Sudden dizziness, double vision, loss of vision in one eye, or inability to touch one’s nose — all warrant calling 120 for stroke suspicion

No cost involved. Besides the three FAST signs — facial droop, arm weakness, and speech difficulty — two additional checks are recommended. First, ask the person to stand straight with eyes closed and see if they lose balance; then ask whether they see double or have blind spots. Second, have them extend a finger toward their nose, close their eyes, and repeat the motion.

In 2014, researchers at the University of Kentucky Stroke Center reviewed 736 cases of acute ischemic stroke. They found that 14.1% of patients exhibited none of the FAST indicators at the time of onset. When additional screening criteria — including gait instability, limb weakness, and visual disturbances — were incorporated, the proportion of missed diagnoses dropped to 4.4%.

Aroor S, Singh R, Goldstein LB (2017). BE-FAST (Balance, Eyes, Face, Arm, Speech, Time): Reducing the Proportion of Strokes Missed Using the FAST Mnemonic. Stroke, 48(2), 479-481. https://doi.org/10.1161/STROKEAHA.116.015169

Infarctions affecting the cerebellum or brainstem — known as posterior circulation strokes — often lack facial droop or limb weakness. Instead, they manifest as vertigo, gait deviation, double vision, or difficulty swallowing, which are frequently mistaken for cervical spine disorders, hypoglycemia, or benign paroxysmal positional vertigo. Inability to touch one’s nose or maintain balance with eyes closed are telltale signs of cerebellar involvement. However, no single test can definitively rule out stroke; any sudden onset of these symptoms demands immediate emergency care and accurate timing recording. This study relied on records from a single medical center, and the authors themselves acknowledge the need for further validation.