Horner syndrome
Pronunciation: HOR-ner SIN-drome
A neurological condition characterized by ptosis, miosis, and anhidrosis due to sympathetic nerve pathway disruption.
Full Definition
Horner syndrome results from interruption of the sympathetic nerve pathway that supplies the eye and face. The classic triad includes ptosis (drooping eyelid), miosis (constricted pupil), and anhidrosis (absence of sweating) on the affected side. The syndrome can result from lesions anywhere along the three-neuron sympathetic pathway, from the hypothalamus to the eye. Causes include stroke, tumor, trauma, or iatrogenic injury during surgery. Pharmacological testing with apraclonidine or cocaine can confirm the diagnosis and help localize the lesion.
Usage
Usage note: Named after Johann Friedrich Horner; always capitalize the proper noun portion.
In Context
- "The patient presented with left-sided Horner syndrome following neck surgery." — Post-operative consultation
- "Pharmacological testing confirmed Horner syndrome and suggested a preganglionic lesion." — Diagnostic workup report