Tiny Tips: Altered Mental Status

In Medical Concepts, Tiny Tips by Brent Thoma6 Comments

Altered mental status is a frequent presentation with a very broad differential. Having a solid approach helps provide structure to the workup of a difficult group of patients.

IS IT MEAT is a common mnemonic for this presentation and the best one that I have come across (thanks to Nadim Lalani from ermentor.com for teaching it to me and George Farjou for the quick comments to improve it). Not only do the letters have fairly intuitive meaning, but they also provide a structural approach with IS IT representing intracranial causes while MEAT represents extracranial causes.


Medical students, the next time an attending asks you for a differential of altered mental status, bust out something like this:

Altered mental status can be caused by intracranial and extracranial pathology. Intracranial causes can include… while extracranial causes can include… Based on this patient’s presentation, I think x or y is the most likely but can’t forget about a, b or c because missing them could lead to a disastrous outcome.

And they’ll think you’re all clever and organized and stuff.

While it’s a very good acronym, there are unfortunately a few things it doesn’t mention that are important to consider. Specifically, hypertensive encephalopathy and post-ictal state do not have a place (although they can lead to or be the result of some of the other things on the list).

This memory device, as well as the rest of the Tiny Tips, have been made into flashcards that can be downloaded and used as outlined on the Boring Cards page. Check it out!

Dr. Brent Thoma is a medical educator, blogging geek, and trauma/emergency physician who works at the University of Saskatchewan College of Medicine. He founded BoringEM and is the CEO of CanadiEM.