====== Horner syndrome and Cocaine ======

====Action of Cocaine====
Cocaine blocks reuptake of norepinepherine that is normally released from nerve endings.
In a sympathetic lesion, norepinepherine is not released.

====Effects of Cocaine on Horner's pupil====
little or no effect
====Effects of Cocaine on Normal pupil====
dilation
====Test procedure====
  * Place not more than 2 drops of cocaine hydrochloride 10% in both eyes (2% for infants and children,4% and 5% can also work for adults)
  * Measure anisocoria 50-60 minutes later
  * 0.8 mm or greater anisocoria after the cocaine is highly suggestive of Horner syndrome
====False Positive result====
pupil held by membrane, scar or aberrant innervation//
[[cocaine_and_amphetamine_in_horner_syndrome|Image]]
{{tag>syndrome drugs}}