RT Book, Section
A1 Singh, Manpreet
A1 Whitfield, Denise
A2 Knoop, Kevin J.
A2 Stack, Lawrence B.
A2 Storrow, Alan B.
A2 Thurman, R. Jason
SR Print(0)
ID 1181038482
T1 Horner Syndrome
T2 The Atlas of Emergency Medicine, 5e
YR 2021
FD 2021
PB McGraw-Hill
PP New York, NY
SN 9781260134940
LK accessmedicine.mhmedical.com/content.aspx?aid=1181038482
RD 2023/11/29
AB Horner  syndrome  (miosis,  ptosis,  and  anhidrosis)  is  secondary  to  loss  of  ocular  sympathetic  innervation.  Ptosis  is  less  than  2  mm,  the  result  of  paralysis  of  Müller  muscle,  innervated  by  the  sympathetic  pathway.  Anhidrosis  is  often  not  apparent  to  patients  or  clinicians.  A  pupillary  finding  specific  in  Horner  syndrome  is  dilation  lag.  Because  the  dilator  muscle  is  weak,  the  pupil  dilates  more  slowly  than  the  normal  pupil.