Have you ever encountered a patient with progressive patchy weakness in various muscles throughout the body? Have you ever performed an EMG in which the findings don’t always fit perfectly into what you were expecting?  Have you ever wondered whether you even need to perform an EMG in a patient with weakness? Have you ever wondered how much fun it would be to listen to a new episode of Lessons From the Lab? Well, you have come to the right place to find some answers to these questions! Join Drs. Rubin and Narayanaswami as they ponder and discuss many clinical, electrodiagnostic, and practical approaches to an interesting patient with progressive weakness.