In a patient presenting with a deficit that is already improving, the single most useful history question is not what the deficit is now — you can examine that — but what it was at its worst and when. A hemiparesis that was dense at onset and is now mild is a different problem from one that has been slowly worsening over a week, and the examination at the moment you see it cannot distinguish them.
This matters for three decisions. It sets the onset time, which governs thrombolysis eligibility and is the number most often recorded wrongly. It separates a resolving stroke or transient ischaemic attack from a progressive lesion — a subdural, a tumour, a demyelinating episode — which changes the imaging you request. And it identifies the stuttering lacunar syndrome, which fluctuates, worsens after admission, and is regularly discharged as a transient ischaemic attack the evening before it completes.
Ask the person who was present at onset, not only the patient. Someone who has had a dominant-hemisphere event is frequently the worst available witness to their own deficit.
- Establish last-known-well from a witness, and record who gave it.
- Ask explicitly whether the deficit has fluctuated or stepped down — a stuttering course changes admission and monitoring, not just diagnosis.
- A deficit that has worsened over days is not a stroke until imaging says so.
- Re-examine a fluctuating patient yourself a few hours later rather than relying on the admission note.
Why it matters
Onset time and trajectory decide both thrombolysis eligibility and whether you are looking at the right diagnosis, and neither is visible on examination.
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