What is typically observed about pupils in myasthenia gravis testing?

What is typically observed about pupils in myasthenia gravis testing?

• A. Pupils are normal
• B. Pupils dilated
• C. Pupils constricted
• D. Pupils fluctuate with diplopia

Answer: (A)

In myasthenia gravis, the autoimmune attack targets nicotinic acetylcholine receptors at the neuromuscular junction of skeletal muscles, causing fatigable weakness, especially in the eyes and eyelids. The pupil is controlled by the autonomic system and relies on muscarinic receptors in the iris; these autonomic pathways are not the primary target in MG. As a result, pupil size and reactivity are typically normal, even when there is fatigable diplopia or ptosis from extraocular muscle weakness. If you see pupillary abnormalities (dilation or constriction), think of other conditions such as Horner syndrome or CN III palsy rather than MG.

In myasthenia gravis, the autoimmune attack targets nicotinic acetylcholine receptors at the neuromuscular junction of skeletal muscles, causing fatigable weakness, especially in the eyes and eyelids. The pupil is controlled by the autonomic system and relies on muscarinic receptors in the iris; these autonomic pathways are not the primary target in MG. As a result, pupil size and reactivity are typically normal, even when there is fatigable diplopia or ptosis from extraocular muscle weakness. If you see pupillary abnormalities (dilation or constriction), think of other conditions such as Horner syndrome or CN III palsy rather than MG.