Clinical meaning
Rapid stroke recognition determines treatment eligibility and outcomes. Two complementary tools are essential: FAST (prehospital/public screening) and NIHSS (clinical quantification). FAST is a public education and EMS screening acronym: Face (ask patient to smile — look for facial droop/asymmetry), Arms (raise both arms — look for drift or inability to maintain one arm), Speech (repeat a sentence — listen for slurred or garbled speech, wrong words, or inability to speak), Time (note time of symptom onset and call 911 immediately). FAST identifies approximately 85% of strokes but misses posterior circulation strokes (vertigo, diplopia, ataxia, visual field cuts). BE-FAST adds Balance (sudden loss of balance/coordination) and Eyes (sudden visual loss or diplopia), improving sensitivity for posterior circulation events. The NIHSS (National Institutes of Health Stroke Scale) is a 15-item, 42-point validated tool used by clinicians to quantify neurological deficit severity. It assesses: 1a) Level of consciousness, 1b) LOC questions (month, age), 1c) LOC commands (open/close eyes, grip/release), 2) Best gaze (horizontal eye movements), 3) Visual fields, 4) Facial palsy, 5) Motor arm (right then left — drift assessment), 6) Motor leg...