Horner-Bernard syndrome, also known as oculosympathetic palsy, is a condition that happens due to the disruption in a nerve pathway that hinders the brain from reaching the eye on any one side of the body. This generally leads to drooping of the eyelid, shrinking of the pupil, and less sweating on the affected side of the face.

It is seen that Horner-Bernard syndrome usually results because of another health condition, like stroke, spinal cord injury, or tumor. However, the disorder can also happen due to other factors. In some cases, the underlying cause of the condition cannot be identified either, which is known as idiopathic Horner syndrome. To find more information about this condition and your own health, find the nearest low-income health clinic in your area for options.


Horner-Bernard syndrome is linked with the damage caused to a pathway in the sympathetic nervous system. The sympathetic nervous system regulates the pupil size, blood pressure, heart rate, perspiration, and many other functions of the body that trigger due to a change in the environment. The affected nerve pathway in Horner-Bernard syndrome is categorized into three groups.

  • First-order neurons: These nerve cells lead from the hypothalamus into the spinal cord through the brainstem. Problems that could lead to Horner-Bernard syndrome by affecting these neurons include stroke, myelin, tumor, spinal cord cyst, and neck trauma.
  • Second-order neurons: These nerve cells extend from the spinal cord to the side of the neck through the upper portion of the chest. Issues that can cause nerve damage to these neurons include lung cancer, schwannoma, damage to the aorta, chest cavity surgery, and any other traumatic injury.
  • Third-order neurons: These nerve cells extend along the side of the neck to the facial skin and muscles of the eyelids and iris. Nerve damage in this area can be caused due to migraines, cluster headaches, carotid artery damages near the neck, jugular vein damages near the neck, and infection or tumor near the base of the skull.

In children, Horner-Bernard syndrome usually happens because of an injury to the shoulder or neck during childbirth, defect in the aorta, and a tumor in the hormonal and nervous systems. Locate your nearest low-income pediatric clinic for more information.


The most common signs and symptoms associated with Horner-Bernard syndrome include contraction of the pupil (miosis), unequal size of the pupils (anisocoria), delayed opening of a pupil (dilation), drooping upper-eyelid, upside-down ptosis, and sunken eyes. The patient will also experience an inability to sweat normally on the affected side of the face (anhidrosis). In children under 1 year, one of the irises will appear lighter in color. Besides, there will be no flushing or redness on the affected side of the face, which usually happens due to heat or physical exertion.

Horner-Bernard syndrome can be a result of many factors or underlying conditions, which is why it is advised to consult a doctor and diagnose the disorder at the earliest. You should also get emergency care if you experience impaired vision, muscle weakness on the face, dizziness, and severe headache or neck pain after a traumatic injury.

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    About the Author

    Dr. Ghassan M. Al-Jazayrly, MD

    A graduate of University of Aleppo Faculty of Medicine, Dr. Al-Jazayrly or, as he is colloquially known: Dr. AJ, is an oncologist and hematologist of a Complete Care Community Health Center (CCCHC) with more than 36 years of experience. In recent years, he’s been involved with a non profit organization known as Every Woman Counts (EWC) which provides free breast and cervical cancer screening and diagnostic services to California’s underserved populations in order to eliminate health disparities for low-income individuals.

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