Topic: Horner's Syndrome
Subject: Medicine
A 54-year-old white male presents with drooping of his right eyelid for 3 weeks. On examination, he has ptosis of the right upper lid, miosis of the right pupil, and decreased sweating on the right side of his face. Extraocular muscle movements are intact. In addition to a complete history and physical examination, which one of the following would be most appropriate at this point?

A. A chest radiograph

B. MRI of the brain and orbits

C. 131 Iodine thyroid scanning

D. A fasting blood glucose level

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