Horner Syndrome

Key Features

• Caused by an abnormality or lesion to the sympathetic chain

• Congenital variety is most commonly the result of birth trauma

• Acquired cases may occur in children who have had cardiothoracic surgery, trauma, neoplasm, or brainstem vascular malformation

• Most worrisome cause is neuroblastoma of the sympathetic chain in the apical lung region

Clinical Findings

• Ptosis is usually mild with a well-defined upper lid crease

• Heterochromia of the two irides, with the lighter colored iris occurring on the same side as the lesion

• Anhidrosis can occur in congenital and acquired cases

• Of note, not all of the three signs must be present to make the diagnosis

Diagnosis

• Physical examination, including palpation of the neck and abdomen for masses, and MRI of structures in the head, neck, chest, and abdomen should be considered

• An excellent screening test for neuroblastoma is the spot urine vanillylmandelic acid/creatinine ratio

• Pharmacologic assessment of the pupils with topical cocaine and hydroxyamphetamine or epinephrine helps determine whether Horner syndrome is due to a preganglionic or postganglionic lesion of the sympathetic chain

• Apraclonidine may be a more practical drug to use in the diagnosis

Treatment

• Management of any underlying disease is required

• Ptosis and vision should be monitored by an ophthalmologist