Predictors of neurologists confirming or overturning emergency physicians' diagnosis of TIA or stroke.

Background: Transient ischemic attack (TIA) and non-disabling stroke are common emergency department (ED) presentations. Currently, there are no prospective multicenter studies determining predictors of neurologists confirming a diagnosis of cerebral ischemia in patients discharged with a diagnosis of TIA or stroke. The objectives were to (1) calculate the concordance between emergency physicians and neurologists for the outcome of diagnosing TIA or stroke, and (2) identify characteristics associated with neurologists diagnosing a stroke mimic.

Methods: This was a planned sub-study of a prospective cohort study at 14 Canadian EDs enrolling patients diagnosed with TIA or non-disabling stroke from 2006 to 2017. Logistic regression was used to identify factors associated with neurologists' diagnosis of cerebral ischemia. Our primary outcome was the composite outcome of cerebral ischemia (TIA or non-disabling stroke) based on the neurologists' assessment.

Results: The diagnosis of cerebral ischemia was confirmed by neurologists in 5794 patients (55.4%). The most common identified stroke mimics were migraine (18%), peripheral vertigo (7%), syncope (4%), and seizure (3%). Over a third of patients (38.4%) ultimately had an undetermined aetiology for their symptoms. The strongest predictors of cerebral ischemia confirmation were infarct on CT (OR 1.83, 95% CI 1.65-2.02), advanced age (OR comparing 75th-25th percentiles 1.67, 1.55-1.80), language disturbance (OR 1.92, 1.75-2.10), and smoking (OR 1.67, 1.46-1.91). The strongest predictors of stroke mimics were syncope (OR 0.59, 0.48-0.72), vertigo (OR 0.52, 0.45-0.59), bilateral symptoms (OR 0.60, 0.50-0.72), and confusion (OR 0.50, 0.44-0.57).

Conclusion: Physicians should have a high index of suspicion of cerebral ischemia in patients with advanced age, smoking history, language disturbance, or infarcts on CT. Physicians should discriminate in which patients to pursue stroke investigations on when deemed at minimal risk of cerebral ischemia, including those with isolated vertigo, syncope, or bilateral symptoms.