NMJ Diseases Flashcards
What are the two diseases to know that occur at the NMJ?
Myasthenia Gravis and Lambert Eaton Syndrome
What is the biochemical problem with M gravis?
What patient population is it seen in more?
What is the hallmark clinical symptom?
What part of the body is classically affected and what is caused there?
What is good treatment?
What is a high yield association?
Autoantibodies that compete with Ach at the post synaptic receptor in the NMJ.
Women
Muscle weakness that worsens with use because the feedback is to release less Ach.
Eyes causing ptosis and double vision
Anticholinesterase agents improve symptoms and give the Ach more time to compete and get to the receptor.
Thymic hyperplasia or thymoma, so remove it and improves symptoms.
What is the biochemical cause of Lambert Eaton Syndrome and what is the effect?
What is the underlying issue?
What is the classical clinical symptom?
Treatment?
Autoantibodies against the presynaptic calcium channels of the NMJ, so Ach isn’t released.
Usually due to a paraneoplastic syndrome, most commonly lung cancer.
Proximal muscle weakness that improves with use because it builds up the calcium gradient with use and makes it easier for calcium to enter into the neuron.
Resolves with resection of cancer, anticholnesterase agents don’t work because the problem is on the other side of the NMJ.
