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FACP. Colegio de médicos de Tarragona Nº 4305520 / fgcapriles@gmail.com




Friday, November 29, 2013

Vértigo: HiNTS vs ABCD2 Score

Posted by Ryan Radecki - Emergency Medicine Literature of Note - November 29, 2013
"Dizziness in the Emergency Department sends everyone down their favorite diagnostic algorithm, with outcomes ranging from utterly benign to impending permanent disability. I've covered the repurposing of the ABCD2 score for risk-stratification in dizziness before, showing it had some utility in predicting posterior circulation stroke.
However, unsurprisingly, these authors demonstrate examination maneuvers specifically targeted at evaluating cerebellar function outperform risk-stratification. The HINTS (head impulse, nystagmus type, test of skew) evaluation compared with the ABCD2 (age, blood pressure, clinical features, duration, diabetes) in a convenience sample of 190 prospectively collected patients with acute vestibular syndrome. Of these 190 patients, 124 had a central cause for their vertigo (stroke, hemorrhage, space-occupying lesion). The sensitivity and specificity of the ABCD2 score in predicting a central lesion was 58.1% and 60.6%, respectively, while the HINTS score resulted in 96.8% and 98.5%, respectively.
It's a bit of a straw-man comparison – considering the ABCD2 score was never designed to detect posterior circulation stroke, only to affect probability estimates for cerebrovascular disease. The prevalence of disease in this sample probably also leads to an overestimation of the specificity of the HINTS exam, but it has otherwise been found to have very good test characteristics."
"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.