Horner syndrome is sometimes seen in patients diagnosed with the lateral medullary syndrome. Which of the following is a characteristic feature of Horner syndrome?
(A) atrophy of tongue musculature
(B) mydriasis
© paralysis of muscles of facial expression
(D) profuse sweating
(E) red blushing of the skin in the affected area
explanation:(E) The skin in the affected area is red and dry (not moist as in choice D) due to diminished sympathetic activity. The pupil on the affected side is constricted (myosis) (not dilated as in choice B) due to unopposed activity of the sphincter pupillae muscle. Motor deficits such as atrophy of tongue musculature (choice A) or
paralysis of facial expression muscles (choice C) are typically not part of Horner syndrome.