July 16, 2012 Horner’s syndrome is characterized by ptosis and miosis and sometimes unilateral absence of the sweating of the face skin.
Causes:
Cause of Horner’s syndrome is a disorder of sympathetic innervation of smooth muscle of eyelids and pupil dilatators. Disorder can occur in any part of this long sympathetic way (see innervation of the iris muscle). The causes of the disorder are various: congenital, inflammatory, neoplasm (especially metastasis of lung cancer and breast cancer), trauma, or idiopathic.
Symptoms:
Horner pupil in darkness spreads weaker than the normal pupil.
The diagnosis of this syndrome is achieved by instillation of cocaine in both eyes (the cocaine test): normal pupil will expand, and Horner pupil will remain narrow.