Transient ischemic attack versus transient ischemic attack mimics: frequency, clinical characteristics and outcome.

BACKGROUND: There is insufficient evidence regarding which clinical features are best suited to distinguish between transient ischemic attack (TIA) and disorders mimicking TIA (TIA mimics).
METHODS: We compared the frequency, clinical characteristics and outcome of patients with TIA and TIA mimics in a prospective, single-center emergency department cohort over 2 years.
RESULTS: Of 303 patients, 248 (81.8%) had a TIA and 55 (18.2%) had TIA mimics. Epileptic seizures (26/55; 43.7%) and migraine attacks (13/55; 23.6%) were the most common TIA mimics. In patients presenting with unilateral paresis, TIA mimics were less likely than in patients without unilateral paresis [odds ratio (OR) 0.35, 95% confidence interval (CI) 0.17-0.68]. Memory loss (OR 9.17, 95% CI 2.89-32.50), headache (OR 3.71, 95% CI 1.07-12.78) and blurred vision (OR 2.48, 95% CI 0.90-6.59) increased the odds of TIA mimics. Once these clinical features were taken into account, neither aphasia, dysarthria, sensory loss, blood pressure values nor the duration of symptoms were found to improve explanation of the underlying status. At 3 months, stroke, recurrent TIA and myocardial infarction were absent in patients with TIA mimics but occurred in 13 (5.2%), 20 (8.1%) and 3 (1.2%) TIA patients, respectively.
CONCLUSIONS: About 1 in every 5 patients with suspected TIA had a TIA mimic. Paresis suggested TIA, while other clinical variables used in risk assessment scores after TIA were not shown to distinguish between the two entities. Patients with TIA mimics had a better short-term prognosis.