Anisocoria

Q: Anisocoria -unequal pupils - can occur in which of the following

A) Horner syndrome due to carotid dissection
B) Third nerve palsy due to an aneurysm or uncal herniation.
C) Previous cataract extraction
D) Uveitis
E) All of the above



Answer: E

The objective of the above question is to emphasize that anisocoria can happen from life-threatening situations as in choices A and B to relatively benign conditions like in choices C and D. It is extremely important to consider patients' underlying history before embarking on "million dollars workup". On the same note, any newly developed anisocoria in ICU in an intubated patient or with other neurological sign should promptly ring a bell. 

#neurology



References: 

1. Levin LA. The perils of PERRLA. Ann Intern Med. 2007 Apr 17. 146(8):615-6. 

2. Thompson S, Pilley SF. Unequal pupils. A flow chart for sorting out the anisocorias. Surv Ophthalmol. 1976 Jul-Aug. 21(1):45-8. 

3. Martin TJ. Horner's syndrome, Pseudo-Horner's syndrome, and simple anisocoria. Curr Neurol Neurosci Rep. 2007 Sep. 7(5):397-406.