What does Horner syndrome mean?

Generally, Horner syndrome refers to Horner's syndrome. Horner's syndrome is a clinical manifestation rather than a distinct disease. The details are as follows:

Horner's syndrome occurs when any part of the sympathetic nerve pathway from the central nervous system to the eye is compressed or damaged, resulting in a constellation of symptoms including pupil constriction (with preserved pupillary light reflex), enophthalmos (sunken eyeball), ptosis (drooping eyelid), and ipsilateral facial anhidrosis (reduced or absent sweating). Based on the site of injury, it can be classified into central, preganglionic, and postganglionic lesions. Common causes include trauma, inflammation, surgery, tumors, and vascular disorders affecting the cervical or brainstem sympathetic nerves.

Clinical features of Horner's syndrome typically include miosis (constricted pupil) on the affected side, ipsilateral facial anhidrosis, ptosis, and enophthalmos. Treatment primarily targets the underlying cause—for example, anti-infective therapy for inflammatory causes, or surgical intervention, chemotherapy, and radiotherapy for tumor-related cases.

Patients presenting with Horner's syndrome should seek prompt medical evaluation to identify the exact lesion site and receive timely treatment, preventing potential worsening of the condition.