Maybe it's not just another case of vertigo, but something else more serious. Many times, dizziness can be misattributed to some another diagnosis, when in reality posterior circulation strokes (20% of all strokes) should be part of your differential diagnosis. These strokes are elusive and can present atypically - especially for pre-hospital care professionals. A lot of this difficulty lies in the fact that the signs/symptoms are very subtle. While they only represent 1/5 strokes, we have data that demonstrates that these patients often have higher risks of disability/morbidity/mortality.
EMS plays a crucial role in stroke identification because nearly 70% of the time - YOU make the initial patient contact. The same cannot be said of myocardial infarctions. Heart attacks carry with it a certain stigma, so patients will deny their symptoms or chalk it up to something else like indigestion, so, they tend to not summon EMS as often for angina. At my local health system for several years running, the amount of STEMI's that arrived by car was equal to the amount of STEMI's that arrived by ambulance; even after many community facing marketing campaigns. However, when a patient has unilateral paralysis, aphasia, or can't ambulate, they tend to call 911 nearly every time. When the 911 system is activated properly by the patient or bystanders, your influence is greater than you know. You are the main driver in the reduction of door to needle times and we all know that improves patient outcomes which includes less long-term deficits.
One of the key signs of posterior strokes are balance issues, truncal ataxia, and visual disturbances like diplopia. This is why the traditional FAST exam has received a necessary refresh and is now known as the BE-FAST exam. Why???? Because the FAST exam misses nearly half of all posterior circulation strokes. Don't worry the NIHSS exam completed in the hospital - has a history of underestimated these strokes as well. However, with the improved BE-FAST exam, we in essence cast a wider net and identify more strokes beyond those involving the anterior brain territories. Balance or "where you are in space" is determined by your eyes, your inner ear, and your proprioceptors located deep within your muscles, tendons, and joints. If any of those three things are off - this grab bag symptom known as dizziness will be a part of your patients' chief complaint. We must dig deeper in these cases.
Source: Duke Health
We have historically missed a lot of these strokes because we have less awareness and training around their signs and symptoms. Consider the 5 D's as part of your physical assessment.
Dizziness - feeling faint, woozy, or generally unsteady (standing or sitting)
Diplopia - double vision
Dysarthria - vocal changes
Dysphagia - difficulty in swallowing or controlling oral secretions
Dystaxia or ataxia - maybe they just can't sit upright on the stretcher
To help clear up this dizziness complaint - ask the following: (these are all red flags)
Did the dizziness have an acute or spontaneous onset?
Does acute hearing loss accompany this?
Does the patient have vascular risk factors (elderly, atrial fib, atherosclerosis, diabetes)?
Can they no longer walk?
Does the patient exhibit crossed findings? Ex. right sided facial (cranial) deficits with left extremity hemiparesis.
Can they pass the finger to nose test?
Additionally, while an acutely decreased LOC is not typically seen with ischemic strokes, it is actually more likely with posterior involvement. Strokes are often missed in patients with acute coma.
Incorporating a few more items into your current stroke exams are likely to increase your ability to recognize all strokes, including those involving the posterior circulation. The value of "getting it right" in this time sensitive emergency speaks for itself. Remember - maybe they aren't just drunk, maybe it's not simply vertigo, or a benign stomach bug. Always consider posterior cerebral or cerebellar involvement in these scenarios. Your patient will thank you and the local emergency department may be quite impressed with your clinical acumen.
September 30, 2024
Author: Joshua Ishmael, MBA, MLS(ASCP)CM, NRP
Pass with PASS, LLC
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