Author: Nick Hatch, M.D. Educational Pearls The Cincinnati Stroke Scale uses 3 measures to screen for ischemic stroke. The measures are: facial asymmetry, speech quality and arm drift. This scale is used commonly in EMS systems as a screening tool. Studies show that having one out of the 3 elements correlates with a 72% chance of having an ischemic stroke, while having all 3 of the elements correlates with an 85% chance. Overall the scale is highly sensitive but not very specific  (92% and 48%, respectively, in one study). The measures focus on anterior circulation function, and often misses posterior circulation strokes. The Cincinnati Stroke Scale is good for EMS, but not necessarily for emergency physicians. References:  http://onlinelibrary.wiley.com/store/10.1002/9781118783467.app5/asset/app5.pdf?v=1&t=jcf2yn71&s=3c2341ba472c1fcc88003dc0af7eac28691dd980