In suspected myasthenia gravis, which bedside test can transiently improve ptosis?

Prepare for the PANCE Neurology Test with comprehensive materials. Use flashcards and multiple-choice questions, each featuring hints and explanations. Boost your confidence and ace your exam!

Multiple Choice

In suspected myasthenia gravis, which bedside test can transiently improve ptosis?

In myasthenia gravis, ptosis is a fatigable weakness caused by reduced efficiency of neuromuscular transmission. Cooling the eyelid can transiently improve this transmission. The ice pack test applies a cold stimulus to the eyelids for a short period; if ptosis improves with the cold, it suggests MG because cooling slows acetylcholinesterase activity and increases acetylcholine availability at the neuromuscular junction, boosting transmission and lifting the eyelid temporarily. The improvement is brief, which fits the fluctuating nature of MG symptoms. The other options target different functions and are not expected to change ptosis in MG: the pupillary light reflex assesses brainstem pathways, and the Romberg test evaluates balance and proprioception. So the ice pack test best fits the scenario of transient improvement in ptosis due to MG.

In myasthenia gravis, ptosis is a fatigable weakness caused by reduced efficiency of neuromuscular transmission. Cooling the eyelid can transiently improve this transmission. The ice pack test applies a cold stimulus to the eyelids for a short period; if ptosis improves with the cold, it suggests MG because cooling slows acetylcholinesterase activity and increases acetylcholine availability at the neuromuscular junction, boosting transmission and lifting the eyelid temporarily. The improvement is brief, which fits the fluctuating nature of MG symptoms.

The other options target different functions and are not expected to change ptosis in MG: the pupillary light reflex assesses brainstem pathways, and the Romberg test evaluates balance and proprioception. So the ice pack test best fits the scenario of transient improvement in ptosis due to MG.

More practice questions