Horner’s syndrome affects one side of the face. The following are the signs and symptoms experienced by individuals suffering from this syndrome:

• Onset of miosis, a condition wherein there is decrease in the size of the pupil.
• Anisocoria, wherein there is considerable difference between both pupils.
• Delayed dilation of pupil in dim light.
• Onset of upside down ptosis, a condition characterized by elevation of lower eye lid.
• Dropping eye lids, especially the upper one.
• Affected side experiences little or no sweating.
• Children affected by Horner’s syndrome, do not experience the flushing or redness of face in the affected side as one would normally experience after exposure to heat or after physical exertion. In addition, the color of the iris in affected children is lighter than the normal eye [6].

A general medical examination would be carried out in the preliminary stages, followed by other tests to identify the nature of the symptoms and exact cause behind development of Horner’s syndrome. Typically the following tests would be done:

• Eye examination: In this test, eye drops will be administered to both eyes; the pupil of the healthy eye will get dilated, whereas the eye drops will constrict the pupil of the affected eye. This will help in confirming the diagnosis of Horner’s syndrome.
• Imaging studies: Imaging studies such as CT scan, MRI and X-ray will be done in order to locate the site of nerve damage. A chest radiograph would provide insight about the development of apical bronchogenic carcinoma which is considered as one of the most potential causes of Horner’s syndrome. In addition, MRI of the brain and CT scan of the head are also indicated [7].
• Blood and urine tests would also form an important part of the diagnostic procedure and are done if children are suspected to be suffering from Horner’s syndrome. These tests are necessary to diagnose the presence of neuroblastoma [8].
• Pharmacologic testing: This method is very helpful in diagnosis of Horner’s syndrome. These include the topical cocaine test, topical apraclonidine test and topical hydroxyamphetamine test [9].

There is no specific treatment regime for Horner’s syndrome. The major goal of treatment is to successfully treat the underlying disease condition, which would in turn help in appropriate management of the condition.

Surgical intervention may also be required when the carotid artery is involved. The types of surgical procedures indicated in treatment of Horner’s syndrome include neurosurgical procedures, and vascular surgical methods for aneurysm or dissection of the carotid artery [10].

The prognosis of the condition majorly depends on the underlying causative factor. If the underlying causative factor can be successfully treated, then the prognosis of Horner’s syndrome is usually favorable.

Horner’s syndrome occurs when certain groups of nerves of the sympathetic trunk are damaged. The sympathetic nerves are responsible for regulation of the heart rate, blood pressure, perspiration and size of the pupil. Injury or damage to the nerve fibers can stem from the following factors [2]:

• Injury to the carotid artery
• Individuals suffering from migraine [3]
• Development of tumor in the lungs
• Development of tumor in the brainstem
• Stroke
• Sympathectomy, wherein surgery is done to relieve pain by interrupting the nerve fibers
• Injury to the nerves of the brachial plexus
• In many instances, the cause of Horner’s syndrome is unknown and cannot be identified. Such a type of condition is then termed as idiopathic Horner’s syndrome.

Horner’s syndrome is a rare disorder affecting about 1 in 6250 newborns. The condition can also occur later in life; but the exact incidence in such cases is unknown [4].

Horner’s syndrome develops as a result of a lesion which occurs at any point in the pathway of the sympathetic trunk. Due to such a kind of phenomenon, all patients experience abnormalities such as ptosis, elevation of the lower eye lid, development of dilation lag and miosis and impaired flushing and sweating. The degree of severity of these abnormalities depends on the extent of damage to the nerve fibers.

Anatomically, 3 groups of nerves responsible for the sympathetic function of the eye are the first order, second order and third order neurons. The first order neurons travel from the hypothalamus to the cervical spine. The second order neurons travel from neck to the outer side of the spinal region. Lastly, the third order neurons, travel through the outer side of the spinal cord to the eye [5].

Prevention of Horner’s syndrome is geared towards preventing the onset of trigger factors. This would include prevention of trauma of the head, avoiding smoking and controlling various cardiovascular risk factors. All these approaches can help prevent the onset of Horner’s syndrome.

Horner’s syndrome is characterized by development of various kinds of signs and symptoms that occur as result of damage to the sympathetic trunk. Such a type of condition affects the face and eyes. This syndrome produces signs and symptoms that affect one side of the body where there is lesion of the sympathetic trunk. Horner’s syndrome causes decrease in the size of the pupil, drooping eyelid and reduced sweating particularly on the side of the face that has been affected. The condition is also known as oculosympathetic palsy or Horner-Bernard syndrome [1].

• Definition: Horner’s syndrome occurs when the nerve pathway that travels through brain to the face and then reaches the eye, gets damaged. This nerve pathway is disrupted only one side of the body. In this condition, a specific group of symptoms mark the onset of the syndrome.
• Cause: Horner’s syndrome mainly occurs due to underlying disease condition such as tumors, injury to the spinal cord or a stroke. In many cases, no cause can be identified and in such situations, the syndrome is termed as idiopathic Horner’s syndrome.
• Symptoms: Symptoms of Horner’s syndrome include decrease in the size of the pupil, delayed dilation of the pupil in dim light, and reduced sweating on one side of the face that is affected. In children with Horner’s syndrome, the color of the iris of the affected eye is different from the normal. In addition, the part of the face that is affected does not turn red after physical exertion or exposure to hot weather.
• Diagnosis: A preliminary medical examination of the signs and symptoms experienced by the individual forms basis of the diagnostic procedure. An eye examination is also carried out to evaluate the dilation of pupils in response to eye drops. Imaging studies such as chest X-ray, MRI of the brain and CT scan of the head would also be necessary.
• Treatment: Treatment of Horner’s syndrome largely depends on the underlying cause. If the causative factor can be treated then, the syndrome gets corrected by itself.

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