Question

A 52-year-old woman presents with progressive weakness, double vision, and ptosis worse at the end of the day, improving with rest. Examination shows fatigable ptosis and proximal muscle weakness. Which of the following is the most appropriate initial diagnostic test?

Accepted Answer

Edrophonium test or ice pack test

Answer

Serum creatine kinase level

Answer

MRI of the brain

Answer

EMG nerve conduction study only

Answer

Lumbar puncture with CSF analysis

Practice question

A 52-year-old woman presents with progressive weakness, double vision, and ptosis worse at the end of the day, improving with rest. Examination shows fatigable ptosis and proximal muscle weakness. Which of the following is the most appropriate initial diagnostic test?