A 42-year-old woman reports drooping of both upper lids that is worse toward the end of the day and varies in degree between visits. There is mild weakness of neck flexion. Which bedside test provides the most useful immediate support for the suspected diagnosis?
- A Ice pack test over the closed eyelids for 2 minutes ✓
- B Edrophonium chloride intravenous challenge
- C Serum anti-acetylcholine receptor antibody estimation
- D Repetitive nerve stimulation of the facial nerve
Correct answer: A. Ice pack test over the closed eyelids for 2 minutes
Explanation
Variable, fatigable ptosis worse as the day progresses suggests myasthenia gravis. The ice pack test exploits the fact that cooling improves neuromuscular transmission: a measurable rise of the marginal reflex distance after 2 minutes of cooling supports myasthenia. It is safe, cheap and rapid, making it the best first bedside step. Edrophonium testing has largely been abandoned because of cardiac arrhythmia risk, and antibodies are negative in a sizeable proportion of ocular myasthenia patients.
Reference: AAO Basic and Clinical Science Course, Neuro-Ophthalmology, 2023-2024 ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.