Localization via Pupils




  • Round , regular , symmetric , and reactive to light = midbrain intact
  • Unilateral dilated and fixed = CNIII compression (uncal herniation / Pcomm aneurysm)
  • Bilateral dilated and fixed = hypoxic ischemic encephalopathy, opiate withdrawal, and intoxication with barbiturates, atropine, scopolamine, or glutethimide.
  • Pinpoint and reactive = pontine damage, opiate or cholinergic toxicity
  • Midposition fixed or irregular = focal midbrain lesion
  • Unilateral small pupil or isolated miosis ( especially with ipsilateral ptosis , facial anhidrosis , and enophthalmos )= Horner’s syndrome (consider
    carotid or vertebral artery dissection)




“Neurology – 1 Flashcards – Cram.Com”. Google.com. N.p., 2016. Web. 8 Mar. 2016.

Lww.,. Basic Neurology – Practical Neurology + Localization In Clinical Neurology, 6Th Ed. [Place of publication not identified]: Wolters Kluwer, 2014. Print.


Rana, Abdul Qayyum, and John Anthony Morren. Neurological Emergencies In Clinical Practice. London: Springer, 2013. Print.

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