What if I told you that I think that patient you just sent home with vertigo may have been a missed cerebellar stroke? Would you be dialing risk management or could you tell me all of the reasons why I'm wrong? Isolated vertigo without other neurological findings can't be a stroke, right? That is true, if you are doing the right exam, but if you are just doing your standard ED neuro screening exam then you might be missing serious pathology. In this episode of the EMCrit podcast, I discuss how to perform the tests that will differentiate a peripheral cause of continuous vertigo from a cerebellar stroke.
Drs. David Newman-Toker & Jorge Kattah, neurologists at John Hopkins, have done a ton of work on this topic. They have created an mnemonic for the exam you should be doing on all of your patients with continuous vertigo (as opposed to positional, intermittent vertigo, i.e. BPPV). Benign positional paroxysmal vertigo is not ED critical care. Continuous vertigo, also known as acute vestibular syndrome, may be. The mnemonic is HiNTS.
Hi for head impulse testing, or head thrust testing.
N for nystagmus to remind you to look for direction-changing or vertical nystagmus
TS for test of skew.
I will discuss what all of these terms mean and how to perform the exams in the podcast.
Here is the HiNTS article.
Here is a link to another study by the same authors on head impulse testing.
Here is a fantastic review article by James A. Nelson on the topic.
Here is a video demonstrating the exam with positives and negative examples.
Insanely good systematic review on Dizzy Stroke Patients (CMAJ 2011;183(9):E571)
and maybe the best review on Vertigo ever!