Horner Syndrome

Description

• Relaxation of retracting muscles in upper and lower lids:
  • Ptosis (drooping of the lids)
• Loss of pupillary dilator innervation:
  • Miosis (unopposed pupillary constriction)
• Loss of sympathetic stimulation of sweat glands:
  • Anhidrosis (unilateral lack of swelling, difficult to appreciate and may be absent)

Etiology

• 40% unknown (in 1 large series)
• Tumors of lung or metastases to cervical nodes:
  • May interrupt preganglionic sympathetic fibers (between thoracic sympathetic trunk and superior cervical ganglion)
• Trauma: Penetrating neck wounds directly injure sympathetic fibers
• Pneumothorax:
  • Tension pneumothorax may cause traction on sympathetic fibers owing to shift of mediastinal structures
• Infiltration or infection of cervical nodes:
  • Sarcoidosis, tuberculosis
• Vascular disorders:
  • Migraine or cluster headaches
  • Carotid artery dissection
• Lateral medullary infarction produces Horner syndrome as part of the Wallenberg syndrome:
  • Presents with vertigo and ataxia, which may overshadow the Horner syndrome
• Cavernous sinus thrombosis may present with some of the features of Horner syndrome:
  • The condition typically causes headache or eye pain
  • Ocular signs include ocular palsies, pain, chemosis, and proptosis

• Hereditary Horner syndrome:
  • Blue iris (or irregular coloration) on affected side
  • Brown on unaffected side (heterochromia iridis)
• Birth trauma:
  • May cause damage to sympathetic chain
• New Horner syndrome in a child should prompt workup for tumor (neuroblastoma)