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Be the first to edit this page and have your name permanently included as the originating editor, see the
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<div class="editorbox">
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'''Original Editor '''-
[
http://www.physio-pedia.com/User:Wendy_Walker Wendy Walker
]
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'''Lead Editors'''
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</div>
= Definition =
= Definition =
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= Clinically Relevant Anatomy<br> =
= Clinically Relevant Anatomy<br> =
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add text here relating to
'''''
clinically relevant
'
'''' anatomy of the condition
<br>
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[[Image:Neuromuscular junction.png|Neuromuscular Junction]]
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<br>
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'''
Detailed view of a neuromuscular junction
'''<br>
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1. Presynaptic terminal<br>2. Sarcolemma<br>3. Synaptic vesicle<br>4. Nicotinic acetylcholine receptor<br>5. Mitochondrion
== Mechanism of Injury / Pathological Process<br> ==
== Mechanism of Injury / Pathological Process<br> ==
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add text here relating to
the
mechanism
of
injury and
/
or
pathology of the
condition
<br>
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In Myasthenia gravis (MG) antibodies form against nicotinic acetylcholine (ACh) postsynaptic receptors at
the
neuromuscular junction (NMJ)
of
the skeletal muscles<ref>Strauss AJL, Seigal BC, Hsu KC. Immunofluorescence demonstration of a muscle binding complement fixing serum globulin fraction in Myasthenia Gravis. Proc Soc Exp Biol. 1960;105:184<
/
ref>.The basic
pathology
is a reduction in the number
of
ACh receptors (AChRs) at
the
postsynaptic muscle membrane brought about by an acquired autoimmune reaction producing anti-AChR antibodies<ref>Patric J, Lindstrom JM. Autoimmune response to acetylcholine receptor. Science. 1973;180:871</ref>.
<br>
== Clinical Presentation ==
== Clinical Presentation ==
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to the clinical
presentation
of the
condition
<br>
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The usual initial complaint is a specific muscle weakness rather than generalized weakness - frequently ocular (eye) symptoms.<br>Extraocular muscle weakness or ptosis is present initially in 50% of patients, and occurs during the course of illness in 90% of patients.Patients also frequently report diploplia (double vision). <br>The disease remains exclusively ocular in 10 - 40% of patients.<br>Rarely, patients have generalized weakness without ocular muscle weakness.<br>Bulbar muscle weakness is also common, along with weakness of head extension and flexion.<br>Limb weakness may be more severe proximally than distally.<br>Isolated limb muscle weakness is the presenting symptom in fewer than 10% of patients.<br>Weakness is typically least severe in the morning and worsens as the day progresses.<br>Weakness is increased by exertion and alleviated by rest.<br>Weakness progresses from mild
to
more severe over weeks or months, with exacerbations and remissions.<br>Weakness tends to spread from
the
ocular to facial to bulbar muscles and then to truncal and limb muscles.<br>About 87% of patients have generalized disease within 13 months after onset.<br>Less often, symptoms may remain limited to the extraocular and eyelid muscles for many years.<br>
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=== Classification ===
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The most widely utilised classification of MG is the Myasthenia Gravis Foundation of America Clinical Classification<ref>Jaretzki A 3rd, Barohn RJ, Ernstoff RM, et al. Myasthenia gravis: recommendations for
clinical
research standards. Task Force
of the
Medical Scientific Advisory Board of the Myasthenia Gravis Foundation of America. Neurology. Jul 12 2000;55(1):16-23</ref>
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'''Class I''': Any ocular muscle weakness, possible ptosis, no other evidence of muscle weakness elsewhere
<br>
'''Class II''': Mild weakness affecting other than ocular muscles; may also have ocular muscle weakness of any severity<br>'''Class IIa''': Predominantly affecting limb, axial muscles, or both; may also have lesser involvement of oropharyngeal muscles<br>'''Class IIb''': Predominantly bulbar and/or respiratory muscles; may also have lesser or equal involvement of limb, axial muscles, or both<br>'''Class III''': Moderate weakness affecting other than ocular muscles; may also have ocular muscle weakness of any severity<br>'''Class IIIa''': Predominantly affecting limb, axial muscles, or both; may also have lesser involvement of oropharyngeal muscles<br>'''Class IIIb''': Predominantly bulbar and/or respiratory muscles; may also have lesser or equal involvement of limb, axial muscles, or both<br>'''Class IV''': Severe weakness affecting other than ocular muscles; may also have ocular muscle weakness of any severity<br>'''Class IVa''': Predominantly affecting limb, axial muscles, or both; may also have lesser involvement of oropharyngeal muscles<br>'''Class IVb''': Predominantly bulbar and/or respiratory muscles; may also have lesser or equal involvement of limb, axial muscles, or both (Can also include feeding tube without intubation)<br>'''Class V''': Intubation needed to maintain airway, with or without mechanical ventilation
== Diagnostic Procedures ==
== Diagnostic Procedures ==
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== Management / Interventions<br> ==
== Management / Interventions<br> ==
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condition
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=== Medical Management<br> ===
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<div><br></div>
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=== Physiotherapy Management ===
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Rehabilitation alone or in combination with other forms of treatment can relieve or reduce symptoms for some people with MG.
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MG patients should find the optimal balance between physical activity and rest. It is not possible
to
cure
the
weakness by active physical training. However, most MG patients are more passive than they need to be. Physical activity and physical training of low to medium intensity is recommended<ref>Skeie GO, Apostolski S, Evoli A et al. Guidelines for treatment of autoimmune neuromuscular transmission disorders. Eur. J. Neurol.17,893–902 (2010)</ref>.
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One study showed clear benefit from a strength training exercise programme for a group of patients with mild to moderate MG<ref>Lohi EL1, Lindberg C, Andersen O. Physical training effects in myasthenia gravis. Arch Phys Med Rehabil. 1993 Nov;74(11):1178-80</ref>, concluding "physical training can be carried out safely in mild MG and provides some improvement of muscle force".
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General advice for exercise programmes for people with MG:
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*Aim to strengthen large muscle groups, particularly proximal muscles of shoulders and hips
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*Advise patient to do the exercises at their "best time of day" ie. when not feeling tired - for the majority of MG patients this will be morning
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*If patient is taking pyridostigmine, exercise at peak dose ie. 1.5 to 2 hours after taking a dose
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*Moderate intensity of exercise only: patient should not experience worsening of MG symptoms (eg. ptosis or diploplia) during exercise
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*General aerobic exercise is also valuable, helping with respiratory function as well stamina
== Differential Diagnosis<br> ==
== Differential Diagnosis<br> ==
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== Resources <br> ==
== Resources <br> ==
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The [http://www.myasthenia.org/ Myasthenia Gravis Foundation of America] (MGFA) has a comprehensive website
== Case Studies ==
== Case Studies ==
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== References ==
== References ==
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References will automatically be added here, see [[Adding References|adding references tutorial]]. <references />
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<references />
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[[Category:Neurology]]
[[Category:Neurology]]