Neuromusuclar Junction Flashcards
What causes botulism?
Clostridium botulinum - found in soil
Infects food and wounds
IVDUs - black tar heroin
How does botulism affect NMJ?
Toxin cleaves presynaptic proteins involved in vesicle transformation and blocks vesicle docking
Causes of lambert-eaton myasthenic syndrome?
Paraneoplastic - small cell lung cancer
Autoimmune
What happens in lambert-eaton myasthenic syndrome?
Antibodies to presynaptic Ca2+ channels -> less vesicle release
Treatment of lambert eaton myasthenic syndrome?
3,4 diaminopyridine
IV immunoglobulin
Cause of myasthenia gravis?
Autoimmune
What happens in myasthenia gravis?
Antibodies to ACh receptors -> decrease in number of functioning receptors and flattening of end plate folds
Who is myasthenia gravis more common in?
Females under 50
Males over 50
Clinical features of myasthenia gravis?
Weakness - gets worse throughout day
Entraocular, bulbar, facial weakness
Limb weakness - typically proximal
Treatment for symptom control of myasthenia gravis?
Acetylcholinesterase inhibitor - pyridostigmine
Treatment of myasthenic crisis?
Plasmapheresis or IM Ig
Treatment for relapse of myasthenia gravis?
Prednisolone with azathioprine
Treatments for myasthenia gravis?
Pyridostigmine
Thymectomy
Prednisolone with azathioprine
Plasmapheresis or IM Ig
What happens in myasthenic crisis?
Weakness of resp muscles in relapse
