Mad Hatter: “Why is a raven like a writing-desk?”
“Have you guessed the riddle yet?” the Hatter said, turning to Alice again.
“No, I give it up,” Alice replied: “What’s the answer?”
“I haven’t the slightest idea,” said the Hatter.
- Lewis Carroll
It's a common sight in the Emergency Room: a family member brings in mom or dad because they are "acting funny." Sometime's the police bring a patient in for bizarre or aggressive behavior. The presentation can vary wildly, and it is important to identify even the most subtle cases of altered mental status (AMS). Overall, AMS accounts for approximately 1% of all ED visits, and altered patients over 60 years old have over a 10% mortality rate!
Many causes of AMS are temporary and reversible. If identified and treated early, the symptoms may be easily treated and completely reversed (ie. intoxication). Other causes (such as stroke) can have much longer lasting effects, yet still need immediate treatment. In addition to simply identifying AMS, you also need to know how to quickly begin the workup.
Here is our favorite mnemonic for how to remember the most common causes of altered mental status. As an added bonus, we threw in the first steps for workup of these patients, and a few additional labs you should consider with everyone.
Do you have any other mnemonics you like to use? Let us know in the comments!