Clinical Reasoning: A 39-year-old woman with progressive proximal weakness

Abstract

A 39-year-old woman presented with progressive weakness over the past 2½ years. She initially noticed weakness in her legs after falling while getting out of a boat. Her leg weakness slowly progressed over the next 2 years to the point where she was having great difficulty with stairs and getting up from a sitting position, particularly from low surfaces. In the 2 months prior to her initial visit, she had noticed difficulty reaching overhead. She denied any skin changes, rash, or muscle pain. She did not have any double or blurred vision, ptosis, facial weakness, dysarthria, dysphagia, shortness of breath, numbness, or tingling. Prior to the onset of her symptoms, she had no medical problems apart from asthma and was not taking any medications or supplements. A detailed family history was negative for neurologic disease. Her examination demonstrated mild weakness of the neck flexors (Medical Research Council [MRC] grade 4), and moderate, symmetric, proximal arm and leg weakness (MRC grade 3). Distal muscles were strong. Cognition, cranial nerves, muscle bulk and tone, deep tendon reflexes, sensory examination, and coordination were normal. She had a mild Trendelenburg gait. There was no myotonia or fasciculation. The authors thank Dr. Andrew Engel for providing the images in the figure.