Horner's syndrome is caused by injury to the sympathetic nerves of the face which includes a constricted pupil, drooping eyelid ( ptosis ), and facial dryness.

Causes, incidence, and risk factors

There are many potential causes of Horner's syndrome. Any interruption of the sympathetic nerve fibers which start in the hypothalamus (a central brain region) and run via the upper spinal cord near the carotid artery and to the face may lead to Horner's syndrome. Such injuries can result from a stroke in the brainstem, injury to the carotid artery, a tumour in the upper lobe of the lung, and cluster headaches. Rarely, Horner's syndrome may be congenital (present at birth) and associated with a lack of pigmentation of the iris. Eye drops and certain medications may also lead to this condition.

Signs and tests

A careful neurological exam is necessary to establish the diagnosis and to find the cause by determining which, if any, other parts of the nervous system are affected. Tests may include:

Treatment

Treatment depends on the underlying cause. There is no specific treatment for Horner's syndrome itself.

Expectations (prognosis)

Prognosis is dependent on whether treatment of the underlying cause is successful.

Complications

There is no direct complications of Horner's syndrome itself, but complications may be associated with the underlying disease or its treatment.

Calling your health care provider

Call your health care provider if you have any symptoms that may be linked with Horner's syndrome.