Check out today’s Step 1 Qmax Question Challenge.
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A 44-year-old woman visits her primary care physician complaining of a drooping eyelid on her left side and pupils of different sizes, as shown in the image. To localize the lesion, the physician administers two medications in series to the left eye. The first drop is a cocaine-based drop, and the second is hydroxyamphetamine. Based on the results, the physician correctly diagnoses the patient as having Horner syndrome, with a lesion in the postganglionic sympathetic nerve to the ciliary ganglion.
What is observed after the drops are administered?
A. Constriction of the pupil with both drops
B. Constriction with the first drop and no change with the second drop
C. Dilation of the pupil with both drops
D. Dilation with the first drop and no change with the second drop
E. No change with either drop
F. No change with the first drop and constriction with the second drop
G. No change with the first drop and dilation with the second drop
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Categories: USMLE-Rx Step 1 Practice Q's