Question: Mrs. Ramirez is a 59-year-old female who presents with a chief complaint of muscle weakness. She denies any specific injury but reports that in the last several months her muscles appear to become tired so easily and she is not able to sustain normal daily activity for very long without stopping to rest. On physical examination you appreciate both proximal and distal muscle weakness. What would your leading differential diagnoses include? Looking for Course Help? 1. Duchenne muscular dystrophy 2. Sarcoidosis 3. Guillain-Barre syndrome 4. Rheumatoid arthritis