Changes

=Neuromuscular Junction=

=Neuromuscular Junction=

==Myasthenia Gravis==

==Myasthenia Gravis==

*H&P: Autoantibodies against AChR, presents with muscle weakness that worsens as the day progresses and with exercise and improves after sleep. Constantly used muscles (think postural muscles, diaphragm, and eyelids) are affected first. May have positive family history. May have thymoma.

*H&P: Autoantibodies against nAChR, presents with muscle weakness that worsens as the day progresses and with exercise and improves after sleep. Constantly used muscles (think postural muscles, diaphragm, and eyelids) are affected first. May have positive family history. May have thymoma.

*Dx: Look for ptosis that improves with ice pack test. Edrophonium test is positive. '''Single-fiber''' EMG shows unstable "jittery" baseline between APs. '''CT chest to look for thymoma.'''

*Dx: Look for ptosis that improves with ice pack test. Edrophonium test is positive. '''Single-fiber''' EMG shows unstable "jittery" baseline between APs. '''CT chest to look for thymoma.'''

*Tx: 1st line pyridostigmine. '''2nd line steroids or immunomodulating meds (e.g. cyclosporine, azathioprine). Plasmapheresis or IVIG for myasthenia crisis. Thymectomy may reduce symptoms and exacerbations.'''

*Tx: 1st line pyridostigmine. '''2nd line steroids or immunomodulating meds (e.g. cyclosporine, azathioprine). Plasmapheresis or IVIG for myasthenia crisis. Thymectomy may reduce symptoms and exacerbations.'''