Why a brain scan can miss a stroke
A Case of Wallenberg Syndrome Presenting With Thunderclap Headache and Delayed Diagnosis Due to Negative Findings on Two MRI Examinations
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
The stroke was invisible on two 3T MRI scans done within 8 hours, but clearly visible on day 5.
3T MRI is the gold standard for detecting acute strokes via DWI sequences—most strokes show up within minutes to hours. This one took 5 days, which is extremely rare.
Practical Takeaways
If you or someone has a thunderclap headache followed by dizziness, facial numbness, or trouble swallowing—even if the first MRI is normal—demand a repeat scan in 24–48 hours.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
The stroke was invisible on two 3T MRI scans done within 8 hours, but clearly visible on day 5.
3T MRI is the gold standard for detecting acute strokes via DWI sequences—most strokes show up within minutes to hours. This one took 5 days, which is extremely rare.
Practical Takeaways
If you or someone has a thunderclap headache followed by dizziness, facial numbness, or trouble swallowing—even if the first MRI is normal—demand a repeat scan in 24–48 hours.
Publication
Journal
Cureus
Year
2025
Authors
Yoshiro Nozaki, Mitsuharu Yamamoto, Koichiro Demura, Yuto Sakakibara
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Claims (5)
Sometimes, a full-body MRI scan might miss a serious problem, making doctors think everything’s fine when it’s not — and that delay could lead to really bad health results.
An older woman who had a stroke before suddenly got a terrible headache that came out of nowhere, then started having trouble with dizziness, numbness on one side of her face, and swallowing. A scan five days later finally showed a new stroke in her brainstem, even though two earlier scans had come back normal.
A 65-year-old woman had a stroke in her brainstem, but the first two MRI scans didn’t show it—doctors only saw the damage after waiting five days.
A person had a sudden, severe headache and a brain stroke in a specific area called the medulla, but scans showed no broken blood vessels—so the stroke wasn’t caused by a tear in the artery, even though that’s usually what you’d expect with such a headache.
A person with a rare brain condition called Wallenberg syndrome had trouble swallowing and felt dizzy for over a month, so they had to go to a rehab hospital—even though they were already taking blood-thinning medicine.