“How do we test for Horner’s syndrome in the eye, including which neuron is affected?”,”1. Topical cocaine drops (inhibits norepinephrine reuptake, will fail to dilate the miotic Horner’s pupil, relative to the larger normal pupil)2. Hydroxyamphetamine 1% (causes preganglionic norepinephrine release, will dilate preganglionic, but not post-ganglionic Horner’s pupil).Preganglionic is worse (e.g. 1st or 2nd order neuron, defect due to tumours, nerve root damage

“How do we test for Horner’s syndrome in the eye, including which neuron is affected?”,”1. Topical cocaine drops (inhibits norepinephrine reuptake, will fail to dilate the miotic Horner’s pupil, relative to the larger normal pupil)2. Hydroxyamphetamine 1% (causes preganglionic norepinephrine release, will dilate preganglionic, but not post-ganglionic Horner’s pupil).Preganglionic is worse (e.g. 1st or 2nd order neuron, defect due to tumours, nerve root damage

mechanical trauma closer to the roots at the spinal cord)”