brain, spinal cord, and nerve disorders
Horner Syndrome
Diagnosis of Horner Syndrome
Eye drop tests Magnetic resonance imaging or computed tomography to identify the cause Horner syndrome is suspected based on symptoms. To confirm the diagnosis of Horner syndrome and determine where the problem is, doctors do a two-part test: First, they apply eye drops that contain small amounts ofcocaineor another medication (apraclonidine) to both eyes. If Horner syndrome is likely, doctors may do another test 48 hours later. They apply hydroxyamphetamine drops to both eyes. How the pupils react to the medications indicates whether Horner syndrome is likely and helps locate where the problem is. If Horner syndrome is likely, magnetic resonance imaging (MRI) or computed tomography (CT) of the brain, spinal cord, chest, and/or neck is done to look for tumors and other serious disorders that may be disrupting nerve fibers connecting the brain and the eye. 