Abstract TP43: Incidence And Characteristics Of Transient Ischemic Attack Mimics In Emergency Department Observation Unit

Abstract

Objective: Transient Ischemic Attack (TIA) observation units in the emergency department (ED) were developed to expedite medical evaluation and to reduce recurrent strokes. However, TIA remains a clinically challenging diagnosis due to its reliance on patient history and has multiple mimics including complex migraine, seizure, and peripheral vertigo. This study attempts to review the proportion of common mimics in the TIA observation unit at a comprehensive stroke center. Methods: We included 1525 patients enrolled in a TIA registry over 7 years (2013-2020) in a single comprehensive stroke center. Inclusion criteria of TIA unit admissions are age >18 years with focal neurological symptoms for < 24 hours. This population excludes patients with refractory hypertension, baseline immobility, or recurrent deficits. While in the ED, patients were evaluated by neurologists and assigned a final diagnosis of TIA or mimics. Data on demographics, past medical history, home medications, magnetic resonance imaging (MRI) results, and 30-day follow-up were collected. Results: The mean age was 64.2 (SD 15.2), 52.3% were women, and 76.7% were White, 6.0% were Black, 13.6% were Hispanic, and 3.7% other ethnicities. We found 44.7% of patients had neurologist-adjudicated TIA and 15.2% had diffusion-weighted imaging (DWI) positive lesions on MRI. TIA mimics comprised 42% of the cohort, of which 28.9% had migraine, 14.1% had peripheral vertigo, 4.7% had seizure and 52.1% were classified in other miscellaneous diagnoses including medication effect, recrudescence of prior stroke deficits, anxiety, and radiculopathies. Among the 394 patients with the diagnosis of TIA the 30-day recurrent stroke or death rate was 1.3%. Conclusion: In our investigation of TIA unit admissions, we found a relatively high proportion of TIA mimics. In patients with a diagnosis of TIA, however, the rate of subsequent stroke or death is lower than that in prior observational studies. The potential benefit of a TIA unit in stroke prevention needs to be tested against the cost of stroke mimic TIA unit admission.