NMJ Disorders Flashcards
(15 cards)
What is Myasthenia Gravis?
An acquired autoimmune disorder of neuromuscular transmission
Who is more affected by Myasthenia Gravis?
Females more than males, any age
What is the autoimmune target in Myasthenia Gravis?
Post-synaptic acetylcholine receptors (85% of cases)
What thymus abnormalities are associated with Myasthenia Gravis?
Thymic hyperplasia (65%) and thymoma (20%)
What surgical treatment may help in Myasthenia Gravis?
Thymectomy
What are clinical features of Myasthenia Gravis?
Muscle weakness, ptosis, diplopia, dysarthria, dysphagia
What is the pattern of muscle strength variation in Myasthenia Gravis?
Strength best in morning, worsens as day progresses (with repetitive stimulation)
What does muscle histology show in Myasthenia Gravis?
Normal muscle histology
What are treatments for Myasthenia Gravis?
Cholinesterase inhibitors, immunosuppression, plasmapheresis
What is Lambert-Eaton Syndrome?
An autoimmune disorder similar to Myasthenia Gravis
What is the autoimmune target in Lambert-Eaton Syndrome?
Presynaptic calcium channels
What is the pattern of muscle strength in Lambert-Eaton Syndrome?
Improvement after continuous stimulation, but deterioration later
What cancer is associated with Lambert-Eaton Syndrome?
Small cell lung cancer (paraneoplastic syndrome)
How is the prognosis of Lambert-Eaton Syndrome compared to Myasthenia Gravis?
Worse prognosis than Myasthenia Gravis
What are treatments for Lambert-Eaton Syndrome?
Immunosuppression and plasmapheresis
