Brief Answer:
By neurological examination and some work up

Detailed Answer:
Thank you for asking

I read your question and i understand your concern. Stroke is easily differentiated from other etiologies with simple neurological signs doctors look for. There are many less conditions with their own unique presentation that apparently look like weakness in stroke but with slight work up like radiographs, CT scans, MRIs, blood work up for finding focus of infection, carotid artery doppler and last but not the least a thorough neurological exam sorts it out from other differentials.
If the stroke is very small like Transient ischemic attack and then there is complete resolution with in hours, then that solely on history can be confirmed with all the work up normal in Scans .

I hope it helps. Take good care of yourself and dont forget to close the discussion please.

Regards
Khan

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