Case · Trainee · Cerebellar stroke
Isolated vertigo with normal head impulse
68-year-old man, hypertensive, type 2 diabetes, current smoker.
Vignette
A 68-year-old man with hypertension, diabetes, and a 30-pack-year smoking history presents with 6 hours of continuous vertigo. He looks pale and clammy. Gait is grossly ataxic — he cannot stand unaided. No headache, no diplopia, no dysarthria, no hearing change.
Diagnostic question
Which finding most strongly indicates a central lesion?
Teaching point
A normal head impulse plus direction-changing gaze-evoked nystagmus in acute vestibular syndrome is a central pattern (the I and F of INFARCT), even with absent skew and no other focal signs. Early MRI DWI can be falsely negative for small posterior fossa infarcts in the first 48 hours; clinical exam often leads the imaging.