Horner's syndrome is described as a pattern of syndromes affecting the face, caused by traumatic injury to the neck, also called the cervical region of the spine, or by a variety of other conditions. Johann Friedrich Horner who first described the condition in the mid 19th century named the condition. In the medical field, Horner's syndrome may be more accurately called oculosympathetic palsy, because damage to the cervical region results in damage to the sympathetic nervous system which regulates the face, and especially the eye.
Symptoms of Horner's syndrome include a drooping eyelid, a pupil that is constricted, enopthalmos, which makes the eye looks as if it sits deeply in the skull or is sunken, and poor sweat production. Horner's syndrome affects only one side of the face, so there is a large difference in appearance between the eyes. The eye on the affected side may have a different color, and may be continually bloodshot. Further, the affected side of the face may flush and appear reddish.
Causes of the condition are numerous. Injuries to the neck can cause damage to the sympathetic nervous system, as well as certain illnesses. Sometimes medications can cause the condition. At other times, Horner's syndrome may actually be a genetic condition, present at birth.
When the spine receives an injury, particularly the neck and frequently from blunt trauma, Horner's syndrome can be a result. People can also frequently get extremely painful headaches called cluster headaches that can cause the condition. Goiter, extreme swelling of the thyroid gland, is a potentially causal factor, as is cancer of the thyroid and lung cancer that affects the bronchi. Stroke, or blood clots in the aorta may result in Horner’s syndrome. In some cases, chronic middle ear infections may damage the sympathetic nervous system in the face, creating the condition, though this is rare.
Other causes include cysts in the cervix, anesthesia to the cervical area, multiple sclerosis, and neurofibratosis. Neurofibratosis is a genetic condition in which small lesions or tumors appear on various points of the spine. When they affect the cervical spine, they can result in Horner’s syndrome.
Since other conditions can mimic Horner's syndrome, testing to achieve the appropriate diagnosis is important. A couple of tests, like administering cocaine, or paredrine, determine if the affected eye will dilate, causing the pupil to enlarge. If it does not dilate appropriately, the condition is probably Horner’s syndrome.
Horner’s syndrome is often transient and does not necessarily require treatment. Some symptoms may be treated — eyedrops can be used if the difference in pupil size in each eye is a concern. Fortunately, the condition often resolves itself when the underlying cause is treated. For example, antibiotics and possibly the insertion of tubes in the ears treat chronic ear infections. Sometimes underlying causes like multiple sclerosis resist treatment and result in a semi-permanent or permanent state of Horner’s syndrome. Obviously with any incurable illness, or illness likely to repeat like neurofibratosis, Horner’s syndrome may remain.