A 76-year-old woman's husband noticed that 90 minutes ago she suddenly became unsteady on her feet, complained of seeing double, and felt dizzy when trying to walk to the bathroom. Her face is symmetric, her handgrip strength is equal bilaterally, and her speech is clear. She denies numbness. Using the BE FAST stroke recognition framework, which statement best explains this clinical scenario?

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Accepted Answer

✅ D. She has positive Balance and Eyes findings
BE FAST flags this as a possible posterior-circulation stroke that FAST alone would miss.
"B" (Balance: sudden unsteadiness) and "E" (Eyes: diplopia) are both positive. Her Face, Arms, and Speech are normal, so the traditional FAST mnemonic would read as negative and risk missing a posterior-circulation (vertebrobasilar) stroke. BE FAST was created specifically for this scenario, improving stroke detection sensitivity by approximately 20%. The next step is immediate stroke protocol activation, noting "last known well" at 90 minutes ago (within the 4.5-hour tPA window).

❌ A. She has no BE FAST findings — the symptoms are more consistent with benign positional vertigo.
Sudden-onset diplopia combined with imbalance is a red flag for posterior stroke, not BPPV. BPPV causes episodic vertigo triggered by head position changes without diplopia and is not a stroke syndrome.

❌ B. She has only a positive Time finding, which alone does not require stroke workup.
Time (noting "last known well") is an organizational element, not a sign — it doesn't "trigger" the workup. The triggers here are the Balance and Eye findings. Any positive letter requires stroke activation.

❌ C. Because her Face, Arms, and Speech are normal, stroke is ruled out.
This is the exact trap BE FAST addresses. A classic FAST screen would be negative, but posterior strokes commonly spare face/arm/speech. Ruling out stroke based on FAST alone misses these patients.

:::danger
Posterior-circulation strokes often have NO face/arm/speech findings — FAST misses them. BE FAST adds Balance and Eyes to catch these.
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BE FAST

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