Which of the following signs does Horner's syndrome include?

A. Ptosis

C. Miosis.

DISCUSSION: Horner's syndrome is due to loss of sympathetic innervation to the head and neck and includes ptosis, anhidrosis, miosis, and the appearance of enophthalmos. The pupil is small owing to loss of the tonic dilating effect of the sympathetics in the presence of continued parasympathetic activity. There is sympathetic innervation to Muller's muscle in the upper lid. Sympathetic nerves supply the sweat glands. It commonly follows stellate ganglion resection and involves removal of the T1 cord level sympathetic outflow.