Definition of Horner's syndrome in US English:

Horner's syndrome


  • A condition marked by a contracted pupil, drooping upper eyelid, and local inability to sweat on one side of the face, caused by damage to sympathetic nerves on that side of the neck.

    • ‘The swallowing difficulty begins suddenly, along with signs of cerebellar dysfunction and, sometimes, Horner's syndrome.’
    • ‘An apical lung tumor, also known as a Pancoast tumor, may invade local neural structures and produce a characteristic syndrome of pain and possible Horner's syndrome.’
    • ‘Other unusual but recognised presentations of cervical disc degeneration include headache, hemiparesis, hemidiaphragm paralysis, and Horner's syndrome because of involvement of the sympathetic chain.’
    • ‘The clinical manifestations are broad but include ipsilateral ataxia, facial pain, dysphagia, loss of taste, vertigo, nausea, nystagmus, diplopia, Horner's syndrome, hiccups and contralateral pain and temperature loss.’
    • ‘He remains well seven years later, with a persistent left Horner's syndrome and lack of sweating on the left side of his head.’


Early 20th century: named after Johann F. Horner (1831–86), Swiss ophthalmologist.


Horner's syndrome

/ˈhôrnərz ˌsindrōm/