What is the role of lab studies in the diagnosis of Horner syndrome?

Updated: May 01, 2019
  • Author: Christopher M Bardorf, MD, MS; Chief Editor: Edsel Ing, MD, MPH, FRCSC  more...
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In general, laboratory studies do not play a significant role in the diagnosis and management of Horner syndrome. However, depending on the localization and suspected etiology, certain laboratory tests may be considered, as follows:

  • Urine test (ie, vanillylmandelic acid [VMA] and homovanillic acid [HVA]) in pediatric Horner syndrome to rule out neuroblastoma
  • Complete blood count (CBC)
  • Fluorescent treponemal antibody absorption (FTA-ABS) test
  • Venereal Disease Research Laboratory (VDRL) test (for rare cases of syphilitic basilar meningitis or when Argyll Robertson pupil is suspected)
  • Purified protein derivative (PPD) placement

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