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Horner’s Syndrome: A Positive Apraclonidine Test—Now What?

Historically, topical liquid 10% cocaine was used to identify the presence of Horner’s syndrome, and topical hydroxyamphetamine was used to aid in localizing a postganglionic lesion. Today, these agents are not practically available; instead, the diagnosis of a suspected Horner’s syndrome can be confirmed by pharmacological testing with apraclonidine 0.5% or 1%.

In Horner’s syndrome, the affected pupil and levator undergo denervation hypersensitivity. Apraclonidine is an alpha-2 adrenergic agonist that also acts as a very weak alpha 1-adrenergic agonist; when topically applied in Horner’s syndrome, it causes dilation of the affected pupil and possibly lid elevation, without change…

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 Horner Syndrome in Children

One important condition to keep in mind is Neuroblastoma. Unusual, but is the most significant treatable cause of Horner Syndrome in children. 2nd most common malignant solid tumor in pediatric patients.

 Horner's Syndrome: What Optometrists Should Know

Remember the rhyming triad you learned in optometry school? Here are some in-depth tips on how to properly identify and manage a patient with Horner’s Syndrome if they end up in your chair.

 Shedding light on Horner syndrome

Horner syndrome is characterized by ipsilateral ptosis, miosis, and anhidrosis that result from a lesion affecting the oculosympathetic pathway. The syndrome can be benign if idiopathic or iatrogenic but can be predictive of a life-threatening event such as demyelinating inflammatory, infectious, vascular, or neoplastic problems.

Articles of Interest

Anisocoria and Horner's Syndrome

Horner’s syndrome is caused by injury to the sympathetic nerves, which are responsible for dilating the pupil and raising the eyelid on the same side of the face. In Horner’s syndrome, the pupil in the involved eye is smaller and does not get bigger (dilate) as well as the other eye. The difference in pupil size between the two eyes is more noticeable under dim light. The child may have mild droopiness (ptosis) of the upper eyelid [See figure 2]. Sometimes the lower eyelid may be slightly higher than normal (known as inverse ptosis). When the upper eyelid is slightly lower than normal and the lower eyelid is slightly higher than normal, the eye may appear smaller. If the Horner’s syndrome developed during the first year of life, the colored part of the eye (iris) on the affected side may appear lighter in color than the uninvolved side (heterochromia).

Horner syndrome: clinical perspectives

Apraclonidine is an alpha-2 adrenergic agonist that is sometimes used to lower intraocular pressure in patients with glaucoma; however, it also has a weak alpha-1 adrenergic effect. Thus, it minimally constricts a normal pupil but dilates a Horner pupil due to denervation supersensitivity of the alpha-1 receptors on its iris dilator muscle, producing a reversal of anisocoria in patients with unilateral Horner syndrome.

The High Coast of Smoking: An Interesting Case of Pancoast Syndrome

In fact, Pancoast tumors that invade the brachial plexus may result in Pancoast syndrome, which includes arm pain, weakness, and paresthesias, most commonly in the ulnar distribution, as well as Horner syndrome due to invasion of the stellate ganglion.[2] If suspected, a chest x-ray is often the first step in diagnosis, although the sensitivity is low. If present, a Pancoast tumor may appear as a subtle soft tissue mass. CT scan is the primary modality for diagnosis, being very sensitive for identification of lung lesions. MRI, however, provides the best assessment of soft tissue involvement, as well as extension into the vertebral bodies, neural foramina, and spinal cord.

Resources

MedComic

Horner syndrome results from disruption of the sympathetic pathway that runs from the hypothalamus to the eye. Classic signs include miosis, ptosis, and anhidrosis of the affected side. Causes include brain tumor, brain stem infarct, pancoast tumor, cervical adenopathy, skull and neck trauma, carotid dissection, and thoracic aortic aneurysm. Instilling cocaine or apraclonidine drops into both eyes can confirm the diagnosis of Horner syndrome. Imaging studies such as MRI, CT, or MRA may be obtained based on the history and physical exam. Treatment depends on the underlying cause of Horner syndrome.

Case report and literature review: Horner syndrome subsequent to endoscopic thyroid surgery

Horner syndrome (HS), mainly characterized by symptoms including ptosis, miosis, and anhidrosis on the affected face, is a condition that is well documented but rarely reported as a postoperative complication of thyroidectomy, particularly in endoscopic thyroid surgery (ETS).

HealthEngine

Horner syndrome is an uncommon to rare condition. There is no statistical data on the incidence of Horner syndrome because it is the causative factor that is important.

Life in the Fastlane

Johann Friedrich Horner (1831-1886) reported the findings of ptosis, miosis, and enophthalmos in a 40-year-old peasant woman. He also observed increased skin temperature and dryness of the ipsilateral face. He pharmacologically confirmed the impairment of sympathetic innervation to the eye after noting poor dilation of the affected pupil following instillation of atropine and preserved pupillary constriction to the parasympathomimetic agent calabar.

Patient

Ipsilateral dry skin on the face due to loss of sweating: Take both index fingers and place then together in the middle of the forehead. Then run them laterally over the forehead to just lateral to the eyebrows. On the affected side there may be more friction as the skin is drier because there is no sweating on that side.