Horner’s syndrome (Claude-Bernard-Horner syndrome) is a clinical condition caused by a lesion of the nerve fibers, which start in a part of the brain called the hypothalamus and go to the face.

Clinical manifestations include constricted pupil (miosis), drooping of the eyelid (ptosis), sunken eye (enophthalmos) and facial dryness (anhidrosis) on the side of the lesion. The lesion of sympathetic nerve fibers may be located in the brain, brain stem, cervical cord, nerve roots, carotid artery, cavernous sinus or orbit.

Appropriate complementary studies should be performed to demonstrate the cause of the injury.