Prehospital Clinical Presentations and Sex Differences in Stroke Cases and Mimics: A 1-Year Study in a Stroke Unit

Introduction: Stroke is a condition demanding prompt treatment. Differentiating stroke cases from mimics poses a challenge in the prehospital setting. An optimal prehospital scale to identify stroke is still not available. The aims of the study were to (i) explore whether dysphagia, visual impairment, skin sensory loss, or combinations of these symptoms could improve diagnostic stroke accuracy beyond FAST (face, arm, speech, and time) scale and (ii) identify sex differences in stroke diagnostic models.

Materials and Methods: We included 319 patients with stroke or transient ischemic attack (TIA) and 119 stroke mimics in a 1-year period in 2013–2014 and 258 stroke/TIA cases and 90 mimics in a validation cohort in 2023, admitted to the Stroke Unit at the University Hospital of North Norway. Retrospective data on clinical presentations were collected from patient records.

Results: Stroke cases were older than mimics and a larger proportion were men. Age explained 7.5% of the variance in odds ratio (OR) for stroke in women and 1.7% in men, while hypertension or coronary heart disease explained 10.2% in women and 3.7% in men. Adding dysphagia to FAST increased OR for stroke from 3.95 (95% confidence interval (CI) 2.00–7.81) to 4.30 (95% CI 2.14–8.64) and explained variance in OR for stroke by 0.5% in women. Adding visual impairment to FAST increased OR from 5.72 (95% CI 2.74–12.0) to 7.69 (95% CI 3.50–16.9) and explained variance in OR for stroke by 1.9% in men. In the validation cohort, the explained variance in OR for stroke did not increase by adding any more clinical presentations to FAST. Stroke mimics accounted for 27.2% and 25.9% in the two cohorts.

Conclusions: By adding clinical presentations to FAST, no meaningful change in diagnostic performance was gained. An optimal scale for prehospital stroke identification is still needed.