Horner syndrome is a rare condition that affects the nerves to the eye and face.
* Decreased sweating on the affected side of the face * Drooping eyelid (ptosis) * Sinking of the eyeball into the face * Small (constricted) pupil There may also be symptoms of the disorder that is causing the problem.
Horner syndrome can be caused by any interruption in the sympathetic nerve fibers, which start in the part of the brain called the hypothalamus and run to the face. Sympathetic nerve fiber injuries can result from: * Injury to the main artery to the brain (carotid artery) * Injury to the nerves running down the arm (brachial plexus) * Migraine or cluster headaches * Stroke or lesion in the brainstem * Tumor in the top of the lung Rarely, Horner syndrome may be present at birth (congenital). The condition may occur with a lack of color (pigmentation) of the iris (colored part of the eye). Eye drops and certain medications may also lead to this condition.
The health care provider will do a nervous system (neurological) exam to diagnose the problem and find out which, if any, other parts of the nervous system are affected. Tests may include: * Blood tests * Carotid ultrasound * Chest x-ray * CT angiogram or magnetic resonance angiography (MRA) * CT scan of the chest * Eye drop tests * MRI of the head
The outcome depends on whether treatment of the cause is successful.
Treatment depends on the cause of the problem. There is no treatment for Horner syndrome itself.