A 55-year-old man with neurosyphilis has small, irregular pupils that do not react to light but constrict during near effort. Instillation of 0.1% pilocarpine causes brisk constriction. This demonstrates which phenomenon?
- A Argyll Robertson pupil with denervation supersensitivity
- B Adie's tonic pupil with cholinergic supersensitivity ✓
- C Horner syndrome with cocaine blockade
- D Parinaud syndrome with light-near dissociation
Correct answer: B. Adie's tonic pupil with cholinergic supersensitivity
Explanation
Adie's tonic pupil shows denervation supersensitivity to dilute (0.1%) pilocarpine due to postganglionic parasympathetic denervation, causing constriction where a normal pupil would not respond. Argyll Robertson pupils are small, irregular, and show light-near dissociation but do NOT demonstrate supersensitivity to dilute pilocarpine. The supersensitivity test distinguishes Adie's pupil from Argyll Robertson pupil.
Reference: Ganong's Review of Medical Physiology, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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