Journal Staff

Best Practices

Dec. 10, 1996, is a day Jill Bolte Taylor will never forget. That was the day she lost her ability to walk, talk, or read when she suffered a massive stroke in her left hemisphere. A Harvard-trained neurologist, Taylor knew exactly what was happening to her when the first symptoms appeared.1 Most of us, however, do not have Taylor’s training. When a member of our family suddenly loses the ability to sit up straight, or starts mumbling random sounds instead of speaking in sentences, we do what we have been trained to do—we call 911.

It’s a good thing we do. According to new research,2 emergency medical dispatchers (EMDs) using a scripted stroke scale accurately identify even more strokes than medics on the scene.

On the face of it, this seems impossible. Paramedics have so many apparent advantages. They can see the patient. They can touch her, move her arms, look into her eyes. They can ask bystanders and family members what they saw. They can run tests and feel the patient’s pulse. All the dispatcher has is a voice. As a result, many dispatchers believe that there’s no point in conducting a stroke diagnostic at the dispatch point; after all, the paramedics will get so much more information once they arrive that the whole thing will end up being redundant.

The numbers tell a different story. Our study (published in the attached issue of the Annals of Emergency Dispatch & Response) found that, out of 603 hospital-confirmed strokes, EMDs identified a full 99 that the field responders missed, and identified clear evidence of a stroke in another 31 cases where the responder’s test was inconclusive.

How is this possible? It’s simple: things change.

Stroke is one of the most highly variable conditions handled by EMDs. Not only can stroke symptoms vary widely from one person to another, but a single person’s symptoms can change, or even disappear, from one moment to the next. This is especially true for people suffering transient ischemic attacks (TIAs), or “mini-strokes,” which are predictive of later full strokes and other negative outcomes.

Repeated studies have shown that any stroke assessment is likely to be far more accurate closer to the time of the initial stroke. In other words, the first first responder (the EMD) is the most likely person to capture the true symptoms of a stroke in any given case. By the time responders arrive on scene, the patient’s symptoms may have changed or receded, or the patient may be unresponsive and unable to complete a stroke diagnostic at all.

The danger in these cases is that a stroke that isn’t identified early may not be identified as a stroke at all. Why? Emergency department (ED) physicians miss as many as 38 percent of the strokes that appear in their EDs. If it’s missed at dispatch—or the Stroke Diagnostic Tool is not performed—it may never be identified. And it’s pretty clear that when a stroke is missed or misidentified, it gets worse. The patient misses the optimal time window for treatment. Often, serious neurological damage or death is the result.

It may seem logical to think that responders on the scene, with their greater access to tools and their ability to evaluate the patient in person, would have such a huge advantage in identifying stroke that conducting the assessment at dispatch is just extra work. Nothing could be further from the truth. Because they are so close in time to the initial stroke, EMDs can and do identify tens of thousands of strokes per year—maybe more—that would otherwise be missed.

The next time that Stroke Diagnostic Tool pops up on your ProQA® screen, remember: The best chance this patient has may be the one at your fingertips.

Check out the full study in the attached issue of the AEDR.


  1. Taylor JB. My Stroke of Insight: A Brain Scientist’s Personal Journey. Viking; New York. 2008.
  2. Gardett I, Broadbent M, Olola C, Scott G, Clawson J. “Comparison of Emergency Medical Dispatcher Stroke Identification and Paramedic On-Scene Stroke Assessment.” Annals of Emergency Dispatch & Response. 2017;5(1).