Sofia is a 35-year-old woman. Upon entering the clinic she says, “I’m glad I finally made it in! I feel like my muscles sometimes get tired quickly these days. If I rest for a while, I feel better, but then I get tired again once I’m active. I’ve also noticed that my eyelids are droopy. Sometimes it feels difficult to swallow. These things certainly don’t happen all the time, but they seem to happen more and more often.” You find that Sofia’s muscles respond poorly to electrical stimulation and she tests positive for AChR antibodies.