Horner Syndrome

Eye nerves affected

There are many nerves that go to the eye. These nerves are involved in the movements of the eye, eyelid, and the widening (dilation) and narrowing (constriction) of the pupil. If some part of the nerve supply is interrupted, Horner syndrome results. Conditions that may cause Horner syndrome include something pressing on the nerves (such as a tumor or bulging artery), injury to the nerves, or disease of the nerves. In fact, a tumor at the top of one of the lungs is a common cause. Horner syndrome affects both males and females of all ethnic backgrounds. It may occur at any age.

Symptoms
The symptoms of Horner syndrome depend on what is the cause of the syndrome, but in most individuals the symptoms are present only on one side of the face. There are three main symptoms that most individuals experience:

• pupil constriction (miosis)
• drooping eyelid (ptosis)
• inability to sweat on the affected side (anhidrosis)

The individual may not be able to completely open the affected eye, and may have eye pain or severe headache. The face may flush on the affected side, especially with exercise.

Diagnosis
The individual’s symptoms will suggest the diagnosis of Horner syndrome. Special eye tests can be done to determine where the nerve supply is being interrupted. A chest x-ray may be done if an upper lung tumor is suspected. Other special tests may be done to help determine the cause of the symptoms.

Treatment
Treatment of Horner syndrome focuses on eliminating the cause of the symptoms. Sometimes, though, this is not possible, and Horner syndrome may persist.

Information for this article was taken from:
Parmar, M.S. (2004). Horner syndrome. eMedicine, accessed at http://www.emedicine.com/med/topic1029.htm