Lambert-Eaton Myasthenia syndrome Flashcards
What is it
Autoimmune condition affecting the neuromuscular junction
What usually causes it?
Paraneoplastic syndrome usually alongside small cell lung cancer
Explain the pathophysiology
Antibodies produced against voltage-gated calcium channels
They are responsible for assisting release of acetylcholine
Therefore less acetylcholine is released into the synapse
How does it present?
Proximal muscle weakness
Autonomic dysfunction - dry mouth, blurred vision, impotence, dizziness
Reduced or absent tendon reflexes
How does it differ to myasthenia gravis?
Symptoms improve after periods of muscle contraction
In myasthenia gravis - symptoms approve with rest
What investigations would you do
Exclude underlying malignancy e.g. small cell lung cancer
What medications can be given?
Amifampridine -blocks voltage gated potassium channels prolonging depolarisation of the cell membrane so calcium channels can Carry out their action
Pyridostigmine
Immunosuppressants
IvIg
Plasmapharesis
