Horner syndrome is a rare condition that affects the nerves to the eye and face.
Horner syndrome can be caused by any interruption in a set of nerve fibers that start in the part of the brain called the hypothalamus and travel to the face and eyes.
Sympathetic nerve fiber injuries can result from:
- Injury to one of the main arteries to the brain (carotid artery)
- Injury to nerves at the base of the neck called the brachial plexus
- Migraine or cluster headaches
- Stroke, tumor, or other damage to a part of the brain called the brainstem
- Tumor in the top of the lung
- Injections or surgery done to interrupt the nerve fibers and relieve pain (sympathectomy)
In rare cases, Horner syndrome is present at birth (congenital). The condition may occur with a lack of color (pigmentation) of the iris (colored part of the eye).
Symptoms may include:
- Decreased sweating on the affected side of the face
- Drooping eyelid (ptosis)
- Sinking of the eyeball into the face
- Small (constricted) pupil (the black part in the center of the eye)
There may also be symptoms of the disorder that is causing the problem.
Exams and Tests
An eye examination may show:
- Changes in how the pupil opens or closes
- Eyelid drooping
- Red eye
Your health care provider will do a complete examination to determine the possible effect on other parts of the nervous system. Depending on the suspected cause, you may need:
- Blood tests
- Blood vessel tests (cerebral angiogram, CT angiogram, or MR angiogram
- Chest x-ray or chest CT scan
- MRI or CT scan of the brain
- Spinal tap (lumbar puncture)
You may need to be referred to a doctor who specializes in vision problems related to the nervous system (neuro-ophthalmologist).
Treatment depends on the cause of the problem. There is no treatment for Horner syndrome itself.
The outcome depends on whether treatment of the cause is successful.
There are no direct complications of Horner syndrome itself. However, there may be complications from the disease that caused Horner syndrome or from its treatment.
When to Contact a Medical Professional
Call your health care provider if you have symptoms of Horner syndrome.
Rucker JC. Pupillary and eyelid abnormalities. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC, eds. Bradley's Neurology in Clinical Practice. 6th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 16.