Briggs D, Greenan M. Complications of therapeutic plasma exchange: a prospective study of 1,727 procedures. J Clin Apher. 2007; 22(5):270-6.
- Lacomis D. Myasthenic crisis. Neurocrit Care. 2005; 3(3):189-94.
- Godoy DA, Mello LJ, Masotti L, et al. The myasthenic patient in crisis: an update of the management in Neurointensive Care Unit. Arq Neuropsiquiatr. 2013; 71(9A):627-39.
- Hart IK, Sathasivam S, Sharshar T. Immunosuppressive agents for myasthenia gravis. Cochrane Database Syst Rev. 2007; CD005224.
- Grob D, Brunner N, Namba T, et al. Lifetime course of myasthenia gravis. Muscle Nerve. 2008; 37(2):141-9.
- Vincent A, Palace J, Hilton-Jones D. Myasthenia gravis. Lancet. 2001; 357(9274):2122-8.