Myasthenia Gravis

• autoimmune disorder affecting the myoneural juction 
• characterized by varying degrees of weakness of the voluntary muscles

• Approx 60,000
• affects women for than men
• women age 20 to 40
• men age 50-60

antibodies directe at the acetylcholine receptors sites impaire transmissionof impulses accross the myoneural junction. The re for fewer receptors are avalible for stimulation resulting in volunatry muscle weakness

• thymic hyperplasia or
• thymic tumor and the thymus gland is belive to be the site for antibody production

• 2/3's involves teh ocular muscles.
• Diplopia (double vision)
• ptosis (drooping of the eyelids)
• may also have muscle weakness in face and throat (bulbar symptoms)

in bland facial expressions 

• Dysphonia (voice impairment)
• and increase risk of choking and aspiraton 

All the extremities and the intercostal muscles resulting in decreasing vital capacityand resp failure.

No it is purley a motor disorder

Acetylcholinesterase inhibitor test is use to DX MG

• Edrophonium cholrid (Tensilon) is admin via IV.
• 30 secs after injection facial muscle weakness and ptosis resolve for about 5 min.
• Immediate improvement in  muscle strength after admin ofthis agent represent a positive test.

should be avalible to contro side effects of Tensilon which include bradycardia, sweating, and cramping

Thymus gland

• improve function 
• reducing and removing circulating antibodies

• NOOOO Cure!!!
• treatments do not stop teh production of acetylcholine receptor antibodies.

• the first line of therapy, 
• provides symptom relief by inhibiting breakdown of actyl and increasind the relative concentration of actyl at the neuromusculalr junction
• side effect-
• Fasciculations
• abd pain diarrhea 
• increased oropharyngeal secreations

improve muscle strength and control fatigue

to reduce production of the antibody

suppress the PT;s immune response decreasing the production of the antibody

there is and inaduquate respone to corticosteriod meds 

• inhibits T lymphocytes and reduces actly receptor antibody levels but take 3-12 months
• side effects-
• leukopenia and hepatotoxicity
• evaluate liver enzymes and WBC monthly

to treat exacerbation and n selected patients use in long term.

Plasma exchange and is used to treat exacerbations. The plasma and componants are removed through a centrally place large-bore double lumen cath  the blood cells and antibodies are seperated then a substite is infused.  which reduces antibodies. imporves symptoms in 75% but only lasts a few weeks

Avoided

• removal of the thymus gland.
• results in partial or complete remission
• Use transternal surgical approach
• placed in ICU to watch Resp function
• after thymus is remove it may take 3 years for improvement 

a myastenic crisis is and exacerbation, characterized by sever generalized muslce weakness and resp and bulbar weakness may result in Resp Failure