Other Names: Bernard-Horner Syndrome; Oculosympathetic Palsy Summary Horner's syndrome is a rare condition characterized by miosis (constriction of the pupil), ptosis (drooping of the upper eyelid), and anhidrosis (absence of sweating of the face).[1][2] It is caused by damage to the sympathetic nerves of the face. The underlying causes of Horner's syndrome vary greatly and may include a tumor, stroke, or other damage to a part of the brain called the brain stem; injury to the carotid artery; and trauma to the brachial plexus. In rare cases, Horner's syndrome is congenital (present from birth) and associated with a lack of pigmentation of the iris (colored part of the eye).[1][2][3] Treatment of Horner's syndrome depends on the underlying cause.[3] Symptoms Symptoms of Horner's syndrome typically include drooping of the upper eyelid (ptosis), constriction of the pupil (miosis), sinking of the eyeball into the face, and decreased sweating on the affected side of the face (anhidrosis). These symptoms may vary and other symptoms may occur depending on the underlying cause of the condition.[1][2] Other symptoms which may be seen include the inability to completely close or open the eyelid, facial flushing, headaches, and pain.[2][3] Heterochromia iridium (i.e., a relative deficiency of pigment in the iris of affected side of the face) is usually present when the syndrome is congenital or caused by a lesion that has occurred before the age of 1-2 years of age.[3] Signs and Symptoms Approximate number of patients (when available) Autosomal dominant inheritance - Congenital Horner syndrome - Deeply set eye - Heterochromia iridis - Ipsilateral lack of facial sweating - Cause There are many potential causes of Horner's syndrome. It can be caused by any interruption of the sympathetic nerve fibers, which start in the hypothalamus and run via the upper spinal cord near the carotid artery to the face. Sympathetic nerve fiber injuries can result from a stroke in the brainstem, injury to the carotid artery, a tumor in the upper lobe of the lung, migraines, and cluster headaches.[1] Horner's syndrome can also be caused by the following:[2][3] Neck trauma and neck surgery A tumor in the brainstem or in the hypothalamus Diseases that cause damage to the protective covering that surrounds nerve fibers (demyelinating disease) Development of a fluid-filled cavity or cyst within the spinal cord (syringomyelia) Arnold-Chiari malformation Diagnosis An ophthalmologist may confirm the diagnosis by special eye tests.[4] In addition, a careful neurological exam may be necessary to find the cause by determining which, if any, other parts of the nervous system are affected. Tests may include[1]: MRI of the head Carotid ultrasound Chest x-ray CT scan of the chest Blood tests Angiogram Eye drop tests Treatment Treatment depends on the underlying cause. There is no specific treatment for Horner's syndrome itself.[1] In many cases, no effective treatment is known. References: 1. Horner syndrome. MedlinePlus. 5/30/2016; http://www.nlm.nih.gov/medlineplus/ency/article/000708.htm. 2. Horner's syndrome. National Organization for Rare Disorders (NORD). 2003; https://rarediseases.org/rare-diseases/horners-syndrome/. 3. Bardorf, CM. Horner Syndrome. Medscape. May 17, 2016; http://emedicine.medscape.com/article/1220091. 4. Dennis Robertson. Horner syndrome: What causes it?. MayoClinic.com. May 06, 2014; http://www.mayoclinic.org/diseases-conditions/horner-syndrome/basics/definition/con-20034650. Source
