Clinical Reasoning: A 68-Year-Old Man With Proximal Weakness and Seizures

A 68-year-old man developed progressive weakness over 4 weeks. He had difficulty rising from a low position, climbing stairs, and raising his arms overhead, particularly toward evenings. no pain, sensory, or bowel bladder symptoms, denied ptosis, diplopia, dysphagia, dyspnea. mild unintentional weight loss but fevers. His medical history revealed eczema active smoking (50 pack-years). There was family of neuromuscular disorders.