Myasthenia Gravis Flashcards
What specifically does Myasthenia Gravis affect?
- what causes it to lead to paralysis?
Damages nicotinic receptors
can speed up the breakdown of acetylcholine
- can cause muscle weakness bc acetylcholine activates muscle contraction
Define Myasthenia Gravis
chronic autoimmune neuromuscular disease that causes
- muscle weakness in skeletal muscles
- Improves after periods of rest
- Affect neuromuscaulr junction at postsynpatic level
What are 2 clinical types of Myasthenia Gravis?
Ocular Myasthenia Gravis
generalized Myasthenia Gravis
Myastheninc crisis
what is Seropositive myasthenia gravis?
when a pt has a detectable antibodies to nicotinic receptors (AChR) or muscle specific receptor tyrosine kinases (MuSK)
Those who don’t have AChR and MuSK antibodies and receptors are categorized to have
Seronegative Myasthenia Gravis
Why is the thymus gland relevant to Myasthenia Gravis?
The thymus is altered in pts w/Myasthenia Gravis.
- They have nicotinic receptor antibodies of anti-Ach receptor antibodies
- a thymectomy can be beneficial to those with seropositive Myasthenia Gravis
what is a benefit of Edrophonium?
Prevents the breakdown of AcH
Clinical manifestations of Myasthenia Gravis
descending paralysis and chronic muscle fatigue
- facial muscle weakness
- difficulty breathing, speaking, chewing
- unstable gate
- weakness in arms
- tendon reflex almost always intact
what is ptosis
Drooping of one or both eyelids
what is diploipia?
Double vision
Clinical Manifestations;
Add slide 25 later PNS slide
Screening and Diagnosis
slide 26 & 27
What can you aspect for a RR for a pt w/Myasthenia Gravis?
Varying Resp. Rate (depending on lvl of paralysis)
- Diminished breath sounds
- Apnea
- early course crackles and/late fine inspiratory crackles
signs of ventilatory failure from VC, NIF, pH, PaCO2
VC < 20ml/kg
NIF < -30cmH2O
pH <7.35
PaCO2 >45mmHg
What does treatment typically aim to do for myasthenia gravis?
treat the targeting and underlying pathological immune response
i.e rapid immunotherapy
First line of treatment for facilitating neuromuscular transmission?
Acetylcholinesterase inhibitors
Treatments for myasthenia gravis that assist with immunosuppressive treatments and facilitation of neuromuscular transmissions?
- Acetylcholinesterase inhibitors
- Glucorticosteroids (chronic immunotherapy)
- Plaspheresis/IVIG (rapid immunotherapy)
How could a Thyectomy assist with myasthenia gravis?
Thymus is the source of Anti-AcH receptor antibodies, removing could prevent the breakdown of AcH
- recommended for generalized myasthenia gravis
What are general treatments myasthenia gravis?
Oxygen therapy (prevent hypoxemia)
Bronchial hygiene
lung expansion
